Commit f0ee7acf authored by Manfred Rudigier's avatar Manfred Rudigier Committed by David S. Miller
Browse files

gianfar: Add hardware TX timestamping support 



If a packet has the skb_shared_tx->hardware flag set the device is
instructed to generate a TX timestamp and write it back to memory after
the frame is transmitted. During the clean_tx_ring operation the
timestamp will be extracted and copied into the skb_shared_hwtstamps
struct of the skb.

TX timestamping is enabled by setting the tx_type to something else
than HWTSTAMP_TX_OFF with the SIOCSHWTSTAMP ioctl command. It is only
supported by eTSEC devices.

Signed-off-by: default avatarManfred Rudigier <manfred.rudigier@omicron.at>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cc772ab7

drivers/net/gianfar.c

+99 −19
Original line number Diff line number Diff line
@@ -795,8 +795,18 @@ static int gfar_hwtstamp_ioctl(struct net_device *netdev, 
	if (config.flags)

		return -EINVAL;



	if (config.tx_type)

	switch (config.tx_type) {

	case HWTSTAMP_TX_OFF:

		priv->hwts_tx_en = 0;

		break;

	case HWTSTAMP_TX_ON:

		if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER))

			return -ERANGE;

		priv->hwts_tx_en = 1;

		break;

	default:

		return -ERANGE;

	}



	switch (config.rx_filter) {

	case HWTSTAMP_FILTER_NONE:
@@ -1972,23 +1982,29 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	struct netdev_queue *txq;

	struct gfar __iomem *regs = NULL;

	struct txfcb *fcb = NULL;

	struct txbd8 *txbdp, *txbdp_start, *base;

	struct txbd8 *txbdp, *txbdp_start, *base, *txbdp_tstamp = NULL;

	u32 lstatus;

	int i, rq = 0;

	int i, rq = 0, do_tstamp = 0;

	u32 bufaddr;

	unsigned long flags;

	unsigned int nr_frags, length;



	unsigned int nr_frags, nr_txbds, length;

	union skb_shared_tx *shtx;



	rq = skb->queue_mapping;

	tx_queue = priv->tx_queue[rq];

	txq = netdev_get_tx_queue(dev, rq);

	base = tx_queue->tx_bd_base;

	regs = tx_queue->grp->regs;

	shtx = skb_tx(skb);



	/* check if time stamp should be generated */

	if (unlikely(shtx->hardware && priv->hwts_tx_en))

		do_tstamp = 1;



	/* make space for additional header when fcb is needed */

	if (((skb->ip_summed == CHECKSUM_PARTIAL) ||

			(priv->vlgrp && vlan_tx_tag_present(skb))) &&

			(priv->vlgrp && vlan_tx_tag_present(skb)) ||

			unlikely(do_tstamp)) &&

			(skb_headroom(skb) < GMAC_FCB_LEN)) {

		struct sk_buff *skb_new;
@@ -2005,8 +2021,14 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	/* total number of fragments in the SKB */

	nr_frags = skb_shinfo(skb)->nr_frags;



	/* calculate the required number of TxBDs for this skb */

	if (unlikely(do_tstamp))

		nr_txbds = nr_frags + 2;

	else

		nr_txbds = nr_frags + 1;



	/* check if there is space to queue this packet */

	if ((nr_frags+1) > tx_queue->num_txbdfree) {

	if (nr_txbds > tx_queue->num_txbdfree) {

		/* no space, stop the queue */

		netif_tx_stop_queue(txq);

		dev->stats.tx_fifo_errors++;
@@ -2018,9 +2040,19 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	txq->tx_packets ++;



	txbdp = txbdp_start = tx_queue->cur_tx;

	lstatus = txbdp->lstatus;



	/* Time stamp insertion requires one additional TxBD */

	if (unlikely(do_tstamp))

		txbdp_tstamp = txbdp = next_txbd(txbdp, base,

				tx_queue->tx_ring_size);



	if (nr_frags == 0) {

		lstatus = txbdp->lstatus | BD_LFLAG(TXBD_LAST | TXBD_INTERRUPT);

		if (unlikely(do_tstamp))

			txbdp_tstamp->lstatus |= BD_LFLAG(TXBD_LAST |

					TXBD_INTERRUPT);

		else

			lstatus |= BD_LFLAG(TXBD_LAST | TXBD_INTERRUPT);

	} else {

		/* Place the fragment addresses and lengths into the TxBDs */

		for (i = 0; i < nr_frags; i++) {
@@ -2066,11 +2098,32 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) 
		gfar_tx_vlan(skb, fcb);

	}



	/* setup the TxBD length and buffer pointer for the first BD */

	/* Setup tx hardware time stamping if requested */

	if (unlikely(do_tstamp)) {

		shtx->in_progress = 1;

		if (fcb == NULL)

			fcb = gfar_add_fcb(skb);

		fcb->ptp = 1;

		lstatus |= BD_LFLAG(TXBD_TOE);

	}



	txbdp_start->bufPtr = dma_map_single(&priv->ofdev->dev, skb->data,

			skb_headlen(skb), DMA_TO_DEVICE);



	/*

	 * If time stamping is requested one additional TxBD must be set up. The

	 * first TxBD points to the FCB and must have a data length of

	 * GMAC_FCB_LEN. The second TxBD points to the actual frame data with

	 * the full frame length.

	 */

	if (unlikely(do_tstamp)) {

		txbdp_tstamp->bufPtr = txbdp_start->bufPtr + GMAC_FCB_LEN;

		txbdp_tstamp->lstatus |= BD_LFLAG(TXBD_READY) |

				(skb_headlen(skb) - GMAC_FCB_LEN);

		lstatus |= BD_LFLAG(TXBD_CRC | TXBD_READY) | GMAC_FCB_LEN;

	} else {

		lstatus |= BD_LFLAG(TXBD_CRC | TXBD_READY) | skb_headlen(skb);

	}



	/*

	 * We can work in parallel with gfar_clean_tx_ring(), except
@@ -2110,7 +2163,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	tx_queue->cur_tx = next_txbd(txbdp, base, tx_queue->tx_ring_size);



	/* reduce TxBD free count */

	tx_queue->num_txbdfree -= (nr_frags + 1);

	tx_queue->num_txbdfree -= (nr_txbds);



	dev->trans_start = jiffies;
@@ -2301,16 +2354,18 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) 
	struct net_device *dev = tx_queue->dev;

	struct gfar_private *priv = netdev_priv(dev);

	struct gfar_priv_rx_q *rx_queue = NULL;

	struct txbd8 *bdp;

	struct txbd8 *bdp, *next = NULL;

	struct txbd8 *lbdp = NULL;

	struct txbd8 *base = tx_queue->tx_bd_base;

	struct sk_buff *skb;

	int skb_dirtytx;

	int tx_ring_size = tx_queue->tx_ring_size;

	int frags = 0;

	int frags = 0, nr_txbds = 0;

	int i;

	int howmany = 0;

	u32 lstatus;

	size_t buflen;

	union skb_shared_tx *shtx;



	rx_queue = priv->rx_queue[tx_queue->qindex];

	bdp = tx_queue->dirty_tx;
@@ -2320,7 +2375,18 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) 
		unsigned long flags;



		frags = skb_shinfo(skb)->nr_frags;

		lbdp = skip_txbd(bdp, frags, base, tx_ring_size);



		/*

		 * When time stamping, one additional TxBD must be freed.

		 * Also, we need to dma_unmap_single() the TxPAL.

		 */

		shtx = skb_tx(skb);

		if (unlikely(shtx->in_progress))

			nr_txbds = frags + 2;

		else

			nr_txbds = frags + 1;



		lbdp = skip_txbd(bdp, nr_txbds - 1, base, tx_ring_size);



		lstatus = lbdp->lstatus;
@@ -2329,10 +2395,24 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) 
				(lstatus & BD_LENGTH_MASK))

			break;



		dma_unmap_single(&priv->ofdev->dev,

				bdp->bufPtr,

				bdp->length,

				DMA_TO_DEVICE);

		if (unlikely(shtx->in_progress)) {

			next = next_txbd(bdp, base, tx_ring_size);

			buflen = next->length + GMAC_FCB_LEN;

		} else

			buflen = bdp->length;



		dma_unmap_single(&priv->ofdev->dev, bdp->bufPtr,

				buflen, DMA_TO_DEVICE);



		if (unlikely(shtx->in_progress)) {

			struct skb_shared_hwtstamps shhwtstamps;

			u64 *ns = (u64*) (((u32)skb->data + 0x10) & ~0x7);

			memset(&shhwtstamps, 0, sizeof(shhwtstamps));

			shhwtstamps.hwtstamp = ns_to_ktime(*ns);

			skb_tstamp_tx(skb, &shhwtstamps);

			bdp->lstatus &= BD_LFLAG(TXBD_WRAP);

			bdp = next;

		}



		bdp->lstatus &= BD_LFLAG(TXBD_WRAP);

		bdp = next_txbd(bdp, base, tx_ring_size);
@@ -2364,7 +2444,7 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) 


		howmany++;

		spin_lock_irqsave(&tx_queue->txlock, flags);

		tx_queue->num_txbdfree += frags + 1;

		tx_queue->num_txbdfree += nr_txbds;

		spin_unlock_irqrestore(&tx_queue->txlock, flags);

	}

drivers/net/gianfar.h

+2 −1
Original line number Diff line number Diff line
@@ -540,7 +540,7 @@ struct txbd8 


struct txfcb {

	u8	flags;

	u8	reserved;

	u8	ptp;    /* Flag to enable tx timestamping */

	u8	l4os;	/* Level 4 Header Offset */

	u8	l3os; 	/* Level 3 Header Offset */

	u16	phcs;	/* Pseudo-header Checksum */
@@ -1105,6 +1105,7 @@ struct gfar_private { 


	/* HW time stamping enabled flag */

	int hwts_rx_en;

	int hwts_tx_en;

};



extern unsigned int ftp_rqfpr[MAX_FILER_IDX + 1];

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