| Message ID | 1471340976-5379-9-git-send-email-jonathanh@nvidia.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 16 August 2016 at 11:49, Jon Hunter <jonathanh@nvidia.com> wrote: > The genpd framework allows users to add PM domains via the pm_genpd_init() > function, however, there is no corresponding function to remove a PM > domain. For most devices this may be fine as the PM domains are never > removed, however, for devices that wish to populate the PM domains from > within a driver, having the ability to remove a PM domain if the probing > of the device fails or the driver is unloaded is necessary. > > Add the function pm_genpd_remove() to remove a PM domain by referencing > it's generic_pm_domain structure. > > PM domains can only be removed if they are not a parent domain to > another PM domain and have no devices associated with them. I think we should also check if the there's is a provider registered for the genpd, as it should also prevent the genpd from being removed. Right? I noticed that you are adding the ->provider pointer to the genpd struct in patch 9/10. Perhaps re-structure $subject patch and 9/10 a bit to deal with this, so we can add the pm_genpd_remove() API in a more safe manner. Kind regards Uffe > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > --- > drivers/base/power/domain.c | 46 +++++++++++++++++++++++++++++++++++++++++++++ > include/linux/pm_domain.h | 5 +++++ > 2 files changed, 51 insertions(+) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 7ce4608bbbe0..72b973539205 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -1356,6 +1356,52 @@ int pm_genpd_init(struct generic_pm_domain *genpd, > } > EXPORT_SYMBOL_GPL(pm_genpd_init); > > +/** > + * pm_genpd_remove - Remove a generic I/O PM domain > + * @genpd: Pointer to PM domain that is to be removed. > + * > + * To remove the PM domain, this function: > + * - Removes the PM domain as a subdomain to any parent domains, > + * if it was added. > + * - Removes the PM domain from the list of registered PM domains. > + * > + * The PM domain will only be removed, if it is not a parent to any > + * other PM domain and has no devices associated with it. > + */ > +int pm_genpd_remove(struct generic_pm_domain *genpd) > +{ > + struct gpd_link *l, *link; > + int ret = 0; > + > + if (IS_ERR_OR_NULL(genpd)) > + return -EINVAL; > + > + mutex_lock(&gpd_list_lock); > + mutex_lock(&genpd->lock); > + > + if (!list_empty(&genpd->master_links) || genpd->device_count) { > + mutex_unlock(&genpd->lock); > + mutex_unlock(&gpd_list_lock); > + pr_err("%s: unable to remove %s\n", __func__, genpd->name); > + return -EBUSY; > + } > + > + list_for_each_entry_safe(link, l, &genpd->slave_links, slave_node) { > + list_del(&link->master_node); > + list_del(&link->slave_node); > + kfree(link); > + } > + > + list_del(&genpd->gpd_list_node); > + mutex_unlock(&genpd->lock); > + cancel_work_sync(&genpd->power_off_work); > + mutex_unlock(&gpd_list_lock); > + pr_debug("%s: removed %s\n", __func__, genpd->name); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(pm_genpd_remove); > + > #ifdef CONFIG_PM_GENERIC_DOMAINS_OF > > typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args, > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index f103869db443..fbdc5c4588ef 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -128,6 +128,7 @@ extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, > struct generic_pm_domain *target); > extern int pm_genpd_init(struct generic_pm_domain *genpd, > struct dev_power_governor *gov, bool is_off); > +extern int pm_genpd_remove(struct generic_pm_domain *genpd); > > extern struct dev_power_governor simple_qos_governor; > extern struct dev_power_governor pm_domain_always_on_gov; > @@ -163,6 +164,10 @@ static inline int pm_genpd_init(struct generic_pm_domain *genpd, > { > return -ENOSYS; > } > +static inline int pm_genpd_remove(struct generic_pm_domain *genpd) > +{ > + return -ENOTSUPP; > +} > #endif > > static inline int pm_genpd_add_device(struct generic_pm_domain *genpd, > -- > 2.1.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/09/16 12:49, Ulf Hansson wrote: > On 16 August 2016 at 11:49, Jon Hunter <jonathanh@nvidia.com> wrote: >> The genpd framework allows users to add PM domains via the pm_genpd_init() >> function, however, there is no corresponding function to remove a PM >> domain. For most devices this may be fine as the PM domains are never >> removed, however, for devices that wish to populate the PM domains from >> within a driver, having the ability to remove a PM domain if the probing >> of the device fails or the driver is unloaded is necessary. >> >> Add the function pm_genpd_remove() to remove a PM domain by referencing >> it's generic_pm_domain structure. >> >> PM domains can only be removed if they are not a parent domain to >> another PM domain and have no devices associated with them. > > I think we should also check if the there's is a provider registered > for the genpd, as it should also prevent the genpd from being removed. > Right? Yes I would agree. I had thought that after patch #4 of this series that only the provider itself would be able to call this. However, we should probably still verify that the provider has correctly remove itself. > I noticed that you are adding the ->provider pointer to the genpd > struct in patch 9/10. Perhaps re-structure $subject patch and 9/10 a > bit to deal with this, so we can add the pm_genpd_remove() API in a > more safe manner. Yes I can add the >provider member before this patch. Cheers Jon
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 7ce4608bbbe0..72b973539205 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1356,6 +1356,52 @@ int pm_genpd_init(struct generic_pm_domain *genpd, } EXPORT_SYMBOL_GPL(pm_genpd_init); +/** + * pm_genpd_remove - Remove a generic I/O PM domain + * @genpd: Pointer to PM domain that is to be removed. + * + * To remove the PM domain, this function: + * - Removes the PM domain as a subdomain to any parent domains, + * if it was added. + * - Removes the PM domain from the list of registered PM domains. + * + * The PM domain will only be removed, if it is not a parent to any + * other PM domain and has no devices associated with it. + */ +int pm_genpd_remove(struct generic_pm_domain *genpd) +{ + struct gpd_link *l, *link; + int ret = 0; + + if (IS_ERR_OR_NULL(genpd)) + return -EINVAL; + + mutex_lock(&gpd_list_lock); + mutex_lock(&genpd->lock); + + if (!list_empty(&genpd->master_links) || genpd->device_count) { + mutex_unlock(&genpd->lock); + mutex_unlock(&gpd_list_lock); + pr_err("%s: unable to remove %s\n", __func__, genpd->name); + return -EBUSY; + } + + list_for_each_entry_safe(link, l, &genpd->slave_links, slave_node) { + list_del(&link->master_node); + list_del(&link->slave_node); + kfree(link); + } + + list_del(&genpd->gpd_list_node); + mutex_unlock(&genpd->lock); + cancel_work_sync(&genpd->power_off_work); + mutex_unlock(&gpd_list_lock); + pr_debug("%s: removed %s\n", __func__, genpd->name); + + return ret; +} +EXPORT_SYMBOL_GPL(pm_genpd_remove); + #ifdef CONFIG_PM_GENERIC_DOMAINS_OF typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args, diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index f103869db443..fbdc5c4588ef 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -128,6 +128,7 @@ extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, struct generic_pm_domain *target); extern int pm_genpd_init(struct generic_pm_domain *genpd, struct dev_power_governor *gov, bool is_off); +extern int pm_genpd_remove(struct generic_pm_domain *genpd); extern struct dev_power_governor simple_qos_governor; extern struct dev_power_governor pm_domain_always_on_gov; @@ -163,6 +164,10 @@ static inline int pm_genpd_init(struct generic_pm_domain *genpd, { return -ENOSYS; } +static inline int pm_genpd_remove(struct generic_pm_domain *genpd) +{ + return -ENOTSUPP; +} #endif static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
The genpd framework allows users to add PM domains via the pm_genpd_init() function, however, there is no corresponding function to remove a PM domain. For most devices this may be fine as the PM domains are never removed, however, for devices that wish to populate the PM domains from within a driver, having the ability to remove a PM domain if the probing of the device fails or the driver is unloaded is necessary. Add the function pm_genpd_remove() to remove a PM domain by referencing it's generic_pm_domain structure. PM domains can only be removed if they are not a parent domain to another PM domain and have no devices associated with them. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> --- drivers/base/power/domain.c | 46 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 5 +++++ 2 files changed, 51 insertions(+)