[PATCH net 2/2] qede: fix memory allocation failures under heavy load

[Bhaskar Upadhaya]

when the system is heavily stressed, kernel get lots of memory
allocation failures which causes kernel panic, so enable proper
error handling during skb allocation

Fixes: 8a8633978b84 ("qede: Add build_skb() support.")
Signed-off-by: Bhaskar Upadhaya <bupadh...@marvell.com>
Signed-off-by: Igor Russkikh <irussk...@marvell.com>
Signed-off-by: Ariel Elior <ael...@marvell.com>
---
 drivers/net/ethernet/qlogic/qede/qede_fp.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qede/qede_fp.c 
b/drivers/net/ethernet/qlogic/qede/qede_fp.c
index 8c47a9d2a965..f2d74b53e421 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_fp.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_fp.c
@@ -751,6 +751,8 @@ qede_build_skb(struct qede_rx_queue *rxq,
 
        buf = page_address(bd->data) + bd->page_offset;
        skb = build_skb(buf, rxq->rx_buf_seg_size);
+       if (unlikely(!skb))
+               return NULL;
 
        skb_reserve(skb, pad);
        skb_put(skb, len);
@@ -767,6 +769,9 @@ qede_tpa_rx_build_skb(struct qede_dev *edev,
        struct sk_buff *skb;
 
        skb = qede_build_skb(rxq, bd, len, pad);
+       if (unlikely(!skb))
+               return NULL;
+
        bd->page_offset += rxq->rx_buf_seg_size;
 
        if (bd->page_offset == PAGE_SIZE) {
@@ -814,6 +819,8 @@ qede_rx_build_skb(struct qede_dev *edev,
        }
 
        skb = qede_build_skb(rxq, bd, len, pad);
+       if (unlikely(!skb))
+               return NULL;
 
        if (unlikely(qede_realloc_rx_buffer(rxq, bd))) {
                /* Incr page ref count to reuse on allocation failure so
@@ -851,11 +858,16 @@ static void qede_tpa_start(struct qede_dev *edev,
        if (unlikely(!tpa_info->skb)) {
                DP_NOTICE(edev, "Failed to allocate SKB for gro\n");
 
+               /* Re-use the buffer instantly instead doing it at tpa_end
+                * as we are already going to throw away this aggregated packet
+                * (i.e CQEs till tpa_end) and then going to update the
+                * producer, so it's safe to pin the buffer here only.
+                */
+               qede_reuse_page(rxq, sw_rx_data_cons);
                /* Consume from ring but do not produce since
                 * this might be used by FW still, it will be re-used
                 * at TPA end.
                 */
-               tpa_info->tpa_start_fail = true;
                qede_rx_bd_ring_consume(rxq);
                tpa_info->state = QEDE_AGG_STATE_ERROR;
                goto cons_buf;
@@ -1025,11 +1037,6 @@ static int qede_tpa_end(struct qede_dev *edev,
 err:
        tpa_info->state = QEDE_AGG_STATE_NONE;
 
-       if (tpa_info->tpa_start_fail) {
-               qede_reuse_page(rxq, &tpa_info->buffer);
-               tpa_info->tpa_start_fail = false;
-       }
-
        dev_kfree_skb_any(tpa_info->skb);
        tpa_info->skb = NULL;
        return 0;
-- 
2.17.1