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authorYi Li <yi.li@analog.com>2009-09-15 06:50:51 +0000
committerMike Frysinger <vapier@gentoo.org>2009-12-15 00:13:41 -0500
commitceb33be95afcfbc4079af334835a345288f9f6ca (patch)
tree7244fbd018015de1139df8620f52e2d52751c68e /arch/blackfin
parentf7036d649c88ad14b482b2787ffb1063c8a719d7 (diff)
Blackfin: unify sched_clock() handling between clock sources
Currently sched_clock() is only defined when using CYCLES as a clock source. Declare sched_clock() in common code and mark it with notrace to prevent invoking sched_clock() recursively (because ftrace uses sched_clock() to record time). Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'arch/blackfin')
-rw-r--r--arch/blackfin/kernel/time-ts.c43
1 files changed, 33 insertions, 10 deletions
diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c
index a54e569e3b6..2855f0ff865 100644
--- a/arch/blackfin/kernel/time-ts.c
+++ b/arch/blackfin/kernel/time-ts.c
@@ -22,8 +22,6 @@
#include <asm/time.h>
#include <asm/gptimers.h>
-#if defined(CONFIG_CYCLES_CLOCKSOURCE)
-
/* Accelerators for sched_clock()
* convert from cycles(64bits) => nanoseconds (64bits)
* basic equation:
@@ -46,20 +44,23 @@
* -johnstul@us.ibm.com "math is hard, lets go shopping!"
*/
-static unsigned long cyc2ns_scale;
#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
-static inline void set_cyc2ns_scale(unsigned long cpu_khz)
+static inline unsigned long cyc2ns_scale(unsigned long cpu_khz)
{
- cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR) / cpu_khz;
+ return (1000000 << CYC2NS_SCALE_FACTOR) / cpu_khz;
}
-static inline unsigned long long cycles_2_ns(cycle_t cyc)
+static inline unsigned long long cycles_2_ns(cycle_t cyc, unsigned long cyc2ns_scale)
{
return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
}
-static cycle_t bfin_read_cycles(struct clocksource *cs)
+#if defined(CONFIG_CYCLES_CLOCKSOURCE)
+
+static unsigned long cycles_cyc2ns_scale;
+
+static notrace cycle_t bfin_read_cycles(struct clocksource *cs)
{
return __bfin_cycles_off + (get_cycles() << __bfin_cycles_mod);
}
@@ -73,14 +74,14 @@ static struct clocksource bfin_cs_cycles = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-unsigned long long sched_clock(void)
+static inline unsigned long long bfin_cs_cycles_sched_clock(void)
{
- return cycles_2_ns(bfin_read_cycles(&bfin_cs_cycles));
+ return cycles_2_ns(bfin_read_cycles(&bfin_cs_cycles), cycles_cyc2ns_scale);
}
static int __init bfin_cs_cycles_init(void)
{
- set_cyc2ns_scale(get_cclk() / 1000);
+ cycles_cyc2ns_scale = cyc2ns_scale(get_cclk() / 1000);
bfin_cs_cycles.mult = \
clocksource_hz2mult(get_cclk(), bfin_cs_cycles.shift);
@@ -96,6 +97,8 @@ static int __init bfin_cs_cycles_init(void)
#ifdef CONFIG_GPTMR0_CLOCKSOURCE
+unsigned long gptimer0_cyc2ns_scale;
+
void __init setup_gptimer0(void)
{
disable_gptimers(TIMER0bit);
@@ -122,8 +125,15 @@ static struct clocksource bfin_cs_gptimer0 = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
+static inline unsigned long long bfin_cs_gptimer0_sched_clock(void)
+{
+ return cycles_2_ns(bfin_read_TIMER0_COUNTER(), gptimer0_cyc2ns_scale);
+}
+
static int __init bfin_cs_gptimer0_init(void)
{
+ gptimer0_cyc2ns_scale = cyc2ns_scale(get_sclk() / 1000);
+
setup_gptimer0();
bfin_cs_gptimer0.mult = \
@@ -138,6 +148,19 @@ static int __init bfin_cs_gptimer0_init(void)
# define bfin_cs_gptimer0_init()
#endif
+
+#if defined(CONFIG_GPTMR0_CLOCKSOURCE) || defined(CONFIG_CYCLES_CLOCKSOURCE)
+/* prefer to use cycles since it has higher rating */
+notrace unsigned long long sched_clock(void)
+{
+#if defined(CONFIG_CYCLES_CLOCKSOURCE)
+ return bfin_cs_cycles_sched_clock();
+#else
+ return bfin_cs_gptimer0_sched_clock();
+#endif
+}
+#endif
+
#ifdef CONFIG_CORE_TIMER_IRQ_L1
__attribute__((l1_text))
#endif