From 0077dc60f274b9a7e9aa705a34784fefb87e0eee Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 16 Jul 2014 21:04:13 +0000 Subject: [PATCH] timekeeping: Provide ktime_get_with_offset() Provide a helper function which lets us implement ktime_t based interfaces for real, boot and tai clocks. Signed-off-by: Thomas Gleixner Signed-off-by: John Stultz --- include/linux/timekeeping.h | 9 +++++++++ kernel/time/timekeeping.c | 27 +++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 3eb19e34cc20..a58e4b1879db 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -98,7 +98,16 @@ extern void getboottime(struct timespec *ts); /* * ktime_t based interfaces */ + +enum tk_offsets { + TK_OFFS_REAL, + TK_OFFS_BOOT, + TK_OFFS_TAI, + TK_OFFS_MAX, +}; + extern ktime_t ktime_get(void); +extern ktime_t ktime_get_with_offset(enum tk_offsets offs); extern ktime_t ktime_get_real(void); extern ktime_t ktime_get_boottime(void); extern ktime_t ktime_get_monotonic_offset(void); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index d5be1425cc03..7c5f5e4a006c 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -423,6 +423,33 @@ ktime_t ktime_get(void) } EXPORT_SYMBOL_GPL(ktime_get); +static ktime_t *offsets[TK_OFFS_MAX] = { + [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real, + [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot, + [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai, +}; + +ktime_t ktime_get_with_offset(enum tk_offsets offs) +{ + struct timekeeper *tk = &tk_core.timekeeper; + unsigned int seq; + ktime_t base, *offset = offsets[offs]; + s64 nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqcount_begin(&tk_core.seq); + base = ktime_add(tk->base_mono, *offset); + nsecs = timekeeping_get_ns(tk); + + } while (read_seqcount_retry(&tk_core.seq, seq)); + + return ktime_add_ns(base, nsecs); + +} +EXPORT_SYMBOL_GPL(ktime_get_with_offset); + /** * ktime_get_ts64 - get the monotonic clock in timespec64 format * @ts: pointer to timespec variable -- 2.20.1