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Diffstat (limited to 'arch/x86_64/kernel/time.c')
-rw-r--r--arch/x86_64/kernel/time.c166
1 files changed, 75 insertions, 91 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 3080f84bf7b..473b514b66e 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -88,7 +88,8 @@ static inline unsigned int do_gettimeoffset_tsc(void)
unsigned long t;
unsigned long x;
t = get_cycles_sync();
- if (t < vxtime.last_tsc) t = vxtime.last_tsc; /* hack */
+ if (t < vxtime.last_tsc)
+ t = vxtime.last_tsc; /* hack */
x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> 32;
return x;
}
@@ -178,8 +179,9 @@ unsigned long profile_pc(struct pt_regs *regs)
{
unsigned long pc = instruction_pointer(regs);
- /* Assume the lock function has either no stack frame or only a single word.
- This checks if the address on the stack looks like a kernel text address.
+ /* Assume the lock function has either no stack frame or only a single
+ word. This checks if the address on the stack looks like a kernel
+ text address.
There is a small window for false hits, but in that case the tick
is just accounted to the spinlock function.
Better would be to write these functions in assembler again
@@ -242,17 +244,10 @@ static void set_rtc_mmss(unsigned long nowtime)
real_minutes += 30; /* correct for half hour time zone */
real_minutes %= 60;
-#if 0
- /* AMD 8111 is a really bad time keeper and hits this regularly.
- It probably was an attempt to avoid screwing up DST, but ignore
- that for now. */
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);
- } else
-#endif
-
- {
+ } else {
BIN_TO_BCD(real_seconds);
BIN_TO_BCD(real_minutes);
CMOS_WRITE(real_seconds, RTC_SECONDS);
@@ -293,8 +288,7 @@ unsigned long long monotonic_clock(void)
this_offset = hpet_readl(HPET_COUNTER);
} while (read_seqretry(&xtime_lock, seq));
offset = (this_offset - last_offset);
- offset *=(NSEC_PER_SEC/HZ)/hpet_tick;
- return base + offset;
+ offset *= (NSEC_PER_SEC/HZ) / hpet_tick;
} else {
do {
seq = read_seqbegin(&xtime_lock);
@@ -303,50 +297,46 @@ unsigned long long monotonic_clock(void)
base = monotonic_base;
} while (read_seqretry(&xtime_lock, seq));
this_offset = get_cycles_sync();
- offset = (this_offset - last_offset)*1000/cpu_khz;
- return base + offset;
+ offset = (this_offset - last_offset)*1000 / cpu_khz;
}
+ return base + offset;
}
EXPORT_SYMBOL(monotonic_clock);
static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
{
- static long lost_count;
- static int warned;
-
- if (report_lost_ticks) {
- printk(KERN_WARNING "time.c: Lost %d timer "
- "tick(s)! ", lost);
- print_symbol("rip %s)\n", regs->rip);
- }
-
- if (lost_count == 1000 && !warned) {
- printk(KERN_WARNING
- "warning: many lost ticks.\n"
- KERN_WARNING "Your time source seems to be instable or "
+ static long lost_count;
+ static int warned;
+ if (report_lost_ticks) {
+ printk(KERN_WARNING "time.c: Lost %d timer tick(s)! ", lost);
+ print_symbol("rip %s)\n", regs->rip);
+ }
+
+ if (lost_count == 1000 && !warned) {
+ printk(KERN_WARNING "warning: many lost ticks.\n"
+ KERN_WARNING "Your time source seems to be instable or "
"some driver is hogging interupts\n");
- print_symbol("rip %s\n", regs->rip);
- if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
- printk(KERN_WARNING "Falling back to HPET\n");
- if (hpet_use_timer)
- vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
- else
- vxtime.last = hpet_readl(HPET_COUNTER);
- vxtime.mode = VXTIME_HPET;
- do_gettimeoffset = do_gettimeoffset_hpet;
- }
- /* else should fall back to PIT, but code missing. */
- warned = 1;
- } else
- lost_count++;
+ print_symbol("rip %s\n", regs->rip);
+ if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
+ printk(KERN_WARNING "Falling back to HPET\n");
+ if (hpet_use_timer)
+ vxtime.last = hpet_readl(HPET_T0_CMP) -
+ hpet_tick;
+ else
+ vxtime.last = hpet_readl(HPET_COUNTER);
+ vxtime.mode = VXTIME_HPET;
+ do_gettimeoffset = do_gettimeoffset_hpet;
+ }
+ /* else should fall back to PIT, but code missing. */
+ warned = 1;
+ } else
+ lost_count++;
#ifdef CONFIG_CPU_FREQ
- /* In some cases the CPU can change frequency without us noticing
- (like going into thermal throttle)
- Give cpufreq a change to catch up. */
- if ((lost_count+1) % 25 == 0) {
- cpufreq_delayed_get();
- }
+ /* In some cases the CPU can change frequency without us noticing
+ Give cpufreq a change to catch up. */
+ if ((lost_count+1) % 25 == 0)
+ cpufreq_delayed_get();
#endif
}
@@ -354,7 +344,7 @@ void main_timer_handler(struct pt_regs *regs)
{
static unsigned long rtc_update = 0;
unsigned long tsc;
- int delay, offset = 0, lost = 0;
+ int delay = 0, offset = 0, lost = 0;
/*
* Here we are in the timer irq handler. We have irqs locally disabled (so we
@@ -375,7 +365,7 @@ void main_timer_handler(struct pt_regs *regs)
*/
offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
delay = hpet_readl(HPET_COUNTER) - offset;
- } else {
+ } else if (!pmtmr_ioport) {
spin_lock(&i8253_lock);
outb_p(0x00, 0x43);
delay = inb_p(0x40);
@@ -477,7 +467,7 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
return IRQ_HANDLED;
}
-static unsigned int cyc2ns_scale;
+static unsigned int cyc2ns_scale __read_mostly;
#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
static inline void set_cyc2ns_scale(unsigned long cpu_khz)
@@ -514,43 +504,32 @@ unsigned long long sched_clock(void)
static unsigned long get_cmos_time(void)
{
- unsigned int timeout = 1000000, year, mon, day, hour, min, sec;
- unsigned char uip = 0, this = 0;
+ unsigned int year, mon, day, hour, min, sec;
unsigned long flags;
-
-/*
- * The Linux interpretation of the CMOS clock register contents: When the
- * Update-In-Progress (UIP) flag goes from 1 to 0, the RTC registers show the
- * second which has precisely just started. Waiting for this can take up to 1
- * second, we timeout approximately after 2.4 seconds on a machine with
- * standard 8.3 MHz ISA bus.
- */
+ unsigned extyear = 0;
spin_lock_irqsave(&rtc_lock, flags);
- while (timeout && (!uip || this)) {
- uip |= this;
- this = CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP;
- timeout--;
- }
-
- /*
- * Here we are safe to assume the registers won't change for a whole
- * second, so we just go ahead and read them.
- */
- sec = CMOS_READ(RTC_SECONDS);
- min = CMOS_READ(RTC_MINUTES);
- hour = CMOS_READ(RTC_HOURS);
- day = CMOS_READ(RTC_DAY_OF_MONTH);
- mon = CMOS_READ(RTC_MONTH);
- year = CMOS_READ(RTC_YEAR);
+ do {
+ sec = CMOS_READ(RTC_SECONDS);
+ min = CMOS_READ(RTC_MINUTES);
+ hour = CMOS_READ(RTC_HOURS);
+ day = CMOS_READ(RTC_DAY_OF_MONTH);
+ mon = CMOS_READ(RTC_MONTH);
+ year = CMOS_READ(RTC_YEAR);
+#ifdef CONFIG_ACPI
+ if (acpi_fadt.revision >= FADT2_REVISION_ID &&
+ acpi_fadt.century)
+ extyear = CMOS_READ(acpi_fadt.century);
+#endif
+ } while (sec != CMOS_READ(RTC_SECONDS));
spin_unlock_irqrestore(&rtc_lock, flags);
/*
* We know that x86-64 always uses BCD format, no need to check the
* config register.
- */
+ */
BCD_TO_BIN(sec);
BCD_TO_BIN(min);
@@ -559,11 +538,17 @@ static unsigned long get_cmos_time(void)
BCD_TO_BIN(mon);
BCD_TO_BIN(year);
- /*
- * x86-64 systems only exists since 2002.
- * This will work up to Dec 31, 2100
- */
- year += 2000;
+ if (extyear) {
+ BCD_TO_BIN(extyear);
+ year += extyear;
+ printk(KERN_INFO "Extended CMOS year: %d\n", extyear);
+ } else {
+ /*
+ * x86-64 systems only exists since 2002.
+ * This will work up to Dec 31, 2100
+ */
+ year += 2000;
+ }
return mktime(year, mon, day, hour, min, sec);
}
@@ -606,7 +591,8 @@ static void cpufreq_delayed_get(void)
cpufreq_delayed_issched = 1;
if (!warned) {
warned = 1;
- printk(KERN_DEBUG "Losing some ticks... checking if CPU frequency changed.\n");
+ printk(KERN_DEBUG
+ "Losing some ticks... checking if CPU frequency changed.\n");
}
schedule_work(&cpufreq_delayed_get_work);
}
@@ -629,9 +615,9 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
lpj = &dummy;
if (!(freq->flags & CPUFREQ_CONST_LOOPS))
#ifdef CONFIG_SMP
- lpj = &cpu_data[freq->cpu].loops_per_jiffy;
+ lpj = &cpu_data[freq->cpu].loops_per_jiffy;
#else
- lpj = &boot_cpu_data.loops_per_jiffy;
+ lpj = &boot_cpu_data.loops_per_jiffy;
#endif
if (!ref_freq) {
@@ -768,9 +754,8 @@ static __init int late_hpet_init(void)
int i;
hpet = (struct hpet *) fix_to_virt(FIX_HPET_BASE);
-
- for (i = 2, timer = &hpet->hpet_timers[2]; i < ntimer;
- timer++, i++)
+ timer = &hpet->hpet_timers[2];
+ for (i = 2; i < ntimer; timer++, i++)
hd.hd_irq[i] = (timer->hpet_config &
Tn_INT_ROUTE_CNF_MASK) >>
Tn_INT_ROUTE_CNF_SHIFT;
@@ -927,8 +912,7 @@ void __init time_init(void)
-xtime.tv_sec, -xtime.tv_nsec);
if (!hpet_init())
- vxtime_hz = (1000000000000000L + hpet_period / 2) /
- hpet_period;
+ vxtime_hz = (1000000000000000L + hpet_period / 2) / hpet_period;
else
vxtime.hpet_address = 0;
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-25 17:59:39 +0000