xref: /openbsd-src/sys/dev/pci/drm/ttm/ttm_device.c (revision c1a45aed656e7d5627c30c92421893a76f370ccb)
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 	int ret = 0;
71 
72 	mutex_lock(&ttm_global_mutex);
73 	if (++ttm_glob_use_count > 1)
74 		goto out;
75 
76 	ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
77 	if (IS_ERR(ttm_debugfs_root)) {
78 		ttm_debugfs_root = NULL;
79 	}
80 
81 	/* Limit the number of pages in the pool to about 50% of the total
82 	 * system memory.
83 	 */
84 	num_pages = physmem;
85 	num_pages /= 2;
86 
87 	/* But for DMA32 we limit ourself to only use 2GiB maximum. */
88 	num_dma32 = physmem;
89 	num_dma32 = min(num_dma32, 2UL << (30 - PAGE_SHIFT));
90 
91 	ttm_pool_mgr_init(num_pages);
92 	ttm_tt_mgr_init(num_pages, num_dma32);
93 
94 	glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
95 
96 	if (unlikely(glob->dummy_read_page == NULL)) {
97 		ret = -ENOMEM;
98 		goto out;
99 	}
100 
101 	INIT_LIST_HEAD(&glob->device_list);
102 	atomic_set(&glob->bo_count, 0);
103 
104 	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
105 				&glob->bo_count);
106 out:
107 	if (ret && ttm_debugfs_root)
108 		debugfs_remove(ttm_debugfs_root);
109 	if (ret)
110 		--ttm_glob_use_count;
111 	mutex_unlock(&ttm_global_mutex);
112 	return ret;
113 }
114 
115 /*
116  * A buffer object shrink method that tries to swap out the first
117  * buffer object on the global::swap_lru list.
118  */
119 int ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags)
120 {
121 	struct ttm_global *glob = &ttm_glob;
122 	struct ttm_device *bdev;
123 	int ret = 0;
124 
125 	mutex_lock(&ttm_global_mutex);
126 	list_for_each_entry(bdev, &glob->device_list, device_list) {
127 		ret = ttm_device_swapout(bdev, ctx, gfp_flags);
128 		if (ret > 0) {
129 			list_move_tail(&bdev->device_list, &glob->device_list);
130 			break;
131 		}
132 	}
133 	mutex_unlock(&ttm_global_mutex);
134 	return ret;
135 }
136 EXPORT_SYMBOL(ttm_global_swapout);
137 
138 int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
139 		       gfp_t gfp_flags)
140 {
141 	struct ttm_resource_manager *man;
142 	struct ttm_buffer_object *bo;
143 	unsigned i, j;
144 	int ret;
145 
146 	spin_lock(&bdev->lru_lock);
147 	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
148 		man = ttm_manager_type(bdev, i);
149 		if (!man || !man->use_tt)
150 			continue;
151 
152 		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j) {
153 			list_for_each_entry(bo, &man->lru[j], lru) {
154 				uint32_t num_pages = PFN_UP(bo->base.size);
155 
156 				ret = ttm_bo_swapout(bo, ctx, gfp_flags);
157 				/* ttm_bo_swapout has dropped the lru_lock */
158 				if (!ret)
159 					return num_pages;
160 				if (ret != -EBUSY)
161 					return ret;
162 			}
163 		}
164 	}
165 	spin_unlock(&bdev->lru_lock);
166 	return 0;
167 }
168 EXPORT_SYMBOL(ttm_device_swapout);
169 
170 static void ttm_device_delayed_workqueue(struct work_struct *work)
171 {
172 	struct ttm_device *bdev =
173 		container_of(work, struct ttm_device, wq.work);
174 
175 	if (!ttm_bo_delayed_delete(bdev, false))
176 		schedule_delayed_work(&bdev->wq,
177 				      ((HZ / 100) < 1) ? 1 : HZ / 100);
178 }
179 
180 /**
181  * ttm_device_init
182  *
183  * @bdev: A pointer to a struct ttm_device to initialize.
184  * @funcs: Function table for the device.
185  * @dev: The core kernel device pointer for DMA mappings and allocations.
186  * @mapping: The address space to use for this bo.
187  * @vma_manager: A pointer to a vma manager.
188  * @use_dma_alloc: If coherent DMA allocation API should be used.
189  * @use_dma32: If we should use GFP_DMA32 for device memory allocations.
190  *
191  * Initializes a struct ttm_device:
192  * Returns:
193  * !0: Failure.
194  */
195 int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs,
196 		    struct device *dev, struct address_space *mapping,
197 		    struct drm_vma_offset_manager *vma_manager,
198 		    bool use_dma_alloc, bool use_dma32)
199 {
200 	struct ttm_global *glob = &ttm_glob;
201 	int ret;
202 
203 	if (WARN_ON(vma_manager == NULL))
204 		return -EINVAL;
205 
206 	ret = ttm_global_init();
207 	if (ret)
208 		return ret;
209 
210 	bdev->funcs = funcs;
211 
212 	ttm_sys_man_init(bdev);
213 	ttm_pool_init(&bdev->pool, dev, use_dma_alloc, use_dma32);
214 
215 	bdev->vma_manager = vma_manager;
216 	INIT_DELAYED_WORK(&bdev->wq, ttm_device_delayed_workqueue);
217 	mtx_init(&bdev->lru_lock, IPL_NONE);
218 	INIT_LIST_HEAD(&bdev->ddestroy);
219 	bdev->dev_mapping = mapping;
220 	mutex_lock(&ttm_global_mutex);
221 	list_add_tail(&bdev->device_list, &glob->device_list);
222 	mutex_unlock(&ttm_global_mutex);
223 
224 	return 0;
225 }
226 EXPORT_SYMBOL(ttm_device_init);
227 
228 void ttm_device_fini(struct ttm_device *bdev)
229 {
230 	struct ttm_resource_manager *man;
231 	unsigned i;
232 
233 	man = ttm_manager_type(bdev, TTM_PL_SYSTEM);
234 	ttm_resource_manager_set_used(man, false);
235 	ttm_set_driver_manager(bdev, TTM_PL_SYSTEM, NULL);
236 
237 	mutex_lock(&ttm_global_mutex);
238 	list_del(&bdev->device_list);
239 	mutex_unlock(&ttm_global_mutex);
240 
241 	cancel_delayed_work_sync(&bdev->wq);
242 
243 	if (ttm_bo_delayed_delete(bdev, true))
244 		pr_debug("Delayed destroy list was clean\n");
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 }
255 EXPORT_SYMBOL(ttm_device_fini);
256