nvme: allow integrity when PI is not in first bytes

NVM command set 1.0 (or later) mandates PI to be in the last bytes of
metadata. But this was not supported in the block-layer, and driver
registered a nop profile.

Since block-integrity can now handle flexible PI offset, change the
driver to support this configuration.

Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240201130126.211402-4-joshi.k@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Kanchan Joshi

drivers/nvme/host/core.c

@@ -1771,6 +1771,7 @@ static void nvme_init_integrity(struct gendisk *disk,
 	}
 
 	integrity.tuple_size = head->ms;
+	integrity.pi_offset = head->pi_offset;
 	blk_integrity_register(disk, &integrity);
 	blk_queue_max_integrity_segments(disk->queue, max_integrity_segments);
 }
@@ -1880,11 +1881,16 @@ static int nvme_init_ms(struct nvme_ctrl *ctrl, struct nvme_ns_head *head,
 free_data:
 	kfree(nvm);
 set_pi:
-	if (head->pi_size && (first || head->ms == head->pi_size))
+	if (head->pi_size && head->ms >= head->pi_size)
 		head->pi_type = id->dps & NVME_NS_DPS_PI_MASK;
 	else
 		head->pi_type = 0;
 
+	if (first)
+		head->pi_offset = 0;
+	else
+		head->pi_offset = head->ms - head->pi_size;
+
 	return ret;
 }
 

drivers/nvme/host/nvme.h

@@ -463,6 +463,7 @@ struct nvme_ns_head {
 	u16			ms;
 	u16			pi_size;
 	u8			pi_type;
+	u8			pi_offset;
 	u8			guard_type;
 	u16			sgs;
 	u32			sws;