greybus: embed gbufs into operation message structure

Embed the gbuf structures for operation messages into the message
structure rather than pointing to a dynamically allocated one.

Use a null gbuf->transfer_buffer pointer rather than a null gbuf
pointer to indicate an unused gbuf.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c
index ab03e3edc8072db2bb1afba43219f380256111f0..7eaea71f86049ad11cbd94e0c1897ffff32b2491 100644 (file)
--- a/drivers/staging/greybus/operation.c
+++ b/drivers/staging/greybus/operation.c
@@ -72,7 +72,7 @@ static void gb_pending_operation_insert(struct gb_operation *operation)
        spin_unlock_irq(&gb_operations_lock);
 
        /* Store the operation id in the request header */
-       header = operation->request.gbuf->transfer_buffer;
+       header = operation->request.gbuf.transfer_buffer;
        header->id = cpu_to_le16(operation->id);
 }
 
@@ -125,7 +125,7 @@ int gb_operation_wait(struct gb_operation *operation)
        ret = wait_for_completion_interruptible(&operation->completion);
        /* If interrupted, cancel the in-flight buffer */
        if (ret < 0)
-               greybus_kill_gbuf(operation->request.gbuf);
+               greybus_kill_gbuf(&operation->request.gbuf);
        return ret;
 
 }
@@ -135,7 +135,7 @@ static void gb_operation_request_handle(struct gb_operation *operation)
        struct gb_protocol *protocol = operation->connection->protocol;
        struct gb_operation_msg_hdr *header;
 
-       header = operation->request.gbuf->transfer_buffer;
+       header = operation->request.gbuf.transfer_buffer;
 
        /*
         * If the protocol has no incoming request handler, report
@@ -165,7 +165,7 @@ static void gb_operation_recv_work(struct work_struct *recv_work)
        bool incoming_request;
 
        operation = container_of(recv_work, struct gb_operation, recv_work);
-       incoming_request = operation->response.gbuf == NULL;
+       incoming_request = operation->response.gbuf.transfer_buffer == NULL;
        if (incoming_request)
                gb_operation_request_handle(operation);
        gb_operation_complete(operation);
@@ -212,6 +212,7 @@ static int gb_operation_message_init(struct gb_operation *operation,
 
        if (size > GB_OPERATION_MESSAGE_SIZE_MAX)
                return -E2BIG;
+       size += sizeof(*header);
 
        if (request) {
                message = &operation->request;
@@ -219,25 +220,19 @@ static int gb_operation_message_init(struct gb_operation *operation,
                message = &operation->response;
                type |= GB_OPERATION_TYPE_RESPONSE;
        }
+       gbuf = &message->gbuf;
+
        if (data_out)
                dest_cport_id = connection->interface_cport_id;
        else
                dest_cport_id = CPORT_ID_BAD;
 
-       if (message->gbuf)
-               return -EALREADY;       /* Sanity check */
-       size += sizeof(*header);
-       gbuf = greybus_alloc_gbuf(hd, dest_cport_id, size, gfp_flags);
-       if (!gbuf)
-               return -ENOMEM;
        gbuf->hd = hd;
        gbuf->dest_cport_id = dest_cport_id;
        gbuf->status = -EBADR;  /* Initial value--means "never set" */
        ret = hd->driver->alloc_gbuf_data(gbuf, size, gfp_flags);
-       if (ret) {
-               greybus_free_gbuf(gbuf);
+       if (ret)
                return ret;
-       }
 
        /* Fill in the header structure */
        header = (struct gb_operation_msg_hdr *)gbuf->transfer_buffer;
@@ -247,7 +242,6 @@ static int gb_operation_message_init(struct gb_operation *operation,
 
        message->payload = header + 1;
        message->operation = operation;
-       message->gbuf = gbuf;
 
        return 0;
 }
@@ -256,9 +250,7 @@ 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);
-       greybus_free_gbuf(message->gbuf);
-       message->gbuf = NULL;
+       message->gbuf.hd->driver->free_gbuf_data(&message->gbuf);
 }
 
 /*
@@ -375,7 +367,7 @@ int gb_operation_request_send(struct gb_operation *operation,
         */
        operation->callback = callback;
        gb_pending_operation_insert(operation);
-       ret = greybus_submit_gbuf(operation->request.gbuf, GFP_KERNEL);
+       ret = greybus_submit_gbuf(&operation->request.gbuf, GFP_KERNEL);
        if (ret)
                return ret;
 
@@ -440,7 +432,7 @@ void gb_connection_operation_recv(struct gb_connection *connection,
                }
                cancel_delayed_work(&operation->timeout_work);
                gb_pending_operation_remove(operation);
-               gbuf = operation->response.gbuf;
+               gbuf = &operation->response.gbuf;
                if (size > gbuf->transfer_buffer_length) {
                        operation->result = GB_OP_OVERFLOW;
                        gb_connection_err(connection, "recv buffer too small");
@@ -455,7 +447,7 @@ void gb_connection_operation_recv(struct gb_connection *connection,
                        gb_connection_err(connection, "can't create operation");
                        return;
                }
-               gbuf = operation->request.gbuf;
+               gbuf = &operation->request.gbuf;
        }
 
        memcpy(gbuf->transfer_buffer, data, msg_size);
@@ -470,9 +462,9 @@ void gb_connection_operation_recv(struct gb_connection *connection,
 void gb_operation_cancel(struct gb_operation *operation)
 {
        operation->canceled = true;
-       greybus_kill_gbuf(operation->request.gbuf);
-       if (operation->response.gbuf)
-               greybus_kill_gbuf(operation->response.gbuf);
+       greybus_kill_gbuf(&operation->request.gbuf);
+       if (operation->response.gbuf.transfer_buffer)
+               greybus_kill_gbuf(&operation->response.gbuf);
 }
 
 int gb_operation_init(void)

diff --git a/drivers/staging/greybus/operation.h b/drivers/staging/greybus/operation.h
index a18713457ba17073eecf13f3f3465011aaeb3856..f43531dbcf3321f65e8b582bbc3b740b6f1a6e62 100644 (file)
--- a/drivers/staging/greybus/operation.h
+++ b/drivers/staging/greybus/operation.h
@@ -38,7 +38,7 @@ struct gbuf {
 struct gb_message {
        void                    *payload;
        struct gb_operation     *operation;
-       struct gbuf             *gbuf;
+       struct gbuf             gbuf;
 };
 
 /*