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x86, hpet: Disable per-cpu hpet timer if ARAT is supported

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If CPU support always running local APIC timer, per-cpu hpet
timer could be disabled, which is useless and wasteful in such
case. Let's leave the timers to others.

The effect is that we reserve less timers.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: venkatesh.pallipadi@intel.com
LKML-Reference: <20090812031612.GA10062@sli10-desk.sh.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Shaohua Li 2009-08-12 11:16:12 +08:00 • committed by Ingo Molnar
parent 7cb7beb31a
commit 39fe05e58c
1 changed files with 10 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

12
arch/x86/kernel/hpet.c
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@ -584,6 +584,8 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
unsigned int num_timers_used = 0; unsigned int num_timers_used = 0;
int i; int i;
if (boot_cpu_has(X86_FEATURE_ARAT))
return;
id = hpet_readl(HPET_ID); id = hpet_readl(HPET_ID);
num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT); num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
@ -872,10 +874,8 @@ int __init hpet_enable(void)
if (id & HPET_ID_LEGSUP) { if (id & HPET_ID_LEGSUP) {
hpet_legacy_clockevent_register(); hpet_legacy_clockevent_register();
hpet_msi_capability_lookup(2);
return 1; return 1;
} }
hpet_msi_capability_lookup(0);
return 0; return 0;
out_nohpet: out_nohpet:
@ -908,9 +908,17 @@ static __init int hpet_late_init(void)
if (!hpet_virt_address) if (!hpet_virt_address)
return -ENODEV; return -ENODEV;
if (hpet_readl(HPET_ID) & HPET_ID_LEGSUP)
hpet_msi_capability_lookup(2);
else
hpet_msi_capability_lookup(0);
hpet_reserve_platform_timers(hpet_readl(HPET_ID)); hpet_reserve_platform_timers(hpet_readl(HPET_ID));
hpet_print_config(); hpet_print_config();
if (boot_cpu_has(X86_FEATURE_ARAT))
return 0;
for_each_online_cpu(cpu) { for_each_online_cpu(cpu) {
hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu); hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
} }