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>

3 files changed, 122 insertions, 1 deletions

diff --git a/net/mac802154/Makefile b/net/mac802154/Makefile
index e00fe474dce4..490beef7176e 100644
--- a/net/mac802154/Makefile
+++ b/net/mac802154/Makefile
@@ -1,2 +1,2 @@
 obj-$(CONFIG_MAC802154) += mac802154.o
-mac802154-objs          := ieee802154_dev.o rx.o
+mac802154-objs          := ieee802154_dev.o rx.o tx.o
diff --git a/net/mac802154/mac802154.h b/net/mac802154/mac802154.h
index 980d0a24040e..4f2d97506c6a 100644
--- a/net/mac802154/mac802154.h
+++ b/net/mac802154/mac802154.h
@@ -60,4 +60,9 @@ struct mac802154_priv {
 
 #define mac802154_to_priv(_hw)  container_of(_hw, struct mac802154_priv, hw)
 
+#define MAC802154_MAX_XMIT_ATTEMPTS     3
+
+netdev_tx_t mac802154_tx(struct mac802154_priv *priv, struct sk_buff *skb,
+                         u8 page, u8 chan);
+
 #endif /* MAC802154_H */
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;
+}