diff options
Diffstat (limited to 'drivers/staging/wimax/i2400m/netdev.c')
| -rw-r--r-- | drivers/staging/wimax/i2400m/netdev.c | 603 |
1 files changed, 0 insertions, 603 deletions
diff --git a/drivers/staging/wimax/i2400m/netdev.c b/drivers/staging/wimax/i2400m/netdev.c deleted file mode 100644 index cd06eaf75e8b..000000000000 --- a/drivers/staging/wimax/i2400m/netdev.c +++ /dev/null @@ -1,603 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Intel Wireless WiMAX Connection 2400m - * Glue with the networking stack - * - * Copyright (C) 2007 Intel Corporation <linux-wimax@intel.com> - * Yanir Lubetkin <yanirx.lubetkin@intel.com> - * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> - * - * This implements an ethernet device for the i2400m. - * - * We fake being an ethernet device to simplify the support from user - * space and from the other side. The world is (sadly) configured to - * take in only Ethernet devices... - * - * 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 - * just give the skb to the TX subsystem and by the time it is - * transmitted, we have long forgotten about it. So we just don't care - * too much about it. - * - * Note that when the device is in idle mode with the basestation, we - * need to negotiate coming back up online. That involves negotiation - * and possible user space interaction. Thus, we defer to a workqueue - * to do all that. By default, we only queue a single packet and drop - * the rest, as potentially the time to go back from idle to normal is - * long. - * - * ROADMAP - * - * i2400m_open Called on ifconfig up - * i2400m_stop Called on ifconfig down - * - * i2400m_hard_start_xmit Called by the network stack to send a packet - * i2400m_net_wake_tx Wake up device from basestation-IDLE & TX - * i2400m_wake_tx_work - * i2400m_cmd_exit_idle - * i2400m_tx - * i2400m_net_tx TX a data frame - * i2400m_tx - * - * i2400m_change_mtu Called on ifconfig mtu XXX - * - * i2400m_tx_timeout Called when the device times out - * - * i2400m_net_rx Called by the RX code when a data frame is - * 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. - */ -#include <linux/if_arp.h> -#include <linux/slab.h> -#include <linux/netdevice.h> -#include <linux/ethtool.h> -#include <linux/export.h> -#include "i2400m.h" - - -#define D_SUBMODULE netdev -#include "debug-levels.h" - -enum { -/* netdev interface */ - /* 20 secs? yep, this is the maximum timeout that the device - * might take to get out of IDLE / negotiate it with the base - * station. We add 1sec for good measure. */ - I2400M_TX_TIMEOUT = 21 * HZ, - /* - * Experimentation has determined that, 20 to be a good value - * for minimizing the jitter in the throughput. - */ - I2400M_TX_QLEN = 20, -}; - - -static -int i2400m_open(struct net_device *net_dev) -{ - int result; - struct i2400m *i2400m = net_dev_to_i2400m(net_dev); - struct device *dev = i2400m_dev(i2400m); - - d_fnstart(3, dev, "(net_dev %p [i2400m %p])\n", net_dev, i2400m); - /* Make sure we wait until init is complete... */ - mutex_lock(&i2400m->init_mutex); - if (i2400m->updown) - result = 0; - else - result = -EBUSY; - mutex_unlock(&i2400m->init_mutex); - d_fnend(3, dev, "(net_dev %p [i2400m %p]) = %d\n", - net_dev, i2400m, result); - return result; -} - - -static -int i2400m_stop(struct net_device *net_dev) -{ - struct i2400m *i2400m = net_dev_to_i2400m(net_dev); - struct device *dev = i2400m_dev(i2400m); - - d_fnstart(3, dev, "(net_dev %p [i2400m %p])\n", net_dev, i2400m); - i2400m_net_wake_stop(i2400m); - d_fnend(3, dev, "(net_dev %p [i2400m %p]) = 0\n", net_dev, i2400m); - return 0; -} - - -/* - * Wake up the device and transmit a held SKB, then restart the net queue - * - * When the device goes into basestation-idle mode, we need to tell it - * to exit that mode; it will negotiate with the base station, user - * space may have to intervene to rehandshake crypto and then tell us - * when it is ready to transmit the packet we have "queued". Still we - * need to give it sometime after it reports being ok. - * - * On error, there is not much we can do. If the error was on TX, we - * still wake the queue up to see if the next packet will be luckier. - * - * If _cmd_exit_idle() fails...well, it could be many things; most - * commonly it is that something else took the device out of IDLE mode - * (for example, the base station). In that case we get an -EILSEQ and - * we are just going to ignore that one. If the device is back to - * connected, then fine -- if it is someother state, the packet will - * be dropped anyway. - */ -void i2400m_wake_tx_work(struct work_struct *ws) -{ - int result; - struct i2400m *i2400m = container_of(ws, struct i2400m, wake_tx_ws); - struct net_device *net_dev = i2400m->wimax_dev.net_dev; - struct device *dev = i2400m_dev(i2400m); - struct sk_buff *skb; - unsigned long flags; - - spin_lock_irqsave(&i2400m->tx_lock, flags); - skb = i2400m->wake_tx_skb; - i2400m->wake_tx_skb = NULL; - spin_unlock_irqrestore(&i2400m->tx_lock, flags); - - d_fnstart(3, dev, "(ws %p i2400m %p skb %p)\n", ws, i2400m, skb); - result = -EINVAL; - if (skb == NULL) { - dev_err(dev, "WAKE&TX: skb disappeared!\n"); - goto out_put; - } - /* If we have, somehow, lost the connection after this was - * queued, don't do anything; this might be the device got - * reset or just disconnected. */ - if (unlikely(!netif_carrier_ok(net_dev))) - goto out_kfree; - result = i2400m_cmd_exit_idle(i2400m); - if (result == -EILSEQ) - result = 0; - if (result < 0) { - dev_err(dev, "WAKE&TX: device didn't get out of idle: " - "%d - resetting\n", result); - i2400m_reset(i2400m, I2400M_RT_BUS); - goto error; - } - result = wait_event_timeout(i2400m->state_wq, - i2400m->state != I2400M_SS_IDLE, - net_dev->watchdog_timeo - HZ/2); - if (result == 0) - result = -ETIMEDOUT; - if (result < 0) { - dev_err(dev, "WAKE&TX: error waiting for device to exit IDLE: " - "%d - resetting\n", result); - i2400m_reset(i2400m, I2400M_RT_BUS); - goto error; - } - msleep(20); /* device still needs some time or it drops it */ - result = i2400m_tx(i2400m, skb->data, skb->len, I2400M_PT_DATA); -error: - netif_wake_queue(net_dev); -out_kfree: - kfree_skb(skb); /* refcount transferred by _hard_start_xmit() */ -out_put: - i2400m_put(i2400m); - d_fnend(3, dev, "(ws %p i2400m %p skb %p) = void [%d]\n", - ws, i2400m, skb, result); -} - - -/* - * Prepare the data payload TX header - * - * The i2400m expects a 4 byte header in front of a data packet. - * - * Because we pretend to be an ethernet device, this packet comes with - * an ethernet header. Pull it and push our header. - */ -static -void i2400m_tx_prep_header(struct sk_buff *skb) -{ - struct i2400m_pl_data_hdr *pl_hdr; - skb_pull(skb, ETH_HLEN); - pl_hdr = skb_push(skb, sizeof(*pl_hdr)); - pl_hdr->reserved = 0; -} - - - -/* - * Cleanup resources acquired during i2400m_net_wake_tx() - * - * This is called by __i2400m_dev_stop and means we have to make sure - * the workqueue is flushed from any pending work. - */ -void i2400m_net_wake_stop(struct i2400m *i2400m) -{ - struct device *dev = i2400m_dev(i2400m); - struct sk_buff *wake_tx_skb; - unsigned long flags; - - d_fnstart(3, dev, "(i2400m %p)\n", i2400m); - /* - * See i2400m_hard_start_xmit(), references are taken there and - * here we release them if the packet was still pending. - */ - cancel_work_sync(&i2400m->wake_tx_ws); - - spin_lock_irqsave(&i2400m->tx_lock, flags); - wake_tx_skb = i2400m->wake_tx_skb; - i2400m->wake_tx_skb = NULL; - spin_unlock_irqrestore(&i2400m->tx_lock, flags); - - if (wake_tx_skb) { - i2400m_put(i2400m); - kfree_skb(wake_tx_skb); - } - - d_fnend(3, dev, "(i2400m %p) = void\n", i2400m); -} - - -/* - * TX an skb to an idle device - * - * When the device is in basestation-idle mode, we need to wake it up - * and then TX. So we queue a work_struct for doing so. - * - * We need to get an extra ref for the skb (so it is not dropped), as - * well as be careful not to queue more than one request (won't help - * at all). If more than one request comes or there are errors, we - * just drop the packets (see i2400m_hard_start_xmit()). - */ -static -int i2400m_net_wake_tx(struct i2400m *i2400m, struct net_device *net_dev, - struct sk_buff *skb) -{ - int result; - struct device *dev = i2400m_dev(i2400m); - unsigned long flags; - - d_fnstart(3, dev, "(skb %p net_dev %p)\n", skb, net_dev); - if (net_ratelimit()) { - d_printf(3, dev, "WAKE&NETTX: " - "skb %p sending %d bytes to radio\n", - skb, skb->len); - d_dump(4, dev, skb->data, skb->len); - } - /* We hold a ref count for i2400m and skb, so when - * stopping() the device, we need to cancel that work - * and if pending, release those resources. */ - result = 0; - spin_lock_irqsave(&i2400m->tx_lock, flags); - if (!i2400m->wake_tx_skb) { - netif_stop_queue(net_dev); - i2400m_get(i2400m); - i2400m->wake_tx_skb = skb_get(skb); /* transfer ref count */ - i2400m_tx_prep_header(skb); - result = schedule_work(&i2400m->wake_tx_ws); - WARN_ON(result == 0); - } - spin_unlock_irqrestore(&i2400m->tx_lock, flags); - if (result == 0) { - /* Yes, this happens even if we stopped the - * queue -- blame the queue disciplines that - * queue without looking -- I guess there is a reason - * for that. */ - if (net_ratelimit()) - d_printf(1, dev, "NETTX: device exiting idle, " - "dropping skb %p, queue running %d\n", - skb, netif_queue_stopped(net_dev)); - result = -EBUSY; - } - d_fnend(3, dev, "(skb %p net_dev %p) = %d\n", skb, net_dev, result); - return result; -} - - -/* - * Transmit a packet to the base station on behalf of the network stack. - * - * Returns: 0 if ok, < 0 errno code on error. - * - * We need to pull the ethernet header and add the hardware header, - * which is currently set to all zeroes and reserved. - */ -static -int i2400m_net_tx(struct i2400m *i2400m, struct net_device *net_dev, - struct sk_buff *skb) -{ - int result; - struct device *dev = i2400m_dev(i2400m); - - d_fnstart(3, dev, "(i2400m %p net_dev %p skb %p)\n", - i2400m, net_dev, skb); - /* FIXME: check eth hdr, only IPv4 is routed by the device as of now */ - netif_trans_update(net_dev); - i2400m_tx_prep_header(skb); - d_printf(3, dev, "NETTX: skb %p sending %d bytes to radio\n", - skb, skb->len); - d_dump(4, dev, skb->data, skb->len); - result = i2400m_tx(i2400m, skb->data, skb->len, I2400M_PT_DATA); - d_fnend(3, dev, "(i2400m %p net_dev %p skb %p) = %d\n", - i2400m, net_dev, skb, result); - return result; -} - - -/* - * Transmit a packet to the base station on behalf of the network stack - * - * - * Returns: NETDEV_TX_OK (always, even in case of error) - * - * In case of error, we just drop it. Reasons: - * - * - we add a hw header to each skb, and if the network stack - * retries, we have no way to know if that skb has it or not. - * - * - network protocols have their own drop-recovery mechanisms - * - * - there is not much else we can do - * - * If the device is idle, we need to wake it up; that is an operation - * that will sleep. See i2400m_net_wake_tx() for details. - */ -static -netdev_tx_t i2400m_hard_start_xmit(struct sk_buff *skb, - struct net_device *net_dev) -{ - struct i2400m *i2400m = net_dev_to_i2400m(net_dev); - struct device *dev = i2400m_dev(i2400m); - int result = -1; - - d_fnstart(3, dev, "(skb %p net_dev %p)\n", skb, net_dev); - - if (skb_cow_head(skb, 0)) - goto drop; - - if (i2400m->state == I2400M_SS_IDLE) - result = i2400m_net_wake_tx(i2400m, net_dev, skb); - else - result = i2400m_net_tx(i2400m, net_dev, skb); - if (result < 0) { -drop: - net_dev->stats.tx_dropped++; - } else { - net_dev->stats.tx_packets++; - net_dev->stats.tx_bytes += skb->len; - } - dev_kfree_skb(skb); - d_fnend(3, dev, "(skb %p net_dev %p) = %d\n", skb, net_dev, result); - return NETDEV_TX_OK; -} - - -static -void i2400m_tx_timeout(struct net_device *net_dev, unsigned int txqueue) -{ - /* - * We might want to kick the device - * - * There is not much we can do though, as the device requires - * that we send the data aggregated. By the time we receive - * this, there might be data pending to be sent or not... - */ - net_dev->stats.tx_errors++; -} - - -/* - * Create a fake ethernet header - * - * For emulating an ethernet device, every received IP header has to - * 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, __be16 protocol) -{ - struct i2400m *i2400m = net_dev_to_i2400m(net_dev); - struct ethhdr *eth_hdr = _eth_hdr; - - memcpy(eth_hdr->h_dest, net_dev->dev_addr, sizeof(eth_hdr->h_dest)); - memcpy(eth_hdr->h_source, i2400m->src_mac_addr, - sizeof(eth_hdr->h_source)); - eth_hdr->h_proto = protocol; -} - - -/* - * i2400m_net_rx - pass a network packet to the stack - * - * @i2400m: device instance - * @skb_rx: the skb where the buffer pointed to by @buf is - * @i: 1 if payload is the only one - * @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. - * - * Note that if the payload is the last (or the only one) in a - * multi-payload message, we don't clone the SKB but just reuse it. - * - * 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. - * - * FIXME: currently we don't do any efforts at distinguishing if what - * we got was an IPv4 or IPv6 header, to setup the protocol field - * correctly. - */ -void i2400m_net_rx(struct i2400m *i2400m, struct sk_buff *skb_rx, - unsigned i, const void *buf, int buf_len) -{ - struct net_device *net_dev = i2400m->wimax_dev.net_dev; - struct device *dev = i2400m_dev(i2400m); - struct sk_buff *skb; - - d_fnstart(2, dev, "(i2400m %p buf %p buf_len %d)\n", - i2400m, buf, buf_len); - if (i) { - skb = skb_get(skb_rx); - d_printf(2, dev, "RX: reusing first payload skb %p\n", skb); - skb_pull(skb, buf - (void *) skb->data); - skb_trim(skb, (void *) skb_end_pointer(skb) - buf); - } else { - /* Yes, this is bad -- a lot of overhead -- see - * comments at the top of the file */ - skb = __netdev_alloc_skb(net_dev, buf_len, GFP_KERNEL); - if (skb == NULL) { - dev_err(dev, "NETRX: no memory to realloc skb\n"); - net_dev->stats.rx_dropped++; - goto error_skb_realloc; - } - skb_put_data(skb, buf, buf_len); - } - 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 += buf_len; - d_printf(3, dev, "NETRX: receiving %d bytes to network stack\n", - buf_len); - d_dump(4, dev, buf, buf_len); - netif_rx_ni(skb); /* see notes in function header */ -error_skb_realloc: - d_fnend(2, dev, "(i2400m %p buf %p buf_len %d) = void\n", - i2400m, buf, buf_len); -} - - -/* - * 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); - - 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: - 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, -}; - -static void i2400m_get_drvinfo(struct net_device *net_dev, - struct ethtool_drvinfo *info) -{ - struct i2400m *i2400m = net_dev_to_i2400m(net_dev); - - strscpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); - strscpy(info->fw_version, i2400m->fw_name ? : "", - sizeof(info->fw_version)); - if (net_dev->dev.parent) - strscpy(info->bus_info, dev_name(net_dev->dev.parent), - sizeof(info->bus_info)); -} - -static const struct ethtool_ops i2400m_ethtool_ops = { - .get_drvinfo = i2400m_get_drvinfo, - .get_link = ethtool_op_get_link, -}; - -/* - * i2400m_netdev_setup - Setup setup @net_dev's i2400m private data - * - * Called by alloc_netdev() - */ -void i2400m_netdev_setup(struct net_device *net_dev) -{ - d_fnstart(3, NULL, "(net_dev %p)\n", net_dev); - ether_setup(net_dev); - net_dev->mtu = I2400M_MAX_MTU; - net_dev->min_mtu = 0; - net_dev->max_mtu = I2400M_MAX_MTU; - net_dev->tx_queue_len = I2400M_TX_QLEN; - net_dev->features = - NETIF_F_VLAN_CHALLENGED - | NETIF_F_HIGHDMA; - net_dev->flags = - IFF_NOARP /* i2400m is apure IP device */ - & (~IFF_BROADCAST /* i2400m is P2P */ - & ~IFF_MULTICAST); - net_dev->watchdog_timeo = I2400M_TX_TIMEOUT; - net_dev->netdev_ops = &i2400m_netdev_ops; - net_dev->ethtool_ops = &i2400m_ethtool_ops; - d_fnend(3, NULL, "(net_dev %p) = void\n", net_dev); -} -EXPORT_SYMBOL_GPL(i2400m_netdev_setup); - |