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Commit 6b84daca authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

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: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ee5f68fe

drivers/net/sky2.c

+31 −49
Original line number Original line Diff line number Diff line
@@ -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)

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 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);

	*slot = RING_NEXT(*slot, sky2->tx_ring_size);

	re->flags = 0;

	re->skb = NULL;

	le->ctrl = 0;

	le->ctrl = 0;

	return le;

	return le;

}

}
@@ -1021,12 +1024,6 @@ static void tx_init(struct sky2_port *sky2) 
	sky2->tx_last_upper = 0;

	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 */

/* Update chip's next pointer */

static inline void sky2_put_idx(struct sky2_hw *hw, unsigned q, u16 idx)

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;

	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.

 * Put one packet in ring for transmit.

 * A single packet can generate multiple list elements, and

 * 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 = get_tx_le(sky2, &slot);

	le->addr = cpu_to_le32(lower_32_bits(mapping));

	le->addr = cpu_to_le32(lower_32_bits(mapping));

	le->length = cpu_to_le16(len);

	le->length = cpu_to_le16(len);

	le->ctrl = ctrl;

	le->ctrl = ctrl;

	le->opcode = mss ? (OP_LARGESEND | HW_OWNER) : (OP_PACKET | HW_OWNER);

	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++) {

	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {

		const skb_frag_t *frag = &skb_shinfo(skb)->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;

			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 = get_tx_le(sky2, &slot);

		le->addr = cpu_to_le32(lower_32_bits(mapping));

		le->addr = cpu_to_le32(lower_32_bits(mapping));

		le->length = cpu_to_le16(frag->size);

		le->length = cpu_to_le16(frag->size);

		le->ctrl = ctrl;

		le->ctrl = ctrl;

		le->opcode = OP_BUFFER | HW_OWNER;

		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;

	le->ctrl |= EOP;





	sky2->tx_prod = slot;

	sky2->tx_prod = slot;
@@ -1720,23 +1732,9 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) 




mapping_unwind:

mapping_unwind:

	for (i = sky2->tx_prod; i != slot; i = RING_NEXT(i, sky2->tx_ring_size)) {

	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;

		re = sky2->tx_ring + i;





		switch(le->opcode & ~HW_OWNER) {

		sky2_tx_unmap(hw->pdev, re);

		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;

		}

	}

	}





mapping_error:

mapping_error:
@@ -1759,34 +1757,18 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) 
static void sky2_tx_complete(struct sky2_port *sky2, u16 done)

static void sky2_tx_complete(struct sky2_port *sky2, u16 done)

{

{

	struct net_device *dev = sky2->netdev;

	struct net_device *dev = sky2->netdev;

	struct pci_dev *pdev = sky2->hw->pdev;

	unsigned idx;

	unsigned idx;





	BUG_ON(done >= sky2->tx_ring_size);

	BUG_ON(done >= sky2->tx_ring_size);





	for (idx = sky2->tx_cons; idx != done;

	for (idx = sky2->tx_cons; idx != done;

	     idx = RING_NEXT(idx, sky2->tx_ring_size)) {

	     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 tx_ring_info *re = sky2->tx_ring + idx;



		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;

		struct sk_buff *skb = re->skb;





		sky2_tx_unmap(sky2->hw->pdev, re);



		if (skb) {

			if (unlikely(netif_msg_tx_done(sky2)))

			if (unlikely(netif_msg_tx_done(sky2)))

				printk(KERN_DEBUG "%s: tx done %u\n",

				printk(KERN_DEBUG "%s: tx done %u\n",

				       dev->name, idx);

				       dev->name, idx);

drivers/net/sky2.h

+3 −0
Original line number Original line Diff line number Diff line
@@ -1984,6 +1984,9 @@ struct sky2_status_le { 




struct tx_ring_info {

struct tx_ring_info {

	struct sk_buff	*skb;

	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_ADDR(mapaddr);

	DECLARE_PCI_UNMAP_LEN(maplen);

	DECLARE_PCI_UNMAP_LEN(maplen);

};

};