drivers/firewire/fw-device-cdev.c

   1 /*                                              -*- c-basic-offset: 8 -*-
   2  *
   3  * fw-device-cdev.c - Char device for device raw access
   4  *
   5  * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software Foundation,
  19  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/kernel.h>
  24 #include <linux/wait.h>
  25 #include <linux/errno.h>
  26 #include <linux/device.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/poll.h>
  29 #include <linux/delay.h>
  30 #include <linux/mm.h>
  31 #include <linux/compat.h>
  32 #include <asm/uaccess.h>
  33 #include "fw-transaction.h"
  34 #include "fw-topology.h"
  35 #include "fw-device.h"
  36 #include "fw-device-cdev.h"
  37
  38 /*
  39  * todo
  40  *
  41  * - bus resets sends a new packet with new generation and node id
  42  *
  43  */
  44
  45 /* dequeue_event() just kfree()'s the event, so the event has to be
  46  * the first field in the struct. */
  47
  48 struct event {
  49         struct { void *data; size_t size; } v[2];
  50         struct list_head link;
  51 };
  52
  53 struct response {
  54         struct event event;
  55         struct fw_transaction transaction;
  56         struct client *client;
  57         struct fw_cdev_event_response response;
  58 };
  59
  60 struct iso_interrupt {
  61         struct event event;
  62         struct fw_cdev_event_iso_interrupt interrupt;
  63 };
  64
  65 struct client {
  66         struct fw_device *device;
  67         spinlock_t lock;
  68         struct list_head handler_list;
  69         struct list_head request_list;
  70         u32 request_serial;
  71         struct list_head event_list;
  72         struct semaphore event_list_sem;
  73         wait_queue_head_t wait;
  74         unsigned long vm_start;
  75         struct fw_iso_context *iso_context;
  76 };
  77
  78 static inline void __user *
  79 u64_to_uptr(__u64 value)
  80 {
  81         return (void __user *)(unsigned long)value;
  82 }
  83
  84 static inline __u64
  85 uptr_to_u64(void __user *ptr)
  86 {
  87         return (__u64)(unsigned long)ptr;
  88 }
  89
  90 static int fw_device_op_open(struct inode *inode, struct file *file)
  91 {
  92         struct fw_device *device;
  93         struct client *client;
  94
  95         device = container_of(inode->i_cdev, struct fw_device, cdev);
  96
  97         client = kzalloc(sizeof *client, GFP_KERNEL);
  98         if (client == NULL)
  99                 return -ENOMEM;
 100
 101         client->device = fw_device_get(device);
 102         INIT_LIST_HEAD(&client->event_list);
 103         sema_init(&client->event_list_sem, 0);
 104         INIT_LIST_HEAD(&client->handler_list);
 105         INIT_LIST_HEAD(&client->request_list);
 106         spin_lock_init(&client->lock);
 107         init_waitqueue_head(&client->wait);
 108
 109         file->private_data = client;
 110
 111         return 0;
 112 }
 113
 114 static void queue_event(struct client *client, struct event *event,
 115                         void *data0, size_t size0, void *data1, size_t size1)
 116 {
 117         unsigned long flags;
 118
 119         event->v[0].data = data0;
 120         event->v[0].size = size0;
 121         event->v[1].data = data1;
 122         event->v[1].size = size1;
 123
 124         spin_lock_irqsave(&client->lock, flags);
 125
 126         list_add_tail(&event->link, &client->event_list);
 127
 128         up(&client->event_list_sem);
 129         wake_up_interruptible(&client->wait);
 130
 131         spin_unlock_irqrestore(&client->lock, flags);
 132 }
 133
 134 static int dequeue_event(struct client *client, char __user *buffer, size_t count)
 135 {
 136         unsigned long flags;
 137         struct event *event;
 138         size_t size, total;
 139         int i, retval = -EFAULT;
 140
 141         if (down_interruptible(&client->event_list_sem) < 0)
 142                 return -EINTR;
 143
 144         spin_lock_irqsave(&client->lock, flags);
 145
 146         event = container_of(client->event_list.next, struct event, link);
 147         list_del(&event->link);
 148
 149         spin_unlock_irqrestore(&client->lock, flags);
 150
 151         if (buffer == NULL)
 152                 goto out;
 153
 154         total = 0;
 155         for (i = 0; i < ARRAY_SIZE(event->v) && total < count; i++) {
 156                 size = min(event->v[i].size, count - total);
 157                 if (copy_to_user(buffer + total, event->v[i].data, size))
 158                         goto out;
 159                 total += size;
 160         }
 161         retval = total;
 162
 163  out:
 164         kfree(event);
 165
 166         return retval;
 167 }
 168
 169 static ssize_t
 170 fw_device_op_read(struct file *file,
 171                   char __user *buffer, size_t count, loff_t *offset)
 172 {
 173         struct client *client = file->private_data;
 174
 175         return dequeue_event(client, buffer, count);
 176 }
 177
 178 static int ioctl_config_rom(struct client *client, void __user *arg)
 179 {
 180         struct fw_cdev_get_config_rom rom;
 181
 182         rom.length = client->device->config_rom_length;
 183         memcpy(rom.data, client->device->config_rom, rom.length * 4);
 184         if (copy_to_user(arg, &rom,
 185                          (char *)&rom.data[rom.length] - (char *)&rom))
 186                 return -EFAULT;
 187
 188         return 0;
 189 }
 190
 191 static void
 192 complete_transaction(struct fw_card *card, int rcode,
 193                      void *payload, size_t length, void *data)
 194 {
 195         struct response *response = data;
 196         struct client *client = response->client;
 197
 198         if (length < response->response.length)
 199                 response->response.length = length;
 200         if (rcode == RCODE_COMPLETE)
 201                 memcpy(response->response.data, payload,
 202                        response->response.length);
 203
 204         response->response.type   = FW_CDEV_EVENT_RESPONSE;
 205         response->response.rcode  = rcode;
 206         queue_event(client, &response->event,
 207                     &response->response, sizeof response->response,
 208                     response->response.data, response->response.length);
 209 }
 210
 211 static ssize_t ioctl_send_request(struct client *client, void __user *arg)
 212 {
 213         struct fw_device *device = client->device;
 214         struct fw_cdev_send_request request;
 215         struct response *response;
 216
 217         if (copy_from_user(&request, arg, sizeof request))
 218                 return -EFAULT;
 219
 220         /* What is the biggest size we'll accept, really? */
 221         if (request.length > 4096)
 222                 return -EINVAL;
 223
 224         response = kmalloc(sizeof *response + request.length, GFP_KERNEL);
 225         if (response == NULL)
 226                 return -ENOMEM;
 227
 228         response->client = client;
 229         response->response.length = request.length;
 230         response->response.closure = request.closure;
 231
 232         if (request.data &&
 233             copy_from_user(response->response.data,
 234                            u64_to_uptr(request.data), request.length)) {
 235                 kfree(response);
 236                 return -EFAULT;
 237         }
 238
 239         fw_send_request(device->card, &response->transaction,
 240                         request.tcode,
 241                         device->node->node_id | LOCAL_BUS,
 242                         device->card->generation,
 243                         device->node->max_speed,
 244                         request.offset,
 245                         response->response.data, request.length,
 246                         complete_transaction, response);
 247
 248         if (request.data)
 249                 return sizeof request + request.length;
 250         else
 251                 return sizeof request;
 252 }
 253
 254 struct address_handler {
 255         struct fw_address_handler handler;
 256         __u64 closure;
 257         struct client *client;
 258         struct list_head link;
 259 };
 260
 261 struct request {
 262         struct fw_request *request;
 263         void *data;
 264         size_t length;
 265         u32 serial;
 266         struct list_head link;
 267 };
 268
 269 struct request_event {
 270         struct event event;
 271         struct fw_cdev_event_request request;
 272 };
 273
 274 static void
 275 handle_request(struct fw_card *card, struct fw_request *r,
 276                int tcode, int destination, int source,
 277                int generation, int speed,
 278                unsigned long long offset,
 279                void *payload, size_t length, void *callback_data)
 280 {
 281         struct address_handler *handler = callback_data;
 282         struct request *request;
 283         struct request_event *e;
 284         unsigned long flags;
 285         struct client *client = handler->client;
 286
 287         request = kmalloc(sizeof *request, GFP_ATOMIC);
 288         e = kmalloc(sizeof *e, GFP_ATOMIC);
 289         if (request == NULL || e == NULL) {
 290                 kfree(request);
 291                 kfree(e);
 292                 fw_send_response(card, r, RCODE_CONFLICT_ERROR);
 293                 return;
 294         }
 295
 296         request->request = r;
 297         request->data    = payload;
 298         request->length  = length;
 299
 300         spin_lock_irqsave(&client->lock, flags);
 301         request->serial = client->request_serial++;
 302         list_add_tail(&request->link, &client->request_list);
 303         spin_unlock_irqrestore(&client->lock, flags);
 304
 305         e->request.type    = FW_CDEV_EVENT_REQUEST;
 306         e->request.tcode   = tcode;
 307         e->request.offset  = offset;
 308         e->request.length  = length;
 309         e->request.serial  = request->serial;
 310         e->request.closure = handler->closure;
 311
 312         queue_event(client, &e->event,
 313                     &e->request, sizeof e->request, payload, length);
 314 }
 315
 316 static int ioctl_allocate(struct client *client, void __user *arg)
 317 {
 318         struct fw_cdev_allocate request;
 319         struct address_handler *handler;
 320         unsigned long flags;
 321         struct fw_address_region region;
 322
 323         if (copy_from_user(&request, arg, sizeof request))
 324                 return -EFAULT;
 325
 326         handler = kmalloc(sizeof *handler, GFP_KERNEL);
 327         if (handler == NULL)
 328                 return -ENOMEM;
 329
 330         region.start = request.offset;
 331         region.end = request.offset + request.length;
 332         handler->handler.length = request.length;
 333         handler->handler.address_callback = handle_request;
 334         handler->handler.callback_data = handler;
 335         handler->closure = request.closure;
 336         handler->client = client;
 337
 338         if (fw_core_add_address_handler(&handler->handler, &region) < 0) {
 339                 kfree(handler);
 340                 return -EBUSY;
 341         }
 342
 343         spin_lock_irqsave(&client->lock, flags);
 344         list_add_tail(&handler->link, &client->handler_list);
 345         spin_unlock_irqrestore(&client->lock, flags);
 346
 347         return 0;
 348 }
 349
 350 static int ioctl_send_response(struct client *client, void __user *arg)
 351 {
 352         struct fw_cdev_send_response request;
 353         struct request *r;
 354         unsigned long flags;
 355
 356         if (copy_from_user(&request, arg, sizeof request))
 357                 return -EFAULT;
 358
 359         spin_lock_irqsave(&client->lock, flags);
 360         list_for_each_entry(r, &client->request_list, link) {
 361                 if (r->serial == request.serial) {
 362                         list_del(&r->link);
 363                         break;
 364                 }
 365         }
 366         spin_unlock_irqrestore(&client->lock, flags);
 367
 368         if (&r->link == &client->request_list)
 369                 return -EINVAL;
 370
 371         if (request.length < r->length)
 372                 r->length = request.length;
 373         if (copy_from_user(r->data, u64_to_uptr(request.data), r->length))
 374                 return -EFAULT;
 375
 376         fw_send_response(client->device->card, r->request, request.rcode);
 377
 378         kfree(r);
 379
 380         return 0;
 381 }
 382
 383 static void
 384 iso_callback(struct fw_iso_context *context, int status, u32 cycle, void *data)
 385 {
 386         struct client *client = data;
 387         struct iso_interrupt *interrupt;
 388
 389         interrupt = kzalloc(sizeof *interrupt, GFP_ATOMIC);
 390         if (interrupt == NULL)
 391                 return;
 392
 393         interrupt->interrupt.type      = FW_CDEV_EVENT_ISO_INTERRUPT;
 394         interrupt->interrupt.closure   = 0;
 395         interrupt->interrupt.cycle     = cycle;
 396         queue_event(client, &interrupt->event,
 397                     &interrupt->interrupt, sizeof interrupt->interrupt, NULL, 0);
 398 }
 399
 400 static int ioctl_create_iso_context(struct client *client, void __user *arg)
 401 {
 402         struct fw_cdev_create_iso_context request;
 403
 404         if (copy_from_user(&request, arg, sizeof request))
 405                 return -EFAULT;
 406
 407         client->iso_context = fw_iso_context_create(client->device->card,
 408                                                     FW_ISO_CONTEXT_TRANSMIT,
 409                                                     request.buffer_size,
 410                                                     iso_callback, client);
 411         if (IS_ERR(client->iso_context))
 412                 return PTR_ERR(client->iso_context);
 413
 414         return 0;
 415 }
 416
 417 static int ioctl_queue_iso(struct client *client, void __user *arg)
 418 {
 419         struct fw_cdev_queue_iso request;
 420         struct fw_cdev_iso_packet __user *p, *end, *next;
 421         void *payload, *payload_end;
 422         unsigned long index;
 423         int count;
 424         struct {
 425                 struct fw_iso_packet packet;
 426                 u8 header[256];
 427         } u;
 428
 429         if (client->iso_context == NULL)
 430                 return -EINVAL;
 431         if (copy_from_user(&request, arg, sizeof request))
 432                 return -EFAULT;
 433
 434         /* If the user passes a non-NULL data pointer, has mmap()'ed
 435          * the iso buffer, and the pointer points inside the buffer,
 436          * we setup the payload pointers accordingly.  Otherwise we
 437          * set them both to NULL, which will still let packets with
 438          * payload_length == 0 through.  In other words, if no packets
 439          * use the indirect payload, the iso buffer need not be mapped
 440          * and the request.data pointer is ignored.*/
 441
 442         index = (unsigned long)request.data - client->vm_start;
 443         if (request.data != 0 && client->vm_start != 0 &&
 444             index <= client->iso_context->buffer_size) {
 445                 payload = client->iso_context->buffer + index;
 446                 payload_end = client->iso_context->buffer +
 447                         client->iso_context->buffer_size;
 448         } else {
 449                 payload = NULL;
 450                 payload_end = NULL;
 451         }
 452
 453         if (!access_ok(VERIFY_READ, request.packets, request.size))
 454                 return -EFAULT;
 455
 456         p = (struct fw_cdev_iso_packet __user *)u64_to_uptr(request.packets);
 457         end = (void __user *)p + request.size;
 458         count = 0;
 459         while (p < end) {
 460                 if (__copy_from_user(&u.packet, p, sizeof *p))
 461                         return -EFAULT;
 462                 next = (struct fw_cdev_iso_packet __user *)
 463                         &p->header[u.packet.header_length / 4];
 464                 if (next > end)
 465                         return -EINVAL;
 466                 if (__copy_from_user
 467                     (u.packet.header, p->header, u.packet.header_length))
 468                         return -EFAULT;
 469                 if (u.packet.skip &&
 470                     u.packet.header_length + u.packet.payload_length > 0)
 471                         return -EINVAL;
 472                 if (payload + u.packet.payload_length > payload_end)
 473                         return -EINVAL;
 474
 475                 if (fw_iso_context_queue(client->iso_context,
 476                                          &u.packet, payload))
 477                         break;
 478
 479                 p = next;
 480                 payload += u.packet.payload_length;
 481                 count++;
 482         }
 483
 484         request.size    -= uptr_to_u64(p) - request.packets;
 485         request.packets  = uptr_to_u64(p);
 486         request.data     =
 487                 client->vm_start + (payload - client->iso_context->buffer);
 488
 489         if (copy_to_user(arg, &request, sizeof request))
 490                 return -EFAULT;
 491
 492         return count;
 493 }
 494
 495 static int ioctl_send_iso(struct client *client, void __user *arg)
 496 {
 497         struct fw_cdev_send_iso request;
 498
 499         if (copy_from_user(&request, arg, sizeof request))
 500                 return -EFAULT;
 501
 502         return fw_iso_context_send(client->iso_context, request.channel,
 503                                    request.speed, request.cycle);
 504 }
 505
 506 static int
 507 dispatch_ioctl(struct client *client, unsigned int cmd, void __user *arg)
 508 {
 509         switch (cmd) {
 510         case FW_CDEV_IOC_GET_CONFIG_ROM:
 511                 return ioctl_config_rom(client, arg);
 512         case FW_CDEV_IOC_SEND_REQUEST:
 513                 return ioctl_send_request(client, arg);
 514         case FW_CDEV_IOC_ALLOCATE:
 515                 return ioctl_allocate(client, arg);
 516         case FW_CDEV_IOC_SEND_RESPONSE:
 517                 return ioctl_send_response(client, arg);
 518         case FW_CDEV_IOC_CREATE_ISO_CONTEXT:
 519                 return ioctl_create_iso_context(client, arg);
 520         case FW_CDEV_IOC_QUEUE_ISO:
 521                 return ioctl_queue_iso(client, arg);
 522         case FW_CDEV_IOC_SEND_ISO:
 523                 return ioctl_send_iso(client, arg);
 524         default:
 525                 return -EINVAL;
 526         }
 527 }
 528
 529 static long
 530 fw_device_op_ioctl(struct file *file,
 531                    unsigned int cmd, unsigned long arg)
 532 {
 533         struct client *client = file->private_data;
 534
 535         return dispatch_ioctl(client, cmd, (void __user *) arg);
 536 }
 537
 538 #ifdef CONFIG_COMPAT
 539 static long
 540 fw_device_op_compat_ioctl(struct file *file,
 541                           unsigned int cmd, unsigned long arg)
 542 {
 543         struct client *client = file->private_data;
 544
 545         return dispatch_ioctl(client, cmd, compat_ptr(arg));
 546 }
 547 #endif
 548
 549 static int fw_device_op_mmap(struct file *file, struct vm_area_struct *vma)
 550 {
 551         struct client *client = file->private_data;
 552
 553         if (client->iso_context->buffer == NULL)
 554                 return -EINVAL;
 555
 556         client->vm_start = vma->vm_start;
 557
 558         return remap_vmalloc_range(vma, client->iso_context->buffer, 0);
 559 }
 560
 561 static int fw_device_op_release(struct inode *inode, struct file *file)
 562 {
 563         struct client *client = file->private_data;
 564         struct address_handler *h, *next;
 565         struct request *r, *next_r;
 566
 567         if (client->iso_context)
 568                 fw_iso_context_destroy(client->iso_context);
 569
 570         list_for_each_entry_safe(h, next, &client->handler_list, link) {
 571                 fw_core_remove_address_handler(&h->handler);
 572                 kfree(h);
 573         }
 574
 575         list_for_each_entry_safe(r, next_r, &client->request_list, link) {
 576                 fw_send_response(client->device->card, r->request,
 577                                  RCODE_CONFLICT_ERROR);
 578                 kfree(r);
 579         }
 580
 581         /* TODO: wait for all transactions to finish so
 582          * complete_transaction doesn't try to queue up responses
 583          * after we free client. */
 584         while (!list_empty(&client->event_list))
 585                 dequeue_event(client, NULL, 0);
 586
 587         fw_device_put(client->device);
 588         kfree(client);
 589
 590         return 0;
 591 }
 592
 593 static unsigned int fw_device_op_poll(struct file *file, poll_table * pt)
 594 {
 595         struct client *client = file->private_data;
 596
 597         poll_wait(file, &client->wait, pt);
 598
 599         if (!list_empty(&client->event_list))
 600                 return POLLIN | POLLRDNORM;
 601         else
 602                 return 0;
 603 }
 604
 605 const struct file_operations fw_device_ops = {
 606         .owner          = THIS_MODULE,
 607         .open           = fw_device_op_open,
 608         .read           = fw_device_op_read,
 609         .unlocked_ioctl = fw_device_op_ioctl,
 610         .poll           = fw_device_op_poll,
 611         .release        = fw_device_op_release,
 612         .mmap           = fw_device_op_mmap,
 613
 614 #ifdef CONFIG_COMPAT
 615         .compat_ioctl   = fw_device_op_compat_ioctl
 616 #endif
 617 };