block: sed-opal: Set MBRDone on S3 resume path if TPER is MBREnabled

Users who are booting off their Opal enabled drives are having
issues when they have a shadow MBR set up after s3/resume cycle.
When the Drive has a shadow MBR setup the MBRDone flag is set to
false upon power loss (S3/S4/S5). When the MBRDone flag is false
I/O to LBA 0 -> LBA_END_MBR are remapped to the shadow mbr
of the drive. If the drive contains useful data in the 0 -> end_mbr
range upon s3 resume the user can never get to that data as the
drive will keep remapping it to the MBR. To fix this when we unlock
on S3 resume, we need to tell the drive that we're done with the
shadow mbr (even though we didnt use it) by setting true to MBRDone.
This way the drive will stop the remapping and the user can access
their data.

Acked-by Jon Derrick: <jonathan.derrick@intel.com>
Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/opal_proto.h

@@ -46,6 +46,7 @@ enum opal_response_token {
 #define GENERIC_HOST_SESSION_NUM 0x41
 
 #define TPER_SYNC_SUPPORTED 0x01
+#define MBR_ENABLED_MASK 0x10
 
 #define TINY_ATOM_DATA_MASK 0x3F
 #define TINY_ATOM_SIGNED 0x40

block/sed-opal.c

@@ -80,6 +80,7 @@ struct parsed_resp {
 
 struct opal_dev {
 	bool supported;
+	bool mbr_enabled;
 
 	void *data;
 	sec_send_recv *send_recv;
@@ -283,6 +284,14 @@ static bool check_tper(const void *data)
 	return true;
 }
 
+static bool check_mbrenabled(const void *data)
+{
+	const struct d0_locking_features *lfeat = data;
+	u8 sup_feat = lfeat->supported_features;
+
+	return !!(sup_feat & MBR_ENABLED_MASK);
+}
+
 static bool check_sum(const void *data)
 {
 	const struct d0_single_user_mode *sum = data;
@@ -417,6 +426,7 @@ static int opal_discovery0_end(struct opal_dev *dev)
 	u32 hlen = be32_to_cpu(hdr->length);
 
 	print_buffer(dev->resp, hlen);
+	dev->mbr_enabled = false;
 
 	if (hlen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
 		pr_debug("Discovery length overflows buffer (%zu+%u)/%u\n",
@@ -442,6 +452,8 @@ static int opal_discovery0_end(struct opal_dev *dev)
 			check_geometry(dev, body);
 			break;
 		case FC_LOCKING:
+			dev->mbr_enabled = check_mbrenabled(body->features);
+			break;
 		case FC_ENTERPRISE:
 		case FC_DATASTORE:
 			/* some ignored properties */
@@ -2190,6 +2202,21 @@ static int __opal_lock_unlock(struct opal_dev *dev,
 	return next(dev);
 }
 
+static int __opal_set_mbr_done(struct opal_dev *dev, struct opal_key *key)
+{
+	u8 mbr_done_tf = 1;
+	const struct opal_step mbrdone_step [] = {
+		{ opal_discovery0, },
+		{ start_admin1LSP_opal_session, key },
+		{ set_mbr_done, &mbr_done_tf },
+		{ end_opal_session, },
+		{ NULL, }
+	};
+
+	dev->steps = mbrdone_step;
+	return next(dev);
+}
+
 static int opal_lock_unlock(struct opal_dev *dev,
 			    struct opal_lock_unlock *lk_unlk)
 {
@@ -2345,6 +2372,11 @@ bool opal_unlock_from_suspend(struct opal_dev *dev)
 				 suspend->unlk.session.sum);
 			was_failure = true;
 		}
+		if (dev->mbr_enabled) {
+			ret = __opal_set_mbr_done(dev, &suspend->unlk.session.opal_key);
+			if (ret)
+				pr_debug("Failed to set MBR Done in S3 resume\n");
+		}
 	}
 	mutex_unlock(&dev->dev_lock);
 	return was_failure;