xref: /openbmc/linux/include/drm/ttm/ttm_device.h (revision 8e7a49e0)
1 /*
2  * Copyright 2020 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Christian König
23  */
24 
25 #ifndef _TTM_DEVICE_H_
26 #define _TTM_DEVICE_H_
27 
28 #include <linux/types.h>
29 #include <linux/workqueue.h>
30 #include <drm/ttm/ttm_resource.h>
31 #include <drm/ttm/ttm_pool.h>
32 
33 struct ttm_device;
34 struct ttm_placement;
35 struct ttm_buffer_object;
36 struct ttm_operation_ctx;
37 
38 /**
39  * struct ttm_global - Buffer object driver global data.
40  */
41 extern struct ttm_global {
42 
43 	/**
44 	 * @dummy_read_page: Pointer to a dummy page used for mapping requests
45 	 * of unpopulated pages. Constant after init.
46 	 */
47 	struct page *dummy_read_page;
48 
49 	/**
50 	 * @device_list: List of buffer object devices. Protected by
51 	 * ttm_global_mutex.
52 	 */
53 	struct list_head device_list;
54 
55 	/**
56 	 * @bo_count: Number of buffer objects allocated by devices.
57 	 */
58 	atomic_t bo_count;
59 } ttm_glob;
60 
61 struct ttm_device_funcs {
62 	/**
63 	 * ttm_tt_create
64 	 *
65 	 * @bo: The buffer object to create the ttm for.
66 	 * @page_flags: Page flags as identified by TTM_TT_FLAG_XX flags.
67 	 *
68 	 * Create a struct ttm_tt to back data with system memory pages.
69 	 * No pages are actually allocated.
70 	 * Returns:
71 	 * NULL: Out of memory.
72 	 */
73 	struct ttm_tt *(*ttm_tt_create)(struct ttm_buffer_object *bo,
74 					uint32_t page_flags);
75 
76 	/**
77 	 * ttm_tt_populate
78 	 *
79 	 * @ttm: The struct ttm_tt to contain the backing pages.
80 	 *
81 	 * Allocate all backing pages
82 	 * Returns:
83 	 * -ENOMEM: Out of memory.
84 	 */
85 	int (*ttm_tt_populate)(struct ttm_device *bdev,
86 			       struct ttm_tt *ttm,
87 			       struct ttm_operation_ctx *ctx);
88 
89 	/**
90 	 * ttm_tt_unpopulate
91 	 *
92 	 * @ttm: The struct ttm_tt to contain the backing pages.
93 	 *
94 	 * Free all backing page
95 	 */
96 	void (*ttm_tt_unpopulate)(struct ttm_device *bdev,
97 				  struct ttm_tt *ttm);
98 
99 	/**
100 	 * ttm_tt_destroy
101 	 *
102 	 * @bdev: Pointer to a ttm device
103 	 * @ttm: Pointer to a struct ttm_tt.
104 	 *
105 	 * Destroy the backend. This will be call back from ttm_tt_destroy so
106 	 * don't call ttm_tt_destroy from the callback or infinite loop.
107 	 */
108 	void (*ttm_tt_destroy)(struct ttm_device *bdev, struct ttm_tt *ttm);
109 
110 	/**
111 	 * struct ttm_bo_driver member eviction_valuable
112 	 *
113 	 * @bo: the buffer object to be evicted
114 	 * @place: placement we need room for
115 	 *
116 	 * Check with the driver if it is valuable to evict a BO to make room
117 	 * for a certain placement.
118 	 */
119 	bool (*eviction_valuable)(struct ttm_buffer_object *bo,
120 				  const struct ttm_place *place);
121 	/**
122 	 * struct ttm_bo_driver member evict_flags:
123 	 *
124 	 * @bo: the buffer object to be evicted
125 	 *
126 	 * Return the bo flags for a buffer which is not mapped to the hardware.
127 	 * These will be placed in proposed_flags so that when the move is
128 	 * finished, they'll end up in bo->mem.flags
129 	 * This should not cause multihop evictions, and the core will warn
130 	 * if one is proposed.
131 	 */
132 
133 	void (*evict_flags)(struct ttm_buffer_object *bo,
134 			    struct ttm_placement *placement);
135 
136 	/**
137 	 * struct ttm_bo_driver member move:
138 	 *
139 	 * @bo: the buffer to move
140 	 * @evict: whether this motion is evicting the buffer from
141 	 * the graphics address space
142 	 * @ctx: context for this move with parameters
143 	 * @new_mem: the new memory region receiving the buffer
144 	 * @hop: placement for driver directed intermediate hop
145 	 *
146 	 * Move a buffer between two memory regions.
147 	 * Returns errno -EMULTIHOP if driver requests a hop
148 	 */
149 	int (*move)(struct ttm_buffer_object *bo, bool evict,
150 		    struct ttm_operation_ctx *ctx,
151 		    struct ttm_resource *new_mem,
152 		    struct ttm_place *hop);
153 
154 	/**
155 	 * Hook to notify driver about a resource delete.
156 	 */
157 	void (*delete_mem_notify)(struct ttm_buffer_object *bo);
158 
159 	/**
160 	 * notify the driver that we're about to swap out this bo
161 	 */
162 	void (*swap_notify)(struct ttm_buffer_object *bo);
163 
164 	/**
165 	 * Driver callback on when mapping io memory (for bo_move_memcpy
166 	 * for instance). TTM will take care to call io_mem_free whenever
167 	 * the mapping is not use anymore. io_mem_reserve & io_mem_free
168 	 * are balanced.
169 	 */
170 	int (*io_mem_reserve)(struct ttm_device *bdev,
171 			      struct ttm_resource *mem);
172 	void (*io_mem_free)(struct ttm_device *bdev,
173 			    struct ttm_resource *mem);
174 
175 	/**
176 	 * Return the pfn for a given page_offset inside the BO.
177 	 *
178 	 * @bo: the BO to look up the pfn for
179 	 * @page_offset: the offset to look up
180 	 */
181 	unsigned long (*io_mem_pfn)(struct ttm_buffer_object *bo,
182 				    unsigned long page_offset);
183 
184 	/**
185 	 * Read/write memory buffers for ptrace access
186 	 *
187 	 * @bo: the BO to access
188 	 * @offset: the offset from the start of the BO
189 	 * @buf: pointer to source/destination buffer
190 	 * @len: number of bytes to copy
191 	 * @write: whether to read (0) from or write (non-0) to BO
192 	 *
193 	 * If successful, this function should return the number of
194 	 * bytes copied, -EIO otherwise. If the number of bytes
195 	 * returned is < len, the function may be called again with
196 	 * the remainder of the buffer to copy.
197 	 */
198 	int (*access_memory)(struct ttm_buffer_object *bo, unsigned long offset,
199 			     void *buf, int len, int write);
200 
201 	/**
202 	 * Notify the driver that we're about to release a BO
203 	 *
204 	 * @bo: BO that is about to be released
205 	 *
206 	 * Gives the driver a chance to do any cleanup, including
207 	 * adding fences that may force a delayed delete
208 	 */
209 	void (*release_notify)(struct ttm_buffer_object *bo);
210 };
211 
212 /**
213  * struct ttm_device - Buffer object driver device-specific data.
214  */
215 struct ttm_device {
216 	/**
217 	 * @device_list: Our entry in the global device list.
218 	 * Constant after bo device init
219 	 */
220 	struct list_head device_list;
221 
222 	/**
223 	 * @funcs: Function table for the device.
224 	 * Constant after bo device init
225 	 */
226 	struct ttm_device_funcs *funcs;
227 
228 	/**
229 	 * @sysman: Resource manager for the system domain.
230 	 * Access via ttm_manager_type.
231 	 */
232 	struct ttm_resource_manager sysman;
233 
234 	/**
235 	 * @man_drv: An array of resource_managers, one per resource type.
236 	 */
237 	struct ttm_resource_manager *man_drv[TTM_NUM_MEM_TYPES];
238 
239 	/**
240 	 * @vma_manager: Address space manager for finding BOs to mmap.
241 	 */
242 	struct drm_vma_offset_manager *vma_manager;
243 
244 	/**
245 	 * @pool: page pool for the device.
246 	 */
247 	struct ttm_pool pool;
248 
249 	/**
250 	 * @lru_lock: Protection for the per manager LRU and ddestroy lists.
251 	 */
252 	spinlock_t lru_lock;
253 
254 	/**
255 	 * @pinned: Buffer objects which are pinned and so not on any LRU list.
256 	 */
257 	struct list_head pinned;
258 
259 	/**
260 	 * @dev_mapping: A pointer to the struct address_space for invalidating
261 	 * CPU mappings on buffer move. Protected by load/unload sync.
262 	 */
263 	struct address_space *dev_mapping;
264 
265 	/**
266 	 * @wq: Work queue structure for the delayed delete workqueue.
267 	 */
268 	struct workqueue_struct *wq;
269 };
270 
271 int ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags);
272 int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
273 		       gfp_t gfp_flags);
274 
275 static inline struct ttm_resource_manager *
276 ttm_manager_type(struct ttm_device *bdev, int mem_type)
277 {
278 	BUILD_BUG_ON(__builtin_constant_p(mem_type)
279 		     && mem_type >= TTM_NUM_MEM_TYPES);
280 	return bdev->man_drv[mem_type];
281 }
282 
283 static inline void ttm_set_driver_manager(struct ttm_device *bdev, int type,
284 					  struct ttm_resource_manager *manager)
285 {
286 	BUILD_BUG_ON(__builtin_constant_p(type) && type >= TTM_NUM_MEM_TYPES);
287 	bdev->man_drv[type] = manager;
288 }
289 
290 int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs,
291 		    struct device *dev, struct address_space *mapping,
292 		    struct drm_vma_offset_manager *vma_manager,
293 		    bool use_dma_alloc, bool use_dma32);
294 void ttm_device_fini(struct ttm_device *bdev);
295 void ttm_device_clear_dma_mappings(struct ttm_device *bdev);
296 
297 #endif
298