On Thu, Aug 14, 2025 at 9:32 AM Yaxiong Tian <tianyaxiong@xxxxxxxxxx> wrote: > > Some drivers need to obtain the cpuidle_driver via CPU ID before the > cpuidle_device is registered. Therefore, this interface is added. > > Tested-by: Shaobo Huang <huangshaobo2075@xxxxxxxxxxxxxx> > Signed-off-by: Yaxiong Tian <tianyaxiong@xxxxxxxxxx> > Signed-off-by: Shaobo Huang <huangshaobo2075@xxxxxxxxxxxxxx> > Signed-off-by: Yinfeng Wang <wangyinfeng@xxxxxxxxxxxxxx> > Signed-off-by: Xu Wang<wangxu@xxxxxxxxxxxxxx> > --- > drivers/cpuidle/driver.c | 16 ++++++++++++++++ > include/linux/cpuidle.h | 4 ++++ > 2 files changed, 20 insertions(+) > > diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c > index 9bbfa594c442..8647f8165863 100644 > --- a/drivers/cpuidle/driver.c > +++ b/drivers/cpuidle/driver.c > @@ -353,6 +353,22 @@ struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev) > } > EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver); > > +/** > + * cpuidle_get_cpu_driver_by_cpu - return the driver registered for a CPU. > + * @cpu_num: a valid cpu num > + * > + * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered > + * for the CPU associated with @cpu. > + */ > +struct cpuidle_driver *cpuidle_get_cpu_driver_by_cpu(int cpu_num) > +{ > + if (cpu_num < 0 || cpu_num >= nr_cpu_ids) > + return NULL; What about changing the __cpuidle_get_cpu_driver() parameter type to unsigned int and also passing unsigned int to this function? The first check above can go away then. > + > + return __cpuidle_get_cpu_driver(cpu_num); > +} > +EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver_by_cpu); > + > /** > * cpuidle_driver_state_disabled - Disable or enable an idle state > * @drv: cpuidle driver owning the state > diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h > index a9ee4fe55dcf..aebbaae6a501 100644 > --- a/include/linux/cpuidle.h > +++ b/include/linux/cpuidle.h > @@ -200,6 +200,7 @@ extern void cpuidle_disable_device(struct cpuidle_device *dev); > extern int cpuidle_play_dead(void); > > extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); > +extern struct cpuidle_driver *cpuidle_get_cpu_driver_by_cpu(int cpu_num); > static inline struct cpuidle_device *cpuidle_get_device(void) > {return __this_cpu_read(cpuidle_devices); } > #else > @@ -240,6 +241,9 @@ static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } > static inline int cpuidle_play_dead(void) {return -ENODEV; } > static inline struct cpuidle_driver *cpuidle_get_cpu_driver( > struct cpuidle_device *dev) {return NULL; } > + > +static inline struct cpuidle_driver *cpuidle_get_cpu_driver_by_cpu( > + int cpu_num) {return NULL; }; > static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } > #endif > > -- > 2.25.1 >