From 50c2e9107f176a82e14567b39c5d0f2a208cc82c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 13 Dec 2018 16:17:03 +0100 Subject: [PATCH] scsi: introduce a max_segment_size host_template parameters This allows the host driver to indicate the maximum supported segment size in a nice an easy way, so that the driver doesn't have to worry about DMA-layer imposed limitations. Signed-off-by: Christoph Hellwig Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen --- drivers/scsi/be2iscsi/be_main.c | 8 +------- drivers/scsi/hosts.c | 5 +++++ drivers/scsi/scsi_debug.c | 2 +- drivers/scsi/scsi_lib.c | 3 ++- include/scsi/scsi_host.h | 6 ++++++ 5 files changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c index c4108b17d5ab..39f3820572b4 100644 --- a/drivers/scsi/be2iscsi/be_main.c +++ b/drivers/scsi/be2iscsi/be_main.c @@ -214,12 +214,6 @@ static char const *cqe_desc[] = { "CXN_KILLED_IMM_DATA_RCVD" }; -static int beiscsi_slave_configure(struct scsi_device *sdev) -{ - blk_queue_max_segment_size(sdev->request_queue, 65536); - return 0; -} - static int beiscsi_eh_abort(struct scsi_cmnd *sc) { struct iscsi_task *abrt_task = (struct iscsi_task *)sc->SCp.ptr; @@ -393,7 +387,6 @@ static struct scsi_host_template beiscsi_sht = { .proc_name = DRV_NAME, .queuecommand = iscsi_queuecommand, .change_queue_depth = scsi_change_queue_depth, - .slave_configure = beiscsi_slave_configure, .target_alloc = iscsi_target_alloc, .eh_timed_out = iscsi_eh_cmd_timed_out, .eh_abort_handler = beiscsi_eh_abort, @@ -404,6 +397,7 @@ static struct scsi_host_template beiscsi_sht = { .can_queue = BE2_IO_DEPTH, .this_id = -1, .max_sectors = BEISCSI_MAX_SECTORS, + .max_segment_size = 65536, .cmd_per_lun = BEISCSI_CMD_PER_LUN, .vendor_id = SCSI_NL_VID_TYPE_PCI | BE_VENDOR_ID, .track_queue_depth = 1, diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index ea4b0bb0c1cd..e8148ba414a3 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -464,6 +464,11 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) else shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; + if (sht->max_segment_size) + shost->max_segment_size = sht->max_segment_size; + else + shost->max_segment_size = BLK_MAX_SEGMENT_SIZE; + /* * assume a 4GB boundary, if not set */ diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 53ba417bef8a..57d418d7d74e 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -3973,7 +3973,6 @@ static int scsi_debug_slave_configure(struct scsi_device *sdp) return 1; /* no resources, will be marked offline */ } sdp->hostdata = devip; - blk_queue_max_segment_size(sdp->request_queue, -1U); if (sdebug_no_uld) sdp->no_uld_attach = 1; config_cdb_len(sdp); @@ -5851,6 +5850,7 @@ static struct scsi_host_template sdebug_driver_template = { .sg_tablesize = SG_MAX_SEGMENTS, .cmd_per_lun = DEF_CMD_PER_LUN, .max_sectors = -1U, + .max_segment_size = -1U, .module = THIS_MODULE, .track_queue_depth = 1, }; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index f6900e0b3024..2d4fd6b4bd92 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2227,7 +2227,8 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) blk_queue_segment_boundary(q, shost->dma_boundary); dma_set_seg_boundary(dev, shost->dma_boundary); - blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); + blk_queue_max_segment_size(q, + min(shost->max_segment_size, dma_get_max_seg_size(dev))); if (shost->use_clustering == DISABLE_CLUSTERING) q->limits.cluster = 0; diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 7dc534c794dc..834204681ca3 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -365,6 +365,11 @@ struct scsi_host_template { unsigned int max_sectors; /* + * Maximum size in bytes of a single segment. + */ + unsigned int max_segment_size; + + /* * DMA scatter gather segment boundary limit. A segment crossing this * boundary will be split in two. */ @@ -603,6 +608,7 @@ struct Scsi_Host { short unsigned int sg_tablesize; short unsigned int sg_prot_tablesize; unsigned int max_sectors; + unsigned int max_segment_size; unsigned long dma_boundary; /* * In scsi-mq mode, the number of hardware queues supported by the LLD. -- 2.11.0