^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * arch/arm/common/bL_switcher.c -- big.LITTLE cluster switcher core driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Created by: Nicolas Pitre, March 2012
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Copyright: (C) 2012-2013 Linaro Limited
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/atomic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <uapi/linux/sched/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/cpu_pm.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/cpumask.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/kthread.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/wait.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/time.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/clockchips.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/hrtimer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/tick.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/notifier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/smp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/sysfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/irqchip/arm-gic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/moduleparam.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <asm/smp_plat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <asm/cputype.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <asm/suspend.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <asm/mcpm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <asm/bL_switcher.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #define CREATE_TRACE_POINTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #include <trace/events/power_cpu_migrate.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * Use our own MPIDR accessors as the generic ones in asm/cputype.h have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * __attribute_const__ and we don't want the compiler to assume any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * constness here as the value _does_ change along some code paths.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) static int read_mpidr(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) unsigned int id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) asm volatile ("mrc p15, 0, %0, c0, c0, 5" : "=r" (id));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) return id & MPIDR_HWID_BITMASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * bL switcher core code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) static void bL_do_switch(void *_arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) unsigned ib_mpidr, ib_cpu, ib_cluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) long volatile handshake, **handshake_ptr = _arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) pr_debug("%s\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) ib_mpidr = cpu_logical_map(smp_processor_id());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) ib_cpu = MPIDR_AFFINITY_LEVEL(ib_mpidr, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) ib_cluster = MPIDR_AFFINITY_LEVEL(ib_mpidr, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) /* Advertise our handshake location */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (handshake_ptr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) handshake = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) *handshake_ptr = &handshake;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) handshake = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * Our state has been saved at this point. Let's release our
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * inbound CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) mcpm_set_entry_vector(ib_cpu, ib_cluster, cpu_resume);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) sev();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * From this point, we must assume that our counterpart CPU might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * have taken over in its parallel world already, as if execution
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) * just returned from cpu_suspend(). It is therefore important to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * be very careful not to make any change the other guy is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) * expecting. This is why we need stack isolation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * Fancy under cover tasks could be performed here. For now
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * we have none.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * Let's wait until our inbound is alive.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) while (!handshake) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) wfe();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) smp_mb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) /* Let's put ourself down. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) mcpm_cpu_power_down();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) /* should never get here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) }
^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) * Stack isolation. To ensure 'current' remains valid, we just use another
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * piece of our thread's stack space which should be fairly lightly used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * The selected area starts just above the thread_info structure located
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) * at the very bottom of the stack, aligned to a cache line, and indexed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) * with the cluster number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) #define STACK_SIZE 512
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) static int bL_switchpoint(unsigned long _arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) unsigned int mpidr = read_mpidr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) unsigned int clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) void *stack = current_thread_info() + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) stack = PTR_ALIGN(stack, L1_CACHE_BYTES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) stack += clusterid * STACK_SIZE + STACK_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) call_with_stack(bL_do_switch, (void *)_arg, stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) * Generic switcher interface
^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 unsigned int bL_gic_id[MAX_CPUS_PER_CLUSTER][MAX_NR_CLUSTERS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) static int bL_switcher_cpu_pairing[NR_CPUS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) * bL_switch_to - Switch to a specific cluster for the current CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) * @new_cluster_id: the ID of the cluster to switch to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * This function must be called on the CPU to be switched.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) * Returns 0 on success, else a negative status code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) static int bL_switch_to(unsigned int new_cluster_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) unsigned int mpidr, this_cpu, that_cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) unsigned int ob_mpidr, ob_cpu, ob_cluster, ib_mpidr, ib_cpu, ib_cluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) struct completion inbound_alive;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) long volatile *handshake_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) int ipi_nr, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) this_cpu = smp_processor_id();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) ob_mpidr = read_mpidr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) ob_cpu = MPIDR_AFFINITY_LEVEL(ob_mpidr, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) ob_cluster = MPIDR_AFFINITY_LEVEL(ob_mpidr, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) BUG_ON(cpu_logical_map(this_cpu) != ob_mpidr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) if (new_cluster_id == ob_cluster)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) that_cpu = bL_switcher_cpu_pairing[this_cpu];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) ib_mpidr = cpu_logical_map(that_cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) ib_cpu = MPIDR_AFFINITY_LEVEL(ib_mpidr, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) ib_cluster = MPIDR_AFFINITY_LEVEL(ib_mpidr, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) pr_debug("before switch: CPU %d MPIDR %#x -> %#x\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) this_cpu, ob_mpidr, ib_mpidr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) this_cpu = smp_processor_id();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) /* Close the gate for our entry vectors */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) mcpm_set_entry_vector(ob_cpu, ob_cluster, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) mcpm_set_entry_vector(ib_cpu, ib_cluster, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) /* Install our "inbound alive" notifier. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) init_completion(&inbound_alive);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) ipi_nr = register_ipi_completion(&inbound_alive, this_cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) ipi_nr |= ((1 << 16) << bL_gic_id[ob_cpu][ob_cluster]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) mcpm_set_early_poke(ib_cpu, ib_cluster, gic_get_sgir_physaddr(), ipi_nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) * Let's wake up the inbound CPU now in case it requires some delay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) * to come online, but leave it gated in our entry vector code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) ret = mcpm_cpu_power_up(ib_cpu, ib_cluster);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) pr_err("%s: mcpm_cpu_power_up() returned %d\n", __func__, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) * Raise a SGI on the inbound CPU to make sure it doesn't stall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * in a possible WFI, such as in bL_power_down().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) gic_send_sgi(bL_gic_id[ib_cpu][ib_cluster], 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) * Wait for the inbound to come up. This allows for other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) * tasks to be scheduled in the mean time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) wait_for_completion(&inbound_alive);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) mcpm_set_early_poke(ib_cpu, ib_cluster, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) * From this point we are entering the switch critical zone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) * and can't take any interrupts anymore.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) local_irq_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) local_fiq_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) trace_cpu_migrate_begin(ktime_get_real_ns(), ob_mpidr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) /* redirect GIC's SGIs to our counterpart */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) gic_migrate_target(bL_gic_id[ib_cpu][ib_cluster]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) tick_suspend_local();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) ret = cpu_pm_enter();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) /* we can not tolerate errors at this point */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) panic("%s: cpu_pm_enter() returned %d\n", __func__, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) /* Swap the physical CPUs in the logical map for this logical CPU. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) cpu_logical_map(this_cpu) = ib_mpidr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) cpu_logical_map(that_cpu) = ob_mpidr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) /* Let's do the actual CPU switch. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) ret = cpu_suspend((unsigned long)&handshake_ptr, bL_switchpoint);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) if (ret > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) panic("%s: cpu_suspend() returned %d\n", __func__, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) /* We are executing on the inbound CPU at this point */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) mpidr = read_mpidr();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) pr_debug("after switch: CPU %d MPIDR %#x\n", this_cpu, mpidr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) BUG_ON(mpidr != ib_mpidr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) mcpm_cpu_powered_up();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) ret = cpu_pm_exit();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) tick_resume_local();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) trace_cpu_migrate_finish(ktime_get_real_ns(), ib_mpidr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) local_fiq_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) local_irq_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) *handshake_ptr = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) dsb_sev();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) pr_err("%s exiting with error %d\n", __func__, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) struct bL_thread {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) spinlock_t lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) wait_queue_head_t wq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) int wanted_cluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) struct completion started;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) bL_switch_completion_handler completer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) void *completer_cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) static struct bL_thread bL_threads[NR_CPUS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) static int bL_switcher_thread(void *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) struct bL_thread *t = arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) int cluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) bL_switch_completion_handler completer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) void *completer_cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) sched_set_fifo_low(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) complete(&t->started);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) if (signal_pending(current))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) flush_signals(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) wait_event_interruptible(t->wq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) t->wanted_cluster != -1 ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) kthread_should_stop());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) spin_lock(&t->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) cluster = t->wanted_cluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) completer = t->completer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) completer_cookie = t->completer_cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) t->wanted_cluster = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) t->completer = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) spin_unlock(&t->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) if (cluster != -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) bL_switch_to(cluster);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) if (completer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) completer(completer_cookie);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) } while (!kthread_should_stop());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) static struct task_struct *bL_switcher_thread_create(int cpu, void *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) task = kthread_create_on_node(bL_switcher_thread, arg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) cpu_to_node(cpu), "kswitcher_%d", cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) if (!IS_ERR(task)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) kthread_bind(task, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) wake_up_process(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) pr_err("%s failed for CPU %d\n", __func__, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) return task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) * bL_switch_request_cb - Switch to a specific cluster for the given CPU,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * with completion notification via a callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) * @cpu: the CPU to switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * @new_cluster_id: the ID of the cluster to switch to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * @completer: switch completion callback. if non-NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * @completer(@completer_cookie) will be called on completion of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) * the switch, in non-atomic context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) * @completer_cookie: opaque context argument for @completer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) * This function causes a cluster switch on the given CPU by waking up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) * the appropriate switcher thread. This function may or may not return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) * before the switch has occurred.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) * If a @completer callback function is supplied, it will be called when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) * the switch is complete. This can be used to determine asynchronously
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) * when the switch is complete, regardless of when bL_switch_request()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) * returns. When @completer is supplied, no new switch request is permitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) * for the affected CPU until after the switch is complete, and @completer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) * has returned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) int bL_switch_request_cb(unsigned int cpu, unsigned int new_cluster_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) bL_switch_completion_handler completer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) void *completer_cookie)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) struct bL_thread *t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) if (cpu >= ARRAY_SIZE(bL_threads)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) pr_err("%s: cpu %d out of bounds\n", __func__, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) return -EINVAL;
^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) t = &bL_threads[cpu];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) if (IS_ERR(t->task))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) return PTR_ERR(t->task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) if (!t->task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) return -ESRCH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) spin_lock(&t->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) if (t->completer) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) spin_unlock(&t->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) t->completer = completer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) t->completer_cookie = completer_cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) t->wanted_cluster = new_cluster_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) spin_unlock(&t->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) wake_up(&t->wq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) EXPORT_SYMBOL_GPL(bL_switch_request_cb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) * Activation and configuration code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) static DEFINE_MUTEX(bL_switcher_activation_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) static BLOCKING_NOTIFIER_HEAD(bL_activation_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) static unsigned int bL_switcher_active;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) static unsigned int bL_switcher_cpu_original_cluster[NR_CPUS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) static cpumask_t bL_switcher_removed_logical_cpus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) int bL_switcher_register_notifier(struct notifier_block *nb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) return blocking_notifier_chain_register(&bL_activation_notifier, nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) EXPORT_SYMBOL_GPL(bL_switcher_register_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) int bL_switcher_unregister_notifier(struct notifier_block *nb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) return blocking_notifier_chain_unregister(&bL_activation_notifier, nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) EXPORT_SYMBOL_GPL(bL_switcher_unregister_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) static int bL_activation_notify(unsigned long val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) ret = blocking_notifier_call_chain(&bL_activation_notifier, val, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) if (ret & NOTIFY_STOP_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) pr_err("%s: notifier chain failed with status 0x%x\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) __func__, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) return notifier_to_errno(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) static void bL_switcher_restore_cpus(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) for_each_cpu(i, &bL_switcher_removed_logical_cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) struct device *cpu_dev = get_cpu_device(i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) int ret = device_online(cpu_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) dev_err(cpu_dev, "switcher: unable to restore CPU\n");
^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)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) static int bL_switcher_halve_cpus(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) int i, j, cluster_0, gic_id, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) unsigned int cpu, cluster, mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) cpumask_t available_cpus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) /* First pass to validate what we have */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) for_each_online_cpu(i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) if (cluster >= 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) pr_err("%s: only dual cluster systems are supported\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) if (WARN_ON(cpu >= MAX_CPUS_PER_CLUSTER))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) mask |= (1 << cluster);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) if (mask != 3) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) pr_err("%s: no CPU pairing possible\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) return -EINVAL;
^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) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) * Now let's do the pairing. We match each CPU with another CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * from a different cluster. To get a uniform scheduling behavior
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * without fiddling with CPU topology and compute capacity data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) * we'll use logical CPUs initially belonging to the same cluster.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) memset(bL_switcher_cpu_pairing, -1, sizeof(bL_switcher_cpu_pairing));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) cpumask_copy(&available_cpus, cpu_online_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) cluster_0 = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) for_each_cpu(i, &available_cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) int match = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) if (cluster_0 == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) cluster_0 = cluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) if (cluster != cluster_0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) cpumask_clear_cpu(i, &available_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) for_each_cpu(j, &available_cpus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(j), 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) * Let's remember the last match to create "odd"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) * pairings on purpose in order for other code not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) * to assume any relation between physical and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) * logical CPU numbers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) if (cluster != cluster_0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) match = j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) if (match != -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) bL_switcher_cpu_pairing[i] = match;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) cpumask_clear_cpu(match, &available_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) pr_info("CPU%d paired with CPU%d\n", i, match);
^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)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) * Now we disable the unwanted CPUs i.e. everything that has no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) * pairing information (that includes the pairing counterparts).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) cpumask_clear(&bL_switcher_removed_logical_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) for_each_online_cpu(i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) /* Let's take note of the GIC ID for this CPU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) gic_id = gic_get_cpu_id(i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) if (gic_id < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) pr_err("%s: bad GIC ID for CPU %d\n", __func__, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) bL_switcher_restore_cpus();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) bL_gic_id[cpu][cluster] = gic_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) pr_info("GIC ID for CPU %u cluster %u is %u\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) cpu, cluster, gic_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) if (bL_switcher_cpu_pairing[i] != -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) bL_switcher_cpu_original_cluster[i] = cluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) ret = device_offline(get_cpu_device(i));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) bL_switcher_restore_cpus();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) cpumask_set_cpu(i, &bL_switcher_removed_logical_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) return 0;
^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) /* Determine the logical CPU a given physical CPU is grouped on. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) int bL_switcher_get_logical_index(u32 mpidr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) if (!bL_switcher_active)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) return -EUNATCH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) mpidr &= MPIDR_HWID_BITMASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) for_each_online_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) int pairing = bL_switcher_cpu_pairing[cpu];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) if (pairing == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) if ((mpidr == cpu_logical_map(cpu)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) (mpidr == cpu_logical_map(pairing)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) return cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) static void bL_switcher_trace_trigger_cpu(void *__always_unused info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) trace_cpu_migrate_current(ktime_get_real_ns(), read_mpidr());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) int bL_switcher_trace_trigger(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) bL_switcher_trace_trigger_cpu(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) smp_call_function(bL_switcher_trace_trigger_cpu, NULL, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) preempt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) EXPORT_SYMBOL_GPL(bL_switcher_trace_trigger);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) static int bL_switcher_enable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) int cpu, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) mutex_lock(&bL_switcher_activation_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) lock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) if (bL_switcher_active) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) unlock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) mutex_unlock(&bL_switcher_activation_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) pr_info("big.LITTLE switcher initializing\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) ret = bL_activation_notify(BL_NOTIFY_PRE_ENABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) ret = bL_switcher_halve_cpus();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) bL_switcher_trace_trigger();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) for_each_online_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) struct bL_thread *t = &bL_threads[cpu];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) spin_lock_init(&t->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) init_waitqueue_head(&t->wq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) init_completion(&t->started);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) t->wanted_cluster = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) t->task = bL_switcher_thread_create(cpu, t);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) bL_switcher_active = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) bL_activation_notify(BL_NOTIFY_POST_ENABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) pr_info("big.LITTLE switcher initialized\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) pr_warn("big.LITTLE switcher initialization failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) bL_activation_notify(BL_NOTIFY_POST_DISABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) unlock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) mutex_unlock(&bL_switcher_activation_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) #ifdef CONFIG_SYSFS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) static void bL_switcher_disable(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) unsigned int cpu, cluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) struct bL_thread *t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) mutex_lock(&bL_switcher_activation_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) lock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) if (!bL_switcher_active)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) if (bL_activation_notify(BL_NOTIFY_PRE_DISABLE) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) bL_activation_notify(BL_NOTIFY_POST_ENABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) bL_switcher_active = 0;
^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) * To deactivate the switcher, we must shut down the switcher
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) * threads to prevent any other requests from being accepted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) * Then, if the final cluster for given logical CPU is not the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) * same as the original one, we'll recreate a switcher thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) * just for the purpose of switching the CPU back without any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) * possibility for interference from external requests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) for_each_online_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) t = &bL_threads[cpu];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) task = t->task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) t->task = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) if (!task || IS_ERR(task))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) kthread_stop(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) /* no more switch may happen on this CPU at this point */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) if (cluster == bL_switcher_cpu_original_cluster[cpu])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) init_completion(&t->started);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) t->wanted_cluster = bL_switcher_cpu_original_cluster[cpu];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) task = bL_switcher_thread_create(cpu, t);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) if (!IS_ERR(task)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) wait_for_completion(&t->started);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) kthread_stop(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) if (cluster == bL_switcher_cpu_original_cluster[cpu])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) /* If execution gets here, we're in trouble. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) pr_crit("%s: unable to restore original cluster for CPU %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) __func__, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) pr_crit("%s: CPU %d can't be restored\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) __func__, bL_switcher_cpu_pairing[cpu]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) cpumask_clear_cpu(bL_switcher_cpu_pairing[cpu],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) &bL_switcher_removed_logical_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) bL_switcher_restore_cpus();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) bL_switcher_trace_trigger();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) bL_activation_notify(BL_NOTIFY_POST_DISABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) unlock_device_hotplug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) mutex_unlock(&bL_switcher_activation_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) static ssize_t bL_switcher_active_show(struct kobject *kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) struct kobj_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) return sprintf(buf, "%u\n", bL_switcher_active);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) static ssize_t bL_switcher_active_store(struct kobject *kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) struct kobj_attribute *attr, const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) switch (buf[0]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) case '0':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) bL_switcher_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) case '1':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) ret = bL_switcher_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) return (ret >= 0) ? count : ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) static ssize_t bL_switcher_trace_trigger_store(struct kobject *kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) struct kobj_attribute *attr, const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) int ret = bL_switcher_trace_trigger();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) return ret ? ret : count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) static struct kobj_attribute bL_switcher_active_attr =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) __ATTR(active, 0644, bL_switcher_active_show, bL_switcher_active_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) static struct kobj_attribute bL_switcher_trace_trigger_attr =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) __ATTR(trace_trigger, 0200, NULL, bL_switcher_trace_trigger_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) static struct attribute *bL_switcher_attrs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) &bL_switcher_active_attr.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) &bL_switcher_trace_trigger_attr.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) static struct attribute_group bL_switcher_attr_group = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) .attrs = bL_switcher_attrs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) static struct kobject *bL_switcher_kobj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) static int __init bL_switcher_sysfs_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) bL_switcher_kobj = kobject_create_and_add("bL_switcher", kernel_kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) if (!bL_switcher_kobj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) ret = sysfs_create_group(bL_switcher_kobj, &bL_switcher_attr_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) kobject_put(bL_switcher_kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) #endif /* CONFIG_SYSFS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) bool bL_switcher_get_enabled(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) mutex_lock(&bL_switcher_activation_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) return bL_switcher_active;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) EXPORT_SYMBOL_GPL(bL_switcher_get_enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) void bL_switcher_put_enabled(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) mutex_unlock(&bL_switcher_activation_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) EXPORT_SYMBOL_GPL(bL_switcher_put_enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) * Veto any CPU hotplug operation on those CPUs we've removed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) * while the switcher is active.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) * We're just not ready to deal with that given the trickery involved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) static int bL_switcher_cpu_pre(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) int pairing;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) if (!bL_switcher_active)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) pairing = bL_switcher_cpu_pairing[cpu];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) if (pairing == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) static bool no_bL_switcher;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) core_param(no_bL_switcher, no_bL_switcher, bool, 0644);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) static int __init bL_switcher_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) if (!mcpm_is_available())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) cpuhp_setup_state_nocalls(CPUHP_ARM_BL_PREPARE, "arm/bl:prepare",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) bL_switcher_cpu_pre, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "arm/bl:predown",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) NULL, bL_switcher_cpu_pre);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) cpuhp_remove_state_nocalls(CPUHP_ARM_BL_PREPARE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) pr_err("bL_switcher: Failed to allocate a hotplug state\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) if (!no_bL_switcher) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) ret = bL_switcher_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) #ifdef CONFIG_SYSFS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) ret = bL_switcher_sysfs_init();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) pr_err("%s: unable to create sysfs entry\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) late_initcall(bL_switcher_init);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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