From d4f587c67fc39e0030ddd718675e252e208da4d7 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:31 +0200 Subject: timekeeping: Increase granularity of read_persistent_clock() The persistent clock of some architectures (e.g. s390) have a better granularity than seconds. To reduce the delta between the host clock and the guest clock in a virtualized system change the read_persistent_clock function to return a struct timespec. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134811.013873340@de.ibm.com> Signed-off-by: Thomas Gleixner --- arch/m68knommu/kernel/time.c | 5 +++-- arch/mips/dec/time.c | 5 +++-- arch/mips/lasat/ds1603.c | 5 +++-- arch/mips/lasat/sysctl.c | 8 ++++++-- arch/mips/lemote/lm2e/setup.c | 5 +++-- arch/mips/mti-malta/malta-time.c | 5 +++-- arch/mips/pmc-sierra/yosemite/setup.c | 5 +++-- arch/mips/sibyte/swarm/setup.c | 15 +++++++++++---- arch/mips/sni/time.c | 5 +++-- arch/powerpc/kernel/time.c | 7 ++++--- arch/s390/kernel/time.c | 22 ++++------------------ arch/sh/kernel/time.c | 6 ++---- arch/x86/kernel/rtc.c | 5 +++-- arch/xtensa/kernel/time.c | 5 ++--- 14 files changed, 53 insertions(+), 50 deletions(-) (limited to 'arch') diff --git a/arch/m68knommu/kernel/time.c b/arch/m68knommu/kernel/time.c index d182b2f72211..68432248515c 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 463136e6685a..02f505f23c32 100644 --- a/arch/mips/dec/time.c +++ b/arch/mips/dec/time.c @@ -18,7 +18,7 @@ #include #include -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 52cb1436a12a..c6fd96ff118d 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 8f88886feb12..3f04d4c406b7 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/lemote/lm2e/setup.c b/arch/mips/lemote/lm2e/setup.c index ebd6ceaef2fd..24b355df6127 100644 --- a/arch/mips/lemote/lm2e/setup.c +++ b/arch/mips/lemote/lm2e/setup.c @@ -54,9 +54,10 @@ 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 = mc146818_get_cmos_time(); + ts->tv_nsec = 0; } void (*__wbflush)(void); diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c index 0b97d47691fc..3c6f190aa61c 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 2d3c0dca275d..3498ac9c35af 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 672e45d495a9..623ffc933c4c 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 0d9ec1a5c24a..62df6a598e0a 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 eae4511ceeac..ad63f30fe3da 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -769,7 +769,7 @@ 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; @@ -787,8 +787,9 @@ unsigned long read_persistent_clock(void) 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); + ts->tv_nsec = 0; } /* clocksource code */ diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index e76c2e7a8b9a..a94ec48587b4 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -182,12 +182,9 @@ 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); - return ts.tv_sec; + tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, ts); } static cycle_t read_tod_clock(struct clocksource *cs) @@ -248,7 +245,6 @@ void __init time_init(void) { struct timespec ts; unsigned long flags; - cycle_t now; /* Reset time synchronization interfaces. */ etr_reset(); @@ -266,20 +262,10 @@ void __init time_init(void) 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. + * Reset wall_to_monotonic to the initial timestamp created + * in head.S to get a precise value in /proc/uptime. */ write_seqlock_irqsave(&xtime_lock, flags); - now = get_clock(); - tod_to_timeval(now - TOD_UNIX_EPOCH, &xtime); - clocksource_tod.cycle_last = now; 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); diff --git a/arch/sh/kernel/time.c b/arch/sh/kernel/time.c index 9b352a1e3fb4..3f4706aa975e 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/kernel/rtc.c b/arch/x86/kernel/rtc.c index 5d465b207e72..bf67dcb4a44c 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/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c index 8848120d291b..19085ff0484a 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); -- cgit v1.2.3