bnx2x: properly calculate lro_mss

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 42 insertions, 6 deletions

diff --git a/drivers/net/bnx2x/bnx2x_cmn.c b/drivers/net/bnx2x/bnx2x_cmn.c
index a58baf35d229..93798129061b 100644
--- a/drivers/net/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/bnx2x/bnx2x_cmn.c
@@ -259,10 +259,44 @@ static void bnx2x_tpa_start(struct bnx2x_fastpath *fp, u16 queue,
 #endif
 }
 
+/* Timestamp option length allowed for TPA aggregation:
+ *
+ *              nop nop kind length echo val
+ */
+#define TPA_TSTAMP_OPT_LEN      12
+/**
+ * Calculate the approximate value of the MSS for this
+ * aggregation using the first packet of it.
+ *
+ * @param bp
+ * @param parsing_flags Parsing flags from the START CQE
+ * @param len_on_bd Total length of the first packet for the
+ *                   aggregation.
+ */
+static inline u16 bnx2x_set_lro_mss(struct bnx2x *bp, u16 parsing_flags,
+                                    u16 len_on_bd)
+{
+        /* TPA arrgregation won't have an IP options and TCP options
+         * other than timestamp.
+         */
+        u16 hdrs_len = ETH_HLEN + sizeof(struct iphdr) + sizeof(struct tcphdr);
+
+
+        /* Check if there was a TCP timestamp, if there is it's will
+         * always be 12 bytes length: nop nop kind length echo val.
+         *
+         * Otherwise FW would close the aggregation.
+         */
+        if (parsing_flags & PARSING_FLAGS_TIME_STAMP_EXIST_FLAG)
+                hdrs_len += TPA_TSTAMP_OPT_LEN;
+
+        return len_on_bd - hdrs_len;
+}
+
 static int bnx2x_fill_frag_skb(struct bnx2x *bp, struct bnx2x_fastpath *fp,
                                struct sk_buff *skb,
                                struct eth_fast_path_rx_cqe *fp_cqe,
-                               u16 cqe_idx)
+                               u16 cqe_idx, u16 parsing_flags)
 {
         struct sw_rx_page *rx_pg, old_rx_pg;
         u16 len_on_bd = le16_to_cpu(fp_cqe->len_on_bd);
@@ -275,8 +309,8 @@ static int bnx2x_fill_frag_skb(struct bnx2x *bp, struct bnx2x_fastpath *fp,
 
         /* This is needed in order to enable forwarding support */
         if (frag_size)
-                skb_shinfo(skb)->gso_size = min((u32)SGE_PAGE_SIZE,
-                                               max(frag_size, (u32)len_on_bd));
+                skb_shinfo(skb)->gso_size = bnx2x_set_lro_mss(bp, parsing_flags,
+                                                              len_on_bd);
 
 #ifdef BNX2X_STOP_ON_ERROR
         if (pages > min_t(u32, 8, MAX_SKB_FRAGS)*SGE_PAGE_SIZE*PAGES_PER_SGE) {
@@ -344,6 +378,8 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp,
         if (likely(new_skb)) {
                 /* fix ip xsum and give it to the stack */
                 /* (no need to map the new skb) */
+                u16 parsing_flags =
+                        le16_to_cpu(cqe->fast_path_cqe.pars_flags.flags);
 
                 prefetch(skb);
                 prefetch(((char *)(skb)) + L1_CACHE_BYTES);
@@ -373,9 +409,9 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp,
                 }
 
                 if (!bnx2x_fill_frag_skb(bp, fp, skb,
-                                         &cqe->fast_path_cqe, cqe_idx)) {
-                        if ((le16_to_cpu(cqe->fast_path_cqe.
-                            pars_flags.flags) & PARSING_FLAGS_VLAN))
+                                         &cqe->fast_path_cqe, cqe_idx,
+                                         parsing_flags)) {
+                        if (parsing_flags & PARSING_FLAGS_VLAN)
                                 __vlan_hwaccel_put_tag(skb,
                                                  le16_to_cpu(cqe->fast_path_cqe.
                                                              vlan_tag));