block/scsi: Provide a limit on the number of integrity segments
Some controllers have a hardware limit on the number of protection
information scatter-gather list segments they can handle.
Introduce a max_integrity_segments limit in the block layer and provide
a new scsi_host_template setting that allows HBA drivers to provide a
value suitable for the hardware.
Add support for honoring the integrity segment limit when merging both
bios and requests.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 5274103..2c3fd74 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -496,6 +496,10 @@
#define bip_for_each_vec(bvl, bip, i) \
__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
+#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
+ for_each_bio(_bio) \
+ bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
+
#define bio_integrity(bio) (bio->bi_integrity != NULL)
extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2c54906..7e66110 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -124,6 +124,9 @@
* physical address coalescing is performed.
*/
unsigned short nr_phys_segments;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+ unsigned short nr_integrity_segments;
+#endif
unsigned short ioprio;
@@ -243,6 +246,7 @@
unsigned short logical_block_size;
unsigned short max_segments;
+ unsigned short max_integrity_segments;
unsigned char misaligned;
unsigned char discard_misaligned;
@@ -1213,8 +1217,13 @@
extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
extern void blk_integrity_unregister(struct gendisk *);
extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
-extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
-extern int blk_rq_count_integrity_sg(struct request *);
+extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
+ struct scatterlist *);
+extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
+extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
+ struct request *);
+extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
+ struct bio *);
static inline
struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
@@ -1235,16 +1244,32 @@
return bio_integrity(rq->bio);
}
+static inline void blk_queue_max_integrity_segments(struct request_queue *q,
+ unsigned int segs)
+{
+ q->limits.max_integrity_segments = segs;
+}
+
+static inline unsigned short
+queue_max_integrity_segments(struct request_queue *q)
+{
+ return q->limits.max_integrity_segments;
+}
+
#else /* CONFIG_BLK_DEV_INTEGRITY */
#define blk_integrity_rq(rq) (0)
-#define blk_rq_count_integrity_sg(a) (0)
-#define blk_rq_map_integrity_sg(a, b) (0)
+#define blk_rq_count_integrity_sg(a, b) (0)
+#define blk_rq_map_integrity_sg(a, b, c) (0)
#define bdev_get_integrity(a) (0)
#define blk_get_integrity(a) (0)
#define blk_integrity_compare(a, b) (0)
#define blk_integrity_register(a, b) (0)
#define blk_integrity_unregister(a) do { } while (0);
+#define blk_queue_max_integrity_segments(a, b) do { } while (0);
+#define queue_max_integrity_segments(a) (0)
+#define blk_integrity_merge_rq(a, b, c) (0)
+#define blk_integrity_merge_bio(a, b, c) (0)
#endif /* CONFIG_BLK_DEV_INTEGRITY */
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 8fcb6e0..d63533a 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -32,6 +32,12 @@
#endif
/*
+ * DIX-capable adapters effectively support infinite chaining for the
+ * protection information scatterlist
+ */
+#define SCSI_MAX_PROT_SG_SEGMENTS 0xFFFF
+
+/*
* Special value for scanning to specify scanning or rescanning of all
* possible channels, (target) ids, or luns on a given shost.
*/
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index b7bdecb..d0a6a84 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -388,6 +388,7 @@
* of scatter-gather.
*/
unsigned short sg_tablesize;
+ unsigned short sg_prot_tablesize;
/*
* Set this if the host adapter has limitations beside segment count.
@@ -599,6 +600,7 @@
int can_queue;
short cmd_per_lun;
short unsigned int sg_tablesize;
+ short unsigned int sg_prot_tablesize;
short unsigned int max_sectors;
unsigned long dma_boundary;
/*
@@ -823,6 +825,11 @@
return shost->prot_capabilities;
}
+static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
+{
+ return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
+}
+
static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
{
static unsigned char cap[] = { 0,