From be4c186c80113f95a5946594687a8e70f876e857 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 2 Jun 2017 14:21:59 -0700 Subject: [PATCH] scsi: Introduce scsi_mq_sgl_size() This patch does not change any functionality but makes the next patch easier to read. Signed-off-by: Bart Van Assche Reviewed-by: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn Signed-off-by: Martin K. Petersen --- drivers/scsi/scsi_lib.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 1470c93..c2a9601 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1859,6 +1859,13 @@ static inline int prep_to_mq(int ret) } } +/* Size in bytes of the sg-list stored in the scsi-mq command-private data. */ +static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost) +{ + return min_t(unsigned int, shost->sg_tablesize, SG_CHUNK_SIZE) * + sizeof(struct scatterlist); +} + static int scsi_mq_prep_fn(struct request *req) { struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); @@ -1893,10 +1900,7 @@ static int scsi_mq_prep_fn(struct request *req) cmd->sdb.table.sgl = sg; if (scsi_host_get_prot(shost)) { - cmd->prot_sdb = (void *)sg + - min_t(unsigned int, - shost->sg_tablesize, SG_CHUNK_SIZE) * - sizeof(struct scatterlist); + cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost); memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); cmd->prot_sdb->table.sgl = @@ -2202,12 +2206,9 @@ struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) int scsi_mq_setup_tags(struct Scsi_Host *shost) { - unsigned int cmd_size, sgl_size, tbl_size; + unsigned int cmd_size, sgl_size; - tbl_size = shost->sg_tablesize; - if (tbl_size > SG_CHUNK_SIZE) - tbl_size = SG_CHUNK_SIZE; - sgl_size = tbl_size * sizeof(struct scatterlist); + sgl_size = scsi_mq_sgl_size(shost); cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; if (scsi_host_get_prot(shost)) cmd_size += sizeof(struct scsi_data_buffer) + sgl_size; -- 2.7.4