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