diff options
Diffstat (limited to 'arch/x86_64/kernel')
| -rw-r--r-- | arch/x86_64/kernel/apic.c | 2 | ||||
| -rw-r--r-- | arch/x86_64/kernel/hpet.c | 64 | ||||
| -rw-r--r-- | arch/x86_64/kernel/pmtimer.c | 58 | ||||
| -rw-r--r-- | arch/x86_64/kernel/smpboot.c | 1 | ||||
| -rw-r--r-- | arch/x86_64/kernel/time.c | 300 | ||||
| -rw-r--r-- | arch/x86_64/kernel/tsc.c | 103 |
6 files changed, 120 insertions, 408 deletions
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c index 7ce77977964..723417d924c 100644 --- a/arch/x86_64/kernel/apic.c +++ b/arch/x86_64/kernel/apic.c @@ -786,7 +786,7 @@ static void setup_APIC_timer(unsigned int clocks) /* Turn off PIT interrupt if we use APIC timer as main timer. Only works with the PM timer right now TBD fix it for HPET too. */ - if (vxtime.mode == VXTIME_PMTMR && + if ((pmtmr_ioport != 0) && smp_processor_id() == boot_cpu_id && apic_runs_main_timer == 1 && !cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) { diff --git a/arch/x86_64/kernel/hpet.c b/arch/x86_64/kernel/hpet.c index 08ab37c966c..c23738899ae 100644 --- a/arch/x86_64/kernel/hpet.c +++ b/arch/x86_64/kernel/hpet.c @@ -21,12 +21,6 @@ unsigned long hpet_tick; /* HPET clocks / interrupt */ int hpet_use_timer; /* Use counter of hpet for time keeping, * otherwise PIT */ -unsigned int do_gettimeoffset_hpet(void) -{ - /* 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) >> US_SCALE; -} #ifdef CONFIG_HPET static __init int late_hpet_init(void) @@ -451,3 +445,61 @@ static int __init nohpet_setup(char *s) __setup("nohpet", nohpet_setup); +#define HPET_MASK 0xFFFFFFFF +#define HPET_SHIFT 22 + +/* FSEC = 10^-15 NSEC = 10^-9 */ +#define FSEC_PER_NSEC 1000000 + +static void *hpet_ptr; + +static cycle_t read_hpet(void) +{ + return (cycle_t)readl(hpet_ptr); +} + +struct clocksource clocksource_hpet = { + .name = "hpet", + .rating = 250, + .read = read_hpet, + .mask = (cycle_t)HPET_MASK, + .mult = 0, /* set below */ + .shift = HPET_SHIFT, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static int __init init_hpet_clocksource(void) +{ + unsigned long hpet_period; + void __iomem *hpet_base; + u64 tmp; + + if (!hpet_address) + return -ENODEV; + + /* calculate the hpet address: */ + hpet_base = ioremap_nocache(hpet_address, HPET_MMAP_SIZE); + hpet_ptr = hpet_base + HPET_COUNTER; + + /* calculate the frequency: */ + hpet_period = readl(hpet_base + HPET_PERIOD); + + /* + * hpet period is in femto seconds per cycle + * so we need to convert this to ns/cyc units + * aproximated by mult/2^shift + * + * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift + * fsec/cyc * 1ns/1000000fsec * 2^shift = mult + * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult + * (fsec/cyc << shift)/1000000 = mult + * (hpet_period << shift)/FSEC_PER_NSEC = mult + */ + tmp = (u64)hpet_period << HPET_SHIFT; + do_div(tmp, FSEC_PER_NSEC); + clocksource_hpet.mult = (u32)tmp; + + return clocksource_register(&clocksource_hpet); +} + +module_init(init_hpet_clocksource); diff --git a/arch/x86_64/kernel/pmtimer.c b/arch/x86_64/kernel/pmtimer.c index 7554458dc9c..ae8f91214f1 100644 --- a/arch/x86_64/kernel/pmtimer.c +++ b/arch/x86_64/kernel/pmtimer.c @@ -24,15 +24,6 @@ #include <asm/msr.h> #include <asm/vsyscall.h> -/* The I/O port the PMTMR resides at. - * The location is detected during setup_arch(), - * in arch/i386/kernel/acpi/boot.c */ -u32 pmtmr_ioport __read_mostly; - -/* value of the Power timer at last timer interrupt */ -static u32 offset_delay; -static u32 last_pmtmr_tick; - #define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */ static inline u32 cyc2us(u32 cycles) @@ -48,38 +39,6 @@ static inline u32 cyc2us(u32 cycles) return (cycles >> 10); } -int pmtimer_mark_offset(void) -{ - static int first_run = 1; - unsigned long tsc; - u32 lost; - - u32 tick = inl(pmtmr_ioport); - u32 delta; - - delta = cyc2us((tick - last_pmtmr_tick) & ACPI_PM_MASK); - - last_pmtmr_tick = tick; - monotonic_base += delta * NSEC_PER_USEC; - - delta += offset_delay; - - lost = delta / (USEC_PER_SEC / HZ); - offset_delay = delta % (USEC_PER_SEC / HZ); - - rdtscll(tsc); - vxtime.last_tsc = tsc - offset_delay * (u64)cpu_khz / 1000; - - /* don't calculate delay for first run, - or if we've got less then a tick */ - if (first_run || (lost < 1)) { - first_run = 0; - offset_delay = 0; - } - - return lost - 1; -} - static unsigned pmtimer_wait_tick(void) { u32 a, b; @@ -101,23 +60,6 @@ void pmtimer_wait(unsigned us) } while (cyc2us(b - a) < us); } -void pmtimer_resume(void) -{ - last_pmtmr_tick = inl(pmtmr_ioport); -} - -unsigned int do_gettimeoffset_pm(void) -{ - u32 now, offset, delta = 0; - - offset = last_pmtmr_tick; - now = inl(pmtmr_ioport); - delta = (now - offset) & ACPI_PM_MASK; - - return offset_delay + cyc2us(delta); -} - - static int __init nopmtimer_setup(char *s) { pmtmr_ioport = 0; diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c index 62d828433c3..35443729aad 100644 --- a/arch/x86_64/kernel/smpboot.c +++ b/arch/x86_64/kernel/smpboot.c @@ -982,7 +982,6 @@ void __init smp_cpus_done(unsigned int max_cpus) smp_cleanup_boot(); setup_ioapic_dest(); check_nmi_watchdog(); - time_init_gtod(); } #ifdef CONFIG_HOTPLUG_CPU diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 216fc9d7424..d84208e3c61 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -44,9 +44,6 @@ #include <asm/apic.h> #include <asm/hpet.h> -#ifdef CONFIG_CPU_FREQ -extern void cpufreq_delayed_get(void); -#endif extern void i8254_timer_resume(void); extern int using_apic_timer; @@ -57,8 +54,6 @@ EXPORT_SYMBOL(rtc_lock); DEFINE_SPINLOCK(i8253_lock); unsigned long vxtime_hz = PIT_TICK_RATE; -int report_lost_ticks; /* command line option */ -unsigned long long monotonic_base; struct vxtime_data __vxtime __section_vxtime; /* for vsyscalls */ @@ -66,76 +61,6 @@ volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; struct timespec __xtime __section_xtime; struct timezone __sys_tz __section_sys_tz; -unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc; - -/* - * This version of gettimeofday() has microsecond resolution and better than - * microsecond precision, as we're using at least a 10 MHz (usually 14.31818 - * MHz) HPET timer. - */ - -void do_gettimeofday(struct timeval *tv) -{ - unsigned long seq; - unsigned int sec, usec; - - do { - seq = read_seqbegin(&xtime_lock); - - sec = xtime.tv_sec; - usec = xtime.tv_nsec / NSEC_PER_USEC; - - /* i386 does some correction here to keep the clock - monotonous even when ntpd is fixing drift. - But they didn't work for me, there is a non monotonic - clock anyways with ntp. - I dropped all corrections now until a real solution can - 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 */ - usec += do_gettimeoffset(); - - } while (read_seqretry(&xtime_lock, seq)); - - tv->tv_sec = sec + usec / USEC_PER_SEC; - tv->tv_usec = usec % USEC_PER_SEC; -} - -EXPORT_SYMBOL(do_gettimeofday); - -/* - * settimeofday() first undoes the correction that gettimeofday would do - * on the time, and then saves it. This is ugly, but has been like this for - * ages already. - */ - -int do_settimeofday(struct timespec *tv) -{ - time_t wtm_sec, sec = tv->tv_sec; - long wtm_nsec, nsec = tv->tv_nsec; - - if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) - return -EINVAL; - - write_seqlock_irq(&xtime_lock); - - 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); - - set_normalized_timespec(&xtime, sec, nsec); - set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); - - ntp_clear(); - - write_sequnlock_irq(&xtime_lock); - clock_was_set(); - return 0; -} - -EXPORT_SYMBOL(do_settimeofday); - unsigned long profile_pc(struct pt_regs *regs) { unsigned long pc = instruction_pointer(regs); @@ -225,85 +150,9 @@ static void set_rtc_mmss(unsigned long nowtime) } -/* monotonic_clock(): returns # of nanoseconds passed since time_init() - * Note: This function is required to return accurate - * time even in the absence of multiple timer ticks. - */ -extern unsigned long long cycles_2_ns(unsigned long long cyc); -unsigned long long monotonic_clock(void) -{ - unsigned long seq; - u32 last_offset, this_offset, offset; - unsigned long long base; - - if (vxtime.mode == VXTIME_HPET) { - do { - seq = read_seqbegin(&xtime_lock); - - last_offset = vxtime.last; - base = monotonic_base; - this_offset = hpet_readl(HPET_COUNTER); - } while (read_seqretry(&xtime_lock, seq)); - offset = (this_offset - last_offset); - offset *= NSEC_PER_TICK / hpet_tick; - } else { - do { - seq = read_seqbegin(&xtime_lock); - - last_offset = vxtime.last_tsc; - base = monotonic_base; - } while (read_seqretry(&xtime_lock, seq)); - this_offset = get_cycles_sync(); - offset = cycles_2_ns(this_offset - last_offset); - } - return base + offset; -} -EXPORT_SYMBOL(monotonic_clock); - -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", 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", get_irq_regs()->rip); - if (vxtime.mode == VXTIME_TSC && 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; - vxtime.hpet_address = hpet_address; - 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 - Give cpufreq a change to catch up. */ - if ((lost_count+1) % 25 == 0) - cpufreq_delayed_get(); -#endif -} - void main_timer_handler(void) { static unsigned long rtc_update = 0; - unsigned long tsc; - int delay = 0, offset = 0, lost = 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 @@ -313,72 +162,11 @@ void main_timer_handler(void) write_seqlock(&xtime_lock); - if (hpet_address) - offset = hpet_readl(HPET_COUNTER); - - if (hpet_use_timer) { - /* if we're using the hpet timer functionality, - * we can more accurately know the counter value - * when the timer interrupt occured. - */ - offset = hpet_readl(HPET_T0_CMP) - hpet_tick; - delay = hpet_readl(HPET_COUNTER) - offset; - } else if (!pmtmr_ioport) { - spin_lock(&i8253_lock); - outb_p(0x00, 0x43); - delay = inb_p(0x40); - delay |= inb(0x40) << 8; - spin_unlock(&i8253_lock); - delay = LATCH - 1 - delay; - } - - tsc = get_cycles_sync(); - - if (vxtime.mode == VXTIME_HPET) { - if (offset - vxtime.last > hpet_tick) { - lost = (offset - vxtime.last) / hpet_tick - 1; - } - - monotonic_base += - (offset - vxtime.last) * NSEC_PER_TICK / hpet_tick; - - vxtime.last = offset; -#ifdef CONFIG_X86_PM_TIMER - } else if (vxtime.mode == VXTIME_PMTMR) { - lost = pmtimer_mark_offset(); -#endif - } else { - offset = (((tsc - vxtime.last_tsc) * - vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK; - - if (offset < 0) - offset = 0; - - if (offset > USEC_PER_TICK) { - lost = offset / USEC_PER_TICK; - offset %= USEC_PER_TICK; - } - - 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) >> US_SCALE) < offset) - vxtime.last_tsc = tsc - - (((long) offset << US_SCALE) / vxtime.tsc_quot) - 1; - } - - if (lost > 0) - handle_lost_ticks(lost); - else - lost = 0; - /* * Do the timer stuff. */ - do_timer(lost + 1); + do_timer(1); #ifndef CONFIG_SMP update_process_times(user_mode(get_irq_regs())); #endif @@ -537,12 +325,6 @@ void __init stop_timer_interrupt(void) printk(KERN_INFO "timer: %s interrupt stopped.\n", name); } -int __init time_setup(char *str) -{ - report_lost_ticks = 1; - return 1; -} - static struct irqaction irq0 = { timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL }; @@ -557,9 +339,7 @@ void __init time_init(void) set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); - if (!hpet_arch_init()) - vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period; - else + if (hpet_arch_init()) hpet_address = 0; if (hpet_use_timer) { @@ -567,82 +347,26 @@ void __init time_init(void) tick_nsec = TICK_NSEC_HPET; cpu_khz = hpet_calibrate_tsc(); timename = "HPET"; -#ifdef CONFIG_X86_PM_TIMER - } else if (pmtmr_ioport && !hpet_address) { - vxtime_hz = PM_TIMER_FREQUENCY; - timename = "PM"; - pit_init(); - cpu_khz = pit_calibrate_tsc(); -#endif } else { pit_init(); cpu_khz = pit_calibrate_tsc(); timename = "PIT"; } - vxtime.mode = VXTIME_TSC; - 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); - -#ifndef CONFIG_SMP - time_init_gtod(); -#endif -} - -/* - * Decide what mode gettimeofday should use. - */ -void time_init_gtod(void) -{ - char *timetype; - if (unsynchronized_tsc()) - notsc = 1; + mark_tsc_unstable(); if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP)) vgetcpu_mode = VGETCPU_RDTSCP; else vgetcpu_mode = VGETCPU_LSL; - if (hpet_address && notsc) { - timetype = hpet_use_timer ? "HPET" : "PIT/HPET"; - if (hpet_use_timer) - vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; - else - vxtime.last = hpet_readl(HPET_COUNTER); - vxtime.mode = VXTIME_HPET; - vxtime.hpet_address = hpet_address; - do_gettimeoffset = do_gettimeoffset_hpet; -#ifdef CONFIG_X86_PM_TIMER - /* Using PM for gettimeofday is quite slow, but we have no other - choice because the TSC is too unreliable on some systems. */ - } else if (pmtmr_ioport && !hpet_address && notsc) { - timetype = "PM"; - do_gettimeoffset = do_gettimeoffset_pm; - vxtime.mode = VXTIME_PMTMR; - sysctl_vsyscall = 0; - printk(KERN_INFO "Disabling vsyscall due to use of PM timer\n"); -#endif - } else { - timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC"; - vxtime.mode = VXTIME_TSC; - } - - printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n", - vxtime_hz / 1000000, vxtime_hz % 1000000, timename, timetype); + set_cyc2ns_scale(cpu_khz); 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_irq(0, &irq0); } -__setup("report_lost_ticks", time_setup); static long clock_cmos_diff; static unsigned long sleep_start; @@ -688,20 +412,8 @@ static int timer_resume(struct sys_device *dev) write_seqlock_irqsave(&xtime_lock,flags); xtime.tv_sec = sec; xtime.tv_nsec = 0; - if (vxtime.mode == VXTIME_HPET) { - if (hpet_use_timer) - vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; - else - vxtime.last = hpet_readl(HPET_COUNTER); -#ifdef CONFIG_X86_PM_TIMER - } else if (vxtime.mode == VXTIME_PMTMR) { - pmtimer_resume(); -#endif - } else - vxtime.last_tsc = get_cycles_sync(); - write_sequnlock_irqrestore(&xtime_lock,flags); jiffies += sleep_length; - monotonic_base += sleep_length * (NSEC_PER_SEC/HZ); + write_sequnlock_irqrestore(&xtime_lock,flags); touch_softlockup_watchdog(); return 0; } diff --git a/arch/x86_64/kernel/tsc.c b/arch/x86_64/kernel/tsc.c index 2dbac15ab1f..8c92f2fe7e2 100644 --- a/arch/x86_64/kernel/tsc.c +++ b/arch/x86_64/kernel/tsc.c @@ -9,32 +9,11 @@ #include <asm/timex.h> -int notsc __initdata = 0; +static int notsc __initdata = 0; unsigned int cpu_khz; /* TSC clocks / usec, not used here */ EXPORT_SYMBOL(cpu_khz); -/* - * do_gettimeoffset() returns microseconds since last timer interrupt was - * triggered by hardware. A memory read of HPET is slower than a register read - * of TSC, but much more reliable. It's also synchronized to the timer - * interrupt. Note that do_gettimeoffset() may return more than hpet_tick, if a - * timer interrupt has happened already, but vxtime.trigger wasn't updated yet. - * This is not a problem, because jiffies hasn't updated either. They are bound - * together by xtime_lock. - */ - -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 */ - x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> US_SCALE; - return x; -} - static unsigned int cyc2ns_scale __read_mostly; void set_cyc2ns_scale(unsigned long khz) @@ -42,7 +21,7 @@ void set_cyc2ns_scale(unsigned long khz) cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / khz; } -unsigned long long cycles_2_ns(unsigned long long cyc) +static unsigned long long cycles_2_ns(unsigned long long cyc) { return (cyc * cyc2ns_scale) >> NS_SCALE; } @@ -61,6 +40,12 @@ unsigned long long sched_clock(void) return cycles_2_ns(a); } +static int tsc_unstable; + +static inline int check_tsc_unstable(void) +{ + return tsc_unstable; +} #ifdef CONFIG_CPU_FREQ /* Frequency scaling support. Adjust the TSC based timer when the cpu frequency @@ -89,24 +74,6 @@ static void handle_cpufreq_delayed_get(struct work_struct *v) cpufreq_delayed_issched = 0; } -/* if we notice lost ticks, schedule a call to cpufreq_get() as it tries - * to verify the CPU frequency the timing core thinks the CPU is running - * at is still correct. - */ -void cpufreq_delayed_get(void) -{ - static int warned; - if (cpufreq_init && !cpufreq_delayed_issched) { - cpufreq_delayed_issched = 1; - if (!warned) { - warned = 1; - printk(KERN_DEBUG "Losing some ticks... " - "checking if CPU frequency changed.\n"); - } - schedule_work(&cpufreq_delayed_get_work); - } -} - static unsigned int ref_freq = 0; static unsigned long loops_per_jiffy_ref = 0; @@ -142,7 +109,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new); if (!(freq->flags & CPUFREQ_CONST_LOOPS)) - vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz; + mark_tsc_unstable(); } set_cyc2ns_scale(cpu_khz_ref); @@ -169,12 +136,6 @@ core_initcall(cpufreq_tsc); static int tsc_unstable = 0; -void mark_tsc_unstable(void) -{ - tsc_unstable = 1; -} -EXPORT_SYMBOL_GPL(mark_tsc_unstable); - /* * Make an educated guess if the TSC is trustworthy and synchronized * over all CPUs. @@ -210,3 +171,49 @@ int __init notsc_setup(char *s) } __setup("notsc", notsc_setup); + + +/* clock source code: */ +static cycle_t read_tsc(void) +{ + cycle_t ret = (cycle_t)get_cycles_sync(); + return ret; +} + +static struct clocksource clocksource_tsc = { + .name = "tsc", + .rating = 300, + .read = read_tsc, + .mask = CLOCKSOURCE_MASK(64), + .shift = 22, + .flags = CLOCK_SOURCE_IS_CONTINUOUS | + CLOCK_SOURCE_MUST_VERIFY, +}; + +void mark_tsc_unstable(void) +{ + if (!tsc_unstable) { + tsc_unstable = 1; + /* Change only the rating, when not registered */ + if (clocksource_tsc.mult) + clocksource_change_rating(&clocksource_tsc, 0); + else + clocksource_tsc.rating = 0; + } +} +EXPORT_SYMBOL_GPL(mark_tsc_unstable); + +static int __init init_tsc_clocksource(void) +{ + if (!notsc) { + clocksource_tsc.mult = clocksource_khz2mult(cpu_khz, + clocksource_tsc.shift); + if (check_tsc_unstable()) + clocksource_tsc.rating = 0; + + return clocksource_register(&clocksource_tsc); + } + return 0; +} + +module_init(init_tsc_clocksource); |