/*
* AMD Erratum 400 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 amd_e400_idle(void)
{
if (!amd_e400_c1e_detected) {
u32 lo, hi;
rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
if (lo & K8_INTP_C1E_ACTIVE_MASK) {
amd_e400_c1e_detected = true;
if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
mark_tsc_unstable("TSC halt in AMD C1E");
pr_info("System has AMD C1E enabled\n");
}
}
if (amd_e400_c1e_detected) {
int cpu = smp_processor_id();
if (!cpumask_test_cpu(cpu, amd_e400_c1e_mask)) {
cpumask_set_cpu(cpu, amd_e400_c1e_mask);
/* Force broadcast so ACPI can not interfere. */
tick_broadcast_force();
pr_info("Switch to broadcast mode on CPU%d\n", cpu);
}
tick_broadcast_enter();
default_idle();
/*
* The switch back from broadcast mode needs to be
* called with interrupts disabled.
*/
local_irq_disable();
tick_broadcast_exit();
local_irq_enable();
} else
default_idle();
}
void amd_e400_c1e_apic_setup(void)
{
if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) {
pr_info("Switch to broadcast mode on CPU%d\n", smp_processor_id());
local_irq_disable();
tick_broadcast_force();
local_irq_enable();
}
}