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

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commit 39fe05e58c upstream.

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>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Shaohua Li
2009-08-12 11:16:12 +08:00
committed by Greg Kroah-Hartman
parent cfa3f57bab
commit bf8c4fb747
1 changed files with 10 additions and 2 deletions
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12
arch/x86/kernel/hpet.c
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@@ -606,6 +606,8 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
if (hpet_msi_disable)
return;
if (boot_cpu_has(X86_FEATURE_ARAT))
return;
id = hpet_readl(HPET_ID);
num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
@@ -894,10 +896,8 @@ int __init hpet_enable(void)
if (id & HPET_ID_LEGSUP) {
hpet_legacy_clockevent_register();
hpet_msi_capability_lookup(2);
return 1;
}
hpet_msi_capability_lookup(0);
return 0;
out_nohpet:
@@ -930,12 +930,20 @@ static __init int hpet_late_init(void)
if (!hpet_virt_address)
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_print_config();
if (hpet_msi_disable)
return 0;
if (boot_cpu_has(X86_FEATURE_ARAT))
return 0;
for_each_online_cpu(cpu) {
hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
}