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-rw-r--r--Documentation/x86_64/boot-options.txt7
-rw-r--r--arch/x86_64/kernel/apic.c34
-rw-r--r--arch/x86_64/kernel/time.c45
-rw-r--r--include/asm-x86_64/apic.h1
-rw-r--r--include/asm-x86_64/proto.h5
5 files changed, 83 insertions, 9 deletions
diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index 9c5fc15..654ea4f 100644
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -40,6 +40,13 @@ APICs
no_timer_check Don't check the IO-APIC timer. This can work around
problems with incorrect timer initialization on some boards.
+ apicmaintimer Run time keeping from the local APIC timer instead
+ of using the PIT/HPET interrupt for this. This is useful
+ when the PIT/HPET interrupts are unreliable.
+
+ noapicmaintimer Don't do time keeping using the APIC timer.
+ Useful when this option was auto selected, but doesn't work.
+
Early Console
syntax: earlyprintk=vga
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 5d3c5b0..14751dd 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 f8c47c6..91a448a 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;
diff --git a/include/asm-x86_64/apic.h b/include/asm-x86_64/apic.h
index 4f6a4dc..bdbd893 100644
--- a/include/asm-x86_64/apic.h
+++ b/include/asm-x86_64/apic.h
@@ -17,6 +17,7 @@
#define APIC_DEBUG 2
extern int apic_verbosity;
+extern int apic_runs_main_timer;
/*
* Define the default level of output to be very little
diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h
index d35c7e0..c1e2307 100644
--- a/include/asm-x86_64/proto.h
+++ b/include/asm-x86_64/proto.h
@@ -49,6 +49,8 @@ extern u32 pmtmr_ioport;
#endif
extern unsigned long long monotonic_base;
extern int sysctl_vsyscall;
+extern int nohpet;
+extern unsigned long vxtime_hz;
extern void do_softirq_thunk(void);
@@ -69,6 +71,9 @@ extern void free_bootmem_generic(unsigned long phys, unsigned len);
extern void load_gs_index(unsigned gs);
+extern void stop_timer_interrupt(void);
+extern void main_timer_handler(struct pt_regs *regs);
+
extern unsigned long end_pfn_map;
extern void show_trace(unsigned long * rsp);
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