From 5c15332bed4c59fff6423f08ef6bd6894af38a99 Mon Sep 17 00:00:00 2001 From: Olof Johansson Date: Wed, 28 Nov 2007 20:56:41 -0600 Subject: [PATCH] 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: Olof Johansson Signed-off-by: Jeff Garzik --- drivers/net/pasemi_mac.c | 114 +++++++++++++++++++++++---------------- 1 file changed, 68 insertions(+), 46 deletions(-) diff --git a/drivers/net/pasemi_mac.c b/drivers/net/pasemi_mac.c index a50eb34ece..c6e24a8dcf 100644 --- a/drivers/net/pasemi_mac.c +++ b/drivers/net/pasemi_mac.c @@ -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 @@ out_chan: } 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 @@ next: 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 @@ restart: 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 @@ out_err_nolock: 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) { -- 2.39.5