diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2007-10-12 23:04:07 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@inhelltoy.tec.linutronix.de> | 2007-10-12 23:04:07 +0200 |
| commit | fb79d22e1d4b06385796cc0db0084a2e07beccee (patch) | |
| tree | f62b850b9b8ee1b7a4264b29e30fd7c360e23c94 /arch | |
| parent | 4e77ae3e105d28aa9410585715d83818f0abe871 (diff) | |
x86: disable apic timer for AMD C1E enabled CPUs
AMDs C1E enabled CPUs stop the local apic timer, when both cores are
idle. This is a hardware feature which breaks highres/dynticks.
Add the same quirk as we have for 32 bit already.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/apic_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/setup_64.c | 34 |
2 files changed, 35 insertions, 1 deletions
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c index b0237caff71..118830cba1a 100644 --- a/arch/x86/kernel/apic_64.c +++ b/arch/x86/kernel/apic_64.c @@ -44,7 +44,7 @@ int apic_verbosity; int apic_runs_main_timer; int apic_calibrate_pmtmr __initdata; -int disable_apic_timer __initdata; +int disable_apic_timer __cpuinitdata; /* Local APIC timer works in C2? */ int local_apic_timer_c2_ok; diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c index af838f6b0b7..32054bf5ba4 100644 --- a/arch/x86/kernel/setup_64.c +++ b/arch/x86/kernel/setup_64.c @@ -546,6 +546,37 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c) #endif } +#define ENABLE_C1E_MASK 0x18000000 +#define CPUID_PROCESSOR_SIGNATURE 1 +#define CPUID_XFAM 0x0ff00000 +#define CPUID_XFAM_K8 0x00000000 +#define CPUID_XFAM_10H 0x00100000 +#define CPUID_XFAM_11H 0x00200000 +#define CPUID_XMOD 0x000f0000 +#define CPUID_XMOD_REV_F 0x00040000 + +/* AMD systems with C1E don't have a working lAPIC timer. Check for that. */ +static __cpuinit int amd_apic_timer_broken(void) +{ + u32 lo, hi; + u32 eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE); + switch (eax & CPUID_XFAM) { + case CPUID_XFAM_K8: + if ((eax & CPUID_XMOD) < CPUID_XMOD_REV_F) + break; + case CPUID_XFAM_10H: + case CPUID_XFAM_11H: + rdmsr(MSR_K8_ENABLE_C1E, lo, hi); + if (lo & ENABLE_C1E_MASK) + return 1; + break; + default: + /* err on the side of caution */ + return 1; + } + return 0; +} + static void __cpuinit init_amd(struct cpuinfo_x86 *c) { unsigned level; @@ -617,6 +648,9 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) /* Family 10 doesn't support C states in MWAIT so don't use it */ if (c->x86 == 0x10 && !force_mwait) clear_bit(X86_FEATURE_MWAIT, &c->x86_capability); + + if (amd_apic_timer_broken()) + disable_apic_timer = 1; } static void __cpuinit detect_ht(struct cpuinfo_x86 *c) |