1/* SPDX-License-Identifier: GPL-2.0 OR MIT */
  2
  3/*
  4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
  5 * Copyright 2020 Advanced Micro Devices, Inc.
  6 *
  7 * Permission is hereby granted, free of charge, to any person obtaining a
  8 * copy of this software and associated documentation files (the "Software"),
  9 * to deal in the Software without restriction, including without limitation
 10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 11 * and/or sell copies of the Software, and to permit persons to whom the
 12 * Software is furnished to do so, subject to the following conditions:
 13 *
 14 * The above copyright notice and this permission notice shall be included in
 15 * all copies or substantial portions of the Software.
 16 *
 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 20 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 23 * OTHER DEALINGS IN THE SOFTWARE.
 24 *
 25 * Authors: Christian König
 26 */
 27
 28#define pr_fmt(fmt) "[TTM DEVICE] " fmt
 29
 30#include <linux/mm.h>
 31
 32#include <drm/ttm/ttm_device.h>
 33#include <drm/ttm/ttm_tt.h>
 34#include <drm/ttm/ttm_placement.h>
 35#include <drm/ttm/ttm_bo_api.h>
 36
 37#include "ttm_module.h"
 38
 39/*
 40 * ttm_global_mutex - protecting the global state
 41 */
 42static DEFINE_MUTEX(ttm_global_mutex);
 43static unsigned ttm_glob_use_count;
 44struct ttm_global ttm_glob;
 45EXPORT_SYMBOL(ttm_glob);
 46
 47struct dentry *ttm_debugfs_root;
 48
 49static void ttm_global_release(void)
 50{
 51	struct ttm_global *glob = &ttm_glob;
 52
 53	mutex_lock(&ttm_global_mutex);
 54	if (--ttm_glob_use_count > 0)
 55		goto out;
 56
 57	ttm_pool_mgr_fini();
 58	debugfs_remove(ttm_debugfs_root);
 59
 60	__free_page(glob->dummy_read_page);
 61	memset(glob, 0, sizeof(*glob));
 62out:
 63	mutex_unlock(&ttm_global_mutex);
 64}
 65
 66static int ttm_global_init(void)
 67{
 68	struct ttm_global *glob = &ttm_glob;
 69	unsigned long num_pages, num_dma32;
 70	struct sysinfo si;
 71	int ret = 0;
 72
 73	mutex_lock(&ttm_global_mutex);
 74	if (++ttm_glob_use_count > 1)
 75		goto out;
 76
 77	si_meminfo(&si);
 78
 79	ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
 80	if (IS_ERR(ttm_debugfs_root)) {
 81		ttm_debugfs_root = NULL;
 82	}
 83
 84	/* Limit the number of pages in the pool to about 50% of the total
 85	 * system memory.
 86	 */
 87	num_pages = ((u64)si.totalram * si.mem_unit) >> PAGE_SHIFT;
 88	num_pages /= 2;
 89
 90	/* But for DMA32 we limit ourself to only use 2GiB maximum. */
 91	num_dma32 = (u64)(si.totalram - si.totalhigh) * si.mem_unit
 92		>> PAGE_SHIFT;
 93	num_dma32 = min(num_dma32, 2UL << (30 - PAGE_SHIFT));
 94
 95	ttm_pool_mgr_init(num_pages);
 96	ttm_tt_mgr_init(num_pages, num_dma32);
 97
 98	glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
 99
100	if (unlikely(glob->dummy_read_page == NULL)) {
101		ret = -ENOMEM;
102		goto out;
103	}
104
105	INIT_LIST_HEAD(&glob->device_list);
106	atomic_set(&glob->bo_count, 0);
107
108	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
109				&glob->bo_count);
110out:
111	if (ret && ttm_debugfs_root)
112		debugfs_remove(ttm_debugfs_root);
113	if (ret)
114		--ttm_glob_use_count;
115	mutex_unlock(&ttm_global_mutex);
116	return ret;
117}
118
119/*
120 * A buffer object shrink method that tries to swap out the first
121 * buffer object on the global::swap_lru list.
122 */
123int ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags)
124{
125	struct ttm_global *glob = &ttm_glob;
126	struct ttm_device *bdev;
127	int ret = 0;
128
129	mutex_lock(&ttm_global_mutex);
130	list_for_each_entry(bdev, &glob->device_list, device_list) {
131		ret = ttm_device_swapout(bdev, ctx, gfp_flags);
132		if (ret > 0) {
133			list_move_tail(&bdev->device_list, &glob->device_list);
134			break;
135		}
136	}
137	mutex_unlock(&ttm_global_mutex);
138	return ret;
139}
140EXPORT_SYMBOL(ttm_global_swapout);
141
142int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
143		       gfp_t gfp_flags)
144{
145	struct ttm_resource_manager *man;
146	struct ttm_buffer_object *bo;
147	unsigned i, j;
148	int ret;
149
150	spin_lock(&bdev->lru_lock);
151	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
152		man = ttm_manager_type(bdev, i);
153		if (!man || !man->use_tt)
154			continue;
155
156		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j) {
157			list_for_each_entry(bo, &man->lru[j], lru) {
158				uint32_t num_pages = PFN_UP(bo->base.size);
159
160				ret = ttm_bo_swapout(bo, ctx, gfp_flags);
161				/* ttm_bo_swapout has dropped the lru_lock */
162				if (!ret)
163					return num_pages;
164				if (ret != -EBUSY)
165					return ret;
166			}
167		}
168	}
169	spin_unlock(&bdev->lru_lock);
170	return 0;
171}
172EXPORT_SYMBOL(ttm_device_swapout);
173
174static void ttm_device_delayed_workqueue(struct work_struct *work)
175{
176	struct ttm_device *bdev =
177		container_of(work, struct ttm_device, wq.work);
178
179	if (!ttm_bo_delayed_delete(bdev, false))
180		schedule_delayed_work(&bdev->wq,
181				      ((HZ / 100) < 1) ? 1 : HZ / 100);
182}
183
184/**
185 * ttm_device_init
186 *
187 * @bdev: A pointer to a struct ttm_device to initialize.
188 * @funcs: Function table for the device.
189 * @dev: The core kernel device pointer for DMA mappings and allocations.
190 * @mapping: The address space to use for this bo.
191 * @vma_manager: A pointer to a vma manager.
192 * @use_dma_alloc: If coherent DMA allocation API should be used.
193 * @use_dma32: If we should use GFP_DMA32 for device memory allocations.
194 *
195 * Initializes a struct ttm_device:
196 * Returns:
197 * !0: Failure.
198 */
199int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs,
200		    struct device *dev, struct address_space *mapping,
201		    struct drm_vma_offset_manager *vma_manager,
202		    bool use_dma_alloc, bool use_dma32)
203{
204	struct ttm_global *glob = &ttm_glob;
205	int ret;
206
207	if (WARN_ON(vma_manager == NULL))
208		return -EINVAL;
209
210	ret = ttm_global_init();
211	if (ret)
212		return ret;
213
214	bdev->funcs = funcs;
215
216	ttm_sys_man_init(bdev);
217	ttm_pool_init(&bdev->pool, dev, use_dma_alloc, use_dma32);
218
219	bdev->vma_manager = vma_manager;
220	INIT_DELAYED_WORK(&bdev->wq, ttm_device_delayed_workqueue);
221	spin_lock_init(&bdev->lru_lock);
222	INIT_LIST_HEAD(&bdev->ddestroy);
223	bdev->dev_mapping = mapping;
224	mutex_lock(&ttm_global_mutex);
225	list_add_tail(&bdev->device_list, &glob->device_list);
226	mutex_unlock(&ttm_global_mutex);
227
228	return 0;
229}
230EXPORT_SYMBOL(ttm_device_init);
231
232void ttm_device_fini(struct ttm_device *bdev)
233{
234	struct ttm_resource_manager *man;
235	unsigned i;
236
237	man = ttm_manager_type(bdev, TTM_PL_SYSTEM);
238	ttm_resource_manager_set_used(man, false);
239	ttm_set_driver_manager(bdev, TTM_PL_SYSTEM, NULL);
240
241	mutex_lock(&ttm_global_mutex);
242	list_del(&bdev->device_list);
243	mutex_unlock(&ttm_global_mutex);
244
245	cancel_delayed_work_sync(&bdev->wq);
246
247	if (ttm_bo_delayed_delete(bdev, true))
248		pr_debug("Delayed destroy list was clean\n");
249
250	spin_lock(&bdev->lru_lock);
251	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
252		if (list_empty(&man->lru[0]))
253			pr_debug("Swap list %d was clean\n", i);
254	spin_unlock(&bdev->lru_lock);
255
256	ttm_pool_fini(&bdev->pool);
257	ttm_global_release();
258}
259EXPORT_SYMBOL(ttm_device_fini);