2 files changed, 70 insertions, 9 deletions

diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 5d3c5b07b8d..14751dda7dc 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -35,8 +35,11 @@
 #include <asm/mach_apic.h>
 #include <asm/nmi.h>
 #include <asm/idle.h>
+#include <asm/proto.h>
+#include <asm/timex.h>
 
 int apic_verbosity;
+int apic_runs_main_timer;
 
 int disable_apic_timer __initdata;
 
@@ -702,9 +705,17 @@ static void setup_APIC_timer(unsigned int clocks)
 			c2 |= inb_p(0x40) << 8;
 		} while (c2 - c1 < 300);
 	}
-
 	__setup_APIC_LVTT(clocks);
-
+	/* Turn off PIT interrupt if we use APIC timer as main timer.
+	   Only works with the PM timer right now
+	   TBD fix it for HPET too. */
+	if (vxtime.mode == VXTIME_PMTMR &&
+		smp_processor_id() == boot_cpu_id &&
+		apic_runs_main_timer == 1 &&
+		!cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {
+		stop_timer_interrupt();
+		apic_runs_main_timer++;
+	}
 	local_irq_restore(flags);
 }
 
@@ -872,6 +883,8 @@ void smp_local_timer_interrupt(struct pt_regs *regs)
 #ifdef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
+	if (apic_runs_main_timer > 1 && smp_processor_id() == boot_cpu_id)
+		main_timer_handler(regs);
 	/*
 	 * We take the 'long' return path, and there every subsystem
 	 * grabs the appropriate locks (kernel lock/ irq lock).
@@ -1081,10 +1094,27 @@ static __init int setup_nolapic(char *str)
 
 static __init int setup_noapictimer(char *str) 
 { 
+	if (str[0] != ' ' && str[0] != 0)
+		return -1;
 	disable_apic_timer = 1;
 	return 0;
 } 
 
+static __init int setup_apicmaintimer(char *str)
+{
+	apic_runs_main_timer = 1;
+	nohpet = 1;
+	return 0;
+}
+__setup("apicmaintimer", setup_apicmaintimer);
+
+static __init int setup_noapicmaintimer(char *str)
+{
+	apic_runs_main_timer = -1;
+	return 0;
+}
+__setup("noapicmaintimer", setup_noapicmaintimer);
+
 /* dummy parsing: see setup.c */
 
 __setup("disableapic", setup_disableapic); 
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index f8c47c68844..91a448a86eb 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -51,7 +51,7 @@ extern int using_apic_timer;
 DEFINE_SPINLOCK(rtc_lock);
 DEFINE_SPINLOCK(i8253_lock);
 
-static int nohpet __initdata = 0;
+int nohpet __initdata = 0;
 static int notsc __initdata = 0;
 
 #undef HPET_HACK_ENABLE_DANGEROUS
@@ -345,7 +345,7 @@ static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
 #endif
 }
 
-static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+void main_timer_handler(struct pt_regs *regs)
 {
 	static unsigned long rtc_update = 0;
 	unsigned long tsc;
@@ -458,12 +458,17 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	}
  
 	write_sequnlock(&xtime_lock);
+}
 
+static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	if (apic_runs_main_timer > 1)
+		return IRQ_HANDLED;
+	main_timer_handler(regs);
 #ifdef CONFIG_X86_LOCAL_APIC
 	if (using_apic_timer)
 		smp_send_timer_broadcast_ipi();
 #endif
-
 	return IRQ_HANDLED;
 }
 
@@ -843,17 +848,43 @@ static int hpet_reenable(void)
 	return hpet_timer_stop_set_go(hpet_tick);
 }
 
-void __init pit_init(void)
+#define PIT_MODE 0x43
+#define PIT_CH0  0x40
+
+static void __init __pit_init(int val, u8 mode)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&i8253_lock, flags);
-	outb_p(0x34, 0x43);		/* binary, mode 2, LSB/MSB, ch 0 */
-	outb_p(LATCH & 0xff, 0x40);	/* LSB */
-	outb_p(LATCH >> 8, 0x40);	/* MSB */
+	outb_p(mode, PIT_MODE);
+	outb_p(val & 0xff, PIT_CH0);	/* LSB */
+	outb_p(val >> 8, PIT_CH0);	/* MSB */
 	spin_unlock_irqrestore(&i8253_lock, flags);
 }
 
+void __init pit_init(void)
+{
+	__pit_init(LATCH, 0x34); /* binary, mode 2, LSB/MSB, ch 0 */
+}
+
+void __init pit_stop_interrupt(void)
+{
+	__pit_init(0, 0x30); /* mode 0 */
+}
+
+void __init stop_timer_interrupt(void)
+{
+	char *name;
+	if (vxtime.hpet_address) {
+		name = "HPET";
+		hpet_timer_stop_set_go(0);
+	} else {
+		name = "PIT";
+		pit_stop_interrupt();
+	}
+	printk(KERN_INFO "timer: %s interrupt stopped.\n", name);
+}
+
 int __init time_setup(char *str)
 {
 	report_lost_ticks = 1;