RDMA/bnxt_re: Fix max_qp_wrs reported

While creating qps, driver adds one extra entry to the sq size
passed by the ULPs in order to avoid queue full condition.
When ULPs creates QPs with max_qp_wr reported, driver creates
QP with 1 more than the max_wqes supported by HW. Create QP fails
in this case. To avoid this error, reduce 1 entry in max_qp_wqes
and report it to the stack.

Fixes: 1ac5a40 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://patch.msgid.link/20241217102649.1377704-2-kalesh-anakkur.purayil@broadcom.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/bnxt_re/qplib_sp.c

@@ -129,7 +129,7 @@ int bnxt_qplib_get_dev_attr(struct bnxt_qplib_rcfw *rcfw,
 	attr->max_qp_init_rd_atom =
 		sb->max_qp_init_rd_atom > BNXT_QPLIB_MAX_OUT_RD_ATOM ?
 		BNXT_QPLIB_MAX_OUT_RD_ATOM : sb->max_qp_init_rd_atom;
-	attr->max_qp_wqes = le16_to_cpu(sb->max_qp_wr);
+	attr->max_qp_wqes = le16_to_cpu(sb->max_qp_wr) - 1;
 	/*
 	 * 128 WQEs needs to be reserved for the HW (8916). Prevent
 	 * reporting the max number