diff options
32 files changed, 917 insertions, 640 deletions
diff --git a/arch/arm/plat-omap/common.c b/arch/arm/plat-omap/common.c index ebcf0064..95587b6 100644 --- a/arch/arm/plat-omap/common.c +++ b/arch/arm/plat-omap/common.c @@ -253,11 +253,8 @@ static struct clocksource clocksource_32k = { */ unsigned long long sched_clock(void) { - unsigned long long ret; - - ret = (unsigned long long)clocksource_32k.read(&clocksource_32k); - ret = (ret * clocksource_32k.mult_orig) >> clocksource_32k.shift; - return ret; + return clocksource_cyc2ns(clocksource_32k.read(&clocksource_32k), + clocksource_32k.mult, clocksource_32k.shift); } static int __init omap_init_clocksource_32k(void) diff --git a/arch/m68knommu/kernel/time.c b/arch/m68knommu/kernel/time.c index c2aa717..a90acf5 100644 --- a/arch/m68knommu/kernel/time.c +++ b/arch/m68knommu/kernel/time.c @@ -72,9 +72,10 @@ static unsigned long read_rtc_mmss(void) return mktime(year, mon, day, hour, min, sec); } -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { - return read_rtc_mmss(); + ts->tv_sec = read_rtc_mmss(); + ts->tv_nsec = 0; } int update_persistent_clock(struct timespec now) diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c index 463136e..02f505f 100644 --- a/arch/mips/dec/time.c +++ b/arch/mips/dec/time.c @@ -18,7 +18,7 @@ #include <asm/dec/ioasic.h> #include <asm/dec/machtype.h> -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { unsigned int year, mon, day, hour, min, sec, real_year; unsigned long flags; @@ -53,7 +53,8 @@ unsigned long read_persistent_clock(void) year += real_year - 72 + 2000; - return mktime(year, mon, day, hour, min, sec); + ts->tv_sec = mktime(year, mon, day, hour, min, sec); + ts->tv_nsec = 0; } /* diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c index 52cb143..c6fd96f 100644 --- a/arch/mips/lasat/ds1603.c +++ b/arch/mips/lasat/ds1603.c @@ -135,7 +135,7 @@ static void rtc_end_op(void) lasat_ndelay(1000); } -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { unsigned long word; unsigned long flags; @@ -147,7 +147,8 @@ unsigned long read_persistent_clock(void) rtc_end_op(); spin_unlock_irqrestore(&rtc_lock, flags); - return word; + ts->tv_sec = word; + ts->tv_nsec = 0; } int rtc_mips_set_mmss(unsigned long time) diff --git a/arch/mips/lasat/sysctl.c b/arch/mips/lasat/sysctl.c index 8f88886..3f04d4c 100644 --- a/arch/mips/lasat/sysctl.c +++ b/arch/mips/lasat/sysctl.c @@ -92,10 +92,12 @@ static int rtctmp; int proc_dolasatrtc(ctl_table *table, int write, struct file *filp, void *buffer, size_t *lenp, loff_t *ppos) { + struct timespec ts; int r; if (!write) { - rtctmp = read_persistent_clock(); + read_persistent_clock(&ts); + rtctmp = ts.tv_sec; /* check for time < 0 and set to 0 */ if (rtctmp < 0) rtctmp = 0; @@ -134,9 +136,11 @@ int sysctl_lasat_rtc(ctl_table *table, void *oldval, size_t *oldlenp, void *newval, size_t newlen) { + struct timespec ts; int r; - rtctmp = read_persistent_clock(); + read_persistent_clock(&ts); + rtctmp = ts.tv_sec; if (rtctmp < 0) rtctmp = 0; r = sysctl_intvec(table, oldval, oldlenp, newval, newlen); diff --git a/arch/mips/loongson/common/time.c b/arch/mips/loongson/common/time.c index b13d171..0edbef3 100644 --- a/arch/mips/loongson/common/time.c +++ b/arch/mips/loongson/common/time.c @@ -21,7 +21,8 @@ void __init plat_time_init(void) mips_hpt_frequency = cpu_clock_freq / 2; } -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { - return mc146818_get_cmos_time(); + ts->tv_sec = return mc146818_get_cmos_time(); + ts->tv_nsec = 0; } diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c index 0b97d47..3c6f190 100644 --- a/arch/mips/mti-malta/malta-time.c +++ b/arch/mips/mti-malta/malta-time.c @@ -100,9 +100,10 @@ static unsigned int __init estimate_cpu_frequency(void) return count; } -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { - return mc146818_get_cmos_time(); + ts->tv_sec = mc146818_get_cmos_time(); + ts->tv_nsec = 0; } static void __init plat_perf_setup(void) diff --git a/arch/mips/pmc-sierra/yosemite/setup.c b/arch/mips/pmc-sierra/yosemite/setup.c index 2d3c0dc..3498ac9 100644 --- a/arch/mips/pmc-sierra/yosemite/setup.c +++ b/arch/mips/pmc-sierra/yosemite/setup.c @@ -70,7 +70,7 @@ void __init bus_error_init(void) } -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { unsigned int year, month, day, hour, min, sec; unsigned long flags; @@ -92,7 +92,8 @@ unsigned long read_persistent_clock(void) m48t37_base->control = 0x00; spin_unlock_irqrestore(&rtc_lock, flags); - return mktime(year, month, day, hour, min, sec); + ts->tv_sec = mktime(year, month, day, hour, min, sec); + ts->tv_nsec = 0; } int rtc_mips_set_time(unsigned long tim) diff --git a/arch/mips/sibyte/swarm/setup.c b/arch/mips/sibyte/swarm/setup.c index 672e45d..623ffc9 100644 --- a/arch/mips/sibyte/swarm/setup.c +++ b/arch/mips/sibyte/swarm/setup.c @@ -87,19 +87,26 @@ enum swarm_rtc_type { enum swarm_rtc_type swarm_rtc_type; -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { + unsigned long sec; + switch (swarm_rtc_type) { case RTC_XICOR: - return xicor_get_time(); + sec = xicor_get_time(); + break; case RTC_M4LT81: - return m41t81_get_time(); + sec = m41t81_get_time(); + break; case RTC_NONE: default: - return mktime(2000, 1, 1, 0, 0, 0); + sec = mktime(2000, 1, 1, 0, 0, 0); + break; } + ts->tv_sec = sec; + tv->tv_nsec = 0; } int rtc_mips_set_time(unsigned long sec) diff --git a/arch/mips/sni/time.c b/arch/mips/sni/time.c index 0d9ec1a..62df6a5 100644 --- a/arch/mips/sni/time.c +++ b/arch/mips/sni/time.c @@ -182,7 +182,8 @@ void __init plat_time_init(void) setup_pit_timer(); } -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { - return -1; + ts->tv_sec = -1; + ts->tv_nsec = 0; } diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index a180b4f..465e498 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -774,11 +774,12 @@ int update_persistent_clock(struct timespec now) return ppc_md.set_rtc_time(&tm); } -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { struct rtc_time tm; static int first = 1; + ts->tv_nsec = 0; /* XXX this is a litle fragile but will work okay in the short term */ if (first) { first = 0; @@ -786,14 +787,18 @@ unsigned long read_persistent_clock(void) timezone_offset = ppc_md.time_init(); /* get_boot_time() isn't guaranteed to be safe to call late */ - if (ppc_md.get_boot_time) - return ppc_md.get_boot_time() -timezone_offset; + if (ppc_md.get_boot_time) { + ts->tv_sec = ppc_md.get_boot_time() - timezone_offset; + return; + } + } + if (!ppc_md.get_rtc_time) { + ts->tv_sec = 0; + return; } - if (!ppc_md.get_rtc_time) - return 0; ppc_md.get_rtc_time(&tm); - return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, - tm.tm_hour, tm.tm_min, tm.tm_sec); + ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, + tm.tm_hour, tm.tm_min, tm.tm_sec); } /* clocksource code */ diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index e3dc28b..34162a0 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -184,12 +184,14 @@ static void timing_alert_interrupt(__u16 code) static void etr_reset(void); static void stp_reset(void); -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { - struct timespec ts; + tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, ts); +} - tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, &ts); - return ts.tv_sec; +void read_boot_clock(struct timespec *ts) +{ + tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, ts); } static cycle_t read_tod_clock(struct clocksource *cs) @@ -207,6 +209,10 @@ static struct clocksource clocksource_tod = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +struct clocksource * __init clocksource_default_clock(void) +{ + return &clocksource_tod; +} void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) { @@ -244,10 +250,6 @@ void update_vsyscall_tz(void) */ void __init time_init(void) { - struct timespec ts; - unsigned long flags; - cycle_t now; - /* Reset time synchronization interfaces. */ etr_reset(); stp_reset(); @@ -263,26 +265,6 @@ void __init time_init(void) if (clocksource_register(&clocksource_tod) != 0) panic("Could not register TOD clock source"); - /* - * The TOD clock is an accurate clock. The xtime should be - * initialized in a way that the difference between TOD and - * xtime is reasonably small. Too bad that timekeeping_init - * sets xtime.tv_nsec to zero. In addition the clock source - * change from the jiffies clock source to the TOD clock - * source add another error of up to 1/HZ second. The same - * function sets wall_to_monotonic to a value that is too - * small for /proc/uptime to be accurate. - * Reset xtime and wall_to_monotonic to sane values. - */ - write_seqlock_irqsave(&xtime_lock, flags); - now = get_clock(); - tod_to_timeval(now - TOD_UNIX_EPOCH, &xtime); - clocksource_tod.cycle_last = now; - clocksource_tod.raw_time = xtime; - tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, &ts); - set_normalized_timespec(&wall_to_monotonic, -ts.tv_sec, -ts.tv_nsec); - write_sequnlock_irqrestore(&xtime_lock, flags); - /* Enable TOD clock interrupts on the boot cpu. */ init_cpu_timer(); diff --git a/arch/sh/kernel/time.c b/arch/sh/kernel/time.c index 9b352a1..0e0e858 100644 --- a/arch/sh/kernel/time.c +++ b/arch/sh/kernel/time.c @@ -39,11 +39,9 @@ void (*rtc_sh_get_time)(struct timespec *) = null_rtc_get_time; int (*rtc_sh_set_time)(const time_t) = null_rtc_set_time; #ifdef CONFIG_GENERIC_CMOS_UPDATE -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { - struct timespec tv; - rtc_sh_get_time(&tv); - return tv.tv_sec; + rtc_sh_get_time(ts); } int update_persistent_clock(struct timespec now) diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index dc27a69..3d61e20 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -21,6 +21,7 @@ struct vsyscall_gtod_data { u32 shift; } clock; struct timespec wall_to_monotonic; + struct timespec wall_time_coarse; }; extern struct vsyscall_gtod_data __vsyscall_gtod_data __section_vsyscall_gtod_data; diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c index 5cf36c0..23c1679 100644 --- a/arch/x86/kernel/i8253.c +++ b/arch/x86/kernel/i8253.c @@ -19,12 +19,6 @@ DEFINE_SPINLOCK(i8253_lock); EXPORT_SYMBOL(i8253_lock); -#ifdef CONFIG_X86_32 -static void pit_disable_clocksource(void); -#else -static inline void pit_disable_clocksource(void) { } -#endif - /* * HPET replaces the PIT, when enabled. So we need to know, which of * the two timers is used @@ -57,12 +51,10 @@ static void init_pit_timer(enum clock_event_mode mode, outb_pit(0, PIT_CH0); outb_pit(0, PIT_CH0); } - pit_disable_clocksource(); break; case CLOCK_EVT_MODE_ONESHOT: /* One shot setup */ - pit_disable_clocksource(); outb_pit(0x38, PIT_MODE); break; @@ -200,17 +192,6 @@ static struct clocksource pit_cs = { .shift = 20, }; -static void pit_disable_clocksource(void) -{ - /* - * Use mult to check whether it is registered or not - */ - if (pit_cs.mult) { - clocksource_unregister(&pit_cs); - pit_cs.mult = 0; - } -} - static int __init init_pit_clocksource(void) { /* diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index 5d465b2..bf67dcb 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -178,7 +178,7 @@ static int set_rtc_mmss(unsigned long nowtime) } /* not static: needed by APM */ -unsigned long read_persistent_clock(void) +void read_persistent_clock(struct timespec *ts) { unsigned long retval, flags; @@ -186,7 +186,8 @@ unsigned long read_persistent_clock(void) retval = get_wallclock(); spin_unlock_irqrestore(&rtc_lock, flags); - return retval; + ts->tv_sec = retval; + ts->tv_nsec = 0; } int update_persistent_clock(struct timespec now) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 71f4368..fc3672a 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -744,10 +744,16 @@ static cycle_t __vsyscall_fn vread_tsc(void) } #endif +static void resume_tsc(void) +{ + clocksource_tsc.cycle_last = 0; +} + static struct clocksource clocksource_tsc = { .name = "tsc", .rating = 300, .read = read_tsc, + .resume = resume_tsc, .mask = CLOCKSOURCE_MASK(64), .shift = 22, .flags = CLOCK_SOURCE_IS_CONTINUOUS | @@ -761,12 +767,14 @@ void mark_tsc_unstable(char *reason) { if (!tsc_unstable) { tsc_unstable = 1; - printk("Marking TSC unstable due to %s\n", reason); + printk(KERN_INFO "Marking TSC unstable due to %s\n", reason); /* Change only the rating, when not registered */ if (clocksource_tsc.mult) - clocksource_change_rating(&clocksource_tsc, 0); - else + clocksource_mark_unstable(&clocksource_tsc); + else { + clocksource_tsc.flags |= CLOCK_SOURCE_UNSTABLE; clocksource_tsc.rating = 0; + } } } diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 25ee06a..cf53a78 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -87,6 +87,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) vsyscall_gtod_data.wall_time_sec = wall_time->tv_sec; vsyscall_gtod_data.wall_time_nsec = wall_time->tv_nsec; vsyscall_gtod_data.wall_to_monotonic = wall_to_monotonic; + vsyscall_gtod_data.wall_time_coarse = __current_kernel_time(); write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags); } diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 6a40b78..ee55754 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -86,14 +86,47 @@ notrace static noinline int do_monotonic(struct timespec *ts) return 0; } +notrace static noinline int do_realtime_coarse(struct timespec *ts) +{ + unsigned long seq; + do { + seq = read_seqbegin(>od->lock); + ts->tv_sec = gtod->wall_time_coarse.tv_sec; + ts->tv_nsec = gtod->wall_time_coarse.tv_nsec; + } while (unlikely(read_seqretry(>od->lock, seq))); + return 0; +} + +notrace static noinline int do_monotonic_coarse(struct timespec *ts) +{ + unsigned long seq, ns, secs; + do { + seq = read_seqbegin(>od->lock); + secs = gtod->wall_time_coarse.tv_sec; + ns = gtod->wall_time_coarse.tv_nsec; + secs += gtod->wall_to_monotonic.tv_sec; + ns += gtod->wall_to_monotonic.tv_nsec; + } while (unlikely(read_seqretry(>od->lock, seq))); + vset_normalized_timespec(ts, secs, ns); + return 0; +} + notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) { - if (likely(gtod->sysctl_enabled && gtod->clock.vread)) + if (likely(gtod->sysctl_enabled)) switch (clock) { case CLOCK_REALTIME: - return do_realtime(ts); + if (likely(gtod->clock.vread)) + return do_realtime(ts); + break; case CLOCK_MONOTONIC: - return do_monotonic(ts); + if (likely(gtod->clock.vread)) + return do_monotonic(ts); + break; + case CLOCK_REALTIME_COARSE: + return do_realtime_coarse(ts); + case CLOCK_MONOTONIC_COARSE: + return do_monotonic_coarse(ts); } return vdso_fallback_gettime(clock, ts); } diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c index 8848120..19085ff 100644 --- a/arch/xtensa/kernel/time.c +++ b/arch/xtensa/kernel/time.c @@ -59,9 +59,8 @@ static struct irqaction timer_irqaction = { void __init time_init(void) { - xtime.tv_nsec = 0; - xtime.tv_sec = read_persistent_clock(); - + /* FIXME: xtime&wall_to_monotonic are set in timekeeping_init. */ + read_persistent_clock(&xtime); set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 1219be4..83d2fbd 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -14,6 +14,7 @@ #include <linux/list.h> #include <linux/cache.h> #include <linux/timer.h> +#include <linux/init.h> #include <asm/div64.h> #include <asm/io.h> @@ -148,14 +149,11 @@ extern u64 timecounter_cyc2time(struct timecounter *tc, * @disable: optional function to disable the clocksource * @mask: bitmask for two's complement * subtraction of non 64 bit counters - * @mult: cycle to nanosecond multiplier (adjusted by NTP) - * @mult_orig: cycle to nanosecond multiplier (unadjusted by NTP) + * @mult: cycle to nanosecond multiplier * @shift: cycle to nanosecond divisor (power of two) * @flags: flags describing special properties * @vread: vsyscall based read * @resume: resume function for the clocksource, if necessary - * @cycle_interval: Used internally by timekeeping core, please ignore. - * @xtime_interval: Used internally by timekeeping core, please ignore. */ struct clocksource { /* @@ -169,7 +167,6 @@ struct clocksource { void (*disable)(struct clocksource *cs); cycle_t mask; u32 mult; - u32 mult_orig; u32 shift; unsigned long flags; cycle_t (*vread)(void); @@ -181,19 +178,12 @@ struct clocksource { #define CLKSRC_FSYS_MMIO_SET(mmio, addr) do { } while (0) #endif - /* timekeeping specific data, ignore */ - cycle_t cycle_interval; - u64 xtime_interval; - u32 raw_interval; /* * Second part is written at each timer interrupt * Keep it in a different cache line to dirty no * more than one cache line. */ cycle_t cycle_last ____cacheline_aligned_in_smp; - u64 xtime_nsec; - s64 error; - struct timespec raw_time; #ifdef CONFIG_CLOCKSOURCE_WATCHDOG /* Watchdog related data, used by the framework */ @@ -202,8 +192,6 @@ struct clocksource { #endif }; -extern struct clocksource *clock; /* current clocksource */ - /* * Clock source flags bits:: */ @@ -212,6 +200,7 @@ extern struct clocksource *clock; /* current clocksource */ #define CLOCK_SOURCE_WATCHDOG 0x10 #define CLOCK_SOURCE_VALID_FOR_HRES 0x20 +#define CLOCK_SOURCE_UNSTABLE 0x40 /* simplify initialization of mask field */ #define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1) @@ -268,108 +257,15 @@ static inline u32 clocksource_hz2mult(u32 hz, u32 shift_constant) } /** - * clocksource_read: - Access the clocksource's current cycle value - * @cs: pointer to clocksource being read - * - * Uses the clocksource to return the current cycle_t value - */ -static inline cycle_t clocksource_read(struct clocksource *cs) -{ - return cs->read(cs); -} - -/** - * clocksource_enable: - enable clocksource - * @cs: pointer to clocksource - * - * Enables the specified clocksource. The clocksource callback - * function should start up the hardware and setup mult and field - * members of struct clocksource to reflect hardware capabilities. - */ -static inline int clocksource_enable(struct clocksource *cs) -{ - int ret = 0; - - if (cs->enable) - ret = cs->enable(cs); - - /* - * The frequency may have changed while the clocksource - * was disabled. If so the code in ->enable() must update - * the mult value to reflect the new frequency. Make sure - * mult_orig follows this change. - */ - cs->mult_orig = cs->mult; - - return ret; -} - -/** - * clocksource_disable: - disable clocksource - * @cs: pointer to clocksource - * - * Disables the specified clocksource. The clocksource callback - * function should power down the now unused hardware block to - * save power. - */ -static inline void clocksource_disable(struct clocksource *cs) -{ - /* - * Save mult_orig in mult so clocksource_enable() can - * restore the value regardless if ->enable() updates - * the value of mult or not. - */ - cs->mult = cs->mult_orig; - - if (cs->disable) - cs->disable(cs); -} - -/** - * cyc2ns - converts clocksource cycles to nanoseconds - * @cs: Pointer to clocksource - * @cycles: Cycles + * clocksource_cyc2ns - converts clocksource cycles to nanoseconds * - * Uses the clocksource and ntp ajdustment to convert cycle_ts to nanoseconds. + * Converts cycles to nanoseconds, using the given mult and shift. * * XXX - This could use some mult_lxl_ll() asm optimization */ -static inline s64 cyc2ns(struct clocksource *cs, cycle_t cycles) -{ - u64 ret = (u64)cycles; - ret = (ret * cs->mult) >> cs->shift; - return ret; -} - -/** - * clocksource_calculate_interval - Calculates a clocksource interval struct - * - * @c: Pointer to clocksource. - * @length_nsec: Desired interval length in nanoseconds. - * - * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment - * pair and interval request. - * - * Unless you're the timekeeping code, you should not be using this! - */ -static inline void clocksource_calculate_interval(struct clocksource *c, - unsigned long length_nsec) +static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift) { - u64 tmp; - - /* Do the ns -> cycle conversion first, using original mult */ - tmp = length_nsec; - tmp <<= c->shift; - tmp += c->mult_orig/2; - do_div(tmp, c->mult_orig); - - c->cycle_interval = (cycle_t)tmp; - if (c->cycle_interval == 0) - c->cycle_interval = 1; - - /* Go back from cycles -> shifted ns, this time use ntp adjused mult */ - c->xtime_interval = (u64)c->cycle_interval * c->mult; - c->raw_interval = ((u64)c->cycle_interval * c->mult_orig) >> c->shift; + return ((u64) cycles * mult) >> shift; } @@ -380,6 +276,8 @@ extern void clocksource_touch_watchdog(void); extern struct clocksource* clocksource_get_next(void); extern void clocksource_change_rating(struct clocksource *cs, int rating); extern void clocksource_resume(void); +extern struct clocksource * __init __weak clocksource_default_clock(void); +extern void clocksource_mark_unstable(struct clocksource *cs); #ifdef CONFIG_GENERIC_TIME_VSYSCALL extern void update_vsyscall(struct timespec *ts, struct clocksource *c); @@ -394,4 +292,6 @@ static inline void update_vsyscall_tz(void) } #endif +extern void timekeeping_notify(struct clocksource *clock); + #endif /* _LINUX_CLOCKSOURCE_H */ diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 4759917..ff037f0 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -91,7 +91,6 @@ enum hrtimer_restart { * @function: timer expiry callback function * @base: pointer to the timer base (per cpu and per clock) * @state: state information (See bit values above) - * @cb_entry: list head to enqueue an expired timer into the callback list * @start_site: timer statistics field to store the site where the timer * was started * @start_comm: timer statistics field to store the name of the process which @@ -108,7 +107,6 @@ struct hrtimer { enum hrtimer_restart (*function)(struct hrtimer *); struct hrtimer_clock_base *base; unsigned long state; - struct list_head cb_entry; #ifdef CONFIG_TIMER_STATS int start_pid; void *start_site; diff --git a/include/linux/time.h b/include/linux/time.h index ea16c1a..56787c0 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -75,7 +75,7 @@ extern unsigned long mktime(const unsigned int year, const unsigned int mon, const unsigned int day, const unsigned int hour, const unsigned int min, const unsigned int sec); -extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec); +extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec); extern struct timespec timespec_add_safe(const struct timespec lhs, const struct timespec rhs); @@ -101,7 +101,8 @@ extern struct timespec xtime; extern struct timespec wall_to_monotonic; extern seqlock_t xtime_lock; -extern unsigned long read_persistent_clock(void); +extern void read_persistent_clock(struct timespec *ts); +extern void read_boot_clock(struct timespec *ts); extern int update_persistent_clock(struct timespec now); extern int no_sync_cmos_clock __read_mostly; void timekeeping_init(void); @@ -109,6 +110,8 @@ extern int timekeeping_suspended; unsigned long get_seconds(void); struct timespec current_kernel_time(void); +struct timespec __current_kernel_time(void); /* does not hold xtime_lock */ +struct timespec get_monotonic_coarse(void); #define CURRENT_TIME (current_kernel_time()) #define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 }) @@ -147,6 +150,7 @@ extern struct timespec timespec_trunc(struct timespec t, unsigned gran); extern int timekeeping_valid_for_hres(void); extern void update_wall_time(void); extern void update_xtime_cache(u64 nsec); +extern void timekeeping_leap_insert(int leapsecond); struct tms; extern void do_sys_times(struct tms *); @@ -241,6 +245,8 @@ struct itimerval { #define CLOCK_PROCESS_CPUTIME_ID 2 #define CLOCK_THREAD_CPUTIME_ID 3 #define CLOCK_MONOTONIC_RAW 4 +#define CLOCK_REALTIME_COARSE 5 +#define CLOCK_MONOTONIC_COARSE 6 /* * The IDs of various hardware clocks: diff --git a/include/linux/timer.h b/include/linux/timer.h index be62ec2..a2d1eb6 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -175,11 +175,6 @@ extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires); /* * Return when the next timer-wheel timeout occurs (in absolute jiffies), - * locks the timer base: - */ -extern unsigned long next_timer_interrupt(void); -/* - * Return when the next timer-wheel timeout occurs (in absolute jiffies), * locks the timer base and does the comparison against the given * jiffie. */ diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 05071bf..c03f221 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -48,37 +48,6 @@ #include <asm/uaccess.h> -/** - * ktime_get - get the monotonic time in ktime_t format - * - * returns the time in ktime_t format - */ -ktime_t ktime_get(void) -{ - struct timespec now; - - ktime_get_ts(&now); - - return timespec_to_ktime(now); -} -EXPORT_SYMBOL_GPL(ktime_get); - -/** - * ktime_get_real - get the real (wall-) time in ktime_t format - * - * returns the time in ktime_t format - */ -ktime_t ktime_get_real(void) -{ - struct timespec now; - - getnstimeofday(&now); - - return timespec_to_ktime(now); -} - -EXPORT_SYMBOL_GPL(ktime_get_real); - /* * The timer bases: * @@ -106,31 +75,6 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = } }; -/** - * ktime_get_ts - get the monotonic clock in timespec format - * @ts: pointer to timespec variable - * - * The function calculates the monotonic clock from the realtime - * clock and the wall_to_monotonic offset and stores the result - * in normalized timespec format in the variable pointed to by @ts. - */ -void ktime_get_ts(struct timespec *ts) -{ - struct timespec tomono; - unsigned long seq; - - do { - seq = read_seqbegin(&xtime_lock); - getnstimeofday(ts); - tomono = wall_to_monotonic; - - } while (read_seqretry(&xtime_lock, seq)); - - set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, - ts->tv_nsec + tomono.tv_nsec); -} -EXPORT_SYMBOL_GPL(ktime_get_ts); - /* * Get the coarse grained time at the softirq based on xtime and * wall_to_monotonic. @@ -1155,7 +1099,6 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, clock_id = CLOCK_MONOTONIC; timer->base = &cpu_base->clock_base[clock_id]; - INIT_LIST_HEAD(&timer->cb_entry); hrtimer_init_timer_hres(timer); #ifdef CONFIG_TIMER_STATS diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index d089d05..4954407 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -242,6 +242,25 @@ static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp) return 0; } + +static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp) +{ + *tp = current_kernel_time(); + return 0; +} + +static int posix_get_monotonic_coarse(clockid_t which_clock, + struct timespec *tp) +{ + *tp = get_monotonic_coarse(); + return 0; +} + +int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp) +{ + *tp = ktime_to_timespec(KTIME_LOW_RES); + return 0; +} /* * Initialize everything, well, just everything in Posix clocks/timers ;) */ @@ -262,10 +281,26 @@ static __init int init_posix_timers(void) .timer_create = no_timer_create, .nsleep = no_nsleep, }; + struct k_clock clock_realtime_coarse = { + .clock_getres = posix_get_coarse_res, + .clock_get = posix_get_realtime_coarse, + .clock_set = do_posix_clock_nosettime, + .timer_create = no_timer_create, + .nsleep = no_nsleep, + }; + struct k_clock clock_monotonic_coarse = { + .clock_getres = posix_get_coarse_res, + .clock_get = posix_get_monotonic_coarse, + .clock_set = do_posix_clock_nosettime, + .timer_create = no_timer_create, + .nsleep = no_nsleep, + }; register_posix_clock(CLOCK_REALTIME, &clock_realtime); register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw); + register_posix_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse); + register_posix_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse); posix_timers_cache = kmem_cache_create("posix_timers_cache", sizeof (struct k_itimer), 0, SLAB_PANIC, diff --git a/kernel/time.c b/kernel/time.c index 2951194..2e2e469 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -370,13 +370,20 @@ EXPORT_SYMBOL(mktime); * 0 <= tv_nsec < NSEC_PER_SEC * For negative values only the tv_sec field is negative ! */ -void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec) +void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec) { while (nsec >= NSEC_PER_SEC) { + /* + * The following asm() prevents the compiler from + * optimising this loop into a modulo operation. See + * also __iter_div_u64_rem() in include/linux/time.h + */ + asm("" : "+rm"(nsec)); nsec -= NSEC_PER_SEC; ++sec; } while (nsec < 0) { + asm("" : "+rm"(nsec)); nsec += NSEC_PER_SEC; --sec; } diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 7466cb8..0911334 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -21,7 +21,6 @@ * * TODO WishList: * o Allow clocksource drivers to be unregistered - * o get rid of clocksource_jiffies extern */ #include <linux/clocksource.h> @@ -30,6 +29,7 @@ #include <linux/module.h> #include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */ #include <linux/tick.h> +#include <linux/kthread.h> void timecounter_init(struct timecounter *tc, const struct cyclecounter *cc, @@ -107,50 +107,35 @@ u64 timecounter_cyc2time(struct timecounter *tc, } EXPORT_SYMBOL(timecounter_cyc2time); -/* XXX - Would like a better way for initializing curr_clocksource */ -extern struct clocksource clocksource_jiffies; - /*[Clocksource internal variables]--------- * curr_clocksource: - * currently selected clocksource. Initialized to clocksource_jiffies. - * next_clocksource: - * pending next selected clocksource. + * currently selected clocksource. * clocksource_list: * linked list with the registered clocksources - * clocksource_lock: - * protects manipulations to curr_clocksource and next_clocksource - * and the clocksource_list + * clocksource_mutex: + * protects manipulations to curr_clocksource and the clocksource_list * override_name: * Name of the user-specified clocksource. */ -static struct clocksource *curr_clocksource = &clocksource_jiffies; -static struct clocksource *next_clocksource; -static struct clocksource *clocksource_override; +static struct clocksource *curr_clocksource; static LIST_HEAD(clocksource_list); -static DEFINE_SPINLOCK(clocksource_lock); +static DEFINE_MUTEX(clocksource_mutex); static char override_name[32]; static int finished_booting; -/* clocksource_done_booting - Called near the end of core bootup - * - * Hack to avoid lots of clocksource churn at boot time. - * We use fs_initcall because we want this to start before - * device_initcall but after subsys_initcall. - */ -static int __init clocksource_done_booting(void) -{ - finished_booting = 1; - return 0; -} -fs_initcall(clocksource_done_booting); - #ifdef CONFIG_CLOCKSOURCE_WATCHDOG +static void clocksource_watchdog_work(struct work_struct *work); + static LIST_HEAD(watchdog_list); static struct clocksource *watchdog; static struct timer_list watchdog_timer; +static DECLARE_WORK(watchdog_work, clocksource_watchdog_work); static DEFINE_SPINLOCK(watchdog_lock); static cycle_t watchdog_last; -static unsigned long watchdog_resumed; +static int watchdog_running; + +static int clocksource_watchdog_kthread(void *data); +static void __clocksource_change_rating(struct clocksource *cs, int rating); /* * Interval: 0.5sec Threshold: 0.0625s @@ -158,135 +143,249 @@ static unsigned long watchdog_resumed; #define WATCHDOG_INTERVAL (HZ >> 1) #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) -static void clocksource_ratewd(struct clocksource *cs, int64_t delta) +static void clocksource_watchdog_work(struct work_struct *work) { - if (delta > -WATCHDOG_THRESHOLD && delta < WATCHDOG_THRESHOLD) - return; + /* + * If kthread_run fails the next watchdog scan over the + * watchdog_list will find the unstable clock again. + */ + kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog"); +} +static void __clocksource_unstable(struct clocksource *cs) +{ + cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); + cs->flags |= CLOCK_SOURCE_UNSTABLE; + if (finished_booting) + schedule_work(&watchdog_work); +} + +static void clocksource_unstable(struct clocksource *cs, int64_t delta) +{ printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n", cs->name, delta); - cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); - clocksource_change_rating(cs, 0); - list_del(&cs->wd_list); + __clocksource_unstable(cs); +} + +/** + * clocksource_mark_unstable - mark clocksource unstable via watchdog + * @cs: clocksource to be marked unstable + * + * This function is called instead of clocksource_change_rating from + * cpu hotplug code to avoid a deadlock between the clocksource mutex + * and the cpu hotplug mutex. It defers the update of the clocksource + * to the watchdog thread. + */ +void clocksource_mark_unstable(struct clocksource *cs) +{ + unsigned long flags; + + spin_lock_irqsave(&watchdog_lock, flags); + if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) { + if (list_empty(&cs->wd_list)) + list_add(&cs->wd_list, &watchdog_list); + __clocksource_unstable(cs); + } + spin_unlock_irqrestore(&watchdog_lock, flags); } static void clocksource_watchdog(unsigned long data) { - struct clocksource *cs, *tmp; + struct clocksource *cs; cycle_t csnow, wdnow; int64_t wd_nsec, cs_nsec; - int resumed; + int next_cpu; spin_lock(&watchdog_lock); - - resumed = test_and_clear_bit(0, &watchdog_resumed); + if (!watchdog_running) + goto out; wdnow = watchdog->read(watchdog); - wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask); + wd_nsec = clocksource_cyc2ns((wdnow - watchdog_last) & watchdog->mask, + watchdog->mult, watchdog->shift); watchdog_last = wdnow; - list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) { - csnow = cs->read(cs); + list_for_each_entry(cs, &watchdog_list, wd_list) { - if (unlikely(resumed)) { - cs->wd_last = csnow; + /* Clocksource already marked unstable? */ + if (cs->flags & CLOCK_SOURCE_UNSTABLE) { + if (finished_booting) + schedule_work(&watchdog_work); continue; } - /* Initialized ? */ + csnow = cs->read(cs); + + /* Clocksource initialized ? */ if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) { - if ((cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) && - (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) { - cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; - /* - * We just marked the clocksource as - * highres-capable, notify the rest of the - * system as well so that we transition - * into high-res mode: - */ - tick_clock_notify(); - } cs->flags |= CLOCK_SOURCE_WATCHDOG; cs->wd_last = csnow; - } else { - cs_nsec = cyc2ns(cs, (csnow - cs->wd_last) & cs->mask); - cs->wd_last = csnow; - /* Check the delta. Might remove from the list ! */ - clocksource_ratewd(cs, cs_nsec - wd_nsec); + continue; } - } - if (!list_empty(&watchdog_list)) { - /* - * Cycle through CPUs to check if the CPUs stay - * synchronized to each other. - */ - int next_cpu = cpumask_next(raw_smp_processor_id(), - cpu_online_mask); + /* Check the deviation from the watchdog clocksource. */ + cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) & + cs->mask, cs->mult, cs->shift); + cs->wd_last = csnow; + if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) { + clocksource_unstable(cs, cs_nsec - wd_nsec); + continue; + } - if (next_cpu >= nr_cpu_ids) - next_cpu = cpumask_first(cpu_online_mask); - watchdog_timer.expires += WATCHDOG_INTERVAL; - add_timer_on(&watchdog_timer, next_cpu); + if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) && + (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) && + (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) { + cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; + /* + * We just marked the clocksource as highres-capable, + * notify the rest of the system as well so that we + * transition into high-res mode: + */ + tick_clock_notify(); + } } + + /* + * Cycle through CPUs to check if the CPUs stay synchronized + * to each other. + */ + next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask); + if (next_cpu >= nr_cpu_ids) + next_cpu = cpumask_first(cpu_online_mask); + watchdog_timer.expires += WATCHDOG_INTERVAL; + add_timer_on(&watchdog_timer, next_cpu); +out: spin_unlock(&watchdog_lock); } + +static inline void clocksource_start_watchdog(void) +{ + if (watchdog_running || !watchdog || list_empty(&watchdog_list)) + return; + init_timer(&watchdog_timer); + watchdog_timer.function = clocksource_watchdog; + watchdog_last = watchdog->read(watchdog); + watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL; + add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask)); + watchdog_running = 1; +} + +static inline void clocksource_stop_watchdog(void) +{ + if (!watchdog_running || (watchdog && !list_empty(&watchdog_list))) + return; + del_timer(&watchdog_timer); + watchdog_running = 0; +} + +static inline void clocksource_reset_watchdog(void) +{ + struct clocksource *cs; + + list_for_each_entry(cs, &watchdog_list, wd_list) + cs->flags &= ~CLOCK_SOURCE_WATCHDOG; +} + static void clocksource_resume_watchdog(void) { - set_bit(0, &watchdog_resumed); + unsigned long flags; + + spin_lock_irqsave(&watchdog_lock, flags); + clocksource_reset_watchdog(); + spin_unlock_irqrestore(&watchdog_lock, flags); } -static void clocksource_check_watchdog(struct clocksource *cs) +static void clocksource_enqueue_watchdog(struct clocksource *cs) { - struct clocksource *cse; unsigned long flags; spin_lock_irqsave(&watchdog_lock, flags); if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) { - int started = !list_empty(&watchdog_list); - + /* cs is a clocksource to be watched. */ list_add(&cs->wd_list, &watchdog_list); - if (!started && watchdog) { - watchdog_last = watchdog->read(watchdog); - watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL; - add_timer_on(&watchdog_timer, - cpumask_first(cpu_online_mask)); - } + cs->flags &= ~CLOCK_SOURCE_WATCHDOG; } else { + /* cs is a watchdog. */ if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; - + /* Pick the best watchdog. */ if (!watchdog || cs->rating > watchdog->rating) { - if (watchdog) - del_timer(&watchdog_timer); watchdog = cs; - init_timer(&watchdog_timer); - watchdog_timer.function = clocksource_watchdog; - /* Reset watchdog cycles */ - list_for_each_entry(cse, &watchdog_list, wd_list) - cse->flags &= ~CLOCK_SOURCE_WATCHDOG; - /* Start if list is not empty */ - if (!list_empty(&watchdog_list)) { - watchdog_last = watchdog->read(watchdog); - watchdog_timer.expires = - jiffies + WATCHDOG_INTERVAL; - add_timer_on(&watchdog_timer, - cpumask_first(cpu_online_mask)); - } + clocksource_reset_watchdog(); + } + } + /* Check if the watchdog timer needs to be started. */ + clocksource_start_watchdog(); + spin_unlock_irqrestore(&watchdog_lock, flags); +} + +static void clocksource_dequeue_watchdog(struct clocksource *cs) +{ + struct clocksource *tmp; + unsigned long flags; + + spin_lock_irqsave(&watchdog_lock, flags); + if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) { + /* cs is a watched clocksource. */ + list_del_init(&cs->wd_list); + } else if (cs == watchdog) { + /* Reset watchdog cycles */ + clocksource_reset_watchdog(); + /* Current watchdog is removed. Find an alternative. */ + watchdog = NULL; + list_for_each_entry(tmp, &clocksource_list, list) { + if (tmp == cs || tmp->flags & CLOCK_SOURCE_MUST_VERIFY) + continue; + if (!watchdog || tmp->rating > watchdog->rating) + watchdog = tmp; } } + cs->flags &= ~CLOCK_SOURCE_WATCHDOG; + /* Check if the watchdog timer needs to be stopped. */ + clocksource_stop_watchdog(); spin_unlock_irqrestore(&watchdog_lock, flags); } -#else -static void clocksource_check_watchdog(struct clocksource *cs) + +static int clocksource_watchdog_kthread(void *data) +{ + struct clocksource *cs, *tmp; + unsigned long flags; + LIST_HEAD(unstable); + + mutex_lock(&clocksource_mutex); + spin_lock_irqsave(&watchdog_lock, flags); + list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) + if (cs->flags & CLOCK_SOURCE_UNSTABLE) { + list_del_init(&cs->wd_list); + list_add(&cs->wd_list, &unstable); + } + /* Check if the watchdog timer needs to be stopped. */ + clocksource_stop_watchdog(); + spin_unlock_irqrestore(&watchdog_lock, flags); + + /* Needs to be done outside of watchdog lock */ + list_for_each_entry_safe(cs, tmp, &unstable, wd_list) { + list_del_init(&cs->wd_list); + __clocksource_change_rating(cs, 0); + } + mutex_unlock(&clocksource_mutex); + return 0; +} + +#else /* CONFIG_CLOCKSOURCE_WATCHDOG */ + +static void clocksource_enqueue_watchdog(struct clocksource *cs) { if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; } +static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { } static inline void clocksource_resume_watchdog(void) { } -#endif +static inline int clocksource_watchdog_kthread(void *data) { return 0; } + +#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */ /** * clocksource_resume - resume the clocksource(s) @@ -294,18 +393,16 @@ static inline void clocksource_resume_watchdog(void) { } void clocksource_resume(void) { struct clocksource *cs; - unsigned long flags; - spin_lock_irqsave(&clocksource_lock, flags); + mutex_lock(&clocksource_mutex); - list_for_each_entry(cs, &clocksource_list, list) { + list_for_each_entry(cs, &clocksource_list, list) if (cs->resume) cs->resume(); - } clocksource_resume_watchdog(); - spin_unlock_irqrestore(&clocksource_lock, flags); + mutex_unlock(&clocksource_mutex); } /** @@ -320,75 +417,94 @@ void clocksource_touch_watchdog(void) clocksource_resume_watchdog(); } +#ifdef CONFIG_GENERIC_TIME + /** - * clocksource_get_next - Returns the selected clocksource + * clocksource_select - Select the best clocksource available + * + * Private function. Must hold clocksource_mutex when called. * + * Select the clocksource with the best rating, or the clocksource, + * which is selected by userspace override. */ -struct clocksource *clocksource_get_next(void) +static void clocksource_select(void) { - unsigned long flags; + struct clocksource *best, *cs; - spin_lock_irqsave(&clocksource_lock, flags); - if (next_clocksource && finished_booting) { - curr_clocksource = next_clocksource; - next_clocksource = NULL; + if (!finished_booting || list_empty(&clocksource_list)) + return; + /* First clocksource on the list has the best rating. */ + best = list_first_entry(&clocksource_list, struct clocksource, list); + /* Check for the override clocksource. */ + list_for_each_entry(cs, &clocksource_list, list) { + if (strcmp(cs->name, override_name) != 0) + continue; + /* + * Check to make sure we don't switch to a non-highres + * capable clocksource if the tick code is in oneshot + * mode (highres or nohz) + */ + if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) && + tick_oneshot_mode_active()) { + /* Override clocksource cannot be used. */ + printk(KERN_WARNING "Override clocksource %s is not " + "HRT compatible. Cannot switch while in " + "HRT/NOHZ mode\n", cs->name); + override_name[0] = 0; + } else + /* Override clocksource can be used. */ + best = cs; + break; + } + if (curr_clocksource != best) { + printk(KERN_INFO "Switching to clocksource %s\n", best->name); + curr_clocksource = best; + timekeeping_notify(curr_clocksource); } - spin_unlock_irqrestore(&clocksource_lock, flags); - - return curr_clocksource; } -/** - * select_clocksource - Selects the best registered clocksource. - * - * Private function. Must hold clocksource_lock when called. +#else /* CONFIG_GENERIC_TIME */ + +static inline void clocksource_select(void) { } + +#endif + +/* + * clocksource_done_booting - Called near the end of core bootup * - * Select the clocksource with the best rating, or the clocksource, - * which is selected by userspace override. + * Hack to avoid lots of clocksource churn at boot time. + * We use fs_initcall because we want this to start before + * device_initcall but after subsys_initcall. */ -static struct clocksource *select_clocksource(void) +static int __init clocksource_done_booting(void) { - struct clocksource *next; - - if (list_empty(&clocksource_list)) - return NULL; - - if (clocksource_override) - next = clocksource_override; - else - next = list_entry(clocksource_list.next, struct clocksource, - list); + finished_booting = 1; - if (next == curr_clocksource) - return NULL; + /* + * Run the watchdog first to eliminate unstable clock sources + */ + clocksource_watchdog_kthread(NULL); - return next; + mutex_lock(&clocksource_mutex); + clocksource_select(); + mutex_unlock(&clocksource_mutex); + return 0; } +fs_initcall(clocksource_done_booting); /* * Enqueue the clocksource sorted by rating */ -static int clocksource_enqueue(struct clocksource *c) +static void clocksource_enqueue(struct clocksource *cs) { - struct list_head *tmp, *entry = &clocksource_list; + struct list_head *entry = &clocksource_list; + struct clocksource *tmp; - list_for_each(tmp, &clocksource_list) { - struct clocksource *cs; - - cs = list_entry(tmp, struct clocksource, list); - if (cs == c) - return -EBUSY; + list_for_each_entry(tmp, &clocksource_list, list) /* Keep track of the place, where to insert */ - if (cs->rating >= c->rating) - entry = tmp; - } - list_add(&c->list, entry); - - if (strlen(c->name) == strlen(override_name) && - !strcmp(c->name, override_name)) - clocksource_override = c; - - return 0; + if (tmp->rating >= cs->rating) + entry = &tmp->list; + list_add(&cs->list, entry); } /** @@ -397,52 +513,48 @@ static int clocksource_enqueue(struct clocksource *c) * * Returns -EBUSY if registration fails, zero otherwise. */ -int clocksource_register(struct clocksource *c) +int clocksource_register(struct clocksource *cs) { - unsigned long flags; - int ret; - - spin_lock_irqsave(&clocksource_lock, flags); - ret = clocksource_enqueue(c); - if (!ret) - next_clocksource = select_clocksource(); - spin_unlock_irqrestore(&clocksource_lock, flags); - if (!ret) - clocksource_check_watchdog(c); - return ret; + mutex_lock(&clocksource_mutex); + clocksource_enqueue(cs); + clocksource_select(); + clocksource_enqueue_watchdog(cs); + mutex_unlock(&clocksource_mutex); + return 0; } EXPORT_SYMBOL(clocksource_register); +static void __clocksource_change_rating(struct clocksource *cs, int rating) +{ + list_del(&cs->list); + cs->rating = rating; + clocksource_enqueue(cs); + clocksource_select(); +} + /** * clocksource_change_rating - Change the rating of a registered clocksource - * */ void clocksource_change_rating(struct clocksource *cs, int rating) { - unsigned long flags; - - spin_lock_irqsave(&clocksource_lock, flags); - list_del(&cs->list); - cs->rating = rating; - clocksource_enqueue(cs); - next_clocksource = select_clocksource(); - spin_unlock_irqrestore(&clocksource_lock, flags); + mutex_lock(&clocksource_mutex); + __clocksource_change_rating(cs, rating); + mutex_unlock(&clocksource_mutex); } +EXPORT_SYMBOL(clocksource_change_rating); /** * clocksource_unregister - remove a registered clocksource */ void clocksource_unregister(struct clocksource *cs) { - unsigned long flags; - - spin_lock_irqsave(&clocksource_lock, flags); + mutex_lock(&clocksource_mutex); + clocksource_dequeue_watchdog(cs); list_del(&cs->list); - if (clocksource_override == cs) - clocksource_override = NULL; - next_clocksource = select_clocksource(); - spin_unlock_irqrestore(&clocksource_lock, flags); + clocksource_select(); + mutex_unlock(&clocksource_mutex); } +EXPORT_SYMBOL(clocksource_unregister); #ifdef CONFIG_SYSFS /** @@ -458,9 +570,9 @@ sysfs_show_current_clocksources(struct sys_device *dev, { ssize_t count = 0; - spin_lock_irq(&clocksource_lock); + mutex_lock(&clocksource_mutex); count = snprintf(buf, PAGE_SIZE, "%s\n", curr_clocksource->name); - spin_unlock_irq(&clocksource_lock); + mutex_unlock(&clocksource_mutex); return count; } @@ -478,9 +590,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev, struct sysdev_attribute *attr, const char *buf, size_t count) { - struct clocksource *ovr = NULL; size_t ret = count; - int len; /* strings from sysfs write are not 0 terminated! */ if (count >= sizeof(override_name)) @@ -490,44 +600,14 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev, if (buf[count-1] == '\n') count--; - spin_lock_irq(&clocksource_lock); + mutex_lock(&clocksource_mutex); if (count > 0) memcpy(override_name, buf, count); override_name[count] = 0; + clocksource_select(); - len = strlen(override_name); - if (len) { - struct clocksource *cs; - - ovr = clocksource_override; - /* try to select it: */ - list_for_each_entry(cs, &clocksource_list, list) { - if (strlen(cs->name) == len && - !strcmp(cs->name, override_name)) - ovr = cs; - } - } - - /* - * Check to make sure we don't switch to a non-highres capable - * clocksource if the tick code is in oneshot mode (highres or nohz) - */ - if (tick_oneshot_mode_active() && ovr && - !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) { - printk(KERN_WARNING "%s clocksource is not HRT compatible. " - "Cannot switch while in HRT/NOHZ mode\n", ovr->name); - ovr = NULL; - override_name[0] = 0; - } - - /* Reselect, when the override name has changed */ - if (ovr != clocksource_override) { - clocksource_override = ovr; - next_clocksource = select_clocksource(); - } - - spin_unlock_irq(&clocksource_lock); + mutex_unlock(&clocksource_mutex); return ret; } @@ -547,7 +627,7 @@ sysfs_show_available_clocksources(struct sys_device *dev, struct clocksource *src; ssize_t count = 0; - spin_lock_irq(&clocksource_lock); + mutex_lock(&clocksource_mutex); list_for_each_entry(src, &clocksource_list, list) { /* * Don't show non-HRES clocksource if the tick code is @@ -559,7 +639,7 @@ sysfs_show_available_clocksources(struct sys_device *dev, max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "%s ", src->name); } - spin_unlock_irq(&clocksource_lock); + mutex_unlock(&clocksource_mutex); count += snprintf(buf + count, max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n"); @@ -614,11 +694,10 @@ device_initcall(init_clocksource_sysfs); */ static int __init boot_override_clocksource(char* str) { - unsigned long flags; - spin_lock_irqsave(&clocksource_lock, flags); + mutex_lock(&clocksource_mutex); if (str) strlcpy(override_name, str, sizeof(override_name)); - spin_unlock_irqrestore(&clocksource_lock, flags); + mutex_unlock(&clocksource_mutex); return 1; } diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c index c3f6c30..5404a84 100644 --- a/kernel/time/jiffies.c +++ b/kernel/time/jiffies.c @@ -61,7 +61,6 @@ struct clocksource clocksource_jiffies = { .read = jiffies_read, .mask = 0xffffffff, /*32bits*/ .mult = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */ - .mult_orig = NSEC_PER_JIFFY << JIFFIES_SHIFT, .shift = JIFFIES_SHIFT, }; @@ -71,3 +70,8 @@ static int __init init_jiffies_clocksource(void) } core_initcall(init_jiffies_clocksource); + +struct clocksource * __init __weak clocksource_default_clock(void) +{ + return &clocksource_jiffies; +} diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 7fc6437..4800f93 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -194,8 +194,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) case TIME_OK: break; case TIME_INS: - xtime.tv_sec--; - wall_to_monotonic.tv_sec++; + timekeeping_leap_insert(-1); time_state = TIME_OOP; printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n"); @@ -203,9 +202,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) res = HRTIMER_RESTART; break; case TIME_DEL: - xtime.tv_sec++; + timekeeping_leap_insert(1); time_tai--; - wall_to_monotonic.tv_sec--; time_state = TIME_WAIT; printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n"); @@ -219,7 +217,6 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) time_state = TIME_OK; break; } - update_vsyscall(&xtime, clock); write_sequnlock(&xtime_lock); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index e8c77d9..fb0f46f 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -18,7 +18,117 @@ #include <linux/jiffies.h> #include <linux/time.h> #include <linux/tick.h> +#include <linux/stop_machine.h> + +/* Structure holding internal timekeeping values. */ +struct timekeeper { + /* Current clocksource used for timekeeping. */ + struct clocksource *clock; + /* The shift value of the current clocksource. */ + int shift; + + /* Number of clock cycles in one NTP interval. */ + cycle_t cycle_interval; + /* Number of clock shifted nano seconds in one NTP interval. */ + u64 xtime_interval; + /* Raw nano seconds accumulated per NTP interval. */ + u32 raw_interval; + + /* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */ + u64 xtime_nsec; + /* Difference between accumulated time and NTP time in ntp + * shifted nano seconds. */ + s64 ntp_error; + /* Shift conversion between clock shifted nano seconds and + * ntp shifted nano seconds. */ + int ntp_error_shift; + /* NTP adjusted clock multiplier */ + u32 mult; +}; + +struct timekeeper timekeeper; + +/** + * timekeeper_setup_internals - Set up internals to use clocksource clock. + * + * @clock: Pointer to clocksource. + * + * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment + * pair and interval request. + * + * Unless you're the timekeeping code, you should not be using this! + */ +static void timekeeper_setup_internals(struct clocksource *clock) +{ + cycle_t interval; + u64 tmp; + + timekeeper.clock = clock; + clock->cycle_last = clock->read(clock); + /* Do the ns -> cycle conversion first, using original mult */ + tmp = NTP_INTERVAL_LENGTH; + tmp <<= clock->shift; + tmp += clock->mult/2; + do_div(tmp, clock->mult); + if (tmp == 0) + tmp = 1; + + interval = (cycle_t) tmp; + timekeeper.cycle_interval = interval; + + /* Go back from cycles -> shifted ns */ + timekeeper.xtime_interval = (u64) interval * clock->mult; + timekeeper.raw_interval = + ((u64) interval * clock->mult) >> clock->shift; + + timekeeper.xtime_nsec = 0; + timekeeper.shift = clock->shift; + + timekeeper.ntp_error = 0; + timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; + + /* + * The timekeeper keeps its own mult values for the currently + * active clocksource. These value will be adjusted via NTP + * to counteract clock drifting. + */ + timekeeper.mult = clock->mult; +} + +/* Timekeeper helper functions. */ +static inline s64 timekeeping_get_ns(void) +{ + cycle_t cycle_now, cycle_delta; + struct clocksource *clock; + + /* read clocksource: */ + clock = timekeeper.clock; + cycle_now = clock->read(clock); + + /* calculate the delta since the last update_wall_time: */ + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* return delta convert to nanoseconds using ntp adjusted mult. */ + return clocksource_cyc2ns(cycle_delta, timekeeper.mult, + timekeeper.shift); +} + +static inline s64 timekeeping_get_ns_raw(void) +{ + cycle_t cycle_now, cycle_delta; + struct clocksource *clock; + + /* read clocksource: */ + clock = timekeeper.clock; + cycle_now = clock->read(clock); + + /* calculate the delta since the last update_wall_time: */ + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* return delta convert to nanoseconds using ntp adjusted mult. */ + return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); +} /* * This read-write spinlock protects us from races in SMP while @@ -44,7 +154,12 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); */ struct timespec xtime __attribute__ ((aligned (16))); struct timespec wall_to_monotonic __attribute__ ((aligned (16))); -static unsigned long total_sleep_time; /* seconds */ +static struct timespec total_sleep_time; + +/* + * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. + */ +struct timespec raw_time; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; @@ -56,35 +171,44 @@ void update_xtime_cache(u64 nsec) timespec_add_ns(&xtime_cache, nsec); } -struct clocksource *clock; - +/* must hold xtime_lock */ +void timekeeping_leap_insert(int leapsecond) +{ + xtime.tv_sec += leapsecond; + wall_to_monotonic.tv_sec -= leapsecond; + update_vsyscall(&xtime, timekeeper.clock); +} #ifdef CONFIG_GENERIC_TIME + /** - * clocksource_forward_now - update clock to the current time + * timekeeping_forward_now - update clock to the current time * * Forward the current clock to update its state since the last call to * update_wall_time(). This is useful before significant clock changes, * as it avoids having to deal with this time offset explicitly. */ -static void clocksource_forward_now(void) +static void timekeeping_forward_now(void) { cycle_t cycle_now, cycle_delta; + struct clocksource *clock; s64 nsec; - cycle_now = clocksource_read(clock); + clock = timekeeper.clock; + cycle_now = clock->read(clock); cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; clock->cycle_last = cycle_now; - nsec = cyc2ns(clock, cycle_delta); + nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult, + timekeeper.shift); /* If arch requires, add in gettimeoffset() */ nsec += arch_gettimeoffset(); timespec_add_ns(&xtime, nsec); - nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift; - clock->raw_time.tv_nsec += nsec; + nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); + timespec_add_ns(&raw_time, nsec); } /** @@ -95,7 +219,6 @@ static void clocksource_forward_now(void) */ void getnstimeofday(struct timespec *ts) { - cycle_t cycle_now, cycle_delta; unsigned long seq; s64 nsecs; @@ -105,15 +228,7 @@ void getnstimeofday(struct timespec *ts) seq = read_seqbegin(&xtime_lock); *ts = xtime; - - /* read clocksource: */ - cycle_now = clocksource_read(clock); - - /* calculate the delta since the last update_wall_time: */ - cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - - /* convert to nanoseconds: */ - nsecs = cyc2ns(clock, cycle_delta); + nsecs = timekeeping_get_ns(); /* If arch requires, add in gettimeoffset() */ nsecs += arch_gettimeoffset(); @@ -125,6 +240,57 @@ void getnstimeofday(struct timespec *ts) EXPORT_SYMBOL(getnstimeofday); +ktime_t ktime_get(void) +{ + unsigned int seq; + s64 secs, nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqbegin(&xtime_lock); + secs = xtime.tv_sec + wall_to_monotonic.tv_sec; + nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; + nsecs += timekeeping_get_ns(); + + } while (read_seqretry(&xtime_lock, seq)); + /* + * Use ktime_set/ktime_add_ns to create a proper ktime on + * 32-bit architectures without CONFIG_KTIME_SCALAR. + */ + return ktime_add_ns(ktime_set(secs, 0), nsecs); +} +EXPORT_SYMBOL_GPL(ktime_get); + +/** + * ktime_get_ts - get the monotonic clock in timespec format + * @ts: pointer to timespec variable + * + * The function calculates the monotonic clock from the realtime + * clock and the wall_to_monotonic offset and stores the result + * in normalized timespec format in the variable pointed to by @ts. + */ +void ktime_get_ts(struct timespec *ts) +{ + struct timespec tomono; + unsigned int seq; + s64 nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqbegin(&xtime_lock); + *ts = xtime; + tomono = wall_to_monotonic; + nsecs = timekeeping_get_ns(); + + } while (read_seqretry(&xtime_lock, seq)); + + set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, + ts->tv_nsec + tomono.tv_nsec + nsecs); +} +EXPORT_SYMBOL_GPL(ktime_get_ts); + /** * do_gettimeofday - Returns the time of day in a timeval * @tv: pointer to the timeval to be set @@ -157,7 +323,7 @@ int do_settimeofday(struct timespec *tv) write_seqlock_irqsave(&xtime_lock, flags); - clocksource_forward_now(); + timekeeping_forward_now(); ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; @@ -167,10 +333,10 @@ int do_settimeofday(struct timespec *tv) update_xtime_cache(0); - clock->error = 0; + timekeeper.ntp_error = 0; ntp_clear(); - update_vsyscall(&xtime, clock); + update_vsyscall(&xtime, timekeeper.clock); write_sequnlock_irqrestore(&xtime_lock, flags); @@ -187,44 +353,97 @@ EXPORT_SYMBOL(do_settimeofday); * * Accumulates current time interval and initializes new clocksource */ -static void change_clocksource(void) +static int change_clocksource(void *data) { struct clocksource *new, *old; - new = clocksource_get_next(); + new = (struct clocksource *) data; + + timekeeping_forward_now(); + if (!new->enable || new->enable(new) == 0) { + old = timekeeper.clock; + timekeeper_setup_internals(new); + if (old->disable) + old->disable(old); + } + return 0; +} - if (clock == new) +/** + * timekeeping_notify - Install a new clock source + * @clock: pointer to the clock source + * + * This function is called from clocksource.c after a new, better clock + * source has been registered. The caller holds the clocksource_mutex. + */ +void timekeeping_notify(struct clocksource *clock) +{ + if (timekeeper.clock == clock) return; + stop_machine(change_clocksource, clock, NULL); + tick_clock_notify(); +} - clocksource_forward_now(); +#else /* GENERIC_TIME */ - if (clocksource_enable(new)) - return; +static inline void timekeeping_forward_now(void) { } - new->raw_time = clock->raw_time; - old = clock; - clock = new; - clocksource_disable(old); +/** + * ktime_get - get the monotonic time in ktime_t format + * + * returns the time in ktime_t format + */ +ktime_t ktime_get(void) +{ + struct timespec now; - clock->cycle_last = 0; - clock->cycle_last = clocksource_read(clock); - clock->error = 0; - clock->xtime_nsec = 0; - clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); + ktime_get_ts(&now); - tick_clock_notify(); + return timespec_to_ktime(now); +} +EXPORT_SYMBOL_GPL(ktime_get); - /* - * We're holding xtime lock and waking up klogd would deadlock - * us on enqueue. So no printing! - printk(KERN_INFO "Time: %s clocksource has been installed.\n", - clock->name); - */ +/** + * ktime_get_ts - get the monotonic clock in timespec format + * @ts: pointer to timespec variable + * + * The function calculates the monotonic clock from the realtime + * clock and the wall_to_monotonic offset and stores the result + * in normalized timespec format in the variable pointed to by @ts. + */ +void ktime_get_ts(struct timespec *ts) +{ + struct timespec tomono; + unsigned long seq; + + do { + seq = read_seqbegin(&xtime_lock); + getnstimeofday(ts); + tomono = wall_to_monotonic; + + } while (read_seqretry(&xtime_lock, seq)); + + set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, + ts->tv_nsec + tomono.tv_nsec); } -#else -static inline void clocksource_forward_now(void) { } -static inline void change_clocksource(void) { } -#endif +EXPORT_SYMBOL_GPL(ktime_get_ts); + +#endif /* !GENERIC_TIME */ + +/** + * ktime_get_real - get the real (wall-) time in ktime_t format + * + * returns the time in ktime_t format + */ +ktime_t ktime_get_real(void) +{ + struct timespec now; + + getnstimeofday(&now); + + return timespec_to_ktime(now); +} +EXPORT_SYMBOL_GPL(ktime_get_real); /** * getrawmonotonic - Returns the raw monotonic time in a timespec @@ -236,21 +455,11 @@ void getrawmonotonic(struct timespec *ts) { unsigned long seq; s64 nsecs; - cycle_t cycle_now, cycle_delta; do { seq = read_seqbegin(&xtime_lock); - - /* read clocksource: */ - cycle_now = clocksource_read(clock); - - /* calculate the delta since the last update_wall_time: */ - cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - - /* convert to nanoseconds: */ - nsecs = ((s64)cycle_delta * clock->mult_orig) >> clock->shift; - - *ts = clock->raw_time; + nsecs = timekeeping_get_ns_raw(); + *ts = raw_time; } while (read_seqretry(&xtime_lock, seq)); @@ -270,7 +479,7 @@ int timekeeping_valid_for_hres(void) do { seq = read_seqbegin(&xtime_lock); - ret = clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; + ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; } while (read_seqretry(&xtime_lock, seq)); @@ -278,17 +487,33 @@ int timekeeping_valid_for_hres(void) } /** - * read_persistent_clock - Return time in seconds from the persistent clock. + * read_persistent_clock - Return time from the persistent clock. * * Weak dummy function for arches that do not yet support it. - * Returns seconds from epoch using the battery backed persistent clock. - * Returns zero if unsupported. + * Reads the time from the battery backed persistent clock. + * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. * * XXX - Do be sure to remove it once all arches implement it. */ -unsigned long __attribute__((weak)) read_persistent_clock(void) +void __attribute__((weak)) read_persistent_clock(struct timespec *ts) { - return 0; + ts->tv_sec = 0; + ts->tv_nsec = 0; +} + +/** + * read_boot_clock - Return time of the system start. + * + * Weak dummy function for arches that do not yet support it. + * Function to read the exact time the system has been started. + * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. + * + * XXX - Do be sure to remove it once all arches implement it. + */ +void __attribute__((weak)) read_boot_clock(struct timespec *ts) +{ + ts->tv_sec = 0; + ts->tv_nsec = 0; } /* @@ -296,29 +521,40 @@ unsigned long __attribute__((weak)) read_persistent_clock(void) */ void __init timekeeping_init(void) { + struct clocksource *clock; unsigned long flags; - unsigned long sec = read_persistent_clock(); + struct timespec now, boot; + + read_persistent_clock(&now); + read_boot_clock(&boot); write_seqlock_irqsave(&xtime_lock, flags); ntp_init(); - clock = clocksource_get_next(); - clocksource_enable(clock); - clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); - clock->cycle_last = clocksource_read(clock); - - xtime.tv_sec = sec; - xtime.tv_nsec = 0; + clock = clocksource_default_clock(); + if (clock->enable) + clock->enable(clock); + timekeeper_setup_internals(clock); + + xtime.tv_sec = now.tv_sec; + xtime.tv_nsec = now.tv_nsec; + raw_time.tv_sec = 0; + raw_time.tv_nsec = 0; + if (boot.tv_sec == 0 && boot.tv_nsec == 0) { + boot.tv_sec = xtime.tv_sec; + boot.tv_nsec = xtime.tv_nsec; + } set_normalized_timespec(&wall_to_monotonic, - -xtime.tv_sec, -xtime.tv_nsec); + -boot.tv_sec, -boot.tv_nsec); update_xtime_cache(0); - total_sleep_time = 0; + total_sleep_time.tv_sec = 0; + total_sleep_time.tv_nsec = 0; write_sequnlock_irqrestore(&xtime_lock, flags); } /* time in seconds when suspend began */ -static unsigned long timekeeping_suspend_time; +static struct timespec timekeeping_suspend_time; /** * timekeeping_resume - Resumes the generic timekeeping subsystem. @@ -331,24 +567,24 @@ static unsigned long timekeeping_suspend_time; static int timekeeping_resume(struct sys_device *dev) { unsigned long flags; - unsigned long now = read_persistent_clock(); + struct timespec ts; + + read_persistent_clock(&ts); clocksource_resume(); write_seqlock_irqsave(&xtime_lock, flags); - if (now && (now > timekeeping_suspend_time)) { - unsigned long sleep_length = now - timekeeping_suspend_time; - - xtime.tv_sec += sleep_length; - wall_to_monotonic.tv_sec -= sleep_length; - total_sleep_time += sleep_length; + if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { + ts = timespec_sub(ts, timekeeping_suspend_time); + xtime = timespec_add_safe(xtime, ts); + wall_to_monotonic = timespec_sub(wall_to_monotonic, ts); + total_sleep_time = timespec_add_safe(total_sleep_time, ts); } update_xtime_cache(0); /* re-base the last cycle value */ - clock->cycle_last = 0; - clock->cycle_last = clocksource_read(clock); - clock->error = 0; + timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); + timekeeper.ntp_error = 0; timekeeping_suspended = 0; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -366,10 +602,10 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) { unsigned long flags; - timekeeping_suspend_time = read_persistent_clock(); + read_persistent_clock(&timekeeping_suspend_time); write_seqlock_irqsave(&xtime_lock, flags); - clocksource_forward_now(); + timekeeping_forward_now(); timekeeping_suspended = 1; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -404,7 +640,7 @@ device_initcall(timekeeping_init_device); * If the error is already larger, we look ahead even further * to compensate for late or lost adjustments. */ -static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, +static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, s64 *offset) { s64 tick_error, i; @@ -420,7 +656,7 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, * here. This is tuned so that an error of about 1 msec is adjusted * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). */ - error2 = clock->error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); + error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); error2 = abs(error2); for (look_ahead = 0; error2 > 0; look_ahead++) error2 >>= 2; @@ -429,8 +665,8 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, * Now calculate the error in (1 << look_ahead) ticks, but first * remove the single look ahead already included in the error. */ - tick_error = tick_length >> (NTP_SCALE_SHIFT - clock->shift + 1); - tick_error -= clock->xtime_interval >> 1; + tick_error = tick_length >> (timekeeper.ntp_error_shift + 1); + tick_error -= timekeeper.xtime_interval >> 1; error = ((error - tick_error) >> look_ahead) + tick_error; /* Finally calculate the adjustment shift value. */ @@ -455,18 +691,18 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, * this is optimized for the most common adjustments of -1,0,1, * for other values we can do a bit more work. */ -static void clocksource_adjust(s64 offset) +static void timekeeping_adjust(s64 offset) { - s64 error, interval = clock->cycle_interval; + s64 error, interval = timekeeper.cycle_interval; int adj; - error = clock->error >> (NTP_SCALE_SHIFT - clock->shift - 1); + error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1); if (error > interval) { error >>= 2; if (likely(error <= interval)) adj = 1; else - adj = clocksource_bigadjust(error, &interval, &offset); + adj = timekeeping_bigadjust(error, &interval, &offset); } else if (error < -interval) { error >>= 2; if (likely(error >= -interval)) { @@ -474,15 +710,15 @@ static void clocksource_adjust(s64 offset) interval = -interval; offset = -offset; } else - adj = clocksource_bigadjust(error, &interval, &offset); + adj = timekeeping_bigadjust(error, &interval, &offset); } else return; - clock->mult += adj; - clock->xtime_interval += interval; - clock->xtime_nsec -= offset; - clock->error -= (interval - offset) << - (NTP_SCALE_SHIFT - clock->shift); + timekeeper.mult += adj; + timekeeper.xtime_interval += interval; + timekeeper.xtime_nsec -= offset; + timekeeper.ntp_error -= (interval - offset) << + timekeeper.ntp_error_shift; } /** @@ -492,53 +728,59 @@ static void clocksource_adjust(s64 offset) */ void update_wall_time(void) { + struct clocksource *clock; cycle_t offset; + u64 nsecs; /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) return; + clock = timekeeper.clock; #ifdef CONFIG_GENERIC_TIME - offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask; + offset = (clock->read(clock) - clock->cycle_last) & clock->mask; #else - offset = clock->cycle_interval; + offset = timekeeper.cycle_interval; #endif - clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift; + timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; /* normally this loop will run just once, however in the * case of lost or late ticks, it will accumulate correctly. */ - while (offset >= clock->cycle_interval) { + while (offset >= timekeeper.cycle_interval) { + u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; + /* accumulate one interval */ - offset -= clock->cycle_interval; - clock->cycle_last += clock->cycle_interval; + offset -= timekeeper.cycle_interval; + clock->cycle_last += timekeeper.cycle_interval; - clock->xtime_nsec += clock->xtime_interval; - if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) { - clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift; + timekeeper.xtime_nsec += timekeeper.xtime_interval; + if (timekeeper.xtime_nsec >= nsecps) { + timekeeper.xtime_nsec -= nsecps; xtime.tv_sec++; second_overflow(); } - clock->raw_time.tv_nsec += clock->raw_interval; - if (clock->raw_time.tv_nsec >= NSEC_PER_SEC) { - clock->raw_time.tv_nsec -= NSEC_PER_SEC; - clock->raw_time.tv_sec++; + raw_time.tv_nsec += timekeeper.raw_interval; + if (raw_time.tv_nsec >= NSEC_PER_SEC) { + raw_time.tv_nsec -= NSEC_PER_SEC; + raw_time.tv_sec++; } /* accumulate error between NTP and clock interval */ - clock->error += tick_length; - clock->error -= clock->xtime_interval << (NTP_SCALE_SHIFT - clock->shift); + timekeeper.ntp_error += tick_length; + timekeeper.ntp_error -= timekeeper.xtime_interval << + timekeeper.ntp_error_shift; } /* correct the clock when NTP error is too big */ - clocksource_adjust(offset); + timekeeping_adjust(offset); /* * Since in the loop above, we accumulate any amount of time * in xtime_nsec over a second into xtime.tv_sec, its possible for * xtime_nsec to be fairly small after the loop. Further, if we're - * slightly speeding the clocksource up in clocksource_adjust(), + * slightly speeding the clocksource up in timekeeping_adjust(), * its possible the required corrective factor to xtime_nsec could * cause it to underflow. * @@ -550,24 +792,25 @@ void update_wall_time(void) * We'll correct this error next time through this function, when * xtime_nsec is not as small. */ - if (unlikely((s64)clock->xtime_nsec < 0)) { - s64 neg = -(s64)clock->xtime_nsec; - clock->xtime_nsec = 0; - clock->error += neg << (NTP_SCALE_SHIFT - clock->shift); + if (unlikely((s64)timekeeper.xtime_nsec < 0)) { + s64 neg = -(s64)timekeeper.xtime_nsec; + timekeeper.xtime_nsec = 0; + timekeeper.ntp_error += neg << timekeeper.ntp_error_shift; } /* store full nanoseconds into xtime after rounding it up and * add the remainder to the error difference. */ - xtime.tv_nsec = ((s64)clock->xtime_nsec >> clock->shift) + 1; - clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift; - clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift); + xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1; + timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift; + timekeeper.ntp_error += timekeeper.xtime_nsec << + timekeeper.ntp_error_shift; - update_xtime_cache(cyc2ns(clock, offset)); + nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift); + update_xtime_cache(nsecs); /* check to see if there is a new clocksource to use */ - change_clocksource(); - update_vsyscall(&xtime, clock); + update_vsyscall(&xtime, timekeeper.clock); } /** @@ -583,9 +826,12 @@ void update_wall_time(void) */ void getboottime(struct timespec *ts) { - set_normalized_timespec(ts, - - (wall_to_monotonic.tv_sec + total_sleep_time), - - wall_to_monotonic.tv_nsec); + struct timespec boottime = { + .tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec, + .tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec + }; + + set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); } /** @@ -594,7 +840,7 @@ void getboottime(struct timespec *ts) */ void monotonic_to_bootbased(struct timespec *ts) { - ts->tv_sec += total_sleep_time; + *ts = timespec_add_safe(*ts, total_sleep_time); } unsigned long get_seconds(void) @@ -603,6 +849,10 @@ unsigned long get_seconds(void) } EXPORT_SYMBOL(get_seconds); +struct timespec __current_kernel_time(void) +{ + return xtime_cache; +} struct timespec current_kernel_time(void) { @@ -618,3 +868,20 @@ struct timespec current_kernel_time(void) return now; } EXPORT_SYMBOL(current_kernel_time); + +struct timespec get_monotonic_coarse(void) +{ + struct timespec now, mono; + unsigned long seq; + + do { + seq = read_seqbegin(&xtime_lock); + + now = xtime_cache; + mono = wall_to_monotonic; + } while (read_seqretry(&xtime_lock, seq)); + + set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, + now.tv_nsec + mono.tv_nsec); + return now; +} diff --git a/kernel/timer.c b/kernel/timer.c index a3d25f415..bbb5107 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -72,6 +72,7 @@ struct tvec_base { spinlock_t lock; struct timer_list *running_timer; unsigned long timer_jiffies; + unsigned long next_timer; struct tvec_root tv1; struct tvec tv2; struct tvec tv3; @@ -622,6 +623,9 @@ __mod_timer(struct timer_list *timer, unsigned long expires, if (timer_pending(timer)) { detach_timer(timer, 0); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; } else { if (pending_only) @@ -663,6 +667,9 @@ __mod_timer(struct timer_list *timer, unsigned long expires, } timer->expires = expires; + if (time_before(timer->expires, base->next_timer) && + !tbase_get_deferrable(timer->base)) + base->next_timer = timer->expires; internal_add_timer(base, timer); out_unlock: @@ -781,6 +788,9 @@ void add_timer_on(struct timer_list *timer, int cpu) spin_lock_irqsave(&base->lock, flags); timer_set_base(timer, base); debug_timer_activate(timer); + if (time_before(timer->expires, base->next_timer) && + !tbase_get_deferrable(timer->base)) + base->next_timer = timer->expires; internal_add_timer(base, timer); /* * Check whether the other CPU is idle and needs to be @@ -817,6 +827,9 @@ int del_timer(struct timer_list *timer) base = lock_timer_base(timer, &flags); if (timer_pending(timer)) { detach_timer(timer, 1); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; } spin_unlock_irqrestore(&base->lock, flags); @@ -850,6 +863,9 @@ int try_to_del_timer_sync(struct timer_list *timer) ret = 0; if (timer_pending(timer)) { detach_timer(timer, 1); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; } out: @@ -1007,8 +1023,8 @@ static inline void __run_timers(struct tvec_base *base) #ifdef CONFIG_NO_HZ /* * Find out when the next timer event is due to happen. This - * is used on S/390 to stop all activity when a cpus is idle. - * This functions needs to be called disabled. + * is used on S/390 to stop all activity when a CPU is idle. + * This function needs to be called with interrupts disabled. */ static unsigned long __next_timer_interrupt(struct tvec_base *base) { @@ -1134,7 +1150,9 @@ unsigned long get_next_timer_interrupt(unsigned long now) unsigned long expires; spin_lock(&base->lock); - expires = __next_timer_interrupt(base); + if (time_before_eq(base->next_timer, base->timer_jiffies)) + base->next_timer = __next_timer_interrupt(base); + expires = base->next_timer; spin_unlock(&base->lock); if (time_before_eq(expires, now)) @@ -1522,6 +1540,7 @@ static int __cpuinit init_timers_cpu(int cpu) INIT_LIST_HEAD(base->tv1.vec + j); base->timer_jiffies = jiffies; + base->next_timer = base->timer_jiffies; return 0; } @@ -1534,6 +1553,9 @@ static void migrate_timer_list(struct tvec_base *new_base, struct list_head *hea timer = list_first_entry(head, struct timer_list, entry); detach_timer(timer, 0); timer_set_base(timer, new_base); + if (time_before(timer->expires, new_base->next_timer) && + !tbase_get_deferrable(timer->base)) + new_base->next_timer = timer->expires; internal_add_timer(new_base, timer); } } |
