^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) * Kernel internal timers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 1991, 1992 Linus Torvalds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * 1997-01-28 Modified by Finn Arne Gangstad to make timers scale better.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * "A Kernel Model for Precision Timekeeping" by Dave Mills
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * 1998-12-24 Fixed a xtime SMP race (we need the xtime_lock rw spinlock to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * serialize accesses to xtime/lost_ticks).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * Copyright (C) 1998 Andrea Arcangeli
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * 1999-03-10 Improved NTP compatibility by Ulrich Windl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * 2002-05-31 Move sys_sysinfo here and make its locking sane, Robert Love
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * 2000-10-05 Implemented scalable SMP per-CPU timer handling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * Copyright (C) 2000, 2001, 2002 Ingo Molnar
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * Designed by David S. Miller, Alexey Kuznetsov and Ingo Molnar
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/kernel_stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/percpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/swap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/pid_namespace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/notifier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/thread_info.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/time.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/jiffies.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/posix-timers.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/cpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/syscalls.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/tick.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/kallsyms.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <linux/irq_work.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <linux/sched/sysctl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #include <linux/sched/nohz.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #include <linux/sched/debug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <linux/compat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #include <linux/random.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #include <asm/unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #include <asm/div64.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #include <asm/timex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) #include <asm/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) #include "tick-internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) #define CREATE_TRACE_POINTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) #include <trace/events/timer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) #undef CREATE_TRACE_POINTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) #include <trace/hooks/timer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) EXPORT_TRACEPOINT_SYMBOL_GPL(hrtimer_expire_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) EXPORT_TRACEPOINT_SYMBOL_GPL(hrtimer_expire_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) __visible u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) EXPORT_SYMBOL(jiffies_64);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * The timer wheel has LVL_DEPTH array levels. Each level provides an array of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * LVL_SIZE buckets. Each level is driven by its own clock and therefor each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * level has a different granularity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) * The level granularity is: LVL_CLK_DIV ^ lvl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * The level clock frequency is: HZ / (LVL_CLK_DIV ^ level)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) * The array level of a newly armed timer depends on the relative expiry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * time. The farther the expiry time is away the higher the array level and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * therefor the granularity becomes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * Contrary to the original timer wheel implementation, which aims for 'exact'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * expiry of the timers, this implementation removes the need for recascading
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * the timers into the lower array levels. The previous 'classic' timer wheel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) * implementation of the kernel already violated the 'exact' expiry by adding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * slack to the expiry time to provide batched expiration. The granularity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * levels provide implicit batching.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * This is an optimization of the original timer wheel implementation for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * majority of the timer wheel use cases: timeouts. The vast majority of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * timeout timers (networking, disk I/O ...) are canceled before expiry. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) * the timeout expires it indicates that normal operation is disturbed, so it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * does not matter much whether the timeout comes with a slight delay.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) * The only exception to this are networking timers with a small expiry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * time. They rely on the granularity. Those fit into the first wheel level,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * which has HZ granularity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * We don't have cascading anymore. timers with a expiry time above the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * capacity of the last wheel level are force expired at the maximum timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * value of the last wheel level. From data sampling we know that the maximum
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * value observed is 5 days (network connection tracking), so this should not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * be an issue.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * The currently chosen array constants values are a good compromise between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * array size and granularity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * This results in the following granularity and range levels:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * HZ 1000 steps
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) * Level Offset Granularity Range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * 0 0 1 ms 0 ms - 63 ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) * 1 64 8 ms 64 ms - 511 ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) * 2 128 64 ms 512 ms - 4095 ms (512ms - ~4s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) * 3 192 512 ms 4096 ms - 32767 ms (~4s - ~32s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * 4 256 4096 ms (~4s) 32768 ms - 262143 ms (~32s - ~4m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * 5 320 32768 ms (~32s) 262144 ms - 2097151 ms (~4m - ~34m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * 6 384 262144 ms (~4m) 2097152 ms - 16777215 ms (~34m - ~4h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) * 7 448 2097152 ms (~34m) 16777216 ms - 134217727 ms (~4h - ~1d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) * 8 512 16777216 ms (~4h) 134217728 ms - 1073741822 ms (~1d - ~12d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * HZ 300
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * Level Offset Granularity Range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * 0 0 3 ms 0 ms - 210 ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * 1 64 26 ms 213 ms - 1703 ms (213ms - ~1s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) * 2 128 213 ms 1706 ms - 13650 ms (~1s - ~13s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * 3 192 1706 ms (~1s) 13653 ms - 109223 ms (~13s - ~1m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * 4 256 13653 ms (~13s) 109226 ms - 873810 ms (~1m - ~14m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * 5 320 109226 ms (~1m) 873813 ms - 6990503 ms (~14m - ~1h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * 6 384 873813 ms (~14m) 6990506 ms - 55924050 ms (~1h - ~15h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * 7 448 6990506 ms (~1h) 55924053 ms - 447392423 ms (~15h - ~5d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * 8 512 55924053 ms (~15h) 447392426 ms - 3579139406 ms (~5d - ~41d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) * HZ 250
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) * Level Offset Granularity Range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) * 0 0 4 ms 0 ms - 255 ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) * 1 64 32 ms 256 ms - 2047 ms (256ms - ~2s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * 2 128 256 ms 2048 ms - 16383 ms (~2s - ~16s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * 3 192 2048 ms (~2s) 16384 ms - 131071 ms (~16s - ~2m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * 4 256 16384 ms (~16s) 131072 ms - 1048575 ms (~2m - ~17m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) * 5 320 131072 ms (~2m) 1048576 ms - 8388607 ms (~17m - ~2h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) * 6 384 1048576 ms (~17m) 8388608 ms - 67108863 ms (~2h - ~18h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) * 7 448 8388608 ms (~2h) 67108864 ms - 536870911 ms (~18h - ~6d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) * 8 512 67108864 ms (~18h) 536870912 ms - 4294967288 ms (~6d - ~49d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * HZ 100
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) * Level Offset Granularity Range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * 0 0 10 ms 0 ms - 630 ms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * 1 64 80 ms 640 ms - 5110 ms (640ms - ~5s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) * 2 128 640 ms 5120 ms - 40950 ms (~5s - ~40s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) * 3 192 5120 ms (~5s) 40960 ms - 327670 ms (~40s - ~5m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) * 4 256 40960 ms (~40s) 327680 ms - 2621430 ms (~5m - ~43m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) * 5 320 327680 ms (~5m) 2621440 ms - 20971510 ms (~43m - ~5h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) * 6 384 2621440 ms (~43m) 20971520 ms - 167772150 ms (~5h - ~1d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * 7 448 20971520 ms (~5h) 167772160 ms - 1342177270 ms (~1d - ~15d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) /* Clock divisor for the next level */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) #define LVL_CLK_SHIFT 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) #define LVL_CLK_DIV (1UL << LVL_CLK_SHIFT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) #define LVL_CLK_MASK (LVL_CLK_DIV - 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) #define LVL_SHIFT(n) ((n) * LVL_CLK_SHIFT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) #define LVL_GRAN(n) (1UL << LVL_SHIFT(n))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * The time start value for each level to select the bucket at enqueue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * time. We start from the last possible delta of the previous level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * so that we can later add an extra LVL_GRAN(n) to n (see calc_index()).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) #define LVL_START(n) ((LVL_SIZE - 1) << (((n) - 1) * LVL_CLK_SHIFT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) /* Size of each clock level */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) #define LVL_BITS 6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) #define LVL_SIZE (1UL << LVL_BITS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) #define LVL_MASK (LVL_SIZE - 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) #define LVL_OFFS(n) ((n) * LVL_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) /* Level depth */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) #if HZ > 100
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) # define LVL_DEPTH 9
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) # else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) # define LVL_DEPTH 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) /* The cutoff (max. capacity of the wheel) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) #define WHEEL_TIMEOUT_CUTOFF (LVL_START(LVL_DEPTH))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) #define WHEEL_TIMEOUT_MAX (WHEEL_TIMEOUT_CUTOFF - LVL_GRAN(LVL_DEPTH - 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) * The resulting wheel size. If NOHZ is configured we allocate two
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) * wheels so we have a separate storage for the deferrable timers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) #define WHEEL_SIZE (LVL_SIZE * LVL_DEPTH)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) #ifdef CONFIG_NO_HZ_COMMON
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) # define NR_BASES 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) # define BASE_STD 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) # define BASE_DEF 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) # define NR_BASES 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) # define BASE_STD 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) # define BASE_DEF 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) struct timer_base {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) raw_spinlock_t lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) struct timer_list *running_timer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) #ifdef CONFIG_PREEMPT_RT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) spinlock_t expiry_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) atomic_t timer_waiters;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) unsigned long clk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) unsigned long next_expiry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) unsigned int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) bool next_expiry_recalc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) bool is_idle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) bool timers_pending;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) DECLARE_BITMAP(pending_map, WHEEL_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) struct hlist_head vectors[WHEEL_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) } ____cacheline_aligned;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) static DEFINE_PER_CPU(struct timer_base, timer_bases[NR_BASES]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) #ifdef CONFIG_NO_HZ_COMMON
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) static DEFINE_STATIC_KEY_FALSE(timers_nohz_active);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) static DEFINE_MUTEX(timer_keys_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) static void timer_update_keys(struct work_struct *work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) static DECLARE_WORK(timer_update_work, timer_update_keys);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) #ifdef CONFIG_SMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) unsigned int sysctl_timer_migration = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) DEFINE_STATIC_KEY_FALSE(timers_migration_enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) static void timers_update_migration(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) if (sysctl_timer_migration && tick_nohz_active)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) static_branch_enable(&timers_migration_enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) static_branch_disable(&timers_migration_enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) static inline void timers_update_migration(void) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) #endif /* !CONFIG_SMP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) static void timer_update_keys(struct work_struct *work)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) mutex_lock(&timer_keys_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) timers_update_migration();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) static_branch_enable(&timers_nohz_active);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) mutex_unlock(&timer_keys_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) void timers_update_nohz(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) schedule_work(&timer_update_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) int timer_migration_handler(struct ctl_table *table, int write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) void *buffer, size_t *lenp, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) mutex_lock(&timer_keys_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (!ret && write)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) timers_update_migration();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) mutex_unlock(&timer_keys_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) static inline bool is_timers_nohz_active(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) return static_branch_unlikely(&timers_nohz_active);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) static inline bool is_timers_nohz_active(void) { return false; }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) #endif /* NO_HZ_COMMON */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) static unsigned long round_jiffies_common(unsigned long j, int cpu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) bool force_up)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) int rem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) unsigned long original = j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) * We don't want all cpus firing their timers at once hitting the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * same lock or cachelines, so we skew each extra cpu with an extra
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) * 3 jiffies. This 3 jiffies came originally from the mm/ code which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * already did this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * The skew is done by adding 3*cpunr, then round, then subtract this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * extra offset again.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) j += cpu * 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) rem = j % HZ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) * If the target jiffie is just after a whole second (which can happen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) * due to delays of the timer irq, long irq off times etc etc) then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) * we should round down to the whole second, not up. Use 1/4th second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * as cutoff for this rounding as an extreme upper bound for this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * But never round down if @force_up is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) if (rem < HZ/4 && !force_up) /* round down */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) j = j - rem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) else /* round up */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) j = j - rem + HZ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) /* now that we have rounded, subtract the extra skew again */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) j -= cpu * 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) * Make sure j is still in the future. Otherwise return the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) * unmodified value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) return time_is_after_jiffies(j) ? j : original;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) * __round_jiffies - function to round jiffies to a full second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * @j: the time in (absolute) jiffies that should be rounded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) * @cpu: the processor number on which the timeout will happen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * __round_jiffies() rounds an absolute time in the future (in jiffies)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * up or down to (approximately) full seconds. This is useful for timers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * for which the exact time they fire does not matter too much, as long as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) * they fire approximately every X seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) * By rounding these timers to whole seconds, all such timers will fire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) * at the same time, rather than at various times spread out. The goal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) * of this is to have the CPU wake up less, which saves power.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) * The exact rounding is skewed for each processor to avoid all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) * processors firing at the exact same time, which could lead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) * to lock contention or spurious cache line bouncing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) * The return value is the rounded version of the @j parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) unsigned long __round_jiffies(unsigned long j, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) return round_jiffies_common(j, cpu, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) EXPORT_SYMBOL_GPL(__round_jiffies);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) * __round_jiffies_relative - function to round jiffies to a full second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) * @j: the time in (relative) jiffies that should be rounded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * @cpu: the processor number on which the timeout will happen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) * __round_jiffies_relative() rounds a time delta in the future (in jiffies)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) * up or down to (approximately) full seconds. This is useful for timers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * for which the exact time they fire does not matter too much, as long as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) * they fire approximately every X seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * By rounding these timers to whole seconds, all such timers will fire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) * at the same time, rather than at various times spread out. The goal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) * of this is to have the CPU wake up less, which saves power.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) * The exact rounding is skewed for each processor to avoid all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) * processors firing at the exact same time, which could lead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) * to lock contention or spurious cache line bouncing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) * The return value is the rounded version of the @j parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) unsigned long __round_jiffies_relative(unsigned long j, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) unsigned long j0 = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) /* Use j0 because jiffies might change while we run */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) return round_jiffies_common(j + j0, cpu, false) - j0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) EXPORT_SYMBOL_GPL(__round_jiffies_relative);
^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) * round_jiffies - function to round jiffies to a full second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) * @j: the time in (absolute) jiffies that should be rounded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) * round_jiffies() rounds an absolute time in the future (in jiffies)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) * up or down to (approximately) full seconds. This is useful for timers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * for which the exact time they fire does not matter too much, as long as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) * they fire approximately every X seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) * By rounding these timers to whole seconds, all such timers will fire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) * at the same time, rather than at various times spread out. The goal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) * of this is to have the CPU wake up less, which saves power.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) * The return value is the rounded version of the @j parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) unsigned long round_jiffies(unsigned long j)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) return round_jiffies_common(j, raw_smp_processor_id(), false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) EXPORT_SYMBOL_GPL(round_jiffies);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) * round_jiffies_relative - function to round jiffies to a full second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) * @j: the time in (relative) jiffies that should be rounded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) * round_jiffies_relative() rounds a time delta in the future (in jiffies)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) * up or down to (approximately) full seconds. This is useful for timers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) * for which the exact time they fire does not matter too much, as long as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) * they fire approximately every X seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * By rounding these timers to whole seconds, all such timers will fire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * at the same time, rather than at various times spread out. The goal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * of this is to have the CPU wake up less, which saves power.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) * The return value is the rounded version of the @j parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) unsigned long round_jiffies_relative(unsigned long j)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) return __round_jiffies_relative(j, raw_smp_processor_id());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) EXPORT_SYMBOL_GPL(round_jiffies_relative);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * __round_jiffies_up - function to round jiffies up to a full second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) * @j: the time in (absolute) jiffies that should be rounded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) * @cpu: the processor number on which the timeout will happen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) * This is the same as __round_jiffies() except that it will never
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) * round down. This is useful for timeouts for which the exact time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) * of firing does not matter too much, as long as they don't fire too
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) * early.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) unsigned long __round_jiffies_up(unsigned long j, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) return round_jiffies_common(j, cpu, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) EXPORT_SYMBOL_GPL(__round_jiffies_up);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) * __round_jiffies_up_relative - function to round jiffies up to a full second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) * @j: the time in (relative) jiffies that should be rounded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) * @cpu: the processor number on which the timeout will happen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) * This is the same as __round_jiffies_relative() except that it will never
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) * round down. This is useful for timeouts for which the exact time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) * of firing does not matter too much, as long as they don't fire too
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) * early.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) unsigned long __round_jiffies_up_relative(unsigned long j, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) unsigned long j0 = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) /* Use j0 because jiffies might change while we run */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) return round_jiffies_common(j + j0, cpu, true) - j0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) EXPORT_SYMBOL_GPL(__round_jiffies_up_relative);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) * round_jiffies_up - function to round jiffies up to a full second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) * @j: the time in (absolute) jiffies that should be rounded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) * This is the same as round_jiffies() except that it will never
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) * round down. This is useful for timeouts for which the exact time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) * of firing does not matter too much, as long as they don't fire too
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) * early.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) unsigned long round_jiffies_up(unsigned long j)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) return round_jiffies_common(j, raw_smp_processor_id(), true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) EXPORT_SYMBOL_GPL(round_jiffies_up);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) * round_jiffies_up_relative - function to round jiffies up to a full second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) * @j: the time in (relative) jiffies that should be rounded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) * This is the same as round_jiffies_relative() except that it will never
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) * round down. This is useful for timeouts for which the exact time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) * of firing does not matter too much, as long as they don't fire too
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) * early.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) unsigned long round_jiffies_up_relative(unsigned long j)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) return __round_jiffies_up_relative(j, raw_smp_processor_id());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) EXPORT_SYMBOL_GPL(round_jiffies_up_relative);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) static inline unsigned int timer_get_idx(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) return (timer->flags & TIMER_ARRAYMASK) >> TIMER_ARRAYSHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) static inline void timer_set_idx(struct timer_list *timer, unsigned int idx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) timer->flags = (timer->flags & ~TIMER_ARRAYMASK) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) idx << TIMER_ARRAYSHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) * Helper function to calculate the array index for a given expiry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) * time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) static inline unsigned calc_index(unsigned long expires, unsigned lvl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) unsigned long *bucket_expiry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) * The timer wheel has to guarantee that a timer does not fire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) * early. Early expiry can happen due to:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) * - Timer is armed at the edge of a tick
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) * - Truncation of the expiry time in the outer wheel levels
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) * Round up with level granularity to prevent this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) trace_android_vh_timer_calc_index(lvl, &expires);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) expires = (expires + LVL_GRAN(lvl)) >> LVL_SHIFT(lvl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) *bucket_expiry = expires << LVL_SHIFT(lvl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) return LVL_OFFS(lvl) + (expires & LVL_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) static int calc_wheel_index(unsigned long expires, unsigned long clk,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) unsigned long *bucket_expiry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) unsigned long delta = expires - clk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) unsigned int idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) if (delta < LVL_START(1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) idx = calc_index(expires, 0, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) } else if (delta < LVL_START(2)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) idx = calc_index(expires, 1, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) } else if (delta < LVL_START(3)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) idx = calc_index(expires, 2, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) } else if (delta < LVL_START(4)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) idx = calc_index(expires, 3, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) } else if (delta < LVL_START(5)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) idx = calc_index(expires, 4, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) } else if (delta < LVL_START(6)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) idx = calc_index(expires, 5, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) } else if (delta < LVL_START(7)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) idx = calc_index(expires, 6, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) } else if (LVL_DEPTH > 8 && delta < LVL_START(8)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) idx = calc_index(expires, 7, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) } else if ((long) delta < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) idx = clk & LVL_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) *bucket_expiry = clk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) * Force expire obscene large timeouts to expire at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) * capacity limit of the wheel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) if (delta >= WHEEL_TIMEOUT_CUTOFF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) expires = clk + WHEEL_TIMEOUT_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) idx = calc_index(expires, LVL_DEPTH - 1, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) return idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) if (!is_timers_nohz_active())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) * TODO: This wants some optimizing similar to the code below, but we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) * will do that when we switch from push to pull for deferrable timers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) if (timer->flags & TIMER_DEFERRABLE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) if (tick_nohz_full_cpu(base->cpu))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) wake_up_nohz_cpu(base->cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) * We might have to IPI the remote CPU if the base is idle and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) * timer is not deferrable. If the other CPU is on the way to idle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) * then it can't set base->is_idle as we hold the base lock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) if (base->is_idle)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) wake_up_nohz_cpu(base->cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) * Enqueue the timer into the hash bucket, mark it pending in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) * the bitmap, store the index in the timer flags then wake up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) * the target CPU if needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) static void enqueue_timer(struct timer_base *base, struct timer_list *timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) unsigned int idx, unsigned long bucket_expiry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) hlist_add_head(&timer->entry, base->vectors + idx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) __set_bit(idx, base->pending_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) timer_set_idx(timer, idx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) trace_timer_start(timer, timer->expires, timer->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) * Check whether this is the new first expiring timer. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) * effective expiry time of the timer is required here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) * (bucket_expiry) instead of timer->expires.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) if (time_before(bucket_expiry, base->next_expiry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) * Set the next expiry time and kick the CPU so it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) * can reevaluate the wheel:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) base->next_expiry = bucket_expiry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) base->timers_pending = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) base->next_expiry_recalc = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) trigger_dyntick_cpu(base, timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) static void internal_add_timer(struct timer_base *base, struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) unsigned long bucket_expiry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) unsigned int idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) idx = calc_wheel_index(timer->expires, base->clk, &bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) enqueue_timer(base, timer, idx, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) static const struct debug_obj_descr timer_debug_descr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) static void *timer_debug_hint(void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) return ((struct timer_list *) addr)->function;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) static bool timer_is_static_object(void *addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) struct timer_list *timer = addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) return (timer->entry.pprev == NULL &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) timer->entry.next == TIMER_ENTRY_STATIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) * fixup_init is called when:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) * - an active object is initialized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) static bool timer_fixup_init(void *addr, enum debug_obj_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) struct timer_list *timer = addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) switch (state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) case ODEBUG_STATE_ACTIVE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) del_timer_sync(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) debug_object_init(timer, &timer_debug_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) /* Stub timer callback for improperly used timers. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) static void stub_timer(struct timer_list *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) * fixup_activate is called when:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) * - an active object is activated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) * - an unknown non-static object is activated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) static bool timer_fixup_activate(void *addr, enum debug_obj_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) struct timer_list *timer = addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) switch (state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) case ODEBUG_STATE_NOTAVAILABLE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) timer_setup(timer, stub_timer, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) case ODEBUG_STATE_ACTIVE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) * fixup_free is called when:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) * - an active object is freed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) static bool timer_fixup_free(void *addr, enum debug_obj_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) struct timer_list *timer = addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) switch (state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) case ODEBUG_STATE_ACTIVE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) del_timer_sync(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) debug_object_free(timer, &timer_debug_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) * fixup_assert_init is called when:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) * - an untracked/uninit-ed object is found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) static bool timer_fixup_assert_init(void *addr, enum debug_obj_state state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) struct timer_list *timer = addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) switch (state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) case ODEBUG_STATE_NOTAVAILABLE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) timer_setup(timer, stub_timer, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) static const struct debug_obj_descr timer_debug_descr = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) .name = "timer_list",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) .debug_hint = timer_debug_hint,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) .is_static_object = timer_is_static_object,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) .fixup_init = timer_fixup_init,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) .fixup_activate = timer_fixup_activate,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) .fixup_free = timer_fixup_free,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) .fixup_assert_init = timer_fixup_assert_init,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) static inline void debug_timer_init(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) debug_object_init(timer, &timer_debug_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) static inline void debug_timer_activate(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) debug_object_activate(timer, &timer_debug_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) static inline void debug_timer_deactivate(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) debug_object_deactivate(timer, &timer_debug_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) static inline void debug_timer_assert_init(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) debug_object_assert_init(timer, &timer_debug_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) static void do_init_timer(struct timer_list *timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) void (*func)(struct timer_list *),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) unsigned int flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) const char *name, struct lock_class_key *key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) void init_timer_on_stack_key(struct timer_list *timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) void (*func)(struct timer_list *),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) unsigned int flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) const char *name, struct lock_class_key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) debug_object_init_on_stack(timer, &timer_debug_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) do_init_timer(timer, func, flags, name, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) EXPORT_SYMBOL_GPL(init_timer_on_stack_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) void destroy_timer_on_stack(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) debug_object_free(timer, &timer_debug_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) EXPORT_SYMBOL_GPL(destroy_timer_on_stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) static inline void debug_timer_init(struct timer_list *timer) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) static inline void debug_timer_activate(struct timer_list *timer) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) static inline void debug_timer_deactivate(struct timer_list *timer) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) static inline void debug_timer_assert_init(struct timer_list *timer) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) static inline void debug_init(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) debug_timer_init(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) trace_timer_init(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) static inline void debug_deactivate(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) debug_timer_deactivate(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) trace_timer_cancel(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) static inline void debug_assert_init(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) debug_timer_assert_init(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) static void do_init_timer(struct timer_list *timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) void (*func)(struct timer_list *),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) unsigned int flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) const char *name, struct lock_class_key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) timer->entry.pprev = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) timer->function = func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) if (WARN_ON_ONCE(flags & ~TIMER_INIT_FLAGS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) flags &= TIMER_INIT_FLAGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) timer->flags = flags | raw_smp_processor_id();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) lockdep_init_map(&timer->lockdep_map, name, key, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) * init_timer_key - initialize a timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) * @timer: the timer to be initialized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) * @func: timer callback function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) * @flags: timer flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) * @name: name of the timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) * @key: lockdep class key of the fake lock used for tracking timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) * sync lock dependencies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) * init_timer_key() must be done to a timer prior calling *any* of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) * other timer functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) void init_timer_key(struct timer_list *timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) void (*func)(struct timer_list *), unsigned int flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) const char *name, struct lock_class_key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) debug_init(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) do_init_timer(timer, func, flags, name, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) EXPORT_SYMBOL(init_timer_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) static inline void detach_timer(struct timer_list *timer, bool clear_pending)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) struct hlist_node *entry = &timer->entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) debug_deactivate(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) __hlist_del(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) if (clear_pending)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) entry->pprev = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) entry->next = LIST_POISON2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) static int detach_if_pending(struct timer_list *timer, struct timer_base *base,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) bool clear_pending)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) unsigned idx = timer_get_idx(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) if (!timer_pending(timer))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) if (hlist_is_singular_node(&timer->entry, base->vectors + idx)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) __clear_bit(idx, base->pending_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) base->next_expiry_recalc = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) detach_timer(timer, clear_pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) static inline struct timer_base *get_timer_cpu_base(u32 tflags, u32 cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) struct timer_base *base = per_cpu_ptr(&timer_bases[BASE_STD], cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) * If the timer is deferrable and NO_HZ_COMMON is set then we need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) * to use the deferrable base.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && (tflags & TIMER_DEFERRABLE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) base = per_cpu_ptr(&timer_bases[BASE_DEF], cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) return base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) static inline struct timer_base *get_timer_this_cpu_base(u32 tflags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) * If the timer is deferrable and NO_HZ_COMMON is set then we need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) * to use the deferrable base.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && (tflags & TIMER_DEFERRABLE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) base = this_cpu_ptr(&timer_bases[BASE_DEF]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) return base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) static inline struct timer_base *get_timer_base(u32 tflags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) return get_timer_cpu_base(tflags, tflags & TIMER_CPUMASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) static inline struct timer_base *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) get_target_base(struct timer_base *base, unsigned tflags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) if (static_branch_likely(&timers_migration_enabled) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) !(tflags & TIMER_PINNED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) return get_timer_cpu_base(tflags, get_nohz_timer_target());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) return get_timer_this_cpu_base(tflags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) static inline void forward_timer_base(struct timer_base *base)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) unsigned long jnow = READ_ONCE(jiffies);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) * No need to forward if we are close enough below jiffies.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) * Also while executing timers, base->clk is 1 offset ahead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) * of jiffies to avoid endless requeuing to current jffies.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) if ((long)(jnow - base->clk) < 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) * If the next expiry value is > jiffies, then we fast forward to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) * jiffies otherwise we forward to the next expiry value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) if (time_after(base->next_expiry, jnow)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) base->clk = jnow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) if (WARN_ON_ONCE(time_before(base->next_expiry, base->clk)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) base->clk = base->next_expiry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) * We are using hashed locking: Holding per_cpu(timer_bases[x]).lock means
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) * that all timers which are tied to this base are locked, and the base itself
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) * is locked too.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) * So __run_timers/migrate_timers can safely modify all timers which could
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) * be found in the base->vectors array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) * When a timer is migrating then the TIMER_MIGRATING flag is set and we need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) * to wait until the migration is done.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) static struct timer_base *lock_timer_base(struct timer_list *timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) unsigned long *flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) __acquires(timer->base->lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) struct timer_base *base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) u32 tf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) * We need to use READ_ONCE() here, otherwise the compiler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) * might re-read @tf between the check for TIMER_MIGRATING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) * and spin_lock().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) tf = READ_ONCE(timer->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) if (!(tf & TIMER_MIGRATING)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) base = get_timer_base(tf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) raw_spin_lock_irqsave(&base->lock, *flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) if (timer->flags == tf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) return base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) raw_spin_unlock_irqrestore(&base->lock, *flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) cpu_relax();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) #define MOD_TIMER_PENDING_ONLY 0x01
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) #define MOD_TIMER_REDUCE 0x02
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) #define MOD_TIMER_NOTPENDING 0x04
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) static inline int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) __mod_timer(struct timer_list *timer, unsigned long expires, unsigned int options)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) unsigned long clk = 0, flags, bucket_expiry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) struct timer_base *base, *new_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) unsigned int idx = UINT_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) BUG_ON(!timer->function);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) * This is a common optimization triggered by the networking code - if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) * the timer is re-modified to have the same timeout or ends up in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) * same array bucket then just return:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) if (!(options & MOD_TIMER_NOTPENDING) && timer_pending(timer)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) * The downside of this optimization is that it can result in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) * larger granularity than you would get from adding a new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) * timer with this expiry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) long diff = timer->expires - expires;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) if (!diff)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) if (options & MOD_TIMER_REDUCE && diff <= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) * We lock timer base and calculate the bucket index right
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) * here. If the timer ends up in the same bucket, then we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) * just update the expiry time and avoid the whole
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) * dequeue/enqueue dance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) base = lock_timer_base(timer, &flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) forward_timer_base(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) if (timer_pending(timer) && (options & MOD_TIMER_REDUCE) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) time_before_eq(timer->expires, expires)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) clk = base->clk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) idx = calc_wheel_index(expires, clk, &bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) * Retrieve and compare the array index of the pending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) * timer. If it matches set the expiry to the new value so a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) * subsequent call will exit in the expires check above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) if (idx == timer_get_idx(timer)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) if (!(options & MOD_TIMER_REDUCE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) timer->expires = expires;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) else if (time_after(timer->expires, expires))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) timer->expires = expires;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) base = lock_timer_base(timer, &flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) forward_timer_base(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) ret = detach_if_pending(timer, base, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) if (!ret && (options & MOD_TIMER_PENDING_ONLY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) new_base = get_target_base(base, timer->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) if (base != new_base) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) * We are trying to schedule the timer on the new base.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) * However we can't change timer's base while it is running,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) * otherwise del_timer_sync() can't detect that the timer's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) * handler yet has not finished. This also guarantees that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) * timer is serialized wrt itself.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) if (likely(base->running_timer != timer)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) /* See the comment in lock_timer_base() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) timer->flags |= TIMER_MIGRATING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) raw_spin_unlock(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) base = new_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) raw_spin_lock(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) WRITE_ONCE(timer->flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) (timer->flags & ~TIMER_BASEMASK) | base->cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) forward_timer_base(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) debug_timer_activate(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) timer->expires = expires;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) * If 'idx' was calculated above and the base time did not advance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) * between calculating 'idx' and possibly switching the base, only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) * enqueue_timer() is required. Otherwise we need to (re)calculate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) * the wheel index via internal_add_timer().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) if (idx != UINT_MAX && clk == base->clk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) enqueue_timer(base, timer, idx, bucket_expiry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) internal_add_timer(base, timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) out_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) raw_spin_unlock_irqrestore(&base->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) * mod_timer_pending - modify a pending timer's timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) * @timer: the pending timer to be modified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) * @expires: new timeout in jiffies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) * mod_timer_pending() is the same for pending timers as mod_timer(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) * but will not re-activate and modify already deleted timers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) * It is useful for unserialized use of timers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) int mod_timer_pending(struct timer_list *timer, unsigned long expires)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) return __mod_timer(timer, expires, MOD_TIMER_PENDING_ONLY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) EXPORT_SYMBOL(mod_timer_pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) * mod_timer - modify a timer's timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) * @timer: the timer to be modified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) * @expires: new timeout in jiffies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) * mod_timer() is a more efficient way to update the expire field of an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) * active timer (if the timer is inactive it will be activated)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) * mod_timer(timer, expires) is equivalent to:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) * del_timer(timer); timer->expires = expires; add_timer(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) * Note that if there are multiple unserialized concurrent users of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) * same timer, then mod_timer() is the only safe way to modify the timeout,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) * since add_timer() cannot modify an already running timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) * The function returns whether it has modified a pending timer or not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) * active timer returns 1.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) int mod_timer(struct timer_list *timer, unsigned long expires)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) return __mod_timer(timer, expires, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) EXPORT_SYMBOL(mod_timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) * timer_reduce - Modify a timer's timeout if it would reduce the timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) * @timer: The timer to be modified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) * @expires: New timeout in jiffies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) * timer_reduce() is very similar to mod_timer(), except that it will only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) * modify a running timer if that would reduce the expiration time (it will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) * start a timer that isn't running).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) int timer_reduce(struct timer_list *timer, unsigned long expires)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) return __mod_timer(timer, expires, MOD_TIMER_REDUCE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) EXPORT_SYMBOL(timer_reduce);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) * add_timer - start a timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) * @timer: the timer to be added
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) * The kernel will do a ->function(@timer) callback from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) * timer interrupt at the ->expires point in the future. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) * current time is 'jiffies'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) * The timer's ->expires, ->function fields must be set prior calling this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) * function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) * Timers with an ->expires field in the past will be executed in the next
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) * timer tick.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) void add_timer(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) BUG_ON(timer_pending(timer));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) __mod_timer(timer, timer->expires, MOD_TIMER_NOTPENDING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) EXPORT_SYMBOL(add_timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) * add_timer_on - start a timer on a particular CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) * @timer: the timer to be added
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) * @cpu: the CPU to start it on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) * This is not very scalable on SMP. Double adds are not possible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) void add_timer_on(struct timer_list *timer, int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) struct timer_base *new_base, *base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) BUG_ON(timer_pending(timer) || !timer->function);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) new_base = get_timer_cpu_base(timer->flags, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) * If @timer was on a different CPU, it should be migrated with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) * old base locked to prevent other operations proceeding with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) * wrong base locked. See lock_timer_base().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) base = lock_timer_base(timer, &flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) if (base != new_base) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) timer->flags |= TIMER_MIGRATING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) raw_spin_unlock(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) base = new_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) raw_spin_lock(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) WRITE_ONCE(timer->flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) (timer->flags & ~TIMER_BASEMASK) | cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) forward_timer_base(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) debug_timer_activate(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) internal_add_timer(base, timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) raw_spin_unlock_irqrestore(&base->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) EXPORT_SYMBOL_GPL(add_timer_on);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) * del_timer - deactivate a timer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) * @timer: the timer to be deactivated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) * del_timer() deactivates a timer - this works on both active and inactive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) * timers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) * The function returns whether it has deactivated a pending timer or not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) * (ie. del_timer() of an inactive timer returns 0, del_timer() of an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) * active timer returns 1.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) int del_timer(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) struct timer_base *base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) debug_assert_init(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) if (timer_pending(timer)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) base = lock_timer_base(timer, &flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) ret = detach_if_pending(timer, base, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) raw_spin_unlock_irqrestore(&base->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) EXPORT_SYMBOL(del_timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) * try_to_del_timer_sync - Try to deactivate a timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) * @timer: timer to delete
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) * This function tries to deactivate a timer. Upon successful (ret >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) * exit the timer is not queued and the handler is not running on any CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) int try_to_del_timer_sync(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) struct timer_base *base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) int ret = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) debug_assert_init(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) base = lock_timer_base(timer, &flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) if (base->running_timer != timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) ret = detach_if_pending(timer, base, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) raw_spin_unlock_irqrestore(&base->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) EXPORT_SYMBOL(try_to_del_timer_sync);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) #ifdef CONFIG_PREEMPT_RT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) static __init void timer_base_init_expiry_lock(struct timer_base *base)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) spin_lock_init(&base->expiry_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) static inline void timer_base_lock_expiry(struct timer_base *base)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) spin_lock(&base->expiry_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) static inline void timer_base_unlock_expiry(struct timer_base *base)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) spin_unlock(&base->expiry_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) * The counterpart to del_timer_wait_running().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) * If there is a waiter for base->expiry_lock, then it was waiting for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) * timer callback to finish. Drop expiry_lock and reaquire it. That allows
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) * the waiter to acquire the lock and make progress.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) static void timer_sync_wait_running(struct timer_base *base)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273) if (atomic_read(&base->timer_waiters)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) raw_spin_unlock_irq(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) spin_unlock(&base->expiry_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) spin_lock(&base->expiry_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) raw_spin_lock_irq(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) * This function is called on PREEMPT_RT kernels when the fast path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) * deletion of a timer failed because the timer callback function was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) * running.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) * This prevents priority inversion, if the softirq thread on a remote CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) * got preempted, and it prevents a life lock when the task which tries to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) * delete a timer preempted the softirq thread running the timer callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) * function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) static void del_timer_wait_running(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) u32 tf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) tf = READ_ONCE(timer->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) if (!(tf & TIMER_MIGRATING)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) struct timer_base *base = get_timer_base(tf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) * Mark the base as contended and grab the expiry lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) * which is held by the softirq across the timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) * callback. Drop the lock immediately so the softirq can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) * expire the next timer. In theory the timer could already
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) * be running again, but that's more than unlikely and just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) * causes another wait loop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) atomic_inc(&base->timer_waiters);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) spin_lock_bh(&base->expiry_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) atomic_dec(&base->timer_waiters);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) spin_unlock_bh(&base->expiry_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) static inline void timer_base_init_expiry_lock(struct timer_base *base) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) static inline void timer_base_lock_expiry(struct timer_base *base) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) static inline void timer_base_unlock_expiry(struct timer_base *base) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) static inline void timer_sync_wait_running(struct timer_base *base) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) static inline void del_timer_wait_running(struct timer_list *timer) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) * del_timer_sync - deactivate a timer and wait for the handler to finish.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) * @timer: the timer to be deactivated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) * This function only differs from del_timer() on SMP: besides deactivating
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) * the timer it also makes sure the handler has finished executing on other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) * CPUs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) * Synchronization rules: Callers must prevent restarting of the timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) * otherwise this function is meaningless. It must not be called from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) * interrupt contexts unless the timer is an irqsafe one. The caller must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) * not hold locks which would prevent completion of the timer's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) * handler. The timer's handler must not call add_timer_on(). Upon exit the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) * timer is not queued and the handler is not running on any CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) * Note: For !irqsafe timers, you must not hold locks that are held in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) * interrupt context while calling this function. Even if the lock has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) * nothing to do with the timer in question. Here's why::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) * CPU0 CPU1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) * ---- ----
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) * <SOFTIRQ>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) * call_timer_fn();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) * base->running_timer = mytimer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) * spin_lock_irq(somelock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) * <IRQ>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) * spin_lock(somelock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349) * del_timer_sync(mytimer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) * while (base->running_timer == mytimer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) * Now del_timer_sync() will never return and never release somelock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) * The interrupt on the other CPU is waiting to grab somelock but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) * it has interrupted the softirq that CPU0 is waiting to finish.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) * The function returns whether it has deactivated a pending timer or not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) int del_timer_sync(struct timer_list *timer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) #ifdef CONFIG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) * If lockdep gives a backtrace here, please reference
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) * the synchronization rules above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369) local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) lock_map_acquire(&timer->lockdep_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) lock_map_release(&timer->lockdep_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) * don't use it in hardirq context, because it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) * could lead to deadlock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) WARN_ON(in_irq() && !(timer->flags & TIMER_IRQSAFE));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) ret = try_to_del_timer_sync(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) if (unlikely(ret < 0)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) del_timer_wait_running(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) cpu_relax();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) } while (ret < 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) EXPORT_SYMBOL(del_timer_sync);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) static void call_timer_fn(struct timer_list *timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) void (*fn)(struct timer_list *),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396) unsigned long baseclk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) int count = preempt_count();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) #ifdef CONFIG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) * It is permissible to free the timer from inside the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) * function that is called from it, this we need to take into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404) * account for lockdep too. To avoid bogus "held lock freed"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) * warnings as well as problems when looking into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) * timer->lockdep_map, make a copy and use that here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) struct lockdep_map lockdep_map;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410) lockdep_copy_map(&lockdep_map, &timer->lockdep_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) * Couple the lock chain with the lock chain at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) * del_timer_sync() by acquiring the lock_map around the fn()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) * call here and in del_timer_sync().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) lock_map_acquire(&lockdep_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) trace_timer_expire_entry(timer, baseclk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) fn(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) trace_timer_expire_exit(timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423) lock_map_release(&lockdep_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) if (count != preempt_count()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) WARN_ONCE(1, "timer: %pS preempt leak: %08x -> %08x\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) fn, count, preempt_count());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429) * Restore the preempt count. That gives us a decent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430) * chance to survive and extract information. If the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) * callback kept a lock held, bad luck, but not worse
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432) * than the BUG() we had.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434) preempt_count_set(count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) static void expire_timers(struct timer_base *base, struct hlist_head *head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) * This value is required only for tracing. base->clk was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) * incremented directly before expire_timers was called. But expiry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) * is related to the old base->clk value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) unsigned long baseclk = base->clk - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) while (!hlist_empty(head)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) struct timer_list *timer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) void (*fn)(struct timer_list *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451) timer = hlist_entry(head->first, struct timer_list, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) base->running_timer = timer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) detach_timer(timer, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) fn = timer->function;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) if (timer->flags & TIMER_IRQSAFE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) raw_spin_unlock(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) call_timer_fn(timer, fn, baseclk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) raw_spin_lock(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) base->running_timer = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464) raw_spin_unlock_irq(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) call_timer_fn(timer, fn, baseclk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) raw_spin_lock_irq(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) base->running_timer = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468) timer_sync_wait_running(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) static int collect_expired_timers(struct timer_base *base,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) struct hlist_head *heads)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) unsigned long clk = base->clk = base->next_expiry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) struct hlist_head *vec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) int i, levels = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) unsigned int idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) for (i = 0; i < LVL_DEPTH; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) idx = (clk & LVL_MASK) + i * LVL_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) if (__test_and_clear_bit(idx, base->pending_map)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485) vec = base->vectors + idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) hlist_move_list(vec, heads++);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) levels++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489) /* Is it time to look at the next level? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) if (clk & LVL_CLK_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492) /* Shift clock for the next level granularity */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493) clk >>= LVL_CLK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) return levels;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499) * Find the next pending bucket of a level. Search from level start (@offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) * + @clk upwards and if nothing there, search from start of the level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) * (@offset) up to @offset + clk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) static int next_pending_bucket(struct timer_base *base, unsigned offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504) unsigned clk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) unsigned pos, start = offset + clk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) unsigned end = offset + LVL_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) pos = find_next_bit(base->pending_map, end, start);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) if (pos < end)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511) return pos - start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) pos = find_next_bit(base->pending_map, start, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) return pos < start ? pos + LVL_SIZE - start : -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518) * Search the first expiring timer in the various clock levels. Caller must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) * hold base->lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) static unsigned long __next_timer_interrupt(struct timer_base *base)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) unsigned long clk, next, adj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524) unsigned lvl, offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) next = base->clk + NEXT_TIMER_MAX_DELTA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527) clk = base->clk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) for (lvl = 0; lvl < LVL_DEPTH; lvl++, offset += LVL_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) int pos = next_pending_bucket(base, offset, clk & LVL_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) unsigned long lvl_clk = clk & LVL_CLK_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532) if (pos >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) unsigned long tmp = clk + (unsigned long) pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) tmp <<= LVL_SHIFT(lvl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) if (time_before(tmp, next))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) next = tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540) * If the next expiration happens before we reach
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541) * the next level, no need to check further.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) if (pos <= ((LVL_CLK_DIV - lvl_clk) & LVL_CLK_MASK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547) * Clock for the next level. If the current level clock lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548) * bits are zero, we look at the next level as is. If not we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549) * need to advance it by one because that's going to be the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550) * next expiring bucket in that level. base->clk is the next
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) * expiring jiffie. So in case of:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) * LVL5 LVL4 LVL3 LVL2 LVL1 LVL0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) * 0 0 0 0 0 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556) * we have to look at all levels @index 0. With
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) * LVL5 LVL4 LVL3 LVL2 LVL1 LVL0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) * 0 0 0 0 0 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) * LVL0 has the next expiring bucket @index 2. The upper
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562) * levels have the next expiring bucket @index 1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) * In case that the propagation wraps the next level the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565) * rules apply:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) * LVL5 LVL4 LVL3 LVL2 LVL1 LVL0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568) * 0 0 0 0 F 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) * So after looking at LVL0 we get:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) * LVL5 LVL4 LVL3 LVL2 LVL1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573) * 0 0 0 1 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) * So no propagation from LVL1 to LVL2 because that happened
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576) * with the add already, but then we need to propagate further
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) * from LVL2 to LVL3.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579) * So the simple check whether the lower bits of the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) * level are 0 or not is sufficient for all cases.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582) adj = lvl_clk ? 1 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) clk >>= LVL_CLK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584) clk += adj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) base->next_expiry_recalc = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) base->timers_pending = !(next == base->clk + NEXT_TIMER_MAX_DELTA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) return next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593) #ifdef CONFIG_NO_HZ_COMMON
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) * Check, if the next hrtimer event is before the next timer wheel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596) * event:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598) static u64 cmp_next_hrtimer_event(u64 basem, u64 expires)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) u64 nextevt = hrtimer_get_next_event();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) * If high resolution timers are enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) * hrtimer_get_next_event() returns KTIME_MAX.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606) if (expires <= nextevt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) return expires;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) * If the next timer is already expired, return the tick base
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611) * time so the tick is fired immediately.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) if (nextevt <= basem)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) return basem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) * Round up to the next jiffie. High resolution timers are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618) * off, so the hrtimers are expired in the tick and we need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) * make sure that this tick really expires the timer to avoid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620) * a ping pong of the nohz stop code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622) * Use DIV_ROUND_UP_ULL to prevent gcc calling __divdi3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) return DIV_ROUND_UP_ULL(nextevt, TICK_NSEC) * TICK_NSEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628) * get_next_timer_interrupt - return the time (clock mono) of the next timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) * @basej: base time jiffies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) * @basem: base time clock monotonic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) * Returns the tick aligned clock monotonic time of the next pending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633) * timer or KTIME_MAX if no timer is pending.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) u64 get_next_timer_interrupt(unsigned long basej, u64 basem)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) u64 expires = KTIME_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) unsigned long nextevt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) * Pretend that there is no timer pending if the cpu is offline.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643) * Possible pending timers will be migrated later to an active cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645) if (cpu_is_offline(smp_processor_id()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) return expires;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) raw_spin_lock(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649) if (base->next_expiry_recalc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) base->next_expiry = __next_timer_interrupt(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) nextevt = base->next_expiry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654) * We have a fresh next event. Check whether we can forward the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) * base. We can only do that when @basej is past base->clk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) * otherwise we might rewind base->clk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) if (time_after(basej, base->clk)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659) if (time_after(nextevt, basej))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) base->clk = basej;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) else if (time_after(nextevt, base->clk))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) base->clk = nextevt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665) if (time_before_eq(nextevt, basej)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) expires = basem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) base->is_idle = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669) if (base->timers_pending)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) expires = basem + (u64)(nextevt - basej) * TICK_NSEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) * If we expect to sleep more than a tick, mark the base idle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673) * Also the tick is stopped so any added timer must forward
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) * the base clk itself to keep granularity small. This idle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675) * logic is only maintained for the BASE_STD base, deferrable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) * timers may still see large granularity skew (by design).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) if ((expires - basem) > TICK_NSEC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) base->is_idle = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) raw_spin_unlock(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) return cmp_next_hrtimer_event(basem, expires);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) * timer_clear_idle - Clear the idle state of the timer base
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) * Called with interrupts disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691) void timer_clear_idle(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693) struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) * We do this unlocked. The worst outcome is a remote enqueue sending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) * a pointless IPI, but taking the lock would just make the window for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698) * sending the IPI a few instructions smaller for the cost of taking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699) * the lock in the exit from idle path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) base->is_idle = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706) * Called from the timer interrupt handler to charge one tick to the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) * process. user_tick is 1 if the tick is user time, 0 for system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) void update_process_times(int user_tick)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711) struct task_struct *p = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713) PRANDOM_ADD_NOISE(jiffies, user_tick, p, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) /* Note: this timer irq context must be accounted for as well. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) account_process_tick(p, user_tick);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) run_local_timers();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) rcu_sched_clock_irq(user_tick);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719) #ifdef CONFIG_IRQ_WORK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) if (in_irq())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) irq_work_tick();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) scheduler_tick();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724) if (IS_ENABLED(CONFIG_POSIX_TIMERS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) run_posix_cpu_timers();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) * __run_timers - run all expired timers (if any) on this CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730) * @base: the timer vector to be processed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) static inline void __run_timers(struct timer_base *base)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) struct hlist_head heads[LVL_DEPTH];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) int levels;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) if (time_before(jiffies, base->next_expiry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) timer_base_lock_expiry(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741) raw_spin_lock_irq(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) while (time_after_eq(jiffies, base->clk) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) time_after_eq(jiffies, base->next_expiry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745) levels = collect_expired_timers(base, heads);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747) * The only possible reason for not finding any expired
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) * timer at this clk is that all matching timers have been
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) * dequeued.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751) WARN_ON_ONCE(!levels && !base->next_expiry_recalc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) base->clk++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) base->next_expiry = __next_timer_interrupt(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755) while (levels--)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) expire_timers(base, heads + levels);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) raw_spin_unlock_irq(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759) timer_base_unlock_expiry(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) * This function runs timers and the timer-tq in bottom half context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765) static __latent_entropy void run_timer_softirq(struct softirq_action *h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1766) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1767) struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1769) __run_timers(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1770) if (IS_ENABLED(CONFIG_NO_HZ_COMMON))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1771) __run_timers(this_cpu_ptr(&timer_bases[BASE_DEF]));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1772) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1773)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1774) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1775) * Called by the local, per-CPU timer interrupt on SMP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1776) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1777) void run_local_timers(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1778) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1779) struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1780)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1781) hrtimer_run_queues();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1782) /* Raise the softirq only if required. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1783) if (time_before(jiffies, base->next_expiry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1784) if (!IS_ENABLED(CONFIG_NO_HZ_COMMON))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1785) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1786) /* CPU is awake, so check the deferrable base. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1787) base++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1788) if (time_before(jiffies, base->next_expiry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1789) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1790) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1791) raise_softirq(TIMER_SOFTIRQ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1792) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1793)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1794) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1795) * Since schedule_timeout()'s timer is defined on the stack, it must store
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1796) * the target task on the stack as well.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1797) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1798) struct process_timer {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1799) struct timer_list timer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1800) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1801) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1802)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1803) static void process_timeout(struct timer_list *t)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1804) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1805) struct process_timer *timeout = from_timer(timeout, t, timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1806)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1807) wake_up_process(timeout->task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1808) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1809)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1810) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1811) * schedule_timeout - sleep until timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1812) * @timeout: timeout value in jiffies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1813) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1814) * Make the current task sleep until @timeout jiffies have elapsed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1815) * The function behavior depends on the current task state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1816) * (see also set_current_state() description):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1817) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1818) * %TASK_RUNNING - the scheduler is called, but the task does not sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1819) * at all. That happens because sched_submit_work() does nothing for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1820) * tasks in %TASK_RUNNING state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1821) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1822) * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1823) * pass before the routine returns unless the current task is explicitly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1824) * woken up, (e.g. by wake_up_process()).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1825) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1826) * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1827) * delivered to the current task or the current task is explicitly woken
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1828) * up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1829) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1830) * The current task state is guaranteed to be %TASK_RUNNING when this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1831) * routine returns.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1832) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1833) * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1834) * the CPU away without a bound on the timeout. In this case the return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1835) * value will be %MAX_SCHEDULE_TIMEOUT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1836) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1837) * Returns 0 when the timer has expired otherwise the remaining time in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1838) * jiffies will be returned. In all cases the return value is guaranteed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1839) * to be non-negative.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1840) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1841) signed long __sched schedule_timeout(signed long timeout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1842) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1843) struct process_timer timer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1844) unsigned long expire;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1845)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1846) switch (timeout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1847) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1848) case MAX_SCHEDULE_TIMEOUT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1849) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1850) * These two special cases are useful to be comfortable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1851) * in the caller. Nothing more. We could take
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1852) * MAX_SCHEDULE_TIMEOUT from one of the negative value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1853) * but I' d like to return a valid offset (>=0) to allow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1854) * the caller to do everything it want with the retval.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1855) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1856) schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1857) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1858) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1859) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1860) * Another bit of PARANOID. Note that the retval will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1861) * 0 since no piece of kernel is supposed to do a check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1862) * for a negative retval of schedule_timeout() (since it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1863) * should never happens anyway). You just have the printk()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1864) * that will tell you if something is gone wrong and where.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1865) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1866) if (timeout < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1867) printk(KERN_ERR "schedule_timeout: wrong timeout "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1868) "value %lx\n", timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1869) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1870) current->state = TASK_RUNNING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1871) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1872) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1873) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1874)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1875) expire = timeout + jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1876)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1877) timer.task = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1878) timer_setup_on_stack(&timer.timer, process_timeout, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1879) __mod_timer(&timer.timer, expire, MOD_TIMER_NOTPENDING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1880) schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1881) del_singleshot_timer_sync(&timer.timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1882)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1883) /* Remove the timer from the object tracker */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1884) destroy_timer_on_stack(&timer.timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1885)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1886) timeout = expire - jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1887)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1888) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1889) return timeout < 0 ? 0 : timeout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1890) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1891) EXPORT_SYMBOL(schedule_timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1892)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1893) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1894) * We can use __set_current_state() here because schedule_timeout() calls
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1895) * schedule() unconditionally.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1896) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1897) signed long __sched schedule_timeout_interruptible(signed long timeout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1898) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1899) __set_current_state(TASK_INTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1900) return schedule_timeout(timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1901) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1902) EXPORT_SYMBOL(schedule_timeout_interruptible);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1903)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1904) signed long __sched schedule_timeout_killable(signed long timeout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1905) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1906) __set_current_state(TASK_KILLABLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1907) return schedule_timeout(timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1908) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1909) EXPORT_SYMBOL(schedule_timeout_killable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1910)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1911) signed long __sched schedule_timeout_uninterruptible(signed long timeout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1912) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1913) __set_current_state(TASK_UNINTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1914) return schedule_timeout(timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1915) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1916) EXPORT_SYMBOL(schedule_timeout_uninterruptible);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1917)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1918) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1919) * Like schedule_timeout_uninterruptible(), except this task will not contribute
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1920) * to load average.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1921) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1922) signed long __sched schedule_timeout_idle(signed long timeout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1923) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1924) __set_current_state(TASK_IDLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1925) return schedule_timeout(timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1926) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1927) EXPORT_SYMBOL(schedule_timeout_idle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1928)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1929) #ifdef CONFIG_HOTPLUG_CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1930) static void migrate_timer_list(struct timer_base *new_base, struct hlist_head *head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1931) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1932) struct timer_list *timer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1933) int cpu = new_base->cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1934)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1935) while (!hlist_empty(head)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1936) timer = hlist_entry(head->first, struct timer_list, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1937) detach_timer(timer, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1938) timer->flags = (timer->flags & ~TIMER_BASEMASK) | cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1939) internal_add_timer(new_base, timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1940) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1941) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1942)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1943) int timers_prepare_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1944) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1945) struct timer_base *base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1946) int b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1947)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1948) for (b = 0; b < NR_BASES; b++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1949) base = per_cpu_ptr(&timer_bases[b], cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1950) base->clk = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1951) base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1952) base->timers_pending = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1953) base->is_idle = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1954) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1955) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1956) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1957)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1958) int timers_dead_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1959) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1960) struct timer_base *old_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1961) struct timer_base *new_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1962) int b, i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1963)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1964) BUG_ON(cpu_online(cpu));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1965)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1966) for (b = 0; b < NR_BASES; b++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1967) old_base = per_cpu_ptr(&timer_bases[b], cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1968) new_base = get_cpu_ptr(&timer_bases[b]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1969) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1970) * The caller is globally serialized and nobody else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1971) * takes two locks at once, deadlock is not possible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1972) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1973) raw_spin_lock_irq(&new_base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1974) raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1975)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1976) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1977) * The current CPUs base clock might be stale. Update it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1978) * before moving the timers over.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1979) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1980) forward_timer_base(new_base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1981)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1982) BUG_ON(old_base->running_timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1983)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1984) for (i = 0; i < WHEEL_SIZE; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1985) migrate_timer_list(new_base, old_base->vectors + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1986)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1987) raw_spin_unlock(&old_base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1988) raw_spin_unlock_irq(&new_base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1989) put_cpu_ptr(&timer_bases);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1990) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1991) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1992) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1993)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1994) #endif /* CONFIG_HOTPLUG_CPU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1995)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1996) static void __init init_timer_cpu(int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1997) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1998) struct timer_base *base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1999) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2001) for (i = 0; i < NR_BASES; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2002) base = per_cpu_ptr(&timer_bases[i], cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2003) base->cpu = cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2004) raw_spin_lock_init(&base->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2005) base->clk = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2006) base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2007) timer_base_init_expiry_lock(base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2008) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2009) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2010)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2011) static void __init init_timer_cpus(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2012) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2013) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2014)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2015) for_each_possible_cpu(cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2016) init_timer_cpu(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2017) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2018)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2019) void __init init_timers(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2020) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2021) init_timer_cpus();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2022) posix_cputimers_init_work();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2023) open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2024) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2025)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2026) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2027) * msleep - sleep safely even with waitqueue interruptions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2028) * @msecs: Time in milliseconds to sleep for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2029) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2030) void msleep(unsigned int msecs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2031) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2032) unsigned long timeout = msecs_to_jiffies(msecs) + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2033)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2034) while (timeout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2035) timeout = schedule_timeout_uninterruptible(timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2036) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2037)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2038) EXPORT_SYMBOL(msleep);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2039)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2040) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2041) * msleep_interruptible - sleep waiting for signals
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2042) * @msecs: Time in milliseconds to sleep for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2043) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2044) unsigned long msleep_interruptible(unsigned int msecs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2045) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2046) unsigned long timeout = msecs_to_jiffies(msecs) + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2047)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2048) while (timeout && !signal_pending(current))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2049) timeout = schedule_timeout_interruptible(timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2050) return jiffies_to_msecs(timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2051) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2052)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2053) EXPORT_SYMBOL(msleep_interruptible);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2054)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2055) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2056) * usleep_range_state - Sleep for an approximate time in a given state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2057) * @min: Minimum time in usecs to sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2058) * @max: Maximum time in usecs to sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2059) * @state: State of the current task that will be while sleeping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2060) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2061) * In non-atomic context where the exact wakeup time is flexible, use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2062) * usleep_range_state() instead of udelay(). The sleep improves responsiveness
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2063) * by avoiding the CPU-hogging busy-wait of udelay(), and the range reduces
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2064) * power usage by allowing hrtimers to take advantage of an already-
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2065) * scheduled interrupt instead of scheduling a new one just for this sleep.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2066) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2067) void __sched usleep_range_state(unsigned long min, unsigned long max,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2068) unsigned int state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2069) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2070) ktime_t exp = ktime_add_us(ktime_get(), min);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2071) u64 delta = (u64)(max - min) * NSEC_PER_USEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2073) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2074) __set_current_state(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2075) /* Do not return before the requested sleep time has elapsed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2076) if (!schedule_hrtimeout_range(&exp, delta, HRTIMER_MODE_ABS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2077) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2078) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2079) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2080)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2081) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2082) * usleep_range - Sleep for an approximate time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2083) * @min: Minimum time in usecs to sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2084) * @max: Maximum time in usecs to sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2085) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2086) * In non-atomic context where the exact wakeup time is flexible, use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2087) * usleep_range() instead of udelay(). The sleep improves responsiveness
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2088) * by avoiding the CPU-hogging busy-wait of udelay(), and the range reduces
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2089) * power usage by allowing hrtimers to take advantage of an already-
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2090) * scheduled interrupt instead of scheduling a new one just for this sleep.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2091) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2092) void __sched usleep_range(unsigned long min, unsigned long max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2093) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2094) usleep_range_state(min, max, TASK_UNINTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2095) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2096) EXPORT_SYMBOL(usleep_range);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags