xref: /openbmc/linux/drivers/gpu/drm/ttm/ttm_device.c (revision 0da908c2)
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  */
42 static DEFINE_MUTEX(ttm_global_mutex);
43 static unsigned ttm_glob_use_count;
44 struct ttm_global ttm_glob;
45 EXPORT_SYMBOL(ttm_glob);
46 
47 struct dentry *ttm_debugfs_root;
48 
49 static 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));
62 out:
63 	mutex_unlock(&ttm_global_mutex);
64 }
65 
66 static 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);
110 out:
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  */
123 int 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 EXPORT_SYMBOL(ttm_global_swapout);
141 
142 int 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 }
176 EXPORT_SYMBOL(ttm_device_swapout);
177 
178 static 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  */
203 int 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 }
235 EXPORT_SYMBOL(ttm_device_init);
236 
237 void 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 }
264 EXPORT_SYMBOL(ttm_device_fini);
265 
266 static 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 
291 void 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 }
307 EXPORT_SYMBOL(ttm_device_clear_dma_mappings);
308