x86, hpet: Disable per-cpu hpet timer if ARAT is supported
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>
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index dedc2bd..5969e10 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -584,6 +584,8 @@
unsigned int num_timers_used = 0;
int i;
+ if (boot_cpu_has(X86_FEATURE_ARAT))
+ return;
id = hpet_readl(HPET_ID);
num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
@@ -872,10 +874,8 @@
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:
@@ -908,9 +908,17 @@
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 (boot_cpu_has(X86_FEATURE_ARAT))
+ return 0;
+
for_each_online_cpu(cpu) {
hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
}