[GIT PULL] timer changes for v3.9

From: Ingo Molnar
Date: Tue Feb 19 2013 - 09:47:14 EST

Linus,

Please pull the latest timers-core-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-core-for-linus

HEAD: 36dfbbf136db0d645bacfd42ce7d9d6928ea532d timers/x86/hpet: Use HPET_COUNTER to specify the hpet counter in vread_hpet()


Main changes:

* ntp: Add CONFIG_RTC_SYSTOHC: a generic RTC driver facility
complementing the existing CONFIG_RTC_HCTOSYS, which uses NTP
to keep the hardware clock updated.

* posix-timers: Fix clock_adjtime to always return timex data
on success. This is changing the ABI, but no breakage was
expected and found - caution is warranted nevertheless.

* platform persistent clock improvements/cleanups.

* clockevents: refactor timer broadcast handling to be more
generic and less duplicated with matching architecture code.
(mostly ARM motivated.)

* various fixes and cleanups

Thanks,

Ingo

------------------>
Bernd Faust (1):
Round the calculated scale factor in set_cyc2ns_scale()

Bjorn Helgaas (1):
x86/time/rtc: Don't print extended CMOS year when reading RTC

Feng Tang (3):
timekeeping: Add persistent_clock_exist flag
rtc: Skip the suspend/resume handling if persistent clock exist
timekeeping: Add CONFIG_HAS_PERSISTENT_CLOCK option

Jason Gunthorpe (1):
NTP: Add a CONFIG_RTC_SYSTOHC configuration

John Stultz (3):
MAINTAINERS: Update John Stultz's email
x86: Select HAS_PERSISTENT_CLOCK on x86
timekeeping: Switch HAS_PERSISTENT_CLOCK to ALWAYS_USE_PERSISTENT_CLOCK

Kees Cook (1):
time: create __getnstimeofday for WARNless calls

Leonid Shatz (1):
hrtimer: Prevent hrtimer_enqueue_reprogram race

Mark Rutland (3):
clockevents: Add generic timer broadcast receiver
clockevents: Add generic timer broadcast function
clockevents: Fix generic broadcast for FEAT_C3STOP

Miroslav Lichvar (1):
posix-timers: Fix clock_adjtime to always return timex data on success

Prarit Bhargava (1):
time, Fix setting of hardware clock in NTP code

Satoru Takeuchi (1):
timers/x86/hpet: Use HPET_COUNTER to specify the hpet counter in vread_hpet()

Stanislaw Gruszka (1):
posix-cpu-timers: Fix nanosleep task_struct leak


MAINTAINERS | 2 +-
arch/powerpc/kernel/time.c | 2 +-
arch/x86/Kconfig | 1 +
arch/x86/kernel/rtc.c | 1 -
arch/x86/kernel/tsc.c | 3 ++-
arch/x86/vdso/vclock_gettime.c | 2 +-
drivers/rtc/Kconfig | 12 ++++++++++-
drivers/rtc/Makefile | 1 +
drivers/rtc/class.c | 7 +++++++
drivers/rtc/systohc.c | 44 +++++++++++++++++++++++++++++++++++++++++
fs/pstore/ram.c | 10 +++++++---
include/linux/clockchips.h | 9 +++++++++
include/linux/rtc.h | 1 +
include/linux/time.h | 13 ++++++++++++
kernel/hrtimer.c | 36 ++++++++++++++++-----------------
kernel/posix-cpu-timers.c | 23 +++++++++++++++++++--
kernel/posix-timers.c | 2 +-
kernel/time.c | 8 ++++++++
kernel/time/Kconfig | 9 +++++++++
kernel/time/ntp.c | 22 ++++++++++++++++-----
kernel/time/tick-broadcast.c | 38 ++++++++++++++++++++++++++++++++++-
kernel/time/timekeeping.c | 45 ++++++++++++++++++++++++++++++++----------
22 files changed, 245 insertions(+), 46 deletions(-)
create mode 100644 drivers/rtc/systohc.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 212c255..f5bda78 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6598,7 +6598,7 @@ F: drivers/dma/dw_dmac_regs.h
F: drivers/dma/dw_dmac.c

TIMEKEEPING, NTP
-M: John Stultz <johnstul@xxxxxxxxxx>
+M: John Stultz <john.stultz@xxxxxxxxxx>
M: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core
S: Supported
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 127361e..aaba2e0 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -668,7 +668,7 @@ int update_persistent_clock(struct timespec now)
struct rtc_time tm;

if (!ppc_md.set_rtc_time)
- return 0;
+ return -ENODEV;

to_tm(now.tv_sec + 1 + timezone_offset, &tm);
tm.tm_year -= 1900;
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 225543b..97b023f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -106,6 +106,7 @@ config X86
select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
select GENERIC_TIME_VSYSCALL if X86_64
select KTIME_SCALAR if X86_32
+ select ALWAYS_USE_PERSISTENT_CLOCK
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select HAVE_CONTEXT_TRACKING if X86_64
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 801602b..2e8f3d3 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -149,7 +149,6 @@ unsigned long mach_get_cmos_time(void)
if (century) {
century = bcd2bin(century);
year += century * 100;
- printk(KERN_INFO "Extended CMOS year: %d\n", century * 100);
} else
year += CMOS_YEARS_OFFS;

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 06ccb50..4b9ea10 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -623,7 +623,8 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
ns_now = __cycles_2_ns(tsc_now);

if (cpu_khz) {
- *scale = (NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR)/cpu_khz;
+ *scale = ((NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR) +
+ cpu_khz / 2) / cpu_khz;
*offset = ns_now - mult_frac(tsc_now, *scale,
(1UL << CYC2NS_SCALE_FACTOR));
}
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 205ad32..c74436e 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -60,7 +60,7 @@ notrace static cycle_t vread_tsc(void)

static notrace cycle_t vread_hpet(void)
{
- return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
+ return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + HPET_COUNTER);
}

#ifdef CONFIG_PARAVIRT_CLOCK
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 923a9da..5e44eaa 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -20,14 +20,24 @@ if RTC_CLASS
config RTC_HCTOSYS
bool "Set system time from RTC on startup and resume"
default y
+ depends on !ALWAYS_USE_PERSISTENT_CLOCK
help
If you say yes here, the system time (wall clock) will be set using
the value read from a specified RTC device. This is useful to avoid
unnecessary fsck runs at boot time, and to network better.

+config RTC_SYSTOHC
+ bool "Set the RTC time based on NTP synchronization"
+ default y
+ depends on !ALWAYS_USE_PERSISTENT_CLOCK
+ help
+ If you say yes here, the system time (wall clock) will be stored
+ in the RTC specified by RTC_HCTOSYS_DEVICE approximately every 11
+ minutes if userspace reports synchronized NTP status.
+
config RTC_HCTOSYS_DEVICE
string "RTC used to set the system time"
- depends on RTC_HCTOSYS = y
+ depends on RTC_HCTOSYS = y || RTC_SYSTOHC = y
default "rtc0"
help
The RTC device that will be used to (re)initialize the system
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 4418ef3..ec2988b 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -6,6 +6,7 @@ ccflags-$(CONFIG_RTC_DEBUG) := -DDEBUG

obj-$(CONFIG_RTC_LIB) += rtc-lib.o
obj-$(CONFIG_RTC_HCTOSYS) += hctosys.o
+obj-$(CONFIG_RTC_SYSTOHC) += systohc.o
obj-$(CONFIG_RTC_CLASS) += rtc-core.o
rtc-core-y := class.o interface.o

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 5143629..26388f1 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -50,6 +50,10 @@ static int rtc_suspend(struct device *dev, pm_message_t mesg)
struct rtc_device *rtc = to_rtc_device(dev);
struct rtc_time tm;
struct timespec delta, delta_delta;
+
+ if (has_persistent_clock())
+ return 0;
+
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;

@@ -88,6 +92,9 @@ static int rtc_resume(struct device *dev)
struct timespec new_system, new_rtc;
struct timespec sleep_time;

+ if (has_persistent_clock())
+ return 0;
+
rtc_hctosys_ret = -ENODEV;
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c
new file mode 100644
index 0000000..bf3e242
--- /dev/null
+++ b/drivers/rtc/systohc.c
@@ -0,0 +1,44 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ */
+#include <linux/rtc.h>
+#include <linux/time.h>
+
+/**
+ * rtc_set_ntp_time - Save NTP synchronized time to the RTC
+ * @now: Current time of day
+ *
+ * Replacement for the NTP platform function update_persistent_clock
+ * that stores time for later retrieval by rtc_hctosys.
+ *
+ * Returns 0 on successful RTC update, -ENODEV if a RTC update is not
+ * possible at all, and various other -errno for specific temporary failure
+ * cases.
+ *
+ * If temporary failure is indicated the caller should try again 'soon'
+ */
+int rtc_set_ntp_time(struct timespec now)
+{
+ struct rtc_device *rtc;
+ struct rtc_time tm;
+ int err = -ENODEV;
+
+ if (now.tv_nsec < (NSEC_PER_SEC >> 1))
+ rtc_time_to_tm(now.tv_sec, &tm);
+ else
+ rtc_time_to_tm(now.tv_sec + 1, &tm);
+
+ rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
+ if (rtc) {
+ /* rtc_hctosys exclusively uses UTC, so we call set_time here,
+ * not set_mmss. */
+ if (rtc->ops && (rtc->ops->set_time || rtc->ops->set_mmss))
+ err = rtc_set_time(rtc, &tm);
+ rtc_class_close(rtc);
+ }
+
+ return err;
+}
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 7003e52..288f068 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -167,12 +167,16 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
{
char *hdr;
- struct timeval timestamp;
+ struct timespec timestamp;
size_t len;

- do_gettimeofday(&timestamp);
+ /* Report zeroed timestamp if called before timekeeping has resumed. */
+ if (__getnstimeofday(&timestamp)) {
+ timestamp.tv_sec = 0;
+ timestamp.tv_nsec = 0;
+ }
hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
- (long)timestamp.tv_sec, (long)timestamp.tv_usec);
+ (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000));
WARN_ON_ONCE(!hdr);
len = hdr ? strlen(hdr) : 0;
persistent_ram_write(prz, hdr, len);
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index 8a7096f..6634652 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -161,6 +161,15 @@ clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
extern void clockevents_suspend(void);
extern void clockevents_resume(void);

+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+#ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
+extern void tick_broadcast(const struct cpumask *mask);
+#else
+#define tick_broadcast NULL
+#endif
+extern int tick_receive_broadcast(void);
+#endif
+
#ifdef CONFIG_GENERIC_CLOCKEVENTS
extern void clockevents_notify(unsigned long reason, void *arg);
#else
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 9531845..11d05f9 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -138,6 +138,7 @@ extern void rtc_device_unregister(struct rtc_device *rtc);
extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs);
+extern int rtc_set_ntp_time(struct timespec now);
int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
extern int rtc_read_alarm(struct rtc_device *rtc,
struct rtc_wkalrm *alrm);
diff --git a/include/linux/time.h b/include/linux/time.h
index 4d358e9..a3ab6a8 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -115,8 +115,20 @@ static inline bool timespec_valid_strict(const struct timespec *ts)
return true;
}

+extern bool persistent_clock_exist;
+
+#ifdef ALWAYS_USE_PERSISTENT_CLOCK
+#define has_persistent_clock() true
+#else
+static inline bool has_persistent_clock(void)
+{
+ return persistent_clock_exist;
+}
+#endif
+
extern void read_persistent_clock(struct timespec *ts);
extern void read_boot_clock(struct timespec *ts);
+extern int persistent_clock_is_local;
extern int update_persistent_clock(struct timespec now);
void timekeeping_init(void);
extern int timekeeping_suspended;
@@ -158,6 +170,7 @@ extern int do_setitimer(int which, struct itimerval *value,
struct itimerval *ovalue);
extern unsigned int alarm_setitimer(unsigned int seconds);
extern int do_getitimer(int which, struct itimerval *value);
+extern int __getnstimeofday(struct timespec *tv);
extern void getnstimeofday(struct timespec *tv);
extern void getrawmonotonic(struct timespec *ts);
extern void getnstime_raw_and_real(struct timespec *ts_raw,
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 6db7a5e..cdd5607 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -640,21 +640,9 @@ static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
* and expiry check is done in the hrtimer_interrupt or in the softirq.
*/
static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
- struct hrtimer_clock_base *base,
- int wakeup)
+ struct hrtimer_clock_base *base)
{
- if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
- if (wakeup) {
- raw_spin_unlock(&base->cpu_base->lock);
- raise_softirq_irqoff(HRTIMER_SOFTIRQ);
- raw_spin_lock(&base->cpu_base->lock);
- } else
- __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
-
- return 1;
- }
-
- return 0;
+ return base->cpu_base->hres_active && hrtimer_reprogram(timer, base);
}

static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
@@ -735,8 +723,7 @@ static inline int hrtimer_switch_to_hres(void) { return 0; }
static inline void
hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
- struct hrtimer_clock_base *base,
- int wakeup)
+ struct hrtimer_clock_base *base)
{
return 0;
}
@@ -995,8 +982,21 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
*
* XXX send_remote_softirq() ?
*/
- if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases))
- hrtimer_enqueue_reprogram(timer, new_base, wakeup);
+ if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)
+ && hrtimer_enqueue_reprogram(timer, new_base)) {
+ if (wakeup) {
+ /*
+ * We need to drop cpu_base->lock to avoid a
+ * lock ordering issue vs. rq->lock.
+ */
+ raw_spin_unlock(&new_base->cpu_base->lock);
+ raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+ local_irq_restore(flags);
+ return ret;
+ } else {
+ __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+ }
+ }

unlock_hrtimer_base(timer, &flags);

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index a278cad..942ca27 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1401,8 +1401,10 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
while (!signal_pending(current)) {
if (timer.it.cpu.expires.sched == 0) {
/*
- * Our timer fired and was reset.
+ * Our timer fired and was reset, below
+ * deletion can not fail.
*/
+ posix_cpu_timer_del(&timer);
spin_unlock_irq(&timer.it_lock);
return 0;
}
@@ -1420,9 +1422,26 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
* We were interrupted by a signal.
*/
sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
- posix_cpu_timer_set(&timer, 0, &zero_it, it);
+ error = posix_cpu_timer_set(&timer, 0, &zero_it, it);
+ if (!error) {
+ /*
+ * Timer is now unarmed, deletion can not fail.
+ */
+ posix_cpu_timer_del(&timer);
+ }
spin_unlock_irq(&timer.it_lock);

+ while (error == TIMER_RETRY) {
+ /*
+ * We need to handle case when timer was or is in the
+ * middle of firing. In other cases we already freed
+ * resources.
+ */
+ spin_lock_irq(&timer.it_lock);
+ error = posix_cpu_timer_del(&timer);
+ spin_unlock_irq(&timer.it_lock);
+ }
+
if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
/*
* It actually did fire already.
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 69185ae..10349d5 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -997,7 +997,7 @@ SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,

err = kc->clock_adj(which_clock, &ktx);

- if (!err && copy_to_user(utx, &ktx, sizeof(ktx)))
+ if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
return -EFAULT;

return err;
diff --git a/kernel/time.c b/kernel/time.c
index d226c6a..c2a27dd 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -115,6 +115,12 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv,
}

/*
+ * Indicates if there is an offset between the system clock and the hardware
+ * clock/persistent clock/rtc.
+ */
+int persistent_clock_is_local;
+
+/*
* Adjust the time obtained from the CMOS to be UTC time instead of
* local time.
*
@@ -135,6 +141,8 @@ static inline void warp_clock(void)
struct timespec adjust;

adjust = current_kernel_time();
+ if (sys_tz.tz_minuteswest != 0)
+ persistent_clock_is_local = 1;
adjust.tv_sec += sys_tz.tz_minuteswest * 60;
do_settimeofday(&adjust);
}
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 8601f0d..24510d8 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -12,6 +12,11 @@ config CLOCKSOURCE_WATCHDOG
config ARCH_CLOCKSOURCE_DATA
bool

+# Platforms has a persistent clock
+config ALWAYS_USE_PERSISTENT_CLOCK
+ bool
+ default n
+
# Timekeeping vsyscall support
config GENERIC_TIME_VSYSCALL
bool
@@ -38,6 +43,10 @@ config GENERIC_CLOCKEVENTS_BUILD
default y
depends on GENERIC_CLOCKEVENTS

+# Architecture can handle broadcast in a driver-agnostic way
+config ARCH_HAS_TICK_BROADCAST
+ bool
+
# Clockevents broadcasting infrastructure
config GENERIC_CLOCKEVENTS_BROADCAST
bool
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 24174b4..b10a42b 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -15,6 +15,7 @@
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/rtc.h>

#include "tick-internal.h"

@@ -483,8 +484,7 @@ out:
return leap;
}

-#ifdef CONFIG_GENERIC_CMOS_UPDATE
-
+#if defined(CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC)
static void sync_cmos_clock(struct work_struct *work);

static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
@@ -510,14 +510,26 @@ static void sync_cmos_clock(struct work_struct *work)
}

getnstimeofday(&now);
- if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
- fail = update_persistent_clock(now);
+ if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) {
+ struct timespec adjust = now;
+
+ fail = -ENODEV;
+ if (persistent_clock_is_local)
+ adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);
+#ifdef CONFIG_GENERIC_CMOS_UPDATE
+ fail = update_persistent_clock(adjust);
+#endif
+#ifdef CONFIG_RTC_SYSTOHC
+ if (fail == -ENODEV)
+ fail = rtc_set_ntp_time(adjust);
+#endif
+ }

next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2);
if (next.tv_nsec <= 0)
next.tv_nsec += NSEC_PER_SEC;

- if (!fail)
+ if (!fail || fail == -ENODEV)
next.tv_sec = 659;
else
next.tv_sec = 0;
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index f113755..2fb8cb8 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -18,6 +18,7 @@
#include <linux/percpu.h>
#include <linux/profile.h>
#include <linux/sched.h>
+#include <linux/smp.h>

#include "tick-internal.h"

@@ -86,6 +87,22 @@ int tick_is_broadcast_device(struct clock_event_device *dev)
return (dev && tick_broadcast_device.evtdev == dev);
}

+static void err_broadcast(const struct cpumask *mask)
+{
+ pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n");
+}
+
+static void tick_device_setup_broadcast_func(struct clock_event_device *dev)
+{
+ if (!dev->broadcast)
+ dev->broadcast = tick_broadcast;
+ if (!dev->broadcast) {
+ pr_warn_once("%s depends on broadcast, but no broadcast function available\n",
+ dev->name);
+ dev->broadcast = err_broadcast;
+ }
+}
+
/*
* Check, if the device is disfunctional and a place holder, which
* needs to be handled by the broadcast device.
@@ -105,6 +122,7 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
*/
if (!tick_device_is_functional(dev)) {
dev->event_handler = tick_handle_periodic;
+ tick_device_setup_broadcast_func(dev);
cpumask_set_cpu(cpu, tick_get_broadcast_mask());
tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
ret = 1;
@@ -116,15 +134,33 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
*/
if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) {
int cpu = smp_processor_id();
-
cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
tick_broadcast_clear_oneshot(cpu);
+ } else {
+ tick_device_setup_broadcast_func(dev);
}
}
raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
return ret;
}

+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+int tick_receive_broadcast(void)
+{
+ struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
+ struct clock_event_device *evt = td->evtdev;
+
+ if (!evt)
+ return -ENODEV;
+
+ if (!evt->event_handler)
+ return -EINVAL;
+
+ evt->event_handler(evt);
+ return 0;
+}
+#endif
+
/*
* Broadcast the event to the cpus, which are set in the mask (mangled).
*/
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cbc6acb..1e35515 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -29,6 +29,9 @@ static struct timekeeper timekeeper;
/* flag for if timekeeping is suspended */
int __read_mostly timekeeping_suspended;

+/* Flag for if there is a persistent clock on this platform */
+bool __read_mostly persistent_clock_exist = false;
+
static inline void tk_normalize_xtime(struct timekeeper *tk)
{
while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
@@ -264,19 +267,18 @@ static void timekeeping_forward_now(struct timekeeper *tk)
}

/**
- * getnstimeofday - Returns the time of day in a timespec
+ * __getnstimeofday - Returns the time of day in a timespec.
* @ts: pointer to the timespec to be set
*
- * Returns the time of day in a timespec.
+ * Updates the time of day in the timespec.
+ * Returns 0 on success, or -ve when suspended (timespec will be undefined).
*/
-void getnstimeofday(struct timespec *ts)
+int __getnstimeofday(struct timespec *ts)
{
struct timekeeper *tk = &timekeeper;
unsigned long seq;
s64 nsecs = 0;

- WARN_ON(timekeeping_suspended);
-
do {
seq = read_seqbegin(&tk->lock);

@@ -287,6 +289,26 @@ void getnstimeofday(struct timespec *ts)

ts->tv_nsec = 0;
timespec_add_ns(ts, nsecs);
+
+ /*
+ * Do not bail out early, in case there were callers still using
+ * the value, even in the face of the WARN_ON.
+ */
+ if (unlikely(timekeeping_suspended))
+ return -EAGAIN;
+ return 0;
+}
+EXPORT_SYMBOL(__getnstimeofday);
+
+/**
+ * getnstimeofday - Returns the time of day in a timespec.
+ * @ts: pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec (WARN if suspended).
+ */
+void getnstimeofday(struct timespec *ts)
+{
+ WARN_ON(__getnstimeofday(ts));
}
EXPORT_SYMBOL(getnstimeofday);

@@ -640,12 +662,14 @@ void __init timekeeping_init(void)
struct timespec now, boot, tmp;

read_persistent_clock(&now);
+
if (!timespec_valid_strict(&now)) {
pr_warn("WARNING: Persistent clock returned invalid value!\n"
" Check your CMOS/BIOS settings.\n");
now.tv_sec = 0;
now.tv_nsec = 0;
- }
+ } else if (now.tv_sec || now.tv_nsec)
+ persistent_clock_exist = true;

read_boot_clock(&boot);
if (!timespec_valid_strict(&boot)) {
@@ -718,11 +742,12 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
{
struct timekeeper *tk = &timekeeper;
unsigned long flags;
- struct timespec ts;

- /* Make sure we don't set the clock twice */
- read_persistent_clock(&ts);
- if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
+ /*
+ * Make sure we don't set the clock twice, as timekeeping_resume()
+ * already did it
+ */
+ if (has_persistent_clock())
return;

write_seqlock_irqsave(&tk->lock, flags);
--
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