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 K��nig
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					   __GFP_NOWARN);
100
101	/* Retry without GFP_DMA32 for platforms DMA32 is not available */
102	if (unlikely(glob->dummy_read_page == NULL)) {
103		glob->dummy_read_page = alloc_page(__GFP_ZERO);
104		if (unlikely(glob->dummy_read_page == NULL)) {
105			ret = -ENOMEM;
106			goto out;
107		}
108		pr_warn("Using GFP_DMA32 fallback for dummy_read_page\n");
109	}
110
111	INIT_LIST_HEAD(&glob->device_list);
112	atomic_set(&glob->bo_count, 0);
113
114	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
115				&glob->bo_count);
116out:
117	if (ret && ttm_debugfs_root)
118		debugfs_remove(ttm_debugfs_root);
119	if (ret)
120		--ttm_glob_use_count;
121	mutex_unlock(&ttm_global_mutex);
122	return ret;
123}
124
125/*
126 * A buffer object shrink method that tries to swap out the first
127 * buffer object on the global::swap_lru list.
128 */
129int ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags)
130{
131	struct ttm_global *glob = &ttm_glob;
132	struct ttm_device *bdev;
133	int ret = 0;
134
135	mutex_lock(&ttm_global_mutex);
136	list_for_each_entry(bdev, &glob->device_list, device_list) {
137		ret = ttm_device_swapout(bdev, ctx, gfp_flags);
138		if (ret > 0) {
139			list_move_tail(&bdev->device_list, &glob->device_list);
140			break;
141		}
142	}
143	mutex_unlock(&ttm_global_mutex);
144	return ret;
145}
146
147int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
148		       gfp_t gfp_flags)
149{
150	struct ttm_resource_cursor cursor;
151	struct ttm_resource_manager *man;
152	struct ttm_resource *res;
153	unsigned i;
154	int ret;
155
156	spin_lock(&bdev->lru_lock);
157	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
158		man = ttm_manager_type(bdev, i);
159		if (!man || !man->use_tt)
160			continue;
161
162		ttm_resource_manager_for_each_res(man, &cursor, res) {
163			struct ttm_buffer_object *bo = res->bo;
164			uint32_t num_pages;
165
166			if (!bo || bo->resource != res)
167				continue;
168
169			num_pages = PFN_UP(bo->base.size);
170			ret = ttm_bo_swapout(bo, ctx, gfp_flags);
171			/* ttm_bo_swapout has dropped the lru_lock */
172			if (!ret)
173				return num_pages;
174			if (ret != -EBUSY)
175				return ret;
176		}
177	}
178	spin_unlock(&bdev->lru_lock);
179	return 0;
180}
181EXPORT_SYMBOL(ttm_device_swapout);
182
183/**
184 * ttm_device_init
185 *
186 * @bdev: A pointer to a struct ttm_device to initialize.
187 * @funcs: Function table for the device.
188 * @dev: The core kernel device pointer for DMA mappings and allocations.
189 * @mapping: The address space to use for this bo.
190 * @vma_manager: A pointer to a vma manager.
191 * @use_dma_alloc: If coherent DMA allocation API should be used.
192 * @use_dma32: If we should use GFP_DMA32 for device memory allocations.
193 *
194 * Initializes a struct ttm_device:
195 * Returns:
196 * !0: Failure.
197 */
198int ttm_device_init(struct ttm_device *bdev, const struct ttm_device_funcs *funcs,
199		    struct device *dev, struct address_space *mapping,
200		    struct drm_vma_offset_manager *vma_manager,
201		    bool use_dma_alloc, bool use_dma32)
202{
203	struct ttm_global *glob = &ttm_glob;
204	int ret, nid;
205
206	if (WARN_ON(vma_manager == NULL))
207		return -EINVAL;
208
209	ret = ttm_global_init();
210	if (ret)
211		return ret;
212
213	bdev->wq = alloc_workqueue("ttm",
214				   WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 16);
215	if (!bdev->wq) {
216		ttm_global_release();
217		return -ENOMEM;
218	}
219
220	bdev->funcs = funcs;
221
222	ttm_sys_man_init(bdev);
223
224	if (dev)
225		nid = dev_to_node(dev);
226	else
227		nid = NUMA_NO_NODE;
228
229	ttm_pool_init(&bdev->pool, dev, nid, use_dma_alloc, use_dma32);
230
231	bdev->vma_manager = vma_manager;
232	spin_lock_init(&bdev->lru_lock);
233	INIT_LIST_HEAD(&bdev->pinned);
234	bdev->dev_mapping = mapping;
235	mutex_lock(&ttm_global_mutex);
236	list_add_tail(&bdev->device_list, &glob->device_list);
237	mutex_unlock(&ttm_global_mutex);
238
239	return 0;
240}
241EXPORT_SYMBOL(ttm_device_init);
242
243void ttm_device_fini(struct ttm_device *bdev)
244{
245	struct ttm_resource_manager *man;
246	unsigned i;
247
248	mutex_lock(&ttm_global_mutex);
249	list_del(&bdev->device_list);
250	mutex_unlock(&ttm_global_mutex);
251
252	drain_workqueue(bdev->wq);
253	destroy_workqueue(bdev->wq);
254
255	man = ttm_manager_type(bdev, TTM_PL_SYSTEM);
256	ttm_resource_manager_set_used(man, false);
257	ttm_set_driver_manager(bdev, TTM_PL_SYSTEM, NULL);
258
259	spin_lock(&bdev->lru_lock);
260	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
261		if (list_empty(&man->lru[0]))
262			pr_debug("Swap list %d was clean\n", i);
263	spin_unlock(&bdev->lru_lock);
264
265	ttm_pool_fini(&bdev->pool);
266	ttm_global_release();
267}
268EXPORT_SYMBOL(ttm_device_fini);
269
270static void ttm_device_clear_lru_dma_mappings(struct ttm_device *bdev,
271					      struct list_head *list)
272{
273	struct ttm_resource *res;
274
275	spin_lock(&bdev->lru_lock);
276	while ((res = list_first_entry_or_null(list, typeof(*res), lru))) {
277		struct ttm_buffer_object *bo = res->bo;
278
279		/* Take ref against racing releases once lru_lock is unlocked */
280		if (!ttm_bo_get_unless_zero(bo))
281			continue;
282
283		list_del_init(&res->lru);
284		spin_unlock(&bdev->lru_lock);
285
286		if (bo->ttm)
287			ttm_tt_unpopulate(bo->bdev, bo->ttm);
288
289		ttm_bo_put(bo);
290		spin_lock(&bdev->lru_lock);
291	}
292	spin_unlock(&bdev->lru_lock);
293}
294
295void ttm_device_clear_dma_mappings(struct ttm_device *bdev)
296{
297	struct ttm_resource_manager *man;
298	unsigned int i, j;
299
300	ttm_device_clear_lru_dma_mappings(bdev, &bdev->pinned);
301
302	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
303		man = ttm_manager_type(bdev, i);
304		if (!man || !man->use_tt)
305			continue;
306
307		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j)
308			ttm_device_clear_lru_dma_mappings(bdev, &man->lru[j]);
309	}
310}
311EXPORT_SYMBOL(ttm_device_clear_dma_mappings);
312