[PATCH 2/6] timekeeping: Pass readout base to update_fast_timekeeper()

Rafael J. Wysocki
2015-02-11T04:01:52Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Modify update_fast_timekeeper() to take a struct tk_read_base
pointer as its argument (instead of a struct timekeeper pointer)
and update its kerneldoc comment to reflect that.

That will allow a struct tk_read_base that is not part of a
struct timekeeper to be passed to it in the next patch.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
kernel/time/timekeeping.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

Index: linux-pm/kernel/time/timekeeping.c
===================================================================
--- linux-pm.orig/kernel/time/timekeeping.c
+++ linux-pm/kernel/time/timekeeping.c
@@ -230,9 +230,7 @@ static inline s64 timekeeping_get_ns_raw

/**
* update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper.
- * @tk: The timekeeper from which we take the update
- * @tkf: The fast timekeeper to update
- * @tbase: The time base for the fast timekeeper (mono/raw)
+ * @tkr: Timekeeping readout base from which we take the update
*
* We want to use this from any context including NMI and tracing /
* instrumenting the timekeeping code itself.
@@ -244,11 +242,11 @@ static inline s64 timekeeping_get_ns_raw
* smp_wmb(); <- Ensure that the last base[1] update is visible
* tkf->seq++;
* smp_wmb(); <- Ensure that the seqcount update is visible
- * update(tkf->base[0], tk);
+ * update(tkf->base[0], tkr);
* smp_wmb(); <- Ensure that the base[0] update is visible
* tkf->seq++;
* smp_wmb(); <- Ensure that the seqcount update is visible
- * update(tkf->base[1], tk);
+ * update(tkf->base[1], tkr);
*
* The reader side does:
*
@@ -269,7 +267,7 @@ static inline s64 timekeeping_get_ns_raw
* slightly wrong timestamp (a few nanoseconds). See
* @ktime_get_mono_fast_ns.
*/
-static void update_fast_timekeeper(struct timekeeper *tk)
+static void update_fast_timekeeper(struct tk_read_base *tkr)
{
struct tk_read_base *base = tk_fast_mono.base;

@@ -277,7 +275,7 @@ static void update_fast_timekeeper(struc
raw_write_seqcount_latch(&tk_fast_mono.seq);

/* Update base[0] */
- memcpy(base, &tk->tkr, sizeof(*base));
+ memcpy(base, tkr, sizeof(*base));

/* Force readers back to base[0] */
raw_write_seqcount_latch(&tk_fast_mono.seq);
@@ -462,7 +460,7 @@ static void timekeeping_update(struct ti
memcpy(&shadow_timekeeper, &tk_core.timekeeper,
sizeof(tk_core.timekeeper));

- update_fast_timekeeper(tk);
+ update_fast_timekeeper(&tk->tkr);
}

/**