From c2af62256e8d6f3c2f72f8678efde75423490c76 Mon Sep 17 00:00:00 2001
From: "Dwip N. Banerjee" <dnbanerg@us.ibm.com>
Date: Wed, 9 Dec 2020 20:53:31 -0500
Subject: [PATCH] ibmvnic: fix rx buffer tracking and index management in
 replenish_rx_pool partial success

References: jsc#SLE-17268 bsc#1179929 ltc#189960
Patch-mainline: v5.11-rc1
Git-commit: c2af62256e8d6f3c2f72f8678efde75423490c76

We observed that in the error case for batched send_subcrq_indirect() the
driver does not account for the partial success case. This caused Linux to
crash when free_map and pool index are inconsistent.

Driver needs to update the rx pools "available" count when some batched
sends worked but an error was encountered as part of the whole operation.
Also track replenish_add_buff_failure for statistic purposes.

Fixes: 4f0b6812e9b9a ("ibmvnic: Introduce batched RX buffer descriptor transmission")
Signed-off-by: Dwip N. Banerjee <dnbanerg@us.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index cb701a6c0712..a2191392ca4f 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -398,6 +398,8 @@ static void replenish_rx_pool(struct ibmvnic_adapter *adapter,
 		dev_kfree_skb_any(pool->rx_buff[index].skb);
 		pool->rx_buff[index].skb = NULL;
 	}
+	adapter->replenish_add_buff_failure += ind_bufp->index;
+	atomic_add(buffers_added, &pool->available);
 	ind_bufp->index = 0;
 	if (lpar_rc == H_CLOSED || adapter->failover_pending) {
 		/* Disable buffer pool replenishment and report carrier off if
-- 
2.26.2