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Diffstat (limited to 'arch/x86/kernel/i8253.c')
-rw-r--r--arch/x86/kernel/i8253.c68
1 files changed, 33 insertions, 35 deletions
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index 10f92fb532f..3475440baa5 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -3,17 +3,17 @@
*
*/
#include <linux/clockchips.h>
-#include <linux/init.h>
#include <linux/interrupt.h>
+#include <linux/spinlock.h>
#include <linux/jiffies.h>
#include <linux/module.h>
-#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
-#include <asm/smp.h>
-#include <asm/delay.h>
#include <asm/i8253.h>
-#include <asm/io.h>
#include <asm/hpet.h>
+#include <asm/smp.h>
DEFINE_SPINLOCK(i8253_lock);
EXPORT_SYMBOL(i8253_lock);
@@ -40,7 +40,7 @@ static void init_pit_timer(enum clock_event_mode mode,
{
spin_lock(&i8253_lock);
- switch(mode) {
+ switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* binary, mode 2, LSB/MSB, ch 0 */
outb_pit(0x34, PIT_MODE);
@@ -95,7 +95,7 @@ static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
* registered. This mechanism replaces the previous #ifdef LOCAL_APIC -
* !using_apic_timer decisions in do_timer_interrupt_hook()
*/
-static struct clock_event_device pit_clockevent = {
+static struct clock_event_device pit_ce = {
.name = "pit",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = init_pit_timer,
@@ -114,15 +114,13 @@ 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_clockevent.cpumask = cpumask_of(smp_processor_id());
- pit_clockevent.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC,
- pit_clockevent.shift);
- pit_clockevent.max_delta_ns =
- clockevent_delta2ns(0x7FFF, &pit_clockevent);
- pit_clockevent.min_delta_ns =
- clockevent_delta2ns(0xF, &pit_clockevent);
- clockevents_register_device(&pit_clockevent);
- global_clock_event = &pit_clockevent;
+ pit_ce.cpumask = cpumask_of(smp_processor_id());
+ pit_ce.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, pit_ce.shift);
+ pit_ce.max_delta_ns = clockevent_delta2ns(0x7FFF, &pit_ce);
+ pit_ce.min_delta_ns = clockevent_delta2ns(0xF, &pit_ce);
+
+ clockevents_register_device(&pit_ce);
+ global_clock_event = &pit_ce;
}
#ifndef CONFIG_X86_64
@@ -133,11 +131,11 @@ void __init setup_pit_timer(void)
*/
static cycle_t pit_read(void)
{
+ static int old_count;
+ static u32 old_jifs;
unsigned long flags;
int count;
u32 jifs;
- static int old_count;
- static u32 old_jifs;
spin_lock_irqsave(&i8253_lock, flags);
/*
@@ -179,9 +177,9 @@ static cycle_t pit_read(void)
* Previous attempts to handle these cases intelligently were
* buggy, so we just do the simple thing now.
*/
- if (count > old_count && jifs == old_jifs) {
+ if (count > old_count && jifs == old_jifs)
count = old_count;
- }
+
old_count = count;
old_jifs = jifs;
@@ -192,13 +190,13 @@ static cycle_t pit_read(void)
return (cycle_t)(jifs * LATCH) + count;
}
-static struct clocksource clocksource_pit = {
- .name = "pit",
- .rating = 110,
- .read = pit_read,
- .mask = CLOCKSOURCE_MASK(32),
- .mult = 0,
- .shift = 20,
+static struct clocksource pit_cs = {
+ .name = "pit",
+ .rating = 110,
+ .read = pit_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .mult = 0,
+ .shift = 20,
};
static void pit_disable_clocksource(void)
@@ -206,9 +204,9 @@ static void pit_disable_clocksource(void)
/*
* Use mult to check whether it is registered or not
*/
- if (clocksource_pit.mult) {
- clocksource_unregister(&clocksource_pit);
- clocksource_pit.mult = 0;
+ if (pit_cs.mult) {
+ clocksource_unregister(&pit_cs);
+ pit_cs.mult = 0;
}
}
@@ -222,13 +220,13 @@ 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_clockevent.mode != CLOCK_EVT_MODE_PERIODIC)
+ pit_ce.mode != CLOCK_EVT_MODE_PERIODIC)
return 0;
- clocksource_pit.mult = clocksource_hz2mult(CLOCK_TICK_RATE,
- clocksource_pit.shift);
- return clocksource_register(&clocksource_pit);
+ pit_cs.mult = clocksource_hz2mult(CLOCK_TICK_RATE, pit_cs.shift);
+
+ return clocksource_register(&pit_cs);
}
arch_initcall(init_pit_clocksource);
-#endif
+#endif /* !CONFIG_X86_64 */