From 64fcbac1f38882d8ae82c44a1c2a676cfa5e79e1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 20 Aug 2009 15:54:21 +0200 Subject: 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 --- arch/x86/kernel/time_64.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'arch/x86/kernel/time_64.c') 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 -- cgit v1.2.3-59-g8ed1b