| Message ID | 20231228114157.104822-2-ulf.hansson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | PM: domains: Add helpers for multi PM domains to avoid open-coding | expand |
On 12/28/2023 3:41 AM, Ulf Hansson wrote: > Attaching/detaching of a device to multiple PM domains has started to > become a common operation for many drivers, typically during ->probe() and > ->remove(). In most cases, this has lead to lots of boilerplate code in the > drivers. > > To fixup up the situation, let's introduce a pair of helper functions, > dev_pm_domain_attach|detach_list(), that driver can use instead of the > open-coding. Note that, it seems reasonable to limit the support for these > helpers to DT based platforms, at it's the only valid use case for now. > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > drivers/base/power/common.c | 133 ++++++++++++++++++++++++++++++++++++ > include/linux/pm_domain.h | 38 +++++++++++ > 2 files changed, 171 insertions(+) > > diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c > index 44ec20918a4d..1ef51889fc6f 100644 > --- a/drivers/base/power/common.c > +++ b/drivers/base/power/common.c > @@ -167,6 +167,114 @@ struct device *dev_pm_domain_attach_by_name(struct device *dev, > } > EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_name); > > +/** > + * dev_pm_domain_attach_list - Associate a device with its PM domains. > + * @dev: The device used to lookup the PM domains for. > + * @data: The data used for attaching to the PM domains. > + * @list: An out-parameter with an allocated list of attached PM domains. > + * > + * This function helps to attach a device to its multiple PM domains. The > + * caller, which is typically a driver's probe function, may provide a list of > + * names for the PM domains that we should try to attach the device to, but it > + * may also provide an empty list, in case the attach should be done for all of > + * the available PM domains. > + * > + * Callers must ensure proper synchronization of this function with power > + * management callbacks. > + * > + * Returns the number of attached PM domains or a negative error code in case of > + * a failure. Note that, to detach the list of PM domains, the driver shall call > + * dev_pm_domain_detach_list(), typically during the remove phase. > + */ > +int dev_pm_domain_attach_list(struct device *dev, > + const struct dev_pm_domain_attach_data *data, > + struct dev_pm_domain_list **list) > +{ > + struct device_node *np = dev->of_node; > + struct dev_pm_domain_list *pds; > + struct device *pd_dev = NULL; > + int ret, i, num_pds = 0; > + bool by_id = true; > + u32 link_flags = data && data->pd_flags & PD_FLAG_NO_DEV_LINK ? 0 : > + DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME; > + > + if (dev->pm_domain) > + return -EEXIST; > + > + /* For now this is limited to OF based platforms. */ > + if (!np) > + return 0; > + > + if (data && data->pd_names) { > + num_pds = data->num_pd_names; > + by_id = false; > + } else { > + num_pds = of_count_phandle_with_args(np, "power-domains", > + "#power-domain-cells"); > + } > + > + if (num_pds <= 0) > + return 0; > + > + pds = devm_kzalloc(dev, sizeof(*pds), GFP_KERNEL); > + if (!pds) > + return -ENOMEM; > + > + pds->pd_devs = devm_kcalloc(dev, num_pds, sizeof(*pds->pd_devs), > + GFP_KERNEL); > + if (!pds->pd_devs) > + return -ENOMEM; > + > + pds->pd_links = devm_kcalloc(dev, num_pds, sizeof(*pds->pd_links), > + GFP_KERNEL); > + if (!pds->pd_links) > + return -ENOMEM; > + > + if (link_flags && data->pd_flags & PD_FLAG_DEV_LINK_ON) Since data is optional, this check results in crash if data is NULL. Thanks > + link_flags |= DL_FLAG_RPM_ACTIVE; > + > + for (i = 0; i < num_pds; i++) { > + if (by_id) > + pd_dev = dev_pm_domain_attach_by_id(dev, i); > + else > + pd_dev = dev_pm_domain_attach_by_name(dev, > + data->pd_names[i]); > + if (IS_ERR_OR_NULL(pd_dev)) { > + ret = pd_dev ? PTR_ERR(pd_dev) : -ENODEV; > + goto err_attach; > + } > + > + if (link_flags) { > + struct device_link *link; > + > + link = device_link_add(dev, pd_dev, link_flags); > + if (!link) { > + ret = -ENODEV; > + goto err_link; > + } > + > + pds->pd_links[i] = link; > + } > + > + pds->pd_devs[i] = pd_dev; > + } > + > + pds->num_pds = num_pds; > + *list = pds; > + return num_pds; > + > +err_link: > + dev_pm_domain_detach(pd_dev, true); > +err_attach: > + while (--i >= 0) { > + if (pds->pd_links[i]) > + device_link_del(pds->pd_links[i]); > + dev_pm_domain_detach(pds->pd_devs[i], true); > + } > + return ret; > +} > +EXPORT_SYMBOL_GPL(dev_pm_domain_attach_list); > + > /** > * dev_pm_domain_detach - Detach a device from its PM domain. > * @dev: Device to detach. > @@ -187,6 +295,31 @@ void dev_pm_domain_detach(struct device *dev, bool power_off) > } > EXPORT_SYMBOL_GPL(dev_pm_domain_detach); > > +/** > + * dev_pm_domain_detach_list - Detach a list of PM domains. > + * @list: The list of PM domains to detach. > + * > + * This function reverse the actions from dev_pm_domain_attach_list(). > + * Typically it should be invoked during the remove phase from drivers. > + * > + * Callers must ensure proper synchronization of this function with power > + * management callbacks. > + */ > +void dev_pm_domain_detach_list(struct dev_pm_domain_list *list) > +{ > + int i; > + > + if (!list) > + return; > + > + for (i = 0; i < list->num_pds; i++) { > + if (list->pd_links[i]) > + device_link_del(list->pd_links[i]); > + dev_pm_domain_detach(list->pd_devs[i], true); > + } > +} > +EXPORT_SYMBOL_GPL(dev_pm_domain_detach_list); > + > /** > * dev_pm_domain_start - Start the device through its PM domain. > * @dev: Device to start. > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index 34663d0d5c55..6b71fb69c349 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -19,6 +19,33 @@ > #include <linux/cpumask.h> > #include <linux/time64.h> > > +/* > + * Flags to control the behaviour when attaching a device to its PM domains. > + * > + * PD_FLAG_NO_DEV_LINK: As the default behaviour creates a device-link > + * for every PM domain that gets attached, this > + * flag can be used to skip that. > + * > + * PD_FLAG_DEV_LINK_ON: Add the DL_FLAG_RPM_ACTIVE to power-on the > + * supplier and its PM domain when creating the > + * device-links. > + * > + */ > +#define PD_FLAG_NO_DEV_LINK BIT(0) > +#define PD_FLAG_DEV_LINK_ON BIT(1) > + > +struct dev_pm_domain_attach_data { > + const char * const *pd_names; > + const u32 num_pd_names; > + const u32 pd_flags; > +}; > + > +struct dev_pm_domain_list { > + struct device **pd_devs; > + struct device_link **pd_links; > + u32 num_pds; > +}; > + > /* > * Flags to control the behaviour of a genpd. > * > @@ -432,7 +459,11 @@ struct device *dev_pm_domain_attach_by_id(struct device *dev, > unsigned int index); > struct device *dev_pm_domain_attach_by_name(struct device *dev, > const char *name); > +int dev_pm_domain_attach_list(struct device *dev, > + const struct dev_pm_domain_attach_data *data, > + struct dev_pm_domain_list **list); > void dev_pm_domain_detach(struct device *dev, bool power_off); > +void dev_pm_domain_detach_list(struct dev_pm_domain_list *list); > int dev_pm_domain_start(struct device *dev); > void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd); > int dev_pm_domain_set_performance_state(struct device *dev, unsigned int state); > @@ -451,7 +482,14 @@ static inline struct device *dev_pm_domain_attach_by_name(struct device *dev, > { > return NULL; > } > +static inline int dev_pm_domain_attach_list(struct device *dev, > + const struct dev_pm_domain_attach_data *data, > + struct dev_pm_domain_list **list) > +{ > + return 0; > +} > static inline void dev_pm_domain_detach(struct device *dev, bool power_off) {} > +static inline void dev_pm_domain_detach_list(struct dev_pm_domain_list *list) {} > static inline int dev_pm_domain_start(struct device *dev) > { > return 0;
On Fri, 29 Dec 2023 at 21:21, Nikunj Kela <quic_nkela@quicinc.com> wrote: > > > On 12/28/2023 3:41 AM, Ulf Hansson wrote: > > Attaching/detaching of a device to multiple PM domains has started to > > become a common operation for many drivers, typically during ->probe() and > > ->remove(). In most cases, this has lead to lots of boilerplate code in the > > drivers. > > > > To fixup up the situation, let's introduce a pair of helper functions, > > dev_pm_domain_attach|detach_list(), that driver can use instead of the > > open-coding. Note that, it seems reasonable to limit the support for these > > helpers to DT based platforms, at it's the only valid use case for now. > > > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > > --- > > drivers/base/power/common.c | 133 ++++++++++++++++++++++++++++++++++++ > > include/linux/pm_domain.h | 38 +++++++++++ > > 2 files changed, 171 insertions(+) > > > > diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c > > index 44ec20918a4d..1ef51889fc6f 100644 > > --- a/drivers/base/power/common.c > > +++ b/drivers/base/power/common.c > > @@ -167,6 +167,114 @@ struct device *dev_pm_domain_attach_by_name(struct device *dev, > > } > > EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_name); > > > > +/** > > + * dev_pm_domain_attach_list - Associate a device with its PM domains. > > + * @dev: The device used to lookup the PM domains for. > > + * @data: The data used for attaching to the PM domains. > > + * @list: An out-parameter with an allocated list of attached PM domains. > > + * > > + * This function helps to attach a device to its multiple PM domains. The > > + * caller, which is typically a driver's probe function, may provide a list of > > + * names for the PM domains that we should try to attach the device to, but it > > + * may also provide an empty list, in case the attach should be done for all of > > + * the available PM domains. > > + * > > + * Callers must ensure proper synchronization of this function with power > > + * management callbacks. > > + * > > + * Returns the number of attached PM domains or a negative error code in case of > > + * a failure. Note that, to detach the list of PM domains, the driver shall call > > + * dev_pm_domain_detach_list(), typically during the remove phase. > > + */ > > +int dev_pm_domain_attach_list(struct device *dev, > > + const struct dev_pm_domain_attach_data *data, > > + struct dev_pm_domain_list **list) > > +{ > > + struct device_node *np = dev->of_node; > > + struct dev_pm_domain_list *pds; > > + struct device *pd_dev = NULL; > > + int ret, i, num_pds = 0; > > + bool by_id = true; > > + u32 link_flags = data && data->pd_flags & PD_FLAG_NO_DEV_LINK ? 0 : > > + DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME; > > + > > + if (dev->pm_domain) > > + return -EEXIST; > > + > > + /* For now this is limited to OF based platforms. */ > > + if (!np) > > + return 0; > > + > > + if (data && data->pd_names) { > > + num_pds = data->num_pd_names; > > + by_id = false; > > + } else { > > + num_pds = of_count_phandle_with_args(np, "power-domains", > > + "#power-domain-cells"); > > + } > > + > > + if (num_pds <= 0) > > + return 0; > > + > > + pds = devm_kzalloc(dev, sizeof(*pds), GFP_KERNEL); > > + if (!pds) > > + return -ENOMEM; > > + > > + pds->pd_devs = devm_kcalloc(dev, num_pds, sizeof(*pds->pd_devs), > > + GFP_KERNEL); > > + if (!pds->pd_devs) > > + return -ENOMEM; > > + > > + pds->pd_links = devm_kcalloc(dev, num_pds, sizeof(*pds->pd_links), > > + GFP_KERNEL); > > + if (!pds->pd_links) > > + return -ENOMEM; > > + > > + if (link_flags && data->pd_flags & PD_FLAG_DEV_LINK_ON) > > Since data is optional, this check results in crash if data is NULL. Thanks Thanks for spotting this! I certainly tested that option too, but must have been on some earlier internal version. :-) I will iterate the series tomorrow to fix this up. [...] Kind regards Uffe
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c index 44ec20918a4d..1ef51889fc6f 100644 --- a/drivers/base/power/common.c +++ b/drivers/base/power/common.c @@ -167,6 +167,114 @@ struct device *dev_pm_domain_attach_by_name(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_name); +/** + * dev_pm_domain_attach_list - Associate a device with its PM domains. + * @dev: The device used to lookup the PM domains for. + * @data: The data used for attaching to the PM domains. + * @list: An out-parameter with an allocated list of attached PM domains. + * + * This function helps to attach a device to its multiple PM domains. The + * caller, which is typically a driver's probe function, may provide a list of + * names for the PM domains that we should try to attach the device to, but it + * may also provide an empty list, in case the attach should be done for all of + * the available PM domains. + * + * Callers must ensure proper synchronization of this function with power + * management callbacks. + * + * Returns the number of attached PM domains or a negative error code in case of + * a failure. Note that, to detach the list of PM domains, the driver shall call + * dev_pm_domain_detach_list(), typically during the remove phase. + */ +int dev_pm_domain_attach_list(struct device *dev, + const struct dev_pm_domain_attach_data *data, + struct dev_pm_domain_list **list) +{ + struct device_node *np = dev->of_node; + struct dev_pm_domain_list *pds; + struct device *pd_dev = NULL; + int ret, i, num_pds = 0; + bool by_id = true; + u32 link_flags = data && data->pd_flags & PD_FLAG_NO_DEV_LINK ? 0 : + DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME; + + if (dev->pm_domain) + return -EEXIST; + + /* For now this is limited to OF based platforms. */ + if (!np) + return 0; + + if (data && data->pd_names) { + num_pds = data->num_pd_names; + by_id = false; + } else { + num_pds = of_count_phandle_with_args(np, "power-domains", + "#power-domain-cells"); + } + + if (num_pds <= 0) + return 0; + + pds = devm_kzalloc(dev, sizeof(*pds), GFP_KERNEL); + if (!pds) + return -ENOMEM; + + pds->pd_devs = devm_kcalloc(dev, num_pds, sizeof(*pds->pd_devs), + GFP_KERNEL); + if (!pds->pd_devs) + return -ENOMEM; + + pds->pd_links = devm_kcalloc(dev, num_pds, sizeof(*pds->pd_links), + GFP_KERNEL); + if (!pds->pd_links) + return -ENOMEM; + + if (link_flags && data->pd_flags & PD_FLAG_DEV_LINK_ON) + link_flags |= DL_FLAG_RPM_ACTIVE; + + for (i = 0; i < num_pds; i++) { + if (by_id) + pd_dev = dev_pm_domain_attach_by_id(dev, i); + else + pd_dev = dev_pm_domain_attach_by_name(dev, + data->pd_names[i]); + if (IS_ERR_OR_NULL(pd_dev)) { + ret = pd_dev ? PTR_ERR(pd_dev) : -ENODEV; + goto err_attach; + } + + if (link_flags) { + struct device_link *link; + + link = device_link_add(dev, pd_dev, link_flags); + if (!link) { + ret = -ENODEV; + goto err_link; + } + + pds->pd_links[i] = link; + } + + pds->pd_devs[i] = pd_dev; + } + + pds->num_pds = num_pds; + *list = pds; + return num_pds; + +err_link: + dev_pm_domain_detach(pd_dev, true); +err_attach: + while (--i >= 0) { + if (pds->pd_links[i]) + device_link_del(pds->pd_links[i]); + dev_pm_domain_detach(pds->pd_devs[i], true); + } + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_domain_attach_list); + /** * dev_pm_domain_detach - Detach a device from its PM domain. * @dev: Device to detach. @@ -187,6 +295,31 @@ void dev_pm_domain_detach(struct device *dev, bool power_off) } EXPORT_SYMBOL_GPL(dev_pm_domain_detach); +/** + * dev_pm_domain_detach_list - Detach a list of PM domains. + * @list: The list of PM domains to detach. + * + * This function reverse the actions from dev_pm_domain_attach_list(). + * Typically it should be invoked during the remove phase from drivers. + * + * Callers must ensure proper synchronization of this function with power + * management callbacks. + */ +void dev_pm_domain_detach_list(struct dev_pm_domain_list *list) +{ + int i; + + if (!list) + return; + + for (i = 0; i < list->num_pds; i++) { + if (list->pd_links[i]) + device_link_del(list->pd_links[i]); + dev_pm_domain_detach(list->pd_devs[i], true); + } +} +EXPORT_SYMBOL_GPL(dev_pm_domain_detach_list); + /** * dev_pm_domain_start - Start the device through its PM domain. * @dev: Device to start. diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 34663d0d5c55..6b71fb69c349 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -19,6 +19,33 @@ #include <linux/cpumask.h> #include <linux/time64.h> +/* + * Flags to control the behaviour when attaching a device to its PM domains. + * + * PD_FLAG_NO_DEV_LINK: As the default behaviour creates a device-link + * for every PM domain that gets attached, this + * flag can be used to skip that. + * + * PD_FLAG_DEV_LINK_ON: Add the DL_FLAG_RPM_ACTIVE to power-on the + * supplier and its PM domain when creating the + * device-links. + * + */ +#define PD_FLAG_NO_DEV_LINK BIT(0) +#define PD_FLAG_DEV_LINK_ON BIT(1) + +struct dev_pm_domain_attach_data { + const char * const *pd_names; + const u32 num_pd_names; + const u32 pd_flags; +}; + +struct dev_pm_domain_list { + struct device **pd_devs; + struct device_link **pd_links; + u32 num_pds; +}; + /* * Flags to control the behaviour of a genpd. * @@ -432,7 +459,11 @@ struct device *dev_pm_domain_attach_by_id(struct device *dev, unsigned int index); struct device *dev_pm_domain_attach_by_name(struct device *dev, const char *name); +int dev_pm_domain_attach_list(struct device *dev, + const struct dev_pm_domain_attach_data *data, + struct dev_pm_domain_list **list); void dev_pm_domain_detach(struct device *dev, bool power_off); +void dev_pm_domain_detach_list(struct dev_pm_domain_list *list); int dev_pm_domain_start(struct device *dev); void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd); int dev_pm_domain_set_performance_state(struct device *dev, unsigned int state); @@ -451,7 +482,14 @@ static inline struct device *dev_pm_domain_attach_by_name(struct device *dev, { return NULL; } +static inline int dev_pm_domain_attach_list(struct device *dev, + const struct dev_pm_domain_attach_data *data, + struct dev_pm_domain_list **list) +{ + return 0; +} static inline void dev_pm_domain_detach(struct device *dev, bool power_off) {} +static inline void dev_pm_domain_detach_list(struct dev_pm_domain_list *list) {} static inline int dev_pm_domain_start(struct device *dev) { return 0;
Attaching/detaching of a device to multiple PM domains has started to become a common operation for many drivers, typically during ->probe() and ->remove(). In most cases, this has lead to lots of boilerplate code in the drivers. To fixup up the situation, let's introduce a pair of helper functions, dev_pm_domain_attach|detach_list(), that driver can use instead of the open-coding. Note that, it seems reasonable to limit the support for these helpers to DT based platforms, at it's the only valid use case for now. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/base/power/common.c | 133 ++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 38 +++++++++++ 2 files changed, 171 insertions(+)