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authorJon Hunter <jonathanh@nvidia.com>2016-09-12 14:01:13 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-09-13 03:49:34 +0300
commit3fe577107ccf1974958701df710e0b07ef16db75 (patch)
tree3dd76befaccad67978dd0db1e9ba898705067c00 /drivers/base
parentde0aa06d8b1c39df1071bfe169b3b97ca6bc01ac (diff)
downloadlinux-3fe577107ccf1974958701df710e0b07ef16db75.tar.xz
PM / Domains: Add support for removing PM domains
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 <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/power/domain.c60
1 files changed, 60 insertions, 0 deletions
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,