VXTIME_PMTMR will be replaced by a more generic "Master Timer"
Signed-off-by: Jiri Bohac <[email protected]>
Index: linux-2.6.20-rc5/arch/x86_64/kernel/apic.c
===================================================================
--- linux-2.6.20-rc5.orig/arch/x86_64/kernel/apic.c
+++ linux-2.6.20-rc5/arch/x86_64/kernel/apic.c
@@ -784,16 +784,7 @@ static void setup_APIC_timer(unsigned in
} 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);
}
Index: linux-2.6.20-rc5/arch/x86_64/kernel/pmtimer.c
===================================================================
--- linux-2.6.20-rc5.orig/arch/x86_64/kernel/pmtimer.c
+++ linux-2.6.20-rc5/arch/x86_64/kernel/pmtimer.c
@@ -29,10 +29,6 @@
* in arch/i386/kernel/acpi/boot.c */
u32 pmtmr_ioport __read_mostly;
-/* value of the Power timer at last timer interrupt */
-static u32 offset_delay;
-static u32 last_pmtmr_tick;
-
#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */
static inline u32 cyc2us(u32 cycles)
@@ -48,38 +44,6 @@ static inline u32 cyc2us(u32 cycles)
return (cycles >> 10);
}
-int pmtimer_mark_offset(void)
-{
- static int first_run = 1;
- unsigned long tsc;
- u32 lost;
-
- u32 tick = inl(pmtmr_ioport);
- u32 delta;
-
- delta = cyc2us((tick - last_pmtmr_tick) & ACPI_PM_MASK);
-
- last_pmtmr_tick = tick;
- monotonic_base += delta * NSEC_PER_USEC;
-
- delta += offset_delay;
-
- lost = delta / (USEC_PER_SEC / HZ);
- offset_delay = delta % (USEC_PER_SEC / HZ);
-
- rdtscll(tsc);
- vxtime.last_tsc = tsc - offset_delay * (u64)cpu_khz / 1000;
-
- /* don't calculate delay for first run,
- or if we've got less then a tick */
- if (first_run || (lost < 1)) {
- first_run = 0;
- offset_delay = 0;
- }
-
- return lost - 1;
-}
-
static unsigned pmtimer_wait_tick(void)
{
u32 a, b;
@@ -100,28 +64,3 @@ void pmtimer_wait(unsigned us)
cpu_relax();
} while (cyc2us(b - a) < us);
}
-
-void pmtimer_resume(void)
-{
- last_pmtmr_tick = inl(pmtmr_ioport);
-}
-
-unsigned int do_gettimeoffset_pm(void)
-{
- u32 now, offset, delta = 0;
-
- offset = last_pmtmr_tick;
- now = inl(pmtmr_ioport);
- delta = (now - offset) & ACPI_PM_MASK;
-
- return offset_delay + cyc2us(delta);
-}
-
-
-static int __init nopmtimer_setup(char *s)
-{
- pmtmr_ioport = 0;
- return 1;
-}
-
-__setup("nopmtimer", nopmtimer_setup);
Index: linux-2.6.20-rc5/arch/x86_64/kernel/time.c
===================================================================
--- linux-2.6.20-rc5.orig/arch/x86_64/kernel/time.c
+++ linux-2.6.20-rc5/arch/x86_64/kernel/time.c
@@ -364,13 +364,6 @@ void main_timer_handler(void)
*/
offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
delay = hpet_readl(HPET_COUNTER) - offset;
- } else if (!pmtmr_ioport) {
- spin_lock(&i8253_lock);
- outb_p(0x00, 0x43);
- delay = inb_p(0x40);
- delay |= inb(0x40) << 8;
- spin_unlock(&i8253_lock);
- delay = LATCH - 1 - delay;
}
tsc = get_cycles_sync();
@@ -384,10 +377,6 @@ void main_timer_handler(void)
(offset - vxtime.last) * NSEC_PER_TICK / hpet_tick;
vxtime.last = offset;
-#ifdef CONFIG_X86_PM_TIMER
- } else if (vxtime.mode == VXTIME_PMTMR) {
- lost = pmtimer_mark_offset();
-#endif
} else {
offset = (((tsc - vxtime.last_tsc) *
vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK;
@@ -914,13 +903,6 @@ void __init time_init(void)
tick_nsec = TICK_NSEC_HPET;
cpu_khz = hpet_calibrate_tsc();
timename = "HPET";
-#ifdef CONFIG_X86_PM_TIMER
- } else if (pmtmr_ioport && !vxtime.hpet_address) {
- vxtime_hz = PM_TIMER_FREQUENCY;
- timename = "PM";
- pit_init();
- cpu_khz = pit_calibrate_tsc();
-#endif
} else {
pit_init();
cpu_khz = pit_calibrate_tsc();
@@ -987,16 +969,6 @@ void time_init_gtod(void)
vxtime.last = hpet_readl(HPET_COUNTER);
vxtime.mode = VXTIME_HPET;
do_gettimeoffset = do_gettimeoffset_hpet;
-#ifdef CONFIG_X86_PM_TIMER
- /* Using PM for gettimeofday is quite slow, but we have no other
- choice because the TSC is too unreliable on some systems. */
- } else if (pmtmr_ioport && !vxtime.hpet_address && notsc) {
- timetype = "PM";
- do_gettimeoffset = do_gettimeoffset_pm;
- vxtime.mode = VXTIME_PMTMR;
- sysctl_vsyscall = 0;
- printk(KERN_INFO "Disabling vsyscall due to use of PM timer\n");
-#endif
} else {
timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC";
vxtime.mode = VXTIME_TSC;
@@ -1064,10 +1036,6 @@ static int timer_resume(struct sys_devic
vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
else
vxtime.last = hpet_readl(HPET_COUNTER);
-#ifdef CONFIG_X86_PM_TIMER
- } else if (vxtime.mode == VXTIME_PMTMR) {
- pmtimer_resume();
-#endif
} else
vxtime.last_tsc = get_cycles_sync();
write_sequnlock_irqrestore(&xtime_lock,flags);
Index: linux-2.6.20-rc5/include/asm-x86_64/vsyscall.h
===================================================================
--- linux-2.6.20-rc5.orig/include/asm-x86_64/vsyscall.h
+++ linux-2.6.20-rc5/include/asm-x86_64/vsyscall.h
@@ -26,7 +26,6 @@ enum vsyscall_num {
#define VXTIME_TSC 1
#define VXTIME_HPET 2
-#define VXTIME_PMTMR 3
#define VGETCPU_RDTSCP 1
#define VGETCPU_LSL 2
--
On Thursday 01 February 2007 10:59, [email protected] wrote:
> VXTIME_PMTMR will be replaced by a more generic "Master Timer"
This means we have no fallback if something goes wrong with the Master timer?
A little risky.
-Andi
On Thu, Feb 01, 2007 at 12:13:31PM +0100, Andi Kleen wrote:
> On Thursday 01 February 2007 10:59, [email protected] wrote:
> > VXTIME_PMTMR will be replaced by a more generic "Master Timer"
>
> This means we have no fallback if something goes wrong with the Master timer?
>
> A little risky.
No, either HPET or PM Timer will become the Master Timer (elected
on boot). Master timer is just an abstraction of these, so the
rest of the timekeeping code needn't care which hardware timer is
being used. That's why the VXTIME_PMTMR mode is not needed.
--
Jiri Bohac <[email protected]>
SUSE Labs, SUSE CZ
On Thursday 01 February 2007 14:13, Jiri Bohac wrote:
> On Thu, Feb 01, 2007 at 12:13:31PM +0100, Andi Kleen wrote:
> > On Thursday 01 February 2007 10:59, [email protected] wrote:
> > > VXTIME_PMTMR will be replaced by a more generic "Master Timer"
> >
> > This means we have no fallback if something goes wrong with the Master timer?
> >
> > A little risky.
>
> No, either HPET or PM Timer will become the Master Timer (elected
> on boot). Master timer is just an abstraction of these, so the
> rest of the timekeeping code needn't care which hardware timer is
> being used. That's why the VXTIME_PMTMR mode is not needed.
But there is no option for the user to force so, is there?
-Andi
On Thu, Feb 01, 2007 at 02:13:00PM +0100, Andi Kleen wrote:
> On Thursday 01 February 2007 14:13, Jiri Bohac wrote:
> > On Thu, Feb 01, 2007 at 12:13:31PM +0100, Andi Kleen wrote:
> > > On Thursday 01 February 2007 10:59, [email protected] wrote:
> > > > VXTIME_PMTMR will be replaced by a more generic "Master Timer"
> > >
> > > This means we have no fallback if something goes wrong with the Master timer?
> > >
> > > A little risky.
> >
> > No, either HPET or PM Timer will become the Master Timer (elected
> > on boot). Master timer is just an abstraction of these, so the
> > rest of the timekeeping code needn't care which hardware timer is
> > being used. That's why the VXTIME_PMTMR mode is not needed.
>
> But there is no option for the user to force so, is there?
HPET is the default. If it's not available or with the "nohpet"
commandline option, PM Timer will be used as the Master Timer.
If this is not enough, it can be easily fixed in time_init().
--
Jiri Bohac <[email protected]>
SUSE Labs, SUSE CZ
On Thursday 01 February 2007 14:59, Jiri Bohac wrote:
> On Thu, Feb 01, 2007 at 02:13:00PM +0100, Andi Kleen wrote:
> > On Thursday 01 February 2007 14:13, Jiri Bohac wrote:
> > > On Thu, Feb 01, 2007 at 12:13:31PM +0100, Andi Kleen wrote:
> > > > On Thursday 01 February 2007 10:59, [email protected] wrote:
> > > > > VXTIME_PMTMR will be replaced by a more generic "Master Timer"
> > > >
> > > > This means we have no fallback if something goes wrong with the Master timer?
> > > >
> > > > A little risky.
> > >
> > > No, either HPET or PM Timer will become the Master Timer (elected
> > > on boot). Master timer is just an abstraction of these, so the
> > > rest of the timekeeping code needn't care which hardware timer is
> > > being used. That's why the VXTIME_PMTMR mode is not needed.
> >
> > But there is no option for the user to force so, is there?
>
> HPET is the default. If it's not available or with the "nohpet"
> commandline option, PM Timer will be used as the Master Timer.
This assumes all your algorithms are always correct.
> If this is not enough, it can be easily fixed in time_init().
I think we want at least one option that forces HPET/PMtimer as primary
time source.
-Andi