Commit dd829d23 authored by Boaz Harrosh's avatar Boaz Harrosh Committed by James Bottomley
Browse files

[SCSI] usb: protocol - convert to accessors and !use_sg code path removal 



 - Use scsi data accessors and remove of !use_sg code path

Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
Acked-by: default avatarMatthew Dharm <mdharm-scsi@one-eyed-alien.net>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent caa1e8c3

drivers/usb/storage/protocol.c

+53 −73
Original line number Diff line number Diff line
@@ -149,11 +149,7 @@ void usb_stor_transparent_scsi_command(struct scsi_cmnd *srb, 
 ***********************************************************************/



/* Copy a buffer of length buflen to/from the srb's transfer buffer.

 * (Note: for scatter-gather transfers (srb->use_sg > 0), srb->request_buffer

 * points to a list of s-g entries and we ignore srb->request_bufflen.

 * For non-scatter-gather transfers, srb->request_buffer points to the

 * transfer buffer itself and srb->request_bufflen is the buffer's length.)

 * Update the *index and *offset variables so that the next copy will

 * Update the **sgptr and *offset variables so that the next copy will

 * pick up from where this one left off. */



unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
@@ -162,37 +158,22 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, 
{

	unsigned int cnt;



	/* If not using scatter-gather, just transfer the data directly.

	 * Make certain it will fit in the available buffer space. */

	if (srb->use_sg == 0) {

		if (*offset >= srb->request_bufflen)

			return 0;

		cnt = min(buflen, srb->request_bufflen - *offset);

		if (dir == TO_XFER_BUF)

			memcpy((unsigned char *) srb->request_buffer + *offset,

					buffer, cnt);

		else

			memcpy(buffer, (unsigned char *) srb->request_buffer +

					*offset, cnt);

		*offset += cnt;



	/* Using scatter-gather.  We have to go through the list one entry

	/* We have to go through the list one entry

	 * at a time.  Each s-g entry contains some number of pages, and

	 * each page has to be kmap()'ed separately.  If the page is already

	 * in kernel-addressable memory then kmap() will return its address.

	 * If the page is not directly accessible -- such as a user buffer

	 * located in high memory -- then kmap() will map it to a temporary

	 * position in the kernel's virtual address space. */

	} else {

	struct scatterlist *sg = *sgptr;



	if (!sg)

			sg = (struct scatterlist *) srb->request_buffer;

		sg = scsi_sglist(srb);



	/* This loop handles a single s-g list entry, which may

		* include multiple pages.  Find the initial page structure

		* and the starting offset within the page, and update

		 * the *offset and *index values for the next loop. */

		* the *offset and **sgptr values for the next loop. */

	cnt = 0;

	while (cnt < buflen) {

		struct page *page = sg_page(sg) +
@@ -235,7 +216,6 @@ unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, 
		}

	}

	*sgptr = sg;

	}



	/* Return the amount actually transferred */

	return cnt;
@@ -251,6 +231,6 @@ void usb_stor_set_xfer_buf(unsigned char *buffer, 


	usb_stor_access_xfer_buf(buffer, buflen, srb, &sg, &offset,

			TO_XFER_BUF);

	if (buflen < srb->request_bufflen)

		srb->resid = srb->request_bufflen - buflen;

	if (buflen < scsi_bufflen(srb))

		scsi_set_resid(srb, scsi_bufflen(srb) - buflen);

}