diff options
| author | David S. Miller <davem@davemloft.net> | 2010-04-03 15:49:14 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-03 15:49:14 -0700 |
| commit | 87e8b821ed8db3dab03d96cd542e29666bf210aa (patch) | |
| tree | 0027060473aafbbb125655ba027319c8a1a665fc /arch/x86/kernel/process.c | |
| parent | 33cd9dfa3a13e3d8e41aef225a9f98169816723b (diff) | |
| parent | 5e11611a5d22252f3f9c169a3c9377eac0c32033 (diff) | |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 02d678065d7..28ad9f4d8b9 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -526,21 +526,37 @@ static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) } /* - * Check for AMD CPUs, which have potentially C1E support + * Check for AMD CPUs, where APIC timer interrupt does not wake up CPU from C1e. + * For more information see + * - Erratum #400 for NPT family 0xf and family 0x10 CPUs + * - Erratum #365 for family 0x11 (not affected because C1e not in use) */ static int __cpuinit check_c1e_idle(const struct cpuinfo_x86 *c) { + u64 val; if (c->x86_vendor != X86_VENDOR_AMD) - return 0; - - if (c->x86 < 0x0F) - return 0; + goto no_c1e_idle; /* Family 0x0f models < rev F do not have C1E */ - if (c->x86 == 0x0f && c->x86_model < 0x40) - return 0; + if (c->x86 == 0x0F && c->x86_model >= 0x40) + return 1; - return 1; + if (c->x86 == 0x10) { + /* + * check OSVW bit for CPUs that are not affected + * by erratum #400 + */ + rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, val); + if (val >= 2) { + rdmsrl(MSR_AMD64_OSVW_STATUS, val); + if (!(val & BIT(1))) + goto no_c1e_idle; + } + return 1; + } + +no_c1e_idle: + return 0; } static cpumask_var_t c1e_mask; @@ -607,7 +623,7 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) { #ifdef CONFIG_SMP if (pm_idle == poll_idle && smp_num_siblings > 1) { - printk(KERN_WARNING "WARNING: polling idle and HT enabled," + printk_once(KERN_WARNING "WARNING: polling idle and HT enabled," " performance may degrade.\n"); } #endif |