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authorRalf Baechle <ralf@linux-mips.org>2008-01-30 07:30:47 -0500
committerIngo Molnar <mingo@elte.hu>2008-01-30 07:30:47 -0500
commit5f627f8e122a163ce53908d55e088247db31f1d7 (patch)
tree15e48b30394cbfd014aaf7f99f5a4bfee5b8efbb /arch/x86/kernel/i8253.c
parentb263295dbffd33b0fbff670720fa178c30e3392a (diff)
mips, x86: optimize the i8259 code a bit
The timer code always calls the clock_event_device set_net_event and set_mode methods with interrupts disabled, so no need to use spin_lock_irqsave / spin_unlock_irqrestore for those. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Acked-by:Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/i8253.c')
-rw-r--r--arch/x86/kernel/i8253.c12
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index 377c3f8411f8..c76fef1ce355 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -38,9 +38,7 @@ struct clock_event_device *global_clock_event;
38static void init_pit_timer(enum clock_event_mode mode, 38static void init_pit_timer(enum clock_event_mode mode,
39 struct clock_event_device *evt) 39 struct clock_event_device *evt)
40{ 40{
41 unsigned long flags; 41 spin_lock(&i8253_lock);
42
43 spin_lock_irqsave(&i8253_lock, flags);
44 42
45 switch(mode) { 43 switch(mode) {
46 case CLOCK_EVT_MODE_PERIODIC: 44 case CLOCK_EVT_MODE_PERIODIC:
@@ -71,7 +69,7 @@ static void init_pit_timer(enum clock_event_mode mode,
71 /* Nothing to do here */ 69 /* Nothing to do here */
72 break; 70 break;
73 } 71 }
74 spin_unlock_irqrestore(&i8253_lock, flags); 72 spin_unlock(&i8253_lock);
75} 73}
76 74
77/* 75/*
@@ -81,12 +79,10 @@ static void init_pit_timer(enum clock_event_mode mode,
81 */ 79 */
82static int pit_next_event(unsigned long delta, struct clock_event_device *evt) 80static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
83{ 81{
84 unsigned long flags; 82 spin_lock(&i8253_lock);
85
86 spin_lock_irqsave(&i8253_lock, flags);
87 outb_p(delta & 0xff , PIT_CH0); /* LSB */ 83 outb_p(delta & 0xff , PIT_CH0); /* LSB */
88 outb(delta >> 8 , PIT_CH0); /* MSB */ 84 outb(delta >> 8 , PIT_CH0); /* MSB */
89 spin_unlock_irqrestore(&i8253_lock, flags); 85 spin_unlock(&i8253_lock);
90 86
91 return 0; 87 return 0;
92} 88}