* Copyright (c) 1995 Markus Kuhn
* Copyright (c) 1996 Ingo Molnar
* Copyright (c) 1998 Andrea Arcangeli
- * Copyright (c) 2002 Vojtech Pavlik
+ * Copyright (c) 2002,2006 Vojtech Pavlik
* Copyright (c) 2003 Andi Kleen
* RTC support code taken from arch/i386/kernel/timers/time_hpet.c
*/
#include <linux/device.h>
#include <linux/sysdev.h>
#include <linux/bcd.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
#include <linux/kallsyms.h>
#include <linux/acpi.h>
#ifdef CONFIG_ACPI
#include <acpi/achware.h> /* for PM timer frequency */
+#include <acpi/acpi_bus.h>
#endif
#include <asm/8253pit.h>
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <linux/cpufreq.h>
#include <linux/hpet.h>
-#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/apic.h>
-#endif
#ifdef CONFIG_CPU_FREQ
static void cpufreq_delayed_get(void);
extern void i8254_timer_resume(void);
extern int using_apic_timer;
-static char *time_init_gtod(void);
+static char *timename = NULL;
DEFINE_SPINLOCK(rtc_lock);
+EXPORT_SYMBOL(rtc_lock);
DEFINE_SPINLOCK(i8253_lock);
int nohpet __initdata = 0;
static int notsc __initdata = 0;
-#undef HPET_HACK_ENABLE_DANGEROUS
+#define USEC_PER_TICK (USEC_PER_SEC / HZ)
+#define NSEC_PER_TICK (NSEC_PER_SEC / HZ)
+#define FSEC_PER_TICK (FSEC_PER_SEC / HZ)
+
+#define NS_SCALE 10 /* 2^10, carefully chosen */
+#define US_SCALE 32 /* 2^32, arbitralrily chosen */
unsigned int cpu_khz; /* TSC clocks / usec, not used here */
+EXPORT_SYMBOL(cpu_khz);
static unsigned long hpet_period; /* fsecs / HPET clock */
unsigned long hpet_tick; /* HPET clocks / interrupt */
int hpet_use_timer; /* Use counter of hpet for time keeping, otherwise PIT */
struct vxtime_data __vxtime __section_vxtime; /* for vsyscalls */
volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
-unsigned long __wall_jiffies __section_wall_jiffies = INITIAL_JIFFIES;
struct timespec __xtime __section_xtime;
struct timezone __sys_tz __section_sys_tz;
unsigned long t;
unsigned long x;
t = get_cycles_sync();
- if (t < vxtime.last_tsc) t = vxtime.last_tsc; /* hack */
- x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> 32;
+ if (t < vxtime.last_tsc)
+ t = vxtime.last_tsc; /* hack */
+ x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> US_SCALE;
return x;
}
{
/* cap counter read to one tick to avoid inconsistencies */
unsigned long counter = hpet_readl(HPET_COUNTER) - vxtime.last;
- return (min(counter,hpet_tick) * vxtime.quot) >> 32;
+ return (min(counter,hpet_tick) * vxtime.quot) >> US_SCALE;
}
unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc;
void do_gettimeofday(struct timeval *tv)
{
- unsigned long seq, t;
+ unsigned long seq;
unsigned int sec, usec;
do {
seq = read_seqbegin(&xtime_lock);
sec = xtime.tv_sec;
- usec = xtime.tv_nsec / 1000;
+ usec = xtime.tv_nsec / NSEC_PER_USEC;
/* i386 does some correction here to keep the clock
monotonous even when ntpd is fixing drift.
be found. Note when you fix it here you need to do the same
in arch/x86_64/kernel/vsyscall.c and export all needed
variables in vmlinux.lds. -AK */
-
- t = (jiffies - wall_jiffies) * (1000000L / HZ) +
- do_gettimeoffset();
- usec += t;
+ usec += do_gettimeoffset();
} while (read_seqretry(&xtime_lock, seq));
- tv->tv_sec = sec + usec / 1000000;
- tv->tv_usec = usec % 1000000;
+ tv->tv_sec = sec + usec / USEC_PER_SEC;
+ tv->tv_usec = usec % USEC_PER_SEC;
}
EXPORT_SYMBOL(do_gettimeofday);
write_seqlock_irq(&xtime_lock);
- nsec -= do_gettimeoffset() * 1000 +
- (jiffies - wall_jiffies) * (NSEC_PER_SEC/HZ);
+ nsec -= do_gettimeoffset() * NSEC_PER_USEC;
wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
{
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.
- 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
- and check exactly. */
- if (in_lock_functions(pc)) {
- char *v = *(char **)regs->rsp;
- if ((v >= _stext && v <= _etext) ||
- (v >= _sinittext && v <= _einittext) ||
- (v >= (char *)MODULES_VADDR && v <= (char *)MODULES_END))
- return (unsigned long)v;
- return ((unsigned long *)regs->rsp)[1];
+ /* Assume the lock function has either no stack frame or a copy
+ of eflags from PUSHF
+ Eflags always has bits 22 and up cleared unlike kernel addresses. */
+ if (!user_mode(regs) && in_lock_functions(pc)) {
+ unsigned long *sp = (unsigned long *)regs->rsp;
+ if (sp[0] >> 22)
+ return sp[0];
+ if (sp[1] >> 22)
+ return sp[1];
}
return pc;
}
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);
* Note: This function is required to return accurate
* time even in the absence of multiple timer ticks.
*/
+static inline unsigned long long cycles_2_ns(unsigned long long cyc);
unsigned long long monotonic_clock(void)
{
unsigned long seq;
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_TICK / hpet_tick;
} else {
do {
seq = read_seqbegin(&xtime_lock);
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 = cycles_2_ns(this_offset - last_offset);
}
+ return base + offset;
}
EXPORT_SYMBOL(monotonic_clock);
-static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
+static noinline void handle_lost_ticks(int lost)
{
- 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", get_irq_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", get_irq_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
}
-void main_timer_handler(struct pt_regs *regs)
+void main_timer_handler(void)
{
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
*/
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);
}
monotonic_base +=
- (offset - vxtime.last)*(NSEC_PER_SEC/HZ) / hpet_tick;
+ (offset - vxtime.last) * NSEC_PER_TICK / hpet_tick;
vxtime.last = offset;
#ifdef CONFIG_X86_PM_TIMER
#endif
} else {
offset = (((tsc - vxtime.last_tsc) *
- vxtime.tsc_quot) >> 32) - (USEC_PER_SEC / HZ);
+ vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK;
if (offset < 0)
offset = 0;
- if (offset > (USEC_PER_SEC / HZ)) {
- lost = offset / (USEC_PER_SEC / HZ);
- offset %= (USEC_PER_SEC / HZ);
+ if (offset > USEC_PER_TICK) {
+ lost = offset / USEC_PER_TICK;
+ offset %= USEC_PER_TICK;
}
- monotonic_base += (tsc - vxtime.last_tsc)*1000000/cpu_khz ;
+ monotonic_base += cycles_2_ns(tsc - vxtime.last_tsc);
vxtime.last_tsc = tsc - vxtime.quot * delay / vxtime.tsc_quot;
if ((((tsc - vxtime.last_tsc) *
- vxtime.tsc_quot) >> 32) < offset)
+ vxtime.tsc_quot) >> US_SCALE) < offset)
vxtime.last_tsc = tsc -
- (((long) offset << 32) / vxtime.tsc_quot) - 1;
+ (((long) offset << US_SCALE) / vxtime.tsc_quot) - 1;
}
- if (lost > 0) {
- handle_lost_ticks(lost, regs);
- jiffies += lost;
- }
+ if (lost > 0)
+ handle_lost_ticks(lost);
+ else
+ lost = 0;
/*
* Do the timer stuff.
*/
- do_timer(regs);
+ do_timer(lost + 1);
#ifndef CONFIG_SMP
- update_process_times(user_mode(regs));
+ update_process_times(user_mode(get_irq_regs()));
#endif
/*
* have to call the local interrupt handler.
*/
-#ifndef CONFIG_X86_LOCAL_APIC
- profile_tick(CPU_PROFILING, regs);
-#else
if (!using_apic_timer)
- smp_local_timer_interrupt(regs);
-#endif
+ smp_local_timer_interrupt();
/*
* If we have an externally synchronized Linux clock, then update CMOS clock
write_sequnlock(&xtime_lock);
}
-static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
if (apic_runs_main_timer > 1)
return IRQ_HANDLED;
- main_timer_handler(regs);
-#ifdef CONFIG_X86_LOCAL_APIC
+ main_timer_handler();
if (using_apic_timer)
smp_send_timer_broadcast_ipi();
-#endif
return IRQ_HANDLED;
}
-static unsigned int cyc2ns_scale;
-#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
+static unsigned int cyc2ns_scale __read_mostly;
static inline void set_cyc2ns_scale(unsigned long cpu_khz)
{
- cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR)/cpu_khz;
+ cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / cpu_khz;
}
static inline unsigned long long cycles_2_ns(unsigned long long cyc)
{
- return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
+ return (cyc * cyc2ns_scale) >> NS_SCALE;
}
unsigned long long sched_clock(void)
Disadvantage is a small drift between CPUs in some configurations,
but that should be tolerable. */
if (__vxtime.mode == VXTIME_HPET)
- return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> 32;
+ return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> US_SCALE;
#endif
/* Could do CPU core sync here. Opteron can execute rdtsc speculatively,
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);
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);
}
static unsigned int cpufreq_init = 0;
static struct work_struct cpufreq_delayed_get_work;
-static void handle_cpufreq_delayed_get(void *v)
+static void handle_cpufreq_delayed_get(struct work_struct *v)
{
unsigned int cpu;
for_each_online_cpu(cpu) {
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);
}
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) {
cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
if (!(freq->flags & CPUFREQ_CONST_LOOPS))
- vxtime.tsc_quot = (1000L << 32) / cpu_khz;
+ vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
}
set_cyc2ns_scale(cpu_khz_ref);
static int __init cpufreq_tsc(void)
{
- INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get, NULL);
+ INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get);
if (!cpufreq_register_notifier(&time_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER))
cpufreq_init = 1;
*/
#define TICK_COUNT 100000000
+#define TICK_MIN 5000
+
+/*
+ * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none
+ * occurs between the reads of the hpet & TSC.
+ */
+static void __init read_hpet_tsc(int *hpet, int *tsc)
+{
+ int tsc1, tsc2, hpet1;
+
+ do {
+ tsc1 = get_cycles_sync();
+ hpet1 = hpet_readl(HPET_COUNTER);
+ tsc2 = get_cycles_sync();
+ } while (tsc2 - tsc1 > TICK_MIN);
+ *hpet = hpet1;
+ *tsc = tsc2;
+}
+
static unsigned int __init hpet_calibrate_tsc(void)
{
local_irq_save(flags);
local_irq_disable();
- hpet_start = hpet_readl(HPET_COUNTER);
- rdtscl(tsc_start);
+ read_hpet_tsc(&hpet_start, &tsc_start);
do {
local_irq_disable();
- hpet_now = hpet_readl(HPET_COUNTER);
- tsc_now = get_cycles_sync();
+ read_hpet_tsc(&hpet_now, &tsc_now);
local_irq_restore(flags);
} while ((tsc_now - tsc_start) < TICK_COUNT &&
(hpet_now - hpet_start) < TICK_COUNT);
unsigned int ntimer;
if (!vxtime.hpet_address)
- return -1;
+ return 0;
memset(&hd, 0, sizeof (hd));
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;
if (hpet_use_timer) {
hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
HPET_TN_32BIT, HPET_T0_CFG);
- hpet_writel(hpet_tick, HPET_T0_CMP);
- hpet_writel(hpet_tick, HPET_T0_CMP); /* AK: why twice? */
+ hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */
+ hpet_writel(hpet_tick, HPET_T0_CMP); /* period */
cfg |= HPET_CFG_LEGACY;
}
/*
if (hpet_period < 100000 || hpet_period > 100000000)
return -1;
- hpet_tick = (1000000000L * (USEC_PER_SEC / HZ) + hpet_period / 2) /
- hpet_period;
+ hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period;
hpet_use_timer = (id & HPET_ID_LEGSUP);
}
static struct irqaction irq0 = {
- timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, "timer", NULL, NULL
+ timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL
};
void __init time_init(void)
{
- char *timename;
- char *gtod;
-
-#ifdef HPET_HACK_ENABLE_DANGEROUS
- if (!vxtime.hpet_address) {
- printk(KERN_WARNING "time.c: WARNING: Enabling HPET base "
- "manually!\n");
- outl(0x800038a0, 0xcf8);
- outl(0xff000001, 0xcfc);
- outl(0x800038a0, 0xcf8);
- vxtime.hpet_address = inl(0xcfc) & 0xfffffffe;
- printk(KERN_WARNING "time.c: WARNING: Enabled HPET "
- "at %#lx.\n", vxtime.hpet_address);
- }
-#endif
if (nohpet)
vxtime.hpet_address = 0;
-xtime.tv_sec, -xtime.tv_nsec);
if (!hpet_init())
- vxtime_hz = (1000000000000000L + hpet_period / 2) /
- hpet_period;
+ vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period;
else
vxtime.hpet_address = 0;
if (hpet_use_timer) {
+ /* set tick_nsec to use the proper rate for HPET */
+ tick_nsec = TICK_NSEC_HPET;
cpu_khz = hpet_calibrate_tsc();
timename = "HPET";
#ifdef CONFIG_X86_PM_TIMER
}
vxtime.mode = VXTIME_TSC;
- gtod = time_init_gtod();
-
- printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n",
- vxtime_hz / 1000000, vxtime_hz % 1000000, timename, gtod);
- printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
- cpu_khz / 1000, cpu_khz % 1000);
- vxtime.quot = (1000000L << 32) / vxtime_hz;
- vxtime.tsc_quot = (1000L << 32) / cpu_khz;
+ vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz;
+ vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
vxtime.last_tsc = get_cycles_sync();
+ set_cyc2ns_scale(cpu_khz);
setup_irq(0, &irq0);
- set_cyc2ns_scale(cpu_khz);
+#ifndef CONFIG_SMP
+ time_init_gtod();
+#endif
}
/*
__cpuinit int unsynchronized_tsc(void)
{
#ifdef CONFIG_SMP
- if (oem_force_hpet_timer())
+ if (apic_is_clustered_box())
return 1;
- /* Intel systems are normally all synchronized. Exceptions
- are handled in the OEM check above. */
- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
- return 0;
#endif
+ /* Most intel systems have synchronized TSCs except for
+ multi node systems */
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
+#ifdef CONFIG_ACPI
+ /* But TSC doesn't tick in C3 so don't use it there */
+ if (acpi_fadt.length > 0 && acpi_fadt.plvl3_lat < 1000)
+ return 1;
+#endif
+ return 0;
+ }
+
/* Assume multi socket systems are not synchronized */
return num_present_cpus() > 1;
}
/*
* Decide what mode gettimeofday should use.
*/
-__init static char *time_init_gtod(void)
+void time_init_gtod(void)
{
char *timetype;
if (unsynchronized_tsc())
notsc = 1;
+
+ if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
+ vgetcpu_mode = VGETCPU_RDTSCP;
+ else
+ vgetcpu_mode = VGETCPU_LSL;
+
if (vxtime.hpet_address && notsc) {
timetype = hpet_use_timer ? "HPET" : "PIT/HPET";
if (hpet_use_timer)
timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC";
vxtime.mode = VXTIME_TSC;
}
- return timetype;
+
+ printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n",
+ vxtime_hz / 1000000, vxtime_hz % 1000000, timename, timetype);
+ printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
+ cpu_khz / 1000, cpu_khz % 1000);
+ vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz;
+ vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
+ vxtime.last_tsc = get_cycles_sync();
+
+ set_cyc2ns_scale(cpu_khz);
}
__setup("report_lost_ticks", time_setup);
unsigned long flags;
unsigned long sec;
unsigned long ctime = get_cmos_time();
- unsigned long sleep_length = (ctime - sleep_start) * HZ;
+ 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 (vxtime.hpet_address)
hpet_reenable();
else
vxtime.last_tsc = get_cycles_sync();
write_sequnlock_irqrestore(&xtime_lock,flags);
jiffies += sleep_length;
- wall_jiffies += sleep_length;
monotonic_base += sleep_length * (NSEC_PER_SEC/HZ);
touch_softlockup_watchdog();
return 0;
hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
local_irq_save(flags);
+
cnt = hpet_readl(HPET_COUNTER);
cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
hpet_writel(cnt, HPET_T1_CMP);
hpet_t1_cmp = cnt;
- local_irq_restore(flags);
cfg = hpet_readl(HPET_T1_CFG);
cfg &= ~HPET_TN_PERIODIC;
cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
hpet_writel(cfg, HPET_T1_CFG);
+ local_irq_restore(flags);
+
return 1;
}
static void hpet_rtc_timer_reinit(void)
{
- unsigned int cfg, cnt;
+ unsigned int cfg, cnt, ticks_per_int, lost_ints;
if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
cfg = hpet_readl(HPET_T1_CFG);
hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
/* It is more accurate to use the comparator value than current count.*/
- cnt = hpet_t1_cmp;
- cnt += hpet_tick*HZ/hpet_rtc_int_freq;
- hpet_writel(cnt, HPET_T1_CMP);
- hpet_t1_cmp = cnt;
+ ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq;
+ hpet_t1_cmp += ticks_per_int;
+ hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
+
+ /*
+ * If the interrupt handler was delayed too long, the write above tries
+ * to schedule the next interrupt in the past and the hardware would
+ * not interrupt until the counter had wrapped around.
+ * So we have to check that the comparator wasn't set to a past time.
+ */
+ cnt = hpet_readl(HPET_COUNTER);
+ if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) {
+ lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1;
+ /* Make sure that, even with the time needed to execute
+ * this code, the next scheduled interrupt has been moved
+ * back to the future: */
+ lost_ints++;
+
+ hpet_t1_cmp += lost_ints * ticks_per_int;
+ hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
+
+ if (PIE_on)
+ PIE_count += lost_ints;
+
+ printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
+ hpet_rtc_int_freq);
+ }
}
/*
}
if (call_rtc_interrupt) {
rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
- rtc_interrupt(rtc_int_flag, dev_id, regs);
+ rtc_interrupt(rtc_int_flag, dev_id);
}
return IRQ_HANDLED;
}
static int __init nohpet_setup(char *s)
{
nohpet = 1;
- return 0;
+ return 1;
}
__setup("nohpet", nohpet_setup);
int __init notsc_setup(char *s)
{
notsc = 1;
- return 0;
+ return 1;
}
__setup("notsc", notsc_setup);
git://git.onelab.eu / linux-2.6.git / blobdiff