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 <linux/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/signal.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_DESC     "Generic USB ATM/DSL I/O"
  97
  98 static const char usbatm_driver_name[] = "usbatm";
  99
 100 #define UDSL_MAX_RCV_URBS               16
 101 #define UDSL_MAX_SND_URBS               16
 102 #define UDSL_MAX_BUF_SIZE               65536
 103 #define UDSL_DEFAULT_RCV_URBS           4
 104 #define UDSL_DEFAULT_SND_URBS           4
 105 #define UDSL_DEFAULT_RCV_BUF_SIZE       3392    /* 64 * ATM_CELL_SIZE */
 106 #define UDSL_DEFAULT_SND_BUF_SIZE       3392    /* 64 * ATM_CELL_SIZE */
 107
 108 #define ATM_CELL_HEADER                 (ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
 109
 110 #define THROTTLE_MSECS                  100     /* delay to recover processing after urb submission fails */
 111
 112 static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
 113 static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
 114 static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
 115 static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
 116
 117 module_param(num_rcv_urbs, uint, S_IRUGO);
 118 MODULE_PARM_DESC(num_rcv_urbs,
 119                  "Number of urbs used for reception (range: 0-"
 120                  __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
 121                  __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
 122
 123 module_param(num_snd_urbs, uint, S_IRUGO);
 124 MODULE_PARM_DESC(num_snd_urbs,
 125                  "Number of urbs used for transmission (range: 0-"
 126                  __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
 127                  __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
 128
 129 module_param(rcv_buf_bytes, uint, S_IRUGO);
 130 MODULE_PARM_DESC(rcv_buf_bytes,
 131                  "Size of the buffers used for reception, in bytes (range: 1-"
 132                  __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
 133                  __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
 134
 135 module_param(snd_buf_bytes, uint, S_IRUGO);
 136 MODULE_PARM_DESC(snd_buf_bytes,
 137                  "Size of the buffers used for transmission, in bytes (range: 1-"
 138                  __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
 139                  __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
 140
 141
 142 /* receive */
 143
 144 struct usbatm_vcc_data {
 145         /* vpi/vci lookup */
 146         struct list_head list;
 147         short vpi;
 148         int vci;
 149         struct atm_vcc *vcc;
 150
 151         /* raw cell reassembly */
 152         struct sk_buff *sarb;
 153 };
 154
 155
 156 /* send */
 157
 158 struct usbatm_control {
 159         struct atm_skb_data atm;
 160         u32 len;
 161         u32 crc;
 162 };
 163
 164 #define UDSL_SKB(x)             ((struct usbatm_control *)(x)->cb)
 165
 166
 167 /* ATM */
 168
 169 static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
 170 static int usbatm_atm_open(struct atm_vcc *vcc);
 171 static void usbatm_atm_close(struct atm_vcc *vcc);
 172 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user *arg);
 173 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
 174 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page);
 175
 176 static const struct atmdev_ops usbatm_atm_devops = {
 177         .dev_close      = usbatm_atm_dev_close,
 178         .open           = usbatm_atm_open,
 179         .close          = usbatm_atm_close,
 180         .ioctl          = usbatm_atm_ioctl,
 181         .send           = usbatm_atm_send,
 182         .proc_read      = usbatm_atm_proc_read,
 183         .owner          = THIS_MODULE,
 184 };
 185
 186
 187 /***********
 188 **  misc  **
 189 ***********/
 190
 191 static inline unsigned int usbatm_pdu_length(unsigned int length)
 192 {
 193         length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
 194         return length - length % ATM_CELL_PAYLOAD;
 195 }
 196
 197 static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 198 {
 199         if (vcc->pop)
 200                 vcc->pop(vcc, skb);
 201         else
 202                 dev_kfree_skb_any(skb);
 203 }
 204
 205
 206 /***********
 207 **  urbs  **
 208 ************/
 209
 210 static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
 211 {
 212         struct urb *urb;
 213
 214         spin_lock_irq(&channel->lock);
 215         if (list_empty(&channel->list)) {
 216                 spin_unlock_irq(&channel->lock);
 217                 return NULL;
 218         }
 219
 220         urb = list_entry(channel->list.next, struct urb, urb_list);
 221         list_del(&urb->urb_list);
 222         spin_unlock_irq(&channel->lock);
 223
 224         return urb;
 225 }
 226
 227 static int usbatm_submit_urb(struct urb *urb)
 228 {
 229         struct usbatm_channel *channel = urb->context;
 230         int ret;
 231
 232         /* vdbg("%s: submitting urb 0x%p, size %u",
 233              __func__, urb, urb->transfer_buffer_length); */
 234
 235         ret = usb_submit_urb(urb, GFP_ATOMIC);
 236         if (ret) {
 237                 if (printk_ratelimit())
 238                         atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
 239                                 __func__, urb, ret);
 240
 241                 /* consider all errors transient and return the buffer back to the queue */
 242                 urb->status = -EAGAIN;
 243                 spin_lock_irq(&channel->lock);
 244
 245                 /* must add to the front when sending; doesn't matter when receiving */
 246                 list_add(&urb->urb_list, &channel->list);
 247
 248                 spin_unlock_irq(&channel->lock);
 249
 250                 /* make sure the channel doesn't stall */
 251                 mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
 252         }
 253
 254         return ret;
 255 }
 256
 257 static void usbatm_complete(struct urb *urb)
 258 {
 259         struct usbatm_channel *channel = urb->context;
 260         unsigned long flags;
 261         int status = urb->status;
 262
 263         /* vdbg("%s: urb 0x%p, status %d, actual_length %d",
 264              __func__, urb, status, urb->actual_length); */
 265
 266         /* usually in_interrupt(), but not always */
 267         spin_lock_irqsave(&channel->lock, flags);
 268
 269         /* must add to the back when receiving; doesn't matter when sending */
 270         list_add_tail(&urb->urb_list, &channel->list);
 271
 272         spin_unlock_irqrestore(&channel->lock, flags);
 273
 274         if (unlikely(status) &&
 275                         (!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
 276                          status != -EILSEQ)) {
 277                 if (status == -ESHUTDOWN)
 278                         return;
 279
 280                 if (printk_ratelimit())
 281                         atm_warn(channel->usbatm, "%s: urb 0x%p failed (%d)!\n",
 282                                 __func__, urb, status);
 283                 /* throttle processing in case of an error */
 284                 mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
 285         } else
 286                 tasklet_schedule(&channel->tasklet);
 287 }
 288
 289
 290 /*************
 291 **  decode  **
 292 *************/
 293
 294 static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
 295                                                   short vpi, int vci)
 296 {
 297         struct usbatm_vcc_data *vcc_data;
 298
 299         list_for_each_entry(vcc_data, &instance->vcc_list, list)
 300                 if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
 301                         return vcc_data;
 302         return NULL;
 303 }
 304
 305 static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
 306 {
 307         struct atm_vcc *vcc;
 308         struct sk_buff *sarb;
 309         short vpi = ((source[0] & 0x0f) << 4)  | (source[1] >> 4);
 310         int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
 311         u8 pti = ((source[3] & 0xe) >> 1);
 312
 313         if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
 314                 instance->cached_vpi = vpi;
 315                 instance->cached_vci = vci;
 316
 317                 instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
 318
 319                 if (!instance->cached_vcc)
 320                         atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
 321         }
 322
 323         if (!instance->cached_vcc)
 324                 return;
 325
 326         vcc = instance->cached_vcc->vcc;
 327
 328         /* OAM F5 end-to-end */
 329         if (pti == ATM_PTI_E2EF5) {
 330                 if (printk_ratelimit())
 331                         atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
 332                                 __func__, vpi, vci);
 333                 atomic_inc(&vcc->stats->rx_err);
 334                 return;
 335         }
 336
 337         sarb = instance->cached_vcc->sarb;
 338
 339         if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
 340                 atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
 341                                 __func__, sarb->len, vcc);
 342                 /* discard cells already received */
 343                 skb_trim(sarb, 0);
 344         }
 345
 346         memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
 347         __skb_put(sarb, ATM_CELL_PAYLOAD);
 348
 349         if (pti & 1) {
 350                 struct sk_buff *skb;
 351                 unsigned int length;
 352                 unsigned int pdu_length;
 353
 354                 length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
 355
 356                 /* guard against overflow */
 357                 if (length > ATM_MAX_AAL5_PDU) {
 358                         atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
 359                                   __func__, length, vcc);
 360                         atomic_inc(&vcc->stats->rx_err);
 361                         goto out;
 362                 }
 363
 364                 pdu_length = usbatm_pdu_length(length);
 365
 366                 if (sarb->len < pdu_length) {
 367                         atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
 368                                   __func__, pdu_length, sarb->len, vcc);
 369                         atomic_inc(&vcc->stats->rx_err);
 370                         goto out;
 371                 }
 372
 373                 if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
 374                         atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
 375                                   __func__, vcc);
 376                         atomic_inc(&vcc->stats->rx_err);
 377                         goto out;
 378                 }
 379
 380                 vdbg(&instance->usb_intf->dev,
 381                      "%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)",
 382                      __func__, length, pdu_length, vcc);
 383
 384                 skb = dev_alloc_skb(length);
 385                 if (!skb) {
 386                         if (printk_ratelimit())
 387                                 atm_err(instance, "%s: no memory for skb (length: %u)!\n",
 388                                         __func__, length);
 389                         atomic_inc(&vcc->stats->rx_drop);
 390                         goto out;
 391                 }
 392
 393                 vdbg(&instance->usb_intf->dev,
 394                      "%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)",
 395                      __func__, skb, skb->truesize);
 396
 397                 if (!atm_charge(vcc, skb->truesize)) {
 398                         atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
 399                                   __func__, skb->truesize);
 400                         dev_kfree_skb_any(skb);
 401                         goto out;       /* atm_charge increments rx_drop */
 402                 }
 403
 404                 skb_copy_to_linear_data(skb,
 405                                         skb_tail_pointer(sarb) - pdu_length,
 406                                         length);
 407                 __skb_put(skb, length);
 408
 409                 vdbg(&instance->usb_intf->dev,
 410                      "%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
 411                      __func__, skb, skb->len, skb->truesize);
 412
 413                 PACKETDEBUG(instance, skb->data, skb->len);
 414
 415                 vcc->push(vcc, skb);
 416
 417                 atomic_inc(&vcc->stats->rx);
 418         out:
 419                 skb_trim(sarb, 0);
 420         }
 421 }
 422
 423 static void usbatm_extract_cells(struct usbatm_data *instance,
 424                 unsigned char *source, unsigned int avail_data)
 425 {
 426         unsigned int stride = instance->rx_channel.stride;
 427         unsigned int buf_usage = instance->buf_usage;
 428
 429         /* extract cells from incoming data, taking into account that
 430          * the length of avail data may not be a multiple of stride */
 431
 432         if (buf_usage > 0) {
 433                 /* we have a partially received atm cell */
 434                 unsigned char *cell_buf = instance->cell_buf;
 435                 unsigned int space_left = stride - buf_usage;
 436
 437                 if (avail_data >= space_left) {
 438                         /* add new data and process cell */
 439                         memcpy(cell_buf + buf_usage, source, space_left);
 440                         source += space_left;
 441                         avail_data -= space_left;
 442                         usbatm_extract_one_cell(instance, cell_buf);
 443                         instance->buf_usage = 0;
 444                 } else {
 445                         /* not enough data to fill the cell */
 446                         memcpy(cell_buf + buf_usage, source, avail_data);
 447                         instance->buf_usage = buf_usage + avail_data;
 448                         return;
 449                 }
 450         }
 451
 452         for (; avail_data >= stride; avail_data -= stride, source += stride)
 453                 usbatm_extract_one_cell(instance, source);
 454
 455         if (avail_data > 0) {
 456                 /* length was not a multiple of stride -
 457                  * save remaining data for next call */
 458                 memcpy(instance->cell_buf, source, avail_data);
 459                 instance->buf_usage = avail_data;
 460         }
 461 }
 462
 463
 464 /*************
 465 **  encode  **
 466 *************/
 467
 468 static unsigned int usbatm_write_cells(struct usbatm_data *instance,
 469                                        struct sk_buff *skb,
 470                                        u8 *target, unsigned int avail_space)
 471 {
 472         struct usbatm_control *ctrl = UDSL_SKB(skb);
 473         struct atm_vcc *vcc = ctrl->atm.vcc;
 474         unsigned int bytes_written;
 475         unsigned int stride = instance->tx_channel.stride;
 476
 477         for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
 478              bytes_written += stride, target += stride) {
 479                 unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
 480                 unsigned int left = ATM_CELL_PAYLOAD - data_len;
 481                 u8 *ptr = target;
 482
 483                 ptr[0] = vcc->vpi >> 4;
 484                 ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
 485                 ptr[2] = vcc->vci >> 4;
 486                 ptr[3] = vcc->vci << 4;
 487                 ptr[4] = 0xec;
 488                 ptr += ATM_CELL_HEADER;
 489
 490                 skb_copy_from_linear_data(skb, ptr, data_len);
 491                 ptr += data_len;
 492                 __skb_pull(skb, data_len);
 493
 494                 if (!left)
 495                         continue;
 496
 497                 memset(ptr, 0, left);
 498
 499                 if (left >= ATM_AAL5_TRAILER) { /* trailer will go in this cell */
 500                         u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
 501                         /* trailer[0] = 0;              UU = 0 */
 502                         /* trailer[1] = 0;              CPI = 0 */
 503                         trailer[2] = ctrl->len >> 8;
 504                         trailer[3] = ctrl->len;
 505
 506                         ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
 507
 508                         trailer[4] = ctrl->crc >> 24;
 509                         trailer[5] = ctrl->crc >> 16;
 510                         trailer[6] = ctrl->crc >> 8;
 511                         trailer[7] = ctrl->crc;
 512
 513                         target[3] |= 0x2;       /* adjust PTI */
 514
 515                         ctrl->len = 0;          /* tag this skb finished */
 516                 } else
 517                         ctrl->crc = crc32_be(ctrl->crc, ptr, left);
 518         }
 519
 520         return bytes_written;
 521 }
 522
 523
 524 /**************
 525 **  receive  **
 526 **************/
 527
 528 static void usbatm_rx_process(unsigned long data)
 529 {
 530         struct usbatm_data *instance = (struct usbatm_data *)data;
 531         struct urb *urb;
 532
 533         while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
 534                 vdbg(&instance->usb_intf->dev,
 535                      "%s: processing urb 0x%p", __func__, urb);
 536
 537                 if (usb_pipeisoc(urb->pipe)) {
 538                         unsigned char *merge_start = NULL;
 539                         unsigned int merge_length = 0;
 540                         const unsigned int packet_size = instance->rx_channel.packet_size;
 541                         int i;
 542
 543                         for (i = 0; i < urb->number_of_packets; i++) {
 544                                 if (!urb->iso_frame_desc[i].status) {
 545                                         unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
 546
 547                                         if (!merge_length)
 548                                                 merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 549                                         merge_length += actual_length;
 550                                         if (merge_length && (actual_length < packet_size)) {
 551                                                 usbatm_extract_cells(instance, merge_start, merge_length);
 552                                                 merge_length = 0;
 553                                         }
 554                                 } else {
 555                                         atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
 556                                         if (merge_length)
 557                                                 usbatm_extract_cells(instance, merge_start, merge_length);
 558                                         merge_length = 0;
 559                                         instance->buf_usage = 0;
 560                                 }
 561                         }
 562
 563                         if (merge_length)
 564                                 usbatm_extract_cells(instance, merge_start, merge_length);
 565                 } else
 566                         if (!urb->status)
 567                                 usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
 568                         else
 569                                 instance->buf_usage = 0;
 570
 571                 if (usbatm_submit_urb(urb))
 572                         return;
 573         }
 574 }
 575
 576
 577 /***********
 578 **  send  **
 579 ***********/
 580
 581 static void usbatm_tx_process(unsigned long data)
 582 {
 583         struct usbatm_data *instance = (struct usbatm_data *)data;
 584         struct sk_buff *skb = instance->current_skb;
 585         struct urb *urb = NULL;
 586         const unsigned int buf_size = instance->tx_channel.buf_size;
 587         unsigned int bytes_written = 0;
 588         u8 *buffer = NULL;
 589
 590         if (!skb)
 591                 skb = skb_dequeue(&instance->sndqueue);
 592
 593         while (skb) {
 594                 if (!urb) {
 595                         urb = usbatm_pop_urb(&instance->tx_channel);
 596                         if (!urb)
 597                                 break;          /* no more senders */
 598                         buffer = urb->transfer_buffer;
 599                         bytes_written = (urb->status == -EAGAIN) ?
 600                                 urb->transfer_buffer_length : 0;
 601                 }
 602
 603                 bytes_written += usbatm_write_cells(instance, skb,
 604                                                   buffer + bytes_written,
 605                                                   buf_size - bytes_written);
 606
 607                 vdbg(&instance->usb_intf->dev,
 608                      "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
 609                      __func__, bytes_written, skb, urb);
 610
 611                 if (!UDSL_SKB(skb)->len) {
 612                         struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
 613
 614                         usbatm_pop(vcc, skb);
 615                         atomic_inc(&vcc->stats->tx);
 616
 617                         skb = skb_dequeue(&instance->sndqueue);
 618                 }
 619
 620                 if (bytes_written == buf_size || (!skb && bytes_written)) {
 621                         urb->transfer_buffer_length = bytes_written;
 622
 623                         if (usbatm_submit_urb(urb))
 624                                 break;
 625                         urb = NULL;
 626                 }
 627         }
 628
 629         instance->current_skb = skb;
 630 }
 631
 632 static void usbatm_cancel_send(struct usbatm_data *instance,
 633                                struct atm_vcc *vcc)
 634 {
 635         struct sk_buff *skb, *n;
 636
 637         spin_lock_irq(&instance->sndqueue.lock);
 638         skb_queue_walk_safe(&instance->sndqueue, skb, n) {
 639                 if (UDSL_SKB(skb)->atm.vcc == vcc) {
 640                         atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
 641                         __skb_unlink(skb, &instance->sndqueue);
 642                         usbatm_pop(vcc, skb);
 643                 }
 644         }
 645         spin_unlock_irq(&instance->sndqueue.lock);
 646
 647         tasklet_disable(&instance->tx_channel.tasklet);
 648         if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
 649                 atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
 650                 instance->current_skb = NULL;
 651                 usbatm_pop(vcc, skb);
 652         }
 653         tasklet_enable(&instance->tx_channel.tasklet);
 654 }
 655
 656 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
 657 {
 658         struct usbatm_data *instance = vcc->dev->dev_data;
 659         struct usbatm_control *ctrl = UDSL_SKB(skb);
 660         int err;
 661
 662         /* racy disconnection check - fine */
 663         if (!instance || instance->disconnected) {
 664 #ifdef VERBOSE_DEBUG
 665                 printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
 666 #endif
 667                 err = -ENODEV;
 668                 goto fail;
 669         }
 670
 671         if (vcc->qos.aal != ATM_AAL5) {
 672                 atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
 673                 err = -EINVAL;
 674                 goto fail;
 675         }
 676
 677         if (skb->len > ATM_MAX_AAL5_PDU) {
 678                 atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
 679                                 __func__, skb->len, ATM_MAX_AAL5_PDU);
 680                 err = -EINVAL;
 681                 goto fail;
 682         }
 683
 684         PACKETDEBUG(instance, skb->data, skb->len);
 685
 686         /* initialize the control block */
 687         ctrl->atm.vcc = vcc;
 688         ctrl->len = skb->len;
 689         ctrl->crc = crc32_be(~0, skb->data, skb->len);
 690
 691         skb_queue_tail(&instance->sndqueue, skb);
 692         tasklet_schedule(&instance->tx_channel.tasklet);
 693
 694         return 0;
 695
 696  fail:
 697         usbatm_pop(vcc, skb);
 698         return err;
 699 }
 700
 701
 702 /********************
 703 **  bean counting  **
 704 ********************/
 705
 706 static void usbatm_destroy_instance(struct kref *kref)
 707 {
 708         struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
 709
 710         tasklet_kill(&instance->rx_channel.tasklet);
 711         tasklet_kill(&instance->tx_channel.tasklet);
 712         usb_put_dev(instance->usb_dev);
 713         kfree(instance);
 714 }
 715
 716 static void usbatm_get_instance(struct usbatm_data *instance)
 717 {
 718         kref_get(&instance->refcount);
 719 }
 720
 721 static void usbatm_put_instance(struct usbatm_data *instance)
 722 {
 723         kref_put(&instance->refcount, usbatm_destroy_instance);
 724 }
 725
 726
 727 /**********
 728 **  ATM  **
 729 **********/
 730
 731 static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
 732 {
 733         struct usbatm_data *instance = atm_dev->dev_data;
 734
 735         if (!instance)
 736                 return;
 737
 738         atm_dev->dev_data = NULL; /* catch bugs */
 739         usbatm_put_instance(instance);  /* taken in usbatm_atm_init */
 740 }
 741
 742 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
 743 {
 744         struct usbatm_data *instance = atm_dev->dev_data;
 745         int left = *pos;
 746
 747         if (!instance)
 748                 return -ENODEV;
 749
 750         if (!left--)
 751                 return sprintf(page, "%s\n", instance->description);
 752
 753         if (!left--)
 754                 return sprintf(page, "MAC: %pM\n", atm_dev->esi);
 755
 756         if (!left--)
 757                 return sprintf(page,
 758                                "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
 759                                atomic_read(&atm_dev->stats.aal5.tx),
 760                                atomic_read(&atm_dev->stats.aal5.tx_err),
 761                                atomic_read(&atm_dev->stats.aal5.rx),
 762                                atomic_read(&atm_dev->stats.aal5.rx_err),
 763                                atomic_read(&atm_dev->stats.aal5.rx_drop));
 764
 765         if (!left--) {
 766                 if (instance->disconnected)
 767                         return sprintf(page, "Disconnected\n");
 768                 else
 769                         switch (atm_dev->signal) {
 770                         case ATM_PHY_SIG_FOUND:
 771                                 return sprintf(page, "Line up\n");
 772                         case ATM_PHY_SIG_LOST:
 773                                 return sprintf(page, "Line down\n");
 774                         default:
 775                                 return sprintf(page, "Line state unknown\n");
 776                         }
 777         }
 778
 779         return 0;
 780 }
 781
 782 static int usbatm_atm_open(struct atm_vcc *vcc)
 783 {
 784         struct usbatm_data *instance = vcc->dev->dev_data;
 785         struct usbatm_vcc_data *new = NULL;
 786         int ret;
 787         int vci = vcc->vci;
 788         short vpi = vcc->vpi;
 789
 790         if (!instance)
 791                 return -ENODEV;
 792
 793         /* only support AAL5 */
 794         if ((vcc->qos.aal != ATM_AAL5)) {
 795                 atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
 796                 return -EINVAL;
 797         }
 798
 799         /* sanity checks */
 800         if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
 801                 atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
 802                 return -EINVAL;
 803         }
 804
 805         mutex_lock(&instance->serialize);       /* vs self, usbatm_atm_close, usbatm_usb_disconnect */
 806
 807         if (instance->disconnected) {
 808                 atm_dbg(instance, "%s: disconnected!\n", __func__);
 809                 ret = -ENODEV;
 810                 goto fail;
 811         }
 812
 813         if (usbatm_find_vcc(instance, vpi, vci)) {
 814                 atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
 815                 ret = -EADDRINUSE;
 816                 goto fail;
 817         }
 818
 819         new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL);
 820         if (!new) {
 821                 ret = -ENOMEM;
 822                 goto fail;
 823         }
 824
 825         new->vcc = vcc;
 826         new->vpi = vpi;
 827         new->vci = vci;
 828
 829         new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
 830         if (!new->sarb) {
 831                 atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
 832                 ret = -ENOMEM;
 833                 goto fail;
 834         }
 835
 836         vcc->dev_data = new;
 837
 838         tasklet_disable(&instance->rx_channel.tasklet);
 839         instance->cached_vcc = new;
 840         instance->cached_vpi = vpi;
 841         instance->cached_vci = vci;
 842         list_add(&new->list, &instance->vcc_list);
 843         tasklet_enable(&instance->rx_channel.tasklet);
 844
 845         set_bit(ATM_VF_ADDR, &vcc->flags);
 846         set_bit(ATM_VF_PARTIAL, &vcc->flags);
 847         set_bit(ATM_VF_READY, &vcc->flags);
 848
 849         mutex_unlock(&instance->serialize);
 850
 851         atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
 852
 853         return 0;
 854
 855 fail:
 856         kfree(new);
 857         mutex_unlock(&instance->serialize);
 858         return ret;
 859 }
 860
 861 static void usbatm_atm_close(struct atm_vcc *vcc)
 862 {
 863         struct usbatm_data *instance = vcc->dev->dev_data;
 864         struct usbatm_vcc_data *vcc_data = vcc->dev_data;
 865
 866         if (!instance || !vcc_data)
 867                 return;
 868
 869         usbatm_cancel_send(instance, vcc);
 870
 871         mutex_lock(&instance->serialize);       /* vs self, usbatm_atm_open, usbatm_usb_disconnect */
 872
 873         tasklet_disable(&instance->rx_channel.tasklet);
 874         if (instance->cached_vcc == vcc_data) {
 875                 instance->cached_vcc = NULL;
 876                 instance->cached_vpi = ATM_VPI_UNSPEC;
 877                 instance->cached_vci = ATM_VCI_UNSPEC;
 878         }
 879         list_del(&vcc_data->list);
 880         tasklet_enable(&instance->rx_channel.tasklet);
 881
 882         kfree_skb(vcc_data->sarb);
 883         vcc_data->sarb = NULL;
 884
 885         kfree(vcc_data);
 886         vcc->dev_data = NULL;
 887
 888         vcc->vpi = ATM_VPI_UNSPEC;
 889         vcc->vci = ATM_VCI_UNSPEC;
 890         clear_bit(ATM_VF_READY, &vcc->flags);
 891         clear_bit(ATM_VF_PARTIAL, &vcc->flags);
 892         clear_bit(ATM_VF_ADDR, &vcc->flags);
 893
 894         mutex_unlock(&instance->serialize);
 895 }
 896
 897 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
 898                           void __user *arg)
 899 {
 900         struct usbatm_data *instance = atm_dev->dev_data;
 901
 902         if (!instance || instance->disconnected)
 903                 return -ENODEV;
 904
 905         switch (cmd) {
 906         case ATM_QUERYLOOP:
 907                 return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
 908         default:
 909                 return -ENOIOCTLCMD;
 910         }
 911 }
 912
 913 static int usbatm_atm_init(struct usbatm_data *instance)
 914 {
 915         struct atm_dev *atm_dev;
 916         int ret, i;
 917
 918         /* ATM init.  The ATM initialization scheme suffers from an intrinsic race
 919          * condition: callbacks we register can be executed at once, before we have
 920          * initialized the struct atm_dev.  To protect against this, all callbacks
 921          * abort if atm_dev->dev_data is NULL. */
 922         atm_dev = atm_dev_register(instance->driver_name,
 923                                    &instance->usb_intf->dev, &usbatm_atm_devops,
 924                                    -1, NULL);
 925         if (!atm_dev) {
 926                 usb_err(instance, "%s: failed to register ATM device!\n", __func__);
 927                 return -1;
 928         }
 929
 930         instance->atm_dev = atm_dev;
 931
 932         atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
 933         atm_dev->ci_range.vci_bits = ATM_CI_MAX;
 934         atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
 935
 936         /* temp init ATM device, set to 128kbit */
 937         atm_dev->link_rate = 128 * 1000 / 424;
 938
 939         if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
 940                 atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
 941                 goto fail;
 942         }
 943
 944         usbatm_get_instance(instance);  /* dropped in usbatm_atm_dev_close */
 945
 946         /* ready for ATM callbacks */
 947         mb();
 948         atm_dev->dev_data = instance;
 949
 950         /* submit all rx URBs */
 951         for (i = 0; i < num_rcv_urbs; i++)
 952                 usbatm_submit_urb(instance->urbs[i]);
 953
 954         return 0;
 955
 956  fail:
 957         instance->atm_dev = NULL;
 958         atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
 959         return ret;
 960 }
 961
 962
 963 /**********
 964 **  USB  **
 965 **********/
 966
 967 static int usbatm_do_heavy_init(void *arg)
 968 {
 969         struct usbatm_data *instance = arg;
 970         int ret;
 971
 972         allow_signal(SIGTERM);
 973         complete(&instance->thread_started);
 974
 975         ret = instance->driver->heavy_init(instance, instance->usb_intf);
 976
 977         if (!ret)
 978                 ret = usbatm_atm_init(instance);
 979
 980         mutex_lock(&instance->serialize);
 981         instance->thread = NULL;
 982         mutex_unlock(&instance->serialize);
 983
 984         complete_and_exit(&instance->thread_exited, ret);
 985 }
 986
 987 static int usbatm_heavy_init(struct usbatm_data *instance)
 988 {
 989         struct task_struct *t;
 990
 991         t = kthread_create(usbatm_do_heavy_init, instance, "%s",
 992                         instance->driver->driver_name);
 993         if (IS_ERR(t)) {
 994                 usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
 995                                 __func__, PTR_ERR(t));
 996                 return PTR_ERR(t);
 997         }
 998
 999         instance->thread = t;
1000         wake_up_process(t);
1001         wait_for_completion(&instance->thread_started);
1002
1003         return 0;
1004 }
1005
1006 static void usbatm_tasklet_schedule(unsigned long data)
1007 {
1008         tasklet_schedule((struct tasklet_struct *) data);
1009 }
1010
1011 static void usbatm_init_channel(struct usbatm_channel *channel)
1012 {
1013         spin_lock_init(&channel->lock);
1014         INIT_LIST_HEAD(&channel->list);
1015         channel->delay.function = usbatm_tasklet_schedule;
1016         channel->delay.data = (unsigned long) &channel->tasklet;
1017         init_timer(&channel->delay);
1018 }
1019
1020 int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1021                      struct usbatm_driver *driver)
1022 {
1023         struct device *dev = &intf->dev;
1024         struct usb_device *usb_dev = interface_to_usbdev(intf);
1025         struct usbatm_data *instance;
1026         char *buf;
1027         int error = -ENOMEM;
1028         int i, length;
1029         unsigned int maxpacket, num_packets;
1030
1031         /* instance init */
1032         instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1033         if (!instance)
1034                 return -ENOMEM;
1035
1036         /* public fields */
1037
1038         instance->driver = driver;
1039         strlcpy(instance->driver_name, driver->driver_name,
1040                 sizeof(instance->driver_name));
1041
1042         instance->usb_dev = usb_dev;
1043         instance->usb_intf = intf;
1044
1045         buf = instance->description;
1046         length = sizeof(instance->description);
1047
1048         if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1049                 goto bind;
1050
1051         buf += i;
1052         length -= i;
1053
1054         i = scnprintf(buf, length, " (");
1055         buf += i;
1056         length -= i;
1057
1058         if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1059                 goto bind;
1060
1061         buf += i;
1062         length -= i;
1063
1064         snprintf(buf, length, ")");
1065
1066  bind:
1067         if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1068                         dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1069                         goto fail_free;
1070         }
1071
1072         /* private fields */
1073
1074         kref_init(&instance->refcount);         /* dropped in usbatm_usb_disconnect */
1075         mutex_init(&instance->serialize);
1076
1077         instance->thread = NULL;
1078         init_completion(&instance->thread_started);
1079         init_completion(&instance->thread_exited);
1080
1081         INIT_LIST_HEAD(&instance->vcc_list);
1082         skb_queue_head_init(&instance->sndqueue);
1083
1084         usbatm_init_channel(&instance->rx_channel);
1085         usbatm_init_channel(&instance->tx_channel);
1086         tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1087         tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1088         instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1089         instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1090         instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1091
1092         if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1093                 instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1094         else
1095                 instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1096
1097         instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1098
1099         /* tx buffer size must be a positive multiple of the stride */
1100         instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1101                         snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1102
1103         /* rx buffer size must be a positive multiple of the endpoint maxpacket */
1104         maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1105
1106         if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1107                 dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1108                                 usb_pipeendpoint(instance->rx_channel.endpoint));
1109                 error = -EINVAL;
1110                 goto fail_unbind;
1111         }
1112
1113         num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1114
1115         if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1116                 num_packets--;
1117
1118         instance->rx_channel.buf_size = num_packets * maxpacket;
1119         instance->rx_channel.packet_size = maxpacket;
1120
1121         for (i = 0; i < 2; i++) {
1122                 struct usbatm_channel *channel = i ?
1123                         &instance->tx_channel : &instance->rx_channel;
1124
1125                 dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1126                         __func__, channel->buf_size, i ? "tx" : "rx", channel);
1127         }
1128
1129         /* initialize urbs */
1130
1131         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1132                 u8 *buffer;
1133                 struct usbatm_channel *channel = i < num_rcv_urbs ?
1134                         &instance->rx_channel : &instance->tx_channel;
1135                 struct urb *urb;
1136                 unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1137
1138                 urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1139                 if (!urb) {
1140                         error = -ENOMEM;
1141                         goto fail_unbind;
1142                 }
1143
1144                 instance->urbs[i] = urb;
1145
1146                 /* zero the tx padding to avoid leaking information */
1147                 buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1148                 if (!buffer) {
1149                         error = -ENOMEM;
1150                         goto fail_unbind;
1151                 }
1152
1153                 usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1154                                   buffer, channel->buf_size, usbatm_complete, channel);
1155                 if (iso_packets) {
1156                         int j;
1157                         urb->interval = 1;
1158                         urb->transfer_flags = URB_ISO_ASAP;
1159                         urb->number_of_packets = iso_packets;
1160                         for (j = 0; j < iso_packets; j++) {
1161                                 urb->iso_frame_desc[j].offset = channel->packet_size * j;
1162                                 urb->iso_frame_desc[j].length = channel->packet_size;
1163                         }
1164                 }
1165
1166                 /* put all tx URBs on the list of spares */
1167                 if (i >= num_rcv_urbs)
1168                         list_add_tail(&urb->urb_list, &channel->list);
1169
1170                 vdbg(&intf->dev, "%s: alloced buffer 0x%p buf size %u urb 0x%p",
1171                      __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1172         }
1173
1174         instance->cached_vpi = ATM_VPI_UNSPEC;
1175         instance->cached_vci = ATM_VCI_UNSPEC;
1176         instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1177
1178         if (!instance->cell_buf) {
1179                 error = -ENOMEM;
1180                 goto fail_unbind;
1181         }
1182
1183         if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1184                 error = usbatm_heavy_init(instance);
1185         } else {
1186                 complete(&instance->thread_exited);     /* pretend that heavy_init was run */
1187                 error = usbatm_atm_init(instance);
1188         }
1189
1190         if (error < 0)
1191                 goto fail_unbind;
1192
1193         usb_get_dev(usb_dev);
1194         usb_set_intfdata(intf, instance);
1195
1196         return 0;
1197
1198  fail_unbind:
1199         if (instance->driver->unbind)
1200                 instance->driver->unbind(instance, intf);
1201  fail_free:
1202         kfree(instance->cell_buf);
1203
1204         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1205                 if (instance->urbs[i])
1206                         kfree(instance->urbs[i]->transfer_buffer);
1207                 usb_free_urb(instance->urbs[i]);
1208         }
1209
1210         kfree(instance);
1211
1212         return error;
1213 }
1214 EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1215
1216 void usbatm_usb_disconnect(struct usb_interface *intf)
1217 {
1218         struct device *dev = &intf->dev;
1219         struct usbatm_data *instance = usb_get_intfdata(intf);
1220         struct usbatm_vcc_data *vcc_data;
1221         int i;
1222
1223         if (!instance) {
1224                 dev_dbg(dev, "%s: NULL instance!\n", __func__);
1225                 return;
1226         }
1227
1228         usb_set_intfdata(intf, NULL);
1229
1230         mutex_lock(&instance->serialize);
1231         instance->disconnected = 1;
1232         if (instance->thread != NULL)
1233                 send_sig(SIGTERM, instance->thread, 1);
1234         mutex_unlock(&instance->serialize);
1235
1236         wait_for_completion(&instance->thread_exited);
1237
1238         mutex_lock(&instance->serialize);
1239         list_for_each_entry(vcc_data, &instance->vcc_list, list)
1240                 vcc_release_async(vcc_data->vcc, -EPIPE);
1241         mutex_unlock(&instance->serialize);
1242
1243         tasklet_disable(&instance->rx_channel.tasklet);
1244         tasklet_disable(&instance->tx_channel.tasklet);
1245
1246         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1247                 usb_kill_urb(instance->urbs[i]);
1248
1249         del_timer_sync(&instance->rx_channel.delay);
1250         del_timer_sync(&instance->tx_channel.delay);
1251
1252         /* turn usbatm_[rt]x_process into something close to a no-op */
1253         /* no need to take the spinlock */
1254         INIT_LIST_HEAD(&instance->rx_channel.list);
1255         INIT_LIST_HEAD(&instance->tx_channel.list);
1256
1257         tasklet_enable(&instance->rx_channel.tasklet);
1258         tasklet_enable(&instance->tx_channel.tasklet);
1259
1260         if (instance->atm_dev && instance->driver->atm_stop)
1261                 instance->driver->atm_stop(instance, instance->atm_dev);
1262
1263         if (instance->driver->unbind)
1264                 instance->driver->unbind(instance, intf);
1265
1266         instance->driver_data = NULL;
1267
1268         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1269                 kfree(instance->urbs[i]->transfer_buffer);
1270                 usb_free_urb(instance->urbs[i]);
1271         }
1272
1273         kfree(instance->cell_buf);
1274
1275         /* ATM finalize */
1276         if (instance->atm_dev) {
1277                 atm_dev_deregister(instance->atm_dev);
1278                 instance->atm_dev = NULL;
1279         }
1280
1281         usbatm_put_instance(instance);  /* taken in usbatm_usb_probe */
1282 }
1283 EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1284
1285
1286 /***********
1287 **  init  **
1288 ***********/
1289
1290 static int __init usbatm_usb_init(void)
1291 {
1292         if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
1293                 printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1294                 return -EIO;
1295         }
1296
1297         if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1298             || (num_snd_urbs > UDSL_MAX_SND_URBS)
1299             || (rcv_buf_bytes < 1)
1300             || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1301             || (snd_buf_bytes < 1)
1302             || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1303                 return -EINVAL;
1304
1305         return 0;
1306 }
1307 module_init(usbatm_usb_init);
1308
1309 static void __exit usbatm_usb_exit(void)
1310 {
1311 }
1312 module_exit(usbatm_usb_exit);
1313
1314 MODULE_AUTHOR(DRIVER_AUTHOR);
1315 MODULE_DESCRIPTION(DRIVER_DESC);
1316 MODULE_LICENSE("GPL");
1317
1318 /************
1319 **  debug  **
1320 ************/
1321
1322 #ifdef VERBOSE_DEBUG
1323 static int usbatm_print_packet(struct usbatm_data *instance,
1324                                const unsigned char *data, int len)
1325 {
1326         unsigned char buffer[256];
1327         int i = 0, j = 0;
1328
1329         for (i = 0; i < len;) {
1330                 buffer[0] = '\0';
1331                 sprintf(buffer, "%.3d :", i);
1332                 for (j = 0; (j < 16) && (i < len); j++, i++)
1333                         sprintf(buffer, "%s %2.2x", buffer, data[i]);
1334                 dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1335         }
1336         return i;
1337 }
1338 #endif