From c8381cc3d8a9cc6c80f65bf60863c776651f245c Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 15 Oct 2010 20:43:06 -0400 Subject: [PATCH 1/5] intel_idle: simplify test for leave_mm() A run-time test to invoke leave_mm() for the deepest supported C-state is redundant, since the appropriate C-states already have flags with CPUIDLE_FLAG_TLB_FLUSHED set. Signed-off-by: Len Brown --- drivers/idle/intel_idle.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index c37ef64d1465..ad0fb0182b4c 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -186,13 +186,10 @@ static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state) local_irq_disable(); /* - * If the state flag indicates that the TLB will be flushed or if this - * is the deepest c-state supported, do a voluntary leave mm to avoid - * costly and mostly unnecessary wakeups for flushing the user TLB's - * associated with the active mm. + * leave_mm() to avoid costly and often unnecessary wakeups + * for flushing the user TLB's associated with the active mm. */ - if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED || - (&dev->states[dev->state_count - 1] == state)) + if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED) leave_mm(cpu); if (!(lapic_timer_reliable_states & (1 << (cstate)))) From dea44c6b7df7f8bb67cb059b4c14b24288c4cd04 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 15 Oct 2010 21:23:25 -0400 Subject: [PATCH 2/5] intel_idle: delete bogus data from cpuidle_state.power_usage The mW data in this field is a total fabrication and serves no purpose other than to mislead those who might see it in sysfs. Delete it. Signed-off-by: Len Brown --- drivers/idle/intel_idle.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index ad0fb0182b4c..8e35c89d0927 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -101,7 +101,6 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { .driver_data = (void *) 0x00, .flags = CPUIDLE_FLAG_TIME_VALID, .exit_latency = 3, - .power_usage = 1000, .target_residency = 6, .enter = &intel_idle }, { /* MWAIT C2 */ @@ -110,7 +109,6 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { .driver_data = (void *) 0x10, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 20, - .power_usage = 500, .target_residency = 80, .enter = &intel_idle }, { /* MWAIT C3 */ @@ -119,7 +117,6 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { .driver_data = (void *) 0x20, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 200, - .power_usage = 350, .target_residency = 800, .enter = &intel_idle }, }; @@ -132,7 +129,6 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { .driver_data = (void *) 0x00, .flags = CPUIDLE_FLAG_TIME_VALID, .exit_latency = 1, - .power_usage = 1000, .target_residency = 4, .enter = &intel_idle }, { /* MWAIT C2 */ @@ -141,7 +137,6 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { .driver_data = (void *) 0x10, .flags = CPUIDLE_FLAG_TIME_VALID, .exit_latency = 20, - .power_usage = 500, .target_residency = 80, .enter = &intel_idle }, { /* MWAIT C3 */ }, @@ -151,7 +146,6 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { .driver_data = (void *) 0x30, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 100, - .power_usage = 250, .target_residency = 400, .enter = &intel_idle }, { /* MWAIT C5 */ }, @@ -161,7 +155,6 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { .driver_data = (void *) 0x52, .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 140, - .power_usage = 150, .target_residency = 560, .enter = &intel_idle }, }; From 0f3f164d9794f57d8afb033819f508a486c1304d Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 15 Oct 2010 21:25:02 -0400 Subject: [PATCH 3/5] acpi_idle: delete bogus data from cpuidle_state.power_usage The mW data in this field comes from AML _CST, which was typed in by a BIOS writer, and is thus considered unreliable. Linux does not use it for making any decisions. We do display it in sysfs where somebody might read it and assume it is meaningful, so delete it. Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index f4428e82b352..07a8bb6506f7 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1013,7 +1013,6 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); state->exit_latency = cx->latency; state->target_residency = cx->latency * latency_factor; - state->power_usage = cx->power; state->flags = 0; switch (cx->type) { From d13780d439d08a57c87c1a07b6e76ddde61da1aa Mon Sep 17 00:00:00 2001 From: Len Brown Date: Wed, 7 Jul 2010 00:12:03 -0400 Subject: [PATCH 4/5] intel_idle: add initial Sandy Bridge support Signed-off-by: Len Brown --- drivers/idle/intel_idle.c | 44 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 43 insertions(+), 1 deletion(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 54f0fb4cd5d2..84476be69b38 100755 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -83,7 +83,7 @@ static unsigned int substates; static int (*choose_substate)(int); /* Reliable LAPIC Timer States, bit 1 for C1 etc. */ -static unsigned int lapic_timer_reliable_states; +static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */ static struct cpuidle_device *intel_idle_cpuidle_devices; static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state); @@ -126,6 +126,42 @@ static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { .enter = &intel_idle }, }; +static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = { + { /* MWAIT C0 */ }, + { /* MWAIT C1 */ + .name = "SNB-C1", + .desc = "MWAIT 0x00", + .driver_data = (void *) 0x00, + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 1, + .target_residency = 4, + .enter = &intel_idle }, + { /* MWAIT C2 */ + .name = "SNB-C3", + .desc = "MWAIT 0x10", + .driver_data = (void *) 0x10, + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 80, + .target_residency = 160, + .enter = &intel_idle }, + { /* MWAIT C3 */ + .name = "SNB-C6", + .desc = "MWAIT 0x20", + .driver_data = (void *) 0x20, + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 104, + .target_residency = 208, + .enter = &intel_idle }, + { /* MWAIT C4 */ + .name = "SNB-C7", + .desc = "MWAIT 0x30", + .driver_data = (void *) 0x30, + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 109, + .target_residency = 300, + .enter = &intel_idle }, +}; + static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { { /* MWAIT C0 */ }, { /* MWAIT C1 */ @@ -312,6 +348,12 @@ static int intel_idle_probe(void) cpuidle_state_table = atom_cstates; choose_substate = choose_zero_substate; break; + + case 0x2A: /* SNB */ + case 0x2D: /* SNB Xeon */ + cpuidle_state_table = snb_cstates; + choose_substate = choose_zero_substate; + break; #ifdef FUTURE_USE case 0x17: /* 23 - Core 2 Duo */ lapic_timer_reliable_states = (1 << 2) | (1 << 1); /* C2, C1 */ From c25d29952b2a8c9aaf00e081c9162a0e383030cd Mon Sep 17 00:00:00 2001 From: Len Brown Date: Sat, 23 Oct 2010 23:25:53 -0400 Subject: [PATCH 5/5] intel_idle: do not use the LAPIC timer for ATOM C2 If we use the LAPIC timer during ATOM C2 on some nvidia chisets, the system stalls. https://bugzilla.kernel.org/show_bug.cgi?id=21032 Signed-off-by: Len Brown --- drivers/idle/intel_idle.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index d310590598f9..b68d594b8432 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -302,7 +302,7 @@ static int intel_idle_probe(void) case 0x1C: /* 28 - Atom Processor */ case 0x26: /* 38 - Lincroft Atom Processor */ - lapic_timer_reliable_states = (1 << 2) | (1 << 1); /* C2, C1 */ + lapic_timer_reliable_states = (1 << 1); /* C1 */ cpuidle_state_table = atom_cstates; break;