be2net: fix a Tx stall bug caused by a specific ipv6 packet
The ASIC could lockup in the transmit path when it tries
to insert VLAN in a specific ipv6 packet.
1) Identify the packet which can cause this.
2) Check if the firmware provides a workaround to prevent this.
3) If workaround is not present, drop the packet.
4) If the firmware provides a workaround, insert the VLAN tag in the
packet and inform the firmware to skip further VLAN insertions.
Signed-off-by: Ajit Khaparde <ajit.khaparde@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index a254942..21109b5 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -627,7 +627,7 @@
}
static void wrb_fill_hdr(struct be_adapter *adapter, struct be_eth_hdr_wrb *hdr,
- struct sk_buff *skb, u32 wrb_cnt, u32 len)
+ struct sk_buff *skb, u32 wrb_cnt, u32 len, bool skip_hw_vlan)
{
u16 vlan_tag;
@@ -654,8 +654,9 @@
AMAP_SET_BITS(struct amap_eth_hdr_wrb, vlan_tag, hdr, vlan_tag);
}
+ /* To skip HW VLAN tagging: evt = 1, compl = 0 */
+ AMAP_SET_BITS(struct amap_eth_hdr_wrb, complete, hdr, !skip_hw_vlan);
AMAP_SET_BITS(struct amap_eth_hdr_wrb, event, hdr, 1);
- AMAP_SET_BITS(struct amap_eth_hdr_wrb, complete, hdr, 1);
AMAP_SET_BITS(struct amap_eth_hdr_wrb, num_wrb, hdr, wrb_cnt);
AMAP_SET_BITS(struct amap_eth_hdr_wrb, len, hdr, len);
}
@@ -678,7 +679,8 @@
}
static int make_tx_wrbs(struct be_adapter *adapter, struct be_queue_info *txq,
- struct sk_buff *skb, u32 wrb_cnt, bool dummy_wrb)
+ struct sk_buff *skb, u32 wrb_cnt, bool dummy_wrb,
+ bool skip_hw_vlan)
{
dma_addr_t busaddr;
int i, copied = 0;
@@ -727,7 +729,7 @@
queue_head_inc(txq);
}
- wrb_fill_hdr(adapter, hdr, first_skb, wrb_cnt, copied);
+ wrb_fill_hdr(adapter, hdr, first_skb, wrb_cnt, copied, skip_hw_vlan);
be_dws_cpu_to_le(hdr, sizeof(*hdr));
return copied;
@@ -744,7 +746,8 @@
}
static struct sk_buff *be_insert_vlan_in_pkt(struct be_adapter *adapter,
- struct sk_buff *skb)
+ struct sk_buff *skb,
+ bool *skip_hw_vlan)
{
u16 vlan_tag = 0;
@@ -759,9 +762,67 @@
skb->vlan_tci = 0;
}
+ if (qnq_async_evt_rcvd(adapter) && adapter->pvid) {
+ if (!vlan_tag)
+ vlan_tag = adapter->pvid;
+ if (skip_hw_vlan)
+ *skip_hw_vlan = true;
+ }
+
+ if (vlan_tag) {
+ skb = __vlan_put_tag(skb, vlan_tag);
+ if (unlikely(!skb))
+ return skb;
+
+ skb->vlan_tci = 0;
+ }
+
+ /* Insert the outer VLAN, if any */
+ if (adapter->qnq_vid) {
+ vlan_tag = adapter->qnq_vid;
+ skb = __vlan_put_tag(skb, vlan_tag);
+ if (unlikely(!skb))
+ return skb;
+ if (skip_hw_vlan)
+ *skip_hw_vlan = true;
+ }
+
return skb;
}
+static bool be_ipv6_exthdr_check(struct sk_buff *skb)
+{
+ struct ethhdr *eh = (struct ethhdr *)skb->data;
+ u16 offset = ETH_HLEN;
+
+ if (eh->h_proto == htons(ETH_P_IPV6)) {
+ struct ipv6hdr *ip6h = (struct ipv6hdr *)(skb->data + offset);
+
+ offset += sizeof(struct ipv6hdr);
+ if (ip6h->nexthdr != NEXTHDR_TCP &&
+ ip6h->nexthdr != NEXTHDR_UDP) {
+ struct ipv6_opt_hdr *ehdr =
+ (struct ipv6_opt_hdr *) (skb->data + offset);
+
+ /* offending pkt: 2nd byte following IPv6 hdr is 0xff */
+ if (ehdr->hdrlen == 0xff)
+ return true;
+ }
+ }
+ return false;
+}
+
+static int be_vlan_tag_tx_chk(struct be_adapter *adapter, struct sk_buff *skb)
+{
+ return vlan_tx_tag_present(skb) || adapter->pvid || adapter->qnq_vid;
+}
+
+static int be_ipv6_tx_stall_chk(struct be_adapter *adapter, struct sk_buff *skb)
+{
+ return BE3_chip(adapter) &&
+ be_ipv6_exthdr_check(skb);
+}
+
static netdev_tx_t be_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
@@ -772,6 +833,7 @@
u32 wrb_cnt = 0, copied = 0;
u32 start = txq->head, eth_hdr_len;
bool dummy_wrb, stopped = false;
+ bool skip_hw_vlan = false;
eth_hdr_len = ntohs(skb->protocol) == ETH_P_8021Q ?
VLAN_ETH_HLEN : ETH_HLEN;
@@ -790,14 +852,37 @@
*/
if (skb->ip_summed != CHECKSUM_PARTIAL &&
vlan_tx_tag_present(skb)) {
- skb = be_insert_vlan_in_pkt(adapter, skb);
+ skb = be_insert_vlan_in_pkt(adapter, skb, &skip_hw_vlan);
+ if (unlikely(!skb))
+ goto tx_drop;
+ }
+
+ /* HW may lockup when VLAN HW tagging is requested on
+ * certain ipv6 packets. Drop such pkts if the HW workaround to
+ * skip HW tagging is not enabled by FW.
+ */
+ if (unlikely(be_ipv6_tx_stall_chk(adapter, skb) &&
+ (adapter->pvid || adapter->qnq_vid) &&
+ !qnq_async_evt_rcvd(adapter)))
+ goto tx_drop;
+
+ /* Manual VLAN tag insertion to prevent:
+ * ASIC lockup when the ASIC inserts VLAN tag into
+ * certain ipv6 packets. Insert VLAN tags in driver,
+ * and set event, completion, vlan bits accordingly
+ * in the Tx WRB.
+ */
+ if (be_ipv6_tx_stall_chk(adapter, skb) &&
+ be_vlan_tag_tx_chk(adapter, skb)) {
+ skb = be_insert_vlan_in_pkt(adapter, skb, &skip_hw_vlan);
if (unlikely(!skb))
goto tx_drop;
}
wrb_cnt = wrb_cnt_for_skb(adapter, skb, &dummy_wrb);
- copied = make_tx_wrbs(adapter, txq, skb, wrb_cnt, dummy_wrb);
+ copied = make_tx_wrbs(adapter, txq, skb, wrb_cnt, dummy_wrb,
+ skip_hw_vlan);
if (copied) {
int gso_segs = skb_shinfo(skb)->gso_segs;