diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2009-08-20 15:54:21 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2009-08-31 09:35:46 +0200 |
| commit | 64fcbac1f38882d8ae82c44a1c2a676cfa5e79e1 (patch) | |
| tree | ec1206322a8ca2a775db5ca552d5666b968be77c | |
| parent | dd3e6e8c6e7a2294f137c4dbccb3e73e7fa8ba15 (diff) | |
x86: Simplify timer_ack magic in time_32.c
Let the compiler optimize the timer_ack magic away in the 32bit timer
interrupt and put the same code into time_64.c. It's optimized out for
CONFIG_X86_IO_APIC on 32bit and for 64bit because timer_ack is const 0
in both cases.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/x86/include/asm/timer.h | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/time_32.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/time_64.c | 14 |
3 files changed, 21 insertions, 4 deletions
diff --git a/arch/x86/include/asm/timer.h b/arch/x86/include/asm/timer.h index e854c7ab4169..65228ccc5f0d 100644 --- a/arch/x86/include/asm/timer.h +++ b/arch/x86/include/asm/timer.h @@ -9,11 +9,13 @@ unsigned long long native_sched_clock(void); unsigned long native_calibrate_tsc(void); +extern int recalibrate_cpu_khz(void); -#ifdef CONFIG_X86_32 +#if defined(CONFIG_X86_32) && defined(CONFIG_X86_IO_APIC) extern int timer_ack; +#else +# define timer_ack (0) #endif -extern int recalibrate_cpu_khz(void); extern int no_timer_check; diff --git a/arch/x86/kernel/time_32.c b/arch/x86/kernel/time_32.c index acbaefd61e8e..7a26bcf887f6 100644 --- a/arch/x86/kernel/time_32.c +++ b/arch/x86/kernel/time_32.c @@ -23,7 +23,9 @@ #include <asm/time.h> #include <asm/nmi.h> +#if defined(CONFIG_X86_32) && defined(CONFIG_X86_IO_APIC) int timer_ack; +#endif unsigned long profile_pc(struct pt_regs *regs) { @@ -60,7 +62,7 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) /* Keep nmi watchdog up to date */ inc_irq_stat(irq0_irqs); -#ifdef CONFIG_X86_IO_APIC + /* Optimized out for !IO_APIC and x86_64 */ if (timer_ack) { /* * Subtle, when I/O APICs are used we have to ack timer IRQ @@ -73,7 +75,6 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) inb(PIC_MASTER_POLL); spin_unlock(&i8259A_lock); } -#endif global_clock_event->event_handler(global_clock_event); diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c index 45914f8844a7..35e0a925da56 100644 --- a/arch/x86/kernel/time_64.c +++ b/arch/x86/kernel/time_64.c @@ -51,6 +51,20 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) { inc_irq_stat(irq0_irqs); + /* Optimized out for !IO_APIC and x86_64 */ + if (timer_ack) { + /* + * Subtle, when I/O APICs are used we have to ack timer IRQ + * manually to deassert NMI lines for the watchdog if run + * on an 82489DX-based system. + */ + spin_lock(&i8259A_lock); + outb(0x0c, PIC_MASTER_OCW3); + /* Ack the IRQ; AEOI will end it automatically. */ + inb(PIC_MASTER_POLL); + spin_unlock(&i8259A_lock); + } + global_clock_event->event_handler(global_clock_event); #ifdef CONFIG_MCA |