nvme: add support for passing on the application tag

With user integrity buffer, there is a way to specify the app_tag.
Set the corresponding protocol specific flags and send the app_tag down.

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Anuj Gupta <[email protected]>
Signed-off-by: Kanchan Joshi <[email protected]>
Reviewed-by: Keith Busch <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: Kanchan Joshi

drivers/nvme/host/core.c

@@ -885,6 +885,12 @@ static blk_status_t nvme_setup_discard(struct nvme_ns *ns, struct request *req,
 	return BLK_STS_OK;
 }
 
+static void nvme_set_app_tag(struct request *req, struct nvme_command *cmnd)
+{
+	cmnd->rw.lbat = cpu_to_le16(bio_integrity(req->bio)->app_tag);
+	cmnd->rw.lbatm = cpu_to_le16(0xffff);
+}
+
 static void nvme_set_ref_tag(struct nvme_ns *ns, struct nvme_command *cmnd,
 			      struct request *req)
 {
@@ -1025,6 +1031,10 @@ static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns,
 				control |= NVME_RW_APPEND_PIREMAP;
 			nvme_set_ref_tag(ns, cmnd, req);
 		}
+		if (bio_integrity_flagged(req->bio, BIP_CHECK_APPTAG)) {
+			control |= NVME_RW_PRINFO_PRCHK_APP;
+			nvme_set_app_tag(req, cmnd);
+		}
 	}
 
 	cmnd->rw.control = cpu_to_le16(control);