Date: Fri, 16 Aug 2019 17:35:57 -0400
From: Jonathan Toppins <jtoppins@redhat.com>
To: rhkernel-list@redhat.com
Cc: darcari@redhat.com, nhorman@redhat.com, linville@redhat.com
Subject: [PATCH RHEL7 5/7] bnxt_en: Cap the returned MSIX vectors to the RDMA
 driver.

In an earlier commit to improve NQ reservations on 57500 chips, we
set the resv_irqs on the 57500 VFs to the fixed value assigned by
the PF regardless of how many are actually used.  The current
code assumes that resv_irqs minus the ones used by the network driver
must be the ones for the RDMA driver.  This is no longer true and
we may return more MSIX vectors than requested, causing inconsistency.
Fix it by capping the value.

Fixes: 01989c6b69d9 ("bnxt_en: Improve NQ reservations.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 1dbc59fa4bbaa108b641cd65a54f662b75e4ed36)
Bugzilla: 1738649
Build Info: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=23050341
Tested: netperf with ipv4 & ipv6 testing
Signed-off-by: Jonathan Toppins <jtoppins@redhat.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
index bfa342a98d08..fc77caf0a076 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
@@ -157,8 +157,10 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, int ulp_id,
 
 	if (BNXT_NEW_RM(bp)) {
 		struct bnxt_hw_resc *hw_resc = &bp->hw_resc;
+		int resv_msix;
 
-		avail_msix = hw_resc->resv_irqs - bp->cp_nr_rings;
+		resv_msix = hw_resc->resv_irqs - bp->cp_nr_rings;
+		avail_msix = min_t(int, resv_msix, avail_msix);
 		edev->ulp_tbl[ulp_id].msix_requested = avail_msix;
 	}
 	bnxt_fill_msix_vecs(bp, ent);
-- 
2.16.4