ibmveth can scatter gather up to 6 segments. If we go over this then we have no option but to call skb_linearize, like other drivers with similar limitations do. Signed-off-by: Anton Blanchard --- Index: net-next-2.6/drivers/net/ibmveth.c =================================================================== --- net-next-2.6.orig/drivers/net/ibmveth.c 2010-08-23 08:52:30.283755038 +1000 +++ net-next-2.6/drivers/net/ibmveth.c 2010-08-23 08:52:30.633730198 +1000 @@ -897,6 +897,7 @@ static const struct ethtool_ops netdev_e .get_strings = ibmveth_get_strings, .get_sset_count = ibmveth_get_sset_count, .get_ethtool_stats = ibmveth_get_ethtool_stats, + .set_sg = ethtool_op_set_sg, }; static int ibmveth_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) @@ -906,96 +907,158 @@ static int ibmveth_ioctl(struct net_devi #define page_offset(v) ((unsigned long)(v) & ((1 << 12) - 1)) -static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb, - struct net_device *netdev) +static int ibmveth_send(struct ibmveth_adapter *adapter, + union ibmveth_buf_desc *descs) { - struct ibmveth_adapter *adapter = netdev_priv(netdev); - union ibmveth_buf_desc desc; - unsigned long lpar_rc; unsigned long correlator; unsigned int retry_count; - unsigned int tx_dropped = 0; - unsigned int tx_bytes = 0; - unsigned int tx_packets = 0; - unsigned int tx_send_failed = 0; - unsigned int tx_map_failed = 0; - int used_bounce = 0; - unsigned long data_dma_addr; + unsigned long ret; + + /* + * The retry count sets a maximum for the number of broadcast and + * multicast destinations within the system. + */ + retry_count = 1024; + correlator = 0; + do { + ret = h_send_logical_lan(adapter->vdev->unit_address, + descs[0].desc, descs[1].desc, + descs[2].desc, descs[3].desc, + descs[4].desc, descs[5].desc, + correlator, &correlator); + } while ((ret == H_BUSY) && (retry_count--)); + + if (ret != H_SUCCESS && ret != H_DROPPED) { + ibmveth_error_printk("tx: h_send_logical_lan failed with " + "rc=%ld\n", ret); + return 1; + } + + return 0; +} - desc.fields.flags_len = IBMVETH_BUF_VALID | skb->len; +static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb, + struct net_device *netdev) +{ + struct ibmveth_adapter *adapter = netdev_priv(netdev); + unsigned int desc_flags; + union ibmveth_buf_desc descs[6]; + int last, i; + int force_bounce = 0; + + /* + * veth handles a maximum of 6 segments including the header, so + * we have to linearize the skb if there are more than this. + */ + if (skb_shinfo(skb)->nr_frags > 5 && __skb_linearize(skb)) { + netdev->stats.tx_dropped++; + goto out; + } + /* veth can't checksum offload UDP */ if (skb->ip_summed == CHECKSUM_PARTIAL && ip_hdr(skb)->protocol != IPPROTO_TCP && skb_checksum_help(skb)) { ibmveth_error_printk("tx: failed to checksum packet\n"); - tx_dropped++; + netdev->stats.tx_dropped++; goto out; } + desc_flags = IBMVETH_BUF_VALID; + if (skb->ip_summed == CHECKSUM_PARTIAL) { - unsigned char *buf = skb_transport_header(skb) + skb->csum_offset; + unsigned char *buf = skb_transport_header(skb) + + skb->csum_offset; - desc.fields.flags_len |= (IBMVETH_BUF_NO_CSUM | IBMVETH_BUF_CSUM_GOOD); + desc_flags |= (IBMVETH_BUF_NO_CSUM | IBMVETH_BUF_CSUM_GOOD); /* Need to zero out the checksum */ buf[0] = 0; buf[1] = 0; } - if (skb->len < tx_copybreak) { - used_bounce = 1; - } else { - data_dma_addr = dma_map_single(&adapter->vdev->dev, skb->data, - skb->len, DMA_TO_DEVICE); - if (dma_mapping_error(&adapter->vdev->dev, data_dma_addr)) { - if (!firmware_has_feature(FW_FEATURE_CMO)) - ibmveth_error_printk("tx: unable to map " - "xmit buffer\n"); - tx_map_failed++; - used_bounce = 1; - } - } +retry_bounce: + memset(descs, 0, sizeof(descs)); - if (used_bounce) { + /* + * If a linear packet is below the rx threshold then + * copy it into the static bounce buffer. This avoids the + * cost of a TCE insert and remove. + */ + if (force_bounce || (!skb_is_nonlinear(skb) && + (skb->len < tx_copybreak))) { skb_copy_from_linear_data(skb, adapter->bounce_buffer, skb->len); - desc.fields.address = adapter->bounce_buffer_dma; - } else - desc.fields.address = data_dma_addr; - /* send the frame. Arbitrarily set retrycount to 1024 */ - correlator = 0; - retry_count = 1024; - do { - lpar_rc = h_send_logical_lan(adapter->vdev->unit_address, - desc.desc, 0, 0, 0, 0, 0, - correlator, &correlator); - } while ((lpar_rc == H_BUSY) && (retry_count--)); + descs[0].fields.flags_len = desc_flags | skb->len; + descs[0].fields.address = adapter->bounce_buffer_dma; - if(lpar_rc != H_SUCCESS && lpar_rc != H_DROPPED) { - ibmveth_error_printk("tx: h_send_logical_lan failed with rc=%ld\n", lpar_rc); - ibmveth_error_printk("tx: valid=%d, len=%d, address=0x%08x\n", - (desc.fields.flags_len & IBMVETH_BUF_VALID) ? 1 : 0, - skb->len, desc.fields.address); - tx_send_failed++; - tx_dropped++; + if (ibmveth_send(adapter, descs)) { + adapter->tx_send_failed++; + netdev->stats.tx_dropped++; + } else { + netdev->stats.tx_packets++; + netdev->stats.tx_bytes += skb->len; + } + + goto out; + } + + /* Map the header */ + descs[0].fields.address = dma_map_single(&adapter->vdev->dev, skb->data, + skb_headlen(skb), + DMA_TO_DEVICE); + if (dma_mapping_error(&adapter->vdev->dev, descs[0].fields.address)) + goto map_failed; + + descs[0].fields.flags_len = desc_flags | skb_headlen(skb); + + /* Map the frags */ + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { + unsigned long dma_addr; + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + + dma_addr = dma_map_page(&adapter->vdev->dev, frag->page, + frag->page_offset, frag->size, + DMA_TO_DEVICE); + + if (dma_mapping_error(&adapter->vdev->dev, dma_addr)) + goto map_failed_frags; + + descs[i+1].fields.flags_len = desc_flags | frag->size; + descs[i+1].fields.address = dma_addr; + } + + if (ibmveth_send(adapter, descs)) { + adapter->tx_send_failed++; + netdev->stats.tx_dropped++; } else { - tx_packets++; - tx_bytes += skb->len; + netdev->stats.tx_packets++; + netdev->stats.tx_bytes += skb->len; } - if (!used_bounce) - dma_unmap_single(&adapter->vdev->dev, data_dma_addr, - skb->len, DMA_TO_DEVICE); + for (i = 0; i < skb_shinfo(skb)->nr_frags + 1; i++) + dma_unmap_page(&adapter->vdev->dev, descs[i].fields.address, + descs[i].fields.flags_len & IBMVETH_BUF_LEN_MASK, + DMA_TO_DEVICE); out: - netdev->stats.tx_dropped += tx_dropped; - netdev->stats.tx_bytes += tx_bytes; - netdev->stats.tx_packets += tx_packets; - adapter->tx_send_failed += tx_send_failed; - adapter->tx_map_failed += tx_map_failed; - dev_kfree_skb(skb); return NETDEV_TX_OK; + +map_failed_frags: + last = i+1; + for (i = 0; i < last; i++) + dma_unmap_page(&adapter->vdev->dev, descs[i].fields.address, + descs[i].fields.flags_len & IBMVETH_BUF_LEN_MASK, + DMA_TO_DEVICE); + +map_failed: + if (!firmware_has_feature(FW_FEATURE_CMO)) + ibmveth_error_printk("tx: unable to map xmit buffer\n"); + adapter->tx_map_failed++; + skb_linearize(skb); + force_bounce = 1; + goto retry_bounce; } static int ibmveth_poll(struct napi_struct *napi, int budget) @@ -1316,6 +1379,7 @@ static int __devinit ibmveth_probe(struc netdev->netdev_ops = &ibmveth_netdev_ops; netdev->ethtool_ops = &netdev_ethtool_ops; SET_NETDEV_DEV(netdev, &dev->dev); + netdev->features |= NETIF_F_SG; memcpy(netdev->dev_addr, &adapter->mac_addr, netdev->addr_len); -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html