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