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Commit 5c15332b authored by Olof Johansson's avatar Olof Johansson Committed by David S. Miller
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pasemi_mac: performance tweaks 



pasemi_mac: performance tweaks

* Seems like we do better with a smaller RX ring, probably because chances of
  still having the SKB cached are better
* Const-ify variables to get better code generation and fewer reloads
* Move prefetching around a little, and try to prefetch the whole SKB
* Set NETIF_F_HIGHDMA
* Misc other minor tweaks

Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 34c20624

drivers/net/pasemi_mac.c

+68 −46
Original line number Diff line number Diff line
@@ -56,7 +56,7 @@ 




/* Must be a power of two */

#define RX_RING_SIZE 4096

#define RX_RING_SIZE 1024

#define TX_RING_SIZE 4096



#define DEFAULT_MSG_ENABLE	  \
@@ -103,12 +103,12 @@ static void write_iob_reg(unsigned int reg, unsigned int val) 
	pasemi_write_iob_reg(reg, val);

}



static unsigned int read_mac_reg(struct pasemi_mac *mac, unsigned int reg)

static unsigned int read_mac_reg(const struct pasemi_mac *mac, unsigned int reg)

{

	return pasemi_read_mac_reg(mac->dma_if, reg);

}



static void write_mac_reg(struct pasemi_mac *mac, unsigned int reg,

static void write_mac_reg(const struct pasemi_mac *mac, unsigned int reg,

			  unsigned int val)

{

	pasemi_write_mac_reg(mac->dma_if, reg, val);
@@ -124,16 +124,26 @@ static void write_dma_reg(unsigned int reg, unsigned int val) 
	pasemi_write_dma_reg(reg, val);

}



static struct pasemi_mac_rxring *rx_ring(struct pasemi_mac *mac)

static struct pasemi_mac_rxring *rx_ring(const struct pasemi_mac *mac)

{

	return mac->rx;

}



static struct pasemi_mac_txring *tx_ring(struct pasemi_mac *mac)

static struct pasemi_mac_txring *tx_ring(const struct pasemi_mac *mac)

{

	return mac->tx;

}



static inline void prefetch_skb(const struct sk_buff *skb)

{

	const void *d = skb;



	prefetch(d);

	prefetch(d+64);

	prefetch(d+128);

	prefetch(d+192);

}



static int mac_to_intf(struct pasemi_mac *mac)

{

	struct pci_dev *pdev = mac->pdev;
@@ -211,19 +221,18 @@ static int pasemi_get_mac_addr(struct pasemi_mac *mac) 


static int pasemi_mac_unmap_tx_skb(struct pasemi_mac *mac,

				    struct sk_buff *skb,

				    dma_addr_t *dmas)

				    const dma_addr_t *dmas)

{

	int f;

	int nfrags = skb_shinfo(skb)->nr_frags;

	struct pci_dev *pdev = mac->dma_pdev;



	pci_unmap_single(mac->dma_pdev, dmas[0], skb_headlen(skb),

			 PCI_DMA_TODEVICE);

	pci_unmap_single(pdev, dmas[0], skb_headlen(skb), PCI_DMA_TODEVICE);



	for (f = 0; f < nfrags; f++) {

		skb_frag_t *frag = &skb_shinfo(skb)->frags[f];



		pci_unmap_page(mac->dma_pdev, dmas[f+1], frag->size,

			       PCI_DMA_TODEVICE);

		pci_unmap_page(pdev, dmas[f+1], frag->size, PCI_DMA_TODEVICE);

	}

	dev_kfree_skb_irq(skb);
@@ -233,7 +242,7 @@ static int pasemi_mac_unmap_tx_skb(struct pasemi_mac *mac, 
	return (nfrags + 3) & ~1;

}



static int pasemi_mac_setup_rx_resources(struct net_device *dev)

static int pasemi_mac_setup_rx_resources(const struct net_device *dev)

{

	struct pasemi_mac_rxring *ring;

	struct pasemi_mac *mac = netdev_priv(dev);
@@ -277,7 +286,7 @@ static int pasemi_mac_setup_rx_resources(struct net_device *dev) 
		      PAS_DMA_RXCHAN_BASEU_BRBH(ring->chan.ring_dma >> 32) |

		      PAS_DMA_RXCHAN_BASEU_SIZ(RX_RING_SIZE >> 3));



	cfg = PAS_DMA_RXCHAN_CFG_HBU(1);

	cfg = PAS_DMA_RXCHAN_CFG_HBU(2);



	if (translation_enabled())

		cfg |= PAS_DMA_RXCHAN_CFG_CTR;
@@ -291,7 +300,7 @@ static int pasemi_mac_setup_rx_resources(struct net_device *dev) 
		      PAS_DMA_RXINT_BASEU_BRBH(ring->buf_dma >> 32) |

		      PAS_DMA_RXINT_BASEU_SIZ(RX_RING_SIZE >> 3));



	cfg = PAS_DMA_RXINT_CFG_DHL(1) | PAS_DMA_RXINT_CFG_L2 |

	cfg = PAS_DMA_RXINT_CFG_DHL(2) | PAS_DMA_RXINT_CFG_L2 |

	      PAS_DMA_RXINT_CFG_LW | PAS_DMA_RXINT_CFG_RBP |

	      PAS_DMA_RXINT_CFG_HEN;
@@ -316,7 +325,7 @@ static int pasemi_mac_setup_rx_resources(struct net_device *dev) 
}



static struct pasemi_mac_txring *

pasemi_mac_setup_tx_resources(struct net_device *dev)

pasemi_mac_setup_tx_resources(const struct net_device *dev)

{

	struct pasemi_mac *mac = netdev_priv(dev);

	u32 val;
@@ -439,9 +448,10 @@ static void pasemi_mac_free_rx_resources(struct pasemi_mac *mac) 
	mac->rx = NULL;

}



static void pasemi_mac_replenish_rx_ring(struct net_device *dev, int limit)

static void pasemi_mac_replenish_rx_ring(const struct net_device *dev,

					 const int limit)

{

	struct pasemi_mac *mac = netdev_priv(dev);

	const struct pasemi_mac *mac = netdev_priv(dev);

	struct pasemi_mac_rxring *rx = rx_ring(mac);

	int fill, count;
@@ -492,7 +502,7 @@ static void pasemi_mac_replenish_rx_ring(struct net_device *dev, int limit) 
				(RX_RING_SIZE - 1);

}



static void pasemi_mac_restart_rx_intr(struct pasemi_mac *mac)

static void pasemi_mac_restart_rx_intr(const struct pasemi_mac *mac)

{

	unsigned int reg, pcnt;

	/* Re-enable packet count interrupts: finally
@@ -506,7 +516,7 @@ static void pasemi_mac_restart_rx_intr(struct pasemi_mac *mac) 
	write_iob_reg(PAS_IOB_DMA_RXCH_RESET(mac->rx->chan.chno), reg);

}



static void pasemi_mac_restart_tx_intr(struct pasemi_mac *mac)

static void pasemi_mac_restart_tx_intr(const struct pasemi_mac *mac)

{

	unsigned int reg, pcnt;
@@ -519,7 +529,8 @@ static void pasemi_mac_restart_tx_intr(struct pasemi_mac *mac) 
}





static inline void pasemi_mac_rx_error(struct pasemi_mac *mac, u64 macrx)

static inline void pasemi_mac_rx_error(const struct pasemi_mac *mac,

				       const u64 macrx)

{

	unsigned int rcmdsta, ccmdsta;

	struct pasemi_dmachan *chan = &rx_ring(mac)->chan;
@@ -537,7 +548,8 @@ static inline void pasemi_mac_rx_error(struct pasemi_mac *mac, u64 macrx) 
		rcmdsta, ccmdsta);

}



static inline void pasemi_mac_tx_error(struct pasemi_mac *mac, u64 mactx)

static inline void pasemi_mac_tx_error(const struct pasemi_mac *mac,

				       const u64 mactx)

{

	unsigned int cmdsta;

	struct pasemi_dmachan *chan = &tx_ring(mac)->chan;
@@ -553,19 +565,22 @@ static inline void pasemi_mac_tx_error(struct pasemi_mac *mac, u64 mactx) 
	printk(KERN_ERR "pasemi_mac: tcmdsta 0x%08x\n", cmdsta);

}



static int pasemi_mac_clean_rx(struct pasemi_mac_rxring *rx, int limit)

static int pasemi_mac_clean_rx(struct pasemi_mac_rxring *rx,

			       const int limit)

{

	struct pasemi_dmachan *chan = &rx->chan;

	const struct pasemi_dmachan *chan = &rx->chan;

	struct pasemi_mac *mac = rx->mac;

	struct pci_dev *pdev = mac->dma_pdev;

	unsigned int n;

	int count;

	int count, buf_index, tot_bytes, packets;

	struct pasemi_mac_buffer *info;

	struct sk_buff *skb;

	unsigned int len;

	u64 macrx;

	u64 macrx, eval;

	dma_addr_t dma;

	int buf_index;

	u64 eval;



	tot_bytes = 0;

	packets = 0;



	spin_lock(&rx->lock);
@@ -575,6 +590,7 @@ static int pasemi_mac_clean_rx(struct pasemi_mac_rxring *rx, int limit) 


	for (count = 0; count < limit; count++) {

		macrx = RX_DESC(rx, n);

		prefetch(&RX_DESC(rx, n+4));



		if ((macrx & XCT_MACRX_E) ||

		    (*chan->status & PAS_STATUS_ERROR))
@@ -596,12 +612,12 @@ static int pasemi_mac_clean_rx(struct pasemi_mac_rxring *rx, int limit) 


		skb = info->skb;



		prefetch(skb);

		prefetch(&skb->data_len);

		prefetch_skb(skb);



		len = (macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;



		pci_unmap_single(mac->dma_pdev, dma, len, PCI_DMA_FROMDEVICE);

		pci_unmap_single(pdev, dma, BUF_SIZE-LOCAL_SKB_ALIGN,

				 PCI_DMA_FROMDEVICE);



		if (macrx & XCT_MACRX_CRC) {

			/* CRC error flagged */
@@ -628,9 +644,6 @@ static int pasemi_mac_clean_rx(struct pasemi_mac_rxring *rx, int limit) 


		info->dma = 0;



		/* Don't include CRC */

		skb_put(skb, len-4);



		if (likely((macrx & XCT_MACRX_HTY_M) == XCT_MACRX_HTY_IPV4_OK)) {

			skb->ip_summed = CHECKSUM_UNNECESSARY;

			skb->csum = (macrx & XCT_MACRX_CSUM_M) >>
@@ -638,8 +651,11 @@ static int pasemi_mac_clean_rx(struct pasemi_mac_rxring *rx, int limit) 
		} else

			skb->ip_summed = CHECKSUM_NONE;



		mac->netdev->stats.rx_bytes += len;

		mac->netdev->stats.rx_packets++;

		packets++;

		tot_bytes += len;



		/* Don't include CRC */

		skb_put(skb, len-4);



		skb->protocol = eth_type_trans(skb, mac->netdev);

		netif_receive_skb(skb);
@@ -672,6 +688,9 @@ static int pasemi_mac_clean_rx(struct pasemi_mac_rxring *rx, int limit) 


	pasemi_mac_replenish_rx_ring(mac->netdev, count);



	mac->netdev->stats.rx_bytes += tot_bytes;

	mac->netdev->stats.rx_packets += packets;



	spin_unlock(&rx_ring(mac)->lock);



	return count;
@@ -758,10 +777,10 @@ static int pasemi_mac_clean_tx(struct pasemi_mac_txring *txring) 


static irqreturn_t pasemi_mac_rx_intr(int irq, void *data)

{

	struct pasemi_mac_rxring *rxring = data;

	const struct pasemi_mac_rxring *rxring = data;

	struct pasemi_mac *mac = rxring->mac;

	struct net_device *dev = mac->netdev;

	struct pasemi_dmachan *chan = &rxring->chan;

	const struct pasemi_dmachan *chan = &rxring->chan;

	unsigned int reg;



	if (!(*chan->status & PAS_STATUS_CAUSE_M))
@@ -789,7 +808,7 @@ static irqreturn_t pasemi_mac_rx_intr(int irq, void *data) 
static irqreturn_t pasemi_mac_tx_intr(int irq, void *data)

{

	struct pasemi_mac_txring *txring = data;

	struct pasemi_dmachan *chan = &txring->chan;

	const struct pasemi_dmachan *chan = &txring->chan;

	unsigned int reg, pcnt;



	if (!(*chan->status & PAS_STATUS_CAUSE_M))
@@ -1158,6 +1177,7 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) 
	unsigned int map_size[MAX_SKB_FRAGS+1];

	unsigned long flags;

	int i, nfrags;

	int fill;



	dflags = XCT_MACTX_O | XCT_MACTX_ST | XCT_MACTX_CRC_PAD;
@@ -1205,6 +1225,8 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) 


	spin_lock_irqsave(&txring->lock, flags);



	fill = txring->next_to_fill;



	/* Avoid stepping on the same cache line that the DMA controller

	 * is currently about to send, so leave at least 8 words available.

	 * Total free space needed is mactx + fragments + 8
@@ -1215,13 +1237,13 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) 
		goto out_err;

	}



	TX_DESC(txring, txring->next_to_fill) = mactx;

	txring->next_to_fill++;

	TX_DESC_INFO(txring, txring->next_to_fill).skb = skb;

	TX_DESC(txring, fill) = mactx;

	fill++;

	TX_DESC_INFO(txring, fill).skb = skb;

	for (i = 0; i <= nfrags; i++) {

		TX_DESC(txring, txring->next_to_fill+i) =

		TX_DESC(txring, fill+i) =

			XCT_PTR_LEN(map_size[i]) | XCT_PTR_ADDR(map[i]);

		TX_DESC_INFO(txring, txring->next_to_fill+i).dma = map[i];

		TX_DESC_INFO(txring, fill+i).dma = map[i];

	}



	/* We have to add an even number of 8-byte entries to the ring
@@ -1231,8 +1253,7 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) 
	if (nfrags & 1)

		nfrags++;



	txring->next_to_fill = (txring->next_to_fill + nfrags + 1) &

				(TX_RING_SIZE-1);

	txring->next_to_fill = (fill + nfrags + 1) & (TX_RING_SIZE-1);



	dev->stats.tx_packets++;

	dev->stats.tx_bytes += skb->len;
@@ -1255,7 +1276,7 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) 


static void pasemi_mac_set_rx_mode(struct net_device *dev)

{

	struct pasemi_mac *mac = netdev_priv(dev);

	const struct pasemi_mac *mac = netdev_priv(dev);

	unsigned int flags;



	flags = read_mac_reg(mac, PAS_MAC_CFG_PCFG);
@@ -1317,7 +1338,8 @@ pasemi_mac_probe(struct pci_dev *pdev, const struct pci_device_id *ent) 


	netif_napi_add(dev, &mac->napi, pasemi_mac_poll, 64);



	dev->features = NETIF_F_IP_CSUM | NETIF_F_LLTX | NETIF_F_SG;

	dev->features = NETIF_F_IP_CSUM | NETIF_F_LLTX | NETIF_F_SG |

			NETIF_F_HIGHDMA;



	mac->dma_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa007, NULL);

	if (!mac->dma_pdev) {