release/src-rt-6.x/linux/linux-2.6/drivers/char/agp/frontend.c

   1 /*
   2  * AGPGART driver frontend
   3  * Copyright (C) 2004 Silicon Graphics, Inc.
   4  * Copyright (C) 2002-2003 Dave Jones
   5  * Copyright (C) 1999 Jeff Hartmann
   6  * Copyright (C) 1999 Precision Insight, Inc.
   7  * Copyright (C) 1999 Xi Graphics, Inc.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * JEFF HARTMANN, OR ANY OTHER CONTRIBUTORS BE LIABLE FOR ANY CLAIM,
  23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
  25  * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  */
  28
  29 #include <linux/types.h>
  30 #include <linux/kernel.h>
  31 #include <linux/module.h>
  32 #include <linux/mman.h>
  33 #include <linux/pci.h>
  34 #include <linux/init.h>
  35 #include <linux/miscdevice.h>
  36 #include <linux/agp_backend.h>
  37 #include <linux/agpgart.h>
  38 #include <linux/slab.h>
  39 #include <linux/mm.h>
  40 #include <linux/sched.h>
  41 #include <asm/uaccess.h>
  42 #include <asm/pgtable.h>
  43 #include "agp.h"
  44
  45 struct agp_front_data agp_fe;
  46
  47 struct agp_memory *agp_find_mem_by_key(int key)
  48 {
  49         struct agp_memory *curr;
  50
  51         if (agp_fe.current_controller == NULL)
  52                 return NULL;
  53
  54         curr = agp_fe.current_controller->pool;
  55
  56         while (curr != NULL) {
  57                 if (curr->key == key)
  58                         break;
  59                 curr = curr->next;
  60         }
  61
  62         DBG("key=%d -> mem=%p", key, curr);
  63         return curr;
  64 }
  65
  66 static void agp_remove_from_pool(struct agp_memory *temp)
  67 {
  68         struct agp_memory *prev;
  69         struct agp_memory *next;
  70
  71         /* Check to see if this is even in the memory pool */
  72
  73         DBG("mem=%p", temp);
  74         if (agp_find_mem_by_key(temp->key) != NULL) {
  75                 next = temp->next;
  76                 prev = temp->prev;
  77
  78                 if (prev != NULL) {
  79                         prev->next = next;
  80                         if (next != NULL)
  81                                 next->prev = prev;
  82
  83                 } else {
  84                         /* This is the first item on the list */
  85                         if (next != NULL)
  86                                 next->prev = NULL;
  87
  88                         agp_fe.current_controller->pool = next;
  89                 }
  90         }
  91 }
  92
  93 /*
  94  * Routines for managing each client's segment list -
  95  * These routines handle adding and removing segments
  96  * to each auth'ed client.
  97  */
  98
  99 static struct
 100 agp_segment_priv *agp_find_seg_in_client(const struct agp_client *client,
 101                                                 unsigned long offset,
 102                                             int size, pgprot_t page_prot)
 103 {
 104         struct agp_segment_priv *seg;
 105         int num_segments, i;
 106         off_t pg_start;
 107         size_t pg_count;
 108
 109         pg_start = offset / 4096;
 110         pg_count = size / 4096;
 111         seg = *(client->segments);
 112         num_segments = client->num_segments;
 113
 114         for (i = 0; i < client->num_segments; i++) {
 115                 if ((seg[i].pg_start == pg_start) &&
 116                     (seg[i].pg_count == pg_count) &&
 117                     (pgprot_val(seg[i].prot) == pgprot_val(page_prot))) {
 118                         return seg + i;
 119                 }
 120         }
 121
 122         return NULL;
 123 }
 124
 125 static void agp_remove_seg_from_client(struct agp_client *client)
 126 {
 127         DBG("client=%p", client);
 128
 129         if (client->segments != NULL) {
 130                 if (*(client->segments) != NULL) {
 131                         DBG("Freeing %p from client %p", *(client->segments), client);
 132                         kfree(*(client->segments));
 133                 }
 134                 DBG("Freeing %p from client %p", client->segments, client);
 135                 kfree(client->segments);
 136                 client->segments = NULL;
 137         }
 138 }
 139
 140 static void agp_add_seg_to_client(struct agp_client *client,
 141                                struct agp_segment_priv ** seg, int num_segments)
 142 {
 143         struct agp_segment_priv **prev_seg;
 144
 145         prev_seg = client->segments;
 146
 147         if (prev_seg != NULL)
 148                 agp_remove_seg_from_client(client);
 149
 150         DBG("Adding seg %p (%d segments) to client %p", seg, num_segments, client);
 151         client->num_segments = num_segments;
 152         client->segments = seg;
 153 }
 154
 155 static pgprot_t agp_convert_mmap_flags(int prot)
 156 {
 157         unsigned long prot_bits;
 158
 159         prot_bits = calc_vm_prot_bits(prot) | VM_SHARED;
 160         return vm_get_page_prot(prot_bits);
 161 }
 162
 163 int agp_create_segment(struct agp_client *client, struct agp_region *region)
 164 {
 165         struct agp_segment_priv **ret_seg;
 166         struct agp_segment_priv *seg;
 167         struct agp_segment *user_seg;
 168         size_t i;
 169
 170         seg = kzalloc((sizeof(struct agp_segment_priv) * region->seg_count), GFP_KERNEL);
 171         if (seg == NULL) {
 172                 kfree(region->seg_list);
 173                 region->seg_list = NULL;
 174                 return -ENOMEM;
 175         }
 176         user_seg = region->seg_list;
 177
 178         for (i = 0; i < region->seg_count; i++) {
 179                 seg[i].pg_start = user_seg[i].pg_start;
 180                 seg[i].pg_count = user_seg[i].pg_count;
 181                 seg[i].prot = agp_convert_mmap_flags(user_seg[i].prot);
 182         }
 183         kfree(region->seg_list);
 184         region->seg_list = NULL;
 185
 186         ret_seg = kmalloc(sizeof(void *), GFP_KERNEL);
 187         if (ret_seg == NULL) {
 188                 kfree(seg);
 189                 return -ENOMEM;
 190         }
 191         *ret_seg = seg;
 192         agp_add_seg_to_client(client, ret_seg, region->seg_count);
 193         return 0;
 194 }
 195
 196 /* End - Routines for managing each client's segment list */
 197
 198 /* This function must only be called when current_controller != NULL */
 199 static void agp_insert_into_pool(struct agp_memory * temp)
 200 {
 201         struct agp_memory *prev;
 202
 203         prev = agp_fe.current_controller->pool;
 204
 205         if (prev != NULL) {
 206                 prev->prev = temp;
 207                 temp->next = prev;
 208         }
 209         agp_fe.current_controller->pool = temp;
 210 }
 211
 212
 213 /* File private list routines */
 214
 215 struct agp_file_private *agp_find_private(pid_t pid)
 216 {
 217         struct agp_file_private *curr;
 218
 219         curr = agp_fe.file_priv_list;
 220
 221         while (curr != NULL) {
 222                 if (curr->my_pid == pid)
 223                         return curr;
 224                 curr = curr->next;
 225         }
 226
 227         return NULL;
 228 }
 229
 230 static void agp_insert_file_private(struct agp_file_private * priv)
 231 {
 232         struct agp_file_private *prev;
 233
 234         prev = agp_fe.file_priv_list;
 235
 236         if (prev != NULL)
 237                 prev->prev = priv;
 238         priv->next = prev;
 239         agp_fe.file_priv_list = priv;
 240 }
 241
 242 static void agp_remove_file_private(struct agp_file_private * priv)
 243 {
 244         struct agp_file_private *next;
 245         struct agp_file_private *prev;
 246
 247         next = priv->next;
 248         prev = priv->prev;
 249
 250         if (prev != NULL) {
 251                 prev->next = next;
 252
 253                 if (next != NULL)
 254                         next->prev = prev;
 255
 256         } else {
 257                 if (next != NULL)
 258                         next->prev = NULL;
 259
 260                 agp_fe.file_priv_list = next;
 261         }
 262 }
 263
 264 /* End - File flag list routines */
 265
 266 /*
 267  * Wrappers for agp_free_memory & agp_allocate_memory
 268  * These make sure that internal lists are kept updated.
 269  */
 270 void agp_free_memory_wrap(struct agp_memory *memory)
 271 {
 272         agp_remove_from_pool(memory);
 273         agp_free_memory(memory);
 274 }
 275
 276 struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
 277 {
 278         struct agp_memory *memory;
 279
 280         memory = agp_allocate_memory(agp_bridge, pg_count, type);
 281         if (memory == NULL)
 282                 return NULL;
 283
 284         agp_insert_into_pool(memory);
 285         return memory;
 286 }
 287
 288 /* Routines for managing the list of controllers -
 289  * These routines manage the current controller, and the list of
 290  * controllers
 291  */
 292
 293 static struct agp_controller *agp_find_controller_by_pid(pid_t id)
 294 {
 295         struct agp_controller *controller;
 296
 297         controller = agp_fe.controllers;
 298
 299         while (controller != NULL) {
 300                 if (controller->pid == id)
 301                         return controller;
 302                 controller = controller->next;
 303         }
 304
 305         return NULL;
 306 }
 307
 308 static struct agp_controller *agp_create_controller(pid_t id)
 309 {
 310         struct agp_controller *controller;
 311
 312         controller = kzalloc(sizeof(struct agp_controller), GFP_KERNEL);
 313         if (controller == NULL)
 314                 return NULL;
 315
 316         controller->pid = id;
 317         return controller;
 318 }
 319
 320 static int agp_insert_controller(struct agp_controller *controller)
 321 {
 322         struct agp_controller *prev_controller;
 323
 324         prev_controller = agp_fe.controllers;
 325         controller->next = prev_controller;
 326
 327         if (prev_controller != NULL)
 328                 prev_controller->prev = controller;
 329
 330         agp_fe.controllers = controller;
 331
 332         return 0;
 333 }
 334
 335 static void agp_remove_all_clients(struct agp_controller *controller)
 336 {
 337         struct agp_client *client;
 338         struct agp_client *temp;
 339
 340         client = controller->clients;
 341
 342         while (client) {
 343                 struct agp_file_private *priv;
 344
 345                 temp = client;
 346                 agp_remove_seg_from_client(temp);
 347                 priv = agp_find_private(temp->pid);
 348
 349                 if (priv != NULL) {
 350                         clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
 351                         clear_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 352                 }
 353                 client = client->next;
 354                 kfree(temp);
 355         }
 356 }
 357
 358 static void agp_remove_all_memory(struct agp_controller *controller)
 359 {
 360         struct agp_memory *memory;
 361         struct agp_memory *temp;
 362
 363         memory = controller->pool;
 364
 365         while (memory) {
 366                 temp = memory;
 367                 memory = memory->next;
 368                 agp_free_memory_wrap(temp);
 369         }
 370 }
 371
 372 static int agp_remove_controller(struct agp_controller *controller)
 373 {
 374         struct agp_controller *prev_controller;
 375         struct agp_controller *next_controller;
 376
 377         prev_controller = controller->prev;
 378         next_controller = controller->next;
 379
 380         if (prev_controller != NULL) {
 381                 prev_controller->next = next_controller;
 382                 if (next_controller != NULL)
 383                         next_controller->prev = prev_controller;
 384
 385         } else {
 386                 if (next_controller != NULL)
 387                         next_controller->prev = NULL;
 388
 389                 agp_fe.controllers = next_controller;
 390         }
 391
 392         agp_remove_all_memory(controller);
 393         agp_remove_all_clients(controller);
 394
 395         if (agp_fe.current_controller == controller) {
 396                 agp_fe.current_controller = NULL;
 397                 agp_fe.backend_acquired = FALSE;
 398                 agp_backend_release(agp_bridge);
 399         }
 400         kfree(controller);
 401         return 0;
 402 }
 403
 404 static void agp_controller_make_current(struct agp_controller *controller)
 405 {
 406         struct agp_client *clients;
 407
 408         clients = controller->clients;
 409
 410         while (clients != NULL) {
 411                 struct agp_file_private *priv;
 412
 413                 priv = agp_find_private(clients->pid);
 414
 415                 if (priv != NULL) {
 416                         set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 417                         set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 418                 }
 419                 clients = clients->next;
 420         }
 421
 422         agp_fe.current_controller = controller;
 423 }
 424
 425 static void agp_controller_release_current(struct agp_controller *controller,
 426                                       struct agp_file_private *controller_priv)
 427 {
 428         struct agp_client *clients;
 429
 430         clear_bit(AGP_FF_IS_VALID, &controller_priv->access_flags);
 431         clients = controller->clients;
 432
 433         while (clients != NULL) {
 434                 struct agp_file_private *priv;
 435
 436                 priv = agp_find_private(clients->pid);
 437
 438                 if (priv != NULL)
 439                         clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
 440
 441                 clients = clients->next;
 442         }
 443
 444         agp_fe.current_controller = NULL;
 445         agp_fe.used_by_controller = FALSE;
 446         agp_backend_release(agp_bridge);
 447 }
 448
 449 /*
 450  * Routines for managing client lists -
 451  * These routines are for managing the list of auth'ed clients.
 452  */
 453
 454 static struct agp_client
 455 *agp_find_client_in_controller(struct agp_controller *controller, pid_t id)
 456 {
 457         struct agp_client *client;
 458
 459         if (controller == NULL)
 460                 return NULL;
 461
 462         client = controller->clients;
 463
 464         while (client != NULL) {
 465                 if (client->pid == id)
 466                         return client;
 467                 client = client->next;
 468         }
 469
 470         return NULL;
 471 }
 472
 473 static struct agp_controller *agp_find_controller_for_client(pid_t id)
 474 {
 475         struct agp_controller *controller;
 476
 477         controller = agp_fe.controllers;
 478
 479         while (controller != NULL) {
 480                 if ((agp_find_client_in_controller(controller, id)) != NULL)
 481                         return controller;
 482                 controller = controller->next;
 483         }
 484
 485         return NULL;
 486 }
 487
 488 struct agp_client *agp_find_client_by_pid(pid_t id)
 489 {
 490         struct agp_client *temp;
 491
 492         if (agp_fe.current_controller == NULL)
 493                 return NULL;
 494
 495         temp = agp_find_client_in_controller(agp_fe.current_controller, id);
 496         return temp;
 497 }
 498
 499 static void agp_insert_client(struct agp_client *client)
 500 {
 501         struct agp_client *prev_client;
 502
 503         prev_client = agp_fe.current_controller->clients;
 504         client->next = prev_client;
 505
 506         if (prev_client != NULL)
 507                 prev_client->prev = client;
 508
 509         agp_fe.current_controller->clients = client;
 510         agp_fe.current_controller->num_clients++;
 511 }
 512
 513 struct agp_client *agp_create_client(pid_t id)
 514 {
 515         struct agp_client *new_client;
 516
 517         new_client = kzalloc(sizeof(struct agp_client), GFP_KERNEL);
 518         if (new_client == NULL)
 519                 return NULL;
 520
 521         new_client->pid = id;
 522         agp_insert_client(new_client);
 523         return new_client;
 524 }
 525
 526 int agp_remove_client(pid_t id)
 527 {
 528         struct agp_client *client;
 529         struct agp_client *prev_client;
 530         struct agp_client *next_client;
 531         struct agp_controller *controller;
 532
 533         controller = agp_find_controller_for_client(id);
 534         if (controller == NULL)
 535                 return -EINVAL;
 536
 537         client = agp_find_client_in_controller(controller, id);
 538         if (client == NULL)
 539                 return -EINVAL;
 540
 541         prev_client = client->prev;
 542         next_client = client->next;
 543
 544         if (prev_client != NULL) {
 545                 prev_client->next = next_client;
 546                 if (next_client != NULL)
 547                         next_client->prev = prev_client;
 548
 549         } else {
 550                 if (next_client != NULL)
 551                         next_client->prev = NULL;
 552                 controller->clients = next_client;
 553         }
 554
 555         controller->num_clients--;
 556         agp_remove_seg_from_client(client);
 557         kfree(client);
 558         return 0;
 559 }
 560
 561 /* End - Routines for managing client lists */
 562
 563 /* File Operations */
 564
 565 static int agp_mmap(struct file *file, struct vm_area_struct *vma)
 566 {
 567         unsigned int size, current_size;
 568         unsigned long offset;
 569         struct agp_client *client;
 570         struct agp_file_private *priv = file->private_data;
 571         struct agp_kern_info kerninfo;
 572
 573         mutex_lock(&(agp_fe.agp_mutex));
 574
 575         if (agp_fe.backend_acquired != TRUE)
 576                 goto out_eperm;
 577
 578         if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
 579                 goto out_eperm;
 580
 581         agp_copy_info(agp_bridge, &kerninfo);
 582         size = vma->vm_end - vma->vm_start;
 583         current_size = kerninfo.aper_size;
 584         current_size = current_size * 0x100000;
 585         offset = vma->vm_pgoff << PAGE_SHIFT;
 586         DBG("%lx:%lx", offset, offset+size);
 587
 588         if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
 589                 if ((size + offset) > current_size)
 590                         goto out_inval;
 591
 592                 client = agp_find_client_by_pid(current->pid);
 593
 594                 if (client == NULL)
 595                         goto out_eperm;
 596
 597                 if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
 598                         goto out_inval;
 599
 600                 DBG("client vm_ops=%p", kerninfo.vm_ops);
 601                 if (kerninfo.vm_ops) {
 602                         vma->vm_ops = kerninfo.vm_ops;
 603                 } else if (io_remap_pfn_range(vma, vma->vm_start,
 604                                 (kerninfo.aper_base + offset) >> PAGE_SHIFT,
 605                                             size, vma->vm_page_prot)) {
 606                         goto out_again;
 607                 }
 608                 mutex_unlock(&(agp_fe.agp_mutex));
 609                 return 0;
 610         }
 611
 612         if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
 613                 if (size != current_size)
 614                         goto out_inval;
 615
 616                 DBG("controller vm_ops=%p", kerninfo.vm_ops);
 617                 if (kerninfo.vm_ops) {
 618                         vma->vm_ops = kerninfo.vm_ops;
 619                 } else if (io_remap_pfn_range(vma, vma->vm_start,
 620                                             kerninfo.aper_base >> PAGE_SHIFT,
 621                                             size, vma->vm_page_prot)) {
 622                         goto out_again;
 623                 }
 624                 mutex_unlock(&(agp_fe.agp_mutex));
 625                 return 0;
 626         }
 627
 628 out_eperm:
 629         mutex_unlock(&(agp_fe.agp_mutex));
 630         return -EPERM;
 631
 632 out_inval:
 633         mutex_unlock(&(agp_fe.agp_mutex));
 634         return -EINVAL;
 635
 636 out_again:
 637         mutex_unlock(&(agp_fe.agp_mutex));
 638         return -EAGAIN;
 639 }
 640
 641 static int agp_release(struct inode *inode, struct file *file)
 642 {
 643         struct agp_file_private *priv = file->private_data;
 644
 645         mutex_lock(&(agp_fe.agp_mutex));
 646
 647         DBG("priv=%p", priv);
 648
 649         if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
 650                 struct agp_controller *controller;
 651
 652                 controller = agp_find_controller_by_pid(priv->my_pid);
 653
 654                 if (controller != NULL) {
 655                         if (controller == agp_fe.current_controller)
 656                                 agp_controller_release_current(controller, priv);
 657                         agp_remove_controller(controller);
 658                         controller = NULL;
 659                 }
 660         }
 661
 662         if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
 663                 agp_remove_client(priv->my_pid);
 664
 665         agp_remove_file_private(priv);
 666         kfree(priv);
 667         file->private_data = NULL;
 668         mutex_unlock(&(agp_fe.agp_mutex));
 669         return 0;
 670 }
 671
 672 static int agp_open(struct inode *inode, struct file *file)
 673 {
 674         int minor = iminor(inode);
 675         struct agp_file_private *priv;
 676         struct agp_client *client;
 677         int rc = -ENXIO;
 678
 679         mutex_lock(&(agp_fe.agp_mutex));
 680
 681         if (minor != AGPGART_MINOR)
 682                 goto err_out;
 683
 684         priv = kzalloc(sizeof(struct agp_file_private), GFP_KERNEL);
 685         if (priv == NULL)
 686                 goto err_out_nomem;
 687
 688         set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
 689         priv->my_pid = current->pid;
 690
 691         if ((current->uid == 0) || (current->suid == 0)) {
 692                 /* Root priv, can be controller */
 693                 set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
 694         }
 695         client = agp_find_client_by_pid(current->pid);
 696
 697         if (client != NULL) {
 698                 set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 699                 set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 700         }
 701         file->private_data = (void *) priv;
 702         agp_insert_file_private(priv);
 703         DBG("private=%p, client=%p", priv, client);
 704         mutex_unlock(&(agp_fe.agp_mutex));
 705         return 0;
 706
 707 err_out_nomem:
 708         rc = -ENOMEM;
 709 err_out:
 710         mutex_unlock(&(agp_fe.agp_mutex));
 711         return rc;
 712 }
 713
 714
 715 static ssize_t agp_read(struct file *file, char __user *buf,
 716                         size_t count, loff_t * ppos)
 717 {
 718         return -EINVAL;
 719 }
 720
 721 static ssize_t agp_write(struct file *file, const char __user *buf,
 722                          size_t count, loff_t * ppos)
 723 {
 724         return -EINVAL;
 725 }
 726
 727 static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
 728 {
 729         struct agp_info userinfo;
 730         struct agp_kern_info kerninfo;
 731
 732         agp_copy_info(agp_bridge, &kerninfo);
 733
 734         userinfo.version.major = kerninfo.version.major;
 735         userinfo.version.minor = kerninfo.version.minor;
 736         userinfo.bridge_id = kerninfo.device->vendor |
 737             (kerninfo.device->device << 16);
 738         userinfo.agp_mode = kerninfo.mode;
 739         userinfo.aper_base = kerninfo.aper_base;
 740         userinfo.aper_size = kerninfo.aper_size;
 741         userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
 742         userinfo.pg_used = kerninfo.current_memory;
 743
 744         if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
 745                 return -EFAULT;
 746
 747         return 0;
 748 }
 749
 750 int agpioc_acquire_wrap(struct agp_file_private *priv)
 751 {
 752         struct agp_controller *controller;
 753
 754         DBG("");
 755
 756         if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
 757                 return -EPERM;
 758
 759         if (agp_fe.current_controller != NULL)
 760                 return -EBUSY;
 761
 762         if (!agp_bridge)
 763                 return -ENODEV;
 764
 765         if (atomic_read(&agp_bridge->agp_in_use))
 766                 return -EBUSY;
 767
 768         atomic_inc(&agp_bridge->agp_in_use);
 769
 770         agp_fe.backend_acquired = TRUE;
 771
 772         controller = agp_find_controller_by_pid(priv->my_pid);
 773
 774         if (controller != NULL) {
 775                 agp_controller_make_current(controller);
 776         } else {
 777                 controller = agp_create_controller(priv->my_pid);
 778
 779                 if (controller == NULL) {
 780                         agp_fe.backend_acquired = FALSE;
 781                         agp_backend_release(agp_bridge);
 782                         return -ENOMEM;
 783                 }
 784                 agp_insert_controller(controller);
 785                 agp_controller_make_current(controller);
 786         }
 787
 788         set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
 789         set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 790         return 0;
 791 }
 792
 793 int agpioc_release_wrap(struct agp_file_private *priv)
 794 {
 795         DBG("");
 796         agp_controller_release_current(agp_fe.current_controller, priv);
 797         return 0;
 798 }
 799
 800 int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
 801 {
 802         struct agp_setup mode;
 803
 804         DBG("");
 805         if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
 806                 return -EFAULT;
 807
 808         agp_enable(agp_bridge, mode.agp_mode);
 809         return 0;
 810 }
 811
 812 static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
 813 {
 814         struct agp_region reserve;
 815         struct agp_client *client;
 816         struct agp_file_private *client_priv;
 817
 818         DBG("");
 819         if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
 820                 return -EFAULT;
 821
 822         if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
 823                 return -EFAULT;
 824
 825         client = agp_find_client_by_pid(reserve.pid);
 826
 827         if (reserve.seg_count == 0) {
 828                 /* remove a client */
 829                 client_priv = agp_find_private(reserve.pid);
 830
 831                 if (client_priv != NULL) {
 832                         set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
 833                         set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
 834                 }
 835                 if (client == NULL) {
 836                         /* client is already removed */
 837                         return 0;
 838                 }
 839                 return agp_remove_client(reserve.pid);
 840         } else {
 841                 struct agp_segment *segment;
 842
 843                 if (reserve.seg_count >= 16384)
 844                         return -EINVAL;
 845
 846                 segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
 847                                   GFP_KERNEL);
 848
 849                 if (segment == NULL)
 850                         return -ENOMEM;
 851
 852                 if (copy_from_user(segment, (void __user *) reserve.seg_list,
 853                                    sizeof(struct agp_segment) * reserve.seg_count)) {
 854                         kfree(segment);
 855                         return -EFAULT;
 856                 }
 857                 reserve.seg_list = segment;
 858
 859                 if (client == NULL) {
 860                         /* Create the client and add the segment */
 861                         client = agp_create_client(reserve.pid);
 862
 863                         if (client == NULL) {
 864                                 kfree(segment);
 865                                 return -ENOMEM;
 866                         }
 867                         client_priv = agp_find_private(reserve.pid);
 868
 869                         if (client_priv != NULL) {
 870                                 set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
 871                                 set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
 872                         }
 873                 }
 874                 return agp_create_segment(client, &reserve);
 875         }
 876         /* Will never really happen */
 877         return -EINVAL;
 878 }
 879
 880 int agpioc_protect_wrap(struct agp_file_private *priv)
 881 {
 882         DBG("");
 883         /* This function is not currently implemented */
 884         return -EINVAL;
 885 }
 886
 887 static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
 888 {
 889         struct agp_memory *memory;
 890         struct agp_allocate alloc;
 891
 892         DBG("");
 893         if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
 894                 return -EFAULT;
 895
 896         if (alloc.type >= AGP_USER_TYPES)
 897                 return -EINVAL;
 898
 899         memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);
 900
 901         if (memory == NULL)
 902                 return -ENOMEM;
 903
 904         alloc.key = memory->key;
 905         alloc.physical = memory->physical;
 906
 907         if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
 908                 agp_free_memory_wrap(memory);
 909                 return -EFAULT;
 910         }
 911         return 0;
 912 }
 913
 914 int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
 915 {
 916         struct agp_memory *memory;
 917
 918         DBG("");
 919         memory = agp_find_mem_by_key(arg);
 920
 921         if (memory == NULL)
 922                 return -EINVAL;
 923
 924         agp_free_memory_wrap(memory);
 925         return 0;
 926 }
 927
 928 static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
 929 {
 930         struct agp_bind bind_info;
 931         struct agp_memory *memory;
 932
 933         DBG("");
 934         if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
 935                 return -EFAULT;
 936
 937         memory = agp_find_mem_by_key(bind_info.key);
 938
 939         if (memory == NULL)
 940                 return -EINVAL;
 941
 942         return agp_bind_memory(memory, bind_info.pg_start);
 943 }
 944
 945 static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
 946 {
 947         struct agp_memory *memory;
 948         struct agp_unbind unbind;
 949
 950         DBG("");
 951         if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
 952                 return -EFAULT;
 953
 954         memory = agp_find_mem_by_key(unbind.key);
 955
 956         if (memory == NULL)
 957                 return -EINVAL;
 958
 959         return agp_unbind_memory(memory);
 960 }
 961
 962 static int agp_ioctl(struct inode *inode, struct file *file,
 963                      unsigned int cmd, unsigned long arg)
 964 {
 965         struct agp_file_private *curr_priv = file->private_data;
 966         int ret_val = -ENOTTY;
 967
 968         DBG("priv=%p, cmd=%x", curr_priv, cmd);
 969         mutex_lock(&(agp_fe.agp_mutex));
 970
 971         if ((agp_fe.current_controller == NULL) &&
 972             (cmd != AGPIOC_ACQUIRE)) {
 973                 ret_val = -EINVAL;
 974                 goto ioctl_out;
 975         }
 976         if ((agp_fe.backend_acquired != TRUE) &&
 977             (cmd != AGPIOC_ACQUIRE)) {
 978                 ret_val = -EBUSY;
 979                 goto ioctl_out;
 980         }
 981         if (cmd != AGPIOC_ACQUIRE) {
 982                 if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
 983                         ret_val = -EPERM;
 984                         goto ioctl_out;
 985                 }
 986                 /* Use the original pid of the controller,
 987                  * in case it's threaded */
 988
 989                 if (agp_fe.current_controller->pid != curr_priv->my_pid) {
 990                         ret_val = -EBUSY;
 991                         goto ioctl_out;
 992                 }
 993         }
 994
 995         switch (cmd) {
 996         case AGPIOC_INFO:
 997                 ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
 998                 break;
 999
1000         case AGPIOC_ACQUIRE:
1001                 ret_val = agpioc_acquire_wrap(curr_priv);
1002                 break;
1003
1004         case AGPIOC_RELEASE:
1005                 ret_val = agpioc_release_wrap(curr_priv);
1006                 break;
1007
1008         case AGPIOC_SETUP:
1009                 ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
1010                 break;
1011
1012         case AGPIOC_RESERVE:
1013                 ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
1014                 break;
1015
1016         case AGPIOC_PROTECT:
1017                 ret_val = agpioc_protect_wrap(curr_priv);
1018                 break;
1019
1020         case AGPIOC_ALLOCATE:
1021                 ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
1022                 break;
1023
1024         case AGPIOC_DEALLOCATE:
1025                 ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
1026                 break;
1027
1028         case AGPIOC_BIND:
1029                 ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
1030                 break;
1031
1032         case AGPIOC_UNBIND:
1033                 ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
1034                 break;
1035         }
1036
1037 ioctl_out:
1038         DBG("ioctl returns %d\n", ret_val);
1039         mutex_unlock(&(agp_fe.agp_mutex));
1040         return ret_val;
1041 }
1042
1043 static const struct file_operations agp_fops =
1044 {
1045         .owner          = THIS_MODULE,
1046         .llseek         = no_llseek,
1047         .read           = agp_read,
1048         .write          = agp_write,
1049         .ioctl          = agp_ioctl,
1050 #ifdef CONFIG_COMPAT
1051         .compat_ioctl   = compat_agp_ioctl,
1052 #endif
1053         .mmap           = agp_mmap,
1054         .open           = agp_open,
1055         .release        = agp_release,
1056 };
1057
1058 static struct miscdevice agp_miscdev =
1059 {
1060         .minor  = AGPGART_MINOR,
1061         .name   = "agpgart",
1062         .fops   = &agp_fops
1063 };
1064
1065 int agp_frontend_initialize(void)
1066 {
1067         memset(&agp_fe, 0, sizeof(struct agp_front_data));
1068         mutex_init(&(agp_fe.agp_mutex));
1069
1070         if (misc_register(&agp_miscdev)) {
1071                 printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
1072                 return -EIO;
1073         }
1074         return 0;
1075 }
1076
1077 void agp_frontend_cleanup(void)
1078 {
1079         misc_deregister(&agp_miscdev);
1080 }