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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-10-21 15:52:04 +1100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-10-21 15:52:04 +1100
commita02efb906d12c9d4eb2ab7c59049ba9545e5412d (patch)
treebf1f6467978ec63a22f42299ecac2ee7f7e73336 /include/linux/clocksource.h
parent84dfcb4b318463cd4883b6a19937824f49aee564 (diff)
parent2515ddc6db8eb49a79f0fe5e67ff09ac7c81eab4 (diff)
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Merge commit 'origin' into master
Manual merge of: arch/powerpc/Kconfig arch/powerpc/include/asm/page.h
Diffstat (limited to 'include/linux/clocksource.h')
-rw-r--r--include/linux/clocksource.h14
1 files changed, 10 insertions, 4 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 55e434feec99..f88d32f8ff7c 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -45,7 +45,8 @@ struct clocksource;
* @read: returns a cycle value
* @mask: bitmask for two's complement
* subtraction of non 64 bit counters
- * @mult: cycle to nanosecond multiplier
+ * @mult: cycle to nanosecond multiplier (adjusted by NTP)
+ * @mult_orig: cycle to nanosecond multiplier (unadjusted by NTP)
* @shift: cycle to nanosecond divisor (power of two)
* @flags: flags describing special properties
* @vread: vsyscall based read
@@ -63,6 +64,7 @@ struct clocksource {
cycle_t (*read)(void);
cycle_t mask;
u32 mult;
+ u32 mult_orig;
u32 shift;
unsigned long flags;
cycle_t (*vread)(void);
@@ -77,6 +79,7 @@ struct clocksource {
/* timekeeping specific data, ignore */
cycle_t cycle_interval;
u64 xtime_interval;
+ u32 raw_interval;
/*
* Second part is written at each timer interrupt
* Keep it in a different cache line to dirty no
@@ -85,6 +88,7 @@ struct clocksource {
cycle_t cycle_last ____cacheline_aligned_in_smp;
u64 xtime_nsec;
s64 error;
+ struct timespec raw_time;
#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
/* Watchdog related data, used by the framework */
@@ -201,17 +205,19 @@ static inline void clocksource_calculate_interval(struct clocksource *c,
{
u64 tmp;
- /* XXX - All of this could use a whole lot of optimization */
+ /* Do the ns -> cycle conversion first, using original mult */
tmp = length_nsec;
tmp <<= c->shift;
- tmp += c->mult/2;
- do_div(tmp, c->mult);
+ tmp += c->mult_orig/2;
+ do_div(tmp, c->mult_orig);
c->cycle_interval = (cycle_t)tmp;
if (c->cycle_interval == 0)
c->cycle_interval = 1;
+ /* Go back from cycles -> shifted ns, this time use ntp adjused mult */
c->xtime_interval = (u64)c->cycle_interval * c->mult;
+ c->raw_interval = ((u64)c->cycle_interval * c->mult_orig) >> c->shift;
}