xref: /openbmc/linux/drivers/usb/atm/usbatm.c (revision 9ac8d3fb)
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 	{
278 		if (status == -ESHUTDOWN)
279 			return;
280 
281 		if (printk_ratelimit())
282 			atm_warn(channel->usbatm, "%s: urb 0x%p failed (%d)!\n",
283 				__func__, urb, status);
284 		/* throttle processing in case of an error */
285 		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
286 	} else
287 		tasklet_schedule(&channel->tasklet);
288 }
289 
290 
291 /*************
292 **  decode  **
293 *************/
294 
295 static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
296 						  short vpi, int vci)
297 {
298 	struct usbatm_vcc_data *vcc_data;
299 
300 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
301 		if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
302 			return vcc_data;
303 	return NULL;
304 }
305 
306 static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
307 {
308 	struct atm_vcc *vcc;
309 	struct sk_buff *sarb;
310 	short vpi = ((source[0] & 0x0f) << 4)  | (source[1] >> 4);
311 	int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
312 	u8 pti = ((source[3] & 0xe) >> 1);
313 
314 	vdbg("%s: vpi %hd, vci %d, pti %d", __func__, vpi, vci, pti);
315 
316 	if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
317 		instance->cached_vpi = vpi;
318 		instance->cached_vci = vci;
319 
320 		instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
321 
322 		if (!instance->cached_vcc)
323 			atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
324 	}
325 
326 	if (!instance->cached_vcc)
327 		return;
328 
329 	vcc = instance->cached_vcc->vcc;
330 
331 	/* OAM F5 end-to-end */
332 	if (pti == ATM_PTI_E2EF5) {
333 		if (printk_ratelimit())
334 			atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
335 				__func__, vpi, vci);
336 		atomic_inc(&vcc->stats->rx_err);
337 		return;
338 	}
339 
340 	sarb = instance->cached_vcc->sarb;
341 
342 	if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
343 		atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
344 				__func__, sarb->len, vcc);
345 		/* discard cells already received */
346 		skb_trim(sarb, 0);
347 		UDSL_ASSERT(instance, sarb->tail + ATM_CELL_PAYLOAD <= sarb->end);
348 	}
349 
350 	memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
351 	__skb_put(sarb, ATM_CELL_PAYLOAD);
352 
353 	if (pti & 1) {
354 		struct sk_buff *skb;
355 		unsigned int length;
356 		unsigned int pdu_length;
357 
358 		length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
359 
360 		/* guard against overflow */
361 		if (length > ATM_MAX_AAL5_PDU) {
362 			atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
363 				  __func__, length, vcc);
364 			atomic_inc(&vcc->stats->rx_err);
365 			goto out;
366 		}
367 
368 		pdu_length = usbatm_pdu_length(length);
369 
370 		if (sarb->len < pdu_length) {
371 			atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
372 				  __func__, pdu_length, sarb->len, vcc);
373 			atomic_inc(&vcc->stats->rx_err);
374 			goto out;
375 		}
376 
377 		if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
378 			atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
379 				  __func__, vcc);
380 			atomic_inc(&vcc->stats->rx_err);
381 			goto out;
382 		}
383 
384 		vdbg("%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)", __func__, length, pdu_length, vcc);
385 
386 		if (!(skb = dev_alloc_skb(length))) {
387 			if (printk_ratelimit())
388 				atm_err(instance, "%s: no memory for skb (length: %u)!\n",
389 					__func__, length);
390 			atomic_inc(&vcc->stats->rx_drop);
391 			goto out;
392 		}
393 
394 		vdbg("%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)", __func__, skb, skb->truesize);
395 
396 		if (!atm_charge(vcc, skb->truesize)) {
397 			atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
398 				  __func__, skb->truesize);
399 			dev_kfree_skb_any(skb);
400 			goto out;	/* atm_charge increments rx_drop */
401 		}
402 
403 		skb_copy_to_linear_data(skb,
404 					skb_tail_pointer(sarb) - pdu_length,
405 					length);
406 		__skb_put(skb, length);
407 
408 		vdbg("%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
409 		     __func__, skb, skb->len, skb->truesize);
410 
411 		PACKETDEBUG(skb->data, skb->len);
412 
413 		vcc->push(vcc, skb);
414 
415 		atomic_inc(&vcc->stats->rx);
416 	out:
417 		skb_trim(sarb, 0);
418 	}
419 }
420 
421 static void usbatm_extract_cells(struct usbatm_data *instance,
422 		unsigned char *source, unsigned int avail_data)
423 {
424 	unsigned int stride = instance->rx_channel.stride;
425 	unsigned int buf_usage = instance->buf_usage;
426 
427 	/* extract cells from incoming data, taking into account that
428 	 * the length of avail data may not be a multiple of stride */
429 
430 	if (buf_usage > 0) {
431 		/* we have a partially received atm cell */
432 		unsigned char *cell_buf = instance->cell_buf;
433 		unsigned int space_left = stride - buf_usage;
434 
435 		UDSL_ASSERT(instance, buf_usage <= stride);
436 
437 		if (avail_data >= space_left) {
438 			/* add new data and process cell */
439 			memcpy(cell_buf + buf_usage, source, space_left);
440 			source += space_left;
441 			avail_data -= space_left;
442 			usbatm_extract_one_cell(instance, cell_buf);
443 			instance->buf_usage = 0;
444 		} else {
445 			/* not enough data to fill the cell */
446 			memcpy(cell_buf + buf_usage, source, avail_data);
447 			instance->buf_usage = buf_usage + avail_data;
448 			return;
449 		}
450 	}
451 
452 	for (; avail_data >= stride; avail_data -= stride, source += stride)
453 		usbatm_extract_one_cell(instance, source);
454 
455 	if (avail_data > 0) {
456 		/* length was not a multiple of stride -
457 		 * save remaining data for next call */
458 		memcpy(instance->cell_buf, source, avail_data);
459 		instance->buf_usage = avail_data;
460 	}
461 }
462 
463 
464 /*************
465 **  encode  **
466 *************/
467 
468 static unsigned int usbatm_write_cells(struct usbatm_data *instance,
469 				       struct sk_buff *skb,
470 				       u8 *target, unsigned int avail_space)
471 {
472 	struct usbatm_control *ctrl = UDSL_SKB(skb);
473 	struct atm_vcc *vcc = ctrl->atm.vcc;
474 	unsigned int bytes_written;
475 	unsigned int stride = instance->tx_channel.stride;
476 
477 	vdbg("%s: skb->len=%d, avail_space=%u", __func__, skb->len, avail_space);
478 	UDSL_ASSERT(instance, !(avail_space % stride));
479 
480 	for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
481 	     bytes_written += stride, target += stride) {
482 		unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
483 		unsigned int left = ATM_CELL_PAYLOAD - data_len;
484 		u8 *ptr = target;
485 
486 		ptr[0] = vcc->vpi >> 4;
487 		ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
488 		ptr[2] = vcc->vci >> 4;
489 		ptr[3] = vcc->vci << 4;
490 		ptr[4] = 0xec;
491 		ptr += ATM_CELL_HEADER;
492 
493 		skb_copy_from_linear_data(skb, ptr, data_len);
494 		ptr += data_len;
495 		__skb_pull(skb, data_len);
496 
497 		if(!left)
498 			continue;
499 
500 		memset(ptr, 0, left);
501 
502 		if (left >= ATM_AAL5_TRAILER) {	/* trailer will go in this cell */
503 			u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
504 			/* trailer[0] = 0;		UU = 0 */
505 			/* trailer[1] = 0;		CPI = 0 */
506 			trailer[2] = ctrl->len >> 8;
507 			trailer[3] = ctrl->len;
508 
509 			ctrl->crc = ~ crc32_be(ctrl->crc, ptr, left - 4);
510 
511 			trailer[4] = ctrl->crc >> 24;
512 			trailer[5] = ctrl->crc >> 16;
513 			trailer[6] = ctrl->crc >> 8;
514 			trailer[7] = ctrl->crc;
515 
516 			target[3] |= 0x2;	/* adjust PTI */
517 
518 			ctrl->len = 0;		/* tag this skb finished */
519 		}
520 		else
521 			ctrl->crc = crc32_be(ctrl->crc, ptr, left);
522 	}
523 
524 	return bytes_written;
525 }
526 
527 
528 /**************
529 **  receive  **
530 **************/
531 
532 static void usbatm_rx_process(unsigned long data)
533 {
534 	struct usbatm_data *instance = (struct usbatm_data *)data;
535 	struct urb *urb;
536 
537 	while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
538 		vdbg("%s: processing urb 0x%p", __func__, urb);
539 
540 		if (usb_pipeisoc(urb->pipe)) {
541 			unsigned char *merge_start = NULL;
542 			unsigned int merge_length = 0;
543 			const unsigned int packet_size = instance->rx_channel.packet_size;
544 			int i;
545 
546 			for (i = 0; i < urb->number_of_packets; i++) {
547 				if (!urb->iso_frame_desc[i].status) {
548 					unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
549 
550 					UDSL_ASSERT(instance, actual_length <= packet_size);
551 
552 					if (!merge_length)
553 						merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
554 					merge_length += actual_length;
555 					if (merge_length && (actual_length < packet_size)) {
556 						usbatm_extract_cells(instance, merge_start, merge_length);
557 						merge_length = 0;
558 					}
559 				} else {
560 					atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
561 					if (merge_length)
562 						usbatm_extract_cells(instance, merge_start, merge_length);
563 					merge_length = 0;
564 					instance->buf_usage = 0;
565 				}
566 			}
567 
568 			if (merge_length)
569 				usbatm_extract_cells(instance, merge_start, merge_length);
570 		} else
571 			if (!urb->status)
572 				usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
573 			else
574 				instance->buf_usage = 0;
575 
576 		if (usbatm_submit_urb(urb))
577 			return;
578 	}
579 }
580 
581 
582 /***********
583 **  send  **
584 ***********/
585 
586 static void usbatm_tx_process(unsigned long data)
587 {
588 	struct usbatm_data *instance = (struct usbatm_data *)data;
589 	struct sk_buff *skb = instance->current_skb;
590 	struct urb *urb = NULL;
591 	const unsigned int buf_size = instance->tx_channel.buf_size;
592 	unsigned int bytes_written = 0;
593 	u8 *buffer = NULL;
594 
595 	if (!skb)
596 		skb = skb_dequeue(&instance->sndqueue);
597 
598 	while (skb) {
599 		if (!urb) {
600 			urb = usbatm_pop_urb(&instance->tx_channel);
601 			if (!urb)
602 				break;		/* no more senders */
603 			buffer = urb->transfer_buffer;
604 			bytes_written = (urb->status == -EAGAIN) ?
605 				urb->transfer_buffer_length : 0;
606 		}
607 
608 		bytes_written += usbatm_write_cells(instance, skb,
609 						  buffer + bytes_written,
610 						  buf_size - bytes_written);
611 
612 		vdbg("%s: wrote %u bytes from skb 0x%p to urb 0x%p",
613 		     __func__, bytes_written, skb, urb);
614 
615 		if (!UDSL_SKB(skb)->len) {
616 			struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
617 
618 			usbatm_pop(vcc, skb);
619 			atomic_inc(&vcc->stats->tx);
620 
621 			skb = skb_dequeue(&instance->sndqueue);
622 		}
623 
624 		if (bytes_written == buf_size || (!skb && bytes_written)) {
625 			urb->transfer_buffer_length = bytes_written;
626 
627 			if (usbatm_submit_urb(urb))
628 				break;
629 			urb = NULL;
630 		}
631 	}
632 
633 	instance->current_skb = skb;
634 }
635 
636 static void usbatm_cancel_send(struct usbatm_data *instance,
637 			       struct atm_vcc *vcc)
638 {
639 	struct sk_buff *skb, *n;
640 
641 	atm_dbg(instance, "%s entered\n", __func__);
642 	spin_lock_irq(&instance->sndqueue.lock);
643 	skb_queue_walk_safe(&instance->sndqueue, skb, n) {
644 		if (UDSL_SKB(skb)->atm.vcc == vcc) {
645 			atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
646 			__skb_unlink(skb, &instance->sndqueue);
647 			usbatm_pop(vcc, skb);
648 		}
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 	allow_signal(SIGTERM);
1018 	complete(&instance->thread_started);
1019 
1020 	ret = instance->driver->heavy_init(instance, instance->usb_intf);
1021 
1022 	if (!ret)
1023 		ret = usbatm_atm_init(instance);
1024 
1025 	mutex_lock(&instance->serialize);
1026 	instance->thread = NULL;
1027 	mutex_unlock(&instance->serialize);
1028 
1029 	complete_and_exit(&instance->thread_exited, ret);
1030 }
1031 
1032 static int usbatm_heavy_init(struct usbatm_data *instance)
1033 {
1034 	struct task_struct *t;
1035 
1036 	t = kthread_create(usbatm_do_heavy_init, instance,
1037 			instance->driver->driver_name);
1038 	if (IS_ERR(t)) {
1039 		usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
1040 				__func__, PTR_ERR(t));
1041 		return PTR_ERR(t);
1042 	}
1043 
1044 	instance->thread = t;
1045 	wake_up_process(t);
1046 	wait_for_completion(&instance->thread_started);
1047 
1048 	return 0;
1049 }
1050 
1051 static void usbatm_tasklet_schedule(unsigned long data)
1052 {
1053 	tasklet_schedule((struct tasklet_struct *) data);
1054 }
1055 
1056 static void usbatm_init_channel(struct usbatm_channel *channel)
1057 {
1058 	spin_lock_init(&channel->lock);
1059 	INIT_LIST_HEAD(&channel->list);
1060 	channel->delay.function = usbatm_tasklet_schedule;
1061 	channel->delay.data = (unsigned long) &channel->tasklet;
1062 	init_timer(&channel->delay);
1063 }
1064 
1065 int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1066 		     struct usbatm_driver *driver)
1067 {
1068 	struct device *dev = &intf->dev;
1069 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1070 	struct usbatm_data *instance;
1071 	char *buf;
1072 	int error = -ENOMEM;
1073 	int i, length;
1074 	unsigned int maxpacket, num_packets;
1075 
1076 	dev_dbg(dev, "%s: trying driver %s with vendor=%04x, product=%04x, ifnum %2d\n",
1077 			__func__, driver->driver_name,
1078 			le16_to_cpu(usb_dev->descriptor.idVendor),
1079 			le16_to_cpu(usb_dev->descriptor.idProduct),
1080 			intf->altsetting->desc.bInterfaceNumber);
1081 
1082 	/* instance init */
1083 	instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1084 	if (!instance) {
1085 		dev_err(dev, "%s: no memory for instance data!\n", __func__);
1086 		return -ENOMEM;
1087 	}
1088 
1089 	/* public fields */
1090 
1091 	instance->driver = driver;
1092 	snprintf(instance->driver_name, sizeof(instance->driver_name), driver->driver_name);
1093 
1094 	instance->usb_dev = usb_dev;
1095 	instance->usb_intf = intf;
1096 
1097 	buf = instance->description;
1098 	length = sizeof(instance->description);
1099 
1100 	if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1101 		goto bind;
1102 
1103 	buf += i;
1104 	length -= i;
1105 
1106 	i = scnprintf(buf, length, " (");
1107 	buf += i;
1108 	length -= i;
1109 
1110 	if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1111 		goto bind;
1112 
1113 	buf += i;
1114 	length -= i;
1115 
1116 	snprintf(buf, length, ")");
1117 
1118  bind:
1119 	if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1120 			dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1121 			goto fail_free;
1122 	}
1123 
1124 	/* private fields */
1125 
1126 	kref_init(&instance->refcount);		/* dropped in usbatm_usb_disconnect */
1127 	mutex_init(&instance->serialize);
1128 
1129 	instance->thread = NULL;
1130 	init_completion(&instance->thread_started);
1131 	init_completion(&instance->thread_exited);
1132 
1133 	INIT_LIST_HEAD(&instance->vcc_list);
1134 	skb_queue_head_init(&instance->sndqueue);
1135 
1136 	usbatm_init_channel(&instance->rx_channel);
1137 	usbatm_init_channel(&instance->tx_channel);
1138 	tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1139 	tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1140 	instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1141 	instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1142 	instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1143 
1144 	if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1145 		instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1146 	else
1147 		instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1148 
1149 	instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1150 
1151 	/* tx buffer size must be a positive multiple of the stride */
1152 	instance->tx_channel.buf_size = max (instance->tx_channel.stride,
1153 			snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1154 
1155 	/* rx buffer size must be a positive multiple of the endpoint maxpacket */
1156 	maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1157 
1158 	if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1159 		dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1160 				usb_pipeendpoint(instance->rx_channel.endpoint));
1161 		error = -EINVAL;
1162 		goto fail_unbind;
1163 	}
1164 
1165 	num_packets = max (1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1166 
1167 	if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1168 		num_packets--;
1169 
1170 	instance->rx_channel.buf_size = num_packets * maxpacket;
1171 	instance->rx_channel.packet_size = maxpacket;
1172 
1173 #ifdef DEBUG
1174 	for (i = 0; i < 2; i++) {
1175 		struct usbatm_channel *channel = i ?
1176 			&instance->tx_channel : &instance->rx_channel;
1177 
1178 		dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n", __func__, channel->buf_size, i ? "tx" : "rx", channel);
1179 	}
1180 #endif
1181 
1182 	/* initialize urbs */
1183 
1184 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1185 		u8 *buffer;
1186 		struct usbatm_channel *channel = i < num_rcv_urbs ?
1187 			&instance->rx_channel : &instance->tx_channel;
1188 		struct urb *urb;
1189 		unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1190 
1191 		UDSL_ASSERT(instance, !usb_pipeisoc(channel->endpoint) || usb_pipein(channel->endpoint));
1192 
1193 		urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1194 		if (!urb) {
1195 			dev_err(dev, "%s: no memory for urb %d!\n", __func__, i);
1196 			error = -ENOMEM;
1197 			goto fail_unbind;
1198 		}
1199 
1200 		instance->urbs[i] = urb;
1201 
1202 		/* zero the tx padding to avoid leaking information */
1203 		buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1204 		if (!buffer) {
1205 			dev_err(dev, "%s: no memory for buffer %d!\n", __func__, i);
1206 			error = -ENOMEM;
1207 			goto fail_unbind;
1208 		}
1209 
1210 		usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1211 				  buffer, channel->buf_size, usbatm_complete, channel);
1212 		if (iso_packets) {
1213 			int j;
1214 			urb->interval = 1;
1215 			urb->transfer_flags = URB_ISO_ASAP;
1216 			urb->number_of_packets = iso_packets;
1217 			for (j = 0; j < iso_packets; j++) {
1218 				urb->iso_frame_desc[j].offset = channel->packet_size * j;
1219 				urb->iso_frame_desc[j].length = channel->packet_size;
1220 			}
1221 		}
1222 
1223 		/* put all tx URBs on the list of spares */
1224 		if (i >= num_rcv_urbs)
1225 			list_add_tail(&urb->urb_list, &channel->list);
1226 
1227 		vdbg("%s: alloced buffer 0x%p buf size %u urb 0x%p",
1228 		     __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1229 	}
1230 
1231 	instance->cached_vpi = ATM_VPI_UNSPEC;
1232 	instance->cached_vci = ATM_VCI_UNSPEC;
1233 	instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1234 
1235 	if (!instance->cell_buf) {
1236 		dev_err(dev, "%s: no memory for cell buffer!\n", __func__);
1237 		error = -ENOMEM;
1238 		goto fail_unbind;
1239 	}
1240 
1241 	if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1242 		error = usbatm_heavy_init(instance);
1243 	} else {
1244 		complete(&instance->thread_exited);	/* pretend that heavy_init was run */
1245 		error = usbatm_atm_init(instance);
1246 	}
1247 
1248 	if (error < 0)
1249 		goto fail_unbind;
1250 
1251 	usb_get_dev(usb_dev);
1252 	usb_set_intfdata(intf, instance);
1253 
1254 	return 0;
1255 
1256  fail_unbind:
1257 	if (instance->driver->unbind)
1258 		instance->driver->unbind(instance, intf);
1259  fail_free:
1260 	kfree(instance->cell_buf);
1261 
1262 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1263 		if (instance->urbs[i])
1264 			kfree(instance->urbs[i]->transfer_buffer);
1265 		usb_free_urb(instance->urbs[i]);
1266 	}
1267 
1268 	kfree (instance);
1269 
1270 	return error;
1271 }
1272 EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1273 
1274 void usbatm_usb_disconnect(struct usb_interface *intf)
1275 {
1276 	struct device *dev = &intf->dev;
1277 	struct usbatm_data *instance = usb_get_intfdata(intf);
1278 	struct usbatm_vcc_data *vcc_data;
1279 	int i;
1280 
1281 	dev_dbg(dev, "%s entered\n", __func__);
1282 
1283 	if (!instance) {
1284 		dev_dbg(dev, "%s: NULL instance!\n", __func__);
1285 		return;
1286 	}
1287 
1288 	usb_set_intfdata(intf, NULL);
1289 
1290 	mutex_lock(&instance->serialize);
1291 	instance->disconnected = 1;
1292 	if (instance->thread != NULL)
1293 		send_sig(SIGTERM, instance->thread, 1);
1294 	mutex_unlock(&instance->serialize);
1295 
1296 	wait_for_completion(&instance->thread_exited);
1297 
1298 	mutex_lock(&instance->serialize);
1299 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
1300 		vcc_release_async(vcc_data->vcc, -EPIPE);
1301 	mutex_unlock(&instance->serialize);
1302 
1303 	tasklet_disable(&instance->rx_channel.tasklet);
1304 	tasklet_disable(&instance->tx_channel.tasklet);
1305 
1306 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1307 		usb_kill_urb(instance->urbs[i]);
1308 
1309 	del_timer_sync(&instance->rx_channel.delay);
1310 	del_timer_sync(&instance->tx_channel.delay);
1311 
1312 	/* turn usbatm_[rt]x_process into something close to a no-op */
1313 	/* no need to take the spinlock */
1314 	INIT_LIST_HEAD(&instance->rx_channel.list);
1315 	INIT_LIST_HEAD(&instance->tx_channel.list);
1316 
1317 	tasklet_enable(&instance->rx_channel.tasklet);
1318 	tasklet_enable(&instance->tx_channel.tasklet);
1319 
1320 	if (instance->atm_dev && instance->driver->atm_stop)
1321 		instance->driver->atm_stop(instance, instance->atm_dev);
1322 
1323 	if (instance->driver->unbind)
1324 		instance->driver->unbind(instance, intf);
1325 
1326 	instance->driver_data = NULL;
1327 
1328 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1329 		kfree(instance->urbs[i]->transfer_buffer);
1330 		usb_free_urb(instance->urbs[i]);
1331 	}
1332 
1333 	kfree(instance->cell_buf);
1334 
1335 	/* ATM finalize */
1336 	if (instance->atm_dev) {
1337 		sysfs_remove_link(&instance->atm_dev->class_dev.kobj, "device");
1338 		atm_dev_deregister(instance->atm_dev);
1339 	}
1340 
1341 	usbatm_put_instance(instance);	/* taken in usbatm_usb_probe */
1342 }
1343 EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1344 
1345 
1346 /***********
1347 **  init  **
1348 ***********/
1349 
1350 static int __init usbatm_usb_init(void)
1351 {
1352 	dbg("%s: driver version %s", __func__, DRIVER_VERSION);
1353 
1354 	if (sizeof(struct usbatm_control) > sizeof(((struct sk_buff *) 0)->cb)) {
1355 		printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1356 		return -EIO;
1357 	}
1358 
1359 	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1360 	    || (num_snd_urbs > UDSL_MAX_SND_URBS)
1361 	    || (rcv_buf_bytes < 1)
1362 	    || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1363 	    || (snd_buf_bytes < 1)
1364 	    || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1365 		return -EINVAL;
1366 
1367 	return 0;
1368 }
1369 module_init(usbatm_usb_init);
1370 
1371 static void __exit usbatm_usb_exit(void)
1372 {
1373 	dbg("%s", __func__);
1374 }
1375 module_exit(usbatm_usb_exit);
1376 
1377 MODULE_AUTHOR(DRIVER_AUTHOR);
1378 MODULE_DESCRIPTION(DRIVER_DESC);
1379 MODULE_LICENSE("GPL");
1380 MODULE_VERSION(DRIVER_VERSION);
1381 
1382 /************
1383 **  debug  **
1384 ************/
1385 
1386 #ifdef VERBOSE_DEBUG
1387 static int usbatm_print_packet(const unsigned char *data, int len)
1388 {
1389 	unsigned char buffer[256];
1390 	int i = 0, j = 0;
1391 
1392 	for (i = 0; i < len;) {
1393 		buffer[0] = '\0';
1394 		sprintf(buffer, "%.3d :", i);
1395 		for (j = 0; (j < 16) && (i < len); j++, i++) {
1396 			sprintf(buffer, "%s %2.2x", buffer, data[i]);
1397 		}
1398 		dbg("%s", buffer);
1399 	}
1400 	return i;
1401 }
1402 #endif
1403