Commit 0d0cffdc authored by Claudiu Manoil's avatar Claudiu Manoil Committed by David S. Miller
Browse files

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: default avatarClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 02d88fb4

drivers/net/ethernet/freescale/gianfar.c

+33 −29
Original line number Diff line number Diff line
@@ -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);

			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);