From aa276e1cafb3ce9d01d1e837bcd67e92616013ac Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 9 Jun 2008 19:15:00 +0200 Subject: x86, clockevents: add C1E aware idle function C1E on AMD machines is like C3 but without control from the OS. Up to now we disabled the local apic timer for those machines as it stops when the CPU goes into C1E. This excludes those machines from high resolution timers / dynamic ticks, which hurts especially X2 based laptops. The current boot time C1E detection has another, more serious flaw as well: some BIOSes do not enable C1E until the ACPI processor module is loaded. This causes systems to stop working after that point. To work nicely with C1E enabled machines we use a separate idle function, which checks on idle entry whether C1E was enabled in the Interrupt Pending Message MSR. This allows us to do timer broadcasting for C1E and covers the late enablement of C1E as well. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/amd_64.c | 25 ------------------------- 1 file changed, 25 deletions(-) (limited to 'arch/x86/kernel/cpu/amd_64.c') diff --git a/arch/x86/kernel/cpu/amd_64.c b/arch/x86/kernel/cpu/amd_64.c index f5fc161d8f2..f8d20588bde 100644 --- a/arch/x86/kernel/cpu/amd_64.c +++ b/arch/x86/kernel/cpu/amd_64.c @@ -110,28 +110,6 @@ static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c) #endif } -/* AMD systems with C1E don't have a working lAPIC timer. Check for that. */ -static __cpuinit int amd_apic_timer_broken(struct cpuinfo_x86 *c) -{ - u32 lo, hi; - - if (c->x86 < 0x0F) - return 0; - - /* Family 0x0f models < rev F do not have this MSR */ - if (c->x86 == 0x0f && c->x86_model < 0x40) - return 0; - - rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi); - if (lo & K8_INTP_C1E_ACTIVE_MASK) { - if (smp_processor_id() != boot_cpu_physical_apicid) - printk(KERN_INFO "AMD C1E detected late. " - "Force timer broadcast.\n"); - return 1; - } - return 0; -} - void __cpuinit early_init_amd(struct cpuinfo_x86 *c) { early_init_amd_mc(c); @@ -212,9 +190,6 @@ void __cpuinit init_amd(struct cpuinfo_x86 *c) if (c->x86 == 0x10) amd_enable_pci_ext_cfg(c); - if (amd_apic_timer_broken(c)) - disable_apic_timer = 1; - if (c == &boot_cpu_data && c->x86 >= 0xf && c->x86 <= 0x11) { unsigned long long tseg; -- cgit v1.2.3