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x86: Use common i8253 clockevent 

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20110609130622.026152527@linutronix.de
This commit is contained in:
Thomas Gleixner 2011-06-09 13:08:26 +00:00
parent e6220bdc94
commit 0a779c5713
2 changed files with 4 additions and 91 deletions
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2
arch/x86/Kconfig
View File

@ -71,7 +71,7 @@ config X86
select IRQ_FORCED_THREADING select IRQ_FORCED_THREADING
select USE_GENERIC_SMP_HELPERS if SMP select USE_GENERIC_SMP_HELPERS if SMP
select HAVE_BPF_JIT if (X86_64 && NET) select HAVE_BPF_JIT if (X86_64 && NET)
select I8253_LOCK select CLKEVT_I8253
config INSTRUCTION_DECODER config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS) def_bool (KPROBES || PERF_EVENTS)

93
arch/x86/kernel/i8253.c
View File

@ -3,15 +3,9 @@
* *
*/ */
#include <linux/clockchips.h> #include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/timex.h> #include <linux/timex.h>
#include <linux/delay.h>
#include <linux/i8253.h> #include <linux/i8253.h>
#include <linux/init.h>
#include <linux/io.h>
#include <asm/hpet.h> #include <asm/hpet.h>
#include <asm/time.h> #include <asm/time.h>
@ -23,91 +17,10 @@
*/ */
struct clock_event_device *global_clock_event; struct clock_event_device *global_clock_event;
/*
* Initialize the PIT timer.
*
* This is also called after resume to bring the PIT into operation again.
*/
static void init_pit_timer(enum clock_event_mode mode,
struct clock_event_device *evt)
{
raw_spin_lock(&i8253_lock);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* binary, mode 2, LSB/MSB, ch 0 */
outb_pit(0x34, PIT_MODE);
outb_pit(LATCH & 0xff , PIT_CH0); /* LSB */
outb_pit(LATCH >> 8 , PIT_CH0); /* MSB */
break;
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
if (evt->mode == CLOCK_EVT_MODE_PERIODIC ||
evt->mode == CLOCK_EVT_MODE_ONESHOT) {
outb_pit(0x30, PIT_MODE);
outb_pit(0, PIT_CH0);
outb_pit(0, PIT_CH0);
}
break;
case CLOCK_EVT_MODE_ONESHOT:
/* One shot setup */
outb_pit(0x38, PIT_MODE);
break;
case CLOCK_EVT_MODE_RESUME:
/* Nothing to do here */
break;
}
raw_spin_unlock(&i8253_lock);
}
/*
* Program the next event in oneshot mode
*
* Delta is given in PIT ticks
*/
static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
{
raw_spin_lock(&i8253_lock);
outb_pit(delta & 0xff , PIT_CH0); /* LSB */
outb_pit(delta >> 8 , PIT_CH0); /* MSB */
raw_spin_unlock(&i8253_lock);
return 0;
}
/*
* On UP the PIT can serve all of the possible timer functions. On SMP systems
* it can be solely used for the global tick.
*
* The profiling and update capabilities are switched off once the local apic is
* registered. This mechanism replaces the previous #ifdef LOCAL_APIC -
* !using_apic_timer decisions in do_timer_interrupt_hook()
*/
static struct clock_event_device pit_ce = {
.name = "pit",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = init_pit_timer,
.set_next_event = pit_next_event,
.irq = 0,
};
/*
* Initialize the conversion factor and the min/max deltas of the clock event
* structure and register the clock event source with the framework.
*/
void __init setup_pit_timer(void) void __init setup_pit_timer(void)
{ {
/* clockevent_i8253_init(true);
* Start pit with the boot cpu mask and make it global after the global_clock_event = &i8253_clockevent;
* IO_APIC has been initialized.
*/
pit_ce.cpumask = cpumask_of(smp_processor_id());
clockevents_config_and_register(&pit_ce, CLOCK_TICK_RATE, 0xF, 0x7FFF);
global_clock_event = &pit_ce;
} }
#ifndef CONFIG_X86_64 #ifndef CONFIG_X86_64
@ -121,7 +34,7 @@ static int __init init_pit_clocksource(void)
* - when local APIC timer is active (PIT is switched off) * - when local APIC timer is active (PIT is switched off)
*/ */
if (num_possible_cpus() > 1 || is_hpet_enabled() || if (num_possible_cpus() > 1 || is_hpet_enabled() ||
pit_ce.mode != CLOCK_EVT_MODE_PERIODIC) i8253_clockevent.mode != CLOCK_EVT_MODE_PERIODIC)
return 0; return 0;
return clocksource_i8253_init(); return clocksource_i8253_init();