3 files changed, 46 insertions, 8 deletions

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 7784b597e959..6013021a3b39 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -62,12 +62,18 @@ struct module;
  * @suspend:            suspend function for the clocksource, if necessary
  * @resume:             resume function for the clocksource, if necessary
  * @owner:              module reference, must be set by clocksource in modules
+ *
+ * Note: This struct is not used in hotpathes of the timekeeping code
+ * because the timekeeper caches the hot path fields in its own data
+ * structure, so no line cache alignment is required,
+ *
+ * The pointer to the clocksource itself is handed to the read
+ * callback. If you need extra information there you can wrap struct
+ * clocksource into your own struct. Depending on the amount of
+ * information you need you should consider to cache line align that
+ * structure.
  */
 struct clocksource {
-        /*
-         * Hotpath data, fits in a single cache line when the
-         * clocksource itself is cacheline aligned.
-         */
         cycle_t (*read)(struct clocksource *cs);
         cycle_t mask;
         u32 mult;
@@ -95,7 +101,7 @@ struct clocksource {
         cycle_t wd_last;
 #endif
         struct module *owner;
-} ____cacheline_aligned;
+};
 
 /*
  * Clock source flags bits::
diff --git a/include/linux/sched_clock.h b/include/linux/sched_clock.h
index efa931c5cef1..411b52e424e1 100644
--- a/include/linux/sched_clock.h
+++ b/include/linux/sched_clock.h
@@ -10,11 +10,17 @@
 
 #ifdef CONFIG_GENERIC_SCHED_CLOCK
 extern void sched_clock_postinit(void);
-#else
-static inline void sched_clock_postinit(void) { }
-#endif
 
 extern void sched_clock_register(u64 (*read)(void), int bits,
                                  unsigned long rate);
+#else
+static inline void sched_clock_postinit(void) { }
+
+static inline void sched_clock_register(u64 (*read)(void), int bits,
+                                        unsigned long rate)
+{
+        ;
+}
+#endif
 
 #endif
diff --git a/include/linux/time.h b/include/linux/time.h
index beebe3a02d43..297f09f23896 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -125,6 +125,32 @@ static inline bool timeval_valid(const struct timeval *tv)
 
 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 
+/*
+ * Validates if a timespec/timeval used to inject a time offset is valid.
+ * Offsets can be postive or negative. The value of the timeval/timespec
+ * is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must
+ * always be non-negative.
+ */
+static inline bool timeval_inject_offset_valid(const struct timeval *tv)
+{
+        /* We don't check the tv_sec as it can be positive or negative */
+
+        /* Can't have more microseconds then a second */
+        if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
+                return false;
+        return true;
+}
+
+static inline bool timespec_inject_offset_valid(const struct timespec *ts)
+{
+        /* We don't check the tv_sec as it can be positive or negative */
+
+        /* Can't have more nanoseconds then a second */
+        if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
+                return false;
+        return true;
+}
+
 #define CURRENT_TIME            (current_kernel_time())
 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })