1 /************************************************************************** 2 * 3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA. 4 * All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sub license, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice (including the 15 * next paragraph) shall be included in all copies or substantial portions 16 * of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 24 * USE OR OTHER DEALINGS IN THE SOFTWARE. 25 * 26 * 27 **************************************************************************/ 28 29 /* 30 * Generic simple memory manager implementation. Intended to be used as a base 31 * class implementation for more advanced memory managers. 32 * 33 * Note that the algorithm used is quite simple and there might be substantial 34 * performance gains if a smarter free list is implemented. Currently it is just an 35 * unordered stack of free regions. This could easily be improved if an RB-tree 36 * is used instead. At least if we expect heavy fragmentation. 37 * 38 * Aligned allocations can also see improvement. 39 * 40 * Authors: 41 * Thomas Hellström <thomas-at-tungstengraphics-dot-com> 42 */ 43 44 #include <drm/drmP.h> 45 #include <drm/drm_mm.h> 46 #include <linux/slab.h> 47 #include <linux/seq_file.h> 48 #include <linux/export.h> 49 50 #define MM_UNUSED_TARGET 4 51 52 static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic) 53 { 54 struct drm_mm_node *child; 55 56 if (atomic) 57 child = kzalloc(sizeof(*child), GFP_ATOMIC); 58 else 59 child = kzalloc(sizeof(*child), GFP_KERNEL); 60 61 if (unlikely(child == NULL)) { 62 spin_lock(&mm->unused_lock); 63 if (list_empty(&mm->unused_nodes)) 64 child = NULL; 65 else { 66 child = 67 list_entry(mm->unused_nodes.next, 68 struct drm_mm_node, node_list); 69 list_del(&child->node_list); 70 --mm->num_unused; 71 } 72 spin_unlock(&mm->unused_lock); 73 } 74 return child; 75 } 76 77 int drm_mm_pre_get(struct drm_mm *mm) 78 { 79 struct drm_mm_node *node; 80 81 spin_lock(&mm->unused_lock); 82 while (mm->num_unused < MM_UNUSED_TARGET) { 83 spin_unlock(&mm->unused_lock); 84 node = kzalloc(sizeof(*node), GFP_KERNEL); 85 spin_lock(&mm->unused_lock); 86 87 if (unlikely(node == NULL)) { 88 int ret = (mm->num_unused < 2) ? -ENOMEM : 0; 89 spin_unlock(&mm->unused_lock); 90 return ret; 91 } 92 ++mm->num_unused; 93 list_add_tail(&node->node_list, &mm->unused_nodes); 94 } 95 spin_unlock(&mm->unused_lock); 96 return 0; 97 } 98 99 /** 100 * DOC: Overview 101 * 102 * drm_mm provides a simple range allocator. The drivers are free to use the 103 * resource allocator from the linux core if it suits them, the upside of drm_mm 104 * is that it's in the DRM core. Which means that it's easier to extend for 105 * some of the crazier special purpose needs of gpus. 106 * 107 * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node. 108 * Drivers are free to embed either of them into their own suitable 109 * datastructures. drm_mm itself will not do any allocations of its own, so if 110 * drivers choose not to embed nodes they need to still allocate them 111 * themselves. 112 * 113 * The range allocator also supports reservation of preallocated blocks. This is 114 * useful for taking over initial mode setting configurations from the firmware, 115 * where an object needs to be created which exactly matches the firmware's 116 * scanout target. As long as the range is still free it can be inserted anytime 117 * after the allocator is initialized, which helps with avoiding looped 118 * depencies in the driver load sequence. 119 * 120 * drm_mm maintains a stack of most recently freed holes, which of all 121 * simplistic datastructures seems to be a fairly decent approach to clustering 122 * allocations and avoiding too much fragmentation. This means free space 123 * searches are O(num_holes). Given that all the fancy features drm_mm supports 124 * something better would be fairly complex and since gfx thrashing is a fairly 125 * steep cliff not a real concern. Removing a node again is O(1). 126 * 127 * drm_mm supports a few features: Alignment and range restrictions can be 128 * supplied. Further more every &drm_mm_node has a color value (which is just an 129 * opaqua unsigned long) which in conjunction with a driver callback can be used 130 * to implement sophisticated placement restrictions. The i915 DRM driver uses 131 * this to implement guard pages between incompatible caching domains in the 132 * graphics TT. 133 * 134 * Two behaviors are supported for searching and allocating: bottom-up and top-down. 135 * The default is bottom-up. Top-down allocation can be used if the memory area 136 * has different restrictions, or just to reduce fragmentation. 137 * 138 * Finally iteration helpers to walk all nodes and all holes are provided as are 139 * some basic allocator dumpers for debugging. 140 */ 141 142 static void drm_mm_insert_helper(struct drm_mm_node *hole_node, 143 struct drm_mm_node *node, 144 unsigned long size, unsigned alignment, 145 unsigned long color, 146 enum drm_mm_allocator_flags flags) 147 { 148 struct drm_mm *mm = hole_node->mm; 149 unsigned long hole_start = drm_mm_hole_node_start(hole_node); 150 unsigned long hole_end = drm_mm_hole_node_end(hole_node); 151 unsigned long adj_start = hole_start; 152 unsigned long adj_end = hole_end; 153 154 BUG_ON(node->allocated); 155 156 if (mm->color_adjust) 157 mm->color_adjust(hole_node, color, &adj_start, &adj_end); 158 159 if (flags & DRM_MM_CREATE_TOP) 160 adj_start = adj_end - size; 161 162 if (alignment) { 163 unsigned tmp = adj_start % alignment; 164 if (tmp) { 165 if (flags & DRM_MM_CREATE_TOP) 166 adj_start -= tmp; 167 else 168 adj_start += alignment - tmp; 169 } 170 } 171 172 BUG_ON(adj_start < hole_start); 173 BUG_ON(adj_end > hole_end); 174 175 if (adj_start == hole_start) { 176 hole_node->hole_follows = 0; 177 list_del(&hole_node->hole_stack); 178 } 179 180 node->start = adj_start; 181 node->size = size; 182 node->mm = mm; 183 node->color = color; 184 node->allocated = 1; 185 186 INIT_LIST_HEAD(&node->hole_stack); 187 list_add(&node->node_list, &hole_node->node_list); 188 189 BUG_ON(node->start + node->size > adj_end); 190 191 node->hole_follows = 0; 192 if (__drm_mm_hole_node_start(node) < hole_end) { 193 list_add(&node->hole_stack, &mm->hole_stack); 194 node->hole_follows = 1; 195 } 196 } 197 198 /** 199 * drm_mm_reserve_node - insert an pre-initialized node 200 * @mm: drm_mm allocator to insert @node into 201 * @node: drm_mm_node to insert 202 * 203 * This functions inserts an already set-up drm_mm_node into the allocator, 204 * meaning that start, size and color must be set by the caller. This is useful 205 * to initialize the allocator with preallocated objects which must be set-up 206 * before the range allocator can be set-up, e.g. when taking over a firmware 207 * framebuffer. 208 * 209 * Returns: 210 * 0 on success, -ENOSPC if there's no hole where @node is. 211 */ 212 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) 213 { 214 struct drm_mm_node *hole; 215 unsigned long end = node->start + node->size; 216 unsigned long hole_start; 217 unsigned long hole_end; 218 219 BUG_ON(node == NULL); 220 221 /* Find the relevant hole to add our node to */ 222 drm_mm_for_each_hole(hole, mm, hole_start, hole_end) { 223 if (hole_start > node->start || hole_end < end) 224 continue; 225 226 node->mm = mm; 227 node->allocated = 1; 228 229 INIT_LIST_HEAD(&node->hole_stack); 230 list_add(&node->node_list, &hole->node_list); 231 232 if (node->start == hole_start) { 233 hole->hole_follows = 0; 234 list_del_init(&hole->hole_stack); 235 } 236 237 node->hole_follows = 0; 238 if (end != hole_end) { 239 list_add(&node->hole_stack, &mm->hole_stack); 240 node->hole_follows = 1; 241 } 242 243 return 0; 244 } 245 246 return -ENOSPC; 247 } 248 EXPORT_SYMBOL(drm_mm_reserve_node); 249 250 struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node, 251 unsigned long size, 252 unsigned alignment, 253 unsigned long color, 254 int atomic) 255 { 256 struct drm_mm_node *node; 257 258 node = drm_mm_kmalloc(hole_node->mm, atomic); 259 if (unlikely(node == NULL)) 260 return NULL; 261 262 drm_mm_insert_helper(hole_node, node, size, alignment, color, DRM_MM_CREATE_DEFAULT); 263 264 return node; 265 } 266 267 /** 268 * drm_mm_insert_node_generic - search for space and insert @node 269 * @mm: drm_mm to allocate from 270 * @node: preallocate node to insert 271 * @size: size of the allocation 272 * @alignment: alignment of the allocation 273 * @color: opaque tag value to use for this node 274 * @sflags: flags to fine-tune the allocation search 275 * @aflags: flags to fine-tune the allocation behavior 276 * 277 * The preallocated node must be cleared to 0. 278 * 279 * Returns: 280 * 0 on success, -ENOSPC if there's no suitable hole. 281 */ 282 int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node, 283 unsigned long size, unsigned alignment, 284 unsigned long color, 285 enum drm_mm_search_flags sflags, 286 enum drm_mm_allocator_flags aflags) 287 { 288 struct drm_mm_node *hole_node; 289 290 hole_node = drm_mm_search_free_generic(mm, size, alignment, 291 color, sflags); 292 if (!hole_node) 293 return -ENOSPC; 294 295 drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags); 296 return 0; 297 } 298 EXPORT_SYMBOL(drm_mm_insert_node_generic); 299 300 static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node, 301 struct drm_mm_node *node, 302 unsigned long size, unsigned alignment, 303 unsigned long color, 304 unsigned long start, unsigned long end, 305 enum drm_mm_allocator_flags flags) 306 { 307 struct drm_mm *mm = hole_node->mm; 308 unsigned long hole_start = drm_mm_hole_node_start(hole_node); 309 unsigned long hole_end = drm_mm_hole_node_end(hole_node); 310 unsigned long adj_start = hole_start; 311 unsigned long adj_end = hole_end; 312 313 BUG_ON(!hole_node->hole_follows || node->allocated); 314 315 if (adj_start < start) 316 adj_start = start; 317 if (adj_end > end) 318 adj_end = end; 319 320 if (flags & DRM_MM_CREATE_TOP) 321 adj_start = adj_end - size; 322 323 if (mm->color_adjust) 324 mm->color_adjust(hole_node, color, &adj_start, &adj_end); 325 326 if (alignment) { 327 unsigned tmp = adj_start % alignment; 328 if (tmp) { 329 if (flags & DRM_MM_CREATE_TOP) 330 adj_start -= tmp; 331 else 332 adj_start += alignment - tmp; 333 } 334 } 335 336 if (adj_start == hole_start) { 337 hole_node->hole_follows = 0; 338 list_del(&hole_node->hole_stack); 339 } 340 341 node->start = adj_start; 342 node->size = size; 343 node->mm = mm; 344 node->color = color; 345 node->allocated = 1; 346 347 INIT_LIST_HEAD(&node->hole_stack); 348 list_add(&node->node_list, &hole_node->node_list); 349 350 BUG_ON(node->start < start); 351 BUG_ON(node->start < adj_start); 352 BUG_ON(node->start + node->size > adj_end); 353 BUG_ON(node->start + node->size > end); 354 355 node->hole_follows = 0; 356 if (__drm_mm_hole_node_start(node) < hole_end) { 357 list_add(&node->hole_stack, &mm->hole_stack); 358 node->hole_follows = 1; 359 } 360 } 361 362 struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node, 363 unsigned long size, 364 unsigned alignment, 365 unsigned long color, 366 unsigned long start, 367 unsigned long end, 368 int atomic) 369 { 370 struct drm_mm_node *node; 371 372 node = drm_mm_kmalloc(hole_node->mm, atomic); 373 if (unlikely(node == NULL)) 374 return NULL; 375 376 drm_mm_insert_helper_range(hole_node, node, size, alignment, color, 377 start, end, DRM_MM_CREATE_DEFAULT); 378 379 return node; 380 } 381 382 /** 383 * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node 384 * @mm: drm_mm to allocate from 385 * @node: preallocate node to insert 386 * @size: size of the allocation 387 * @alignment: alignment of the allocation 388 * @color: opaque tag value to use for this node 389 * @start: start of the allowed range for this node 390 * @end: end of the allowed range for this node 391 * @sflags: flags to fine-tune the allocation search 392 * @aflags: flags to fine-tune the allocation behavior 393 * 394 * The preallocated node must be cleared to 0. 395 * 396 * Returns: 397 * 0 on success, -ENOSPC if there's no suitable hole. 398 */ 399 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node, 400 unsigned long size, unsigned alignment, 401 unsigned long color, 402 unsigned long start, unsigned long end, 403 enum drm_mm_search_flags sflags, 404 enum drm_mm_allocator_flags aflags) 405 { 406 struct drm_mm_node *hole_node; 407 408 hole_node = drm_mm_search_free_in_range_generic(mm, 409 size, alignment, color, 410 start, end, sflags); 411 if (!hole_node) 412 return -ENOSPC; 413 414 drm_mm_insert_helper_range(hole_node, node, 415 size, alignment, color, 416 start, end, aflags); 417 return 0; 418 } 419 EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic); 420 421 /** 422 * drm_mm_remove_node - Remove a memory node from the allocator. 423 * @node: drm_mm_node to remove 424 * 425 * This just removes a node from its drm_mm allocator. The node does not need to 426 * be cleared again before it can be re-inserted into this or any other drm_mm 427 * allocator. It is a bug to call this function on a un-allocated node. 428 */ 429 void drm_mm_remove_node(struct drm_mm_node *node) 430 { 431 struct drm_mm *mm = node->mm; 432 struct drm_mm_node *prev_node; 433 434 if (WARN_ON(!node->allocated)) 435 return; 436 437 BUG_ON(node->scanned_block || node->scanned_prev_free 438 || node->scanned_next_free); 439 440 prev_node = 441 list_entry(node->node_list.prev, struct drm_mm_node, node_list); 442 443 if (node->hole_follows) { 444 BUG_ON(__drm_mm_hole_node_start(node) == 445 __drm_mm_hole_node_end(node)); 446 list_del(&node->hole_stack); 447 } else 448 BUG_ON(__drm_mm_hole_node_start(node) != 449 __drm_mm_hole_node_end(node)); 450 451 452 if (!prev_node->hole_follows) { 453 prev_node->hole_follows = 1; 454 list_add(&prev_node->hole_stack, &mm->hole_stack); 455 } else 456 list_move(&prev_node->hole_stack, &mm->hole_stack); 457 458 list_del(&node->node_list); 459 node->allocated = 0; 460 } 461 EXPORT_SYMBOL(drm_mm_remove_node); 462 463 /* 464 * Remove a memory node from the allocator and free the allocated struct 465 * drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the 466 * drm_mm_get_block functions. 467 */ 468 void drm_mm_put_block(struct drm_mm_node *node) 469 { 470 471 struct drm_mm *mm = node->mm; 472 473 drm_mm_remove_node(node); 474 475 spin_lock(&mm->unused_lock); 476 if (mm->num_unused < MM_UNUSED_TARGET) { 477 list_add(&node->node_list, &mm->unused_nodes); 478 ++mm->num_unused; 479 } else 480 kfree(node); 481 spin_unlock(&mm->unused_lock); 482 } 483 484 static int check_free_hole(unsigned long start, unsigned long end, 485 unsigned long size, unsigned alignment) 486 { 487 if (end - start < size) 488 return 0; 489 490 if (alignment) { 491 unsigned tmp = start % alignment; 492 if (tmp) 493 start += alignment - tmp; 494 } 495 496 return end >= start + size; 497 } 498 499 struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, 500 unsigned long size, 501 unsigned alignment, 502 unsigned long color, 503 enum drm_mm_search_flags flags) 504 { 505 struct drm_mm_node *entry; 506 struct drm_mm_node *best; 507 unsigned long adj_start; 508 unsigned long adj_end; 509 unsigned long best_size; 510 511 BUG_ON(mm->scanned_blocks); 512 513 best = NULL; 514 best_size = ~0UL; 515 516 __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, 517 flags & DRM_MM_SEARCH_BELOW) { 518 unsigned long hole_size = adj_end - adj_start; 519 520 if (mm->color_adjust) { 521 mm->color_adjust(entry, color, &adj_start, &adj_end); 522 if (adj_end <= adj_start) 523 continue; 524 } 525 526 if (!check_free_hole(adj_start, adj_end, size, alignment)) 527 continue; 528 529 if (!(flags & DRM_MM_SEARCH_BEST)) 530 return entry; 531 532 if (hole_size < best_size) { 533 best = entry; 534 best_size = hole_size; 535 } 536 } 537 538 return best; 539 } 540 541 struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, 542 unsigned long size, 543 unsigned alignment, 544 unsigned long color, 545 unsigned long start, 546 unsigned long end, 547 enum drm_mm_search_flags flags) 548 { 549 struct drm_mm_node *entry; 550 struct drm_mm_node *best; 551 unsigned long adj_start; 552 unsigned long adj_end; 553 unsigned long best_size; 554 555 BUG_ON(mm->scanned_blocks); 556 557 best = NULL; 558 best_size = ~0UL; 559 560 __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, 561 flags & DRM_MM_SEARCH_BELOW) { 562 unsigned long hole_size = adj_end - adj_start; 563 564 if (adj_start < start) 565 adj_start = start; 566 if (adj_end > end) 567 adj_end = end; 568 569 if (mm->color_adjust) { 570 mm->color_adjust(entry, color, &adj_start, &adj_end); 571 if (adj_end <= adj_start) 572 continue; 573 } 574 575 if (!check_free_hole(adj_start, adj_end, size, alignment)) 576 continue; 577 578 if (!(flags & DRM_MM_SEARCH_BEST)) 579 return entry; 580 581 if (hole_size < best_size) { 582 best = entry; 583 best_size = hole_size; 584 } 585 } 586 587 return best; 588 } 589 590 /** 591 * drm_mm_replace_node - move an allocation from @old to @new 592 * @old: drm_mm_node to remove from the allocator 593 * @new: drm_mm_node which should inherit @old's allocation 594 * 595 * This is useful for when drivers embed the drm_mm_node structure and hence 596 * can't move allocations by reassigning pointers. It's a combination of remove 597 * and insert with the guarantee that the allocation start will match. 598 */ 599 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new) 600 { 601 list_replace(&old->node_list, &new->node_list); 602 list_replace(&old->hole_stack, &new->hole_stack); 603 new->hole_follows = old->hole_follows; 604 new->mm = old->mm; 605 new->start = old->start; 606 new->size = old->size; 607 new->color = old->color; 608 609 old->allocated = 0; 610 new->allocated = 1; 611 } 612 EXPORT_SYMBOL(drm_mm_replace_node); 613 614 /** 615 * DOC: lru scan roaster 616 * 617 * Very often GPUs need to have continuous allocations for a given object. When 618 * evicting objects to make space for a new one it is therefore not most 619 * efficient when we simply start to select all objects from the tail of an LRU 620 * until there's a suitable hole: Especially for big objects or nodes that 621 * otherwise have special allocation constraints there's a good chance we evict 622 * lots of (smaller) objects unecessarily. 623 * 624 * The DRM range allocator supports this use-case through the scanning 625 * interfaces. First a scan operation needs to be initialized with 626 * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds 627 * objects to the roaster (probably by walking an LRU list, but this can be 628 * freely implemented) until a suitable hole is found or there's no further 629 * evitable object. 630 * 631 * The the driver must walk through all objects again in exactly the reverse 632 * order to restore the allocator state. Note that while the allocator is used 633 * in the scan mode no other operation is allowed. 634 * 635 * Finally the driver evicts all objects selected in the scan. Adding and 636 * removing an object is O(1), and since freeing a node is also O(1) the overall 637 * complexity is O(scanned_objects). So like the free stack which needs to be 638 * walked before a scan operation even begins this is linear in the number of 639 * objects. It doesn't seem to hurt badly. 640 */ 641 642 /** 643 * drm_mm_init_scan - initialize lru scanning 644 * @mm: drm_mm to scan 645 * @size: size of the allocation 646 * @alignment: alignment of the allocation 647 * @color: opaque tag value to use for the allocation 648 * 649 * This simply sets up the scanning routines with the parameters for the desired 650 * hole. Note that there's no need to specify allocation flags, since they only 651 * change the place a node is allocated from within a suitable hole. 652 * 653 * Warning: 654 * As long as the scan list is non-empty, no other operations than 655 * adding/removing nodes to/from the scan list are allowed. 656 */ 657 void drm_mm_init_scan(struct drm_mm *mm, 658 unsigned long size, 659 unsigned alignment, 660 unsigned long color) 661 { 662 mm->scan_color = color; 663 mm->scan_alignment = alignment; 664 mm->scan_size = size; 665 mm->scanned_blocks = 0; 666 mm->scan_hit_start = 0; 667 mm->scan_hit_end = 0; 668 mm->scan_check_range = 0; 669 mm->prev_scanned_node = NULL; 670 } 671 EXPORT_SYMBOL(drm_mm_init_scan); 672 673 /** 674 * drm_mm_init_scan - initialize range-restricted lru scanning 675 * @mm: drm_mm to scan 676 * @size: size of the allocation 677 * @alignment: alignment of the allocation 678 * @color: opaque tag value to use for the allocation 679 * @start: start of the allowed range for the allocation 680 * @end: end of the allowed range for the allocation 681 * 682 * This simply sets up the scanning routines with the parameters for the desired 683 * hole. Note that there's no need to specify allocation flags, since they only 684 * change the place a node is allocated from within a suitable hole. 685 * 686 * Warning: 687 * As long as the scan list is non-empty, no other operations than 688 * adding/removing nodes to/from the scan list are allowed. 689 */ 690 void drm_mm_init_scan_with_range(struct drm_mm *mm, 691 unsigned long size, 692 unsigned alignment, 693 unsigned long color, 694 unsigned long start, 695 unsigned long end) 696 { 697 mm->scan_color = color; 698 mm->scan_alignment = alignment; 699 mm->scan_size = size; 700 mm->scanned_blocks = 0; 701 mm->scan_hit_start = 0; 702 mm->scan_hit_end = 0; 703 mm->scan_start = start; 704 mm->scan_end = end; 705 mm->scan_check_range = 1; 706 mm->prev_scanned_node = NULL; 707 } 708 EXPORT_SYMBOL(drm_mm_init_scan_with_range); 709 710 /** 711 * drm_mm_scan_add_block - add a node to the scan list 712 * @node: drm_mm_node to add 713 * 714 * Add a node to the scan list that might be freed to make space for the desired 715 * hole. 716 * 717 * Returns: 718 * True if a hole has been found, false otherwise. 719 */ 720 bool drm_mm_scan_add_block(struct drm_mm_node *node) 721 { 722 struct drm_mm *mm = node->mm; 723 struct drm_mm_node *prev_node; 724 unsigned long hole_start, hole_end; 725 unsigned long adj_start, adj_end; 726 727 mm->scanned_blocks++; 728 729 BUG_ON(node->scanned_block); 730 node->scanned_block = 1; 731 732 prev_node = list_entry(node->node_list.prev, struct drm_mm_node, 733 node_list); 734 735 node->scanned_preceeds_hole = prev_node->hole_follows; 736 prev_node->hole_follows = 1; 737 list_del(&node->node_list); 738 node->node_list.prev = &prev_node->node_list; 739 node->node_list.next = &mm->prev_scanned_node->node_list; 740 mm->prev_scanned_node = node; 741 742 adj_start = hole_start = drm_mm_hole_node_start(prev_node); 743 adj_end = hole_end = drm_mm_hole_node_end(prev_node); 744 745 if (mm->scan_check_range) { 746 if (adj_start < mm->scan_start) 747 adj_start = mm->scan_start; 748 if (adj_end > mm->scan_end) 749 adj_end = mm->scan_end; 750 } 751 752 if (mm->color_adjust) 753 mm->color_adjust(prev_node, mm->scan_color, 754 &adj_start, &adj_end); 755 756 if (check_free_hole(adj_start, adj_end, 757 mm->scan_size, mm->scan_alignment)) { 758 mm->scan_hit_start = hole_start; 759 mm->scan_hit_end = hole_end; 760 return true; 761 } 762 763 return false; 764 } 765 EXPORT_SYMBOL(drm_mm_scan_add_block); 766 767 /** 768 * drm_mm_scan_remove_block - remove a node from the scan list 769 * @node: drm_mm_node to remove 770 * 771 * Nodes _must_ be removed in the exact same order from the scan list as they 772 * have been added, otherwise the internal state of the memory manager will be 773 * corrupted. 774 * 775 * When the scan list is empty, the selected memory nodes can be freed. An 776 * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then 777 * return the just freed block (because its at the top of the free_stack list). 778 * 779 * Returns: 780 * True if this block should be evicted, false otherwise. Will always 781 * return false when no hole has been found. 782 */ 783 bool drm_mm_scan_remove_block(struct drm_mm_node *node) 784 { 785 struct drm_mm *mm = node->mm; 786 struct drm_mm_node *prev_node; 787 788 mm->scanned_blocks--; 789 790 BUG_ON(!node->scanned_block); 791 node->scanned_block = 0; 792 793 prev_node = list_entry(node->node_list.prev, struct drm_mm_node, 794 node_list); 795 796 prev_node->hole_follows = node->scanned_preceeds_hole; 797 list_add(&node->node_list, &prev_node->node_list); 798 799 return (drm_mm_hole_node_end(node) > mm->scan_hit_start && 800 node->start < mm->scan_hit_end); 801 } 802 EXPORT_SYMBOL(drm_mm_scan_remove_block); 803 804 /** 805 * drm_mm_clean - checks whether an allocator is clean 806 * @mm: drm_mm allocator to check 807 * 808 * Returns: 809 * True if the allocator is completely free, false if there's still a node 810 * allocated in it. 811 */ 812 bool drm_mm_clean(struct drm_mm * mm) 813 { 814 struct list_head *head = &mm->head_node.node_list; 815 816 return (head->next->next == head); 817 } 818 EXPORT_SYMBOL(drm_mm_clean); 819 820 /** 821 * drm_mm_init - initialize a drm-mm allocator 822 * @mm: the drm_mm structure to initialize 823 * @start: start of the range managed by @mm 824 * @size: end of the range managed by @mm 825 * 826 * Note that @mm must be cleared to 0 before calling this function. 827 */ 828 void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size) 829 { 830 INIT_LIST_HEAD(&mm->hole_stack); 831 INIT_LIST_HEAD(&mm->unused_nodes); 832 mm->num_unused = 0; 833 mm->scanned_blocks = 0; 834 835 /* Clever trick to avoid a special case in the free hole tracking. */ 836 INIT_LIST_HEAD(&mm->head_node.node_list); 837 INIT_LIST_HEAD(&mm->head_node.hole_stack); 838 mm->head_node.hole_follows = 1; 839 mm->head_node.scanned_block = 0; 840 mm->head_node.scanned_prev_free = 0; 841 mm->head_node.scanned_next_free = 0; 842 mm->head_node.mm = mm; 843 mm->head_node.start = start + size; 844 mm->head_node.size = start - mm->head_node.start; 845 list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack); 846 847 mm->color_adjust = NULL; 848 } 849 EXPORT_SYMBOL(drm_mm_init); 850 851 /** 852 * drm_mm_takedown - clean up a drm_mm allocator 853 * @mm: drm_mm allocator to clean up 854 * 855 * Note that it is a bug to call this function on an allocator which is not 856 * clean. 857 */ 858 void drm_mm_takedown(struct drm_mm * mm) 859 { 860 WARN(!list_empty(&mm->head_node.node_list), 861 "Memory manager not clean during takedown.\n"); 862 } 863 EXPORT_SYMBOL(drm_mm_takedown); 864 865 static unsigned long drm_mm_debug_hole(struct drm_mm_node *entry, 866 const char *prefix) 867 { 868 unsigned long hole_start, hole_end, hole_size; 869 870 if (entry->hole_follows) { 871 hole_start = drm_mm_hole_node_start(entry); 872 hole_end = drm_mm_hole_node_end(entry); 873 hole_size = hole_end - hole_start; 874 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n", 875 prefix, hole_start, hole_end, 876 hole_size); 877 return hole_size; 878 } 879 880 return 0; 881 } 882 883 /** 884 * drm_mm_debug_table - dump allocator state to dmesg 885 * @mm: drm_mm allocator to dump 886 * @prefix: prefix to use for dumping to dmesg 887 */ 888 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix) 889 { 890 struct drm_mm_node *entry; 891 unsigned long total_used = 0, total_free = 0, total = 0; 892 893 total_free += drm_mm_debug_hole(&mm->head_node, prefix); 894 895 drm_mm_for_each_node(entry, mm) { 896 printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n", 897 prefix, entry->start, entry->start + entry->size, 898 entry->size); 899 total_used += entry->size; 900 total_free += drm_mm_debug_hole(entry, prefix); 901 } 902 total = total_free + total_used; 903 904 printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total, 905 total_used, total_free); 906 } 907 EXPORT_SYMBOL(drm_mm_debug_table); 908 909 #if defined(CONFIG_DEBUG_FS) 910 static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry) 911 { 912 unsigned long hole_start, hole_end, hole_size; 913 914 if (entry->hole_follows) { 915 hole_start = drm_mm_hole_node_start(entry); 916 hole_end = drm_mm_hole_node_end(entry); 917 hole_size = hole_end - hole_start; 918 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n", 919 hole_start, hole_end, hole_size); 920 return hole_size; 921 } 922 923 return 0; 924 } 925 926 /** 927 * drm_mm_dump_table - dump allocator state to a seq_file 928 * @m: seq_file to dump to 929 * @mm: drm_mm allocator to dump 930 */ 931 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm) 932 { 933 struct drm_mm_node *entry; 934 unsigned long total_used = 0, total_free = 0, total = 0; 935 936 total_free += drm_mm_dump_hole(m, &mm->head_node); 937 938 drm_mm_for_each_node(entry, mm) { 939 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n", 940 entry->start, entry->start + entry->size, 941 entry->size); 942 total_used += entry->size; 943 total_free += drm_mm_dump_hole(m, entry); 944 } 945 total = total_free + total_used; 946 947 seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free); 948 return 0; 949 } 950 EXPORT_SYMBOL(drm_mm_dump_table); 951 #endif 952