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[PATCH] ACPI keep track of timer broadcasting 

This is a preperatory patch for highres/dyntick:

- replace the big #ifdef ARCH_APICTIMER_STOPS_ON_C3 hackery by functions

- remove the double switch in the power verify function (in the worst case
  we switched ipi to apic and 20usec later apic to ipi)

- keep track of the the state which stops local APIC timer

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Len Brown <len.brown@intel.com>
Cc: <linux-acpi@vger.kernel.org>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thomas Gleixner 2007-02-16 01:27:55 -08:00 committed by Linus Torvalds
parent 3434933b17
commit 169a0abbe3
2 changed files with 48 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
drivers/acpi/processor_idle.c
View File

@ -248,6 +248,48 @@ static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
}
}
#ifdef ARCH_APICTIMER_STOPS_ON_C3
/*
* Some BIOS implementations switch to C3 in the published C2 state.
* This seems to be a common problem on AMD boxen, but other vendors
* are affected too. We pick the most conservative approach: we assume
* that the local APIC stops in both C2 and C3.
*/
static void acpi_timer_check_state(int state, struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
struct acpi_processor_power *pwr = &pr->power;
/*
* Check, if one of the previous states already marked the lapic
* unstable
*/
if (pwr->timer_broadcast_on_state < state)
return;
if (cx->type >= ACPI_STATE_C2)
pr->power.timer_broadcast_on_state = state;
}
static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
{
cpumask_t mask = cpumask_of_cpu(pr->id);
if (pr->power.timer_broadcast_on_state < INT_MAX)
on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
else
on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
}
#else
static void acpi_timer_check_state(int state, struct acpi_processor *pr,
struct acpi_processor_cx *cstate) { }
static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
#endif
static void acpi_processor_idle(void)
{
struct acpi_processor *pr = NULL;
@ -914,11 +956,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
unsigned int i;
unsigned int working = 0;
#ifdef ARCH_APICTIMER_STOPS_ON_C3
int timer_broadcast = 0;
cpumask_t mask = cpumask_of_cpu(pr->id);
on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
#endif
pr->power.timer_broadcast_on_state = INT_MAX;
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
struct acpi_processor_cx *cx = &pr->power.states[i];
@ -930,21 +968,14 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
case ACPI_STATE_C2:
acpi_processor_power_verify_c2(cx);
#ifdef ARCH_APICTIMER_STOPS_ON_C3
/* Some AMD systems fake C3 as C2, but still
have timer troubles */
if (cx->valid &&
boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
timer_broadcast++;
#endif
if (cx->valid)
acpi_timer_check_state(i, pr, cx);
break;
case ACPI_STATE_C3:
acpi_processor_power_verify_c3(pr, cx);
#ifdef ARCH_APICTIMER_STOPS_ON_C3
if (cx->valid)
timer_broadcast++;
#endif
acpi_timer_check_state(i, pr, cx);
break;
}
@ -952,10 +983,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
working++;
}
#ifdef ARCH_APICTIMER_STOPS_ON_C3
if (timer_broadcast)
on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
#endif
acpi_propagate_timer_broadcast(pr);
return (working);
}

1
include/acpi/processor.h
View File

@ -79,6 +79,7 @@ struct acpi_processor_power {
u32 bm_activity;
int count;
struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
int timer_broadcast_on_state;
};
/* Performance Management */