xref: /openbmc/linux/net/mac802154/tx.c (revision 6774def6)
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 		goto err_tx;
93 	}
94 
95 	mac802154_monitors_rx(mac802154_to_priv(&priv->hw), skb);
96 
97 	if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
98 		u16 crc = crc_ccitt(0, skb->data, skb->len);
99 		u8 *data = skb_put(skb, 2);
100 
101 		data[0] = crc & 0xff;
102 		data[1] = crc >> 8;
103 	}
104 
105 	if (skb_cow_head(skb, priv->hw.extra_tx_headroom))
106 		goto err_tx;
107 
108 	work = kzalloc(sizeof(*work), GFP_ATOMIC);
109 	if (!work) {
110 		kfree_skb(skb);
111 		return NETDEV_TX_BUSY;
112 	}
113 
114 	/* Stop the netif queue on each sub_if_data object. */
115 	rcu_read_lock();
116 	list_for_each_entry_rcu(sdata, &priv->slaves, list)
117 		netif_stop_queue(sdata->dev);
118 	rcu_read_unlock();
119 
120 	INIT_WORK(&work->work, mac802154_xmit_worker);
121 	work->skb = skb;
122 	work->priv = priv;
123 	work->page = page;
124 	work->chan = chan;
125 
126 	queue_work(priv->dev_workqueue, &work->work);
127 
128 	return NETDEV_TX_OK;
129 
130 err_tx:
131 	kfree_skb(skb);
132 	return NETDEV_TX_OK;
133 }
134