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authorIngo Molnar <mingo@elte.hu>2010-04-02 20:02:55 +0200
committerIngo Molnar <mingo@elte.hu>2010-04-02 20:03:08 +0200
commitc9494727cf293ae2ec66af57547a3e79c724fec2 (patch)
tree44ae197b64fa7530ee695a90ad31326dda06f1e1 /arch/x86/kernel/process.c
parent6427462bfa50f50dc6c088c07037264fcc73eca1 (diff)
parent42be79e37e264557f12860fa4cc84b4de3685954 (diff)
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Merge branch 'linus' into sched/core
Merge reason: update to latest upstream Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r--arch/x86/kernel/process.c34
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