firmware loader: introduce cache_firmware and uncache_firmware

This patches introduce two kernel APIs of cache_firmware and
uncache_firmware, both of which take the firmware file name
as the only parameter.

So any drivers can call cache_firmware to cache the specified
firmware file into kernel memory, and can use the cached firmware
in situations which can't request firmware from user space.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index e85b771f3d8c..e4279fedb93a 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -47,6 +47,8 @@ int request_firmware_nowait(
         void (*cont)(const struct firmware *fw, void *context));
 
 void release_firmware(const struct firmware *fw);
+int cache_firmware(const char *name);
+int uncache_firmware(const char *name);
 #else
 static inline int request_firmware(const struct firmware **fw,
                                    const char *name,
@@ -65,6 +67,16 @@ static inline int request_firmware_nowait(
 static inline void release_firmware(const struct firmware *fw)
 {
 }
+
+static inline int cache_firmware(const char *name)
+{
+        return -ENOENT;
+}
+
+static inline int uncache_firmware(const char *name)
+{
+        return -EINVAL;
+}
 #endif
 
 #endif