xref: /openbmc/linux/drivers/usb/atm/usbatm.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 
84 #ifdef VERBOSE_DEBUG
85 static int usbatm_print_packet(const unsigned char *data, int len);
86 #define PACKETDEBUG(arg...)	usbatm_print_packet (arg)
87 #define vdbg(arg...)		dbg (arg)
88 #else
89 #define PACKETDEBUG(arg...)
90 #define vdbg(arg...)
91 #endif
92 
93 #define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
94 #define DRIVER_VERSION	"1.10"
95 #define DRIVER_DESC	"Generic USB ATM/DSL I/O, version " DRIVER_VERSION
96 
97 static const char usbatm_driver_name[] = "usbatm";
98 
99 #define UDSL_MAX_RCV_URBS		16
100 #define UDSL_MAX_SND_URBS		16
101 #define UDSL_MAX_BUF_SIZE		65536
102 #define UDSL_DEFAULT_RCV_URBS		4
103 #define UDSL_DEFAULT_SND_URBS		4
104 #define UDSL_DEFAULT_RCV_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
105 #define UDSL_DEFAULT_SND_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
106 
107 #define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
108 
109 #define THROTTLE_MSECS			100	/* delay to recover processing after urb submission fails */
110 
111 static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
112 static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
113 static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
114 static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
115 
116 module_param(num_rcv_urbs, uint, S_IRUGO);
117 MODULE_PARM_DESC(num_rcv_urbs,
118 		 "Number of urbs used for reception (range: 0-"
119 		 __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
120 		 __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
121 
122 module_param(num_snd_urbs, uint, S_IRUGO);
123 MODULE_PARM_DESC(num_snd_urbs,
124 		 "Number of urbs used for transmission (range: 0-"
125 		 __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
126 		 __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
127 
128 module_param(rcv_buf_bytes, uint, S_IRUGO);
129 MODULE_PARM_DESC(rcv_buf_bytes,
130 		 "Size of the buffers used for reception, in bytes (range: 1-"
131 		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
132 		 __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
133 
134 module_param(snd_buf_bytes, uint, S_IRUGO);
135 MODULE_PARM_DESC(snd_buf_bytes,
136 		 "Size of the buffers used for transmission, in bytes (range: 1-"
137 		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
138 		 __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
139 
140 
141 /* receive */
142 
143 struct usbatm_vcc_data {
144 	/* vpi/vci lookup */
145 	struct list_head list;
146 	short vpi;
147 	int vci;
148 	struct atm_vcc *vcc;
149 
150 	/* raw cell reassembly */
151 	struct sk_buff *sarb;
152 };
153 
154 
155 /* send */
156 
157 struct usbatm_control {
158 	struct atm_skb_data atm;
159 	u32 len;
160 	u32 crc;
161 };
162 
163 #define UDSL_SKB(x)		((struct usbatm_control *)(x)->cb)
164 
165 
166 /* ATM */
167 
168 static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
169 static int usbatm_atm_open(struct atm_vcc *vcc);
170 static void usbatm_atm_close(struct atm_vcc *vcc);
171 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user * arg);
172 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
173 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t * pos, char *page);
174 
175 static struct atmdev_ops usbatm_atm_devops = {
176 	.dev_close	= usbatm_atm_dev_close,
177 	.open		= usbatm_atm_open,
178 	.close		= usbatm_atm_close,
179 	.ioctl		= usbatm_atm_ioctl,
180 	.send		= usbatm_atm_send,
181 	.proc_read	= usbatm_atm_proc_read,
182 	.owner		= THIS_MODULE,
183 };
184 
185 
186 /***********
187 **  misc  **
188 ***********/
189 
190 static inline unsigned int usbatm_pdu_length(unsigned int length)
191 {
192 	length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
193 	return length - length % ATM_CELL_PAYLOAD;
194 }
195 
196 static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
197 {
198 	if (vcc->pop)
199 		vcc->pop(vcc, skb);
200 	else
201 		dev_kfree_skb_any(skb);
202 }
203 
204 
205 /***********
206 **  urbs  **
207 ************/
208 
209 static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
210 {
211 	struct urb *urb;
212 
213 	spin_lock_irq(&channel->lock);
214 	if (list_empty(&channel->list)) {
215 		spin_unlock_irq(&channel->lock);
216 		return NULL;
217 	}
218 
219 	urb = list_entry(channel->list.next, struct urb, urb_list);
220 	list_del(&urb->urb_list);
221 	spin_unlock_irq(&channel->lock);
222 
223 	return urb;
224 }
225 
226 static int usbatm_submit_urb(struct urb *urb)
227 {
228 	struct usbatm_channel *channel = urb->context;
229 	int ret;
230 
231 	vdbg("%s: submitting urb 0x%p, size %u",
232 	     __func__, urb, urb->transfer_buffer_length);
233 
234 	ret = usb_submit_urb(urb, GFP_ATOMIC);
235 	if (ret) {
236 		if (printk_ratelimit())
237 			atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
238 				__func__, urb, ret);
239 
240 		/* consider all errors transient and return the buffer back to the queue */
241 		urb->status = -EAGAIN;
242 		spin_lock_irq(&channel->lock);
243 
244 		/* must add to the front when sending; doesn't matter when receiving */
245 		list_add(&urb->urb_list, &channel->list);
246 
247 		spin_unlock_irq(&channel->lock);
248 
249 		/* make sure the channel doesn't stall */
250 		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
251 	}
252 
253 	return ret;
254 }
255 
256 static void usbatm_complete(struct urb *urb)
257 {
258 	struct usbatm_channel *channel = urb->context;
259 	unsigned long flags;
260 	int status = urb->status;
261 
262 	vdbg("%s: urb 0x%p, status %d, actual_length %d",
263 	     __func__, urb, status, urb->actual_length);
264 
265 	/* usually in_interrupt(), but not always */
266 	spin_lock_irqsave(&channel->lock, flags);
267 
268 	/* must add to the back when receiving; doesn't matter when sending */
269 	list_add_tail(&urb->urb_list, &channel->list);
270 
271 	spin_unlock_irqrestore(&channel->lock, flags);
272 
273 	if (unlikely(status) &&
274 			(!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
275 			 status != -EILSEQ ))
276 	{
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(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(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(!(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 		}
519 		else
520 			ctrl->crc = crc32_be(ctrl->crc, ptr, left);
521 	}
522 
523 	return bytes_written;
524 }
525 
526 
527 /**************
528 **  receive  **
529 **************/
530 
531 static void usbatm_rx_process(unsigned long data)
532 {
533 	struct usbatm_data *instance = (struct usbatm_data *)data;
534 	struct urb *urb;
535 
536 	while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
537 		vdbg("%s: processing urb 0x%p", __func__, urb);
538 
539 		if (usb_pipeisoc(urb->pipe)) {
540 			unsigned char *merge_start = NULL;
541 			unsigned int merge_length = 0;
542 			const unsigned int packet_size = instance->rx_channel.packet_size;
543 			int i;
544 
545 			for (i = 0; i < urb->number_of_packets; i++) {
546 				if (!urb->iso_frame_desc[i].status) {
547 					unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
548 
549 					UDSL_ASSERT(actual_length <= packet_size);
550 
551 					if (!merge_length)
552 						merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
553 					merge_length += actual_length;
554 					if (merge_length && (actual_length < packet_size)) {
555 						usbatm_extract_cells(instance, merge_start, merge_length);
556 						merge_length = 0;
557 					}
558 				} else {
559 					atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
560 					if (merge_length)
561 						usbatm_extract_cells(instance, merge_start, merge_length);
562 					merge_length = 0;
563 					instance->buf_usage = 0;
564 				}
565 			}
566 
567 			if (merge_length)
568 				usbatm_extract_cells(instance, merge_start, merge_length);
569 		} else
570 			if (!urb->status)
571 				usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
572 			else
573 				instance->buf_usage = 0;
574 
575 		if (usbatm_submit_urb(urb))
576 			return;
577 	}
578 }
579 
580 
581 /***********
582 **  send  **
583 ***********/
584 
585 static void usbatm_tx_process(unsigned long data)
586 {
587 	struct usbatm_data *instance = (struct usbatm_data *)data;
588 	struct sk_buff *skb = instance->current_skb;
589 	struct urb *urb = NULL;
590 	const unsigned int buf_size = instance->tx_channel.buf_size;
591 	unsigned int bytes_written = 0;
592 	u8 *buffer = NULL;
593 
594 	if (!skb)
595 		skb = skb_dequeue(&instance->sndqueue);
596 
597 	while (skb) {
598 		if (!urb) {
599 			urb = usbatm_pop_urb(&instance->tx_channel);
600 			if (!urb)
601 				break;		/* no more senders */
602 			buffer = urb->transfer_buffer;
603 			bytes_written = (urb->status == -EAGAIN) ?
604 				urb->transfer_buffer_length : 0;
605 		}
606 
607 		bytes_written += usbatm_write_cells(instance, skb,
608 						  buffer + bytes_written,
609 						  buf_size - bytes_written);
610 
611 		vdbg("%s: wrote %u bytes from skb 0x%p to urb 0x%p",
612 		     __func__, bytes_written, skb, urb);
613 
614 		if (!UDSL_SKB(skb)->len) {
615 			struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
616 
617 			usbatm_pop(vcc, skb);
618 			atomic_inc(&vcc->stats->tx);
619 
620 			skb = skb_dequeue(&instance->sndqueue);
621 		}
622 
623 		if (bytes_written == buf_size || (!skb && bytes_written)) {
624 			urb->transfer_buffer_length = bytes_written;
625 
626 			if (usbatm_submit_urb(urb))
627 				break;
628 			urb = NULL;
629 		}
630 	}
631 
632 	instance->current_skb = skb;
633 }
634 
635 static void usbatm_cancel_send(struct usbatm_data *instance,
636 			       struct atm_vcc *vcc)
637 {
638 	struct sk_buff *skb, *n;
639 
640 	atm_dbg(instance, "%s entered\n", __func__);
641 	spin_lock_irq(&instance->sndqueue.lock);
642 	for (skb = instance->sndqueue.next, n = skb->next;
643 	     skb != (struct sk_buff *)&instance->sndqueue;
644 	     skb = n, n = skb->next)
645 		if (UDSL_SKB(skb)->atm.vcc == vcc) {
646 			atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
647 			__skb_unlink(skb, &instance->sndqueue);
648 			usbatm_pop(vcc, skb);
649 		}
650 	spin_unlock_irq(&instance->sndqueue.lock);
651 
652 	tasklet_disable(&instance->tx_channel.tasklet);
653 	if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
654 		atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
655 		instance->current_skb = NULL;
656 		usbatm_pop(vcc, skb);
657 	}
658 	tasklet_enable(&instance->tx_channel.tasklet);
659 	atm_dbg(instance, "%s done\n", __func__);
660 }
661 
662 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
663 {
664 	struct usbatm_data *instance = vcc->dev->dev_data;
665 	struct usbatm_control *ctrl = UDSL_SKB(skb);
666 	int err;
667 
668 	vdbg("%s called (skb 0x%p, len %u)", __func__, skb, skb->len);
669 
670 	/* racy disconnection check - fine */
671 	if (!instance || instance->disconnected) {
672 #ifdef DEBUG
673 		if (printk_ratelimit())
674 			printk(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
675 #endif
676 		err = -ENODEV;
677 		goto fail;
678 	}
679 
680 	if (vcc->qos.aal != ATM_AAL5) {
681 		atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
682 		err = -EINVAL;
683 		goto fail;
684 	}
685 
686 	if (skb->len > ATM_MAX_AAL5_PDU) {
687 		atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
688 				__func__, skb->len, ATM_MAX_AAL5_PDU);
689 		err = -EINVAL;
690 		goto fail;
691 	}
692 
693 	PACKETDEBUG(skb->data, skb->len);
694 
695 	/* initialize the control block */
696 	ctrl->atm.vcc = vcc;
697 	ctrl->len = skb->len;
698 	ctrl->crc = crc32_be(~0, skb->data, skb->len);
699 
700 	skb_queue_tail(&instance->sndqueue, skb);
701 	tasklet_schedule(&instance->tx_channel.tasklet);
702 
703 	return 0;
704 
705  fail:
706 	usbatm_pop(vcc, skb);
707 	return err;
708 }
709 
710 
711 /********************
712 **  bean counting  **
713 ********************/
714 
715 static void usbatm_destroy_instance(struct kref *kref)
716 {
717 	struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
718 
719 	dbg("%s", __func__);
720 
721 	tasklet_kill(&instance->rx_channel.tasklet);
722 	tasklet_kill(&instance->tx_channel.tasklet);
723 	usb_put_dev(instance->usb_dev);
724 	kfree(instance);
725 }
726 
727 static void usbatm_get_instance(struct usbatm_data *instance)
728 {
729 	dbg("%s", __func__);
730 
731 	kref_get(&instance->refcount);
732 }
733 
734 static void usbatm_put_instance(struct usbatm_data *instance)
735 {
736 	dbg("%s", __func__);
737 
738 	kref_put(&instance->refcount, usbatm_destroy_instance);
739 }
740 
741 
742 /**********
743 **  ATM  **
744 **********/
745 
746 static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
747 {
748 	struct usbatm_data *instance = atm_dev->dev_data;
749 
750 	dbg("%s", __func__);
751 
752 	if (!instance)
753 		return;
754 
755 	atm_dev->dev_data = NULL; /* catch bugs */
756 	usbatm_put_instance(instance);	/* taken in usbatm_atm_init */
757 }
758 
759 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t * pos, char *page)
760 {
761 	struct usbatm_data *instance = atm_dev->dev_data;
762 	int left = *pos;
763 
764 	if (!instance) {
765 		dbg("%s: NULL instance!", __func__);
766 		return -ENODEV;
767 	}
768 
769 	if (!left--)
770 		return sprintf(page, "%s\n", instance->description);
771 
772 	if (!left--)
773 		return sprintf(page, "MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
774 			       atm_dev->esi[0], atm_dev->esi[1],
775 			       atm_dev->esi[2], atm_dev->esi[3],
776 			       atm_dev->esi[4], atm_dev->esi[5]);
777 
778 	if (!left--)
779 		return sprintf(page,
780 			       "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
781 			       atomic_read(&atm_dev->stats.aal5.tx),
782 			       atomic_read(&atm_dev->stats.aal5.tx_err),
783 			       atomic_read(&atm_dev->stats.aal5.rx),
784 			       atomic_read(&atm_dev->stats.aal5.rx_err),
785 			       atomic_read(&atm_dev->stats.aal5.rx_drop));
786 
787 	if (!left--) {
788 		if (instance->disconnected)
789 			return sprintf(page, "Disconnected\n");
790 		else
791 			switch (atm_dev->signal) {
792 			case ATM_PHY_SIG_FOUND:
793 				return sprintf(page, "Line up\n");
794 			case ATM_PHY_SIG_LOST:
795 				return sprintf(page, "Line down\n");
796 			default:
797 				return sprintf(page, "Line state unknown\n");
798 			}
799 	}
800 
801 	return 0;
802 }
803 
804 static int usbatm_atm_open(struct atm_vcc *vcc)
805 {
806 	struct usbatm_data *instance = vcc->dev->dev_data;
807 	struct usbatm_vcc_data *new = NULL;
808 	int ret;
809 	int vci = vcc->vci;
810 	short vpi = vcc->vpi;
811 
812 	if (!instance) {
813 		dbg("%s: NULL data!", __func__);
814 		return -ENODEV;
815 	}
816 
817 	atm_dbg(instance, "%s: vpi %hd, vci %d\n", __func__, vpi, vci);
818 
819 	/* only support AAL5 */
820 	if ((vcc->qos.aal != ATM_AAL5)) {
821 		atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
822 		return -EINVAL;
823 	}
824 
825 	/* sanity checks */
826 	if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
827 		atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
828 		return -EINVAL;
829 	}
830 
831 	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_close, usbatm_usb_disconnect */
832 
833 	if (instance->disconnected) {
834 		atm_dbg(instance, "%s: disconnected!\n", __func__);
835 		ret = -ENODEV;
836 		goto fail;
837 	}
838 
839 	if (usbatm_find_vcc(instance, vpi, vci)) {
840 		atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
841 		ret = -EADDRINUSE;
842 		goto fail;
843 	}
844 
845 	if (!(new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL))) {
846 		atm_err(instance, "%s: no memory for vcc_data!\n", __func__);
847 		ret = -ENOMEM;
848 		goto fail;
849 	}
850 
851 	new->vcc = vcc;
852 	new->vpi = vpi;
853 	new->vci = vci;
854 
855 	new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
856 	if (!new->sarb) {
857 		atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
858 		ret = -ENOMEM;
859 		goto fail;
860 	}
861 
862 	vcc->dev_data = new;
863 
864 	tasklet_disable(&instance->rx_channel.tasklet);
865 	instance->cached_vcc = new;
866 	instance->cached_vpi = vpi;
867 	instance->cached_vci = vci;
868 	list_add(&new->list, &instance->vcc_list);
869 	tasklet_enable(&instance->rx_channel.tasklet);
870 
871 	set_bit(ATM_VF_ADDR, &vcc->flags);
872 	set_bit(ATM_VF_PARTIAL, &vcc->flags);
873 	set_bit(ATM_VF_READY, &vcc->flags);
874 
875 	mutex_unlock(&instance->serialize);
876 
877 	atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
878 
879 	return 0;
880 
881 fail:
882 	kfree(new);
883 	mutex_unlock(&instance->serialize);
884 	return ret;
885 }
886 
887 static void usbatm_atm_close(struct atm_vcc *vcc)
888 {
889 	struct usbatm_data *instance = vcc->dev->dev_data;
890 	struct usbatm_vcc_data *vcc_data = vcc->dev_data;
891 
892 	if (!instance || !vcc_data) {
893 		dbg("%s: NULL data!", __func__);
894 		return;
895 	}
896 
897 	atm_dbg(instance, "%s entered\n", __func__);
898 
899 	atm_dbg(instance, "%s: deallocating vcc 0x%p with vpi %d vci %d\n",
900 		__func__, vcc_data, vcc_data->vpi, vcc_data->vci);
901 
902 	usbatm_cancel_send(instance, vcc);
903 
904 	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_open, usbatm_usb_disconnect */
905 
906 	tasklet_disable(&instance->rx_channel.tasklet);
907 	if (instance->cached_vcc == vcc_data) {
908 		instance->cached_vcc = NULL;
909 		instance->cached_vpi = ATM_VPI_UNSPEC;
910 		instance->cached_vci = ATM_VCI_UNSPEC;
911 	}
912 	list_del(&vcc_data->list);
913 	tasklet_enable(&instance->rx_channel.tasklet);
914 
915 	kfree_skb(vcc_data->sarb);
916 	vcc_data->sarb = NULL;
917 
918 	kfree(vcc_data);
919 	vcc->dev_data = NULL;
920 
921 	vcc->vpi = ATM_VPI_UNSPEC;
922 	vcc->vci = ATM_VCI_UNSPEC;
923 	clear_bit(ATM_VF_READY, &vcc->flags);
924 	clear_bit(ATM_VF_PARTIAL, &vcc->flags);
925 	clear_bit(ATM_VF_ADDR, &vcc->flags);
926 
927 	mutex_unlock(&instance->serialize);
928 
929 	atm_dbg(instance, "%s successful\n", __func__);
930 }
931 
932 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
933 			  void __user * arg)
934 {
935 	struct usbatm_data *instance = atm_dev->dev_data;
936 
937 	if (!instance || instance->disconnected) {
938 		dbg("%s: %s!", __func__, instance ? "disconnected" : "NULL instance");
939 		return -ENODEV;
940 	}
941 
942 	switch (cmd) {
943 	case ATM_QUERYLOOP:
944 		return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
945 	default:
946 		return -ENOIOCTLCMD;
947 	}
948 }
949 
950 static int usbatm_atm_init(struct usbatm_data *instance)
951 {
952 	struct atm_dev *atm_dev;
953 	int ret, i;
954 
955 	/* ATM init.  The ATM initialization scheme suffers from an intrinsic race
956 	 * condition: callbacks we register can be executed at once, before we have
957 	 * initialized the struct atm_dev.  To protect against this, all callbacks
958 	 * abort if atm_dev->dev_data is NULL. */
959 	atm_dev = atm_dev_register(instance->driver_name, &usbatm_atm_devops, -1, NULL);
960 	if (!atm_dev) {
961 		usb_err(instance, "%s: failed to register ATM device!\n", __func__);
962 		return -1;
963 	}
964 
965 	instance->atm_dev = atm_dev;
966 
967 	atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
968 	atm_dev->ci_range.vci_bits = ATM_CI_MAX;
969 	atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
970 
971 	/* temp init ATM device, set to 128kbit */
972 	atm_dev->link_rate = 128 * 1000 / 424;
973 
974 	ret = sysfs_create_link(&atm_dev->class_dev.kobj,
975 				&instance->usb_intf->dev.kobj, "device");
976 	if (ret) {
977 		atm_err(instance, "%s: sysfs_create_link failed: %d\n",
978 					__func__, ret);
979 		goto fail_sysfs;
980 	}
981 
982 	if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
983 		atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
984 		goto fail;
985 	}
986 
987 	usbatm_get_instance(instance);	/* dropped in usbatm_atm_dev_close */
988 
989 	/* ready for ATM callbacks */
990 	mb();
991 	atm_dev->dev_data = instance;
992 
993 	/* submit all rx URBs */
994 	for (i = 0; i < num_rcv_urbs; i++)
995 		usbatm_submit_urb(instance->urbs[i]);
996 
997 	return 0;
998 
999  fail:
1000 	sysfs_remove_link(&atm_dev->class_dev.kobj, "device");
1001  fail_sysfs:
1002 	instance->atm_dev = NULL;
1003 	atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
1004 	return ret;
1005 }
1006 
1007 
1008 /**********
1009 **  USB  **
1010 **********/
1011 
1012 static int usbatm_do_heavy_init(void *arg)
1013 {
1014 	struct usbatm_data *instance = arg;
1015 	int ret;
1016 
1017 	daemonize(instance->driver->driver_name);
1018 	allow_signal(SIGTERM);
1019 	instance->thread_pid = current->pid;
1020 
1021 	complete(&instance->thread_started);
1022 
1023 	ret = instance->driver->heavy_init(instance, instance->usb_intf);
1024 
1025 	if (!ret)
1026 		ret = usbatm_atm_init(instance);
1027 
1028 	mutex_lock(&instance->serialize);
1029 	instance->thread_pid = -1;
1030 	mutex_unlock(&instance->serialize);
1031 
1032 	complete_and_exit(&instance->thread_exited, ret);
1033 }
1034 
1035 static int usbatm_heavy_init(struct usbatm_data *instance)
1036 {
1037 	int ret = kernel_thread(usbatm_do_heavy_init, instance, CLONE_FS | CLONE_FILES);
1038 
1039 	if (ret < 0) {
1040 		usb_err(instance, "%s: failed to create kernel_thread (%d)!\n", __func__, ret);
1041 		return ret;
1042 	}
1043 
1044 	wait_for_completion(&instance->thread_started);
1045 
1046 	return 0;
1047 }
1048 
1049 static void usbatm_tasklet_schedule(unsigned long data)
1050 {
1051 	tasklet_schedule((struct tasklet_struct *) data);
1052 }
1053 
1054 static void usbatm_init_channel(struct usbatm_channel *channel)
1055 {
1056 	spin_lock_init(&channel->lock);
1057 	INIT_LIST_HEAD(&channel->list);
1058 	channel->delay.function = usbatm_tasklet_schedule;
1059 	channel->delay.data = (unsigned long) &channel->tasklet;
1060 	init_timer(&channel->delay);
1061 }
1062 
1063 int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1064 		     struct usbatm_driver *driver)
1065 {
1066 	struct device *dev = &intf->dev;
1067 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1068 	struct usbatm_data *instance;
1069 	char *buf;
1070 	int error = -ENOMEM;
1071 	int i, length;
1072 	unsigned int maxpacket, num_packets;
1073 
1074 	dev_dbg(dev, "%s: trying driver %s with vendor=%04x, product=%04x, ifnum %2d\n",
1075 			__func__, driver->driver_name,
1076 			le16_to_cpu(usb_dev->descriptor.idVendor),
1077 			le16_to_cpu(usb_dev->descriptor.idProduct),
1078 			intf->altsetting->desc.bInterfaceNumber);
1079 
1080 	/* instance init */
1081 	instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1082 	if (!instance) {
1083 		dev_err(dev, "%s: no memory for instance data!\n", __func__);
1084 		return -ENOMEM;
1085 	}
1086 
1087 	/* public fields */
1088 
1089 	instance->driver = driver;
1090 	snprintf(instance->driver_name, sizeof(instance->driver_name), driver->driver_name);
1091 
1092 	instance->usb_dev = usb_dev;
1093 	instance->usb_intf = intf;
1094 
1095 	buf = instance->description;
1096 	length = sizeof(instance->description);
1097 
1098 	if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1099 		goto bind;
1100 
1101 	buf += i;
1102 	length -= i;
1103 
1104 	i = scnprintf(buf, length, " (");
1105 	buf += i;
1106 	length -= i;
1107 
1108 	if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1109 		goto bind;
1110 
1111 	buf += i;
1112 	length -= i;
1113 
1114 	snprintf(buf, length, ")");
1115 
1116  bind:
1117 	if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1118 			dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1119 			goto fail_free;
1120 	}
1121 
1122 	/* private fields */
1123 
1124 	kref_init(&instance->refcount);		/* dropped in usbatm_usb_disconnect */
1125 	mutex_init(&instance->serialize);
1126 
1127 	instance->thread_pid = -1;
1128 	init_completion(&instance->thread_started);
1129 	init_completion(&instance->thread_exited);
1130 
1131 	INIT_LIST_HEAD(&instance->vcc_list);
1132 	skb_queue_head_init(&instance->sndqueue);
1133 
1134 	usbatm_init_channel(&instance->rx_channel);
1135 	usbatm_init_channel(&instance->tx_channel);
1136 	tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1137 	tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1138 	instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1139 	instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1140 	instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1141 
1142 	if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1143 		instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1144 	else
1145 		instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1146 
1147 	instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1148 
1149 	/* tx buffer size must be a positive multiple of the stride */
1150 	instance->tx_channel.buf_size = max (instance->tx_channel.stride,
1151 			snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1152 
1153 	/* rx buffer size must be a positive multiple of the endpoint maxpacket */
1154 	maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1155 
1156 	if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1157 		dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1158 				usb_pipeendpoint(instance->rx_channel.endpoint));
1159 		error = -EINVAL;
1160 		goto fail_unbind;
1161 	}
1162 
1163 	num_packets = max (1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1164 
1165 	if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1166 		num_packets--;
1167 
1168 	instance->rx_channel.buf_size = num_packets * maxpacket;
1169 	instance->rx_channel.packet_size = maxpacket;
1170 
1171 #ifdef DEBUG
1172 	for (i = 0; i < 2; i++) {
1173 		struct usbatm_channel *channel = i ?
1174 			&instance->tx_channel : &instance->rx_channel;
1175 
1176 		dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n", __func__, channel->buf_size, i ? "tx" : "rx", channel);
1177 	}
1178 #endif
1179 
1180 	/* initialize urbs */
1181 
1182 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1183 		u8 *buffer;
1184 		struct usbatm_channel *channel = i < num_rcv_urbs ?
1185 			&instance->rx_channel : &instance->tx_channel;
1186 		struct urb *urb;
1187 		unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1188 
1189 		UDSL_ASSERT(!usb_pipeisoc(channel->endpoint) || usb_pipein(channel->endpoint));
1190 
1191 		urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1192 		if (!urb) {
1193 			dev_err(dev, "%s: no memory for urb %d!\n", __func__, i);
1194 			error = -ENOMEM;
1195 			goto fail_unbind;
1196 		}
1197 
1198 		instance->urbs[i] = urb;
1199 
1200 		/* zero the tx padding to avoid leaking information */
1201 		buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1202 		if (!buffer) {
1203 			dev_err(dev, "%s: no memory for buffer %d!\n", __func__, i);
1204 			error = -ENOMEM;
1205 			goto fail_unbind;
1206 		}
1207 
1208 		usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1209 				  buffer, channel->buf_size, usbatm_complete, channel);
1210 		if (iso_packets) {
1211 			int j;
1212 			urb->interval = 1;
1213 			urb->transfer_flags = URB_ISO_ASAP;
1214 			urb->number_of_packets = iso_packets;
1215 			for (j = 0; j < iso_packets; j++) {
1216 				urb->iso_frame_desc[j].offset = channel->packet_size * j;
1217 				urb->iso_frame_desc[j].length = channel->packet_size;
1218 			}
1219 		}
1220 
1221 		/* put all tx URBs on the list of spares */
1222 		if (i >= num_rcv_urbs)
1223 			list_add_tail(&urb->urb_list, &channel->list);
1224 
1225 		vdbg("%s: alloced buffer 0x%p buf size %u urb 0x%p",
1226 		     __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1227 	}
1228 
1229 	instance->cached_vpi = ATM_VPI_UNSPEC;
1230 	instance->cached_vci = ATM_VCI_UNSPEC;
1231 	instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1232 
1233 	if (!instance->cell_buf) {
1234 		dev_err(dev, "%s: no memory for cell buffer!\n", __func__);
1235 		error = -ENOMEM;
1236 		goto fail_unbind;
1237 	}
1238 
1239 	if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1240 		error = usbatm_heavy_init(instance);
1241 	} else {
1242 		complete(&instance->thread_exited);	/* pretend that heavy_init was run */
1243 		error = usbatm_atm_init(instance);
1244 	}
1245 
1246 	if (error < 0)
1247 		goto fail_unbind;
1248 
1249 	usb_get_dev(usb_dev);
1250 	usb_set_intfdata(intf, instance);
1251 
1252 	return 0;
1253 
1254  fail_unbind:
1255 	if (instance->driver->unbind)
1256 		instance->driver->unbind(instance, intf);
1257  fail_free:
1258 	kfree(instance->cell_buf);
1259 
1260 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1261 		if (instance->urbs[i])
1262 			kfree(instance->urbs[i]->transfer_buffer);
1263 		usb_free_urb(instance->urbs[i]);
1264 	}
1265 
1266 	kfree (instance);
1267 
1268 	return error;
1269 }
1270 EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1271 
1272 void usbatm_usb_disconnect(struct usb_interface *intf)
1273 {
1274 	struct device *dev = &intf->dev;
1275 	struct usbatm_data *instance = usb_get_intfdata(intf);
1276 	struct usbatm_vcc_data *vcc_data;
1277 	int i;
1278 
1279 	dev_dbg(dev, "%s entered\n", __func__);
1280 
1281 	if (!instance) {
1282 		dev_dbg(dev, "%s: NULL instance!\n", __func__);
1283 		return;
1284 	}
1285 
1286 	usb_set_intfdata(intf, NULL);
1287 
1288 	mutex_lock(&instance->serialize);
1289 	instance->disconnected = 1;
1290 	if (instance->thread_pid >= 0)
1291 		kill_proc(instance->thread_pid, SIGTERM, 1);
1292 	mutex_unlock(&instance->serialize);
1293 
1294 	wait_for_completion(&instance->thread_exited);
1295 
1296 	mutex_lock(&instance->serialize);
1297 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
1298 		vcc_release_async(vcc_data->vcc, -EPIPE);
1299 	mutex_unlock(&instance->serialize);
1300 
1301 	tasklet_disable(&instance->rx_channel.tasklet);
1302 	tasklet_disable(&instance->tx_channel.tasklet);
1303 
1304 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1305 		usb_kill_urb(instance->urbs[i]);
1306 
1307 	del_timer_sync(&instance->rx_channel.delay);
1308 	del_timer_sync(&instance->tx_channel.delay);
1309 
1310 	/* turn usbatm_[rt]x_process into something close to a no-op */
1311 	/* no need to take the spinlock */
1312 	INIT_LIST_HEAD(&instance->rx_channel.list);
1313 	INIT_LIST_HEAD(&instance->tx_channel.list);
1314 
1315 	tasklet_enable(&instance->rx_channel.tasklet);
1316 	tasklet_enable(&instance->tx_channel.tasklet);
1317 
1318 	if (instance->atm_dev && instance->driver->atm_stop)
1319 		instance->driver->atm_stop(instance, instance->atm_dev);
1320 
1321 	if (instance->driver->unbind)
1322 		instance->driver->unbind(instance, intf);
1323 
1324 	instance->driver_data = NULL;
1325 
1326 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1327 		kfree(instance->urbs[i]->transfer_buffer);
1328 		usb_free_urb(instance->urbs[i]);
1329 	}
1330 
1331 	kfree(instance->cell_buf);
1332 
1333 	/* ATM finalize */
1334 	if (instance->atm_dev) {
1335 		sysfs_remove_link(&instance->atm_dev->class_dev.kobj, "device");
1336 		atm_dev_deregister(instance->atm_dev);
1337 	}
1338 
1339 	usbatm_put_instance(instance);	/* taken in usbatm_usb_probe */
1340 }
1341 EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1342 
1343 
1344 /***********
1345 **  init  **
1346 ***********/
1347 
1348 static int __init usbatm_usb_init(void)
1349 {
1350 	dbg("%s: driver version %s", __func__, DRIVER_VERSION);
1351 
1352 	if (sizeof(struct usbatm_control) > sizeof(((struct sk_buff *) 0)->cb)) {
1353 		printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1354 		return -EIO;
1355 	}
1356 
1357 	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1358 	    || (num_snd_urbs > UDSL_MAX_SND_URBS)
1359 	    || (rcv_buf_bytes < 1)
1360 	    || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1361 	    || (snd_buf_bytes < 1)
1362 	    || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1363 		return -EINVAL;
1364 
1365 	return 0;
1366 }
1367 module_init(usbatm_usb_init);
1368 
1369 static void __exit usbatm_usb_exit(void)
1370 {
1371 	dbg("%s", __func__);
1372 }
1373 module_exit(usbatm_usb_exit);
1374 
1375 MODULE_AUTHOR(DRIVER_AUTHOR);
1376 MODULE_DESCRIPTION(DRIVER_DESC);
1377 MODULE_LICENSE("GPL");
1378 MODULE_VERSION(DRIVER_VERSION);
1379 
1380 /************
1381 **  debug  **
1382 ************/
1383 
1384 #ifdef VERBOSE_DEBUG
1385 static int usbatm_print_packet(const unsigned char *data, int len)
1386 {
1387 	unsigned char buffer[256];
1388 	int i = 0, j = 0;
1389 
1390 	for (i = 0; i < len;) {
1391 		buffer[0] = '\0';
1392 		sprintf(buffer, "%.3d :", i);
1393 		for (j = 0; (j < 16) && (i < len); j++, i++) {
1394 			sprintf(buffer, "%s %2.2x", buffer, data[i]);
1395 		}
1396 		dbg("%s", buffer);
1397 	}
1398 	return i;
1399 }
1400 #endif
1401