[tip:timers/cleanup] x86: Use common i8253 clockevent

From: tip-bot for Thomas Gleixner
Date: Fri Jul 01 2011 - 04:40:55 EST


Commit-ID: 0a779c571314b7951ff12edac80aa0cbe7c12b6e
Gitweb: http://git.kernel.org/tip/0a779c571314b7951ff12edac80aa0cbe7c12b6e
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 9 Jun 2011 13:08:26 +0000
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 1 Jul 2011 10:37:14 +0200

x86: Use common i8253 clockevent

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20110609130622.026152527@xxxxxxxxxxxxx
---
arch/x86/Kconfig | 2 +-
arch/x86/kernel/i8253.c | 93 ++---------------------------------------------
2 files changed, 4 insertions(+), 91 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2dd95b5..26a14b4 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -71,7 +71,7 @@ config X86
select IRQ_FORCED_THREADING
select USE_GENERIC_SMP_HELPERS if SMP
select HAVE_BPF_JIT if (X86_64 && NET)
- select I8253_LOCK
+ select CLKEVT_I8253

config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index 5783e6d..f2b96de 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -3,15 +3,9 @@
*
*/
#include <linux/clockchips.h>
-#include <linux/interrupt.h>
-#include <linux/spinlock.h>
-#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/timex.h>
-#include <linux/delay.h>
#include <linux/i8253.h>
-#include <linux/init.h>
-#include <linux/io.h>

#include <asm/hpet.h>
#include <asm/time.h>
@@ -23,91 +17,10 @@
*/
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)
{
- /*
- * Start pit with the boot cpu mask and make it global after the
- * 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;
+ clockevent_i8253_init(true);
+ global_clock_event = &i8253_clockevent;
}

#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)
*/
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 clocksource_i8253_init();
--
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