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ARM: pxa: convert sched_clock() to use new infrastructure

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Convert pxa to use the new sched_clock() infrastructure for extending
32bit counters to full 64-bit nanoseconds.

Tested-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2010-12-15 21:48:15 +00:00
parent 28bb7bc61a
commit 7ce8301881
2 changed files with 12 additions and 22 deletions
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1
arch/arm/Kconfig
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@ -593,6 +593,7 @@ config ARCH_PXA
select COMMON_CLKDEV
select ARCH_REQUIRE_GPIOLIB
select GENERIC_CLOCKEVENTS
select HAVE_SCHED_CLOCK
select TICK_ONESHOT
select PLAT_PXA
select SPARSE_IRQ

33
arch/arm/mach-pxa/time.c
View File

@ -17,11 +17,11 @@
#include <linux/interrupt.h>
#include <linux/clockchips.h>
#include <linux/sched.h>
#include <linux/cnt32_to_63.h>
#include <asm/div64.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#include <asm/sched_clock.h>
#include <mach/regs-ost.h>
/*
@ -32,29 +32,18 @@
* long as there is always less than 582 seconds between successive
* calls to sched_clock() which should always be the case in practice.
*/
#define OSCR2NS_SCALE_FACTOR 10
static unsigned long oscr2ns_scale;
static void __init set_oscr2ns_scale(unsigned long oscr_rate)
{
unsigned long long v = 1000000000ULL << OSCR2NS_SCALE_FACTOR;
do_div(v, oscr_rate);
oscr2ns_scale = v;
/*
* We want an even value to automatically clear the top bit
* returned by cnt32_to_63() without an additional run time
* instruction. So if the LSB is 1 then round it up.
*/
if (oscr2ns_scale & 1)
oscr2ns_scale++;
}
static DEFINE_CLOCK_DATA(cd);
unsigned long long notrace sched_clock(void)
{
unsigned long long v = cnt32_to_63(OSCR);
return (v * oscr2ns_scale) >> OSCR2NS_SCALE_FACTOR;
u32 cyc = OSCR;
return cyc_to_sched_clock(&cd, cyc, (u32)~0);
}
static void notrace pxa_update_sched_clock(void)
{
u32 cyc = OSCR;
update_sched_clock(&cd, cyc, (u32)~0);
}
@ -144,7 +133,7 @@ static void __init pxa_timer_init(void)
OIER = 0;
OSSR = OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3;
set_oscr2ns_scale(clock_tick_rate);
init_sched_clock(&cd, pxa_update_sched_clock, 32, clock_tick_rate);
ckevt_pxa_osmr0.mult =
div_sc(clock_tick_rate, NSEC_PER_SEC, ckevt_pxa_osmr0.shift);