timekeeping: create arch_gettimeoffset infrastructure (7d27558c) · Commits · 戴 / test

include/linux/time.h

+15 −0

Original line number	Diff line number	Diff line
		@@ -113,6 +113,21 @@ struct timespec current_kernel_time(void);
		#define CURRENT_TIME (current_kernel_time())
		#define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 })

		/* Some architectures do not supply their own clocksource.
		* This is mainly the case in architectures that get their
		* inter-tick times by reading the counter on their interval
		* timer. Since these timers wrap every tick, they're not really
		* useful as clocksources. Wrapping them to act like one is possible
		* but not very efficient. So we provide a callout these arches
		* can implement for use with the jiffies clocksource to provide
		* finer then tick granular time.
		*/
		#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
		extern u32 arch_gettimeoffset(void);
		#else
		static inline u32 arch_gettimeoffset(void) { return 0; }
		#endif

		extern void do_gettimeofday(struct timeval *tv);
		extern int do_settimeofday(struct timespec *tv);
		extern int do_sys_settimeofday(struct timespec tv, struct timezone tz);

+7 −0

Original line number	Diff line number	Diff line
		@@ -77,6 +77,10 @@ static void clocksource_forward_now(void)
		clock->cycle_last = cycle_now;

		nsec = cyc2ns(clock, cycle_delta);

		/* If arch requires, add in gettimeoffset() */
		nsec += arch_gettimeoffset();

		timespec_add_ns(&xtime, nsec);

		nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
		@@ -111,6 +115,9 @@ void getnstimeofday(struct timespec *ts)
		/* convert to nanoseconds: */
		nsecs = cyc2ns(clock, cycle_delta);

		/* If arch requires, add in gettimeoffset() */
		nsecs += arch_gettimeoffset();

		} while (read_seqretry(&xtime_lock, seq));

		timespec_add_ns(ts, nsecs);