Commit-ID: 64fcbac1f38882d8ae82c44a1c2a676cfa5e79e1
Gitweb: http://git.kernel.org/tip/64fcbac1f38882d8ae82c44a1c2a676cfa5e79e1
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 20 Aug 2009 15:54:21 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 31 Aug 2009 09:35:46 +0200
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@xxxxxxxxxxxxx>
---
arch/x86/include/asm/timer.h | 6 ++++--
arch/x86/kernel/time_32.c | 5 +++--
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 e854c7a..65228cc 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 acbaefd..7a26bcf 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 45914f8..35e0a92 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
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|