net: simplify flags for tx timestamping

This patch removes the abstraction introduced by the union skb_shared_tx in
the shared skb data.

The access of the different union elements at several places led to some
confusion about accessing the shared tx_flags e.g. in skb_orphan_try().

    http://marc.info/?l=linux-netdev&m=128084897415886&w=2

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 16 insertions, 22 deletions

diff --git a/drivers/net/bfin_mac.c b/drivers/net/bfin_mac.c
index 012613f..7a0e415 100644
--- a/drivers/net/bfin_mac.c
+++ b/drivers/net/bfin_mac.c
@@ -803,15 +803,14 @@ static void bfin_dump_hwtamp(char *s, ktime_t *hw, ktime_t *ts, struct timecompa
 static void bfin_tx_hwtstamp(struct net_device *netdev, struct sk_buff *skb)
 {
 	struct bfin_mac_local *lp = netdev_priv(netdev);
-	union skb_shared_tx *shtx = skb_tx(skb);
 
-	if (shtx->hardware) {
+	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {
 		int timeout_cnt = MAX_TIMEOUT_CNT;
 
 		/* When doing time stamping, keep the connection to the socket
 		 * a while longer
 		 */
-		shtx->in_progress = 1;
+		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 
 		/*
 		 * The timestamping is done at the EMAC module's MII/RMII interface
@@ -991,7 +990,6 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
 	struct bfin_mac_local *lp = netdev_priv(dev);
 	u16 *data;
 	u32 data_align = (unsigned long)(skb->data) & 0x3;
-	union skb_shared_tx *shtx = skb_tx(skb);
 
 	current_tx_ptr->skb = skb;
 
@@ -1005,7 +1003,7 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
 		 * of this field are the length of the packet payload in bytes and the higher
 		 * 4 bits are the timestamping enable field.
 		 */
-		if (shtx->hardware)
+		if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)
 			*data |= 0x1000;
 
 		current_tx_ptr->desc_a.start_addr = (u32)data;
@@ -1015,7 +1013,7 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
 	} else {
 		*((u16 *)(current_tx_ptr->packet)) = (u16)(skb->len);
 		/* enable timestamping for the sent packet */
-		if (shtx->hardware)
+		if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)
 			*((u16 *)(current_tx_ptr->packet)) |= 0x1000;
 		memcpy((u8 *)(current_tx_ptr->packet + 2), skb->data,
 			skb->len);
diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 3d9f958..e6048d6 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -2048,7 +2048,6 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	u32 bufaddr;
 	unsigned long flags;
 	unsigned int nr_frags, nr_txbds, length;
-	union skb_shared_tx *shtx;
 
 	/*
 	 * TOE=1 frames larger than 2500 bytes may see excess delays
@@ -2069,10 +2068,10 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	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))
+	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
+		     priv->hwts_tx_en))
 		do_tstamp = 1;
 
 	/* make space for additional header when fcb is needed */
@@ -2174,7 +2173,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	/* Setup tx hardware time stamping if requested */
 	if (unlikely(do_tstamp)) {
-		shtx->in_progress = 1;
+		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 		if (fcb == NULL)
 			fcb = gfar_add_fcb(skb);
 		fcb->ptp = 1;
@@ -2446,7 +2445,6 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
 	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;
@@ -2461,8 +2459,7 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
 		 * 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))
+		if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
 			nr_txbds = frags + 2;
 		else
 			nr_txbds = frags + 1;
@@ -2476,7 +2473,7 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
 				(lstatus & BD_LENGTH_MASK))
 			break;
 
-		if (unlikely(shtx->in_progress)) {
+		if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) {
 			next = next_txbd(bdp, base, tx_ring_size);
 			buflen = next->length + GMAC_FCB_LEN;
 		} else
@@ -2485,7 +2482,7 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
 		dma_unmap_single(&priv->ofdev->dev, bdp->bufPtr,
 				buflen, DMA_TO_DEVICE);
 
-		if (unlikely(shtx->in_progress)) {
+		if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) {
 			struct skb_shared_hwtstamps shhwtstamps;
 			u64 *ns = (u64*) (((u32)skb->data + 0x10) & ~0x7);
 			memset(&shhwtstamps, 0, sizeof(shhwtstamps));
diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h
index 6e63d9a..44e0ff1 100644
--- a/drivers/net/igb/igb.h
+++ b/drivers/net/igb/igb.h
@@ -143,7 +143,7 @@ struct igb_buffer {
 			u16 next_to_watch;
 			unsigned int bytecount;
 			u16 gso_segs;
-			union skb_shared_tx shtx;
+			u8 tx_flags;
 			u8 mapped_as_page;
 		};
 		/* RX */
diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 9b4e589..985e37c 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -3954,7 +3954,7 @@ static inline int igb_tx_map_adv(struct igb_ring *tx_ring, struct sk_buff *skb,
 	}
 
 	tx_ring->buffer_info[i].skb = skb;
-	tx_ring->buffer_info[i].shtx = skb_shinfo(skb)->tx_flags;
+	tx_ring->buffer_info[i].tx_flags = skb_shinfo(skb)->tx_flags;
 	/* multiply data chunks by size of headers */
 	tx_ring->buffer_info[i].bytecount = ((gso_segs - 1) * hlen) + skb->len;
 	tx_ring->buffer_info[i].gso_segs = gso_segs;
@@ -4088,7 +4088,6 @@ netdev_tx_t igb_xmit_frame_ring_adv(struct sk_buff *skb,
 	u32 tx_flags = 0;
 	u16 first;
 	u8 hdr_len = 0;
-	union skb_shared_tx *shtx = skb_tx(skb);
 
 	/* need: 1 descriptor per page,
 	 *       + 2 desc gap to keep tail from touching head,
@@ -4100,8 +4099,8 @@ netdev_tx_t igb_xmit_frame_ring_adv(struct sk_buff *skb,
 		return NETDEV_TX_BUSY;
 	}
 
-	if (unlikely(shtx->hardware)) {
-		shtx->in_progress = 1;
+	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
+		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 		tx_flags |= IGB_TX_FLAGS_TSTAMP;
 	}
 
@@ -5319,7 +5318,7 @@ static void igb_tx_hwtstamp(struct igb_q_vector *q_vector, struct igb_buffer *bu
 	u64 regval;
 
 	/* if skb does not support hw timestamp or TX stamp not valid exit */
-	if (likely(!buffer_info->shtx.hardware) ||
+	if (likely(!(buffer_info->tx_flags & SKBTX_HW_TSTAMP)) ||
 	    !(rd32(E1000_TSYNCTXCTL) & E1000_TSYNCTXCTL_VALID))
 		return;
 
@@ -5500,7 +5499,7 @@ static void igb_rx_hwtstamp(struct igb_q_vector *q_vector, u32 staterr,
 	 * values must belong to this one here and therefore we don't need to
 	 * compare any of the additional attributes stored for it.
 	 *
-	 * If nothing went wrong, then it should have a skb_shared_tx that we
+	 * If nothing went wrong, then it should have a shared tx_flags that we
 	 * can turn into a skb_shared_hwtstamps.
 	 */
 	if (staterr & E1000_RXDADV_STAT_TSIP) {