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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-02-10 23:01:52 -0500
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-02-13 17:49:36 -0500
commitaffe3e85ae78507cc953f3f700e0644e50844cff (patch)
tree7f29d6565dc433a42492187537d7473b192652f1 /kernel
parent3810631332465d967ba5e27ea2c7dff2c9afac6c (diff)
timekeeping: Pass readout base to update_fast_timekeeper()
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> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/time/timekeeping.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index b124af259800..abf08f4366c1 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -230,9 +230,7 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
230 230
231/** 231/**
232 * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper. 232 * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper.
233 * @tk: The timekeeper from which we take the update 233 * @tkr: Timekeeping readout base from which we take the update
234 * @tkf: The fast timekeeper to update
235 * @tbase: The time base for the fast timekeeper (mono/raw)
236 * 234 *
237 * We want to use this from any context including NMI and tracing / 235 * We want to use this from any context including NMI and tracing /
238 * instrumenting the timekeeping code itself. 236 * instrumenting the timekeeping code itself.
@@ -244,11 +242,11 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
244 * smp_wmb(); <- Ensure that the last base[1] update is visible 242 * smp_wmb(); <- Ensure that the last base[1] update is visible
245 * tkf->seq++; 243 * tkf->seq++;
246 * smp_wmb(); <- Ensure that the seqcount update is visible 244 * smp_wmb(); <- Ensure that the seqcount update is visible
247 * update(tkf->base[0], tk); 245 * update(tkf->base[0], tkr);
248 * smp_wmb(); <- Ensure that the base[0] update is visible 246 * smp_wmb(); <- Ensure that the base[0] update is visible
249 * tkf->seq++; 247 * tkf->seq++;
250 * smp_wmb(); <- Ensure that the seqcount update is visible 248 * smp_wmb(); <- Ensure that the seqcount update is visible
251 * update(tkf->base[1], tk); 249 * update(tkf->base[1], tkr);
252 * 250 *
253 * The reader side does: 251 * The reader side does:
254 * 252 *
@@ -269,7 +267,7 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
269 * slightly wrong timestamp (a few nanoseconds). See 267 * slightly wrong timestamp (a few nanoseconds). See
270 * @ktime_get_mono_fast_ns. 268 * @ktime_get_mono_fast_ns.
271 */ 269 */
272static void update_fast_timekeeper(struct timekeeper *tk) 270static void update_fast_timekeeper(struct tk_read_base *tkr)
273{ 271{
274 struct tk_read_base *base = tk_fast_mono.base; 272 struct tk_read_base *base = tk_fast_mono.base;
275 273
@@ -277,7 +275,7 @@ static void update_fast_timekeeper(struct timekeeper *tk)
277 raw_write_seqcount_latch(&tk_fast_mono.seq); 275 raw_write_seqcount_latch(&tk_fast_mono.seq);
278 276
279 /* Update base[0] */ 277 /* Update base[0] */
280 memcpy(base, &tk->tkr, sizeof(*base)); 278 memcpy(base, tkr, sizeof(*base));
281 279
282 /* Force readers back to base[0] */ 280 /* Force readers back to base[0] */
283 raw_write_seqcount_latch(&tk_fast_mono.seq); 281 raw_write_seqcount_latch(&tk_fast_mono.seq);
@@ -462,7 +460,7 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
462 memcpy(&shadow_timekeeper, &tk_core.timekeeper, 460 memcpy(&shadow_timekeeper, &tk_core.timekeeper,
463 sizeof(tk_core.timekeeper)); 461 sizeof(tk_core.timekeeper));
464 462
465 update_fast_timekeeper(tk); 463 update_fast_timekeeper(&tk->tkr);
466} 464}
467 465
468/** 466/**