nvme: Check for Security send/recv support before issuing commands.

We need to verify that the controller supports the security
commands before actually trying to issue them.
Signed-off-by: Scott Bauer <scott.bauer@intel.com>
[hch: moved the check so that we don't call into the OPAL code if not
      supported]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/nvme/host/core.c

@@ -1264,6 +1264,7 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
 		return -EIO;
 	}
 
+	ctrl->oacs = le16_to_cpu(id->oacs);
 	ctrl->vid = le16_to_cpu(id->vid);
 	ctrl->oncs = le16_to_cpup(&id->oncs);
 	atomic_set(&ctrl->abort_limit, id->acl + 1);

drivers/nvme/host/nvme.h

@@ -140,6 +140,7 @@ struct nvme_ctrl {
 	u32 max_hw_sectors;
 	u16 oncs;
 	u16 vid;
+	u16 oacs;
 	atomic_t abort_limit;
 	u8 event_limit;
 	u8 vwc;

drivers/nvme/host/pci.c

@@ -1792,7 +1792,7 @@ static void nvme_reset_work(struct work_struct *work)
 	if (result)
 		goto out;
 
-	if (!dev->ctrl.opal_dev) {
+	if ((dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) && !dev->ctrl.opal_dev) {
 		dev->ctrl.opal_dev =
 			init_opal_dev(&dev->ctrl, &nvme_sec_submit);
 	}

include/linux/nvme.h

@@ -244,6 +244,7 @@ enum {
 	NVME_CTRL_ONCS_DSM			= 1 << 2,
 	NVME_CTRL_ONCS_WRITE_ZEROES		= 1 << 3,
 	NVME_CTRL_VWC_PRESENT			= 1 << 0,
+	NVME_CTRL_OACS_SEC_SUPP                 = 1 << 0,
 };
 
 struct nvme_lbaf {