Merge branch 'linux-2.6'

[linux.git] / include / linux / time.h

diff --git a/include/linux/time.h b/include/linux/time.h
index c05f8bb9a323d575853350cc0b8b5e9baf1d939d..8ea8dea713c7c5d7a7da0fcd2e72d3d70f9112af 100644 (file)
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -46,7 +46,7 @@ static inline int timespec_equal(struct timespec *a, struct timespec *b)
  * lhs == rhs: return 0
  * lhs > rhs:  return >0
  */
-static inline int timespec_compare(struct timespec *lhs, struct timespec *rhs)
+static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
 {
        if (lhs->tv_sec < rhs->tv_sec)
                return -1;
@@ -55,7 +55,7 @@ static inline int timespec_compare(struct timespec *lhs, struct timespec *rhs)
        return lhs->tv_nsec - rhs->tv_nsec;
 }
 
-static inline int timeval_compare(struct timeval *lhs, struct timeval *rhs)
+static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
 {
        if (lhs->tv_sec < rhs->tv_sec)
                return -1;
@@ -70,6 +70,18 @@ extern unsigned long mktime(const unsigned int year, const unsigned int mon,
 
 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
 
+/*
+ * sub = lhs - rhs, in normalized form
+ */
+static inline struct timespec timespec_sub(struct timespec lhs,
+                                               struct timespec rhs)
+{
+       struct timespec ts_delta;
+       set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
+                               lhs.tv_nsec - rhs.tv_nsec);
+       return ts_delta;
+}
+
 /*
  * Returns true if the timespec is norm, false if denorm:
  */
@@ -78,8 +90,9 @@ extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
 
 extern struct timespec xtime;
 extern struct timespec wall_to_monotonic;
-extern seqlock_t xtime_lock;
+extern seqlock_t xtime_lock __attribute__((weak));
 
+extern unsigned long read_persistent_clock(void);
 void timekeeping_init(void);
 
 static inline unsigned long get_seconds(void)