speedtch.c

优龙2410linux2.6.8内核源代码

/******************************************************************************
 *  speedtouch.c  -  Alcatel SpeedTouch USB xDSL modem driver
 *
 *  Copyright (C) 2001, Alcatel
 *  Copyright (C) 2003, Duncan Sands
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by the Free
 *  Software Foundation; either version 2 of the License, or (at your option)
 *  any later version.
 *
 *  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., 59
 *  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 ******************************************************************************/

/*
 *  Written by Johan Verrept, maintained by Duncan Sands ([e-mail])
 *
 *  1.7+:	- See the check-in logs
 *
 *  1.6:	- No longer opens a connection if the firmware is not loaded
 *  		- Added support for the speedtouch 330
 *  		- Removed the limit on the number of devices
 *  		- Module now autoloads on device plugin
 *  		- Merged relevant parts of sarlib
 *  		- Replaced the kernel thread with a tasklet
 *  		- New packet transmission code
 *  		- Changed proc file contents
 *  		- Fixed all known SMP races
 *  		- Many fixes and cleanups
 *  		- Various fixes by Oliver Neukum ([e-mail])
 *
 *  1.5A:	- Version for inclusion in 2.5 series kernel
 *		- Modifications by Richard Purdie ([e-mail])
 *		- made compatible with kernel 2.5.6 onwards by changing
 *		udsl_usb_send_data_context->urb to a pointer and adding code
 *		to alloc and free it
 *		- remove_wait_queue() added to udsl_atm_processqueue_thread()
 *
 *  1.5:	- fixed memory leak when atmsar_decode_aal5 returned NULL.
 *		(reported by [e-mail])
 *
 *  1.4:	- changed the spin_lock() under interrupt to spin_lock_irqsave()
 *		- unlink all active send urbs of a vcc that is being closed.
 *
 *  1.3.1:	- added the version number
 *
 *  1.3:	- Added multiple send urb support
 *		- fixed memory leak and vcc->tx_inuse starvation bug
 *		  when not enough memory left in vcc.
 *
 *  1.2:	- Fixed race condition in udsl_usb_send_data()
 *  1.1:	- Turned off packet debugging
 *
 */

#include <asm/semaphore.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <asm/uaccess.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/atm.h>
#include <linux/atmdev.h>
#include <linux/crc32.h>
#include <linux/init.h>

/*
#define DEBUG
#define VERBOSE_DEBUG
*/

#if !defined (DEBUG) && defined (CONFIG_USB_DEBUG)
#	define DEBUG
#endif

#include <linux/usb.h>

#ifdef DEBUG
#define DEBUG_ON(x)	BUG_ON(x)
#else
#define DEBUG_ON(x)	do { if (x); } while (0)
#endif

#ifdef VERBOSE_DEBUG
static int udsl_print_packet (const unsigned char *data, int len);
#define PACKETDEBUG(arg...)	udsl_print_packet (arg)
#define vdbg(arg...)		dbg (arg)
#else
#define PACKETDEBUG(arg...)
#define vdbg(arg...)
#endif

#define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <[e-mail]>"
#define DRIVER_VERSION	"1.8"
#define DRIVER_DESC	"Alcatel SpeedTouch USB driver version " DRIVER_VERSION

static const char udsl_driver_name [] = "speedtch";

#define SPEEDTOUCH_VENDORID		0x06b9
#define SPEEDTOUCH_PRODUCTID		0x4061

#define UDSL_MAX_RCV_URBS		4
#define UDSL_MAX_SND_URBS		4
#define UDSL_MAX_RCV_BUFS		8
#define UDSL_MAX_SND_BUFS		8
#define UDSL_MAX_RCV_BUF_SIZE		1024 /* ATM cells */
#define UDSL_MAX_SND_BUF_SIZE		1024 /* ATM cells */
#define UDSL_DEFAULT_RCV_URBS		2
#define UDSL_DEFAULT_SND_URBS		2
#define UDSL_DEFAULT_RCV_BUFS		4
#define UDSL_DEFAULT_SND_BUFS		4
#define UDSL_DEFAULT_RCV_BUF_SIZE	64 /* ATM cells */
#define UDSL_DEFAULT_SND_BUF_SIZE	64 /* ATM cells */

static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
static unsigned int num_rcv_bufs = UDSL_DEFAULT_RCV_BUFS;
static unsigned int num_snd_bufs = UDSL_DEFAULT_SND_BUFS;
static unsigned int rcv_buf_size = UDSL_DEFAULT_RCV_BUF_SIZE;
static unsigned int snd_buf_size = UDSL_DEFAULT_SND_BUF_SIZE;

module_param (num_rcv_urbs, uint, 0444);
MODULE_PARM_DESC (num_rcv_urbs, "Number of urbs used for reception (range: 0-" __MODULE_STRING (UDSL_MAX_RCV_URBS) ", default: " __MODULE_STRING (UDSL_DEFAULT_RCV_URBS) ")");

module_param (num_snd_urbs, uint, 0444);
MODULE_PARM_DESC (num_snd_urbs, "Number of urbs used for transmission (range: 0-" __MODULE_STRING (UDSL_MAX_SND_URBS) ", default: " __MODULE_STRING (UDSL_DEFAULT_SND_URBS) ")");

module_param (num_rcv_bufs, uint, 0444);
MODULE_PARM_DESC (num_rcv_bufs, "Number of buffers used for reception (range: 0-" __MODULE_STRING (UDSL_MAX_RCV_BUFS) ", default: " __MODULE_STRING (UDSL_DEFAULT_RCV_BUFS) ")");

module_param (num_snd_bufs, uint, 0444);
MODULE_PARM_DESC (num_snd_bufs, "Number of buffers used for transmission (range: 0-" __MODULE_STRING (UDSL_MAX_SND_BUFS) ", default: " __MODULE_STRING (UDSL_DEFAULT_SND_BUFS) ")");

module_param (rcv_buf_size, uint, 0444);
MODULE_PARM_DESC (rcv_buf_size, "Size of the buffers used for reception (range: 0-" __MODULE_STRING (UDSL_MAX_RCV_BUF_SIZE) ", default: " __MODULE_STRING (UDSL_DEFAULT_RCV_BUF_SIZE) ")");

module_param (snd_buf_size, uint, 0444);
MODULE_PARM_DESC (snd_buf_size, "Size of the buffers used for transmission (range: 0-" __MODULE_STRING (UDSL_MAX_SND_BUF_SIZE) ", default: " __MODULE_STRING (UDSL_DEFAULT_SND_BUF_SIZE) ")");

#define UDSL_IOCTL_LINE_UP		1
#define UDSL_IOCTL_LINE_DOWN		2

#define UDSL_ENDPOINT_DATA_OUT		0x07
#define UDSL_ENDPOINT_DATA_IN		0x87

#define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
#define UDSL_NUM_CELLS(x)		(((x) + ATM_AAL5_TRAILER + ATM_CELL_PAYLOAD - 1) / ATM_CELL_PAYLOAD)

#define hex2int(c) ( (c >= '0') && (c <= '9') ? (c - '0') : ((c & 0xf) + 9) )

static struct usb_device_id udsl_usb_ids [] = {
	{ USB_DEVICE (SPEEDTOUCH_VENDORID, SPEEDTOUCH_PRODUCTID) },
	{ }
};

MODULE_DEVICE_TABLE (usb, udsl_usb_ids);

/* receive */

struct udsl_receive_buffer {
	struct list_head list;
	unsigned char *base;
	unsigned int filled_cells;
};

struct udsl_receiver {
	struct list_head list;
	struct udsl_receive_buffer *buffer;
	struct urb *urb;
	struct udsl_instance_data *instance;
};

struct udsl_vcc_data {
	/* vpi/vci lookup */
	struct list_head list;
	short vpi;
	int vci;
	struct atm_vcc *vcc;

	/* raw cell reassembly */
	struct sk_buff *sarb;
};

/* send */

struct udsl_send_buffer {
	struct list_head list;
	unsigned char *base;
	unsigned char *free_start;
	unsigned int free_cells;
};

struct udsl_sender {
	struct list_head list;
	struct udsl_send_buffer *buffer;
	struct urb *urb;
	struct udsl_instance_data *instance;
};

struct udsl_control {
	struct atm_skb_data atm_data;
	unsigned int num_cells;
	unsigned int num_entire;
	unsigned int pdu_padding;
	unsigned char cell_header [ATM_CELL_HEADER];
	unsigned char aal5_trailer [ATM_AAL5_TRAILER];
};

#define UDSL_SKB(x)		((struct udsl_control *)(x)->cb)

/* main driver data */

struct udsl_instance_data {
	struct semaphore serialize;

	/* USB device part */
	struct usb_device *usb_dev;
	char description [64];
	int firmware_loaded;

	/* ATM device part */
	struct atm_dev *atm_dev;
	struct list_head vcc_list;

	/* receive */
	struct udsl_receiver receivers [UDSL_MAX_RCV_URBS];
	struct udsl_receive_buffer receive_buffers [UDSL_MAX_RCV_BUFS];

	spinlock_t receive_lock;
	struct list_head spare_receivers;
	struct list_head filled_receive_buffers;

	struct tasklet_struct receive_tasklet;
	struct list_head spare_receive_buffers;

	/* send */
	struct udsl_sender senders [UDSL_MAX_SND_URBS];
	struct udsl_send_buffer send_buffers [UDSL_MAX_SND_BUFS];

	struct sk_buff_head sndqueue;

	spinlock_t send_lock;
	struct list_head spare_senders;
	struct list_head spare_send_buffers;

	struct tasklet_struct send_tasklet;
	struct sk_buff *current_skb;			/* being emptied */
	struct udsl_send_buffer *current_buffer;	/* being filled */
	struct list_head filled_send_buffers;
};

/* ATM */

static void udsl_atm_dev_close (struct atm_dev *dev);
static int udsl_atm_open (struct atm_vcc *vcc);
static void udsl_atm_close (struct atm_vcc *vcc);
static int udsl_atm_ioctl (struct atm_dev *dev, unsigned int cmd, void __user *arg);
static int udsl_atm_send (struct atm_vcc *vcc, struct sk_buff *skb);
static int udsl_atm_proc_read (struct atm_dev *atm_dev, loff_t *pos, char *page);

static struct atmdev_ops udsl_atm_devops = {
	.dev_close =	udsl_atm_dev_close,
	.open =		udsl_atm_open,
	.close =	udsl_atm_close,
	.ioctl =	udsl_atm_ioctl,
	.send =		udsl_atm_send,
	.proc_read =	udsl_atm_proc_read,
	.owner =	THIS_MODULE,
};

/* USB */

static int udsl_usb_probe (struct usb_interface *intf, const struct usb_device_id *id);
static void udsl_usb_disconnect (struct usb_interface *intf);
static int udsl_usb_ioctl (struct usb_interface *intf, unsigned int code, void *user_data);

static struct usb_driver udsl_usb_driver = {
	.owner =	THIS_MODULE,
	.name =		udsl_driver_name,
	.probe =	udsl_usb_probe,
	.disconnect =	udsl_usb_disconnect,
	.ioctl =	udsl_usb_ioctl,
	.id_table =	udsl_usb_ids,
};


/***********
**  misc  **
***********/

static inline void udsl_pop (struct atm_vcc *vcc, struct sk_buff *skb)
{
	if (vcc->pop)
		vcc->pop (vcc, skb);
	else
		dev_kfree_skb (skb);
}


/*************
**  decode  **
*************/

static inline struct udsl_vcc_data *udsl_find_vcc (struct udsl_instance_data *instance, short vpi, int vci)
{
	struct udsl_vcc_data *vcc;

	list_for_each_entry (vcc, &instance->vcc_list, list)
		if ((vcc->vci == vci) && (vcc->vpi == vpi))
			return vcc;
	return NULL;
}

static void udsl_extract_cells (struct udsl_instance_data *instance, unsigned char *source, unsigned int howmany)
{
	struct udsl_vcc_data *cached_vcc = NULL;
	struct atm_vcc *vcc;
	struct sk_buff *sarb;
	struct udsl_vcc_data *vcc_data;
	int cached_vci = 0;
	unsigned int i;
	int pti;
	int vci;
	short cached_vpi = 0;
	short vpi;

	for (i = 0; i < howmany; i++, source += ATM_CELL_SIZE) {
		vpi = ((source [0] & 0x0f) << 4) | (source [1] >> 4);
		vci = ((source [1] & 0x0f) << 12) | (source [2] << 4) | (source [3] >> 4);
		pti = (source [3] & 0x2) != 0;

		vdbg ("udsl_extract_cells: vpi %hd, vci %d, pti %d", vpi, vci, pti);

		if (cached_vcc && (vci == cached_vci) && (vpi == cached_vpi))
			vcc_data = cached_vcc;
		else if ((vcc_data = udsl_find_vcc (instance, vpi, vci))) {
			cached_vcc = vcc_data;
			cached_vpi = vpi;
			cached_vci = vci;
		} else {
			dbg ("udsl_extract_cells: unknown vpi/vci (%hd/%d)!", vpi, vci);
			continue;
		}

		vcc = vcc_data->vcc;
		sarb = vcc_data->sarb;

		if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
			dbg ("udsl_extract_cells: buffer overrun (sarb->len %u, vcc: 0x%p)!", sarb->len, vcc);
			/* discard cells already received */
			skb_trim (sarb, 0);
		}

		memcpy (sarb->tail, source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
		__skb_put (sarb, ATM_CELL_PAYLOAD);

		if (pti) {
			struct sk_buff *skb;
			unsigned int length;
			unsigned int pdu_length;

			length = (source [ATM_CELL_SIZE - 6] << 8) + source [ATM_CELL_SIZE - 5];

			/* guard against overflow */
			if (length > ATM_MAX_AAL5_PDU) {
				dbg ("udsl_extract_cells: bogus length %u (vcc: 0x%p)!", length, vcc);
				atomic_inc (&vcc->stats->rx_err);
				goto out;
			}

			pdu_length = UDSL_NUM_CELLS (length) * ATM_CELL_PAYLOAD;

			if (sarb->len < pdu_length) {
				dbg ("udsl_extract_cells: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!", pdu_length, sarb->len, vcc);
				atomic_inc (&vcc->stats->rx_err);
				goto out;
			}

			if (crc32_be (~0, sarb->tail - pdu_length, pdu_length) != 0xc704dd7b) {
				dbg ("udsl_extract_cells: packet failed crc check (vcc: 0x%p)!", vcc);
				atomic_inc (&vcc->stats->rx_err);
				goto out;
			}

			vdbg ("udsl_extract_cells: got packet (length: %u, pdu_length: %u, vcc: 0x%p)", length, pdu_length, vcc);

			if (!(skb = dev_alloc_skb (length))) {
				dbg ("udsl_extract_cells: no memory for skb (length: %u)!", length);
				atomic_inc (&vcc->stats->rx_drop);
				goto out;
			}

			vdbg ("udsl_extract_cells: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)", skb, skb->truesize);

			if (!atm_charge (vcc, skb->truesize)) {
				dbg ("udsl_extract_cells: failed atm_charge (skb->truesize: %u)!", skb->truesize);
				dev_kfree_skb (skb);
				goto out; /* atm_charge increments rx_drop */
			}

			memcpy (skb->data, sarb->tail - pdu_length, length);
			__skb_put (skb, length);

			vdbg ("udsl_extract_cells: sending skb 0x%p, skb->len %u, skb->truesize %u", skb, skb->len, skb->truesize);

			PACKETDEBUG (skb->data, skb->len);

			vcc->push (vcc, skb);

			atomic_inc (&vcc->stats->rx);
out:
			skb_trim (sarb, 0);
		}
	}
}


/*************
**  encode  **
*************/

static const unsigned char zeros [ATM_CELL_PAYLOAD];

static void udsl_groom_skb (struct atm_vcc *vcc, struct sk_buff *skb)
{
	struct udsl_control *ctrl = UDSL_SKB (skb);
	unsigned int zero_padding;
	u32 crc;

	ctrl->atm_data.vcc = vcc;
	ctrl->cell_header [0] = vcc->vpi >> 4;
	ctrl->cell_header [1] = (vcc->vpi << 4) | (vcc->vci >> 12);
	ctrl->cell_header [2] = vcc->vci >> 4;
	ctrl->cell_header [3] = vcc->vci << 4;
	ctrl->cell_header [4] = 0xec;

	ctrl->num_cells = UDSL_NUM_CELLS (skb->len);
	ctrl->num_entire = skb->len / ATM_CELL_PAYLOAD;

	zero_padding = ctrl->num_cells * ATM_CELL_PAYLOAD - skb->len - ATM_AAL5_TRAILER;

	if (ctrl->num_entire + 1 < ctrl->num_cells)
		ctrl->pdu_padding = zero_padding - (ATM_CELL_PAYLOAD - ATM_AAL5_TRAILER);