| Message ID | E1YWSMv-0006Fx-E6@rmk-PC.arm.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Russell King <rmk+kernel@arm.linux.org.uk> writes: > The PM domain code contains two methods to get the generic PM domain > for a struct device. One is dev_to_genpd() which is only safe when > we know for certain that the device has a generic PM domain attached. > The other is coded into genpd_dev_pm_detach() which ensures that the > PM domain in the struct device is a generic PM domain (and so is safer). > > This commit factors out the safer version and documents it. > > Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Kevin Hilman <khilman@linaro.org> On top of this, I assume you're thinking that the externally available dev_to_genpd() should probably be replaced by pm_genpd_lookup_dev(), and dev_to_genpd() should only be used internally to genpd? Kevin
On Fri, Mar 13, 2015 at 10:20:21AM -0700, Kevin Hilman wrote: > Russell King <rmk+kernel@arm.linux.org.uk> writes: > > > The PM domain code contains two methods to get the generic PM domain > > for a struct device. One is dev_to_genpd() which is only safe when > > we know for certain that the device has a generic PM domain attached. > > The other is coded into genpd_dev_pm_detach() which ensures that the > > PM domain in the struct device is a generic PM domain (and so is safer). > > > > This commit factors out the safer version and documents it. > > > > Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> > > Acked-by: Kevin Hilman <khilman@linaro.org> > > On top of this, I assume you're thinking that the externally available > dev_to_genpd() should probably be replaced by pm_genpd_lookup_dev(), and > dev_to_genpd() should only be used internally to genpd? I think that would be a sensible improvement over leaving the unsafe dev_to_genpd() exposed.
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index b3fbc21da2dc..b9000b245e62 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -68,6 +68,31 @@ static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name) return genpd; } +/* + * Get the generic PM domain for a particular struct device. + * This validates the struct device pointer, the PM domain pointer, + * and checks that the PM domain pointer is a real generic PM domain. + * Any failure results in NULL being returned. + */ +static struct generic_pm_domain *pm_genpd_lookup_dev(struct device *dev) +{ + struct generic_pm_domain *genpd = NULL, *gpd; + + if (IS_ERR_OR_NULL(dev) || IS_ERR_OR_NULL(dev->pm_domain)) + return NULL; + + mutex_lock(&gpd_list_lock); + list_for_each_entry(gpd, &gpd_list, gpd_list_node) { + if (&gpd->domain == dev->pm_domain) { + genpd = gpd; + break; + } + } + mutex_unlock(&gpd_list_lock); + + return genpd; +} + struct generic_pm_domain *dev_to_genpd(struct device *dev) { if (IS_ERR_OR_NULL(dev->pm_domain)) @@ -2120,21 +2145,10 @@ EXPORT_SYMBOL_GPL(of_genpd_get_from_provider); */ static void genpd_dev_pm_detach(struct device *dev, bool power_off) { - struct generic_pm_domain *pd = NULL, *gpd; + struct generic_pm_domain *pd; int ret = 0; - if (!dev->pm_domain) - return; - - mutex_lock(&gpd_list_lock); - list_for_each_entry(gpd, &gpd_list, gpd_list_node) { - if (&gpd->domain == dev->pm_domain) { - pd = gpd; - break; - } - } - mutex_unlock(&gpd_list_lock); - + pd = pm_genpd_lookup_dev(dev); if (!pd) return;
The PM domain code contains two methods to get the generic PM domain for a struct device. One is dev_to_genpd() which is only safe when we know for certain that the device has a generic PM domain attached. The other is coded into genpd_dev_pm_detach() which ensures that the PM domain in the struct device is a generic PM domain (and so is safer). This commit factors out the safer version and documents it. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> --- drivers/base/power/domain.c | 40 +++++++++++++++++++++++++++------------- 1 file changed, 27 insertions(+), 13 deletions(-)