Commit dc779229 authored by Alex Elder's avatar Alex Elder Committed by Greg Kroah-Hartman
Browse files

greybus: introduce gb_operation_message_init() 



Separate the allocation of a message structure from its basic
initialization.  This will allow very common fixed-size operation
response buffers to be allocated from a slab cache.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <greg@kroah.com>
parent ea64cd9a

drivers/staging/greybus/operation.c

+39 −27
Original line number Diff line number Diff line
@@ -301,6 +301,43 @@ gb_hd_message_find(struct greybus_host_device *hd, void *header) 
	return message;

}



static void gb_operation_message_init(struct greybus_host_device *hd,

				struct gb_message *message, u16 operation_id,

				size_t message_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;



	/*

	 * The type supplied for incoming message buffers will be

	 * 0x00.  Such buffers will be overwritten by arriving data

	 * so there's no need to initialize the message header.

	 */

	if (type) {

		/*

		 * For a request, the operation id gets filled in

		 * when the message is sent.  For a response, it

		 * will be copied from the request by the caller.

		 *

		 * The result field in a request message must be

		 * zero.  It will be set just prior to sending for

		 * a response.

		 */

		header->size = cpu_to_le16(message_size);

		header->operation_id = 0;

		header->type = type;

		header->result = 0;

	}

}



/*

 * Allocate a message to be used for an operation request or response.

 * Both types of message contain a common header.  The request message
@@ -325,7 +362,6 @@ gb_operation_message_alloc(struct greybus_host_device *hd, u8 type, 
	struct gb_operation_msg_hdr *header;

	size_t message_size = payload_size + sizeof(*header);

	size_t size;

	u8 *buffer;



	if (hd->buffer_size_max > GB_OPERATION_MESSAGE_SIZE_MAX) {

		pr_warn("limiting buffer size to %u\n",
@@ -340,33 +376,9 @@ gb_operation_message_alloc(struct greybus_host_device *hd, u8 type, 
	message = kzalloc(size, gfp_flags);

	if (!message)

		return NULL;

	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;



	/*

	 * The type supplied for incoming message buffers will be

	 * 0x00.  Such buffers will be overwritten by arriving data

	 * so there's no need to initialize the message header.

	 */

	if (type) {

		/*

		 * For a request, the operation id gets filled in

		 * when the message is sent.  For a response, it

		 * will be copied from the request by the caller.

		 *

		 * The result field in a request message must be

		 * zero.  It will be set just prior to sending for

		 * a response.

		 */

		header->size = cpu_to_le16(message_size);

		header->operation_id = 0;

		header->type = type;

		header->result = 0;

	}

	/* Initialize the message.  Operation id is filled in later. */

	gb_operation_message_init(hd, message, 0, message_size, type);



	return message;

}