Commit d11b6916 authored by Martin K. Petersen's avatar Martin K. Petersen Committed by James Bottomley
Browse files

sd: Block limits VPD support 



Query the block limits VPD page and adjust queue minimum and optimal I/O
sizes.

Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 3821d768

drivers/scsi/sd.c

+24 −0
Original line number Diff line number Diff line
@@ -1794,6 +1794,29 @@ void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer) 
	return;

}



/**

 * sd_read_block_limits - Query disk device for preferred I/O sizes.

 * @disk: disk to query

 */

static void sd_read_block_limits(struct scsi_disk *sdkp)

{

	unsigned int sector_sz = sdkp->device->sector_size;

	char *buffer;



	/* Block Limits VPD */

	buffer = scsi_get_vpd_page(sdkp->device, 0xb0);



	if (buffer == NULL)

		return;



	blk_queue_io_min(sdkp->disk->queue,

			 get_unaligned_be16(&buffer[6]) * sector_sz);

	blk_queue_io_opt(sdkp->disk->queue,

			 get_unaligned_be32(&buffer[12]) * sector_sz);



	kfree(buffer);

}



/**

 * sd_read_block_characteristics - Query block dev. characteristics

 * @disk: disk to query
@@ -1854,6 +1877,7 @@ static int sd_revalidate_disk(struct gendisk *disk) 
	 */

	if (sdkp->media_present) {

		sd_read_capacity(sdkp, buffer);

		sd_read_block_limits(sdkp);

		sd_read_block_characteristics(sdkp);

		sd_read_write_protect_flag(sdkp, buffer);

		sd_read_cache_type(sdkp, buffer);