diff options
Diffstat (limited to 'drivers/idle/intel_idle.c')
| -rw-r--r-- | drivers/idle/intel_idle.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 7acb32e7f817..4a5c4a44ffb1 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -62,6 +62,7 @@ #include <linux/notifier.h> #include <linux/cpu.h> #include <asm/mwait.h> +#include <asm/msr.h> #define INTEL_IDLE_VERSION "0.4" #define PREFIX "intel_idle: " @@ -85,6 +86,12 @@ static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state); static struct cpuidle_state *cpuidle_state_table; /* + * Hardware C-state auto-demotion may not always be optimal. + * Indicate which enable bits to clear here. + */ +static unsigned long long auto_demotion_disable_flags; + +/* * Set this flag for states where the HW flushes the TLB for us * and so we don't need cross-calls to keep it consistent. * If this flag is set, SW flushes the TLB, so even if the @@ -263,7 +270,7 @@ static void __setup_broadcast_timer(void *arg) clockevents_notify(reason, &cpu); } -static int __cpuinit setup_broadcast_cpuhp_notify(struct notifier_block *n, +static int setup_broadcast_cpuhp_notify(struct notifier_block *n, unsigned long action, void *hcpu) { int hotcpu = (unsigned long)hcpu; @@ -273,18 +280,23 @@ static int __cpuinit setup_broadcast_cpuhp_notify(struct notifier_block *n, smp_call_function_single(hotcpu, __setup_broadcast_timer, (void *)true, 1); break; - case CPU_DOWN_PREPARE: - smp_call_function_single(hotcpu, __setup_broadcast_timer, - (void *)false, 1); - break; } return NOTIFY_OK; } -static struct notifier_block __cpuinitdata setup_broadcast_notifier = { +static struct notifier_block setup_broadcast_notifier = { .notifier_call = setup_broadcast_cpuhp_notify, }; +static void auto_demotion_disable(void *dummy) +{ + unsigned long long msr_bits; + + rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits); + msr_bits &= ~auto_demotion_disable_flags; + wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits); +} + /* * intel_idle_probe() */ @@ -328,11 +340,17 @@ static int intel_idle_probe(void) case 0x25: /* Westmere */ case 0x2C: /* Westmere */ cpuidle_state_table = nehalem_cstates; + auto_demotion_disable_flags = + (NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE); break; case 0x1C: /* 28 - Atom Processor */ + cpuidle_state_table = atom_cstates; + break; + case 0x26: /* 38 - Lincroft Atom Processor */ cpuidle_state_table = atom_cstates; + auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE; break; case 0x2A: /* SNB */ @@ -440,6 +458,8 @@ static int intel_idle_cpuidle_devices_init(void) return -EIO; } } + if (auto_demotion_disable_flags) + smp_call_function(auto_demotion_disable, NULL, 1); return 0; } |