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_cursor cursor;
146	struct ttm_resource_manager *man;
147	struct ttm_resource *res;
148	unsigned i;
149	int ret;
150
151	spin_lock(&bdev->lru_lock);
152	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
153		man = ttm_manager_type(bdev, i);
154		if (!man || !man->use_tt)
155			continue;
156
157		ttm_resource_manager_for_each_res(man, &cursor, res) {
158			struct ttm_buffer_object *bo = res->bo;
159			uint32_t num_pages;
160
161			if (!bo)
162				continue;
163
164			num_pages = PFN_UP(bo->base.size);
165			ret = ttm_bo_swapout(bo, ctx, gfp_flags);
166			/* ttm_bo_swapout has dropped the lru_lock */
167			if (!ret)
168				return num_pages;
169			if (ret != -EBUSY)
170				return ret;
171		}
172	}
173	spin_unlock(&bdev->lru_lock);
174	return 0;
175}
176EXPORT_SYMBOL(ttm_device_swapout);
177
178static void ttm_device_delayed_workqueue(struct work_struct *work)
179{
180	struct ttm_device *bdev =
181		container_of(work, struct ttm_device, wq.work);
182
183	if (!ttm_bo_delayed_delete(bdev, false))
184		schedule_delayed_work(&bdev->wq,
185				      ((HZ / 100) < 1) ? 1 : HZ / 100);
186}
187
188/**
189 * ttm_device_init
190 *
191 * @bdev: A pointer to a struct ttm_device to initialize.
192 * @funcs: Function table for the device.
193 * @dev: The core kernel device pointer for DMA mappings and allocations.
194 * @mapping: The address space to use for this bo.
195 * @vma_manager: A pointer to a vma manager.
196 * @use_dma_alloc: If coherent DMA allocation API should be used.
197 * @use_dma32: If we should use GFP_DMA32 for device memory allocations.
198 *
199 * Initializes a struct ttm_device:
200 * Returns:
201 * !0: Failure.
202 */
203int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs,
204		    struct device *dev, struct address_space *mapping,
205		    struct drm_vma_offset_manager *vma_manager,
206		    bool use_dma_alloc, bool use_dma32)
207{
208	struct ttm_global *glob = &ttm_glob;
209	int ret;
210
211	if (WARN_ON(vma_manager == NULL))
212		return -EINVAL;
213
214	ret = ttm_global_init();
215	if (ret)
216		return ret;
217
218	bdev->funcs = funcs;
219
220	ttm_sys_man_init(bdev);
221	ttm_pool_init(&bdev->pool, dev, use_dma_alloc, use_dma32);
222
223	bdev->vma_manager = vma_manager;
224	INIT_DELAYED_WORK(&bdev->wq, ttm_device_delayed_workqueue);
225	spin_lock_init(&bdev->lru_lock);
226	INIT_LIST_HEAD(&bdev->ddestroy);
227	INIT_LIST_HEAD(&bdev->pinned);
228	bdev->dev_mapping = mapping;
229	mutex_lock(&ttm_global_mutex);
230	list_add_tail(&bdev->device_list, &glob->device_list);
231	mutex_unlock(&ttm_global_mutex);
232
233	return 0;
234}
235EXPORT_SYMBOL(ttm_device_init);
236
237void ttm_device_fini(struct ttm_device *bdev)
238{
239	struct ttm_resource_manager *man;
240	unsigned i;
241
242	man = ttm_manager_type(bdev, TTM_PL_SYSTEM);
243	ttm_resource_manager_set_used(man, false);
244	ttm_set_driver_manager(bdev, TTM_PL_SYSTEM, NULL);
245
246	mutex_lock(&ttm_global_mutex);
247	list_del(&bdev->device_list);
248	mutex_unlock(&ttm_global_mutex);
249
250	cancel_delayed_work_sync(&bdev->wq);
251
252	if (ttm_bo_delayed_delete(bdev, true))
253		pr_debug("Delayed destroy list was clean\n");
254
255	spin_lock(&bdev->lru_lock);
256	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
257		if (list_empty(&man->lru[0]))
258			pr_debug("Swap list %d was clean\n", i);
259	spin_unlock(&bdev->lru_lock);
260
261	ttm_pool_fini(&bdev->pool);
262	ttm_global_release();
263}
264EXPORT_SYMBOL(ttm_device_fini);
265
266static void ttm_device_clear_lru_dma_mappings(struct ttm_device *bdev,
267					      struct list_head *list)
268{
269	struct ttm_resource *res;
270
271	spin_lock(&bdev->lru_lock);
272	while ((res = list_first_entry_or_null(list, typeof(*res), lru))) {
273		struct ttm_buffer_object *bo = res->bo;
274
275		/* Take ref against racing releases once lru_lock is unlocked */
276		if (!ttm_bo_get_unless_zero(bo))
277			continue;
278
279		list_del_init(&res->lru);
280		spin_unlock(&bdev->lru_lock);
281
282		if (bo->ttm)
283			ttm_tt_unpopulate(bo->bdev, bo->ttm);
284
285		ttm_bo_put(bo);
286		spin_lock(&bdev->lru_lock);
287	}
288	spin_unlock(&bdev->lru_lock);
289}
290
291void ttm_device_clear_dma_mappings(struct ttm_device *bdev)
292{
293	struct ttm_resource_manager *man;
294	unsigned int i, j;
295
296	ttm_device_clear_lru_dma_mappings(bdev, &bdev->pinned);
297
298	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
299		man = ttm_manager_type(bdev, i);
300		if (!man || !man->use_tt)
301			continue;
302
303		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j)
304			ttm_device_clear_lru_dma_mappings(bdev, &man->lru[j]);
305	}
306}
307EXPORT_SYMBOL(ttm_device_clear_dma_mappings);