1 /* 2 * Copyright 2007-2012 Siemens AG 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 6 * as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License along 14 * with this program; if not, write to the Free Software Foundation, Inc., 15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 16 * 17 * Written by: 18 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> 19 * Sergey Lapin <slapin@ossfans.org> 20 * Maxim Gorbachyov <maxim.gorbachev@siemens.com> 21 * Alexander Smirnov <alex.bluesman.smirnov@gmail.com> 22 */ 23 24 #include <linux/netdevice.h> 25 #include <linux/if_arp.h> 26 #include <linux/crc-ccitt.h> 27 28 #include <net/ieee802154_netdev.h> 29 #include <net/mac802154.h> 30 #include <net/wpan-phy.h> 31 32 #include "mac802154.h" 33 34 /* IEEE 802.15.4 transceivers can sleep during the xmit session, so process 35 * packets through the workqueue. 36 */ 37 struct xmit_work { 38 struct sk_buff *skb; 39 struct work_struct work; 40 struct mac802154_priv *priv; 41 u8 chan; 42 u8 page; 43 }; 44 45 static void mac802154_xmit_worker(struct work_struct *work) 46 { 47 struct xmit_work *xw = container_of(work, struct xmit_work, work); 48 struct mac802154_sub_if_data *sdata; 49 int res; 50 51 mutex_lock(&xw->priv->phy->pib_lock); 52 if (xw->priv->phy->current_channel != xw->chan || 53 xw->priv->phy->current_page != xw->page) { 54 res = xw->priv->ops->set_channel(&xw->priv->hw, 55 xw->page, 56 xw->chan); 57 if (res) { 58 pr_debug("set_channel failed\n"); 59 goto out; 60 } 61 62 xw->priv->phy->current_channel = xw->chan; 63 xw->priv->phy->current_page = xw->page; 64 } 65 66 res = xw->priv->ops->xmit(&xw->priv->hw, xw->skb); 67 if (res) 68 pr_debug("transmission failed\n"); 69 70 out: 71 mutex_unlock(&xw->priv->phy->pib_lock); 72 73 /* Restart the netif queue on each sub_if_data object. */ 74 rcu_read_lock(); 75 list_for_each_entry_rcu(sdata, &xw->priv->slaves, list) 76 netif_wake_queue(sdata->dev); 77 rcu_read_unlock(); 78 79 dev_kfree_skb(xw->skb); 80 81 kfree(xw); 82 } 83 84 netdev_tx_t mac802154_tx(struct mac802154_priv *priv, struct sk_buff *skb, 85 u8 page, u8 chan) 86 { 87 struct xmit_work *work; 88 struct mac802154_sub_if_data *sdata; 89 90 if (!(priv->phy->channels_supported[page] & (1 << chan))) { 91 WARN_ON(1); 92 kfree_skb(skb); 93 return NETDEV_TX_OK; 94 } 95 96 mac802154_monitors_rx(mac802154_to_priv(&priv->hw), skb); 97 98 if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) { 99 u16 crc = crc_ccitt(0, skb->data, skb->len); 100 u8 *data = skb_put(skb, 2); 101 data[0] = crc & 0xff; 102 data[1] = crc >> 8; 103 } 104 105 if (skb_cow_head(skb, priv->hw.extra_tx_headroom)) { 106 kfree_skb(skb); 107 return NETDEV_TX_OK; 108 } 109 110 work = kzalloc(sizeof(struct xmit_work), GFP_ATOMIC); 111 if (!work) { 112 kfree_skb(skb); 113 return NETDEV_TX_BUSY; 114 } 115 116 /* Stop the netif queue on each sub_if_data object. */ 117 rcu_read_lock(); 118 list_for_each_entry_rcu(sdata, &priv->slaves, list) 119 netif_stop_queue(sdata->dev); 120 rcu_read_unlock(); 121 122 INIT_WORK(&work->work, mac802154_xmit_worker); 123 work->skb = skb; 124 work->priv = priv; 125 work->page = page; 126 work->chan = chan; 127 128 queue_work(priv->dev_workqueue, &work->work); 129 130 return NETDEV_TX_OK; 131 } 132