From ad3c20d1ab586884f1815c315e3f303a8b8a7d7d Mon Sep 17 00:00:00 2001 From: Olof Johansson Date: Tue, 2 Oct 2007 16:26:13 -0500 Subject: [PATCH] pasemi_mac: implement sg support pasemi_mac: implement sg support Implement SG support for pasemi_mac Signed-off-by: Olof Johansson Signed-off-by: Jeff Garzik --- drivers/net/pasemi_mac.c | 163 ++++++++++++++++++++++++++++----------- 1 file changed, 117 insertions(+), 46 deletions(-) diff --git a/drivers/net/pasemi_mac.c b/drivers/net/pasemi_mac.c index c2a3524a5411..5eb5e47120d0 100644 --- a/drivers/net/pasemi_mac.c +++ b/drivers/net/pasemi_mac.c @@ -160,6 +160,30 @@ static int pasemi_get_mac_addr(struct pasemi_mac *mac) return 0; } +static int pasemi_mac_unmap_tx_skb(struct pasemi_mac *mac, + struct sk_buff *skb, + dma_addr_t *dmas) +{ + int f; + int nfrags = skb_shinfo(skb)->nr_frags; + + pci_unmap_single(mac->dma_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); + } + dev_kfree_skb_irq(skb); + + /* Freed descriptor slot + main SKB ptr + nfrags additional ptrs, + * aligned up to a power of 2 + */ + return (nfrags + 3) & ~1; +} + static int pasemi_mac_setup_rx_resources(struct net_device *dev) { struct pasemi_mac_rxring *ring; @@ -300,24 +324,24 @@ out_ring: static void pasemi_mac_free_tx_resources(struct net_device *dev) { struct pasemi_mac *mac = netdev_priv(dev); - unsigned int i; + unsigned int i, j; struct pasemi_mac_buffer *info; + dma_addr_t dmas[MAX_SKB_FRAGS+1]; + int freed; - for (i = 0; i < TX_RING_SIZE; i += 2) { + for (i = 0; i < TX_RING_SIZE; i += freed) { info = &TX_RING_INFO(mac, i+1); if (info->dma && info->skb) { - pci_unmap_single(mac->dma_pdev, - info->dma, - info->skb->len, - PCI_DMA_TODEVICE); - dev_kfree_skb_any(info->skb); - } - TX_RING(mac, i) = 0; - TX_RING(mac, i+1) = 0; - info->dma = 0; - info->skb = NULL; + for (j = 0; j <= skb_shinfo(info->skb)->nr_frags; j++) + dmas[j] = TX_RING_INFO(mac, i+1+j).dma; + freed = pasemi_mac_unmap_tx_skb(mac, info->skb, dmas); + } else + freed = 2; } + for (i = 0; i < TX_RING_SIZE; i++) + TX_RING(mac, i) = 0; + dma_free_coherent(&mac->dma_pdev->dev, TX_RING_SIZE * sizeof(u64), mac->tx->ring, mac->tx->dma); @@ -573,27 +597,34 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit) return count; } +/* Can't make this too large or we blow the kernel stack limits */ +#define TX_CLEAN_BATCHSIZE (128/MAX_SKB_FRAGS) + static int pasemi_mac_clean_tx(struct pasemi_mac *mac) { - int i; + int i, j; struct pasemi_mac_buffer *info; - unsigned int start, count, limit; + unsigned int start, descr_count, buf_count, limit; unsigned int total_count; unsigned long flags; - struct sk_buff *skbs[32]; - dma_addr_t dmas[32]; + struct sk_buff *skbs[TX_CLEAN_BATCHSIZE]; + dma_addr_t dmas[TX_CLEAN_BATCHSIZE][MAX_SKB_FRAGS+1]; total_count = 0; + limit = TX_CLEAN_BATCHSIZE; restart: spin_lock_irqsave(&mac->tx->lock, flags); start = mac->tx->next_to_clean; - limit = min(mac->tx->next_to_fill, start+32); - count = 0; + buf_count = 0; + descr_count = 0; - for (i = start; i < limit; i += 2) { + for (i = start; + descr_count < limit && i < mac->tx->next_to_fill; + i += buf_count) { u64 mactx = TX_RING(mac, i); + if ((mactx & XCT_MACTX_E) || (*mac->tx_status & PAS_STATUS_ERROR)) pasemi_mac_tx_error(mac, mactx); @@ -603,30 +634,38 @@ restart: break; info = &TX_RING_INFO(mac, i+1); - skbs[count] = info->skb; - dmas[count] = info->dma; + skbs[descr_count] = info->skb; + + buf_count = 2 + skb_shinfo(info->skb)->nr_frags; + for (j = 0; j <= skb_shinfo(info->skb)->nr_frags; j++) + dmas[descr_count][j] = TX_RING_INFO(mac, i+1+j).dma; + info->dma = 0; TX_RING(mac, i) = 0; TX_RING(mac, i+1) = 0; + TX_RING_INFO(mac, i+1).skb = 0; + TX_RING_INFO(mac, i+1).dma = 0; - - count++; + /* Since we always fill with an even number of entries, make + * sure we skip any unused one at the end as well. + */ + if (buf_count & 1) + buf_count++; + descr_count++; } - mac->tx->next_to_clean += count * 2; + mac->tx->next_to_clean = i; + spin_unlock_irqrestore(&mac->tx->lock, flags); netif_wake_queue(mac->netdev); - for (i = 0; i < count; i++) { - pci_unmap_single(mac->dma_pdev, dmas[i], - skbs[i]->len, PCI_DMA_TODEVICE); - dev_kfree_skb_irq(skbs[i]); - } + for (i = 0; i < descr_count; i++) + pasemi_mac_unmap_tx_skb(mac, skbs[i], dmas[i]); - total_count += count; + total_count += descr_count; /* If the batch was full, try to clean more */ - if (count == 32) + if (descr_count == limit) goto restart; return total_count; @@ -997,9 +1036,11 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) { struct pasemi_mac *mac = netdev_priv(dev); struct pasemi_mac_txring *txring; - u64 dflags, mactx, ptr; - dma_addr_t map; + u64 dflags, mactx; + dma_addr_t map[MAX_SKB_FRAGS+1]; + unsigned int map_size[MAX_SKB_FRAGS+1]; unsigned long flags; + int i, nfrags; dflags = XCT_MACTX_O | XCT_MACTX_ST | XCT_MACTX_SS | XCT_MACTX_CRC_PAD; @@ -1020,25 +1061,40 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) } } - map = pci_map_single(mac->dma_pdev, skb->data, skb->len, PCI_DMA_TODEVICE); + nfrags = skb_shinfo(skb)->nr_frags; - if (dma_mapping_error(map)) - return NETDEV_TX_BUSY; + map[0] = pci_map_single(mac->dma_pdev, skb->data, skb_headlen(skb), + PCI_DMA_TODEVICE); + map_size[0] = skb_headlen(skb); + if (dma_mapping_error(map[0])) + goto out_err_nolock; + + for (i = 0; i < nfrags; i++) { + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + + map[i+1] = pci_map_page(mac->dma_pdev, frag->page, + frag->page_offset, frag->size, + PCI_DMA_TODEVICE); + map_size[i+1] = frag->size; + if (dma_mapping_error(map[i+1])) { + nfrags = i; + goto out_err_nolock; + } + } mactx = dflags | XCT_MACTX_LLEN(skb->len); - ptr = XCT_PTR_LEN(skb->len) | XCT_PTR_ADDR(map); txring = mac->tx; spin_lock_irqsave(&txring->lock, flags); - if (RING_AVAIL(txring) <= 2) { + if (RING_AVAIL(txring) <= nfrags+3) { spin_unlock_irqrestore(&txring->lock, flags); pasemi_mac_clean_tx(mac); pasemi_mac_restart_tx_intr(mac); spin_lock_irqsave(&txring->lock, flags); - if (RING_AVAIL(txring) <= 2) { + if (RING_AVAIL(txring) <= nfrags+3) { /* Still no room -- stop the queue and wait for tx * intr when there's room. */ @@ -1048,25 +1104,40 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) } TX_RING(mac, txring->next_to_fill) = mactx; - TX_RING(mac, txring->next_to_fill+1) = ptr; + txring->next_to_fill++; + TX_RING_INFO(mac, txring->next_to_fill).skb = skb; + for (i = 0; i <= nfrags; i++) { + TX_RING(mac, txring->next_to_fill+i) = + XCT_PTR_LEN(map_size[i]) | XCT_PTR_ADDR(map[i]); + TX_RING_INFO(mac, txring->next_to_fill+i).dma = map[i]; + } - TX_RING_INFO(mac, txring->next_to_fill+1).dma = map; - TX_RING_INFO(mac, txring->next_to_fill+1).skb = skb; + /* We have to add an even number of 8-byte entries to the ring + * even if the last one is unused. That means always an odd number + * of pointers + one mactx descriptor. + */ + if (nfrags & 1) + nfrags++; + + txring->next_to_fill += nfrags + 1; - txring->next_to_fill += 2; dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; spin_unlock_irqrestore(&txring->lock, flags); - write_dma_reg(mac, PAS_DMA_TXCHAN_INCR(mac->dma_txch), 1); + write_dma_reg(mac, PAS_DMA_TXCHAN_INCR(mac->dma_txch), (nfrags+2) >> 1); return NETDEV_TX_OK; out_err: spin_unlock_irqrestore(&txring->lock, flags); - pci_unmap_single(mac->dma_pdev, map, skb->len, PCI_DMA_TODEVICE); +out_err_nolock: + while (nfrags--) + pci_unmap_single(mac->dma_pdev, map[nfrags], map_size[nfrags], + PCI_DMA_TODEVICE); + return NETDEV_TX_BUSY; } @@ -1202,7 +1273,7 @@ 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_HW_CSUM | NETIF_F_LLTX; + dev->features = NETIF_F_HW_CSUM | NETIF_F_LLTX | NETIF_F_SG; /* These should come out of the device tree eventually */ mac->dma_txch = index;