+ if (c->cpuid_level < MWAIT_INFO)
+ return 0;
+
+ cpuid(MWAIT_INFO, &eax, &ebx, &ecx, &edx);
+ /* Check, whether EDX has extended info about MWAIT */
+ if (!(ecx & MWAIT_ECX_EXTENDED_INFO))
+ return 1;
+
+ /*
+ * edx enumeratios MONITOR/MWAIT extensions. Check, whether
+ * C1 supports MWAIT
+ */
+ return (edx & MWAIT_EDX_C1);
+}
+
+/*
+ * Check for AMD CPUs, which have potentially C1E support
+ */
+static int __cpuinit check_c1e_idle(const struct cpuinfo_x86 *c)
+{
+ if (c->x86_vendor != X86_VENDOR_AMD)
+ return 0;
+
+ if (c->x86 < 0x0F)
+ return 0;
+
+ /* Family 0x0f models < rev F do not have C1E */
+ if (c->x86 == 0x0f && c->x86_model < 0x40)
+ return 0;
+
+ return 1;
+}
+
+/*
+ * C1E aware idle routine. We check for C1E active in the interrupt
+ * pending message MSR. If we detect C1E, then we handle it the same
+ * way as C3 power states (local apic timer and TSC stop)
+ */
+static void c1e_idle(void)
+{
+ static cpumask_t c1e_mask = CPU_MASK_NONE;
+ static int c1e_detected;
+
+ if (need_resched())
+ return;
+
+ if (!c1e_detected) {
+ u32 lo, hi;
+
+ rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
+ if (lo & K8_INTP_C1E_ACTIVE_MASK) {
+ c1e_detected = 1;
+ mark_tsc_unstable("TSC halt in C1E");
+ printk(KERN_INFO "System has C1E enabled\n");