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>

2 files changed, 6 insertions, 7 deletions

diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h
index 6e63d9a7fc75..44e0ff1494e0 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 9b4e5895f5f9..985e37cf17b6 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) {