From d9e651bc06690c5a5326e8d019fa7668409bc819 Mon Sep 17 00:00:00 2001 From: Dhananjay Phadke Date: Mon, 21 Jul 2008 19:44:08 -0700 Subject: netxen: cut-through rx changes NX3031 supports cut-through operation where ingress packets are directly dma'ed into host buffers to reduce latency. This requires larger dma buffers (2kb) and different alignemnt. The buffer posting logic is changed a bit. The free rx buffers are maintained in linked list, since the received reference handles can be out of order. However rx descriptors are still posted sequentially, indexed by producer. Signed-off-by: Dhananjay Phadke Signed-off-by: Jeff Garzik --- drivers/net/netxen/netxen_nic_init.c | 191 ++++++++++++++++++++++++----------- 1 file changed, 130 insertions(+), 61 deletions(-) (limited to 'drivers/net/netxen/netxen_nic_init.c') diff --git a/drivers/net/netxen/netxen_nic_init.c b/drivers/net/netxen/netxen_nic_init.c index 7b5124057664..01ab31b34a85 100644 --- a/drivers/net/netxen/netxen_nic_init.c +++ b/drivers/net/netxen/netxen_nic_init.c @@ -262,17 +262,30 @@ int netxen_alloc_sw_resources(struct netxen_adapter *adapter) rds_ring->max_rx_desc_count = adapter->max_rx_desc_count; rds_ring->flags = RCV_DESC_NORMAL; - rds_ring->dma_size = RX_DMA_MAP_LEN; - rds_ring->skb_size = MAX_RX_BUFFER_LENGTH; + if (adapter->ahw.cut_through) { + rds_ring->dma_size = + NX_CT_DEFAULT_RX_BUF_LEN; + rds_ring->skb_size = + NX_CT_DEFAULT_RX_BUF_LEN; + } else { + rds_ring->dma_size = RX_DMA_MAP_LEN; + rds_ring->skb_size = + MAX_RX_BUFFER_LENGTH; + } break; case RCV_DESC_JUMBO: rds_ring->max_rx_desc_count = adapter->max_jumbo_rx_desc_count; rds_ring->flags = RCV_DESC_JUMBO; - rds_ring->dma_size = RX_JUMBO_DMA_MAP_LEN; + if (NX_IS_REVISION_P3(adapter->ahw.revision_id)) + rds_ring->dma_size = + NX_P3_RX_JUMBO_BUF_MAX_LEN; + else + rds_ring->dma_size = + NX_P2_RX_JUMBO_BUF_MAX_LEN; rds_ring->skb_size = - MAX_RX_JUMBO_BUFFER_LENGTH; + rds_ring->dma_size + NET_IP_ALIGN; break; case RCV_RING_LRO: @@ -294,6 +307,7 @@ int netxen_alloc_sw_resources(struct netxen_adapter *adapter) goto err_out; } memset(rds_ring->rx_buf_arr, 0, RCV_BUFFSIZE); + INIT_LIST_HEAD(&rds_ring->free_list); rds_ring->begin_alloc = 0; /* * Now go through all of them, set reference handles @@ -302,6 +316,8 @@ int netxen_alloc_sw_resources(struct netxen_adapter *adapter) num_rx_bufs = rds_ring->max_rx_desc_count; rx_buf = rds_ring->rx_buf_arr; for (i = 0; i < num_rx_bufs; i++) { + list_add_tail(&rx_buf->list, + &rds_ring->free_list); rx_buf->ref_handle = i; rx_buf->state = NETXEN_BUFFER_FREE; rx_buf++; @@ -1137,15 +1153,47 @@ int netxen_receive_peg_ready(struct netxen_adapter *adapter) return 0; } +static struct sk_buff *netxen_process_rxbuf(struct netxen_adapter *adapter, + struct nx_host_rds_ring *rds_ring, u16 index, u16 cksum) +{ + struct netxen_rx_buffer *buffer; + struct sk_buff *skb; + + buffer = &rds_ring->rx_buf_arr[index]; + + pci_unmap_single(adapter->pdev, buffer->dma, rds_ring->dma_size, + PCI_DMA_FROMDEVICE); + + skb = buffer->skb; + if (!skb) + goto no_skb; + + if (likely(adapter->rx_csum && cksum == STATUS_CKSUM_OK)) { + adapter->stats.csummed++; + skb->ip_summed = CHECKSUM_UNNECESSARY; + } else + skb->ip_summed = CHECKSUM_NONE; + + skb->dev = adapter->netdev; + + buffer->skb = NULL; + +no_skb: + buffer->state = NETXEN_BUFFER_FREE; + buffer->lro_current_frags = 0; + buffer->lro_expected_frags = 0; + list_add_tail(&buffer->list, &rds_ring->free_list); + return skb; +} + /* * netxen_process_rcv() send the received packet to the protocol stack. * and if the number of receives exceeds RX_BUFFERS_REFILL, then we * invoke the routine to send more rx buffers to the Phantom... */ static void netxen_process_rcv(struct netxen_adapter *adapter, int ctxid, - struct status_desc *desc) + struct status_desc *desc, struct status_desc *frag_desc) { - struct pci_dev *pdev = adapter->pdev; struct net_device *netdev = adapter->netdev; u64 sts_data = le64_to_cpu(desc->status_desc_data); int index = netxen_get_sts_refhandle(sts_data); @@ -1154,8 +1202,8 @@ static void netxen_process_rcv(struct netxen_adapter *adapter, int ctxid, struct sk_buff *skb; u32 length = netxen_get_sts_totallength(sts_data); u32 desc_ctx; + u16 pkt_offset = 0, cksum; struct nx_host_rds_ring *rds_ring; - int ret; desc_ctx = netxen_get_sts_type(sts_data); if (unlikely(desc_ctx >= NUM_RCV_DESC_RINGS)) { @@ -1191,41 +1239,52 @@ static void netxen_process_rcv(struct netxen_adapter *adapter, int ctxid, } } - pci_unmap_single(pdev, buffer->dma, rds_ring->dma_size, - PCI_DMA_FROMDEVICE); - - skb = (struct sk_buff *)buffer->skb; + cksum = netxen_get_sts_status(sts_data); - if (likely(adapter->rx_csum && - netxen_get_sts_status(sts_data) == STATUS_CKSUM_OK)) { - adapter->stats.csummed++; - skb->ip_summed = CHECKSUM_UNNECESSARY; - } else - skb->ip_summed = CHECKSUM_NONE; + skb = netxen_process_rxbuf(adapter, rds_ring, index, cksum); + if (!skb) + return; - skb->dev = netdev; if (desc_ctx == RCV_DESC_LRO_CTXID) { /* True length was only available on the last pkt */ skb_put(skb, buffer->lro_length); } else { - skb_put(skb, length); + if (length > rds_ring->skb_size) + skb_put(skb, rds_ring->skb_size); + else + skb_put(skb, length); + + pkt_offset = netxen_get_sts_pkt_offset(sts_data); + if (pkt_offset) + skb_pull(skb, pkt_offset); } skb->protocol = eth_type_trans(skb, netdev); - ret = netif_receive_skb(skb); - netdev->last_rx = jiffies; - /* - * We just consumed one buffer so post a buffer. + * rx buffer chaining is disabled, walk and free + * any spurious rx buffer chain. */ - buffer->skb = NULL; - buffer->state = NETXEN_BUFFER_FREE; - buffer->lro_current_frags = 0; - buffer->lro_expected_frags = 0; + if (frag_desc) { + u16 i, nr_frags = desc->nr_frags; + + dev_kfree_skb_any(skb); + for (i = 0; i < nr_frags; i++) { + index = frag_desc->frag_handles[i]; + skb = netxen_process_rxbuf(adapter, + rds_ring, index, cksum); + if (skb) + dev_kfree_skb_any(skb); + } + adapter->stats.rxdropped++; + } else { - adapter->stats.no_rcv++; - adapter->stats.rxbytes += length; + netif_receive_skb(skb); + netdev->last_rx = jiffies; + + adapter->stats.no_rcv++; + adapter->stats.rxbytes += length; + } } /* Process Receive status ring */ @@ -1233,9 +1292,11 @@ u32 netxen_process_rcv_ring(struct netxen_adapter *adapter, int ctxid, int max) { struct netxen_recv_context *recv_ctx = &(adapter->recv_ctx[ctxid]); struct status_desc *desc_head = recv_ctx->rcv_status_desc_head; - struct status_desc *desc; /* used to read status desc here */ + struct status_desc *desc, *frag_desc; u32 consumer = recv_ctx->status_rx_consumer; int count = 0, ring; + u64 sts_data; + u16 opcode; while (count < max) { desc = &desc_head[consumer]; @@ -1244,9 +1305,26 @@ u32 netxen_process_rcv_ring(struct netxen_adapter *adapter, int ctxid, int max) netxen_get_sts_owner(desc)); break; } - netxen_process_rcv(adapter, ctxid, desc); + + sts_data = le64_to_cpu(desc->status_desc_data); + opcode = netxen_get_sts_opcode(sts_data); + frag_desc = NULL; + if (opcode == NETXEN_NIC_RXPKT_DESC) { + if (desc->nr_frags) { + consumer = get_next_index(consumer, + adapter->max_rx_desc_count); + frag_desc = &desc_head[consumer]; + netxen_set_sts_owner(frag_desc, + STATUS_OWNER_PHANTOM); + } + } + + netxen_process_rcv(adapter, ctxid, desc, frag_desc); + netxen_set_sts_owner(desc, STATUS_OWNER_PHANTOM); - consumer = (consumer + 1) & (adapter->max_rx_desc_count - 1); + + consumer = get_next_index(consumer, + adapter->max_rx_desc_count); count++; } for (ring = 0; ring < adapter->max_rds_rings; ring++) @@ -1348,36 +1426,31 @@ void netxen_post_rx_buffers(struct netxen_adapter *adapter, u32 ctx, u32 ringid) int index = 0; netxen_ctx_msg msg = 0; dma_addr_t dma; + struct list_head *head; rds_ring = &recv_ctx->rds_rings[ringid]; producer = rds_ring->producer; index = rds_ring->begin_alloc; - buffer = &rds_ring->rx_buf_arr[index]; + head = &rds_ring->free_list; + /* We can start writing rx descriptors into the phantom memory. */ - while (buffer->state == NETXEN_BUFFER_FREE) { + while (!list_empty(head)) { + skb = dev_alloc_skb(rds_ring->skb_size); if (unlikely(!skb)) { - /* - * TODO - * We need to schedule the posting of buffers to the pegs. - */ rds_ring->begin_alloc = index; - DPRINTK(ERR, "netxen_post_rx_buffers: " - " allocated only %d buffers\n", count); break; } + buffer = list_entry(head->next, struct netxen_rx_buffer, list); + list_del(&buffer->list); + count++; /* now there should be no failure */ pdesc = &rds_ring->desc_head[producer]; -#if defined(XGB_DEBUG) - *(unsigned long *)(skb->head) = 0xc0debabe; - if (skb_is_nonlinear(skb)) { - printk("Allocated SKB @%p is nonlinear\n"); - } -#endif - skb_reserve(skb, 2); + if (!adapter->ahw.cut_through) + skb_reserve(skb, 2); /* This will be setup when we receive the * buffer after it has been filled FSL TBD TBD * skb->dev = netdev; @@ -1395,7 +1468,6 @@ void netxen_post_rx_buffers(struct netxen_adapter *adapter, u32 ctx, u32 ringid) producer = get_next_index(producer, rds_ring->max_rx_desc_count); index = get_next_index(index, rds_ring->max_rx_desc_count); - buffer = &rds_ring->rx_buf_arr[index]; } /* if we did allocate buffers, then write the count to Phantom */ if (count) { @@ -1439,32 +1511,29 @@ static void netxen_post_rx_buffers_nodb(struct netxen_adapter *adapter, struct netxen_rx_buffer *buffer; int count = 0; int index = 0; + struct list_head *head; rds_ring = &recv_ctx->rds_rings[ringid]; producer = rds_ring->producer; index = rds_ring->begin_alloc; - buffer = &rds_ring->rx_buf_arr[index]; + head = &rds_ring->free_list; /* We can start writing rx descriptors into the phantom memory. */ - while (buffer->state == NETXEN_BUFFER_FREE) { + while (!list_empty(head)) { + skb = dev_alloc_skb(rds_ring->skb_size); if (unlikely(!skb)) { - /* - * We need to schedule the posting of buffers to the pegs. - */ rds_ring->begin_alloc = index; - DPRINTK(ERR, "netxen_post_rx_buffers_nodb: " - " allocated only %d buffers\n", count); break; } + + buffer = list_entry(head->next, struct netxen_rx_buffer, list); + list_del(&buffer->list); + count++; /* now there should be no failure */ pdesc = &rds_ring->desc_head[producer]; - skb_reserve(skb, 2); - /* - * This will be setup when we receive the - * buffer after it has been filled - * skb->dev = netdev; - */ + if (!adapter->ahw.cut_through) + skb_reserve(skb, 2); buffer->skb = skb; buffer->state = NETXEN_BUFFER_BUSY; buffer->dma = pci_map_single(pdev, skb->data, -- cgit v1.2.2