From 6b84dacadbdc3dab6a5b313d20d5a93b0d998641 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 18 Aug 2009 15:17:09 +0000 Subject: sky2: optimize transmit completion Don't reference the list element in hardware transmit ring on transmit completion. The list element is updated by hardware, therefore it causes a cache miss. Do book keeping in software structure. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/sky2.c | 80 +++++++++++++++++++++--------------------------------- drivers/net/sky2.h | 3 ++ 2 files changed, 34 insertions(+), 49 deletions(-) diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index 7c1880d8b31f..a3e40d70c071 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c @@ -1001,8 +1001,11 @@ static void sky2_prefetch_init(struct sky2_hw *hw, u32 qaddr, static inline struct sky2_tx_le *get_tx_le(struct sky2_port *sky2, u16 *slot) { struct sky2_tx_le *le = sky2->tx_le + *slot; + struct tx_ring_info *re = sky2->tx_ring + *slot; *slot = RING_NEXT(*slot, sky2->tx_ring_size); + re->flags = 0; + re->skb = NULL; le->ctrl = 0; return le; } @@ -1021,12 +1024,6 @@ static void tx_init(struct sky2_port *sky2) sky2->tx_last_upper = 0; } -static inline struct tx_ring_info *tx_le_re(struct sky2_port *sky2, - struct sky2_tx_le *le) -{ - return sky2->tx_ring + (le - sky2->tx_le); -} - /* Update chip's next pointer */ static inline void sky2_put_idx(struct sky2_hw *hw, unsigned q, u16 idx) { @@ -1563,6 +1560,19 @@ static unsigned tx_le_req(const struct sk_buff *skb) return count; } +static void sky2_tx_unmap(struct pci_dev *pdev, + const struct tx_ring_info *re) +{ + if (re->flags & TX_MAP_SINGLE) + pci_unmap_single(pdev, pci_unmap_addr(re, mapaddr), + pci_unmap_len(re, maplen), + PCI_DMA_TODEVICE); + else if (re->flags & TX_MAP_PAGE) + pci_unmap_page(pdev, pci_unmap_addr(re, mapaddr), + pci_unmap_len(re, maplen), + PCI_DMA_TODEVICE); +} + /* * Put one packet in ring for transmit. * A single packet can generate multiple list elements, and @@ -1667,16 +1677,17 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) } } + re = sky2->tx_ring + slot; + re->flags = TX_MAP_SINGLE; + pci_unmap_addr_set(re, mapaddr, mapping); + pci_unmap_len_set(re, maplen, len); + le = get_tx_le(sky2, &slot); le->addr = cpu_to_le32(lower_32_bits(mapping)); le->length = cpu_to_le16(len); le->ctrl = ctrl; le->opcode = mss ? (OP_LARGESEND | HW_OWNER) : (OP_PACKET | HW_OWNER); - re = tx_le_re(sky2, le); - re->skb = skb; - pci_unmap_addr_set(re, mapaddr, mapping); - pci_unmap_len_set(re, maplen, len); for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { const skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; @@ -1695,18 +1706,19 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) le->opcode = OP_ADDR64 | HW_OWNER; } + re = sky2->tx_ring + slot; + re->flags = TX_MAP_PAGE; + pci_unmap_addr_set(re, mapaddr, mapping); + pci_unmap_len_set(re, maplen, frag->size); + le = get_tx_le(sky2, &slot); le->addr = cpu_to_le32(lower_32_bits(mapping)); le->length = cpu_to_le16(frag->size); le->ctrl = ctrl; le->opcode = OP_BUFFER | HW_OWNER; - - re = tx_le_re(sky2, le); - re->skb = skb; - pci_unmap_addr_set(re, mapaddr, mapping); - pci_unmap_len_set(re, maplen, frag->size); } + re->skb = skb; le->ctrl |= EOP; sky2->tx_prod = slot; @@ -1720,23 +1732,9 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) mapping_unwind: for (i = sky2->tx_prod; i != slot; i = RING_NEXT(i, sky2->tx_ring_size)) { - le = sky2->tx_le + i; re = sky2->tx_ring + i; - switch(le->opcode & ~HW_OWNER) { - case OP_LARGESEND: - case OP_PACKET: - pci_unmap_single(hw->pdev, - pci_unmap_addr(re, mapaddr), - pci_unmap_len(re, maplen), - PCI_DMA_TODEVICE); - break; - case OP_BUFFER: - pci_unmap_page(hw->pdev, pci_unmap_addr(re, mapaddr), - pci_unmap_len(re, maplen), - PCI_DMA_TODEVICE); - break; - } + sky2_tx_unmap(hw->pdev, re); } mapping_error: @@ -1759,34 +1757,18 @@ mapping_error: static void sky2_tx_complete(struct sky2_port *sky2, u16 done) { struct net_device *dev = sky2->netdev; - struct pci_dev *pdev = sky2->hw->pdev; unsigned idx; BUG_ON(done >= sky2->tx_ring_size); for (idx = sky2->tx_cons; idx != done; idx = RING_NEXT(idx, sky2->tx_ring_size)) { - struct sky2_tx_le *le = sky2->tx_le + idx; struct tx_ring_info *re = sky2->tx_ring + idx; + struct sk_buff *skb = re->skb; - switch(le->opcode & ~HW_OWNER) { - case OP_LARGESEND: - case OP_PACKET: - pci_unmap_single(pdev, - pci_unmap_addr(re, mapaddr), - pci_unmap_len(re, maplen), - PCI_DMA_TODEVICE); - break; - case OP_BUFFER: - pci_unmap_page(pdev, pci_unmap_addr(re, mapaddr), - pci_unmap_len(re, maplen), - PCI_DMA_TODEVICE); - break; - } - - if (le->ctrl & EOP) { - struct sk_buff *skb = re->skb; + sky2_tx_unmap(sky2->hw->pdev, re); + if (skb) { if (unlikely(netif_msg_tx_done(sky2))) printk(KERN_DEBUG "%s: tx done %u\n", dev->name, idx); diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h index 2c262f763f93..9d07a466aec1 100644 --- a/drivers/net/sky2.h +++ b/drivers/net/sky2.h @@ -1984,6 +1984,9 @@ struct sky2_status_le { struct tx_ring_info { struct sk_buff *skb; + unsigned long flags; +#define TX_MAP_SINGLE 0x0001 +#define TX_MAP_PAGE 000002 DECLARE_PCI_UNMAP_ADDR(mapaddr); DECLARE_PCI_UNMAP_LEN(maplen); }; -- cgit v1.2.3