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_bo.h>
33#include <drm/ttm/ttm_device.h>
34#include <drm/ttm/ttm_tt.h>
35#include <drm/ttm/ttm_placement.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}
140
141int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
142		       gfp_t gfp_flags)
143{
144	struct ttm_resource_cursor cursor;
145	struct ttm_resource_manager *man;
146	struct ttm_resource *res;
147	unsigned i;
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		ttm_resource_manager_for_each_res(man, &cursor, res) {
157			struct ttm_buffer_object *bo = res->bo;
158			uint32_t num_pages;
159
160			if (!bo || bo->resource != res)
161				continue;
162
163			num_pages = PFN_UP(bo->base.size);
164			ret = ttm_bo_swapout(bo, ctx, gfp_flags);
165			/* ttm_bo_swapout has dropped the lru_lock */
166			if (!ret)
167				return num_pages;
168			if (ret != -EBUSY)
169				return ret;
170		}
171	}
172	spin_unlock(&bdev->lru_lock);
173	return 0;
174}
175EXPORT_SYMBOL(ttm_device_swapout);
176
177/**
178 * ttm_device_init
179 *
180 * @bdev: A pointer to a struct ttm_device to initialize.
181 * @funcs: Function table for the device.
182 * @dev: The core kernel device pointer for DMA mappings and allocations.
183 * @mapping: The address space to use for this bo.
184 * @vma_manager: A pointer to a vma manager.
185 * @use_dma_alloc: If coherent DMA allocation API should be used.
186 * @use_dma32: If we should use GFP_DMA32 for device memory allocations.
187 *
188 * Initializes a struct ttm_device:
189 * Returns:
190 * !0: Failure.
191 */
192int ttm_device_init(struct ttm_device *bdev, const struct ttm_device_funcs *funcs,
193		    struct device *dev, struct address_space *mapping,
194		    struct drm_vma_offset_manager *vma_manager,
195		    bool use_dma_alloc, bool use_dma32)
196{
197	struct ttm_global *glob = &ttm_glob;
198	int ret;
199
200	if (WARN_ON(vma_manager == NULL))
201		return -EINVAL;
202
203	ret = ttm_global_init();
204	if (ret)
205		return ret;
206
207	bdev->wq = alloc_workqueue("ttm", WQ_MEM_RECLAIM | WQ_HIGHPRI, 16);
208	if (!bdev->wq) {
209		ttm_global_release();
210		return -ENOMEM;
211	}
212
213	bdev->funcs = funcs;
214
215	ttm_sys_man_init(bdev);
216	ttm_pool_init(&bdev->pool, dev, NUMA_NO_NODE, use_dma_alloc, use_dma32);
217
218	bdev->vma_manager = vma_manager;
219	spin_lock_init(&bdev->lru_lock);
220	INIT_LIST_HEAD(&bdev->pinned);
221	bdev->dev_mapping = mapping;
222	mutex_lock(&ttm_global_mutex);
223	list_add_tail(&bdev->device_list, &glob->device_list);
224	mutex_unlock(&ttm_global_mutex);
225
226	return 0;
227}
228EXPORT_SYMBOL(ttm_device_init);
229
230void ttm_device_fini(struct ttm_device *bdev)
231{
232	struct ttm_resource_manager *man;
233	unsigned i;
234
235	mutex_lock(&ttm_global_mutex);
236	list_del(&bdev->device_list);
237	mutex_unlock(&ttm_global_mutex);
238
239	drain_workqueue(bdev->wq);
240	destroy_workqueue(bdev->wq);
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	spin_lock(&bdev->lru_lock);
247	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
248		if (list_empty(&man->lru[0]))
249			pr_debug("Swap list %d was clean\n", i);
250	spin_unlock(&bdev->lru_lock);
251
252	ttm_pool_fini(&bdev->pool);
253	ttm_global_release();
254}
255EXPORT_SYMBOL(ttm_device_fini);
256
257static void ttm_device_clear_lru_dma_mappings(struct ttm_device *bdev,
258					      struct list_head *list)
259{
260	struct ttm_resource *res;
261
262	spin_lock(&bdev->lru_lock);
263	while ((res = list_first_entry_or_null(list, typeof(*res), lru))) {
264		struct ttm_buffer_object *bo = res->bo;
265
266		/* Take ref against racing releases once lru_lock is unlocked */
267		if (!ttm_bo_get_unless_zero(bo))
268			continue;
269
270		list_del_init(&res->lru);
271		spin_unlock(&bdev->lru_lock);
272
273		if (bo->ttm)
274			ttm_tt_unpopulate(bo->bdev, bo->ttm);
275
276		ttm_bo_put(bo);
277		spin_lock(&bdev->lru_lock);
278	}
279	spin_unlock(&bdev->lru_lock);
280}
281
282void ttm_device_clear_dma_mappings(struct ttm_device *bdev)
283{
284	struct ttm_resource_manager *man;
285	unsigned int i, j;
286
287	ttm_device_clear_lru_dma_mappings(bdev, &bdev->pinned);
288
289	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
290		man = ttm_manager_type(bdev, i);
291		if (!man || !man->use_tt)
292			continue;
293
294		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j)
295			ttm_device_clear_lru_dma_mappings(bdev, &man->lru[j]);
296	}
297}
298EXPORT_SYMBOL(ttm_device_clear_dma_mappings);
299