xref: /openbmc/linux/drivers/usb/atm/usbatm.c (revision 9be08a27)
1 // SPDX-License-Identifier: GPL-2.0+
2 /******************************************************************************
3  *  usbatm.c - Generic USB xDSL driver core
4  *
5  *  Copyright (C) 2001, Alcatel
6  *  Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
7  *  Copyright (C) 2004, David Woodhouse, Roman Kagan
8  ******************************************************************************/
9 
10 /*
11  *  Written by Johan Verrept, Duncan Sands (duncan.sands@free.fr) and David Woodhouse
12  *
13  *  1.7+:	- See the check-in logs
14  *
15  *  1.6:	- No longer opens a connection if the firmware is not loaded
16  *  		- Added support for the speedtouch 330
17  *  		- Removed the limit on the number of devices
18  *  		- Module now autoloads on device plugin
19  *  		- Merged relevant parts of sarlib
20  *  		- Replaced the kernel thread with a tasklet
21  *  		- New packet transmission code
22  *  		- Changed proc file contents
23  *  		- Fixed all known SMP races
24  *  		- Many fixes and cleanups
25  *  		- Various fixes by Oliver Neukum (oliver@neukum.name)
26  *
27  *  1.5A:	- Version for inclusion in 2.5 series kernel
28  *		- Modifications by Richard Purdie (rpurdie@rpsys.net)
29  *		- made compatible with kernel 2.5.6 onwards by changing
30  *		usbatm_usb_send_data_context->urb to a pointer and adding code
31  *		to alloc and free it
32  *		- remove_wait_queue() added to usbatm_atm_processqueue_thread()
33  *
34  *  1.5:	- fixed memory leak when atmsar_decode_aal5 returned NULL.
35  *		(reported by stephen.robinson@zen.co.uk)
36  *
37  *  1.4:	- changed the spin_lock() under interrupt to spin_lock_irqsave()
38  *		- unlink all active send urbs of a vcc that is being closed.
39  *
40  *  1.3.1:	- added the version number
41  *
42  *  1.3:	- Added multiple send urb support
43  *		- fixed memory leak and vcc->tx_inuse starvation bug
44  *		  when not enough memory left in vcc.
45  *
46  *  1.2:	- Fixed race condition in usbatm_usb_send_data()
47  *  1.1:	- Turned off packet debugging
48  *
49  */
50 
51 #include "usbatm.h"
52 
53 #include <linux/uaccess.h>
54 #include <linux/crc32.h>
55 #include <linux/errno.h>
56 #include <linux/init.h>
57 #include <linux/interrupt.h>
58 #include <linux/kernel.h>
59 #include <linux/module.h>
60 #include <linux/moduleparam.h>
61 #include <linux/netdevice.h>
62 #include <linux/proc_fs.h>
63 #include <linux/sched/signal.h>
64 #include <linux/signal.h>
65 #include <linux/slab.h>
66 #include <linux/stat.h>
67 #include <linux/timer.h>
68 #include <linux/wait.h>
69 #include <linux/kthread.h>
70 #include <linux/ratelimit.h>
71 
72 #ifdef VERBOSE_DEBUG
73 static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
74 #define PACKETDEBUG(arg...)	usbatm_print_packet(arg)
75 #define vdbg(arg...)		dev_dbg(arg)
76 #else
77 #define PACKETDEBUG(arg...)
78 #define vdbg(arg...)
79 #endif
80 
81 #define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
82 #define DRIVER_DESC	"Generic USB ATM/DSL I/O"
83 
84 static const char usbatm_driver_name[] = "usbatm";
85 
86 #define UDSL_MAX_RCV_URBS		16
87 #define UDSL_MAX_SND_URBS		16
88 #define UDSL_MAX_BUF_SIZE		65536
89 #define UDSL_DEFAULT_RCV_URBS		4
90 #define UDSL_DEFAULT_SND_URBS		4
91 #define UDSL_DEFAULT_RCV_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
92 #define UDSL_DEFAULT_SND_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
93 
94 #define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
95 
96 #define THROTTLE_MSECS			100	/* delay to recover processing after urb submission fails */
97 
98 static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
99 static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
100 static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
101 static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
102 
103 module_param(num_rcv_urbs, uint, S_IRUGO);
104 MODULE_PARM_DESC(num_rcv_urbs,
105 		 "Number of urbs used for reception (range: 0-"
106 		 __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
107 		 __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
108 
109 module_param(num_snd_urbs, uint, S_IRUGO);
110 MODULE_PARM_DESC(num_snd_urbs,
111 		 "Number of urbs used for transmission (range: 0-"
112 		 __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
113 		 __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
114 
115 module_param(rcv_buf_bytes, uint, S_IRUGO);
116 MODULE_PARM_DESC(rcv_buf_bytes,
117 		 "Size of the buffers used for reception, in bytes (range: 1-"
118 		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
119 		 __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
120 
121 module_param(snd_buf_bytes, uint, S_IRUGO);
122 MODULE_PARM_DESC(snd_buf_bytes,
123 		 "Size of the buffers used for transmission, in bytes (range: 1-"
124 		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
125 		 __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
126 
127 
128 /* receive */
129 
130 struct usbatm_vcc_data {
131 	/* vpi/vci lookup */
132 	struct list_head list;
133 	short vpi;
134 	int vci;
135 	struct atm_vcc *vcc;
136 
137 	/* raw cell reassembly */
138 	struct sk_buff *sarb;
139 };
140 
141 
142 /* send */
143 
144 struct usbatm_control {
145 	struct atm_skb_data atm;
146 	u32 len;
147 	u32 crc;
148 };
149 
150 #define UDSL_SKB(x)		((struct usbatm_control *)(x)->cb)
151 
152 
153 /* ATM */
154 
155 static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
156 static int usbatm_atm_open(struct atm_vcc *vcc);
157 static void usbatm_atm_close(struct atm_vcc *vcc);
158 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user *arg);
159 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
160 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page);
161 
162 static const struct atmdev_ops usbatm_atm_devops = {
163 	.dev_close	= usbatm_atm_dev_close,
164 	.open		= usbatm_atm_open,
165 	.close		= usbatm_atm_close,
166 	.ioctl		= usbatm_atm_ioctl,
167 	.send		= usbatm_atm_send,
168 	.proc_read	= usbatm_atm_proc_read,
169 	.owner		= THIS_MODULE,
170 };
171 
172 
173 /***********
174 **  misc  **
175 ***********/
176 
177 static inline unsigned int usbatm_pdu_length(unsigned int length)
178 {
179 	length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
180 	return length - length % ATM_CELL_PAYLOAD;
181 }
182 
183 static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
184 {
185 	if (vcc->pop)
186 		vcc->pop(vcc, skb);
187 	else
188 		dev_kfree_skb_any(skb);
189 }
190 
191 
192 /***********
193 **  urbs  **
194 ************/
195 
196 static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
197 {
198 	struct urb *urb;
199 
200 	spin_lock_irq(&channel->lock);
201 	if (list_empty(&channel->list)) {
202 		spin_unlock_irq(&channel->lock);
203 		return NULL;
204 	}
205 
206 	urb = list_entry(channel->list.next, struct urb, urb_list);
207 	list_del(&urb->urb_list);
208 	spin_unlock_irq(&channel->lock);
209 
210 	return urb;
211 }
212 
213 static int usbatm_submit_urb(struct urb *urb)
214 {
215 	struct usbatm_channel *channel = urb->context;
216 	int ret;
217 
218 	/* vdbg("%s: submitting urb 0x%p, size %u",
219 	     __func__, urb, urb->transfer_buffer_length); */
220 
221 	ret = usb_submit_urb(urb, GFP_ATOMIC);
222 	if (ret) {
223 		if (printk_ratelimit())
224 			atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
225 				__func__, urb, ret);
226 
227 		/* consider all errors transient and return the buffer back to the queue */
228 		urb->status = -EAGAIN;
229 		spin_lock_irq(&channel->lock);
230 
231 		/* must add to the front when sending; doesn't matter when receiving */
232 		list_add(&urb->urb_list, &channel->list);
233 
234 		spin_unlock_irq(&channel->lock);
235 
236 		/* make sure the channel doesn't stall */
237 		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
238 	}
239 
240 	return ret;
241 }
242 
243 static void usbatm_complete(struct urb *urb)
244 {
245 	struct usbatm_channel *channel = urb->context;
246 	unsigned long flags;
247 	int status = urb->status;
248 
249 	/* vdbg("%s: urb 0x%p, status %d, actual_length %d",
250 	     __func__, urb, status, urb->actual_length); */
251 
252 	/* usually in_interrupt(), but not always */
253 	spin_lock_irqsave(&channel->lock, flags);
254 
255 	/* must add to the back when receiving; doesn't matter when sending */
256 	list_add_tail(&urb->urb_list, &channel->list);
257 
258 	spin_unlock_irqrestore(&channel->lock, flags);
259 
260 	if (unlikely(status) &&
261 			(!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
262 			 status != -EILSEQ)) {
263 		if (status == -ESHUTDOWN)
264 			return;
265 
266 		if (printk_ratelimit())
267 			atm_warn(channel->usbatm, "%s: urb 0x%p failed (%d)!\n",
268 				__func__, urb, status);
269 		/* throttle processing in case of an error */
270 		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
271 	} else
272 		tasklet_schedule(&channel->tasklet);
273 }
274 
275 
276 /*************
277 **  decode  **
278 *************/
279 
280 static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
281 						  short vpi, int vci)
282 {
283 	struct usbatm_vcc_data *vcc_data;
284 
285 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
286 		if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
287 			return vcc_data;
288 	return NULL;
289 }
290 
291 static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
292 {
293 	struct atm_vcc *vcc;
294 	struct sk_buff *sarb;
295 	short vpi = ((source[0] & 0x0f) << 4)  | (source[1] >> 4);
296 	int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
297 	u8 pti = ((source[3] & 0xe) >> 1);
298 
299 	if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
300 		instance->cached_vpi = vpi;
301 		instance->cached_vci = vci;
302 
303 		instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
304 
305 		if (!instance->cached_vcc)
306 			atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
307 	}
308 
309 	if (!instance->cached_vcc)
310 		return;
311 
312 	vcc = instance->cached_vcc->vcc;
313 
314 	/* OAM F5 end-to-end */
315 	if (pti == ATM_PTI_E2EF5) {
316 		if (printk_ratelimit())
317 			atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
318 				__func__, vpi, vci);
319 		atomic_inc(&vcc->stats->rx_err);
320 		return;
321 	}
322 
323 	sarb = instance->cached_vcc->sarb;
324 
325 	if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
326 		atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
327 				__func__, sarb->len, vcc);
328 		/* discard cells already received */
329 		skb_trim(sarb, 0);
330 	}
331 
332 	memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
333 	__skb_put(sarb, ATM_CELL_PAYLOAD);
334 
335 	if (pti & 1) {
336 		struct sk_buff *skb;
337 		unsigned int length;
338 		unsigned int pdu_length;
339 
340 		length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
341 
342 		/* guard against overflow */
343 		if (length > ATM_MAX_AAL5_PDU) {
344 			atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
345 				  __func__, length, vcc);
346 			atomic_inc(&vcc->stats->rx_err);
347 			goto out;
348 		}
349 
350 		pdu_length = usbatm_pdu_length(length);
351 
352 		if (sarb->len < pdu_length) {
353 			atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
354 				  __func__, pdu_length, sarb->len, vcc);
355 			atomic_inc(&vcc->stats->rx_err);
356 			goto out;
357 		}
358 
359 		if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
360 			atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
361 				  __func__, vcc);
362 			atomic_inc(&vcc->stats->rx_err);
363 			goto out;
364 		}
365 
366 		vdbg(&instance->usb_intf->dev,
367 		     "%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)",
368 		     __func__, length, pdu_length, vcc);
369 
370 		skb = dev_alloc_skb(length);
371 		if (!skb) {
372 			if (printk_ratelimit())
373 				atm_err(instance, "%s: no memory for skb (length: %u)!\n",
374 					__func__, length);
375 			atomic_inc(&vcc->stats->rx_drop);
376 			goto out;
377 		}
378 
379 		vdbg(&instance->usb_intf->dev,
380 		     "%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)",
381 		     __func__, skb, skb->truesize);
382 
383 		if (!atm_charge(vcc, skb->truesize)) {
384 			atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
385 				  __func__, skb->truesize);
386 			dev_kfree_skb_any(skb);
387 			goto out;	/* atm_charge increments rx_drop */
388 		}
389 
390 		skb_copy_to_linear_data(skb,
391 					skb_tail_pointer(sarb) - pdu_length,
392 					length);
393 		__skb_put(skb, length);
394 
395 		vdbg(&instance->usb_intf->dev,
396 		     "%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
397 		     __func__, skb, skb->len, skb->truesize);
398 
399 		PACKETDEBUG(instance, skb->data, skb->len);
400 
401 		vcc->push(vcc, skb);
402 
403 		atomic_inc(&vcc->stats->rx);
404 	out:
405 		skb_trim(sarb, 0);
406 	}
407 }
408 
409 static void usbatm_extract_cells(struct usbatm_data *instance,
410 		unsigned char *source, unsigned int avail_data)
411 {
412 	unsigned int stride = instance->rx_channel.stride;
413 	unsigned int buf_usage = instance->buf_usage;
414 
415 	/* extract cells from incoming data, taking into account that
416 	 * the length of avail data may not be a multiple of stride */
417 
418 	if (buf_usage > 0) {
419 		/* we have a partially received atm cell */
420 		unsigned char *cell_buf = instance->cell_buf;
421 		unsigned int space_left = stride - buf_usage;
422 
423 		if (avail_data >= space_left) {
424 			/* add new data and process cell */
425 			memcpy(cell_buf + buf_usage, source, space_left);
426 			source += space_left;
427 			avail_data -= space_left;
428 			usbatm_extract_one_cell(instance, cell_buf);
429 			instance->buf_usage = 0;
430 		} else {
431 			/* not enough data to fill the cell */
432 			memcpy(cell_buf + buf_usage, source, avail_data);
433 			instance->buf_usage = buf_usage + avail_data;
434 			return;
435 		}
436 	}
437 
438 	for (; avail_data >= stride; avail_data -= stride, source += stride)
439 		usbatm_extract_one_cell(instance, source);
440 
441 	if (avail_data > 0) {
442 		/* length was not a multiple of stride -
443 		 * save remaining data for next call */
444 		memcpy(instance->cell_buf, source, avail_data);
445 		instance->buf_usage = avail_data;
446 	}
447 }
448 
449 
450 /*************
451 **  encode  **
452 *************/
453 
454 static unsigned int usbatm_write_cells(struct usbatm_data *instance,
455 				       struct sk_buff *skb,
456 				       u8 *target, unsigned int avail_space)
457 {
458 	struct usbatm_control *ctrl = UDSL_SKB(skb);
459 	struct atm_vcc *vcc = ctrl->atm.vcc;
460 	unsigned int bytes_written;
461 	unsigned int stride = instance->tx_channel.stride;
462 
463 	for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
464 	     bytes_written += stride, target += stride) {
465 		unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
466 		unsigned int left = ATM_CELL_PAYLOAD - data_len;
467 		u8 *ptr = target;
468 
469 		ptr[0] = vcc->vpi >> 4;
470 		ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
471 		ptr[2] = vcc->vci >> 4;
472 		ptr[3] = vcc->vci << 4;
473 		ptr[4] = 0xec;
474 		ptr += ATM_CELL_HEADER;
475 
476 		skb_copy_from_linear_data(skb, ptr, data_len);
477 		ptr += data_len;
478 		__skb_pull(skb, data_len);
479 
480 		if (!left)
481 			continue;
482 
483 		memset(ptr, 0, left);
484 
485 		if (left >= ATM_AAL5_TRAILER) {	/* trailer will go in this cell */
486 			u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
487 			/* trailer[0] = 0;		UU = 0 */
488 			/* trailer[1] = 0;		CPI = 0 */
489 			trailer[2] = ctrl->len >> 8;
490 			trailer[3] = ctrl->len;
491 
492 			ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
493 
494 			trailer[4] = ctrl->crc >> 24;
495 			trailer[5] = ctrl->crc >> 16;
496 			trailer[6] = ctrl->crc >> 8;
497 			trailer[7] = ctrl->crc;
498 
499 			target[3] |= 0x2;	/* adjust PTI */
500 
501 			ctrl->len = 0;		/* tag this skb finished */
502 		} else
503 			ctrl->crc = crc32_be(ctrl->crc, ptr, left);
504 	}
505 
506 	return bytes_written;
507 }
508 
509 
510 /**************
511 **  receive  **
512 **************/
513 
514 static void usbatm_rx_process(unsigned long data)
515 {
516 	struct usbatm_data *instance = (struct usbatm_data *)data;
517 	struct urb *urb;
518 
519 	while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
520 		vdbg(&instance->usb_intf->dev,
521 		     "%s: processing urb 0x%p", __func__, urb);
522 
523 		if (usb_pipeisoc(urb->pipe)) {
524 			unsigned char *merge_start = NULL;
525 			unsigned int merge_length = 0;
526 			const unsigned int packet_size = instance->rx_channel.packet_size;
527 			int i;
528 
529 			for (i = 0; i < urb->number_of_packets; i++) {
530 				if (!urb->iso_frame_desc[i].status) {
531 					unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
532 
533 					if (!merge_length)
534 						merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
535 					merge_length += actual_length;
536 					if (merge_length && (actual_length < packet_size)) {
537 						usbatm_extract_cells(instance, merge_start, merge_length);
538 						merge_length = 0;
539 					}
540 				} else {
541 					atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
542 					if (merge_length)
543 						usbatm_extract_cells(instance, merge_start, merge_length);
544 					merge_length = 0;
545 					instance->buf_usage = 0;
546 				}
547 			}
548 
549 			if (merge_length)
550 				usbatm_extract_cells(instance, merge_start, merge_length);
551 		} else
552 			if (!urb->status)
553 				usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
554 			else
555 				instance->buf_usage = 0;
556 
557 		if (usbatm_submit_urb(urb))
558 			return;
559 	}
560 }
561 
562 
563 /***********
564 **  send  **
565 ***********/
566 
567 static void usbatm_tx_process(unsigned long data)
568 {
569 	struct usbatm_data *instance = (struct usbatm_data *)data;
570 	struct sk_buff *skb = instance->current_skb;
571 	struct urb *urb = NULL;
572 	const unsigned int buf_size = instance->tx_channel.buf_size;
573 	unsigned int bytes_written = 0;
574 	u8 *buffer = NULL;
575 
576 	if (!skb)
577 		skb = skb_dequeue(&instance->sndqueue);
578 
579 	while (skb) {
580 		if (!urb) {
581 			urb = usbatm_pop_urb(&instance->tx_channel);
582 			if (!urb)
583 				break;		/* no more senders */
584 			buffer = urb->transfer_buffer;
585 			bytes_written = (urb->status == -EAGAIN) ?
586 				urb->transfer_buffer_length : 0;
587 		}
588 
589 		bytes_written += usbatm_write_cells(instance, skb,
590 						  buffer + bytes_written,
591 						  buf_size - bytes_written);
592 
593 		vdbg(&instance->usb_intf->dev,
594 		     "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
595 		     __func__, bytes_written, skb, urb);
596 
597 		if (!UDSL_SKB(skb)->len) {
598 			struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
599 
600 			usbatm_pop(vcc, skb);
601 			atomic_inc(&vcc->stats->tx);
602 
603 			skb = skb_dequeue(&instance->sndqueue);
604 		}
605 
606 		if (bytes_written == buf_size || (!skb && bytes_written)) {
607 			urb->transfer_buffer_length = bytes_written;
608 
609 			if (usbatm_submit_urb(urb))
610 				break;
611 			urb = NULL;
612 		}
613 	}
614 
615 	instance->current_skb = skb;
616 }
617 
618 static void usbatm_cancel_send(struct usbatm_data *instance,
619 			       struct atm_vcc *vcc)
620 {
621 	struct sk_buff *skb, *n;
622 
623 	spin_lock_irq(&instance->sndqueue.lock);
624 	skb_queue_walk_safe(&instance->sndqueue, skb, n) {
625 		if (UDSL_SKB(skb)->atm.vcc == vcc) {
626 			atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
627 			__skb_unlink(skb, &instance->sndqueue);
628 			usbatm_pop(vcc, skb);
629 		}
630 	}
631 	spin_unlock_irq(&instance->sndqueue.lock);
632 
633 	tasklet_disable(&instance->tx_channel.tasklet);
634 	if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
635 		atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
636 		instance->current_skb = NULL;
637 		usbatm_pop(vcc, skb);
638 	}
639 	tasklet_enable(&instance->tx_channel.tasklet);
640 }
641 
642 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
643 {
644 	struct usbatm_data *instance = vcc->dev->dev_data;
645 	struct usbatm_control *ctrl = UDSL_SKB(skb);
646 	int err;
647 
648 	/* racy disconnection check - fine */
649 	if (!instance || instance->disconnected) {
650 #ifdef VERBOSE_DEBUG
651 		printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
652 #endif
653 		err = -ENODEV;
654 		goto fail;
655 	}
656 
657 	if (vcc->qos.aal != ATM_AAL5) {
658 		atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
659 		err = -EINVAL;
660 		goto fail;
661 	}
662 
663 	if (skb->len > ATM_MAX_AAL5_PDU) {
664 		atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
665 				__func__, skb->len, ATM_MAX_AAL5_PDU);
666 		err = -EINVAL;
667 		goto fail;
668 	}
669 
670 	PACKETDEBUG(instance, skb->data, skb->len);
671 
672 	/* initialize the control block */
673 	ctrl->atm.vcc = vcc;
674 	ctrl->len = skb->len;
675 	ctrl->crc = crc32_be(~0, skb->data, skb->len);
676 
677 	skb_queue_tail(&instance->sndqueue, skb);
678 	tasklet_schedule(&instance->tx_channel.tasklet);
679 
680 	return 0;
681 
682  fail:
683 	usbatm_pop(vcc, skb);
684 	return err;
685 }
686 
687 
688 /********************
689 **  bean counting  **
690 ********************/
691 
692 static void usbatm_destroy_instance(struct kref *kref)
693 {
694 	struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
695 
696 	tasklet_kill(&instance->rx_channel.tasklet);
697 	tasklet_kill(&instance->tx_channel.tasklet);
698 	usb_put_dev(instance->usb_dev);
699 	kfree(instance);
700 }
701 
702 static void usbatm_get_instance(struct usbatm_data *instance)
703 {
704 	kref_get(&instance->refcount);
705 }
706 
707 static void usbatm_put_instance(struct usbatm_data *instance)
708 {
709 	kref_put(&instance->refcount, usbatm_destroy_instance);
710 }
711 
712 
713 /**********
714 **  ATM  **
715 **********/
716 
717 static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
718 {
719 	struct usbatm_data *instance = atm_dev->dev_data;
720 
721 	if (!instance)
722 		return;
723 
724 	atm_dev->dev_data = NULL; /* catch bugs */
725 	usbatm_put_instance(instance);	/* taken in usbatm_atm_init */
726 }
727 
728 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
729 {
730 	struct usbatm_data *instance = atm_dev->dev_data;
731 	int left = *pos;
732 
733 	if (!instance)
734 		return -ENODEV;
735 
736 	if (!left--)
737 		return sprintf(page, "%s\n", instance->description);
738 
739 	if (!left--)
740 		return sprintf(page, "MAC: %pM\n", atm_dev->esi);
741 
742 	if (!left--)
743 		return sprintf(page,
744 			       "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
745 			       atomic_read(&atm_dev->stats.aal5.tx),
746 			       atomic_read(&atm_dev->stats.aal5.tx_err),
747 			       atomic_read(&atm_dev->stats.aal5.rx),
748 			       atomic_read(&atm_dev->stats.aal5.rx_err),
749 			       atomic_read(&atm_dev->stats.aal5.rx_drop));
750 
751 	if (!left--) {
752 		if (instance->disconnected)
753 			return sprintf(page, "Disconnected\n");
754 		else
755 			switch (atm_dev->signal) {
756 			case ATM_PHY_SIG_FOUND:
757 				return sprintf(page, "Line up\n");
758 			case ATM_PHY_SIG_LOST:
759 				return sprintf(page, "Line down\n");
760 			default:
761 				return sprintf(page, "Line state unknown\n");
762 			}
763 	}
764 
765 	return 0;
766 }
767 
768 static int usbatm_atm_open(struct atm_vcc *vcc)
769 {
770 	struct usbatm_data *instance = vcc->dev->dev_data;
771 	struct usbatm_vcc_data *new = NULL;
772 	int ret;
773 	int vci = vcc->vci;
774 	short vpi = vcc->vpi;
775 
776 	if (!instance)
777 		return -ENODEV;
778 
779 	/* only support AAL5 */
780 	if ((vcc->qos.aal != ATM_AAL5)) {
781 		atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
782 		return -EINVAL;
783 	}
784 
785 	/* sanity checks */
786 	if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
787 		atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
788 		return -EINVAL;
789 	}
790 
791 	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_close, usbatm_usb_disconnect */
792 
793 	if (instance->disconnected) {
794 		atm_dbg(instance, "%s: disconnected!\n", __func__);
795 		ret = -ENODEV;
796 		goto fail;
797 	}
798 
799 	if (usbatm_find_vcc(instance, vpi, vci)) {
800 		atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
801 		ret = -EADDRINUSE;
802 		goto fail;
803 	}
804 
805 	new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL);
806 	if (!new) {
807 		ret = -ENOMEM;
808 		goto fail;
809 	}
810 
811 	new->vcc = vcc;
812 	new->vpi = vpi;
813 	new->vci = vci;
814 
815 	new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
816 	if (!new->sarb) {
817 		atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
818 		ret = -ENOMEM;
819 		goto fail;
820 	}
821 
822 	vcc->dev_data = new;
823 
824 	tasklet_disable(&instance->rx_channel.tasklet);
825 	instance->cached_vcc = new;
826 	instance->cached_vpi = vpi;
827 	instance->cached_vci = vci;
828 	list_add(&new->list, &instance->vcc_list);
829 	tasklet_enable(&instance->rx_channel.tasklet);
830 
831 	set_bit(ATM_VF_ADDR, &vcc->flags);
832 	set_bit(ATM_VF_PARTIAL, &vcc->flags);
833 	set_bit(ATM_VF_READY, &vcc->flags);
834 
835 	mutex_unlock(&instance->serialize);
836 
837 	atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
838 
839 	return 0;
840 
841 fail:
842 	kfree(new);
843 	mutex_unlock(&instance->serialize);
844 	return ret;
845 }
846 
847 static void usbatm_atm_close(struct atm_vcc *vcc)
848 {
849 	struct usbatm_data *instance = vcc->dev->dev_data;
850 	struct usbatm_vcc_data *vcc_data = vcc->dev_data;
851 
852 	if (!instance || !vcc_data)
853 		return;
854 
855 	usbatm_cancel_send(instance, vcc);
856 
857 	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_open, usbatm_usb_disconnect */
858 
859 	tasklet_disable(&instance->rx_channel.tasklet);
860 	if (instance->cached_vcc == vcc_data) {
861 		instance->cached_vcc = NULL;
862 		instance->cached_vpi = ATM_VPI_UNSPEC;
863 		instance->cached_vci = ATM_VCI_UNSPEC;
864 	}
865 	list_del(&vcc_data->list);
866 	tasklet_enable(&instance->rx_channel.tasklet);
867 
868 	kfree_skb(vcc_data->sarb);
869 	vcc_data->sarb = NULL;
870 
871 	kfree(vcc_data);
872 	vcc->dev_data = NULL;
873 
874 	vcc->vpi = ATM_VPI_UNSPEC;
875 	vcc->vci = ATM_VCI_UNSPEC;
876 	clear_bit(ATM_VF_READY, &vcc->flags);
877 	clear_bit(ATM_VF_PARTIAL, &vcc->flags);
878 	clear_bit(ATM_VF_ADDR, &vcc->flags);
879 
880 	mutex_unlock(&instance->serialize);
881 }
882 
883 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
884 			  void __user *arg)
885 {
886 	struct usbatm_data *instance = atm_dev->dev_data;
887 
888 	if (!instance || instance->disconnected)
889 		return -ENODEV;
890 
891 	switch (cmd) {
892 	case ATM_QUERYLOOP:
893 		return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
894 	default:
895 		return -ENOIOCTLCMD;
896 	}
897 }
898 
899 static int usbatm_atm_init(struct usbatm_data *instance)
900 {
901 	struct atm_dev *atm_dev;
902 	int ret, i;
903 
904 	/* ATM init.  The ATM initialization scheme suffers from an intrinsic race
905 	 * condition: callbacks we register can be executed at once, before we have
906 	 * initialized the struct atm_dev.  To protect against this, all callbacks
907 	 * abort if atm_dev->dev_data is NULL. */
908 	atm_dev = atm_dev_register(instance->driver_name,
909 				   &instance->usb_intf->dev, &usbatm_atm_devops,
910 				   -1, NULL);
911 	if (!atm_dev) {
912 		usb_err(instance, "%s: failed to register ATM device!\n", __func__);
913 		return -1;
914 	}
915 
916 	instance->atm_dev = atm_dev;
917 
918 	atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
919 	atm_dev->ci_range.vci_bits = ATM_CI_MAX;
920 	atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
921 
922 	/* temp init ATM device, set to 128kbit */
923 	atm_dev->link_rate = 128 * 1000 / 424;
924 
925 	if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
926 		atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
927 		goto fail;
928 	}
929 
930 	usbatm_get_instance(instance);	/* dropped in usbatm_atm_dev_close */
931 
932 	/* ready for ATM callbacks */
933 	mb();
934 	atm_dev->dev_data = instance;
935 
936 	/* submit all rx URBs */
937 	for (i = 0; i < num_rcv_urbs; i++)
938 		usbatm_submit_urb(instance->urbs[i]);
939 
940 	return 0;
941 
942  fail:
943 	instance->atm_dev = NULL;
944 	atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
945 	return ret;
946 }
947 
948 
949 /**********
950 **  USB  **
951 **********/
952 
953 static int usbatm_do_heavy_init(void *arg)
954 {
955 	struct usbatm_data *instance = arg;
956 	int ret;
957 
958 	allow_signal(SIGTERM);
959 	complete(&instance->thread_started);
960 
961 	ret = instance->driver->heavy_init(instance, instance->usb_intf);
962 
963 	if (!ret)
964 		ret = usbatm_atm_init(instance);
965 
966 	mutex_lock(&instance->serialize);
967 	instance->thread = NULL;
968 	mutex_unlock(&instance->serialize);
969 
970 	complete_and_exit(&instance->thread_exited, ret);
971 }
972 
973 static int usbatm_heavy_init(struct usbatm_data *instance)
974 {
975 	struct task_struct *t;
976 
977 	t = kthread_create(usbatm_do_heavy_init, instance, "%s",
978 			instance->driver->driver_name);
979 	if (IS_ERR(t)) {
980 		usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
981 				__func__, PTR_ERR(t));
982 		return PTR_ERR(t);
983 	}
984 
985 	instance->thread = t;
986 	wake_up_process(t);
987 	wait_for_completion(&instance->thread_started);
988 
989 	return 0;
990 }
991 
992 static void usbatm_tasklet_schedule(struct timer_list *t)
993 {
994 	struct usbatm_channel *channel = from_timer(channel, t, delay);
995 
996 	tasklet_schedule(&channel->tasklet);
997 }
998 
999 static void usbatm_init_channel(struct usbatm_channel *channel)
1000 {
1001 	spin_lock_init(&channel->lock);
1002 	INIT_LIST_HEAD(&channel->list);
1003 	timer_setup(&channel->delay, usbatm_tasklet_schedule, 0);
1004 }
1005 
1006 int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1007 		     struct usbatm_driver *driver)
1008 {
1009 	struct device *dev = &intf->dev;
1010 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1011 	struct usbatm_data *instance;
1012 	char *buf;
1013 	int error = -ENOMEM;
1014 	int i, length;
1015 	unsigned int maxpacket, num_packets;
1016 
1017 	/* instance init */
1018 	instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1019 	if (!instance)
1020 		return -ENOMEM;
1021 
1022 	/* public fields */
1023 
1024 	instance->driver = driver;
1025 	strlcpy(instance->driver_name, driver->driver_name,
1026 		sizeof(instance->driver_name));
1027 
1028 	instance->usb_dev = usb_dev;
1029 	instance->usb_intf = intf;
1030 
1031 	buf = instance->description;
1032 	length = sizeof(instance->description);
1033 
1034 	if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1035 		goto bind;
1036 
1037 	buf += i;
1038 	length -= i;
1039 
1040 	i = scnprintf(buf, length, " (");
1041 	buf += i;
1042 	length -= i;
1043 
1044 	if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1045 		goto bind;
1046 
1047 	buf += i;
1048 	length -= i;
1049 
1050 	snprintf(buf, length, ")");
1051 
1052  bind:
1053 	if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1054 			dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1055 			goto fail_free;
1056 	}
1057 
1058 	/* private fields */
1059 
1060 	kref_init(&instance->refcount);		/* dropped in usbatm_usb_disconnect */
1061 	mutex_init(&instance->serialize);
1062 
1063 	instance->thread = NULL;
1064 	init_completion(&instance->thread_started);
1065 	init_completion(&instance->thread_exited);
1066 
1067 	INIT_LIST_HEAD(&instance->vcc_list);
1068 	skb_queue_head_init(&instance->sndqueue);
1069 
1070 	usbatm_init_channel(&instance->rx_channel);
1071 	usbatm_init_channel(&instance->tx_channel);
1072 	tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1073 	tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1074 	instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1075 	instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1076 	instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1077 
1078 	if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1079 		instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1080 	else
1081 		instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1082 
1083 	instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1084 
1085 	/* tx buffer size must be a positive multiple of the stride */
1086 	instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1087 			snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1088 
1089 	/* rx buffer size must be a positive multiple of the endpoint maxpacket */
1090 	maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1091 
1092 	if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1093 		dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1094 				usb_pipeendpoint(instance->rx_channel.endpoint));
1095 		error = -EINVAL;
1096 		goto fail_unbind;
1097 	}
1098 
1099 	num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1100 
1101 	if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1102 		num_packets--;
1103 
1104 	instance->rx_channel.buf_size = num_packets * maxpacket;
1105 	instance->rx_channel.packet_size = maxpacket;
1106 
1107 	for (i = 0; i < 2; i++) {
1108 		struct usbatm_channel *channel = i ?
1109 			&instance->tx_channel : &instance->rx_channel;
1110 
1111 		dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1112 			__func__, channel->buf_size, i ? "tx" : "rx", channel);
1113 	}
1114 
1115 	/* initialize urbs */
1116 
1117 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1118 		u8 *buffer;
1119 		struct usbatm_channel *channel = i < num_rcv_urbs ?
1120 			&instance->rx_channel : &instance->tx_channel;
1121 		struct urb *urb;
1122 		unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1123 
1124 		urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1125 		if (!urb) {
1126 			error = -ENOMEM;
1127 			goto fail_unbind;
1128 		}
1129 
1130 		instance->urbs[i] = urb;
1131 
1132 		/* zero the tx padding to avoid leaking information */
1133 		buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1134 		if (!buffer) {
1135 			error = -ENOMEM;
1136 			goto fail_unbind;
1137 		}
1138 
1139 		usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1140 				  buffer, channel->buf_size, usbatm_complete, channel);
1141 		if (iso_packets) {
1142 			int j;
1143 			urb->interval = 1;
1144 			urb->transfer_flags = URB_ISO_ASAP;
1145 			urb->number_of_packets = iso_packets;
1146 			for (j = 0; j < iso_packets; j++) {
1147 				urb->iso_frame_desc[j].offset = channel->packet_size * j;
1148 				urb->iso_frame_desc[j].length = channel->packet_size;
1149 			}
1150 		}
1151 
1152 		/* put all tx URBs on the list of spares */
1153 		if (i >= num_rcv_urbs)
1154 			list_add_tail(&urb->urb_list, &channel->list);
1155 
1156 		vdbg(&intf->dev, "%s: alloced buffer 0x%p buf size %u urb 0x%p",
1157 		     __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1158 	}
1159 
1160 	instance->cached_vpi = ATM_VPI_UNSPEC;
1161 	instance->cached_vci = ATM_VCI_UNSPEC;
1162 	instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1163 
1164 	if (!instance->cell_buf) {
1165 		error = -ENOMEM;
1166 		goto fail_unbind;
1167 	}
1168 
1169 	if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1170 		error = usbatm_heavy_init(instance);
1171 	} else {
1172 		complete(&instance->thread_exited);	/* pretend that heavy_init was run */
1173 		error = usbatm_atm_init(instance);
1174 	}
1175 
1176 	if (error < 0)
1177 		goto fail_unbind;
1178 
1179 	usb_get_dev(usb_dev);
1180 	usb_set_intfdata(intf, instance);
1181 
1182 	return 0;
1183 
1184  fail_unbind:
1185 	if (instance->driver->unbind)
1186 		instance->driver->unbind(instance, intf);
1187  fail_free:
1188 	kfree(instance->cell_buf);
1189 
1190 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1191 		if (instance->urbs[i])
1192 			kfree(instance->urbs[i]->transfer_buffer);
1193 		usb_free_urb(instance->urbs[i]);
1194 	}
1195 
1196 	kfree(instance);
1197 
1198 	return error;
1199 }
1200 EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1201 
1202 void usbatm_usb_disconnect(struct usb_interface *intf)
1203 {
1204 	struct device *dev = &intf->dev;
1205 	struct usbatm_data *instance = usb_get_intfdata(intf);
1206 	struct usbatm_vcc_data *vcc_data;
1207 	int i;
1208 
1209 	if (!instance) {
1210 		dev_dbg(dev, "%s: NULL instance!\n", __func__);
1211 		return;
1212 	}
1213 
1214 	usb_set_intfdata(intf, NULL);
1215 
1216 	mutex_lock(&instance->serialize);
1217 	instance->disconnected = 1;
1218 	if (instance->thread != NULL)
1219 		send_sig(SIGTERM, instance->thread, 1);
1220 	mutex_unlock(&instance->serialize);
1221 
1222 	wait_for_completion(&instance->thread_exited);
1223 
1224 	mutex_lock(&instance->serialize);
1225 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
1226 		vcc_release_async(vcc_data->vcc, -EPIPE);
1227 	mutex_unlock(&instance->serialize);
1228 
1229 	tasklet_disable(&instance->rx_channel.tasklet);
1230 	tasklet_disable(&instance->tx_channel.tasklet);
1231 
1232 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1233 		usb_kill_urb(instance->urbs[i]);
1234 
1235 	del_timer_sync(&instance->rx_channel.delay);
1236 	del_timer_sync(&instance->tx_channel.delay);
1237 
1238 	/* turn usbatm_[rt]x_process into something close to a no-op */
1239 	/* no need to take the spinlock */
1240 	INIT_LIST_HEAD(&instance->rx_channel.list);
1241 	INIT_LIST_HEAD(&instance->tx_channel.list);
1242 
1243 	tasklet_enable(&instance->rx_channel.tasklet);
1244 	tasklet_enable(&instance->tx_channel.tasklet);
1245 
1246 	if (instance->atm_dev && instance->driver->atm_stop)
1247 		instance->driver->atm_stop(instance, instance->atm_dev);
1248 
1249 	if (instance->driver->unbind)
1250 		instance->driver->unbind(instance, intf);
1251 
1252 	instance->driver_data = NULL;
1253 
1254 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1255 		kfree(instance->urbs[i]->transfer_buffer);
1256 		usb_free_urb(instance->urbs[i]);
1257 	}
1258 
1259 	kfree(instance->cell_buf);
1260 
1261 	/* ATM finalize */
1262 	if (instance->atm_dev) {
1263 		atm_dev_deregister(instance->atm_dev);
1264 		instance->atm_dev = NULL;
1265 	}
1266 
1267 	usbatm_put_instance(instance);	/* taken in usbatm_usb_probe */
1268 }
1269 EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1270 
1271 
1272 /***********
1273 **  init  **
1274 ***********/
1275 
1276 static int __init usbatm_usb_init(void)
1277 {
1278 	if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
1279 		printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1280 		return -EIO;
1281 	}
1282 
1283 	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1284 	    || (num_snd_urbs > UDSL_MAX_SND_URBS)
1285 	    || (rcv_buf_bytes < 1)
1286 	    || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1287 	    || (snd_buf_bytes < 1)
1288 	    || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1289 		return -EINVAL;
1290 
1291 	return 0;
1292 }
1293 module_init(usbatm_usb_init);
1294 
1295 static void __exit usbatm_usb_exit(void)
1296 {
1297 }
1298 module_exit(usbatm_usb_exit);
1299 
1300 MODULE_AUTHOR(DRIVER_AUTHOR);
1301 MODULE_DESCRIPTION(DRIVER_DESC);
1302 MODULE_LICENSE("GPL");
1303 
1304 /************
1305 **  debug  **
1306 ************/
1307 
1308 #ifdef VERBOSE_DEBUG
1309 static int usbatm_print_packet(struct usbatm_data *instance,
1310 			       const unsigned char *data, int len)
1311 {
1312 	unsigned char buffer[256];
1313 	int i = 0, j = 0;
1314 
1315 	for (i = 0; i < len;) {
1316 		buffer[0] = '\0';
1317 		sprintf(buffer, "%.3d :", i);
1318 		for (j = 0; (j < 16) && (i < len); j++, i++)
1319 			sprintf(buffer, "%s %2.2x", buffer, data[i]);
1320 		dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1321 	}
1322 	return i;
1323 }
1324 #endif
1325