scsi: ufs: Allow reading descriptor via raw upiu

Allow to read descriptors via raw upiu. This in fact was forbidden just as
a precaution, as ufs-bsg actually enforces which functionality is
supported.
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -5769,6 +5769,20 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,
 
 	/* just copy the upiu response as it is */
 	memcpy(rsp_upiu, lrbp->ucd_rsp_ptr, sizeof(*rsp_upiu));
+	if (desc_buff && desc_op == UPIU_QUERY_OPCODE_READ_DESC) {
+		u8 *descp = (u8 *)lrbp->ucd_rsp_ptr + sizeof(*rsp_upiu);
+		u16 resp_len = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_2) &
+			       MASK_QUERY_DATA_SEG_LEN;
+
+		if (*buff_len >= resp_len) {
+			memcpy(desc_buff, descp, resp_len);
+			*buff_len = resp_len;
+		} else {
+			dev_warn(hba->dev, "rsp size is bigger than buffer");
+			*buff_len = 0;
+			err = -EINVAL;
+		}
+	}
 
 	ufshcd_put_dev_cmd_tag(hba, tag);
 	wake_up(&hba->dev_cmd.tag_wq);
@@ -5804,11 +5818,6 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
 	int ocs_value;
 	u8 tm_f = be32_to_cpu(req_upiu->header.dword_1) >> 16 & MASK_TM_FUNC;
 
-	if (desc_buff && desc_op != UPIU_QUERY_OPCODE_WRITE_DESC) {
-		err = -ENOTSUPP;
-		goto out;
-	}
-
 	switch (msgcode) {
 	case UPIU_TRANSACTION_NOP_OUT:
 		cmd_type = DEV_CMD_TYPE_NOP;
@@ -5849,7 +5858,6 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
 		break;
 	}
 
-out:
 	return err;
 }