5e4f46c5a3004677be8f18e731035afb5d06a9ec
[cascardo/linux.git] / drivers / usb / atm / usbatm.c
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 #include <linux/ratelimit.h>
85
86 #ifdef VERBOSE_DEBUG
87 static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
88 #define PACKETDEBUG(arg...)     usbatm_print_packet(arg)
89 #define vdbg(arg...)            dev_dbg(arg)
90 #else
91 #define PACKETDEBUG(arg...)
92 #define vdbg(arg...)
93 #endif
94
95 #define DRIVER_AUTHOR   "Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
96 #define DRIVER_VERSION  "1.10"
97 #define DRIVER_DESC     "Generic USB ATM/DSL I/O, version " DRIVER_VERSION
98
99 static const char usbatm_driver_name[] = "usbatm";
100
101 #define UDSL_MAX_RCV_URBS               16
102 #define UDSL_MAX_SND_URBS               16
103 #define UDSL_MAX_BUF_SIZE               65536
104 #define UDSL_DEFAULT_RCV_URBS           4
105 #define UDSL_DEFAULT_SND_URBS           4
106 #define UDSL_DEFAULT_RCV_BUF_SIZE       3392    /* 64 * ATM_CELL_SIZE */
107 #define UDSL_DEFAULT_SND_BUF_SIZE       3392    /* 64 * ATM_CELL_SIZE */
108
109 #define ATM_CELL_HEADER                 (ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
110
111 #define THROTTLE_MSECS                  100     /* delay to recover processing after urb submission fails */
112
113 static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
114 static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
115 static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
116 static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
117
118 module_param(num_rcv_urbs, uint, S_IRUGO);
119 MODULE_PARM_DESC(num_rcv_urbs,
120                  "Number of urbs used for reception (range: 0-"
121                  __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
122                  __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
123
124 module_param(num_snd_urbs, uint, S_IRUGO);
125 MODULE_PARM_DESC(num_snd_urbs,
126                  "Number of urbs used for transmission (range: 0-"
127                  __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
128                  __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
129
130 module_param(rcv_buf_bytes, uint, S_IRUGO);
131 MODULE_PARM_DESC(rcv_buf_bytes,
132                  "Size of the buffers used for reception, in bytes (range: 1-"
133                  __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
134                  __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
135
136 module_param(snd_buf_bytes, uint, S_IRUGO);
137 MODULE_PARM_DESC(snd_buf_bytes,
138                  "Size of the buffers used for transmission, in bytes (range: 1-"
139                  __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
140                  __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
141
142
143 /* receive */
144
145 struct usbatm_vcc_data {
146         /* vpi/vci lookup */
147         struct list_head list;
148         short vpi;
149         int vci;
150         struct atm_vcc *vcc;
151
152         /* raw cell reassembly */
153         struct sk_buff *sarb;
154 };
155
156
157 /* send */
158
159 struct usbatm_control {
160         struct atm_skb_data atm;
161         u32 len;
162         u32 crc;
163 };
164
165 #define UDSL_SKB(x)             ((struct usbatm_control *)(x)->cb)
166
167
168 /* ATM */
169
170 static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
171 static int usbatm_atm_open(struct atm_vcc *vcc);
172 static void usbatm_atm_close(struct atm_vcc *vcc);
173 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user *arg);
174 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
175 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page);
176
177 static struct atmdev_ops usbatm_atm_devops = {
178         .dev_close      = usbatm_atm_dev_close,
179         .open           = usbatm_atm_open,
180         .close          = usbatm_atm_close,
181         .ioctl          = usbatm_atm_ioctl,
182         .send           = usbatm_atm_send,
183         .proc_read      = usbatm_atm_proc_read,
184         .owner          = THIS_MODULE,
185 };
186
187
188 /***********
189 **  misc  **
190 ***********/
191
192 static inline unsigned int usbatm_pdu_length(unsigned int length)
193 {
194         length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
195         return length - length % ATM_CELL_PAYLOAD;
196 }
197
198 static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
199 {
200         if (vcc->pop)
201                 vcc->pop(vcc, skb);
202         else
203                 dev_kfree_skb_any(skb);
204 }
205
206
207 /***********
208 **  urbs  **
209 ************/
210
211 static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
212 {
213         struct urb *urb;
214
215         spin_lock_irq(&channel->lock);
216         if (list_empty(&channel->list)) {
217                 spin_unlock_irq(&channel->lock);
218                 return NULL;
219         }
220
221         urb = list_entry(channel->list.next, struct urb, urb_list);
222         list_del(&urb->urb_list);
223         spin_unlock_irq(&channel->lock);
224
225         return urb;
226 }
227
228 static int usbatm_submit_urb(struct urb *urb)
229 {
230         struct usbatm_channel *channel = urb->context;
231         int ret;
232
233         /* vdbg("%s: submitting urb 0x%p, size %u",
234              __func__, urb, urb->transfer_buffer_length); */
235
236         ret = usb_submit_urb(urb, GFP_ATOMIC);
237         if (ret) {
238                 if (printk_ratelimit())
239                         atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
240                                 __func__, urb, ret);
241
242                 /* consider all errors transient and return the buffer back to the queue */
243                 urb->status = -EAGAIN;
244                 spin_lock_irq(&channel->lock);
245
246                 /* must add to the front when sending; doesn't matter when receiving */
247                 list_add(&urb->urb_list, &channel->list);
248
249                 spin_unlock_irq(&channel->lock);
250
251                 /* make sure the channel doesn't stall */
252                 mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
253         }
254
255         return ret;
256 }
257
258 static void usbatm_complete(struct urb *urb)
259 {
260         struct usbatm_channel *channel = urb->context;
261         unsigned long flags;
262         int status = urb->status;
263
264         /* vdbg("%s: urb 0x%p, status %d, actual_length %d",
265              __func__, urb, status, urb->actual_length); */
266
267         /* usually in_interrupt(), but not always */
268         spin_lock_irqsave(&channel->lock, flags);
269
270         /* must add to the back when receiving; doesn't matter when sending */
271         list_add_tail(&urb->urb_list, &channel->list);
272
273         spin_unlock_irqrestore(&channel->lock, flags);
274
275         if (unlikely(status) &&
276                         (!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
277                          status != -EILSEQ)) {
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         if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
315                 instance->cached_vpi = vpi;
316                 instance->cached_vci = vci;
317
318                 instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
319
320                 if (!instance->cached_vcc)
321                         atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
322         }
323
324         if (!instance->cached_vcc)
325                 return;
326
327         vcc = instance->cached_vcc->vcc;
328
329         /* OAM F5 end-to-end */
330         if (pti == ATM_PTI_E2EF5) {
331                 if (printk_ratelimit())
332                         atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
333                                 __func__, vpi, vci);
334                 atomic_inc(&vcc->stats->rx_err);
335                 return;
336         }
337
338         sarb = instance->cached_vcc->sarb;
339
340         if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
341                 atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
342                                 __func__, sarb->len, vcc);
343                 /* discard cells already received */
344                 skb_trim(sarb, 0);
345         }
346
347         memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
348         __skb_put(sarb, ATM_CELL_PAYLOAD);
349
350         if (pti & 1) {
351                 struct sk_buff *skb;
352                 unsigned int length;
353                 unsigned int pdu_length;
354
355                 length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
356
357                 /* guard against overflow */
358                 if (length > ATM_MAX_AAL5_PDU) {
359                         atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
360                                   __func__, length, vcc);
361                         atomic_inc(&vcc->stats->rx_err);
362                         goto out;
363                 }
364
365                 pdu_length = usbatm_pdu_length(length);
366
367                 if (sarb->len < pdu_length) {
368                         atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
369                                   __func__, pdu_length, sarb->len, vcc);
370                         atomic_inc(&vcc->stats->rx_err);
371                         goto out;
372                 }
373
374                 if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
375                         atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
376                                   __func__, vcc);
377                         atomic_inc(&vcc->stats->rx_err);
378                         goto out;
379                 }
380
381                 vdbg(&instance->usb_intf->dev,
382                      "%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)",
383                      __func__, length, pdu_length, vcc);
384
385                 skb = dev_alloc_skb(length);
386                 if (!skb) {
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(&instance->usb_intf->dev,
395                      "%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)",
396                      __func__, skb, skb->truesize);
397
398                 if (!atm_charge(vcc, skb->truesize)) {
399                         atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
400                                   __func__, skb->truesize);
401                         dev_kfree_skb_any(skb);
402                         goto out;       /* atm_charge increments rx_drop */
403                 }
404
405                 skb_copy_to_linear_data(skb,
406                                         skb_tail_pointer(sarb) - pdu_length,
407                                         length);
408                 __skb_put(skb, length);
409
410                 vdbg(&instance->usb_intf->dev,
411                      "%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
412                      __func__, skb, skb->len, skb->truesize);
413
414                 PACKETDEBUG(instance, skb->data, skb->len);
415
416                 vcc->push(vcc, skb);
417
418                 atomic_inc(&vcc->stats->rx);
419         out:
420                 skb_trim(sarb, 0);
421         }
422 }
423
424 static void usbatm_extract_cells(struct usbatm_data *instance,
425                 unsigned char *source, unsigned int avail_data)
426 {
427         unsigned int stride = instance->rx_channel.stride;
428         unsigned int buf_usage = instance->buf_usage;
429
430         /* extract cells from incoming data, taking into account that
431          * the length of avail data may not be a multiple of stride */
432
433         if (buf_usage > 0) {
434                 /* we have a partially received atm cell */
435                 unsigned char *cell_buf = instance->cell_buf;
436                 unsigned int space_left = stride - buf_usage;
437
438                 if (avail_data >= space_left) {
439                         /* add new data and process cell */
440                         memcpy(cell_buf + buf_usage, source, space_left);
441                         source += space_left;
442                         avail_data -= space_left;
443                         usbatm_extract_one_cell(instance, cell_buf);
444                         instance->buf_usage = 0;
445                 } else {
446                         /* not enough data to fill the cell */
447                         memcpy(cell_buf + buf_usage, source, avail_data);
448                         instance->buf_usage = buf_usage + avail_data;
449                         return;
450                 }
451         }
452
453         for (; avail_data >= stride; avail_data -= stride, source += stride)
454                 usbatm_extract_one_cell(instance, source);
455
456         if (avail_data > 0) {
457                 /* length was not a multiple of stride -
458                  * save remaining data for next call */
459                 memcpy(instance->cell_buf, source, avail_data);
460                 instance->buf_usage = avail_data;
461         }
462 }
463
464
465 /*************
466 **  encode  **
467 *************/
468
469 static unsigned int usbatm_write_cells(struct usbatm_data *instance,
470                                        struct sk_buff *skb,
471                                        u8 *target, unsigned int avail_space)
472 {
473         struct usbatm_control *ctrl = UDSL_SKB(skb);
474         struct atm_vcc *vcc = ctrl->atm.vcc;
475         unsigned int bytes_written;
476         unsigned int stride = instance->tx_channel.stride;
477
478         for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
479              bytes_written += stride, target += stride) {
480                 unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
481                 unsigned int left = ATM_CELL_PAYLOAD - data_len;
482                 u8 *ptr = target;
483
484                 ptr[0] = vcc->vpi >> 4;
485                 ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
486                 ptr[2] = vcc->vci >> 4;
487                 ptr[3] = vcc->vci << 4;
488                 ptr[4] = 0xec;
489                 ptr += ATM_CELL_HEADER;
490
491                 skb_copy_from_linear_data(skb, ptr, data_len);
492                 ptr += data_len;
493                 __skb_pull(skb, data_len);
494
495                 if (!left)
496                         continue;
497
498                 memset(ptr, 0, left);
499
500                 if (left >= ATM_AAL5_TRAILER) { /* trailer will go in this cell */
501                         u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
502                         /* trailer[0] = 0;              UU = 0 */
503                         /* trailer[1] = 0;              CPI = 0 */
504                         trailer[2] = ctrl->len >> 8;
505                         trailer[3] = ctrl->len;
506
507                         ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
508
509                         trailer[4] = ctrl->crc >> 24;
510                         trailer[5] = ctrl->crc >> 16;
511                         trailer[6] = ctrl->crc >> 8;
512                         trailer[7] = ctrl->crc;
513
514                         target[3] |= 0x2;       /* adjust PTI */
515
516                         ctrl->len = 0;          /* tag this skb finished */
517                 } else
518                         ctrl->crc = crc32_be(ctrl->crc, ptr, left);
519         }
520
521         return bytes_written;
522 }
523
524
525 /**************
526 **  receive  **
527 **************/
528
529 static void usbatm_rx_process(unsigned long data)
530 {
531         struct usbatm_data *instance = (struct usbatm_data *)data;
532         struct urb *urb;
533
534         while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
535                 vdbg(&instance->usb_intf->dev,
536                      "%s: processing urb 0x%p", __func__, urb);
537
538                 if (usb_pipeisoc(urb->pipe)) {
539                         unsigned char *merge_start = NULL;
540                         unsigned int merge_length = 0;
541                         const unsigned int packet_size = instance->rx_channel.packet_size;
542                         int i;
543
544                         for (i = 0; i < urb->number_of_packets; i++) {
545                                 if (!urb->iso_frame_desc[i].status) {
546                                         unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
547
548                                         if (!merge_length)
549                                                 merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
550                                         merge_length += actual_length;
551                                         if (merge_length && (actual_length < packet_size)) {
552                                                 usbatm_extract_cells(instance, merge_start, merge_length);
553                                                 merge_length = 0;
554                                         }
555                                 } else {
556                                         atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
557                                         if (merge_length)
558                                                 usbatm_extract_cells(instance, merge_start, merge_length);
559                                         merge_length = 0;
560                                         instance->buf_usage = 0;
561                                 }
562                         }
563
564                         if (merge_length)
565                                 usbatm_extract_cells(instance, merge_start, merge_length);
566                 } else
567                         if (!urb->status)
568                                 usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
569                         else
570                                 instance->buf_usage = 0;
571
572                 if (usbatm_submit_urb(urb))
573                         return;
574         }
575 }
576
577
578 /***********
579 **  send  **
580 ***********/
581
582 static void usbatm_tx_process(unsigned long data)
583 {
584         struct usbatm_data *instance = (struct usbatm_data *)data;
585         struct sk_buff *skb = instance->current_skb;
586         struct urb *urb = NULL;
587         const unsigned int buf_size = instance->tx_channel.buf_size;
588         unsigned int bytes_written = 0;
589         u8 *buffer = NULL;
590
591         if (!skb)
592                 skb = skb_dequeue(&instance->sndqueue);
593
594         while (skb) {
595                 if (!urb) {
596                         urb = usbatm_pop_urb(&instance->tx_channel);
597                         if (!urb)
598                                 break;          /* no more senders */
599                         buffer = urb->transfer_buffer;
600                         bytes_written = (urb->status == -EAGAIN) ?
601                                 urb->transfer_buffer_length : 0;
602                 }
603
604                 bytes_written += usbatm_write_cells(instance, skb,
605                                                   buffer + bytes_written,
606                                                   buf_size - bytes_written);
607
608                 vdbg(&instance->usb_intf->dev,
609                      "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
610                      __func__, bytes_written, skb, urb);
611
612                 if (!UDSL_SKB(skb)->len) {
613                         struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
614
615                         usbatm_pop(vcc, skb);
616                         atomic_inc(&vcc->stats->tx);
617
618                         skb = skb_dequeue(&instance->sndqueue);
619                 }
620
621                 if (bytes_written == buf_size || (!skb && bytes_written)) {
622                         urb->transfer_buffer_length = bytes_written;
623
624                         if (usbatm_submit_urb(urb))
625                                 break;
626                         urb = NULL;
627                 }
628         }
629
630         instance->current_skb = skb;
631 }
632
633 static void usbatm_cancel_send(struct usbatm_data *instance,
634                                struct atm_vcc *vcc)
635 {
636         struct sk_buff *skb, *n;
637
638         spin_lock_irq(&instance->sndqueue.lock);
639         skb_queue_walk_safe(&instance->sndqueue, skb, n) {
640                 if (UDSL_SKB(skb)->atm.vcc == vcc) {
641                         atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
642                         __skb_unlink(skb, &instance->sndqueue);
643                         usbatm_pop(vcc, skb);
644                 }
645         }
646         spin_unlock_irq(&instance->sndqueue.lock);
647
648         tasklet_disable(&instance->tx_channel.tasklet);
649         if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
650                 atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
651                 instance->current_skb = NULL;
652                 usbatm_pop(vcc, skb);
653         }
654         tasklet_enable(&instance->tx_channel.tasklet);
655 }
656
657 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
658 {
659         struct usbatm_data *instance = vcc->dev->dev_data;
660         struct usbatm_control *ctrl = UDSL_SKB(skb);
661         int err;
662
663         /* racy disconnection check - fine */
664         if (!instance || instance->disconnected) {
665 #ifdef VERBOSE_DEBUG
666                 printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
667 #endif
668                 err = -ENODEV;
669                 goto fail;
670         }
671
672         if (vcc->qos.aal != ATM_AAL5) {
673                 atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
674                 err = -EINVAL;
675                 goto fail;
676         }
677
678         if (skb->len > ATM_MAX_AAL5_PDU) {
679                 atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
680                                 __func__, skb->len, ATM_MAX_AAL5_PDU);
681                 err = -EINVAL;
682                 goto fail;
683         }
684
685         PACKETDEBUG(instance, skb->data, skb->len);
686
687         /* initialize the control block */
688         ctrl->atm.vcc = vcc;
689         ctrl->len = skb->len;
690         ctrl->crc = crc32_be(~0, skb->data, skb->len);
691
692         skb_queue_tail(&instance->sndqueue, skb);
693         tasklet_schedule(&instance->tx_channel.tasklet);
694
695         return 0;
696
697  fail:
698         usbatm_pop(vcc, skb);
699         return err;
700 }
701
702
703 /********************
704 **  bean counting  **
705 ********************/
706
707 static void usbatm_destroy_instance(struct kref *kref)
708 {
709         struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
710
711         tasklet_kill(&instance->rx_channel.tasklet);
712         tasklet_kill(&instance->tx_channel.tasklet);
713         usb_put_dev(instance->usb_dev);
714         kfree(instance);
715 }
716
717 static void usbatm_get_instance(struct usbatm_data *instance)
718 {
719         kref_get(&instance->refcount);
720 }
721
722 static void usbatm_put_instance(struct usbatm_data *instance)
723 {
724         kref_put(&instance->refcount, usbatm_destroy_instance);
725 }
726
727
728 /**********
729 **  ATM  **
730 **********/
731
732 static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
733 {
734         struct usbatm_data *instance = atm_dev->dev_data;
735
736         if (!instance)
737                 return;
738
739         atm_dev->dev_data = NULL; /* catch bugs */
740         usbatm_put_instance(instance);  /* taken in usbatm_atm_init */
741 }
742
743 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
744 {
745         struct usbatm_data *instance = atm_dev->dev_data;
746         int left = *pos;
747
748         if (!instance)
749                 return -ENODEV;
750
751         if (!left--)
752                 return sprintf(page, "%s\n", instance->description);
753
754         if (!left--)
755                 return sprintf(page, "MAC: %pM\n", atm_dev->esi);
756
757         if (!left--)
758                 return sprintf(page,
759                                "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
760                                atomic_read(&atm_dev->stats.aal5.tx),
761                                atomic_read(&atm_dev->stats.aal5.tx_err),
762                                atomic_read(&atm_dev->stats.aal5.rx),
763                                atomic_read(&atm_dev->stats.aal5.rx_err),
764                                atomic_read(&atm_dev->stats.aal5.rx_drop));
765
766         if (!left--) {
767                 if (instance->disconnected)
768                         return sprintf(page, "Disconnected\n");
769                 else
770                         switch (atm_dev->signal) {
771                         case ATM_PHY_SIG_FOUND:
772                                 return sprintf(page, "Line up\n");
773                         case ATM_PHY_SIG_LOST:
774                                 return sprintf(page, "Line down\n");
775                         default:
776                                 return sprintf(page, "Line state unknown\n");
777                         }
778         }
779
780         return 0;
781 }
782
783 static int usbatm_atm_open(struct atm_vcc *vcc)
784 {
785         struct usbatm_data *instance = vcc->dev->dev_data;
786         struct usbatm_vcc_data *new = NULL;
787         int ret;
788         int vci = vcc->vci;
789         short vpi = vcc->vpi;
790
791         if (!instance)
792                 return -ENODEV;
793
794         /* only support AAL5 */
795         if ((vcc->qos.aal != ATM_AAL5)) {
796                 atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
797                 return -EINVAL;
798         }
799
800         /* sanity checks */
801         if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
802                 atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
803                 return -EINVAL;
804         }
805
806         mutex_lock(&instance->serialize);       /* vs self, usbatm_atm_close, usbatm_usb_disconnect */
807
808         if (instance->disconnected) {
809                 atm_dbg(instance, "%s: disconnected!\n", __func__);
810                 ret = -ENODEV;
811                 goto fail;
812         }
813
814         if (usbatm_find_vcc(instance, vpi, vci)) {
815                 atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
816                 ret = -EADDRINUSE;
817                 goto fail;
818         }
819
820         new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL);
821         if (!new) {
822                 atm_err(instance, "%s: no memory for vcc_data!\n", __func__);
823                 ret = -ENOMEM;
824                 goto fail;
825         }
826
827         new->vcc = vcc;
828         new->vpi = vpi;
829         new->vci = vci;
830
831         new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
832         if (!new->sarb) {
833                 atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
834                 ret = -ENOMEM;
835                 goto fail;
836         }
837
838         vcc->dev_data = new;
839
840         tasklet_disable(&instance->rx_channel.tasklet);
841         instance->cached_vcc = new;
842         instance->cached_vpi = vpi;
843         instance->cached_vci = vci;
844         list_add(&new->list, &instance->vcc_list);
845         tasklet_enable(&instance->rx_channel.tasklet);
846
847         set_bit(ATM_VF_ADDR, &vcc->flags);
848         set_bit(ATM_VF_PARTIAL, &vcc->flags);
849         set_bit(ATM_VF_READY, &vcc->flags);
850
851         mutex_unlock(&instance->serialize);
852
853         atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
854
855         return 0;
856
857 fail:
858         kfree(new);
859         mutex_unlock(&instance->serialize);
860         return ret;
861 }
862
863 static void usbatm_atm_close(struct atm_vcc *vcc)
864 {
865         struct usbatm_data *instance = vcc->dev->dev_data;
866         struct usbatm_vcc_data *vcc_data = vcc->dev_data;
867
868         if (!instance || !vcc_data)
869                 return;
870
871         usbatm_cancel_send(instance, vcc);
872
873         mutex_lock(&instance->serialize);       /* vs self, usbatm_atm_open, usbatm_usb_disconnect */
874
875         tasklet_disable(&instance->rx_channel.tasklet);
876         if (instance->cached_vcc == vcc_data) {
877                 instance->cached_vcc = NULL;
878                 instance->cached_vpi = ATM_VPI_UNSPEC;
879                 instance->cached_vci = ATM_VCI_UNSPEC;
880         }
881         list_del(&vcc_data->list);
882         tasklet_enable(&instance->rx_channel.tasklet);
883
884         kfree_skb(vcc_data->sarb);
885         vcc_data->sarb = NULL;
886
887         kfree(vcc_data);
888         vcc->dev_data = NULL;
889
890         vcc->vpi = ATM_VPI_UNSPEC;
891         vcc->vci = ATM_VCI_UNSPEC;
892         clear_bit(ATM_VF_READY, &vcc->flags);
893         clear_bit(ATM_VF_PARTIAL, &vcc->flags);
894         clear_bit(ATM_VF_ADDR, &vcc->flags);
895
896         mutex_unlock(&instance->serialize);
897 }
898
899 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
900                           void __user *arg)
901 {
902         struct usbatm_data *instance = atm_dev->dev_data;
903
904         if (!instance || instance->disconnected)
905                 return -ENODEV;
906
907         switch (cmd) {
908         case ATM_QUERYLOOP:
909                 return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
910         default:
911                 return -ENOIOCTLCMD;
912         }
913 }
914
915 static int usbatm_atm_init(struct usbatm_data *instance)
916 {
917         struct atm_dev *atm_dev;
918         int ret, i;
919
920         /* ATM init.  The ATM initialization scheme suffers from an intrinsic race
921          * condition: callbacks we register can be executed at once, before we have
922          * initialized the struct atm_dev.  To protect against this, all callbacks
923          * abort if atm_dev->dev_data is NULL. */
924         atm_dev = atm_dev_register(instance->driver_name,
925                                    &instance->usb_intf->dev, &usbatm_atm_devops,
926                                    -1, NULL);
927         if (!atm_dev) {
928                 usb_err(instance, "%s: failed to register ATM device!\n", __func__);
929                 return -1;
930         }
931
932         instance->atm_dev = atm_dev;
933
934         atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
935         atm_dev->ci_range.vci_bits = ATM_CI_MAX;
936         atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
937
938         /* temp init ATM device, set to 128kbit */
939         atm_dev->link_rate = 128 * 1000 / 424;
940
941         if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
942                 atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
943                 goto fail;
944         }
945
946         usbatm_get_instance(instance);  /* dropped in usbatm_atm_dev_close */
947
948         /* ready for ATM callbacks */
949         mb();
950         atm_dev->dev_data = instance;
951
952         /* submit all rx URBs */
953         for (i = 0; i < num_rcv_urbs; i++)
954                 usbatm_submit_urb(instance->urbs[i]);
955
956         return 0;
957
958  fail:
959         instance->atm_dev = NULL;
960         atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
961         return ret;
962 }
963
964
965 /**********
966 **  USB  **
967 **********/
968
969 static int usbatm_do_heavy_init(void *arg)
970 {
971         struct usbatm_data *instance = arg;
972         int ret;
973
974         allow_signal(SIGTERM);
975         complete(&instance->thread_started);
976
977         ret = instance->driver->heavy_init(instance, instance->usb_intf);
978
979         if (!ret)
980                 ret = usbatm_atm_init(instance);
981
982         mutex_lock(&instance->serialize);
983         instance->thread = NULL;
984         mutex_unlock(&instance->serialize);
985
986         complete_and_exit(&instance->thread_exited, ret);
987 }
988
989 static int usbatm_heavy_init(struct usbatm_data *instance)
990 {
991         struct task_struct *t;
992
993         t = kthread_create(usbatm_do_heavy_init, instance, "%s",
994                         instance->driver->driver_name);
995         if (IS_ERR(t)) {
996                 usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
997                                 __func__, PTR_ERR(t));
998                 return PTR_ERR(t);
999         }
1000
1001         instance->thread = t;
1002         wake_up_process(t);
1003         wait_for_completion(&instance->thread_started);
1004
1005         return 0;
1006 }
1007
1008 static void usbatm_tasklet_schedule(unsigned long data)
1009 {
1010         tasklet_schedule((struct tasklet_struct *) data);
1011 }
1012
1013 static void usbatm_init_channel(struct usbatm_channel *channel)
1014 {
1015         spin_lock_init(&channel->lock);
1016         INIT_LIST_HEAD(&channel->list);
1017         channel->delay.function = usbatm_tasklet_schedule;
1018         channel->delay.data = (unsigned long) &channel->tasklet;
1019         init_timer(&channel->delay);
1020 }
1021
1022 int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1023                      struct usbatm_driver *driver)
1024 {
1025         struct device *dev = &intf->dev;
1026         struct usb_device *usb_dev = interface_to_usbdev(intf);
1027         struct usbatm_data *instance;
1028         char *buf;
1029         int error = -ENOMEM;
1030         int i, length;
1031         unsigned int maxpacket, num_packets;
1032
1033         /* instance init */
1034         instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1035         if (!instance) {
1036                 dev_err(dev, "%s: no memory for instance data!\n", __func__);
1037                 return -ENOMEM;
1038         }
1039
1040         /* public fields */
1041
1042         instance->driver = driver;
1043         strlcpy(instance->driver_name, driver->driver_name,
1044                 sizeof(instance->driver_name));
1045
1046         instance->usb_dev = usb_dev;
1047         instance->usb_intf = intf;
1048
1049         buf = instance->description;
1050         length = sizeof(instance->description);
1051
1052         if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1053                 goto bind;
1054
1055         buf += i;
1056         length -= i;
1057
1058         i = scnprintf(buf, length, " (");
1059         buf += i;
1060         length -= i;
1061
1062         if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1063                 goto bind;
1064
1065         buf += i;
1066         length -= i;
1067
1068         snprintf(buf, length, ")");
1069
1070  bind:
1071         if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1072                         dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1073                         goto fail_free;
1074         }
1075
1076         /* private fields */
1077
1078         kref_init(&instance->refcount);         /* dropped in usbatm_usb_disconnect */
1079         mutex_init(&instance->serialize);
1080
1081         instance->thread = NULL;
1082         init_completion(&instance->thread_started);
1083         init_completion(&instance->thread_exited);
1084
1085         INIT_LIST_HEAD(&instance->vcc_list);
1086         skb_queue_head_init(&instance->sndqueue);
1087
1088         usbatm_init_channel(&instance->rx_channel);
1089         usbatm_init_channel(&instance->tx_channel);
1090         tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1091         tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1092         instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1093         instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1094         instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1095
1096         if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1097                 instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1098         else
1099                 instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1100
1101         instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1102
1103         /* tx buffer size must be a positive multiple of the stride */
1104         instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1105                         snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1106
1107         /* rx buffer size must be a positive multiple of the endpoint maxpacket */
1108         maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1109
1110         if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1111                 dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1112                                 usb_pipeendpoint(instance->rx_channel.endpoint));
1113                 error = -EINVAL;
1114                 goto fail_unbind;
1115         }
1116
1117         num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1118
1119         if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1120                 num_packets--;
1121
1122         instance->rx_channel.buf_size = num_packets * maxpacket;
1123         instance->rx_channel.packet_size = maxpacket;
1124
1125         for (i = 0; i < 2; i++) {
1126                 struct usbatm_channel *channel = i ?
1127                         &instance->tx_channel : &instance->rx_channel;
1128
1129                 dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1130                         __func__, channel->buf_size, i ? "tx" : "rx", channel);
1131         }
1132
1133         /* initialize urbs */
1134
1135         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1136                 u8 *buffer;
1137                 struct usbatm_channel *channel = i < num_rcv_urbs ?
1138                         &instance->rx_channel : &instance->tx_channel;
1139                 struct urb *urb;
1140                 unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1141
1142                 urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1143                 if (!urb) {
1144                         error = -ENOMEM;
1145                         goto fail_unbind;
1146                 }
1147
1148                 instance->urbs[i] = urb;
1149
1150                 /* zero the tx padding to avoid leaking information */
1151                 buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1152                 if (!buffer) {
1153                         dev_err(dev, "%s: no memory for buffer %d!\n", __func__, i);
1154                         error = -ENOMEM;
1155                         goto fail_unbind;
1156                 }
1157
1158                 usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1159                                   buffer, channel->buf_size, usbatm_complete, channel);
1160                 if (iso_packets) {
1161                         int j;
1162                         urb->interval = 1;
1163                         urb->transfer_flags = URB_ISO_ASAP;
1164                         urb->number_of_packets = iso_packets;
1165                         for (j = 0; j < iso_packets; j++) {
1166                                 urb->iso_frame_desc[j].offset = channel->packet_size * j;
1167                                 urb->iso_frame_desc[j].length = channel->packet_size;
1168                         }
1169                 }
1170
1171                 /* put all tx URBs on the list of spares */
1172                 if (i >= num_rcv_urbs)
1173                         list_add_tail(&urb->urb_list, &channel->list);
1174
1175                 vdbg(&intf->dev, "%s: alloced buffer 0x%p buf size %u urb 0x%p",
1176                      __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1177         }
1178
1179         instance->cached_vpi = ATM_VPI_UNSPEC;
1180         instance->cached_vci = ATM_VCI_UNSPEC;
1181         instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1182
1183         if (!instance->cell_buf) {
1184                 dev_err(dev, "%s: no memory for cell buffer!\n", __func__);
1185                 error = -ENOMEM;
1186                 goto fail_unbind;
1187         }
1188
1189         if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1190                 error = usbatm_heavy_init(instance);
1191         } else {
1192                 complete(&instance->thread_exited);     /* pretend that heavy_init was run */
1193                 error = usbatm_atm_init(instance);
1194         }
1195
1196         if (error < 0)
1197                 goto fail_unbind;
1198
1199         usb_get_dev(usb_dev);
1200         usb_set_intfdata(intf, instance);
1201
1202         return 0;
1203
1204  fail_unbind:
1205         if (instance->driver->unbind)
1206                 instance->driver->unbind(instance, intf);
1207  fail_free:
1208         kfree(instance->cell_buf);
1209
1210         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1211                 if (instance->urbs[i])
1212                         kfree(instance->urbs[i]->transfer_buffer);
1213                 usb_free_urb(instance->urbs[i]);
1214         }
1215
1216         kfree(instance);
1217
1218         return error;
1219 }
1220 EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1221
1222 void usbatm_usb_disconnect(struct usb_interface *intf)
1223 {
1224         struct device *dev = &intf->dev;
1225         struct usbatm_data *instance = usb_get_intfdata(intf);
1226         struct usbatm_vcc_data *vcc_data;
1227         int i;
1228
1229         if (!instance) {
1230                 dev_dbg(dev, "%s: NULL instance!\n", __func__);
1231                 return;
1232         }
1233
1234         usb_set_intfdata(intf, NULL);
1235
1236         mutex_lock(&instance->serialize);
1237         instance->disconnected = 1;
1238         if (instance->thread != NULL)
1239                 send_sig(SIGTERM, instance->thread, 1);
1240         mutex_unlock(&instance->serialize);
1241
1242         wait_for_completion(&instance->thread_exited);
1243
1244         mutex_lock(&instance->serialize);
1245         list_for_each_entry(vcc_data, &instance->vcc_list, list)
1246                 vcc_release_async(vcc_data->vcc, -EPIPE);
1247         mutex_unlock(&instance->serialize);
1248
1249         tasklet_disable(&instance->rx_channel.tasklet);
1250         tasklet_disable(&instance->tx_channel.tasklet);
1251
1252         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1253                 usb_kill_urb(instance->urbs[i]);
1254
1255         del_timer_sync(&instance->rx_channel.delay);
1256         del_timer_sync(&instance->tx_channel.delay);
1257
1258         /* turn usbatm_[rt]x_process into something close to a no-op */
1259         /* no need to take the spinlock */
1260         INIT_LIST_HEAD(&instance->rx_channel.list);
1261         INIT_LIST_HEAD(&instance->tx_channel.list);
1262
1263         tasklet_enable(&instance->rx_channel.tasklet);
1264         tasklet_enable(&instance->tx_channel.tasklet);
1265
1266         if (instance->atm_dev && instance->driver->atm_stop)
1267                 instance->driver->atm_stop(instance, instance->atm_dev);
1268
1269         if (instance->driver->unbind)
1270                 instance->driver->unbind(instance, intf);
1271
1272         instance->driver_data = NULL;
1273
1274         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1275                 kfree(instance->urbs[i]->transfer_buffer);
1276                 usb_free_urb(instance->urbs[i]);
1277         }
1278
1279         kfree(instance->cell_buf);
1280
1281         /* ATM finalize */
1282         if (instance->atm_dev) {
1283                 atm_dev_deregister(instance->atm_dev);
1284                 instance->atm_dev = NULL;
1285         }
1286
1287         usbatm_put_instance(instance);  /* taken in usbatm_usb_probe */
1288 }
1289 EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1290
1291
1292 /***********
1293 **  init  **
1294 ***********/
1295
1296 static int __init usbatm_usb_init(void)
1297 {
1298         if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
1299                 printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1300                 return -EIO;
1301         }
1302
1303         if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1304             || (num_snd_urbs > UDSL_MAX_SND_URBS)
1305             || (rcv_buf_bytes < 1)
1306             || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1307             || (snd_buf_bytes < 1)
1308             || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1309                 return -EINVAL;
1310
1311         return 0;
1312 }
1313 module_init(usbatm_usb_init);
1314
1315 static void __exit usbatm_usb_exit(void)
1316 {
1317 }
1318 module_exit(usbatm_usb_exit);
1319
1320 MODULE_AUTHOR(DRIVER_AUTHOR);
1321 MODULE_DESCRIPTION(DRIVER_DESC);
1322 MODULE_LICENSE("GPL");
1323 MODULE_VERSION(DRIVER_VERSION);
1324
1325 /************
1326 **  debug  **
1327 ************/
1328
1329 #ifdef VERBOSE_DEBUG
1330 static int usbatm_print_packet(struct usbatm_data *instance,
1331                                const unsigned char *data, int len)
1332 {
1333         unsigned char buffer[256];
1334         int i = 0, j = 0;
1335
1336         for (i = 0; i < len;) {
1337                 buffer[0] = '\0';
1338                 sprintf(buffer, "%.3d :", i);
1339                 for (j = 0; (j < 16) && (i < len); j++, i++)
1340                         sprintf(buffer, "%s %2.2x", buffer, data[i]);
1341                 dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1342         }
1343         return i;
1344 }
1345 #endif