^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) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * This file contains the functions which manage clocksource drivers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2004, 2005 IBM, John Stultz (johnstul@us.ibm.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/clocksource.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/tick.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/kthread.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include "tick-internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include "timekeeping_internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * clocks_calc_mult_shift - calculate mult/shift factors for scaled math of clocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * @mult: pointer to mult variable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * @shift: pointer to shift variable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * @from: frequency to convert from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * @to: frequency to convert to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * @maxsec: guaranteed runtime conversion range in seconds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * The function evaluates the shift/mult pair for the scaled math
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * operations of clocksources and clockevents.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * @to and @from are frequency values in HZ. For clock sources @to is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * NSEC_PER_SEC == 1GHz and @from is the counter frequency. For clock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * event @to is the counter frequency and @from is NSEC_PER_SEC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * The @maxsec conversion range argument controls the time frame in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * seconds which must be covered by the runtime conversion with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * calculated mult and shift factors. This guarantees that no 64bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * overflow happens when the input value of the conversion is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * multiplied with the calculated mult factor. Larger ranges may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * reduce the conversion accuracy by chosing smaller mult and shift
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * factors.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 maxsec)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) u64 tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) u32 sft, sftacc= 32;
^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) * Calculate the shift factor which is limiting the conversion
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * range:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) tmp = ((u64)maxsec * from) >> 32;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) while (tmp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) tmp >>=1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) sftacc--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * Find the conversion shift/mult pair which has the best
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * accuracy and fits the maxsec conversion range:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) for (sft = 32; sft > 0; sft--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) tmp = (u64) to << sft;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) tmp += from / 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) do_div(tmp, from);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) if ((tmp >> sftacc) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) *mult = tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) *shift = sft;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) EXPORT_SYMBOL_GPL(clocks_calc_mult_shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) /*[Clocksource internal variables]---------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * curr_clocksource:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * currently selected clocksource.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * suspend_clocksource:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * used to calculate the suspend time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * clocksource_list:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * linked list with the registered clocksources
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) * clocksource_mutex:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * protects manipulations to curr_clocksource and the clocksource_list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * override_name:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * Name of the user-specified clocksource.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) static struct clocksource *curr_clocksource;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) static struct clocksource *suspend_clocksource;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) static LIST_HEAD(clocksource_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) static DEFINE_MUTEX(clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) static char override_name[CS_NAME_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) static int finished_booting;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) static u64 suspend_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) static void clocksource_watchdog_work(struct work_struct *work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) static void clocksource_select(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) static LIST_HEAD(watchdog_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) static struct clocksource *watchdog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) static struct timer_list watchdog_timer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static DECLARE_WORK(watchdog_work, clocksource_watchdog_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) static DEFINE_SPINLOCK(watchdog_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) static int watchdog_running;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) static atomic_t watchdog_reset_pending;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static inline void clocksource_watchdog_lock(unsigned long *flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) spin_lock_irqsave(&watchdog_lock, *flags);
^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) static inline void clocksource_watchdog_unlock(unsigned long *flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) spin_unlock_irqrestore(&watchdog_lock, *flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) static int clocksource_watchdog_kthread(void *data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) static void __clocksource_change_rating(struct clocksource *cs, int rating);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * Interval: 0.5sec Threshold: 0.0625s
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) #define WATCHDOG_INTERVAL (HZ >> 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * Maximum permissible delay between two readouts of the watchdog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * clocksource surrounding a read of the clocksource being validated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * This delay could be due to SMIs, NMIs, or to VCPU preemptions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) #define WATCHDOG_MAX_SKEW (100 * NSEC_PER_USEC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) static void clocksource_watchdog_work(struct work_struct *work)
^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) * We cannot directly run clocksource_watchdog_kthread() here, because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * clocksource_select() calls timekeeping_notify() which uses
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) * stop_machine(). One cannot use stop_machine() from a workqueue() due
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) * lock inversions wrt CPU hotplug.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) * Also, we only ever run this work once or twice during the lifetime
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) * of the kernel, so there is no point in creating a more permanent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * kthread for this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * If kthread_run fails the next watchdog scan over the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * watchdog_list will find the unstable clock again.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) static void __clocksource_unstable(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) cs->flags |= CLOCK_SOURCE_UNSTABLE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * If the clocksource is registered clocksource_watchdog_kthread() will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * re-rate and re-select.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) if (list_empty(&cs->list)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) cs->rating = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) if (cs->mark_unstable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) cs->mark_unstable(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) /* kick clocksource_watchdog_kthread() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) if (finished_booting)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) schedule_work(&watchdog_work);
^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) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * clocksource_mark_unstable - mark clocksource unstable via watchdog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) * @cs: clocksource to be marked unstable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) * This function is called by the x86 TSC code to mark clocksources as unstable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) * it defers demotion and re-selection to a kthread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) void clocksource_mark_unstable(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) spin_lock_irqsave(&watchdog_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) if (!list_empty(&cs->list) && list_empty(&cs->wd_list))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) list_add(&cs->wd_list, &watchdog_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) __clocksource_unstable(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) spin_unlock_irqrestore(&watchdog_lock, flags);
^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) static ulong max_cswd_read_retries = 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) module_param(max_cswd_read_retries, ulong, 0644);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) static bool cs_watchdog_read(struct clocksource *cs, u64 *csnow, u64 *wdnow)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) unsigned int nretries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) u64 wd_end, wd_delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) int64_t wd_delay;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) for (nretries = 0; nretries <= max_cswd_read_retries; nretries++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) local_irq_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) *wdnow = watchdog->read(watchdog);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) *csnow = cs->read(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) wd_end = watchdog->read(watchdog);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) local_irq_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) wd_delta = clocksource_delta(wd_end, *wdnow, watchdog->mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) wd_delay = clocksource_cyc2ns(wd_delta, watchdog->mult,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) watchdog->shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) if (wd_delay <= WATCHDOG_MAX_SKEW) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) if (nretries > 1 || nretries >= max_cswd_read_retries) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) pr_warn("timekeeping watchdog on CPU%d: %s retried %d times before success\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) smp_processor_id(), watchdog->name, nretries);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) pr_warn("timekeeping watchdog on CPU%d: %s read-back delay of %lldns, attempt %d, marking unstable\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) smp_processor_id(), watchdog->name, wd_delay, nretries);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) static u64 csnow_mid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) static cpumask_t cpus_ahead;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) static cpumask_t cpus_behind;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) static void clocksource_verify_one_cpu(void *csin)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) struct clocksource *cs = (struct clocksource *)csin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) csnow_mid = cs->read(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) static void clocksource_verify_percpu(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) int64_t cs_nsec, cs_nsec_max = 0, cs_nsec_min = LLONG_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) u64 csnow_begin, csnow_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) int cpu, testcpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) s64 delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) cpumask_clear(&cpus_ahead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) cpumask_clear(&cpus_behind);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) testcpu = smp_processor_id();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) pr_warn("Checking clocksource %s synchronization from CPU %d.\n", cs->name, testcpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) for_each_online_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) if (cpu == testcpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) csnow_begin = cs->read(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) smp_call_function_single(cpu, clocksource_verify_one_cpu, cs, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) csnow_end = cs->read(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) delta = (s64)((csnow_mid - csnow_begin) & cs->mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) if (delta < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) cpumask_set_cpu(cpu, &cpus_behind);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) delta = (csnow_end - csnow_mid) & cs->mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) if (delta < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) cpumask_set_cpu(cpu, &cpus_ahead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) delta = clocksource_delta(csnow_end, csnow_begin, cs->mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) cs_nsec = clocksource_cyc2ns(delta, cs->mult, cs->shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) if (cs_nsec > cs_nsec_max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) cs_nsec_max = cs_nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (cs_nsec < cs_nsec_min)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) cs_nsec_min = cs_nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) preempt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) if (!cpumask_empty(&cpus_ahead))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) pr_warn(" CPUs %*pbl ahead of CPU %d for clocksource %s.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) cpumask_pr_args(&cpus_ahead), testcpu, cs->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) if (!cpumask_empty(&cpus_behind))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) pr_warn(" CPUs %*pbl behind CPU %d for clocksource %s.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) cpumask_pr_args(&cpus_behind), testcpu, cs->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) if (!cpumask_empty(&cpus_ahead) || !cpumask_empty(&cpus_behind))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) pr_warn(" CPU %d check durations %lldns - %lldns for clocksource %s.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) testcpu, cs_nsec_min, cs_nsec_max, cs->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) static void clocksource_watchdog(struct timer_list *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) u64 csnow, wdnow, cslast, wdlast, delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) int next_cpu, reset_pending;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) int64_t wd_nsec, cs_nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) struct clocksource *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) spin_lock(&watchdog_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) if (!watchdog_running)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) reset_pending = atomic_read(&watchdog_reset_pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) list_for_each_entry(cs, &watchdog_list, wd_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) /* Clocksource already marked unstable? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) if (finished_booting)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) schedule_work(&watchdog_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) if (!cs_watchdog_read(cs, &csnow, &wdnow)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) /* Clock readout unreliable, so give it up. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) __clocksource_unstable(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) /* Clocksource initialized ? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) if (!(cs->flags & CLOCK_SOURCE_WATCHDOG) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) atomic_read(&watchdog_reset_pending)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) cs->flags |= CLOCK_SOURCE_WATCHDOG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) cs->wd_last = wdnow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) cs->cs_last = csnow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) delta = clocksource_delta(wdnow, cs->wd_last, watchdog->mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) wd_nsec = clocksource_cyc2ns(delta, watchdog->mult,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) watchdog->shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) delta = clocksource_delta(csnow, cs->cs_last, cs->mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) cs_nsec = clocksource_cyc2ns(delta, cs->mult, cs->shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) wdlast = cs->wd_last; /* save these in case we print them */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) cslast = cs->cs_last;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) cs->cs_last = csnow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) cs->wd_last = wdnow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) if (atomic_read(&watchdog_reset_pending))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) /* Check the deviation from the watchdog clocksource. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) pr_warn("timekeeping watchdog on CPU%d: Marking clocksource '%s' as unstable because the skew is too large:\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) smp_processor_id(), cs->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) pr_warn(" '%s' wd_now: %llx wd_last: %llx mask: %llx\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) watchdog->name, wdnow, wdlast, watchdog->mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) pr_warn(" '%s' cs_now: %llx cs_last: %llx mask: %llx\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) cs->name, csnow, cslast, cs->mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) __clocksource_unstable(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) if (cs == curr_clocksource && cs->tick_stable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) cs->tick_stable(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) /* Mark it valid for high-res. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) * clocksource_done_booting() will sort it if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) * finished_booting is not set yet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) if (!finished_booting)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) * If this is not the current clocksource let
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) * the watchdog thread reselect it. Due to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) * change to high res this clocksource might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) * be preferred now. If it is the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) * clocksource let the tick code know about
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) * that change.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) if (cs != curr_clocksource) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) cs->flags |= CLOCK_SOURCE_RESELECT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) schedule_work(&watchdog_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) tick_clock_notify();
^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) }
^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) * We only clear the watchdog_reset_pending, when we did a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) * full cycle through all clocksources.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) if (reset_pending)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) atomic_dec(&watchdog_reset_pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) * Cycle through CPUs to check if the CPUs stay synchronized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) * to each other.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) if (next_cpu >= nr_cpu_ids)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) next_cpu = cpumask_first(cpu_online_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) * Arm timer if not already pending: could race with concurrent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) * pair clocksource_stop_watchdog() clocksource_start_watchdog().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) if (!timer_pending(&watchdog_timer)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) watchdog_timer.expires += WATCHDOG_INTERVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) add_timer_on(&watchdog_timer, next_cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) spin_unlock(&watchdog_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) static inline void clocksource_start_watchdog(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) if (watchdog_running || !watchdog || list_empty(&watchdog_list))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) timer_setup(&watchdog_timer, clocksource_watchdog, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) watchdog_running = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) static inline void clocksource_stop_watchdog(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) if (!watchdog_running || (watchdog && !list_empty(&watchdog_list)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) del_timer(&watchdog_timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) watchdog_running = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) static inline void clocksource_reset_watchdog(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) struct clocksource *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) list_for_each_entry(cs, &watchdog_list, wd_list)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) static void clocksource_resume_watchdog(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) atomic_inc(&watchdog_reset_pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) static void clocksource_enqueue_watchdog(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) INIT_LIST_HEAD(&cs->wd_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) /* cs is a clocksource to be watched. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) list_add(&cs->wd_list, &watchdog_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) /* cs is a watchdog. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) static void clocksource_select_watchdog(bool fallback)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) struct clocksource *cs, *old_wd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) spin_lock_irqsave(&watchdog_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) /* save current watchdog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) old_wd = watchdog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) if (fallback)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) watchdog = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) list_for_each_entry(cs, &clocksource_list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) /* cs is a clocksource to be watched. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) if (cs->flags & CLOCK_SOURCE_MUST_VERIFY)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) /* Skip current if we were requested for a fallback. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) if (fallback && cs == old_wd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) /* Pick the best watchdog. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) if (!watchdog || cs->rating > watchdog->rating)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) watchdog = cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) /* If we failed to find a fallback restore the old one. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) if (!watchdog)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) watchdog = old_wd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) /* If we changed the watchdog we need to reset cycles. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) if (watchdog != old_wd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) clocksource_reset_watchdog();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) /* Check if the watchdog timer needs to be started. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) clocksource_start_watchdog();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) spin_unlock_irqrestore(&watchdog_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) static void clocksource_dequeue_watchdog(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) if (cs != watchdog) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) /* cs is a watched clocksource. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) list_del_init(&cs->wd_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) /* Check if the watchdog timer needs to be stopped. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) clocksource_stop_watchdog();
^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) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) static int __clocksource_watchdog_kthread(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) struct clocksource *cs, *tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) int select = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) /* Do any required per-CPU skew verification. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) if (curr_clocksource &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) curr_clocksource->flags & CLOCK_SOURCE_UNSTABLE &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) curr_clocksource->flags & CLOCK_SOURCE_VERIFY_PERCPU)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) clocksource_verify_percpu(curr_clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) spin_lock_irqsave(&watchdog_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) list_del_init(&cs->wd_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) __clocksource_change_rating(cs, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) select = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) if (cs->flags & CLOCK_SOURCE_RESELECT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) cs->flags &= ~CLOCK_SOURCE_RESELECT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) select = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) /* Check if the watchdog timer needs to be stopped. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) clocksource_stop_watchdog();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) spin_unlock_irqrestore(&watchdog_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) return select;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) static int clocksource_watchdog_kthread(void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) if (__clocksource_watchdog_kthread())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) clocksource_select();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) return 0;
^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) static bool clocksource_is_watchdog(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) return cs == watchdog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) #else /* CONFIG_CLOCKSOURCE_WATCHDOG */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) static void clocksource_enqueue_watchdog(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) static void clocksource_select_watchdog(bool fallback) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) static inline void clocksource_resume_watchdog(void) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) static inline int __clocksource_watchdog_kthread(void) { return 0; }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) static bool clocksource_is_watchdog(struct clocksource *cs) { return false; }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) void clocksource_mark_unstable(struct clocksource *cs) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) static inline void clocksource_watchdog_lock(unsigned long *flags) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) static inline void clocksource_watchdog_unlock(unsigned long *flags) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) #endif /* CONFIG_CLOCKSOURCE_WATCHDOG */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) static bool clocksource_is_suspend(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) return cs == suspend_clocksource;
^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) static void __clocksource_suspend_select(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) * Skip the clocksource which will be stopped in suspend state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) if (!(cs->flags & CLOCK_SOURCE_SUSPEND_NONSTOP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) * The nonstop clocksource can be selected as the suspend clocksource to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) * calculate the suspend time, so it should not supply suspend/resume
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) * interfaces to suspend the nonstop clocksource when system suspends.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) if (cs->suspend || cs->resume) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) pr_warn("Nonstop clocksource %s should not supply suspend/resume interfaces\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) cs->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) /* Pick the best rating. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) if (!suspend_clocksource || cs->rating > suspend_clocksource->rating)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) suspend_clocksource = cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) * clocksource_suspend_select - Select the best clocksource for suspend timing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) * @fallback: if select a fallback clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) static void clocksource_suspend_select(bool fallback)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) struct clocksource *cs, *old_suspend;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) old_suspend = suspend_clocksource;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) if (fallback)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) suspend_clocksource = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) list_for_each_entry(cs, &clocksource_list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) /* Skip current if we were requested for a fallback. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) if (fallback && cs == old_suspend)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) __clocksource_suspend_select(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) * clocksource_start_suspend_timing - Start measuring the suspend timing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) * @cs: current clocksource from timekeeping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) * @start_cycles: current cycles from timekeeping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) * This function will save the start cycle values of suspend timer to calculate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) * the suspend time when resuming system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) * This function is called late in the suspend process from timekeeping_suspend(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) * that means processes are freezed, non-boot cpus and interrupts are disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) * now. It is therefore possible to start the suspend timer without taking the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) * clocksource mutex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) void clocksource_start_suspend_timing(struct clocksource *cs, u64 start_cycles)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) if (!suspend_clocksource)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) * If current clocksource is the suspend timer, we should use the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) * tkr_mono.cycle_last value as suspend_start to avoid same reading
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) * from suspend timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) if (clocksource_is_suspend(cs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) suspend_start = start_cycles;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) if (suspend_clocksource->enable &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) suspend_clocksource->enable(suspend_clocksource)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) pr_warn_once("Failed to enable the non-suspend-able clocksource.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) suspend_start = suspend_clocksource->read(suspend_clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) * clocksource_stop_suspend_timing - Stop measuring the suspend timing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) * @cs: current clocksource from timekeeping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) * @cycle_now: current cycles from timekeeping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) * This function will calculate the suspend time from suspend timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) * Returns nanoseconds since suspend started, 0 if no usable suspend clocksource.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) * This function is called early in the resume process from timekeeping_resume(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) * that means there is only one cpu, no processes are running and the interrupts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) * are disabled. It is therefore possible to stop the suspend timer without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) * taking the clocksource mutex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) u64 clocksource_stop_suspend_timing(struct clocksource *cs, u64 cycle_now)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) u64 now, delta, nsec = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) if (!suspend_clocksource)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) * If current clocksource is the suspend timer, we should use the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) * tkr_mono.cycle_last value from timekeeping as current cycle to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) * avoid same reading from suspend timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) if (clocksource_is_suspend(cs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) now = cycle_now;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) now = suspend_clocksource->read(suspend_clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) if (now > suspend_start) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) delta = clocksource_delta(now, suspend_start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) suspend_clocksource->mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) nsec = mul_u64_u32_shr(delta, suspend_clocksource->mult,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) suspend_clocksource->shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) * Disable the suspend timer to save power if current clocksource is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) * not the suspend timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) if (!clocksource_is_suspend(cs) && suspend_clocksource->disable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) suspend_clocksource->disable(suspend_clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) return nsec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) * clocksource_suspend - suspend the clocksource(s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) void clocksource_suspend(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) struct clocksource *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) list_for_each_entry_reverse(cs, &clocksource_list, list)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) if (cs->suspend)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) cs->suspend(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) * clocksource_resume - resume the clocksource(s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) void clocksource_resume(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) struct clocksource *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) list_for_each_entry(cs, &clocksource_list, list)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) if (cs->resume)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) cs->resume(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) clocksource_resume_watchdog();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) * clocksource_touch_watchdog - Update watchdog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) * Update the watchdog after exception contexts such as kgdb so as not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) * to incorrectly trip the watchdog. This might fail when the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) * was stopped in code which holds watchdog_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) void clocksource_touch_watchdog(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) clocksource_resume_watchdog();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) * clocksource_max_adjustment- Returns max adjustment amount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) * @cs: Pointer to clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) static u32 clocksource_max_adjustment(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) u64 ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) * We won't try to correct for more than 11% adjustments (110,000 ppm),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) ret = (u64)cs->mult * 11;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) do_div(ret,100);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) return (u32)ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) * clocks_calc_max_nsecs - Returns maximum nanoseconds that can be converted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) * @mult: cycle to nanosecond multiplier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) * @shift: cycle to nanosecond divisor (power of two)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) * @maxadj: maximum adjustment value to mult (~11%)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) * @mask: bitmask for two's complement subtraction of non 64 bit counters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) * @max_cyc: maximum cycle value before potential overflow (does not include
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) * any safety margin)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) * NOTE: This function includes a safety margin of 50%, in other words, we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) * return half the number of nanoseconds the hardware counter can technically
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) * cover. This is done so that we can potentially detect problems caused by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) * delayed timers or bad hardware, which might result in time intervals that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) * are larger than what the math used can handle without overflows.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) u64 clocks_calc_max_nsecs(u32 mult, u32 shift, u32 maxadj, u64 mask, u64 *max_cyc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) u64 max_nsecs, max_cycles;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) * Calculate the maximum number of cycles that we can pass to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) * cyc2ns() function without overflowing a 64-bit result.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) max_cycles = ULLONG_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) do_div(max_cycles, mult+maxadj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) * The actual maximum number of cycles we can defer the clocksource is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) * determined by the minimum of max_cycles and mask.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) * Note: Here we subtract the maxadj to make sure we don't sleep for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) * too long if there's a large negative adjustment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) max_cycles = min(max_cycles, mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) max_nsecs = clocksource_cyc2ns(max_cycles, mult - maxadj, shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) /* return the max_cycles value as well if requested */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) if (max_cyc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) *max_cyc = max_cycles;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) /* Return 50% of the actual maximum, so we can detect bad values */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) max_nsecs >>= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) return max_nsecs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) }
^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) * clocksource_update_max_deferment - Updates the clocksource max_idle_ns & max_cycles
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) * @cs: Pointer to clocksource to be updated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) static inline void clocksource_update_max_deferment(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) cs->max_idle_ns = clocks_calc_max_nsecs(cs->mult, cs->shift,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) cs->maxadj, cs->mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) &cs->max_cycles);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) #ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) static struct clocksource *clocksource_find_best(bool oneshot, bool skipcur)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) struct clocksource *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) if (!finished_booting || list_empty(&clocksource_list))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) * We pick the clocksource with the highest rating. If oneshot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) * mode is active, we pick the highres valid clocksource with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) * the best rating.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) list_for_each_entry(cs, &clocksource_list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) if (skipcur && cs == curr_clocksource)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) if (oneshot && !(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) return cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) return NULL;
^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) static void __clocksource_select(bool skipcur)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) bool oneshot = tick_oneshot_mode_active();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) struct clocksource *best, *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) /* Find the best suitable clocksource */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) best = clocksource_find_best(oneshot, skipcur);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) if (!best)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) if (!strlen(override_name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) goto found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) /* Check for the override clocksource. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) list_for_each_entry(cs, &clocksource_list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) if (skipcur && cs == curr_clocksource)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) if (strcmp(cs->name, override_name) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) * Check to make sure we don't switch to a non-highres
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) * capable clocksource if the tick code is in oneshot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) * mode (highres or nohz)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) && oneshot) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) /* Override clocksource cannot be used. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) pr_warn("Override clocksource %s is unstable and not HRT compatible - cannot switch while in HRT/NOHZ mode\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) cs->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) override_name[0] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) * The override cannot be currently verified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) * Deferring to let the watchdog check.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) pr_info("Override clocksource %s is not currently HRT compatible - deferring\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) cs->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) /* Override clocksource can be used. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) best = cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) found:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) if (curr_clocksource != best && !timekeeping_notify(best)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) pr_info("Switched to clocksource %s\n", best->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) curr_clocksource = best;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) }
^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) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) * clocksource_select - Select the best clocksource available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) * Private function. Must hold clocksource_mutex when called.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) * Select the clocksource with the best rating, or the clocksource,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) * which is selected by userspace override.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) static void clocksource_select(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) __clocksource_select(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) static void clocksource_select_fallback(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) __clocksource_select(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) #else /* !CONFIG_ARCH_USES_GETTIMEOFFSET */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) static inline void clocksource_select(void) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) static inline void clocksource_select_fallback(void) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) * clocksource_done_booting - Called near the end of core bootup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) * Hack to avoid lots of clocksource churn at boot time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) * We use fs_initcall because we want this to start before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) * device_initcall but after subsys_initcall.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) static int __init clocksource_done_booting(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) curr_clocksource = clocksource_default_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) finished_booting = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) * Run the watchdog first to eliminate unstable clock sources
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) __clocksource_watchdog_kthread();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) clocksource_select();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) fs_initcall(clocksource_done_booting);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) * Enqueue the clocksource sorted by rating
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) static void clocksource_enqueue(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) struct list_head *entry = &clocksource_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) struct clocksource *tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) list_for_each_entry(tmp, &clocksource_list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) /* Keep track of the place, where to insert */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) if (tmp->rating < cs->rating)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) entry = &tmp->list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) list_add(&cs->list, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) * __clocksource_update_freq_scale - Used update clocksource with new freq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) * @cs: clocksource to be registered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) * @scale: Scale factor multiplied against freq to get clocksource hz
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) * @freq: clocksource frequency (cycles per second) divided by scale
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) * This should only be called from the clocksource->enable() method.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) * This *SHOULD NOT* be called directly! Please use the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) * __clocksource_update_freq_hz() or __clocksource_update_freq_khz() helper
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) * functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) void __clocksource_update_freq_scale(struct clocksource *cs, u32 scale, u32 freq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) u64 sec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) * Default clocksources are *special* and self-define their mult/shift.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) * But, you're not special, so you should specify a freq value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) if (freq) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) * Calc the maximum number of seconds which we can run before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) * wrapping around. For clocksources which have a mask > 32-bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) * we need to limit the max sleep time to have a good
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) * conversion precision. 10 minutes is still a reasonable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) * amount. That results in a shift value of 24 for a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) * clocksource with mask >= 40-bit and f >= 4GHz. That maps to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) * ~ 0.06ppm granularity for NTP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) sec = cs->mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) do_div(sec, freq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) do_div(sec, scale);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) if (!sec)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) sec = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) else if (sec > 600 && cs->mask > UINT_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) sec = 600;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) clocks_calc_mult_shift(&cs->mult, &cs->shift, freq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) NSEC_PER_SEC / scale, sec * scale);
^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) * Ensure clocksources that have large 'mult' values don't overflow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) * when adjusted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) cs->maxadj = clocksource_max_adjustment(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) while (freq && ((cs->mult + cs->maxadj < cs->mult)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) || (cs->mult - cs->maxadj > cs->mult))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) cs->mult >>= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) cs->shift--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) cs->maxadj = clocksource_max_adjustment(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) * Only warn for *special* clocksources that self-define
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) * their mult/shift values and don't specify a freq.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) WARN_ONCE(cs->mult + cs->maxadj < cs->mult,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) "timekeeping: Clocksource %s might overflow on 11%% adjustment\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) cs->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) clocksource_update_max_deferment(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) pr_info("%s: mask: 0x%llx max_cycles: 0x%llx, max_idle_ns: %lld ns\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) cs->name, cs->mask, cs->max_cycles, cs->max_idle_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) EXPORT_SYMBOL_GPL(__clocksource_update_freq_scale);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) * __clocksource_register_scale - Used to install new clocksources
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) * @cs: clocksource to be registered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) * @scale: Scale factor multiplied against freq to get clocksource hz
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) * @freq: clocksource frequency (cycles per second) divided by scale
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) * Returns -EBUSY if registration fails, zero otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) * This *SHOULD NOT* be called directly! Please use the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) * clocksource_register_hz() or clocksource_register_khz helper functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) clocksource_arch_init(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) if (cs->vdso_clock_mode < 0 ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) cs->vdso_clock_mode >= VDSO_CLOCKMODE_MAX) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) pr_warn("clocksource %s registered with invalid VDSO mode %d. Disabling VDSO support.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) cs->name, cs->vdso_clock_mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) /* Initialize mult/shift and max_idle_ns */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) __clocksource_update_freq_scale(cs, scale, freq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) /* Add clocksource to the clocksource list */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) clocksource_watchdog_lock(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) clocksource_enqueue(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) clocksource_enqueue_watchdog(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) clocksource_watchdog_unlock(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) clocksource_select();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) clocksource_select_watchdog(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) __clocksource_suspend_select(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) EXPORT_SYMBOL_GPL(__clocksource_register_scale);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) static void __clocksource_change_rating(struct clocksource *cs, int rating)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) list_del(&cs->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) cs->rating = rating;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) clocksource_enqueue(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) * clocksource_change_rating - Change the rating of a registered clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) * @cs: clocksource to be changed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) * @rating: new rating
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) void clocksource_change_rating(struct clocksource *cs, int rating)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) clocksource_watchdog_lock(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) __clocksource_change_rating(cs, rating);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) clocksource_watchdog_unlock(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) clocksource_select();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) clocksource_select_watchdog(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) clocksource_suspend_select(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) EXPORT_SYMBOL(clocksource_change_rating);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) * Unbind clocksource @cs. Called with clocksource_mutex held
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) static int clocksource_unbind(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) if (clocksource_is_watchdog(cs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) /* Select and try to install a replacement watchdog. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) clocksource_select_watchdog(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) if (clocksource_is_watchdog(cs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) if (cs == curr_clocksource) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) /* Select and try to install a replacement clock source */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) clocksource_select_fallback();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) if (curr_clocksource == cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) return -EBUSY;
^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) if (clocksource_is_suspend(cs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) * Select and try to install a replacement suspend clocksource.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) * If no replacement suspend clocksource, we will just let the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) * clocksource go and have no suspend clocksource.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) clocksource_suspend_select(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) clocksource_watchdog_lock(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) clocksource_dequeue_watchdog(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) list_del_init(&cs->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) clocksource_watchdog_unlock(&flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) * clocksource_unregister - remove a registered clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) * @cs: clocksource to be unregistered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) int clocksource_unregister(struct clocksource *cs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) if (!list_empty(&cs->list))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) ret = clocksource_unbind(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) EXPORT_SYMBOL(clocksource_unregister);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) #ifdef CONFIG_SYSFS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) * current_clocksource_show - sysfs interface for current clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) * @dev: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) * @attr: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) * @buf: char buffer to be filled with clocksource list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) * Provides sysfs interface for listing current clocksource.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) static ssize_t current_clocksource_show(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) ssize_t count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) count = snprintf(buf, PAGE_SIZE, "%s\n", curr_clocksource->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) size_t ret = cnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) /* strings from sysfs write are not 0 terminated! */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167) if (!cnt || cnt >= CS_NAME_LEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) /* strip of \n: */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) if (buf[cnt-1] == '\n')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) cnt--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) if (cnt > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) memcpy(dst, buf, cnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) dst[cnt] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) * current_clocksource_store - interface for manually overriding clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) * @dev: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) * @attr: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) * @buf: name of override clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) * @count: length of buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) * Takes input from sysfs interface for manually overriding the default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) * clocksource selection.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) static ssize_t current_clocksource_store(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) ssize_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) ret = sysfs_get_uname(buf, override_name, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) if (ret >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) clocksource_select();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) static DEVICE_ATTR_RW(current_clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) * unbind_clocksource_store - interface for manually unbinding clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) * @dev: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) * @attr: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) * @buf: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) * @count: length of buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) * Takes input from sysfs interface for manually unbinding a clocksource.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) static ssize_t unbind_clocksource_store(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) struct clocksource *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221) char name[CS_NAME_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) ssize_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) ret = sysfs_get_uname(buf, name, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) ret = -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) list_for_each_entry(cs, &clocksource_list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) if (strcmp(cs->name, name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) ret = clocksource_unbind(cs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) return ret ? ret : count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) static DEVICE_ATTR_WO(unbind_clocksource);
^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) * available_clocksource_show - sysfs interface for listing clocksource
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) * @dev: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) * @attr: unused
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) * @buf: char buffer to be filled with clocksource list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) * Provides sysfs interface for listing registered clocksources
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) static ssize_t available_clocksource_show(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) struct clocksource *src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) ssize_t count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) list_for_each_entry(src, &clocksource_list, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) * Don't show non-HRES clocksource if the tick code is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) * in one shot mode (highres=on or nohz=on)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) if (!tick_oneshot_mode_active() ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) (src->flags & CLOCK_SOURCE_VALID_FOR_HRES))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) count += snprintf(buf + count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) max((ssize_t)PAGE_SIZE - count, (ssize_t)0),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) "%s ", src->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) count += snprintf(buf + count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) static DEVICE_ATTR_RO(available_clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) static struct attribute *clocksource_attrs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) &dev_attr_current_clocksource.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) &dev_attr_unbind_clocksource.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) &dev_attr_available_clocksource.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) ATTRIBUTE_GROUPS(clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) static struct bus_type clocksource_subsys = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) .name = "clocksource",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) .dev_name = "clocksource",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) static struct device device_clocksource = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) .id = 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) .bus = &clocksource_subsys,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) .groups = clocksource_groups,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) static int __init init_clocksource_sysfs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) int error = subsys_system_register(&clocksource_subsys, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) if (!error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) error = device_register(&device_clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) return error;
^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) device_initcall(init_clocksource_sysfs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) #endif /* CONFIG_SYSFS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) * boot_override_clocksource - boot clock override
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) * @str: override name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) * Takes a clocksource= boot argument and uses it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) * as the clocksource override name.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) static int __init boot_override_clocksource(char* str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) mutex_lock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) if (str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) strlcpy(override_name, str, sizeof(override_name));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) mutex_unlock(&clocksource_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) __setup("clocksource=", boot_override_clocksource);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) * boot_override_clock - Compatibility layer for deprecated boot option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) * @str: override name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) * DEPRECATED! Takes a clock= boot argument and uses it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) * as the clocksource override name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) static int __init boot_override_clock(char* str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) if (!strcmp(str, "pmtmr")) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) pr_warn("clock=pmtmr is deprecated - use clocksource=acpi_pm\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) return boot_override_clocksource("acpi_pm");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) pr_warn("clock= boot option is deprecated - use clocksource=xyz\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) return boot_override_clocksource(str);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) __setup("clock=", boot_override_clock);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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