PM / Domains: Allocate memory outside domain locks

In preparation for supporting IRQ-safe domains, allocate domain data
outside the domain locks. These functions are not called in an atomic
context, so we can always allocate memory using GFP_KERNEL. By
allocating memory before the locks, we can safely lock the domain using
spinlocks instead of mutexes.

Reviewed-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index e1c017411aeba1abad85bec79c369e29e89c3e0b..f932058b5db68de07c4bb2dabfccf321a10d3ce6 100644 (file)
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1311,13 +1311,17 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
                           struct generic_pm_domain *subdomain)
 {
-       struct gpd_link *link;
+       struct gpd_link *link, *itr;
        int ret = 0;
 
        if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
            || genpd == subdomain)
                return -EINVAL;
 
+       link = kzalloc(sizeof(*link), GFP_KERNEL);
+       if (!link)
+               return -ENOMEM;
+
        mutex_lock(&genpd->lock);
        mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
 
@@ -1327,18 +1331,13 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
                goto out;
        }
 
-       list_for_each_entry(link, &genpd->master_links, master_node) {
-               if (link->slave == subdomain && link->master == genpd) {
+       list_for_each_entry(itr, &genpd->master_links, master_node) {
+               if (itr->slave == subdomain && itr->master == genpd) {
                        ret = -EINVAL;
                        goto out;
                }
        }
 
-       link = kzalloc(sizeof(*link), GFP_KERNEL);
-       if (!link) {
-               ret = -ENOMEM;
-               goto out;
-       }
        link->master = genpd;
        list_add_tail(&link->master_node, &genpd->master_links);
        link->slave = subdomain;
@@ -1349,7 +1348,8 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
  out:
        mutex_unlock(&subdomain->lock);
        mutex_unlock(&genpd->lock);
-
+       if (ret)
+               kfree(link);
        return ret;
 }