drivers/gpu/drm/ttm/ttm_pool.c

   1 // SPDX-License-Identifier: GPL-2.0 OR MIT
   2 /*
   3  * Copyright 2020 Advanced Micro Devices, Inc.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  21  * OTHER DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors: Christian König
  24  */
  25
  26 /* Pooling of allocated pages is necessary because changing the caching
  27  * attributes on x86 of the linear mapping requires a costly cross CPU TLB
  28  * invalidate for those addresses.
  29  *
  30  * Additional to that allocations from the DMA coherent API are pooled as well
  31  * cause they are rather slow compared to alloc_pages+map.
  32  */
  33
  34 #include <linux/module.h>
  35 #include <linux/dma-mapping.h>
  36 #include <linux/debugfs.h>
  37 #include <linux/highmem.h>
  38 #include <linux/sched/mm.h>
  39
  40 #ifdef CONFIG_X86
  41 #include <asm/set_memory.h>
  42 #endif
  43
  44 #include <drm/ttm/ttm_pool.h>
  45 #include <drm/ttm/ttm_tt.h>
  46 #include <drm/ttm/ttm_bo.h>
  47
  48 #include "ttm_module.h"
  49
  50 /**
  51  * struct ttm_pool_dma - Helper object for coherent DMA mappings
  52  *
  53  * @addr: original DMA address returned for the mapping
  54  * @vaddr: original vaddr return for the mapping and order in the lower bits
  55  */
  56 struct ttm_pool_dma {
  57         dma_addr_t addr;
  58         unsigned long vaddr;
  59 };
  60
  61 static unsigned long page_pool_size;
  62
  63 MODULE_PARM_DESC(page_pool_size, "Number of pages in the WC/UC/DMA pool");
  64 module_param(page_pool_size, ulong, 0644);
  65
  66 static atomic_long_t allocated_pages;
  67
  68 static struct ttm_pool_type global_write_combined[MAX_ORDER];
  69 static struct ttm_pool_type global_uncached[MAX_ORDER];
  70
  71 static struct ttm_pool_type global_dma32_write_combined[MAX_ORDER];
  72 static struct ttm_pool_type global_dma32_uncached[MAX_ORDER];
  73
  74 static spinlock_t shrinker_lock;
  75 static struct list_head shrinker_list;
  76 static struct shrinker mm_shrinker;
  77
  78 /* Allocate pages of size 1 << order with the given gfp_flags */
  79 static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
  80                                         unsigned int order)
  81 {
  82         unsigned long attr = DMA_ATTR_FORCE_CONTIGUOUS;
  83         struct ttm_pool_dma *dma;
  84         struct page *p;
  85         void *vaddr;
  86
  87         /* Don't set the __GFP_COMP flag for higher order allocations.
  88          * Mapping pages directly into an userspace process and calling
  89          * put_page() on a TTM allocated page is illegal.
  90          */
  91         if (order)
  92                 gfp_flags |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN |
  93                         __GFP_KSWAPD_RECLAIM;
  94
  95         if (!pool->use_dma_alloc) {
  96                 p = alloc_pages(gfp_flags, order);
  97                 if (p)
  98                         p->private = order;
  99                 return p;
 100         }
 101
 102         dma = kmalloc(sizeof(*dma), GFP_KERNEL);
 103         if (!dma)
 104                 return NULL;
 105
 106         if (order)
 107                 attr |= DMA_ATTR_NO_WARN;
 108
 109         vaddr = dma_alloc_attrs(pool->dev, (1ULL << order) * PAGE_SIZE,
 110                                 &dma->addr, gfp_flags, attr);
 111         if (!vaddr)
 112                 goto error_free;
 113
 114         /* TODO: This is an illegal abuse of the DMA API, but we need to rework
 115          * TTM page fault handling and extend the DMA API to clean this up.
 116          */
 117         if (is_vmalloc_addr(vaddr))
 118                 p = vmalloc_to_page(vaddr);
 119         else
 120                 p = virt_to_page(vaddr);
 121
 122         dma->vaddr = (unsigned long)vaddr | order;
 123         p->private = (unsigned long)dma;
 124         return p;
 125
 126 error_free:
 127         kfree(dma);
 128         return NULL;
 129 }
 130
 131 /* Reset the caching and pages of size 1 << order */
 132 static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching,
 133                                unsigned int order, struct page *p)
 134 {
 135         unsigned long attr = DMA_ATTR_FORCE_CONTIGUOUS;
 136         struct ttm_pool_dma *dma;
 137         void *vaddr;
 138
 139 #ifdef CONFIG_X86
 140         /* We don't care that set_pages_wb is inefficient here. This is only
 141          * used when we have to shrink and CPU overhead is irrelevant then.
 142          */
 143         if (caching != ttm_cached && !PageHighMem(p))
 144                 set_pages_wb(p, 1 << order);
 145 #endif
 146
 147         if (!pool || !pool->use_dma_alloc) {
 148                 __free_pages(p, order);
 149                 return;
 150         }
 151
 152         if (order)
 153                 attr |= DMA_ATTR_NO_WARN;
 154
 155         dma = (void *)p->private;
 156         vaddr = (void *)(dma->vaddr & PAGE_MASK);
 157         dma_free_attrs(pool->dev, (1UL << order) * PAGE_SIZE, vaddr, dma->addr,
 158                        attr);
 159         kfree(dma);
 160 }
 161
 162 /* Apply a new caching to an array of pages */
 163 static int ttm_pool_apply_caching(struct page **first, struct page **last,
 164                                   enum ttm_caching caching)
 165 {
 166 #ifdef CONFIG_X86
 167         unsigned int num_pages = last - first;
 168
 169         if (!num_pages)
 170                 return 0;
 171
 172         switch (caching) {
 173         case ttm_cached:
 174                 break;
 175         case ttm_write_combined:
 176                 return set_pages_array_wc(first, num_pages);
 177         case ttm_uncached:
 178                 return set_pages_array_uc(first, num_pages);
 179         }
 180 #endif
 181         return 0;
 182 }
 183
 184 /* Map pages of 1 << order size and fill the DMA address array  */
 185 static int ttm_pool_map(struct ttm_pool *pool, unsigned int order,
 186                         struct page *p, dma_addr_t **dma_addr)
 187 {
 188         dma_addr_t addr;
 189         unsigned int i;
 190
 191         if (pool->use_dma_alloc) {
 192                 struct ttm_pool_dma *dma = (void *)p->private;
 193
 194                 addr = dma->addr;
 195         } else {
 196                 size_t size = (1ULL << order) * PAGE_SIZE;
 197
 198                 addr = dma_map_page(pool->dev, p, 0, size, DMA_BIDIRECTIONAL);
 199                 if (dma_mapping_error(pool->dev, addr))
 200                         return -EFAULT;
 201         }
 202
 203         for (i = 1 << order; i ; --i) {
 204                 *(*dma_addr)++ = addr;
 205                 addr += PAGE_SIZE;
 206         }
 207
 208         return 0;
 209 }
 210
 211 /* Unmap pages of 1 << order size */
 212 static void ttm_pool_unmap(struct ttm_pool *pool, dma_addr_t dma_addr,
 213                            unsigned int num_pages)
 214 {
 215         /* Unmapped while freeing the page */
 216         if (pool->use_dma_alloc)
 217                 return;
 218
 219         dma_unmap_page(pool->dev, dma_addr, (long)num_pages << PAGE_SHIFT,
 220                        DMA_BIDIRECTIONAL);
 221 }
 222
 223 /* Give pages into a specific pool_type */
 224 static void ttm_pool_type_give(struct ttm_pool_type *pt, struct page *p)
 225 {
 226         unsigned int i, num_pages = 1 << pt->order;
 227
 228         for (i = 0; i < num_pages; ++i) {
 229                 if (PageHighMem(p))
 230                         clear_highpage(p + i);
 231                 else
 232                         clear_page(page_address(p + i));
 233         }
 234
 235         spin_lock(&pt->lock);
 236         list_add(&p->lru, &pt->pages);
 237         spin_unlock(&pt->lock);
 238         atomic_long_add(1 << pt->order, &allocated_pages);
 239 }
 240
 241 /* Take pages from a specific pool_type, return NULL when nothing available */
 242 static struct page *ttm_pool_type_take(struct ttm_pool_type *pt)
 243 {
 244         struct page *p;
 245
 246         spin_lock(&pt->lock);
 247         p = list_first_entry_or_null(&pt->pages, typeof(*p), lru);
 248         if (p) {
 249                 atomic_long_sub(1 << pt->order, &allocated_pages);
 250                 list_del(&p->lru);
 251         }
 252         spin_unlock(&pt->lock);
 253
 254         return p;
 255 }
 256
 257 /* Initialize and add a pool type to the global shrinker list */
 258 static void ttm_pool_type_init(struct ttm_pool_type *pt, struct ttm_pool *pool,
 259                                enum ttm_caching caching, unsigned int order)
 260 {
 261         pt->pool = pool;
 262         pt->caching = caching;
 263         pt->order = order;
 264         spin_lock_init(&pt->lock);
 265         INIT_LIST_HEAD(&pt->pages);
 266
 267         spin_lock(&shrinker_lock);
 268         list_add_tail(&pt->shrinker_list, &shrinker_list);
 269         spin_unlock(&shrinker_lock);
 270 }
 271
 272 /* Remove a pool_type from the global shrinker list and free all pages */
 273 static void ttm_pool_type_fini(struct ttm_pool_type *pt)
 274 {
 275         struct page *p;
 276
 277         spin_lock(&shrinker_lock);
 278         list_del(&pt->shrinker_list);
 279         spin_unlock(&shrinker_lock);
 280
 281         while ((p = ttm_pool_type_take(pt)))
 282                 ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
 283 }
 284
 285 /* Return the pool_type to use for the given caching and order */
 286 static struct ttm_pool_type *ttm_pool_select_type(struct ttm_pool *pool,
 287                                                   enum ttm_caching caching,
 288                                                   unsigned int order)
 289 {
 290         if (pool->use_dma_alloc)
 291                 return &pool->caching[caching].orders[order];
 292
 293 #ifdef CONFIG_X86
 294         switch (caching) {
 295         case ttm_write_combined:
 296                 if (pool->use_dma32)
 297                         return &global_dma32_write_combined[order];
 298
 299                 return &global_write_combined[order];
 300         case ttm_uncached:
 301                 if (pool->use_dma32)
 302                         return &global_dma32_uncached[order];
 303
 304                 return &global_uncached[order];
 305         default:
 306                 break;
 307         }
 308 #endif
 309
 310         return NULL;
 311 }
 312
 313 /* Free pages using the global shrinker list */
 314 static unsigned int ttm_pool_shrink(void)
 315 {
 316         struct ttm_pool_type *pt;
 317         unsigned int num_pages;
 318         struct page *p;
 319
 320         spin_lock(&shrinker_lock);
 321         pt = list_first_entry(&shrinker_list, typeof(*pt), shrinker_list);
 322         list_move_tail(&pt->shrinker_list, &shrinker_list);
 323         spin_unlock(&shrinker_lock);
 324
 325         p = ttm_pool_type_take(pt);
 326         if (p) {
 327                 ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
 328                 num_pages = 1 << pt->order;
 329         } else {
 330                 num_pages = 0;
 331         }
 332
 333         return num_pages;
 334 }
 335
 336 /* Return the allocation order based for a page */
 337 static unsigned int ttm_pool_page_order(struct ttm_pool *pool, struct page *p)
 338 {
 339         if (pool->use_dma_alloc) {
 340                 struct ttm_pool_dma *dma = (void *)p->private;
 341
 342                 return dma->vaddr & ~PAGE_MASK;
 343         }
 344
 345         return p->private;
 346 }
 347
 348 /* Called when we got a page, either from a pool or newly allocated */
 349 static int ttm_pool_page_allocated(struct ttm_pool *pool, unsigned int order,
 350                                    struct page *p, dma_addr_t **dma_addr,
 351                                    unsigned long *num_pages,
 352                                    struct page ***pages)
 353 {
 354         unsigned int i;
 355         int r;
 356
 357         if (*dma_addr) {
 358                 r = ttm_pool_map(pool, order, p, dma_addr);
 359                 if (r)
 360                         return r;
 361         }
 362
 363         *num_pages -= 1 << order;
 364         for (i = 1 << order; i; --i, ++(*pages), ++p)
 365                 **pages = p;
 366
 367         return 0;
 368 }
 369
 370 /**
 371  * ttm_pool_alloc - Fill a ttm_tt object
 372  *
 373  * @pool: ttm_pool to use
 374  * @tt: ttm_tt object to fill
 375  * @ctx: operation context
 376  *
 377  * Fill the ttm_tt object with pages and also make sure to DMA map them when
 378  * necessary.
 379  *
 380  * Returns: 0 on successe, negative error code otherwise.
 381  */
 382 int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
 383                    struct ttm_operation_ctx *ctx)
 384 {
 385         unsigned long num_pages = tt->num_pages;
 386         dma_addr_t *dma_addr = tt->dma_address;
 387         struct page **caching = tt->pages;
 388         struct page **pages = tt->pages;
 389         gfp_t gfp_flags = GFP_USER;
 390         unsigned int i, order;
 391         struct page *p;
 392         int r;
 393
 394         WARN_ON(!num_pages || ttm_tt_is_populated(tt));
 395         WARN_ON(dma_addr && !pool->dev);
 396
 397         if (tt->page_flags & TTM_TT_FLAG_ZERO_ALLOC)
 398                 gfp_flags |= __GFP_ZERO;
 399
 400         if (ctx->gfp_retry_mayfail)
 401                 gfp_flags |= __GFP_RETRY_MAYFAIL;
 402
 403         if (pool->use_dma32)
 404                 gfp_flags |= GFP_DMA32;
 405         else
 406                 gfp_flags |= GFP_HIGHUSER;
 407
 408         for (order = min_t(unsigned int, MAX_ORDER - 1, __fls(num_pages));
 409              num_pages;
 410              order = min_t(unsigned int, order, __fls(num_pages))) {
 411                 struct ttm_pool_type *pt;
 412
 413                 pt = ttm_pool_select_type(pool, tt->caching, order);
 414                 p = pt ? ttm_pool_type_take(pt) : NULL;
 415                 if (p) {
 416                         r = ttm_pool_apply_caching(caching, pages,
 417                                                    tt->caching);
 418                         if (r)
 419                                 goto error_free_page;
 420
 421                         do {
 422                                 r = ttm_pool_page_allocated(pool, order, p,
 423                                                             &dma_addr,
 424                                                             &num_pages,
 425                                                             &pages);
 426                                 if (r)
 427                                         goto error_free_page;
 428
 429                                 if (num_pages < (1 << order))
 430                                         break;
 431
 432                                 p = ttm_pool_type_take(pt);
 433                         } while (p);
 434                         caching = pages;
 435                 }
 436
 437                 while (num_pages >= (1 << order) &&
 438                        (p = ttm_pool_alloc_page(pool, gfp_flags, order))) {
 439
 440                         if (PageHighMem(p)) {
 441                                 r = ttm_pool_apply_caching(caching, pages,
 442                                                            tt->caching);
 443                                 if (r)
 444                                         goto error_free_page;
 445                         }
 446                         r = ttm_pool_page_allocated(pool, order, p, &dma_addr,
 447                                                     &num_pages, &pages);
 448                         if (r)
 449                                 goto error_free_page;
 450                         if (PageHighMem(p))
 451                                 caching = pages;
 452                 }
 453
 454                 if (!p) {
 455                         if (order) {
 456                                 --order;
 457                                 continue;
 458                         }
 459                         r = -ENOMEM;
 460                         goto error_free_all;
 461                 }
 462         }
 463
 464         r = ttm_pool_apply_caching(caching, pages, tt->caching);
 465         if (r)
 466                 goto error_free_all;
 467
 468         return 0;
 469
 470 error_free_page:
 471         ttm_pool_free_page(pool, tt->caching, order, p);
 472
 473 error_free_all:
 474         num_pages = tt->num_pages - num_pages;
 475         for (i = 0; i < num_pages; ) {
 476                 order = ttm_pool_page_order(pool, tt->pages[i]);
 477                 ttm_pool_free_page(pool, tt->caching, order, tt->pages[i]);
 478                 i += 1 << order;
 479         }
 480
 481         return r;
 482 }
 483 EXPORT_SYMBOL(ttm_pool_alloc);
 484
 485 /**
 486  * ttm_pool_free - Free the backing pages from a ttm_tt object
 487  *
 488  * @pool: Pool to give pages back to.
 489  * @tt: ttm_tt object to unpopulate
 490  *
 491  * Give the packing pages back to a pool or free them
 492  */
 493 void ttm_pool_free(struct ttm_pool *pool, struct ttm_tt *tt)
 494 {
 495         unsigned int i;
 496
 497         for (i = 0; i < tt->num_pages; ) {
 498                 struct page *p = tt->pages[i];
 499                 unsigned int order, num_pages;
 500                 struct ttm_pool_type *pt;
 501
 502                 order = ttm_pool_page_order(pool, p);
 503                 num_pages = 1ULL << order;
 504                 if (tt->dma_address)
 505                         ttm_pool_unmap(pool, tt->dma_address[i], num_pages);
 506
 507                 pt = ttm_pool_select_type(pool, tt->caching, order);
 508                 if (pt)
 509                         ttm_pool_type_give(pt, tt->pages[i]);
 510                 else
 511                         ttm_pool_free_page(pool, tt->caching, order,
 512                                            tt->pages[i]);
 513
 514                 i += num_pages;
 515         }
 516
 517         while (atomic_long_read(&allocated_pages) > page_pool_size)
 518                 ttm_pool_shrink();
 519 }
 520 EXPORT_SYMBOL(ttm_pool_free);
 521
 522 /**
 523  * ttm_pool_init - Initialize a pool
 524  *
 525  * @pool: the pool to initialize
 526  * @dev: device for DMA allocations and mappings
 527  * @use_dma_alloc: true if coherent DMA alloc should be used
 528  * @use_dma32: true if GFP_DMA32 should be used
 529  *
 530  * Initialize the pool and its pool types.
 531  */
 532 void ttm_pool_init(struct ttm_pool *pool, struct device *dev,
 533                    bool use_dma_alloc, bool use_dma32)
 534 {
 535         unsigned int i, j;
 536
 537         WARN_ON(!dev && use_dma_alloc);
 538
 539         pool->dev = dev;
 540         pool->use_dma_alloc = use_dma_alloc;
 541         pool->use_dma32 = use_dma32;
 542
 543         if (use_dma_alloc) {
 544                 for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
 545                         for (j = 0; j < MAX_ORDER; ++j)
 546                                 ttm_pool_type_init(&pool->caching[i].orders[j],
 547                                                    pool, i, j);
 548         }
 549 }
 550
 551 /**
 552  * ttm_pool_fini - Cleanup a pool
 553  *
 554  * @pool: the pool to clean up
 555  *
 556  * Free all pages in the pool and unregister the types from the global
 557  * shrinker.
 558  */
 559 void ttm_pool_fini(struct ttm_pool *pool)
 560 {
 561         unsigned int i, j;
 562
 563         if (pool->use_dma_alloc) {
 564                 for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
 565                         for (j = 0; j < MAX_ORDER; ++j)
 566                                 ttm_pool_type_fini(&pool->caching[i].orders[j]);
 567         }
 568
 569         /* We removed the pool types from the LRU, but we need to also make sure
 570          * that no shrinker is concurrently freeing pages from the pool.
 571          */
 572         synchronize_shrinkers();
 573 }
 574
 575 /* As long as pages are available make sure to release at least one */
 576 static unsigned long ttm_pool_shrinker_scan(struct shrinker *shrink,
 577                                             struct shrink_control *sc)
 578 {
 579         unsigned long num_freed = 0;
 580
 581         do
 582                 num_freed += ttm_pool_shrink();
 583         while (!num_freed && atomic_long_read(&allocated_pages));
 584
 585         return num_freed;
 586 }
 587
 588 /* Return the number of pages available or SHRINK_EMPTY if we have none */
 589 static unsigned long ttm_pool_shrinker_count(struct shrinker *shrink,
 590                                              struct shrink_control *sc)
 591 {
 592         unsigned long num_pages = atomic_long_read(&allocated_pages);
 593
 594         return num_pages ? num_pages : SHRINK_EMPTY;
 595 }
 596
 597 #ifdef CONFIG_DEBUG_FS
 598 /* Count the number of pages available in a pool_type */
 599 static unsigned int ttm_pool_type_count(struct ttm_pool_type *pt)
 600 {
 601         unsigned int count = 0;
 602         struct page *p;
 603
 604         spin_lock(&pt->lock);
 605         /* Only used for debugfs, the overhead doesn't matter */
 606         list_for_each_entry(p, &pt->pages, lru)
 607                 ++count;
 608         spin_unlock(&pt->lock);
 609
 610         return count;
 611 }
 612
 613 /* Print a nice header for the order */
 614 static void ttm_pool_debugfs_header(struct seq_file *m)
 615 {
 616         unsigned int i;
 617
 618         seq_puts(m, "\t ");
 619         for (i = 0; i < MAX_ORDER; ++i)
 620                 seq_printf(m, " ---%2u---", i);
 621         seq_puts(m, "\n");
 622 }
 623
 624 /* Dump information about the different pool types */
 625 static void ttm_pool_debugfs_orders(struct ttm_pool_type *pt,
 626                                     struct seq_file *m)
 627 {
 628         unsigned int i;
 629
 630         for (i = 0; i < MAX_ORDER; ++i)
 631                 seq_printf(m, " %8u", ttm_pool_type_count(&pt[i]));
 632         seq_puts(m, "\n");
 633 }
 634
 635 /* Dump the total amount of allocated pages */
 636 static void ttm_pool_debugfs_footer(struct seq_file *m)
 637 {
 638         seq_printf(m, "\ntotal\t: %8lu of %8lu\n",
 639                    atomic_long_read(&allocated_pages), page_pool_size);
 640 }
 641
 642 /* Dump the information for the global pools */
 643 static int ttm_pool_debugfs_globals_show(struct seq_file *m, void *data)
 644 {
 645         ttm_pool_debugfs_header(m);
 646
 647         spin_lock(&shrinker_lock);
 648         seq_puts(m, "wc\t:");
 649         ttm_pool_debugfs_orders(global_write_combined, m);
 650         seq_puts(m, "uc\t:");
 651         ttm_pool_debugfs_orders(global_uncached, m);
 652         seq_puts(m, "wc 32\t:");
 653         ttm_pool_debugfs_orders(global_dma32_write_combined, m);
 654         seq_puts(m, "uc 32\t:");
 655         ttm_pool_debugfs_orders(global_dma32_uncached, m);
 656         spin_unlock(&shrinker_lock);
 657
 658         ttm_pool_debugfs_footer(m);
 659
 660         return 0;
 661 }
 662 DEFINE_SHOW_ATTRIBUTE(ttm_pool_debugfs_globals);
 663
 664 /**
 665  * ttm_pool_debugfs - Debugfs dump function for a pool
 666  *
 667  * @pool: the pool to dump the information for
 668  * @m: seq_file to dump to
 669  *
 670  * Make a debugfs dump with the per pool and global information.
 671  */
 672 int ttm_pool_debugfs(struct ttm_pool *pool, struct seq_file *m)
 673 {
 674         unsigned int i;
 675
 676         if (!pool->use_dma_alloc) {
 677                 seq_puts(m, "unused\n");
 678                 return 0;
 679         }
 680
 681         ttm_pool_debugfs_header(m);
 682
 683         spin_lock(&shrinker_lock);
 684         for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
 685                 seq_puts(m, "DMA ");
 686                 switch (i) {
 687                 case ttm_cached:
 688                         seq_puts(m, "\t:");
 689                         break;
 690                 case ttm_write_combined:
 691                         seq_puts(m, "wc\t:");
 692                         break;
 693                 case ttm_uncached:
 694                         seq_puts(m, "uc\t:");
 695                         break;
 696                 }
 697                 ttm_pool_debugfs_orders(pool->caching[i].orders, m);
 698         }
 699         spin_unlock(&shrinker_lock);
 700
 701         ttm_pool_debugfs_footer(m);
 702         return 0;
 703 }
 704 EXPORT_SYMBOL(ttm_pool_debugfs);
 705
 706 /* Test the shrinker functions and dump the result */
 707 static int ttm_pool_debugfs_shrink_show(struct seq_file *m, void *data)
 708 {
 709         struct shrink_control sc = { .gfp_mask = GFP_NOFS };
 710
 711         fs_reclaim_acquire(GFP_KERNEL);
 712         seq_printf(m, "%lu/%lu\n", ttm_pool_shrinker_count(&mm_shrinker, &sc),
 713                    ttm_pool_shrinker_scan(&mm_shrinker, &sc));
 714         fs_reclaim_release(GFP_KERNEL);
 715
 716         return 0;
 717 }
 718 DEFINE_SHOW_ATTRIBUTE(ttm_pool_debugfs_shrink);
 719
 720 #endif
 721
 722 /**
 723  * ttm_pool_mgr_init - Initialize globals
 724  *
 725  * @num_pages: default number of pages
 726  *
 727  * Initialize the global locks and lists for the MM shrinker.
 728  */
 729 int ttm_pool_mgr_init(unsigned long num_pages)
 730 {
 731         unsigned int i;
 732
 733         if (!page_pool_size)
 734                 page_pool_size = num_pages;
 735
 736         spin_lock_init(&shrinker_lock);
 737         INIT_LIST_HEAD(&shrinker_list);
 738
 739         for (i = 0; i < MAX_ORDER; ++i) {
 740                 ttm_pool_type_init(&global_write_combined[i], NULL,
 741                                    ttm_write_combined, i);
 742                 ttm_pool_type_init(&global_uncached[i], NULL, ttm_uncached, i);
 743
 744                 ttm_pool_type_init(&global_dma32_write_combined[i], NULL,
 745                                    ttm_write_combined, i);
 746                 ttm_pool_type_init(&global_dma32_uncached[i], NULL,
 747                                    ttm_uncached, i);
 748         }
 749
 750 #ifdef CONFIG_DEBUG_FS
 751         debugfs_create_file("page_pool", 0444, ttm_debugfs_root, NULL,
 752                             &ttm_pool_debugfs_globals_fops);
 753         debugfs_create_file("page_pool_shrink", 0400, ttm_debugfs_root, NULL,
 754                             &ttm_pool_debugfs_shrink_fops);
 755 #endif
 756
 757         mm_shrinker.count_objects = ttm_pool_shrinker_count;
 758         mm_shrinker.scan_objects = ttm_pool_shrinker_scan;
 759         mm_shrinker.seeks = 1;
 760         return register_shrinker(&mm_shrinker, "drm-ttm_pool");
 761 }
 762
 763 /**
 764  * ttm_pool_mgr_fini - Finalize globals
 765  *
 766  * Cleanup the global pools and unregister the MM shrinker.
 767  */
 768 void ttm_pool_mgr_fini(void)
 769 {
 770         unsigned int i;
 771
 772         for (i = 0; i < MAX_ORDER; ++i) {
 773                 ttm_pool_type_fini(&global_write_combined[i]);
 774                 ttm_pool_type_fini(&global_uncached[i]);
 775
 776                 ttm_pool_type_fini(&global_dma32_write_combined[i]);
 777                 ttm_pool_type_fini(&global_dma32_uncached[i]);
 778         }
 779
 780         unregister_shrinker(&mm_shrinker);
 781         WARN_ON(!list_empty(&shrinker_list));
 782 }