nvme: define constants for identification values

Improve code readability by defining the specification's constants that
the driver is using when decoding identification payloads.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Bart van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/host/core.c

@@ -1859,13 +1859,13 @@ static void nvme_update_disk_info(struct gendisk *disk,
 		 * and whether it should be used instead of AWUPF. If NAWUPF ==
 		 * 0 then AWUPF must be used instead.
 		 */
-		if (id->nsfeat & (1 << 1) && id->nawupf)
+		if (id->nsfeat & NVME_NS_FEAT_ATOMICS && id->nawupf)
 			atomic_bs = (1 + le16_to_cpu(id->nawupf)) * bs;
 		else
 			atomic_bs = (1 + ns->ctrl->subsys->awupf) * bs;
 	}
 
-	if (id->nsfeat & (1 << 4)) {
+	if (id->nsfeat & NVME_NS_FEAT_IO_OPT) {
 		/* NPWG = Namespace Preferred Write Granularity */
 		phys_bs = bs * (1 + le16_to_cpu(id->npwg));
 		/* NOWS = Namespace Optimal Write Size */
@@ -1894,7 +1894,7 @@ static void nvme_update_disk_info(struct gendisk *disk,
 	nvme_config_discard(disk, ns);
 	nvme_config_write_zeroes(disk, ns);
 
-	if (id->nsattr & (1 << 0))
+	if (id->nsattr & NVME_NS_ATTR_RO)
 		set_disk_ro(disk, true);
 	else
 		set_disk_ro(disk, false);
@@ -2685,7 +2685,7 @@ static bool nvme_validate_cntlid(struct nvme_subsystem *subsys,
 			return false;
 		}
 
-		if ((id->cmic & (1 << 1)) ||
+		if ((id->cmic & NVME_CTRL_CMIC_MULTI_CTRL) ||
 		    (ctrl->opts && ctrl->opts->discovery_nqn))
 			continue;
 
@@ -3497,7 +3497,7 @@ static int nvme_init_ns_head(struct nvme_ns *ns, unsigned nsid,
 		struct nvme_id_ns *id)
 {
 	struct nvme_ctrl *ctrl = ns->ctrl;
-	bool is_shared = id->nmic & (1 << 0);
+	bool is_shared = id->nmic & NVME_NS_NMIC_SHARED;
 	struct nvme_ns_head *head = NULL;
 	struct nvme_ns_ids ids;
 	int ret = 0;

drivers/nvme/host/multipath.c

@@ -372,7 +372,7 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
 	 * We also do this for private namespaces as the namespace sharing data could
 	 * change after a rescan.
 	 */
-	if (!(ctrl->subsys->cmic & (1 << 1)) || !multipath)
+	if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) || !multipath)
 		return 0;
 
 	q = blk_alloc_queue(nvme_ns_head_make_request, ctrl->numa_node);
@@ -694,7 +694,8 @@ int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 	int error;
 
 	/* check if multipath is enabled and we have the capability */
-	if (!multipath || !ctrl->subsys || !(ctrl->subsys->cmic & (1 << 3)))
+	if (!multipath || !ctrl->subsys ||
+	    !(ctrl->subsys->cmic & NVME_CTRL_CMIC_ANA))
 		return 0;
 
 	ctrl->anacap = id->anacap;

include/linux/nvme.h

@@ -301,6 +301,8 @@ struct nvme_id_ctrl {
 };
 
 enum {
+	NVME_CTRL_CMIC_MULTI_CTRL		= 1 << 1,
+	NVME_CTRL_CMIC_ANA			= 1 << 3,
 	NVME_CTRL_ONCS_COMPARE			= 1 << 0,
 	NVME_CTRL_ONCS_WRITE_UNCORRECTABLE	= 1 << 1,
 	NVME_CTRL_ONCS_DSM			= 1 << 2,
@@ -396,8 +398,12 @@ enum {
 
 enum {
 	NVME_NS_FEAT_THIN	= 1 << 0,
+	NVME_NS_FEAT_ATOMICS	= 1 << 1,
+	NVME_NS_FEAT_IO_OPT	= 1 << 4,
+	NVME_NS_ATTR_RO		= 1 << 0,
 	NVME_NS_FLBAS_LBA_MASK	= 0xf,
 	NVME_NS_FLBAS_META_EXT	= 0x10,
+	NVME_NS_NMIC_SHARED	= 1 << 0,
 	NVME_LBAF_RP_BEST	= 0,
 	NVME_LBAF_RP_BETTER	= 1,
 	NVME_LBAF_RP_GOOD	= 2,