aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/timex.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/timex.h')
-rw-r--r--include/linux/timex.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/timex.h b/include/linux/timex.h
index b3726e61368e..9d3f1a5b6178 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -64,6 +64,20 @@
#include <asm/timex.h>
+#ifndef random_get_entropy
+/*
+ * The random_get_entropy() function is used by the /dev/random driver
+ * in order to extract entropy via the relative unpredictability of
+ * when an interrupt takes places versus a high speed, fine-grained
+ * timing source or cycle counter. Since it will be occurred on every
+ * single interrupt, it must have a very low cost/overhead.
+ *
+ * By default we use get_cycles() for this purpose, but individual
+ * architectures may override this in their asm/timex.h header file.
+ */
+#define random_get_entropy() get_cycles()
+#endif
+
/*
* SHIFT_PLL is used as a dampening factor to define how much we
* adjust the frequency correction for a given offset in PLL mode.
@@ -141,6 +155,7 @@ extern int do_adjtimex(struct timex *);
extern void hardpps(const struct timespec *, const struct timespec *);
int read_current_timer(unsigned long *timer_val);
+void ntp_notify_cmos_timer(void);
/* The clock frequency of the i8253/i8254 PIT */
#define PIT_TICK_RATE 1193182ul