The patch titled
GTOD: persistent clock support
has been added to the -mm tree. Its filename is
gtod-persistent-clock-support.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: GTOD: persistent clock support
From: John Stultz <johnstul@xxxxxxxxxx>
Persistent clock support: do proper timekeeping across suspend/resume.
[ cleanup from Adrian Bunk <bunk@xxxxxxxxx> ]
Signed-off-by: John Stultz <johnstul@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Cc: Roman Zippel <zippel@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/hrtimer.h | 3 +++
include/linux/time.h | 1 +
kernel/hrtimer.c | 8 ++++++++
kernel/timer.c | 37 ++++++++++++++++++++++++++++++++++++-
4 files changed, 48 insertions(+), 1 deletion(-)
diff -puN include/linux/hrtimer.h~gtod-persistent-clock-support include/linux/hrtimer.h
--- a/include/linux/hrtimer.h~gtod-persistent-clock-support
+++ a/include/linux/hrtimer.h
@@ -146,6 +146,9 @@ extern void hrtimer_init_sleeper(struct
/* Soft interrupt function to run the hrtimer queues: */
extern void hrtimer_run_queues(void);
+/* Resume notification */
+void hrtimer_notify_resume(void);
+
/* Bootup initialization: */
extern void __init hrtimers_init(void);
diff -puN include/linux/time.h~gtod-persistent-clock-support include/linux/time.h
--- a/include/linux/time.h~gtod-persistent-clock-support
+++ a/include/linux/time.h
@@ -92,6 +92,7 @@ extern struct timespec xtime;
extern struct timespec wall_to_monotonic;
extern seqlock_t xtime_lock __attribute__((weak));
+extern unsigned long read_persistent_clock(void);
void timekeeping_init(void);
static inline unsigned long get_seconds(void)
diff -puN kernel/hrtimer.c~gtod-persistent-clock-support kernel/hrtimer.c
--- a/kernel/hrtimer.c~gtod-persistent-clock-support
+++ a/kernel/hrtimer.c
@@ -292,6 +292,14 @@ static unsigned long ktime_divns(const k
#endif /* BITS_PER_LONG >= 64 */
/*
+ * Timekeeping resumed notification
+ */
+void hrtimer_notify_resume(void)
+{
+ clock_was_set();
+}
+
+/*
* Counterpart to lock_timer_base above:
*/
static inline
diff -puN kernel/timer.c~gtod-persistent-clock-support kernel/timer.c
--- a/kernel/timer.c~gtod-persistent-clock-support
+++ a/kernel/timer.c
@@ -878,12 +878,27 @@ int timekeeping_is_continuous(void)
return ret;
}
+/**
+ * read_persistent_clock - Return time in seconds from the persistent clock.
+ *
+ * Weak dummy function for arches that do not yet support it.
+ * Returns seconds from epoch using the battery backed persistent clock.
+ * Returns zero if unsupported.
+ *
+ * XXX - Do be sure to remove it once all arches implement it.
+ */
+unsigned long __attribute__((weak)) read_persistent_clock(void)
+{
+ return 0;
+}
+
/*
* timekeeping_init - Initializes the clocksource and common timekeeping values
*/
void __init timekeeping_init(void)
{
unsigned long flags;
+ unsigned long sec = read_persistent_clock();
write_seqlock_irqsave(&xtime_lock, flags);
@@ -893,11 +908,20 @@ void __init timekeeping_init(void)
clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
clock->cycle_last = clocksource_read(clock);
+ xtime.tv_sec = sec;
+ xtime.tv_nsec = 0;
+ set_normalized_timespec(&wall_to_monotonic,
+ -xtime.tv_sec, -xtime.tv_nsec);
+
write_sequnlock_irqrestore(&xtime_lock, flags);
}
+/* flag for if timekeeping is suspended */
static int timekeeping_suspended;
+/* time in seconds when suspend began */
+static unsigned long timekeeping_suspend_time;
+
/**
* timekeeping_resume - Resumes the generic timekeeping subsystem.
* @dev: unused
@@ -909,13 +933,23 @@ static int timekeeping_suspended;
static int timekeeping_resume(struct sys_device *dev)
{
unsigned long flags;
+ unsigned long now = read_persistent_clock();
write_seqlock_irqsave(&xtime_lock, flags);
- /* restart the last cycle value */
+
+ if (now && (now > timekeeping_suspend_time)) {
+ unsigned long sleep_length = now - timekeeping_suspend_time;
+ xtime.tv_sec += sleep_length;
+ jiffies_64 += (u64)sleep_length * HZ;
+ }
+ /* re-base the last cycle value */
clock->cycle_last = clocksource_read(clock);
clock->error = 0;
timekeeping_suspended = 0;
write_sequnlock_irqrestore(&xtime_lock, flags);
+
+ hrtimer_notify_resume();
+
return 0;
}
@@ -925,6 +959,7 @@ static int timekeeping_suspend(struct sy
write_seqlock_irqsave(&xtime_lock, flags);
timekeeping_suspended = 1;
+ timekeeping_suspend_time = read_persistent_clock();
write_sequnlock_irqrestore(&xtime_lock, flags);
return 0;
}
_
Patches currently in -mm which might be from johnstul@xxxxxxxxxx are
add-irq-flag-to-disable-balancing-for-an-interrupt.patch
add-a-functions-to-handle-interrupt-affinity-setting.patch
hz-free-ntp.patch
uninline-jiffiesh-functions.patch
fix-multiple-conversion-bugs-in-msecs_to_jiffies.patch
fix-timeout-overflow-with-jiffies.patch
gtod-persistent-clock-support.patch
i386-use-gtod-persistent-clock-support.patch
i386-remove-useless-code-in-tscc.patch
simplify-the-registration-of-clocksources.patch
x86-rewrite-smp-tsc-sync-code.patch
clocksource-replace-is_continuous-by-a-flag-field.patch
clocksource-replace-is_continuous-by-a-flag-field-fix.patch
clocksource-fixup-is_continous-changes-on-arm.patch
clocksource-fixup-is_continous-changes-on-avr32.patch
clocksource-fixup-is_continous-changes-on-s390.patch
clocksource-fixup-is_continous-changes-on-mips.patch
clocksource-remove-the-update-callback.patch
clocksource-add-verification-watchdog-helper.patch
clocksource-add-verification-watchdog-helper-fix.patch
mark-tsc-on-geodelx-reliable.patch
uninline-irq_enter.patch
fix-cascade-lookup-of-next_timer_interrupt.patch
extend-next_timer_interrupt-to-use-a-reference-jiffie.patch
hrtimers-namespace-and-enum-cleanup.patch
hrtimers-namespace-and-enum-cleanup-vs-git-input.patch
hrtimers-cleanup-locking.patch
hrtimers-add-state-tracking.patch
hrtimers-clean-up-callback-tracking.patch
hrtimers-move-and-add-documentation.patch
acpi-fix-missing-include-for-up.patch
acpi-keep-track-of-timer-broadcasting.patch
allow-early-access-to-the-power-management-timer.patch
i386-apic-clean-up-the-apic-code.patch
clockevents-add-core-functionality.patch
tick-management-core-functionality.patch
tick-management-broadcast-functionality.patch
tick-management-dyntick--highres-functionality.patch
clockevents-i383-drivers.patch
i386-rework-local-apic-timer-calibration.patch
i386-prepare-for-dyntick.patch
i386-prepare-nmi-watchdog-for-dynticks.patch
i386-enable-dynticks-in-kconfig.patch
hrtimers-add-high-resolution-timer-support.patch
hrtimers-prevent-possible-itimer-dos.patch
add-debugging-feature-proc-timer_stat.patch
add-debugging-feature-proc-timer_list.patch
add-sysrq-q-to-print-timer_list-debug-info.patch
generic-vsyscall-gtod-support-for-generic_time.patch
generic-vsyscall-gtod-support-for-generic_time-tidy.patch
time-x86_64-hpet_address-cleanup.patch
revert-x86_64-mm-ignore-long-smi-interrupts-in-clock-calibration.patch
time-x86_64-split-x86_64-kernel-timec-up.patch
time-x86_64-split-x86_64-kernel-timec-up-tidy.patch
time-x86_64-split-x86_64-kernel-timec-up-fix.patch
reapply-x86_64-mm-ignore-long-smi-interrupts-in-clock-calibration.patch
time-x86_64-convert-x86_64-to-use-generic_time.patch
time-x86_64-convert-x86_64-to-use-generic_time-fix.patch
time-x86_64-convert-x86_64-to-use-generic_time-tidy.patch
time-x86_64-re-enable-vsyscall-support-for-x86_64.patch
time-x86_64-re-enable-vsyscall-support-for-x86_64-tidy.patch
profile-likely-unlikely-macros-x86_64-fix.patch
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