RDMA/bnxt_re: Fail probe early when not enough MSI-x vectors are reserved

L2 driver allocates and populates the MSI-x vector details for RoCE
in the en_dev structure. RoCE driver requires minimum 2 MSIx vectors.
Hence during probe, driver has to check and bail out if there are not
enough MSI-x vectors reserved for it before proceeding further
initialization.

Reviewed-by: Andy Gospodarek <[email protected]>
Reviewed-by: Ajit Khaparde <[email protected]>
Reviewed-by: Hongguang Gao <[email protected]>
Reviewed-by: Bhargava Chenna Marreddy <[email protected]>
Reviewed-by: Kashyap Desai <[email protected]>
Reviewed-by: Chandramohan Akula <[email protected]>
Signed-off-by: Kalesh AP <[email protected]>
Signed-off-by: Selvin Xavier <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Leon Romanovsky <[email protected]>

Author: Kalesh AP

drivers/infiniband/hw/bnxt_re/bnxt_re.h

@@ -154,6 +154,8 @@ struct bnxt_re_pacing {
 
 #define BNXT_RE_GRC_FIFO_REG_BASE 0x2000
 
+#define BNXT_RE_MIN_MSIX		2
+
 #define MAX_CQ_HASH_BITS		(16)
 #define MAX_SRQ_HASH_BITS		(16)
 

drivers/infiniband/hw/bnxt_re/main.c

@@ -1936,6 +1936,18 @@ static int bnxt_re_dev_init(struct bnxt_re_dev *rdev, u8 op_type)
 	}
 	set_bit(BNXT_RE_FLAG_NETDEV_REGISTERED, &rdev->flags);
 
+	if (rdev->en_dev->ulp_tbl->msix_requested < BNXT_RE_MIN_MSIX) {
+		ibdev_err(&rdev->ibdev,
+			  "RoCE requires minimum 2 MSI-X vectors, but only %d reserved\n",
+			  rdev->en_dev->ulp_tbl->msix_requested);
+		bnxt_unregister_dev(rdev->en_dev);
+		clear_bit(BNXT_RE_FLAG_NETDEV_REGISTERED, &rdev->flags);
+		return -EINVAL;
+	}
+	ibdev_dbg(&rdev->ibdev, "Got %d MSI-X vectors\n",
+		  rdev->en_dev->ulp_tbl->msix_requested);
+	rdev->num_msix = rdev->en_dev->ulp_tbl->msix_requested;
+
 	rc = bnxt_re_setup_chip_ctx(rdev);
 	if (rc) {
 		bnxt_unregister_dev(rdev->en_dev);
@@ -1947,16 +1959,6 @@ static int bnxt_re_dev_init(struct bnxt_re_dev *rdev, u8 op_type)
 	/* Check whether VF or PF */
 	bnxt_re_get_sriov_func_type(rdev);
 
-	if (!rdev->en_dev->ulp_tbl->msix_requested) {
-		ibdev_err(&rdev->ibdev,
-			  "Failed to get MSI-X vectors: %#x\n", rc);
-		rc = -EINVAL;
-		goto fail;
-	}
-	ibdev_dbg(&rdev->ibdev, "Got %d MSI-X vectors\n",
-		  rdev->en_dev->ulp_tbl->msix_requested);
-	rdev->num_msix = rdev->en_dev->ulp_tbl->msix_requested;
-
 	bnxt_re_query_hwrm_intf_version(rdev);
 
 	/* Establish RCFW Communication Channel to initialize the context