1// SPDX-License-Identifier: GPL-2.0+
2/******************************************************************************
3 * usbatm.c - Generic USB xDSL driver core
4 *
5 * Copyright (C) 2001, Alcatel
6 * Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
7 * Copyright (C) 2004, David Woodhouse, Roman Kagan
8 ******************************************************************************/
9
10/*
11 * Written by Johan Verrept, Duncan Sands (duncan.sands@free.fr) and David Woodhouse
12 *
13 * 1.7+: - See the check-in logs
14 *
15 * 1.6: - No longer opens a connection if the firmware is not loaded
16 * - Added support for the speedtouch 330
17 * - Removed the limit on the number of devices
18 * - Module now autoloads on device plugin
19 * - Merged relevant parts of sarlib
20 * - Replaced the kernel thread with a tasklet
21 * - New packet transmission code
22 * - Changed proc file contents
23 * - Fixed all known SMP races
24 * - Many fixes and cleanups
25 * - Various fixes by Oliver Neukum (oliver@neukum.name)
26 *
27 * 1.5A: - Version for inclusion in 2.5 series kernel
28 * - Modifications by Richard Purdie (rpurdie@rpsys.net)
29 * - made compatible with kernel 2.5.6 onwards by changing
30 * usbatm_usb_send_data_context->urb to a pointer and adding code
31 * to alloc and free it
32 * - remove_wait_queue() added to usbatm_atm_processqueue_thread()
33 *
34 * 1.5: - fixed memory leak when atmsar_decode_aal5 returned NULL.
35 * (reported by stephen.robinson@zen.co.uk)
36 *
37 * 1.4: - changed the spin_lock() under interrupt to spin_lock_irqsave()
38 * - unlink all active send urbs of a vcc that is being closed.
39 *
40 * 1.3.1: - added the version number
41 *
42 * 1.3: - Added multiple send urb support
43 * - fixed memory leak and vcc->tx_inuse starvation bug
44 * when not enough memory left in vcc.
45 *
46 * 1.2: - Fixed race condition in usbatm_usb_send_data()
47 * 1.1: - Turned off packet debugging
48 *
49 */
50
51#include "usbatm.h"
52
53#include <linux/uaccess.h>
54#include <linux/crc32.h>
55#include <linux/errno.h>
56#include <linux/init.h>
57#include <linux/interrupt.h>
58#include <linux/kernel.h>
59#include <linux/module.h>
60#include <linux/moduleparam.h>
61#include <linux/netdevice.h>
62#include <linux/proc_fs.h>
63#include <linux/sched/signal.h>
64#include <linux/signal.h>
65#include <linux/slab.h>
66#include <linux/stat.h>
67#include <linux/timer.h>
68#include <linux/wait.h>
69#include <linux/kthread.h>
70#include <linux/ratelimit.h>
71
72#ifdef VERBOSE_DEBUG
73static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
74#define PACKETDEBUG(arg...) usbatm_print_packet(arg)
75#define vdbg(arg...) dev_dbg(arg)
76#else
77#define PACKETDEBUG(arg...)
78#define vdbg(arg...)
79#endif
80
81#define DRIVER_AUTHOR "Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
82#define DRIVER_DESC "Generic USB ATM/DSL I/O"
83
84static const char usbatm_driver_name[] = "usbatm";
85
86#define UDSL_MAX_RCV_URBS 16
87#define UDSL_MAX_SND_URBS 16
88#define UDSL_MAX_BUF_SIZE 65536
89#define UDSL_DEFAULT_RCV_URBS 4
90#define UDSL_DEFAULT_SND_URBS 4
91#define UDSL_DEFAULT_RCV_BUF_SIZE 3392 /* 64 * ATM_CELL_SIZE */
92#define UDSL_DEFAULT_SND_BUF_SIZE 3392 /* 64 * ATM_CELL_SIZE */
93
94#define ATM_CELL_HEADER (ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
95
96#define THROTTLE_MSECS 100 /* delay to recover processing after urb submission fails */
97
98static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
99static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
100static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
101static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
102
103module_param(num_rcv_urbs, uint, S_IRUGO);
104MODULE_PARM_DESC(num_rcv_urbs,
105 "Number of urbs used for reception (range: 0-"
106 __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
107 __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
108
109module_param(num_snd_urbs, uint, S_IRUGO);
110MODULE_PARM_DESC(num_snd_urbs,
111 "Number of urbs used for transmission (range: 0-"
112 __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
113 __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
114
115module_param(rcv_buf_bytes, uint, S_IRUGO);
116MODULE_PARM_DESC(rcv_buf_bytes,
117 "Size of the buffers used for reception, in bytes (range: 1-"
118 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
119 __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
120
121module_param(snd_buf_bytes, uint, S_IRUGO);
122MODULE_PARM_DESC(snd_buf_bytes,
123 "Size of the buffers used for transmission, in bytes (range: 1-"
124 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
125 __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
126
127
128/* receive */
129
130struct usbatm_vcc_data {
131 /* vpi/vci lookup */
132 struct list_head list;
133 short vpi;
134 int vci;
135 struct atm_vcc *vcc;
136
137 /* raw cell reassembly */
138 struct sk_buff *sarb;
139};
140
141
142/* send */
143
144struct usbatm_control {
145 struct atm_skb_data atm;
146 u32 len;
147 u32 crc;
148};
149
150#define UDSL_SKB(x) ((struct usbatm_control *)(x)->cb)
151
152
153/* ATM */
154
155static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
156static int usbatm_atm_open(struct atm_vcc *vcc);
157static void usbatm_atm_close(struct atm_vcc *vcc);
158static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user *arg);
159static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
160static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page);
161
162static const struct atmdev_ops usbatm_atm_devops = {
163 .dev_close = usbatm_atm_dev_close,
164 .open = usbatm_atm_open,
165 .close = usbatm_atm_close,
166 .ioctl = usbatm_atm_ioctl,
167 .send = usbatm_atm_send,
168 .proc_read = usbatm_atm_proc_read,
169 .owner = THIS_MODULE,
170};
171
172
173/***********
174** misc **
175***********/
176
177static inline unsigned int usbatm_pdu_length(unsigned int length)
178{
179 length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
180 return length - length % ATM_CELL_PAYLOAD;
181}
182
183static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
184{
185 if (vcc->pop)
186 vcc->pop(vcc, skb);
187 else
188 dev_kfree_skb_any(skb);
189}
190
191
192/***********
193** urbs **
194************/
195
196static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
197{
198 struct urb *urb;
199
200 spin_lock_irq(lock: &channel->lock);
201 if (list_empty(head: &channel->list)) {
202 spin_unlock_irq(lock: &channel->lock);
203 return NULL;
204 }
205
206 urb = list_entry(channel->list.next, struct urb, urb_list);
207 list_del(entry: &urb->urb_list);
208 spin_unlock_irq(lock: &channel->lock);
209
210 return urb;
211}
212
213static int usbatm_submit_urb(struct urb *urb)
214{
215 struct usbatm_channel *channel = urb->context;
216 int ret;
217
218 /* vdbg("%s: submitting urb 0x%p, size %u",
219 __func__, urb, urb->transfer_buffer_length); */
220
221 ret = usb_submit_urb(urb, GFP_ATOMIC);
222 if (ret) {
223 if (printk_ratelimit())
224 atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
225 __func__, urb, ret);
226
227 /* consider all errors transient and return the buffer back to the queue */
228 urb->status = -EAGAIN;
229 spin_lock_irq(lock: &channel->lock);
230
231 /* must add to the front when sending; doesn't matter when receiving */
232 list_add(new: &urb->urb_list, head: &channel->list);
233
234 spin_unlock_irq(lock: &channel->lock);
235
236 /* make sure the channel doesn't stall */
237 mod_timer(timer: &channel->delay, expires: jiffies + msecs_to_jiffies(THROTTLE_MSECS));
238 }
239
240 return ret;
241}
242
243static void usbatm_complete(struct urb *urb)
244{
245 struct usbatm_channel *channel = urb->context;
246 unsigned long flags;
247 int status = urb->status;
248
249 /* vdbg("%s: urb 0x%p, status %d, actual_length %d",
250 __func__, urb, status, urb->actual_length); */
251
252 /* Can be invoked from task context, protect against interrupts */
253 spin_lock_irqsave(&channel->lock, flags);
254
255 /* must add to the back when receiving; doesn't matter when sending */
256 list_add_tail(new: &urb->urb_list, head: &channel->list);
257
258 spin_unlock_irqrestore(lock: &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(timer: &channel->delay, expires: jiffies + msecs_to_jiffies(THROTTLE_MSECS));
271 } else
272 tasklet_schedule(t: &channel->tasklet);
273}
274
275
276/*************
277** decode **
278*************/
279
280static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
281 short vpi, int vci)
282{
283 struct usbatm_vcc_data *vcc_data;
284
285 list_for_each_entry(vcc_data, &instance->vcc_list, list)
286 if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
287 return vcc_data;
288 return NULL;
289}
290
291static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
292{
293 struct atm_vcc *vcc;
294 struct sk_buff *sarb;
295 short vpi = ((source[0] & 0x0f) << 4) | (source[1] >> 4);
296 int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
297 u8 pti = ((source[3] & 0xe) >> 1);
298
299 if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
300 instance->cached_vpi = vpi;
301 instance->cached_vci = vci;
302
303 instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
304
305 if (!instance->cached_vcc)
306 atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
307 }
308
309 if (!instance->cached_vcc)
310 return;
311
312 vcc = instance->cached_vcc->vcc;
313
314 /* OAM F5 end-to-end */
315 if (pti == ATM_PTI_E2EF5) {
316 if (printk_ratelimit())
317 atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
318 __func__, vpi, vci);
319 atomic_inc(v: &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(skb: sarb, len: 0);
330 }
331
332 memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
333 __skb_put(skb: 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(v: &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(v: &vcc->stats->rx_err);
356 goto out;
357 }
358
359 if (crc32_be(crc: ~0, p: skb_tail_pointer(skb: sarb) - pdu_length, len: pdu_length) != 0xc704dd7b) {
360 atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
361 __func__, vcc);
362 atomic_inc(v: &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(v: &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, truesize: 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 from: skb_tail_pointer(skb: sarb) - pdu_length,
392 len: length);
393 __skb_put(skb, len: 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(v: &vcc->stats->rx);
404 out:
405 skb_trim(skb: sarb, len: 0);
406 }
407}
408
409static void usbatm_extract_cells(struct usbatm_data *instance,
410 unsigned char *source, unsigned int avail_data)
411{
412 unsigned int stride = instance->rx_channel.stride;
413 unsigned int buf_usage = instance->buf_usage;
414
415 /* extract cells from incoming data, taking into account that
416 * the length of avail data may not be a multiple of stride */
417
418 if (buf_usage > 0) {
419 /* we have a partially received atm cell */
420 unsigned char *cell_buf = instance->cell_buf;
421 unsigned int space_left = stride - buf_usage;
422
423 if (avail_data >= space_left) {
424 /* add new data and process cell */
425 memcpy(cell_buf + buf_usage, source, space_left);
426 source += space_left;
427 avail_data -= space_left;
428 usbatm_extract_one_cell(instance, source: cell_buf);
429 instance->buf_usage = 0;
430 } else {
431 /* not enough data to fill the cell */
432 memcpy(cell_buf + buf_usage, source, avail_data);
433 instance->buf_usage = buf_usage + avail_data;
434 return;
435 }
436 }
437
438 for (; avail_data >= stride; avail_data -= stride, source += stride)
439 usbatm_extract_one_cell(instance, source);
440
441 if (avail_data > 0) {
442 /* length was not a multiple of stride -
443 * save remaining data for next call */
444 memcpy(instance->cell_buf, source, avail_data);
445 instance->buf_usage = avail_data;
446 }
447}
448
449
450/*************
451** encode **
452*************/
453
454static unsigned int usbatm_write_cells(struct usbatm_data *instance,
455 struct sk_buff *skb,
456 u8 *target, unsigned int avail_space)
457{
458 struct usbatm_control *ctrl = UDSL_SKB(skb);
459 struct atm_vcc *vcc = ctrl->atm.vcc;
460 unsigned int bytes_written;
461 unsigned int stride = instance->tx_channel.stride;
462
463 for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
464 bytes_written += stride, target += stride) {
465 unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
466 unsigned int left = ATM_CELL_PAYLOAD - data_len;
467 u8 *ptr = target;
468
469 ptr[0] = vcc->vpi >> 4;
470 ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
471 ptr[2] = vcc->vci >> 4;
472 ptr[3] = vcc->vci << 4;
473 ptr[4] = 0xec;
474 ptr += ATM_CELL_HEADER;
475
476 skb_copy_from_linear_data(skb, to: ptr, len: data_len);
477 ptr += data_len;
478 __skb_pull(skb, len: 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(crc: ctrl->crc, p: ptr, len: 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(crc: ctrl->crc, p: ptr, len: left);
504 }
505
506 return bytes_written;
507}
508
509
510/**************
511** receive **
512**************/
513
514static void usbatm_rx_process(struct tasklet_struct *t)
515{
516 struct usbatm_data *instance = from_tasklet(instance, t,
517 rx_channel.tasklet);
518 struct urb *urb;
519
520 while ((urb = usbatm_pop_urb(channel: &instance->rx_channel))) {
521 vdbg(&instance->usb_intf->dev,
522 "%s: processing urb 0x%p", __func__, urb);
523
524 if (usb_pipeisoc(urb->pipe)) {
525 unsigned char *merge_start = NULL;
526 unsigned int merge_length = 0;
527 const unsigned int packet_size = instance->rx_channel.packet_size;
528 int i;
529
530 for (i = 0; i < urb->number_of_packets; i++) {
531 if (!urb->iso_frame_desc[i].status) {
532 unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
533
534 if (!merge_length)
535 merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
536 merge_length += actual_length;
537 if (merge_length && (actual_length < packet_size)) {
538 usbatm_extract_cells(instance, source: merge_start, avail_data: merge_length);
539 merge_length = 0;
540 }
541 } else {
542 atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
543 if (merge_length)
544 usbatm_extract_cells(instance, source: merge_start, avail_data: merge_length);
545 merge_length = 0;
546 instance->buf_usage = 0;
547 }
548 }
549
550 if (merge_length)
551 usbatm_extract_cells(instance, source: merge_start, avail_data: merge_length);
552 } else
553 if (!urb->status)
554 usbatm_extract_cells(instance, source: urb->transfer_buffer, avail_data: urb->actual_length);
555 else
556 instance->buf_usage = 0;
557
558 if (usbatm_submit_urb(urb))
559 return;
560 }
561}
562
563
564/***********
565** send **
566***********/
567
568static void usbatm_tx_process(struct tasklet_struct *t)
569{
570 struct usbatm_data *instance = from_tasklet(instance, t,
571 tx_channel.tasklet);
572 struct sk_buff *skb = instance->current_skb;
573 struct urb *urb = NULL;
574 const unsigned int buf_size = instance->tx_channel.buf_size;
575 unsigned int bytes_written = 0;
576 u8 *buffer = NULL;
577
578 if (!skb)
579 skb = skb_dequeue(list: &instance->sndqueue);
580
581 while (skb) {
582 if (!urb) {
583 urb = usbatm_pop_urb(channel: &instance->tx_channel);
584 if (!urb)
585 break; /* no more senders */
586 buffer = urb->transfer_buffer;
587 bytes_written = (urb->status == -EAGAIN) ?
588 urb->transfer_buffer_length : 0;
589 }
590
591 bytes_written += usbatm_write_cells(instance, skb,
592 target: buffer + bytes_written,
593 avail_space: buf_size - bytes_written);
594
595 vdbg(&instance->usb_intf->dev,
596 "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
597 __func__, bytes_written, skb, urb);
598
599 if (!UDSL_SKB(skb)->len) {
600 struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
601
602 usbatm_pop(vcc, skb);
603 atomic_inc(v: &vcc->stats->tx);
604
605 skb = skb_dequeue(list: &instance->sndqueue);
606 }
607
608 if (bytes_written == buf_size || (!skb && bytes_written)) {
609 urb->transfer_buffer_length = bytes_written;
610
611 if (usbatm_submit_urb(urb))
612 break;
613 urb = NULL;
614 }
615 }
616
617 instance->current_skb = skb;
618}
619
620static void usbatm_cancel_send(struct usbatm_data *instance,
621 struct atm_vcc *vcc)
622{
623 struct sk_buff *skb, *n;
624
625 spin_lock_irq(lock: &instance->sndqueue.lock);
626 skb_queue_walk_safe(&instance->sndqueue, skb, n) {
627 if (UDSL_SKB(skb)->atm.vcc == vcc) {
628 atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
629 __skb_unlink(skb, list: &instance->sndqueue);
630 usbatm_pop(vcc, skb);
631 }
632 }
633 spin_unlock_irq(lock: &instance->sndqueue.lock);
634
635 tasklet_disable(t: &instance->tx_channel.tasklet);
636 if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
637 atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
638 instance->current_skb = NULL;
639 usbatm_pop(vcc, skb);
640 }
641 tasklet_enable(t: &instance->tx_channel.tasklet);
642}
643
644static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
645{
646 struct usbatm_data *instance = vcc->dev->dev_data;
647 struct usbatm_control *ctrl = UDSL_SKB(skb);
648 int err;
649
650 /* racy disconnection check - fine */
651 if (!instance || instance->disconnected) {
652#ifdef VERBOSE_DEBUG
653 printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
654#endif
655 err = -ENODEV;
656 goto fail;
657 }
658
659 if (vcc->qos.aal != ATM_AAL5) {
660 atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
661 err = -EINVAL;
662 goto fail;
663 }
664
665 if (skb->len > ATM_MAX_AAL5_PDU) {
666 atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
667 __func__, skb->len, ATM_MAX_AAL5_PDU);
668 err = -EINVAL;
669 goto fail;
670 }
671
672 PACKETDEBUG(instance, skb->data, skb->len);
673
674 /* initialize the control block */
675 ctrl->atm.vcc = vcc;
676 ctrl->len = skb->len;
677 ctrl->crc = crc32_be(crc: ~0, p: skb->data, len: skb->len);
678
679 skb_queue_tail(list: &instance->sndqueue, newsk: skb);
680 tasklet_schedule(t: &instance->tx_channel.tasklet);
681
682 return 0;
683
684 fail:
685 usbatm_pop(vcc, skb);
686 return err;
687}
688
689
690/********************
691** bean counting **
692********************/
693
694static void usbatm_destroy_instance(struct kref *kref)
695{
696 struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
697
698 tasklet_kill(t: &instance->rx_channel.tasklet);
699 tasklet_kill(t: &instance->tx_channel.tasklet);
700 usb_put_dev(dev: instance->usb_dev);
701 kfree(objp: instance);
702}
703
704static void usbatm_get_instance(struct usbatm_data *instance)
705{
706 kref_get(kref: &instance->refcount);
707}
708
709static void usbatm_put_instance(struct usbatm_data *instance)
710{
711 kref_put(kref: &instance->refcount, release: usbatm_destroy_instance);
712}
713
714
715/**********
716** ATM **
717**********/
718
719static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
720{
721 struct usbatm_data *instance = atm_dev->dev_data;
722
723 if (!instance)
724 return;
725
726 atm_dev->dev_data = NULL; /* catch bugs */
727 usbatm_put_instance(instance); /* taken in usbatm_atm_init */
728}
729
730static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
731{
732 struct usbatm_data *instance = atm_dev->dev_data;
733 int left = *pos;
734
735 if (!instance)
736 return -ENODEV;
737
738 if (!left--)
739 return sprintf(buf: page, fmt: "%s\n", instance->description);
740
741 if (!left--)
742 return sprintf(buf: page, fmt: "MAC: %pM\n", atm_dev->esi);
743
744 if (!left--)
745 return sprintf(buf: page,
746 fmt: "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
747 atomic_read(v: &atm_dev->stats.aal5.tx),
748 atomic_read(v: &atm_dev->stats.aal5.tx_err),
749 atomic_read(v: &atm_dev->stats.aal5.rx),
750 atomic_read(v: &atm_dev->stats.aal5.rx_err),
751 atomic_read(v: &atm_dev->stats.aal5.rx_drop));
752
753 if (!left--) {
754 if (instance->disconnected)
755 return sprintf(buf: page, fmt: "Disconnected\n");
756 else
757 switch (atm_dev->signal) {
758 case ATM_PHY_SIG_FOUND:
759 return sprintf(buf: page, fmt: "Line up\n");
760 case ATM_PHY_SIG_LOST:
761 return sprintf(buf: page, fmt: "Line down\n");
762 default:
763 return sprintf(buf: page, fmt: "Line state unknown\n");
764 }
765 }
766
767 return 0;
768}
769
770static int usbatm_atm_open(struct atm_vcc *vcc)
771{
772 struct usbatm_data *instance = vcc->dev->dev_data;
773 struct usbatm_vcc_data *new = NULL;
774 int ret;
775 int vci = vcc->vci;
776 short vpi = vcc->vpi;
777
778 if (!instance)
779 return -ENODEV;
780
781 /* only support AAL5 */
782 if ((vcc->qos.aal != ATM_AAL5)) {
783 atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
784 return -EINVAL;
785 }
786
787 /* sanity checks */
788 if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
789 atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
790 return -EINVAL;
791 }
792
793 mutex_lock(&instance->serialize); /* vs self, usbatm_atm_close, usbatm_usb_disconnect */
794
795 if (instance->disconnected) {
796 atm_dbg(instance, "%s: disconnected!\n", __func__);
797 ret = -ENODEV;
798 goto fail;
799 }
800
801 if (usbatm_find_vcc(instance, vpi, vci)) {
802 atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
803 ret = -EADDRINUSE;
804 goto fail;
805 }
806
807 new = kzalloc(size: sizeof(struct usbatm_vcc_data), GFP_KERNEL);
808 if (!new) {
809 ret = -ENOMEM;
810 goto fail;
811 }
812
813 new->vcc = vcc;
814 new->vpi = vpi;
815 new->vci = vci;
816
817 new->sarb = alloc_skb(size: usbatm_pdu_length(length: vcc->qos.rxtp.max_sdu), GFP_KERNEL);
818 if (!new->sarb) {
819 atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
820 ret = -ENOMEM;
821 goto fail;
822 }
823
824 vcc->dev_data = new;
825
826 tasklet_disable(t: &instance->rx_channel.tasklet);
827 instance->cached_vcc = new;
828 instance->cached_vpi = vpi;
829 instance->cached_vci = vci;
830 list_add(new: &new->list, head: &instance->vcc_list);
831 tasklet_enable(t: &instance->rx_channel.tasklet);
832
833 set_bit(nr: ATM_VF_ADDR, addr: &vcc->flags);
834 set_bit(nr: ATM_VF_PARTIAL, addr: &vcc->flags);
835 set_bit(nr: ATM_VF_READY, addr: &vcc->flags);
836
837 mutex_unlock(lock: &instance->serialize);
838
839 atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
840
841 return 0;
842
843fail:
844 kfree(objp: new);
845 mutex_unlock(lock: &instance->serialize);
846 return ret;
847}
848
849static void usbatm_atm_close(struct atm_vcc *vcc)
850{
851 struct usbatm_data *instance = vcc->dev->dev_data;
852 struct usbatm_vcc_data *vcc_data = vcc->dev_data;
853
854 if (!instance || !vcc_data)
855 return;
856
857 usbatm_cancel_send(instance, vcc);
858
859 mutex_lock(&instance->serialize); /* vs self, usbatm_atm_open, usbatm_usb_disconnect */
860
861 tasklet_disable(t: &instance->rx_channel.tasklet);
862 if (instance->cached_vcc == vcc_data) {
863 instance->cached_vcc = NULL;
864 instance->cached_vpi = ATM_VPI_UNSPEC;
865 instance->cached_vci = ATM_VCI_UNSPEC;
866 }
867 list_del(entry: &vcc_data->list);
868 tasklet_enable(t: &instance->rx_channel.tasklet);
869
870 kfree_skb(skb: vcc_data->sarb);
871 vcc_data->sarb = NULL;
872
873 kfree(objp: vcc_data);
874 vcc->dev_data = NULL;
875
876 vcc->vpi = ATM_VPI_UNSPEC;
877 vcc->vci = ATM_VCI_UNSPEC;
878 clear_bit(nr: ATM_VF_READY, addr: &vcc->flags);
879 clear_bit(nr: ATM_VF_PARTIAL, addr: &vcc->flags);
880 clear_bit(nr: ATM_VF_ADDR, addr: &vcc->flags);
881
882 mutex_unlock(lock: &instance->serialize);
883}
884
885static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
886 void __user *arg)
887{
888 struct usbatm_data *instance = atm_dev->dev_data;
889
890 if (!instance || instance->disconnected)
891 return -ENODEV;
892
893 switch (cmd) {
894 case ATM_QUERYLOOP:
895 return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
896 default:
897 return -ENOIOCTLCMD;
898 }
899}
900
901static int usbatm_atm_init(struct usbatm_data *instance)
902{
903 struct atm_dev *atm_dev;
904 int ret, i;
905
906 /* ATM init. The ATM initialization scheme suffers from an intrinsic race
907 * condition: callbacks we register can be executed at once, before we have
908 * initialized the struct atm_dev. To protect against this, all callbacks
909 * abort if atm_dev->dev_data is NULL. */
910 atm_dev = atm_dev_register(type: instance->driver_name,
911 parent: &instance->usb_intf->dev, ops: &usbatm_atm_devops,
912 number: -1, NULL);
913 if (!atm_dev) {
914 usb_err(instance, "%s: failed to register ATM device!\n", __func__);
915 return -1;
916 }
917
918 instance->atm_dev = atm_dev;
919
920 atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
921 atm_dev->ci_range.vci_bits = ATM_CI_MAX;
922 atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
923
924 /* temp init ATM device, set to 128kbit */
925 atm_dev->link_rate = 128 * 1000 / 424;
926
927 if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
928 atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
929 goto fail;
930 }
931
932 usbatm_get_instance(instance); /* dropped in usbatm_atm_dev_close */
933
934 /* ready for ATM callbacks */
935 mb();
936 atm_dev->dev_data = instance;
937
938 /* submit all rx URBs */
939 for (i = 0; i < num_rcv_urbs; i++)
940 usbatm_submit_urb(urb: instance->urbs[i]);
941
942 return 0;
943
944 fail:
945 instance->atm_dev = NULL;
946 atm_dev_deregister(dev: atm_dev); /* usbatm_atm_dev_close will eventually be called */
947 return ret;
948}
949
950
951/**********
952** USB **
953**********/
954
955static int usbatm_do_heavy_init(void *arg)
956{
957 struct usbatm_data *instance = arg;
958 int ret;
959
960 allow_signal(SIGTERM);
961 complete(&instance->thread_started);
962
963 ret = instance->driver->heavy_init(instance, instance->usb_intf);
964
965 if (!ret)
966 ret = usbatm_atm_init(instance);
967
968 mutex_lock(&instance->serialize);
969 instance->thread = NULL;
970 mutex_unlock(lock: &instance->serialize);
971
972 kthread_complete_and_exit(&instance->thread_exited, ret);
973}
974
975static int usbatm_heavy_init(struct usbatm_data *instance)
976{
977 struct task_struct *t;
978
979 t = kthread_create(usbatm_do_heavy_init, instance, "%s",
980 instance->driver->driver_name);
981 if (IS_ERR(ptr: t)) {
982 usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
983 __func__, PTR_ERR(t));
984 return PTR_ERR(ptr: t);
985 }
986
987 instance->thread = t;
988 wake_up_process(tsk: t);
989 wait_for_completion(&instance->thread_started);
990
991 return 0;
992}
993
994static void usbatm_tasklet_schedule(struct timer_list *t)
995{
996 struct usbatm_channel *channel = from_timer(channel, t, delay);
997
998 tasklet_schedule(t: &channel->tasklet);
999}
1000
1001static void usbatm_init_channel(struct usbatm_channel *channel)
1002{
1003 spin_lock_init(&channel->lock);
1004 INIT_LIST_HEAD(list: &channel->list);
1005 timer_setup(&channel->delay, usbatm_tasklet_schedule, 0);
1006}
1007
1008int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1009 struct usbatm_driver *driver)
1010{
1011 struct device *dev = &intf->dev;
1012 struct usb_device *usb_dev = interface_to_usbdev(intf);
1013 struct usbatm_data *instance;
1014 char *buf;
1015 int error = -ENOMEM;
1016 int i, length;
1017 unsigned int maxpacket, num_packets;
1018 size_t size;
1019
1020 /* instance init */
1021 size = struct_size(instance, urbs,
1022 size_add(num_rcv_urbs, num_snd_urbs));
1023 instance = kzalloc(size, GFP_KERNEL);
1024 if (!instance)
1025 return -ENOMEM;
1026
1027 /* public fields */
1028
1029 instance->driver = driver;
1030 strscpy(p: instance->driver_name, q: driver->driver_name,
1031 size: sizeof(instance->driver_name));
1032
1033 instance->usb_dev = usb_dev;
1034 instance->usb_intf = intf;
1035
1036 buf = instance->description;
1037 length = sizeof(instance->description);
1038
1039 if ((i = usb_string(dev: usb_dev, index: usb_dev->descriptor.iProduct, buf, size: length)) < 0)
1040 goto bind;
1041
1042 buf += i;
1043 length -= i;
1044
1045 i = scnprintf(buf, size: length, fmt: " (");
1046 buf += i;
1047 length -= i;
1048
1049 if (length <= 0 || (i = usb_make_path(dev: usb_dev, buf, size: length)) < 0)
1050 goto bind;
1051
1052 buf += i;
1053 length -= i;
1054
1055 snprintf(buf, size: length, fmt: ")");
1056
1057 bind:
1058 if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1059 dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1060 goto fail_free;
1061 }
1062
1063 /* private fields */
1064
1065 kref_init(kref: &instance->refcount); /* dropped in usbatm_usb_disconnect */
1066 mutex_init(&instance->serialize);
1067
1068 instance->thread = NULL;
1069 init_completion(x: &instance->thread_started);
1070 init_completion(x: &instance->thread_exited);
1071
1072 INIT_LIST_HEAD(list: &instance->vcc_list);
1073 skb_queue_head_init(list: &instance->sndqueue);
1074
1075 usbatm_init_channel(channel: &instance->rx_channel);
1076 usbatm_init_channel(channel: &instance->tx_channel);
1077 tasklet_setup(t: &instance->rx_channel.tasklet, callback: usbatm_rx_process);
1078 tasklet_setup(t: &instance->tx_channel.tasklet, callback: usbatm_tx_process);
1079 instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1080 instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1081 instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1082
1083 if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1084 instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1085 else
1086 instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1087
1088 instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1089
1090 /* tx buffer size must be a positive multiple of the stride */
1091 instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1092 snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1093
1094 /* rx buffer size must be a positive multiple of the endpoint maxpacket */
1095 maxpacket = usb_maxpacket(udev: usb_dev, pipe: instance->rx_channel.endpoint);
1096
1097 if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1098 dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1099 usb_pipeendpoint(instance->rx_channel.endpoint));
1100 error = -EINVAL;
1101 goto fail_unbind;
1102 }
1103
1104 num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1105
1106 if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1107 num_packets--;
1108
1109 instance->rx_channel.buf_size = num_packets * maxpacket;
1110 instance->rx_channel.packet_size = maxpacket;
1111
1112 for (i = 0; i < 2; i++) {
1113 struct usbatm_channel *channel = i ?
1114 &instance->tx_channel : &instance->rx_channel;
1115
1116 dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1117 __func__, channel->buf_size, i ? "tx" : "rx", channel);
1118 }
1119
1120 /* initialize urbs */
1121
1122 for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1123 u8 *buffer;
1124 struct usbatm_channel *channel = i < num_rcv_urbs ?
1125 &instance->rx_channel : &instance->tx_channel;
1126 struct urb *urb;
1127 unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1128
1129 urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1130 if (!urb) {
1131 error = -ENOMEM;
1132 goto fail_unbind;
1133 }
1134
1135 instance->urbs[i] = urb;
1136
1137 /* zero the tx padding to avoid leaking information */
1138 buffer = kzalloc(size: channel->buf_size, GFP_KERNEL);
1139 if (!buffer) {
1140 error = -ENOMEM;
1141 goto fail_unbind;
1142 }
1143
1144 usb_fill_bulk_urb(urb, dev: instance->usb_dev, pipe: channel->endpoint,
1145 transfer_buffer: buffer, buffer_length: channel->buf_size, complete_fn: usbatm_complete, context: channel);
1146 if (iso_packets) {
1147 int j;
1148 urb->interval = 1;
1149 urb->transfer_flags = URB_ISO_ASAP;
1150 urb->number_of_packets = iso_packets;
1151 for (j = 0; j < iso_packets; j++) {
1152 urb->iso_frame_desc[j].offset = channel->packet_size * j;
1153 urb->iso_frame_desc[j].length = channel->packet_size;
1154 }
1155 }
1156
1157 /* put all tx URBs on the list of spares */
1158 if (i >= num_rcv_urbs)
1159 list_add_tail(new: &urb->urb_list, head: &channel->list);
1160
1161 vdbg(&intf->dev, "%s: alloced buffer 0x%p buf size %u urb 0x%p",
1162 __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1163 }
1164
1165 instance->cached_vpi = ATM_VPI_UNSPEC;
1166 instance->cached_vci = ATM_VCI_UNSPEC;
1167 instance->cell_buf = kmalloc(size: instance->rx_channel.stride, GFP_KERNEL);
1168
1169 if (!instance->cell_buf) {
1170 error = -ENOMEM;
1171 goto fail_unbind;
1172 }
1173
1174 if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1175 error = usbatm_heavy_init(instance);
1176 } else {
1177 complete(&instance->thread_exited); /* pretend that heavy_init was run */
1178 error = usbatm_atm_init(instance);
1179 }
1180
1181 if (error < 0)
1182 goto fail_unbind;
1183
1184 usb_get_dev(dev: usb_dev);
1185 usb_set_intfdata(intf, data: instance);
1186
1187 return 0;
1188
1189 fail_unbind:
1190 if (instance->driver->unbind)
1191 instance->driver->unbind(instance, intf);
1192 fail_free:
1193 kfree(objp: instance->cell_buf);
1194
1195 for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1196 if (instance->urbs[i])
1197 kfree(objp: instance->urbs[i]->transfer_buffer);
1198 usb_free_urb(urb: instance->urbs[i]);
1199 }
1200
1201 kfree(objp: instance);
1202
1203 return error;
1204}
1205EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1206
1207void usbatm_usb_disconnect(struct usb_interface *intf)
1208{
1209 struct device *dev = &intf->dev;
1210 struct usbatm_data *instance = usb_get_intfdata(intf);
1211 struct usbatm_vcc_data *vcc_data;
1212 int i;
1213
1214 if (!instance) {
1215 dev_dbg(dev, "%s: NULL instance!\n", __func__);
1216 return;
1217 }
1218
1219 usb_set_intfdata(intf, NULL);
1220
1221 mutex_lock(&instance->serialize);
1222 instance->disconnected = 1;
1223 if (instance->thread != NULL)
1224 send_sig(SIGTERM, instance->thread, 1);
1225 mutex_unlock(lock: &instance->serialize);
1226
1227 wait_for_completion(&instance->thread_exited);
1228
1229 mutex_lock(&instance->serialize);
1230 list_for_each_entry(vcc_data, &instance->vcc_list, list)
1231 vcc_release_async(vcc: vcc_data->vcc, reply: -EPIPE);
1232 mutex_unlock(lock: &instance->serialize);
1233
1234 tasklet_disable(t: &instance->rx_channel.tasklet);
1235 tasklet_disable(t: &instance->tx_channel.tasklet);
1236
1237 for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1238 usb_kill_urb(urb: instance->urbs[i]);
1239
1240 del_timer_sync(timer: &instance->rx_channel.delay);
1241 del_timer_sync(timer: &instance->tx_channel.delay);
1242
1243 /* turn usbatm_[rt]x_process into something close to a no-op */
1244 /* no need to take the spinlock */
1245 INIT_LIST_HEAD(list: &instance->rx_channel.list);
1246 INIT_LIST_HEAD(list: &instance->tx_channel.list);
1247
1248 tasklet_enable(t: &instance->rx_channel.tasklet);
1249 tasklet_enable(t: &instance->tx_channel.tasklet);
1250
1251 if (instance->atm_dev && instance->driver->atm_stop)
1252 instance->driver->atm_stop(instance, instance->atm_dev);
1253
1254 if (instance->driver->unbind)
1255 instance->driver->unbind(instance, intf);
1256
1257 instance->driver_data = NULL;
1258
1259 for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1260 kfree(objp: instance->urbs[i]->transfer_buffer);
1261 usb_free_urb(urb: instance->urbs[i]);
1262 }
1263
1264 kfree(objp: instance->cell_buf);
1265
1266 /* ATM finalize */
1267 if (instance->atm_dev) {
1268 atm_dev_deregister(dev: instance->atm_dev);
1269 instance->atm_dev = NULL;
1270 }
1271
1272 usbatm_put_instance(instance); /* taken in usbatm_usb_probe */
1273}
1274EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1275
1276
1277/***********
1278** init **
1279***********/
1280
1281static int __init usbatm_usb_init(void)
1282{
1283 if (sizeof(struct usbatm_control) > sizeof_field(struct sk_buff, cb)) {
1284 pr_err("%s unusable with this kernel!\n", usbatm_driver_name);
1285 return -EIO;
1286 }
1287
1288 if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1289 || (num_snd_urbs > UDSL_MAX_SND_URBS)
1290 || (rcv_buf_bytes < 1)
1291 || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1292 || (snd_buf_bytes < 1)
1293 || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1294 return -EINVAL;
1295
1296 return 0;
1297}
1298module_init(usbatm_usb_init);
1299
1300static void __exit usbatm_usb_exit(void)
1301{
1302}
1303module_exit(usbatm_usb_exit);
1304
1305MODULE_AUTHOR(DRIVER_AUTHOR);
1306MODULE_DESCRIPTION(DRIVER_DESC);
1307MODULE_LICENSE("GPL");
1308
1309/************
1310** debug **
1311************/
1312
1313#ifdef VERBOSE_DEBUG
1314static int usbatm_print_packet(struct usbatm_data *instance,
1315 const unsigned char *data, int len)
1316{
1317 unsigned char buffer[256];
1318 int i = 0, j = 0;
1319
1320 for (i = 0; i < len;) {
1321 buffer[0] = '\0';
1322 sprintf(buffer, "%.3d :", i);
1323 for (j = 0; (j < 16) && (i < len); j++, i++)
1324 sprintf(buffer, "%s %2.2x", buffer, data[i]);
1325 dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1326 }
1327 return i;
1328}
1329#endif
1330

source code of linux/drivers/usb/atm/usbatm.c