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authoralex.bluesman.smirnov@gmail.com <alex.bluesman.smirnov@gmail.com>2012-05-16 00:50:22 +0400
committerDavid S. Miller <davem@davemloft.net>2012-05-16 23:16:49 +0400
commit5b641ebeec348761c9ebac9454c672d4d2d3ef91 (patch)
tree75cec47761ebbc97e0f35ac5c2a1a97eb332425b /net/mac802154/tx.c
parent1cd829c83eab8b899b85d597c767fcf8b4cf8fd6 (diff)
downloadlinux-5b641ebeec348761c9ebac9454c672d4d2d3ef91.tar.xz
mac802154: TX data path
Main TX data path implementation between upper and physical layers. Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mac802154/tx.c')
-rw-r--r--net/mac802154/tx.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c
new file mode 100644
index 000000000000..8781d8f904d9
--- /dev/null
+++ b/net/mac802154/tx.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2007-2012 Siemens AG
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Written by:
+ * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
+ * Sergey Lapin <slapin@ossfans.org>
+ * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
+ * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ */
+
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/crc-ccitt.h>
+
+#include <net/mac802154.h>
+#include <net/wpan-phy.h>
+
+#include "mac802154.h"
+
+/* IEEE 802.15.4 transceivers can sleep during the xmit session, so process
+ * packets through the workqueue.
+ */
+struct xmit_work {
+ struct sk_buff *skb;
+ struct work_struct work;
+ struct mac802154_priv *priv;
+ u8 chan;
+ u8 page;
+ u8 xmit_attempts;
+};
+
+static void mac802154_xmit_worker(struct work_struct *work)
+{
+ struct xmit_work *xw = container_of(work, struct xmit_work, work);
+ int res;
+
+ mutex_lock(&xw->priv->phy->pib_lock);
+ if (xw->priv->phy->current_channel != xw->chan ||
+ xw->priv->phy->current_page != xw->page) {
+ res = xw->priv->ops->set_channel(&xw->priv->hw,
+ xw->page,
+ xw->chan);
+ if (res) {
+ pr_debug("set_channel failed\n");
+ goto out;
+ }
+ }
+
+ res = xw->priv->ops->xmit(&xw->priv->hw, xw->skb);
+
+out:
+ mutex_unlock(&xw->priv->phy->pib_lock);
+
+ if (res) {
+ if (xw->xmit_attempts++ < MAC802154_MAX_XMIT_ATTEMPTS) {
+ queue_work(xw->priv->dev_workqueue, &xw->work);
+ return;
+ } else
+ pr_debug("transmission failed for %d times",
+ MAC802154_MAX_XMIT_ATTEMPTS);
+ }
+
+ dev_kfree_skb(xw->skb);
+
+ kfree(xw);
+}
+
+netdev_tx_t mac802154_tx(struct mac802154_priv *priv, struct sk_buff *skb,
+ u8 page, u8 chan)
+{
+ struct xmit_work *work;
+
+ if (!(priv->phy->channels_supported[page] & (1 << chan)))
+ WARN_ON(1);
+ return NETDEV_TX_OK;
+
+ if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
+ u16 crc = crc_ccitt(0, skb->data, skb->len);
+ u8 *data = skb_put(skb, 2);
+ data[0] = crc & 0xff;
+ data[1] = crc >> 8;
+ }
+
+ if (skb_cow_head(skb, priv->hw.extra_tx_headroom)) {
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+ }
+
+ work = kzalloc(sizeof(struct xmit_work), GFP_ATOMIC);
+ if (!work)
+ return NETDEV_TX_BUSY;
+
+ INIT_WORK(&work->work, mac802154_xmit_worker);
+ work->skb = skb;
+ work->priv = priv;
+ work->page = page;
+ work->chan = chan;
+ work->xmit_attempts = 0;
+
+ queue_work(priv->dev_workqueue, &work->work);
+
+ return NETDEV_TX_OK;
+}