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.h b/drivers/net/ethernet/emulex/benet/be.h
index 29aff55f2eea414bf8dec52d61bee70a034fc12c..941aa1f5cf9b05b12648f5aed8cb46c59f3eec1e 100644 (file)
--- a/drivers/net/ethernet/emulex/benet/be.h
+++ b/drivers/net/ethernet/emulex/benet/be.h
@@ -328,6 +328,7 @@ enum vf_state {
 #define BE_FLAGS_WORKER_SCHEDULED              (1 << 3)
 #define BE_UC_PMAC_COUNT               30
 #define BE_VF_UC_PMAC_COUNT            2
+#define BE_FLAGS_QNQ_ASYNC_EVT_RCVD            (1 << 11)
 
 struct phy_info {
        u8 transceiver;
@@ -434,6 +435,7 @@ struct be_adapter {
        u8 wol_cap;
        bool wol;
        u32 uc_macs;            /* Count of secondary UC MAC programmed */
+       u16 qnq_vid;
        u32 msg_enable;
        int be_get_temp_freq;
        u16 max_mcast_mac;
@@ -648,6 +650,11 @@ static inline bool be_is_wol_excluded(struct be_adapter *adapter)
        }
 }
 
+static inline int qnq_async_evt_rcvd(struct be_adapter *adapter)
+{
+       return adapter->flags & BE_FLAGS_QNQ_ASYNC_EVT_RCVD;
+}
+
 extern void be_cq_notify(struct be_adapter *adapter, u16 qid, bool arm,
                u16 num_popped);
 extern void be_link_status_update(struct be_adapter *adapter, u8 link_status);

diff --git a/drivers/net/ethernet/emulex/benet/be_cmds.c b/drivers/net/ethernet/emulex/benet/be_cmds.c
index 3c9b4f12e3e516ff8775c208a3b138c9acd5c109..ce5af9b3b70468bfa4b3962454a0c359c5924dc2 100644 (file)
--- a/drivers/net/ethernet/emulex/benet/be_cmds.c
+++ b/drivers/net/ethernet/emulex/benet/be_cmds.c
@@ -263,6 +263,27 @@ static void be_async_grp5_evt_process(struct be_adapter *adapter,
        }
 }
 
+static void be_async_dbg_evt_process(struct be_adapter *adapter,
+               u32 trailer, struct be_mcc_compl *cmp)
+{
+       u8 event_type = 0;
+       struct be_async_event_qnq *evt = (struct be_async_event_qnq *) cmp;
+
+       event_type = (trailer >> ASYNC_TRAILER_EVENT_TYPE_SHIFT) &
+               ASYNC_TRAILER_EVENT_TYPE_MASK;
+
+       switch (event_type) {
+       case ASYNC_DEBUG_EVENT_TYPE_QNQ:
+               if (evt->valid)
+                       adapter->qnq_vid = le16_to_cpu(evt->vlan_tag);
+               adapter->flags |= BE_FLAGS_QNQ_ASYNC_EVT_RCVD;
+       break;
+       default:
+               dev_warn(&adapter->pdev->dev, "Unknown debug event\n");
+       break;
+       }
+}
+
 static inline bool is_link_state_evt(u32 trailer)
 {
        return ((trailer >> ASYNC_TRAILER_EVENT_CODE_SHIFT) &
@@ -277,6 +298,13 @@ static inline bool is_grp5_evt(u32 trailer)
                                ASYNC_EVENT_CODE_GRP_5);
 }
 
+static inline bool is_dbg_evt(u32 trailer)
+{
+       return (((trailer >> ASYNC_TRAILER_EVENT_CODE_SHIFT) &
+               ASYNC_TRAILER_EVENT_CODE_MASK) ==
+                               ASYNC_EVENT_CODE_QNQ);
+}
+
 static struct be_mcc_compl *be_mcc_compl_get(struct be_adapter *adapter)
 {
        struct be_queue_info *mcc_cq = &adapter->mcc_obj.cq;
@@ -325,6 +353,9 @@ int be_process_mcc(struct be_adapter *adapter)
                        else if (is_grp5_evt(compl->flags))
                                be_async_grp5_evt_process(adapter,
                                compl->flags, compl);
+                       else if (is_dbg_evt(compl->flags))
+                               be_async_dbg_evt_process(adapter,
+                               compl->flags, compl);
                } else if (compl->flags & CQE_FLAGS_COMPLETED_MASK) {
                                status = be_mcc_compl_process(adapter, compl);
                                atomic_dec(&mcc_obj->q.used);
@@ -1022,6 +1053,7 @@ int be_cmd_mccq_ext_create(struct be_adapter *adapter,
 
        /* Subscribe to Link State and Group 5 Events(bits 1 and 5 set) */
        req->async_event_bitmap[0] = cpu_to_le32(0x00000022);
+       req->async_event_bitmap[0] |= cpu_to_le32(1 << ASYNC_EVENT_CODE_QNQ);
        be_dws_cpu_to_le(ctxt, sizeof(req->context));
 
        be_cmd_page_addrs_prepare(req->pages, ARRAY_SIZE(req->pages), q_mem);

diff --git a/drivers/net/ethernet/emulex/benet/be_cmds.h b/drivers/net/ethernet/emulex/benet/be_cmds.h
index 96970860c9150853570f89268095c25b6d04b2ba..07fd9277d3cb354d580ddc034cb6b4ca94b3464e 100644 (file)
--- a/drivers/net/ethernet/emulex/benet/be_cmds.h
+++ b/drivers/net/ethernet/emulex/benet/be_cmds.h
@@ -84,6 +84,9 @@ struct be_mcc_compl {
 #define ASYNC_EVENT_QOS_SPEED          0x1
 #define ASYNC_EVENT_COS_PRIORITY       0x2
 #define ASYNC_EVENT_PVID_STATE         0x3
+#define ASYNC_EVENT_CODE_QNQ           0x6
+#define ASYNC_DEBUG_EVENT_TYPE_QNQ     1
+
 struct be_async_event_trailer {
        u32 code;
 };
@@ -144,6 +147,16 @@ struct be_async_event_grp5_pvid_state {
        struct be_async_event_trailer trailer;
 } __packed;
 
+/* async event indicating outer VLAN tag in QnQ */
+struct be_async_event_qnq {
+       u8 valid;       /* Indicates if outer VLAN is valid */
+       u8 rsvd0;
+       u16 vlan_tag;
+       u32 event_tag;
+       u8 rsvd1[4];
+       struct be_async_event_trailer trailer;
+} __packed;
+
 struct be_mcc_mailbox {
        struct be_mcc_wrb wrb;
        struct be_mcc_compl compl;

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index a254942ed5a609a7148b860ae995ad2618ed7ed8..21109b59fcfcbd61ba3da51b3d620cefca20937b 100644 (file)
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -627,7 +627,7 @@ static inline u16 be_get_tx_vlan_tag(struct be_adapter *adapter,
 }
 
 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 @@ static void wrb_fill_hdr(struct be_adapter *adapter, struct be_eth_hdr_wrb *hdr,
                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 void unmap_tx_frag(struct device *dev, struct be_eth_wrb *wrb,
 }
 
 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 @@ static int make_tx_wrbs(struct be_adapter *adapter, struct be_queue_info *txq,
                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 @@ dma_err:
 }
 
 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 @@ static struct sk_buff *be_insert_vlan_in_pkt(struct be_adapter *adapter,
                        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 @@ static netdev_tx_t be_xmit(struct sk_buff *skb,
        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 @@ static netdev_tx_t be_xmit(struct sk_buff *skb,
         */
        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;