From: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Introduce two new genpd helper functions, of_genpd_attach|detach_cpu(), which takes the CPU-number as an in-parameter. To attach a CPU to a genpd, of_genpd_attach_cpu() starts by fetching the struct device belonging to the CPU. Then it calls genpd_dev_pm_attach(), which via DT tries to hook up the CPU device to its corresponding PM domain. If it succeeds, of_genpd_attach_cpu() continues to prepare/enable runtime PM of the device. To detach a CPU from its PM domain, of_genpd_attach_cpu() reverse the operations made from of_genpd_attach_cpu(). However, first it checks that the CPU device has a valid PM domain pointer assigned, as to make sure it belongs to genpd. Cc: Lina Iyer <ilina@xxxxxxxxxxxxxx> Co-developed-by: Lina Iyer <lina.iyer@xxxxxxxxxx> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> [rplsssn@xxxxxxxxxxxxxx: Fix compilation issue] Signed-off-by: Raju P.L.S.S.S.N <rplsssn@xxxxxxxxxxxxxx> (am from https://patchwork.kernel.org/patch/10478167/) --- drivers/base/power/domain.c | 70 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 9 ++++++ 2 files changed, 79 insertions(+) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 4b57141..82973e3 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -6,6 +6,7 @@ * This file is released under the GPLv2. */ +#include <linux/cpu.h> #include <linux/delay.h> #include <linux/kernel.h> #include <linux/io.h> @@ -2398,6 +2399,75 @@ struct device *genpd_dev_pm_attach_by_name(struct device *dev, char *name) return genpd_dev_pm_attach_by_id(dev, index); } +/* + * of_genpd_attach_cpu() - Attach a CPU to its PM domain + * @cpu: The CPU to be attached. + * + * Parses the OF node of the CPU's device, to find a PM domain specifier. If + * such is found, attaches the CPU's device to the retrieved pm_domain ops and + * enables runtime PM for it. This to allow the CPU to be power managed through + * its PM domain. + * + * Returns zero when successfully attached the CPU's device to its PM domain, + * else a negative error code. + */ +int of_genpd_attach_cpu(int cpu) +{ + struct device *dev = get_cpu_device(cpu); + int ret; + + if (!dev) { + pr_warn("genpd: no dev for cpu%d\n", cpu); + return -ENODEV; + } + + ret = genpd_dev_pm_attach(dev); + if (ret != 1) { + dev_warn(dev, "genpd: attach cpu failed %d\n", ret); + return ret < 0 ? ret : -ENODEV; + } + + pm_runtime_irq_safe(dev); + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + + dev_info(dev, "genpd: attached cpu\n"); + return 0; +} +EXPORT_SYMBOL(of_genpd_attach_cpu); + +/** + * of_genpd_detach_cpu() - Detach a CPU from its PM domain + * @cpu: The CPU to be detached. + * + * Detach the CPU's device from its corresponding PM domain. If detaching is + * completed successfully, disable runtime PM and restore the runtime PM usage + * count for the CPU's device. + */ +void of_genpd_detach_cpu(int cpu) +{ + struct device *dev = get_cpu_device(cpu); + + if (!dev) { + pr_warn("genpd: no dev for cpu%d\n", cpu); + return; + } + + /* Check that the device is attached to a genpd. */ + if (!(dev->pm_domain && dev->pm_domain->detach == genpd_dev_pm_detach)) + return; + + genpd_dev_pm_detach(dev, true); + + pm_runtime_disable(dev); + pm_runtime_put_noidle(dev); + pm_runtime_reinit(dev); + + dev_info(dev, "genpd: detached cpu\n"); +} +EXPORT_SYMBOL(of_genpd_detach_cpu); + static const struct of_device_id idle_state_match[] = { { .compatible = "domain-idle-state", }, { } diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 776c546..48850af 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -241,6 +241,8 @@ struct device *genpd_dev_pm_attach_by_id(struct device *dev, unsigned int index); struct device *genpd_dev_pm_attach_by_name(struct device *dev, char *name); +int of_genpd_attach_cpu(int cpu); +void of_genpd_detach_cpu(int cpu); #else /* !CONFIG_PM_GENERIC_DOMAINS_OF */ static inline int of_genpd_add_provider_simple(struct device_node *np, struct generic_pm_domain *genpd) @@ -298,6 +300,13 @@ static inline struct device *genpd_dev_pm_attach_by_name(struct device *dev, return NULL; } +static inline int of_genpd_attach_cpu(int cpu) +{ + return -ENODEV; +} + +static inline void of_genpd_detach_cpu(int cpu) {} + static inline struct generic_pm_domain *of_genpd_remove_last(struct device_node *np) { -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation.
