From 14796fca2bd22acc73dd0887248d003b0f441d08 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Tue, 18 Jan 2011 20:48:27 -0500 Subject: intel_idle: disable NHM/WSM HW C-state auto-demotion Hardware C-state auto-demotion is a mechanism where the HW overrides the OS C-state request, instead demoting to a shallower state, which is less expensive, but saves less power. Modern Linux should generally get exactly the states it requests. In particular, when a CPU is taken off-line, it must not be demoted, else it can prevent the entire package from reaching deep C-states. https://bugzilla.kernel.org/show_bug.cgi?id=25252 Signed-off-by: Len Brown --- drivers/idle/intel_idle.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'drivers/idle/intel_idle.c') diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 1fa091e05690..32b25bcaf865 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -62,6 +62,7 @@ #include #include #include +#include #define INTEL_IDLE_VERSION "0.4" #define PREFIX "intel_idle: " @@ -84,6 +85,12 @@ 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. @@ -281,6 +288,15 @@ 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() */ @@ -324,6 +340,8 @@ 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 */ @@ -436,6 +454,8 @@ 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; } -- cgit v1.2.3 From bfb53ccf1c734b1907df7189eef4c08489827951 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Wed, 16 Feb 2011 01:32:48 -0500 Subject: intel_idle: disable Atom/Lincroft HW C-state auto-demotion Just as we had to disable auto-demotion for NHM/WSM, we need to do the same for Atom (Lincroft version). In particular, auto-demotion will prevent Lincroft from entering the S0i3 idle power saving state. https://bugzilla.kernel.org/show_bug.cgi?id=25252 Signed-off-by: Len Brown --- arch/x86/include/asm/msr-index.h | 1 + drivers/idle/intel_idle.c | 4 ++++ 2 files changed, 5 insertions(+) (limited to 'drivers/idle/intel_idle.c') diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index b75eeab2b1ea..43a18c77676d 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -39,6 +39,7 @@ #define MSR_NHM_SNB_PKG_CST_CFG_CTL 0x000000e2 #define NHM_C3_AUTO_DEMOTE (1UL << 25) #define NHM_C1_AUTO_DEMOTE (1UL << 26) +#define ATM_LNC_C6_AUTO_DEMOTE (1UL << 25) #define MSR_MTRRcap 0x000000fe #define MSR_IA32_BBL_CR_CTL 0x00000119 diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 32b25bcaf865..4a5c4a44ffb1 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -345,8 +345,12 @@ static int intel_idle_probe(void) 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 */ -- cgit v1.2.3 From 15e123e5d7e8ee9ba3717e743d8eb5fd0fe57712 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Sun, 27 Feb 2011 22:36:43 +0100 Subject: intel_idle: Rename cpuidle states Userspace apps might have to cut off parts off the idle state name for display reasons. Switch NHM-C1 to C1-NHM (and others) so that a cut off name is unique and makes sense to the user. Signed-off-by: Thomas Renninger CC: lenb@kernel.org Signed-off-by: Len Brown --- drivers/idle/intel_idle.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) (limited to 'drivers/idle/intel_idle.c') diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 4a5c4a44ffb1..a46dddf61078 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -107,7 +107,7 @@ static unsigned long long auto_demotion_disable_flags; static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { { /* MWAIT C0 */ }, { /* MWAIT C1 */ - .name = "NHM-C1", + .name = "C1-NHM", .desc = "MWAIT 0x00", .driver_data = (void *) 0x00, .flags = CPUIDLE_FLAG_TIME_VALID, @@ -115,7 +115,7 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { .target_residency = 6, .enter = &intel_idle }, { /* MWAIT C2 */ - .name = "NHM-C3", + .name = "C3-NHM", .desc = "MWAIT 0x10", .driver_data = (void *) 0x10, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -123,7 +123,7 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { .target_residency = 80, .enter = &intel_idle }, { /* MWAIT C3 */ - .name = "NHM-C6", + .name = "C6-NHM", .desc = "MWAIT 0x20", .driver_data = (void *) 0x20, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -135,7 +135,7 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = { { /* MWAIT C0 */ }, { /* MWAIT C1 */ - .name = "SNB-C1", + .name = "C1-SNB", .desc = "MWAIT 0x00", .driver_data = (void *) 0x00, .flags = CPUIDLE_FLAG_TIME_VALID, @@ -143,7 +143,7 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = { .target_residency = 1, .enter = &intel_idle }, { /* MWAIT C2 */ - .name = "SNB-C3", + .name = "C3-SNB", .desc = "MWAIT 0x10", .driver_data = (void *) 0x10, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -151,7 +151,7 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = { .target_residency = 211, .enter = &intel_idle }, { /* MWAIT C3 */ - .name = "SNB-C6", + .name = "C6-SNB", .desc = "MWAIT 0x20", .driver_data = (void *) 0x20, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -159,7 +159,7 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = { .target_residency = 345, .enter = &intel_idle }, { /* MWAIT C4 */ - .name = "SNB-C7", + .name = "C7-SNB", .desc = "MWAIT 0x30", .driver_data = (void *) 0x30, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -171,7 +171,7 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = { static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { { /* MWAIT C0 */ }, { /* MWAIT C1 */ - .name = "ATM-C1", + .name = "C1-ATM", .desc = "MWAIT 0x00", .driver_data = (void *) 0x00, .flags = CPUIDLE_FLAG_TIME_VALID, @@ -179,7 +179,7 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { .target_residency = 4, .enter = &intel_idle }, { /* MWAIT C2 */ - .name = "ATM-C2", + .name = "C2-ATM", .desc = "MWAIT 0x10", .driver_data = (void *) 0x10, .flags = CPUIDLE_FLAG_TIME_VALID, @@ -188,7 +188,7 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { .enter = &intel_idle }, { /* MWAIT C3 */ }, { /* MWAIT C4 */ - .name = "ATM-C4", + .name = "C4-ATM", .desc = "MWAIT 0x30", .driver_data = (void *) 0x30, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, @@ -197,7 +197,7 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { .enter = &intel_idle }, { /* MWAIT C5 */ }, { /* MWAIT C6 */ - .name = "ATM-C6", + .name = "C6-ATM", .desc = "MWAIT 0x52", .driver_data = (void *) 0x52, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, -- cgit v1.2.3