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authorDaniel Vetter <daniel.vetter@ffwll.ch>2012-10-22 14:34:51 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2012-10-22 14:34:51 +0200
commitc2fb7916927e989ea424e61ce5fe617e54878827 (patch)
tree02f9d5482075f8931637d82bb697a6470270136a /kernel/time/jiffies.c
parent29de6ce574870a0d3fd157afdbf51c0282e2bf63 (diff)
parent6f0c0580b70c89094b3422ba81118c7b959c7556 (diff)
Merge tag 'v3.7-rc2' into drm-intel-next-queued
Linux 3.7-rc2 Backmerge to solve two ugly conflicts: - uapi. We've already added new ioctl definitions for -next. Do I need to say more? - wc support gtt ptes. We've had to revert this for snb+ for 3.7 and also fix a few other things in the code. Now we know how to make it work on snb+, but to avoid losing the other fixes do the backmerge first before re-enabling wc gtt ptes on snb+. And a few other minor things, among them git getting confused in intel_dp.c and seemingly causing a conflict out of nothing ... Conflicts: drivers/gpu/drm/i915/i915_reg.h drivers/gpu/drm/i915/intel_display.c drivers/gpu/drm/i915/intel_dp.c drivers/gpu/drm/i915/intel_modes.c include/drm/i915_drm.h Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'kernel/time/jiffies.c')
-rw-r--r--kernel/time/jiffies.c32
1 files changed, 31 insertions, 1 deletions
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 46da0537c10..6629bf7b528 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -37,7 +37,7 @@
* requested HZ value. It is also not recommended
* for "tick-less" systems.
*/
-#define NSEC_PER_JIFFY ((u32)((((u64)NSEC_PER_SEC)<<8)/SHIFTED_HZ))
+#define NSEC_PER_JIFFY ((NSEC_PER_SEC+HZ/2)/HZ)
/* Since jiffies uses a simple NSEC_PER_JIFFY multiplier
* conversion, the .shift value could be zero. However
@@ -95,3 +95,33 @@ struct clocksource * __init __weak clocksource_default_clock(void)
{
return &clocksource_jiffies;
}
+
+struct clocksource refined_jiffies;
+
+int register_refined_jiffies(long cycles_per_second)
+{
+ u64 nsec_per_tick, shift_hz;
+ long cycles_per_tick;
+
+
+
+ refined_jiffies = clocksource_jiffies;
+ refined_jiffies.name = "refined-jiffies";
+ refined_jiffies.rating++;
+
+ /* Calc cycles per tick */
+ cycles_per_tick = (cycles_per_second + HZ/2)/HZ;
+ /* shift_hz stores hz<<8 for extra accuracy */
+ shift_hz = (u64)cycles_per_second << 8;
+ shift_hz += cycles_per_tick/2;
+ do_div(shift_hz, cycles_per_tick);
+ /* Calculate nsec_per_tick using shift_hz */
+ nsec_per_tick = (u64)NSEC_PER_SEC << 8;
+ nsec_per_tick += (u32)shift_hz/2;
+ do_div(nsec_per_tick, (u32)shift_hz);
+
+ refined_jiffies.mult = ((u32)nsec_per_tick) << JIFFIES_SHIFT;
+
+ clocksource_register(&refined_jiffies);
+ return 0;
+}