drivers/gpu/drm/ttm/ttm_bo.c

   1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
   2 /**************************************************************************
   3  *
   4  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  22  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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 OR THE
  25  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28 /*
  29  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  30  */
  31
  32 #define pr_fmt(fmt) "[TTM] " fmt
  33
  34 #include <drm/ttm/ttm_bo_driver.h>
  35 #include <drm/ttm/ttm_placement.h>
  36 #include <linux/jiffies.h>
  37 #include <linux/slab.h>
  38 #include <linux/sched.h>
  39 #include <linux/mm.h>
  40 #include <linux/file.h>
  41 #include <linux/module.h>
  42 #include <linux/atomic.h>
  43 #include <linux/dma-resv.h>
  44
  45 #include "ttm_module.h"
  46
  47 static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
  48                                         struct ttm_placement *placement)
  49 {
  50         struct drm_printer p = drm_debug_printer(TTM_PFX);
  51         struct ttm_resource_manager *man;
  52         int i, mem_type;
  53
  54         drm_printf(&p, "No space for %p (%lu pages, %zuK, %zuM)\n",
  55                    bo, bo->resource->num_pages, bo->base.size >> 10,
  56                    bo->base.size >> 20);
  57         for (i = 0; i < placement->num_placement; i++) {
  58                 mem_type = placement->placement[i].mem_type;
  59                 drm_printf(&p, "  placement[%d]=0x%08X (%d)\n",
  60                            i, placement->placement[i].flags, mem_type);
  61                 man = ttm_manager_type(bo->bdev, mem_type);
  62                 ttm_resource_manager_debug(man, &p);
  63         }
  64 }
  65
  66 /**
  67  * ttm_bo_move_to_lru_tail
  68  *
  69  * @bo: The buffer object.
  70  *
  71  * Move this BO to the tail of all lru lists used to lookup and reserve an
  72  * object. This function must be called with struct ttm_global::lru_lock
  73  * held, and is used to make a BO less likely to be considered for eviction.
  74  */
  75 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo)
  76 {
  77         dma_resv_assert_held(bo->base.resv);
  78
  79         if (bo->resource)
  80                 ttm_resource_move_to_lru_tail(bo->resource);
  81 }
  82 EXPORT_SYMBOL(ttm_bo_move_to_lru_tail);
  83
  84 /**
  85  * ttm_bo_set_bulk_move - update BOs bulk move object
  86  *
  87  * @bo: The buffer object.
  88  *
  89  * Update the BOs bulk move object, making sure that resources are added/removed
  90  * as well. A bulk move allows to move many resource on the LRU at once,
  91  * resulting in much less overhead of maintaining the LRU.
  92  * The only requirement is that the resources stay together on the LRU and are
  93  * never separated. This is enforces by setting the bulk_move structure on a BO.
  94  * ttm_lru_bulk_move_tail() should be used to move all resources to the tail of
  95  * their LRU list.
  96  */
  97 void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
  98                           struct ttm_lru_bulk_move *bulk)
  99 {
 100         dma_resv_assert_held(bo->base.resv);
 101
 102         if (bo->bulk_move == bulk)
 103                 return;
 104
 105         spin_lock(&bo->bdev->lru_lock);
 106         if (bo->resource)
 107                 ttm_resource_del_bulk_move(bo->resource, bo);
 108         bo->bulk_move = bulk;
 109         if (bo->resource)
 110                 ttm_resource_add_bulk_move(bo->resource, bo);
 111         spin_unlock(&bo->bdev->lru_lock);
 112 }
 113 EXPORT_SYMBOL(ttm_bo_set_bulk_move);
 114
 115 static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
 116                                   struct ttm_resource *mem, bool evict,
 117                                   struct ttm_operation_ctx *ctx,
 118                                   struct ttm_place *hop)
 119 {
 120         struct ttm_device *bdev = bo->bdev;
 121         bool old_use_tt, new_use_tt;
 122         int ret;
 123
 124         old_use_tt = bo->resource &&
 125                 ttm_manager_type(bdev, bo->resource->mem_type)->use_tt;
 126         new_use_tt = ttm_manager_type(bdev, mem->mem_type)->use_tt;
 127
 128         ttm_bo_unmap_virtual(bo);
 129
 130         /*
 131          * Create and bind a ttm if required.
 132          */
 133
 134         if (new_use_tt) {
 135                 /* Zero init the new TTM structure if the old location should
 136                  * have used one as well.
 137                  */
 138                 ret = ttm_tt_create(bo, old_use_tt);
 139                 if (ret)
 140                         goto out_err;
 141
 142                 if (mem->mem_type != TTM_PL_SYSTEM) {
 143                         ret = ttm_tt_populate(bo->bdev, bo->ttm, ctx);
 144                         if (ret)
 145                                 goto out_err;
 146                 }
 147         }
 148
 149         ret = dma_resv_reserve_fences(bo->base.resv, 1);
 150         if (ret)
 151                 goto out_err;
 152
 153         ret = bdev->funcs->move(bo, evict, ctx, mem, hop);
 154         if (ret) {
 155                 if (ret == -EMULTIHOP)
 156                         return ret;
 157                 goto out_err;
 158         }
 159
 160         ctx->bytes_moved += bo->base.size;
 161         return 0;
 162
 163 out_err:
 164         if (!old_use_tt)
 165                 ttm_bo_tt_destroy(bo);
 166
 167         return ret;
 168 }
 169
 170 /*
 171  * Call bo::reserved.
 172  * Will release GPU memory type usage on destruction.
 173  * This is the place to put in driver specific hooks to release
 174  * driver private resources.
 175  * Will release the bo::reserved lock.
 176  */
 177
 178 static void ttm_bo_cleanup_memtype_use(struct ttm_buffer_object *bo)
 179 {
 180         if (bo->bdev->funcs->delete_mem_notify)
 181                 bo->bdev->funcs->delete_mem_notify(bo);
 182
 183         ttm_bo_tt_destroy(bo);
 184         ttm_resource_free(bo, &bo->resource);
 185 }
 186
 187 static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
 188 {
 189         int r;
 190
 191         if (bo->base.resv == &bo->base._resv)
 192                 return 0;
 193
 194         BUG_ON(!dma_resv_trylock(&bo->base._resv));
 195
 196         r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
 197         dma_resv_unlock(&bo->base._resv);
 198         if (r)
 199                 return r;
 200
 201         if (bo->type != ttm_bo_type_sg) {
 202                 /* This works because the BO is about to be destroyed and nobody
 203                  * reference it any more. The only tricky case is the trylock on
 204                  * the resv object while holding the lru_lock.
 205                  */
 206                 spin_lock(&bo->bdev->lru_lock);
 207                 bo->base.resv = &bo->base._resv;
 208                 spin_unlock(&bo->bdev->lru_lock);
 209         }
 210
 211         return r;
 212 }
 213
 214 static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
 215 {
 216         struct dma_resv *resv = &bo->base._resv;
 217         struct dma_resv_iter cursor;
 218         struct dma_fence *fence;
 219
 220         dma_resv_iter_begin(&cursor, resv, DMA_RESV_USAGE_BOOKKEEP);
 221         dma_resv_for_each_fence_unlocked(&cursor, fence) {
 222                 if (!fence->ops->signaled)
 223                         dma_fence_enable_sw_signaling(fence);
 224         }
 225         dma_resv_iter_end(&cursor);
 226 }
 227
 228 /**
 229  * ttm_bo_cleanup_refs
 230  * If bo idle, remove from lru lists, and unref.
 231  * If not idle, block if possible.
 232  *
 233  * Must be called with lru_lock and reservation held, this function
 234  * will drop the lru lock and optionally the reservation lock before returning.
 235  *
 236  * @bo:                    The buffer object to clean-up
 237  * @interruptible:         Any sleeps should occur interruptibly.
 238  * @no_wait_gpu:           Never wait for gpu. Return -EBUSY instead.
 239  * @unlock_resv:           Unlock the reservation lock as well.
 240  */
 241
 242 static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
 243                                bool interruptible, bool no_wait_gpu,
 244                                bool unlock_resv)
 245 {
 246         struct dma_resv *resv = &bo->base._resv;
 247         int ret;
 248
 249         if (dma_resv_test_signaled(resv, DMA_RESV_USAGE_BOOKKEEP))
 250                 ret = 0;
 251         else
 252                 ret = -EBUSY;
 253
 254         if (ret && !no_wait_gpu) {
 255                 long lret;
 256
 257                 if (unlock_resv)
 258                         dma_resv_unlock(bo->base.resv);
 259                 spin_unlock(&bo->bdev->lru_lock);
 260
 261                 lret = dma_resv_wait_timeout(resv, DMA_RESV_USAGE_BOOKKEEP,
 262                                              interruptible,
 263                                              30 * HZ);
 264
 265                 if (lret < 0)
 266                         return lret;
 267                 else if (lret == 0)
 268                         return -EBUSY;
 269
 270                 spin_lock(&bo->bdev->lru_lock);
 271                 if (unlock_resv && !dma_resv_trylock(bo->base.resv)) {
 272                         /*
 273                          * We raced, and lost, someone else holds the reservation now,
 274                          * and is probably busy in ttm_bo_cleanup_memtype_use.
 275                          *
 276                          * Even if it's not the case, because we finished waiting any
 277                          * delayed destruction would succeed, so just return success
 278                          * here.
 279                          */
 280                         spin_unlock(&bo->bdev->lru_lock);
 281                         return 0;
 282                 }
 283                 ret = 0;
 284         }
 285
 286         if (ret || unlikely(list_empty(&bo->ddestroy))) {
 287                 if (unlock_resv)
 288                         dma_resv_unlock(bo->base.resv);
 289                 spin_unlock(&bo->bdev->lru_lock);
 290                 return ret;
 291         }
 292
 293         list_del_init(&bo->ddestroy);
 294         spin_unlock(&bo->bdev->lru_lock);
 295         ttm_bo_cleanup_memtype_use(bo);
 296
 297         if (unlock_resv)
 298                 dma_resv_unlock(bo->base.resv);
 299
 300         ttm_bo_put(bo);
 301
 302         return 0;
 303 }
 304
 305 /*
 306  * Traverse the delayed list, and call ttm_bo_cleanup_refs on all
 307  * encountered buffers.
 308  */
 309 bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all)
 310 {
 311         struct list_head removed;
 312         bool empty;
 313
 314         INIT_LIST_HEAD(&removed);
 315
 316         spin_lock(&bdev->lru_lock);
 317         while (!list_empty(&bdev->ddestroy)) {
 318                 struct ttm_buffer_object *bo;
 319
 320                 bo = list_first_entry(&bdev->ddestroy, struct ttm_buffer_object,
 321                                       ddestroy);
 322                 list_move_tail(&bo->ddestroy, &removed);
 323                 if (!ttm_bo_get_unless_zero(bo))
 324                         continue;
 325
 326                 if (remove_all || bo->base.resv != &bo->base._resv) {
 327                         spin_unlock(&bdev->lru_lock);
 328                         dma_resv_lock(bo->base.resv, NULL);
 329
 330                         spin_lock(&bdev->lru_lock);
 331                         ttm_bo_cleanup_refs(bo, false, !remove_all, true);
 332
 333                 } else if (dma_resv_trylock(bo->base.resv)) {
 334                         ttm_bo_cleanup_refs(bo, false, !remove_all, true);
 335                 } else {
 336                         spin_unlock(&bdev->lru_lock);
 337                 }
 338
 339                 ttm_bo_put(bo);
 340                 spin_lock(&bdev->lru_lock);
 341         }
 342         list_splice_tail(&removed, &bdev->ddestroy);
 343         empty = list_empty(&bdev->ddestroy);
 344         spin_unlock(&bdev->lru_lock);
 345
 346         return empty;
 347 }
 348
 349 static void ttm_bo_release(struct kref *kref)
 350 {
 351         struct ttm_buffer_object *bo =
 352             container_of(kref, struct ttm_buffer_object, kref);
 353         struct ttm_device *bdev = bo->bdev;
 354         int ret;
 355
 356         WARN_ON_ONCE(bo->pin_count);
 357         WARN_ON_ONCE(bo->bulk_move);
 358
 359         if (!bo->deleted) {
 360                 ret = ttm_bo_individualize_resv(bo);
 361                 if (ret) {
 362                         /* Last resort, if we fail to allocate memory for the
 363                          * fences block for the BO to become idle
 364                          */
 365                         dma_resv_wait_timeout(bo->base.resv,
 366                                               DMA_RESV_USAGE_BOOKKEEP, false,
 367                                               30 * HZ);
 368                 }
 369
 370                 if (bo->bdev->funcs->release_notify)
 371                         bo->bdev->funcs->release_notify(bo);
 372
 373                 drm_vma_offset_remove(bdev->vma_manager, &bo->base.vma_node);
 374                 ttm_mem_io_free(bdev, bo->resource);
 375         }
 376
 377         if (!dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP) ||
 378             !dma_resv_trylock(bo->base.resv)) {
 379                 /* The BO is not idle, resurrect it for delayed destroy */
 380                 ttm_bo_flush_all_fences(bo);
 381                 bo->deleted = true;
 382
 383                 spin_lock(&bo->bdev->lru_lock);
 384
 385                 /*
 386                  * Make pinned bos immediately available to
 387                  * shrinkers, now that they are queued for
 388                  * destruction.
 389                  *
 390                  * FIXME: QXL is triggering this. Can be removed when the
 391                  * driver is fixed.
 392                  */
 393                 if (bo->pin_count) {
 394                         bo->pin_count = 0;
 395                         ttm_resource_move_to_lru_tail(bo->resource);
 396                 }
 397
 398                 kref_init(&bo->kref);
 399                 list_add_tail(&bo->ddestroy, &bdev->ddestroy);
 400                 spin_unlock(&bo->bdev->lru_lock);
 401
 402                 schedule_delayed_work(&bdev->wq,
 403                                       ((HZ / 100) < 1) ? 1 : HZ / 100);
 404                 return;
 405         }
 406
 407         spin_lock(&bo->bdev->lru_lock);
 408         list_del(&bo->ddestroy);
 409         spin_unlock(&bo->bdev->lru_lock);
 410
 411         ttm_bo_cleanup_memtype_use(bo);
 412         dma_resv_unlock(bo->base.resv);
 413
 414         atomic_dec(&ttm_glob.bo_count);
 415         bo->destroy(bo);
 416 }
 417
 418 void ttm_bo_put(struct ttm_buffer_object *bo)
 419 {
 420         kref_put(&bo->kref, ttm_bo_release);
 421 }
 422 EXPORT_SYMBOL(ttm_bo_put);
 423
 424 int ttm_bo_lock_delayed_workqueue(struct ttm_device *bdev)
 425 {
 426         return cancel_delayed_work_sync(&bdev->wq);
 427 }
 428 EXPORT_SYMBOL(ttm_bo_lock_delayed_workqueue);
 429
 430 void ttm_bo_unlock_delayed_workqueue(struct ttm_device *bdev, int resched)
 431 {
 432         if (resched)
 433                 schedule_delayed_work(&bdev->wq,
 434                                       ((HZ / 100) < 1) ? 1 : HZ / 100);
 435 }
 436 EXPORT_SYMBOL(ttm_bo_unlock_delayed_workqueue);
 437
 438 static int ttm_bo_bounce_temp_buffer(struct ttm_buffer_object *bo,
 439                                      struct ttm_resource **mem,
 440                                      struct ttm_operation_ctx *ctx,
 441                                      struct ttm_place *hop)
 442 {
 443         struct ttm_placement hop_placement;
 444         struct ttm_resource *hop_mem;
 445         int ret;
 446
 447         hop_placement.num_placement = hop_placement.num_busy_placement = 1;
 448         hop_placement.placement = hop_placement.busy_placement = hop;
 449
 450         /* find space in the bounce domain */
 451         ret = ttm_bo_mem_space(bo, &hop_placement, &hop_mem, ctx);
 452         if (ret)
 453                 return ret;
 454         /* move to the bounce domain */
 455         ret = ttm_bo_handle_move_mem(bo, hop_mem, false, ctx, NULL);
 456         if (ret) {
 457                 ttm_resource_free(bo, &hop_mem);
 458                 return ret;
 459         }
 460         return 0;
 461 }
 462
 463 static int ttm_bo_evict(struct ttm_buffer_object *bo,
 464                         struct ttm_operation_ctx *ctx)
 465 {
 466         struct ttm_device *bdev = bo->bdev;
 467         struct ttm_resource *evict_mem;
 468         struct ttm_placement placement;
 469         struct ttm_place hop;
 470         int ret = 0;
 471
 472         memset(&hop, 0, sizeof(hop));
 473
 474         dma_resv_assert_held(bo->base.resv);
 475
 476         placement.num_placement = 0;
 477         placement.num_busy_placement = 0;
 478         bdev->funcs->evict_flags(bo, &placement);
 479
 480         if (!placement.num_placement && !placement.num_busy_placement) {
 481                 ret = ttm_bo_wait(bo, true, false);
 482                 if (ret)
 483                         return ret;
 484
 485                 /*
 486                  * Since we've already synced, this frees backing store
 487                  * immediately.
 488                  */
 489                 return ttm_bo_pipeline_gutting(bo);
 490         }
 491
 492         ret = ttm_bo_mem_space(bo, &placement, &evict_mem, ctx);
 493         if (ret) {
 494                 if (ret != -ERESTARTSYS) {
 495                         pr_err("Failed to find memory space for buffer 0x%p eviction\n",
 496                                bo);
 497                         ttm_bo_mem_space_debug(bo, &placement);
 498                 }
 499                 goto out;
 500         }
 501
 502 bounce:
 503         ret = ttm_bo_handle_move_mem(bo, evict_mem, true, ctx, &hop);
 504         if (ret == -EMULTIHOP) {
 505                 ret = ttm_bo_bounce_temp_buffer(bo, &evict_mem, ctx, &hop);
 506                 if (ret) {
 507                         pr_err("Buffer eviction failed\n");
 508                         ttm_resource_free(bo, &evict_mem);
 509                         goto out;
 510                 }
 511                 /* try and move to final place now. */
 512                 goto bounce;
 513         }
 514 out:
 515         return ret;
 516 }
 517
 518 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
 519                               const struct ttm_place *place)
 520 {
 521         struct ttm_resource *res = bo->resource;
 522         struct ttm_device *bdev = bo->bdev;
 523
 524         dma_resv_assert_held(bo->base.resv);
 525         if (bo->resource->mem_type == TTM_PL_SYSTEM)
 526                 return true;
 527
 528         /* Don't evict this BO if it's outside of the
 529          * requested placement range
 530          */
 531         return ttm_resource_intersects(bdev, res, place, bo->base.size);
 532 }
 533 EXPORT_SYMBOL(ttm_bo_eviction_valuable);
 534
 535 /*
 536  * Check the target bo is allowable to be evicted or swapout, including cases:
 537  *
 538  * a. if share same reservation object with ctx->resv, have assumption
 539  * reservation objects should already be locked, so not lock again and
 540  * return true directly when either the opreation allow_reserved_eviction
 541  * or the target bo already is in delayed free list;
 542  *
 543  * b. Otherwise, trylock it.
 544  */
 545 static bool ttm_bo_evict_swapout_allowable(struct ttm_buffer_object *bo,
 546                                            struct ttm_operation_ctx *ctx,
 547                                            const struct ttm_place *place,
 548                                            bool *locked, bool *busy)
 549 {
 550         bool ret = false;
 551
 552         if (bo->base.resv == ctx->resv) {
 553                 dma_resv_assert_held(bo->base.resv);
 554                 if (ctx->allow_res_evict)
 555                         ret = true;
 556                 *locked = false;
 557                 if (busy)
 558                         *busy = false;
 559         } else {
 560                 ret = dma_resv_trylock(bo->base.resv);
 561                 *locked = ret;
 562                 if (busy)
 563                         *busy = !ret;
 564         }
 565
 566         if (ret && place && (bo->resource->mem_type != place->mem_type ||
 567                 !bo->bdev->funcs->eviction_valuable(bo, place))) {
 568                 ret = false;
 569                 if (*locked) {
 570                         dma_resv_unlock(bo->base.resv);
 571                         *locked = false;
 572                 }
 573         }
 574
 575         return ret;
 576 }
 577
 578 /**
 579  * ttm_mem_evict_wait_busy - wait for a busy BO to become available
 580  *
 581  * @busy_bo: BO which couldn't be locked with trylock
 582  * @ctx: operation context
 583  * @ticket: acquire ticket
 584  *
 585  * Try to lock a busy buffer object to avoid failing eviction.
 586  */
 587 static int ttm_mem_evict_wait_busy(struct ttm_buffer_object *busy_bo,
 588                                    struct ttm_operation_ctx *ctx,
 589                                    struct ww_acquire_ctx *ticket)
 590 {
 591         int r;
 592
 593         if (!busy_bo || !ticket)
 594                 return -EBUSY;
 595
 596         if (ctx->interruptible)
 597                 r = dma_resv_lock_interruptible(busy_bo->base.resv,
 598                                                           ticket);
 599         else
 600                 r = dma_resv_lock(busy_bo->base.resv, ticket);
 601
 602         /*
 603          * TODO: It would be better to keep the BO locked until allocation is at
 604          * least tried one more time, but that would mean a much larger rework
 605          * of TTM.
 606          */
 607         if (!r)
 608                 dma_resv_unlock(busy_bo->base.resv);
 609
 610         return r == -EDEADLK ? -EBUSY : r;
 611 }
 612
 613 int ttm_mem_evict_first(struct ttm_device *bdev,
 614                         struct ttm_resource_manager *man,
 615                         const struct ttm_place *place,
 616                         struct ttm_operation_ctx *ctx,
 617                         struct ww_acquire_ctx *ticket)
 618 {
 619         struct ttm_buffer_object *bo = NULL, *busy_bo = NULL;
 620         struct ttm_resource_cursor cursor;
 621         struct ttm_resource *res;
 622         bool locked = false;
 623         int ret;
 624
 625         spin_lock(&bdev->lru_lock);
 626         ttm_resource_manager_for_each_res(man, &cursor, res) {
 627                 bool busy;
 628
 629                 if (!ttm_bo_evict_swapout_allowable(res->bo, ctx, place,
 630                                                     &locked, &busy)) {
 631                         if (busy && !busy_bo && ticket !=
 632                             dma_resv_locking_ctx(res->bo->base.resv))
 633                                 busy_bo = res->bo;
 634                         continue;
 635                 }
 636
 637                 if (ttm_bo_get_unless_zero(res->bo)) {
 638                         bo = res->bo;
 639                         break;
 640                 }
 641                 if (locked)
 642                         dma_resv_unlock(res->bo->base.resv);
 643         }
 644
 645         if (!bo) {
 646                 if (busy_bo && !ttm_bo_get_unless_zero(busy_bo))
 647                         busy_bo = NULL;
 648                 spin_unlock(&bdev->lru_lock);
 649                 ret = ttm_mem_evict_wait_busy(busy_bo, ctx, ticket);
 650                 if (busy_bo)
 651                         ttm_bo_put(busy_bo);
 652                 return ret;
 653         }
 654
 655         if (bo->deleted) {
 656                 ret = ttm_bo_cleanup_refs(bo, ctx->interruptible,
 657                                           ctx->no_wait_gpu, locked);
 658                 ttm_bo_put(bo);
 659                 return ret;
 660         }
 661
 662         spin_unlock(&bdev->lru_lock);
 663
 664         ret = ttm_bo_evict(bo, ctx);
 665         if (locked)
 666                 ttm_bo_unreserve(bo);
 667         else
 668                 ttm_bo_move_to_lru_tail_unlocked(bo);
 669
 670         ttm_bo_put(bo);
 671         return ret;
 672 }
 673
 674 /**
 675  * ttm_bo_pin - Pin the buffer object.
 676  * @bo: The buffer object to pin
 677  *
 678  * Make sure the buffer is not evicted any more during memory pressure.
 679  * @bo must be unpinned again by calling ttm_bo_unpin().
 680  */
 681 void ttm_bo_pin(struct ttm_buffer_object *bo)
 682 {
 683         dma_resv_assert_held(bo->base.resv);
 684         WARN_ON_ONCE(!kref_read(&bo->kref));
 685         spin_lock(&bo->bdev->lru_lock);
 686         if (bo->resource)
 687                 ttm_resource_del_bulk_move(bo->resource, bo);
 688         ++bo->pin_count;
 689         spin_unlock(&bo->bdev->lru_lock);
 690 }
 691 EXPORT_SYMBOL(ttm_bo_pin);
 692
 693 /**
 694  * ttm_bo_unpin - Unpin the buffer object.
 695  * @bo: The buffer object to unpin
 696  *
 697  * Allows the buffer object to be evicted again during memory pressure.
 698  */
 699 void ttm_bo_unpin(struct ttm_buffer_object *bo)
 700 {
 701         dma_resv_assert_held(bo->base.resv);
 702         WARN_ON_ONCE(!kref_read(&bo->kref));
 703         if (WARN_ON_ONCE(!bo->pin_count))
 704                 return;
 705
 706         spin_lock(&bo->bdev->lru_lock);
 707         --bo->pin_count;
 708         if (bo->resource)
 709                 ttm_resource_add_bulk_move(bo->resource, bo);
 710         spin_unlock(&bo->bdev->lru_lock);
 711 }
 712 EXPORT_SYMBOL(ttm_bo_unpin);
 713
 714 /*
 715  * Add the last move fence to the BO as kernel dependency and reserve a new
 716  * fence slot.
 717  */
 718 static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo,
 719                                  struct ttm_resource_manager *man,
 720                                  struct ttm_resource *mem,
 721                                  bool no_wait_gpu)
 722 {
 723         struct dma_fence *fence;
 724         int ret;
 725
 726         spin_lock(&man->move_lock);
 727         fence = dma_fence_get(man->move);
 728         spin_unlock(&man->move_lock);
 729
 730         if (!fence)
 731                 return 0;
 732
 733         if (no_wait_gpu) {
 734                 ret = dma_fence_is_signaled(fence) ? 0 : -EBUSY;
 735                 dma_fence_put(fence);
 736                 return ret;
 737         }
 738
 739         dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_KERNEL);
 740
 741         ret = dma_resv_reserve_fences(bo->base.resv, 1);
 742         dma_fence_put(fence);
 743         return ret;
 744 }
 745
 746 /*
 747  * Repeatedly evict memory from the LRU for @mem_type until we create enough
 748  * space, or we've evicted everything and there isn't enough space.
 749  */
 750 static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
 751                                   const struct ttm_place *place,
 752                                   struct ttm_resource **mem,
 753                                   struct ttm_operation_ctx *ctx)
 754 {
 755         struct ttm_device *bdev = bo->bdev;
 756         struct ttm_resource_manager *man;
 757         struct ww_acquire_ctx *ticket;
 758         int ret;
 759
 760         man = ttm_manager_type(bdev, place->mem_type);
 761         ticket = dma_resv_locking_ctx(bo->base.resv);
 762         do {
 763                 ret = ttm_resource_alloc(bo, place, mem);
 764                 if (likely(!ret))
 765                         break;
 766                 if (unlikely(ret != -ENOSPC))
 767                         return ret;
 768                 ret = ttm_mem_evict_first(bdev, man, place, ctx,
 769                                           ticket);
 770                 if (unlikely(ret != 0))
 771                         return ret;
 772         } while (1);
 773
 774         return ttm_bo_add_move_fence(bo, man, *mem, ctx->no_wait_gpu);
 775 }
 776
 777 /*
 778  * Creates space for memory region @mem according to its type.
 779  *
 780  * This function first searches for free space in compatible memory types in
 781  * the priority order defined by the driver.  If free space isn't found, then
 782  * ttm_bo_mem_force_space is attempted in priority order to evict and find
 783  * space.
 784  */
 785 int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 786                         struct ttm_placement *placement,
 787                         struct ttm_resource **mem,
 788                         struct ttm_operation_ctx *ctx)
 789 {
 790         struct ttm_device *bdev = bo->bdev;
 791         bool type_found = false;
 792         int i, ret;
 793
 794         ret = dma_resv_reserve_fences(bo->base.resv, 1);
 795         if (unlikely(ret))
 796                 return ret;
 797
 798         for (i = 0; i < placement->num_placement; ++i) {
 799                 const struct ttm_place *place = &placement->placement[i];
 800                 struct ttm_resource_manager *man;
 801
 802                 man = ttm_manager_type(bdev, place->mem_type);
 803                 if (!man || !ttm_resource_manager_used(man))
 804                         continue;
 805
 806                 type_found = true;
 807                 ret = ttm_resource_alloc(bo, place, mem);
 808                 if (ret == -ENOSPC)
 809                         continue;
 810                 if (unlikely(ret))
 811                         goto error;
 812
 813                 ret = ttm_bo_add_move_fence(bo, man, *mem, ctx->no_wait_gpu);
 814                 if (unlikely(ret)) {
 815                         ttm_resource_free(bo, mem);
 816                         if (ret == -EBUSY)
 817                                 continue;
 818
 819                         goto error;
 820                 }
 821                 return 0;
 822         }
 823
 824         for (i = 0; i < placement->num_busy_placement; ++i) {
 825                 const struct ttm_place *place = &placement->busy_placement[i];
 826                 struct ttm_resource_manager *man;
 827
 828                 man = ttm_manager_type(bdev, place->mem_type);
 829                 if (!man || !ttm_resource_manager_used(man))
 830                         continue;
 831
 832                 type_found = true;
 833                 ret = ttm_bo_mem_force_space(bo, place, mem, ctx);
 834                 if (likely(!ret))
 835                         return 0;
 836
 837                 if (ret && ret != -EBUSY)
 838                         goto error;
 839         }
 840
 841         ret = -ENOMEM;
 842         if (!type_found) {
 843                 pr_err(TTM_PFX "No compatible memory type found\n");
 844                 ret = -EINVAL;
 845         }
 846
 847 error:
 848         return ret;
 849 }
 850 EXPORT_SYMBOL(ttm_bo_mem_space);
 851
 852 static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 853                               struct ttm_placement *placement,
 854                               struct ttm_operation_ctx *ctx)
 855 {
 856         struct ttm_resource *mem;
 857         struct ttm_place hop;
 858         int ret;
 859
 860         dma_resv_assert_held(bo->base.resv);
 861
 862         /*
 863          * Determine where to move the buffer.
 864          *
 865          * If driver determines move is going to need
 866          * an extra step then it will return -EMULTIHOP
 867          * and the buffer will be moved to the temporary
 868          * stop and the driver will be called to make
 869          * the second hop.
 870          */
 871         ret = ttm_bo_mem_space(bo, placement, &mem, ctx);
 872         if (ret)
 873                 return ret;
 874 bounce:
 875         ret = ttm_bo_handle_move_mem(bo, mem, false, ctx, &hop);
 876         if (ret == -EMULTIHOP) {
 877                 ret = ttm_bo_bounce_temp_buffer(bo, &mem, ctx, &hop);
 878                 if (ret)
 879                         goto out;
 880                 /* try and move to final place now. */
 881                 goto bounce;
 882         }
 883 out:
 884         if (ret)
 885                 ttm_resource_free(bo, &mem);
 886         return ret;
 887 }
 888
 889 int ttm_bo_validate(struct ttm_buffer_object *bo,
 890                     struct ttm_placement *placement,
 891                     struct ttm_operation_ctx *ctx)
 892 {
 893         int ret;
 894
 895         dma_resv_assert_held(bo->base.resv);
 896
 897         /*
 898          * Remove the backing store if no placement is given.
 899          */
 900         if (!placement->num_placement && !placement->num_busy_placement)
 901                 return ttm_bo_pipeline_gutting(bo);
 902
 903         /*
 904          * Check whether we need to move buffer.
 905          */
 906         if (!bo->resource || !ttm_resource_compat(bo->resource, placement)) {
 907                 ret = ttm_bo_move_buffer(bo, placement, ctx);
 908                 if (ret)
 909                         return ret;
 910         }
 911         /*
 912          * We might need to add a TTM.
 913          */
 914         if (!bo->resource || bo->resource->mem_type == TTM_PL_SYSTEM) {
 915                 ret = ttm_tt_create(bo, true);
 916                 if (ret)
 917                         return ret;
 918         }
 919         return 0;
 920 }
 921 EXPORT_SYMBOL(ttm_bo_validate);
 922
 923 /**
 924  * ttm_bo_init_reserved
 925  *
 926  * @bdev: Pointer to a ttm_device struct.
 927  * @bo: Pointer to a ttm_buffer_object to be initialized.
 928  * @type: Requested type of buffer object.
 929  * @placement: Initial placement for buffer object.
 930  * @alignment: Data alignment in pages.
 931  * @ctx: TTM operation context for memory allocation.
 932  * @sg: Scatter-gather table.
 933  * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
 934  * @destroy: Destroy function. Use NULL for kfree().
 935  *
 936  * This function initializes a pre-allocated struct ttm_buffer_object.
 937  * As this object may be part of a larger structure, this function,
 938  * together with the @destroy function, enables driver-specific objects
 939  * derived from a ttm_buffer_object.
 940  *
 941  * On successful return, the caller owns an object kref to @bo. The kref and
 942  * list_kref are usually set to 1, but note that in some situations, other
 943  * tasks may already be holding references to @bo as well.
 944  * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
 945  * and it is the caller's responsibility to call ttm_bo_unreserve.
 946  *
 947  * If a failure occurs, the function will call the @destroy function. Thus,
 948  * after a failure, dereferencing @bo is illegal and will likely cause memory
 949  * corruption.
 950  *
 951  * Returns
 952  * -ENOMEM: Out of memory.
 953  * -EINVAL: Invalid placement flags.
 954  * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
 955  */
 956 int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,
 957                          enum ttm_bo_type type, struct ttm_placement *placement,
 958                          uint32_t alignment, struct ttm_operation_ctx *ctx,
 959                          struct sg_table *sg, struct dma_resv *resv,
 960                          void (*destroy) (struct ttm_buffer_object *))
 961 {
 962         static const struct ttm_place sys_mem = { .mem_type = TTM_PL_SYSTEM };
 963         int ret;
 964
 965         kref_init(&bo->kref);
 966         INIT_LIST_HEAD(&bo->ddestroy);
 967         bo->bdev = bdev;
 968         bo->type = type;
 969         bo->page_alignment = alignment;
 970         bo->destroy = destroy;
 971         bo->pin_count = 0;
 972         bo->sg = sg;
 973         bo->bulk_move = NULL;
 974         if (resv)
 975                 bo->base.resv = resv;
 976         else
 977                 bo->base.resv = &bo->base._resv;
 978         atomic_inc(&ttm_glob.bo_count);
 979
 980         ret = ttm_resource_alloc(bo, &sys_mem, &bo->resource);
 981         if (unlikely(ret)) {
 982                 ttm_bo_put(bo);
 983                 return ret;
 984         }
 985
 986         /*
 987          * For ttm_bo_type_device buffers, allocate
 988          * address space from the device.
 989          */
 990         if (bo->type == ttm_bo_type_device || bo->type == ttm_bo_type_sg) {
 991                 ret = drm_vma_offset_add(bdev->vma_manager, &bo->base.vma_node,
 992                                          PFN_UP(bo->base.size));
 993                 if (ret)
 994                         goto err_put;
 995         }
 996
 997         /* passed reservation objects should already be locked,
 998          * since otherwise lockdep will be angered in radeon.
 999          */
1000         if (!resv)
1001                 WARN_ON(!dma_resv_trylock(bo->base.resv));
1002         else
1003                 dma_resv_assert_held(resv);
1004
1005         ret = ttm_bo_validate(bo, placement, ctx);
1006         if (unlikely(ret))
1007                 goto err_unlock;
1008
1009         return 0;
1010
1011 err_unlock:
1012         if (!resv)
1013                 dma_resv_unlock(bo->base.resv);
1014
1015 err_put:
1016         ttm_bo_put(bo);
1017         return ret;
1018 }
1019 EXPORT_SYMBOL(ttm_bo_init_reserved);
1020
1021 /**
1022  * ttm_bo_init_validate
1023  *
1024  * @bdev: Pointer to a ttm_device struct.
1025  * @bo: Pointer to a ttm_buffer_object to be initialized.
1026  * @type: Requested type of buffer object.
1027  * @placement: Initial placement for buffer object.
1028  * @alignment: Data alignment in pages.
1029  * @interruptible: If needing to sleep to wait for GPU resources,
1030  * sleep interruptible.
1031  * pinned in physical memory. If this behaviour is not desired, this member
1032  * holds a pointer to a persistent shmem object. Typically, this would
1033  * point to the shmem object backing a GEM object if TTM is used to back a
1034  * GEM user interface.
1035  * @sg: Scatter-gather table.
1036  * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
1037  * @destroy: Destroy function. Use NULL for kfree().
1038  *
1039  * This function initializes a pre-allocated struct ttm_buffer_object.
1040  * As this object may be part of a larger structure, this function,
1041  * together with the @destroy function,
1042  * enables driver-specific objects derived from a ttm_buffer_object.
1043  *
1044  * On successful return, the caller owns an object kref to @bo. The kref and
1045  * list_kref are usually set to 1, but note that in some situations, other
1046  * tasks may already be holding references to @bo as well.
1047  *
1048  * If a failure occurs, the function will call the @destroy function, Thus,
1049  * after a failure, dereferencing @bo is illegal and will likely cause memory
1050  * corruption.
1051  *
1052  * Returns
1053  * -ENOMEM: Out of memory.
1054  * -EINVAL: Invalid placement flags.
1055  * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
1056  */
1057 int ttm_bo_init_validate(struct ttm_device *bdev, struct ttm_buffer_object *bo,
1058                          enum ttm_bo_type type, struct ttm_placement *placement,
1059                          uint32_t alignment, bool interruptible,
1060                          struct sg_table *sg, struct dma_resv *resv,
1061                          void (*destroy) (struct ttm_buffer_object *))
1062 {
1063         struct ttm_operation_ctx ctx = { interruptible, false };
1064         int ret;
1065
1066         ret = ttm_bo_init_reserved(bdev, bo, type, placement, alignment, &ctx,
1067                                    sg, resv, destroy);
1068         if (ret)
1069                 return ret;
1070
1071         if (!resv)
1072                 ttm_bo_unreserve(bo);
1073
1074         return 0;
1075 }
1076 EXPORT_SYMBOL(ttm_bo_init_validate);
1077
1078 /*
1079  * buffer object vm functions.
1080  */
1081
1082 void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
1083 {
1084         struct ttm_device *bdev = bo->bdev;
1085
1086         drm_vma_node_unmap(&bo->base.vma_node, bdev->dev_mapping);
1087         ttm_mem_io_free(bdev, bo->resource);
1088 }
1089 EXPORT_SYMBOL(ttm_bo_unmap_virtual);
1090
1091 int ttm_bo_wait(struct ttm_buffer_object *bo,
1092                 bool interruptible, bool no_wait)
1093 {
1094         long timeout = 15 * HZ;
1095
1096         if (no_wait) {
1097                 if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP))
1098                         return 0;
1099                 else
1100                         return -EBUSY;
1101         }
1102
1103         timeout = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP,
1104                                         interruptible, timeout);
1105         if (timeout < 0)
1106                 return timeout;
1107
1108         if (timeout == 0)
1109                 return -EBUSY;
1110
1111         return 0;
1112 }
1113 EXPORT_SYMBOL(ttm_bo_wait);
1114
1115 int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
1116                    gfp_t gfp_flags)
1117 {
1118         struct ttm_place place;
1119         bool locked;
1120         int ret;
1121
1122         /*
1123          * While the bo may already reside in SYSTEM placement, set
1124          * SYSTEM as new placement to cover also the move further below.
1125          * The driver may use the fact that we're moving from SYSTEM
1126          * as an indication that we're about to swap out.
1127          */
1128         memset(&place, 0, sizeof(place));
1129         place.mem_type = bo->resource->mem_type;
1130         if (!ttm_bo_evict_swapout_allowable(bo, ctx, &place, &locked, NULL))
1131                 return -EBUSY;
1132
1133         if (!bo->ttm || !ttm_tt_is_populated(bo->ttm) ||
1134             bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL ||
1135             bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED ||
1136             !ttm_bo_get_unless_zero(bo)) {
1137                 if (locked)
1138                         dma_resv_unlock(bo->base.resv);
1139                 return -EBUSY;
1140         }
1141
1142         if (bo->deleted) {
1143                 ret = ttm_bo_cleanup_refs(bo, false, false, locked);
1144                 ttm_bo_put(bo);
1145                 return ret == -EBUSY ? -ENOSPC : ret;
1146         }
1147
1148         /* TODO: Cleanup the locking */
1149         spin_unlock(&bo->bdev->lru_lock);
1150
1151         /*
1152          * Move to system cached
1153          */
1154         if (bo->resource->mem_type != TTM_PL_SYSTEM) {
1155                 struct ttm_operation_ctx ctx = { false, false };
1156                 struct ttm_resource *evict_mem;
1157                 struct ttm_place hop;
1158
1159                 memset(&hop, 0, sizeof(hop));
1160                 place.mem_type = TTM_PL_SYSTEM;
1161                 ret = ttm_resource_alloc(bo, &place, &evict_mem);
1162                 if (unlikely(ret))
1163                         goto out;
1164
1165                 ret = ttm_bo_handle_move_mem(bo, evict_mem, true, &ctx, &hop);
1166                 if (unlikely(ret != 0)) {
1167                         WARN(ret == -EMULTIHOP, "Unexpected multihop in swaput - likely driver bug.\n");
1168                         goto out;
1169                 }
1170         }
1171
1172         /*
1173          * Make sure BO is idle.
1174          */
1175         ret = ttm_bo_wait(bo, false, false);
1176         if (unlikely(ret != 0))
1177                 goto out;
1178
1179         ttm_bo_unmap_virtual(bo);
1180
1181         /*
1182          * Swap out. Buffer will be swapped in again as soon as
1183          * anyone tries to access a ttm page.
1184          */
1185         if (bo->bdev->funcs->swap_notify)
1186                 bo->bdev->funcs->swap_notify(bo);
1187
1188         if (ttm_tt_is_populated(bo->ttm))
1189                 ret = ttm_tt_swapout(bo->bdev, bo->ttm, gfp_flags);
1190 out:
1191
1192         /*
1193          * Unreserve without putting on LRU to avoid swapping out an
1194          * already swapped buffer.
1195          */
1196         if (locked)
1197                 dma_resv_unlock(bo->base.resv);
1198         ttm_bo_put(bo);
1199         return ret == -EBUSY ? -ENOSPC : ret;
1200 }
1201
1202 void ttm_bo_tt_destroy(struct ttm_buffer_object *bo)
1203 {
1204         if (bo->ttm == NULL)
1205                 return;
1206
1207         ttm_tt_unpopulate(bo->bdev, bo->ttm);
1208         ttm_tt_destroy(bo->bdev, bo->ttm);
1209         bo->ttm = NULL;
1210 }