drivers/usb/atm/usbatm.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /******************************************************************************
   3  *  usbatm.c - Generic USB xDSL driver core
   4  *
   5  *  Copyright (C) 2001, Alcatel
   6  *  Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
   7  *  Copyright (C) 2004, David Woodhouse, Roman Kagan
   8  ******************************************************************************/
   9
  10 /*
  11  *  Written by Johan Verrept, Duncan Sands ([email protected]) and David Woodhouse
  12  *
  13  *  1.7+:       - See the check-in logs
  14  *
  15  *  1.6:        - No longer opens a connection if the firmware is not loaded
  16  *              - Added support for the speedtouch 330
  17  *              - Removed the limit on the number of devices
  18  *              - Module now autoloads on device plugin
  19  *              - Merged relevant parts of sarlib
  20  *              - Replaced the kernel thread with a tasklet
  21  *              - New packet transmission code
  22  *              - Changed proc file contents
  23  *              - Fixed all known SMP races
  24  *              - Many fixes and cleanups
  25  *              - Various fixes by Oliver Neukum ([email protected])
  26  *
  27  *  1.5A:       - Version for inclusion in 2.5 series kernel
  28  *              - Modifications by Richard Purdie ([email protected])
  29  *              - made compatible with kernel 2.5.6 onwards by changing
  30  *              usbatm_usb_send_data_context->urb to a pointer and adding code
  31  *              to alloc and free it
  32  *              - remove_wait_queue() added to usbatm_atm_processqueue_thread()
  33  *
  34  *  1.5:        - fixed memory leak when atmsar_decode_aal5 returned NULL.
  35  *              (reported by [email protected])
  36  *
  37  *  1.4:        - changed the spin_lock() under interrupt to spin_lock_irqsave()
  38  *              - unlink all active send urbs of a vcc that is being closed.
  39  *
  40  *  1.3.1:      - added the version number
  41  *
  42  *  1.3:        - Added multiple send urb support
  43  *              - fixed memory leak and vcc->tx_inuse starvation bug
  44  *                when not enough memory left in vcc.
  45  *
  46  *  1.2:        - Fixed race condition in usbatm_usb_send_data()
  47  *  1.1:        - Turned off packet debugging
  48  *
  49  */
  50
  51 #include "usbatm.h"
  52
  53 #include <linux/uaccess.h>
  54 #include <linux/crc32.h>
  55 #include <linux/errno.h>
  56 #include <linux/init.h>
  57 #include <linux/interrupt.h>
  58 #include <linux/kernel.h>
  59 #include <linux/module.h>
  60 #include <linux/moduleparam.h>
  61 #include <linux/netdevice.h>
  62 #include <linux/proc_fs.h>
  63 #include <linux/sched/signal.h>
  64 #include <linux/signal.h>
  65 #include <linux/slab.h>
  66 #include <linux/stat.h>
  67 #include <linux/timer.h>
  68 #include <linux/wait.h>
  69 #include <linux/kthread.h>
  70 #include <linux/ratelimit.h>
  71
  72 #ifdef VERBOSE_DEBUG
  73 static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
  74 #define PACKETDEBUG(arg...)     usbatm_print_packet(arg)
  75 #define vdbg(arg...)            dev_dbg(arg)
  76 #else
  77 #define PACKETDEBUG(arg...)
  78 #define vdbg(arg...)
  79 #endif
  80
  81 #define DRIVER_AUTHOR   "Johan Verrept, Duncan Sands <[email protected]>"
  82 #define DRIVER_DESC     "Generic USB ATM/DSL I/O"
  83
  84 static const char usbatm_driver_name[] = "usbatm";
  85
  86 #define UDSL_MAX_RCV_URBS               16
  87 #define UDSL_MAX_SND_URBS               16
  88 #define UDSL_MAX_BUF_SIZE               65536
  89 #define UDSL_DEFAULT_RCV_URBS           4
  90 #define UDSL_DEFAULT_SND_URBS           4
  91 #define UDSL_DEFAULT_RCV_BUF_SIZE       3392    /* 64 * ATM_CELL_SIZE */
  92 #define UDSL_DEFAULT_SND_BUF_SIZE       3392    /* 64 * ATM_CELL_SIZE */
  93
  94 #define ATM_CELL_HEADER                 (ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
  95
  96 #define THROTTLE_MSECS                  100     /* delay to recover processing after urb submission fails */
  97
  98 static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
  99 static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
 100 static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
 101 static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
 102
 103 module_param(num_rcv_urbs, uint, S_IRUGO);
 104 MODULE_PARM_DESC(num_rcv_urbs,
 105                  "Number of urbs used for reception (range: 0-"
 106                  __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
 107                  __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
 108
 109 module_param(num_snd_urbs, uint, S_IRUGO);
 110 MODULE_PARM_DESC(num_snd_urbs,
 111                  "Number of urbs used for transmission (range: 0-"
 112                  __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
 113                  __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
 114
 115 module_param(rcv_buf_bytes, uint, S_IRUGO);
 116 MODULE_PARM_DESC(rcv_buf_bytes,
 117                  "Size of the buffers used for reception, in bytes (range: 1-"
 118                  __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
 119                  __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
 120
 121 module_param(snd_buf_bytes, uint, S_IRUGO);
 122 MODULE_PARM_DESC(snd_buf_bytes,
 123                  "Size of the buffers used for transmission, in bytes (range: 1-"
 124                  __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
 125                  __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
 126
 127
 128 /* receive */
 129
 130 struct usbatm_vcc_data {
 131         /* vpi/vci lookup */
 132         struct list_head list;
 133         short vpi;
 134         int vci;
 135         struct atm_vcc *vcc;
 136
 137         /* raw cell reassembly */
 138         struct sk_buff *sarb;
 139 };
 140
 141
 142 /* send */
 143
 144 struct usbatm_control {
 145         struct atm_skb_data atm;
 146         u32 len;
 147         u32 crc;
 148 };
 149
 150 #define UDSL_SKB(x)             ((struct usbatm_control *)(x)->cb)
 151
 152
 153 /* ATM */
 154
 155 static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
 156 static int usbatm_atm_open(struct atm_vcc *vcc);
 157 static void usbatm_atm_close(struct atm_vcc *vcc);
 158 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user *arg);
 159 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
 160 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page);
 161
 162 static const struct atmdev_ops usbatm_atm_devops = {
 163         .dev_close      = usbatm_atm_dev_close,
 164         .open           = usbatm_atm_open,
 165         .close          = usbatm_atm_close,
 166         .ioctl          = usbatm_atm_ioctl,
 167         .send           = usbatm_atm_send,
 168         .proc_read      = usbatm_atm_proc_read,
 169         .owner          = THIS_MODULE,
 170 };
 171
 172
 173 /***********
 174 **  misc  **
 175 ***********/
 176
 177 static inline unsigned int usbatm_pdu_length(unsigned int length)
 178 {
 179         length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
 180         return length - length % ATM_CELL_PAYLOAD;
 181 }
 182
 183 static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 184 {
 185         if (vcc->pop)
 186                 vcc->pop(vcc, skb);
 187         else
 188                 dev_kfree_skb_any(skb);
 189 }
 190
 191
 192 /***********
 193 **  urbs  **
 194 ************/
 195
 196 static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
 197 {
 198         struct urb *urb;
 199
 200         spin_lock_irq(&channel->lock);
 201         if (list_empty(&channel->list)) {
 202                 spin_unlock_irq(&channel->lock);
 203                 return NULL;
 204         }
 205
 206         urb = list_entry(channel->list.next, struct urb, urb_list);
 207         list_del(&urb->urb_list);
 208         spin_unlock_irq(&channel->lock);
 209
 210         return urb;
 211 }
 212
 213 static int usbatm_submit_urb(struct urb *urb)
 214 {
 215         struct usbatm_channel *channel = urb->context;
 216         int ret;
 217
 218         /* vdbg("%s: submitting urb 0x%p, size %u",
 219              __func__, urb, urb->transfer_buffer_length); */
 220
 221         ret = usb_submit_urb(urb, GFP_ATOMIC);
 222         if (ret) {
 223                 if (printk_ratelimit())
 224                         atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
 225                                 __func__, urb, ret);
 226
 227                 /* consider all errors transient and return the buffer back to the queue */
 228                 urb->status = -EAGAIN;
 229                 spin_lock_irq(&channel->lock);
 230
 231                 /* must add to the front when sending; doesn't matter when receiving */
 232                 list_add(&urb->urb_list, &channel->list);
 233
 234                 spin_unlock_irq(&channel->lock);
 235
 236                 /* make sure the channel doesn't stall */
 237                 mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
 238         }
 239
 240         return ret;
 241 }
 242
 243 static void usbatm_complete(struct urb *urb)
 244 {
 245         struct usbatm_channel *channel = urb->context;
 246         unsigned long flags;
 247         int status = urb->status;
 248
 249         /* vdbg("%s: urb 0x%p, status %d, actual_length %d",
 250              __func__, urb, status, urb->actual_length); */
 251
 252         /* Can be invoked from task context, protect against interrupts */
 253         spin_lock_irqsave(&channel->lock, flags);
 254
 255         /* must add to the back when receiving; doesn't matter when sending */
 256         list_add_tail(&urb->urb_list, &channel->list);
 257
 258         spin_unlock_irqrestore(&channel->lock, flags);
 259
 260         if (unlikely(status) &&
 261                         (!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
 262                          status != -EILSEQ)) {
 263                 if (status == -ESHUTDOWN)
 264                         return;
 265
 266                 if (printk_ratelimit())
 267                         atm_warn(channel->usbatm, "%s: urb 0x%p failed (%d)!\n",
 268                                 __func__, urb, status);
 269                 /* throttle processing in case of an error */
 270                 mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
 271         } else
 272                 tasklet_schedule(&channel->tasklet);
 273 }
 274
 275
 276 /*************
 277 **  decode  **
 278 *************/
 279
 280 static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
 281                                                   short vpi, int vci)
 282 {
 283         struct usbatm_vcc_data *vcc_data;
 284
 285         list_for_each_entry(vcc_data, &instance->vcc_list, list)
 286                 if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
 287                         return vcc_data;
 288         return NULL;
 289 }
 290
 291 static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
 292 {
 293         struct atm_vcc *vcc;
 294         struct sk_buff *sarb;
 295         short vpi = ((source[0] & 0x0f) << 4)  | (source[1] >> 4);
 296         int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
 297         u8 pti = ((source[3] & 0xe) >> 1);
 298
 299         if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
 300                 instance->cached_vpi = vpi;
 301                 instance->cached_vci = vci;
 302
 303                 instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
 304
 305                 if (!instance->cached_vcc)
 306                         atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
 307         }
 308
 309         if (!instance->cached_vcc)
 310                 return;
 311
 312         vcc = instance->cached_vcc->vcc;
 313
 314         /* OAM F5 end-to-end */
 315         if (pti == ATM_PTI_E2EF5) {
 316                 if (printk_ratelimit())
 317                         atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
 318                                 __func__, vpi, vci);
 319                 atomic_inc(&vcc->stats->rx_err);
 320                 return;
 321         }
 322
 323         sarb = instance->cached_vcc->sarb;
 324
 325         if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
 326                 atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
 327                                 __func__, sarb->len, vcc);
 328                 /* discard cells already received */
 329                 skb_trim(sarb, 0);
 330         }
 331
 332         memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
 333         __skb_put(sarb, ATM_CELL_PAYLOAD);
 334
 335         if (pti & 1) {
 336                 struct sk_buff *skb;
 337                 unsigned int length;
 338                 unsigned int pdu_length;
 339
 340                 length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
 341
 342                 /* guard against overflow */
 343                 if (length > ATM_MAX_AAL5_PDU) {
 344                         atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
 345                                   __func__, length, vcc);
 346                         atomic_inc(&vcc->stats->rx_err);
 347                         goto out;
 348                 }
 349
 350                 pdu_length = usbatm_pdu_length(length);
 351
 352                 if (sarb->len < pdu_length) {
 353                         atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
 354                                   __func__, pdu_length, sarb->len, vcc);
 355                         atomic_inc(&vcc->stats->rx_err);
 356                         goto out;
 357                 }
 358
 359                 if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
 360                         atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
 361                                   __func__, vcc);
 362                         atomic_inc(&vcc->stats->rx_err);
 363                         goto out;
 364                 }
 365
 366                 vdbg(&instance->usb_intf->dev,
 367                      "%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)",
 368                      __func__, length, pdu_length, vcc);
 369
 370                 skb = dev_alloc_skb(length);
 371                 if (!skb) {
 372                         if (printk_ratelimit())
 373                                 atm_err(instance, "%s: no memory for skb (length: %u)!\n",
 374                                         __func__, length);
 375                         atomic_inc(&vcc->stats->rx_drop);
 376                         goto out;
 377                 }
 378
 379                 vdbg(&instance->usb_intf->dev,
 380                      "%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)",
 381                      __func__, skb, skb->truesize);
 382
 383                 if (!atm_charge(vcc, skb->truesize)) {
 384                         atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
 385                                   __func__, skb->truesize);
 386                         dev_kfree_skb_any(skb);
 387                         goto out;       /* atm_charge increments rx_drop */
 388                 }
 389
 390                 skb_copy_to_linear_data(skb,
 391                                         skb_tail_pointer(sarb) - pdu_length,
 392                                         length);
 393                 __skb_put(skb, length);
 394
 395                 vdbg(&instance->usb_intf->dev,
 396                      "%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
 397                      __func__, skb, skb->len, skb->truesize);
 398
 399                 PACKETDEBUG(instance, skb->data, skb->len);
 400
 401                 vcc->push(vcc, skb);
 402
 403                 atomic_inc(&vcc->stats->rx);
 404         out:
 405                 skb_trim(sarb, 0);
 406         }
 407 }
 408
 409 static void usbatm_extract_cells(struct usbatm_data *instance,
 410                 unsigned char *source, unsigned int avail_data)
 411 {
 412         unsigned int stride = instance->rx_channel.stride;
 413         unsigned int buf_usage = instance->buf_usage;
 414
 415         /* extract cells from incoming data, taking into account that
 416          * the length of avail data may not be a multiple of stride */
 417
 418         if (buf_usage > 0) {
 419                 /* we have a partially received atm cell */
 420                 unsigned char *cell_buf = instance->cell_buf;
 421                 unsigned int space_left = stride - buf_usage;
 422
 423                 if (avail_data >= space_left) {
 424                         /* add new data and process cell */
 425                         memcpy(cell_buf + buf_usage, source, space_left);
 426                         source += space_left;
 427                         avail_data -= space_left;
 428                         usbatm_extract_one_cell(instance, cell_buf);
 429                         instance->buf_usage = 0;
 430                 } else {
 431                         /* not enough data to fill the cell */
 432                         memcpy(cell_buf + buf_usage, source, avail_data);
 433                         instance->buf_usage = buf_usage + avail_data;
 434                         return;
 435                 }
 436         }
 437
 438         for (; avail_data >= stride; avail_data -= stride, source += stride)
 439                 usbatm_extract_one_cell(instance, source);
 440
 441         if (avail_data > 0) {
 442                 /* length was not a multiple of stride -
 443                  * save remaining data for next call */
 444                 memcpy(instance->cell_buf, source, avail_data);
 445                 instance->buf_usage = avail_data;
 446         }
 447 }
 448
 449
 450 /*************
 451 **  encode  **
 452 *************/
 453
 454 static unsigned int usbatm_write_cells(struct usbatm_data *instance,
 455                                        struct sk_buff *skb,
 456                                        u8 *target, unsigned int avail_space)
 457 {
 458         struct usbatm_control *ctrl = UDSL_SKB(skb);
 459         struct atm_vcc *vcc = ctrl->atm.vcc;
 460         unsigned int bytes_written;
 461         unsigned int stride = instance->tx_channel.stride;
 462
 463         for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
 464              bytes_written += stride, target += stride) {
 465                 unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
 466                 unsigned int left = ATM_CELL_PAYLOAD - data_len;
 467                 u8 *ptr = target;
 468
 469                 ptr[0] = vcc->vpi >> 4;
 470                 ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
 471                 ptr[2] = vcc->vci >> 4;
 472                 ptr[3] = vcc->vci << 4;
 473                 ptr[4] = 0xec;
 474                 ptr += ATM_CELL_HEADER;
 475
 476                 skb_copy_from_linear_data(skb, ptr, data_len);
 477                 ptr += data_len;
 478                 __skb_pull(skb, data_len);
 479
 480                 if (!left)
 481                         continue;
 482
 483                 memset(ptr, 0, left);
 484
 485                 if (left >= ATM_AAL5_TRAILER) { /* trailer will go in this cell */
 486                         u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
 487                         /* trailer[0] = 0;              UU = 0 */
 488                         /* trailer[1] = 0;              CPI = 0 */
 489                         trailer[2] = ctrl->len >> 8;
 490                         trailer[3] = ctrl->len;
 491
 492                         ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
 493
 494                         trailer[4] = ctrl->crc >> 24;
 495                         trailer[5] = ctrl->crc >> 16;
 496                         trailer[6] = ctrl->crc >> 8;
 497                         trailer[7] = ctrl->crc;
 498
 499                         target[3] |= 0x2;       /* adjust PTI */
 500
 501                         ctrl->len = 0;          /* tag this skb finished */
 502                 } else
 503                         ctrl->crc = crc32_be(ctrl->crc, ptr, left);
 504         }
 505
 506         return bytes_written;
 507 }
 508
 509
 510 /**************
 511 **  receive  **
 512 **************/
 513
 514 static void usbatm_rx_process(struct tasklet_struct *t)
 515 {
 516         struct usbatm_data *instance = from_tasklet(instance, t,
 517                                                     rx_channel.tasklet);
 518         struct urb *urb;
 519
 520         while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
 521                 vdbg(&instance->usb_intf->dev,
 522                      "%s: processing urb 0x%p", __func__, urb);
 523
 524                 if (usb_pipeisoc(urb->pipe)) {
 525                         unsigned char *merge_start = NULL;
 526                         unsigned int merge_length = 0;
 527                         const unsigned int packet_size = instance->rx_channel.packet_size;
 528                         int i;
 529
 530                         for (i = 0; i < urb->number_of_packets; i++) {
 531                                 if (!urb->iso_frame_desc[i].status) {
 532                                         unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
 533
 534                                         if (!merge_length)
 535                                                 merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 536                                         merge_length += actual_length;
 537                                         if (merge_length && (actual_length < packet_size)) {
 538                                                 usbatm_extract_cells(instance, merge_start, merge_length);
 539                                                 merge_length = 0;
 540                                         }
 541                                 } else {
 542                                         atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
 543                                         if (merge_length)
 544                                                 usbatm_extract_cells(instance, merge_start, merge_length);
 545                                         merge_length = 0;
 546                                         instance->buf_usage = 0;
 547                                 }
 548                         }
 549
 550                         if (merge_length)
 551                                 usbatm_extract_cells(instance, merge_start, merge_length);
 552                 } else
 553                         if (!urb->status)
 554                                 usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
 555                         else
 556                                 instance->buf_usage = 0;
 557
 558                 if (usbatm_submit_urb(urb))
 559                         return;
 560         }
 561 }
 562
 563
 564 /***********
 565 **  send  **
 566 ***********/
 567
 568 static void usbatm_tx_process(struct tasklet_struct *t)
 569 {
 570         struct usbatm_data *instance = from_tasklet(instance, t,
 571                                                     tx_channel.tasklet);
 572         struct sk_buff *skb = instance->current_skb;
 573         struct urb *urb = NULL;
 574         const unsigned int buf_size = instance->tx_channel.buf_size;
 575         unsigned int bytes_written = 0;
 576         u8 *buffer = NULL;
 577
 578         if (!skb)
 579                 skb = skb_dequeue(&instance->sndqueue);
 580
 581         while (skb) {
 582                 if (!urb) {
 583                         urb = usbatm_pop_urb(&instance->tx_channel);
 584                         if (!urb)
 585                                 break;          /* no more senders */
 586                         buffer = urb->transfer_buffer;
 587                         bytes_written = (urb->status == -EAGAIN) ?
 588                                 urb->transfer_buffer_length : 0;
 589                 }
 590
 591                 bytes_written += usbatm_write_cells(instance, skb,
 592                                                   buffer + bytes_written,
 593                                                   buf_size - bytes_written);
 594
 595                 vdbg(&instance->usb_intf->dev,
 596                      "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
 597                      __func__, bytes_written, skb, urb);
 598
 599                 if (!UDSL_SKB(skb)->len) {
 600                         struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
 601
 602                         usbatm_pop(vcc, skb);
 603                         atomic_inc(&vcc->stats->tx);
 604
 605                         skb = skb_dequeue(&instance->sndqueue);
 606                 }
 607
 608                 if (bytes_written == buf_size || (!skb && bytes_written)) {
 609                         urb->transfer_buffer_length = bytes_written;
 610
 611                         if (usbatm_submit_urb(urb))
 612                                 break;
 613                         urb = NULL;
 614                 }
 615         }
 616
 617         instance->current_skb = skb;
 618 }
 619
 620 static void usbatm_cancel_send(struct usbatm_data *instance,
 621                                struct atm_vcc *vcc)
 622 {
 623         struct sk_buff *skb, *n;
 624
 625         spin_lock_irq(&instance->sndqueue.lock);
 626         skb_queue_walk_safe(&instance->sndqueue, skb, n) {
 627                 if (UDSL_SKB(skb)->atm.vcc == vcc) {
 628                         atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
 629                         __skb_unlink(skb, &instance->sndqueue);
 630                         usbatm_pop(vcc, skb);
 631                 }
 632         }
 633         spin_unlock_irq(&instance->sndqueue.lock);
 634
 635         tasklet_disable(&instance->tx_channel.tasklet);
 636         if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
 637                 atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
 638                 instance->current_skb = NULL;
 639                 usbatm_pop(vcc, skb);
 640         }
 641         tasklet_enable(&instance->tx_channel.tasklet);
 642 }
 643
 644 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
 645 {
 646         struct usbatm_data *instance = vcc->dev->dev_data;
 647         struct usbatm_control *ctrl = UDSL_SKB(skb);
 648         int err;
 649
 650         /* racy disconnection check - fine */
 651         if (!instance || instance->disconnected) {
 652 #ifdef VERBOSE_DEBUG
 653                 printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
 654 #endif
 655                 err = -ENODEV;
 656                 goto fail;
 657         }
 658
 659         if (vcc->qos.aal != ATM_AAL5) {
 660                 atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
 661                 err = -EINVAL;
 662                 goto fail;
 663         }
 664
 665         if (skb->len > ATM_MAX_AAL5_PDU) {
 666                 atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
 667                                 __func__, skb->len, ATM_MAX_AAL5_PDU);
 668                 err = -EINVAL;
 669                 goto fail;
 670         }
 671
 672         PACKETDEBUG(instance, skb->data, skb->len);
 673
 674         /* initialize the control block */
 675         ctrl->atm.vcc = vcc;
 676         ctrl->len = skb->len;
 677         ctrl->crc = crc32_be(~0, skb->data, skb->len);
 678
 679         skb_queue_tail(&instance->sndqueue, skb);
 680         tasklet_schedule(&instance->tx_channel.tasklet);
 681
 682         return 0;
 683
 684  fail:
 685         usbatm_pop(vcc, skb);
 686         return err;
 687 }
 688
 689
 690 /********************
 691 **  bean counting  **
 692 ********************/
 693
 694 static void usbatm_destroy_instance(struct kref *kref)
 695 {
 696         struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
 697
 698         tasklet_kill(&instance->rx_channel.tasklet);
 699         tasklet_kill(&instance->tx_channel.tasklet);
 700         usb_put_dev(instance->usb_dev);
 701         kfree(instance);
 702 }
 703
 704 static void usbatm_get_instance(struct usbatm_data *instance)
 705 {
 706         kref_get(&instance->refcount);
 707 }
 708
 709 static void usbatm_put_instance(struct usbatm_data *instance)
 710 {
 711         kref_put(&instance->refcount, usbatm_destroy_instance);
 712 }
 713
 714
 715 /**********
 716 **  ATM  **
 717 **********/
 718
 719 static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
 720 {
 721         struct usbatm_data *instance = atm_dev->dev_data;
 722
 723         if (!instance)
 724                 return;
 725
 726         atm_dev->dev_data = NULL; /* catch bugs */
 727         usbatm_put_instance(instance);  /* taken in usbatm_atm_init */
 728 }
 729
 730 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
 731 {
 732         struct usbatm_data *instance = atm_dev->dev_data;
 733         int left = *pos;
 734
 735         if (!instance)
 736                 return -ENODEV;
 737
 738         if (!left--)
 739                 return sprintf(page, "%s\n", instance->description);
 740
 741         if (!left--)
 742                 return sprintf(page, "MAC: %pM\n", atm_dev->esi);
 743
 744         if (!left--)
 745                 return sprintf(page,
 746                                "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
 747                                atomic_read(&atm_dev->stats.aal5.tx),
 748                                atomic_read(&atm_dev->stats.aal5.tx_err),
 749                                atomic_read(&atm_dev->stats.aal5.rx),
 750                                atomic_read(&atm_dev->stats.aal5.rx_err),
 751                                atomic_read(&atm_dev->stats.aal5.rx_drop));
 752
 753         if (!left--) {
 754                 if (instance->disconnected)
 755                         return sprintf(page, "Disconnected\n");
 756                 else
 757                         switch (atm_dev->signal) {
 758                         case ATM_PHY_SIG_FOUND:
 759                                 return sprintf(page, "Line up\n");
 760                         case ATM_PHY_SIG_LOST:
 761                                 return sprintf(page, "Line down\n");
 762                         default:
 763                                 return sprintf(page, "Line state unknown\n");
 764                         }
 765         }
 766
 767         return 0;
 768 }
 769
 770 static int usbatm_atm_open(struct atm_vcc *vcc)
 771 {
 772         struct usbatm_data *instance = vcc->dev->dev_data;
 773         struct usbatm_vcc_data *new = NULL;
 774         int ret;
 775         int vci = vcc->vci;
 776         short vpi = vcc->vpi;
 777
 778         if (!instance)
 779                 return -ENODEV;
 780
 781         /* only support AAL5 */
 782         if ((vcc->qos.aal != ATM_AAL5)) {
 783                 atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
 784                 return -EINVAL;
 785         }
 786
 787         /* sanity checks */
 788         if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
 789                 atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
 790                 return -EINVAL;
 791         }
 792
 793         mutex_lock(&instance->serialize);       /* vs self, usbatm_atm_close, usbatm_usb_disconnect */
 794
 795         if (instance->disconnected) {
 796                 atm_dbg(instance, "%s: disconnected!\n", __func__);
 797                 ret = -ENODEV;
 798                 goto fail;
 799         }
 800
 801         if (usbatm_find_vcc(instance, vpi, vci)) {
 802                 atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
 803                 ret = -EADDRINUSE;
 804                 goto fail;
 805         }
 806
 807         new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL);
 808         if (!new) {
 809                 ret = -ENOMEM;
 810                 goto fail;
 811         }
 812
 813         new->vcc = vcc;
 814         new->vpi = vpi;
 815         new->vci = vci;
 816
 817         new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
 818         if (!new->sarb) {
 819                 atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
 820                 ret = -ENOMEM;
 821                 goto fail;
 822         }
 823
 824         vcc->dev_data = new;
 825
 826         tasklet_disable(&instance->rx_channel.tasklet);
 827         instance->cached_vcc = new;
 828         instance->cached_vpi = vpi;
 829         instance->cached_vci = vci;
 830         list_add(&new->list, &instance->vcc_list);
 831         tasklet_enable(&instance->rx_channel.tasklet);
 832
 833         set_bit(ATM_VF_ADDR, &vcc->flags);
 834         set_bit(ATM_VF_PARTIAL, &vcc->flags);
 835         set_bit(ATM_VF_READY, &vcc->flags);
 836
 837         mutex_unlock(&instance->serialize);
 838
 839         atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
 840
 841         return 0;
 842
 843 fail:
 844         kfree(new);
 845         mutex_unlock(&instance->serialize);
 846         return ret;
 847 }
 848
 849 static void usbatm_atm_close(struct atm_vcc *vcc)
 850 {
 851         struct usbatm_data *instance = vcc->dev->dev_data;
 852         struct usbatm_vcc_data *vcc_data = vcc->dev_data;
 853
 854         if (!instance || !vcc_data)
 855                 return;
 856
 857         usbatm_cancel_send(instance, vcc);
 858
 859         mutex_lock(&instance->serialize);       /* vs self, usbatm_atm_open, usbatm_usb_disconnect */
 860
 861         tasklet_disable(&instance->rx_channel.tasklet);
 862         if (instance->cached_vcc == vcc_data) {
 863                 instance->cached_vcc = NULL;
 864                 instance->cached_vpi = ATM_VPI_UNSPEC;
 865                 instance->cached_vci = ATM_VCI_UNSPEC;
 866         }
 867         list_del(&vcc_data->list);
 868         tasklet_enable(&instance->rx_channel.tasklet);
 869
 870         kfree_skb(vcc_data->sarb);
 871         vcc_data->sarb = NULL;
 872
 873         kfree(vcc_data);
 874         vcc->dev_data = NULL;
 875
 876         vcc->vpi = ATM_VPI_UNSPEC;
 877         vcc->vci = ATM_VCI_UNSPEC;
 878         clear_bit(ATM_VF_READY, &vcc->flags);
 879         clear_bit(ATM_VF_PARTIAL, &vcc->flags);
 880         clear_bit(ATM_VF_ADDR, &vcc->flags);
 881
 882         mutex_unlock(&instance->serialize);
 883 }
 884
 885 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
 886                           void __user *arg)
 887 {
 888         struct usbatm_data *instance = atm_dev->dev_data;
 889
 890         if (!instance || instance->disconnected)
 891                 return -ENODEV;
 892
 893         switch (cmd) {
 894         case ATM_QUERYLOOP:
 895                 return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
 896         default:
 897                 return -ENOIOCTLCMD;
 898         }
 899 }
 900
 901 static int usbatm_atm_init(struct usbatm_data *instance)
 902 {
 903         struct atm_dev *atm_dev;
 904         int ret, i;
 905
 906         /* ATM init.  The ATM initialization scheme suffers from an intrinsic race
 907          * condition: callbacks we register can be executed at once, before we have
 908          * initialized the struct atm_dev.  To protect against this, all callbacks
 909          * abort if atm_dev->dev_data is NULL. */
 910         atm_dev = atm_dev_register(instance->driver_name,
 911                                    &instance->usb_intf->dev, &usbatm_atm_devops,
 912                                    -1, NULL);
 913         if (!atm_dev) {
 914                 usb_err(instance, "%s: failed to register ATM device!\n", __func__);
 915                 return -1;
 916         }
 917
 918         instance->atm_dev = atm_dev;
 919
 920         atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
 921         atm_dev->ci_range.vci_bits = ATM_CI_MAX;
 922         atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
 923
 924         /* temp init ATM device, set to 128kbit */
 925         atm_dev->link_rate = 128 * 1000 / 424;
 926
 927         if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
 928                 atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
 929                 goto fail;
 930         }
 931
 932         usbatm_get_instance(instance);  /* dropped in usbatm_atm_dev_close */
 933
 934         /* ready for ATM callbacks */
 935         mb();
 936         atm_dev->dev_data = instance;
 937
 938         /* submit all rx URBs */
 939         for (i = 0; i < num_rcv_urbs; i++)
 940                 usbatm_submit_urb(instance->urbs[i]);
 941
 942         return 0;
 943
 944  fail:
 945         instance->atm_dev = NULL;
 946         atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
 947         return ret;
 948 }
 949
 950
 951 /**********
 952 **  USB  **
 953 **********/
 954
 955 static int usbatm_do_heavy_init(void *arg)
 956 {
 957         struct usbatm_data *instance = arg;
 958         int ret;
 959
 960         allow_signal(SIGTERM);
 961         complete(&instance->thread_started);
 962
 963         ret = instance->driver->heavy_init(instance, instance->usb_intf);
 964
 965         if (!ret)
 966                 ret = usbatm_atm_init(instance);
 967
 968         mutex_lock(&instance->serialize);
 969         instance->thread = NULL;
 970         mutex_unlock(&instance->serialize);
 971
 972         kthread_complete_and_exit(&instance->thread_exited, ret);
 973 }
 974
 975 static int usbatm_heavy_init(struct usbatm_data *instance)
 976 {
 977         struct task_struct *t;
 978
 979         t = kthread_create(usbatm_do_heavy_init, instance, "%s",
 980                         instance->driver->driver_name);
 981         if (IS_ERR(t)) {
 982                 usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
 983                                 __func__, PTR_ERR(t));
 984                 return PTR_ERR(t);
 985         }
 986
 987         instance->thread = t;
 988         wake_up_process(t);
 989         wait_for_completion(&instance->thread_started);
 990
 991         return 0;
 992 }
 993
 994 static void usbatm_tasklet_schedule(struct timer_list *t)
 995 {
 996         struct usbatm_channel *channel = from_timer(channel, t, delay);
 997
 998         tasklet_schedule(&channel->tasklet);
 999 }
1000
1001 static void usbatm_init_channel(struct usbatm_channel *channel)
1002 {
1003         spin_lock_init(&channel->lock);
1004         INIT_LIST_HEAD(&channel->list);
1005         timer_setup(&channel->delay, usbatm_tasklet_schedule, 0);
1006 }
1007
1008 int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1009                      struct usbatm_driver *driver)
1010 {
1011         struct device *dev = &intf->dev;
1012         struct usb_device *usb_dev = interface_to_usbdev(intf);
1013         struct usbatm_data *instance;
1014         char *buf;
1015         int error = -ENOMEM;
1016         int i, length;
1017         unsigned int maxpacket, num_packets;
1018         size_t size;
1019
1020         /* instance init */
1021         size = struct_size(instance, urbs,
1022                            size_add(num_rcv_urbs, num_snd_urbs));
1023         instance = kzalloc(size, GFP_KERNEL);
1024         if (!instance)
1025                 return -ENOMEM;
1026
1027         /* public fields */
1028
1029         instance->driver = driver;
1030         strscpy(instance->driver_name, driver->driver_name,
1031                 sizeof(instance->driver_name));
1032
1033         instance->usb_dev = usb_dev;
1034         instance->usb_intf = intf;
1035
1036         buf = instance->description;
1037         length = sizeof(instance->description);
1038
1039         if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1040                 goto bind;
1041
1042         buf += i;
1043         length -= i;
1044
1045         i = scnprintf(buf, length, " (");
1046         buf += i;
1047         length -= i;
1048
1049         if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1050                 goto bind;
1051
1052         buf += i;
1053         length -= i;
1054
1055         snprintf(buf, length, ")");
1056
1057  bind:
1058         if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1059                         dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1060                         goto fail_free;
1061         }
1062
1063         /* private fields */
1064
1065         kref_init(&instance->refcount);         /* dropped in usbatm_usb_disconnect */
1066         mutex_init(&instance->serialize);
1067
1068         instance->thread = NULL;
1069         init_completion(&instance->thread_started);
1070         init_completion(&instance->thread_exited);
1071
1072         INIT_LIST_HEAD(&instance->vcc_list);
1073         skb_queue_head_init(&instance->sndqueue);
1074
1075         usbatm_init_channel(&instance->rx_channel);
1076         usbatm_init_channel(&instance->tx_channel);
1077         tasklet_setup(&instance->rx_channel.tasklet, usbatm_rx_process);
1078         tasklet_setup(&instance->tx_channel.tasklet, usbatm_tx_process);
1079         instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1080         instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1081         instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1082
1083         if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1084                 instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1085         else
1086                 instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1087
1088         instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1089
1090         /* tx buffer size must be a positive multiple of the stride */
1091         instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1092                         snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1093
1094         /* rx buffer size must be a positive multiple of the endpoint maxpacket */
1095         maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint);
1096
1097         if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1098                 dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1099                                 usb_pipeendpoint(instance->rx_channel.endpoint));
1100                 error = -EINVAL;
1101                 goto fail_unbind;
1102         }
1103
1104         num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1105
1106         if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1107                 num_packets--;
1108
1109         instance->rx_channel.buf_size = num_packets * maxpacket;
1110         instance->rx_channel.packet_size = maxpacket;
1111
1112         for (i = 0; i < 2; i++) {
1113                 struct usbatm_channel *channel = i ?
1114                         &instance->tx_channel : &instance->rx_channel;
1115
1116                 dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1117                         __func__, channel->buf_size, i ? "tx" : "rx", channel);
1118         }
1119
1120         /* initialize urbs */
1121
1122         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1123                 u8 *buffer;
1124                 struct usbatm_channel *channel = i < num_rcv_urbs ?
1125                         &instance->rx_channel : &instance->tx_channel;
1126                 struct urb *urb;
1127                 unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1128
1129                 urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1130                 if (!urb) {
1131                         error = -ENOMEM;
1132                         goto fail_unbind;
1133                 }
1134
1135                 instance->urbs[i] = urb;
1136
1137                 /* zero the tx padding to avoid leaking information */
1138                 buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1139                 if (!buffer) {
1140                         error = -ENOMEM;
1141                         goto fail_unbind;
1142                 }
1143
1144                 usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1145                                   buffer, channel->buf_size, usbatm_complete, channel);
1146                 if (iso_packets) {
1147                         int j;
1148                         urb->interval = 1;
1149                         urb->transfer_flags = URB_ISO_ASAP;
1150                         urb->number_of_packets = iso_packets;
1151                         for (j = 0; j < iso_packets; j++) {
1152                                 urb->iso_frame_desc[j].offset = channel->packet_size * j;
1153                                 urb->iso_frame_desc[j].length = channel->packet_size;
1154                         }
1155                 }
1156
1157                 /* put all tx URBs on the list of spares */
1158                 if (i >= num_rcv_urbs)
1159                         list_add_tail(&urb->urb_list, &channel->list);
1160
1161                 vdbg(&intf->dev, "%s: allocated buffer 0x%p buf size %u urb 0x%p",
1162                      __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1163         }
1164
1165         instance->cached_vpi = ATM_VPI_UNSPEC;
1166         instance->cached_vci = ATM_VCI_UNSPEC;
1167         instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1168
1169         if (!instance->cell_buf) {
1170                 error = -ENOMEM;
1171                 goto fail_unbind;
1172         }
1173
1174         if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1175                 error = usbatm_heavy_init(instance);
1176         } else {
1177                 complete(&instance->thread_exited);     /* pretend that heavy_init was run */
1178                 error = usbatm_atm_init(instance);
1179         }
1180
1181         if (error < 0)
1182                 goto fail_unbind;
1183
1184         usb_get_dev(usb_dev);
1185         usb_set_intfdata(intf, instance);
1186
1187         return 0;
1188
1189  fail_unbind:
1190         if (instance->driver->unbind)
1191                 instance->driver->unbind(instance, intf);
1192  fail_free:
1193         kfree(instance->cell_buf);
1194
1195         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1196                 if (instance->urbs[i])
1197                         kfree(instance->urbs[i]->transfer_buffer);
1198                 usb_free_urb(instance->urbs[i]);
1199         }
1200
1201         kfree(instance);
1202
1203         return error;
1204 }
1205 EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1206
1207 void usbatm_usb_disconnect(struct usb_interface *intf)
1208 {
1209         struct device *dev = &intf->dev;
1210         struct usbatm_data *instance = usb_get_intfdata(intf);
1211         struct usbatm_vcc_data *vcc_data;
1212         int i;
1213
1214         if (!instance) {
1215                 dev_dbg(dev, "%s: NULL instance!\n", __func__);
1216                 return;
1217         }
1218
1219         usb_set_intfdata(intf, NULL);
1220
1221         mutex_lock(&instance->serialize);
1222         instance->disconnected = 1;
1223         if (instance->thread != NULL)
1224                 send_sig(SIGTERM, instance->thread, 1);
1225         mutex_unlock(&instance->serialize);
1226
1227         wait_for_completion(&instance->thread_exited);
1228
1229         mutex_lock(&instance->serialize);
1230         list_for_each_entry(vcc_data, &instance->vcc_list, list)
1231                 vcc_release_async(vcc_data->vcc, -EPIPE);
1232         mutex_unlock(&instance->serialize);
1233
1234         tasklet_disable(&instance->rx_channel.tasklet);
1235         tasklet_disable(&instance->tx_channel.tasklet);
1236
1237         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1238                 usb_kill_urb(instance->urbs[i]);
1239
1240         del_timer_sync(&instance->rx_channel.delay);
1241         del_timer_sync(&instance->tx_channel.delay);
1242
1243         /* turn usbatm_[rt]x_process into something close to a no-op */
1244         /* no need to take the spinlock */
1245         INIT_LIST_HEAD(&instance->rx_channel.list);
1246         INIT_LIST_HEAD(&instance->tx_channel.list);
1247
1248         tasklet_enable(&instance->rx_channel.tasklet);
1249         tasklet_enable(&instance->tx_channel.tasklet);
1250
1251         if (instance->atm_dev && instance->driver->atm_stop)
1252                 instance->driver->atm_stop(instance, instance->atm_dev);
1253
1254         if (instance->driver->unbind)
1255                 instance->driver->unbind(instance, intf);
1256
1257         instance->driver_data = NULL;
1258
1259         for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1260                 kfree(instance->urbs[i]->transfer_buffer);
1261                 usb_free_urb(instance->urbs[i]);
1262         }
1263
1264         kfree(instance->cell_buf);
1265
1266         /* ATM finalize */
1267         if (instance->atm_dev) {
1268                 atm_dev_deregister(instance->atm_dev);
1269                 instance->atm_dev = NULL;
1270         }
1271
1272         usbatm_put_instance(instance);  /* taken in usbatm_usb_probe */
1273 }
1274 EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1275
1276
1277 /***********
1278 **  init  **
1279 ***********/
1280
1281 static int __init usbatm_usb_init(void)
1282 {
1283         if (sizeof(struct usbatm_control) > sizeof_field(struct sk_buff, cb)) {
1284                 pr_err("%s unusable with this kernel!\n", usbatm_driver_name);
1285                 return -EIO;
1286         }
1287
1288         if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1289             || (num_snd_urbs > UDSL_MAX_SND_URBS)
1290             || (rcv_buf_bytes < 1)
1291             || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1292             || (snd_buf_bytes < 1)
1293             || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1294                 return -EINVAL;
1295
1296         return 0;
1297 }
1298 module_init(usbatm_usb_init);
1299
1300 static void __exit usbatm_usb_exit(void)
1301 {
1302 }
1303 module_exit(usbatm_usb_exit);
1304
1305 MODULE_AUTHOR(DRIVER_AUTHOR);
1306 MODULE_DESCRIPTION(DRIVER_DESC);
1307 MODULE_LICENSE("GPL");
1308
1309 /************
1310 **  debug  **
1311 ************/
1312
1313 #ifdef VERBOSE_DEBUG
1314 static int usbatm_print_packet(struct usbatm_data *instance,
1315                                const unsigned char *data, int len)
1316 {
1317         unsigned char buffer[256];
1318         int i = 0, j = 0;
1319
1320         for (i = 0; i < len;) {
1321                 buffer[0] = '\0';
1322                 sprintf(buffer, "%.3d :", i);
1323                 for (j = 0; (j < 16) && (i < len); j++, i++)
1324                         sprintf(buffer, "%s %2.2x", buffer, data[i]);
1325                 dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1326         }
1327         return i;
1328 }
1329 #endif