From: Rafael J. Wysocki Date: Fri, 26 Sep 2025 15:47:14 +0000 (+0200) Subject: PM: runtime: Add auto-cleanup macros for "resume and get" operations X-Git-Tag: v6.18-rc1~49^2~1^3~4 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9a0abc39450a;p=thirdparty%2Fkernel%2Flinux.git PM: runtime: Add auto-cleanup macros for "resume and get" operations It is generally useful to be able to automatically drop a device's runtime PM usage counter incremented by runtime PM operations that resume a device and bump up its usage counter [1]. To that end, add guard definition macros allowing pm_runtime_put() and pm_runtime_put_autosuspend() to be used for the auto-cleanup in those cases. Simply put, a piece of code like below: pm_runtime_get_sync(dev); ..... pm_runtime_put(dev); return 0; can be transformed with guard() like: guard(pm_runtime_active)(dev); ..... return 0; (see the pm_runtime_put() call is gone). However, it is better to do proper error handling in the majority of cases, so doing something like this instead of the above is recommended: ACQUIRE(pm_runtime_active_try, pm)(dev); if (ACQUIRE_ERR(pm_runtime_active_try, &pm)) return -ENXIO; ..... return 0; In all of the cases in which runtime PM is known to be enabled for the given device or the device can be regarded as operational (and so it can be accessed) with runtime PM disabled, a piece of code like: ret = pm_runtime_resume_and_get(dev); if (ret < 0) return ret; ..... pm_runtime_put(dev); return 0; can be changed as follows: ACQUIRE(pm_runtime_active_try, pm)(dev); ret = ACQUIRE_ERR(pm_runtime_active_try, &pm); if (ret < 0) return ret; ..... return 0; (again, see the pm_runtime_put() call is gone). Still, if the device cannot be accessed unless runtime PM has been enabled for it, the pm_runtime_active_try_enabled guard variant needs to be used, that is (in the context of the example above): ACQUIRE(pm_runtime_active_try_enabled, pm)(dev); ret = ACQUIRE_ERR(pm_runtime_active_try_enabled, &pm); if (ret < 0) return ret; ..... return 0; When the original code calls pm_runtime_put_autosuspend(), use one of the "auto" guard variants, pm_runtime_active_auto/_try/_enabled, so for example, a piece of code like: ret = pm_runtime_resume_and_get(dev); if (ret < 0) return ret; ..... pm_runtime_put_autosuspend(dev); return 0; will become: ACQUIRE(pm_runtime_active_auto_try_enabled, pm)(dev); ret = ACQUIRE_ERR(pm_runtime_active_auto_try_enabled, &pm); if (ret < 0) return ret; ..... return 0; Note that the cases in which the return value of pm_runtime_get_sync() is checked can also be handled with the help of the new guard macros. For example, a piece of code like: ret = pm_runtime_get_sync(dev); if (ret < 0) { pm_runtime_put(dev); return ret; } ..... pm_runtime_put(dev); return 0; can be rewritten as: ACQUIRE(pm_runtime_active_auto_try_enabled, pm)(dev); ret = ACQUIRE_ERR(pm_runtime_active_auto_try_enabled, &pm); if (ret < 0) return ret; ..... return 0; or pm_runtime_get_active_try can be used if transparent handling of disabled runtime PM is desirable. Link: https://lore.kernel.org/linux-pm/878qimv24u.wl-tiwai@suse.de/ [1] Link: https://lore.kernel.org/linux-pm/20250926150613.000073a4@huawei.com/ Signed-off-by: Rafael J. Wysocki Acked-by: Dan Williams Reviewed-by: Takashi Iwai Link: https://patch.msgid.link/2238241.irdbgypaU6@rafael.j.wysocki [ rjw: Fixed leftovers from the previous version in the changelog ] Reviewed-by: Jonathan Cameron Reviewed-by: Dhruva Gole Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index faa68bf9ef3d..0fc825066ede 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -799,6 +799,8 @@ static int rpm_resume(struct device *dev, int rpmflags) if (dev->power.runtime_status == RPM_ACTIVE && dev->power.last_status == RPM_ACTIVE) retval = 1; + else if (rpmflags & RPM_TRANSPARENT) + goto out; else retval = -EACCES; } diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index d1ff76e0e2d0..e5426bdd0c9f 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -21,6 +21,7 @@ #define RPM_GET_PUT 0x04 /* Increment/decrement the usage_count */ #define RPM_AUTO 0x08 /* Use autosuspend_delay */ +#define RPM_TRANSPARENT 0x10 /* Succeed if runtime PM is disabled */ /* * Use this for defining a set of PM operations to be used in all situations @@ -512,6 +513,19 @@ static inline int pm_runtime_get_sync(struct device *dev) return __pm_runtime_resume(dev, RPM_GET_PUT); } +static inline int pm_runtime_get_active(struct device *dev, int rpmflags) +{ + int ret; + + ret = __pm_runtime_resume(dev, RPM_GET_PUT | rpmflags); + if (ret < 0) { + pm_runtime_put_noidle(dev); + return ret; + } + + return 0; +} + /** * pm_runtime_resume_and_get - Bump up usage counter of a device and resume it. * @dev: Target device. @@ -522,15 +536,7 @@ static inline int pm_runtime_get_sync(struct device *dev) */ static inline int pm_runtime_resume_and_get(struct device *dev) { - int ret; - - ret = __pm_runtime_resume(dev, RPM_GET_PUT); - if (ret < 0) { - pm_runtime_put_noidle(dev); - return ret; - } - - return 0; + return pm_runtime_get_active(dev, 0); } /** @@ -610,6 +616,26 @@ static inline int pm_runtime_put_autosuspend(struct device *dev) return __pm_runtime_put_autosuspend(dev); } +DEFINE_GUARD(pm_runtime_active, struct device *, + pm_runtime_get_sync(_T), pm_runtime_put(_T)); +DEFINE_GUARD(pm_runtime_active_auto, struct device *, + pm_runtime_get_sync(_T), pm_runtime_put_autosuspend(_T)); +/* + * Use the following guards with ACQUIRE()/ACQUIRE_ERR(). + * + * The difference between the "_try" and "_try_enabled" variants is that the + * former do not produce an error when runtime PM is disabled for the given + * device. + */ +DEFINE_GUARD_COND(pm_runtime_active, _try, + pm_runtime_get_active(_T, RPM_TRANSPARENT)) +DEFINE_GUARD_COND(pm_runtime_active, _try_enabled, + pm_runtime_resume_and_get(_T)) +DEFINE_GUARD_COND(pm_runtime_active_auto, _try, + pm_runtime_get_active(_T, RPM_TRANSPARENT)) +DEFINE_GUARD_COND(pm_runtime_active_auto, _try_enabled, + pm_runtime_resume_and_get(_T)) + /** * pm_runtime_put_sync - Drop device usage counter and run "idle check" if 0. * @dev: Target device.