[PATCH v6 3/6] scsi: core: Cap shost max_sectors according to DMA limits only once

John Garry
2022-07-14T11:22:49Z

The shost->max_sectors is repeatedly capped according to the host DMA
mapping limit for each sdev in __scsi_init_queue(). This is unnecessary, so
set only once when adding the host.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
---
drivers/scsi/hosts.c | 5 +++++
drivers/scsi/scsi_lib.c | 4 ----
2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 8352f90d997d..d04bd2c7c9f1 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -236,6 +236,11 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,

shost->dma_dev = dma_dev;

+ if (dma_dev->dma_mask) {
+ shost->max_sectors = min_t(unsigned int, shost->max_sectors,
+ dma_max_mapping_size(dma_dev) >> SECTOR_SHIFT);
+ }
+
error = scsi_mq_setup_tags(shost);
if (error)
goto fail;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6ffc9e4258a8..6ce8acea322a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1884,10 +1884,6 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
}

- if (dev->dma_mask) {
- shost->max_sectors = min_t(unsigned int, shost->max_sectors,
- dma_max_mapping_size(dev) >> SECTOR_SHIFT);
- }
blk_queue_max_hw_sectors(q, shost->max_sectors);
blk_queue_segment_boundary(q, shost->dma_boundary);
dma_set_seg_boundary(dev, shost->dma_boundary);
--
2.35.3