summaryrefslogtreecommitdiff
path: root/arch/x86_64/kernel/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86_64/kernel/time.c')
-rw-r--r--arch/x86_64/kernel/time.c158
1 files changed, 58 insertions, 100 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 4a0895bacf51..6d48a4e826d9 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -33,6 +33,7 @@
#include <acpi/acpi_bus.h>
#endif
#include <asm/8253pit.h>
+#include <asm/i8253.h>
#include <asm/pgtable.h>
#include <asm/vsyscall.h>
#include <asm/timex.h>
@@ -44,12 +45,14 @@
#include <asm/hpet.h>
#include <asm/mpspec.h>
#include <asm/nmi.h>
+#include <asm/vgtod.h>
static char *timename = NULL;
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
DEFINE_SPINLOCK(i8253_lock);
+EXPORT_SYMBOL(i8253_lock);
volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
@@ -79,8 +82,9 @@ EXPORT_SYMBOL(profile_pc);
* sheet for details.
*/
-static void set_rtc_mmss(unsigned long nowtime)
+static int set_rtc_mmss(unsigned long nowtime)
{
+ int retval = 0;
int real_seconds, real_minutes, cmos_minutes;
unsigned char control, freq_select;
@@ -120,6 +124,7 @@ static void set_rtc_mmss(unsigned long nowtime)
if (abs(real_minutes - cmos_minutes) >= 30) {
printk(KERN_WARNING "time.c: can't update CMOS clock "
"from %d to %d\n", cmos_minutes, real_minutes);
+ retval = -1;
} else {
BIN_TO_BCD(real_seconds);
BIN_TO_BCD(real_minutes);
@@ -139,12 +144,17 @@ static void set_rtc_mmss(unsigned long nowtime)
CMOS_WRITE(freq_select, RTC_FREQ_SELECT);
spin_unlock(&rtc_lock);
+
+ return retval;
}
+int update_persistent_clock(struct timespec now)
+{
+ return set_rtc_mmss(now.tv_sec);
+}
void main_timer_handler(void)
{
- static unsigned long rtc_update = 0;
/*
* Here we are in the timer irq handler. We have irqs locally disabled (so we
* don't need spin_lock_irqsave()) but we don't know if the timer_bh is running
@@ -172,20 +182,6 @@ void main_timer_handler(void)
if (!using_apic_timer)
smp_local_timer_interrupt();
-/*
- * If we have an externally synchronized Linux clock, then update CMOS clock
- * accordingly every ~11 minutes. set_rtc_mmss() will be called in the jiffy
- * closest to exactly 500 ms before the next second. If the update fails, we
- * don't care, as it'll be updated on the next turn, and the problem (time way
- * off) isn't likely to go away much sooner anyway.
- */
-
- if (ntp_synced() && xtime.tv_sec > rtc_update &&
- abs(xtime.tv_nsec - 500000000) <= tick_nsec / 2) {
- set_rtc_mmss(xtime.tv_sec);
- rtc_update = xtime.tv_sec + 660;
- }
-
write_sequnlock(&xtime_lock);
}
@@ -199,7 +195,7 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
-static unsigned long get_cmos_time(void)
+unsigned long read_persistent_clock(void)
{
unsigned int year, mon, day, hour, min, sec;
unsigned long flags;
@@ -226,7 +222,7 @@ static unsigned long get_cmos_time(void)
/*
* We know that x86-64 always uses BCD format, no need to check the
* config register.
- */
+ */
BCD_TO_BIN(sec);
BCD_TO_BIN(min);
@@ -239,11 +235,11 @@ static unsigned long get_cmos_time(void)
BCD_TO_BIN(century);
year += century * 100;
printk(KERN_INFO "Extended CMOS year: %d\n", century * 100);
- } else {
+ } else {
/*
* x86-64 systems only exists since 2002.
* This will work up to Dec 31, 2100
- */
+ */
year += 2000;
}
@@ -255,45 +251,45 @@ static unsigned long get_cmos_time(void)
#define TICK_COUNT 100000000
static unsigned int __init tsc_calibrate_cpu_khz(void)
{
- int tsc_start, tsc_now;
- int i, no_ctr_free;
- unsigned long evntsel3 = 0, pmc3 = 0, pmc_now = 0;
- unsigned long flags;
-
- for (i = 0; i < 4; i++)
- if (avail_to_resrv_perfctr_nmi_bit(i))
- break;
- no_ctr_free = (i == 4);
- if (no_ctr_free) {
- i = 3;
- rdmsrl(MSR_K7_EVNTSEL3, evntsel3);
- wrmsrl(MSR_K7_EVNTSEL3, 0);
- rdmsrl(MSR_K7_PERFCTR3, pmc3);
- } else {
- reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i);
- reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
- }
- local_irq_save(flags);
- /* start meauring cycles, incrementing from 0 */
- wrmsrl(MSR_K7_PERFCTR0 + i, 0);
- wrmsrl(MSR_K7_EVNTSEL0 + i, 1 << 22 | 3 << 16 | 0x76);
- rdtscl(tsc_start);
- do {
- rdmsrl(MSR_K7_PERFCTR0 + i, pmc_now);
- tsc_now = get_cycles_sync();
- } while ((tsc_now - tsc_start) < TICK_COUNT);
-
- local_irq_restore(flags);
- if (no_ctr_free) {
- wrmsrl(MSR_K7_EVNTSEL3, 0);
- wrmsrl(MSR_K7_PERFCTR3, pmc3);
- wrmsrl(MSR_K7_EVNTSEL3, evntsel3);
- } else {
- release_perfctr_nmi(MSR_K7_PERFCTR0 + i);
- release_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
- }
-
- return pmc_now * tsc_khz / (tsc_now - tsc_start);
+ int tsc_start, tsc_now;
+ int i, no_ctr_free;
+ unsigned long evntsel3 = 0, pmc3 = 0, pmc_now = 0;
+ unsigned long flags;
+
+ for (i = 0; i < 4; i++)
+ if (avail_to_resrv_perfctr_nmi_bit(i))
+ break;
+ no_ctr_free = (i == 4);
+ if (no_ctr_free) {
+ i = 3;
+ rdmsrl(MSR_K7_EVNTSEL3, evntsel3);
+ wrmsrl(MSR_K7_EVNTSEL3, 0);
+ rdmsrl(MSR_K7_PERFCTR3, pmc3);
+ } else {
+ reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i);
+ reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
+ }
+ local_irq_save(flags);
+ /* start meauring cycles, incrementing from 0 */
+ wrmsrl(MSR_K7_PERFCTR0 + i, 0);
+ wrmsrl(MSR_K7_EVNTSEL0 + i, 1 << 22 | 3 << 16 | 0x76);
+ rdtscl(tsc_start);
+ do {
+ rdmsrl(MSR_K7_PERFCTR0 + i, pmc_now);
+ tsc_now = get_cycles_sync();
+ } while ((tsc_now - tsc_start) < TICK_COUNT);
+
+ local_irq_restore(flags);
+ if (no_ctr_free) {
+ wrmsrl(MSR_K7_EVNTSEL3, 0);
+ wrmsrl(MSR_K7_PERFCTR3, pmc3);
+ wrmsrl(MSR_K7_EVNTSEL3, evntsel3);
+ } else {
+ release_perfctr_nmi(MSR_K7_PERFCTR0 + i);
+ release_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
+ }
+
+ return pmc_now * tsc_khz / (tsc_now - tsc_start);
}
/*
@@ -321,7 +317,7 @@ static unsigned int __init pit_calibrate_tsc(void)
end = get_cycles_sync();
spin_unlock_irqrestore(&i8253_lock, flags);
-
+
return (end - start) / 50;
}
@@ -366,25 +362,20 @@ static struct irqaction irq0 = {
.handler = timer_interrupt,
.flags = IRQF_DISABLED | IRQF_IRQPOLL,
.mask = CPU_MASK_NONE,
- .name = "timer"
+ .name = "timer"
};
void __init time_init(void)
{
if (nohpet)
hpet_address = 0;
- xtime.tv_sec = get_cmos_time();
- xtime.tv_nsec = 0;
-
- set_normalized_timespec(&wall_to_monotonic,
- -xtime.tv_sec, -xtime.tv_nsec);
if (hpet_arch_init())
hpet_address = 0;
if (hpet_use_timer) {
/* set tick_nsec to use the proper rate for HPET */
- tick_nsec = TICK_NSEC_HPET;
+ tick_nsec = TICK_NSEC_HPET;
tsc_khz = hpet_calibrate_tsc();
timename = "HPET";
} else {
@@ -415,54 +406,21 @@ void __init time_init(void)
setup_irq(0, &irq0);
}
-
-static long clock_cmos_diff;
-static unsigned long sleep_start;
-
/*
* sysfs support for the timer.
*/
static int timer_suspend(struct sys_device *dev, pm_message_t state)
{
- /*
- * Estimate time zone so that set_time can update the clock
- */
- long cmos_time = get_cmos_time();
-
- clock_cmos_diff = -cmos_time;
- clock_cmos_diff += get_seconds();
- sleep_start = cmos_time;
return 0;
}
static int timer_resume(struct sys_device *dev)
{
- unsigned long flags;
- unsigned long sec;
- unsigned long ctime = get_cmos_time();
- long sleep_length = (ctime - sleep_start) * HZ;
-
- if (sleep_length < 0) {
- printk(KERN_WARNING "Time skew detected in timer resume!\n");
- /* The time after the resume must not be earlier than the time
- * before the suspend or some nasty things will happen
- */
- sleep_length = 0;
- ctime = sleep_start;
- }
if (hpet_address)
hpet_reenable();
else
i8254_timer_resume();
-
- sec = ctime + clock_cmos_diff;
- write_seqlock_irqsave(&xtime_lock,flags);
- xtime.tv_sec = sec;
- xtime.tv_nsec = 0;
- jiffies += sleep_length;
- write_sequnlock_irqrestore(&xtime_lock,flags);
- touch_softlockup_watchdog();
return 0;
}
generated by cgit v1.2.3 (git 2.0.4) at 2024-12-28 18:30:09 +0000