drm/ttm/ttm_tt.c

0001 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
0002 /**************************************************************************
0003  *
0004  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
0005  * All Rights Reserved.
0006  *
0007  * Permission is hereby granted, free of charge, to any person obtaining a
0008  * copy of this software and associated documentation files (the
0009  * "Software"), to deal in the Software without restriction, including
0010  * without limitation the rights to use, copy, modify, merge, publish,
0011  * distribute, sub license, and/or sell copies of the Software, and to
0012  * permit persons to whom the Software is furnished to do so, subject to
0013  * the following conditions:
0014  *
0015  * The above copyright notice and this permission notice (including the
0016  * next paragraph) shall be included in all copies or substantial portions
0017  * of the Software.
0018  *
0019  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0020  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0021  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
0022  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
0023  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
0024  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
0025  * USE OR OTHER DEALINGS IN THE SOFTWARE.
0026  *
0027  **************************************************************************/
0028 /*
0029  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
0030  */
0031
0032 #define pr_fmt(fmt) "[TTM] " fmt
0033
0034 #include <linux/sched.h>
0035 #include <linux/shmem_fs.h>
0036 #include <linux/file.h>
0037 #include <linux/module.h>
0038 #include <drm/drm_cache.h>
0039 #include <drm/ttm/ttm_bo_driver.h>
0040
0041 #include "ttm_module.h"
0042
0043 static unsigned long ttm_pages_limit;
0044
0045 MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages");
0046 module_param_named(pages_limit, ttm_pages_limit, ulong, 0644);
0047
0048 static unsigned long ttm_dma32_pages_limit;
0049
0050 MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages");
0051 module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644);
0052
0053 static atomic_long_t ttm_pages_allocated;
0054 static atomic_long_t ttm_dma32_pages_allocated;
0055
0056 /*
0057  * Allocates a ttm structure for the given BO.
0058  */
0059 int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
0060 {
0061     struct ttm_device *bdev = bo->bdev;
0062     uint32_t page_flags = 0;
0063
0064     dma_resv_assert_held(bo->base.resv);
0065
0066     if (bo->ttm)
0067         return 0;
0068
0069     switch (bo->type) {
0070     case ttm_bo_type_device:
0071         if (zero_alloc)
0072             page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
0073         break;
0074     case ttm_bo_type_kernel:
0075         break;
0076     case ttm_bo_type_sg:
0077         page_flags |= TTM_TT_FLAG_EXTERNAL;
0078         break;
0079     default:
0080         pr_err("Illegal buffer object type\n");
0081         return -EINVAL;
0082     }
0083
0084     bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
0085     if (unlikely(bo->ttm == NULL))
0086         return -ENOMEM;
0087
0088     WARN_ON(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE &&
0089         !(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL));
0090
0091     return 0;
0092 }
0093
0094 /*
0095  * Allocates storage for pointers to the pages that back the ttm.
0096  */
0097 static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
0098 {
0099     ttm->pages = kvcalloc(ttm->num_pages, sizeof(void*), GFP_KERNEL);
0100     if (!ttm->pages)
0101         return -ENOMEM;
0102
0103     return 0;
0104 }
0105
0106 static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
0107 {
0108     ttm->pages = kvcalloc(ttm->num_pages, sizeof(*ttm->pages) +
0109                   sizeof(*ttm->dma_address), GFP_KERNEL);
0110     if (!ttm->pages)
0111         return -ENOMEM;
0112
0113     ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
0114     return 0;
0115 }
0116
0117 static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
0118 {
0119     ttm->dma_address = kvcalloc(ttm->num_pages, sizeof(*ttm->dma_address),
0120                     GFP_KERNEL);
0121     if (!ttm->dma_address)
0122         return -ENOMEM;
0123
0124     return 0;
0125 }
0126
0127 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
0128 {
0129     bdev->funcs->ttm_tt_destroy(bdev, ttm);
0130 }
0131
0132 static void ttm_tt_init_fields(struct ttm_tt *ttm,
0133                    struct ttm_buffer_object *bo,
0134                    uint32_t page_flags,
0135                    enum ttm_caching caching,
0136                    unsigned long extra_pages)
0137 {
0138     ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + extra_pages;
0139     ttm->caching = ttm_cached;
0140     ttm->page_flags = page_flags;
0141     ttm->dma_address = NULL;
0142     ttm->swap_storage = NULL;
0143     ttm->sg = bo->sg;
0144     ttm->caching = caching;
0145 }
0146
0147 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
0148         uint32_t page_flags, enum ttm_caching caching,
0149         unsigned long extra_pages)
0150 {
0151     ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages);
0152
0153     if (ttm_tt_alloc_page_directory(ttm)) {
0154         pr_err("Failed allocating page table\n");
0155         return -ENOMEM;
0156     }
0157     return 0;
0158 }
0159 EXPORT_SYMBOL(ttm_tt_init);
0160
0161 void ttm_tt_fini(struct ttm_tt *ttm)
0162 {
0163     WARN_ON(ttm->page_flags & TTM_TT_FLAG_PRIV_POPULATED);
0164
0165     if (ttm->swap_storage)
0166         fput(ttm->swap_storage);
0167     ttm->swap_storage = NULL;
0168
0169     if (ttm->pages)
0170         kvfree(ttm->pages);
0171     else
0172         kvfree(ttm->dma_address);
0173     ttm->pages = NULL;
0174     ttm->dma_address = NULL;
0175 }
0176 EXPORT_SYMBOL(ttm_tt_fini);
0177
0178 int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
0179            uint32_t page_flags, enum ttm_caching caching)
0180 {
0181     int ret;
0182
0183     ttm_tt_init_fields(ttm, bo, page_flags, caching, 0);
0184
0185     if (page_flags & TTM_TT_FLAG_EXTERNAL)
0186         ret = ttm_sg_tt_alloc_page_directory(ttm);
0187     else
0188         ret = ttm_dma_tt_alloc_page_directory(ttm);
0189     if (ret) {
0190         pr_err("Failed allocating page table\n");
0191         return -ENOMEM;
0192     }
0193     return 0;
0194 }
0195 EXPORT_SYMBOL(ttm_sg_tt_init);
0196
0197 int ttm_tt_swapin(struct ttm_tt *ttm)
0198 {
0199     struct address_space *swap_space;
0200     struct file *swap_storage;
0201     struct page *from_page;
0202     struct page *to_page;
0203     gfp_t gfp_mask;
0204     int i, ret;
0205
0206     swap_storage = ttm->swap_storage;
0207     BUG_ON(swap_storage == NULL);
0208
0209     swap_space = swap_storage->f_mapping;
0210     gfp_mask = mapping_gfp_mask(swap_space);
0211
0212     for (i = 0; i < ttm->num_pages; ++i) {
0213         from_page = shmem_read_mapping_page_gfp(swap_space, i,
0214                             gfp_mask);
0215         if (IS_ERR(from_page)) {
0216             ret = PTR_ERR(from_page);
0217             goto out_err;
0218         }
0219         to_page = ttm->pages[i];
0220         if (unlikely(to_page == NULL)) {
0221             ret = -ENOMEM;
0222             goto out_err;
0223         }
0224
0225         copy_highpage(to_page, from_page);
0226         put_page(from_page);
0227     }
0228
0229     fput(swap_storage);
0230     ttm->swap_storage = NULL;
0231     ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
0232
0233     return 0;
0234
0235 out_err:
0236     return ret;
0237 }
0238
0239 /**
0240  * ttm_tt_swapout - swap out tt object
0241  *
0242  * @bdev: TTM device structure.
0243  * @ttm: The struct ttm_tt.
0244  * @gfp_flags: Flags to use for memory allocation.
0245  *
0246  * Swapout a TT object to a shmem_file, return number of pages swapped out or
0247  * negative error code.
0248  */
0249 int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
0250            gfp_t gfp_flags)
0251 {
0252     loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
0253     struct address_space *swap_space;
0254     struct file *swap_storage;
0255     struct page *from_page;
0256     struct page *to_page;
0257     int i, ret;
0258
0259     swap_storage = shmem_file_setup("ttm swap", size, 0);
0260     if (IS_ERR(swap_storage)) {
0261         pr_err("Failed allocating swap storage\n");
0262         return PTR_ERR(swap_storage);
0263     }
0264
0265     swap_space = swap_storage->f_mapping;
0266     gfp_flags &= mapping_gfp_mask(swap_space);
0267
0268     for (i = 0; i < ttm->num_pages; ++i) {
0269         from_page = ttm->pages[i];
0270         if (unlikely(from_page == NULL))
0271             continue;
0272
0273         to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags);
0274         if (IS_ERR(to_page)) {
0275             ret = PTR_ERR(to_page);
0276             goto out_err;
0277         }
0278         copy_highpage(to_page, from_page);
0279         set_page_dirty(to_page);
0280         mark_page_accessed(to_page);
0281         put_page(to_page);
0282     }
0283
0284     ttm_tt_unpopulate(bdev, ttm);
0285     ttm->swap_storage = swap_storage;
0286     ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
0287
0288     return ttm->num_pages;
0289
0290 out_err:
0291     fput(swap_storage);
0292
0293     return ret;
0294 }
0295
0296 int ttm_tt_populate(struct ttm_device *bdev,
0297             struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
0298 {
0299     int ret;
0300
0301     if (!ttm)
0302         return -EINVAL;
0303
0304     if (ttm_tt_is_populated(ttm))
0305         return 0;
0306
0307     if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
0308         atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
0309         if (bdev->pool.use_dma32)
0310             atomic_long_add(ttm->num_pages,
0311                     &ttm_dma32_pages_allocated);
0312     }
0313
0314     while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit ||
0315            atomic_long_read(&ttm_dma32_pages_allocated) >
0316            ttm_dma32_pages_limit) {
0317
0318         ret = ttm_global_swapout(ctx, GFP_KERNEL);
0319         if (ret == 0)
0320             break;
0321         if (ret < 0)
0322             goto error;
0323     }
0324
0325     if (bdev->funcs->ttm_tt_populate)
0326         ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
0327     else
0328         ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
0329     if (ret)
0330         goto error;
0331
0332     ttm->page_flags |= TTM_TT_FLAG_PRIV_POPULATED;
0333     if (unlikely(ttm->page_flags & TTM_TT_FLAG_SWAPPED)) {
0334         ret = ttm_tt_swapin(ttm);
0335         if (unlikely(ret != 0)) {
0336             ttm_tt_unpopulate(bdev, ttm);
0337             return ret;
0338         }
0339     }
0340
0341     return 0;
0342
0343 error:
0344     if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
0345         atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
0346         if (bdev->pool.use_dma32)
0347             atomic_long_sub(ttm->num_pages,
0348                     &ttm_dma32_pages_allocated);
0349     }
0350     return ret;
0351 }
0352 EXPORT_SYMBOL(ttm_tt_populate);
0353
0354 void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
0355 {
0356     if (!ttm_tt_is_populated(ttm))
0357         return;
0358
0359     if (bdev->funcs->ttm_tt_unpopulate)
0360         bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
0361     else
0362         ttm_pool_free(&bdev->pool, ttm);
0363
0364     if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
0365         atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
0366         if (bdev->pool.use_dma32)
0367             atomic_long_sub(ttm->num_pages,
0368                     &ttm_dma32_pages_allocated);
0369     }
0370
0371     ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
0372 }
0373
0374 #ifdef CONFIG_DEBUG_FS
0375
0376 /* Test the shrinker functions and dump the result */
0377 static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
0378 {
0379     struct ttm_operation_ctx ctx = { false, false };
0380
0381     seq_printf(m, "%d\n", ttm_global_swapout(&ctx, GFP_KERNEL));
0382     return 0;
0383 }
0384 DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
0385
0386 #endif
0387
0388
0389 /*
0390  * ttm_tt_mgr_init - register with the MM shrinker
0391  *
0392  * Register with the MM shrinker for swapping out BOs.
0393  */
0394 void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
0395 {
0396 #ifdef CONFIG_DEBUG_FS
0397     debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
0398                 &ttm_tt_debugfs_shrink_fops);
0399 #endif
0400
0401     if (!ttm_pages_limit)
0402         ttm_pages_limit = num_pages;
0403
0404     if (!ttm_dma32_pages_limit)
0405         ttm_dma32_pages_limit = num_dma32_pages;
0406 }
0407
0408 static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
0409                        struct iosys_map *dmap,
0410                        pgoff_t i)
0411 {
0412     struct ttm_kmap_iter_tt *iter_tt =
0413         container_of(iter, typeof(*iter_tt), base);
0414
0415     iosys_map_set_vaddr(dmap, kmap_local_page_prot(iter_tt->tt->pages[i],
0416                                iter_tt->prot));
0417 }
0418
0419 static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
0420                      struct iosys_map *map)
0421 {
0422     kunmap_local(map->vaddr);
0423 }
0424
0425 static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
0426     .map_local = ttm_kmap_iter_tt_map_local,
0427     .unmap_local = ttm_kmap_iter_tt_unmap_local,
0428     .maps_tt = true,
0429 };
0430
0431 /**
0432  * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
0433  * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
0434  * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
0435  *
0436  * Return: Pointer to the embedded struct ttm_kmap_iter.
0437  */
0438 struct ttm_kmap_iter *
0439 ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
0440               struct ttm_tt *tt)
0441 {
0442     iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
0443     iter_tt->tt = tt;
0444     if (tt)
0445         iter_tt->prot = ttm_prot_from_caching(tt->caching, PAGE_KERNEL);
0446     else
0447         iter_tt->prot = PAGE_KERNEL;
0448
0449     return &iter_tt->base;
0450 }
0451 EXPORT_SYMBOL(ttm_kmap_iter_tt_init);