From 0d0cffdcc6fc4f57080b9a443401e8dad5ca77f8 Mon Sep 17 00:00:00 2001 From: Claudiu Manoil Date: Mon, 5 Aug 2013 17:20:10 +0300 Subject: [PATCH] gianfar: Cleanup TxFCB insertion on xmit Cleanup gfar_start_xmit()'s fast path by factoring out "redundant" FCB insertion code (repeated gfar_add_fcb() calls and related) and by reducing the number of if() clauses (i.e. if(fcb) checks). Improve maintainability (e.g. there's less code and easier to read) also by introducing do_csum and do_vlan to mark the other 2 Tx TOE functionalities, following the same model as do_tstamp. fcb_len may also be 0 now, to mark that Tx FCB insertion conditions (do_csum, do_vlan, do_tstamp) have not been met. Signed-off-by: Claudiu Manoil Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/gianfar.c | 62 +++++++++++++----------- 1 file changed, 33 insertions(+), 29 deletions(-) diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c index 352035e440d8..3cb464780777 100644 --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -2081,10 +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; + unsigned int nr_frags, nr_txbds, length, fcb_len = 0; rq = skb->queue_mapping; tx_queue = priv->tx_queue[rq]; @@ -2092,21 +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); @@ -2189,37 +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); lstatus |= BD_LFLAG(TXBD_TOE); - gfar_tx_checksum(skb, fcb, fcb_length); + } + + /* 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); - lstatus &= ~(BD_LFLAG(TXBD_TOE)); - fcb = NULL; + 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, @@ -2231,9 +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); -- 2.20.1