From a4e6512a79d8486dccf3e8b066e5d6bd5ff95446 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Tue, 25 Nov 2025 12:26:42 +0100 Subject: PM: QoS: Introduce a CPU system wakeup QoS limit Some platforms supports multiple low power states for CPUs that can be used when entering system-wide suspend. Currently we are always selecting the deepest possible state for the CPUs, which can break the system wakeup latency constraint that may be required for a use case. Let's take the first step towards addressing this problem, by introducing an interface for user space, that allows us to specify the CPU system wakeup QoS limit. Subsequent changes will start taking into account the new QoS limit. Reviewed-by: Dhruva Gole Reviewed-by: Kevin Hilman (TI) Tested-by: Kevin Hilman (TI) Signed-off-by: Ulf Hansson Link: https://patch.msgid.link/20251125112650.329269-2-ulf.hansson@linaro.org Signed-off-by: Rafael J. Wysocki --- include/linux/pm_qos.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include') diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 4a69d4af3ff8..6cea4455f867 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -162,6 +162,15 @@ static inline void cpu_latency_qos_update_request(struct pm_qos_request *req, static inline void cpu_latency_qos_remove_request(struct pm_qos_request *req) {} #endif +#ifdef CONFIG_PM_QOS_CPU_SYSTEM_WAKEUP +s32 cpu_wakeup_latency_qos_limit(void); +#else +static inline s32 cpu_wakeup_latency_qos_limit(void) +{ + return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; +} +#endif + #ifdef CONFIG_PM enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask); enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask); -- cgit v1.2.3 From 8e7de6dc420979f4e4443807b71dcc8b72d8c4a9 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Tue, 25 Nov 2025 12:26:43 +0100 Subject: pmdomain: Respect the CPU system wakeup QoS limit for s2idle A CPU system wakeup QoS limit may have been requested by user space. To avoid breaking this constraint when entering a low power state during s2idle through genpd, let's extend the corresponding genpd governor for CPUs. More precisely, during s2idle let the genpd governor select a suitable domain idle state, by taking into account the QoS limit. Reviewed-by: Dhruva Gole Reviewed-by: Kevin Hilman (TI) Tested-by: Kevin Hilman (TI) Signed-off-by: Ulf Hansson Link: https://patch.msgid.link/20251125112650.329269-3-ulf.hansson@linaro.org Signed-off-by: Rafael J. Wysocki --- include/linux/pm_domain.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index f67a2cb7d781..93ba0143ca47 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -153,6 +153,7 @@ enum genpd_sync_state { }; struct dev_power_governor { + bool (*system_power_down_ok)(struct dev_pm_domain *domain); bool (*power_down_ok)(struct dev_pm_domain *domain); bool (*suspend_ok)(struct device *dev); }; -- cgit v1.2.3 From 99b42445f4a4aaff75eca24dfc9e6e376292dd48 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Tue, 25 Nov 2025 12:26:45 +0100 Subject: sched: idle: Respect the CPU system wakeup QoS limit for s2idle A CPU system wakeup QoS limit may have been requested by user space. To avoid breaking this constraint when entering a low power state during s2idle, let's start to take into account the QoS limit. Acked-by: Peter Zijlstra (Intel) Reviewed-by: Dhruva Gole Reviewed-by: Kevin Hilman (TI) Tested-by: Kevin Hilman (TI) Signed-off-by: Ulf Hansson Link: https://patch.msgid.link/20251125112650.329269-5-ulf.hansson@linaro.org Signed-off-by: Rafael J. Wysocki --- include/linux/cpuidle.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index a9ee4fe55dcf..4073690504a7 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -248,7 +248,8 @@ extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev, u64 latency_limit_ns); extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, - struct cpuidle_device *dev); + struct cpuidle_device *dev, + u64 latency_limit_ns); extern void cpuidle_use_deepest_state(u64 latency_limit_ns); #else static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, @@ -256,7 +257,8 @@ static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, u64 latency_limit_ns) {return -ENODEV; } static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, - struct cpuidle_device *dev) + struct cpuidle_device *dev, + u64 latency_limit_ns) {return -ENODEV; } static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) { -- cgit v1.2.3