506 lines
15 KiB
Diff
506 lines
15 KiB
Diff
From a0b5d92787bc37be58a70439b4399f0014840c3b Mon Sep 17 00:00:00 2001
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 1 Mar 2012 15:14:06 +0100
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Subject: [PATCH 023/282] timekeeping: Split xtime_lock
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xtime_lock is going to be split apart in mainline, so we can shorten
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the seqcount protected regions and avoid updating seqcount in some
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code pathes. This is a straight forward split, so we can avoid the
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whole mess with raw seqlocks for RT.
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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[bwh: Forward-ported to 3.2.24: adjust context; drop changes to
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ntp_leap_second() function removed by commit
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6b43ae8a619d17c4935c3320d2ef9e92bdeed05d ('ntp: Fix leap-second hrtimer
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livelock')]
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---
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kernel/time/jiffies.c | 4 +-
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kernel/time/ntp.c | 24 ++++++++----
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kernel/time/tick-common.c | 10 +++--
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kernel/time/tick-internal.h | 3 +-
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kernel/time/tick-sched.c | 16 +++++---
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kernel/time/timekeeping.c | 90 +++++++++++++++++++++++++------------------
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6 files changed, 88 insertions(+), 59 deletions(-)
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--- a/kernel/time/jiffies.c
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+++ b/kernel/time/jiffies.c
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@@ -74,9 +74,9 @@ u64 get_jiffies_64(void)
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u64 ret;
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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ret = jiffies_64;
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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return ret;
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}
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EXPORT_SYMBOL(get_jiffies_64);
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--- a/kernel/time/ntp.c
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+++ b/kernel/time/ntp.c
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@@ -623,7 +623,8 @@ int do_adjtimex(struct timex *txc)
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getnstimeofday(&ts);
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- write_seqlock_irq(&xtime_lock);
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+ raw_spin_lock_irq(&xtime_lock);
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+ write_seqcount_begin(&xtime_seq);
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if (txc->modes & ADJ_ADJTIME) {
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long save_adjust = time_adjust;
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@@ -665,7 +666,8 @@ int do_adjtimex(struct timex *txc)
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/* fill PPS status fields */
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pps_fill_timex(txc);
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- write_sequnlock_irq(&xtime_lock);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irq(&xtime_lock);
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txc->time.tv_sec = ts.tv_sec;
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txc->time.tv_usec = ts.tv_nsec;
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@@ -863,7 +865,8 @@ void hardpps(const struct timespec *phas
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pts_norm = pps_normalize_ts(*phase_ts);
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- write_seqlock_irqsave(&xtime_lock, flags);
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+ raw_spin_lock_irqsave(&xtime_lock, flags);
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+ write_seqcount_begin(&xtime_seq);
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/* clear the error bits, they will be set again if needed */
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time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
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@@ -876,7 +879,8 @@ void hardpps(const struct timespec *phas
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* just start the frequency interval */
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if (unlikely(pps_fbase.tv_sec == 0)) {
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pps_fbase = *raw_ts;
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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return;
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}
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@@ -891,7 +895,8 @@ void hardpps(const struct timespec *phas
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time_status |= STA_PPSJITTER;
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/* restart the frequency calibration interval */
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pps_fbase = *raw_ts;
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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pr_err("hardpps: PPSJITTER: bad pulse\n");
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return;
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}
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@@ -908,7 +913,8 @@ void hardpps(const struct timespec *phas
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hardpps_update_phase(pts_norm.nsec);
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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}
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EXPORT_SYMBOL(hardpps);
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--- a/kernel/time/tick-common.c
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+++ b/kernel/time/tick-common.c
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@@ -63,13 +63,15 @@ int tick_is_oneshot_available(void)
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static void tick_periodic(int cpu)
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{
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if (tick_do_timer_cpu == cpu) {
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- write_seqlock(&xtime_lock);
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+ raw_spin_lock(&xtime_lock);
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+ write_seqcount_begin(&xtime_seq);
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/* Keep track of the next tick event */
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tick_next_period = ktime_add(tick_next_period, tick_period);
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do_timer(1);
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- write_sequnlock(&xtime_lock);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock(&xtime_lock);
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}
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update_process_times(user_mode(get_irq_regs()));
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@@ -130,9 +132,9 @@ void tick_setup_periodic(struct clock_ev
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ktime_t next;
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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next = tick_next_period;
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
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--- a/kernel/time/tick-internal.h
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+++ b/kernel/time/tick-internal.h
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@@ -141,4 +141,5 @@ static inline int tick_device_is_functio
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#endif
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extern void do_timer(unsigned long ticks);
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-extern seqlock_t xtime_lock;
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+extern raw_spinlock_t xtime_lock;
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+extern seqcount_t xtime_seq;
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--- a/kernel/time/tick-sched.c
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+++ b/kernel/time/tick-sched.c
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@@ -56,7 +56,8 @@ static void tick_do_update_jiffies64(kti
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return;
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/* Reevalute with xtime_lock held */
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- write_seqlock(&xtime_lock);
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+ raw_spin_lock(&xtime_lock);
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+ write_seqcount_begin(&xtime_seq);
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delta = ktime_sub(now, last_jiffies_update);
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if (delta.tv64 >= tick_period.tv64) {
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@@ -79,7 +80,8 @@ static void tick_do_update_jiffies64(kti
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/* Keep the tick_next_period variable up to date */
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tick_next_period = ktime_add(last_jiffies_update, tick_period);
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}
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- write_sequnlock(&xtime_lock);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock(&xtime_lock);
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}
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/*
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@@ -89,12 +91,14 @@ static ktime_t tick_init_jiffy_update(vo
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{
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ktime_t period;
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- write_seqlock(&xtime_lock);
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+ raw_spin_lock(&xtime_lock);
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+ write_seqcount_begin(&xtime_seq);
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/* Did we start the jiffies update yet ? */
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if (last_jiffies_update.tv64 == 0)
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last_jiffies_update = tick_next_period;
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period = last_jiffies_update;
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- write_sequnlock(&xtime_lock);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock(&xtime_lock);
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return period;
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}
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@@ -345,11 +349,11 @@ void tick_nohz_stop_sched_tick(int inidl
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ts->idle_calls++;
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/* Read jiffies and the time when jiffies were updated last */
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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last_update = last_jiffies_update;
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last_jiffies = jiffies;
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time_delta = timekeeping_max_deferment();
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) ||
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arch_needs_cpu(cpu)) {
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--- a/kernel/time/timekeeping.c
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+++ b/kernel/time/timekeeping.c
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@@ -139,8 +139,8 @@ static inline s64 timekeeping_get_ns_raw
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* This read-write spinlock protects us from races in SMP while
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* playing with xtime.
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*/
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-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
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-
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+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(xtime_lock);
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+seqcount_t xtime_seq;
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/*
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* The current time
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@@ -242,7 +242,7 @@ void getnstimeofday(struct timespec *ts)
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WARN_ON(timekeeping_suspended);
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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*ts = xtime;
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nsecs = timekeeping_get_ns();
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@@ -250,7 +250,7 @@ void getnstimeofday(struct timespec *ts)
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/* If arch requires, add in gettimeoffset() */
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nsecs += arch_gettimeoffset();
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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timespec_add_ns(ts, nsecs);
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}
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@@ -265,14 +265,14 @@ ktime_t ktime_get(void)
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WARN_ON(timekeeping_suspended);
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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secs = xtime.tv_sec + wall_to_monotonic.tv_sec;
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nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;
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nsecs += timekeeping_get_ns();
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/* If arch requires, add in gettimeoffset() */
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nsecs += arch_gettimeoffset();
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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/*
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* Use ktime_set/ktime_add_ns to create a proper ktime on
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* 32-bit architectures without CONFIG_KTIME_SCALAR.
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@@ -298,14 +298,14 @@ void ktime_get_ts(struct timespec *ts)
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WARN_ON(timekeeping_suspended);
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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*ts = xtime;
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tomono = wall_to_monotonic;
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nsecs = timekeeping_get_ns();
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/* If arch requires, add in gettimeoffset() */
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nsecs += arch_gettimeoffset();
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
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ts->tv_nsec + tomono.tv_nsec + nsecs);
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@@ -333,7 +333,7 @@ void getnstime_raw_and_real(struct times
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do {
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u32 arch_offset;
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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*ts_raw = raw_time;
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*ts_real = xtime;
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@@ -346,7 +346,7 @@ void getnstime_raw_and_real(struct times
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nsecs_raw += arch_offset;
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nsecs_real += arch_offset;
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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timespec_add_ns(ts_raw, nsecs_raw);
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timespec_add_ns(ts_real, nsecs_real);
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@@ -385,7 +385,8 @@ int do_settimeofday(const struct timespe
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if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
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return -EINVAL;
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- write_seqlock_irqsave(&xtime_lock, flags);
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+ raw_spin_lock_irqsave(&xtime_lock, flags);
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+ write_seqcount_begin(&xtime_seq);
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timekeeping_forward_now();
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@@ -397,7 +398,8 @@ int do_settimeofday(const struct timespe
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timekeeping_update(true);
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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/* signal hrtimers about time change */
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clock_was_set();
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@@ -421,7 +423,8 @@ int timekeeping_inject_offset(struct tim
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if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
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return -EINVAL;
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- write_seqlock_irqsave(&xtime_lock, flags);
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+ raw_spin_lock_irqsave(&xtime_lock, flags);
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+ write_seqcount_begin(&xtime_seq);
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timekeeping_forward_now();
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@@ -430,7 +433,8 @@ int timekeeping_inject_offset(struct tim
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timekeeping_update(true);
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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/* signal hrtimers about time change */
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clock_was_set();
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@@ -502,11 +506,11 @@ void getrawmonotonic(struct timespec *ts
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s64 nsecs;
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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nsecs = timekeeping_get_ns_raw();
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*ts = raw_time;
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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timespec_add_ns(ts, nsecs);
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}
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@@ -522,11 +526,11 @@ int timekeeping_valid_for_hres(void)
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int ret;
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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return ret;
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}
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@@ -584,7 +588,8 @@ void __init timekeeping_init(void)
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read_persistent_clock(&now);
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read_boot_clock(&boot);
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- write_seqlock_irqsave(&xtime_lock, flags);
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+ raw_spin_lock_irqsave(&xtime_lock, flags);
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+ write_seqcount_begin(&xtime_seq);
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ntp_init();
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@@ -606,7 +611,8 @@ void __init timekeeping_init(void)
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update_rt_offset();
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total_sleep_time.tv_sec = 0;
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total_sleep_time.tv_nsec = 0;
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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}
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/* time in seconds when suspend began */
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@@ -659,14 +665,16 @@ void timekeeping_inject_sleeptime(struct
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if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
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return;
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- write_seqlock_irqsave(&xtime_lock, flags);
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+ raw_spin_lock_irqsave(&xtime_lock, flags);
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+ write_seqcount_begin(&xtime_seq);
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timekeeping_forward_now();
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__timekeeping_inject_sleeptime(delta);
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timekeeping_update(true);
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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/* signal hrtimers about time change */
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clock_was_set();
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@@ -689,7 +697,8 @@ static void timekeeping_resume(void)
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clocksource_resume();
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- write_seqlock_irqsave(&xtime_lock, flags);
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+ raw_spin_lock_irqsave(&xtime_lock, flags);
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+ write_seqcount_begin(&xtime_seq);
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if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
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ts = timespec_sub(ts, timekeeping_suspend_time);
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@@ -700,7 +709,8 @@ static void timekeeping_resume(void)
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timekeeper.ntp_error = 0;
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timekeeping_suspended = 0;
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timekeeping_update(false);
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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touch_softlockup_watchdog();
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@@ -718,7 +728,8 @@ static int timekeeping_suspend(void)
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read_persistent_clock(&timekeeping_suspend_time);
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- write_seqlock_irqsave(&xtime_lock, flags);
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+ raw_spin_lock_irqsave(&xtime_lock, flags);
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+ write_seqcount_begin(&xtime_seq);
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timekeeping_forward_now();
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timekeeping_suspended = 1;
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@@ -741,7 +752,8 @@ static int timekeeping_suspend(void)
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timekeeping_suspend_time =
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timespec_add(timekeeping_suspend_time, delta_delta);
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}
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- write_sequnlock_irqrestore(&xtime_lock, flags);
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+ write_seqcount_end(&xtime_seq);
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+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
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clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
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clocksource_suspend();
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@@ -1126,13 +1138,13 @@ void get_monotonic_boottime(struct times
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WARN_ON(timekeeping_suspended);
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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*ts = xtime;
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tomono = wall_to_monotonic;
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sleep = total_sleep_time;
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nsecs = timekeeping_get_ns();
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
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ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs);
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@@ -1183,10 +1195,10 @@ struct timespec current_kernel_time(void
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unsigned long seq;
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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now = xtime;
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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return now;
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}
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@@ -1198,11 +1210,11 @@ struct timespec get_monotonic_coarse(voi
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unsigned long seq;
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|
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do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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|
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now = xtime;
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mono = wall_to_monotonic;
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- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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|
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set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
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now.tv_nsec + mono.tv_nsec);
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@@ -1234,11 +1246,11 @@ void get_xtime_and_monotonic_and_sleep_o
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unsigned long seq;
|
|
|
|
do {
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- seq = read_seqbegin(&xtime_lock);
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+ seq = read_seqcount_begin(&xtime_seq);
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|
*xtim = xtime;
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*wtom = wall_to_monotonic;
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*sleep = total_sleep_time;
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|
- } while (read_seqretry(&xtime_lock, seq));
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+ } while (read_seqcount_retry(&xtime_seq, seq));
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|
}
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|
|
|
#ifdef CONFIG_HIGH_RES_TIMERS
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|
@@ -1284,9 +1296,9 @@ ktime_t ktime_get_monotonic_offset(void)
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|
struct timespec wtom;
|
|
|
|
do {
|
|
- seq = read_seqbegin(&xtime_lock);
|
|
+ seq = read_seqcount_begin(&xtime_seq);
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|
wtom = wall_to_monotonic;
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|
- } while (read_seqretry(&xtime_lock, seq));
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|
+ } while (read_seqcount_retry(&xtime_seq, seq));
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|
return timespec_to_ktime(wtom);
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|
}
|
|
|
|
@@ -1298,7 +1310,9 @@ ktime_t ktime_get_monotonic_offset(void)
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|
*/
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|
void xtime_update(unsigned long ticks)
|
|
{
|
|
- write_seqlock(&xtime_lock);
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|
+ raw_spin_lock(&xtime_lock);
|
|
+ write_seqcount_begin(&xtime_seq);
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|
do_timer(ticks);
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|
- write_sequnlock(&xtime_lock);
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|
+ write_seqcount_end(&xtime_seq);
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|
+ raw_spin_unlock(&xtime_lock);
|
|
}
|