sd: Block limits VPD support

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

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Martin K. Petersen 2009-05-23 11:43:39 -04:00 committed by James Bottomley
parent 3821d76891
commit d11b691696

View file

@ -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);