diff options
| -rw-r--r-- | drivers/staging/greybus/operation.c | 34 | ||||
| -rw-r--r-- | drivers/staging/greybus/operation.h | 13 |
2 files changed, 27 insertions, 20 deletions
diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c index 109b94fc26b7..6a1d3e663547 100644 --- a/drivers/staging/greybus/operation.c +++ b/drivers/staging/greybus/operation.c @@ -32,15 +32,13 @@ static DEFINE_MUTEX(gb_message_mutex); /* * All operation messages (both requests and responses) begin with - * a header that encodes the size of the data (header included). - * This header also contains a unique identifier, which is used to - * keep track of in-flight operations. The header contains an + * a header that encodes the size of the message (header included). + * This header also contains a unique identifier, that associates a + * response message with its operation. The header contains an * operation type field, whose interpretation is dependent on what - * type of protocol is used over the connection. - * - * The high bit (0x80) of the operation type field is used to - * indicate whether the message is a request (clear) or a response - * (set). + * type of protocol is used over the connection. The high bit + * (0x80) of the operation type field is used to indicate whether + * the message is a request (clear) or a response (set). * * Response messages include an additional status byte, which * communicates the result of the corresponding request. A zero @@ -163,6 +161,7 @@ gb_operation_find(struct gb_connection *connection, u16 operation_id) static int gb_message_send(struct gb_message *message) { + size_t message_size = sizeof(*message->header) + message->payload_size; struct gb_connection *connection = message->operation->connection; u16 dest_cport_id = connection->interface_cport_id; int ret = 0; @@ -172,7 +171,7 @@ static int gb_message_send(struct gb_message *message) cookie = connection->hd->driver->buffer_send(connection->hd, dest_cport_id, message->header, - message->size, + message_size, GFP_KERNEL); if (IS_ERR(cookie)) ret = PTR_ERR(cookie); @@ -276,18 +275,17 @@ gb_hd_message_find(struct greybus_host_device *hd, void *header) static void gb_operation_message_init(struct greybus_host_device *hd, struct gb_message *message, u16 operation_id, - size_t message_size, u8 type) + size_t payload_size, u8 type) { struct gb_operation_msg_hdr *header; u8 *buffer; - BUG_ON(message_size < sizeof(*header)); buffer = &message->buffer[0]; header = (struct gb_operation_msg_hdr *)(buffer + hd->buffer_headroom); message->header = header; message->payload = header + 1; - message->size = message_size; + message->payload_size = payload_size; /* * The type supplied for incoming message buffers will be @@ -295,6 +293,8 @@ static void gb_operation_message_init(struct greybus_host_device *hd, * so there's no need to initialize the message header. */ if (type != GB_OPERATION_TYPE_INVALID) { + u16 message_size = (u16)(sizeof(*header) + payload_size); + /* * For a request, the operation id gets filled in * when the message is sent. For a response, it @@ -359,14 +359,14 @@ gb_operation_message_alloc(struct greybus_host_device *hd, u8 type, return NULL; /* Initialize the message. Operation id is filled in later. */ - gb_operation_message_init(hd, message, 0, message_size, type); + gb_operation_message_init(hd, message, 0, payload_size, type); return message; } static void gb_operation_message_free(struct gb_message *message) { - if (message->size > sizeof(message->header)) + if (message->payload_size) kfree(message); else kmem_cache_free(gb_simple_message_cache, message); @@ -820,6 +820,7 @@ static void gb_connection_recv_response(struct gb_connection *connection, struct gb_operation *operation; struct gb_message *message; int errno = gb_operation_status_map(result); + size_t message_size; operation = gb_operation_find(connection, operation_id); if (!operation) { @@ -830,9 +831,10 @@ static void gb_connection_recv_response(struct gb_connection *connection, cancel_delayed_work(&operation->timeout_work); message = operation->response; - if (!errno && size != message->size) { + message_size = sizeof(*message->header) + message->payload_size; + if (!errno && size != message_size) { gb_connection_err(connection, "bad message size (%zu != %zu)", - size, message->size); + size, message_size); errno = -EMSGSIZE; } diff --git a/drivers/staging/greybus/operation.h b/drivers/staging/greybus/operation.h index 3415e8b56eb6..a79e88a3b314 100644 --- a/drivers/staging/greybus/operation.h +++ b/drivers/staging/greybus/operation.h @@ -38,13 +38,18 @@ enum gb_operation_result { GB_OP_MALFUNCTION = 0xff, }; +/* + * Protocol code should only examine the payload and payload_size + * fields. All other fields are intended to be private to the + * operations core code. + */ struct gb_message { - struct gb_operation_msg_hdr *header; - void *payload; - size_t size; /* header + payload */ struct gb_operation *operation; - void *cookie; + struct gb_operation_msg_hdr *header; + + void *payload; + size_t payload_size; u8 buffer[]; }; |