greybus: free space without gbufs

Switch the host driver free routine to take a pointer to the
previously-allocated buffer that should be freed.

Rename the method to reflect it's no longer tied to a gbuf.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/core.c

@@ -169,8 +169,7 @@ struct greybus_host_device *greybus_create_hd(struct greybus_host_driver *driver
 	 * Validate that the driver implements all of the callbacks
 	 * so that we don't have to every time we make them.
 	 */
-	if ((!driver->buffer_alloc) ||
-	    (!driver->free_gbuf_data) ||
+	if ((!driver->buffer_alloc) || (!driver->buffer_free) ||
 	    (!driver->submit_svc) ||
 	    (!driver->submit_gbuf) ||
 	    (!driver->kill_gbuf)) {

drivers/staging/greybus/es1-ap-usb.c

@@ -114,19 +114,18 @@ static void *buffer_alloc(unsigned int size, gfp_t gfp_mask)
 	return buffer;
 }
 
-/* Free the memory we allocated with a gbuf */
-static void free_gbuf_data(struct gbuf *gbuf)
+/* Free a previously-allocated buffer */
+static void buffer_free(void *buffer)
 {
-	u8 *transfer_buffer = gbuf->transfer_buffer;
+	u8 *allocated = buffer;
 
-	/* Can be called with a NULL transfer_buffer on some error paths */
-	if (!transfer_buffer)
+	/* Can be called with a NULL buffer on some error paths */
+	if (!allocated)
 		return;
 
 	/* Account for the space set aside for the prepended cport id */
-	transfer_buffer -= GB_BUFFER_ALIGN;
-	kfree(transfer_buffer);
-	gbuf->transfer_buffer = NULL;
+	allocated -= GB_BUFFER_ALIGN;
+	kfree(allocated);
 }
 
 #define ES1_TIMEOUT	500	/* 500 ms for the SVC to do something */
@@ -240,7 +239,7 @@ static void kill_gbuf(struct gbuf *gbuf)
 static struct greybus_host_driver es1_driver = {
 	.hd_priv_size		= sizeof(struct es1_ap_dev),
 	.buffer_alloc		= buffer_alloc,
-	.free_gbuf_data		= free_gbuf_data,
+	.buffer_free		= buffer_free,
 	.submit_svc		= submit_svc,
 	.submit_gbuf		= submit_gbuf,
 	.kill_gbuf		= kill_gbuf,

drivers/staging/greybus/greybus.h

@@ -80,7 +80,7 @@ struct greybus_host_driver {
 	size_t	hd_priv_size;
 
 	void *(*buffer_alloc)(unsigned int size, gfp_t gfp_mask);
-	void (*free_gbuf_data)(struct gbuf *gbuf);
+	void (*buffer_free)(void *buffer);
 	int (*submit_svc)(struct svc_msg *svc_msg,
 			    struct greybus_host_device *hd);
 	int (*submit_gbuf)(struct gbuf *gbuf, gfp_t gfp_mask);

drivers/staging/greybus/operation.c

@@ -264,7 +264,9 @@ static void gb_operation_message_exit(struct gb_message *message)
 {
 	message->operation = NULL;
 	message->payload = NULL;
-	message->gbuf.hd->driver->free_gbuf_data(&message->gbuf);
+	message->gbuf.hd->driver->buffer_free(message->gbuf.transfer_buffer);
+	message->gbuf.transfer_buffer = NULL;
+	message->gbuf.transfer_buffer_length = 0;
 }
 
 /*