From dc2251bf98c66db3f4e055b751968f0871037ae4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 23 Aug 2017 23:19:57 +0200 Subject: cpuidle: Eliminate the CPUIDLE_DRIVER_STATE_START symbol On some architectures the first (index 0) idle state is a polling one and it doesn't really save energy, so there is the CPUIDLE_DRIVER_STATE_START symbol allowing some pieces of cpuidle code to avoid using that state. However, this makes the code rather hard to follow. It is better to explicitly avoid the polling state, so add a new cpuidle state flag CPUIDLE_FLAG_POLLING to mark it and make the relevant code check that flag for the first state instead of using the CPUIDLE_DRIVER_STATE_START symbol. In the ACPI processor driver that cannot always rely on the state flags (like before the states table has been set up) define a new internal symbol ACPI_IDLE_STATE_START equivalent to the CPUIDLE_DRIVER_STATE_START one and drop the latter. Signed-off-by: Rafael J. Wysocki Tested-by: Sudeep Holla Acked-by: Daniel Lezcano --- drivers/acpi/processor_idle.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 5c8aa9cf62d7..39a01ea7a46d 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -48,6 +48,8 @@ #define _COMPONENT ACPI_PROCESSOR_COMPONENT ACPI_MODULE_NAME("processor_idle"); +#define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0) + static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; module_param(max_cstate, uint, 0000); static unsigned int nocst __read_mostly; @@ -761,7 +763,7 @@ static int acpi_idle_enter(struct cpuidle_device *dev, if (cx->type != ACPI_STATE_C1) { if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { - index = CPUIDLE_DRIVER_STATE_START; + index = ACPI_IDLE_STATE_START; cx = per_cpu(acpi_cstate[index], dev->cpu); } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { if (cx->bm_sts_skip || !acpi_idle_bm_check()) { @@ -813,7 +815,7 @@ static void acpi_idle_enter_freeze(struct cpuidle_device *dev, static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, struct cpuidle_device *dev) { - int i, count = CPUIDLE_DRIVER_STATE_START; + int i, count = ACPI_IDLE_STATE_START; struct acpi_processor_cx *cx; if (max_cstate == 0) @@ -840,7 +842,7 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, static int acpi_processor_setup_cstates(struct acpi_processor *pr) { - int i, count = CPUIDLE_DRIVER_STATE_START; + int i, count = ACPI_IDLE_STATE_START; struct acpi_processor_cx *cx; struct cpuidle_state *state; struct cpuidle_driver *drv = &acpi_idle_driver; @@ -1291,7 +1293,7 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) return -EINVAL; drv->safe_state_index = -1; - for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) { + for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { drv->states[i].name[0] = '\0'; drv->states[i].desc[0] = '\0'; } -- cgit v1.2.3 From 1b39e3f813b4685c7a30ae964d5529a1b0e3a286 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 29 Aug 2017 03:14:37 +0200 Subject: cpuidle: Make drivers initialize polling state Make the drivers that want to include the polling state into their states table initialize it explicitly and drop the initialization of it (which in fact is conditional, but that is not obvious from the code) from the core. Signed-off-by: Rafael J. Wysocki Tested-by: Sudeep Holla Acked-by: Daniel Lezcano --- drivers/acpi/processor_idle.c | 9 ++++++++- drivers/cpuidle/driver.c | 2 -- drivers/cpuidle/poll_state.c | 3 ++- drivers/idle/intel_idle.c | 1 + include/linux/cpuidle.h | 4 ++-- 5 files changed, 13 insertions(+), 6 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 39a01ea7a46d..df38e81cc672 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -842,7 +842,7 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, static int acpi_processor_setup_cstates(struct acpi_processor *pr) { - int i, count = ACPI_IDLE_STATE_START; + int i, count; struct acpi_processor_cx *cx; struct cpuidle_state *state; struct cpuidle_driver *drv = &acpi_idle_driver; @@ -850,6 +850,13 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr) if (max_cstate == 0) max_cstate = 1; + if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) { + cpuidle_poll_state_init(drv); + count = 1; + } else { + count = 0; + } + for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { cx = &pr->power.states[i]; diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 6f694c86f3fa..dc32f34e68d9 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -216,8 +216,6 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv) on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer, (void *)1, 1); - poll_idle_init(drv); - return 0; } diff --git a/drivers/cpuidle/poll_state.c b/drivers/cpuidle/poll_state.c index 0db4f7273952..7416b16287de 100644 --- a/drivers/cpuidle/poll_state.c +++ b/drivers/cpuidle/poll_state.c @@ -21,7 +21,7 @@ static int __cpuidle poll_idle(struct cpuidle_device *dev, return index; } -void poll_idle_init(struct cpuidle_driver *drv) +void cpuidle_poll_state_init(struct cpuidle_driver *drv) { struct cpuidle_state *state = &drv->states[0]; @@ -34,3 +34,4 @@ void poll_idle_init(struct cpuidle_driver *drv) state->disabled = false; state->flags = CPUIDLE_FLAG_POLLING; } +EXPORT_SYMBOL_GPL(cpuidle_poll_state_init); diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index c2ae819a871c..7bf8739e33bc 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1331,6 +1331,7 @@ static void __init intel_idle_cpuidle_driver_init(void) intel_idle_state_table_update(); + cpuidle_poll_state_init(drv); drv->state_count = 1; for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) { diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 561bc5365067..5baacd3a0559 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -226,9 +226,9 @@ static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, #endif #ifdef CONFIG_ARCH_HAS_CPU_RELAX -void poll_idle_init(struct cpuidle_driver *drv); +void cpuidle_poll_state_init(struct cpuidle_driver *drv); #else -static void poll_idle_init(struct cpuidle_driver *drv) {} +static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} #endif /****************************** -- cgit v1.2.3