From 8b618628b2bf83512fc8df5e8672619d65adfdfb Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Wed, 3 Dec 2014 14:43:06 -0500 Subject: [PATCH 1/8] ktime: Optimize ktime_divns for constant divisors At least on ARM, do_div() is optimized to turn constant divisors into an inline multiplication by the reciprocal value at compile time. However this optimization is missed entirely whenever ktime_divns() is used and the slow out-of-line division code is used all the time. Let ktime_divns() use do_div() inline whenever the divisor is constant and small enough. This will make things like ktime_to_us() and ktime_to_ms() much faster. Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Nicolas Pitre Acked-by: Arnd Bergmann Signed-off-by: Nicolas Pitre Signed-off-by: John Stultz --- include/linux/ktime.h | 12 +++++++++++- kernel/time/hrtimer.c | 4 ++-- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/include/linux/ktime.h b/include/linux/ktime.h index c9d645ad98ff..411dd8bfe539 100644 --- a/include/linux/ktime.h +++ b/include/linux/ktime.h @@ -166,7 +166,17 @@ static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2) } #if BITS_PER_LONG < 64 -extern u64 ktime_divns(const ktime_t kt, s64 div); +extern u64 __ktime_divns(const ktime_t kt, s64 div); +static inline u64 ktime_divns(const ktime_t kt, s64 div) +{ + if (__builtin_constant_p(div) && !(div >> 32)) { + u64 ns = kt.tv64; + do_div(ns, div); + return ns; + } else { + return __ktime_divns(kt, div); + } +} #else /* BITS_PER_LONG < 64 */ # define ktime_divns(kt, div) (u64)((kt).tv64 / (div)) #endif diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 37e50aadd471..890535c41c2d 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -266,7 +266,7 @@ lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) /* * Divide a ktime value by a nanosecond value */ -u64 ktime_divns(const ktime_t kt, s64 div) +u64 __ktime_divns(const ktime_t kt, s64 div) { u64 dclc; int sft = 0; @@ -282,7 +282,7 @@ u64 ktime_divns(const ktime_t kt, s64 div) return dclc; } -EXPORT_SYMBOL_GPL(ktime_divns); +EXPORT_SYMBOL_GPL(__ktime_divns); #endif /* BITS_PER_LONG >= 64 */ /* From d08c0cdd26d48751c15aa2b4479a410594fee9ac Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 8 Dec 2014 12:00:09 -0800 Subject: [PATCH 2/8] time: Expose getboottime64 for in-kernel uses Adds a timespec64 based getboottime64() implementation that can be used as we convert internal users of getboottime away from using timespecs. Cc: pang.xunlei Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: John Stultz --- include/linux/timekeeping.h | 16 ++++++++++++++-- kernel/time/timekeeping.c | 12 ++++++------ 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 9b63d13ba82b..91480137aa39 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -33,6 +33,7 @@ extern time64_t ktime_get_real_seconds(void); extern int __getnstimeofday64(struct timespec64 *tv); extern void getnstimeofday64(struct timespec64 *tv); +extern void getboottime64(struct timespec64 *ts); #if BITS_PER_LONG == 64 /** @@ -72,6 +73,11 @@ static inline struct timespec get_monotonic_coarse(void) { return get_monotonic_coarse64(); } + +static inline void getboottime(struct timespec *ts) +{ + return getboottime64(ts); +} #else /** * Deprecated. Use do_settimeofday64(). @@ -129,9 +135,15 @@ static inline struct timespec get_monotonic_coarse(void) { return timespec64_to_timespec(get_monotonic_coarse64()); } -#endif -extern void getboottime(struct timespec *ts); +static inline void getboottime(struct timespec *ts) +{ + struct timespec64 ts64; + + getboottime64(&ts64); + *ts = timespec64_to_timespec(ts64); +} +#endif #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts) #define ktime_get_real_ts64(ts) getnstimeofday64(ts) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 6a931852082f..b124af259800 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1659,24 +1659,24 @@ out: } /** - * getboottime - Return the real time of system boot. - * @ts: pointer to the timespec to be set + * getboottime64 - Return the real time of system boot. + * @ts: pointer to the timespec64 to be set * - * Returns the wall-time of boot in a timespec. + * Returns the wall-time of boot in a timespec64. * * This is based on the wall_to_monotonic offset and the total suspend * time. Calls to settimeofday will affect the value returned (which * basically means that however wrong your real time clock is at boot time, * you get the right time here). */ -void getboottime(struct timespec *ts) +void getboottime64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot); - *ts = ktime_to_timespec(t); + *ts = ktime_to_timespec64(t); } -EXPORT_SYMBOL_GPL(getboottime); +EXPORT_SYMBOL_GPL(getboottime64); unsigned long get_seconds(void) { From 2e0c78ee5ba4d777ecf22c8f40cc968b4308ca88 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 18 Dec 2014 18:04:34 -0800 Subject: [PATCH 3/8] time: Expose get_monotonic_boottime64 for in-kernel use As part of the 2038 conversion process, add a get_monotonic_boottime64 accessor so we can depracate get_monotonic_boottime. Cc: pang.xunlei Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: John Stultz --- include/linux/timekeeping.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 91480137aa39..3eaae4754275 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -229,6 +229,11 @@ static inline void get_monotonic_boottime(struct timespec *ts) *ts = ktime_to_timespec(ktime_get_boottime()); } +static inline void get_monotonic_boottime64(struct timespec64 *ts) +{ + *ts = ktime_to_timespec64(ktime_get_boottime()); +} + static inline void timekeeping_clocktai(struct timespec *ts) { *ts = ktime_to_timespec(ktime_get_clocktai()); From bc10aa93a8853d6dac820696ae9a3e757e19f315 Mon Sep 17 00:00:00 2001 From: Xunlei Pang Date: Thu, 22 Jan 2015 02:31:51 +0000 Subject: [PATCH 4/8] rtc: Update interface.c to use y2038-safe time interfaces Currently, interface.c uses y2038 problematic rtc_tm_to_time() and rtc_time_to_tm(). So replace them with their corresponding y2038-safe versions: rtc_tm_to_time64() and rtc_time64_to_tm(). Cc: pang.xunlei Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Xunlei Pang Signed-off-by: John Stultz --- drivers/rtc/interface.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 45bfc28ee3aa..37215cf983e9 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -73,10 +73,8 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) else if (rtc->ops->set_time) err = rtc->ops->set_time(rtc->dev.parent, tm); else if (rtc->ops->set_mmss) { - unsigned long secs; - err = rtc_tm_to_time(tm, &secs); - if (err == 0) - err = rtc->ops->set_mmss(rtc->dev.parent, secs); + time64_t secs64 = rtc_tm_to_time64(tm); + err = rtc->ops->set_mmss(rtc->dev.parent, secs64); } else err = -EINVAL; @@ -105,7 +103,7 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) err = rtc->ops->read_time(rtc->dev.parent, &old); if (err == 0) { - rtc_time_to_tm(secs, &new); + rtc_time64_to_tm(secs, &new); /* * avoid writing when we're going to change the day of @@ -157,7 +155,7 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) int err; struct rtc_time before, now; int first_time = 1; - unsigned long t_now, t_alm; + time64_t t_now, t_alm; enum { none, day, month, year } missing = none; unsigned days; @@ -258,8 +256,8 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) } /* with luck, no rollover is needed */ - rtc_tm_to_time(&now, &t_now); - rtc_tm_to_time(&alarm->time, &t_alm); + t_now = rtc_tm_to_time64(&now); + t_alm = rtc_tm_to_time64(&alarm->time); if (t_now < t_alm) goto done; @@ -273,7 +271,7 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) case day: dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); t_alm += 24 * 60 * 60; - rtc_time_to_tm(t_alm, &alarm->time); + rtc_time64_to_tm(t_alm, &alarm->time); break; /* Month rollover ... if it's the 31th, an alarm on the 3rd will @@ -346,19 +344,19 @@ EXPORT_SYMBOL_GPL(rtc_read_alarm); static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { struct rtc_time tm; - long now, scheduled; + time64_t now, scheduled; int err; err = rtc_valid_tm(&alarm->time); if (err) return err; - rtc_tm_to_time(&alarm->time, &scheduled); + scheduled = rtc_tm_to_time64(&alarm->time); /* Make sure we're not setting alarms in the past */ err = __rtc_read_time(rtc, &tm); if (err) return err; - rtc_tm_to_time(&tm, &now); + now = rtc_tm_to_time64(&tm); if (scheduled <= now) return -ETIME; /* From 4ec2364f4910234030906b3f824b51c0d7065334 Mon Sep 17 00:00:00 2001 From: Xunlei Pang Date: Thu, 22 Jan 2015 02:31:52 +0000 Subject: [PATCH 5/8] rtc: Update rtc-dev to use y2038-safe time interfaces Currently, rtc-dev.c uses y2038 problematic rtc_tm_to_time() and rtc_time_to_tm(). So replace them with their corresponding y2038-safe versions: rtc_tm_to_time64() and rtc_time64_to_tm(). Cc: pang.xunlei Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Xunlei Pang Signed-off-by: John Stultz --- drivers/rtc/rtc-dev.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index d04939369251..799c34bcb26f 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -304,12 +304,12 @@ static long rtc_dev_ioctl(struct file *file, * Not supported here. */ { - unsigned long now, then; + time64_t now, then; err = rtc_read_time(rtc, &tm); if (err < 0) return err; - rtc_tm_to_time(&tm, &now); + now = rtc_tm_to_time64(&tm); alarm.time.tm_mday = tm.tm_mday; alarm.time.tm_mon = tm.tm_mon; @@ -317,11 +317,11 @@ static long rtc_dev_ioctl(struct file *file, err = rtc_valid_tm(&alarm.time); if (err < 0) return err; - rtc_tm_to_time(&alarm.time, &then); + then = rtc_tm_to_time64(&alarm.time); /* alarm may need to wrap into tomorrow */ if (then < now) { - rtc_time_to_tm(now + 24 * 60 * 60, &tm); + rtc_time64_to_tm(now + 24 * 60 * 60, &tm); alarm.time.tm_mday = tm.tm_mday; alarm.time.tm_mon = tm.tm_mon; alarm.time.tm_year = tm.tm_year; From a6d6e1c879efa4b77e250c34fe5fe1c34e6ef070 Mon Sep 17 00:00:00 2001 From: Xunlei Pang Date: Thu, 22 Jan 2015 02:31:53 +0000 Subject: [PATCH 6/8] rtc: Modify rtc_hctosys() to address y2038 issues rtc_hctosys() has a number of y2038 issues. This patch resolves them by: - Replace rtc_tm_to_time() with y2038-safe rtc_tm_to_time64() - Replace do_settimeofday() with y2038-safe do_settimeofday64() After this patch, it should not have any remaining y2038 issues. Cc: pang.xunlei Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Xunlei Pang Signed-off-by: John Stultz --- drivers/rtc/hctosys.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/rtc/hctosys.c b/drivers/rtc/hctosys.c index 4aa60d74004e..2153b526d61f 100644 --- a/drivers/rtc/hctosys.c +++ b/drivers/rtc/hctosys.c @@ -26,7 +26,7 @@ static int __init rtc_hctosys(void) { int err = -ENODEV; struct rtc_time tm; - struct timespec tv = { + struct timespec64 tv64 = { .tv_nsec = NSEC_PER_SEC >> 1, }; struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE); @@ -52,16 +52,16 @@ static int __init rtc_hctosys(void) goto err_invalid; } - rtc_tm_to_time(&tm, &tv.tv_sec); + tv64.tv_sec = rtc_tm_to_time64(&tm); - err = do_settimeofday(&tv); + err = do_settimeofday64(&tv64); dev_info(rtc->dev.parent, "setting system clock to " - "%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n", + "%d-%02d-%02d %02d:%02d:%02d UTC (%lld)\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, - (unsigned int) tv.tv_sec); + (long long) tv64.tv_sec); err_invalid: err_read: From 966301a23ef8ff0a4c5f71b585dafbf334808574 Mon Sep 17 00:00:00 2001 From: Xunlei Pang Date: Thu, 22 Jan 2015 02:31:54 +0000 Subject: [PATCH 7/8] rtc: Remove redundant rtc_valid_tm() from rtc_hctosys() rtc_read_time() has already judged valid tm by rtc_valid_tm(), so just remove it. Cc: pang.xunlei Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Xunlei Pang Signed-off-by: John Stultz --- drivers/rtc/hctosys.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/drivers/rtc/hctosys.c b/drivers/rtc/hctosys.c index 2153b526d61f..6c719f23520a 100644 --- a/drivers/rtc/hctosys.c +++ b/drivers/rtc/hctosys.c @@ -45,13 +45,6 @@ static int __init rtc_hctosys(void) } - err = rtc_valid_tm(&tm); - if (err) { - dev_err(rtc->dev.parent, - "hctosys: invalid date/time\n"); - goto err_invalid; - } - tv64.tv_sec = rtc_tm_to_time64(&tm); err = do_settimeofday64(&tv64); @@ -63,7 +56,6 @@ static int __init rtc_hctosys(void) tm.tm_hour, tm.tm_min, tm.tm_sec, (long long) tv64.tv_sec); -err_invalid: err_read: rtc_class_close(rtc); From 9a4a445e30f0b601ca2d9433274047cbf48ebf9e Mon Sep 17 00:00:00 2001 From: Xunlei Pang Date: Thu, 22 Jan 2015 02:31:55 +0000 Subject: [PATCH 8/8] rtc: Convert rtc_set_ntp_time() to use timespec64 rtc_set_ntp_time() uses timespec which is y2038-unsafe, so modify to use timespec64 which is y2038-safe, then replace rtc_time_to_tm() with rtc_time64_to_tm(). Also adjust all its call sites(only NTP uses it) accordingly. Cc: pang.xunlei Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Xunlei Pang Signed-off-by: John Stultz --- drivers/rtc/systohc.c | 6 +++--- include/linux/rtc.h | 2 +- kernel/time/ntp.c | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c index bf3e242ccc5c..eb71872d0361 100644 --- a/drivers/rtc/systohc.c +++ b/drivers/rtc/systohc.c @@ -20,16 +20,16 @@ * * If temporary failure is indicated the caller should try again 'soon' */ -int rtc_set_ntp_time(struct timespec now) +int rtc_set_ntp_time(struct timespec64 now) { struct rtc_device *rtc; struct rtc_time tm; int err = -ENODEV; if (now.tv_nsec < (NSEC_PER_SEC >> 1)) - rtc_time_to_tm(now.tv_sec, &tm); + rtc_time64_to_tm(now.tv_sec, &tm); else - rtc_time_to_tm(now.tv_sec + 1, &tm); + rtc_time64_to_tm(now.tv_sec + 1, &tm); rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE); if (rtc) { diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 6d6be09a2fe5..dcad7ee0d746 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -161,7 +161,7 @@ extern void devm_rtc_device_unregister(struct device *dev, extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm); extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm); extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs); -extern int rtc_set_ntp_time(struct timespec now); +extern int rtc_set_ntp_time(struct timespec64 now); int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm); extern int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alrm); diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 87a346fd6d61..183dfe2191c6 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -488,13 +488,13 @@ static void sync_cmos_clock(struct work_struct *work) getnstimeofday64(&now); if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec * 5) { - struct timespec adjust = timespec64_to_timespec(now); + struct timespec64 adjust = now; fail = -ENODEV; if (persistent_clock_is_local) adjust.tv_sec -= (sys_tz.tz_minuteswest * 60); #ifdef CONFIG_GENERIC_CMOS_UPDATE - fail = update_persistent_clock(adjust); + fail = update_persistent_clock(timespec64_to_timespec(adjust)); #endif #ifdef CONFIG_RTC_SYSTOHC if (fail == -ENODEV)