diff options
Diffstat (limited to 'arch/x86_64/kernel/time.c')
| -rw-r--r-- | arch/x86_64/kernel/time.c | 94 |
1 files changed, 55 insertions, 39 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 7700e6cd2bd9..1c255ee76e7c 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -24,6 +24,8 @@ #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 @@ -39,9 +41,7 @@ #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); @@ -49,7 +49,7 @@ 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); @@ -187,20 +187,15 @@ 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. - 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. */ + /* 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)) { - 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]; + unsigned long *sp = (unsigned long *)regs->rsp; + if (sp[0] >> 22) + return sp[0]; + if (sp[1] >> 22) + return sp[1]; } return pc; } @@ -281,6 +276,7 @@ static void set_rtc_mmss(unsigned long nowtime) * 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; @@ -305,8 +301,7 @@ unsigned long long monotonic_clock(void) base = monotonic_base; } while (read_seqretry(&xtime_lock, seq)); this_offset = get_cycles_sync(); - /* FIXME: 1000 or 1000000? */ - offset = (this_offset - last_offset)*1000 / cpu_khz; + offset = cycles_2_ns(this_offset - last_offset); } return base + offset; } @@ -410,8 +405,7 @@ void main_timer_handler(struct pt_regs *regs) offset %= USEC_PER_TICK; } - /* FIXME: 1000 or 1000000? */ - 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; @@ -441,12 +435,8 @@ void main_timer_handler(struct pt_regs *regs) * 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 /* * If we have an externally synchronized Linux clock, then update CMOS clock @@ -470,10 +460,8 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) if (apic_runs_main_timer > 1) return IRQ_HANDLED; main_timer_handler(regs); -#ifdef CONFIG_X86_LOCAL_APIC if (using_apic_timer) smp_send_timer_broadcast_ipi(); -#endif return IRQ_HANDLED; } @@ -893,11 +881,17 @@ static struct irqaction irq0 = { timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL }; -void __init time_init(void) +static int __cpuinit +time_cpu_notifier(struct notifier_block *nb, unsigned long action, void *hcpu) { - char *timename; - char *gtod; + unsigned cpu = (unsigned long) hcpu; + if (action == CPU_ONLINE) + vsyscall_set_cpu(cpu); + return NOTIFY_DONE; +} +void __init time_init(void) +{ if (nohpet) vxtime.hpet_address = 0; @@ -931,18 +925,17 @@ void __init time_init(void) } 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 = (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); + hotcpu_notifier(time_cpu_notifier, 0); + time_cpu_notifier(NULL, CPU_ONLINE, (void *)(long)smp_processor_id()); - set_cyc2ns_scale(cpu_khz); +#ifndef CONFIG_SMP + time_init_gtod(); +#endif } /* @@ -973,12 +966,18 @@ __cpuinit int unsynchronized_tsc(void) /* * 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) @@ -1001,7 +1000,16 @@ __init static char *time_init_gtod(void) 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); @@ -1031,8 +1039,16 @@ static int timer_resume(struct sys_device *dev) 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 |