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/mac802154.h> 29 #include <net/wpan-phy.h> 30 31 #include "mac802154.h" 32 33 /* IEEE 802.15.4 transceivers can sleep during the xmit session, so process 34 * packets through the workqueue. 35 */ 36 struct xmit_work { 37 struct sk_buff *skb; 38 struct work_struct work; 39 struct mac802154_priv *priv; 40 u8 chan; 41 u8 page; 42 u8 xmit_attempts; 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 int res; 49 50 mutex_lock(&xw->priv->phy->pib_lock); 51 if (xw->priv->phy->current_channel != xw->chan || 52 xw->priv->phy->current_page != xw->page) { 53 res = xw->priv->ops->set_channel(&xw->priv->hw, 54 xw->page, 55 xw->chan); 56 if (res) { 57 pr_debug("set_channel failed\n"); 58 goto out; 59 } 60 } 61 62 res = xw->priv->ops->xmit(&xw->priv->hw, xw->skb); 63 64 out: 65 mutex_unlock(&xw->priv->phy->pib_lock); 66 67 if (res) { 68 if (xw->xmit_attempts++ < MAC802154_MAX_XMIT_ATTEMPTS) { 69 queue_work(xw->priv->dev_workqueue, &xw->work); 70 return; 71 } else 72 pr_debug("transmission failed for %d times", 73 MAC802154_MAX_XMIT_ATTEMPTS); 74 } 75 76 dev_kfree_skb(xw->skb); 77 78 kfree(xw); 79 } 80 81 netdev_tx_t mac802154_tx(struct mac802154_priv *priv, struct sk_buff *skb, 82 u8 page, u8 chan) 83 { 84 struct xmit_work *work; 85 86 if (!(priv->phy->channels_supported[page] & (1 << chan))) { 87 WARN_ON(1); 88 kfree_skb(skb); 89 return NETDEV_TX_OK; 90 } 91 92 mac802154_monitors_rx(mac802154_to_priv(&priv->hw), skb); 93 94 if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) { 95 u16 crc = crc_ccitt(0, skb->data, skb->len); 96 u8 *data = skb_put(skb, 2); 97 data[0] = crc & 0xff; 98 data[1] = crc >> 8; 99 } 100 101 if (skb_cow_head(skb, priv->hw.extra_tx_headroom)) { 102 kfree_skb(skb); 103 return NETDEV_TX_OK; 104 } 105 106 work = kzalloc(sizeof(struct xmit_work), GFP_ATOMIC); 107 if (!work) { 108 kfree_skb(skb); 109 return NETDEV_TX_BUSY; 110 } 111 112 INIT_WORK(&work->work, mac802154_xmit_worker); 113 work->skb = skb; 114 work->priv = priv; 115 work->page = page; 116 work->chan = chan; 117 work->xmit_attempts = 0; 118 119 queue_work(priv->dev_workqueue, &work->work); 120 121 return NETDEV_TX_OK; 122 } 123