diff options
| author | Ulf Hansson <ulf.hansson@linaro.org> | 2019-10-10 12:01:48 +0200 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2019-12-30 15:14:19 +0100 |
| commit | 4f086aab2e55fad866e115edb2f34a01d2baf678 (patch) | |
| tree | 6a2a6f1b0b614403e3d5e4f3752f64ed79253423 | |
| parent | f4d0883db49f39c7f87fb4602a415617e941f38d (diff) | |
cpuidle: psci: Support CPU hotplug for the hierarchical model
When the hierarchical CPU topology is used and when a CPU is put offline,
that CPU prevents its PM domain from being powered off, which is because
genpd observes the corresponding attached device as being active from a
runtime PM point of view. Furthermore, any potential master PM domains are
also prevented from being powered off.
To address this limitation, let's add add a new CPU hotplug state
(CPUHP_AP_CPU_PM_STARTING) and register up/down callbacks for it, which
allows us to deal with runtime PM accordingly.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
| -rw-r--r-- | drivers/cpuidle/cpuidle-psci.c | 45 | ||||
| -rw-r--r-- | include/linux/cpuhotplug.h | 1 |
2 files changed, 45 insertions, 1 deletions
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index 6e7804e697ed..9d779be27071 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -8,6 +8,7 @@ #define pr_fmt(fmt) "CPUidle PSCI: " fmt +#include <linux/cpuhotplug.h> #include <linux/cpuidle.h> #include <linux/cpumask.h> #include <linux/cpu_pm.h> @@ -31,6 +32,7 @@ struct psci_cpuidle_data { static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data); static DEFINE_PER_CPU(u32, domain_state); +static bool psci_cpuidle_use_cpuhp __initdata; static inline void psci_set_domain_state(u32 state) { @@ -72,6 +74,44 @@ static int psci_enter_domain_idle_state(struct cpuidle_device *dev, return ret; } +static int psci_idle_cpuhp_up(unsigned int cpu) +{ + struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev); + + if (pd_dev) + pm_runtime_get_sync(pd_dev); + + return 0; +} + +static int psci_idle_cpuhp_down(unsigned int cpu) +{ + struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev); + + if (pd_dev) { + pm_runtime_put_sync(pd_dev); + /* Clear domain state to start fresh at next online. */ + psci_set_domain_state(0); + } + + return 0; +} + +static void __init psci_idle_init_cpuhp(void) +{ + int err; + + if (!psci_cpuidle_use_cpuhp) + return; + + err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING, + "cpuidle/psci:online", + psci_idle_cpuhp_up, + psci_idle_cpuhp_down); + if (err) + pr_warn("Failed %d while setup cpuhp state\n", err); +} + static int psci_enter_idle_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, int idx) { @@ -166,9 +206,11 @@ static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv, * selection of a shared state for the domain, assumes the * domain states are all deeper states. */ - if (data->dev) + if (data->dev) { drv->states[state_count - 1].enter = psci_enter_domain_idle_state; + psci_cpuidle_use_cpuhp = true; + } } /* Idle states parsed correctly, store them in the per-cpu struct. */ @@ -289,6 +331,7 @@ static int __init psci_idle_init(void) goto out_fail; } + psci_idle_init_cpuhp(); return 0; out_fail: diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index e51ee772b9f5..01f04ed6ad92 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -95,6 +95,7 @@ enum cpuhp_state { CPUHP_AP_OFFLINE, CPUHP_AP_SCHED_STARTING, CPUHP_AP_RCUTREE_DYING, + CPUHP_AP_CPU_PM_STARTING, CPUHP_AP_IRQ_GIC_STARTING, CPUHP_AP_IRQ_HIP04_STARTING, CPUHP_AP_IRQ_ARMADA_XP_STARTING, |