[PATCH v2 net-next 2/2] gianfar: Add hardware TX timestamping support
Manfred Rudigier
Manfred.Rudigier at omicron.at
Fri Apr 9 19:10:35 EST 2010
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: Manfred Rudigier <manfred.rudigier at omicron.at>
---
drivers/net/gianfar.c | 118 +++++++++++++++++++++++++++++++++++++++++--------
drivers/net/gianfar.h | 3 +-
2 files changed, 101 insertions(+), 20 deletions(-)
diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 552e10d..becc3f3 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -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);
- lstatus |= BD_LFLAG(TXBD_CRC | TXBD_READY) | skb_headlen(skb);
+ /*
+ * 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);
}
diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
index 1ea287c..ac4a92e 100644
--- a/drivers/net/gianfar.h
+++ b/drivers/net/gianfar.h
@@ -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];
--
1.6.3.3
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