1// SPDX-License-Identifier: GPL-2.0+
   2/******************************************************************************
   3 *  usbatm.c - Generic USB xDSL driver core
   4 *
   5 *  Copyright (C) 2001, Alcatel
   6 *  Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
   7 *  Copyright (C) 2004, David Woodhouse, Roman Kagan
   8 ******************************************************************************/
   9
  10/*
  11 *  Written by Johan Verrept, Duncan Sands (duncan.sands@free.fr) and David Woodhouse
  12 *
  13 *  1.7+:	- See the check-in logs
  14 *
  15 *  1.6:	- No longer opens a connection if the firmware is not loaded
  16 *  		- Added support for the speedtouch 330
  17 *  		- Removed the limit on the number of devices
  18 *  		- Module now autoloads on device plugin
  19 *  		- Merged relevant parts of sarlib
  20 *  		- Replaced the kernel thread with a tasklet
  21 *  		- New packet transmission code
  22 *  		- Changed proc file contents
  23 *  		- Fixed all known SMP races
  24 *  		- Many fixes and cleanups
  25 *  		- Various fixes by Oliver Neukum (oliver@neukum.name)
  26 *
  27 *  1.5A:	- Version for inclusion in 2.5 series kernel
  28 *		- Modifications by Richard Purdie (rpurdie@rpsys.net)
  29 *		- made compatible with kernel 2.5.6 onwards by changing
  30 *		usbatm_usb_send_data_context->urb to a pointer and adding code
  31 *		to alloc and free it
  32 *		- remove_wait_queue() added to usbatm_atm_processqueue_thread()
  33 *
  34 *  1.5:	- fixed memory leak when atmsar_decode_aal5 returned NULL.
  35 *		(reported by stephen.robinson@zen.co.uk)
  36 *
  37 *  1.4:	- changed the spin_lock() under interrupt to spin_lock_irqsave()
  38 *		- unlink all active send urbs of a vcc that is being closed.
  39 *
  40 *  1.3.1:	- added the version number
  41 *
  42 *  1.3:	- Added multiple send urb support
  43 *		- fixed memory leak and vcc->tx_inuse starvation bug
  44 *		  when not enough memory left in vcc.
  45 *
  46 *  1.2:	- Fixed race condition in usbatm_usb_send_data()
  47 *  1.1:	- Turned off packet debugging
  48 *
  49 */
  50
  51#include "usbatm.h"
  52
  53#include <linux/uaccess.h>
  54#include <linux/crc32.h>
  55#include <linux/errno.h>
  56#include <linux/init.h>
  57#include <linux/interrupt.h>
  58#include <linux/kernel.h>
  59#include <linux/module.h>
  60#include <linux/moduleparam.h>
  61#include <linux/netdevice.h>
  62#include <linux/proc_fs.h>
  63#include <linux/sched/signal.h>
  64#include <linux/signal.h>
  65#include <linux/slab.h>
  66#include <linux/stat.h>
  67#include <linux/timer.h>
  68#include <linux/wait.h>
  69#include <linux/kthread.h>
  70#include <linux/ratelimit.h>
  71
  72#ifdef VERBOSE_DEBUG
  73static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
  74#define PACKETDEBUG(arg...)	usbatm_print_packet(arg)
  75#define vdbg(arg...)		dev_dbg(arg)
  76#else
  77#define PACKETDEBUG(arg...)
  78#define vdbg(arg...)
  79#endif
  80
  81#define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
  82#define DRIVER_DESC	"Generic USB ATM/DSL I/O"
  83
  84static const char usbatm_driver_name[] = "usbatm";
  85
  86#define UDSL_MAX_RCV_URBS		16
  87#define UDSL_MAX_SND_URBS		16
  88#define UDSL_MAX_BUF_SIZE		65536
  89#define UDSL_DEFAULT_RCV_URBS		4
  90#define UDSL_DEFAULT_SND_URBS		4
  91#define UDSL_DEFAULT_RCV_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
  92#define UDSL_DEFAULT_SND_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
  93
  94#define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
  95
  96#define THROTTLE_MSECS			100	/* delay to recover processing after urb submission fails */
  97
  98static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
  99static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
 100static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
 101static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
 102
 103module_param(num_rcv_urbs, uint, S_IRUGO);
 104MODULE_PARM_DESC(num_rcv_urbs,
 105		 "Number of urbs used for reception (range: 0-"
 106		 __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
 107		 __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
 108
 109module_param(num_snd_urbs, uint, S_IRUGO);
 110MODULE_PARM_DESC(num_snd_urbs,
 111		 "Number of urbs used for transmission (range: 0-"
 112		 __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
 113		 __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
 114
 115module_param(rcv_buf_bytes, uint, S_IRUGO);
 116MODULE_PARM_DESC(rcv_buf_bytes,
 117		 "Size of the buffers used for reception, in bytes (range: 1-"
 118		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
 119		 __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
 120
 121module_param(snd_buf_bytes, uint, S_IRUGO);
 122MODULE_PARM_DESC(snd_buf_bytes,
 123		 "Size of the buffers used for transmission, in bytes (range: 1-"
 124		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
 125		 __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
 126
 127
 128/* receive */
 129
 130struct usbatm_vcc_data {
 131	/* vpi/vci lookup */
 132	struct list_head list;
 133	short vpi;
 134	int vci;
 135	struct atm_vcc *vcc;
 136
 137	/* raw cell reassembly */
 138	struct sk_buff *sarb;
 139};
 140
 141
 142/* send */
 143
 144struct usbatm_control {
 145	struct atm_skb_data atm;
 146	u32 len;
 147	u32 crc;
 148};
 149
 150#define UDSL_SKB(x)		((struct usbatm_control *)(x)->cb)
 151
 152
 153/* ATM */
 154
 155static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
 156static int usbatm_atm_open(struct atm_vcc *vcc);
 157static void usbatm_atm_close(struct atm_vcc *vcc);
 158static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user *arg);
 159static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
 160static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page);
 161
 162static const struct atmdev_ops usbatm_atm_devops = {
 163	.dev_close	= usbatm_atm_dev_close,
 164	.open		= usbatm_atm_open,
 165	.close		= usbatm_atm_close,
 166	.ioctl		= usbatm_atm_ioctl,
 167	.send		= usbatm_atm_send,
 168	.proc_read	= usbatm_atm_proc_read,
 169	.owner		= THIS_MODULE,
 170};
 171
 172
 173/***********
 174**  misc  **
 175***********/
 176
 177static inline unsigned int usbatm_pdu_length(unsigned int length)
 178{
 179	length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
 180	return length - length % ATM_CELL_PAYLOAD;
 181}
 182
 183static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 184{
 185	if (vcc->pop)
 186		vcc->pop(vcc, skb);
 187	else
 188		dev_kfree_skb_any(skb);
 189}
 190
 191
 192/***********
 193**  urbs  **
 194************/
 195
 196static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
 197{
 198	struct urb *urb;
 199
 200	spin_lock_irq(&channel->lock);
 201	if (list_empty(&channel->list)) {
 202		spin_unlock_irq(&channel->lock);
 203		return NULL;
 204	}
 205
 206	urb = list_entry(channel->list.next, struct urb, urb_list);
 207	list_del(&urb->urb_list);
 208	spin_unlock_irq(&channel->lock);
 209
 210	return urb;
 211}
 212
 213static int usbatm_submit_urb(struct urb *urb)
 214{
 215	struct usbatm_channel *channel = urb->context;
 216	int ret;
 217
 218	/* vdbg("%s: submitting urb 0x%p, size %u",
 219	     __func__, urb, urb->transfer_buffer_length); */
 220
 221	ret = usb_submit_urb(urb, GFP_ATOMIC);
 222	if (ret) {
 223		if (printk_ratelimit())
 224			atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
 225				__func__, urb, ret);
 226
 227		/* consider all errors transient and return the buffer back to the queue */
 228		urb->status = -EAGAIN;
 229		spin_lock_irq(&channel->lock);
 230
 231		/* must add to the front when sending; doesn't matter when receiving */
 232		list_add(&urb->urb_list, &channel->list);
 233
 234		spin_unlock_irq(&channel->lock);
 235
 236		/* make sure the channel doesn't stall */
 237		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
 238	}
 239
 240	return ret;
 241}
 242
 243static void usbatm_complete(struct urb *urb)
 244{
 245	struct usbatm_channel *channel = urb->context;
 246	unsigned long flags;
 247	int status = urb->status;
 248
 249	/* vdbg("%s: urb 0x%p, status %d, actual_length %d",
 250	     __func__, urb, status, urb->actual_length); */
 251
 252	/* Can be invoked from task context, protect against interrupts */
 253	spin_lock_irqsave(&channel->lock, flags);
 254
 255	/* must add to the back when receiving; doesn't matter when sending */
 256	list_add_tail(&urb->urb_list, &channel->list);
 257
 258	spin_unlock_irqrestore(&channel->lock, flags);
 259
 260	if (unlikely(status) &&
 261			(!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
 262			 status != -EILSEQ)) {
 263		if (status == -ESHUTDOWN)
 264			return;
 265
 266		if (printk_ratelimit())
 267			atm_warn(channel->usbatm, "%s: urb 0x%p failed (%d)!\n",
 268				__func__, urb, status);
 269		/* throttle processing in case of an error */
 270		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
 271	} else
 272		tasklet_schedule(&channel->tasklet);
 273}
 274
 275
 276/*************
 277**  decode  **
 278*************/
 279
 280static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
 281						  short vpi, int vci)
 282{
 283	struct usbatm_vcc_data *vcc_data;
 284
 285	list_for_each_entry(vcc_data, &instance->vcc_list, list)
 286		if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
 287			return vcc_data;
 288	return NULL;
 289}
 290
 291static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
 292{
 293	struct atm_vcc *vcc;
 294	struct sk_buff *sarb;
 295	short vpi = ((source[0] & 0x0f) << 4)  | (source[1] >> 4);
 296	int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
 297	u8 pti = ((source[3] & 0xe) >> 1);
 298
 299	if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
 300		instance->cached_vpi = vpi;
 301		instance->cached_vci = vci;
 302
 303		instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
 304
 305		if (!instance->cached_vcc)
 306			atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
 307	}
 308
 309	if (!instance->cached_vcc)
 310		return;
 311
 312	vcc = instance->cached_vcc->vcc;
 313
 314	/* OAM F5 end-to-end */
 315	if (pti == ATM_PTI_E2EF5) {
 316		if (printk_ratelimit())
 317			atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
 318				__func__, vpi, vci);
 319		atomic_inc(&vcc->stats->rx_err);
 320		return;
 321	}
 322
 323	sarb = instance->cached_vcc->sarb;
 324
 325	if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
 326		atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
 327				__func__, sarb->len, vcc);
 328		/* discard cells already received */
 329		skb_trim(sarb, 0);
 330	}
 331
 332	memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
 333	__skb_put(sarb, ATM_CELL_PAYLOAD);
 334
 335	if (pti & 1) {
 336		struct sk_buff *skb;
 337		unsigned int length;
 338		unsigned int pdu_length;
 339
 340		length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
 341
 342		/* guard against overflow */
 343		if (length > ATM_MAX_AAL5_PDU) {
 344			atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
 345				  __func__, length, vcc);
 346			atomic_inc(&vcc->stats->rx_err);
 347			goto out;
 348		}
 349
 350		pdu_length = usbatm_pdu_length(length);
 351
 352		if (sarb->len < pdu_length) {
 353			atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
 354				  __func__, pdu_length, sarb->len, vcc);
 355			atomic_inc(&vcc->stats->rx_err);
 356			goto out;
 357		}
 358
 359		if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
 360			atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
 361				  __func__, vcc);
 362			atomic_inc(&vcc->stats->rx_err);
 363			goto out;
 364		}
 365
 366		vdbg(&instance->usb_intf->dev,
 367		     "%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)",
 368		     __func__, length, pdu_length, vcc);
 369
 370		skb = dev_alloc_skb(length);
 371		if (!skb) {
 372			if (printk_ratelimit())
 373				atm_err(instance, "%s: no memory for skb (length: %u)!\n",
 374					__func__, length);
 375			atomic_inc(&vcc->stats->rx_drop);
 376			goto out;
 377		}
 378
 379		vdbg(&instance->usb_intf->dev,
 380		     "%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)",
 381		     __func__, skb, skb->truesize);
 382
 383		if (!atm_charge(vcc, skb->truesize)) {
 384			atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
 385				  __func__, skb->truesize);
 386			dev_kfree_skb_any(skb);
 387			goto out;	/* atm_charge increments rx_drop */
 388		}
 389
 390		skb_copy_to_linear_data(skb,
 391					skb_tail_pointer(sarb) - pdu_length,
 392					length);
 393		__skb_put(skb, length);
 394
 395		vdbg(&instance->usb_intf->dev,
 396		     "%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
 397		     __func__, skb, skb->len, skb->truesize);
 398
 399		PACKETDEBUG(instance, skb->data, skb->len);
 400
 401		vcc->push(vcc, skb);
 402
 403		atomic_inc(&vcc->stats->rx);
 404	out:
 405		skb_trim(sarb, 0);
 406	}
 407}
 408
 409static void usbatm_extract_cells(struct usbatm_data *instance,
 410		unsigned char *source, unsigned int avail_data)
 411{
 412	unsigned int stride = instance->rx_channel.stride;
 413	unsigned int buf_usage = instance->buf_usage;
 414
 415	/* extract cells from incoming data, taking into account that
 416	 * the length of avail data may not be a multiple of stride */
 417
 418	if (buf_usage > 0) {
 419		/* we have a partially received atm cell */
 420		unsigned char *cell_buf = instance->cell_buf;
 421		unsigned int space_left = stride - buf_usage;
 422
 423		if (avail_data >= space_left) {
 424			/* add new data and process cell */
 425			memcpy(cell_buf + buf_usage, source, space_left);
 426			source += space_left;
 427			avail_data -= space_left;
 428			usbatm_extract_one_cell(instance, cell_buf);
 429			instance->buf_usage = 0;
 430		} else {
 431			/* not enough data to fill the cell */
 432			memcpy(cell_buf + buf_usage, source, avail_data);
 433			instance->buf_usage = buf_usage + avail_data;
 434			return;
 435		}
 436	}
 437
 438	for (; avail_data >= stride; avail_data -= stride, source += stride)
 439		usbatm_extract_one_cell(instance, source);
 440
 441	if (avail_data > 0) {
 442		/* length was not a multiple of stride -
 443		 * save remaining data for next call */
 444		memcpy(instance->cell_buf, source, avail_data);
 445		instance->buf_usage = avail_data;
 446	}
 447}
 448
 449
 450/*************
 451**  encode  **
 452*************/
 453
 454static unsigned int usbatm_write_cells(struct usbatm_data *instance,
 455				       struct sk_buff *skb,
 456				       u8 *target, unsigned int avail_space)
 457{
 458	struct usbatm_control *ctrl = UDSL_SKB(skb);
 459	struct atm_vcc *vcc = ctrl->atm.vcc;
 460	unsigned int bytes_written;
 461	unsigned int stride = instance->tx_channel.stride;
 462
 463	for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
 464	     bytes_written += stride, target += stride) {
 465		unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
 466		unsigned int left = ATM_CELL_PAYLOAD - data_len;
 467		u8 *ptr = target;
 468
 469		ptr[0] = vcc->vpi >> 4;
 470		ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
 471		ptr[2] = vcc->vci >> 4;
 472		ptr[3] = vcc->vci << 4;
 473		ptr[4] = 0xec;
 474		ptr += ATM_CELL_HEADER;
 475
 476		skb_copy_from_linear_data(skb, ptr, data_len);
 477		ptr += data_len;
 478		__skb_pull(skb, data_len);
 479
 480		if (!left)
 481			continue;
 482
 483		memset(ptr, 0, left);
 484
 485		if (left >= ATM_AAL5_TRAILER) {	/* trailer will go in this cell */
 486			u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
 487			/* trailer[0] = 0;		UU = 0 */
 488			/* trailer[1] = 0;		CPI = 0 */
 489			trailer[2] = ctrl->len >> 8;
 490			trailer[3] = ctrl->len;
 491
 492			ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
 493
 494			trailer[4] = ctrl->crc >> 24;
 495			trailer[5] = ctrl->crc >> 16;
 496			trailer[6] = ctrl->crc >> 8;
 497			trailer[7] = ctrl->crc;
 498
 499			target[3] |= 0x2;	/* adjust PTI */
 500
 501			ctrl->len = 0;		/* tag this skb finished */
 502		} else
 503			ctrl->crc = crc32_be(ctrl->crc, ptr, left);
 504	}
 505
 506	return bytes_written;
 507}
 508
 509
 510/**************
 511**  receive  **
 512**************/
 513
 514static void usbatm_rx_process(struct tasklet_struct *t)
 515{
 516	struct usbatm_data *instance = from_tasklet(instance, t,
 517						    rx_channel.tasklet);
 518	struct urb *urb;
 519
 520	while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
 521		vdbg(&instance->usb_intf->dev,
 522		     "%s: processing urb 0x%p", __func__, urb);
 523
 524		if (usb_pipeisoc(urb->pipe)) {
 525			unsigned char *merge_start = NULL;
 526			unsigned int merge_length = 0;
 527			const unsigned int packet_size = instance->rx_channel.packet_size;
 528			int i;
 529
 530			for (i = 0; i < urb->number_of_packets; i++) {
 531				if (!urb->iso_frame_desc[i].status) {
 532					unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
 533
 534					if (!merge_length)
 535						merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 536					merge_length += actual_length;
 537					if (merge_length && (actual_length < packet_size)) {
 538						usbatm_extract_cells(instance, merge_start, merge_length);
 539						merge_length = 0;
 540					}
 541				} else {
 542					atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
 543					if (merge_length)
 544						usbatm_extract_cells(instance, merge_start, merge_length);
 545					merge_length = 0;
 546					instance->buf_usage = 0;
 547				}
 548			}
 549
 550			if (merge_length)
 551				usbatm_extract_cells(instance, merge_start, merge_length);
 552		} else
 553			if (!urb->status)
 554				usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
 555			else
 556				instance->buf_usage = 0;
 557
 558		if (usbatm_submit_urb(urb))
 559			return;
 560	}
 561}
 562
 563
 564/***********
 565**  send  **
 566***********/
 567
 568static void usbatm_tx_process(struct tasklet_struct *t)
 569{
 570	struct usbatm_data *instance = from_tasklet(instance, t,
 571						    tx_channel.tasklet);
 572	struct sk_buff *skb = instance->current_skb;
 573	struct urb *urb = NULL;
 574	const unsigned int buf_size = instance->tx_channel.buf_size;
 575	unsigned int bytes_written = 0;
 576	u8 *buffer = NULL;
 577
 578	if (!skb)
 579		skb = skb_dequeue(&instance->sndqueue);
 580
 581	while (skb) {
 582		if (!urb) {
 583			urb = usbatm_pop_urb(&instance->tx_channel);
 584			if (!urb)
 585				break;		/* no more senders */
 586			buffer = urb->transfer_buffer;
 587			bytes_written = (urb->status == -EAGAIN) ?
 588				urb->transfer_buffer_length : 0;
 589		}
 590
 591		bytes_written += usbatm_write_cells(instance, skb,
 592						  buffer + bytes_written,
 593						  buf_size - bytes_written);
 594
 595		vdbg(&instance->usb_intf->dev,
 596		     "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
 597		     __func__, bytes_written, skb, urb);
 598
 599		if (!UDSL_SKB(skb)->len) {
 600			struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
 601
 602			usbatm_pop(vcc, skb);
 603			atomic_inc(&vcc->stats->tx);
 604
 605			skb = skb_dequeue(&instance->sndqueue);
 606		}
 607
 608		if (bytes_written == buf_size || (!skb && bytes_written)) {
 609			urb->transfer_buffer_length = bytes_written;
 610
 611			if (usbatm_submit_urb(urb))
 612				break;
 613			urb = NULL;
 614		}
 615	}
 616
 617	instance->current_skb = skb;
 618}
 619
 620static void usbatm_cancel_send(struct usbatm_data *instance,
 621			       struct atm_vcc *vcc)
 622{
 623	struct sk_buff *skb, *n;
 624
 625	spin_lock_irq(&instance->sndqueue.lock);
 626	skb_queue_walk_safe(&instance->sndqueue, skb, n) {
 627		if (UDSL_SKB(skb)->atm.vcc == vcc) {
 628			atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
 629			__skb_unlink(skb, &instance->sndqueue);
 630			usbatm_pop(vcc, skb);
 631		}
 632	}
 633	spin_unlock_irq(&instance->sndqueue.lock);
 634
 635	tasklet_disable(&instance->tx_channel.tasklet);
 636	if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
 637		atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
 638		instance->current_skb = NULL;
 639		usbatm_pop(vcc, skb);
 640	}
 641	tasklet_enable(&instance->tx_channel.tasklet);
 642}
 643
 644static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
 645{
 646	struct usbatm_data *instance = vcc->dev->dev_data;
 647	struct usbatm_control *ctrl = UDSL_SKB(skb);
 648	int err;
 649
 650	/* racy disconnection check - fine */
 651	if (!instance || instance->disconnected) {
 652#ifdef VERBOSE_DEBUG
 653		printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
 654#endif
 655		err = -ENODEV;
 656		goto fail;
 657	}
 658
 659	if (vcc->qos.aal != ATM_AAL5) {
 660		atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
 661		err = -EINVAL;
 662		goto fail;
 663	}
 664
 665	if (skb->len > ATM_MAX_AAL5_PDU) {
 666		atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
 667				__func__, skb->len, ATM_MAX_AAL5_PDU);
 668		err = -EINVAL;
 669		goto fail;
 670	}
 671
 672	PACKETDEBUG(instance, skb->data, skb->len);
 673
 674	/* initialize the control block */
 675	ctrl->atm.vcc = vcc;
 676	ctrl->len = skb->len;
 677	ctrl->crc = crc32_be(~0, skb->data, skb->len);
 678
 679	skb_queue_tail(&instance->sndqueue, skb);
 680	tasklet_schedule(&instance->tx_channel.tasklet);
 681
 682	return 0;
 683
 684 fail:
 685	usbatm_pop(vcc, skb);
 686	return err;
 687}
 688
 689
 690/********************
 691**  bean counting  **
 692********************/
 693
 694static void usbatm_destroy_instance(struct kref *kref)
 695{
 696	struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
 697
 698	tasklet_kill(&instance->rx_channel.tasklet);
 699	tasklet_kill(&instance->tx_channel.tasklet);
 700	usb_put_dev(instance->usb_dev);
 701	kfree(instance);
 702}
 703
 704static void usbatm_get_instance(struct usbatm_data *instance)
 705{
 706	kref_get(&instance->refcount);
 707}
 708
 709static void usbatm_put_instance(struct usbatm_data *instance)
 710{
 711	kref_put(&instance->refcount, usbatm_destroy_instance);
 712}
 713
 714
 715/**********
 716**  ATM  **
 717**********/
 718
 719static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
 720{
 721	struct usbatm_data *instance = atm_dev->dev_data;
 722
 723	if (!instance)
 724		return;
 725
 726	atm_dev->dev_data = NULL; /* catch bugs */
 727	usbatm_put_instance(instance);	/* taken in usbatm_atm_init */
 728}
 729
 730static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
 731{
 732	struct usbatm_data *instance = atm_dev->dev_data;
 733	int left = *pos;
 734
 735	if (!instance)
 736		return -ENODEV;
 737
 738	if (!left--)
 739		return sprintf(page, "%s\n", instance->description);
 740
 741	if (!left--)
 742		return sprintf(page, "MAC: %pM\n", atm_dev->esi);
 743
 744	if (!left--)
 745		return sprintf(page,
 746			       "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
 747			       atomic_read(&atm_dev->stats.aal5.tx),
 748			       atomic_read(&atm_dev->stats.aal5.tx_err),
 749			       atomic_read(&atm_dev->stats.aal5.rx),
 750			       atomic_read(&atm_dev->stats.aal5.rx_err),
 751			       atomic_read(&atm_dev->stats.aal5.rx_drop));
 752
 753	if (!left--) {
 754		if (instance->disconnected)
 755			return sprintf(page, "Disconnected\n");
 756		else
 757			switch (atm_dev->signal) {
 758			case ATM_PHY_SIG_FOUND:
 759				return sprintf(page, "Line up\n");
 760			case ATM_PHY_SIG_LOST:
 761				return sprintf(page, "Line down\n");
 762			default:
 763				return sprintf(page, "Line state unknown\n");
 764			}
 765	}
 766
 767	return 0;
 768}
 769
 770static int usbatm_atm_open(struct atm_vcc *vcc)
 771{
 772	struct usbatm_data *instance = vcc->dev->dev_data;
 773	struct usbatm_vcc_data *new = NULL;
 774	int ret;
 775	int vci = vcc->vci;
 776	short vpi = vcc->vpi;
 777
 778	if (!instance)
 779		return -ENODEV;
 780
 781	/* only support AAL5 */
 782	if ((vcc->qos.aal != ATM_AAL5)) {
 783		atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
 784		return -EINVAL;
 785	}
 786
 787	/* sanity checks */
 788	if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
 789		atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
 790		return -EINVAL;
 791	}
 792
 793	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_close, usbatm_usb_disconnect */
 794
 795	if (instance->disconnected) {
 796		atm_dbg(instance, "%s: disconnected!\n", __func__);
 797		ret = -ENODEV;
 798		goto fail;
 799	}
 800
 801	if (usbatm_find_vcc(instance, vpi, vci)) {
 802		atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
 803		ret = -EADDRINUSE;
 804		goto fail;
 805	}
 806
 807	new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL);
 808	if (!new) {
 809		ret = -ENOMEM;
 810		goto fail;
 811	}
 812
 813	new->vcc = vcc;
 814	new->vpi = vpi;
 815	new->vci = vci;
 816
 817	new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
 818	if (!new->sarb) {
 819		atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
 820		ret = -ENOMEM;
 821		goto fail;
 822	}
 823
 824	vcc->dev_data = new;
 825
 826	tasklet_disable(&instance->rx_channel.tasklet);
 827	instance->cached_vcc = new;
 828	instance->cached_vpi = vpi;
 829	instance->cached_vci = vci;
 830	list_add(&new->list, &instance->vcc_list);
 831	tasklet_enable(&instance->rx_channel.tasklet);
 832
 833	set_bit(ATM_VF_ADDR, &vcc->flags);
 834	set_bit(ATM_VF_PARTIAL, &vcc->flags);
 835	set_bit(ATM_VF_READY, &vcc->flags);
 836
 837	mutex_unlock(&instance->serialize);
 838
 839	atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
 840
 841	return 0;
 842
 843fail:
 844	kfree(new);
 845	mutex_unlock(&instance->serialize);
 846	return ret;
 847}
 848
 849static void usbatm_atm_close(struct atm_vcc *vcc)
 850{
 851	struct usbatm_data *instance = vcc->dev->dev_data;
 852	struct usbatm_vcc_data *vcc_data = vcc->dev_data;
 853
 854	if (!instance || !vcc_data)
 855		return;
 856
 857	usbatm_cancel_send(instance, vcc);
 858
 859	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_open, usbatm_usb_disconnect */
 860
 861	tasklet_disable(&instance->rx_channel.tasklet);
 862	if (instance->cached_vcc == vcc_data) {
 863		instance->cached_vcc = NULL;
 864		instance->cached_vpi = ATM_VPI_UNSPEC;
 865		instance->cached_vci = ATM_VCI_UNSPEC;
 866	}
 867	list_del(&vcc_data->list);
 868	tasklet_enable(&instance->rx_channel.tasklet);
 869
 870	kfree_skb(vcc_data->sarb);
 871	vcc_data->sarb = NULL;
 872
 873	kfree(vcc_data);
 874	vcc->dev_data = NULL;
 875
 876	vcc->vpi = ATM_VPI_UNSPEC;
 877	vcc->vci = ATM_VCI_UNSPEC;
 878	clear_bit(ATM_VF_READY, &vcc->flags);
 879	clear_bit(ATM_VF_PARTIAL, &vcc->flags);
 880	clear_bit(ATM_VF_ADDR, &vcc->flags);
 881
 882	mutex_unlock(&instance->serialize);
 883}
 884
 885static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
 886			  void __user *arg)
 887{
 888	struct usbatm_data *instance = atm_dev->dev_data;
 889
 890	if (!instance || instance->disconnected)
 891		return -ENODEV;
 892
 893	switch (cmd) {
 894	case ATM_QUERYLOOP:
 895		return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
 896	default:
 897		return -ENOIOCTLCMD;
 898	}
 899}
 900
 901static int usbatm_atm_init(struct usbatm_data *instance)
 902{
 903	struct atm_dev *atm_dev;
 904	int ret, i;
 905
 906	/* ATM init.  The ATM initialization scheme suffers from an intrinsic race
 907	 * condition: callbacks we register can be executed at once, before we have
 908	 * initialized the struct atm_dev.  To protect against this, all callbacks
 909	 * abort if atm_dev->dev_data is NULL. */
 910	atm_dev = atm_dev_register(instance->driver_name,
 911				   &instance->usb_intf->dev, &usbatm_atm_devops,
 912				   -1, NULL);
 913	if (!atm_dev) {
 914		usb_err(instance, "%s: failed to register ATM device!\n", __func__);
 915		return -1;
 916	}
 917
 918	instance->atm_dev = atm_dev;
 919
 920	atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
 921	atm_dev->ci_range.vci_bits = ATM_CI_MAX;
 922	atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
 923
 924	/* temp init ATM device, set to 128kbit */
 925	atm_dev->link_rate = 128 * 1000 / 424;
 926
 927	if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
 928		atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
 929		goto fail;
 930	}
 931
 932	usbatm_get_instance(instance);	/* dropped in usbatm_atm_dev_close */
 933
 934	/* ready for ATM callbacks */
 935	mb();
 936	atm_dev->dev_data = instance;
 937
 938	/* submit all rx URBs */
 939	for (i = 0; i < num_rcv_urbs; i++)
 940		usbatm_submit_urb(instance->urbs[i]);
 941
 942	return 0;
 943
 944 fail:
 945	instance->atm_dev = NULL;
 946	atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
 947	return ret;
 948}
 949
 950
 951/**********
 952**  USB  **
 953**********/
 954
 955static int usbatm_do_heavy_init(void *arg)
 956{
 957	struct usbatm_data *instance = arg;
 958	int ret;
 959
 960	allow_signal(SIGTERM);
 961	complete(&instance->thread_started);
 962
 963	ret = instance->driver->heavy_init(instance, instance->usb_intf);
 964
 965	if (!ret)
 966		ret = usbatm_atm_init(instance);
 967
 968	mutex_lock(&instance->serialize);
 969	instance->thread = NULL;
 970	mutex_unlock(&instance->serialize);
 971
 972	kthread_complete_and_exit(&instance->thread_exited, ret);
 973}
 974
 975static int usbatm_heavy_init(struct usbatm_data *instance)
 976{
 977	struct task_struct *t;
 978
 979	t = kthread_create(usbatm_do_heavy_init, instance, "%s",
 980			instance->driver->driver_name);
 981	if (IS_ERR(t)) {
 982		usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
 983				__func__, PTR_ERR(t));
 984		return PTR_ERR(t);
 985	}
 986
 987	instance->thread = t;
 988	wake_up_process(t);
 989	wait_for_completion(&instance->thread_started);
 990
 991	return 0;
 992}
 993
 994static void usbatm_tasklet_schedule(struct timer_list *t)
 995{
 996	struct usbatm_channel *channel = from_timer(channel, t, delay);
 997
 998	tasklet_schedule(&channel->tasklet);
 999}
1000
1001static void usbatm_init_channel(struct usbatm_channel *channel)
1002{
1003	spin_lock_init(&channel->lock);
1004	INIT_LIST_HEAD(&channel->list);
1005	timer_setup(&channel->delay, usbatm_tasklet_schedule, 0);
1006}
1007
1008int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1009		     struct usbatm_driver *driver)
1010{
1011	struct device *dev = &intf->dev;
1012	struct usb_device *usb_dev = interface_to_usbdev(intf);
1013	struct usbatm_data *instance;
1014	char *buf;
1015	int error = -ENOMEM;
1016	int i, length;
1017	unsigned int maxpacket, num_packets;
1018	size_t size;
1019
1020	/* instance init */
1021	size = struct_size(instance, urbs,
1022			   size_add(num_rcv_urbs, num_snd_urbs));
1023	instance = kzalloc(size, GFP_KERNEL);
1024	if (!instance)
1025		return -ENOMEM;
1026
1027	/* public fields */
1028
1029	instance->driver = driver;
1030	strscpy(instance->driver_name, driver->driver_name,
1031		sizeof(instance->driver_name));
1032
1033	instance->usb_dev = usb_dev;
1034	instance->usb_intf = intf;
1035
1036	buf = instance->description;
1037	length = sizeof(instance->description);
1038
1039	if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1040		goto bind;
1041
1042	buf += i;
1043	length -= i;
1044
1045	i = scnprintf(buf, length, " (");
1046	buf += i;
1047	length -= i;
1048
1049	if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1050		goto bind;
1051
1052	buf += i;
1053	length -= i;
1054
1055	snprintf(buf, length, ")");
1056
1057 bind:
1058	if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1059			dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1060			goto fail_free;
1061	}
1062
1063	/* private fields */
1064
1065	kref_init(&instance->refcount);		/* dropped in usbatm_usb_disconnect */
1066	mutex_init(&instance->serialize);
1067
1068	instance->thread = NULL;
1069	init_completion(&instance->thread_started);
1070	init_completion(&instance->thread_exited);
1071
1072	INIT_LIST_HEAD(&instance->vcc_list);
1073	skb_queue_head_init(&instance->sndqueue);
1074
1075	usbatm_init_channel(&instance->rx_channel);
1076	usbatm_init_channel(&instance->tx_channel);
1077	tasklet_setup(&instance->rx_channel.tasklet, usbatm_rx_process);
1078	tasklet_setup(&instance->tx_channel.tasklet, usbatm_tx_process);
1079	instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1080	instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1081	instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1082
1083	if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1084		instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1085	else
1086		instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1087
1088	instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1089
1090	/* tx buffer size must be a positive multiple of the stride */
1091	instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1092			snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1093
1094	/* rx buffer size must be a positive multiple of the endpoint maxpacket */
1095	maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint);
1096
1097	if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1098		dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1099				usb_pipeendpoint(instance->rx_channel.endpoint));
1100		error = -EINVAL;
1101		goto fail_unbind;
1102	}
1103
1104	num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1105
1106	if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1107		num_packets--;
1108
1109	instance->rx_channel.buf_size = num_packets * maxpacket;
1110	instance->rx_channel.packet_size = maxpacket;
1111
1112	for (i = 0; i < 2; i++) {
1113		struct usbatm_channel *channel = i ?
1114			&instance->tx_channel : &instance->rx_channel;
1115
1116		dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1117			__func__, channel->buf_size, i ? "tx" : "rx", channel);
1118	}
1119
1120	/* initialize urbs */
1121
1122	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1123		u8 *buffer;
1124		struct usbatm_channel *channel = i < num_rcv_urbs ?
1125			&instance->rx_channel : &instance->tx_channel;
1126		struct urb *urb;
1127		unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1128
1129		urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1130		if (!urb) {
1131			error = -ENOMEM;
1132			goto fail_unbind;
1133		}
1134
1135		instance->urbs[i] = urb;
1136
1137		/* zero the tx padding to avoid leaking information */
1138		buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1139		if (!buffer) {
1140			error = -ENOMEM;
1141			goto fail_unbind;
1142		}
1143
1144		usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1145				  buffer, channel->buf_size, usbatm_complete, channel);
1146		if (iso_packets) {
1147			int j;
1148			urb->interval = 1;
1149			urb->transfer_flags = URB_ISO_ASAP;
1150			urb->number_of_packets = iso_packets;
1151			for (j = 0; j < iso_packets; j++) {
1152				urb->iso_frame_desc[j].offset = channel->packet_size * j;
1153				urb->iso_frame_desc[j].length = channel->packet_size;
1154			}
1155		}
1156
1157		/* put all tx URBs on the list of spares */
1158		if (i >= num_rcv_urbs)
1159			list_add_tail(&urb->urb_list, &channel->list);
1160
1161		vdbg(&intf->dev, "%s: alloced buffer 0x%p buf size %u urb 0x%p",
1162		     __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1163	}
1164
1165	instance->cached_vpi = ATM_VPI_UNSPEC;
1166	instance->cached_vci = ATM_VCI_UNSPEC;
1167	instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1168
1169	if (!instance->cell_buf) {
1170		error = -ENOMEM;
1171		goto fail_unbind;
1172	}
1173
1174	if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1175		error = usbatm_heavy_init(instance);
1176	} else {
1177		complete(&instance->thread_exited);	/* pretend that heavy_init was run */
1178		error = usbatm_atm_init(instance);
1179	}
1180
1181	if (error < 0)
1182		goto fail_unbind;
1183
1184	usb_get_dev(usb_dev);
1185	usb_set_intfdata(intf, instance);
1186
1187	return 0;
1188
1189 fail_unbind:
1190	if (instance->driver->unbind)
1191		instance->driver->unbind(instance, intf);
1192 fail_free:
1193	kfree(instance->cell_buf);
1194
1195	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1196		if (instance->urbs[i])
1197			kfree(instance->urbs[i]->transfer_buffer);
1198		usb_free_urb(instance->urbs[i]);
1199	}
1200
1201	kfree(instance);
1202
1203	return error;
1204}
1205EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1206
1207void usbatm_usb_disconnect(struct usb_interface *intf)
1208{
1209	struct device *dev = &intf->dev;
1210	struct usbatm_data *instance = usb_get_intfdata(intf);
1211	struct usbatm_vcc_data *vcc_data;
1212	int i;
1213
1214	if (!instance) {
1215		dev_dbg(dev, "%s: NULL instance!\n", __func__);
1216		return;
1217	}
1218
1219	usb_set_intfdata(intf, NULL);
1220
1221	mutex_lock(&instance->serialize);
1222	instance->disconnected = 1;
1223	if (instance->thread != NULL)
1224		send_sig(SIGTERM, instance->thread, 1);
1225	mutex_unlock(&instance->serialize);
1226
1227	wait_for_completion(&instance->thread_exited);
1228
1229	mutex_lock(&instance->serialize);
1230	list_for_each_entry(vcc_data, &instance->vcc_list, list)
1231		vcc_release_async(vcc_data->vcc, -EPIPE);
1232	mutex_unlock(&instance->serialize);
1233
1234	tasklet_disable(&instance->rx_channel.tasklet);
1235	tasklet_disable(&instance->tx_channel.tasklet);
1236
1237	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1238		usb_kill_urb(instance->urbs[i]);
1239
1240	del_timer_sync(&instance->rx_channel.delay);
1241	del_timer_sync(&instance->tx_channel.delay);
1242
1243	/* turn usbatm_[rt]x_process into something close to a no-op */
1244	/* no need to take the spinlock */
1245	INIT_LIST_HEAD(&instance->rx_channel.list);
1246	INIT_LIST_HEAD(&instance->tx_channel.list);
1247
1248	tasklet_enable(&instance->rx_channel.tasklet);
1249	tasklet_enable(&instance->tx_channel.tasklet);
1250
1251	if (instance->atm_dev && instance->driver->atm_stop)
1252		instance->driver->atm_stop(instance, instance->atm_dev);
1253
1254	if (instance->driver->unbind)
1255		instance->driver->unbind(instance, intf);
1256
1257	instance->driver_data = NULL;
1258
1259	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1260		kfree(instance->urbs[i]->transfer_buffer);
1261		usb_free_urb(instance->urbs[i]);
1262	}
1263
1264	kfree(instance->cell_buf);
1265
1266	/* ATM finalize */
1267	if (instance->atm_dev) {
1268		atm_dev_deregister(instance->atm_dev);
1269		instance->atm_dev = NULL;
1270	}
1271
1272	usbatm_put_instance(instance);	/* taken in usbatm_usb_probe */
1273}
1274EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1275
1276
1277/***********
1278**  init  **
1279***********/
1280
1281static int __init usbatm_usb_init(void)
1282{
1283	if (sizeof(struct usbatm_control) > sizeof_field(struct sk_buff, cb)) {
1284		pr_err("%s unusable with this kernel!\n", usbatm_driver_name);
1285		return -EIO;
1286	}
1287
1288	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1289	    || (num_snd_urbs > UDSL_MAX_SND_URBS)
1290	    || (rcv_buf_bytes < 1)
1291	    || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1292	    || (snd_buf_bytes < 1)
1293	    || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1294		return -EINVAL;
1295
1296	return 0;
1297}
1298module_init(usbatm_usb_init);
1299
1300static void __exit usbatm_usb_exit(void)
1301{
1302}
1303module_exit(usbatm_usb_exit);
1304
1305MODULE_AUTHOR(DRIVER_AUTHOR);
1306MODULE_DESCRIPTION(DRIVER_DESC);
1307MODULE_LICENSE("GPL");
1308
1309/************
1310**  debug  **
1311************/
1312
1313#ifdef VERBOSE_DEBUG
1314static int usbatm_print_packet(struct usbatm_data *instance,
1315			       const unsigned char *data, int len)
1316{
1317	unsigned char buffer[256];
1318	int i = 0, j = 0;
1319
1320	for (i = 0; i < len;) {
1321		buffer[0] = '\0';
1322		sprintf(buffer, "%.3d :", i);
1323		for (j = 0; (j < 16) && (i < len); j++, i++)
1324			sprintf(buffer, "%s %2.2x", buffer, data[i]);
1325		dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1326	}
1327	return i;
1328}
1329#endif