Commit 82e26f73 authored by Alex Elder's avatar Alex Elder Committed by Greg Kroah-Hartman
Browse files

greybus: send operation response messages 



Define a helper function gb_operation_response_alloc() and use it
to allocate the response buffer for outgoing operations in
gb_operation_create_common(.

Use it also in  gb_operation_response_send() if the caller has not
allocated a response buffer.

Once a response buffer is allocated, fill in its result code and
send it.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <greg@kroah.com>
parent 0c90fff4

drivers/staging/greybus/operation.c

+49 −11
Original line number Diff line number Diff line
@@ -471,6 +471,34 @@ static u8 gb_operation_errno_map(int errno) 
	}

}



bool gb_operation_response_alloc(struct gb_operation *operation,

					size_t response_size)

{

	struct greybus_host_device *hd = operation->connection->hd;

	struct gb_operation_msg_hdr *request_header;

	struct gb_message *response;

	u8 type;



	request_header = operation->request->header;

	type = request_header->type | GB_OPERATION_TYPE_RESPONSE;

	response = gb_operation_message_alloc(hd, type, response_size,

						GFP_KERNEL);

	if (!response)

		return false;

	response->operation = operation;



	/*

	 * Size and type get initialized when the message is

	 * allocated.  The errno will be set before sending.  All

	 * that's left is the operation id, which we copy from the

	 * request message header (as-is, in little-endian order).

	 */

	response->header->operation_id = request_header->operation_id;

	operation->response = response;



	return true;

}



/*

 * Create a Greybus operation to be sent over the given connection.

 * The request buffer will be big enough for a payload of the given
@@ -513,14 +541,9 @@ gb_operation_create_common(struct gb_connection *connection, u8 type, 
	operation->request->operation = operation;



	/* Allocate the response buffer for outgoing operations */

	if (type) {

		type |= GB_OPERATION_TYPE_RESPONSE;

		operation->response = gb_operation_message_alloc(hd, type,

						response_size, GFP_KERNEL);

		if (!operation->response)

	if (type)

		if (!gb_operation_response_alloc(operation, response_size))

			goto err_request;

		operation->response->operation = operation;

	}

	operation->errno = -EBADR;  /* Initial value--means "never set" */



	INIT_WORK(&operation->work, gb_operation_work);
@@ -680,7 +703,13 @@ int gb_operation_request_send(struct gb_operation *operation, 
}



/*

 * Send a response for an incoming operation request.

 * Send a response for an incoming operation request.  A non-zero

 * errno indicates a failed operation.

 *

 * If there is any response payload, the incoming request handler is

 * responsible for allocating the response message.  Otherwise the

 * it can simply supply the result errno; this function will

 * allocate the response message if necessary.

 */

int gb_operation_response_send(struct gb_operation *operation, int errno)

{
@@ -689,10 +718,19 @@ int gb_operation_response_send(struct gb_operation *operation, int errno) 
		pr_err("request result already set\n");

		return -EIO;	/* Shouldn't happen */

	}

	(void)gb_operation_errno_map;	/* avoid a build warning */

	gb_operation_destroy(operation);



	return 0;

	if (!operation->response) {

		if (!gb_operation_response_alloc(operation, 0)) {

			pr_err("error allocating response\n");

			/* XXX Respond with pre-allocated -ENOMEM? */

			return -ENOMEM;

		}

	}



	/* Fill in the response header and send it */

	operation->response->header->result = gb_operation_errno_map(errno);



	return gb_message_send(operation->response);

}



/*

drivers/staging/greybus/operation.h

+3 −0
Original line number Diff line number Diff line
@@ -98,6 +98,9 @@ static inline void gb_operation_destroy(struct gb_operation *operation) 
	gb_operation_put(operation);

}



bool gb_operation_response_alloc(struct gb_operation *operation,

					size_t response_size);



int gb_operation_request_send(struct gb_operation *operation,

				gb_operation_callback callback);

int gb_operation_response_send(struct gb_operation *operation, int errno);