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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>
This commit is contained in:
Thomas Gleixner 2007-10-12 23:04:07 +02:00 committed by Thomas Gleixner
parent 4e77ae3e10
commit fb79d22e1d
3 changed files with 36 additions and 1 deletions
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2
arch/x86/kernel/apic_64.c
View File

@ -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;

34
arch/x86/kernel/setup_64.c
View File

@ -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)

1
include/asm-x86/apic_64.h
View File

@ -19,6 +19,7 @@
extern int apic_verbosity;
extern int apic_runs_main_timer;
extern int ioapic_force;
extern int disable_apic_timer;
/*
* Define the default level of output to be very little