Messages in this thread Patch in this message | | | From | "Jason A. Donenfeld" <> | Subject | [PATCH v4 1/4] timekeeping: add missing non-_ns functions for fast accessors | Date | Fri, 21 Jun 2019 17:37:38 +0200 |
| |
Previously there was no analogue to get proper ktime_t versions of the fast variety of ktime invocations. This commit makes the interface uniform with the other accessors.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Thomas Gleixner <tglx@linutronix.de> --- Documentation/core-api/timekeeping.rst | 7 +++- include/linux/timekeeping.h | 28 ++++++++++++-- kernel/time/timekeeping.c | 52 +++++++++++++------------- 3 files changed, 55 insertions(+), 32 deletions(-)
diff --git a/Documentation/core-api/timekeeping.rst b/Documentation/core-api/timekeeping.rst index 93cbeb9daec0..47b41e948459 100644 --- a/Documentation/core-api/timekeeping.rst +++ b/Documentation/core-api/timekeeping.rst @@ -94,7 +94,7 @@ different format depending on what is required by the user: down the seconds to the full seconds of the last timer tick using the respective reference. -Coarse and fast_ns access +Coarse and fast access ------------------------- Some additional variants exist for more specialized cases: @@ -125,6 +125,11 @@ Some additional variants exist for more specialized cases: up to several microseconds on older hardware with an external clocksource. +.. c:function:: ktime_t ktime_get_mono_fast( void ) + ktime_t ktime_get_raw_fast( void ) + ktime_t ktime_get_boottime_fast( void ) + ktime_t ktime_get_real_fast( void ) + .. c:function:: u64 ktime_get_mono_fast_ns( void ) u64 ktime_get_raw_fast_ns( void ) u64 ktime_get_boot_fast_ns( void ) diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index a8ab0f143ac4..c5d360779fab 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -146,10 +146,30 @@ static inline u64 ktime_get_raw_ns(void) return ktime_to_ns(ktime_get_raw()); } -extern u64 ktime_get_mono_fast_ns(void); -extern u64 ktime_get_raw_fast_ns(void); -extern u64 ktime_get_boot_fast_ns(void); -extern u64 ktime_get_real_fast_ns(void); +extern ktime_t ktime_get_mono_fast(void); +extern ktime_t ktime_get_raw_fast(void); +extern ktime_t ktime_get_boottime_fast(void); +extern ktime_t ktime_get_real_fast(void); + +static inline u64 ktime_get_mono_fast_ns(void) +{ + return ktime_to_ns(ktime_get_mono_fast()); +} + +static inline u64 ktime_get_raw_fast_ns(void) +{ + return ktime_to_ns(ktime_get_raw_fast()); +} + +static inline u64 ktime_get_boot_fast_ns(void) +{ + return ktime_to_ns(ktime_get_boottime_fast()); +} + +static inline u64 ktime_get_real_fast_ns(void) +{ + return ktime_to_ns(ktime_get_real_fast()); +} /* * timespec64/time64_t interfaces utilizing the ktime based ones diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 44b726bab4bd..4c97c9c8c217 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -443,41 +443,40 @@ static void update_fast_timekeeper(const struct tk_read_base *tkr, * of the following timestamps. Callers need to be aware of that and * deal with it. */ -static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf) +static __always_inline ktime_t __ktime_get_fast(struct tk_fast *tkf) { struct tk_read_base *tkr; unsigned int seq; - u64 now; + ktime_t now; do { seq = raw_read_seqcount_latch(&tkf->seq); tkr = tkf->base + (seq & 0x01); - now = ktime_to_ns(tkr->base); - - now += timekeeping_delta_to_ns(tkr, + now = ktime_add_ns(tkr->base, + timekeeping_delta_to_ns(tkr, clocksource_delta( tk_clock_read(tkr), tkr->cycle_last, - tkr->mask)); + tkr->mask))); } while (read_seqcount_retry(&tkf->seq, seq)); return now; } -u64 ktime_get_mono_fast_ns(void) +ktime_t ktime_get_mono_fast(void) { - return __ktime_get_fast_ns(&tk_fast_mono); + return __ktime_get_fast(&tk_fast_mono); } -EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns); +EXPORT_SYMBOL_GPL(ktime_get_mono_fast); -u64 ktime_get_raw_fast_ns(void) +ktime_t ktime_get_raw_fast(void) { - return __ktime_get_fast_ns(&tk_fast_raw); + return __ktime_get_fast(&tk_fast_raw); } -EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); +EXPORT_SYMBOL_GPL(ktime_get_raw_fast); /** - * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock. + * ktime_get_boottime_fast - NMI safe and fast access to boot clock. * * To keep it NMI safe since we're accessing from tracing, we're not using a * separate timekeeper with updates to monotonic clock and boot offset @@ -497,47 +496,46 @@ EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); * partially updated. Since the tk->offs_boot update is a rare event, this * should be a rare occurrence which postprocessing should be able to handle. */ -u64 notrace ktime_get_boot_fast_ns(void) +ktime_t notrace ktime_get_boottime_fast(void) { struct timekeeper *tk = &tk_core.timekeeper; - return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot)); + return ktime_add(ktime_get_mono_fast(), tk->offs_boot); } -EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns); +EXPORT_SYMBOL_GPL(ktime_get_boottime_fast); /* - * See comment for __ktime_get_fast_ns() vs. timestamp ordering + * See comment for __ktime_get_fast() vs. timestamp ordering */ -static __always_inline u64 __ktime_get_real_fast_ns(struct tk_fast *tkf) +static __always_inline ktime_t __ktime_get_real_fast(struct tk_fast *tkf) { struct tk_read_base *tkr; unsigned int seq; - u64 now; + ktime_t now; do { seq = raw_read_seqcount_latch(&tkf->seq); tkr = tkf->base + (seq & 0x01); - now = ktime_to_ns(tkr->base_real); - - now += timekeeping_delta_to_ns(tkr, + now = ktime_add_ns(tkr->base_real, + timekeeping_delta_to_ns(tkr, clocksource_delta( tk_clock_read(tkr), tkr->cycle_last, - tkr->mask)); + tkr->mask))); } while (read_seqcount_retry(&tkf->seq, seq)); return now; } /** - * ktime_get_real_fast_ns: - NMI safe and fast access to clock realtime. + * ktime_get_real_fast: - NMI safe and fast access to clock realtime. */ -u64 ktime_get_real_fast_ns(void) +ktime_t ktime_get_real_fast(void) { - return __ktime_get_real_fast_ns(&tk_fast_mono); + return __ktime_get_real_fast(&tk_fast_mono); } -EXPORT_SYMBOL_GPL(ktime_get_real_fast_ns); +EXPORT_SYMBOL_GPL(ktime_get_real_fast); /** * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource. -- 2.21.0
| |