diff options
Diffstat (limited to 'arch/x86_64/kernel/time.c')
-rw-r--r-- | arch/x86_64/kernel/time.c | 170 |
1 files changed, 77 insertions, 93 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 3080f84bf7b..ef8bc46dc14 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; @@ -1322,7 +1306,7 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) static int __init nohpet_setup(char *s) { nohpet = 1; - return 0; + return 1; } __setup("nohpet", nohpet_setup); @@ -1330,7 +1314,7 @@ __setup("nohpet", nohpet_setup); int __init notsc_setup(char *s) { notsc = 1; - return 0; + return 1; } __setup("notsc", notsc_setup); |