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Diffstat (limited to 'arch/i386/kernel/cpu/amd.c')
-rw-r--r--arch/i386/kernel/cpu/amd.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/amd.c b/arch/i386/kernel/cpu/amd.c
index 41cfea57232..2d47db48297 100644
--- a/arch/i386/kernel/cpu/amd.c
+++ b/arch/i386/kernel/cpu/amd.c
@@ -22,6 +22,37 @@
extern void vide(void);
__asm__(".align 4\nvide: ret");
+#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)
{
u32 l, h;
@@ -241,6 +272,9 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
if (cpuid_eax(0x80000000) >= 0x80000006)
num_cache_leaves = 3;
+
+ if (amd_apic_timer_broken())
+ set_bit(X86_FEATURE_LAPIC_TIMER_BROKEN, c->x86_capability);
}
static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)