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