PM / Sleep: introduce dpm_for_each_dev

dpm_list and its pm lock provide a good way to iterate all
devices in system. Except this way, there is no other easy
way to iterate devices in system.

firmware loader need to cache firmware images for devices
before system sleep, so introduce the function to meet its
demand.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/pm.h b/include/linux/pm.h
index f067e60a3832..88f034a23f2c 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -638,6 +638,7 @@ extern void __suspend_report_result(const char *function, void *fn, int ret);
         } while (0)
 
 extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
+extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
 
 extern int pm_generic_prepare(struct device *dev);
 extern int pm_generic_suspend_late(struct device *dev);
@@ -677,6 +678,10 @@ static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
         return 0;
 }
 
+static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
+{
+}
+
 #define pm_generic_prepare      NULL
 #define pm_generic_suspend      NULL
 #define pm_generic_resume       NULL