diff options
Diffstat (limited to 'drivers/net/wimax/i2400m/netdev.c')
| -rw-r--r-- | drivers/net/wimax/i2400m/netdev.c | 120 |
1 files changed, 90 insertions, 30 deletions
diff --git a/drivers/net/wimax/i2400m/netdev.c b/drivers/net/wimax/i2400m/netdev.c index 63fe708e8a31..6b1fe7a81f25 100644 --- a/drivers/net/wimax/i2400m/netdev.c +++ b/drivers/net/wimax/i2400m/netdev.c @@ -28,13 +28,12 @@ * space and from the other side. The world is (sadly) configured to * take in only Ethernet devices... * - * Because of this, currently there is an copy-each-rxed-packet - * overhead on the RX path. Each IP packet has to be reallocated to - * add an ethernet header (as there is no space in what we get from - * the device). This is a known drawback and coming versions of the - * device's firmware are being changed to add header space that can be - * used to insert the ethernet header without having to reallocate and - * copy. + * Because of this, when using firmwares <= v1.3, there is an + * copy-each-rxed-packet overhead on the RX path. Each IP packet has + * to be reallocated to add an ethernet header (as there is no space + * in what we get from the device). This is a known drawback and + * firmwares >= 1.4 add header space that can be used to insert the + * ethernet header without having to reallocate and copy. * * TX error handling is tricky; because we have to FIFO/queue the * buffers for transmission (as the hardware likes it aggregated), we @@ -67,7 +66,9 @@ * i2400m_tx_timeout Called when the device times out * * i2400m_net_rx Called by the RX code when a data frame is - * available. + * available (firmware <= 1.3) + * i2400m_net_erx Called by the RX code when a data frame is + * available (firmware >= 1.4). * i2400m_netdev_setup Called to setup all the netdev stuff from * alloc_netdev. */ @@ -396,30 +397,18 @@ void i2400m_tx_timeout(struct net_device *net_dev) * Create a fake ethernet header * * For emulating an ethernet device, every received IP header has to - * be prefixed with an ethernet header. - * - * What we receive has (potentially) many IP packets concatenated with - * no ETH_HLEN bytes prefixed. Thus there is no space for an eth - * header. - * - * We would have to reallocate or do ugly fragment tricks in order to - * add it. - * - * But what we do is use the header space of the RX transaction - * (*msg_hdr) as we don't need it anymore; then we'll point all the - * data skbs there, as they share the same backing store. - * - * We only support IPv4 for v3 firmware. + * be prefixed with an ethernet header. Fake it with the given + * protocol. */ static void i2400m_rx_fake_eth_header(struct net_device *net_dev, - void *_eth_hdr) + void *_eth_hdr, __be16 protocol) { struct ethhdr *eth_hdr = _eth_hdr; memcpy(eth_hdr->h_dest, net_dev->dev_addr, sizeof(eth_hdr->h_dest)); memset(eth_hdr->h_source, 0, sizeof(eth_hdr->h_dest)); - eth_hdr->h_proto = __constant_cpu_to_be16(ETH_P_IP); + eth_hdr->h_proto = protocol; } @@ -432,6 +421,13 @@ void i2400m_rx_fake_eth_header(struct net_device *net_dev, * @buf: pointer to the buffer containing the data * @len: buffer's length * + * This is only used now for the v1.3 firmware. It will be deprecated + * in >= 2.6.31. + * + * Note that due to firmware limitations, we don't have space to add + * an ethernet header, so we need to copy each packet. Firmware + * versions >= v1.4 fix this [see i2400m_net_erx()]. + * * We just clone the skb and set it up so that it's skb->data pointer * points to "buf" and it's length. * @@ -478,7 +474,8 @@ void i2400m_net_rx(struct i2400m *i2400m, struct sk_buff *skb_rx, memcpy(skb_put(skb, buf_len), buf, buf_len); } i2400m_rx_fake_eth_header(i2400m->wimax_dev.net_dev, - skb->data - ETH_HLEN); + skb->data - ETH_HLEN, + cpu_to_be16(ETH_P_IP)); skb_set_mac_header(skb, -ETH_HLEN); skb->dev = i2400m->wimax_dev.net_dev; skb->protocol = htons(ETH_P_IP); @@ -494,6 +491,73 @@ error_skb_realloc: } +/* + * i2400m_net_erx - pass a network packet to the stack (extended version) + * + * @i2400m: device descriptor + * @skb: the skb where the packet is - the skb should be set to point + * at the IP packet; this function will add ethernet headers if + * needed. + * @cs: packet type + * + * This is only used now for firmware >= v1.4. Note it is quite + * similar to i2400m_net_rx() (used only for v1.3 firmware). + * + * This function is normally run from a thread context. However, we + * still use netif_rx() instead of netif_receive_skb() as was + * recommended in the mailing list. Reason is in some stress tests + * when sending/receiving a lot of data we seem to hit a softlock in + * the kernel's TCP implementation [aroudn tcp_delay_timer()]. Using + * netif_rx() took care of the issue. + * + * This is, of course, still open to do more research on why running + * with netif_receive_skb() hits this softlock. FIXME. + */ +void i2400m_net_erx(struct i2400m *i2400m, struct sk_buff *skb, + enum i2400m_cs cs) +{ + struct net_device *net_dev = i2400m->wimax_dev.net_dev; + struct device *dev = i2400m_dev(i2400m); + int protocol; + + d_fnstart(2, dev, "(i2400m %p skb %p [%u] cs %d)\n", + i2400m, skb, skb->len, cs); + switch(cs) { + case I2400M_CS_IPV4_0: + case I2400M_CS_IPV4: + protocol = ETH_P_IP; + i2400m_rx_fake_eth_header(i2400m->wimax_dev.net_dev, + skb->data - ETH_HLEN, + cpu_to_be16(ETH_P_IP)); + skb_set_mac_header(skb, -ETH_HLEN); + skb->dev = i2400m->wimax_dev.net_dev; + skb->protocol = htons(ETH_P_IP); + net_dev->stats.rx_packets++; + net_dev->stats.rx_bytes += skb->len; + break; + default: + dev_err(dev, "ERX: BUG? CS type %u unsupported\n", cs); + goto error; + + } + d_printf(3, dev, "ERX: receiving %d bytes to the network stack\n", + skb->len); + d_dump(4, dev, skb->data, skb->len); + netif_rx_ni(skb); /* see notes in function header */ +error: + d_fnend(2, dev, "(i2400m %p skb %p [%u] cs %d) = void\n", + i2400m, skb, skb->len, cs); +} + +static const struct net_device_ops i2400m_netdev_ops = { + .ndo_open = i2400m_open, + .ndo_stop = i2400m_stop, + .ndo_start_xmit = i2400m_hard_start_xmit, + .ndo_tx_timeout = i2400m_tx_timeout, + .ndo_change_mtu = i2400m_change_mtu, +}; + + /** * i2400m_netdev_setup - Setup setup @net_dev's i2400m private data * @@ -513,11 +577,7 @@ void i2400m_netdev_setup(struct net_device *net_dev) & (~IFF_BROADCAST /* i2400m is P2P */ & ~IFF_MULTICAST); net_dev->watchdog_timeo = I2400M_TX_TIMEOUT; - net_dev->open = i2400m_open; - net_dev->stop = i2400m_stop; - net_dev->hard_start_xmit = i2400m_hard_start_xmit; - net_dev->change_mtu = i2400m_change_mtu; - net_dev->tx_timeout = i2400m_tx_timeout; + net_dev->netdev_ops = &i2400m_netdev_ops; d_fnend(3, NULL, "(net_dev %p) = void\n", net_dev); } EXPORT_SYMBOL_GPL(i2400m_netdev_setup); |