From 3595990a9ccc1b819bfe801940eb05f8a84f253e Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Fri, 11 May 2012 08:32:40 +0000 Subject: ixgbevf: Cleanup accounting for space needed at start of xmit_frame This change cleans up the accounting needed at the start of xmit_frame so that we can avoid doing too much work to determine how many descriptors we will need. Signed-off-by: Alexander Duyck Signed-off-by: Greg Rose Tested-by: Sibai Li Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 46 ++++++++++++----------- 1 file changed, 24 insertions(+), 22 deletions(-) (limited to 'drivers/net/ethernet') diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index 75af1920b0f7..855bb21824fe 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c @@ -175,10 +175,8 @@ static void ixgbevf_unmap_and_free_tx_resource(struct ixgbevf_adapter *adapter, #define IXGBE_MAX_DATA_PER_TXD (1 << IXGBE_MAX_TXD_PWR) /* Tx Descriptors needed, worst case */ -#define TXD_USE_COUNT(S) (((S) >> IXGBE_MAX_TXD_PWR) + \ - (((S) & (IXGBE_MAX_DATA_PER_TXD - 1)) ? 1 : 0)) -#define DESC_NEEDED (TXD_USE_COUNT(IXGBE_MAX_DATA_PER_TXD) /* skb->data */ + \ - MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1) /* for context */ +#define TXD_USE_COUNT(S) DIV_ROUND_UP((S), IXGBE_MAX_DATA_PER_TXD) +#define DESC_NEEDED (MAX_SKB_FRAGS + 4) static void ixgbevf_tx_timeout(struct net_device *netdev); @@ -2932,33 +2930,37 @@ static int ixgbevf_xmit_frame(struct sk_buff *skb, struct net_device *netdev) unsigned int tx_flags = 0; u8 hdr_len = 0; int r_idx = 0, tso; - int count = 0; - - unsigned int f; + u16 count = TXD_USE_COUNT(skb_headlen(skb)); +#if PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD + unsigned short f; +#endif tx_ring = &adapter->tx_ring[r_idx]; + /* + * need: 1 descriptor per page * PAGE_SIZE/IXGBE_MAX_DATA_PER_TXD, + * + 1 desc for skb_headlen/IXGBE_MAX_DATA_PER_TXD, + * + 2 desc gap to keep tail from touching head, + * + 1 desc for context descriptor, + * otherwise try next time + */ +#if PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD + for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) + count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size); +#else + count += skb_shinfo(skb)->nr_frags; +#endif + if (ixgbevf_maybe_stop_tx(netdev, tx_ring, count + 3)) { + adapter->tx_busy++; + return NETDEV_TX_BUSY; + } + if (vlan_tx_tag_present(skb)) { tx_flags |= vlan_tx_tag_get(skb); tx_flags <<= IXGBE_TX_FLAGS_VLAN_SHIFT; tx_flags |= IXGBE_TX_FLAGS_VLAN; } - /* four things can cause us to need a context descriptor */ - if (skb_is_gso(skb) || - (skb->ip_summed == CHECKSUM_PARTIAL) || - (tx_flags & IXGBE_TX_FLAGS_VLAN)) - count++; - - count += TXD_USE_COUNT(skb_headlen(skb)); - for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) - count += TXD_USE_COUNT(skb_frag_size(&skb_shinfo(skb)->frags[f])); - - if (ixgbevf_maybe_stop_tx(netdev, tx_ring, count)) { - adapter->tx_busy++; - return NETDEV_TX_BUSY; - } - first = tx_ring->next_to_use; if (skb->protocol == htons(ETH_P_IP)) -- cgit v1.2.3