^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #include <linux/ftrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #include <linux/percpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/pgtable.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <asm/alternative.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <asm/cacheflush.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <asm/cpufeature.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <asm/daifflags.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <asm/debug-monitors.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <asm/exec.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <asm/mte.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <asm/memory.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <asm/mmu_context.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <asm/smp_plat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <asm/suspend.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * This is allocated by cpu_suspend_init(), and used to store a pointer to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * the 'struct sleep_stack_data' the contains a particular CPUs state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) unsigned long *sleep_save_stash;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * This hook is provided so that cpu_suspend code can restore HW
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * breakpoints as early as possible in the resume path, before reenabling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * debug exceptions. Code cannot be run from a CPU PM notifier since by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * time the notifier runs debug exceptions might have been enabled already,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * with HW breakpoints registers content still in an unknown state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) static int (*hw_breakpoint_restore)(unsigned int);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) void __init cpu_suspend_set_dbg_restorer(int (*hw_bp_restore)(unsigned int))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) /* Prevent multiple restore hook initializations */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) if (WARN_ON(hw_breakpoint_restore))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) hw_breakpoint_restore = hw_bp_restore;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) void notrace __cpu_suspend_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) unsigned int cpu = smp_processor_id();
^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) * We are resuming from reset with the idmap active in TTBR0_EL1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * We must uninstall the idmap and restore the expected MMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * state before we can possibly return to userspace.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) cpu_uninstall_idmap();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) /* Restore CnP bit in TTBR1_EL1 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) if (system_supports_cnp())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * PSTATE was not saved over suspend/resume, re-enable any detected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * features that might not have been set correctly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) __uaccess_enable_hw_pan();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) uao_thread_switch(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) * Restore HW breakpoint registers to sane values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * before debug exceptions are possibly reenabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * by cpu_suspend()s local_daif_restore() call.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) if (hw_breakpoint_restore)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) hw_breakpoint_restore(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * On resume, firmware implementing dynamic mitigation will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) * have turned the mitigation on. If the user has forcefully
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * disabled it, make sure their wishes are obeyed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) spectre_v4_enable_mitigation(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /* Restore additional feature-specific configuration */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) ptrauth_suspend_exit();
^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) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) * cpu_suspend
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * arg: argument to pass to the finisher function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * fn: finisher function pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) struct sleep_stack_data state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) /* Report any MTE async fault before going to suspend */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) mte_suspend_enter();
^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) * From this point debug exceptions are disabled to prevent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * updates to mdscr register (saved and restored along with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * general purpose registers) from kernel debuggers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) flags = local_daif_save();
^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) * Function graph tracer state gets incosistent when the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) * calls functions that never return (aka suspend finishers) hence
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * disable graph tracing during their execution.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) pause_graph_tracing();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) if (__cpu_suspend_enter(&state)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) /* Call the suspend finisher */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) ret = fn(arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) * Never gets here, unless the suspend finisher fails.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) * Successful cpu_suspend() should return from cpu_resume(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * returning through this code path is considered an error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * If the return value is set to 0 force ret = -EOPNOTSUPP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * to make sure a proper error condition is propagated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) ret = -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) RCU_NONIDLE(__cpu_suspend_exit());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) unpause_graph_tracing();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) * Restore pstate flags. OS lock and mdscr have been already
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) * restored, so from this point onwards, debugging is fully
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) * renabled if it was enabled when core started shutdown.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) local_daif_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) return ret;
^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) static int __init cpu_suspend_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) /* ctx_ptr is an array of physical addresses */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) sleep_save_stash = kcalloc(mpidr_hash_size(), sizeof(*sleep_save_stash),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) if (WARN_ON(!sleep_save_stash))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) early_initcall(cpu_suspend_init);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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