[ 36/36] be2net: Fix to trim skb for padded vlan packets to workaround an ASIC Bug

Greg Kroah-Hartman
2013-02-12T20:42:03Z

From: Somnath Kotur <somnath.kotur@emulex.com>

commit 93040ae5cc8dcc893eca4a4366dc8415af278edf upstream.

Fixed spelling error in a comment as pointed out by DaveM.
Also refactored existing code a bit to provide placeholders for another ASIC
Bug workaround that will be checked-in soon after this.

Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Jacek Luczak <difrost.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/ethernet/emulex/benet/be.h | 5 ++
drivers/net/ethernet/emulex/benet/be_main.c | 56 +++++++++++++++++++++-------
2 files changed, 47 insertions(+), 14 deletions(-)

--- a/drivers/net/ethernet/emulex/benet/be.h
+++ b/drivers/net/ethernet/emulex/benet/be.h
@@ -536,6 +536,11 @@ static inline void be_check_sriov_fn_typ
adapter->is_virtfn = (sli_intf & SLI_INTF_FT_MASK) ? 1 : 0;
}

+static inline bool is_ipv4_pkt(struct sk_buff *skb)
+{
+ return skb->protocol == ntohs(ETH_P_IP) && ip_hdr(skb)->version == 4;
+}
+
static inline void be_vf_eth_addr_generate(struct be_adapter *adapter, u8 *mac)
{
u32 addr;
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -571,6 +571,11 @@ static inline u16 be_get_tx_vlan_tag(str
return vlan_tag;
}

+static int be_vlan_tag_chk(struct be_adapter *adapter, struct sk_buff *skb)
+{
+ return vlan_tx_tag_present(skb) || adapter->pvid;
+}
+
static void wrb_fill_hdr(struct be_adapter *adapter, struct be_eth_hdr_wrb *hdr,
struct sk_buff *skb, u32 wrb_cnt, u32 len)
{
@@ -698,33 +703,56 @@ dma_err:
return 0;
}

+static struct sk_buff *be_insert_vlan_in_pkt(struct be_adapter *adapter,
+ struct sk_buff *skb)
+{
+ u16 vlan_tag = 0;
+
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (unlikely(!skb))
+ return skb;
+
+ if (vlan_tx_tag_present(skb)) {
+ vlan_tag = be_get_tx_vlan_tag(adapter, skb);
+ __vlan_put_tag(skb, vlan_tag);
+ skb->vlan_tci = 0;
+ }
+
+ return skb;
+}
+
static netdev_tx_t be_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
struct be_adapter *adapter = netdev_priv(netdev);
struct be_tx_obj *txo = &adapter->tx_obj[skb_get_queue_mapping(skb)];
struct be_queue_info *txq = &txo->q;
+ struct iphdr *ip = NULL;
u32 wrb_cnt = 0, copied = 0;
- u32 start = txq->head;
+ u32 start = txq->head, eth_hdr_len;
bool dummy_wrb, stopped = false;

- /* For vlan tagged pkts, BE
- * 1) calculates checksum even when CSO is not requested
- * 2) calculates checksum wrongly for padded pkt less than
- * 60 bytes long.
- * As a workaround disable TX vlan offloading in such cases.
+ eth_hdr_len = ntohs(skb->protocol) == ETH_P_8021Q ?
+ VLAN_ETH_HLEN : ETH_HLEN;
+
+ /* HW has a bug which considers padding bytes as legal
+ * and modifies the IPv4 hdr's 'tot_len' field
*/
- if (unlikely(vlan_tx_tag_present(skb) &&
- (skb->ip_summed != CHECKSUM_PARTIAL || skb->len <= 60))) {
- skb = skb_share_check(skb, GFP_ATOMIC);
- if (unlikely(!skb))
- goto tx_drop;
+ if (skb->len <= 60 && be_vlan_tag_chk(adapter, skb) &&
+ is_ipv4_pkt(skb)) {
+ ip = (struct iphdr *)ip_hdr(skb);
+ pskb_trim(skb, eth_hdr_len + ntohs(ip->tot_len));
+ }

- skb = __vlan_put_tag(skb, be_get_tx_vlan_tag(adapter, skb));
+ /* HW has a bug wherein it will calculate CSUM for VLAN
+ * pkts even though it is disabled.
+ * Manually insert VLAN in pkt.
+ */
+ if (skb->ip_summed != CHECKSUM_PARTIAL &&
+ be_vlan_tag_chk(adapter, skb)) {
+ skb = be_insert_vlan_in_pkt(adapter, skb);
if (unlikely(!skb))
goto tx_drop;
-
- skb->vlan_tci = 0;
}

wrb_cnt = wrb_cnt_for_skb(adapter, skb, &dummy_wrb);