#include <linux/timex.h>
#include <linux/time.h>
#include <linux/list.h>
+#include <linux/cache.h>
#include <linux/timer.h>
#include <asm/div64.h>
#include <asm/io.h>
* @mult: cycle to nanosecond multiplier
* @shift: cycle to nanosecond divisor (power of two)
* @flags: flags describing special properties
+ * @vread: vsyscall based read
+ * @resume: resume function for the clocksource, if necessary
* @cycle_interval: Used internally by timekeeping core, please ignore.
* @xtime_interval: Used internally by timekeeping core, please ignore.
*/
struct clocksource {
+ /*
+ * First part of structure is read mostly
+ */
char *name;
struct list_head list;
int rating;
u32 mult;
u32 shift;
unsigned long flags;
+ cycle_t (*vread)(void);
+ void (*resume)(void);
/* timekeeping specific data, ignore */
- cycle_t cycle_last, cycle_interval;
- u64 xtime_nsec, xtime_interval;
+ cycle_t cycle_interval;
+ u64 xtime_interval;
+ /*
+ * Second part is written at each timer interrupt
+ * Keep it in a different cache line to dirty no
+ * more than one cache line.
+ */
+ cycle_t cycle_last ____cacheline_aligned_in_smp;
+ u64 xtime_nsec;
s64 error;
#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
extern int clocksource_register(struct clocksource*);
extern struct clocksource* clocksource_get_next(void);
extern void clocksource_change_rating(struct clocksource *cs, int rating);
+extern void clocksource_resume(void);
+
+#ifdef CONFIG_GENERIC_TIME_VSYSCALL
+extern void update_vsyscall(struct timespec *ts, struct clocksource *c);
+#else
+static inline void update_vsyscall(struct timespec *ts, struct clocksource *c)
+{
+}
+#endif
#endif /* _LINUX_CLOCKSOURCE_H */