uwb: add the i1480 WLP driver

Add the driver for the WLP capability of the Intel i1480 device.
Signed-off-by: David Vrabel <david.vrabel@csr.com>

drivers/uwb/Kconfig

@@ -76,4 +76,14 @@ config UWB_I1480U
          To compile this driver select Y (built in) or M (module). It
          is safe to select any even if you do not have the hardware.
 
+config UWB_I1480U_WLP
+        tristate "Support for Intel Wireless UWB Link 1480 HWA's WLP interface"
+        depends on UWB_I1480U &&  UWB_WLP && NET
+        help
+         This driver enables WLP support for the i1480 when connected via
+         USB. WLP is the WiMedia Link Protocol, or IP over UWB.
+
+         To compile this driver select Y (built in) or M (module). It
+         is safe to select any even if you don't have the hardware.
+
 endif # UWB

drivers/uwb/i1480/Makefile

 obj-$(CONFIG_UWB_I1480U)	+= dfu/ i1480-est.o
+obj-$(CONFIG_UWB_I1480U_WLP)	+= i1480u-wlp/

drivers/uwb/i1480/i1480-wlp.h

+/*
+ * Intel 1480 Wireless UWB Link
+ * WLP specific definitions
+ *
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * 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.
+ *
+ *
+ * FIXME: docs
+ */
+
+#ifndef __i1480_wlp_h__
+#define __i1480_wlp_h__
+
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/uwb.h>
+#include <linux/if_ether.h>
+#include <asm/byteorder.h>
+
+/* New simplified header format? */
+#undef WLP_HDR_FMT_2 		/* FIXME: rename */
+
+/**
+ * Values of the Delivery ID & Type field when PCA or DRP
+ *
+ * The Delivery ID & Type field in the WLP TX header indicates whether
+ * the frame is PCA or DRP. This is done based on the high level bit of
+ * this field.
+ * We use this constant to test if the traffic is PCA or DRP as follows:
+ * if (wlp_tx_hdr_delivery_id_type(wlp_tx_hdr) & WLP_DRP)
+ * 	this is DRP traffic
+ * else
+ * 	this is PCA traffic
+ */
+enum deliver_id_type_bit {
+	WLP_DRP = 8,
+};
+
+/**
+ * WLP TX header
+ *
+ * Indicates UWB/WLP-specific transmission parameters for a network
+ * packet.
+ */
+struct wlp_tx_hdr {
+	/* dword 0 */
+	struct uwb_dev_addr dstaddr;
+	u8                  key_index;
+	u8                  mac_params;
+	/* dword 1 */
+	u8                  phy_params;
+#ifndef WLP_HDR_FMT_2
+	u8                  reserved;
+	__le16              oui01;              /* FIXME: not so sure if __le16 or u8[2] */
+	/* dword 2 */
+	u8                  oui2;               /*        if all LE, it could be merged */
+	__le16              prid;
+#endif
+} __attribute__((packed));
+
+static inline int wlp_tx_hdr_delivery_id_type(const struct wlp_tx_hdr *hdr)
+{
+	return hdr->mac_params & 0x0f;
+}
+
+static inline int wlp_tx_hdr_ack_policy(const struct wlp_tx_hdr *hdr)
+{
+	return (hdr->mac_params >> 4) & 0x07;
+}
+
+static inline int wlp_tx_hdr_rts_cts(const struct wlp_tx_hdr *hdr)
+{
+	return (hdr->mac_params >> 7) & 0x01;
+}
+
+static inline void wlp_tx_hdr_set_delivery_id_type(struct wlp_tx_hdr *hdr, int id)
+{
+	hdr->mac_params = (hdr->mac_params & ~0x0f) | id;
+}
+
+static inline void wlp_tx_hdr_set_ack_policy(struct wlp_tx_hdr *hdr,
+					     enum uwb_ack_pol policy)
+{
+	hdr->mac_params = (hdr->mac_params & ~0x70) | (policy << 4);
+}
+
+static inline void wlp_tx_hdr_set_rts_cts(struct wlp_tx_hdr *hdr, int rts_cts)
+{
+	hdr->mac_params = (hdr->mac_params & ~0x80) | (rts_cts << 7);
+}
+
+static inline enum uwb_phy_rate wlp_tx_hdr_phy_rate(const struct wlp_tx_hdr *hdr)
+{
+	return hdr->phy_params & 0x0f;
+}
+
+static inline int wlp_tx_hdr_tx_power(const struct wlp_tx_hdr *hdr)
+{
+	return (hdr->phy_params >> 4) & 0x0f;
+}
+
+static inline void wlp_tx_hdr_set_phy_rate(struct wlp_tx_hdr *hdr, enum uwb_phy_rate rate)
+{
+	hdr->phy_params = (hdr->phy_params & ~0x0f) | rate;
+}
+
+static inline void wlp_tx_hdr_set_tx_power(struct wlp_tx_hdr *hdr, int pwr)
+{
+	hdr->phy_params = (hdr->phy_params & ~0xf0) | (pwr << 4);
+}
+
+
+/**
+ * WLP RX header
+ *
+ * Provides UWB/WLP-specific transmission data for a received
+ * network packet.
+ */
+struct wlp_rx_hdr {
+	/* dword 0 */
+	struct uwb_dev_addr dstaddr;
+	struct uwb_dev_addr srcaddr;
+	/* dword 1 */
+	u8 		    LQI;
+	s8		    RSSI;
+	u8		    reserved3;
+#ifndef WLP_HDR_FMT_2
+	u8 		    oui0;
+	/* dword 2 */
+	__le16		    oui12;
+	__le16		    prid;
+#endif
+} __attribute__((packed));
+
+
+/** User configurable options for WLP */
+struct wlp_options {
+	struct mutex mutex; /* access to user configurable options*/
+	struct wlp_tx_hdr def_tx_hdr;	/* default tx hdr */
+	u8 pca_base_priority;
+	u8 bw_alloc; /*index into bw_allocs[] for PCA/DRP reservations*/
+};
+
+
+static inline
+void wlp_options_init(struct wlp_options *options)
+{
+	mutex_init(&options->mutex);
+	wlp_tx_hdr_set_ack_policy(&options->def_tx_hdr, UWB_ACK_INM);
+	wlp_tx_hdr_set_rts_cts(&options->def_tx_hdr, 1);
+	/* FIXME: default to phy caps */
+	wlp_tx_hdr_set_phy_rate(&options->def_tx_hdr, UWB_PHY_RATE_480);
+#ifndef WLP_HDR_FMT_2
+	options->def_tx_hdr.prid = cpu_to_le16(0x0000);
+#endif
+}
+
+
+/* sysfs helpers */
+
+extern ssize_t uwb_pca_base_priority_store(struct wlp_options *,
+					   const char *, size_t);
+extern ssize_t uwb_pca_base_priority_show(const struct wlp_options *, char *);
+extern ssize_t uwb_bw_alloc_store(struct wlp_options *, const char *, size_t);
+extern ssize_t uwb_bw_alloc_show(const struct wlp_options *, char *);
+extern ssize_t uwb_ack_policy_store(struct wlp_options *,
+				    const char *, size_t);
+extern ssize_t uwb_ack_policy_show(const struct wlp_options *, char *);
+extern ssize_t uwb_rts_cts_store(struct wlp_options *, const char *, size_t);
+extern ssize_t uwb_rts_cts_show(const struct wlp_options *, char *);
+extern ssize_t uwb_phy_rate_store(struct wlp_options *, const char *, size_t);
+extern ssize_t uwb_phy_rate_show(const struct wlp_options *, char *);
+
+
+/** Simple bandwidth allocation (temporary and too simple) */
+struct wlp_bw_allocs {
+	const char *name;
+	struct {
+		u8 mask, stream;
+	} tx, rx;
+};
+
+
+#endif /* #ifndef __i1480_wlp_h__ */

drivers/uwb/i1480/i1480u-wlp/Makefile

+obj-$(CONFIG_UWB_I1480U_WLP) += i1480u-wlp.o
+
+i1480u-wlp-objs :=	\
+	lc.o		\
+	netdev.o	\
+	rx.o		\
+	sysfs.o		\
+	tx.o

drivers/uwb/i1480/i1480u-wlp/i1480u-wlp.h

+/*
+ * Intel 1480 Wireless UWB Link USB
+ * Header formats, constants, general internal interfaces
+ *
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * 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.
+ *
+ *
+ * This is not an standard interface.
+ *
+ * FIXME: docs
+ *
+ * i1480u-wlp is pretty simple: two endpoints, one for tx, one for
+ * rx. rx is polled. Network packets (ethernet, whatever) are wrapped
+ * in i1480 TX or RX headers (for sending over the air), and these
+ * packets are wrapped in UNTD headers (for sending to the WLP UWB
+ * controller).
+ *
+ * UNTD packets (UNTD hdr + i1480 hdr + network packet) packets
+ * cannot be bigger than i1480u_MAX_FRG_SIZE. When this happens, the
+ * i1480 packet is broken in chunks/packets:
+ *
+ * UNTD-1st.hdr + i1480.hdr + payload
+ * UNTD-next.hdr + payload
+ * ...
+ * UNTD-last.hdr + payload
+ *
+ * so that each packet is smaller or equal than i1480u_MAX_FRG_SIZE.
+ *
+ * All HW structures and bitmaps are little endian, so we need to play
+ * ugly tricks when defining bitfields. Hoping for the day GCC
+ * implements __attribute__((endian(1234))).
+ *
+ * FIXME: ROADMAP to the whole implementation
+ */
+
+#ifndef __i1480u_wlp_h__
+#define __i1480u_wlp_h__
+
+#include <linux/usb.h>
+#include <linux/netdevice.h>
+#include <linux/uwb.h>		/* struct uwb_rc, struct uwb_notifs_handler */
+#include <linux/wlp.h>
+#include "../i1480-wlp.h"
+
+#undef i1480u_FLOW_CONTROL	/* Enable flow control code */
+
+/**
+ * Basic flow control
+ */
+enum {
+	i1480u_TX_INFLIGHT_MAX = 1000,
+	i1480u_TX_INFLIGHT_THRESHOLD = 100,
+};
+
+/** Maximum size of a transaction that we can tx/rx */
+enum {
+	/* Maximum packet size computed as follows: max UNTD header (8) +
+	 * i1480 RX header (8) + max Ethernet header and payload (4096) +
+	 * Padding added by skb_reserve (2) to make post Ethernet payload
+	 * start on 16 byte boundary*/
+	i1480u_MAX_RX_PKT_SIZE = 4114,
+	i1480u_MAX_FRG_SIZE = 512,
+	i1480u_RX_BUFS = 9,
+};
+
+
+/**
+ * UNTD packet type
+ *
+ * We need to fragment any payload whose UNTD packet is going to be
+ * bigger than i1480u_MAX_FRG_SIZE.
+ */
+enum i1480u_pkt_type {
+	i1480u_PKT_FRAG_1ST = 0x1,
+	i1480u_PKT_FRAG_NXT = 0x0,
+	i1480u_PKT_FRAG_LST = 0x2,
+	i1480u_PKT_FRAG_CMP = 0x3
+};
+enum {
+	i1480u_PKT_NONE = 0x4,
+};
+
+/** USB Network Transfer Descriptor - common */
+struct untd_hdr {
+	u8     type;
+	__le16 len;
+} __attribute__((packed));
+
+static inline enum i1480u_pkt_type untd_hdr_type(const struct untd_hdr *hdr)
+{
+	return hdr->type & 0x03;
+}
+
+static inline int untd_hdr_rx_tx(const struct untd_hdr *hdr)
+{
+	return (hdr->type >> 2) & 0x01;
+}
+
+static inline void untd_hdr_set_type(struct untd_hdr *hdr, enum i1480u_pkt_type type)
+{
+	hdr->type = (hdr->type & ~0x03) | type;
+}
+
+static inline void untd_hdr_set_rx_tx(struct untd_hdr *hdr, int rx_tx)
+{
+	hdr->type = (hdr->type & ~0x04) | (rx_tx << 2);
+}
+
+
+/**
+ * USB Network Transfer Descriptor - Complete Packet
+ *
+ * This is for a packet that is smaller (header + payload) than
+ * i1480u_MAX_FRG_SIZE.
+ *
+ * @hdr.total_len is the size of the payload; the payload doesn't
+ * count this header nor the padding, but includes the size of i1480
+ * header.
+ */
+struct untd_hdr_cmp {
+	struct untd_hdr	hdr;
+	u8		padding;
+} __attribute__((packed));
+
+
+/**
+ * USB Network Transfer Descriptor - First fragment
+ *
+ * @hdr.len is the size of the *whole packet* (excluding UNTD
+ * headers); @fragment_len is the size of the payload (excluding UNTD
+ * headers, but including i1480 headers).
+ */
+struct untd_hdr_1st {
+	struct untd_hdr	hdr;
+	__le16		fragment_len;
+	u8		padding[3];
+} __attribute__((packed));
+
+
+/**
+ * USB Network Transfer Descriptor - Next / Last [Rest]
+ *
+ * @hdr.len is the size of the payload, not including headrs.
+ */
+struct untd_hdr_rst {
+	struct untd_hdr	hdr;
+	u8		padding;
+} __attribute__((packed));
+
+
+/**
+ * Transmission context
+ *
+ * Wraps all the stuff needed to track a pending/active tx
+ * operation.
+ */
+struct i1480u_tx {
+	struct list_head list_node;
+	struct i1480u *i1480u;
+	struct urb *urb;
+
+	struct sk_buff *skb;
+	struct wlp_tx_hdr *wlp_tx_hdr;
+
+	void *buf;	/* if NULL, no new buf was used */
+	size_t buf_size;
+};
+
+/**
+ * Basic flow control
+ *
+ * We maintain a basic flow control counter. "count" how many TX URBs are
+ * outstanding. Only allow "max"
+ * TX URBs to be outstanding. If this value is reached the queue will be
+ * stopped. The queue will be restarted when there are
+ * "threshold" URBs outstanding.
+ * Maintain a counter of how many time the TX queue needed to be restarted
+ * due to the "max" being exceeded and the "threshold" reached again. The
+ * timestamp "restart_ts" is to keep track from when the counter was last
+ * queried (see sysfs handling of file wlp_tx_inflight).
+ */
+struct i1480u_tx_inflight {
+	atomic_t count;
+	unsigned long max;
+	unsigned long threshold;
+	unsigned long restart_ts;
+	atomic_t restart_count;
+};
+
+/**
+ * Instance of a i1480u WLP interface
+ *
+ * Keeps references to the USB device that wraps it, as well as it's
+ * interface and associated UWB host controller. As well, it also
+ * keeps a link to the netdevice for integration into the networking
+ * stack.
+ * We maintian separate error history for the tx and rx endpoints because
+ * the implementation does not rely on locking - having one shared
+ * structure between endpoints may cause problems. Adding locking to the
+ * implementation will have higher cost than adding a separate structure.
+ */
+struct i1480u {
+	struct usb_device *usb_dev;
+	struct usb_interface *usb_iface;
+	struct net_device *net_dev;
+
+	spinlock_t lock;
+	struct net_device_stats stats;
+
+	/* RX context handling */
+	struct sk_buff *rx_skb;
+	struct uwb_dev_addr rx_srcaddr;
+	size_t rx_untd_pkt_size;
+	struct i1480u_rx_buf {
+		struct i1480u *i1480u;	/* back pointer */
+		struct urb *urb;
+		struct sk_buff *data;	/* i1480u_MAX_RX_PKT_SIZE each */
+	} rx_buf[i1480u_RX_BUFS];	/* N bufs */
+
+	spinlock_t tx_list_lock;	/* TX context */
+	struct list_head tx_list;
+	u8 tx_stream;
+
+	struct stats lqe_stats, rssi_stats;	/* radio statistics */
+
+	/* Options we can set from sysfs */
+	struct wlp_options options;
+	struct uwb_notifs_handler uwb_notifs_handler;
+	struct edc tx_errors;
+	struct edc rx_errors;
+	struct wlp wlp;
+#ifdef i1480u_FLOW_CONTROL
+	struct urb *notif_urb;
+	struct edc notif_edc;		/* error density counter */
+	u8 notif_buffer[1];
+#endif
+	struct i1480u_tx_inflight tx_inflight;
+};
+
+/* Internal interfaces */
+extern void i1480u_rx_cb(struct urb *urb);
+extern int i1480u_rx_setup(struct i1480u *);
+extern void i1480u_rx_release(struct i1480u *);
+extern void i1480u_tx_release(struct i1480u *);
+extern int i1480u_xmit_frame(struct wlp *, struct sk_buff *,
+			     struct uwb_dev_addr *);
+extern void i1480u_stop_queue(struct wlp *);
+extern void i1480u_start_queue(struct wlp *);
+extern int i1480u_sysfs_setup(struct i1480u *);
+extern void i1480u_sysfs_release(struct i1480u *);
+
+/* netdev interface */
+extern int i1480u_open(struct net_device *);
+extern int i1480u_stop(struct net_device *);
+extern int i1480u_hard_start_xmit(struct sk_buff *, struct net_device *);
+extern void i1480u_tx_timeout(struct net_device *);
+extern int i1480u_set_config(struct net_device *, struct ifmap *);
+extern struct net_device_stats *i1480u_get_stats(struct net_device *);
+extern int i1480u_change_mtu(struct net_device *, int);
+extern void i1480u_uwb_notifs_cb(void *, struct uwb_dev *, enum uwb_notifs);
+
+/* bandwidth allocation callback */
+extern void  i1480u_bw_alloc_cb(struct uwb_rsv *);
+
+/* Sys FS */
+extern struct attribute_group i1480u_wlp_attr_group;
+
+#endif /* #ifndef __i1480u_wlp_h__ */

drivers/uwb/i1480/i1480u-wlp/lc.c

+/*
+ * WUSB Wire Adapter: WLP interface
+ * Driver for the Linux Network stack.
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * 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.
+ *
+ *
+ * FIXME: docs
+ *
+ * This implements a very simple network driver for the WLP USB
+ * device that is associated to a UWB (Ultra Wide Band) host.
+ *
+ * This is seen as an interface of a composite device. Once the UWB
+ * host has an association to another WLP capable device, the
+ * networking interface (aka WLP) can start to send packets back and
+ * forth.
+ *
+ * Limitations:
+ *
+ *  - Hand cranked; can't ifup the interface until there is an association
+ *
+ *  - BW allocation very simplistic [see i1480u_mas_set() and callees].
+ *
+ *
+ * ROADMAP:
+ *
+ *   ENTRY POINTS (driver model):
+ *
+ *     i1480u_driver_{exit,init}(): initialization of the driver.
+ *
+ *     i1480u_probe(): called by the driver code when a device
+ *                     matching 'i1480u_id_table' is connected.
+ *
+ *                     This allocs a netdev instance, inits with
+ *                     i1480u_add(), then registers_netdev().
+ *         i1480u_init()
+ *         i1480u_add()
+ *
+ *     i1480u_disconnect(): device has been disconnected/module
+ *                          is being removed.
+ *         i1480u_rm()
+ */
+#include <linux/version.h>
+#include <linux/if_arp.h>
+#include <linux/etherdevice.h>
+#include <linux/uwb/debug.h>
+#include "i1480u-wlp.h"
+
+
+
+static inline
+void i1480u_init(struct i1480u *i1480u)
+{
+	/* nothing so far... doesn't it suck? */
+	spin_lock_init(&i1480u->lock);
+	INIT_LIST_HEAD(&i1480u->tx_list);
+	spin_lock_init(&i1480u->tx_list_lock);
+	wlp_options_init(&i1480u->options);
+	edc_init(&i1480u->tx_errors);
+	edc_init(&i1480u->rx_errors);
+#ifdef i1480u_FLOW_CONTROL
+	edc_init(&i1480u->notif_edc);
+#endif
+	stats_init(&i1480u->lqe_stats);
+	stats_init(&i1480u->rssi_stats);
+	wlp_init(&i1480u->wlp);
+}
+
+/**
+ * Fill WLP device information structure
+ *
+ * The structure will contain a few character arrays, each ending with a
+ * null terminated string. Each string has to fit (excluding terminating
+ * character) into a specified range obtained from the WLP substack.
+ *
+ * It is still not clear exactly how this device information should be
+ * obtained. Until we find out we use the USB device descriptor as backup, some
+ * information elements have intuitive mappings, other not.
+ */
+static
+void i1480u_fill_device_info(struct wlp *wlp, struct wlp_device_info *dev_info)
+{
+	struct i1480u *i1480u = container_of(wlp, struct i1480u, wlp);
+	struct usb_device *usb_dev = i1480u->usb_dev;
+	/* Treat device name and model name the same */
+	if (usb_dev->descriptor.iProduct) {
+		usb_string(usb_dev, usb_dev->descriptor.iProduct,
+			   dev_info->name, sizeof(dev_info->name));
+		usb_string(usb_dev, usb_dev->descriptor.iProduct,
+			   dev_info->model_name, sizeof(dev_info->model_name));
+	}
+	if (usb_dev->descriptor.iManufacturer)
+		usb_string(usb_dev, usb_dev->descriptor.iManufacturer,
+			   dev_info->manufacturer,
+			   sizeof(dev_info->manufacturer));
+	scnprintf(dev_info->model_nr, sizeof(dev_info->model_nr), "%04x",
+		  __le16_to_cpu(usb_dev->descriptor.bcdDevice));
+	if (usb_dev->descriptor.iSerialNumber)
+		usb_string(usb_dev, usb_dev->descriptor.iSerialNumber,
+			   dev_info->serial, sizeof(dev_info->serial));
+	/* FIXME: where should we obtain category? */
+	dev_info->prim_dev_type.category = cpu_to_le16(WLP_DEV_CAT_OTHER);
+	/* FIXME: Complete OUI and OUIsubdiv attributes */
+}
+
+#ifdef i1480u_FLOW_CONTROL
+/**
+ * Callback for the notification endpoint
+ *
+ * This mostly controls the xon/xoff protocol. In case of hard error,
+ * we stop the queue. If not, we always retry.
+ */
+static
+void i1480u_notif_cb(struct urb *urb, struct pt_regs *regs)
+{
+	struct i1480u *i1480u = urb->context;
+	struct usb_interface *usb_iface = i1480u->usb_iface;
+	struct device *dev = &usb_iface->dev;
+	int result;
+
+	switch (urb->status) {
+	case 0:				/* Got valid data, do xon/xoff */
+		switch (i1480u->notif_buffer[0]) {
+		case 'N':
+			dev_err(dev, "XOFF STOPPING queue at %lu\n", jiffies);
+			netif_stop_queue(i1480u->net_dev);
+			break;
+		case 'A':
+			dev_err(dev, "XON STARTING queue at %lu\n", jiffies);
+			netif_start_queue(i1480u->net_dev);
+			break;
+		default:
+			dev_err(dev, "NEP: unknown data 0x%02hhx\n",
+				i1480u->notif_buffer[0]);
+		}
+		break;
+	case -ECONNRESET:		/* Controlled situation ... */
+	case -ENOENT:			/* we killed the URB... */
+		dev_err(dev, "NEP: URB reset/noent %d\n", urb->status);
+		goto error;
+	case -ESHUTDOWN:		/* going away! */
+		dev_err(dev, "NEP: URB down %d\n", urb->status);
+		goto error;
+	default:			/* Retry unless it gets ugly */
+		if (edc_inc(&i1480u->notif_edc, EDC_MAX_ERRORS,
+			    EDC_ERROR_TIMEFRAME)) {
+			dev_err(dev, "NEP: URB max acceptable errors "
+				"exceeded; resetting device\n");
+			goto error_reset;
+		}
+		dev_err(dev, "NEP: URB error %d\n", urb->status);
+		break;
+	}
+	result = usb_submit_urb(urb, GFP_ATOMIC);
+	if (result < 0) {
+		dev_err(dev, "NEP: Can't resubmit URB: %d; resetting device\n",
+			result);
+		goto error_reset;
+	}
+	return;
+
+error_reset:
+	wlp_reset_all(&i1480-wlp);
+error:
+	netif_stop_queue(i1480u->net_dev);
+	return;
+}
+#endif
+
+static
+int i1480u_add(struct i1480u *i1480u, struct usb_interface *iface)
+{
+	int result = -ENODEV;
+	struct wlp *wlp = &i1480u->wlp;
+	struct usb_device *usb_dev = interface_to_usbdev(iface);
+	struct net_device *net_dev = i1480u->net_dev;
+	struct uwb_rc *rc;
+	struct uwb_dev *uwb_dev;
+#ifdef i1480u_FLOW_CONTROL
+	struct usb_endpoint_descriptor *epd;
+#endif
+
+	i1480u->usb_dev = usb_get_dev(usb_dev);
+	i1480u->usb_iface = iface;
+	rc = uwb_rc_get_by_grandpa(&i1480u->usb_dev->dev);
+	if (rc == NULL) {
+		dev_err(&iface->dev, "Cannot get associated UWB Radio "
+			"Controller\n");
+		goto out;
+	}
+	wlp->xmit_frame = i1480u_xmit_frame;
+	wlp->fill_device_info = i1480u_fill_device_info;
+	wlp->stop_queue = i1480u_stop_queue;
+	wlp->start_queue = i1480u_start_queue;
+	result = wlp_setup(wlp, rc);
+	if (result < 0) {
+		dev_err(&iface->dev, "Cannot setup WLP\n");
+		goto error_wlp_setup;
+	}
+	result = 0;
+	ether_setup(net_dev);			/* make it an etherdevice */
+	uwb_dev = &rc->uwb_dev;
+	/* FIXME: hookup address change notifications? */
+
+	memcpy(net_dev->dev_addr, uwb_dev->mac_addr.data,
+	       sizeof(net_dev->dev_addr));
+
+	net_dev->hard_header_len = sizeof(struct untd_hdr_cmp)
+		+ sizeof(struct wlp_tx_hdr)
+		+ WLP_DATA_HLEN
+		+ ETH_HLEN;
+	net_dev->mtu = 3500;
+	net_dev->tx_queue_len = 20;		/* FIXME: maybe use 1000? */
+
+/*	net_dev->flags &= ~IFF_BROADCAST;	FIXME: BUG in firmware */
+	/* FIXME: multicast disabled */
+	net_dev->flags &= ~IFF_MULTICAST;
+	net_dev->features &= ~NETIF_F_SG;
+	net_dev->features &= ~NETIF_F_FRAGLIST;
+	/* All NETIF_F_*_CSUM disabled */
+	net_dev->features |= NETIF_F_HIGHDMA;
+	net_dev->watchdog_timeo = 5*HZ;		/* FIXME: a better default? */
+
+	net_dev->open = i1480u_open;
+	net_dev->stop = i1480u_stop;
+	net_dev->hard_start_xmit = i1480u_hard_start_xmit;
+	net_dev->tx_timeout = i1480u_tx_timeout;
+	net_dev->get_stats = i1480u_get_stats;
+	net_dev->set_config = i1480u_set_config;
+	net_dev->change_mtu = i1480u_change_mtu;
+
+#ifdef i1480u_FLOW_CONTROL
+	/* Notification endpoint setup (submitted when we open the device) */
+	i1480u->notif_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (i1480u->notif_urb == NULL) {
+		dev_err(&iface->dev, "Unable to allocate notification URB\n");
+		result = -ENOMEM;
+		goto error_urb_alloc;
+	}
+	epd = &iface->cur_altsetting->endpoint[0].desc;
+	usb_fill_int_urb(i1480u->notif_urb, usb_dev,
+			 usb_rcvintpipe(usb_dev, epd->bEndpointAddress),
+			 i1480u->notif_buffer, sizeof(i1480u->notif_buffer),
+			 i1480u_notif_cb, i1480u, epd->bInterval);
+
+#endif
+
+	i1480u->tx_inflight.max = i1480u_TX_INFLIGHT_MAX;
+	i1480u->tx_inflight.threshold = i1480u_TX_INFLIGHT_THRESHOLD;
+	i1480u->tx_inflight.restart_ts = jiffies;
+	usb_set_intfdata(iface, i1480u);
+	return result;
+
+#ifdef i1480u_FLOW_CONTROL
+error_urb_alloc:
+#endif
+	wlp_remove(wlp);
+error_wlp_setup:
+	uwb_rc_put(rc);
+out:
+	usb_put_dev(i1480u->usb_dev);
+	return result;
+}
+
+static void i1480u_rm(struct i1480u *i1480u)
+{
+	struct uwb_rc *rc = i1480u->wlp.rc;
+	usb_set_intfdata(i1480u->usb_iface, NULL);
+#ifdef i1480u_FLOW_CONTROL
+	usb_kill_urb(i1480u->notif_urb);
+	usb_free_urb(i1480u->notif_urb);
+#endif
+	wlp_remove(&i1480u->wlp);
+	uwb_rc_put(rc);
+	usb_put_dev(i1480u->usb_dev);
+}
+
+/** Just setup @net_dev's i1480u private data */
+static void i1480u_netdev_setup(struct net_device *net_dev)
+{
+	struct i1480u *i1480u = netdev_priv(net_dev);
+	/* Initialize @i1480u */
+	memset(i1480u, 0, sizeof(*i1480u));
+	i1480u_init(i1480u);
+}
+
+/**
+ * Probe a i1480u interface and register it
+ *
+ * @iface:   USB interface to link to
+ * @id:      USB class/subclass/protocol id
+ * @returns: 0 if ok, < 0 errno code on error.
+ *
+ * Does basic housekeeping stuff and then allocs a netdev with space
+ * for the i1480u  data. Initializes, registers in i1480u, registers in
+ * netdev, ready to go.
+ */
+static int i1480u_probe(struct usb_interface *iface,
+			const struct usb_device_id *id)
+{
+	int result;
+	struct net_device *net_dev;
+	struct device *dev = &iface->dev;
+	struct i1480u *i1480u;
+
+	/* Allocate instance [calls i1480u_netdev_setup() on it] */
+	result = -ENOMEM;
+	net_dev = alloc_netdev(sizeof(*i1480u), "wlp%d", i1480u_netdev_setup);
+	if (net_dev == NULL) {
+		dev_err(dev, "no memory for network device instance\n");
+		goto error_alloc_netdev;
+	}
+	SET_NETDEV_DEV(net_dev, dev);
+	i1480u = netdev_priv(net_dev);
+	i1480u->net_dev = net_dev;
+	result = i1480u_add(i1480u, iface);	/* Now setup all the wlp stuff */
+	if (result < 0) {
+		dev_err(dev, "cannot add i1480u device: %d\n", result);
+		goto error_i1480u_add;
+	}
+	result = register_netdev(net_dev);	/* Okey dokey, bring it up */
+	if (result < 0) {
+		dev_err(dev, "cannot register network device: %d\n", result);
+		goto error_register_netdev;
+	}
+	i1480u_sysfs_setup(i1480u);
+	if (result < 0)
+		goto error_sysfs_init;
+	return 0;
+
+error_sysfs_init:
+	unregister_netdev(net_dev);
+error_register_netdev:
+	i1480u_rm(i1480u);
+error_i1480u_add:
+	free_netdev(net_dev);
+error_alloc_netdev:
+	return result;
+}
+
+
+/**
+ * Disconect a i1480u from the system.
+ *
+ * i1480u_stop() has been called before, so al the rx and tx contexts
+ * have been taken down already. Make sure the queue is stopped,
+ * unregister netdev and i1480u, free and kill.
+ */
+static void i1480u_disconnect(struct usb_interface *iface)
+{
+	struct i1480u *i1480u;
+	struct net_device *net_dev;
+
+	i1480u = usb_get_intfdata(iface);
+	net_dev = i1480u->net_dev;
+	netif_stop_queue(net_dev);
+#ifdef i1480u_FLOW_CONTROL
+	usb_kill_urb(i1480u->notif_urb);
+#endif
+	i1480u_sysfs_release(i1480u);
+	unregister_netdev(net_dev);
+	i1480u_rm(i1480u);
+	free_netdev(net_dev);
+}
+
+static struct usb_device_id i1480u_id_table[] = {
+	{
+		.match_flags = USB_DEVICE_ID_MATCH_DEVICE \
+				|  USB_DEVICE_ID_MATCH_DEV_INFO \
+				|  USB_DEVICE_ID_MATCH_INT_INFO,
+		.idVendor = 0x8086,
+		.idProduct = 0x0c3b,
+		.bDeviceClass = 0xef,
+		.bDeviceSubClass = 0x02,
+		.bDeviceProtocol = 0x02,
+		.bInterfaceClass = 0xff,
+		.bInterfaceSubClass = 0xff,
+		.bInterfaceProtocol = 0xff,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(usb, i1480u_id_table);
+
+static struct usb_driver i1480u_driver = {
+	.name =		KBUILD_MODNAME,
+	.probe =	i1480u_probe,
+	.disconnect =	i1480u_disconnect,
+	.id_table =	i1480u_id_table,
+};
+
+static int __init i1480u_driver_init(void)
+{
+	return usb_register(&i1480u_driver);
+}
+module_init(i1480u_driver_init);
+
+
+static void __exit i1480u_driver_exit(void)
+{
+	usb_deregister(&i1480u_driver);
+}
+module_exit(i1480u_driver_exit);
+
+MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
+MODULE_DESCRIPTION("i1480 Wireless UWB Link WLP networking for USB");
+MODULE_LICENSE("GPL");

drivers/uwb/i1480/i1480u-wlp/netdev.c

+/*
+ * WUSB Wire Adapter: WLP interface
+ * Driver for the Linux Network stack.
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * 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.
+ *
+ *
+ * FIXME: docs
+ *
+ * Implementation of the netdevice linkage (except tx and rx related stuff).
+ *
+ * ROADMAP:
+ *
+ *   ENTRY POINTS (Net device):
+ *
+ *     i1480u_open(): Called when we ifconfig up the interface;
+ *                    associates to a UWB host controller, reserves
+ *                    bandwidth (MAS), sets up RX USB URB and starts
+ *                    the queue.
+ *
+ *     i1480u_stop(): Called when we ifconfig down a interface;
+ *                    reverses _open().
+ *
+ *     i1480u_set_config():
+ */
+
+#include <linux/if_arp.h>
+#include <linux/etherdevice.h>
+#include <linux/uwb/debug.h>
+#include "i1480u-wlp.h"
+
+struct i1480u_cmd_set_ip_mas {
+	struct uwb_rccb     rccb;
+	struct uwb_dev_addr addr;
+	u8                  stream;
+	u8                  owner;
+	u8                  type;	/* enum uwb_drp_type */
+	u8                  baMAS[32];
+} __attribute__((packed));
+
+
+static
+int i1480u_set_ip_mas(
+	struct uwb_rc *rc,
+	const struct uwb_dev_addr *dstaddr,
+	u8 stream, u8 owner, u8 type, unsigned long *mas)
+{
+
+	int result;
+	struct i1480u_cmd_set_ip_mas *cmd;
+	struct uwb_rc_evt_confirm reply;
+
+	result = -ENOMEM;
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (cmd == NULL)
+		goto error_kzalloc;
+	cmd->rccb.bCommandType = 0xfd;
+	cmd->rccb.wCommand = cpu_to_le16(0x000e);
+	cmd->addr = *dstaddr;
+	cmd->stream = stream;
+	cmd->owner = owner;
+	cmd->type = type;
+	if (mas == NULL)
+		memset(cmd->baMAS, 0x00, sizeof(cmd->baMAS));
+	else
+		memcpy(cmd->baMAS, mas, sizeof(cmd->baMAS));
+	reply.rceb.bEventType = 0xfd;
+	reply.rceb.wEvent = cpu_to_le16(0x000e);
+	result = uwb_rc_cmd(rc, "SET-IP-MAS", &cmd->rccb, sizeof(*cmd),
+			    &reply.rceb, sizeof(reply));
+	if (result < 0)
+		goto error_cmd;
+	if (reply.bResultCode != UWB_RC_RES_FAIL) {
+		dev_err(&rc->uwb_dev.dev,
+			"SET-IP-MAS: command execution failed: %d\n",
+			reply.bResultCode);
+		result = -EIO;
+	}
+error_cmd:
+	kfree(cmd);
+error_kzalloc:
+	return result;
+}
+
+/*
+ * Inform a WLP interface of a MAS reservation
+ *
+ * @rc is assumed refcnted.
+ */
+/* FIXME: detect if remote device is WLP capable? */
+static int i1480u_mas_set_dev(struct uwb_dev *uwb_dev, struct uwb_rc *rc,
+			      u8 stream, u8 owner, u8 type, unsigned long *mas)
+{
+	int result = 0;
+	struct device *dev = &rc->uwb_dev.dev;
+
+	result = i1480u_set_ip_mas(rc, &uwb_dev->dev_addr, stream, owner,
+				   type, mas);
+	if (result < 0) {
+		char rcaddrbuf[UWB_ADDR_STRSIZE], devaddrbuf[UWB_ADDR_STRSIZE];
+		uwb_dev_addr_print(rcaddrbuf, sizeof(rcaddrbuf),
+				   &rc->uwb_dev.dev_addr);
+		uwb_dev_addr_print(devaddrbuf, sizeof(devaddrbuf),
+				   &uwb_dev->dev_addr);
+		dev_err(dev, "Set IP MAS (%s to %s) failed: %d\n",
+			rcaddrbuf, devaddrbuf, result);
+	}
+	return result;
+}
+
+/**
+ * Called by bandwidth allocator when change occurs in reservation.
+ *
+ * @rsv:     The reservation that is being established, modified, or
+ *           terminated.
+ *
+ * When a reservation is established, modified, or terminated the upper layer
+ * (WLP here) needs set/update the currently available Media Access Slots
+ * that can be use for IP traffic.
+ *
+ * Our action taken during failure depends on how the reservation is being
+ * changed:
+ * - if reservation is being established we do nothing if we cannot set the
+ *   new MAS to be used
+ * - if reservation is being terminated we revert back to PCA whether the
+ *   SET IP MAS command succeeds or not.
+ */
+void i1480u_bw_alloc_cb(struct uwb_rsv *rsv)
+{
+	int result = 0;
+	struct i1480u *i1480u = rsv->pal_priv;
+	struct device *dev = &i1480u->usb_iface->dev;
+	struct uwb_dev *target_dev = rsv->target.dev;
+	struct uwb_rc *rc = i1480u->wlp.rc;
+	u8 stream = rsv->stream;
+	int type = rsv->type;
+	int is_owner = rsv->owner == &rc->uwb_dev;
+	unsigned long *bmp = rsv->mas.bm;
+
+	dev_err(dev, "WLP callback called - sending set ip mas\n");
+	/*user cannot change options while setting configuration*/
+	mutex_lock(&i1480u->options.mutex);
+	switch (rsv->state) {
+	case UWB_RSV_STATE_T_ACCEPTED:
+	case UWB_RSV_STATE_O_ESTABLISHED:
+		result = i1480u_mas_set_dev(target_dev, rc, stream, is_owner,
+					type, bmp);
+		if (result < 0) {
+			dev_err(dev, "MAS reservation failed: %d\n", result);
+			goto out;
+		}
+		if (is_owner) {
+			wlp_tx_hdr_set_delivery_id_type(&i1480u->options.def_tx_hdr,
+							WLP_DRP | stream);
+			wlp_tx_hdr_set_rts_cts(&i1480u->options.def_tx_hdr, 0);
+		}
+		break;
+	case UWB_RSV_STATE_NONE:
+		/* revert back to PCA */
+		result = i1480u_mas_set_dev(target_dev, rc, stream, is_owner,
+					    type, bmp);
+		if (result < 0)
+			dev_err(dev, "MAS reservation failed: %d\n", result);
+		/* Revert to PCA even though SET IP MAS failed. */
+		wlp_tx_hdr_set_delivery_id_type(&i1480u->options.def_tx_hdr,
+						i1480u->options.pca_base_priority);
+		wlp_tx_hdr_set_rts_cts(&i1480u->options.def_tx_hdr, 1);
+		break;
+	default:
+		dev_err(dev, "unexpected WLP reservation state: %s (%d).\n",
+			uwb_rsv_state_str(rsv->state), rsv->state);
+		break;
+	}
+out:
+	mutex_unlock(&i1480u->options.mutex);
+	return;
+}
+
+/**
+ *
+ * Called on 'ifconfig up'
+ */
+int i1480u_open(struct net_device *net_dev)
+{
+	int result;
+	struct i1480u *i1480u = netdev_priv(net_dev);
+	struct wlp *wlp = &i1480u->wlp;
+	struct uwb_rc *rc;
+	struct device *dev = &i1480u->usb_iface->dev;
+
+	rc = wlp->rc;
+	result = i1480u_rx_setup(i1480u);		/* Alloc RX stuff */
+	if (result < 0)
+		goto error_rx_setup;
+	netif_wake_queue(net_dev);
+#ifdef i1480u_FLOW_CONTROL
+	result = usb_submit_urb(i1480u->notif_urb, GFP_KERNEL);;
+	if (result < 0) {
+		dev_err(dev, "Can't submit notification URB: %d\n", result);
+		goto error_notif_urb_submit;
+	}
+#endif
+	i1480u->uwb_notifs_handler.cb = i1480u_uwb_notifs_cb;
+	i1480u->uwb_notifs_handler.data = i1480u;
+	if (uwb_bg_joined(rc))
+		netif_carrier_on(net_dev);
+	else
+		netif_carrier_off(net_dev);
+	uwb_notifs_register(rc, &i1480u->uwb_notifs_handler);
+	/* Interface is up with an address, now we can create WSS */
+	result = wlp_wss_setup(net_dev, &wlp->wss);
+	if (result < 0) {
+		dev_err(dev, "Can't create WSS: %d. \n", result);
+		goto error_notif_deregister;
+	}
+	return 0;
+error_notif_deregister:
+	uwb_notifs_deregister(rc, &i1480u->uwb_notifs_handler);
+#ifdef i1480u_FLOW_CONTROL
+error_notif_urb_submit:
+#endif
+	netif_stop_queue(net_dev);
+	i1480u_rx_release(i1480u);
+error_rx_setup:
+	return result;
+}
+
+
+/**
+ * Called on 'ifconfig down'
+ */
+int i1480u_stop(struct net_device *net_dev)
+{
+	struct i1480u *i1480u = netdev_priv(net_dev);
+	struct wlp *wlp = &i1480u->wlp;
+	struct uwb_rc *rc = wlp->rc;
+
+	BUG_ON(wlp->rc == NULL);
+	wlp_wss_remove(&wlp->wss);
+	uwb_notifs_deregister(rc, &i1480u->uwb_notifs_handler);
+	netif_carrier_off(net_dev);
+#ifdef i1480u_FLOW_CONTROL
+	usb_kill_urb(i1480u->notif_urb);
+#endif
+	netif_stop_queue(net_dev);
+	i1480u_rx_release(i1480u);
+	i1480u_tx_release(i1480u);
+	return 0;
+}
+
+
+/** Report statistics */
+struct net_device_stats *i1480u_get_stats(struct net_device *net_dev)
+{
+	struct i1480u *i1480u = netdev_priv(net_dev);
+	return &i1480u->stats;
+}
+
+
+/**
+ *
+ * Change the interface config--we probably don't have to do anything.
+ */
+int i1480u_set_config(struct net_device *net_dev, struct ifmap *map)
+{
+	int result;
+	struct i1480u *i1480u = netdev_priv(net_dev);
+	BUG_ON(i1480u->wlp.rc == NULL);
+	result = 0;
+	return result;
+}
+
+/**
+ * Change the MTU of the interface
+ */
+int i1480u_change_mtu(struct net_device *net_dev, int mtu)
+{
+	static union {
+		struct wlp_tx_hdr tx;
+		struct wlp_rx_hdr rx;
+	} i1480u_all_hdrs;
+
+	if (mtu < ETH_HLEN)	/* We encap eth frames */
+		return -ERANGE;
+	if (mtu > 4000 - sizeof(i1480u_all_hdrs))
+		return -ERANGE;
+	net_dev->mtu = mtu;
+	return 0;
+}
+
+
+/**
+ * Callback function to handle events from UWB
+ * When we see other devices we know the carrier is ok,
+ * if we are the only device in the beacon group we set the carrier
+ * state to off.
+ * */
+void i1480u_uwb_notifs_cb(void *data, struct uwb_dev *uwb_dev,
+			  enum uwb_notifs event)
+{
+	struct i1480u *i1480u = data;
+	struct net_device *net_dev = i1480u->net_dev;
+	struct device *dev = &i1480u->usb_iface->dev;
+	switch (event) {
+	case UWB_NOTIF_BG_JOIN:
+		netif_carrier_on(net_dev);
+		dev_info(dev, "Link is up\n");
+		break;
+	case UWB_NOTIF_BG_LEAVE:
+		netif_carrier_off(net_dev);
+		dev_info(dev, "Link is down\n");
+		break;
+	default:
+		dev_err(dev, "don't know how to handle event %d from uwb\n",
+				event);
+	}
+}
+
+/**
+ * Stop the network queue
+ *
+ * Enable WLP substack to stop network queue. We also set the flow control
+ * threshold at this time to prevent the flow control from restarting the
+ * queue.
+ *
+ * we are loosing the current threshold value here ... FIXME?
+ */
+void i1480u_stop_queue(struct wlp *wlp)
+{
+	struct i1480u *i1480u = container_of(wlp, struct i1480u, wlp);
+	struct net_device *net_dev = i1480u->net_dev;
+	i1480u->tx_inflight.threshold = 0;
+	netif_stop_queue(net_dev);
+}
+
+/**
+ * Start the network queue
+ *
+ * Enable WLP substack to start network queue. Also re-enable the flow
+ * control to manage the queue again.
+ *
+ * We re-enable the flow control by storing the default threshold in the
+ * flow control threshold. This means that if the user modified the
+ * threshold before the queue was stopped and restarted that information
+ * will be lost. FIXME?
+ */
+void i1480u_start_queue(struct wlp *wlp)
+{
+	struct i1480u *i1480u = container_of(wlp, struct i1480u, wlp);
+	struct net_device *net_dev = i1480u->net_dev;
+	i1480u->tx_inflight.threshold = i1480u_TX_INFLIGHT_THRESHOLD;
+	netif_start_queue(net_dev);
+}

drivers/uwb/i1480/i1480u-wlp/rx.c

+/*
+ * WUSB Wire Adapter: WLP interface
+ * Driver for the Linux Network stack.
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * 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.
+ *
+ *
+ * i1480u's RX handling is simple. i1480u will send the received
+ * network packets broken up in fragments; 1 to N fragments make a
+ * packet, we assemble them together and deliver the packet with netif_rx().
+ *
+ * Beacuse each USB transfer is a *single* fragment (except when the
+ * transfer contains a first fragment), each URB called thus
+ * back contains one or two fragments. So we queue N URBs, each with its own
+ * fragment buffer. When a URB is done, we process it (adding to the
+ * current skb from the fragment buffer until complete). Once
+ * processed, we requeue the URB. There is always a bunch of URBs
+ * ready to take data, so the intergap should be minimal.
+ *
+ * An URB's transfer buffer is the data field of a socket buffer. This
+ * reduces copying as data can be passed directly to network layer. If a
+ * complete packet or 1st fragment is received the URB's transfer buffer is
+ * taken away from it and used to send data to the network layer. In this
+ * case a new transfer buffer is allocated to the URB before being requeued.
+ * If a "NEXT" or "LAST" fragment is received, the fragment contents is
+ * appended to the RX packet under construction and the transfer buffer
+ * is reused. To be able to use this buffer to assemble complete packets
+ * we set each buffer's size to that of the MAX ethernet packet that can
+ * be received. There is thus room for improvement in memory usage.
+ *
+ * When the max tx fragment size increases, we should be able to read
+ * data into the skbs directly with very simple code.
+ *
+ * ROADMAP:
+ *
+ *   ENTRY POINTS:
+ *
+ *     i1480u_rx_setup(): setup RX context [from i1480u_open()]
+ *
+ *     i1480u_rx_release(): release RX context [from i1480u_stop()]
+ *
+ *     i1480u_rx_cb(): called when the RX USB URB receives a
+ *                     packet. It removes the header and pushes it up
+ *                     the Linux netdev stack with netif_rx().
+ *
+ *       i1480u_rx_buffer()
+ *         i1480u_drop() and i1480u_fix()
+ *         i1480u_skb_deliver
+ *
+ */
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include "i1480u-wlp.h"
+
+#define D_LOCAL 0
+#include <linux/uwb/debug.h>
+
+
+/**
+ * Setup the RX context
+ *
+ * Each URB is provided with a transfer_buffer that is the data field
+ * of a new socket buffer.
+ */
+int i1480u_rx_setup(struct i1480u *i1480u)
+{
+	int result, cnt;
+	struct device *dev = &i1480u->usb_iface->dev;
+	struct net_device *net_dev = i1480u->net_dev;
+	struct usb_endpoint_descriptor *epd;
+	struct sk_buff *skb;
+
+	/* Alloc RX stuff */
+	i1480u->rx_skb = NULL;	/* not in process of receiving packet */
+	result = -ENOMEM;
+	epd = &i1480u->usb_iface->cur_altsetting->endpoint[1].desc;
+	for (cnt = 0; cnt < i1480u_RX_BUFS; cnt++) {
+		struct i1480u_rx_buf *rx_buf = &i1480u->rx_buf[cnt];
+		rx_buf->i1480u = i1480u;
+		skb = dev_alloc_skb(i1480u_MAX_RX_PKT_SIZE);
+		if (!skb) {
+			dev_err(dev,
+				"RX: cannot allocate RX buffer %d\n", cnt);
+			result = -ENOMEM;
+			goto error;
+		}
+		skb->dev = net_dev;
+		skb->ip_summed = CHECKSUM_NONE;
+		skb_reserve(skb, 2);
+		rx_buf->data = skb;
+		rx_buf->urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (unlikely(rx_buf->urb == NULL)) {
+			dev_err(dev, "RX: cannot allocate URB %d\n", cnt);
+			result = -ENOMEM;
+			goto error;
+		}
+		usb_fill_bulk_urb(rx_buf->urb, i1480u->usb_dev,
+			  usb_rcvbulkpipe(i1480u->usb_dev, epd->bEndpointAddress),
+			  rx_buf->data->data, i1480u_MAX_RX_PKT_SIZE - 2,
+			  i1480u_rx_cb, rx_buf);
+		result = usb_submit_urb(rx_buf->urb, GFP_NOIO);
+		if (unlikely(result < 0)) {
+			dev_err(dev, "RX: cannot submit URB %d: %d\n",
+				cnt, result);
+			goto error;
+		}
+	}
+	return 0;
+
+error:
+	i1480u_rx_release(i1480u);
+	return result;
+}
+
+
+/** Release resources associated to the rx context */
+void i1480u_rx_release(struct i1480u *i1480u)
+{
+	int cnt;
+	for (cnt = 0; cnt < i1480u_RX_BUFS; cnt++) {
+		if (i1480u->rx_buf[cnt].data)
+			dev_kfree_skb(i1480u->rx_buf[cnt].data);
+		if (i1480u->rx_buf[cnt].urb) {
+			usb_kill_urb(i1480u->rx_buf[cnt].urb);
+			usb_free_urb(i1480u->rx_buf[cnt].urb);
+		}
+	}
+	if (i1480u->rx_skb != NULL)
+		dev_kfree_skb(i1480u->rx_skb);
+}
+
+static
+void i1480u_rx_unlink_urbs(struct i1480u *i1480u)
+{
+	int cnt;
+	for (cnt = 0; cnt < i1480u_RX_BUFS; cnt++) {
+		if (i1480u->rx_buf[cnt].urb)
+			usb_unlink_urb(i1480u->rx_buf[cnt].urb);
+	}
+}
+
+/** Fix an out-of-sequence packet */
+#define i1480u_fix(i1480u, msg...)			\
+do {							\
+	if (printk_ratelimit())				\
+		dev_err(&i1480u->usb_iface->dev, msg);	\
+	dev_kfree_skb_irq(i1480u->rx_skb);		\
+	i1480u->rx_skb = NULL;				\
+	i1480u->rx_untd_pkt_size = 0;			\
+} while (0)
+
+
+/** Drop an out-of-sequence packet */
+#define i1480u_drop(i1480u, msg...)			\
+do {							\
+	if (printk_ratelimit())				\
+		dev_err(&i1480u->usb_iface->dev, msg);	\
+	i1480u->stats.rx_dropped++;			\
+} while (0)
+
+
+
+
+/** Finalizes setting up the SKB and delivers it
+ *
+ * We first pass the incoming frame to WLP substack for verification. It
+ * may also be a WLP association frame in which case WLP will take over the
+ * processing. If WLP does not take it over it will still verify it, if the
+ * frame is invalid the skb will be freed by WLP and we will not continue
+ * parsing.
+ * */
+static
+void i1480u_skb_deliver(struct i1480u *i1480u)
+{
+	int should_parse;
+	struct net_device *net_dev = i1480u->net_dev;
+	struct device *dev = &i1480u->usb_iface->dev;
+
+	d_printf(6, dev, "RX delivered pre skb(%p), %u bytes\n",
+		 i1480u->rx_skb, i1480u->rx_skb->len);
+	d_dump(7, dev, i1480u->rx_skb->data, i1480u->rx_skb->len);
+	should_parse = wlp_receive_frame(dev, &i1480u->wlp, i1480u->rx_skb,
+					 &i1480u->rx_srcaddr);
+	if (!should_parse)
+		goto out;
+	i1480u->rx_skb->protocol = eth_type_trans(i1480u->rx_skb, net_dev);
+	d_printf(5, dev, "RX delivered skb(%p), %u bytes\n",
+		 i1480u->rx_skb, i1480u->rx_skb->len);
+	d_dump(7, dev, i1480u->rx_skb->data,
+	       i1480u->rx_skb->len > 72 ? 72 : i1480u->rx_skb->len);
+	i1480u->stats.rx_packets++;
+	i1480u->stats.rx_bytes += i1480u->rx_untd_pkt_size;
+	net_dev->last_rx = jiffies;
+	/* FIXME: flow control: check netif_rx() retval */
+
+	netif_rx(i1480u->rx_skb);		/* deliver */
+out:
+	i1480u->rx_skb = NULL;
+	i1480u->rx_untd_pkt_size = 0;
+}
+
+
+/**
+ * Process a buffer of data received from the USB RX endpoint
+ *
+ * First fragment arrives with next or last fragment. All other fragments
+ * arrive alone.
+ *
+ * /me hates long functions.
+ */
+static
+void i1480u_rx_buffer(struct i1480u_rx_buf *rx_buf)
+{
+	unsigned pkt_completed = 0;	/* !0 when we got all pkt fragments */
+	size_t untd_hdr_size, untd_frg_size;
+	size_t i1480u_hdr_size;
+	struct wlp_rx_hdr *i1480u_hdr = NULL;
+
+	struct i1480u *i1480u = rx_buf->i1480u;
+	struct sk_buff *skb = rx_buf->data;
+	int size_left = rx_buf->urb->actual_length;
+	void *ptr = rx_buf->urb->transfer_buffer; /* also rx_buf->data->data */
+	struct untd_hdr *untd_hdr;
+
+	struct net_device *net_dev = i1480u->net_dev;
+	struct device *dev = &i1480u->usb_iface->dev;
+	struct sk_buff *new_skb;
+
+#if 0
+	dev_fnstart(dev,
+		    "(i1480u %p ptr %p size_left %zu)\n", i1480u, ptr, size_left);
+	dev_err(dev, "RX packet, %zu bytes\n", size_left);
+	dump_bytes(dev, ptr, size_left);
+#endif
+	i1480u_hdr_size = sizeof(struct wlp_rx_hdr);
+
+	while (size_left > 0) {
+		if (pkt_completed) {
+			i1480u_drop(i1480u, "RX: fragment follows completed"
+					 "packet in same buffer. Dropping\n");
+			break;
+		}
+		untd_hdr = ptr;
+		if (size_left < sizeof(*untd_hdr)) {	/*  Check the UNTD header */
+			i1480u_drop(i1480u, "RX: short UNTD header! Dropping\n");
+			goto out;
+		}
+		if (unlikely(untd_hdr_rx_tx(untd_hdr) == 0)) {	/* Paranoia: TX set? */
+			i1480u_drop(i1480u, "RX: TX bit set! Dropping\n");
+			goto out;
+		}
+		switch (untd_hdr_type(untd_hdr)) {	/* Check the UNTD header type */
+		case i1480u_PKT_FRAG_1ST: {
+			struct untd_hdr_1st *untd_hdr_1st = (void *) untd_hdr;
+			dev_dbg(dev, "1st fragment\n");
+			untd_hdr_size = sizeof(struct untd_hdr_1st);
+			if (i1480u->rx_skb != NULL)
+				i1480u_fix(i1480u, "RX: 1st fragment out of "
+					"sequence! Fixing\n");
+			if (size_left < untd_hdr_size + i1480u_hdr_size) {
+				i1480u_drop(i1480u, "RX: short 1st fragment! "
+					"Dropping\n");
+				goto out;
+			}
+			i1480u->rx_untd_pkt_size = le16_to_cpu(untd_hdr->len)
+						 - i1480u_hdr_size;
+			untd_frg_size = le16_to_cpu(untd_hdr_1st->fragment_len);
+			if (size_left < untd_hdr_size + untd_frg_size) {
+				i1480u_drop(i1480u,
+					    "RX: short payload! Dropping\n");
+				goto out;
+			}
+			i1480u->rx_skb = skb;
+			i1480u_hdr = (void *) untd_hdr_1st + untd_hdr_size;
+			i1480u->rx_srcaddr = i1480u_hdr->srcaddr;
+			skb_put(i1480u->rx_skb, untd_hdr_size + untd_frg_size);
+			skb_pull(i1480u->rx_skb, untd_hdr_size + i1480u_hdr_size);
+			stats_add_sample(&i1480u->lqe_stats, (s8) i1480u_hdr->LQI - 7);
+			stats_add_sample(&i1480u->rssi_stats, i1480u_hdr->RSSI + 18);
+			rx_buf->data = NULL; /* need to create new buffer */
+			break;
+		}
+		case i1480u_PKT_FRAG_NXT: {
+			dev_dbg(dev, "nxt fragment\n");
+			untd_hdr_size = sizeof(struct untd_hdr_rst);
+			if (i1480u->rx_skb == NULL) {
+				i1480u_drop(i1480u, "RX: next fragment out of "
+					    "sequence! Dropping\n");
+				goto out;
+			}
+			if (size_left < untd_hdr_size) {
+				i1480u_drop(i1480u, "RX: short NXT fragment! "
+					    "Dropping\n");
+				goto out;
+			}
+			untd_frg_size = le16_to_cpu(untd_hdr->len);
+			if (size_left < untd_hdr_size + untd_frg_size) {
+				i1480u_drop(i1480u,
+					    "RX: short payload! Dropping\n");
+				goto out;
+			}
+			memmove(skb_put(i1480u->rx_skb, untd_frg_size),
+					ptr + untd_hdr_size, untd_frg_size);
+			break;
+		}
+		case i1480u_PKT_FRAG_LST: {
+			dev_dbg(dev, "Lst fragment\n");
+			untd_hdr_size = sizeof(struct untd_hdr_rst);
+			if (i1480u->rx_skb == NULL) {
+				i1480u_drop(i1480u, "RX: last fragment out of "
+					    "sequence! Dropping\n");
+				goto out;
+			}
+			if (size_left < untd_hdr_size) {
+				i1480u_drop(i1480u, "RX: short LST fragment! "
+					    "Dropping\n");
+				goto out;
+			}
+			untd_frg_size = le16_to_cpu(untd_hdr->len);
+			if (size_left < untd_frg_size + untd_hdr_size) {
+				i1480u_drop(i1480u,
+					    "RX: short payload! Dropping\n");
+				goto out;
+			}
+			memmove(skb_put(i1480u->rx_skb, untd_frg_size),
+					ptr + untd_hdr_size, untd_frg_size);
+			pkt_completed = 1;
+			break;
+		}
+		case i1480u_PKT_FRAG_CMP: {
+			dev_dbg(dev, "cmp fragment\n");
+			untd_hdr_size = sizeof(struct untd_hdr_cmp);
+			if (i1480u->rx_skb != NULL)
+				i1480u_fix(i1480u, "RX: fix out-of-sequence CMP"
+					   " fragment!\n");
+			if (size_left < untd_hdr_size + i1480u_hdr_size) {
+				i1480u_drop(i1480u, "RX: short CMP fragment! "
+					    "Dropping\n");
+				goto out;
+			}
+			i1480u->rx_untd_pkt_size = le16_to_cpu(untd_hdr->len);
+			untd_frg_size = i1480u->rx_untd_pkt_size;
+			if (size_left < i1480u->rx_untd_pkt_size + untd_hdr_size) {
+				i1480u_drop(i1480u,
+					    "RX: short payload! Dropping\n");
+				goto out;
+			}
+			i1480u->rx_skb = skb;
+			i1480u_hdr = (void *) untd_hdr + untd_hdr_size;
+			i1480u->rx_srcaddr = i1480u_hdr->srcaddr;
+			stats_add_sample(&i1480u->lqe_stats, (s8) i1480u_hdr->LQI - 7);
+			stats_add_sample(&i1480u->rssi_stats, i1480u_hdr->RSSI + 18);
+			skb_put(i1480u->rx_skb, untd_hdr_size + i1480u->rx_untd_pkt_size);
+			skb_pull(i1480u->rx_skb, untd_hdr_size + i1480u_hdr_size);
+			rx_buf->data = NULL;	/* for hand off skb to network stack */
+			pkt_completed = 1;
+			i1480u->rx_untd_pkt_size -= i1480u_hdr_size; /* accurate stat */
+			break;
+		}
+		default:
+			i1480u_drop(i1480u, "RX: unknown packet type %u! "
+				    "Dropping\n", untd_hdr_type(untd_hdr));
+			goto out;
+		}
+		size_left -= untd_hdr_size + untd_frg_size;
+		if (size_left > 0)
+			ptr += untd_hdr_size + untd_frg_size;
+	}
+	if (pkt_completed)
+		i1480u_skb_deliver(i1480u);
+out:
+	/* recreate needed RX buffers*/
+	if (rx_buf->data == NULL) {
+		/* buffer is being used to receive packet, create new */
+		new_skb = dev_alloc_skb(i1480u_MAX_RX_PKT_SIZE);
+		if (!new_skb) {
+			if (printk_ratelimit())
+				dev_err(dev,
+				"RX: cannot allocate RX buffer\n");
+		} else {
+			new_skb->dev = net_dev;
+			new_skb->ip_summed = CHECKSUM_NONE;
+			skb_reserve(new_skb, 2);
+			rx_buf->data = new_skb;
+		}
+	}
+	return;
+}
+
+
+/**
+ * Called when an RX URB has finished receiving or has found some kind
+ * of error condition.
+ *
+ * LIMITATIONS:
+ *
+ *  - We read USB-transfers, each transfer contains a SINGLE fragment
+ *    (can contain a complete packet, or a 1st, next, or last fragment
+ *    of a packet).
+ *    Looks like a transfer can contain more than one fragment (07/18/06)
+ *
+ *  - Each transfer buffer is the size of the maximum packet size (minus
+ *    headroom), i1480u_MAX_PKT_SIZE - 2
+ *
+ *  - We always read the full USB-transfer, no partials.
+ *
+ *  - Each transfer is read directly into a skb. This skb will be used to
+ *    send data to the upper layers if it is the first fragment or a complete
+ *    packet. In the other cases the data will be copied from the skb to
+ *    another skb that is being prepared for the upper layers from a prev
+ *    first fragment.
+ *
+ * It is simply too much of a pain. Gosh, there should be a unified
+ * SG infrastructure for *everything* [so that I could declare a SG
+ * buffer, pass it to USB for receiving, append some space to it if
+ * I wish, receive more until I have the whole chunk, adapt
+ * pointers on each fragment to remove hardware headers and then
+ * attach that to an skbuff and netif_rx()].
+ */
+void i1480u_rx_cb(struct urb *urb)
+{
+	int result;
+	int do_parse_buffer = 1;
+	struct i1480u_rx_buf *rx_buf = urb->context;
+	struct i1480u *i1480u = rx_buf->i1480u;
+	struct device *dev = &i1480u->usb_iface->dev;
+	unsigned long flags;
+	u8 rx_buf_idx = rx_buf - i1480u->rx_buf;
+
+	switch (urb->status) {
+	case 0:
+		break;
+	case -ECONNRESET:	/* Not an error, but a controlled situation; */
+	case -ENOENT:		/* (we killed the URB)...so, no broadcast */
+	case -ESHUTDOWN:	/* going away! */
+		dev_err(dev, "RX URB[%u]: goind down %d\n",
+			rx_buf_idx, urb->status);
+		goto error;
+	default:
+		dev_err(dev, "RX URB[%u]: unknown status %d\n",
+			rx_buf_idx, urb->status);
+		if (edc_inc(&i1480u->rx_errors, EDC_MAX_ERRORS,
+					EDC_ERROR_TIMEFRAME)) {
+			dev_err(dev, "RX: max acceptable errors exceeded,"
+					" resetting device.\n");
+			i1480u_rx_unlink_urbs(i1480u);
+			wlp_reset_all(&i1480u->wlp);
+			goto error;
+		}
+		do_parse_buffer = 0;
+		break;
+	}
+	spin_lock_irqsave(&i1480u->lock, flags);
+	/* chew the data fragments, extract network packets */
+	if (do_parse_buffer) {
+		i1480u_rx_buffer(rx_buf);
+		if (rx_buf->data) {
+			rx_buf->urb->transfer_buffer = rx_buf->data->data;
+			result = usb_submit_urb(rx_buf->urb, GFP_ATOMIC);
+			if (result < 0) {
+				dev_err(dev, "RX URB[%u]: cannot submit %d\n",
+					rx_buf_idx, result);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&i1480u->lock, flags);
+error:
+	return;
+}
+

drivers/uwb/i1480/i1480u-wlp/sysfs.c

+/*
+ * WUSB Wire Adapter: WLP interface
+ * Sysfs interfaces
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * 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.
+ *
+ *
+ * FIXME: docs
+ */
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/uwb/debug.h>
+#include <linux/device.h>
+#include "i1480u-wlp.h"
+
+
+/**
+ *
+ * @dev: Class device from the net_device; assumed refcnted.
+ *
+ * Yes, I don't lock--we assume it is refcounted and I am getting a
+ * single byte value that is kind of atomic to read.
+ */
+ssize_t uwb_phy_rate_show(const struct wlp_options *options, char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       wlp_tx_hdr_phy_rate(&options->def_tx_hdr));
+}
+EXPORT_SYMBOL_GPL(uwb_phy_rate_show);
+
+
+ssize_t uwb_phy_rate_store(struct wlp_options *options,
+			   const char *buf, size_t size)
+{
+	ssize_t result;
+	unsigned rate;
+
+	result = sscanf(buf, "%u\n", &rate);
+	if (result != 1) {
+		result = -EINVAL;
+		goto out;
+	}
+	result = -EINVAL;
+	if (rate >= UWB_PHY_RATE_INVALID)
+		goto out;
+	wlp_tx_hdr_set_phy_rate(&options->def_tx_hdr, rate);
+	result = 0;
+out:
+	return result < 0 ? result : size;
+}
+EXPORT_SYMBOL_GPL(uwb_phy_rate_store);
+
+
+ssize_t uwb_rts_cts_show(const struct wlp_options *options, char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       wlp_tx_hdr_rts_cts(&options->def_tx_hdr));
+}
+EXPORT_SYMBOL_GPL(uwb_rts_cts_show);
+
+
+ssize_t uwb_rts_cts_store(struct wlp_options *options,
+			  const char *buf, size_t size)
+{
+	ssize_t result;
+	unsigned value;
+
+	result = sscanf(buf, "%u\n", &value);
+	if (result != 1) {
+		result = -EINVAL;
+		goto out;
+	}
+	result = -EINVAL;
+	wlp_tx_hdr_set_rts_cts(&options->def_tx_hdr, !!value);
+	result = 0;
+out:
+	return result < 0 ? result : size;
+}
+EXPORT_SYMBOL_GPL(uwb_rts_cts_store);
+
+
+ssize_t uwb_ack_policy_show(const struct wlp_options *options, char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       wlp_tx_hdr_ack_policy(&options->def_tx_hdr));
+}
+EXPORT_SYMBOL_GPL(uwb_ack_policy_show);
+
+
+ssize_t uwb_ack_policy_store(struct wlp_options *options,
+			     const char *buf, size_t size)
+{
+	ssize_t result;
+	unsigned value;
+
+	result = sscanf(buf, "%u\n", &value);
+	if (result != 1 || value > UWB_ACK_B_REQ) {
+		result = -EINVAL;
+		goto out;
+	}
+	wlp_tx_hdr_set_ack_policy(&options->def_tx_hdr, value);
+	result = 0;
+out:
+	return result < 0 ? result : size;
+}
+EXPORT_SYMBOL_GPL(uwb_ack_policy_store);
+
+
+/**
+ * Show the PCA base priority.
+ *
+ * We can access without locking, as the value is (for now) orthogonal
+ * to other values.
+ */
+ssize_t uwb_pca_base_priority_show(const struct wlp_options *options,
+				   char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       options->pca_base_priority);
+}
+EXPORT_SYMBOL_GPL(uwb_pca_base_priority_show);
+
+
+/**
+ * Set the PCA base priority.
+ *
+ * We can access without locking, as the value is (for now) orthogonal
+ * to other values.
+ */
+ssize_t uwb_pca_base_priority_store(struct wlp_options *options,
+				    const char *buf, size_t size)
+{
+	ssize_t result = -EINVAL;
+	u8 pca_base_priority;
+
+	result = sscanf(buf, "%hhu\n", &pca_base_priority);
+	if (result != 1) {
+		result = -EINVAL;
+		goto out;
+	}
+	result = -EINVAL;
+	if (pca_base_priority >= 8)
+		goto out;
+	options->pca_base_priority = pca_base_priority;
+	/* Update TX header if we are currently using PCA. */
+	if (result >= 0 && (wlp_tx_hdr_delivery_id_type(&options->def_tx_hdr) & WLP_DRP) == 0)
+		wlp_tx_hdr_set_delivery_id_type(&options->def_tx_hdr, options->pca_base_priority);
+	result = 0;
+out:
+	return result < 0 ? result : size;
+}
+EXPORT_SYMBOL_GPL(uwb_pca_base_priority_store);
+
+/**
+ * Show current inflight values
+ *
+ * Will print the current MAX and THRESHOLD values for the basic flow
+ * control. In addition it will report how many times the TX queue needed
+ * to be restarted since the last time this query was made.
+ */
+static ssize_t wlp_tx_inflight_show(struct i1480u_tx_inflight *inflight,
+				    char *buf)
+{
+	ssize_t result;
+	unsigned long sec_elapsed = (jiffies - inflight->restart_ts)/HZ;
+	unsigned long restart_count = atomic_read(&inflight->restart_count);
+
+	result = scnprintf(buf, PAGE_SIZE, "%lu %lu %d %lu %lu %lu\n"
+			   "#read: threshold max inflight_count restarts "
+			   "seconds restarts/sec\n"
+			   "#write: threshold max\n",
+			   inflight->threshold, inflight->max,
+			   atomic_read(&inflight->count),
+			   restart_count, sec_elapsed,
+			   sec_elapsed == 0 ? 0 : restart_count/sec_elapsed);
+	inflight->restart_ts = jiffies;
+	atomic_set(&inflight->restart_count, 0);
+	return result;
+}
+
+static
+ssize_t wlp_tx_inflight_store(struct i1480u_tx_inflight *inflight,
+				const char *buf, size_t size)
+{
+	unsigned long in_threshold, in_max;
+	ssize_t result;
+	result = sscanf(buf, "%lu %lu", &in_threshold, &in_max);
+	if (result != 2)
+		return -EINVAL;
+	if (in_max <= in_threshold)
+		return -EINVAL;
+	inflight->max = in_max;
+	inflight->threshold = in_threshold;
+	return size;
+}
+/*
+ * Glue (or function adaptors) for accesing info on sysfs
+ *
+ * [we need this indirection because the PCI driver does almost the
+ * same]
+ *
+ * Linux 2.6.21 changed how 'struct netdevice' does attributes (from
+ * having a 'struct class_dev' to having a 'struct device'). That is
+ * quite of a pain.
+ *
+ * So we try to abstract that here. i1480u_SHOW() and i1480u_STORE()
+ * create adaptors for extracting the 'struct i1480u' from a 'struct
+ * dev' and calling a function for doing a sysfs operation (as we have
+ * them factorized already). i1480u_ATTR creates the attribute file
+ * (CLASS_DEVICE_ATTR or DEVICE_ATTR) and i1480u_ATTR_NAME produces a
+ * class_device_attr_NAME or device_attr_NAME (for group registration).
+ */
+#include <linux/version.h>
+
+#define i1480u_SHOW(name, fn, param)				\
+static ssize_t i1480u_show_##name(struct device *dev,		\
+				  struct device_attribute *attr,\
+				  char *buf)			\
+{								\
+	struct i1480u *i1480u = netdev_priv(to_net_dev(dev));	\
+	return fn(&i1480u->param, buf);				\
+}
+
+#define i1480u_STORE(name, fn, param)				\
+static ssize_t i1480u_store_##name(struct device *dev,		\
+				   struct device_attribute *attr,\
+				   const char *buf, size_t size)\
+{								\
+	struct i1480u *i1480u = netdev_priv(to_net_dev(dev));	\
+	return fn(&i1480u->param, buf, size);			\
+}
+
+#define i1480u_ATTR(name, perm) static DEVICE_ATTR(name, perm,  \
+					     i1480u_show_##name,\
+					     i1480u_store_##name)
+
+#define i1480u_ATTR_SHOW(name) static DEVICE_ATTR(name,		\
+					S_IRUGO,		\
+					i1480u_show_##name, NULL)
+
+#define i1480u_ATTR_NAME(a) (dev_attr_##a)
+
+
+/*
+ * Sysfs adaptors
+ */
+i1480u_SHOW(uwb_phy_rate, uwb_phy_rate_show, options);
+i1480u_STORE(uwb_phy_rate, uwb_phy_rate_store, options);
+i1480u_ATTR(uwb_phy_rate, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(uwb_rts_cts, uwb_rts_cts_show, options);
+i1480u_STORE(uwb_rts_cts, uwb_rts_cts_store, options);
+i1480u_ATTR(uwb_rts_cts, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(uwb_ack_policy, uwb_ack_policy_show, options);
+i1480u_STORE(uwb_ack_policy, uwb_ack_policy_store, options);
+i1480u_ATTR(uwb_ack_policy, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(uwb_pca_base_priority, uwb_pca_base_priority_show, options);
+i1480u_STORE(uwb_pca_base_priority, uwb_pca_base_priority_store, options);
+i1480u_ATTR(uwb_pca_base_priority, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_eda, wlp_eda_show, wlp);
+i1480u_STORE(wlp_eda, wlp_eda_store, wlp);
+i1480u_ATTR(wlp_eda, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_uuid, wlp_uuid_show, wlp);
+i1480u_STORE(wlp_uuid, wlp_uuid_store, wlp);
+i1480u_ATTR(wlp_uuid, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_name, wlp_dev_name_show, wlp);
+i1480u_STORE(wlp_dev_name, wlp_dev_name_store, wlp);
+i1480u_ATTR(wlp_dev_name, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_manufacturer, wlp_dev_manufacturer_show, wlp);
+i1480u_STORE(wlp_dev_manufacturer, wlp_dev_manufacturer_store, wlp);
+i1480u_ATTR(wlp_dev_manufacturer, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_model_name, wlp_dev_model_name_show, wlp);
+i1480u_STORE(wlp_dev_model_name, wlp_dev_model_name_store, wlp);
+i1480u_ATTR(wlp_dev_model_name, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_model_nr, wlp_dev_model_nr_show, wlp);
+i1480u_STORE(wlp_dev_model_nr, wlp_dev_model_nr_store, wlp);
+i1480u_ATTR(wlp_dev_model_nr, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_serial, wlp_dev_serial_show, wlp);
+i1480u_STORE(wlp_dev_serial, wlp_dev_serial_store, wlp);
+i1480u_ATTR(wlp_dev_serial, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_prim_category, wlp_dev_prim_category_show, wlp);
+i1480u_STORE(wlp_dev_prim_category, wlp_dev_prim_category_store, wlp);
+i1480u_ATTR(wlp_dev_prim_category, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_prim_OUI, wlp_dev_prim_OUI_show, wlp);
+i1480u_STORE(wlp_dev_prim_OUI, wlp_dev_prim_OUI_store, wlp);
+i1480u_ATTR(wlp_dev_prim_OUI, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_prim_OUI_sub, wlp_dev_prim_OUI_sub_show, wlp);
+i1480u_STORE(wlp_dev_prim_OUI_sub, wlp_dev_prim_OUI_sub_store, wlp);
+i1480u_ATTR(wlp_dev_prim_OUI_sub, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_dev_prim_subcat, wlp_dev_prim_subcat_show, wlp);
+i1480u_STORE(wlp_dev_prim_subcat, wlp_dev_prim_subcat_store, wlp);
+i1480u_ATTR(wlp_dev_prim_subcat, S_IRUGO | S_IWUSR);
+
+i1480u_SHOW(wlp_neighborhood, wlp_neighborhood_show, wlp);
+i1480u_ATTR_SHOW(wlp_neighborhood);
+
+i1480u_SHOW(wss_activate, wlp_wss_activate_show, wlp.wss);
+i1480u_STORE(wss_activate, wlp_wss_activate_store, wlp.wss);
+i1480u_ATTR(wss_activate, S_IRUGO | S_IWUSR);
+
+/*
+ * Show the (min, max, avg) Line Quality Estimate (LQE, in dB) as over
+ * the last 256 received WLP frames (ECMA-368 13.3).
+ *
+ * [the -7dB that have to be substracted from the LQI to make the LQE
+ * are already taken into account].
+ */
+i1480u_SHOW(wlp_lqe, stats_show, lqe_stats);
+i1480u_STORE(wlp_lqe, stats_store, lqe_stats);
+i1480u_ATTR(wlp_lqe, S_IRUGO | S_IWUSR);
+
+/*
+ * Show the Receive Signal Strength Indicator averaged over all the
+ * received WLP frames (ECMA-368 13.3). Still is not clear what
+ * this value is, but is kind of a percentage of the signal strength
+ * at the antenna.
+ */
+i1480u_SHOW(wlp_rssi, stats_show, rssi_stats);
+i1480u_STORE(wlp_rssi, stats_store, rssi_stats);
+i1480u_ATTR(wlp_rssi, S_IRUGO | S_IWUSR);
+
+/**
+ * We maintain a basic flow control counter. "count" how many TX URBs are
+ * outstanding. Only allow "max"
+ * TX URBs to be outstanding. If this value is reached the queue will be
+ * stopped. The queue will be restarted when there are
+ * "threshold" URBs outstanding.
+ */
+i1480u_SHOW(wlp_tx_inflight, wlp_tx_inflight_show, tx_inflight);
+i1480u_STORE(wlp_tx_inflight, wlp_tx_inflight_store, tx_inflight);
+i1480u_ATTR(wlp_tx_inflight, S_IRUGO | S_IWUSR);
+
+static struct attribute *i1480u_attrs[] = {
+	&i1480u_ATTR_NAME(uwb_phy_rate).attr,
+	&i1480u_ATTR_NAME(uwb_rts_cts).attr,
+	&i1480u_ATTR_NAME(uwb_ack_policy).attr,
+	&i1480u_ATTR_NAME(uwb_pca_base_priority).attr,
+	&i1480u_ATTR_NAME(wlp_lqe).attr,
+	&i1480u_ATTR_NAME(wlp_rssi).attr,
+	&i1480u_ATTR_NAME(wlp_eda).attr,
+	&i1480u_ATTR_NAME(wlp_uuid).attr,
+	&i1480u_ATTR_NAME(wlp_dev_name).attr,
+	&i1480u_ATTR_NAME(wlp_dev_manufacturer).attr,
+	&i1480u_ATTR_NAME(wlp_dev_model_name).attr,
+	&i1480u_ATTR_NAME(wlp_dev_model_nr).attr,
+	&i1480u_ATTR_NAME(wlp_dev_serial).attr,
+	&i1480u_ATTR_NAME(wlp_dev_prim_category).attr,
+	&i1480u_ATTR_NAME(wlp_dev_prim_OUI).attr,
+	&i1480u_ATTR_NAME(wlp_dev_prim_OUI_sub).attr,
+	&i1480u_ATTR_NAME(wlp_dev_prim_subcat).attr,
+	&i1480u_ATTR_NAME(wlp_neighborhood).attr,
+	&i1480u_ATTR_NAME(wss_activate).attr,
+	&i1480u_ATTR_NAME(wlp_tx_inflight).attr,
+	NULL,
+};
+
+static struct attribute_group i1480u_attr_group = {
+	.name = NULL,	/* we want them in the same directory */
+	.attrs = i1480u_attrs,
+};
+
+int i1480u_sysfs_setup(struct i1480u *i1480u)
+{
+	int result;
+	struct device *dev = &i1480u->usb_iface->dev;
+	result = sysfs_create_group(&i1480u->net_dev->dev.kobj,
+				    &i1480u_attr_group);
+	if (result < 0)
+		dev_err(dev, "cannot initialize sysfs attributes: %d\n",
+			result);
+	return result;
+}
+
+
+void i1480u_sysfs_release(struct i1480u *i1480u)
+{
+	sysfs_remove_group(&i1480u->net_dev->dev.kobj,
+			   &i1480u_attr_group);
+}

drivers/uwb/i1480/i1480u-wlp/tx.c

+/*
+ * WUSB Wire Adapter: WLP interface
+ * Deal with TX (massaging data to transmit, handling it)
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * 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.
+ *
+ *
+ * Transmission engine. Get an skb, create from that a WLP transmit
+ * context, add a WLP TX header (which we keep prefilled in the
+ * device's instance), fill out the target-specific fields and
+ * fire it.
+ *
+ * ROADMAP:
+ *
+ *   Entry points:
+ *
+ *     i1480u_tx_release(): called by i1480u_disconnect() to release
+ *                          pending tx contexts.
+ *
+ *     i1480u_tx_cb(): callback for TX contexts (USB URBs)
+ *       i1480u_tx_destroy():
+ *
+ *     i1480u_tx_timeout(): called for timeout handling from the
+ *                          network stack.
+ *
+ *     i1480u_hard_start_xmit(): called for transmitting an skb from
+ *                               the network stack. Will interact with WLP
+ *                               substack to verify and prepare frame.
+ *       i1480u_xmit_frame(): actual transmission on hardware
+ *
+ *         i1480u_tx_create()	    Creates TX context
+ *            i1480u_tx_create_1()    For packets in 1 fragment
+ *            i1480u_tx_create_n()    For packets in >1 fragments
+ *
+ * TODO:
+ *
+ * - FIXME: rewrite using usb_sg_*(), add asynch support to
+ *          usb_sg_*(). It might not make too much sense as most of
+ *          the times the MTU will be smaller than one page...
+ */
+
+#include "i1480u-wlp.h"
+#define D_LOCAL 5
+#include <linux/uwb/debug.h>
+
+enum {
+	/* This is only for Next and Last TX packets */
+	i1480u_MAX_PL_SIZE = i1480u_MAX_FRG_SIZE
+		- sizeof(struct untd_hdr_rst),
+};
+
+/** Free resources allocated to a i1480u tx context. */
+static
+void i1480u_tx_free(struct i1480u_tx *wtx)
+{
+	kfree(wtx->buf);
+	if (wtx->skb)
+		dev_kfree_skb_irq(wtx->skb);
+	usb_free_urb(wtx->urb);
+	kfree(wtx);
+}
+
+static
+void i1480u_tx_destroy(struct i1480u *i1480u, struct i1480u_tx *wtx)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&i1480u->tx_list_lock, flags);	/* not active any more */
+	list_del(&wtx->list_node);
+	i1480u_tx_free(wtx);
+	spin_unlock_irqrestore(&i1480u->tx_list_lock, flags);
+}
+
+static
+void i1480u_tx_unlink_urbs(struct i1480u *i1480u)
+{
+	unsigned long flags;
+	struct i1480u_tx *wtx, *next;
+
+	spin_lock_irqsave(&i1480u->tx_list_lock, flags);
+	list_for_each_entry_safe(wtx, next, &i1480u->tx_list, list_node) {
+		usb_unlink_urb(wtx->urb);
+	}
+	spin_unlock_irqrestore(&i1480u->tx_list_lock, flags);
+}
+
+
+/**
+ * Callback for a completed tx USB URB.
+ *
+ * TODO:
+ *
+ * - FIXME: recover errors more gracefully
+ * - FIXME: handle NAKs (I dont think they come here) for flow ctl
+ */
+static
+void i1480u_tx_cb(struct urb *urb)
+{
+	struct i1480u_tx *wtx = urb->context;
+	struct i1480u *i1480u = wtx->i1480u;
+	struct net_device *net_dev = i1480u->net_dev;
+	struct device *dev = &i1480u->usb_iface->dev;
+	unsigned long flags;
+
+	switch (urb->status) {
+	case 0:
+		spin_lock_irqsave(&i1480u->lock, flags);
+		i1480u->stats.tx_packets++;
+		i1480u->stats.tx_bytes += urb->actual_length;
+		spin_unlock_irqrestore(&i1480u->lock, flags);
+		break;
+	case -ECONNRESET:	/* Not an error, but a controlled situation; */
+	case -ENOENT:		/* (we killed the URB)...so, no broadcast */
+		dev_dbg(dev, "notif endp: reset/noent %d\n", urb->status);
+		netif_stop_queue(net_dev);
+		break;
+	case -ESHUTDOWN:	/* going away! */
+		dev_dbg(dev, "notif endp: down %d\n", urb->status);
+		netif_stop_queue(net_dev);
+		break;
+	default:
+		dev_err(dev, "TX: unknown URB status %d\n", urb->status);
+		if (edc_inc(&i1480u->tx_errors, EDC_MAX_ERRORS,
+					EDC_ERROR_TIMEFRAME)) {
+			dev_err(dev, "TX: max acceptable errors exceeded."
+					"Reset device.\n");
+			netif_stop_queue(net_dev);
+			i1480u_tx_unlink_urbs(i1480u);
+			wlp_reset_all(&i1480u->wlp);
+		}
+		break;
+	}
+	i1480u_tx_destroy(i1480u, wtx);
+	if (atomic_dec_return(&i1480u->tx_inflight.count)
+	    <= i1480u->tx_inflight.threshold
+	    && netif_queue_stopped(net_dev)
+	    && i1480u->tx_inflight.threshold != 0) {
+		if (d_test(2) && printk_ratelimit())
+			d_printf(2, dev, "Restart queue. \n");
+		netif_start_queue(net_dev);
+		atomic_inc(&i1480u->tx_inflight.restart_count);
+	}
+	return;
+}
+
+
+/**
+ * Given a buffer that doesn't fit in a single fragment, create an
+ * scatter/gather structure for delivery to the USB pipe.
+ *
+ * Implements functionality of i1480u_tx_create().
+ *
+ * @wtx:	tx descriptor
+ * @skb:	skb to send
+ * @gfp_mask:	gfp allocation mask
+ * @returns:    Pointer to @wtx if ok, NULL on error.
+ *
+ * Sorry, TOO LONG a function, but breaking it up is kind of hard
+ *
+ * This will break the buffer in chunks smaller than
+ * i1480u_MAX_FRG_SIZE (including the header) and add proper headers
+ * to each:
+ *
+ *   1st header           \
+ *   i1480 tx header      |  fragment 1
+ *   fragment data        /
+ *   nxt header           \  fragment 2
+ *   fragment data        /
+ *   ..
+ *   ..
+ *   last header          \  fragment 3
+ *   last fragment data   /
+ *
+ * This does not fill the i1480 TX header, it is left up to the
+ * caller to do that; you can get it from @wtx->wlp_tx_hdr.
+ *
+ * This function consumes the skb unless there is an error.
+ */
+static
+int i1480u_tx_create_n(struct i1480u_tx *wtx, struct sk_buff *skb,
+		       gfp_t gfp_mask)
+{
+	int result;
+	void *pl;
+	size_t pl_size;
+
+	void *pl_itr, *buf_itr;
+	size_t pl_size_left, frgs, pl_size_1st, frg_pl_size = 0;
+	struct untd_hdr_1st *untd_hdr_1st;
+	struct wlp_tx_hdr *wlp_tx_hdr;
+	struct untd_hdr_rst *untd_hdr_rst;
+
+	wtx->skb = NULL;
+	pl = skb->data;
+	pl_itr = pl;
+	pl_size = skb->len;
+	pl_size_left = pl_size;	/* payload size */
+	/* First fragment; fits as much as i1480u_MAX_FRG_SIZE minus
+	 * the headers */
+	pl_size_1st = i1480u_MAX_FRG_SIZE
+		- sizeof(struct untd_hdr_1st) - sizeof(struct wlp_tx_hdr);
+	BUG_ON(pl_size_1st > pl_size);
+	pl_size_left -= pl_size_1st;
+	/* The rest have an smaller header (no i1480 TX header). We
+	 * need to break up the payload in blocks smaller than
+	 * i1480u_MAX_PL_SIZE (payload excluding header). */
+	frgs = (pl_size_left + i1480u_MAX_PL_SIZE - 1) / i1480u_MAX_PL_SIZE;
+	/* Allocate space for the new buffer. In this new buffer we'll
+	 * place the headers followed by the data fragment, headers,
+	 * data fragments, etc..
+	 */
+	result = -ENOMEM;
+	wtx->buf_size = sizeof(*untd_hdr_1st)
+		+ sizeof(*wlp_tx_hdr)
+		+ frgs * sizeof(*untd_hdr_rst)
+		+ pl_size;
+	wtx->buf = kmalloc(wtx->buf_size, gfp_mask);
+	if (wtx->buf == NULL)
+		goto error_buf_alloc;
+
+	buf_itr = wtx->buf;		/* We got the space, let's fill it up */
+	/* Fill 1st fragment */
+	untd_hdr_1st = buf_itr;
+	buf_itr += sizeof(*untd_hdr_1st);
+	untd_hdr_set_type(&untd_hdr_1st->hdr, i1480u_PKT_FRAG_1ST);
+	untd_hdr_set_rx_tx(&untd_hdr_1st->hdr, 0);
+	untd_hdr_1st->hdr.len = cpu_to_le16(pl_size + sizeof(*wlp_tx_hdr));
+	untd_hdr_1st->fragment_len =
+		cpu_to_le16(pl_size_1st + sizeof(*wlp_tx_hdr));
+	memset(untd_hdr_1st->padding, 0, sizeof(untd_hdr_1st->padding));
+	/* Set up i1480 header info */
+	wlp_tx_hdr = wtx->wlp_tx_hdr = buf_itr;
+	buf_itr += sizeof(*wlp_tx_hdr);
+	/* Copy the first fragment */
+	memcpy(buf_itr, pl_itr, pl_size_1st);
+	pl_itr += pl_size_1st;
+	buf_itr += pl_size_1st;
+
+	/* Now do each remaining fragment */
+	result = -EINVAL;
+	while (pl_size_left > 0) {
+		d_printf(5, NULL, "ITR HDR: pl_size_left %zu buf_itr %zu\n",
+			 pl_size_left, buf_itr - wtx->buf);
+		if (buf_itr + sizeof(*untd_hdr_rst) - wtx->buf
+		    > wtx->buf_size) {
+			printk(KERN_ERR "BUG: no space for header\n");
+			goto error_bug;
+		}
+		d_printf(5, NULL, "ITR HDR 2: pl_size_left %zu buf_itr %zu\n",
+			 pl_size_left, buf_itr - wtx->buf);
+		untd_hdr_rst = buf_itr;
+		buf_itr += sizeof(*untd_hdr_rst);
+		if (pl_size_left > i1480u_MAX_PL_SIZE) {
+			frg_pl_size = i1480u_MAX_PL_SIZE;
+			untd_hdr_set_type(&untd_hdr_rst->hdr, i1480u_PKT_FRAG_NXT);
+		} else {
+			frg_pl_size = pl_size_left;
+			untd_hdr_set_type(&untd_hdr_rst->hdr, i1480u_PKT_FRAG_LST);
+		}
+		d_printf(5, NULL,
+			 "ITR PL: pl_size_left %zu buf_itr %zu frg_pl_size %zu\n",
+			 pl_size_left, buf_itr - wtx->buf, frg_pl_size);
+		untd_hdr_set_rx_tx(&untd_hdr_rst->hdr, 0);
+		untd_hdr_rst->hdr.len = cpu_to_le16(frg_pl_size);
+		untd_hdr_rst->padding = 0;
+		if (buf_itr + frg_pl_size - wtx->buf
+		    > wtx->buf_size) {
+			printk(KERN_ERR "BUG: no space for payload\n");
+			goto error_bug;
+		}
+		memcpy(buf_itr, pl_itr, frg_pl_size);
+		buf_itr += frg_pl_size;
+		pl_itr += frg_pl_size;
+		pl_size_left -= frg_pl_size;
+		d_printf(5, NULL,
+			 "ITR PL 2: pl_size_left %zu buf_itr %zu frg_pl_size %zu\n",
+			 pl_size_left, buf_itr - wtx->buf, frg_pl_size);
+	}
+	dev_kfree_skb_irq(skb);
+	return 0;
+
+error_bug:
+	printk(KERN_ERR
+	       "BUG: skb %u bytes\n"
+	       "BUG: frg_pl_size %zd i1480u_MAX_FRG_SIZE %u\n"
+	       "BUG: buf_itr %zu buf_size %zu pl_size_left %zu\n",
+	       skb->len,
+	       frg_pl_size, i1480u_MAX_FRG_SIZE,
+	       buf_itr - wtx->buf, wtx->buf_size, pl_size_left);
+
+	kfree(wtx->buf);
+error_buf_alloc:
+	return result;
+}
+
+
+/**
+ * Given a buffer that fits in a single fragment, fill out a @wtx
+ * struct for transmitting it down the USB pipe.
+ *
+ * Uses the fact that we have space reserved in front of the skbuff
+ * for hardware headers :]
+ *
+ * This does not fill the i1480 TX header, it is left up to the
+ * caller to do that; you can get it from @wtx->wlp_tx_hdr.
+ *
+ * @pl:		pointer to payload data
+ * @pl_size:    size of the payuload
+ *
+ * This function does not consume the @skb.
+ */
+static
+int i1480u_tx_create_1(struct i1480u_tx *wtx, struct sk_buff *skb,
+		       gfp_t gfp_mask)
+{
+	struct untd_hdr_cmp *untd_hdr_cmp;
+	struct wlp_tx_hdr *wlp_tx_hdr;
+
+	wtx->buf = NULL;
+	wtx->skb = skb;
+	BUG_ON(skb_headroom(skb) < sizeof(*wlp_tx_hdr));
+	wlp_tx_hdr = (void *) __skb_push(skb, sizeof(*wlp_tx_hdr));
+	wtx->wlp_tx_hdr = wlp_tx_hdr;
+	BUG_ON(skb_headroom(skb) < sizeof(*untd_hdr_cmp));
+	untd_hdr_cmp = (void *) __skb_push(skb, sizeof(*untd_hdr_cmp));
+
+	untd_hdr_set_type(&untd_hdr_cmp->hdr, i1480u_PKT_FRAG_CMP);
+	untd_hdr_set_rx_tx(&untd_hdr_cmp->hdr, 0);
+	untd_hdr_cmp->hdr.len = cpu_to_le16(skb->len - sizeof(*untd_hdr_cmp));
+	untd_hdr_cmp->padding = 0;
+	return 0;
+}
+
+
+/**
+ * Given a skb to transmit, massage it to become palatable for the TX pipe
+ *
+ * This will break the buffer in chunks smaller than
+ * i1480u_MAX_FRG_SIZE and add proper headers to each.
+ *
+ *   1st header           \
+ *   i1480 tx header      |  fragment 1
+ *   fragment data        /
+ *   nxt header           \  fragment 2
+ *   fragment data        /
+ *   ..
+ *   ..
+ *   last header          \  fragment 3
+ *   last fragment data   /
+ *
+ * Each fragment will be always smaller or equal to i1480u_MAX_FRG_SIZE.
+ *
+ * If the first fragment is smaller than i1480u_MAX_FRG_SIZE, then the
+ * following is composed:
+ *
+ *   complete header      \
+ *   i1480 tx header      | single fragment
+ *   packet data          /
+ *
+ * We were going to use s/g support, but because the interface is
+ * synch and at the end there is plenty of overhead to do it, it
+ * didn't seem that worth for data that is going to be smaller than
+ * one page.
+ */
+static
+struct i1480u_tx *i1480u_tx_create(struct i1480u *i1480u,
+				   struct sk_buff *skb, gfp_t gfp_mask)
+{
+	int result;
+	struct usb_endpoint_descriptor *epd;
+	int usb_pipe;
+	unsigned long flags;
+
+	struct i1480u_tx *wtx;
+	const size_t pl_max_size =
+		i1480u_MAX_FRG_SIZE - sizeof(struct untd_hdr_cmp)
+		- sizeof(struct wlp_tx_hdr);
+
+	wtx = kmalloc(sizeof(*wtx), gfp_mask);
+	if (wtx == NULL)
+		goto error_wtx_alloc;
+	wtx->urb = usb_alloc_urb(0, gfp_mask);
+	if (wtx->urb == NULL)
+		goto error_urb_alloc;
+	epd = &i1480u->usb_iface->cur_altsetting->endpoint[2].desc;
+	usb_pipe = usb_sndbulkpipe(i1480u->usb_dev, epd->bEndpointAddress);
+	/* Fits in a single complete packet or need to split? */
+	if (skb->len > pl_max_size) {
+		result = i1480u_tx_create_n(wtx, skb, gfp_mask);
+		if (result < 0)
+			goto error_create;
+		usb_fill_bulk_urb(wtx->urb, i1480u->usb_dev, usb_pipe,
+				  wtx->buf, wtx->buf_size, i1480u_tx_cb, wtx);
+	} else {
+		result = i1480u_tx_create_1(wtx, skb, gfp_mask);
+		if (result < 0)
+			goto error_create;
+		usb_fill_bulk_urb(wtx->urb, i1480u->usb_dev, usb_pipe,
+				  skb->data, skb->len, i1480u_tx_cb, wtx);
+	}
+	spin_lock_irqsave(&i1480u->tx_list_lock, flags);
+	list_add(&wtx->list_node, &i1480u->tx_list);
+	spin_unlock_irqrestore(&i1480u->tx_list_lock, flags);
+	return wtx;
+
+error_create:
+	kfree(wtx->urb);
+error_urb_alloc:
+	kfree(wtx);
+error_wtx_alloc:
+	return NULL;
+}
+
+/**
+ * Actual fragmentation and transmission of frame
+ *
+ * @wlp:  WLP substack data structure
+ * @skb:  To be transmitted
+ * @dst:  Device address of destination
+ * @returns: 0 on success, <0 on failure
+ *
+ * This function can also be called directly (not just from
+ * hard_start_xmit), so we also check here if the interface is up before
+ * taking sending anything.
+ */
+int i1480u_xmit_frame(struct wlp *wlp, struct sk_buff *skb,
+		      struct uwb_dev_addr *dst)
+{
+	int result = -ENXIO;
+	struct i1480u *i1480u = container_of(wlp, struct i1480u, wlp);
+	struct device *dev = &i1480u->usb_iface->dev;
+	struct net_device *net_dev = i1480u->net_dev;
+	struct i1480u_tx *wtx;
+	struct wlp_tx_hdr *wlp_tx_hdr;
+	static unsigned char dev_bcast[2] = { 0xff, 0xff };
+#if 0
+	int lockup = 50;
+#endif
+
+	d_fnstart(6, dev, "(skb %p (%u), net_dev %p)\n", skb, skb->len,
+		  net_dev);
+	BUG_ON(i1480u->wlp.rc == NULL);
+	if ((net_dev->flags & IFF_UP) == 0)
+		goto out;
+	result = -EBUSY;
+	if (atomic_read(&i1480u->tx_inflight.count) >= i1480u->tx_inflight.max) {
+		if (d_test(2) && printk_ratelimit())
+			d_printf(2, dev, "Max frames in flight "
+				 "stopping queue.\n");
+		netif_stop_queue(net_dev);
+		goto error_max_inflight;
+	}
+	result = -ENOMEM;
+	wtx = i1480u_tx_create(i1480u, skb, GFP_ATOMIC);
+	if (unlikely(wtx == NULL)) {
+		if (printk_ratelimit())
+			dev_err(dev, "TX: no memory for WLP TX URB,"
+				"dropping packet (in flight %d)\n",
+				atomic_read(&i1480u->tx_inflight.count));
+		netif_stop_queue(net_dev);
+		goto error_wtx_alloc;
+	}
+	wtx->i1480u = i1480u;
+	/* Fill out the i1480 header; @i1480u->def_tx_hdr read without
+	 * locking. We do so because they are kind of orthogonal to
+	 * each other (and thus not changed in an atomic batch).
+	 * The ETH header is right after the WLP TX header. */
+	wlp_tx_hdr = wtx->wlp_tx_hdr;
+	*wlp_tx_hdr = i1480u->options.def_tx_hdr;
+	wlp_tx_hdr->dstaddr = *dst;
+	if (!memcmp(&wlp_tx_hdr->dstaddr, dev_bcast, sizeof(dev_bcast))
+	    && (wlp_tx_hdr_delivery_id_type(wlp_tx_hdr) & WLP_DRP)) {
+		/*Broadcast message directed to DRP host. Send as best effort
+		 * on PCA. */
+		wlp_tx_hdr_set_delivery_id_type(wlp_tx_hdr, i1480u->options.pca_base_priority);
+	}
+
+#if 0
+	dev_info(dev, "TX delivering skb -> USB, %zu bytes\n", skb->len);
+	dump_bytes(dev, skb->data, skb->len > 72 ? 72 : skb->len);
+#endif
+#if 0
+	/* simulates a device lockup after every lockup# packets */
+	if (lockup && ((i1480u->stats.tx_packets + 1) % lockup) == 0) {
+		/* Simulate a dropped transmit interrupt */
+		net_dev->trans_start = jiffies;
+		netif_stop_queue(net_dev);
+		dev_err(dev, "Simulate lockup at %ld\n", jiffies);
+		return result;
+	}
+#endif
+
+	result = usb_submit_urb(wtx->urb, GFP_ATOMIC);		/* Go baby */
+	if (result < 0) {
+		dev_err(dev, "TX: cannot submit URB: %d\n", result);
+		/* We leave the freeing of skb to calling function */
+		wtx->skb = NULL;
+		goto error_tx_urb_submit;
+	}
+	atomic_inc(&i1480u->tx_inflight.count);
+	net_dev->trans_start = jiffies;
+	d_fnend(6, dev, "(skb %p (%u), net_dev %p) = %d\n", skb, skb->len,
+		net_dev, result);
+	return result;
+
+error_tx_urb_submit:
+	i1480u_tx_destroy(i1480u, wtx);
+error_wtx_alloc:
+error_max_inflight:
+out:
+	d_fnend(6, dev, "(skb %p (%u), net_dev %p) = %d\n", skb, skb->len,
+		net_dev, result);
+	return result;
+}
+
+
+/**
+ * Transmit an skb  Called when an skbuf has to be transmitted
+ *
+ * The skb is first passed to WLP substack to ensure this is a valid
+ * frame. If valid the device address of destination will be filled and
+ * the WLP header prepended to the skb. If this step fails we fake sending
+ * the frame, if we return an error the network stack will just keep trying.
+ *
+ * Broadcast frames inside a WSS needs to be treated special as multicast is
+ * not supported. A broadcast frame is sent as unicast to each member of the
+ * WSS - this is done by the WLP substack when it finds a broadcast frame.
+ * So, we test if the WLP substack took over the skb and only transmit it
+ * if it has not (been taken over).
+ *
+ * @net_dev->xmit_lock is held
+ */
+int i1480u_hard_start_xmit(struct sk_buff *skb, struct net_device *net_dev)
+{
+	int result;
+	struct i1480u *i1480u = netdev_priv(net_dev);
+	struct device *dev = &i1480u->usb_iface->dev;
+	struct uwb_dev_addr dst;
+
+	d_fnstart(6, dev, "(skb %p (%u), net_dev %p)\n", skb, skb->len,
+		  net_dev);
+	BUG_ON(i1480u->wlp.rc == NULL);
+	if ((net_dev->flags & IFF_UP) == 0)
+		goto error;
+	result = wlp_prepare_tx_frame(dev, &i1480u->wlp, skb, &dst);
+	if (result < 0) {
+		dev_err(dev, "WLP verification of TX frame failed (%d). "
+			"Dropping packet.\n", result);
+		goto error;
+	} else if (result == 1) {
+		d_printf(6, dev, "WLP will transmit frame. \n");
+		/* trans_start time will be set when WLP actually transmits
+		 * the frame */
+		goto out;
+	}
+	d_printf(6, dev, "Transmitting frame. \n");
+	result = i1480u_xmit_frame(&i1480u->wlp, skb, &dst);
+	if (result < 0) {
+		dev_err(dev, "Frame TX failed (%d).\n", result);
+		goto error;
+	}
+	d_fnend(6, dev, "(skb %p (%u), net_dev %p) = %d\n", skb, skb->len,
+		net_dev, result);
+	return NETDEV_TX_OK;
+error:
+	dev_kfree_skb_any(skb);
+	i1480u->stats.tx_dropped++;
+out:
+	d_fnend(6, dev, "(skb %p (%u), net_dev %p) = %d\n", skb, skb->len,
+		net_dev, result);
+	return NETDEV_TX_OK;
+}
+
+
+/**
+ * Called when a pkt transmission doesn't complete in a reasonable period
+ * Device reset may sleep - do it outside of interrupt context (delayed)
+ */
+void i1480u_tx_timeout(struct net_device *net_dev)
+{
+	struct i1480u *i1480u = netdev_priv(net_dev);
+
+	wlp_reset_all(&i1480u->wlp);
+}
+
+
+void i1480u_tx_release(struct i1480u *i1480u)
+{
+	unsigned long flags;
+	struct i1480u_tx *wtx, *next;
+	int count = 0, empty;
+
+	spin_lock_irqsave(&i1480u->tx_list_lock, flags);
+	list_for_each_entry_safe(wtx, next, &i1480u->tx_list, list_node) {
+		count++;
+		usb_unlink_urb(wtx->urb);
+	}
+	spin_unlock_irqrestore(&i1480u->tx_list_lock, flags);
+	count = count*10; /* i1480ut 200ms per unlinked urb (intervals of 20ms) */
+	/*
+	 * We don't like this sollution too much (dirty as it is), but
+	 * it is cheaper than putting a refcount on each i1480u_tx and
+	 * i1480uting for all of them to go away...
+	 *
+	 * Called when no more packets can be added to tx_list
+	 * so can i1480ut for it to be empty.
+	 */
+	while (1) {
+		spin_lock_irqsave(&i1480u->tx_list_lock, flags);
+		empty = list_empty(&i1480u->tx_list);
+		spin_unlock_irqrestore(&i1480u->tx_list_lock, flags);
+		if (empty)
+			break;
+		count--;
+		BUG_ON(count == 0);
+		msleep(20);
+	}
+}