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 /* Originally taken from linux/mm/mmap.c from the array
 155  * protection_map.
 156  * The original really should be exported to modules, or
 157  * some routine which does the conversion for you
 158  */
 159
 160 static const pgprot_t my_protect_map[16] =
 161 {
 162         __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
 163         __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
 164 };
 165
 166 static pgprot_t agp_convert_mmap_flags(int prot)
 167 {
 168 #define _trans(x,bit1,bit2) \
 169 ((bit1==bit2)?(x&bit1):(x&bit1)?bit2:0)
 170
 171         unsigned long prot_bits;
 172         pgprot_t temp;
 173
 174         prot_bits = _trans(prot, PROT_READ, VM_READ) |
 175             _trans(prot, PROT_WRITE, VM_WRITE) |
 176             _trans(prot, PROT_EXEC, VM_EXEC);
 177
 178         prot_bits |= VM_SHARED;
 179
 180         temp = my_protect_map[prot_bits & 0x0000000f];
 181
 182         return temp;
 183 }
 184
 185 static int agp_create_segment(struct agp_client *client, struct agp_region *region)
 186 {
 187         struct agp_segment_priv **ret_seg;
 188         struct agp_segment_priv *seg;
 189         struct agp_segment *user_seg;
 190         size_t i;
 191
 192         seg = kmalloc((sizeof(struct agp_segment_priv) * region->seg_count), GFP_KERNEL);
 193         if (seg == NULL) {
 194                 kfree(region->seg_list);
 195                 region->seg_list = NULL;
 196                 return -ENOMEM;
 197         }
 198         memset(seg, 0, (sizeof(struct agp_segment_priv) * region->seg_count));
 199         user_seg = region->seg_list;
 200
 201         for (i = 0; i < region->seg_count; i++) {
 202                 seg[i].pg_start = user_seg[i].pg_start;
 203                 seg[i].pg_count = user_seg[i].pg_count;
 204                 seg[i].prot = agp_convert_mmap_flags(user_seg[i].prot);
 205         }
 206         kfree(region->seg_list);
 207         region->seg_list = NULL;
 208
 209         ret_seg = kmalloc(sizeof(void *), GFP_KERNEL);
 210         if (ret_seg == NULL) {
 211                 kfree(seg);
 212                 return -ENOMEM;
 213         }
 214         *ret_seg = seg;
 215         agp_add_seg_to_client(client, ret_seg, region->seg_count);
 216         return 0;
 217 }
 218
 219 /* End - Routines for managing each client's segment list */
 220
 221 /* This function must only be called when current_controller != NULL */
 222 static void agp_insert_into_pool(struct agp_memory * temp)
 223 {
 224         struct agp_memory *prev;
 225
 226         prev = agp_fe.current_controller->pool;
 227
 228         if (prev != NULL) {
 229                 prev->prev = temp;
 230                 temp->next = prev;
 231         }
 232         agp_fe.current_controller->pool = temp;
 233 }
 234
 235
 236 /* File private list routines */
 237
 238 struct agp_file_private *agp_find_private(pid_t pid)
 239 {
 240         struct agp_file_private *curr;
 241
 242         curr = agp_fe.file_priv_list;
 243
 244         while (curr != NULL) {
 245                 if (curr->my_pid == pid)
 246                         return curr;
 247                 curr = curr->next;
 248         }
 249
 250         return NULL;
 251 }
 252
 253 void agp_insert_file_private(struct agp_file_private * priv)
 254 {
 255         struct agp_file_private *prev;
 256
 257         prev = agp_fe.file_priv_list;
 258
 259         if (prev != NULL)
 260                 prev->prev = priv;
 261         priv->next = prev;
 262         agp_fe.file_priv_list = priv;
 263 }
 264
 265 void agp_remove_file_private(struct agp_file_private * priv)
 266 {
 267         struct agp_file_private *next;
 268         struct agp_file_private *prev;
 269
 270         next = priv->next;
 271         prev = priv->prev;
 272
 273         if (prev != NULL) {
 274                 prev->next = next;
 275
 276                 if (next != NULL)
 277                         next->prev = prev;
 278
 279         } else {
 280                 if (next != NULL)
 281                         next->prev = NULL;
 282
 283                 agp_fe.file_priv_list = next;
 284         }
 285 }
 286
 287 /* End - File flag list routines */
 288
 289 /*
 290  * Wrappers for agp_free_memory & agp_allocate_memory
 291  * These make sure that internal lists are kept updated.
 292  */
 293 static void agp_free_memory_wrap(struct agp_memory *memory)
 294 {
 295         agp_remove_from_pool(memory);
 296         agp_free_memory(memory);
 297 }
 298
 299 static struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
 300 {
 301         struct agp_memory *memory;
 302
 303         memory = agp_allocate_memory(agp_bridge, pg_count, type);
 304         if (memory == NULL)
 305                 return NULL;
 306
 307         agp_insert_into_pool(memory);
 308         return memory;
 309 }
 310
 311 /* Routines for managing the list of controllers -
 312  * These routines manage the current controller, and the list of
 313  * controllers
 314  */
 315
 316 static struct agp_controller *agp_find_controller_by_pid(pid_t id)
 317 {
 318         struct agp_controller *controller;
 319
 320         controller = agp_fe.controllers;
 321
 322         while (controller != NULL) {
 323                 if (controller->pid == id)
 324                         return controller;
 325                 controller = controller->next;
 326         }
 327
 328         return NULL;
 329 }
 330
 331 static struct agp_controller *agp_create_controller(pid_t id)
 332 {
 333         struct agp_controller *controller;
 334
 335         controller = kmalloc(sizeof(struct agp_controller), GFP_KERNEL);
 336
 337         if (controller == NULL)
 338                 return NULL;
 339
 340         memset(controller, 0, sizeof(struct agp_controller));
 341         controller->pid = id;
 342
 343         return controller;
 344 }
 345
 346 static int agp_insert_controller(struct agp_controller *controller)
 347 {
 348         struct agp_controller *prev_controller;
 349
 350         prev_controller = agp_fe.controllers;
 351         controller->next = prev_controller;
 352
 353         if (prev_controller != NULL)
 354                 prev_controller->prev = controller;
 355
 356         agp_fe.controllers = controller;
 357
 358         return 0;
 359 }
 360
 361 static void agp_remove_all_clients(struct agp_controller *controller)
 362 {
 363         struct agp_client *client;
 364         struct agp_client *temp;
 365
 366         client = controller->clients;
 367
 368         while (client) {
 369                 struct agp_file_private *priv;
 370
 371                 temp = client;
 372                 agp_remove_seg_from_client(temp);
 373                 priv = agp_find_private(temp->pid);
 374
 375                 if (priv != NULL) {
 376                         clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
 377                         clear_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 378                 }
 379                 client = client->next;
 380                 kfree(temp);
 381         }
 382 }
 383
 384 static void agp_remove_all_memory(struct agp_controller *controller)
 385 {
 386         struct agp_memory *memory;
 387         struct agp_memory *temp;
 388
 389         memory = controller->pool;
 390
 391         while (memory) {
 392                 temp = memory;
 393                 memory = memory->next;
 394                 agp_free_memory_wrap(temp);
 395         }
 396 }
 397
 398 static int agp_remove_controller(struct agp_controller *controller)
 399 {
 400         struct agp_controller *prev_controller;
 401         struct agp_controller *next_controller;
 402
 403         prev_controller = controller->prev;
 404         next_controller = controller->next;
 405
 406         if (prev_controller != NULL) {
 407                 prev_controller->next = next_controller;
 408                 if (next_controller != NULL)
 409                         next_controller->prev = prev_controller;
 410
 411         } else {
 412                 if (next_controller != NULL)
 413                         next_controller->prev = NULL;
 414
 415                 agp_fe.controllers = next_controller;
 416         }
 417
 418         agp_remove_all_memory(controller);
 419         agp_remove_all_clients(controller);
 420
 421         if (agp_fe.current_controller == controller) {
 422                 agp_fe.current_controller = NULL;
 423                 agp_fe.backend_acquired = FALSE;
 424                 agp_backend_release(agp_bridge);
 425         }
 426         kfree(controller);
 427         return 0;
 428 }
 429
 430 static void agp_controller_make_current(struct agp_controller *controller)
 431 {
 432         struct agp_client *clients;
 433
 434         clients = controller->clients;
 435
 436         while (clients != NULL) {
 437                 struct agp_file_private *priv;
 438
 439                 priv = agp_find_private(clients->pid);
 440
 441                 if (priv != NULL) {
 442                         set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 443                         set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 444                 }
 445                 clients = clients->next;
 446         }
 447
 448         agp_fe.current_controller = controller;
 449 }
 450
 451 static void agp_controller_release_current(struct agp_controller *controller,
 452                                       struct agp_file_private *controller_priv)
 453 {
 454         struct agp_client *clients;
 455
 456         clear_bit(AGP_FF_IS_VALID, &controller_priv->access_flags);
 457         clients = controller->clients;
 458
 459         while (clients != NULL) {
 460                 struct agp_file_private *priv;
 461
 462                 priv = agp_find_private(clients->pid);
 463
 464                 if (priv != NULL)
 465                         clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
 466
 467                 clients = clients->next;
 468         }
 469
 470         agp_fe.current_controller = NULL;
 471         agp_fe.used_by_controller = FALSE;
 472         agp_backend_release(agp_bridge);
 473 }
 474
 475 /*
 476  * Routines for managing client lists -
 477  * These routines are for managing the list of auth'ed clients.
 478  */
 479
 480 static struct agp_client
 481 *agp_find_client_in_controller(struct agp_controller *controller, pid_t id)
 482 {
 483         struct agp_client *client;
 484
 485         if (controller == NULL)
 486                 return NULL;
 487
 488         client = controller->clients;
 489
 490         while (client != NULL) {
 491                 if (client->pid == id)
 492                         return client;
 493                 client = client->next;
 494         }
 495
 496         return NULL;
 497 }
 498
 499 static struct agp_controller *agp_find_controller_for_client(pid_t id)
 500 {
 501         struct agp_controller *controller;
 502
 503         controller = agp_fe.controllers;
 504
 505         while (controller != NULL) {
 506                 if ((agp_find_client_in_controller(controller, id)) != NULL)
 507                         return controller;
 508                 controller = controller->next;
 509         }
 510
 511         return NULL;
 512 }
 513
 514 static struct agp_client *agp_find_client_by_pid(pid_t id)
 515 {
 516         struct agp_client *temp;
 517
 518         if (agp_fe.current_controller == NULL)
 519                 return NULL;
 520
 521         temp = agp_find_client_in_controller(agp_fe.current_controller, id);
 522         return temp;
 523 }
 524
 525 static void agp_insert_client(struct agp_client *client)
 526 {
 527         struct agp_client *prev_client;
 528
 529         prev_client = agp_fe.current_controller->clients;
 530         client->next = prev_client;
 531
 532         if (prev_client != NULL)
 533                 prev_client->prev = client;
 534
 535         agp_fe.current_controller->clients = client;
 536         agp_fe.current_controller->num_clients++;
 537 }
 538
 539 static struct agp_client *agp_create_client(pid_t id)
 540 {
 541         struct agp_client *new_client;
 542
 543         new_client = kmalloc(sizeof(struct agp_client), GFP_KERNEL);
 544
 545         if (new_client == NULL)
 546                 return NULL;
 547
 548         memset(new_client, 0, sizeof(struct agp_client));
 549         new_client->pid = id;
 550         agp_insert_client(new_client);
 551         return new_client;
 552 }
 553
 554 static int agp_remove_client(pid_t id)
 555 {
 556         struct agp_client *client;
 557         struct agp_client *prev_client;
 558         struct agp_client *next_client;
 559         struct agp_controller *controller;
 560
 561         controller = agp_find_controller_for_client(id);
 562         if (controller == NULL)
 563                 return -EINVAL;
 564
 565         client = agp_find_client_in_controller(controller, id);
 566         if (client == NULL)
 567                 return -EINVAL;
 568
 569         prev_client = client->prev;
 570         next_client = client->next;
 571
 572         if (prev_client != NULL) {
 573                 prev_client->next = next_client;
 574                 if (next_client != NULL)
 575                         next_client->prev = prev_client;
 576
 577         } else {
 578                 if (next_client != NULL)
 579                         next_client->prev = NULL;
 580                 controller->clients = next_client;
 581         }
 582
 583         controller->num_clients--;
 584         agp_remove_seg_from_client(client);
 585         kfree(client);
 586         return 0;
 587 }
 588
 589 /* End - Routines for managing client lists */
 590
 591 /* File Operations */
 592
 593 static int agp_mmap(struct file *file, struct vm_area_struct *vma)
 594 {
 595         unsigned int size, current_size;
 596         unsigned long offset;
 597         struct agp_client *client;
 598         struct agp_file_private *priv = file->private_data;
 599         struct agp_kern_info kerninfo;
 600
 601         down(&(agp_fe.agp_mutex));
 602
 603         if (agp_fe.backend_acquired != TRUE)
 604                 goto out_eperm;
 605
 606         if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
 607                 goto out_eperm;
 608
 609         agp_copy_info(agp_bridge, &kerninfo);
 610         size = vma->vm_end - vma->vm_start;
 611         current_size = kerninfo.aper_size;
 612         current_size = current_size * 0x100000;
 613         offset = vma->vm_pgoff << PAGE_SHIFT;
 614         DBG("%lx:%lx", offset, offset+size);
 615
 616         if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
 617                 if ((size + offset) > current_size)
 618                         goto out_inval;
 619
 620                 client = agp_find_client_by_pid(current->pid);
 621
 622                 if (client == NULL)
 623                         goto out_eperm;
 624
 625                 if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
 626                         goto out_inval;
 627
 628                 DBG("client vm_ops=%p", kerninfo.vm_ops);
 629                 if (kerninfo.vm_ops) {
 630                         vma->vm_ops = kerninfo.vm_ops;
 631                 } else if (io_remap_pfn_range(vma, vma->vm_start,
 632                                 (kerninfo.aper_base + offset) >> PAGE_SHIFT,
 633                                             size, vma->vm_page_prot)) {
 634                         goto out_again;
 635                 }
 636                 up(&(agp_fe.agp_mutex));
 637                 return 0;
 638         }
 639
 640         if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
 641                 if (size != current_size)
 642                         goto out_inval;
 643
 644                 DBG("controller vm_ops=%p", kerninfo.vm_ops);
 645                 if (kerninfo.vm_ops) {
 646                         vma->vm_ops = kerninfo.vm_ops;
 647                 } else if (io_remap_pfn_range(vma, vma->vm_start,
 648                                             kerninfo.aper_base >> PAGE_SHIFT,
 649                                             size, vma->vm_page_prot)) {
 650                         goto out_again;
 651                 }
 652                 up(&(agp_fe.agp_mutex));
 653                 return 0;
 654         }
 655
 656 out_eperm:
 657         up(&(agp_fe.agp_mutex));
 658         return -EPERM;
 659
 660 out_inval:
 661         up(&(agp_fe.agp_mutex));
 662         return -EINVAL;
 663
 664 out_again:
 665         up(&(agp_fe.agp_mutex));
 666         return -EAGAIN;
 667 }
 668
 669 static int agp_release(struct inode *inode, struct file *file)
 670 {
 671         struct agp_file_private *priv = file->private_data;
 672
 673         down(&(agp_fe.agp_mutex));
 674
 675         DBG("priv=%p", priv);
 676
 677         if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
 678                 struct agp_controller *controller;
 679
 680                 controller = agp_find_controller_by_pid(priv->my_pid);
 681
 682                 if (controller != NULL) {
 683                         if (controller == agp_fe.current_controller)
 684                                 agp_controller_release_current(controller, priv);
 685                         agp_remove_controller(controller);
 686                         controller = NULL;
 687                 }
 688         }
 689
 690         if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
 691                 agp_remove_client(priv->my_pid);
 692
 693         agp_remove_file_private(priv);
 694         kfree(priv);
 695         file->private_data = NULL;
 696         up(&(agp_fe.agp_mutex));
 697         return 0;
 698 }
 699
 700 static int agp_open(struct inode *inode, struct file *file)
 701 {
 702         int minor = iminor(inode);
 703         struct agp_file_private *priv;
 704         struct agp_client *client;
 705         int rc = -ENXIO;
 706
 707         down(&(agp_fe.agp_mutex));
 708
 709         if (minor != AGPGART_MINOR)
 710                 goto err_out;
 711
 712         priv = kmalloc(sizeof(struct agp_file_private), GFP_KERNEL);
 713         if (priv == NULL)
 714                 goto err_out_nomem;
 715
 716         memset(priv, 0, sizeof(struct agp_file_private));
 717         set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
 718         priv->my_pid = current->pid;
 719
 720         if ((current->uid == 0) || (current->suid == 0)) {
 721                 /* Root priv, can be controller */
 722                 set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
 723         }
 724         client = agp_find_client_by_pid(current->pid);
 725
 726         if (client != NULL) {
 727                 set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
 728                 set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 729         }
 730         file->private_data = (void *) priv;
 731         agp_insert_file_private(priv);
 732         DBG("private=%p, client=%p", priv, client);
 733         up(&(agp_fe.agp_mutex));
 734         return 0;
 735
 736 err_out_nomem:
 737         rc = -ENOMEM;
 738 err_out:
 739         up(&(agp_fe.agp_mutex));
 740         return rc;
 741 }
 742
 743
 744 static ssize_t agp_read(struct file *file, char __user *buf,
 745                         size_t count, loff_t * ppos)
 746 {
 747         return -EINVAL;
 748 }
 749
 750 static ssize_t agp_write(struct file *file, const char __user *buf,
 751                          size_t count, loff_t * ppos)
 752 {
 753         return -EINVAL;
 754 }
 755
 756 static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
 757 {
 758         struct agp_info userinfo;
 759         struct agp_kern_info kerninfo;
 760
 761         agp_copy_info(agp_bridge, &kerninfo);
 762
 763         userinfo.version.major = kerninfo.version.major;
 764         userinfo.version.minor = kerninfo.version.minor;
 765         userinfo.bridge_id = kerninfo.device->vendor |
 766             (kerninfo.device->device << 16);
 767         userinfo.agp_mode = kerninfo.mode;
 768         userinfo.aper_base = kerninfo.aper_base;
 769         userinfo.aper_size = kerninfo.aper_size;
 770         userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
 771         userinfo.pg_used = kerninfo.current_memory;
 772
 773         if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
 774                 return -EFAULT;
 775
 776         return 0;
 777 }
 778
 779 static int agpioc_acquire_wrap(struct agp_file_private *priv)
 780 {
 781         struct agp_controller *controller;
 782
 783         DBG("");
 784
 785         if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
 786                 return -EPERM;
 787
 788         if (agp_fe.current_controller != NULL)
 789                 return -EBUSY;
 790
 791         if(!agp_bridge)
 792                 return -ENODEV;
 793
 794         if (atomic_read(&agp_bridge->agp_in_use))
 795                 return -EBUSY;
 796
 797         atomic_inc(&agp_bridge->agp_in_use);
 798
 799         agp_fe.backend_acquired = TRUE;
 800
 801         controller = agp_find_controller_by_pid(priv->my_pid);
 802
 803         if (controller != NULL) {
 804                 agp_controller_make_current(controller);
 805         } else {
 806                 controller = agp_create_controller(priv->my_pid);
 807
 808                 if (controller == NULL) {
 809                         agp_fe.backend_acquired = FALSE;
 810                         agp_backend_release(agp_bridge);
 811                         return -ENOMEM;
 812                 }
 813                 agp_insert_controller(controller);
 814                 agp_controller_make_current(controller);
 815         }
 816
 817         set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
 818         set_bit(AGP_FF_IS_VALID, &priv->access_flags);
 819         return 0;
 820 }
 821
 822 static int agpioc_release_wrap(struct agp_file_private *priv)
 823 {
 824         DBG("");
 825         agp_controller_release_current(agp_fe.current_controller, priv);
 826         return 0;
 827 }
 828
 829 static int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
 830 {
 831         struct agp_setup mode;
 832
 833         DBG("");
 834         if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
 835                 return -EFAULT;
 836
 837         agp_enable(agp_bridge, mode.agp_mode);
 838         return 0;
 839 }
 840
 841 static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
 842 {
 843         struct agp_region reserve;
 844         struct agp_client *client;
 845         struct agp_file_private *client_priv;
 846
 847         DBG("");
 848         if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
 849                 return -EFAULT;
 850
 851         if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
 852                 return -EFAULT;
 853
 854         client = agp_find_client_by_pid(reserve.pid);
 855
 856         if (reserve.seg_count == 0) {
 857                 /* remove a client */
 858                 client_priv = agp_find_private(reserve.pid);
 859
 860                 if (client_priv != NULL) {
 861                         set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
 862                         set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
 863                 }
 864                 if (client == NULL) {
 865                         /* client is already removed */
 866                         return 0;
 867                 }
 868                 return agp_remove_client(reserve.pid);
 869         } else {
 870                 struct agp_segment *segment;
 871
 872                 if (reserve.seg_count >= 16384)
 873                         return -EINVAL;
 874
 875                 segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
 876                                   GFP_KERNEL);
 877
 878                 if (segment == NULL)
 879                         return -ENOMEM;
 880
 881                 if (copy_from_user(segment, (void __user *) reserve.seg_list,
 882                                    sizeof(struct agp_segment) * reserve.seg_count)) {
 883                         kfree(segment);
 884                         return -EFAULT;
 885                 }
 886                 reserve.seg_list = segment;
 887
 888                 if (client == NULL) {
 889                         /* Create the client and add the segment */
 890                         client = agp_create_client(reserve.pid);
 891
 892                         if (client == NULL) {
 893                                 kfree(segment);
 894                                 return -ENOMEM;
 895                         }
 896                         client_priv = agp_find_private(reserve.pid);
 897
 898                         if (client_priv != NULL) {
 899                                 set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
 900                                 set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
 901                         }
 902                 }
 903                 return agp_create_segment(client, &reserve);
 904         }
 905         /* Will never really happen */
 906         return -EINVAL;
 907 }
 908
 909 static int agpioc_protect_wrap(struct agp_file_private *priv)
 910 {
 911         DBG("");
 912         /* This function is not currently implemented */
 913         return -EINVAL;
 914 }
 915
 916 static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
 917 {
 918         struct agp_memory *memory;
 919         struct agp_allocate alloc;
 920
 921         DBG("");
 922         if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
 923                 return -EFAULT;
 924
 925         memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);
 926
 927         if (memory == NULL)
 928                 return -ENOMEM;
 929
 930         alloc.key = memory->key;
 931         alloc.physical = memory->physical;
 932
 933         if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
 934                 agp_free_memory_wrap(memory);
 935                 return -EFAULT;
 936         }
 937         return 0;
 938 }
 939
 940 static int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
 941 {
 942         struct agp_memory *memory;
 943
 944         DBG("");
 945         memory = agp_find_mem_by_key(arg);
 946
 947         if (memory == NULL)
 948                 return -EINVAL;
 949
 950         agp_free_memory_wrap(memory);
 951         return 0;
 952 }
 953
 954 static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
 955 {
 956         struct agp_bind bind_info;
 957         struct agp_memory *memory;
 958
 959         DBG("");
 960         if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
 961                 return -EFAULT;
 962
 963         memory = agp_find_mem_by_key(bind_info.key);
 964
 965         if (memory == NULL)
 966                 return -EINVAL;
 967
 968         return agp_bind_memory(memory, bind_info.pg_start);
 969 }
 970
 971 static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
 972 {
 973         struct agp_memory *memory;
 974         struct agp_unbind unbind;
 975
 976         DBG("");
 977         if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
 978                 return -EFAULT;
 979
 980         memory = agp_find_mem_by_key(unbind.key);
 981
 982         if (memory == NULL)
 983                 return -EINVAL;
 984
 985         return agp_unbind_memory(memory);
 986 }
 987
 988 static int agp_ioctl(struct inode *inode, struct file *file,
 989                      unsigned int cmd, unsigned long arg)
 990 {
 991         struct agp_file_private *curr_priv = file->private_data;
 992         int ret_val = -ENOTTY;
 993
 994         DBG("priv=%p, cmd=%x", curr_priv, cmd);
 995         down(&(agp_fe.agp_mutex));
 996
 997         if ((agp_fe.current_controller == NULL) &&
 998             (cmd != AGPIOC_ACQUIRE)) {
 999                 ret_val = -EINVAL;
1000                 goto ioctl_out;
1001         }
1002         if ((agp_fe.backend_acquired != TRUE) &&
1003             (cmd != AGPIOC_ACQUIRE)) {
1004                 ret_val = -EBUSY;
1005                 goto ioctl_out;
1006         }
1007         if (cmd != AGPIOC_ACQUIRE) {
1008                 if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
1009                         ret_val = -EPERM;
1010                         goto ioctl_out;
1011                 }
1012                 /* Use the original pid of the controller,
1013                  * in case it's threaded */
1014
1015                 if (agp_fe.current_controller->pid != curr_priv->my_pid) {
1016                         ret_val = -EBUSY;
1017                         goto ioctl_out;
1018                 }
1019         }
1020
1021         switch (cmd) {
1022         case AGPIOC_INFO:
1023                 ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
1024                 break;
1025
1026         case AGPIOC_ACQUIRE:
1027                 ret_val = agpioc_acquire_wrap(curr_priv);
1028                 break;
1029
1030         case AGPIOC_RELEASE:
1031                 ret_val = agpioc_release_wrap(curr_priv);
1032                 break;
1033
1034         case AGPIOC_SETUP:
1035                 ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
1036                 break;
1037
1038         case AGPIOC_RESERVE:
1039                 ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
1040                 break;
1041
1042         case AGPIOC_PROTECT:
1043                 ret_val = agpioc_protect_wrap(curr_priv);
1044                 break;
1045
1046         case AGPIOC_ALLOCATE:
1047                 ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
1048                 break;
1049
1050         case AGPIOC_DEALLOCATE:
1051                 ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
1052                 break;
1053
1054         case AGPIOC_BIND:
1055                 ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
1056                 break;
1057
1058         case AGPIOC_UNBIND:
1059                 ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
1060                 break;
1061         }
1062
1063 ioctl_out:
1064         DBG("ioctl returns %d\n", ret_val);
1065         up(&(agp_fe.agp_mutex));
1066         return ret_val;
1067 }
1068
1069 static struct file_operations agp_fops =
1070 {
1071         .owner          = THIS_MODULE,
1072         .llseek         = no_llseek,
1073         .read           = agp_read,
1074         .write          = agp_write,
1075         .ioctl          = agp_ioctl,
1076         .mmap           = agp_mmap,
1077         .open           = agp_open,
1078         .release        = agp_release,
1079 };
1080
1081 static struct miscdevice agp_miscdev =
1082 {
1083         .minor  = AGPGART_MINOR,
1084         .name   = "agpgart",
1085         .fops   = &agp_fops
1086 };
1087
1088 int agp_frontend_initialize(void)
1089 {
1090         memset(&agp_fe, 0, sizeof(struct agp_front_data));
1091         sema_init(&(agp_fe.agp_mutex), 1);
1092
1093         if (misc_register(&agp_miscdev)) {
1094                 printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
1095                 return -EIO;
1096         }
1097         return 0;
1098 }
1099
1100 void agp_frontend_cleanup(void)
1101 {
1102         misc_deregister(&agp_miscdev);
1103 }