greybus: record gbuf->operation

Currently a gbuf records a pointer to the connection it's associated
with.  We now know only use gbufs in operation messages, so we can
point a gbuf at its operation instead.  This still gives access to
the connection where needed, but it also will provide all the
context we'll ever need for a gbuf, and this allows us (in the next
patch) to remove the gbuf->context field as well.

So switch to recording in a gbuf the operation rather than the
connection it is associated with.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

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

@@ -96,6 +96,7 @@ static void cport_out_callback(struct urb *urb);
 static int alloc_gbuf_data(struct gbuf *gbuf, unsigned int size,
 				gfp_t gfp_mask)
 {
+	struct gb_connection *connection = gbuf->operation->connection;
 	u32 cport_reserve = gbuf->outbound ? 1 : 0;
 	u8 *buffer;
 
@@ -121,16 +122,16 @@ static int alloc_gbuf_data(struct gbuf *gbuf, unsigned int size,
 	 * we will encode the cport number in the first byte of the buffer, so
 	 * set the second byte to be the "transfer buffer"
 	 */
-	if (gbuf->connection->interface_cport_id > (u16)U8_MAX) {
+	if (connection->interface_cport_id > (u16)U8_MAX) {
 		pr_err("gbuf->interface_cport_id (%hd) is out of range!\n",
-			gbuf->connection->interface_cport_id);
+			connection->interface_cport_id);
 		kfree(buffer);
 		return -EINVAL;
 	}
 
 	/* Insert the cport id for outbound buffers */
 	if (gbuf->outbound)
-		*buffer++ = gbuf->connection->interface_cport_id;
+		*buffer++ = connection->interface_cport_id;
 	gbuf->transfer_buffer = buffer;
 	gbuf->transfer_buffer_length = size;
 
@@ -208,7 +209,7 @@ static struct urb *next_free_urb(struct es1_ap_dev *es1, gfp_t gfp_mask)
 
 static int submit_gbuf(struct gbuf *gbuf, gfp_t gfp_mask)
 {
-	struct greybus_host_device *hd = gbuf->connection->hd;
+	struct greybus_host_device *hd = gbuf->operation->connection->hd;
 	struct es1_ap_dev *es1 = hd_to_es1(hd);
 	struct usb_device *udev = es1->usb_dev;
 	int retval;
@@ -394,7 +395,7 @@ static void cport_in_callback(struct urb *urb)
 static void cport_out_callback(struct urb *urb)
 {
 	struct gbuf *gbuf = urb->context;
-	struct es1_ap_dev *es1 = hd_to_es1(gbuf->connection->hd);
+	struct es1_ap_dev *es1 = hd_to_es1(gbuf->operation->connection->hd);
 	unsigned long flags;
 	int i;
 

drivers/staging/greybus/gbuf.c

@@ -35,13 +35,14 @@ static struct kmem_cache *gbuf_head_cache;
  * that the driver can then fill up with the data to be sent out.  Curse
  * hardware designers for this issue...
  */
-struct gbuf *greybus_alloc_gbuf(struct gb_connection *connection,
+struct gbuf *greybus_alloc_gbuf(struct gb_operation *operation,
 				gbuf_complete_t complete,
 				unsigned int size,
 				bool outbound,
 				gfp_t gfp_mask,
 				void *context)
 {
+	struct greybus_host_device *hd = operation->connection->hd;
 	struct gbuf *gbuf;
 	int retval;
 
@@ -50,14 +51,14 @@ struct gbuf *greybus_alloc_gbuf(struct gb_connection *connection,
 		return NULL;
 
 	kref_init(&gbuf->kref);
-	gbuf->connection = connection;
+	gbuf->operation = operation;
 	gbuf->outbound = outbound;
 	gbuf->complete = complete;
 	gbuf->context = context;
 	gbuf->status = -EBADR;	/* Initial value--means "never set" */
 
 	/* Host controller specific allocation for the actual buffer */
-	retval = connection->hd->driver->alloc_gbuf_data(gbuf, size, gfp_mask);
+	retval = hd->driver->alloc_gbuf_data(gbuf, size, gfp_mask);
 	if (retval) {
 		kmem_cache_free(gbuf_head_cache, gbuf);
 		return NULL;
@@ -72,8 +73,9 @@ static DEFINE_MUTEX(gbuf_mutex);
 static void free_gbuf(struct kref *kref)
 {
 	struct gbuf *gbuf = container_of(kref, struct gbuf, kref);
+	struct greybus_host_device *hd = gbuf->operation->connection->hd;
 
-	gbuf->connection->hd->driver->free_gbuf_data(gbuf);
+	hd->driver->free_gbuf_data(gbuf);
 
 	kmem_cache_free(gbuf_head_cache, gbuf);
 	mutex_unlock(&gbuf_mutex);
@@ -97,7 +99,7 @@ EXPORT_SYMBOL_GPL(greybus_get_gbuf);
 
 int greybus_submit_gbuf(struct gbuf *gbuf, gfp_t gfp_mask)
 {
-	struct greybus_host_device *hd = gbuf->connection->hd;
+	struct greybus_host_device *hd = gbuf->operation->connection->hd;
 
 	gbuf->status = -EINPROGRESS;
 
@@ -106,7 +108,7 @@ int greybus_submit_gbuf(struct gbuf *gbuf, gfp_t gfp_mask)
 
 void greybus_kill_gbuf(struct gbuf *gbuf)
 {
-	struct greybus_host_device *hd = gbuf->connection->hd;
+	struct greybus_host_device *hd = gbuf->operation->connection->hd;
 
 	if (gbuf->status != -EINPROGRESS)
 		return;

drivers/staging/greybus/greybus.h

@@ -126,7 +126,7 @@ typedef void (*gbuf_complete_t)(struct gbuf *gbuf);
 struct gbuf {
 	struct kref kref;
 
-	struct gb_connection *connection;
+	struct gb_operation *operation;
 	int status;
 	void *transfer_buffer;
 	u32 transfer_buffer_length;
@@ -194,7 +194,7 @@ void greybus_cport_in(struct greybus_host_device *hd, u16 cport_id,
 			u8 *data, size_t length);
 void greybus_gbuf_finished(struct gbuf *gbuf);
 
-struct gbuf *greybus_alloc_gbuf(struct gb_connection *connection,
+struct gbuf *greybus_alloc_gbuf(struct gb_operation *operation,
 				gbuf_complete_t complete, unsigned int size,
 				bool outbound, gfp_t gfp_mask, void *context);
 void greybus_free_gbuf(struct gbuf *gbuf);

drivers/staging/greybus/operation.c

@@ -295,13 +295,12 @@ static struct gbuf *gb_operation_gbuf_create(struct gb_operation *operation,
 					     u8 type, size_t size,
 					     bool data_out)
 {
-	struct gb_connection *connection = operation->connection;
 	struct gb_operation_msg_hdr *header;
 	struct gbuf *gbuf;
 	gfp_t gfp_flags = data_out ? GFP_KERNEL : GFP_ATOMIC;
 
 	size += sizeof(*header);
-	gbuf = greybus_alloc_gbuf(connection, gb_operation_gbuf_complete,
+	gbuf = greybus_alloc_gbuf(operation, gb_operation_gbuf_complete,
 					size, data_out, gfp_flags, operation);
 	if (!gbuf)
 		return NULL;