From b9ff604cff1135cc576cf952d394ed9401aa234b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 27 Apr 2018 15:40:15 +0200 Subject: [PATCH] timekeeping: Add ktime_get_coarse_with_offset I have run into a couple of drivers using current_kernel_time() suffering from the y2038 problem, and they could be converted to using ktime_t, but don't have interfaces that skip the nanosecond calculation at the moment. This introduces ktime_get_coarse_with_offset() as a simpler variant of ktime_get_with_offset(), and adds wrappers for the three time domains we support with the existing function. Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Cc: Stephen Boyd Cc: y2038@lists.linaro.org Cc: John Stultz Link: https://lkml.kernel.org/r/20180427134016.2525989-5-arnd@arndb.de --- include/linux/timekeeping.h | 16 ++++++++++++++++ kernel/time/timekeeping.c | 19 +++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 3ef9791d7d75..42f71f4b658a 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -51,6 +51,7 @@ enum tk_offsets { extern ktime_t ktime_get(void); extern ktime_t ktime_get_with_offset(enum tk_offsets offs); +extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs); extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs); extern ktime_t ktime_get_raw(void); extern u32 ktime_get_resolution_ns(void); @@ -63,6 +64,11 @@ static inline ktime_t ktime_get_real(void) return ktime_get_with_offset(TK_OFFS_REAL); } +static inline ktime_t ktime_get_coarse_real(void) +{ + return ktime_get_coarse_with_offset(TK_OFFS_REAL); +} + /** * ktime_get_boottime - Returns monotonic time since boot in ktime_t format * @@ -74,6 +80,11 @@ static inline ktime_t ktime_get_boottime(void) return ktime_get_with_offset(TK_OFFS_BOOT); } +static inline ktime_t ktime_get_coarse_boottime(void) +{ + return ktime_get_coarse_with_offset(TK_OFFS_BOOT); +} + /** * ktime_get_clocktai - Returns the TAI time of day in ktime_t format */ @@ -82,6 +93,11 @@ static inline ktime_t ktime_get_clocktai(void) return ktime_get_with_offset(TK_OFFS_TAI); } +static inline ktime_t ktime_get_coarse_clocktai(void) +{ + return ktime_get_coarse_with_offset(TK_OFFS_TAI); +} + /** * ktime_mono_to_real - Convert monotonic time to clock realtime */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index ed9b74ec9c0b..4786df904c22 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -795,6 +795,25 @@ ktime_t ktime_get_with_offset(enum tk_offsets offs) } EXPORT_SYMBOL_GPL(ktime_get_with_offset); +ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs) +{ + struct timekeeper *tk = &tk_core.timekeeper; + unsigned int seq; + ktime_t base, *offset = offsets[offs]; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqcount_begin(&tk_core.seq); + base = ktime_add(tk->tkr_mono.base, *offset); + + } while (read_seqcount_retry(&tk_core.seq, seq)); + + return base; + +} +EXPORT_SYMBOL_GPL(ktime_get_coarse_with_offset); + /** * ktime_mono_to_any() - convert mononotic time to any other time * @tmono: time to convert.