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/fs.h>
  41 #include <linux/sched.h>
  42 #include <linux/smp_lock.h>
  43 #include <asm/uaccess.h>
  44 #include <asm/pgtable.h>
  45 #include "agp.h"
  46
  47 struct agp_front_data agp_fe;
  48
  49 struct agp_memory *agp_find_mem_by_key(int key)
  50 {
  51         struct agp_memory *curr;
  52
  53         if (agp_fe.current_controller == NULL)
  54                 return NULL;
  55
  56         curr = agp_fe.current_controller->pool;
  57
  58         while (curr != NULL) {
  59                 if (curr->key == key)
  60                         break;
  61                 curr = curr->next;
  62         }
  63
  64         DBG("key=%d -> mem=%p", key, curr);
  65         return curr;
  66 }
  67
  68 static void agp_remove_from_pool(struct agp_memory *temp)
  69 {
  70         struct agp_memory *prev;
  71         struct agp_memory *next;
  72
  73         /* Check to see if this is even in the memory pool */
  74
  75         DBG("mem=%p", temp);
  76         if (agp_find_mem_by_key(temp->key) != NULL) {
  77                 next = temp->next;
  78                 prev = temp->prev;
  79
  80                 if (prev != NULL) {
  81                         prev->next = next;
  82                         if (next != NULL)
  83                                 next->prev = prev;
  84
  85                 } else {
  86                         /* This is the first item on the list */
  87                         if (next != NULL)
  88                                 next->prev = NULL;
  89
  90                         agp_fe.current_controller->pool = next;
  91                 }
  92         }
  93 }
  94
  95 /*
  96  * Routines for managing each client's segment list -
  97  * These routines handle adding and removing segments
  98  * to each auth'ed client.
  99  */
 100
 101 static struct
 102 agp_segment_priv *agp_find_seg_in_client(const struct agp_client *client,
 103                                                 unsigned long offset,
 104                                             int size, pgprot_t page_prot)
 105 {
 106         struct agp_segment_priv *seg;
 107         int num_segments, i;
 108         off_t pg_start;
 109         size_t pg_count;
 110
 111         pg_start = offset / 4096;
 112         pg_count = size / 4096;
 113         seg = *(client->segments);
 114         num_segments = client->num_segments;
 115
 116         for (i = 0; i < client->num_segments; i++) {
 117                 if ((seg[i].pg_start == pg_start) &&
 118                     (seg[i].pg_count == pg_count) &&
 119                     (pgprot_val(seg[i].prot) == pgprot_val(page_prot))) {
 120                         return seg + i;
 121                 }
 122         }
 123
 124         return NULL;
 125 }
 126
 127 static void agp_remove_seg_from_client(struct agp_client *client)
 128 {
 129         DBG("client=%p", client);
 130
 131         if (client->segments != NULL) {
 132                 if (*(client->segments) != NULL) {
 133                         DBG("Freeing %p from client %p", *(client->segments), client);
 134                         kfree(*(client->segments));
 135                 }
 136                 DBG("Freeing %p from client %p", client->segments, client);
 137                 kfree(client->segments);
 138                 client->segments = NULL;
 139         }
 140 }
 141
 142 static void agp_add_seg_to_client(struct agp_client *client,
 143                                struct agp_segment_priv ** seg, int num_segments)
 144 {
 145         struct agp_segment_priv **prev_seg;
 146
 147         prev_seg = client->segments;
 148
 149         if (prev_seg != NULL)
 150                 agp_remove_seg_from_client(client);
 151
 152         DBG("Adding seg %p (%d segments) to client %p", seg, num_segments, client);
 153         client->num_segments = num_segments;
 154         client->segments = seg;
 155 }
 156
 157 static pgprot_t agp_convert_mmap_flags(int prot)
 158 {
 159         unsigned long prot_bits;
 160
 161         prot_bits = calc_vm_prot_bits(prot) | VM_SHARED;
 162         return vm_get_page_prot(prot_bits);
 163 }
 164
 165 int agp_create_segment(struct agp_client *client, struct agp_region *region)
 166 {
 167         struct agp_segment_priv **ret_seg;
 168         struct agp_segment_priv *seg;
 169         struct agp_segment *user_seg;
 170         size_t i;
 171
 172         seg = kzalloc((sizeof(struct agp_segment_priv) * region->seg_count), GFP_KERNEL);
 173         if (seg == NULL) {
 174                 kfree(region->seg_list);
 175                 region->seg_list = NULL;
 176                 return -ENOMEM;
 177         }
 178         user_seg = region->seg_list;
 179
 180         for (i = 0; i < region->seg_count; i++) {
 181                 seg[i].pg_start = user_seg[i].pg_start;
 182                 seg[i].pg_count = user_seg[i].pg_count;
 183                 seg[i].prot = agp_convert_mmap_flags(user_seg[i].prot);
 184         }
 185         kfree(region->seg_list);
 186         region->seg_list = NULL;
 187
 188         ret_seg = kmalloc(sizeof(void *), GFP_KERNEL);
 189         if (ret_seg == NULL) {
 190                 kfree(seg);
 191                 return -ENOMEM;
 192         }
 193         *ret_seg = seg;
 194         agp_add_seg_to_client(client, ret_seg, region->seg_count);
 195         return 0;
 196 }
 197
 198 /* End - Routines for managing each client's segment list */
 199
 200 /* This function must only be called when current_controller != NULL */
 201 static void agp_insert_into_pool(struct agp_memory * temp)
 202 {
 203         struct agp_memory *prev;
 204
 205         prev = agp_fe.current_controller->pool;
 206
 207         if (prev != NULL) {
 208                 prev->prev = temp;
 209                 temp->next = prev;
 210         }
 211         agp_fe.current_controller->pool = temp;
 212 }
 213
 214
 215 /* File private list routines */
 216
 217 struct agp_file_private *agp_find_private(pid_t pid)
 218 {
 219         struct agp_file_private *curr;
 220
 221         curr = agp_fe.file_priv_list;
 222
 223         while (curr != NULL) {
 224                 if (curr->my_pid == pid)
 225                         return curr;
 226                 curr = curr->next;
 227         }
 228
 229         return NULL;
 230 }
 231
 232 static void agp_insert_file_private(struct agp_file_private * priv)
 233 {
 234         struct agp_file_private *prev;
 235
 236         prev = agp_fe.file_priv_list;
 237
 238         if (prev != NULL)
 239                 prev->prev = priv;
 240         priv->next = prev;
 241         agp_fe.file_priv_list = priv;
 242 }
 243
 244 static void agp_remove_file_private(struct agp_file_private * priv)
 245 {
 246         struct agp_file_private *next;
 247         struct agp_file_private *prev;
 248
 249         next = priv->next;
 250         prev = priv->prev;
 251
 252         if (prev != NULL) {
 253                 prev->next = next;
 254
 255                 if (next != NULL)
 256                         next->prev = prev;
 257
 258         } else {
 259                 if (next != NULL)
 260                         next->prev = NULL;
 261
 262                 agp_fe.file_priv_list = next;
 263         }
 264 }
 265
 266 /* End - File flag list routines */
 267
 268 /*
 269  * Wrappers for agp_free_memory & agp_allocate_memory
 270  * These make sure that internal lists are kept updated.
 271  */
 272 void agp_free_memory_wrap(struct agp_memory *memory)
 273 {
 274         agp_remove_from_pool(memory);
 275         agp_free_memory(memory);
 276 }
 277
 278 struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
 279 {
 280         struct agp_memory *memory;
 281
 282         memory = agp_allocate_memory(agp_bridge, pg_count, type);
 283         if (memory == NULL)
 284                 return NULL;
 285
 286         agp_insert_into_pool(memory);
 287         return memory;
 288 }
 289
 290 /* Routines for managing the list of controllers -
 291  * These routines manage the current controller, and the list of
 292  * controllers
 293  */
 294
 295 static struct agp_controller *agp_find_controller_by_pid(pid_t id)
 296 {
 297         struct agp_controller *controller;
 298
 299         controller = agp_fe.controllers;
 300
 301         while (controller != NULL) {
 302                 if (controller->pid == id)
 303                         return controller;
 304                 controller = controller->next;
 305         }
 306
 307         return NULL;
 308 }
 309
 310 static struct agp_controller *agp_create_controller(pid_t id)
 311 {
 312         struct agp_controller *controller;
 313
 314         controller = kzalloc(sizeof(struct agp_controller), GFP_KERNEL);
 315         if (controller == NULL)
 316                 return NULL;
 317
 318         controller->pid = id;
 319         return controller;
 320 }
 321
 322 static int agp_insert_controller(struct agp_controller *controller)
 323 {
 324         struct agp_controller *prev_controller;
 325
 326         prev_controller = agp_fe.controllers;
 327         controller->next = prev_controller;
 328
 329         if (prev_controller != NULL)
 330                 prev_controller->prev = controller;
 331
 332         agp_fe.controllers = controller;
 333
 334         return 0;
 335 }
 336
 337 static void agp_remove_all_clients(struct agp_controller *controller)
 338 {
 339         struct agp_client *client;
 340         struct agp_client *temp;
 341
 342         client = controller->clients;
 343
 344         while (client) {
 345                 struct agp_file_private *priv;
 346
 347                 temp = client;
 348                 agp_remove_seg_from_client(temp);
 349                 priv = agp_find_private(temp->pid);
 350
 351                 if (priv != NULL) {
 352                         clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
 353                         clear_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 354                 }
 355                 client = client->next;
 356                 kfree(temp);
 357         }
 358 }
 359
 360 static void agp_remove_all_memory(struct agp_controller *controller)
 361 {
 362         struct agp_memory *memory;
 363         struct agp_memory *temp;
 364
 365         memory = controller->pool;
 366
 367         while (memory) {
 368                 temp = memory;
 369                 memory = memory->next;
 370                 agp_free_memory_wrap(temp);
 371         }
 372 }
 373
 374 static int agp_remove_controller(struct agp_controller *controller)
 375 {
 376         struct agp_controller *prev_controller;
 377         struct agp_controller *next_controller;
 378
 379         prev_controller = controller->prev;
 380         next_controller = controller->next;
 381
 382         if (prev_controller != NULL) {
 383                 prev_controller->next = next_controller;
 384                 if (next_controller != NULL)
 385                         next_controller->prev = prev_controller;
 386
 387         } else {
 388                 if (next_controller != NULL)
 389                         next_controller->prev = NULL;
 390
 391                 agp_fe.controllers = next_controller;
 392         }
 393
 394         agp_remove_all_memory(controller);
 395         agp_remove_all_clients(controller);
 396
 397         if (agp_fe.current_controller == controller) {
 398                 agp_fe.current_controller = NULL;
 399                 agp_fe.backend_acquired = false;
 400                 agp_backend_release(agp_bridge);
 401         }
 402         kfree(controller);
 403         return 0;
 404 }
 405
 406 static void agp_controller_make_current(struct agp_controller *controller)
 407 {
 408         struct agp_client *clients;
 409
 410         clients = controller->clients;
 411
 412         while (clients != NULL) {
 413                 struct agp_file_private *priv;
 414
 415                 priv = agp_find_private(clients->pid);
 416
 417                 if (priv != NULL) {
 418                         set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 419                         set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 420                 }
 421                 clients = clients->next;
 422         }
 423
 424         agp_fe.current_controller = controller;
 425 }
 426
 427 static void agp_controller_release_current(struct agp_controller *controller,
 428                                       struct agp_file_private *controller_priv)
 429 {
 430         struct agp_client *clients;
 431
 432         clear_bit(AGP_FF_IS_VALID, &controller_priv->access_flags);
 433         clients = controller->clients;
 434
 435         while (clients != NULL) {
 436                 struct agp_file_private *priv;
 437
 438                 priv = agp_find_private(clients->pid);
 439
 440                 if (priv != NULL)
 441                         clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
 442
 443                 clients = clients->next;
 444         }
 445
 446         agp_fe.current_controller = NULL;
 447         agp_fe.used_by_controller = false;
 448         agp_backend_release(agp_bridge);
 449 }
 450
 451 /*
 452  * Routines for managing client lists -
 453  * These routines are for managing the list of auth'ed clients.
 454  */
 455
 456 static struct agp_client
 457 *agp_find_client_in_controller(struct agp_controller *controller, pid_t id)
 458 {
 459         struct agp_client *client;
 460
 461         if (controller == NULL)
 462                 return NULL;
 463
 464         client = controller->clients;
 465
 466         while (client != NULL) {
 467                 if (client->pid == id)
 468                         return client;
 469                 client = client->next;
 470         }
 471
 472         return NULL;
 473 }
 474
 475 static struct agp_controller *agp_find_controller_for_client(pid_t id)
 476 {
 477         struct agp_controller *controller;
 478
 479         controller = agp_fe.controllers;
 480
 481         while (controller != NULL) {
 482                 if ((agp_find_client_in_controller(controller, id)) != NULL)
 483                         return controller;
 484                 controller = controller->next;
 485         }
 486
 487         return NULL;
 488 }
 489
 490 struct agp_client *agp_find_client_by_pid(pid_t id)
 491 {
 492         struct agp_client *temp;
 493
 494         if (agp_fe.current_controller == NULL)
 495                 return NULL;
 496
 497         temp = agp_find_client_in_controller(agp_fe.current_controller, id);
 498         return temp;
 499 }
 500
 501 static void agp_insert_client(struct agp_client *client)
 502 {
 503         struct agp_client *prev_client;
 504
 505         prev_client = agp_fe.current_controller->clients;
 506         client->next = prev_client;
 507
 508         if (prev_client != NULL)
 509                 prev_client->prev = client;
 510
 511         agp_fe.current_controller->clients = client;
 512         agp_fe.current_controller->num_clients++;
 513 }
 514
 515 struct agp_client *agp_create_client(pid_t id)
 516 {
 517         struct agp_client *new_client;
 518
 519         new_client = kzalloc(sizeof(struct agp_client), GFP_KERNEL);
 520         if (new_client == NULL)
 521                 return NULL;
 522
 523         new_client->pid = id;
 524         agp_insert_client(new_client);
 525         return new_client;
 526 }
 527
 528 int agp_remove_client(pid_t id)
 529 {
 530         struct agp_client *client;
 531         struct agp_client *prev_client;
 532         struct agp_client *next_client;
 533         struct agp_controller *controller;
 534
 535         controller = agp_find_controller_for_client(id);
 536         if (controller == NULL)
 537                 return -EINVAL;
 538
 539         client = agp_find_client_in_controller(controller, id);
 540         if (client == NULL)
 541                 return -EINVAL;
 542
 543         prev_client = client->prev;
 544         next_client = client->next;
 545
 546         if (prev_client != NULL) {
 547                 prev_client->next = next_client;
 548                 if (next_client != NULL)
 549                         next_client->prev = prev_client;
 550
 551         } else {
 552                 if (next_client != NULL)
 553                         next_client->prev = NULL;
 554                 controller->clients = next_client;
 555         }
 556
 557         controller->num_clients--;
 558         agp_remove_seg_from_client(client);
 559         kfree(client);
 560         return 0;
 561 }
 562
 563 /* End - Routines for managing client lists */
 564
 565 /* File Operations */
 566
 567 static int agp_mmap(struct file *file, struct vm_area_struct *vma)
 568 {
 569         unsigned int size, current_size;
 570         unsigned long offset;
 571         struct agp_client *client;
 572         struct agp_file_private *priv = file->private_data;
 573         struct agp_kern_info kerninfo;
 574
 575         mutex_lock(&(agp_fe.agp_mutex));
 576
 577         if (agp_fe.backend_acquired != true)
 578                 goto out_eperm;
 579
 580         if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
 581                 goto out_eperm;
 582
 583         agp_copy_info(agp_bridge, &kerninfo);
 584         size = vma->vm_end - vma->vm_start;
 585         current_size = kerninfo.aper_size;
 586         current_size = current_size * 0x100000;
 587         offset = vma->vm_pgoff << PAGE_SHIFT;
 588         DBG("%lx:%lx", offset, offset+size);
 589
 590         if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
 591                 if ((size + offset) > current_size)
 592                         goto out_inval;
 593
 594                 client = agp_find_client_by_pid(current->pid);
 595
 596                 if (client == NULL)
 597                         goto out_eperm;
 598
 599                 if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
 600                         goto out_inval;
 601
 602                 DBG("client vm_ops=%p", kerninfo.vm_ops);
 603                 if (kerninfo.vm_ops) {
 604                         vma->vm_ops = kerninfo.vm_ops;
 605                 } else if (io_remap_pfn_range(vma, vma->vm_start,
 606                                 (kerninfo.aper_base + offset) >> PAGE_SHIFT,
 607                                             size, vma->vm_page_prot)) {
 608                         goto out_again;
 609                 }
 610                 mutex_unlock(&(agp_fe.agp_mutex));
 611                 return 0;
 612         }
 613
 614         if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
 615                 if (size != current_size)
 616                         goto out_inval;
 617
 618                 DBG("controller vm_ops=%p", kerninfo.vm_ops);
 619                 if (kerninfo.vm_ops) {
 620                         vma->vm_ops = kerninfo.vm_ops;
 621                 } else if (io_remap_pfn_range(vma, vma->vm_start,
 622                                             kerninfo.aper_base >> PAGE_SHIFT,
 623                                             size, vma->vm_page_prot)) {
 624                         goto out_again;
 625                 }
 626                 mutex_unlock(&(agp_fe.agp_mutex));
 627                 return 0;
 628         }
 629
 630 out_eperm:
 631         mutex_unlock(&(agp_fe.agp_mutex));
 632         return -EPERM;
 633
 634 out_inval:
 635         mutex_unlock(&(agp_fe.agp_mutex));
 636         return -EINVAL;
 637
 638 out_again:
 639         mutex_unlock(&(agp_fe.agp_mutex));
 640         return -EAGAIN;
 641 }
 642
 643 static int agp_release(struct inode *inode, struct file *file)
 644 {
 645         struct agp_file_private *priv = file->private_data;
 646
 647         mutex_lock(&(agp_fe.agp_mutex));
 648
 649         DBG("priv=%p", priv);
 650
 651         if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
 652                 struct agp_controller *controller;
 653
 654                 controller = agp_find_controller_by_pid(priv->my_pid);
 655
 656                 if (controller != NULL) {
 657                         if (controller == agp_fe.current_controller)
 658                                 agp_controller_release_current(controller, priv);
 659                         agp_remove_controller(controller);
 660                         controller = NULL;
 661                 }
 662         }
 663
 664         if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
 665                 agp_remove_client(priv->my_pid);
 666
 667         agp_remove_file_private(priv);
 668         kfree(priv);
 669         file->private_data = NULL;
 670         mutex_unlock(&(agp_fe.agp_mutex));
 671         return 0;
 672 }
 673
 674 static int agp_open(struct inode *inode, struct file *file)
 675 {
 676         int minor = iminor(inode);
 677         struct agp_file_private *priv;
 678         struct agp_client *client;
 679
 680         if (minor != AGPGART_MINOR)
 681                 return -ENXIO;
 682
 683         mutex_lock(&(agp_fe.agp_mutex));
 684
 685         priv = kzalloc(sizeof(struct agp_file_private), GFP_KERNEL);
 686         if (priv == NULL) {
 687                 mutex_unlock(&(agp_fe.agp_mutex));
 688                 return -ENOMEM;
 689         }
 690
 691         set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
 692         priv->my_pid = current->pid;
 693
 694         if (capable(CAP_SYS_RAWIO))
 695                 /* Root priv, can be controller */
 696                 set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
 697
 698         client = agp_find_client_by_pid(current->pid);
 699
 700         if (client != NULL) {
 701                 set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 702                 set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 703         }
 704         file->private_data = (void *) priv;
 705         agp_insert_file_private(priv);
 706         DBG("private=%p, client=%p", priv, client);
 707
 708         mutex_unlock(&(agp_fe.agp_mutex));
 709
 710         return 0;
 711 }
 712
 713
 714 static ssize_t agp_read(struct file *file, char __user *buf,
 715                         size_t count, loff_t * ppos)
 716 {
 717         return -EINVAL;
 718 }
 719
 720 static ssize_t agp_write(struct file *file, const char __user *buf,
 721                          size_t count, loff_t * ppos)
 722 {
 723         return -EINVAL;
 724 }
 725
 726 static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
 727 {
 728         struct agp_info userinfo;
 729         struct agp_kern_info kerninfo;
 730
 731         agp_copy_info(agp_bridge, &kerninfo);
 732
 733         userinfo.version.major = kerninfo.version.major;
 734         userinfo.version.minor = kerninfo.version.minor;
 735         userinfo.bridge_id = kerninfo.device->vendor |
 736             (kerninfo.device->device << 16);
 737         userinfo.agp_mode = kerninfo.mode;
 738         userinfo.aper_base = kerninfo.aper_base;
 739         userinfo.aper_size = kerninfo.aper_size;
 740         userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
 741         userinfo.pg_used = kerninfo.current_memory;
 742
 743         if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
 744                 return -EFAULT;
 745
 746         return 0;
 747 }
 748
 749 int agpioc_acquire_wrap(struct agp_file_private *priv)
 750 {
 751         struct agp_controller *controller;
 752
 753         DBG("");
 754
 755         if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
 756                 return -EPERM;
 757
 758         if (agp_fe.current_controller != NULL)
 759                 return -EBUSY;
 760
 761         if (!agp_bridge)
 762                 return -ENODEV;
 763
 764         if (atomic_read(&agp_bridge->agp_in_use))
 765                 return -EBUSY;
 766
 767         atomic_inc(&agp_bridge->agp_in_use);
 768
 769         agp_fe.backend_acquired = true;
 770
 771         controller = agp_find_controller_by_pid(priv->my_pid);
 772
 773         if (controller != NULL) {
 774                 agp_controller_make_current(controller);
 775         } else {
 776                 controller = agp_create_controller(priv->my_pid);
 777
 778                 if (controller == NULL) {
 779                         agp_fe.backend_acquired = false;
 780                         agp_backend_release(agp_bridge);
 781                         return -ENOMEM;
 782                 }
 783                 agp_insert_controller(controller);
 784                 agp_controller_make_current(controller);
 785         }
 786
 787         set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
 788         set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 789         return 0;
 790 }
 791
 792 int agpioc_release_wrap(struct agp_file_private *priv)
 793 {
 794         DBG("");
 795         agp_controller_release_current(agp_fe.current_controller, priv);
 796         return 0;
 797 }
 798
 799 int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
 800 {
 801         struct agp_setup mode;
 802
 803         DBG("");
 804         if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
 805                 return -EFAULT;
 806
 807         agp_enable(agp_bridge, mode.agp_mode);
 808         return 0;
 809 }
 810
 811 static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
 812 {
 813         struct agp_region reserve;
 814         struct agp_client *client;
 815         struct agp_file_private *client_priv;
 816
 817         DBG("");
 818         if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
 819                 return -EFAULT;
 820
 821         if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
 822                 return -EFAULT;
 823
 824         client = agp_find_client_by_pid(reserve.pid);
 825
 826         if (reserve.seg_count == 0) {
 827                 /* remove a client */
 828                 client_priv = agp_find_private(reserve.pid);
 829
 830                 if (client_priv != NULL) {
 831                         set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
 832                         set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
 833                 }
 834                 if (client == NULL) {
 835                         /* client is already removed */
 836                         return 0;
 837                 }
 838                 return agp_remove_client(reserve.pid);
 839         } else {
 840                 struct agp_segment *segment;
 841
 842                 if (reserve.seg_count >= 16384)
 843                         return -EINVAL;
 844
 845                 segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
 846                                   GFP_KERNEL);
 847
 848                 if (segment == NULL)
 849                         return -ENOMEM;
 850
 851                 if (copy_from_user(segment, (void __user *) reserve.seg_list,
 852                                    sizeof(struct agp_segment) * reserve.seg_count)) {
 853                         kfree(segment);
 854                         return -EFAULT;
 855                 }
 856                 reserve.seg_list = segment;
 857
 858                 if (client == NULL) {
 859                         /* Create the client and add the segment */
 860                         client = agp_create_client(reserve.pid);
 861
 862                         if (client == NULL) {
 863                                 kfree(segment);
 864                                 return -ENOMEM;
 865                         }
 866                         client_priv = agp_find_private(reserve.pid);
 867
 868                         if (client_priv != NULL) {
 869                                 set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
 870                                 set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
 871                         }
 872                 }
 873                 return agp_create_segment(client, &reserve);
 874         }
 875         /* Will never really happen */
 876         return -EINVAL;
 877 }
 878
 879 int agpioc_protect_wrap(struct agp_file_private *priv)
 880 {
 881         DBG("");
 882         /* This function is not currently implemented */
 883         return -EINVAL;
 884 }
 885
 886 static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
 887 {
 888         struct agp_memory *memory;
 889         struct agp_allocate alloc;
 890
 891         DBG("");
 892         if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
 893                 return -EFAULT;
 894
 895         if (alloc.type >= AGP_USER_TYPES)
 896                 return -EINVAL;
 897
 898         memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);
 899
 900         if (memory == NULL)
 901                 return -ENOMEM;
 902
 903         alloc.key = memory->key;
 904         alloc.physical = memory->physical;
 905
 906         if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
 907                 agp_free_memory_wrap(memory);
 908                 return -EFAULT;
 909         }
 910         return 0;
 911 }
 912
 913 int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
 914 {
 915         struct agp_memory *memory;
 916
 917         DBG("");
 918         memory = agp_find_mem_by_key(arg);
 919
 920         if (memory == NULL)
 921                 return -EINVAL;
 922
 923         agp_free_memory_wrap(memory);
 924         return 0;
 925 }
 926
 927 static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
 928 {
 929         struct agp_bind bind_info;
 930         struct agp_memory *memory;
 931
 932         DBG("");
 933         if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
 934                 return -EFAULT;
 935
 936         memory = agp_find_mem_by_key(bind_info.key);
 937
 938         if (memory == NULL)
 939                 return -EINVAL;
 940
 941         return agp_bind_memory(memory, bind_info.pg_start);
 942 }
 943
 944 static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
 945 {
 946         struct agp_memory *memory;
 947         struct agp_unbind unbind;
 948
 949         DBG("");
 950         if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
 951                 return -EFAULT;
 952
 953         memory = agp_find_mem_by_key(unbind.key);
 954
 955         if (memory == NULL)
 956                 return -EINVAL;
 957
 958         return agp_unbind_memory(memory);
 959 }
 960
 961 int agpioc_chipset_flush_wrap(struct agp_file_private *priv)
 962 {
 963         DBG("");
 964         agp_flush_chipset(agp_bridge);
 965         return 0;
 966 }
 967
 968 static long agp_ioctl(struct file *file,
 969                      unsigned int cmd, unsigned long arg)
 970 {
 971         struct agp_file_private *curr_priv = file->private_data;
 972         int ret_val = -ENOTTY;
 973
 974         DBG("priv=%p, cmd=%x", curr_priv, cmd);
 975         mutex_lock(&(agp_fe.agp_mutex));
 976
 977         if ((agp_fe.current_controller == NULL) &&
 978             (cmd != AGPIOC_ACQUIRE)) {
 979                 ret_val = -EINVAL;
 980                 goto ioctl_out;
 981         }
 982         if ((agp_fe.backend_acquired != true) &&
 983             (cmd != AGPIOC_ACQUIRE)) {
 984                 ret_val = -EBUSY;
 985                 goto ioctl_out;
 986         }
 987         if (cmd != AGPIOC_ACQUIRE) {
 988                 if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
 989                         ret_val = -EPERM;
 990                         goto ioctl_out;
 991                 }
 992                 /* Use the original pid of the controller,
 993                  * in case it's threaded */
 994
 995                 if (agp_fe.current_controller->pid != curr_priv->my_pid) {
 996                         ret_val = -EBUSY;
 997                         goto ioctl_out;
 998                 }
 999         }
1000
1001         switch (cmd) {
1002         case AGPIOC_INFO:
1003                 ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
1004                 break;
1005
1006         case AGPIOC_ACQUIRE:
1007                 ret_val = agpioc_acquire_wrap(curr_priv);
1008                 break;
1009
1010         case AGPIOC_RELEASE:
1011                 ret_val = agpioc_release_wrap(curr_priv);
1012                 break;
1013
1014         case AGPIOC_SETUP:
1015                 ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
1016                 break;
1017
1018         case AGPIOC_RESERVE:
1019                 ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
1020                 break;
1021
1022         case AGPIOC_PROTECT:
1023                 ret_val = agpioc_protect_wrap(curr_priv);
1024                 break;
1025
1026         case AGPIOC_ALLOCATE:
1027                 ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
1028                 break;
1029
1030         case AGPIOC_DEALLOCATE:
1031                 ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
1032                 break;
1033
1034         case AGPIOC_BIND:
1035                 ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
1036                 break;
1037
1038         case AGPIOC_UNBIND:
1039                 ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
1040                 break;
1041
1042         case AGPIOC_CHIPSET_FLUSH:
1043                 ret_val = agpioc_chipset_flush_wrap(curr_priv);
1044                 break;
1045         }
1046
1047 ioctl_out:
1048         DBG("ioctl returns %d\n", ret_val);
1049         mutex_unlock(&(agp_fe.agp_mutex));
1050         return ret_val;
1051 }
1052
1053 static const struct file_operations agp_fops =
1054 {
1055         .owner          = THIS_MODULE,
1056         .llseek         = no_llseek,
1057         .read           = agp_read,
1058         .write          = agp_write,
1059         .unlocked_ioctl = agp_ioctl,
1060 #ifdef CONFIG_COMPAT
1061         .compat_ioctl   = compat_agp_ioctl,
1062 #endif
1063         .mmap           = agp_mmap,
1064         .open           = agp_open,
1065         .release        = agp_release,
1066 };
1067
1068 static struct miscdevice agp_miscdev =
1069 {
1070         .minor  = AGPGART_MINOR,
1071         .name   = "agpgart",
1072         .fops   = &agp_fops
1073 };
1074
1075 int agp_frontend_initialize(void)
1076 {
1077         memset(&agp_fe, 0, sizeof(struct agp_front_data));
1078         mutex_init(&(agp_fe.agp_mutex));
1079
1080         if (misc_register(&agp_miscdev)) {
1081                 printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
1082                 return -EIO;
1083         }
1084         return 0;
1085 }
1086
1087 void agp_frontend_cleanup(void)
1088 {
1089         misc_deregister(&agp_miscdev);
1090 }