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Subject[GIT PULL] timer updates for v2.6.30
Linus,

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

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git timers-for-linus

Highlights:

- New mod_timer_pending() timer_list API requested by the
networking folks.

- HPET ICH10 enablement and general debuggability improvements and
fixlets.

- NTP code cleanups and fixlets.

Risks:

- There were no unusual trouble spots during development and there
are no open regressions.

- The ICH10 force-enable hpet change brings regression risks on
such systems and the NTP changes have regression risks too.

Thanks,

Ingo

------------------>
Andi Kleen (1):
x86: hpet: allow force enable on ICH10 HPET
Andreas Herrmann (3):
x86: hpet: print HPET registers during setup (if hpet=verbose is used)
x86: hpet: provide separate functions to stop and start the counter
x86: hpet: stop HPET_COUNTER when programming periodic mode

Frederic Weisbecker (1):
hrtimers: increase clock min delta threshold while interrupt hanging

Ingo Molnar (15):
timers: add mod_timer_pending()
time: ntp: clean up kernel/time/ntp.c
time: ntp: simplify the second_overflow() code flow
time: ntp: simplify the MAX_TICKADJ_SCALED definition
time: ntp: clean up ntp_update_frequency()
time: ntp: refactor up ntp_update_frequency()
time: ntp: refactor and clean up ntp_update_offset()
time: ntp: simplify ntp_update_offset_fll()
time: ntp: micro-optimize ntp_update_offset()
time: ntp: fix bug in ntp_update_offset() & do_adjtimex()
time: ntp: refactor do_adjtimex()
time: ntp: refactor do_adjtimex() some more
time: ntp: make 64-bit constants more robust
time: ntp: simplify ntp_tick_adj calculations
time: ntp: clean up second_overflow()

John Stultz (2):
time: apply NTP frequency/tick changes immediately
time: ntp: fix bug in ntp_update_offset() & do_adjtimex(), fix

Magnus Damm (1):
clockevents: let set_mode() setup delta information

Oleg Nesterov (1):
posix timers: fix RLIMIT_CPU && fork()

Sebastien Dugue (1):
hrtimers: allow the hot-unplugging of all cpus

Thomas Gleixner (1):
hrtimer: prevent negative expiry value after clock_was_set()


Documentation/kernel-parameters.txt | 4 +-
arch/powerpc/platforms/cell/spufs/sched.c | 2 +-
arch/x86/kernel/hpet.c | 80 ++++-
arch/x86/kernel/quirks.c | 3 +-
drivers/infiniband/hw/ipath/ipath_driver.c | 6 +-
include/linux/timer.h | 22 +--
include/linux/timex.h | 2 +-
kernel/posix-cpu-timers.c | 3 +-
kernel/relay.c | 2 +-
kernel/time/clockevents.c | 20 +-
kernel/time/ntp.c | 444 +++++++++++++++++-----------
kernel/timer.c | 110 +++++---
12 files changed, 437 insertions(+), 261 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 54f21a5..46d11a9 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -492,10 +492,12 @@ and is between 256 and 4096 characters. It is defined in the file
Default: 64

hpet= [X86-32,HPET] option to control HPET usage
- Format: { enable (default) | disable | force }
+ Format: { enable (default) | disable | force |
+ verbose }
disable: disable HPET and use PIT instead
force: allow force enabled of undocumented chips (ICH4,
VIA, nVidia)
+ verbose: show contents of HPET registers during setup

com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 6a0ad19..f085369 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -508,7 +508,7 @@ static void __spu_add_to_rq(struct spu_context *ctx)
list_add_tail(&ctx->rq, &spu_prio->runq[ctx->prio]);
set_bit(ctx->prio, spu_prio->bitmap);
if (!spu_prio->nr_waiting++)
- __mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK);
+ mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK);
}
}

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index a00545f..648b3a2 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -80,6 +80,7 @@ static inline void hpet_clear_mapping(void)
*/
static int boot_hpet_disable;
int hpet_force_user;
+static int hpet_verbose;

static int __init hpet_setup(char *str)
{
@@ -88,6 +89,8 @@ static int __init hpet_setup(char *str)
boot_hpet_disable = 1;
if (!strncmp("force", str, 5))
hpet_force_user = 1;
+ if (!strncmp("verbose", str, 7))
+ hpet_verbose = 1;
}
return 1;
}
@@ -119,6 +122,43 @@ int is_hpet_enabled(void)
}
EXPORT_SYMBOL_GPL(is_hpet_enabled);

+static void _hpet_print_config(const char *function, int line)
+{
+ u32 i, timers, l, h;
+ printk(KERN_INFO "hpet: %s(%d):\n", function, line);
+ l = hpet_readl(HPET_ID);
+ h = hpet_readl(HPET_PERIOD);
+ timers = ((l & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
+ printk(KERN_INFO "hpet: ID: 0x%x, PERIOD: 0x%x\n", l, h);
+ l = hpet_readl(HPET_CFG);
+ h = hpet_readl(HPET_STATUS);
+ printk(KERN_INFO "hpet: CFG: 0x%x, STATUS: 0x%x\n", l, h);
+ l = hpet_readl(HPET_COUNTER);
+ h = hpet_readl(HPET_COUNTER+4);
+ printk(KERN_INFO "hpet: COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h);
+
+ for (i = 0; i < timers; i++) {
+ l = hpet_readl(HPET_Tn_CFG(i));
+ h = hpet_readl(HPET_Tn_CFG(i)+4);
+ printk(KERN_INFO "hpet: T%d: CFG_l: 0x%x, CFG_h: 0x%x\n",
+ i, l, h);
+ l = hpet_readl(HPET_Tn_CMP(i));
+ h = hpet_readl(HPET_Tn_CMP(i)+4);
+ printk(KERN_INFO "hpet: T%d: CMP_l: 0x%x, CMP_h: 0x%x\n",
+ i, l, h);
+ l = hpet_readl(HPET_Tn_ROUTE(i));
+ h = hpet_readl(HPET_Tn_ROUTE(i)+4);
+ printk(KERN_INFO "hpet: T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n",
+ i, l, h);
+ }
+}
+
+#define hpet_print_config() \
+do { \
+ if (hpet_verbose) \
+ _hpet_print_config(__FUNCTION__, __LINE__); \
+} while (0)
+
/*
* When the hpet driver (/dev/hpet) is enabled, we need to reserve
* timer 0 and timer 1 in case of RTC emulation.
@@ -191,27 +231,37 @@ static struct clock_event_device hpet_clockevent = {
.rating = 50,
};

-static void hpet_start_counter(void)
+static void hpet_stop_counter(void)
{
unsigned long cfg = hpet_readl(HPET_CFG);
-
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
hpet_writel(0, HPET_COUNTER);
hpet_writel(0, HPET_COUNTER + 4);
+}
+
+static void hpet_start_counter(void)
+{
+ unsigned long cfg = hpet_readl(HPET_CFG);
cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}

+static void hpet_restart_counter(void)
+{
+ hpet_stop_counter();
+ hpet_start_counter();
+}
+
static void hpet_resume_device(void)
{
force_hpet_resume();
}

-static void hpet_restart_counter(void)
+static void hpet_resume_counter(void)
{
hpet_resume_device();
- hpet_start_counter();
+ hpet_restart_counter();
}

static void hpet_enable_legacy_int(void)
@@ -259,29 +309,23 @@ static int hpet_setup_msi_irq(unsigned int irq);
static void hpet_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt, int timer)
{
- unsigned long cfg, cmp, now;
+ unsigned long cfg;
uint64_t delta;

switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
+ hpet_stop_counter();
delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * evt->mult;
delta >>= evt->shift;
- now = hpet_readl(HPET_COUNTER);
- cmp = now + (unsigned long) delta;
cfg = hpet_readl(HPET_Tn_CFG(timer));
/* Make sure we use edge triggered interrupts */
cfg &= ~HPET_TN_LEVEL;
cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
HPET_TN_SETVAL | HPET_TN_32BIT;
hpet_writel(cfg, HPET_Tn_CFG(timer));
- /*
- * The first write after writing TN_SETVAL to the
- * config register sets the counter value, the second
- * write sets the period.
- */
- hpet_writel(cmp, HPET_Tn_CMP(timer));
- udelay(1);
hpet_writel((unsigned long) delta, HPET_Tn_CMP(timer));
+ hpet_start_counter();
+ hpet_print_config();
break;

case CLOCK_EVT_MODE_ONESHOT:
@@ -308,6 +352,7 @@ static void hpet_set_mode(enum clock_event_mode mode,
irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu));
enable_irq(hdev->irq);
}
+ hpet_print_config();
break;
}
}
@@ -526,6 +571,7 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)

num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
num_timers++; /* Value read out starts from 0 */
+ hpet_print_config();

hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL);
if (!hpet_devs)
@@ -695,7 +741,7 @@ static struct clocksource clocksource_hpet = {
.mask = HPET_MASK,
.shift = HPET_SHIFT,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
- .resume = hpet_restart_counter,
+ .resume = hpet_resume_counter,
#ifdef CONFIG_X86_64
.vread = vread_hpet,
#endif
@@ -707,7 +753,7 @@ static int hpet_clocksource_register(void)
cycle_t t1;

/* Start the counter */
- hpet_start_counter();
+ hpet_restart_counter();

/* Verify whether hpet counter works */
t1 = read_hpet();
@@ -793,6 +839,7 @@ int __init hpet_enable(void)
* information and the number of channels
*/
id = hpet_readl(HPET_ID);
+ hpet_print_config();

#ifdef CONFIG_HPET_EMULATE_RTC
/*
@@ -845,6 +892,7 @@ static __init int hpet_late_init(void)
return -ENODEV;

hpet_reserve_platform_timers(hpet_readl(HPET_ID));
+ hpet_print_config();

for_each_online_cpu(cpu) {
hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 309949e..697d1b7 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -172,7 +172,8 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH8_4,
ich_force_enable_hpet);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH9_7,
ich_force_enable_hpet);
-
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3a16, /* ICH10 */
+ ich_force_enable_hpet);

static struct pci_dev *cached_dev;

diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index 69c0ce3..cb9daa6 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -2715,7 +2715,7 @@ static void ipath_hol_signal_up(struct ipath_devdata *dd)
* to prevent HoL blocking, then start the HoL timer that
* periodically continues, then stop procs, so they can detect
* link down if they want, and do something about it.
- * Timer may already be running, so use __mod_timer, not add_timer.
+ * Timer may already be running, so use mod_timer, not add_timer.
*/
void ipath_hol_down(struct ipath_devdata *dd)
{
@@ -2724,7 +2724,7 @@ void ipath_hol_down(struct ipath_devdata *dd)
dd->ipath_hol_next = IPATH_HOL_DOWNCONT;
dd->ipath_hol_timer.expires = jiffies +
msecs_to_jiffies(ipath_hol_timeout_ms);
- __mod_timer(&dd->ipath_hol_timer, dd->ipath_hol_timer.expires);
+ mod_timer(&dd->ipath_hol_timer, dd->ipath_hol_timer.expires);
}

/*
@@ -2763,7 +2763,7 @@ void ipath_hol_event(unsigned long opaque)
else {
dd->ipath_hol_timer.expires = jiffies +
msecs_to_jiffies(ipath_hol_timeout_ms);
- __mod_timer(&dd->ipath_hol_timer,
+ mod_timer(&dd->ipath_hol_timer,
dd->ipath_hol_timer.expires);
}
}
diff --git a/include/linux/timer.h b/include/linux/timer.h
index daf9685..e2d662e 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -86,8 +86,8 @@ static inline int timer_pending(const struct timer_list * timer)

extern void add_timer_on(struct timer_list *timer, int cpu);
extern int del_timer(struct timer_list * timer);
-extern int __mod_timer(struct timer_list *timer, unsigned long expires);
extern int mod_timer(struct timer_list *timer, unsigned long expires);
+extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);

/*
* The jiffies value which is added to now, when there is no timer
@@ -146,25 +146,7 @@ static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
}
#endif

-/**
- * add_timer - start a timer
- * @timer: the timer to be added
- *
- * The kernel will do a ->function(->data) callback from the
- * timer interrupt at the ->expires point in the future. The
- * current time is 'jiffies'.
- *
- * The timer's ->expires, ->function (and if the handler uses it, ->data)
- * fields must be set prior calling this function.
- *
- * Timers with an ->expires field in the past will be executed in the next
- * timer tick.
- */
-static inline void add_timer(struct timer_list *timer)
-{
- BUG_ON(timer_pending(timer));
- __mod_timer(timer, timer->expires);
-}
+extern void add_timer(struct timer_list *timer);

#ifdef CONFIG_SMP
extern int try_to_del_timer_sync(struct timer_list *timer);
diff --git a/include/linux/timex.h b/include/linux/timex.h
index 998a55d..aa3475f 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -190,7 +190,7 @@ struct timex {
* offset and maximum frequency tolerance.
*/
#define SHIFT_USEC 16 /* frequency offset scale (shift) */
-#define PPM_SCALE (NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
+#define PPM_SCALE ((s64)NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
#define PPM_SCALE_INV_SHIFT 19
#define PPM_SCALE_INV ((1ll << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \
PPM_SCALE + 1)
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index e976e50..8e5d9a6 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1370,7 +1370,8 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
}
- return 0;
+
+ return sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY;
}

/*
diff --git a/kernel/relay.c b/kernel/relay.c
index 9d79b78..8f2179c 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -750,7 +750,7 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
* from the scheduler (trying to re-grab
* rq->lock), so defer it.
*/
- __mod_timer(&buf->timer, jiffies + 1);
+ mod_timer(&buf->timer, jiffies + 1);
}

old = buf->data;
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index ea2f48a..d13be21 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -68,6 +68,17 @@ void clockevents_set_mode(struct clock_event_device *dev,
if (dev->mode != mode) {
dev->set_mode(mode, dev);
dev->mode = mode;
+
+ /*
+ * A nsec2cyc multiplicator of 0 is invalid and we'd crash
+ * on it, so fix it up and emit a warning:
+ */
+ if (mode == CLOCK_EVT_MODE_ONESHOT) {
+ if (unlikely(!dev->mult)) {
+ dev->mult = 1;
+ WARN_ON(1);
+ }
+ }
}
}

@@ -168,15 +179,6 @@ void clockevents_register_device(struct clock_event_device *dev)
BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
BUG_ON(!dev->cpumask);

- /*
- * A nsec2cyc multiplicator of 0 is invalid and we'd crash
- * on it, so fix it up and emit a warning:
- */
- if (unlikely(!dev->mult)) {
- dev->mult = 1;
- WARN_ON(1);
- }
-
spin_lock(&clockevents_lock);

list_add(&dev->list, &clockevent_devices);
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index f5f793d..7fc6437 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -1,71 +1,129 @@
/*
- * linux/kernel/time/ntp.c
- *
* NTP state machine interfaces and logic.
*
* This code was mainly moved from kernel/timer.c and kernel/time.c
* Please see those files for relevant copyright info and historical
* changelogs.
*/
-
-#include <linux/mm.h>
-#include <linux/time.h>
-#include <linux/timex.h>
-#include <linux/jiffies.h>
-#include <linux/hrtimer.h>
#include <linux/capability.h>
-#include <linux/math64.h>
#include <linux/clocksource.h>
#include <linux/workqueue.h>
-#include <asm/timex.h>
+#include <linux/hrtimer.h>
+#include <linux/jiffies.h>
+#include <linux/math64.h>
+#include <linux/timex.h>
+#include <linux/time.h>
+#include <linux/mm.h>

/*
- * Timekeeping variables
+ * NTP timekeeping variables:
*/
-unsigned long tick_usec = TICK_USEC; /* USER_HZ period (usec) */
-unsigned long tick_nsec; /* ACTHZ period (nsec) */
-u64 tick_length;
-static u64 tick_length_base;

-static struct hrtimer leap_timer;
+/* USER_HZ period (usecs): */
+unsigned long tick_usec = TICK_USEC;

-#define MAX_TICKADJ 500 /* microsecs */
-#define MAX_TICKADJ_SCALED (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
- NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
+/* ACTHZ period (nsecs): */
+unsigned long tick_nsec;
+
+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)

/*
* phase-lock loop variables
*/
-/* TIME_ERROR prevents overwriting the CMOS clock */
-static int time_state = TIME_OK; /* clock synchronization status */
-int time_status = STA_UNSYNC; /* clock status bits */
-static long time_tai; /* TAI offset (s) */
-static s64 time_offset; /* time adjustment (ns) */
-static long time_constant = 2; /* pll time constant */
-long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
-long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
-static s64 time_freq; /* frequency offset (scaled ns/s)*/
-static long time_reftime; /* time at last adjustment (s) */
-long time_adjust;
-static long ntp_tick_adj;

+/*
+ * clock synchronization status
+ *
+ * (TIME_ERROR prevents overwriting the CMOS clock)
+ */
+static int time_state = TIME_OK;
+
+/* clock status bits: */
+int time_status = STA_UNSYNC;
+
+/* TAI offset (secs): */
+static long time_tai;
+
+/* time adjustment (nsecs): */
+static s64 time_offset;
+
+/* pll time constant: */
+static long time_constant = 2;
+
+/* maximum error (usecs): */
+long time_maxerror = NTP_PHASE_LIMIT;
+
+/* estimated error (usecs): */
+long time_esterror = NTP_PHASE_LIMIT;
+
+/* frequency offset (scaled nsecs/secs): */
+static s64 time_freq;
+
+/* time at last adjustment (secs): */
+static long time_reftime;
+
+long time_adjust;
+
+/* constant (boot-param configurable) NTP tick adjustment (upscaled) */
+static s64 ntp_tick_adj;
+
+/*
+ * NTP methods:
+ */
+
+/*
+ * Update (tick_length, tick_length_base, tick_nsec), based
+ * on (tick_usec, ntp_tick_adj, time_freq):
+ */
static void ntp_update_frequency(void)
{
- u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
- << NTP_SCALE_SHIFT;
- second_length += (s64)ntp_tick_adj << NTP_SCALE_SHIFT;
- second_length += time_freq;
+ u64 second_length;
+ u64 new_base;
+
+ second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
+ << NTP_SCALE_SHIFT;
+
+ second_length += ntp_tick_adj;
+ second_length += time_freq;

- tick_length_base = second_length;
+ tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
+ new_base = div_u64(second_length, NTP_INTERVAL_FREQ);

- tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
- tick_length_base = div_u64(tick_length_base, NTP_INTERVAL_FREQ);
+ /*
+ * Don't wait for the next second_overflow, apply
+ * the change to the tick length immediately:
+ */
+ tick_length += new_base - tick_length_base;
+ tick_length_base = new_base;
+}
+
+static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
+{
+ time_status &= ~STA_MODE;
+
+ if (secs < MINSEC)
+ return 0;
+
+ if (!(time_status & STA_FLL) && (secs <= MAXSEC))
+ return 0;
+
+ time_status |= STA_MODE;
+
+ return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
}

static void ntp_update_offset(long offset)
{
- long mtemp;
s64 freq_adj;
+ s64 offset64;
+ long secs;

if (!(time_status & STA_PLL))
return;
@@ -84,24 +142,23 @@ static void ntp_update_offset(long offset)
* Select how the frequency is to be controlled
* and in which mode (PLL or FLL).
*/
- if (time_status & STA_FREQHOLD || time_reftime == 0)
- time_reftime = xtime.tv_sec;
- mtemp = xtime.tv_sec - time_reftime;
+ secs = xtime.tv_sec - time_reftime;
+ if (unlikely(time_status & STA_FREQHOLD))
+ secs = 0;
+
time_reftime = xtime.tv_sec;

- freq_adj = (s64)offset * mtemp;
- freq_adj <<= NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant);
- time_status &= ~STA_MODE;
- if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
- freq_adj += div_s64((s64)offset << (NTP_SCALE_SHIFT - SHIFT_FLL),
- mtemp);
- time_status |= STA_MODE;
- }
- freq_adj += time_freq;
- freq_adj = min(freq_adj, MAXFREQ_SCALED);
- time_freq = max(freq_adj, -MAXFREQ_SCALED);
+ offset64 = offset;
+ freq_adj = (offset64 * secs) <<
+ (NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));

- time_offset = div_s64((s64)offset << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
+ freq_adj += ntp_update_offset_fll(offset64, secs);
+
+ freq_adj = min(freq_adj + time_freq, MAXFREQ_SCALED);
+
+ time_freq = max(freq_adj, -MAXFREQ_SCALED);
+
+ time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
}

/**
@@ -111,15 +168,15 @@ static void ntp_update_offset(long offset)
*/
void ntp_clear(void)
{
- time_adjust = 0; /* stop active adjtime() */
- time_status |= STA_UNSYNC;
- time_maxerror = NTP_PHASE_LIMIT;
- time_esterror = NTP_PHASE_LIMIT;
+ time_adjust = 0; /* stop active adjtime() */
+ time_status |= STA_UNSYNC;
+ time_maxerror = NTP_PHASE_LIMIT;
+ time_esterror = NTP_PHASE_LIMIT;

ntp_update_frequency();

- tick_length = tick_length_base;
- time_offset = 0;
+ tick_length = tick_length_base;
+ time_offset = 0;
}

/*
@@ -140,8 +197,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
xtime.tv_sec--;
wall_to_monotonic.tv_sec++;
time_state = TIME_OOP;
- printk(KERN_NOTICE "Clock: "
- "inserting leap second 23:59:60 UTC\n");
+ printk(KERN_NOTICE
+ "Clock: inserting leap second 23:59:60 UTC\n");
hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
res = HRTIMER_RESTART;
break;
@@ -150,8 +207,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
time_tai--;
wall_to_monotonic.tv_sec--;
time_state = TIME_WAIT;
- printk(KERN_NOTICE "Clock: "
- "deleting leap second 23:59:59 UTC\n");
+ printk(KERN_NOTICE
+ "Clock: deleting leap second 23:59:59 UTC\n");
break;
case TIME_OOP:
time_tai++;
@@ -179,7 +236,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
*/
void second_overflow(void)
{
- s64 time_adj;
+ s64 delta;

/* Bump the maxerror field */
time_maxerror += MAXFREQ / NSEC_PER_USEC;
@@ -192,24 +249,30 @@ void second_overflow(void)
* Compute the phase adjustment for the next second. The offset is
* reduced by a fixed factor times the time constant.
*/
- tick_length = tick_length_base;
- time_adj = shift_right(time_offset, SHIFT_PLL + time_constant);
- time_offset -= time_adj;
- tick_length += time_adj;
-
- if (unlikely(time_adjust)) {
- if (time_adjust > MAX_TICKADJ) {
- time_adjust -= MAX_TICKADJ;
- tick_length += MAX_TICKADJ_SCALED;
- } else if (time_adjust < -MAX_TICKADJ) {
- time_adjust += MAX_TICKADJ;
- tick_length -= MAX_TICKADJ_SCALED;
- } else {
- tick_length += (s64)(time_adjust * NSEC_PER_USEC /
- NTP_INTERVAL_FREQ) << NTP_SCALE_SHIFT;
- time_adjust = 0;
- }
+ tick_length = tick_length_base;
+
+ delta = shift_right(time_offset, SHIFT_PLL + time_constant);
+ time_offset -= delta;
+ tick_length += delta;
+
+ if (!time_adjust)
+ return;
+
+ if (time_adjust > MAX_TICKADJ) {
+ time_adjust -= MAX_TICKADJ;
+ tick_length += MAX_TICKADJ_SCALED;
+ return;
}
+
+ if (time_adjust < -MAX_TICKADJ) {
+ time_adjust += MAX_TICKADJ;
+ tick_length -= MAX_TICKADJ_SCALED;
+ return;
+ }
+
+ tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
+ << NTP_SCALE_SHIFT;
+ time_adjust = 0;
}

#ifdef CONFIG_GENERIC_CMOS_UPDATE
@@ -233,12 +296,13 @@ static void sync_cmos_clock(struct work_struct *work)
* This code is run on a timer. If the clock is set, that timer
* may not expire at the correct time. Thus, we adjust...
*/
- if (!ntp_synced())
+ if (!ntp_synced()) {
/*
* Not synced, exit, do not restart a timer (if one is
* running, let it run out).
*/
return;
+ }

getnstimeofday(&now);
if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
@@ -270,7 +334,116 @@ static void notify_cmos_timer(void)
static inline void notify_cmos_timer(void) { }
#endif

-/* adjtimex mainly allows reading (and writing, if superuser) of
+/*
+ * 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:
+ */
+static inline void process_adj_status(struct timex *txc, struct timespec *ts)
+{
+ if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) {
+ time_state = TIME_OK;
+ time_status = STA_UNSYNC;
+ }
+
+ /*
+ * If we turn on PLL adjustments then reset the
+ * reference time to current time.
+ */
+ if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
+ time_reftime = xtime.tv_sec;
+
+ /* only set allowed bits */
+ 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
+ * all the global NTP state:
+ */
+static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts)
+{
+ if (txc->modes & ADJ_STATUS)
+ process_adj_status(txc, ts);
+
+ if (txc->modes & ADJ_NANO)
+ time_status |= STA_NANO;
+
+ if (txc->modes & ADJ_MICRO)
+ time_status &= ~STA_NANO;
+
+ if (txc->modes & ADJ_FREQUENCY) {
+ time_freq = txc->freq * PPM_SCALE;
+ time_freq = min(time_freq, MAXFREQ_SCALED);
+ time_freq = max(time_freq, -MAXFREQ_SCALED);
+ }
+
+ if (txc->modes & ADJ_MAXERROR)
+ time_maxerror = txc->maxerror;
+
+ if (txc->modes & ADJ_ESTERROR)
+ time_esterror = txc->esterror;
+
+ if (txc->modes & ADJ_TIMECONST) {
+ time_constant = txc->constant;
+ if (!(time_status & STA_NANO))
+ time_constant += 4;
+ time_constant = min(time_constant, (long)MAXTC);
+ time_constant = max(time_constant, 0l);
+ }
+
+ if (txc->modes & ADJ_TAI && txc->constant > 0)
+ time_tai = txc->constant;
+
+ if (txc->modes & ADJ_OFFSET)
+ ntp_update_offset(txc->offset);
+
+ if (txc->modes & ADJ_TICK)
+ tick_usec = txc->tick;
+
+ if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
+ ntp_update_frequency();
+}
+
+/*
+ * adjtimex mainly allows reading (and writing, if superuser) of
* kernel time-keeping variables. used by xntpd.
*/
int do_adjtimex(struct timex *txc)
@@ -291,11 +464,14 @@ int do_adjtimex(struct timex *txc)
if (txc->modes && !capable(CAP_SYS_TIME))
return -EPERM;

- /* if the quartz is off by more than 10% something is VERY wrong! */
+ /*
+ * if the quartz is off by more than 10% then
+ * something is VERY wrong!
+ */
if (txc->modes & ADJ_TICK &&
(txc->tick < 900000/USER_HZ ||
txc->tick > 1100000/USER_HZ))
- return -EINVAL;
+ return -EINVAL;

if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
hrtimer_cancel(&leap_timer);
@@ -305,7 +481,6 @@ int do_adjtimex(struct timex *txc)

write_seqlock_irq(&xtime_lock);

- /* If there are input parameters, then process them */
if (txc->modes & ADJ_ADJTIME) {
long save_adjust = time_adjust;

@@ -315,98 +490,24 @@ int do_adjtimex(struct timex *txc)
ntp_update_frequency();
}
txc->offset = save_adjust;
- goto adj_done;
- }
- if (txc->modes) {
- long sec;
-
- if (txc->modes & ADJ_STATUS) {
- if ((time_status & STA_PLL) &&
- !(txc->status & STA_PLL)) {
- time_state = TIME_OK;
- time_status = STA_UNSYNC;
- }
- /* only set allowed bits */
- time_status &= STA_RONLY;
- time_status |= txc->status & ~STA_RONLY;
-
- switch (time_state) {
- case TIME_OK:
- start_timer:
- sec = ts.tv_sec;
- if (time_status & STA_INS) {
- time_state = TIME_INS;
- sec += 86400 - sec % 86400;
- hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS);
- } else if (time_status & STA_DEL) {
- time_state = TIME_DEL;
- sec += 86400 - (sec + 1) % 86400;
- hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS);
- }
- break;
- case TIME_INS:
- case TIME_DEL:
- time_state = TIME_OK;
- goto start_timer;
- break;
- case TIME_WAIT:
- if (!(time_status & (STA_INS | STA_DEL)))
- time_state = TIME_OK;
- break;
- case TIME_OOP:
- hrtimer_restart(&leap_timer);
- break;
- }
- }
-
- if (txc->modes & ADJ_NANO)
- time_status |= STA_NANO;
- if (txc->modes & ADJ_MICRO)
- time_status &= ~STA_NANO;
-
- if (txc->modes & ADJ_FREQUENCY) {
- time_freq = (s64)txc->freq * PPM_SCALE;
- time_freq = min(time_freq, MAXFREQ_SCALED);
- time_freq = max(time_freq, -MAXFREQ_SCALED);
- }
-
- if (txc->modes & ADJ_MAXERROR)
- time_maxerror = txc->maxerror;
- if (txc->modes & ADJ_ESTERROR)
- time_esterror = txc->esterror;
-
- if (txc->modes & ADJ_TIMECONST) {
- time_constant = txc->constant;
- if (!(time_status & STA_NANO))
- time_constant += 4;
- time_constant = min(time_constant, (long)MAXTC);
- time_constant = max(time_constant, 0l);
- }
-
- if (txc->modes & ADJ_TAI && txc->constant > 0)
- time_tai = txc->constant;
-
- if (txc->modes & ADJ_OFFSET)
- ntp_update_offset(txc->offset);
- if (txc->modes & ADJ_TICK)
- tick_usec = txc->tick;
+ } else {

- if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
- ntp_update_frequency();
- }
+ /* If there are input parameters, then process them: */
+ if (txc->modes)
+ process_adjtimex_modes(txc, &ts);

- txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
+ txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
NTP_SCALE_SHIFT);
- if (!(time_status & STA_NANO))
- txc->offset /= NSEC_PER_USEC;
+ if (!(time_status & STA_NANO))
+ txc->offset /= NSEC_PER_USEC;
+ }

-adj_done:
result = time_state; /* mostly `TIME_OK' */
if (time_status & (STA_UNSYNC|STA_CLOCKERR))
result = TIME_ERROR;

txc->freq = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *
- (s64)PPM_SCALE_INV, NTP_SCALE_SHIFT);
+ PPM_SCALE_INV, NTP_SCALE_SHIFT);
txc->maxerror = time_maxerror;
txc->esterror = time_esterror;
txc->status = time_status;
@@ -425,6 +526,7 @@ adj_done:
txc->calcnt = 0;
txc->errcnt = 0;
txc->stbcnt = 0;
+
write_sequnlock_irq(&xtime_lock);

txc->time.tv_sec = ts.tv_sec;
@@ -440,6 +542,8 @@ adj_done:
static int __init ntp_tick_adj_setup(char *str)
{
ntp_tick_adj = simple_strtol(str, NULL, 0);
+ ntp_tick_adj <<= NTP_SCALE_SHIFT;
+
return 1;
}

diff --git a/kernel/timer.c b/kernel/timer.c
index 13dd64f..9b77fc9 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -589,11 +589,14 @@ static struct tvec_base *lock_timer_base(struct timer_list *timer,
}
}

-int __mod_timer(struct timer_list *timer, unsigned long expires)
+static inline int
+__mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only)
{
struct tvec_base *base, *new_base;
unsigned long flags;
- int ret = 0;
+ int ret;
+
+ ret = 0;

timer_stats_timer_set_start_info(timer);
BUG_ON(!timer->function);
@@ -603,6 +606,9 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)
if (timer_pending(timer)) {
detach_timer(timer, 0);
ret = 1;
+ } else {
+ if (pending_only)
+ goto out_unlock;
}

debug_timer_activate(timer);
@@ -629,42 +635,28 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)

timer->expires = expires;
internal_add_timer(base, timer);
+
+out_unlock:
spin_unlock_irqrestore(&base->lock, flags);

return ret;
}

-EXPORT_SYMBOL(__mod_timer);
-
/**
- * add_timer_on - start a timer on a particular CPU
- * @timer: the timer to be added
- * @cpu: the CPU to start it on
+ * mod_timer_pending - modify a pending timer's timeout
+ * @timer: the pending timer to be modified
+ * @expires: new timeout in jiffies
*
- * This is not very scalable on SMP. Double adds are not possible.
+ * mod_timer_pending() is the same for pending timers as mod_timer(),
+ * but will not re-activate and modify already deleted timers.
+ *
+ * It is useful for unserialized use of timers.
*/
-void add_timer_on(struct timer_list *timer, int cpu)
+int mod_timer_pending(struct timer_list *timer, unsigned long expires)
{
- struct tvec_base *base = per_cpu(tvec_bases, cpu);
- unsigned long flags;
-
- timer_stats_timer_set_start_info(timer);
- BUG_ON(timer_pending(timer) || !timer->function);
- spin_lock_irqsave(&base->lock, flags);
- timer_set_base(timer, base);
- debug_timer_activate(timer);
- internal_add_timer(base, timer);
- /*
- * Check whether the other CPU is idle and needs to be
- * triggered to reevaluate the timer wheel when nohz is
- * active. We are protected against the other CPU fiddling
- * with the timer by holding the timer base lock. This also
- * makes sure that a CPU on the way to idle can not evaluate
- * the timer wheel.
- */
- wake_up_idle_cpu(cpu);
- spin_unlock_irqrestore(&base->lock, flags);
+ return __mod_timer(timer, expires, true);
}
+EXPORT_SYMBOL(mod_timer_pending);

/**
* mod_timer - modify a timer's timeout
@@ -688,9 +680,6 @@ void add_timer_on(struct timer_list *timer, int cpu)
*/
int mod_timer(struct timer_list *timer, unsigned long expires)
{
- BUG_ON(!timer->function);
-
- timer_stats_timer_set_start_info(timer);
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
@@ -699,12 +688,62 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
if (timer->expires == expires && timer_pending(timer))
return 1;

- return __mod_timer(timer, expires);
+ return __mod_timer(timer, expires, false);
}
-
EXPORT_SYMBOL(mod_timer);

/**
+ * add_timer - start a timer
+ * @timer: the timer to be added
+ *
+ * The kernel will do a ->function(->data) callback from the
+ * timer interrupt at the ->expires point in the future. The
+ * current time is 'jiffies'.
+ *
+ * The timer's ->expires, ->function (and if the handler uses it, ->data)
+ * fields must be set prior calling this function.
+ *
+ * Timers with an ->expires field in the past will be executed in the next
+ * timer tick.
+ */
+void add_timer(struct timer_list *timer)
+{
+ BUG_ON(timer_pending(timer));
+ mod_timer(timer, timer->expires);
+}
+EXPORT_SYMBOL(add_timer);
+
+/**
+ * add_timer_on - start a timer on a particular CPU
+ * @timer: the timer to be added
+ * @cpu: the CPU to start it on
+ *
+ * This is not very scalable on SMP. Double adds are not possible.
+ */
+void add_timer_on(struct timer_list *timer, int cpu)
+{
+ struct tvec_base *base = per_cpu(tvec_bases, cpu);
+ unsigned long flags;
+
+ timer_stats_timer_set_start_info(timer);
+ BUG_ON(timer_pending(timer) || !timer->function);
+ spin_lock_irqsave(&base->lock, flags);
+ timer_set_base(timer, base);
+ debug_timer_activate(timer);
+ internal_add_timer(base, timer);
+ /*
+ * Check whether the other CPU is idle and needs to be
+ * triggered to reevaluate the timer wheel when nohz is
+ * active. We are protected against the other CPU fiddling
+ * with the timer by holding the timer base lock. This also
+ * makes sure that a CPU on the way to idle can not evaluate
+ * the timer wheel.
+ */
+ wake_up_idle_cpu(cpu);
+ spin_unlock_irqrestore(&base->lock, flags);
+}
+
+/**
* del_timer - deactive a timer.
* @timer: the timer to be deactivated
*
@@ -733,7 +772,6 @@ int del_timer(struct timer_list *timer)

return ret;
}
-
EXPORT_SYMBOL(del_timer);

#ifdef CONFIG_SMP
@@ -767,7 +805,6 @@ out:

return ret;
}
-
EXPORT_SYMBOL(try_to_del_timer_sync);

/**
@@ -796,7 +833,6 @@ int del_timer_sync(struct timer_list *timer)
cpu_relax();
}
}
-
EXPORT_SYMBOL(del_timer_sync);
#endif

@@ -1268,7 +1304,7 @@ signed long __sched schedule_timeout(signed long timeout)
expire = timeout + jiffies;

setup_timer_on_stack(&timer, process_timeout, (unsigned long)current);
- __mod_timer(&timer, expire);
+ __mod_timer(&timer, expire, false);
schedule();
del_singleshot_timer_sync(&timer);


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