nvme: introduce ctrl attributes enumeration

We are growing more controller attributes, so use a proper enumeration
for it.  For now just add the 128-bit hostid which we support.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/target/admin-cmd.c

@@ -304,7 +304,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 
 	/* XXX: figure out what to do about RTD3R/RTD3 */
 	id->oaes = cpu_to_le32(NVMET_AEN_CFG_OPTIONAL);
-	id->ctratt = cpu_to_le32(1 << 0);
+	id->ctratt = cpu_to_le32(NVME_CTRL_ATTR_HID_128_BIT);
 
 	id->oacs = 0;
 

include/linux/nvme.h

@@ -198,6 +198,10 @@ enum {
 	NVME_PS_FLAGS_NON_OP_STATE	= 1 << 1,
 };
 
+enum nvme_ctrl_attr {
+	NVME_CTRL_ATTR_HID_128_BIT	= (1 << 0),
+};
+
 struct nvme_id_ctrl {
 	__le16			vid;
 	__le16			ssvid;