[GIT pull] Timer updates for 3.4

From: Thomas Gleixner
Date: Thu Mar 29 2012 - 15:04:15 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

Thanks,

tglx

------------------>
Alok Kataria (1):
x86, tsc: Skip refined tsc calibration on systems with reliable TSC

Andy Lutomirski (2):
x86-64: Simplify and optimize vdso clock_gettime monotonic variants
x86-64: Inline vdso clock_gettime helpers

Cesar Eduardo Barros (1):
time: remove no_sync_cmos_clock

Jim Cromie (1):
kernel-time: fix s/then/than/ spelling errors

John Stultz (6):
time: x86: Fix race switching from vsyscall to non-vsyscall clock
time: Fix change_clocksource locking
rtc: Provide flag for rtc devices that don't support UIE
ntp: Fix leap-second hrtimer livelock
alarmtimer: Make sure we initialize the rtctimer
time: Avoid scary backtraces when warning of > 11% adj

Thomas Gleixner (7):
time: Remove bogus comments
x86: vdso: Remove bogus locking in update_vsyscall_tz()
x86: vdso: Use seqcount instead of seqlock
ia64: vsyscall: Use seqcount instead of seqlock
x86: vdso: Put declaration before code
alarmtimer: Don't call rtc_timer_init() when CONFIG_RTC_CLASS=n
ia64: vsyscall: Add missing paranthesis


arch/ia64/kernel/asm-offsets.c | 4 +-
arch/ia64/kernel/fsys.S | 2 +-
arch/ia64/kernel/fsyscall_gtod_data.h | 2 +-
arch/ia64/kernel/time.c | 10 +--
arch/x86/include/asm/vgtod.h | 17 +++--
arch/x86/kernel/tsc.c | 10 +++
arch/x86/kernel/vsyscall_64.c | 25 +++---
arch/x86/vdso/vclock_gettime.c | 135 ++++++++++++++++-----------------
drivers/rtc/interface.c | 5 +
drivers/rtc/rtc-mpc5121.c | 2 +
include/linux/rtc.h | 3 +-
include/linux/time.h | 1 -
include/linux/timex.h | 2 +-
kernel/time.c | 6 --
kernel/time/alarmtimer.c | 8 ++
kernel/time/clocksource.c | 2 +-
kernel/time/ntp.c | 134 ++++++++++----------------------
kernel/time/timekeeping.c | 51 ++++++------
18 files changed, 193 insertions(+), 226 deletions(-)

diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c
index af56501..a48bd9a 100644
--- a/arch/ia64/kernel/asm-offsets.c
+++ b/arch/ia64/kernel/asm-offsets.c
@@ -269,8 +269,8 @@ void foo(void)
BLANK();

/* used by fsys_gettimeofday in arch/ia64/kernel/fsys.S */
- DEFINE(IA64_GTOD_LOCK_OFFSET,
- offsetof (struct fsyscall_gtod_data_t, lock));
+ DEFINE(IA64_GTOD_SEQ_OFFSET,
+ offsetof (struct fsyscall_gtod_data_t, seq));
DEFINE(IA64_GTOD_WALL_TIME_OFFSET,
offsetof (struct fsyscall_gtod_data_t, wall_time));
DEFINE(IA64_GTOD_MONO_TIME_OFFSET,
diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S
index 331d42b..fa77de7 100644
--- a/arch/ia64/kernel/fsys.S
+++ b/arch/ia64/kernel/fsys.S
@@ -174,7 +174,7 @@ ENTRY(fsys_set_tid_address)
FSYS_RETURN
END(fsys_set_tid_address)

-#if IA64_GTOD_LOCK_OFFSET !=0
+#if IA64_GTOD_SEQ_OFFSET !=0
#error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t
#endif
#if IA64_ITC_JITTER_OFFSET !=0
diff --git a/arch/ia64/kernel/fsyscall_gtod_data.h b/arch/ia64/kernel/fsyscall_gtod_data.h
index 57d2ee6..146b15b 100644
--- a/arch/ia64/kernel/fsyscall_gtod_data.h
+++ b/arch/ia64/kernel/fsyscall_gtod_data.h
@@ -6,7 +6,7 @@
*/

struct fsyscall_gtod_data_t {
- seqlock_t lock;
+ seqcount_t seq;
struct timespec wall_time;
struct timespec monotonic_time;
cycle_t clk_mask;
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 43920de..8e991a0 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -35,9 +35,7 @@

static cycle_t itc_get_cycles(struct clocksource *cs);

-struct fsyscall_gtod_data_t fsyscall_gtod_data = {
- .lock = __SEQLOCK_UNLOCKED(fsyscall_gtod_data.lock),
-};
+struct fsyscall_gtod_data_t fsyscall_gtod_data;

struct itc_jitter_data_t itc_jitter_data;

@@ -460,9 +458,7 @@ void update_vsyscall_tz(void)
void update_vsyscall(struct timespec *wall, struct timespec *wtm,
struct clocksource *c, u32 mult)
{
- unsigned long flags;
-
- write_seqlock_irqsave(&fsyscall_gtod_data.lock, flags);
+ write_seqcount_begin(&fsyscall_gtod_data.seq);

/* copy fsyscall clock data */
fsyscall_gtod_data.clk_mask = c->mask;
@@ -485,6 +481,6 @@ void update_vsyscall(struct timespec *wall, struct timespec *wtm,
fsyscall_gtod_data.monotonic_time.tv_sec++;
}

- write_sequnlock_irqrestore(&fsyscall_gtod_data.lock, flags);
+ write_seqcount_end(&fsyscall_gtod_data.seq);
}

diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h
index 815285b..8b38be2 100644
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -5,13 +5,8 @@
#include <linux/clocksource.h>

struct vsyscall_gtod_data {
- seqlock_t lock;
+ seqcount_t seq;

- /* open coded 'struct timespec' */
- time_t wall_time_sec;
- u32 wall_time_nsec;
-
- struct timezone sys_tz;
struct { /* extract of a clocksource struct */
int vclock_mode;
cycle_t cycle_last;
@@ -19,8 +14,16 @@ struct vsyscall_gtod_data {
u32 mult;
u32 shift;
} clock;
- struct timespec wall_to_monotonic;
+
+ /* open coded 'struct timespec' */
+ time_t wall_time_sec;
+ u32 wall_time_nsec;
+ u32 monotonic_time_nsec;
+ time_t monotonic_time_sec;
+
+ struct timezone sys_tz;
struct timespec wall_time_coarse;
+ struct timespec monotonic_time_coarse;
};
extern struct vsyscall_gtod_data vsyscall_gtod_data;

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index a62c201..6fcfcb3 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -932,6 +932,16 @@ static int __init init_tsc_clocksource(void)
clocksource_tsc.rating = 0;
clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
}
+
+ /*
+ * Trust the results of the earlier calibration on systems
+ * exporting a reliable TSC.
+ */
+ if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) {
+ clocksource_register_khz(&clocksource_tsc, tsc_khz);
+ return 0;
+ }
+
schedule_delayed_work(&tsc_irqwork, 0);
return 0;
}
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index b07ba93..d5c6986 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -52,10 +52,7 @@
#include "vsyscall_trace.h"

DEFINE_VVAR(int, vgetcpu_mode);
-DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data) =
-{
- .lock = __SEQLOCK_UNLOCKED(__vsyscall_gtod_data.lock),
-};
+DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data);

static enum { EMULATE, NATIVE, NONE } vsyscall_mode = EMULATE;

@@ -80,20 +77,15 @@ early_param("vsyscall", vsyscall_setup);

void update_vsyscall_tz(void)
{
- unsigned long flags;
-
- write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags);
- /* sys_tz has changed */
vsyscall_gtod_data.sys_tz = sys_tz;
- write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
}

void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
struct clocksource *clock, u32 mult)
{
- unsigned long flags;
+ struct timespec monotonic;

- write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags);
+ write_seqcount_begin(&vsyscall_gtod_data.seq);

/* copy vsyscall data */
vsyscall_gtod_data.clock.vclock_mode = clock->archdata.vclock_mode;
@@ -101,12 +93,19 @@ void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
vsyscall_gtod_data.clock.mask = clock->mask;
vsyscall_gtod_data.clock.mult = mult;
vsyscall_gtod_data.clock.shift = clock->shift;
+
vsyscall_gtod_data.wall_time_sec = wall_time->tv_sec;
vsyscall_gtod_data.wall_time_nsec = wall_time->tv_nsec;
- vsyscall_gtod_data.wall_to_monotonic = *wtm;
+
+ monotonic = timespec_add(*wall_time, *wtm);
+ vsyscall_gtod_data.monotonic_time_sec = monotonic.tv_sec;
+ vsyscall_gtod_data.monotonic_time_nsec = monotonic.tv_nsec;
+
vsyscall_gtod_data.wall_time_coarse = __current_kernel_time();
+ vsyscall_gtod_data.monotonic_time_coarse =
+ timespec_add(vsyscall_gtod_data.wall_time_coarse, *wtm);

- write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
+ write_seqcount_end(&vsyscall_gtod_data.seq);
}

static void warn_bad_vsyscall(const char *level, struct pt_regs *regs,
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 6bc0e72..885eff4 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -70,100 +70,98 @@ notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
return ret;
}

+notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
+{
+ long ret;
+
+ asm("syscall" : "=a" (ret) :
+ "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
+ return ret;
+}
+
+
notrace static inline long vgetns(void)
{
long v;
cycles_t cycles;
if (gtod->clock.vclock_mode == VCLOCK_TSC)
cycles = vread_tsc();
- else
+ else if (gtod->clock.vclock_mode == VCLOCK_HPET)
cycles = vread_hpet();
+ else
+ return 0;
v = (cycles - gtod->clock.cycle_last) & gtod->clock.mask;
return (v * gtod->clock.mult) >> gtod->clock.shift;
}

-notrace static noinline int do_realtime(struct timespec *ts)
+/* Code size doesn't matter (vdso is 4k anyway) and this is faster. */
+notrace static int __always_inline do_realtime(struct timespec *ts)
{
unsigned long seq, ns;
+ int mode;
+
do {
- seq = read_seqbegin(&gtod->lock);
+ seq = read_seqcount_begin(&gtod->seq);
+ mode = gtod->clock.vclock_mode;
ts->tv_sec = gtod->wall_time_sec;
ts->tv_nsec = gtod->wall_time_nsec;
ns = vgetns();
- } while (unlikely(read_seqretry(&gtod->lock, seq)));
+ } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
+
timespec_add_ns(ts, ns);
- return 0;
+ return mode;
}

-notrace static noinline int do_monotonic(struct timespec *ts)
+notrace static int do_monotonic(struct timespec *ts)
{
- unsigned long seq, ns, secs;
+ unsigned long seq, ns;
+ int mode;
+
do {
- seq = read_seqbegin(&gtod->lock);
- secs = gtod->wall_time_sec;
- ns = gtod->wall_time_nsec + vgetns();
- secs += gtod->wall_to_monotonic.tv_sec;
- ns += gtod->wall_to_monotonic.tv_nsec;
- } while (unlikely(read_seqretry(&gtod->lock, seq)));
-
- /* wall_time_nsec, vgetns(), and wall_to_monotonic.tv_nsec
- * are all guaranteed to be nonnegative.
- */
- while (ns >= NSEC_PER_SEC) {
- ns -= NSEC_PER_SEC;
- ++secs;
- }
- ts->tv_sec = secs;
- ts->tv_nsec = ns;
+ seq = read_seqcount_begin(&gtod->seq);
+ mode = gtod->clock.vclock_mode;
+ ts->tv_sec = gtod->monotonic_time_sec;
+ ts->tv_nsec = gtod->monotonic_time_nsec;
+ ns = vgetns();
+ } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
+ timespec_add_ns(ts, ns);

- return 0;
+ return mode;
}

-notrace static noinline int do_realtime_coarse(struct timespec *ts)
+notrace static int do_realtime_coarse(struct timespec *ts)
{
unsigned long seq;
do {
- seq = read_seqbegin(&gtod->lock);
+ seq = read_seqcount_begin(&gtod->seq);
ts->tv_sec = gtod->wall_time_coarse.tv_sec;
ts->tv_nsec = gtod->wall_time_coarse.tv_nsec;
- } while (unlikely(read_seqretry(&gtod->lock, seq)));
+ } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
return 0;
}

-notrace static noinline int do_monotonic_coarse(struct timespec *ts)
+notrace static int do_monotonic_coarse(struct timespec *ts)
{
- unsigned long seq, ns, secs;
+ unsigned long seq;
do {
- seq = read_seqbegin(&gtod->lock);
- secs = gtod->wall_time_coarse.tv_sec;
- ns = gtod->wall_time_coarse.tv_nsec;
- secs += gtod->wall_to_monotonic.tv_sec;
- ns += gtod->wall_to_monotonic.tv_nsec;
- } while (unlikely(read_seqretry(&gtod->lock, seq)));
-
- /* wall_time_nsec and wall_to_monotonic.tv_nsec are
- * guaranteed to be between 0 and NSEC_PER_SEC.
- */
- if (ns >= NSEC_PER_SEC) {
- ns -= NSEC_PER_SEC;
- ++secs;
- }
- ts->tv_sec = secs;
- ts->tv_nsec = ns;
+ seq = read_seqcount_begin(&gtod->seq);
+ ts->tv_sec = gtod->monotonic_time_coarse.tv_sec;
+ ts->tv_nsec = gtod->monotonic_time_coarse.tv_nsec;
+ } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));

return 0;
}

notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
{
+ int ret = VCLOCK_NONE;
+
switch (clock) {
case CLOCK_REALTIME:
- if (likely(gtod->clock.vclock_mode != VCLOCK_NONE))
- return do_realtime(ts);
+ ret = do_realtime(ts);
break;
case CLOCK_MONOTONIC:
- if (likely(gtod->clock.vclock_mode != VCLOCK_NONE))
- return do_monotonic(ts);
+ ret = do_monotonic(ts);
break;
case CLOCK_REALTIME_COARSE:
return do_realtime_coarse(ts);
@@ -171,32 +169,33 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
return do_monotonic_coarse(ts);
}

- return vdso_fallback_gettime(clock, ts);
+ if (ret == VCLOCK_NONE)
+ return vdso_fallback_gettime(clock, ts);
+ return 0;
}
int clock_gettime(clockid_t, struct timespec *)
__attribute__((weak, alias("__vdso_clock_gettime")));

notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
{
- long ret;
- if (likely(gtod->clock.vclock_mode != VCLOCK_NONE)) {
- if (likely(tv != NULL)) {
- BUILD_BUG_ON(offsetof(struct timeval, tv_usec) !=
- offsetof(struct timespec, tv_nsec) ||
- sizeof(*tv) != sizeof(struct timespec));
- do_realtime((struct timespec *)tv);
- tv->tv_usec /= 1000;
- }
- if (unlikely(tz != NULL)) {
- /* Avoid memcpy. Some old compilers fail to inline it */
- tz->tz_minuteswest = gtod->sys_tz.tz_minuteswest;
- tz->tz_dsttime = gtod->sys_tz.tz_dsttime;
- }
- return 0;
+ long ret = VCLOCK_NONE;
+
+ if (likely(tv != NULL)) {
+ BUILD_BUG_ON(offsetof(struct timeval, tv_usec) !=
+ offsetof(struct timespec, tv_nsec) ||
+ sizeof(*tv) != sizeof(struct timespec));
+ ret = do_realtime((struct timespec *)tv);
+ tv->tv_usec /= 1000;
}
- asm("syscall" : "=a" (ret) :
- "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
- return ret;
+ if (unlikely(tz != NULL)) {
+ /* Avoid memcpy. Some old compilers fail to inline it */
+ tz->tz_minuteswest = gtod->sys_tz.tz_minuteswest;
+ tz->tz_dsttime = gtod->sys_tz.tz_dsttime;
+ }
+
+ if (ret == VCLOCK_NONE)
+ return vdso_fallback_gtod(tv, tz);
+ return 0;
}
int gettimeofday(struct timeval *, struct timezone *)
__attribute__((weak, alias("__vdso_gettimeofday")));
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index dc87eda..eb415bd 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -458,6 +458,11 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
if (rtc->uie_rtctimer.enabled == enabled)
goto out;

+ if (rtc->uie_unsupported) {
+ err = -EINVAL;
+ goto out;
+ }
+
if (enabled) {
struct rtc_time tm;
ktime_t now, onesec;
diff --git a/drivers/rtc/rtc-mpc5121.c b/drivers/rtc/rtc-mpc5121.c
index 9d3cacc..613447a 100644
--- a/drivers/rtc/rtc-mpc5121.c
+++ b/drivers/rtc/rtc-mpc5121.c
@@ -360,6 +360,8 @@ static int __devinit mpc5121_rtc_probe(struct platform_device *op)
&mpc5200_rtc_ops, THIS_MODULE);
}

+ rtc->rtc->uie_unsupported = 1;
+
if (IS_ERR(rtc->rtc)) {
err = PTR_ERR(rtc->rtc);
goto out_free_irq;
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 93f4d03..fcabfb4 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -202,7 +202,8 @@ struct rtc_device
struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
int pie_enabled;
struct work_struct irqwork;
-
+ /* Some hardware can't support UIE mode */
+ int uie_unsupported;

#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
struct work_struct uie_task;
diff --git a/include/linux/time.h b/include/linux/time.h
index b306178..97734e9 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -116,7 +116,6 @@ static inline struct timespec timespec_sub(struct timespec lhs,
extern void read_persistent_clock(struct timespec *ts);
extern void read_boot_clock(struct timespec *ts);
extern int update_persistent_clock(struct timespec now);
-extern int no_sync_cmos_clock __read_mostly;
void timekeeping_init(void);
extern int timekeeping_suspended;

diff --git a/include/linux/timex.h b/include/linux/timex.h
index b75e186..99bc88b 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -252,7 +252,7 @@ extern void ntp_clear(void);
/* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */
extern u64 ntp_tick_length(void);

-extern void second_overflow(void);
+extern int second_overflow(unsigned long secs);
extern int do_adjtimex(struct timex *);
extern void hardpps(const struct timespec *, const struct timespec *);

diff --git a/kernel/time.c b/kernel/time.c
index 73e416d..ba744cf 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -163,7 +163,6 @@ int do_sys_settimeofday(const struct timespec *tv, const struct timezone *tz)
return error;

if (tz) {
- /* SMP safe, global irq locking makes it work. */
sys_tz = *tz;
update_vsyscall_tz();
if (firsttime) {
@@ -173,12 +172,7 @@ int do_sys_settimeofday(const struct timespec *tv, const struct timezone *tz)
}
}
if (tv)
- {
- /* SMP safe, again the code in arch/foo/time.c should
- * globally block out interrupts when it runs.
- */
return do_settimeofday(tv);
- }
return 0;
}

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 8a46f5d..8a538c5 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -96,6 +96,11 @@ static int alarmtimer_rtc_add_device(struct device *dev,
return 0;
}

+static inline void alarmtimer_rtc_timer_init(void)
+{
+ rtc_timer_init(&rtctimer, NULL, NULL);
+}
+
static struct class_interface alarmtimer_rtc_interface = {
.add_dev = &alarmtimer_rtc_add_device,
};
@@ -117,6 +122,7 @@ static inline struct rtc_device *alarmtimer_get_rtcdev(void)
#define rtcdev (NULL)
static inline int alarmtimer_rtc_interface_setup(void) { return 0; }
static inline void alarmtimer_rtc_interface_remove(void) { }
+static inline void alarmtimer_rtc_timer_init(void) { }
#endif

/**
@@ -783,6 +789,8 @@ static int __init alarmtimer_init(void)
.nsleep = alarm_timer_nsleep,
};

+ alarmtimer_rtc_timer_init();
+
posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index a45ca16..c958338 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -500,7 +500,7 @@ static u32 clocksource_max_adjustment(struct clocksource *cs)
{
u64 ret;
/*
- * We won't try to correct for more then 11% adjustments (110,000 ppm),
+ * We won't try to correct for more than 11% adjustments (110,000 ppm),
*/
ret = (u64)cs->mult * 11;
do_div(ret,100);
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 6e039b1..f03fd83 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -34,8 +34,6 @@ unsigned long tick_nsec;
static u64 tick_length;
static u64 tick_length_base;

-static struct hrtimer leap_timer;
-
#define MAX_TICKADJ 500LL /* usecs */
#define MAX_TICKADJ_SCALED \
(((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
@@ -381,70 +379,63 @@ u64 ntp_tick_length(void)


/*
- * Leap second processing. If in leap-insert state at the end of the
- * day, the system clock is set back one second; if in leap-delete
- * state, the system clock is set ahead one second.
+ * this routine handles the overflow of the microsecond field
+ *
+ * The tricky bits of code to handle the accurate clock support
+ * were provided by Dave Mills (Mills@xxxxxxxx) of NTP fame.
+ * They were originally developed for SUN and DEC kernels.
+ * All the kudos should go to Dave for this stuff.
+ *
+ * Also handles leap second processing, and returns leap offset
*/
-static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
+int second_overflow(unsigned long secs)
{
- enum hrtimer_restart res = HRTIMER_NORESTART;
- unsigned long flags;
+ s64 delta;
int leap = 0;
+ unsigned long flags;

spin_lock_irqsave(&ntp_lock, flags);
+
+ /*
+ * Leap second processing. If in leap-insert state at the end of the
+ * day, the system clock is set back one second; if in leap-delete
+ * state, the system clock is set ahead one second.
+ */
switch (time_state) {
case TIME_OK:
+ if (time_status & STA_INS)
+ time_state = TIME_INS;
+ else if (time_status & STA_DEL)
+ time_state = TIME_DEL;
break;
case TIME_INS:
- leap = -1;
- time_state = TIME_OOP;
- printk(KERN_NOTICE
- "Clock: inserting leap second 23:59:60 UTC\n");
- hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
- res = HRTIMER_RESTART;
+ if (secs % 86400 == 0) {
+ leap = -1;
+ time_state = TIME_OOP;
+ printk(KERN_NOTICE
+ "Clock: inserting leap second 23:59:60 UTC\n");
+ }
break;
case TIME_DEL:
- leap = 1;
- time_tai--;
- time_state = TIME_WAIT;
- printk(KERN_NOTICE
- "Clock: deleting leap second 23:59:59 UTC\n");
+ if ((secs + 1) % 86400 == 0) {
+ leap = 1;
+ time_tai--;
+ time_state = TIME_WAIT;
+ printk(KERN_NOTICE
+ "Clock: deleting leap second 23:59:59 UTC\n");
+ }
break;
case TIME_OOP:
time_tai++;
time_state = TIME_WAIT;
- /* fall through */
+ break;
+
case TIME_WAIT:
if (!(time_status & (STA_INS | STA_DEL)))
time_state = TIME_OK;
break;
}
- spin_unlock_irqrestore(&ntp_lock, flags);

- /*
- * We have to call this outside of the ntp_lock to keep
- * the proper locking hierarchy
- */
- if (leap)
- timekeeping_leap_insert(leap);
-
- return res;
-}
-
-/*
- * this routine handles the overflow of the microsecond field
- *
- * The tricky bits of code to handle the accurate clock support
- * were provided by Dave Mills (Mills@xxxxxxxx) of NTP fame.
- * They were originally developed for SUN and DEC kernels.
- * All the kudos should go to Dave for this stuff.
- */
-void second_overflow(void)
-{
- s64 delta;
- unsigned long flags;
-
- spin_lock_irqsave(&ntp_lock, flags);

/* Bump the maxerror field */
time_maxerror += MAXFREQ / NSEC_PER_USEC;
@@ -481,15 +472,17 @@ void second_overflow(void)
tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
<< NTP_SCALE_SHIFT;
time_adjust = 0;
+
+
+
out:
spin_unlock_irqrestore(&ntp_lock, flags);
+
+ return leap;
}

#ifdef CONFIG_GENERIC_CMOS_UPDATE

-/* Disable the cmos update - used by virtualization and embedded */
-int no_sync_cmos_clock __read_mostly;
-
static void sync_cmos_clock(struct work_struct *work);

static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
@@ -536,35 +529,13 @@ static void sync_cmos_clock(struct work_struct *work)

static void notify_cmos_timer(void)
{
- if (!no_sync_cmos_clock)
- schedule_delayed_work(&sync_cmos_work, 0);
+ schedule_delayed_work(&sync_cmos_work, 0);
}

#else
static inline void notify_cmos_timer(void) { }
#endif

-/*
- * Start the leap seconds timer:
- */
-static inline void ntp_start_leap_timer(struct timespec *ts)
-{
- long now = ts->tv_sec;
-
- if (time_status & STA_INS) {
- time_state = TIME_INS;
- now += 86400 - now % 86400;
- hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
-
- return;
- }
-
- if (time_status & STA_DEL) {
- time_state = TIME_DEL;
- now += 86400 - (now + 1) % 86400;
- hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
- }
-}

/*
* Propagate a new txc->status value into the NTP state:
@@ -589,22 +560,6 @@ static inline void process_adj_status(struct timex *txc, struct timespec *ts)
time_status &= STA_RONLY;
time_status |= txc->status & ~STA_RONLY;

- switch (time_state) {
- case TIME_OK:
- ntp_start_leap_timer(ts);
- break;
- case TIME_INS:
- case TIME_DEL:
- time_state = TIME_OK;
- ntp_start_leap_timer(ts);
- case TIME_WAIT:
- if (!(time_status & (STA_INS | STA_DEL)))
- time_state = TIME_OK;
- break;
- case TIME_OOP:
- hrtimer_restart(&leap_timer);
- break;
- }
}
/*
* Called with the xtime lock held, so we can access and modify
@@ -686,9 +641,6 @@ int do_adjtimex(struct timex *txc)
(txc->tick < 900000/USER_HZ ||
txc->tick > 1100000/USER_HZ))
return -EINVAL;
-
- if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
- hrtimer_cancel(&leap_timer);
}

if (txc->modes & ADJ_SETOFFSET) {
@@ -1010,6 +962,4 @@ __setup("ntp_tick_adj=", ntp_tick_adj_setup);
void __init ntp_init(void)
{
ntp_clear();
- hrtimer_init(&leap_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
- leap_timer.function = ntp_leap_second;
}
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 403c2a0..51b9856 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -184,18 +184,6 @@ static void timekeeping_update(bool clearntp)
}


-void timekeeping_leap_insert(int leapsecond)
-{
- unsigned long flags;
-
- write_seqlock_irqsave(&timekeeper.lock, flags);
- timekeeper.xtime.tv_sec += leapsecond;
- timekeeper.wall_to_monotonic.tv_sec -= leapsecond;
- timekeeping_update(false);
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
-
-}
-
/**
* timekeeping_forward_now - update clock to the current time
*
@@ -448,9 +436,12 @@ EXPORT_SYMBOL(timekeeping_inject_offset);
static int change_clocksource(void *data)
{
struct clocksource *new, *old;
+ unsigned long flags;

new = (struct clocksource *) data;

+ write_seqlock_irqsave(&timekeeper.lock, flags);
+
timekeeping_forward_now();
if (!new->enable || new->enable(new) == 0) {
old = timekeeper.clock;
@@ -458,6 +449,10 @@ static int change_clocksource(void *data)
if (old->disable)
old->disable(old);
}
+ timekeeping_update(true);
+
+ write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
return 0;
}

@@ -827,7 +822,7 @@ static void timekeeping_adjust(s64 offset)
int adj;

/*
- * The point of this is to check if the error is greater then half
+ * The point of this is to check if the error is greater than half
* an interval.
*
* First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.
@@ -835,7 +830,7 @@ static void timekeeping_adjust(s64 offset)
* Note we subtract one in the shift, so that error is really error*2.
* This "saves" dividing(shifting) interval twice, but keeps the
* (error > interval) comparison as still measuring if error is
- * larger then half an interval.
+ * larger than half an interval.
*
* Note: It does not "save" on aggravation when reading the code.
*/
@@ -843,7 +838,7 @@ static void timekeeping_adjust(s64 offset)
if (error > interval) {
/*
* We now divide error by 4(via shift), which checks if
- * the error is greater then twice the interval.
+ * the error is greater than twice the interval.
* If it is greater, we need a bigadjust, if its smaller,
* we can adjust by 1.
*/
@@ -874,13 +869,15 @@ static void timekeeping_adjust(s64 offset)
} else /* No adjustment needed */
return;

- WARN_ONCE(timekeeper.clock->maxadj &&
- (timekeeper.mult + adj > timekeeper.clock->mult +
- timekeeper.clock->maxadj),
- "Adjusting %s more then 11%% (%ld vs %ld)\n",
+ if (unlikely(timekeeper.clock->maxadj &&
+ (timekeeper.mult + adj >
+ timekeeper.clock->mult + timekeeper.clock->maxadj))) {
+ printk_once(KERN_WARNING
+ "Adjusting %s more than 11%% (%ld vs %ld)\n",
timekeeper.clock->name, (long)timekeeper.mult + adj,
(long)timekeeper.clock->mult +
timekeeper.clock->maxadj);
+ }
/*
* So the following can be confusing.
*
@@ -952,7 +949,7 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
u64 raw_nsecs;

- /* If the offset is smaller then a shifted interval, do nothing */
+ /* If the offset is smaller than a shifted interval, do nothing */
if (offset < timekeeper.cycle_interval<<shift)
return offset;

@@ -962,9 +959,11 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)

timekeeper.xtime_nsec += timekeeper.xtime_interval << shift;
while (timekeeper.xtime_nsec >= nsecps) {
+ int leap;
timekeeper.xtime_nsec -= nsecps;
timekeeper.xtime.tv_sec++;
- second_overflow();
+ leap = second_overflow(timekeeper.xtime.tv_sec);
+ timekeeper.xtime.tv_sec += leap;
}

/* Accumulate raw time */
@@ -1018,13 +1017,13 @@ static void update_wall_time(void)
* With NO_HZ we may have to accumulate many cycle_intervals
* (think "ticks") worth of time at once. To do this efficiently,
* we calculate the largest doubling multiple of cycle_intervals
- * that is smaller then the offset. We then accumulate that
+ * that is smaller than the offset. We then accumulate that
* chunk in one go, and then try to consume the next smaller
* doubled multiple.
*/
shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
shift = max(0, shift);
- /* Bound shift to one less then what overflows tick_length */
+ /* Bound shift to one less than what overflows tick_length */
maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
shift = min(shift, maxshift);
while (offset >= timekeeper.cycle_interval) {
@@ -1072,12 +1071,14 @@ static void update_wall_time(void)

/*
* Finally, make sure that after the rounding
- * xtime.tv_nsec isn't larger then NSEC_PER_SEC
+ * xtime.tv_nsec isn't larger than NSEC_PER_SEC
*/
if (unlikely(timekeeper.xtime.tv_nsec >= NSEC_PER_SEC)) {
+ int leap;
timekeeper.xtime.tv_nsec -= NSEC_PER_SEC;
timekeeper.xtime.tv_sec++;
- second_overflow();
+ leap = second_overflow(timekeeper.xtime.tv_sec);
+ timekeeper.xtime.tv_sec += leap;
}

timekeeping_update(false);
--
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