Commit f5325225 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'timers-fixes-for-linus' of...

Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  clocksource, acpi_pm.c: check for monotonicity
  clocksource, acpi_pm.c: use proper read function also in errata mode
  ntp: fix calculation of the next jiffie to trigger RTC sync
  x86: HPET: read back compare register before reading counter
  x86: HPET fix moronic 32/64bit thinko
  clockevents: broadcast fixup possible waiters
  HPET: make minimum reprogramming delta useful
  clockevents: prevent endless loop lockup
  clockevents: prevent multiple init/shutdown
  clockevents: enforce reprogram in oneshot setup
  clockevents: prevent endless loop in periodic broadcast handler
  clockevents: prevent clockevent event_handler ending up handler_noop
parents 4747832b 4ab6a219
......@@ -210,8 +210,8 @@ static void hpet_legacy_clockevent_register(void)
/* Calculate the min / max delta */
hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
&hpet_clockevent);
hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30,
&hpet_clockevent);
/* 5 usec minimum reprogramming delta. */
hpet_clockevent.min_delta_ns = 5000;
/*
* Start hpet with the boot cpu mask and make it
......@@ -270,15 +270,22 @@ static void hpet_legacy_set_mode(enum clock_event_mode mode,
}
static int hpet_legacy_next_event(unsigned long delta,
struct clock_event_device *evt)
struct clock_event_device *evt)
{
unsigned long cnt;
u32 cnt;
cnt = hpet_readl(HPET_COUNTER);
cnt += delta;
cnt += (u32) delta;
hpet_writel(cnt, HPET_T0_CMP);
return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0) ? -ETIME : 0;
/*
* We need to read back the CMP register to make sure that
* what we wrote hit the chip before we compare it to the
* counter.
*/
WARN_ON((u32)hpet_readl(HPET_T0_CMP) != cnt);
return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
}
/*
......
......@@ -21,6 +21,7 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <asm/io.h>
/*
......@@ -151,13 +152,13 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE,
*/
static int verify_pmtmr_rate(void)
{
u32 value1, value2;
cycle_t value1, value2;
unsigned long count, delta;
mach_prepare_counter();
value1 = read_pmtmr();
value1 = clocksource_acpi_pm.read();
mach_countup(&count);
value2 = read_pmtmr();
value2 = clocksource_acpi_pm.read();
delta = (value2 - value1) & ACPI_PM_MASK;
/* Check that the PMTMR delta is within 5% of what we expect */
......@@ -175,10 +176,13 @@ static int verify_pmtmr_rate(void)
#define verify_pmtmr_rate() (0)
#endif
/* Number of monotonicity checks to perform during initialization */
#define ACPI_PM_MONOTONICITY_CHECKS 10
static int __init init_acpi_pm_clocksource(void)
{
u32 value1, value2;
unsigned int i;
cycle_t value1, value2;
unsigned int i, j, good = 0;
if (!pmtmr_ioport)
return -ENODEV;
......@@ -187,24 +191,32 @@ static int __init init_acpi_pm_clocksource(void)
clocksource_acpi_pm.shift);
/* "verify" this timing source: */
value1 = read_pmtmr();
for (i = 0; i < 10000; i++) {
value2 = read_pmtmr();
if (value2 == value1)
continue;
if (value2 > value1)
goto pm_good;
if ((value2 < value1) && ((value2) < 0xFFF))
goto pm_good;
printk(KERN_INFO "PM-Timer had inconsistent results:"
" 0x%#x, 0x%#x - aborting.\n", value1, value2);
return -EINVAL;
for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) {
value1 = clocksource_acpi_pm.read();
for (i = 0; i < 10000; i++) {
value2 = clocksource_acpi_pm.read();
if (value2 == value1)
continue;
if (value2 > value1)
good++;
break;
if ((value2 < value1) && ((value2) < 0xFFF))
good++;
break;
printk(KERN_INFO "PM-Timer had inconsistent results:"
" 0x%#llx, 0x%#llx - aborting.\n",
value1, value2);
return -EINVAL;
}
udelay(300 * i);
}
if (good != ACPI_PM_MONOTONICITY_CHECKS) {
printk(KERN_INFO "PM-Timer failed consistency check "
" (0x%#llx) - aborting.\n", value1);
return -ENODEV;
}
printk(KERN_INFO "PM-Timer had no reasonable result:"
" 0x%#x - aborting.\n", value1);
return -ENODEV;
pm_good:
if (verify_pmtmr_rate() != 0)
return -ENODEV;
......
......@@ -127,6 +127,8 @@ extern int clockevents_register_notifier(struct notifier_block *nb);
extern int clockevents_program_event(struct clock_event_device *dev,
ktime_t expires, ktime_t now);
extern void clockevents_handle_noop(struct clock_event_device *dev);
#ifdef CONFIG_GENERIC_CLOCKEVENTS
extern void clockevents_notify(unsigned long reason, void *arg);
#else
......
......@@ -177,7 +177,7 @@ void clockevents_register_device(struct clock_event_device *dev)
/*
* Noop handler when we shut down an event device
*/
static void clockevents_handle_noop(struct clock_event_device *dev)
void clockevents_handle_noop(struct clock_event_device *dev)
{
}
......@@ -199,7 +199,6 @@ void clockevents_exchange_device(struct clock_event_device *old,
* released list and do a notify add later.
*/
if (old) {
old->event_handler = clockevents_handle_noop;
clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
list_del(&old->list);
list_add(&old->list, &clockevents_released);
......
......@@ -245,7 +245,7 @@ static void sync_cmos_clock(unsigned long dummy)
if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
fail = update_persistent_clock(now);
next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec;
next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2);
if (next.tv_nsec <= 0)
next.tv_nsec += NSEC_PER_SEC;
......
......@@ -175,6 +175,8 @@ static void tick_do_periodic_broadcast(void)
*/
static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
{
ktime_t next;
tick_do_periodic_broadcast();
/*
......@@ -185,10 +187,13 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
/*
* Setup the next period for devices, which do not have
* periodic mode:
* periodic mode. We read dev->next_event first and add to it
* when the event alrady expired. clockevents_program_event()
* sets dev->next_event only when the event is really
* programmed to the device.
*/
for (;;) {
ktime_t next = ktime_add(dev->next_event, tick_period);
for (next = dev->next_event; ;) {
next = ktime_add(next, tick_period);
if (!clockevents_program_event(dev, next, ktime_get()))
return;
......@@ -205,7 +210,7 @@ static void tick_do_broadcast_on_off(void *why)
struct clock_event_device *bc, *dev;
struct tick_device *td;
unsigned long flags, *reason = why;
int cpu;
int cpu, bc_stopped;
spin_lock_irqsave(&tick_broadcast_lock, flags);
......@@ -223,6 +228,8 @@ static void tick_do_broadcast_on_off(void *why)
if (!tick_device_is_functional(dev))
goto out;
bc_stopped = cpus_empty(tick_broadcast_mask);
switch (*reason) {
case CLOCK_EVT_NOTIFY_BROADCAST_ON:
case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
......@@ -245,9 +252,10 @@ static void tick_do_broadcast_on_off(void *why)
break;
}
if (cpus_empty(tick_broadcast_mask))
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
else {
if (cpus_empty(tick_broadcast_mask)) {
if (!bc_stopped)
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
} else if (bc_stopped) {
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
tick_broadcast_start_periodic(bc);
else
......@@ -364,16 +372,8 @@ cpumask_t *tick_get_broadcast_oneshot_mask(void)
static int tick_broadcast_set_event(ktime_t expires, int force)
{
struct clock_event_device *bc = tick_broadcast_device.evtdev;
ktime_t now = ktime_get();
int res;
for(;;) {
res = clockevents_program_event(bc, expires, now);
if (!res || !force)
return res;
now = ktime_get();
expires = ktime_add(now, ktime_set(0, bc->min_delta_ns));
}
return tick_dev_program_event(bc, expires, force);
}
int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
......@@ -491,14 +491,52 @@ static void tick_broadcast_clear_oneshot(int cpu)
cpu_clear(cpu, tick_broadcast_oneshot_mask);
}
static void tick_broadcast_init_next_event(cpumask_t *mask, ktime_t expires)
{
struct tick_device *td;
int cpu;
for_each_cpu_mask_nr(cpu, *mask) {
td = &per_cpu(tick_cpu_device, cpu);
if (td->evtdev)
td->evtdev->next_event = expires;
}
}
/**
* tick_broadcast_setup_oneshot - setup the broadcast device
*/
void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
bc->event_handler = tick_handle_oneshot_broadcast;
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
bc->next_event.tv64 = KTIME_MAX;
/* Set it up only once ! */
if (bc->event_handler != tick_handle_oneshot_broadcast) {
int was_periodic = bc->mode == CLOCK_EVT_MODE_PERIODIC;
int cpu = smp_processor_id();
cpumask_t mask;
bc->event_handler = tick_handle_oneshot_broadcast;
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
/* Take the do_timer update */
tick_do_timer_cpu = cpu;
/*
* We must be careful here. There might be other CPUs
* waiting for periodic broadcast. We need to set the
* oneshot_mask bits for those and program the
* broadcast device to fire.
*/
mask = tick_broadcast_mask;
cpu_clear(cpu, mask);
cpus_or(tick_broadcast_oneshot_mask,
tick_broadcast_oneshot_mask, mask);
if (was_periodic && !cpus_empty(mask)) {
tick_broadcast_init_next_event(&mask, tick_next_period);
tick_broadcast_set_event(tick_next_period, 1);
} else
bc->next_event.tv64 = KTIME_MAX;
}
}
/*
......
......@@ -161,6 +161,7 @@ static void tick_setup_device(struct tick_device *td,
} else {
handler = td->evtdev->event_handler;
next_event = td->evtdev->next_event;
td->evtdev->event_handler = clockevents_handle_noop;
}
td->evtdev = newdev;
......
......@@ -17,6 +17,8 @@ extern void tick_handle_periodic(struct clock_event_device *dev);
extern void tick_setup_oneshot(struct clock_event_device *newdev,
void (*handler)(struct clock_event_device *),
ktime_t nextevt);
extern int tick_dev_program_event(struct clock_event_device *dev,
ktime_t expires, int force);
extern int tick_program_event(ktime_t expires, int force);
extern void tick_oneshot_notify(void);
extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
......
......@@ -23,23 +23,57 @@
#include "tick-internal.h"
/**
* tick_program_event
* tick_program_event internal worker function
*/
int tick_program_event(ktime_t expires, int force)
int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires,
int force)
{
struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
ktime_t now = ktime_get();
int i;
while (1) {
for (i = 0;;) {
int ret = clockevents_program_event(dev, expires, now);
if (!ret || !force)
return ret;
/*
* We tried 2 times to program the device with the given
* min_delta_ns. If that's not working then we double it
* and emit a warning.
*/
if (++i > 2) {
printk(KERN_WARNING "CE: __tick_program_event of %s is "
"stuck %llx %llx\n", dev->name ? dev->name : "?",
now.tv64, expires.tv64);
printk(KERN_WARNING
"CE: increasing min_delta_ns %ld to %ld nsec\n",
dev->min_delta_ns, dev->min_delta_ns << 1);
WARN_ON(1);
/* Double the min. delta and try again */
if (!dev->min_delta_ns)
dev->min_delta_ns = 5000;
else
dev->min_delta_ns <<= 1;
i = 0;
}
now = ktime_get();
expires = ktime_add(now, ktime_set(0, dev->min_delta_ns));
expires = ktime_add_ns(now, dev->min_delta_ns);
}
}
/**
* tick_program_event
*/
int tick_program_event(ktime_t expires, int force)
{
struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
return tick_dev_program_event(dev, expires, force);
}
/**
* tick_resume_onshot - resume oneshot mode
*/
......@@ -61,7 +95,7 @@ void tick_setup_oneshot(struct clock_event_device *newdev,
{
newdev->event_handler = handler;
clockevents_set_mode(newdev, CLOCK_EVT_MODE_ONESHOT);
clockevents_program_event(newdev, next_event, ktime_get());
tick_dev_program_event(newdev, next_event, 1);
}
/**
......
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