On Thu, Dec 05, 2019 at 11:33:30AM +0100, Ulf Hansson wrote: > 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@xxxxxxxxxx> > --- > > Lorenzo, Sudeep, Rafael, Daniel, > > Note that, this patch is based upon a recently posted series [1] and the intent > is to queue it on top. I can fold it into the series and resend it all, if that > makes it easier for people. Just tell me what you prefer. > > Kind regards > Uffe > > [1] > https://patchwork.kernel.org/cover/11263735/ > > --- > drivers/cpuidle/cpuidle-psci.c | 45 +++++++++++++++++++++++++++++++++- > include/linux/cpuhotplug.h | 1 + > 2 files changed, 45 insertions(+), 1 deletion(-) > > diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c > index 835c7c3aa118..46b481c524cc 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; > > 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 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); I would make it a cpuhp_setup_state() call and remove if (cpu_online(cpu)) pm_runtime_get_sync_dev(dev); in check in psci_dt_attach_cpu(). Lorenzo > + 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) > { > @@ -161,9 +201,11 @@ static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv, > } > > /* Manage the deepest state via a dedicated enter-function. */ > - if (dev) > + if (dev) { > drv->states[state_count - 1].enter = > psci_enter_domain_idle_state; > + psci_cpuidle_use_cpuhp = true; > + } > > data->dev = dev; > > @@ -285,6 +327,7 @@ 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, > -- > 2.17.1 >
