^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* CPU control.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * (C) 2001, 2002, 2003, 2004 Rusty Russell
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * This code is licenced under the GPL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/proc_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/smp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/notifier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/sched/hotplug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/sched/isolation.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/sched/task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/sched/smt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/cpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/oom.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/rcupdate.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/bug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/kthread.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/stop_machine.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/gfp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/suspend.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/lockdep.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/tick.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/irq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/nmi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/smpboot.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/relay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/scs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/percpu-rwsem.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/cpuset.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <uapi/linux/sched/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <trace/events/power.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #define CREATE_TRACE_POINTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <trace/events/cpuhp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #undef CREATE_TRACE_POINTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include <trace/hooks/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <trace/hooks/cpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #include "smpboot.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * cpuhp_cpu_state - Per cpu hotplug state storage
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * @state: The current cpu state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * @target: The target state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) * @thread: Pointer to the hotplug thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) * @should_run: Thread should execute
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * @rollback: Perform a rollback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * @single: Single callback invocation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * @bringup: Single callback bringup or teardown selector
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * @cb_state: The state for a single callback (install/uninstall)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * @result: Result of the operation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * @done_up: Signal completion to the issuer of the task for cpu-up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * @done_down: Signal completion to the issuer of the task for cpu-down
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) struct cpuhp_cpu_state {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) enum cpuhp_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) enum cpuhp_state target;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) enum cpuhp_state fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) struct task_struct *thread;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) bool should_run;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) bool rollback;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) bool single;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) bool bringup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) struct hlist_node *node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) struct hlist_node *last;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) enum cpuhp_state cb_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) int result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) struct completion done_up;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) struct completion done_down;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state) = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) .fail = CPUHP_INVALID,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) cpumask_t cpus_booted_once_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) #if defined(CONFIG_LOCKDEP) && defined(CONFIG_SMP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) static struct lockdep_map cpuhp_state_up_map =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) STATIC_LOCKDEP_MAP_INIT("cpuhp_state-up", &cpuhp_state_up_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) static struct lockdep_map cpuhp_state_down_map =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) STATIC_LOCKDEP_MAP_INIT("cpuhp_state-down", &cpuhp_state_down_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) static inline void cpuhp_lock_acquire(bool bringup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) lock_map_acquire(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) static inline void cpuhp_lock_release(bool bringup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) lock_map_release(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static inline void cpuhp_lock_acquire(bool bringup) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) static inline void cpuhp_lock_release(bool bringup) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * cpuhp_step - Hotplug state machine step
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * @name: Name of the step
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * @startup: Startup function of the step
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) * @teardown: Teardown function of the step
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) * @cant_stop: Bringup/teardown can't be stopped at this step
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) struct cpuhp_step {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) const char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) union {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) int (*single)(unsigned int cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) int (*multi)(unsigned int cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) struct hlist_node *node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) } startup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) union {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) int (*single)(unsigned int cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) int (*multi)(unsigned int cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) struct hlist_node *node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) } teardown;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) struct hlist_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) bool cant_stop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) bool multi_instance;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) static DEFINE_MUTEX(cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) static struct cpuhp_step cpuhp_hp_states[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) return cpuhp_hp_states + state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * cpuhp_invoke_callback _ Invoke the callbacks for a given state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * @cpu: The cpu for which the callback should be invoked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) * @state: The state to do callbacks for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) * @bringup: True if the bringup callback should be invoked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) * @node: For multi-instance, do a single entry callback for install/remove
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) * @lastp: For multi-instance rollback, remember how far we got
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * Called from cpu hotplug and from the state register machinery.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) bool bringup, struct hlist_node *node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) struct hlist_node **lastp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) struct cpuhp_step *step = cpuhp_get_step(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) int (*cbm)(unsigned int cpu, struct hlist_node *node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) int (*cb)(unsigned int cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) int ret, cnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) if (st->fail == state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) st->fail = CPUHP_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) if (!(bringup ? step->startup.single : step->teardown.single))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) if (!step->multi_instance) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) WARN_ON_ONCE(lastp && *lastp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) cb = bringup ? step->startup.single : step->teardown.single;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) if (!cb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) trace_cpuhp_enter(cpu, st->target, state, cb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) ret = cb(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) trace_cpuhp_exit(cpu, st->state, state, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) cbm = bringup ? step->startup.multi : step->teardown.multi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) if (!cbm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) /* Single invocation for instance add/remove */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) if (node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) WARN_ON_ONCE(lastp && *lastp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) ret = cbm(cpu, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) trace_cpuhp_exit(cpu, st->state, state, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) /* State transition. Invoke on all instances */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) cnt = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) hlist_for_each(node, &step->list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) if (lastp && node == *lastp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) ret = cbm(cpu, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) trace_cpuhp_exit(cpu, st->state, state, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if (!lastp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) *lastp = node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) cnt++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) if (lastp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) *lastp = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) /* Rollback the instances if one failed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) cbm = !bringup ? step->startup.multi : step->teardown.multi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) if (!cbm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) hlist_for_each(node, &step->list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) if (!cnt--)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) ret = cbm(cpu, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) trace_cpuhp_exit(cpu, st->state, state, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) * Rollback must not fail,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) WARN_ON_ONCE(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) static bool cpuhp_is_ap_state(enum cpuhp_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) * The extra check for CPUHP_TEARDOWN_CPU is only for documentation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) * purposes as that state is handled explicitly in cpu_down.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) static inline void wait_for_ap_thread(struct cpuhp_cpu_state *st, bool bringup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) struct completion *done = bringup ? &st->done_up : &st->done_down;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) wait_for_completion(done);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) static inline void complete_ap_thread(struct cpuhp_cpu_state *st, bool bringup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) struct completion *done = bringup ? &st->done_up : &st->done_down;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) complete(done);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) * The former STARTING/DYING states, ran with IRQs disabled and must not fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) static bool cpuhp_is_atomic_state(enum cpuhp_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) return CPUHP_AP_IDLE_DEAD <= state && state < CPUHP_AP_ONLINE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) /* Serializes the updates to cpu_online_mask, cpu_present_mask */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) static DEFINE_MUTEX(cpu_add_remove_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) bool cpuhp_tasks_frozen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) * The following two APIs (cpu_maps_update_begin/done) must be used when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * attempting to serialize the updates to cpu_online_mask & cpu_present_mask.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) void cpu_maps_update_begin(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) mutex_lock(&cpu_add_remove_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) EXPORT_SYMBOL_GPL(cpu_maps_update_begin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) void cpu_maps_update_done(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) mutex_unlock(&cpu_add_remove_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) EXPORT_SYMBOL_GPL(cpu_maps_update_done);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * If set, cpu_up and cpu_down will return -EBUSY and do nothing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * Should always be manipulated under cpu_add_remove_lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) static int cpu_hotplug_disabled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) #ifdef CONFIG_HOTPLUG_CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) DEFINE_STATIC_PERCPU_RWSEM(cpu_hotplug_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) void cpus_read_lock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) percpu_down_read(&cpu_hotplug_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) EXPORT_SYMBOL_GPL(cpus_read_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) int cpus_read_trylock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) return percpu_down_read_trylock(&cpu_hotplug_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) EXPORT_SYMBOL_GPL(cpus_read_trylock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) void cpus_read_unlock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) percpu_up_read(&cpu_hotplug_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) EXPORT_SYMBOL_GPL(cpus_read_unlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) void cpus_write_lock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) percpu_down_write(&cpu_hotplug_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) void cpus_write_unlock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) percpu_up_write(&cpu_hotplug_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) void lockdep_assert_cpus_held(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) * We can't have hotplug operations before userspace starts running,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) * and some init codepaths will knowingly not take the hotplug lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) * This is all valid, so mute lockdep until it makes sense to report
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) * unheld locks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) if (system_state < SYSTEM_RUNNING)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) percpu_rwsem_assert_held(&cpu_hotplug_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) static void lockdep_acquire_cpus_lock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) static void lockdep_release_cpus_lock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) rwsem_release(&cpu_hotplug_lock.dep_map, _THIS_IP_);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * Wait for currently running CPU hotplug operations to complete (if any) and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * hotplug path before performing hotplug operations. So acquiring that lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) * guarantees mutual exclusion from any currently running hotplug operations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) void cpu_hotplug_disable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) cpu_hotplug_disabled++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) EXPORT_SYMBOL_GPL(cpu_hotplug_disable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) static void __cpu_hotplug_enable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) cpu_hotplug_disabled--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) void cpu_hotplug_enable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) __cpu_hotplug_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) static void lockdep_acquire_cpus_lock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) static void lockdep_release_cpus_lock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) #endif /* CONFIG_HOTPLUG_CPU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) * Architectures that need SMT-specific errata handling during SMT hotplug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) * should override this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) void __weak arch_smt_update(void) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) #ifdef CONFIG_HOTPLUG_SMT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) enum cpuhp_smt_control cpu_smt_control __read_mostly = CPU_SMT_ENABLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) void __init cpu_smt_disable(bool force)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) if (!cpu_smt_possible())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) if (force) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) pr_info("SMT: Force disabled\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) cpu_smt_control = CPU_SMT_FORCE_DISABLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) pr_info("SMT: disabled\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) cpu_smt_control = CPU_SMT_DISABLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * The decision whether SMT is supported can only be done after the full
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) * CPU identification. Called from architecture code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) void __init cpu_smt_check_topology(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) if (!topology_smt_supported())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) cpu_smt_control = CPU_SMT_NOT_SUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) static int __init smt_cmdline_disable(char *str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) cpu_smt_disable(str && !strcmp(str, "force"));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) early_param("nosmt", smt_cmdline_disable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) static inline bool cpu_smt_allowed(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) if (cpu_smt_control == CPU_SMT_ENABLED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) if (topology_is_primary_thread(cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) * On x86 it's required to boot all logical CPUs at least once so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) * that the init code can get a chance to set CR4.MCE on each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * CPU. Otherwise, a broadcasted MCE observing CR4.MCE=0b on any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * core will shutdown the machine.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) return !cpumask_test_cpu(cpu, &cpus_booted_once_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) /* Returns true if SMT is not supported of forcefully (irreversibly) disabled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) bool cpu_smt_possible(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) return cpu_smt_control != CPU_SMT_FORCE_DISABLED &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) cpu_smt_control != CPU_SMT_NOT_SUPPORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) EXPORT_SYMBOL_GPL(cpu_smt_possible);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) static inline bool cpu_smt_allowed(unsigned int cpu) { return true; }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) static inline enum cpuhp_state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) cpuhp_set_state(struct cpuhp_cpu_state *st, enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) enum cpuhp_state prev_state = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) st->rollback = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) st->last = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) st->target = target;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) st->single = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) st->bringup = st->state < target;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) return prev_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) static inline void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) cpuhp_reset_state(struct cpuhp_cpu_state *st, enum cpuhp_state prev_state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) st->rollback = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) * If we have st->last we need to undo partial multi_instance of this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) * state first. Otherwise start undo at the previous state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) if (!st->last) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) if (st->bringup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) st->state--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) st->state++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) st->target = prev_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) st->bringup = !st->bringup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) /* Regular hotplug invocation of the AP hotplug thread */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) static void __cpuhp_kick_ap(struct cpuhp_cpu_state *st)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) if (!st->single && st->state == st->target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) st->result = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) * Make sure the above stores are visible before should_run becomes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) * true. Paired with the mb() above in cpuhp_thread_fun()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) smp_mb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) st->should_run = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) wake_up_process(st->thread);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) wait_for_ap_thread(st, st->bringup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) static int cpuhp_kick_ap(struct cpuhp_cpu_state *st, enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) enum cpuhp_state prev_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) prev_state = cpuhp_set_state(st, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) __cpuhp_kick_ap(st);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) if ((ret = st->result)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) cpuhp_reset_state(st, prev_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) __cpuhp_kick_ap(st);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) static int bringup_wait_for_ap(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) /* Wait for the CPU to reach CPUHP_AP_ONLINE_IDLE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) wait_for_ap_thread(st, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) if (WARN_ON_ONCE((!cpu_online(cpu))))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) return -ECANCELED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) /* Unpark the hotplug thread of the target cpu */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) kthread_unpark(st->thread);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) * SMT soft disabling on X86 requires to bring the CPU out of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) * BIOS 'wait for SIPI' state in order to set the CR4.MCE bit. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) * CPU marked itself as booted_once in notify_cpu_starting() so the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) * cpu_smt_allowed() check will now return false if this is not the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) * primary sibling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) if (!cpu_smt_allowed(cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) return -ECANCELED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) if (st->target <= CPUHP_AP_ONLINE_IDLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) return cpuhp_kick_ap(st, st->target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) static int bringup_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) struct task_struct *idle = idle_thread_get(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) * Reset stale stack state from the last time this CPU was online.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) scs_task_reset(idle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) kasan_unpoison_task_stack(idle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) * Some architectures have to walk the irq descriptors to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) * setup the vector space for the cpu which comes online.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) * Prevent irq alloc/free across the bringup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) irq_lock_sparse();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) /* Arch-specific enabling code. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) ret = __cpu_up(cpu, idle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) irq_unlock_sparse();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) return bringup_wait_for_ap(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) static int finish_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) struct task_struct *idle = idle_thread_get(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) struct mm_struct *mm = idle->active_mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) * idle_task_exit() will have switched to &init_mm, now
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) * clean up any remaining active_mm state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) if (mm != &init_mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) idle->active_mm = &init_mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) mmdrop(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) * Hotplug state machine related functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) for (st->state--; st->state > st->target; st->state--)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) static inline bool can_rollback_cpu(struct cpuhp_cpu_state *st)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) if (IS_ENABLED(CONFIG_HOTPLUG_CPU))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) * When CPU hotplug is disabled, then taking the CPU down is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) * possible because takedown_cpu() and the architecture and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) * subsystem specific mechanisms are not available. So the CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) * which would be completely unplugged again needs to stay around
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) * in the current state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) return st->state <= CPUHP_BRINGUP_CPU;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) enum cpuhp_state prev_state = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) while (st->state < target) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) st->state++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) if (can_rollback_cpu(st)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) st->target = prev_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) undo_cpu_up(cpu, st);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) * The cpu hotplug threads manage the bringup and teardown of the cpus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) static void cpuhp_create(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) init_completion(&st->done_up);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) init_completion(&st->done_down);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) static int cpuhp_should_run(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) return st->should_run;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) * callbacks when a state gets [un]installed at runtime.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) * Each invocation of this function by the smpboot thread does a single AP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) * state callback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) * It has 3 modes of operation:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) * - single: runs st->cb_state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) * - up: runs ++st->state, while st->state < st->target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) * - down: runs st->state--, while st->state > st->target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) * When complete or on error, should_run is cleared and the completion is fired.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) static void cpuhp_thread_fun(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) bool bringup = st->bringup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) enum cpuhp_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) if (WARN_ON_ONCE(!st->should_run))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) * ACQUIRE for the cpuhp_should_run() load of ->should_run. Ensures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) * that if we see ->should_run we also see the rest of the state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) smp_mb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) * The BP holds the hotplug lock, but we're now running on the AP,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) * ensure that anybody asserting the lock is held, will actually find
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) * it so.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) lockdep_acquire_cpus_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) cpuhp_lock_acquire(bringup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) if (st->single) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) state = st->cb_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) st->should_run = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) if (bringup) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) st->state++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) state = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) st->should_run = (st->state < st->target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) WARN_ON_ONCE(st->state > st->target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) state = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) st->state--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) st->should_run = (st->state > st->target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) WARN_ON_ONCE(st->state < st->target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) WARN_ON_ONCE(!cpuhp_is_ap_state(state));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) if (cpuhp_is_atomic_state(state)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) local_irq_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) st->result = cpuhp_invoke_callback(cpu, state, bringup, st->node, &st->last);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) local_irq_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) * STARTING/DYING must not fail!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) WARN_ON_ONCE(st->result);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) st->result = cpuhp_invoke_callback(cpu, state, bringup, st->node, &st->last);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) if (st->result) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) * If we fail on a rollback, we're up a creek without no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) * paddle, no way forward, no way back. We loose, thanks for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) * playing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) WARN_ON_ONCE(st->rollback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) st->should_run = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) cpuhp_lock_release(bringup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) lockdep_release_cpus_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) if (!st->should_run)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) complete_ap_thread(st, bringup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) /* Invoke a single callback on a remote cpu */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) struct hlist_node *node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) if (!cpu_online(cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) cpuhp_lock_acquire(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) cpuhp_lock_release(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) cpuhp_lock_acquire(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) cpuhp_lock_release(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) * If we are up and running, use the hotplug thread. For early calls
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) * we invoke the thread function directly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) if (!st->thread)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) return cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) st->rollback = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) st->last = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) st->node = node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) st->bringup = bringup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) st->cb_state = state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) st->single = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) __cpuhp_kick_ap(st);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) * If we failed and did a partial, do a rollback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) if ((ret = st->result) && st->last) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) st->rollback = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) st->bringup = !bringup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) __cpuhp_kick_ap(st);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) * Clean up the leftovers so the next hotplug operation wont use stale
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) * data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) st->node = st->last = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) static int cpuhp_kick_ap_work(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) enum cpuhp_state prev_state = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) cpuhp_lock_acquire(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) cpuhp_lock_release(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) cpuhp_lock_acquire(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) cpuhp_lock_release(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) trace_cpuhp_enter(cpu, st->target, prev_state, cpuhp_kick_ap_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) ret = cpuhp_kick_ap(st, st->target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) trace_cpuhp_exit(cpu, st->state, prev_state, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) static struct smp_hotplug_thread cpuhp_threads = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) .store = &cpuhp_state.thread,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) .create = &cpuhp_create,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) .thread_should_run = cpuhp_should_run,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) .thread_fn = cpuhp_thread_fun,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) .thread_comm = "cpuhp/%u",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) .selfparking = true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) void __init cpuhp_threads_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) kthread_unpark(this_cpu_read(cpuhp_state.thread));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) * Serialize hotplug trainwrecks outside of the cpu_hotplug_lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) * protected region.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) * The operation is still serialized against concurrent CPU hotplug via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) * cpu_add_remove_lock, i.e. CPU map protection. But it is _not_
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) * serialized against other hotplug related activity like adding or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) * removing of state callbacks and state instances, which invoke either the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) * startup or the teardown callback of the affected state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) * This is required for subsystems which are unfixable vs. CPU hotplug and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) * evade lock inversion problems by scheduling work which has to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) * completed _before_ cpu_up()/_cpu_down() returns.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) * Don't even think about adding anything to this for any new code or even
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) * drivers. It's only purpose is to keep existing lock order trainwrecks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) * working.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) * For cpu_down() there might be valid reasons to finish cleanups which are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) * not required to be done under cpu_hotplug_lock, but that's a different
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) * story and would be not invoked via this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) static void cpu_up_down_serialize_trainwrecks(bool tasks_frozen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) * cpusets delegate hotplug operations to a worker to "solve" the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) * lock order problems. Wait for the worker, but only if tasks are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) * _not_ frozen (suspend, hibernate) as that would wait forever.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) * The wait is required because otherwise the hotplug operation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) * returns with inconsistent state, which could even be observed in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) * user space when a new CPU is brought up. The CPU plug uevent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) * would be delivered and user space reacting on it would fail to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) * move tasks to the newly plugged CPU up to the point where the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) * work has finished because up to that point the newly plugged CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) * is not assignable in cpusets/cgroups. On unplug that's not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) * necessarily a visible issue, but it is still inconsistent state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) * which is the real problem which needs to be "fixed". This can't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) * prevent the transient state between scheduling the work and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) * returning from waiting for it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) if (!tasks_frozen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) cpuset_wait_for_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) #ifdef CONFIG_HOTPLUG_CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) #ifndef arch_clear_mm_cpumask_cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) #define arch_clear_mm_cpumask_cpu(cpu, mm) cpumask_clear_cpu(cpu, mm_cpumask(mm))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) * @cpu: a CPU id
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) * This function walks all processes, finds a valid mm struct for each one and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) * then clears a corresponding bit in mm's cpumask. While this all sounds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) * trivial, there are various non-obvious corner cases, which this function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) * tries to solve in a safe manner.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) * Also note that the function uses a somewhat relaxed locking scheme, so it may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) * be called only for an already offlined CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) void clear_tasks_mm_cpumask(int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) struct task_struct *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) * This function is called after the cpu is taken down and marked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) * offline, so its not like new tasks will ever get this cpu set in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) * their mm mask. -- Peter Zijlstra
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) * Thus, we may use rcu_read_lock() here, instead of grabbing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) * full-fledged tasklist_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) WARN_ON(cpu_online(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) for_each_process(p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) struct task_struct *t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) * Main thread might exit, but other threads may still have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) * a valid mm. Find one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) t = find_lock_task_mm(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) if (!t)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) arch_clear_mm_cpumask_cpu(cpu, t->mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) task_unlock(t);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) /* Take this CPU down. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) static int take_cpu_down(void *_param)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) int err, cpu = smp_processor_id();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) /* Ensure this CPU doesn't handle any more interrupts. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) err = __cpu_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) * We get here while we are in CPUHP_TEARDOWN_CPU state and we must not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) * do this step again.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) WARN_ON(st->state != CPUHP_TEARDOWN_CPU);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) st->state--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) /* Invoke the former CPU_DYING callbacks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) for (; st->state > target; st->state--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) ret = cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) * DYING must not fail!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) WARN_ON_ONCE(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) /* Give up timekeeping duties */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) tick_handover_do_timer();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) /* Remove CPU from timer broadcasting */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) tick_offline_cpu(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) /* Park the stopper thread */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) stop_machine_park(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) static int takedown_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) /* Park the smpboot threads */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) * Prevent irq alloc/free while the dying cpu reorganizes the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) * interrupt affinities.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) irq_lock_sparse();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) * So now all preempt/rcu users must observe !cpu_active().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) /* CPU refused to die */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) irq_unlock_sparse();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) /* Unpark the hotplug thread so we can rollback there */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) BUG_ON(cpu_online(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) * The teardown callback for CPUHP_AP_SCHED_STARTING will have removed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) * all runnable tasks from the CPU, there's only the idle task left now
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) * that the migration thread is done doing the stop_machine thing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) * Wait for the stop thread to go away.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) wait_for_ap_thread(st, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) BUG_ON(st->state != CPUHP_AP_IDLE_DEAD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) /* Interrupts are moved away from the dying cpu, reenable alloc/free */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) irq_unlock_sparse();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) hotplug_cpu__broadcast_tick_pull(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) /* This actually kills the CPU. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) __cpu_die(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) tick_cleanup_dead_cpu(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) rcutree_migrate_callbacks(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) static void cpuhp_complete_idle_dead(void *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) struct cpuhp_cpu_state *st = arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) complete_ap_thread(st, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) void cpuhp_report_idle_dead(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) BUG_ON(st->state != CPUHP_AP_OFFLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) rcu_report_dead(smp_processor_id());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) st->state = CPUHP_AP_IDLE_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) * We cannot call complete after rcu_report_dead() so we delegate it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) * to an online cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) smp_call_function_single(cpumask_first(cpu_online_mask),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) cpuhp_complete_idle_dead, st, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) for (st->state++; st->state < st->target; st->state++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) enum cpuhp_state prev_state = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) for (; st->state > target; st->state--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) ret = cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) st->target = prev_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) if (st->state < prev_state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) undo_cpu_down(cpu, st);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) /* Requires cpu_add_remove_lock to be held */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) int prev_state, ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) if (num_active_cpus() == 1 && cpu_active(cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) if (!cpu_present(cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) cpus_write_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) cpuhp_tasks_frozen = tasks_frozen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) prev_state = cpuhp_set_state(st, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) * If the current CPU state is in the range of the AP hotplug thread,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) * then we need to kick the thread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) if (st->state > CPUHP_TEARDOWN_CPU) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) st->target = max((int)target, CPUHP_TEARDOWN_CPU);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) ret = cpuhp_kick_ap_work(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) * The AP side has done the error rollback already. Just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) * return the error code..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) * We might have stopped still in the range of the AP hotplug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) * thread. Nothing to do anymore.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) if (st->state > CPUHP_TEARDOWN_CPU)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) st->target = target;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) * to do the further cleanups.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) ret = cpuhp_down_callbacks(cpu, st, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) if (ret && st->state == CPUHP_TEARDOWN_CPU && st->state < prev_state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) cpuhp_reset_state(st, prev_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) __cpuhp_kick_ap(st);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) cpus_write_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) * Do post unplug cleanup. This is still protected against
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) * concurrent CPU hotplug via cpu_add_remove_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) lockup_detector_cleanup();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) arch_smt_update();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) cpu_up_down_serialize_trainwrecks(tasks_frozen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) static int cpu_down_maps_locked(unsigned int cpu, enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) if (cpu_hotplug_disabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) return _cpu_down(cpu, 0, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) static int cpu_down(unsigned int cpu, enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) err = cpu_down_maps_locked(cpu, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) * cpu_device_down - Bring down a cpu device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) * @dev: Pointer to the cpu device to offline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) * This function is meant to be used by device core cpu subsystem only.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) * Other subsystems should use remove_cpu() instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) int cpu_device_down(struct device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) return cpu_down(dev->id, CPUHP_OFFLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) int remove_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) lock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) ret = device_offline(get_cpu_device(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) unlock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) EXPORT_SYMBOL_GPL(remove_cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) extern bool dl_cpu_busy(unsigned int cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) int __pause_drain_rq(struct cpumask *cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) unsigned int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) * Disabling preemption avoids that one of the stopper, started from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) * sched_cpu_drain_rq(), blocks firing draining for the whole cpumask.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) for_each_cpu(cpu, cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) err = sched_cpu_drain_rq(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) preempt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) void __wait_drain_rq(struct cpumask *cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) unsigned int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) for_each_cpu(cpu, cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) sched_cpu_drain_rq_wait(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) /* if rt task, set to cfs and return previous prio */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) static int pause_reduce_prio(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) int prev_prio = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196) if (current->prio < MAX_RT_PRIO) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) struct sched_param param = { .sched_priority = 0 };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) prev_prio = current->prio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) sched_setscheduler_nocheck(current, SCHED_NORMAL, ¶m);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) return prev_prio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) /* if previous prio was set, restore */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) static void pause_restore_prio(int prev_prio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) if (prev_prio >= 0 && prev_prio < MAX_RT_PRIO) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) struct sched_param param = { .sched_priority = MAX_RT_PRIO-1-prev_prio };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) sched_setscheduler_nocheck(current, SCHED_FIFO, ¶m);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) int pause_cpus(struct cpumask *cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) u64 start_time = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221) int prev_prio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) start_time = sched_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) if (cpu_hotplug_disabled) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) /* Pausing an already inactive CPU isn't an error */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) cpumask_and(cpus, cpus, cpu_active_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) for_each_cpu(cpu, cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) if (!cpu_online(cpu) || dl_cpu_busy(cpu) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) get_cpu_device(cpu)->offline_disabled == true) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243) if (cpumask_weight(cpus) >= num_active_cpus()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) if (cpumask_empty(cpus))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) * Lazy migration:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) * We do care about how fast a CPU can go idle and stay this in this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) * state. If we try to take the cpus_write_lock() here, we would have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) * to wait for a few dozens of ms, as this function might schedule.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) * However, we can, as a first step, flip the active mask and migrate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) * anything currently on the run-queue, to give a chance to the paused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) * CPUs to reach quickly an idle state. There's a risk meanwhile for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) * another CPU to observe an out-of-date active_mask or to incompletely
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) * update a cpuset. Both problems would be resolved later in the slow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) * path, which ensures active_mask synchronization, triggers a cpuset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) * rebuild and migrate any task that would have escaped the lazy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) * migration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) for_each_cpu(cpu, cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) set_cpu_active(cpu, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) err = __pause_drain_rq(cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) __wait_drain_rq(cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) for_each_cpu(cpu, cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) set_cpu_active(cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) prev_prio = pause_reduce_prio();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) * Slow path deactivation:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) * Now that paused CPUs are most likely idle, we can go through a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) * complete scheduler deactivation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) * The cpu_active_mask being already set and cpus_write_lock calling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) * synchronize_rcu(), we know that all preempt-disabled and RCU users
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) * will observe the updated value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) cpus_write_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) __wait_drain_rq(cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) cpuhp_tasks_frozen = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) if (sched_cpus_deactivate_nosync(cpus)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) goto err_cpus_write_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) err = __pause_drain_rq(cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) __wait_drain_rq(cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) for_each_cpu(cpu, cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) sched_cpu_activate(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) goto err_cpus_write_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) * Even if living on the side of the regular HP path, pause is using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) * one of the HP step (CPUHP_AP_ACTIVE). This should be reflected on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) * current state of the CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) for_each_cpu(cpu, cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) st->state = CPUHP_AP_ACTIVE - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) st->target = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) err_cpus_write_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) cpus_write_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) pause_restore_prio(prev_prio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) err_cpu_maps_update:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) trace_cpuhp_pause(cpus, start_time, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) EXPORT_SYMBOL_GPL(pause_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) int resume_cpus(struct cpumask *cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) unsigned int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) u64 start_time = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) int prev_prio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) start_time = sched_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) if (cpu_hotplug_disabled) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) /* Resuming an already active CPU isn't an error */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) cpumask_andnot(cpus, cpus, cpu_active_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) for_each_cpu(cpu, cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) if (!cpu_online(cpu)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) if (cpumask_empty(cpus))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) for_each_cpu(cpu, cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) set_cpu_active(cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) trace_android_rvh_resume_cpus(cpus, &err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) goto err_cpu_maps_update;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) prev_prio = pause_reduce_prio();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369) /* Lazy Resume. Build domains through schedule a workqueue on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) * resuming cpu. This is so that the resuming cpu can work more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) * early, and cannot add additional load to other busy cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) cpuset_update_active_cpus_affine(cpumask_first(cpus));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) cpus_write_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) cpuhp_tasks_frozen = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379) if (sched_cpus_activate(cpus)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) goto err_cpus_write_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) * see pause_cpus.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) for_each_cpu(cpu, cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) st->state = CPUHP_ONLINE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) st->target = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) err_cpus_write_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) cpus_write_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396) pause_restore_prio(prev_prio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) err_cpu_maps_update:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) trace_cpuhp_pause(cpus, start_time, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404) EXPORT_SYMBOL_GPL(resume_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) void smp_shutdown_nonboot_cpus(unsigned int primary_cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) unsigned int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) * Make certain the cpu I'm about to reboot on is online.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) * This is inline to what migrate_to_reboot_cpu() already do.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) if (!cpu_online(primary_cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) primary_cpu = cpumask_first(cpu_online_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) for_each_online_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) if (cpu == primary_cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) error = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) if (error) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) pr_err("Failed to offline CPU%d - error=%d",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428) cpu, error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434) * Ensure all but the reboot CPU are offline.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436) BUG_ON(num_online_cpus() > 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) * Make sure the CPUs won't be enabled by someone else after this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) * point. Kexec will reboot to a new kernel shortly resetting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) * everything along the way.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) cpu_hotplug_disabled++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) #define takedown_cpu NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) #endif /*CONFIG_HOTPLUG_CPU*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) * notify_cpu_starting(cpu) - Invoke the callbacks on the starting CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) * @cpu: cpu that just started
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) * It must be called by the arch code on the new cpu, before the new cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) * enables interrupts and before the "boot" cpu returns from __cpu_up().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) void notify_cpu_starting(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) rcu_cpu_starting(cpu); /* Enables RCU usage on this CPU. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) cpumask_set_cpu(cpu, &cpus_booted_once_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) while (st->state < target) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468) st->state++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471) * STARTING must not fail!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) WARN_ON_ONCE(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) * Called from the idle task. Wake up the controlling task which brings the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) * hotplug thread of the upcoming CPU up and then delegates the rest of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480) * online bringup to the hotplug thread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) void cpuhp_online_idle(enum cpuhp_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) /* Happens for the boot cpu */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) if (state != CPUHP_AP_ONLINE_IDLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) * Unpart the stopper thread before we start the idle loop (and start
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492) * scheduling); this ensures the stopper task is always available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494) stop_machine_unpark(smp_processor_id());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496) st->state = CPUHP_AP_ONLINE_IDLE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497) complete_ap_thread(st, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) static int switch_to_rt_policy(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) unsigned int policy = current->policy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505) if (policy == SCHED_NORMAL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) /* Switch to SCHED_FIFO from SCHED_NORMAL. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) return sched_setscheduler_nocheck(current, SCHED_FIFO, ¶m);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512) static int switch_to_fair_policy(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) struct sched_param param = { .sched_priority = 0 };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516) return sched_setscheduler_nocheck(current, SCHED_NORMAL, ¶m);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) /* Requires cpu_add_remove_lock to be held */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) struct task_struct *idle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) cpus_write_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) if (!cpu_present(cpu)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) * The caller of cpu_up() might have raced with another
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) * caller. Nothing to do.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) if (st->state >= target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540) if (st->state == CPUHP_OFFLINE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541) /* Let it fail before we try to bring the cpu up */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542) idle = idle_thread_get(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) if (IS_ERR(idle)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) ret = PTR_ERR(idle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549) cpuhp_tasks_frozen = tasks_frozen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) cpuhp_set_state(st, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) * If the current CPU state is in the range of the AP hotplug thread,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) * then we need to kick the thread once more.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556) if (st->state > CPUHP_BRINGUP_CPU) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) ret = cpuhp_kick_ap_work(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) * The AP side has done the error rollback already. Just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) * return the error code..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) * Try to reach the target state. We max out on the BP at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568) * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569) * responsible for bringing it up to the target state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) target = min((int)target, CPUHP_BRINGUP_CPU);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) ret = cpuhp_up_callbacks(cpu, st, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) cpus_write_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) arch_smt_update();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576) cpu_up_down_serialize_trainwrecks(tasks_frozen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) static int cpu_up(unsigned int cpu, enum cpuhp_state target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) int switch_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) if (!cpu_possible(cpu)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586) pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) #if defined(CONFIG_IA64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589) pr_err("please check additional_cpus= boot parameter\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594) trace_android_vh_cpu_up(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) * CPU hotplug operations consists of many steps and each step
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598) * calls a callback of core kernel subsystem. CPU hotplug-in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599) * operation may get preempted by other CFS tasks and whole
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) * operation of cpu hotplug in CPU gets delayed. Switch the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601) * current task to SCHED_FIFO from SCHED_NORMAL, so that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602) * hotplug in operation may complete quickly in heavy loaded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) * conditions and new CPU will start handle the workload.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606) switch_err = switch_to_rt_policy();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) err = try_online_node(cpu_to_node(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) goto switch_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) if (cpu_hotplug_disabled) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618) if (!cpu_smt_allowed(cpu)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) err = -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623) err = _cpu_up(cpu, 0, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626) switch_out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) if (!switch_err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628) switch_err = switch_to_fair_policy();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) if (switch_err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) pr_err("Hotplug policy switch err=%d Task %s pid=%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) switch_err, current->comm, current->pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) * cpu_device_up - Bring up a cpu device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) * @dev: Pointer to the cpu device to online
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) * This function is meant to be used by device core cpu subsystem only.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643) * Other subsystems should use add_cpu() instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645) int cpu_device_up(struct device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647) return cpu_up(dev->id, CPUHP_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) int add_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654) lock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) ret = device_online(get_cpu_device(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) unlock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) EXPORT_SYMBOL_GPL(add_cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663) * bringup_hibernate_cpu - Bring up the CPU that we hibernated on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) * @sleep_cpu: The cpu we hibernated on and should be brought up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) * On some architectures like arm64, we can hibernate on any CPU, but on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) * wake up the CPU we hibernated on might be offline as a side effect of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) * using maxcpus= for example.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) int bringup_hibernate_cpu(unsigned int sleep_cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) if (!cpu_online(sleep_cpu)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675) pr_info("Hibernated on a CPU that is offline! Bringing CPU up.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) ret = cpu_up(sleep_cpu, CPUHP_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) pr_err("Failed to bring hibernate-CPU up!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685) void bringup_nonboot_cpus(unsigned int setup_max_cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) unsigned int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) for_each_present_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690) if (num_online_cpus() >= setup_max_cpus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) if (!cpu_online(cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693) cpu_up(cpu, CPUHP_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) #ifdef CONFIG_PM_SLEEP_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698) static cpumask_var_t frozen_cpus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) int freeze_secondary_cpus(int primary)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) int cpu, error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) if (primary == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706) primary = cpumask_first(cpu_online_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) if (!housekeeping_cpu(primary, HK_FLAG_TIMER))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) primary = housekeeping_any_cpu(HK_FLAG_TIMER);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) if (!cpu_online(primary))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711) primary = cpumask_first(cpu_online_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) * We take down all of the non-boot CPUs in one shot to avoid races
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) * with the userspace trying to use the CPU hotplug at the same time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) cpumask_clear(frozen_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) pr_info("Disabling non-boot CPUs ...\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) for_each_online_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) if (cpu == primary)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) if (pm_wakeup_pending()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) pr_info("Wakeup pending. Abort CPU freeze\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) error = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) error = _cpu_down(cpu, 1, CPUHP_OFFLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) if (!error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) cpumask_set_cpu(cpu, frozen_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) pr_err("Error taking CPU%d down: %d\n", cpu, error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) if (!error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) BUG_ON(num_online_cpus() > 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745) pr_err("Non-boot CPUs are not disabled\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) * Make sure the CPUs won't be enabled by someone else. We need to do
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) * this even in case of failure as all freeze_secondary_cpus() users are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) * supposed to do thaw_secondary_cpus() on the failure path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) cpu_hotplug_disabled++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) void __weak arch_thaw_secondary_cpus_begin(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762) void __weak arch_thaw_secondary_cpus_end(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1766) void thaw_secondary_cpus(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1767) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1768) int cpu, error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1769) struct device *cpu_device;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1770)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1771) /* Allow everyone to use the CPU hotplug again */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1772) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1773) __cpu_hotplug_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1774) if (cpumask_empty(frozen_cpus))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1775) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1776)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1777) pr_info("Enabling non-boot CPUs ...\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1779) arch_thaw_secondary_cpus_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1780)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1781) for_each_cpu(cpu, frozen_cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1782) trace_suspend_resume(TPS("CPU_ON"), cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1783) error = _cpu_up(cpu, 1, CPUHP_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1784) trace_suspend_resume(TPS("CPU_ON"), cpu, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1785) if (!error) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1786) pr_info("CPU%d is up\n", cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1787) cpu_device = get_cpu_device(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1788) if (!cpu_device)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1789) pr_err("%s: failed to get cpu%d device\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1790) __func__, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1791) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1792) kobject_uevent(&cpu_device->kobj, KOBJ_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1793) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1794) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1795) pr_warn("Error taking CPU%d up: %d\n", cpu, error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1796) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1797)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1798) arch_thaw_secondary_cpus_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1799)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1800) cpumask_clear(frozen_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1801) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1802) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1803) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1804)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1805) static int __init alloc_frozen_cpus(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1806) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1807) if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1808) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1809) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1810) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1811) core_initcall(alloc_frozen_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1812)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1813) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1814) * When callbacks for CPU hotplug notifications are being executed, we must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1815) * ensure that the state of the system with respect to the tasks being frozen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1816) * or not, as reported by the notification, remains unchanged *throughout the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1817) * duration* of the execution of the callbacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1818) * Hence we need to prevent the freezer from racing with regular CPU hotplug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1819) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1820) * This synchronization is implemented by mutually excluding regular CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1821) * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1822) * Hibernate notifications.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1823) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1824) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1825) cpu_hotplug_pm_callback(struct notifier_block *nb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1826) unsigned long action, void *ptr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1827) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1828) switch (action) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1829)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1830) case PM_SUSPEND_PREPARE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1831) case PM_HIBERNATION_PREPARE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1832) cpu_hotplug_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1833) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1834)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1835) case PM_POST_SUSPEND:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1836) case PM_POST_HIBERNATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1837) cpu_hotplug_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1838) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1839)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1840) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1841) return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1842) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1843)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1844) return NOTIFY_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1845) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1846)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1847)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1848) static int __init cpu_hotplug_pm_sync_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1849) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1850) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1851) * cpu_hotplug_pm_callback has higher priority than x86
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1852) * bsp_pm_callback which depends on cpu_hotplug_pm_callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1853) * to disable cpu hotplug to avoid cpu hotplug race.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1854) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1855) pm_notifier(cpu_hotplug_pm_callback, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1856) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1857) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1858) core_initcall(cpu_hotplug_pm_sync_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1859)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1860) #endif /* CONFIG_PM_SLEEP_SMP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1861)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1862) int __boot_cpu_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1863)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1864) #endif /* CONFIG_SMP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1865)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1866) /* Boot processor state steps */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1867) static struct cpuhp_step cpuhp_hp_states[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1868) [CPUHP_OFFLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1869) .name = "offline",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1870) .startup.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1871) .teardown.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1872) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1873) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1874) [CPUHP_CREATE_THREADS]= {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1875) .name = "threads:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1876) .startup.single = smpboot_create_threads,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1877) .teardown.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1878) .cant_stop = true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1879) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1880) [CPUHP_PERF_PREPARE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1881) .name = "perf:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1882) .startup.single = perf_event_init_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1883) .teardown.single = perf_event_exit_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1884) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1885) [CPUHP_WORKQUEUE_PREP] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1886) .name = "workqueue:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1887) .startup.single = workqueue_prepare_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1888) .teardown.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1889) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1890) [CPUHP_HRTIMERS_PREPARE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1891) .name = "hrtimers:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1892) .startup.single = hrtimers_prepare_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1893) .teardown.single = hrtimers_dead_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1894) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1895) [CPUHP_SMPCFD_PREPARE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1896) .name = "smpcfd:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1897) .startup.single = smpcfd_prepare_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1898) .teardown.single = smpcfd_dead_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1899) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1900) [CPUHP_RELAY_PREPARE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1901) .name = "relay:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1902) .startup.single = relay_prepare_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1903) .teardown.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1904) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1905) [CPUHP_SLAB_PREPARE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1906) .name = "slab:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1907) .startup.single = slab_prepare_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1908) .teardown.single = slab_dead_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1909) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1910) [CPUHP_RCUTREE_PREP] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1911) .name = "RCU/tree:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1912) .startup.single = rcutree_prepare_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1913) .teardown.single = rcutree_dead_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1914) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1915) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1916) * On the tear-down path, timers_dead_cpu() must be invoked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1917) * before blk_mq_queue_reinit_notify() from notify_dead(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1918) * otherwise a RCU stall occurs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1919) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1920) [CPUHP_TIMERS_PREPARE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1921) .name = "timers:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1922) .startup.single = timers_prepare_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1923) .teardown.single = timers_dead_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1924) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1925) /* Kicks the plugged cpu into life */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1926) [CPUHP_BRINGUP_CPU] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1927) .name = "cpu:bringup",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1928) .startup.single = bringup_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1929) .teardown.single = finish_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1930) .cant_stop = true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1931) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1932) /* Final state before CPU kills itself */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1933) [CPUHP_AP_IDLE_DEAD] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1934) .name = "idle:dead",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1935) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1936) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1937) * Last state before CPU enters the idle loop to die. Transient state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1938) * for synchronization.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1939) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1940) [CPUHP_AP_OFFLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1941) .name = "ap:offline",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1942) .cant_stop = true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1943) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1944) /* First state is scheduler control. Interrupts are disabled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1945) [CPUHP_AP_SCHED_STARTING] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1946) .name = "sched:starting",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1947) .startup.single = sched_cpu_starting,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1948) .teardown.single = sched_cpu_dying,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1949) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1950) [CPUHP_AP_RCUTREE_DYING] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1951) .name = "RCU/tree:dying",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1952) .startup.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1953) .teardown.single = rcutree_dying_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1954) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1955) [CPUHP_AP_SMPCFD_DYING] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1956) .name = "smpcfd:dying",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1957) .startup.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1958) .teardown.single = smpcfd_dying_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1959) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1960) /* Entry state on starting. Interrupts enabled from here on. Transient
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1961) * state for synchronsization */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1962) [CPUHP_AP_ONLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1963) .name = "ap:online",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1964) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1965) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1966) * Handled on controll processor until the plugged processor manages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1967) * this itself.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1968) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1969) [CPUHP_TEARDOWN_CPU] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1970) .name = "cpu:teardown",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1971) .startup.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1972) .teardown.single = takedown_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1973) .cant_stop = true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1974) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1975) /* Handle smpboot threads park/unpark */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1976) [CPUHP_AP_SMPBOOT_THREADS] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1977) .name = "smpboot/threads:online",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1978) .startup.single = smpboot_unpark_threads,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1979) .teardown.single = smpboot_park_threads,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1980) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1981) [CPUHP_AP_IRQ_AFFINITY_ONLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1982) .name = "irq/affinity:online",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1983) .startup.single = irq_affinity_online_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1984) .teardown.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1985) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1986) [CPUHP_AP_PERF_ONLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1987) .name = "perf:online",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1988) .startup.single = perf_event_init_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1989) .teardown.single = perf_event_exit_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1990) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1991) [CPUHP_AP_WATCHDOG_ONLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1992) .name = "lockup_detector:online",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1993) .startup.single = lockup_detector_online_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1994) .teardown.single = lockup_detector_offline_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1995) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1996) [CPUHP_AP_WORKQUEUE_ONLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1997) .name = "workqueue:online",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1998) .startup.single = workqueue_online_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1999) .teardown.single = workqueue_offline_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2000) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2001) [CPUHP_AP_RCUTREE_ONLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2002) .name = "RCU/tree:online",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2003) .startup.single = rcutree_online_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2004) .teardown.single = rcutree_offline_cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2005) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2006) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2007) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2008) * The dynamically registered state space is here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2009) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2010)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2011) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2012) /* Last state is scheduler control setting the cpu active */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2013) [CPUHP_AP_ACTIVE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2014) .name = "sched:active",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2015) .startup.single = sched_cpu_activate,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2016) .teardown.single = sched_cpu_deactivate,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2017) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2018) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2019)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2020) /* CPU is fully up and running. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2021) [CPUHP_ONLINE] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2022) .name = "online",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2023) .startup.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2024) .teardown.single = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2025) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2026) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2027)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2028) /* Sanity check for callbacks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2029) static int cpuhp_cb_check(enum cpuhp_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2030) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2031) if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2032) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2033) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2034) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2035)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2036) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2037) * Returns a free for dynamic slot assignment of the Online state. The states
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2038) * are protected by the cpuhp_slot_states mutex and an empty slot is identified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2039) * by having no name assigned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2040) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2041) static int cpuhp_reserve_state(enum cpuhp_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2042) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2043) enum cpuhp_state i, end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2044) struct cpuhp_step *step;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2045)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2046) switch (state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2047) case CPUHP_AP_ONLINE_DYN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2048) step = cpuhp_hp_states + CPUHP_AP_ONLINE_DYN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2049) end = CPUHP_AP_ONLINE_DYN_END;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2050) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2051) case CPUHP_BP_PREPARE_DYN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2052) step = cpuhp_hp_states + CPUHP_BP_PREPARE_DYN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2053) end = CPUHP_BP_PREPARE_DYN_END;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2054) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2055) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2056) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2057) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2058)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2059) for (i = state; i <= end; i++, step++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2060) if (!step->name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2061) return i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2062) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2063) WARN(1, "No more dynamic states available for CPU hotplug\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2064) return -ENOSPC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2065) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2066)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2067) static int cpuhp_store_callbacks(enum cpuhp_state state, const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2068) int (*startup)(unsigned int cpu),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2069) int (*teardown)(unsigned int cpu),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2070) bool multi_instance)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2071) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2072) /* (Un)Install the callbacks for further cpu hotplug operations */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2073) struct cpuhp_step *sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2074) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2075)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2076) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2077) * If name is NULL, then the state gets removed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2078) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2079) * CPUHP_AP_ONLINE_DYN and CPUHP_BP_PREPARE_DYN are handed out on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2080) * the first allocation from these dynamic ranges, so the removal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2081) * would trigger a new allocation and clear the wrong (already
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2082) * empty) state, leaving the callbacks of the to be cleared state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2083) * dangling, which causes wreckage on the next hotplug operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2084) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2085) if (name && (state == CPUHP_AP_ONLINE_DYN ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2086) state == CPUHP_BP_PREPARE_DYN)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2087) ret = cpuhp_reserve_state(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2088) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2089) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2090) state = ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2091) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2092) sp = cpuhp_get_step(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2093) if (name && sp->name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2094) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2095)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2096) sp->startup.single = startup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2097) sp->teardown.single = teardown;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2098) sp->name = name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2099) sp->multi_instance = multi_instance;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2100) INIT_HLIST_HEAD(&sp->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2101) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2102) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2104) static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2105) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2106) return cpuhp_get_step(state)->teardown.single;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2109) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2110) * Call the startup/teardown function for a step either on the AP or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2111) * on the current CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2112) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2113) static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2114) struct hlist_node *node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2115) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2116) struct cpuhp_step *sp = cpuhp_get_step(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2117) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2119) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2120) * If there's nothing to do, we done.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2121) * Relies on the union for multi_instance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2122) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2123) if ((bringup && !sp->startup.single) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2124) (!bringup && !sp->teardown.single))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2125) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2126) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2127) * The non AP bound callbacks can fail on bringup. On teardown
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2128) * e.g. module removal we crash for now.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2129) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2130) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2131) if (cpuhp_is_ap_state(state))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2132) ret = cpuhp_invoke_ap_callback(cpu, state, bringup, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2133) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2134) ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2135) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2136) ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2137) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2138) BUG_ON(ret && !bringup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2139) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2142) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2143) * Called from __cpuhp_setup_state on a recoverable failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2144) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2145) * Note: The teardown callbacks for rollback are not allowed to fail!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2146) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2147) static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2148) struct hlist_node *node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2149) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2150) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2152) /* Roll back the already executed steps on the other cpus */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2153) for_each_present_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2154) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2155) int cpustate = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2157) if (cpu >= failedcpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2158) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2160) /* Did we invoke the startup call on that cpu ? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2161) if (cpustate >= state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2162) cpuhp_issue_call(cpu, state, false, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2166) int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2167) struct hlist_node *node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2168) bool invoke)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2169) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2170) struct cpuhp_step *sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2171) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2172) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2174) lockdep_assert_cpus_held();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2176) sp = cpuhp_get_step(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2177) if (sp->multi_instance == false)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2178) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2180) mutex_lock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2182) if (!invoke || !sp->startup.multi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2183) goto add_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2185) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2186) * Try to call the startup callback for each present cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2187) * depending on the hotplug state of the cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2188) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2189) for_each_present_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2190) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2191) int cpustate = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2193) if (cpustate < state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2194) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2196) ret = cpuhp_issue_call(cpu, state, true, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2197) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2198) if (sp->teardown.multi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2199) cpuhp_rollback_install(cpu, state, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2200) goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2201) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2203) add_node:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2204) ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2205) hlist_add_head(node, &sp->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2206) unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2207) mutex_unlock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2208) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2209) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2211) int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2212) bool invoke)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2213) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2214) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2216) cpus_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2217) ret = __cpuhp_state_add_instance_cpuslocked(state, node, invoke);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2218) cpus_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2219) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2220) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2221) EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2223) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2224) * __cpuhp_setup_state_cpuslocked - Setup the callbacks for an hotplug machine state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2225) * @state: The state to setup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2226) * @invoke: If true, the startup function is invoked for cpus where
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2227) * cpu state >= @state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2228) * @startup: startup callback function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2229) * @teardown: teardown callback function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2230) * @multi_instance: State is set up for multiple instances which get
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2231) * added afterwards.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2232) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2233) * The caller needs to hold cpus read locked while calling this function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2234) * Returns:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2235) * On success:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2236) * Positive state number if @state is CPUHP_AP_ONLINE_DYN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2237) * 0 for all other states
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2238) * On failure: proper (negative) error code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2239) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2240) int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2241) const char *name, bool invoke,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2242) int (*startup)(unsigned int cpu),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2243) int (*teardown)(unsigned int cpu),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2244) bool multi_instance)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2245) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2246) int cpu, ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2247) bool dynstate;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2249) lockdep_assert_cpus_held();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2251) if (cpuhp_cb_check(state) || !name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2252) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2254) mutex_lock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2256) ret = cpuhp_store_callbacks(state, name, startup, teardown,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2257) multi_instance);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2259) dynstate = state == CPUHP_AP_ONLINE_DYN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2260) if (ret > 0 && dynstate) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2261) state = ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2262) ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2263) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2265) if (ret || !invoke || !startup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2266) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2268) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2269) * Try to call the startup callback for each present cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2270) * depending on the hotplug state of the cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2271) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2272) for_each_present_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2273) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2274) int cpustate = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2276) if (cpustate < state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2277) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2279) ret = cpuhp_issue_call(cpu, state, true, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2280) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2281) if (teardown)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2282) cpuhp_rollback_install(cpu, state, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2283) cpuhp_store_callbacks(state, NULL, NULL, NULL, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2284) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2285) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2286) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2287) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2288) mutex_unlock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2289) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2290) * If the requested state is CPUHP_AP_ONLINE_DYN, return the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2291) * dynamically allocated state in case of success.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2292) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2293) if (!ret && dynstate)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2294) return state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2295) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2296) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2297) EXPORT_SYMBOL(__cpuhp_setup_state_cpuslocked);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2299) int __cpuhp_setup_state(enum cpuhp_state state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2300) const char *name, bool invoke,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2301) int (*startup)(unsigned int cpu),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2302) int (*teardown)(unsigned int cpu),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2303) bool multi_instance)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2304) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2305) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2307) cpus_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2308) ret = __cpuhp_setup_state_cpuslocked(state, name, invoke, startup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2309) teardown, multi_instance);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2310) cpus_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2311) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2313) EXPORT_SYMBOL(__cpuhp_setup_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2315) int __cpuhp_state_remove_instance(enum cpuhp_state state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2316) struct hlist_node *node, bool invoke)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2317) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2318) struct cpuhp_step *sp = cpuhp_get_step(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2319) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2321) BUG_ON(cpuhp_cb_check(state));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2323) if (!sp->multi_instance)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2324) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2325)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2326) cpus_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2327) mutex_lock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2329) if (!invoke || !cpuhp_get_teardown_cb(state))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2330) goto remove;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2331) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2332) * Call the teardown callback for each present cpu depending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2333) * on the hotplug state of the cpu. This function is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2334) * allowed to fail currently!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2335) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2336) for_each_present_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2337) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2338) int cpustate = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2340) if (cpustate >= state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2341) cpuhp_issue_call(cpu, state, false, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2342) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2344) remove:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2345) hlist_del(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2346) mutex_unlock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2347) cpus_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2348)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2349) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2351) EXPORT_SYMBOL_GPL(__cpuhp_state_remove_instance);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2352)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2353) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2354) * __cpuhp_remove_state_cpuslocked - Remove the callbacks for an hotplug machine state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2355) * @state: The state to remove
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2356) * @invoke: If true, the teardown function is invoked for cpus where
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2357) * cpu state >= @state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2358) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2359) * The caller needs to hold cpus read locked while calling this function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2360) * The teardown callback is currently not allowed to fail. Think
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2361) * about module removal!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2362) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2363) void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2364) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2365) struct cpuhp_step *sp = cpuhp_get_step(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2366) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2368) BUG_ON(cpuhp_cb_check(state));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2370) lockdep_assert_cpus_held();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2371)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2372) mutex_lock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2373) if (sp->multi_instance) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2374) WARN(!hlist_empty(&sp->list),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2375) "Error: Removing state %d which has instances left.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2376) state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2377) goto remove;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2378) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2380) if (!invoke || !cpuhp_get_teardown_cb(state))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2381) goto remove;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2383) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2384) * Call the teardown callback for each present cpu depending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2385) * on the hotplug state of the cpu. This function is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2386) * allowed to fail currently!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2387) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2388) for_each_present_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2389) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2390) int cpustate = st->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2392) if (cpustate >= state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2393) cpuhp_issue_call(cpu, state, false, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2394) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2395) remove:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2396) cpuhp_store_callbacks(state, NULL, NULL, NULL, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2397) mutex_unlock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2398) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2399) EXPORT_SYMBOL(__cpuhp_remove_state_cpuslocked);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2401) void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2402) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2403) cpus_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2404) __cpuhp_remove_state_cpuslocked(state, invoke);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2405) cpus_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2406) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2407) EXPORT_SYMBOL(__cpuhp_remove_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2409) #ifdef CONFIG_HOTPLUG_SMT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2410) static void cpuhp_offline_cpu_device(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2411) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2412) struct device *dev = get_cpu_device(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2414) dev->offline = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2415) /* Tell user space about the state change */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2416) kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2417) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2419) static void cpuhp_online_cpu_device(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2420) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2421) struct device *dev = get_cpu_device(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2422)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2423) dev->offline = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2424) /* Tell user space about the state change */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2425) kobject_uevent(&dev->kobj, KOBJ_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2426) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2428) int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2429) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2430) int cpu, ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2431)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2432) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2433) for_each_online_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2434) if (topology_is_primary_thread(cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2435) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2436) ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2437) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2438) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2439) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2440) * As this needs to hold the cpu maps lock it's impossible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2441) * to call device_offline() because that ends up calling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2442) * cpu_down() which takes cpu maps lock. cpu maps lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2443) * needs to be held as this might race against in kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2444) * abusers of the hotplug machinery (thermal management).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2445) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2446) * So nothing would update device:offline state. That would
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2447) * leave the sysfs entry stale and prevent onlining after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2448) * smt control has been changed to 'off' again. This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2449) * called under the sysfs hotplug lock, so it is properly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2450) * serialized against the regular offline usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2451) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2452) cpuhp_offline_cpu_device(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2453) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2454) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2455) cpu_smt_control = ctrlval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2456) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2457) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2458) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2460) int cpuhp_smt_enable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2461) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2462) int cpu, ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2463)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2464) cpu_maps_update_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2465) cpu_smt_control = CPU_SMT_ENABLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2466) for_each_present_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2467) /* Skip online CPUs and CPUs on offline nodes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2468) if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2469) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2470) ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2471) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2472) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2473) /* See comment in cpuhp_smt_disable() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2474) cpuhp_online_cpu_device(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2476) cpu_maps_update_done();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2477) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2478) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2479) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2481) #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2482) static ssize_t show_cpuhp_state(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2483) struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2484) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2485) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2487) return sprintf(buf, "%d\n", st->state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2488) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2489) static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2491) static ssize_t write_cpuhp_target(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2492) struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2493) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2494) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2495) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2496) struct cpuhp_step *sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2497) int target, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2498)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2499) ret = kstrtoint(buf, 10, &target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2500) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2501) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2502)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2503) #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2504) if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2505) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2506) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2507) if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2508) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2509) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2511) ret = lock_device_hotplug_sysfs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2512) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2513) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2514)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2515) mutex_lock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2516) sp = cpuhp_get_step(target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2517) ret = !sp->name || sp->cant_stop ? -EINVAL : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2518) mutex_unlock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2519) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2520) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2522) if (st->state < target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2523) ret = cpu_up(dev->id, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2524) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2525) ret = cpu_down(dev->id, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2526) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2527) unlock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2528) return ret ? ret : count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2529) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2530)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2531) static ssize_t show_cpuhp_target(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2532) struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2533) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2534) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2536) return sprintf(buf, "%d\n", st->target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2537) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2538) static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2541) static ssize_t write_cpuhp_fail(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2542) struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2543) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2544) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2545) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2546) struct cpuhp_step *sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2547) int fail, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2549) ret = kstrtoint(buf, 10, &fail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2550) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2551) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2552)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2553) if (fail < CPUHP_OFFLINE || fail > CPUHP_ONLINE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2554) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2555)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2556) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2557) * Cannot fail STARTING/DYING callbacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2558) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2559) if (cpuhp_is_atomic_state(fail))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2560) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2562) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2563) * Cannot fail anything that doesn't have callbacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2564) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2565) mutex_lock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2566) sp = cpuhp_get_step(fail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2567) if (!sp->startup.single && !sp->teardown.single)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2568) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2569) mutex_unlock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2570) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2571) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2572)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2573) st->fail = fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2575) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2576) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2577)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2578) static ssize_t show_cpuhp_fail(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2579) struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2580) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2581) struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2583) return sprintf(buf, "%d\n", st->fail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2584) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2585)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2586) static DEVICE_ATTR(fail, 0644, show_cpuhp_fail, write_cpuhp_fail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2588) static struct attribute *cpuhp_cpu_attrs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2589) &dev_attr_state.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2590) &dev_attr_target.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2591) &dev_attr_fail.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2592) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2593) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2594)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2595) static const struct attribute_group cpuhp_cpu_attr_group = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2596) .attrs = cpuhp_cpu_attrs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2597) .name = "hotplug",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2598) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2599) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2600)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2601) static ssize_t show_cpuhp_states(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2602) struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2603) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2604) ssize_t cur, res = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2605) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2607) mutex_lock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2608) for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2609) struct cpuhp_step *sp = cpuhp_get_step(i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2610)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2611) if (sp->name) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2612) cur = sprintf(buf, "%3d: %s\n", i, sp->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2613) buf += cur;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2614) res += cur;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2615) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2616) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2617) mutex_unlock(&cpuhp_state_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2618) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2619) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2620) static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2621)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2622) static struct attribute *cpuhp_cpu_root_attrs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2623) &dev_attr_states.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2624) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2625) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2627) static const struct attribute_group cpuhp_cpu_root_attr_group = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2628) .attrs = cpuhp_cpu_root_attrs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2629) .name = "hotplug",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2630) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2631) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2632)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2633) #ifdef CONFIG_HOTPLUG_SMT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2634)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2635) static ssize_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2636) __store_smt_control(struct device *dev, struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2637) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2638) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2639) int ctrlval, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2640)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2641) if (sysfs_streq(buf, "on"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2642) ctrlval = CPU_SMT_ENABLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2643) else if (sysfs_streq(buf, "off"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2644) ctrlval = CPU_SMT_DISABLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2645) else if (sysfs_streq(buf, "forceoff"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2646) ctrlval = CPU_SMT_FORCE_DISABLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2647) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2648) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2650) if (cpu_smt_control == CPU_SMT_FORCE_DISABLED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2651) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2653) if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2654) return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2655)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2656) ret = lock_device_hotplug_sysfs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2657) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2658) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2660) if (ctrlval != cpu_smt_control) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2661) switch (ctrlval) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2662) case CPU_SMT_ENABLED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2663) ret = cpuhp_smt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2664) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2665) case CPU_SMT_DISABLED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2666) case CPU_SMT_FORCE_DISABLED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2667) ret = cpuhp_smt_disable(ctrlval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2668) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2669) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2670) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2671)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2672) unlock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2673) return ret ? ret : count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2674) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2676) #else /* !CONFIG_HOTPLUG_SMT */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2677) static ssize_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2678) __store_smt_control(struct device *dev, struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2679) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2680) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2681) return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2682) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2683) #endif /* CONFIG_HOTPLUG_SMT */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2685) static const char *smt_states[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2686) [CPU_SMT_ENABLED] = "on",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2687) [CPU_SMT_DISABLED] = "off",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2688) [CPU_SMT_FORCE_DISABLED] = "forceoff",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2689) [CPU_SMT_NOT_SUPPORTED] = "notsupported",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2690) [CPU_SMT_NOT_IMPLEMENTED] = "notimplemented",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2691) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2692)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2693) static ssize_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2694) show_smt_control(struct device *dev, struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2695) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2696) const char *state = smt_states[cpu_smt_control];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2698) return snprintf(buf, PAGE_SIZE - 2, "%s\n", state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2699) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2700)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2701) static ssize_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2702) store_smt_control(struct device *dev, struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2703) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2704) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2705) return __store_smt_control(dev, attr, buf, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2706) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2707) static DEVICE_ATTR(control, 0644, show_smt_control, store_smt_control);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2708)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2709) static ssize_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2710) show_smt_active(struct device *dev, struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2711) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2712) return snprintf(buf, PAGE_SIZE - 2, "%d\n", sched_smt_active());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2713) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2714) static DEVICE_ATTR(active, 0444, show_smt_active, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2716) static struct attribute *cpuhp_smt_attrs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2717) &dev_attr_control.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2718) &dev_attr_active.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2719) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2720) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2721)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2722) static const struct attribute_group cpuhp_smt_attr_group = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2723) .attrs = cpuhp_smt_attrs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2724) .name = "smt",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2725) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2726) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2727)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2728) static int __init cpu_smt_sysfs_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2729) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2730) return sysfs_create_group(&cpu_subsys.dev_root->kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2731) &cpuhp_smt_attr_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2732) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2733)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2734) static int __init cpuhp_sysfs_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2735) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2736) int cpu, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2737)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2738) ret = cpu_smt_sysfs_init();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2739) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2740) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2741)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2742) ret = sysfs_create_group(&cpu_subsys.dev_root->kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2743) &cpuhp_cpu_root_attr_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2744) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2745) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2747) for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2748) struct device *dev = get_cpu_device(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2750) if (!dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2751) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2752) ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2753) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2754) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2755) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2756) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2757) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2758) device_initcall(cpuhp_sysfs_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2759) #endif /* CONFIG_SYSFS && CONFIG_HOTPLUG_CPU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2760)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2761) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2762) * cpu_bit_bitmap[] is a special, "compressed" data structure that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2763) * represents all NR_CPUS bits binary values of 1<<nr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2764) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2765) * It is used by cpumask_of() to get a constant address to a CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2766) * mask value that has a single bit set only.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2767) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2769) /* cpu_bit_bitmap[0] is empty - so we can back into it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2770) #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2771) #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2772) #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2773) #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2774)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2775) const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2776)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2777) MASK_DECLARE_8(0), MASK_DECLARE_8(8),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2778) MASK_DECLARE_8(16), MASK_DECLARE_8(24),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2779) #if BITS_PER_LONG > 32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2780) MASK_DECLARE_8(32), MASK_DECLARE_8(40),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2781) MASK_DECLARE_8(48), MASK_DECLARE_8(56),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2782) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2783) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2784) EXPORT_SYMBOL_GPL(cpu_bit_bitmap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2785)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2786) const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2787) EXPORT_SYMBOL(cpu_all_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2788)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2789) #ifdef CONFIG_INIT_ALL_POSSIBLE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2790) struct cpumask __cpu_possible_mask __read_mostly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2791) = {CPU_BITS_ALL};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2792) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2793) struct cpumask __cpu_possible_mask __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2794) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2795) EXPORT_SYMBOL(__cpu_possible_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2796)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2797) struct cpumask __cpu_online_mask __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2798) EXPORT_SYMBOL(__cpu_online_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2799)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2800) struct cpumask __cpu_present_mask __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2801) EXPORT_SYMBOL(__cpu_present_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2802)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2803) struct cpumask __cpu_active_mask __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2804) EXPORT_SYMBOL(__cpu_active_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2805)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2806) atomic_t __num_online_cpus __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2807) EXPORT_SYMBOL(__num_online_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2809) void init_cpu_present(const struct cpumask *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2810) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2811) cpumask_copy(&__cpu_present_mask, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2812) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2813)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2814) void init_cpu_possible(const struct cpumask *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2815) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2816) cpumask_copy(&__cpu_possible_mask, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2817) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2818)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2819) void init_cpu_online(const struct cpumask *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2820) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2821) cpumask_copy(&__cpu_online_mask, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2822) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2823)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2824) void set_cpu_online(unsigned int cpu, bool online)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2825) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2826) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2827) * atomic_inc/dec() is required to handle the horrid abuse of this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2828) * function by the reboot and kexec code which invoke it from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2829) * IPI/NMI broadcasts when shutting down CPUs. Invocation from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2830) * regular CPU hotplug is properly serialized.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2831) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2832) * Note, that the fact that __num_online_cpus is of type atomic_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2833) * does not protect readers which are not serialized against
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2834) * concurrent hotplug operations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2835) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2836) if (online) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2837) if (!cpumask_test_and_set_cpu(cpu, &__cpu_online_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2838) atomic_inc(&__num_online_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2839) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2840) if (cpumask_test_and_clear_cpu(cpu, &__cpu_online_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2841) atomic_dec(&__num_online_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2842) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2843) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2844)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2845) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2846) * Activate the first processor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2847) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2848) void __init boot_cpu_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2849) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2850) int cpu = smp_processor_id();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2851)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2852) /* Mark the boot cpu "present", "online" etc for SMP and UP case */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2853) set_cpu_online(cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2854) set_cpu_active(cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2855) set_cpu_present(cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2856) set_cpu_possible(cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2857)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2858) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2859) __boot_cpu_id = cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2860) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2861) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2862)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2863) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2864) * Must be called _AFTER_ setting up the per_cpu areas
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2865) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2866) void __init boot_cpu_hotplug_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2867) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2868) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2869) cpumask_set_cpu(smp_processor_id(), &cpus_booted_once_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2870) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2871) this_cpu_write(cpuhp_state.state, CPUHP_ONLINE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2872) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2873)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2874) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2875) * These are used for a global "mitigations=" cmdline option for toggling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2876) * optional CPU mitigations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2877) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2878) enum cpu_mitigations {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2879) CPU_MITIGATIONS_OFF,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2880) CPU_MITIGATIONS_AUTO,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2881) CPU_MITIGATIONS_AUTO_NOSMT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2882) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2883)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2884) static enum cpu_mitigations cpu_mitigations __ro_after_init =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2885) CPU_MITIGATIONS_AUTO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2886)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2887) static int __init mitigations_parse_cmdline(char *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2888) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2889) if (!strcmp(arg, "off"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2890) cpu_mitigations = CPU_MITIGATIONS_OFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2891) else if (!strcmp(arg, "auto"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2892) cpu_mitigations = CPU_MITIGATIONS_AUTO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2893) else if (!strcmp(arg, "auto,nosmt"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2894) cpu_mitigations = CPU_MITIGATIONS_AUTO_NOSMT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2895) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2896) pr_crit("Unsupported mitigations=%s, system may still be vulnerable\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2897) arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2898)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2899) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2900) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2901) early_param("mitigations", mitigations_parse_cmdline);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2902)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2903) /* mitigations=off */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2904) bool cpu_mitigations_off(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2905) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2906) return cpu_mitigations == CPU_MITIGATIONS_OFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2907) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2908) EXPORT_SYMBOL_GPL(cpu_mitigations_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2909)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2910) /* mitigations=auto,nosmt */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2911) bool cpu_mitigations_auto_nosmt(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2912) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2913) return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2914) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2915) EXPORT_SYMBOL_GPL(cpu_mitigations_auto_nosmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2916)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2917) static ATOMIC_NOTIFIER_HEAD(idle_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2918)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2919) void idle_notifier_register(struct notifier_block *n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2920) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2921) atomic_notifier_chain_register(&idle_notifier, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2922) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2923) EXPORT_SYMBOL_GPL(idle_notifier_register);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2924)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2925) void idle_notifier_unregister(struct notifier_block *n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2926) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2927) atomic_notifier_chain_unregister(&idle_notifier, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2928) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2929) EXPORT_SYMBOL_GPL(idle_notifier_unregister);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2930)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2931) void idle_notifier_call_chain(unsigned long val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2932) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2933) atomic_notifier_call_chain(&idle_notifier, val, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2934) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2935) EXPORT_SYMBOL_GPL(idle_notifier_call_chain);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags