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 <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
Thomas Gleixner 2014-07-16 21:04:13 +00:00 committed by John Stultz
parent a016a5bd62
commit 0077dc60f2
2 changed files with 36 additions and 0 deletions

View File

@ -98,7 +98,16 @@ extern void getboottime(struct timespec *ts);
/* /*
* ktime_t based interfaces * 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(void);
extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
extern ktime_t ktime_get_real(void); extern ktime_t ktime_get_real(void);
extern ktime_t ktime_get_boottime(void); extern ktime_t ktime_get_boottime(void);
extern ktime_t ktime_get_monotonic_offset(void); extern ktime_t ktime_get_monotonic_offset(void);

View File

@ -423,6 +423,33 @@ ktime_t ktime_get(void)
} }
EXPORT_SYMBOL_GPL(ktime_get); 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 * ktime_get_ts64 - get the monotonic clock in timespec64 format
* @ts: pointer to timespec variable * @ts: pointer to timespec variable