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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>
This commit is contained in:
Yi Li 2009-09-15 06:50:51 +00:00 committed by Mike Frysinger
parent f7036d649c
commit ceb33be95a
1 changed files with 33 additions and 10 deletions
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43
arch/blackfin/kernel/time-ts.c
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@ -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