path: root/drivers/usb/atm/usbatm.c

// SPDX-License-Identifier: GPL-2.0+
/******************************************************************************
 *  usbatm.c - Generic USB xDSL driver core
 *
 *  Copyright (C) 2001, Alcatel
 *  Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
 *  Copyright (C) 2004, David Woodhouse, Roman Kagan
 ******************************************************************************/

/*
 *  Written by Johan Verrept, Duncan Sands (duncan.sands@free.fr) and David Woodhouse
 *
 *  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 (oliver@neukum.name)
 *
 *  1.5A:	- Version for inclusion in 2.5 series kernel
 *		- Modifications by Richard Purdie (rpurdie@rpsys.net)
 *		- made compatible with kernel 2.5.6 onwards by changing
 *		usbatm_usb_send_data_context->urb to a pointer and adding code
 *		to alloc and free it
 *		- remove_wait_queue() added to usbatm_atm_processqueue_thread()
 *
 *  1.5:	- fixed memory leak when atmsar_decode_aal5 returned NULL.
 *		(reported by stephen.robinson@zen.co.uk)
 *
 *  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 usbatm_usb_send_data()
 *  1.1:	- Turned off packet debugging
 *
 */

#include "usbatm.h"

#include <linux/uaccess.h>
#include <linux/crc32.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/netdevice.h>
#include <linux/proc_fs.h>
#include <linux/sched/signal.h>
#include <linux/signal.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/kthread.h>
#include <linux/ratelimit.h>

#ifdef VERBOSE_DEBUG
static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
#define PACKETDEBUG(arg...)	usbatm_print_packet(arg)
#define vdbg(arg...)		dev_dbg(arg)
#else
#define PACKETDEBUG(arg...)
#define vdbg(arg...)
#endif

#define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
#define DRIVER_DESC	"Generic USB ATM/DSL I/O"

static const char usbatm_driver_name[] = "usbatm";

#define UDSL_MAX_RCV_URBS		16
#define UDSL_MAX_SND_URBS		16
#define UDSL_MAX_BUF_SIZE		65536
#define UDSL_DEFAULT_RCV_URBS		4
#define UDSL_DEFAULT_SND_URBS		4
#define UDSL_DEFAULT_RCV_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
#define UDSL_DEFAULT_SND_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */

#define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)

#define THROTTLE_MSECS			100	/* delay to recover processing after urb submission fails */

static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;

module_param(num_rcv_urbs, uint, S_IRUGO);
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, S_IRUGO);
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(rcv_buf_bytes, uint, S_IRUGO);
MODULE_PARM_DESC(rcv_buf_bytes,
		 "Size of the buffers used for reception, in bytes (range: 1-"
		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
		 __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");

module_param