[PATCH V2 09/10] PM / Domains: Add support for removing PM domains
From: Ulf Hansson <hidden>
Date: 2016-09-12 12:56:31
Also in:
linux-pm, linux-tegra
On 12 September 2016 at 13:01, Jon Hunter [off-list ref] 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. Note that the bulk of the code that removes the PM domain is placed in a separate local function genpd_remove() (which is called by pm_genpd_remove()). The code is structured in this way to prepare for adding another function to remove a PM domain by provider that will also call genpd_remove(). Note that users of genpd_remove() must call this function with the mutex, gpd_list_lock, held. PM domains can only be removed if the associated provider has been removed, 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>
Acked-by: Ulf Hansson <redacted> Kind regards Uffe
quoted hunk ↗ jump to hunk
--- drivers/base/power/domain.c | 60 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 5 ++++ 2 files changed, 65 insertions(+)diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index d5135caa84db..7481e3e316a2 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c@@ -1358,6 +1358,66 @@ int pm_genpd_init(struct generic_pm_domain *genpd, } EXPORT_SYMBOL_GPL(pm_genpd_init); +static int genpd_remove(struct generic_pm_domain *genpd) +{ + struct gpd_link *l, *link; + + if (IS_ERR_OR_NULL(genpd)) + return -EINVAL; + + mutex_lock(&genpd->lock); + + if (genpd->has_provider) { + mutex_unlock(&genpd->lock); + pr_err("Provider present, unable to remove %s\n", genpd->name); + return -EBUSY; + } + + if (!list_empty(&genpd->master_links) || genpd->device_count) { + mutex_unlock(&genpd->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); + pr_debug("%s: removed %s\n", __func__, genpd->name); + + return 0; +} + +/** + * 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 the associated provider has + * been removed, 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) +{ + int ret; + + mutex_lock(&gpd_list_lock); + ret = genpd_remove(genpd); + mutex_unlock(&gpd_list_lock); + + 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 554f8915c691..85f7d53a9827 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h@@ -130,6 +130,7 @@ 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;@@ -165,6 +166,10 @@ 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