gianfar: Cleanup TxFCB insertion on xmit

[~andy/linux] / drivers / net / ethernet / freescale / gianfar.c

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 8d2db7b808b7cb4321dbc6edeb12ebab94b7b0f0..3cb464780777cbcbe7b2be4567ed381150d58f0b 100644 (file)
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -593,7 +593,6 @@ static int gfar_parse_group(struct device_node *np,
                        return -EINVAL;
        }
 
-       grp->grp_id = priv->num_grps;
        grp->priv = priv;
        spin_lock_init(&grp->grplock);
        if (priv->mode == MQ_MG_MODE) {
@@ -2052,6 +2051,24 @@ static inline struct txbd8 *next_txbd(struct txbd8 *bdp, struct txbd8 *base,
        return skip_txbd(bdp, 1, base, ring_size);
 }
 
+/* eTSEC12: csum generation not supported for some fcb offsets */
+static inline bool gfar_csum_errata_12(struct gfar_private *priv,
+                                      unsigned long fcb_addr)
+{
+       return (gfar_has_errata(priv, GFAR_ERRATA_12) &&
+              (fcb_addr % 0x20) > 0x18);
+}
+
+/* eTSEC76: csum generation for frames larger than 2500 may
+ * cause excess delays before start of transmission
+ */
+static inline bool gfar_csum_errata_76(struct gfar_private *priv,
+                                      unsigned int len)
+{
+       return (gfar_has_errata(priv, GFAR_ERRATA_76) &&
+              (len > 2500));
+}
+
 /* This is called by the kernel when a frame is ready for transmission.
  * It is pointed to by the dev->hard_start_xmit function pointer
  */
@@ -2064,23 +2081,11 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
        struct txfcb *fcb = NULL;
        struct txbd8 *txbdp, *txbdp_start, *base, *txbdp_tstamp = NULL;
        u32 lstatus;
-       int i, rq = 0, do_tstamp = 0;
+       int i, rq = 0;
+       int do_tstamp, do_csum, do_vlan;
        u32 bufaddr;
        unsigned long flags;
-       unsigned int nr_frags, nr_txbds, length, fcb_length = GMAC_FCB_LEN;
-
-       /* TOE=1 frames larger than 2500 bytes may see excess delays
-        * before start of transmission.
-        */
-       if (unlikely(gfar_has_errata(priv, GFAR_ERRATA_76) &&
-                    skb->ip_summed == CHECKSUM_PARTIAL &&
-                    skb->len > 2500)) {
-               int ret;
-
-               ret = skb_checksum_help(skb);
-               if (ret)
-                       return ret;
-       }
+       unsigned int nr_frags, nr_txbds, length, fcb_len = 0;
 
        rq = skb->queue_mapping;
        tx_queue = priv->tx_queue[rq];
@@ -2088,21 +2093,23 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
        base = tx_queue->tx_bd_base;
        regs = tx_queue->grp->regs;
 
+       do_csum = (CHECKSUM_PARTIAL == skb->ip_summed);
+       do_vlan = vlan_tx_tag_present(skb);
+       do_tstamp = (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
+                   priv->hwts_tx_en;
+
+       if (do_csum || do_vlan)
+               fcb_len = GMAC_FCB_LEN;
+
        /* check if time stamp should be generated */
-       if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
-                    priv->hwts_tx_en)) {
-               do_tstamp = 1;
-               fcb_length = GMAC_FCB_LEN + GMAC_TXPAL_LEN;
-       }
+       if (unlikely(do_tstamp))
+               fcb_len = GMAC_FCB_LEN + GMAC_TXPAL_LEN;
 
        /* make space for additional header when fcb is needed */
-       if (((skb->ip_summed == CHECKSUM_PARTIAL) ||
-            vlan_tx_tag_present(skb) ||
-            unlikely(do_tstamp)) &&
-           (skb_headroom(skb) < fcb_length)) {
+       if (fcb_len && unlikely(skb_headroom(skb) < fcb_len)) {
                struct sk_buff *skb_new;
 
-               skb_new = skb_realloc_headroom(skb, fcb_length);
+               skb_new = skb_realloc_headroom(skb, fcb_len);
                if (!skb_new) {
                        dev->stats.tx_errors++;
                        kfree_skb(skb);
@@ -2185,36 +2192,38 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
                memset(skb->data, 0, GMAC_TXPAL_LEN);
        }
 
-       /* Set up checksumming */
-       if (CHECKSUM_PARTIAL == skb->ip_summed) {
+       /* Add TxFCB if required */
+       if (fcb_len) {
                fcb = gfar_add_fcb(skb);
-               /* as specified by errata */
-               if (unlikely(gfar_has_errata(priv, GFAR_ERRATA_12) &&
-                            ((unsigned long)fcb % 0x20) > 0x18)) {
+               lstatus |= BD_LFLAG(TXBD_TOE);
+       }
+
+       /* Set up checksumming */
+       if (do_csum) {
+               gfar_tx_checksum(skb, fcb, fcb_len);
+
+               if (unlikely(gfar_csum_errata_12(priv, (unsigned long)fcb)) ||
+                   unlikely(gfar_csum_errata_76(priv, skb->len))) {
                        __skb_pull(skb, GMAC_FCB_LEN);
                        skb_checksum_help(skb);
-               } else {
-                       lstatus |= BD_LFLAG(TXBD_TOE);
-                       gfar_tx_checksum(skb, fcb, fcb_length);
+                       if (do_vlan || do_tstamp) {
+                               /* put back a new fcb for vlan/tstamp TOE */
+                               fcb = gfar_add_fcb(skb);
+                       } else {
+                               /* Tx TOE not used */
+                               lstatus &= ~(BD_LFLAG(TXBD_TOE));
+                               fcb = NULL;
+                       }
                }
        }
 
-       if (vlan_tx_tag_present(skb)) {
-               if (unlikely(NULL == fcb)) {
-                       fcb = gfar_add_fcb(skb);
-                       lstatus |= BD_LFLAG(TXBD_TOE);
-               }
-
+       if (do_vlan)
                gfar_tx_vlan(skb, fcb);
-       }
 
        /* Setup tx hardware time stamping if requested */
        if (unlikely(do_tstamp)) {
                skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
-               if (fcb == NULL)
-                       fcb = gfar_add_fcb(skb);
                fcb->ptp = 1;
-               lstatus |= BD_LFLAG(TXBD_TOE);
        }
 
        txbdp_start->bufPtr = dma_map_single(priv->dev, skb->data,
@@ -2226,9 +2235,9 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
         * the full frame length.
         */
        if (unlikely(do_tstamp)) {
-               txbdp_tstamp->bufPtr = txbdp_start->bufPtr + fcb_length;
+               txbdp_tstamp->bufPtr = txbdp_start->bufPtr + fcb_len;
                txbdp_tstamp->lstatus |= BD_LFLAG(TXBD_READY) |
-                                        (skb_headlen(skb) - fcb_length);
+                                        (skb_headlen(skb) - fcb_len);
                lstatus |= BD_LFLAG(TXBD_CRC | TXBD_READY) | GMAC_FCB_LEN;
        } else {
                lstatus |= BD_LFLAG(TXBD_CRC | TXBD_READY) | skb_headlen(skb);