xref: /openbmc/linux/drivers/usb/atm/usbatm.c (revision 8ac727c1)
1 /******************************************************************************
2  *  usbatm.c - Generic USB xDSL driver core
3  *
4  *  Copyright (C) 2001, Alcatel
5  *  Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
6  *  Copyright (C) 2004, David Woodhouse, Roman Kagan
7  *
8  *  This program is free software; you can redistribute it and/or modify it
9  *  under the terms of the GNU General Public License as published by the Free
10  *  Software Foundation; either version 2 of the License, or (at your option)
11  *  any later version.
12  *
13  *  This program is distributed in the hope that it will be useful, but WITHOUT
14  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  *  more details.
17  *
18  *  You should have received a copy of the GNU General Public License along with
19  *  this program; if not, write to the Free Software Foundation, Inc., 59
20  *  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
21  *
22  ******************************************************************************/
23 
24 /*
25  *  Written by Johan Verrept, Duncan Sands (duncan.sands@free.fr) and David Woodhouse
26  *
27  *  1.7+:	- See the check-in logs
28  *
29  *  1.6:	- No longer opens a connection if the firmware is not loaded
30  *  		- Added support for the speedtouch 330
31  *  		- Removed the limit on the number of devices
32  *  		- Module now autoloads on device plugin
33  *  		- Merged relevant parts of sarlib
34  *  		- Replaced the kernel thread with a tasklet
35  *  		- New packet transmission code
36  *  		- Changed proc file contents
37  *  		- Fixed all known SMP races
38  *  		- Many fixes and cleanups
39  *  		- Various fixes by Oliver Neukum (oliver@neukum.name)
40  *
41  *  1.5A:	- Version for inclusion in 2.5 series kernel
42  *		- Modifications by Richard Purdie (rpurdie@rpsys.net)
43  *		- made compatible with kernel 2.5.6 onwards by changing
44  *		usbatm_usb_send_data_context->urb to a pointer and adding code
45  *		to alloc and free it
46  *		- remove_wait_queue() added to usbatm_atm_processqueue_thread()
47  *
48  *  1.5:	- fixed memory leak when atmsar_decode_aal5 returned NULL.
49  *		(reported by stephen.robinson@zen.co.uk)
50  *
51  *  1.4:	- changed the spin_lock() under interrupt to spin_lock_irqsave()
52  *		- unlink all active send urbs of a vcc that is being closed.
53  *
54  *  1.3.1:	- added the version number
55  *
56  *  1.3:	- Added multiple send urb support
57  *		- fixed memory leak and vcc->tx_inuse starvation bug
58  *		  when not enough memory left in vcc.
59  *
60  *  1.2:	- Fixed race condition in usbatm_usb_send_data()
61  *  1.1:	- Turned off packet debugging
62  *
63  */
64 
65 #include "usbatm.h"
66 
67 #include <asm/uaccess.h>
68 #include <linux/crc32.h>
69 #include <linux/errno.h>
70 #include <linux/init.h>
71 #include <linux/interrupt.h>
72 #include <linux/kernel.h>
73 #include <linux/module.h>
74 #include <linux/moduleparam.h>
75 #include <linux/netdevice.h>
76 #include <linux/proc_fs.h>
77 #include <linux/sched.h>
78 #include <linux/signal.h>
79 #include <linux/slab.h>
80 #include <linux/stat.h>
81 #include <linux/timer.h>
82 #include <linux/wait.h>
83 #include <linux/kthread.h>
84 
85 #ifdef VERBOSE_DEBUG
86 static int usbatm_print_packet(const unsigned char *data, int len);
87 #define PACKETDEBUG(arg...)	usbatm_print_packet(arg)
88 #define vdbg(arg...)		dbg(arg)
89 #else
90 #define PACKETDEBUG(arg...)
91 #define vdbg(arg...)
92 #endif
93 
94 #define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
95 #define DRIVER_VERSION	"1.10"
96 #define DRIVER_DESC	"Generic USB ATM/DSL I/O, version " DRIVER_VERSION
97 
98 static const char usbatm_driver_name[] = "usbatm";
99 
100 #define UDSL_MAX_RCV_URBS		16
101 #define UDSL_MAX_SND_URBS		16
102 #define UDSL_MAX_BUF_SIZE		65536
103 #define UDSL_DEFAULT_RCV_URBS		4
104 #define UDSL_DEFAULT_SND_URBS		4
105 #define UDSL_DEFAULT_RCV_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
106 #define UDSL_DEFAULT_SND_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
107 
108 #define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
109 
110 #define THROTTLE_MSECS			100	/* delay to recover processing after urb submission fails */
111 
112 static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
113 static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
114 static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
115 static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
116 
117 module_param(num_rcv_urbs, uint, S_IRUGO);
118 MODULE_PARM_DESC(num_rcv_urbs,
119 		 "Number of urbs used for reception (range: 0-"
120 		 __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
121 		 __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
122 
123 module_param(num_snd_urbs, uint, S_IRUGO);
124 MODULE_PARM_DESC(num_snd_urbs,
125 		 "Number of urbs used for transmission (range: 0-"
126 		 __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
127 		 __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
128 
129 module_param(rcv_buf_bytes, uint, S_IRUGO);
130 MODULE_PARM_DESC(rcv_buf_bytes,
131 		 "Size of the buffers used for reception, in bytes (range: 1-"
132 		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
133 		 __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
134 
135 module_param(snd_buf_bytes, uint, S_IRUGO);
136 MODULE_PARM_DESC(snd_buf_bytes,
137 		 "Size of the buffers used for transmission, in bytes (range: 1-"
138 		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
139 		 __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
140 
141 
142 /* receive */
143 
144 struct usbatm_vcc_data {
145 	/* vpi/vci lookup */
146 	struct list_head list;
147 	short vpi;
148 	int vci;
149 	struct atm_vcc *vcc;
150 
151 	/* raw cell reassembly */
152 	struct sk_buff *sarb;
153 };
154 
155 
156 /* send */
157 
158 struct usbatm_control {
159 	struct atm_skb_data atm;
160 	u32 len;
161 	u32 crc;
162 };
163 
164 #define UDSL_SKB(x)		((struct usbatm_control *)(x)->cb)
165 
166 
167 /* ATM */
168 
169 static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
170 static int usbatm_atm_open(struct atm_vcc *vcc);
171 static void usbatm_atm_close(struct atm_vcc *vcc);
172 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user * arg);
173 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
174 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t * pos, char *page);
175 
176 static struct atmdev_ops usbatm_atm_devops = {
177 	.dev_close	= usbatm_atm_dev_close,
178 	.open		= usbatm_atm_open,
179 	.close		= usbatm_atm_close,
180 	.ioctl		= usbatm_atm_ioctl,
181 	.send		= usbatm_atm_send,
182 	.proc_read	= usbatm_atm_proc_read,
183 	.owner		= THIS_MODULE,
184 };
185 
186 
187 /***********
188 **  misc  **
189 ***********/
190 
191 static inline unsigned int usbatm_pdu_length(unsigned int length)
192 {
193 	length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
194 	return length - length % ATM_CELL_PAYLOAD;
195 }
196 
197 static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
198 {
199 	if (vcc->pop)
200 		vcc->pop(vcc, skb);
201 	else
202 		dev_kfree_skb_any(skb);
203 }
204 
205 
206 /***********
207 **  urbs  **
208 ************/
209 
210 static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
211 {
212 	struct urb *urb;
213 
214 	spin_lock_irq(&channel->lock);
215 	if (list_empty(&channel->list)) {
216 		spin_unlock_irq(&channel->lock);
217 		return NULL;
218 	}
219 
220 	urb = list_entry(channel->list.next, struct urb, urb_list);
221 	list_del(&urb->urb_list);
222 	spin_unlock_irq(&channel->lock);
223 
224 	return urb;
225 }
226 
227 static int usbatm_submit_urb(struct urb *urb)
228 {
229 	struct usbatm_channel *channel = urb->context;
230 	int ret;
231 
232 	vdbg("%s: submitting urb 0x%p, size %u",
233 	     __func__, urb, urb->transfer_buffer_length);
234 
235 	ret = usb_submit_urb(urb, GFP_ATOMIC);
236 	if (ret) {
237 		if (printk_ratelimit())
238 			atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
239 				__func__, urb, ret);
240 
241 		/* consider all errors transient and return the buffer back to the queue */
242 		urb->status = -EAGAIN;
243 		spin_lock_irq(&channel->lock);
244 
245 		/* must add to the front when sending; doesn't matter when receiving */
246 		list_add(&urb->urb_list, &channel->list);
247 
248 		spin_unlock_irq(&channel->lock);
249 
250 		/* make sure the channel doesn't stall */
251 		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
252 	}
253 
254 	return ret;
255 }
256 
257 static void usbatm_complete(struct urb *urb)
258 {
259 	struct usbatm_channel *channel = urb->context;
260 	unsigned long flags;
261 	int status = urb->status;
262 
263 	vdbg("%s: urb 0x%p, status %d, actual_length %d",
264 	     __func__, urb, status, urb->actual_length);
265 
266 	/* usually in_interrupt(), but not always */
267 	spin_lock_irqsave(&channel->lock, flags);
268 
269 	/* must add to the back when receiving; doesn't matter when sending */
270 	list_add_tail(&urb->urb_list, &channel->list);
271 
272 	spin_unlock_irqrestore(&channel->lock, flags);
273 
274 	if (unlikely(status) &&
275 			(!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
276 			 status != -EILSEQ)) {
277 		if (status == -ESHUTDOWN)
278 			return;
279 
280 		if (printk_ratelimit())
281 			atm_warn(channel->usbatm, "%s: urb 0x%p failed (%d)!\n",
282 				__func__, urb, status);
283 		/* throttle processing in case of an error */
284 		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
285 	} else
286 		tasklet_schedule(&channel->tasklet);
287 }
288 
289 
290 /*************
291 **  decode  **
292 *************/
293 
294 static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
295 						  short vpi, int vci)
296 {
297 	struct usbatm_vcc_data *vcc_data;
298 
299 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
300 		if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
301 			return vcc_data;
302 	return NULL;
303 }
304 
305 static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
306 {
307 	struct atm_vcc *vcc;
308 	struct sk_buff *sarb;
309 	short vpi = ((source[0] & 0x0f) << 4)  | (source[1] >> 4);
310 	int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
311 	u8 pti = ((source[3] & 0xe) >> 1);
312 
313 	vdbg("%s: vpi %hd, vci %d, pti %d", __func__, vpi, vci, pti);
314 
315 	if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
316 		instance->cached_vpi = vpi;
317 		instance->cached_vci = vci;
318 
319 		instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
320 
321 		if (!instance->cached_vcc)
322 			atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
323 	}
324 
325 	if (!instance->cached_vcc)
326 		return;
327 
328 	vcc = instance->cached_vcc->vcc;
329 
330 	/* OAM F5 end-to-end */
331 	if (pti == ATM_PTI_E2EF5) {
332 		if (printk_ratelimit())
333 			atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
334 				__func__, vpi, vci);
335 		atomic_inc(&vcc->stats->rx_err);
336 		return;
337 	}
338 
339 	sarb = instance->cached_vcc->sarb;
340 
341 	if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
342 		atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
343 				__func__, sarb->len, vcc);
344 		/* discard cells already received */
345 		skb_trim(sarb, 0);
346 		UDSL_ASSERT(instance, sarb->tail + ATM_CELL_PAYLOAD <= sarb->end);
347 	}
348 
349 	memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
350 	__skb_put(sarb, ATM_CELL_PAYLOAD);
351 
352 	if (pti & 1) {
353 		struct sk_buff *skb;
354 		unsigned int length;
355 		unsigned int pdu_length;
356 
357 		length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
358 
359 		/* guard against overflow */
360 		if (length > ATM_MAX_AAL5_PDU) {
361 			atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
362 				  __func__, length, vcc);
363 			atomic_inc(&vcc->stats->rx_err);
364 			goto out;
365 		}
366 
367 		pdu_length = usbatm_pdu_length(length);
368 
369 		if (sarb->len < pdu_length) {
370 			atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
371 				  __func__, pdu_length, sarb->len, vcc);
372 			atomic_inc(&vcc->stats->rx_err);
373 			goto out;
374 		}
375 
376 		if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
377 			atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
378 				  __func__, vcc);
379 			atomic_inc(&vcc->stats->rx_err);
380 			goto out;
381 		}
382 
383 		vdbg("%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)", __func__, length, pdu_length, vcc);
384 
385 		if (!(skb = dev_alloc_skb(length))) {
386 			if (printk_ratelimit())
387 				atm_err(instance, "%s: no memory for skb (length: %u)!\n",
388 					__func__, length);
389 			atomic_inc(&vcc->stats->rx_drop);
390 			goto out;
391 		}
392 
393 		vdbg("%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)", __func__, skb, skb->truesize);
394 
395 		if (!atm_charge(vcc, skb->truesize)) {
396 			atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
397 				  __func__, skb->truesize);
398 			dev_kfree_skb_any(skb);
399 			goto out;	/* atm_charge increments rx_drop */
400 		}
401 
402 		skb_copy_to_linear_data(skb,
403 					skb_tail_pointer(sarb) - pdu_length,
404 					length);
405 		__skb_put(skb, length);
406 
407 		vdbg("%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
408 		     __func__, skb, skb->len, skb->truesize);
409 
410 		PACKETDEBUG(skb->data, skb->len);
411 
412 		vcc->push(vcc, skb);
413 
414 		atomic_inc(&vcc->stats->rx);
415 	out:
416 		skb_trim(sarb, 0);
417 	}
418 }
419 
420 static void usbatm_extract_cells(struct usbatm_data *instance,
421 		unsigned char *source, unsigned int avail_data)
422 {
423 	unsigned int stride = instance->rx_channel.stride;
424 	unsigned int buf_usage = instance->buf_usage;
425 
426 	/* extract cells from incoming data, taking into account that
427 	 * the length of avail data may not be a multiple of stride */
428 
429 	if (buf_usage > 0) {
430 		/* we have a partially received atm cell */
431 		unsigned char *cell_buf = instance->cell_buf;
432 		unsigned int space_left = stride - buf_usage;
433 
434 		UDSL_ASSERT(instance, buf_usage <= stride);
435 
436 		if (avail_data >= space_left) {
437 			/* add new data and process cell */
438 			memcpy(cell_buf + buf_usage, source, space_left);
439 			source += space_left;
440 			avail_data -= space_left;
441 			usbatm_extract_one_cell(instance, cell_buf);
442 			instance->buf_usage = 0;
443 		} else {
444 			/* not enough data to fill the cell */
445 			memcpy(cell_buf + buf_usage, source, avail_data);
446 			instance->buf_usage = buf_usage + avail_data;
447 			return;
448 		}
449 	}
450 
451 	for (; avail_data >= stride; avail_data -= stride, source += stride)
452 		usbatm_extract_one_cell(instance, source);
453 
454 	if (avail_data > 0) {
455 		/* length was not a multiple of stride -
456 		 * save remaining data for next call */
457 		memcpy(instance->cell_buf, source, avail_data);
458 		instance->buf_usage = avail_data;
459 	}
460 }
461 
462 
463 /*************
464 **  encode  **
465 *************/
466 
467 static unsigned int usbatm_write_cells(struct usbatm_data *instance,
468 				       struct sk_buff *skb,
469 				       u8 *target, unsigned int avail_space)
470 {
471 	struct usbatm_control *ctrl = UDSL_SKB(skb);
472 	struct atm_vcc *vcc = ctrl->atm.vcc;
473 	unsigned int bytes_written;
474 	unsigned int stride = instance->tx_channel.stride;
475 
476 	vdbg("%s: skb->len=%d, avail_space=%u", __func__, skb->len, avail_space);
477 	UDSL_ASSERT(instance, !(avail_space % stride));
478 
479 	for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
480 	     bytes_written += stride, target += stride) {
481 		unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
482 		unsigned int left = ATM_CELL_PAYLOAD - data_len;
483 		u8 *ptr = target;
484 
485 		ptr[0] = vcc->vpi >> 4;
486 		ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
487 		ptr[2] = vcc->vci >> 4;
488 		ptr[3] = vcc->vci << 4;
489 		ptr[4] = 0xec;
490 		ptr += ATM_CELL_HEADER;
491 
492 		skb_copy_from_linear_data(skb, ptr, data_len);
493 		ptr += data_len;
494 		__skb_pull(skb, data_len);
495 
496 		if (!left)
497 			continue;
498 
499 		memset(ptr, 0, left);
500 
501 		if (left >= ATM_AAL5_TRAILER) {	/* trailer will go in this cell */
502 			u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
503 			/* trailer[0] = 0;		UU = 0 */
504 			/* trailer[1] = 0;		CPI = 0 */
505 			trailer[2] = ctrl->len >> 8;
506 			trailer[3] = ctrl->len;
507 
508 			ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
509 
510 			trailer[4] = ctrl->crc >> 24;
511 			trailer[5] = ctrl->crc >> 16;
512 			trailer[6] = ctrl->crc >> 8;
513 			trailer[7] = ctrl->crc;
514 
515 			target[3] |= 0x2;	/* adjust PTI */
516 
517 			ctrl->len = 0;		/* tag this skb finished */
518 		} else
519 			ctrl->crc = crc32_be(ctrl->crc, ptr, left);
520 	}
521 
522 	return bytes_written;
523 }
524 
525 
526 /**************
527 **  receive  **
528 **************/
529 
530 static void usbatm_rx_process(unsigned long data)
531 {
532 	struct usbatm_data *instance = (struct usbatm_data *)data;
533 	struct urb *urb;
534 
535 	while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
536 		vdbg("%s: processing urb 0x%p", __func__, urb);
537 
538 		if (usb_pipeisoc(urb->pipe)) {
539 			unsigned char *merge_start = NULL;
540 			unsigned int merge_length = 0;
541 			const unsigned int packet_size = instance->rx_channel.packet_size;
542 			int i;
543 
544 			for (i = 0; i < urb->number_of_packets; i++) {
545 				if (!urb->iso_frame_desc[i].status) {
546 					unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
547 
548 					UDSL_ASSERT(instance, actual_length <= packet_size);
549 
550 					if (!merge_length)
551 						merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
552 					merge_length += actual_length;
553 					if (merge_length && (actual_length < packet_size)) {
554 						usbatm_extract_cells(instance, merge_start, merge_length);
555 						merge_length = 0;
556 					}
557 				} else {
558 					atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
559 					if (merge_length)
560 						usbatm_extract_cells(instance, merge_start, merge_length);
561 					merge_length = 0;
562 					instance->buf_usage = 0;
563 				}
564 			}
565 
566 			if (merge_length)
567 				usbatm_extract_cells(instance, merge_start, merge_length);
568 		} else
569 			if (!urb->status)
570 				usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
571 			else
572 				instance->buf_usage = 0;
573 
574 		if (usbatm_submit_urb(urb))
575 			return;
576 	}
577 }
578 
579 
580 /***********
581 **  send  **
582 ***********/
583 
584 static void usbatm_tx_process(unsigned long data)
585 {
586 	struct usbatm_data *instance = (struct usbatm_data *)data;
587 	struct sk_buff *skb = instance->current_skb;
588 	struct urb *urb = NULL;
589 	const unsigned int buf_size = instance->tx_channel.buf_size;
590 	unsigned int bytes_written = 0;
591 	u8 *buffer = NULL;
592 
593 	if (!skb)
594 		skb = skb_dequeue(&instance->sndqueue);
595 
596 	while (skb) {
597 		if (!urb) {
598 			urb = usbatm_pop_urb(&instance->tx_channel);
599 			if (!urb)
600 				break;		/* no more senders */
601 			buffer = urb->transfer_buffer;
602 			bytes_written = (urb->status == -EAGAIN) ?
603 				urb->transfer_buffer_length : 0;
604 		}
605 
606 		bytes_written += usbatm_write_cells(instance, skb,
607 						  buffer + bytes_written,
608 						  buf_size - bytes_written);
609 
610 		vdbg("%s: wrote %u bytes from skb 0x%p to urb 0x%p",
611 		     __func__, bytes_written, skb, urb);
612 
613 		if (!UDSL_SKB(skb)->len) {
614 			struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
615 
616 			usbatm_pop(vcc, skb);
617 			atomic_inc(&vcc->stats->tx);
618 
619 			skb = skb_dequeue(&instance->sndqueue);
620 		}
621 
622 		if (bytes_written == buf_size || (!skb && bytes_written)) {
623 			urb->transfer_buffer_length = bytes_written;
624 
625 			if (usbatm_submit_urb(urb))
626 				break;
627 			urb = NULL;
628 		}
629 	}
630 
631 	instance->current_skb = skb;
632 }
633 
634 static void usbatm_cancel_send(struct usbatm_data *instance,
635 			       struct atm_vcc *vcc)
636 {
637 	struct sk_buff *skb, *n;
638 
639 	atm_dbg(instance, "%s entered\n", __func__);
640 	spin_lock_irq(&instance->sndqueue.lock);
641 	skb_queue_walk_safe(&instance->sndqueue, skb, n) {
642 		if (UDSL_SKB(skb)->atm.vcc == vcc) {
643 			atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
644 			__skb_unlink(skb, &instance->sndqueue);
645 			usbatm_pop(vcc, skb);
646 		}
647 	}
648 	spin_unlock_irq(&instance->sndqueue.lock);
649 
650 	tasklet_disable(&instance->tx_channel.tasklet);
651 	if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
652 		atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
653 		instance->current_skb = NULL;
654 		usbatm_pop(vcc, skb);
655 	}
656 	tasklet_enable(&instance->tx_channel.tasklet);
657 	atm_dbg(instance, "%s done\n", __func__);
658 }
659 
660 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
661 {
662 	struct usbatm_data *instance = vcc->dev->dev_data;
663 	struct usbatm_control *ctrl = UDSL_SKB(skb);
664 	int err;
665 
666 	vdbg("%s called (skb 0x%p, len %u)", __func__, skb, skb->len);
667 
668 	/* racy disconnection check - fine */
669 	if (!instance || instance->disconnected) {
670 #ifdef DEBUG
671 		if (printk_ratelimit())
672 			printk(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
673 #endif
674 		err = -ENODEV;
675 		goto fail;
676 	}
677 
678 	if (vcc->qos.aal != ATM_AAL5) {
679 		atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
680 		err = -EINVAL;
681 		goto fail;
682 	}
683 
684 	if (skb->len > ATM_MAX_AAL5_PDU) {
685 		atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
686 				__func__, skb->len, ATM_MAX_AAL5_PDU);
687 		err = -EINVAL;
688 		goto fail;
689 	}
690 
691 	PACKETDEBUG(skb->data, skb->len);
692 
693 	/* initialize the control block */
694 	ctrl->atm.vcc = vcc;
695 	ctrl->len = skb->len;
696 	ctrl->crc = crc32_be(~0, skb->data, skb->len);
697 
698 	skb_queue_tail(&instance->sndqueue, skb);
699 	tasklet_schedule(&instance->tx_channel.tasklet);
700 
701 	return 0;
702 
703  fail:
704 	usbatm_pop(vcc, skb);
705 	return err;
706 }
707 
708 
709 /********************
710 **  bean counting  **
711 ********************/
712 
713 static void usbatm_destroy_instance(struct kref *kref)
714 {
715 	struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
716 
717 	dbg("%s", __func__);
718 
719 	tasklet_kill(&instance->rx_channel.tasklet);
720 	tasklet_kill(&instance->tx_channel.tasklet);
721 	usb_put_dev(instance->usb_dev);
722 	kfree(instance);
723 }
724 
725 static void usbatm_get_instance(struct usbatm_data *instance)
726 {
727 	dbg("%s", __func__);
728 
729 	kref_get(&instance->refcount);
730 }
731 
732 static void usbatm_put_instance(struct usbatm_data *instance)
733 {
734 	dbg("%s", __func__);
735 
736 	kref_put(&instance->refcount, usbatm_destroy_instance);
737 }
738 
739 
740 /**********
741 **  ATM  **
742 **********/
743 
744 static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
745 {
746 	struct usbatm_data *instance = atm_dev->dev_data;
747 
748 	dbg("%s", __func__);
749 
750 	if (!instance)
751 		return;
752 
753 	atm_dev->dev_data = NULL; /* catch bugs */
754 	usbatm_put_instance(instance);	/* taken in usbatm_atm_init */
755 }
756 
757 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t * pos, char *page)
758 {
759 	struct usbatm_data *instance = atm_dev->dev_data;
760 	int left = *pos;
761 
762 	if (!instance) {
763 		dbg("%s: NULL instance!", __func__);
764 		return -ENODEV;
765 	}
766 
767 	if (!left--)
768 		return sprintf(page, "%s\n", instance->description);
769 
770 	if (!left--)
771 		return sprintf(page, "MAC: %pM\n", atm_dev->esi);
772 
773 	if (!left--)
774 		return sprintf(page,
775 			       "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
776 			       atomic_read(&atm_dev->stats.aal5.tx),
777 			       atomic_read(&atm_dev->stats.aal5.tx_err),
778 			       atomic_read(&atm_dev->stats.aal5.rx),
779 			       atomic_read(&atm_dev->stats.aal5.rx_err),
780 			       atomic_read(&atm_dev->stats.aal5.rx_drop));
781 
782 	if (!left--) {
783 		if (instance->disconnected)
784 			return sprintf(page, "Disconnected\n");
785 		else
786 			switch (atm_dev->signal) {
787 			case ATM_PHY_SIG_FOUND:
788 				return sprintf(page, "Line up\n");
789 			case ATM_PHY_SIG_LOST:
790 				return sprintf(page, "Line down\n");
791 			default:
792 				return sprintf(page, "Line state unknown\n");
793 			}
794 	}
795 
796 	return 0;
797 }
798 
799 static int usbatm_atm_open(struct atm_vcc *vcc)
800 {
801 	struct usbatm_data *instance = vcc->dev->dev_data;
802 	struct usbatm_vcc_data *new = NULL;
803 	int ret;
804 	int vci = vcc->vci;
805 	short vpi = vcc->vpi;
806 
807 	if (!instance) {
808 		dbg("%s: NULL data!", __func__);
809 		return -ENODEV;
810 	}
811 
812 	atm_dbg(instance, "%s: vpi %hd, vci %d\n", __func__, vpi, vci);
813 
814 	/* only support AAL5 */
815 	if ((vcc->qos.aal != ATM_AAL5)) {
816 		atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
817 		return -EINVAL;
818 	}
819 
820 	/* sanity checks */
821 	if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
822 		atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
823 		return -EINVAL;
824 	}
825 
826 	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_close, usbatm_usb_disconnect */
827 
828 	if (instance->disconnected) {
829 		atm_dbg(instance, "%s: disconnected!\n", __func__);
830 		ret = -ENODEV;
831 		goto fail;
832 	}
833 
834 	if (usbatm_find_vcc(instance, vpi, vci)) {
835 		atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
836 		ret = -EADDRINUSE;
837 		goto fail;
838 	}
839 
840 	if (!(new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL))) {
841 		atm_err(instance, "%s: no memory for vcc_data!\n", __func__);
842 		ret = -ENOMEM;
843 		goto fail;
844 	}
845 
846 	new->vcc = vcc;
847 	new->vpi = vpi;
848 	new->vci = vci;
849 
850 	new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
851 	if (!new->sarb) {
852 		atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
853 		ret = -ENOMEM;
854 		goto fail;
855 	}
856 
857 	vcc->dev_data = new;
858 
859 	tasklet_disable(&instance->rx_channel.tasklet);
860 	instance->cached_vcc = new;
861 	instance->cached_vpi = vpi;
862 	instance->cached_vci = vci;
863 	list_add(&new->list, &instance->vcc_list);
864 	tasklet_enable(&instance->rx_channel.tasklet);
865 
866 	set_bit(ATM_VF_ADDR, &vcc->flags);
867 	set_bit(ATM_VF_PARTIAL, &vcc->flags);
868 	set_bit(ATM_VF_READY, &vcc->flags);
869 
870 	mutex_unlock(&instance->serialize);
871 
872 	atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
873 
874 	return 0;
875 
876 fail:
877 	kfree(new);
878 	mutex_unlock(&instance->serialize);
879 	return ret;
880 }
881 
882 static void usbatm_atm_close(struct atm_vcc *vcc)
883 {
884 	struct usbatm_data *instance = vcc->dev->dev_data;
885 	struct usbatm_vcc_data *vcc_data = vcc->dev_data;
886 
887 	if (!instance || !vcc_data) {
888 		dbg("%s: NULL data!", __func__);
889 		return;
890 	}
891 
892 	atm_dbg(instance, "%s entered\n", __func__);
893 
894 	atm_dbg(instance, "%s: deallocating vcc 0x%p with vpi %d vci %d\n",
895 		__func__, vcc_data, vcc_data->vpi, vcc_data->vci);
896 
897 	usbatm_cancel_send(instance, vcc);
898 
899 	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_open, usbatm_usb_disconnect */
900 
901 	tasklet_disable(&instance->rx_channel.tasklet);
902 	if (instance->cached_vcc == vcc_data) {
903 		instance->cached_vcc = NULL;
904 		instance->cached_vpi = ATM_VPI_UNSPEC;
905 		instance->cached_vci = ATM_VCI_UNSPEC;
906 	}
907 	list_del(&vcc_data->list);
908 	tasklet_enable(&instance->rx_channel.tasklet);
909 
910 	kfree_skb(vcc_data->sarb);
911 	vcc_data->sarb = NULL;
912 
913 	kfree(vcc_data);
914 	vcc->dev_data = NULL;
915 
916 	vcc->vpi = ATM_VPI_UNSPEC;
917 	vcc->vci = ATM_VCI_UNSPEC;
918 	clear_bit(ATM_VF_READY, &vcc->flags);
919 	clear_bit(ATM_VF_PARTIAL, &vcc->flags);
920 	clear_bit(ATM_VF_ADDR, &vcc->flags);
921 
922 	mutex_unlock(&instance->serialize);
923 
924 	atm_dbg(instance, "%s successful\n", __func__);
925 }
926 
927 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
928 			  void __user * arg)
929 {
930 	struct usbatm_data *instance = atm_dev->dev_data;
931 
932 	if (!instance || instance->disconnected) {
933 		dbg("%s: %s!", __func__, instance ? "disconnected" : "NULL instance");
934 		return -ENODEV;
935 	}
936 
937 	switch (cmd) {
938 	case ATM_QUERYLOOP:
939 		return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
940 	default:
941 		return -ENOIOCTLCMD;
942 	}
943 }
944 
945 static int usbatm_atm_init(struct usbatm_data *instance)
946 {
947 	struct atm_dev *atm_dev;
948 	int ret, i;
949 
950 	/* ATM init.  The ATM initialization scheme suffers from an intrinsic race
951 	 * condition: callbacks we register can be executed at once, before we have
952 	 * initialized the struct atm_dev.  To protect against this, all callbacks
953 	 * abort if atm_dev->dev_data is NULL. */
954 	atm_dev = atm_dev_register(instance->driver_name,
955 				   &instance->usb_intf->dev, &usbatm_atm_devops,
956 				   -1, NULL);
957 	if (!atm_dev) {
958 		usb_err(instance, "%s: failed to register ATM device!\n", __func__);
959 		return -1;
960 	}
961 
962 	instance->atm_dev = atm_dev;
963 
964 	atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
965 	atm_dev->ci_range.vci_bits = ATM_CI_MAX;
966 	atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
967 
968 	/* temp init ATM device, set to 128kbit */
969 	atm_dev->link_rate = 128 * 1000 / 424;
970 
971 	if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
972 		atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
973 		goto fail;
974 	}
975 
976 	usbatm_get_instance(instance);	/* dropped in usbatm_atm_dev_close */
977 
978 	/* ready for ATM callbacks */
979 	mb();
980 	atm_dev->dev_data = instance;
981 
982 	/* submit all rx URBs */
983 	for (i = 0; i < num_rcv_urbs; i++)
984 		usbatm_submit_urb(instance->urbs[i]);
985 
986 	return 0;
987 
988  fail:
989 	instance->atm_dev = NULL;
990 	atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
991 	return ret;
992 }
993 
994 
995 /**********
996 **  USB  **
997 **********/
998 
999 static int usbatm_do_heavy_init(void *arg)
1000 {
1001 	struct usbatm_data *instance = arg;
1002 	int ret;
1003 
1004 	allow_signal(SIGTERM);
1005 	complete(&instance->thread_started);
1006 
1007 	ret = instance->driver->heavy_init(instance, instance->usb_intf);
1008 
1009 	if (!ret)
1010 		ret = usbatm_atm_init(instance);
1011 
1012 	mutex_lock(&instance->serialize);
1013 	instance->thread = NULL;
1014 	mutex_unlock(&instance->serialize);
1015 
1016 	complete_and_exit(&instance->thread_exited, ret);
1017 }
1018 
1019 static int usbatm_heavy_init(struct usbatm_data *instance)
1020 {
1021 	struct task_struct *t;
1022 
1023 	t = kthread_create(usbatm_do_heavy_init, instance,
1024 			instance->driver->driver_name);
1025 	if (IS_ERR(t)) {
1026 		usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
1027 				__func__, PTR_ERR(t));
1028 		return PTR_ERR(t);
1029 	}
1030 
1031 	instance->thread = t;
1032 	wake_up_process(t);
1033 	wait_for_completion(&instance->thread_started);
1034 
1035 	return 0;
1036 }
1037 
1038 static void usbatm_tasklet_schedule(unsigned long data)
1039 {
1040 	tasklet_schedule((struct tasklet_struct *) data);
1041 }
1042 
1043 static void usbatm_init_channel(struct usbatm_channel *channel)
1044 {
1045 	spin_lock_init(&channel->lock);
1046 	INIT_LIST_HEAD(&channel->list);
1047 	channel->delay.function = usbatm_tasklet_schedule;
1048 	channel->delay.data = (unsigned long) &channel->tasklet;
1049 	init_timer(&channel->delay);
1050 }
1051 
1052 int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1053 		     struct usbatm_driver *driver)
1054 {
1055 	struct device *dev = &intf->dev;
1056 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1057 	struct usbatm_data *instance;
1058 	char *buf;
1059 	int error = -ENOMEM;
1060 	int i, length;
1061 	unsigned int maxpacket, num_packets;
1062 
1063 	dev_dbg(dev, "%s: trying driver %s with vendor=%04x, product=%04x, ifnum %2d\n",
1064 			__func__, driver->driver_name,
1065 			le16_to_cpu(usb_dev->descriptor.idVendor),
1066 			le16_to_cpu(usb_dev->descriptor.idProduct),
1067 			intf->altsetting->desc.bInterfaceNumber);
1068 
1069 	/* instance init */
1070 	instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1071 	if (!instance) {
1072 		dev_err(dev, "%s: no memory for instance data!\n", __func__);
1073 		return -ENOMEM;
1074 	}
1075 
1076 	/* public fields */
1077 
1078 	instance->driver = driver;
1079 	snprintf(instance->driver_name, sizeof(instance->driver_name), driver->driver_name);
1080 
1081 	instance->usb_dev = usb_dev;
1082 	instance->usb_intf = intf;
1083 
1084 	buf = instance->description;
1085 	length = sizeof(instance->description);
1086 
1087 	if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1088 		goto bind;
1089 
1090 	buf += i;
1091 	length -= i;
1092 
1093 	i = scnprintf(buf, length, " (");
1094 	buf += i;
1095 	length -= i;
1096 
1097 	if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1098 		goto bind;
1099 
1100 	buf += i;
1101 	length -= i;
1102 
1103 	snprintf(buf, length, ")");
1104 
1105  bind:
1106 	if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1107 			dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1108 			goto fail_free;
1109 	}
1110 
1111 	/* private fields */
1112 
1113 	kref_init(&instance->refcount);		/* dropped in usbatm_usb_disconnect */
1114 	mutex_init(&instance->serialize);
1115 
1116 	instance->thread = NULL;
1117 	init_completion(&instance->thread_started);
1118 	init_completion(&instance->thread_exited);
1119 
1120 	INIT_LIST_HEAD(&instance->vcc_list);
1121 	skb_queue_head_init(&instance->sndqueue);
1122 
1123 	usbatm_init_channel(&instance->rx_channel);
1124 	usbatm_init_channel(&instance->tx_channel);
1125 	tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1126 	tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1127 	instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1128 	instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1129 	instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1130 
1131 	if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1132 		instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1133 	else
1134 		instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1135 
1136 	instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1137 
1138 	/* tx buffer size must be a positive multiple of the stride */
1139 	instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1140 			snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1141 
1142 	/* rx buffer size must be a positive multiple of the endpoint maxpacket */
1143 	maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1144 
1145 	if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1146 		dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1147 				usb_pipeendpoint(instance->rx_channel.endpoint));
1148 		error = -EINVAL;
1149 		goto fail_unbind;
1150 	}
1151 
1152 	num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1153 
1154 	if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1155 		num_packets--;
1156 
1157 	instance->rx_channel.buf_size = num_packets * maxpacket;
1158 	instance->rx_channel.packet_size = maxpacket;
1159 
1160 #ifdef DEBUG
1161 	for (i = 0; i < 2; i++) {
1162 		struct usbatm_channel *channel = i ?
1163 			&instance->tx_channel : &instance->rx_channel;
1164 
1165 		dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n", __func__, channel->buf_size, i ? "tx" : "rx", channel);
1166 	}
1167 #endif
1168 
1169 	/* initialize urbs */
1170 
1171 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1172 		u8 *buffer;
1173 		struct usbatm_channel *channel = i < num_rcv_urbs ?
1174 			&instance->rx_channel : &instance->tx_channel;
1175 		struct urb *urb;
1176 		unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1177 
1178 		UDSL_ASSERT(instance, !usb_pipeisoc(channel->endpoint) || usb_pipein(channel->endpoint));
1179 
1180 		urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1181 		if (!urb) {
1182 			dev_err(dev, "%s: no memory for urb %d!\n", __func__, i);
1183 			error = -ENOMEM;
1184 			goto fail_unbind;
1185 		}
1186 
1187 		instance->urbs[i] = urb;
1188 
1189 		/* zero the tx padding to avoid leaking information */
1190 		buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1191 		if (!buffer) {
1192 			dev_err(dev, "%s: no memory for buffer %d!\n", __func__, i);
1193 			error = -ENOMEM;
1194 			goto fail_unbind;
1195 		}
1196 
1197 		usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1198 				  buffer, channel->buf_size, usbatm_complete, channel);
1199 		if (iso_packets) {
1200 			int j;
1201 			urb->interval = 1;
1202 			urb->transfer_flags = URB_ISO_ASAP;
1203 			urb->number_of_packets = iso_packets;
1204 			for (j = 0; j < iso_packets; j++) {
1205 				urb->iso_frame_desc[j].offset = channel->packet_size * j;
1206 				urb->iso_frame_desc[j].length = channel->packet_size;
1207 			}
1208 		}
1209 
1210 		/* put all tx URBs on the list of spares */
1211 		if (i >= num_rcv_urbs)
1212 			list_add_tail(&urb->urb_list, &channel->list);
1213 
1214 		vdbg("%s: alloced buffer 0x%p buf size %u urb 0x%p",
1215 		     __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1216 	}
1217 
1218 	instance->cached_vpi = ATM_VPI_UNSPEC;
1219 	instance->cached_vci = ATM_VCI_UNSPEC;
1220 	instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1221 
1222 	if (!instance->cell_buf) {
1223 		dev_err(dev, "%s: no memory for cell buffer!\n", __func__);
1224 		error = -ENOMEM;
1225 		goto fail_unbind;
1226 	}
1227 
1228 	if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1229 		error = usbatm_heavy_init(instance);
1230 	} else {
1231 		complete(&instance->thread_exited);	/* pretend that heavy_init was run */
1232 		error = usbatm_atm_init(instance);
1233 	}
1234 
1235 	if (error < 0)
1236 		goto fail_unbind;
1237 
1238 	usb_get_dev(usb_dev);
1239 	usb_set_intfdata(intf, instance);
1240 
1241 	return 0;
1242 
1243  fail_unbind:
1244 	if (instance->driver->unbind)
1245 		instance->driver->unbind(instance, intf);
1246  fail_free:
1247 	kfree(instance->cell_buf);
1248 
1249 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1250 		if (instance->urbs[i])
1251 			kfree(instance->urbs[i]->transfer_buffer);
1252 		usb_free_urb(instance->urbs[i]);
1253 	}
1254 
1255 	kfree(instance);
1256 
1257 	return error;
1258 }
1259 EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1260 
1261 void usbatm_usb_disconnect(struct usb_interface *intf)
1262 {
1263 	struct device *dev = &intf->dev;
1264 	struct usbatm_data *instance = usb_get_intfdata(intf);
1265 	struct usbatm_vcc_data *vcc_data;
1266 	int i;
1267 
1268 	dev_dbg(dev, "%s entered\n", __func__);
1269 
1270 	if (!instance) {
1271 		dev_dbg(dev, "%s: NULL instance!\n", __func__);
1272 		return;
1273 	}
1274 
1275 	usb_set_intfdata(intf, NULL);
1276 
1277 	mutex_lock(&instance->serialize);
1278 	instance->disconnected = 1;
1279 	if (instance->thread != NULL)
1280 		send_sig(SIGTERM, instance->thread, 1);
1281 	mutex_unlock(&instance->serialize);
1282 
1283 	wait_for_completion(&instance->thread_exited);
1284 
1285 	mutex_lock(&instance->serialize);
1286 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
1287 		vcc_release_async(vcc_data->vcc, -EPIPE);
1288 	mutex_unlock(&instance->serialize);
1289 
1290 	tasklet_disable(&instance->rx_channel.tasklet);
1291 	tasklet_disable(&instance->tx_channel.tasklet);
1292 
1293 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1294 		usb_kill_urb(instance->urbs[i]);
1295 
1296 	del_timer_sync(&instance->rx_channel.delay);
1297 	del_timer_sync(&instance->tx_channel.delay);
1298 
1299 	/* turn usbatm_[rt]x_process into something close to a no-op */
1300 	/* no need to take the spinlock */
1301 	INIT_LIST_HEAD(&instance->rx_channel.list);
1302 	INIT_LIST_HEAD(&instance->tx_channel.list);
1303 
1304 	tasklet_enable(&instance->rx_channel.tasklet);
1305 	tasklet_enable(&instance->tx_channel.tasklet);
1306 
1307 	if (instance->atm_dev && instance->driver->atm_stop)
1308 		instance->driver->atm_stop(instance, instance->atm_dev);
1309 
1310 	if (instance->driver->unbind)
1311 		instance->driver->unbind(instance, intf);
1312 
1313 	instance->driver_data = NULL;
1314 
1315 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1316 		kfree(instance->urbs[i]->transfer_buffer);
1317 		usb_free_urb(instance->urbs[i]);
1318 	}
1319 
1320 	kfree(instance->cell_buf);
1321 
1322 	/* ATM finalize */
1323 	if (instance->atm_dev) {
1324 		atm_dev_deregister(instance->atm_dev);
1325 		instance->atm_dev = NULL;
1326 	}
1327 
1328 	usbatm_put_instance(instance);	/* taken in usbatm_usb_probe */
1329 }
1330 EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1331 
1332 
1333 /***********
1334 **  init  **
1335 ***********/
1336 
1337 static int __init usbatm_usb_init(void)
1338 {
1339 	dbg("%s: driver version %s", __func__, DRIVER_VERSION);
1340 
1341 	if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
1342 		printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1343 		return -EIO;
1344 	}
1345 
1346 	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1347 	    || (num_snd_urbs > UDSL_MAX_SND_URBS)
1348 	    || (rcv_buf_bytes < 1)
1349 	    || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1350 	    || (snd_buf_bytes < 1)
1351 	    || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1352 		return -EINVAL;
1353 
1354 	return 0;
1355 }
1356 module_init(usbatm_usb_init);
1357 
1358 static void __exit usbatm_usb_exit(void)
1359 {
1360 	dbg("%s", __func__);
1361 }
1362 module_exit(usbatm_usb_exit);
1363 
1364 MODULE_AUTHOR(DRIVER_AUTHOR);
1365 MODULE_DESCRIPTION(DRIVER_DESC);
1366 MODULE_LICENSE("GPL");
1367 MODULE_VERSION(DRIVER_VERSION);
1368 
1369 /************
1370 **  debug  **
1371 ************/
1372 
1373 #ifdef VERBOSE_DEBUG
1374 static int usbatm_print_packet(const unsigned char *data, int len)
1375 {
1376 	unsigned char buffer[256];
1377 	int i = 0, j = 0;
1378 
1379 	for (i = 0; i < len;) {
1380 		buffer[0] = '\0';
1381 		sprintf(buffer, "%.3d :", i);
1382 		for (j = 0; (j < 16) && (i < len); j++, i++)
1383 			sprintf(buffer, "%s %2.2x", buffer, data[i]);
1384 		dbg("%s", buffer);
1385 	}
1386 	return i;
1387 }
1388 #endif
1389