From: Stephen Hemminger Date: Mon, 27 Jun 2005 18:33:15 +0000 (-0700) Subject: [PATCH] skge: Rx buffer optimization X-Git-Tag: v2.6.13-rc1~53 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=19a33d4e6be2b627487676a69638e189e833675f;p=linux-2.6 [PATCH] skge: Rx buffer optimization Optimize the receive buffer management code to replenish the buffers immediately (like tg3). Signed-off-by: Stephen Hemmminger --- diff --git a/drivers/net/skge.c b/drivers/net/skge.c index 9f24714260..9d4ae78b6a 100644 --- a/drivers/net/skge.c +++ b/drivers/net/skge.c @@ -49,6 +49,8 @@ #define DEFAULT_RX_RING_SIZE 512 #define MAX_TX_RING_SIZE 1024 #define MAX_RX_RING_SIZE 4096 +#define RX_COPY_THRESHOLD 128 +#define RX_BUF_SIZE 1536 #define PHY_RETRIES 1000 #define ETH_JUMBO_MTU 9000 #define TX_WATCHDOG (5 * HZ) @@ -746,6 +748,7 @@ static int skge_ring_alloc(struct skge_ring *ring, void *vaddr, u64 base) for (i = 0, e = ring->start, d = vaddr; i < ring->count; i++, e++, d++) { e->desc = d; + e->skb = NULL; if (i == ring->count - 1) { e->next = ring->start; d->next_offset = base; @@ -759,24 +762,23 @@ static int skge_ring_alloc(struct skge_ring *ring, void *vaddr, u64 base) return 0; } -/* Setup buffer for receiving */ -static inline int skge_rx_alloc(struct skge_port *skge, - struct skge_element *e) +static struct sk_buff *skge_rx_alloc(struct net_device *dev, unsigned int size) { - unsigned long bufsize = skge->netdev->mtu + ETH_HLEN; /* VLAN? */ - struct skge_rx_desc *rd = e->desc; - struct sk_buff *skb; - u64 map; + struct sk_buff *skb = dev_alloc_skb(size); - skb = dev_alloc_skb(bufsize + NET_IP_ALIGN); - if (unlikely(!skb)) { - printk(KERN_DEBUG PFX "%s: out of memory for receive\n", - skge->netdev->name); - return -ENOMEM; + if (likely(skb)) { + skb->dev = dev; + skb_reserve(skb, NET_IP_ALIGN); } + return skb; +} - skb->dev = skge->netdev; - skb_reserve(skb, NET_IP_ALIGN); +/* Allocate and setup a new buffer for receiving */ +static void skge_rx_setup(struct skge_port *skge, struct skge_element *e, + struct sk_buff *skb, unsigned int bufsize) +{ + struct skge_rx_desc *rd = e->desc; + u64 map; map = pci_map_single(skge->hw->pdev, skb->data, bufsize, PCI_DMA_FROMDEVICE); @@ -794,55 +796,69 @@ static inline int skge_rx_alloc(struct skge_port *skge, rd->control = BMU_OWN | BMU_STF | BMU_IRQ_EOF | BMU_TCP_CHECK | bufsize; pci_unmap_addr_set(e, mapaddr, map); pci_unmap_len_set(e, maplen, bufsize); - return 0; } -/* Free all unused buffers in receive ring, assumes receiver stopped */ +/* Resume receiving using existing skb, + * Note: DMA address is not changed by chip. + * MTU not changed while receiver active. + */ +static void skge_rx_reuse(struct skge_element *e, unsigned int size) +{ + struct skge_rx_desc *rd = e->desc; + + rd->csum2 = 0; + rd->csum2_start = ETH_HLEN; + + wmb(); + + rd->control = BMU_OWN | BMU_STF | BMU_IRQ_EOF | BMU_TCP_CHECK | size; +} + + +/* Free all buffers in receive ring, assumes receiver stopped */ static void skge_rx_clean(struct skge_port *skge) { struct skge_hw *hw = skge->hw; struct skge_ring *ring = &skge->rx_ring; struct skge_element *e; - for (e = ring->to_clean; e != ring->to_use; e = e->next) { + e = ring->start; + do { struct skge_rx_desc *rd = e->desc; rd->control = 0; - - pci_unmap_single(hw->pdev, - pci_unmap_addr(e, mapaddr), - pci_unmap_len(e, maplen), - PCI_DMA_FROMDEVICE); - dev_kfree_skb(e->skb); - e->skb = NULL; - } - ring->to_clean = e; + if (e->skb) { + pci_unmap_single(hw->pdev, + pci_unmap_addr(e, mapaddr), + pci_unmap_len(e, maplen), + PCI_DMA_FROMDEVICE); + dev_kfree_skb(e->skb); + e->skb = NULL; + } + } while ((e = e->next) != ring->start); } + /* Allocate buffers for receive ring - * For receive: to_use is refill location - * to_clean is next received frame. - * - * if (to_use == to_clean) - * then ring all frames in ring need buffers - * if (to_use->next == to_clean) - * then ring all frames in ring have buffers + * For receive: to_clean is next received frame. */ static int skge_rx_fill(struct skge_port *skge) { struct skge_ring *ring = &skge->rx_ring; struct skge_element *e; - int ret = 0; + unsigned int bufsize = skge->rx_buf_size; - for (e = ring->to_use; e->next != ring->to_clean; e = e->next) { - if (skge_rx_alloc(skge, e)) { - ret = 1; - break; - } + e = ring->start; + do { + struct sk_buff *skb = skge_rx_alloc(skge->netdev, bufsize); - } - ring->to_use = e; + if (!skb) + return -ENOMEM; + + skge_rx_setup(skge, e, skb, bufsize); + } while ( (e = e->next) != ring->start); - return ret; + ring->to_clean = ring->start; + return 0; } static void skge_link_up(struct skge_port *skge) @@ -2048,6 +2064,12 @@ static int skge_up(struct net_device *dev) if (netif_msg_ifup(skge)) printk(KERN_INFO PFX "%s: enabling interface\n", dev->name); + if (dev->mtu > RX_BUF_SIZE) + skge->rx_buf_size = dev->mtu + ETH_HLEN + NET_IP_ALIGN; + else + skge->rx_buf_size = RX_BUF_SIZE; + + rx_size = skge->rx_ring.count * sizeof(struct skge_rx_desc); tx_size = skge->tx_ring.count * sizeof(struct skge_tx_desc); skge->mem_size = tx_size + rx_size; @@ -2060,7 +2082,8 @@ static int skge_up(struct net_device *dev) if ((err = skge_ring_alloc(&skge->rx_ring, skge->mem, skge->dma))) goto free_pci_mem; - if (skge_rx_fill(skge)) + err = skge_rx_fill(skge); + if (err) goto free_rx_ring; if ((err = skge_ring_alloc(&skge->tx_ring, skge->mem + rx_size, @@ -2284,6 +2307,7 @@ static int skge_xmit_frame(struct sk_buff *skb, struct net_device *dev) static inline void skge_tx_free(struct skge_hw *hw, struct skge_element *e) { + /* This ring element can be skb or fragment */ if (e->skb) { pci_unmap_single(hw->pdev, pci_unmap_addr(e, mapaddr), @@ -2328,16 +2352,17 @@ static void skge_tx_timeout(struct net_device *dev) static int skge_change_mtu(struct net_device *dev, int new_mtu) { int err = 0; + int running = netif_running(dev); if (new_mtu < ETH_ZLEN || new_mtu > ETH_JUMBO_MTU) return -EINVAL; - dev->mtu = new_mtu; - if (netif_running(dev)) { + if (running) skge_down(dev); + dev->mtu = new_mtu; + if (running) skge_up(dev); - } return err; } @@ -2436,28 +2461,76 @@ static void skge_rx_error(struct skge_port *skge, int slot, printk(KERN_DEBUG PFX "%s: rx err, slot %d control 0x%x status 0x%x\n", skge->netdev->name, slot, control, status); - if ((control & (BMU_EOF|BMU_STF)) != (BMU_STF|BMU_EOF) - || (control & BMU_BBC) > skge->netdev->mtu + VLAN_ETH_HLEN) + if ((control & (BMU_EOF|BMU_STF)) != (BMU_STF|BMU_EOF)) skge->net_stats.rx_length_errors++; - else { - if (skge->hw->chip_id == CHIP_ID_GENESIS) { - if (status & (XMR_FS_RUNT|XMR_FS_LNG_ERR)) - skge->net_stats.rx_length_errors++; - if (status & XMR_FS_FRA_ERR) - skge->net_stats.rx_frame_errors++; - if (status & XMR_FS_FCS_ERR) - skge->net_stats.rx_crc_errors++; - } else { - if (status & (GMR_FS_LONG_ERR|GMR_FS_UN_SIZE)) - skge->net_stats.rx_length_errors++; - if (status & GMR_FS_FRAGMENT) - skge->net_stats.rx_frame_errors++; - if (status & GMR_FS_CRC_ERR) - skge->net_stats.rx_crc_errors++; + else if (skge->hw->chip_id == CHIP_ID_GENESIS) { + if (status & (XMR_FS_RUNT|XMR_FS_LNG_ERR)) + skge->net_stats.rx_length_errors++; + if (status & XMR_FS_FRA_ERR) + skge->net_stats.rx_frame_errors++; + if (status & XMR_FS_FCS_ERR) + skge->net_stats.rx_crc_errors++; + } else { + if (status & (GMR_FS_LONG_ERR|GMR_FS_UN_SIZE)) + skge->net_stats.rx_length_errors++; + if (status & GMR_FS_FRAGMENT) + skge->net_stats.rx_frame_errors++; + if (status & GMR_FS_CRC_ERR) + skge->net_stats.rx_crc_errors++; + } +} + +/* Get receive buffer from descriptor. + * Handles copy of small buffers and reallocation failures + */ +static inline struct sk_buff *skge_rx_get(struct skge_port *skge, + struct skge_element *e, + unsigned int len) +{ + struct sk_buff *nskb, *skb; + + if (len < RX_COPY_THRESHOLD) { + nskb = skge_rx_alloc(skge->netdev, len + NET_IP_ALIGN); + if (unlikely(!nskb)) + return NULL; + + pci_dma_sync_single_for_cpu(skge->hw->pdev, + pci_unmap_addr(e, mapaddr), + len, PCI_DMA_FROMDEVICE); + memcpy(nskb->data, e->skb->data, len); + pci_dma_sync_single_for_device(skge->hw->pdev, + pci_unmap_addr(e, mapaddr), + len, PCI_DMA_FROMDEVICE); + + if (skge->rx_csum) { + struct skge_rx_desc *rd = e->desc; + nskb->csum = le16_to_cpu(rd->csum2); + nskb->ip_summed = CHECKSUM_HW; + } + skge_rx_reuse(e, skge->rx_buf_size); + return nskb; + } else { + nskb = skge_rx_alloc(skge->netdev, skge->rx_buf_size); + if (unlikely(!nskb)) + return NULL; + + pci_unmap_single(skge->hw->pdev, + pci_unmap_addr(e, mapaddr), + pci_unmap_len(e, maplen), + PCI_DMA_FROMDEVICE); + skb = e->skb; + if (skge->rx_csum) { + struct skge_rx_desc *rd = e->desc; + skb->csum = le16_to_cpu(rd->csum2); + skb->ip_summed = CHECKSUM_HW; } + + skge_rx_setup(skge, e, nskb, skge->rx_buf_size); + return skb; } } + static int skge_poll(struct net_device *dev, int *budget) { struct skge_port *skge = netdev_priv(dev); @@ -2466,14 +2539,12 @@ static int skge_poll(struct net_device *dev, int *budget) struct skge_element *e; unsigned int to_do = min(dev->quota, *budget); unsigned int work_done = 0; - int done; pr_debug("skge_poll\n"); - for (e = ring->to_clean; e != ring->to_use && work_done < to_do; - e = e->next) { + for (e = ring->to_clean; work_done < to_do; e = e->next) { struct skge_rx_desc *rd = e->desc; - struct sk_buff *skb = e->skb; + struct sk_buff *skb; u32 control, len, status; rmb(); @@ -2482,19 +2553,12 @@ static int skge_poll(struct net_device *dev, int *budget) break; len = control & BMU_BBC; - e->skb = NULL; - - pci_unmap_single(hw->pdev, - pci_unmap_addr(e, mapaddr), - pci_unmap_len(e, maplen), - PCI_DMA_FROMDEVICE); - status = rd->status; - if ((control & (BMU_EOF|BMU_STF)) != (BMU_STF|BMU_EOF) - || len > dev->mtu + VLAN_ETH_HLEN - || bad_phy_status(hw, status)) { + + if (unlikely((control & (BMU_EOF|BMU_STF)) != (BMU_STF|BMU_EOF) + || bad_phy_status(hw, status))) { skge_rx_error(skge, e - ring->start, control, status); - dev_kfree_skb(skb); + skge_rx_reuse(e, skge->rx_buf_size); continue; } @@ -2502,42 +2566,37 @@ static int skge_poll(struct net_device *dev, int *budget) printk(KERN_DEBUG PFX "%s: rx slot %td status 0x%x len %d\n", dev->name, e - ring->start, rd->status, len); - skb_put(skb, len); - skb->protocol = eth_type_trans(skb, dev); + skb = skge_rx_get(skge, e, len); + if (likely(skb)) { + skb_put(skb, len); + skb->protocol = eth_type_trans(skb, dev); - if (skge->rx_csum) { - skb->csum = le16_to_cpu(rd->csum2); - skb->ip_summed = CHECKSUM_HW; - } - - dev->last_rx = jiffies; - netif_receive_skb(skb); + dev->last_rx = jiffies; + netif_receive_skb(skb); - ++work_done; + ++work_done; + } else + skge_rx_reuse(e, skge->rx_buf_size); } ring->to_clean = e; - *budget -= work_done; - dev->quota -= work_done; - done = work_done < to_do; - - if (skge_rx_fill(skge)) - done = 0; - /* restart receiver */ wmb(); skge_write8(hw, Q_ADDR(rxqaddr[skge->port], Q_CSR), CSR_START | CSR_IRQ_CL_F); - if (done) { - local_irq_disable(); - __netif_rx_complete(dev); - hw->intr_mask |= portirqmask[skge->port]; - skge_write32(hw, B0_IMSK, hw->intr_mask); - local_irq_enable(); - } + *budget -= work_done; + dev->quota -= work_done; + + if (work_done >= to_do) + return 1; /* not done */ - return !done; + local_irq_disable(); + __netif_rx_complete(dev); + hw->intr_mask |= portirqmask[skge->port]; + skge_write32(hw, B0_IMSK, hw->intr_mask); + local_irq_enable(); + return 0; } static inline void skge_tx_intr(struct net_device *dev) diff --git a/drivers/net/skge.h b/drivers/net/skge.h index 37323cd29e..14d0cc01fb 100644 --- a/drivers/net/skge.h +++ b/drivers/net/skge.h @@ -2503,6 +2503,7 @@ struct skge_port { void *mem; /* PCI memory for rings */ dma_addr_t dma; unsigned long mem_size; + unsigned int rx_buf_size; struct timer_list led_blink; };