/** * efx_enqueue_skb_tso - segment and transmit a TSO socket buffer * @tx_queue: Efx TX queue * @skb: Socket buffer * * Context: You must hold netif_tx_lock() to call this function. * * Add socket buffer @skb to @tx_queue, doing TSO or return != 0 if * @skb was not enqueued. In all cases @skb is consumed. Return * %NETDEV_TX_OK or %NETDEV_TX_BUSY. */ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, struct sk_buff *skb) { struct efx_nic *efx = tx_queue->efx; int frag_i, rc, rc2 = NETDEV_TX_OK; struct tso_state state; /* Find the packet protocol and sanity-check it */ state.protocol = efx_tso_check_protocol(skb); EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count); tso_start(&state, skb); /* Assume that skb header area contains exactly the headers, and * all payload is in the frag list. */ if (skb_headlen(skb) == state.header_len) { /* Grab the first payload fragment. */ EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1); frag_i = 0; rc = tso_get_fragment(&state, efx, skb_shinfo(skb)->frags + frag_i); if (rc) goto mem_err; } else { rc = tso_get_head_fragment(&state, efx, skb); if (rc) goto mem_err; frag_i = -1; } if (tso_start_new_packet(tx_queue, skb, &state) < 0) goto mem_err; while (1) { rc = tso_fill_packet_with_fragment(tx_queue, skb, &state); if (unlikely(rc)) { rc2 = NETDEV_TX_BUSY; goto unwind; } /* Move onto the next fragment? */ if (state.in_len == 0) { if (++frag_i >= skb_shinfo(skb)->nr_frags) /* End of payload reached. */ break; rc = tso_get_fragment(&state, efx, skb_shinfo(skb)->frags + frag_i); if (rc) goto mem_err; } /* Start at new packet? */ if (state.packet_space == 0 && tso_start_new_packet(tx_queue, skb, &state) < 0) goto mem_err; } /* Pass off to hardware */ efx_nic_push_buffers(tx_queue); tx_queue->tso_bursts++; return NETDEV_TX_OK; mem_err: netif_err(efx, tx_err, efx->net_dev, "Out of memory for TSO headers, or PCI mapping error\n"); dev_kfree_skb_any(skb); unwind: /* Free the DMA mapping we were in the process of writing out */ if (state.unmap_len) { if (state.unmap_single) pci_unmap_single(efx->pci_dev, state.unmap_addr, state.unmap_len, PCI_DMA_TODEVICE); else pci_unmap_page(efx->pci_dev, state.unmap_addr, state.unmap_len, PCI_DMA_TODEVICE); } efx_enqueue_unwind(tx_queue); return rc2; }
/** * efx_enqueue_skb_tso - segment and transmit a TSO socket buffer * @tx_queue: Efx TX queue * @skb: Socket buffer * * Context: You must hold netif_tx_lock() to call this function. * * Add socket buffer @skb to @tx_queue, doing TSO or return != 0 if * @skb was not enqueued. In all cases @skb is consumed. Return * %NETDEV_TX_OK or %NETDEV_TX_BUSY. */ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, struct sk_buff *skb) { struct efx_nic *efx = tx_queue->efx; int frag_i, rc, rc2 = NETDEV_TX_OK; struct tso_state state; /* Since the stack does not limit the number of segments per * skb, we must do so. Otherwise an attacker may be able to * make the TCP produce skbs that will never fit in our TX * queue, causing repeated resets. */ if (unlikely(skb_shinfo(skb)->gso_segs > EFX_TSO_MAX_SEGS)) { unsigned int excess = (skb_shinfo(skb)->gso_segs - EFX_TSO_MAX_SEGS) * skb_shinfo(skb)->gso_size; if (__pskb_trim(skb, skb->len - excess)) { dev_kfree_skb_any(skb); return NETDEV_TX_OK; } } /* Find the packet protocol and sanity-check it */ state.protocol = efx_tso_check_protocol(skb); EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count); tso_start(&state, skb); /* Assume that skb header area contains exactly the headers, and * all payload is in the frag list. */ if (skb_headlen(skb) == state.header_len) { /* Grab the first payload fragment. */ EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1); frag_i = 0; rc = tso_get_fragment(&state, efx, skb_shinfo(skb)->frags + frag_i); if (rc) goto mem_err; } else { rc = tso_get_head_fragment(&state, efx, skb); if (rc) goto mem_err; frag_i = -1; } if (tso_start_new_packet(tx_queue, skb, &state) < 0) goto mem_err; while (1) { rc = tso_fill_packet_with_fragment(tx_queue, skb, &state); if (unlikely(rc)) { rc2 = NETDEV_TX_BUSY; goto unwind; } /* Move onto the next fragment? */ if (state.in_len == 0) { if (++frag_i >= skb_shinfo(skb)->nr_frags) /* End of payload reached. */ break; rc = tso_get_fragment(&state, efx, skb_shinfo(skb)->frags + frag_i); if (rc) goto mem_err; } /* Start at new packet? */ if (state.packet_space == 0 && tso_start_new_packet(tx_queue, skb, &state) < 0) goto mem_err; } /* Pass off to hardware */ efx_nic_push_buffers(tx_queue); tx_queue->tso_bursts++; return NETDEV_TX_OK; mem_err: netif_err(efx, tx_err, efx->net_dev, "Out of memory for TSO headers, or PCI mapping error\n"); dev_kfree_skb_any(skb); unwind: /* Free the DMA mapping we were in the process of writing out */ if (state.unmap_len) { if (state.unmap_single) pci_unmap_single(efx->pci_dev, state.unmap_addr, state.unmap_len, PCI_DMA_TODEVICE); else pci_unmap_page(efx->pci_dev, state.unmap_addr, state.unmap_len, PCI_DMA_TODEVICE); } efx_enqueue_unwind(tx_queue); return rc2; }