xref: /openbmc/linux/include/drm/ttm/ttm_device.h (revision 3c8c1539)
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 #define TTM_NUM_MEM_TYPES 8
34 
35 struct ttm_device;
36 struct ttm_placement;
37 struct ttm_buffer_object;
38 struct ttm_operation_ctx;
39 
40 /**
41  * struct ttm_global - Buffer object driver global data.
42  *
43  * @dummy_read_page: Pointer to a dummy page used for mapping requests
44  * of unpopulated pages.
45  * @shrink: A shrink callback object used for buffer object swap.
46  * @device_list_mutex: Mutex protecting the device list.
47  * This mutex is held while traversing the device list for pm options.
48  * @lru_lock: Spinlock protecting the bo subsystem lru lists.
49  * @device_list: List of buffer object devices.
50  * @swap_lru: Lru list of buffer objects used for swapping.
51  */
52 extern struct ttm_global {
53 
54 	/**
55 	 * Constant after init.
56 	 */
57 
58 	struct page *dummy_read_page;
59 
60 	/**
61 	 * Protected by ttm_global_mutex.
62 	 */
63 	struct list_head device_list;
64 
65 	/**
66 	 * Internal protection.
67 	 */
68 	atomic_t bo_count;
69 } ttm_glob;
70 
71 struct ttm_device_funcs {
72 	/**
73 	 * ttm_tt_create
74 	 *
75 	 * @bo: The buffer object to create the ttm for.
76 	 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
77 	 *
78 	 * Create a struct ttm_tt to back data with system memory pages.
79 	 * No pages are actually allocated.
80 	 * Returns:
81 	 * NULL: Out of memory.
82 	 */
83 	struct ttm_tt *(*ttm_tt_create)(struct ttm_buffer_object *bo,
84 					uint32_t page_flags);
85 
86 	/**
87 	 * ttm_tt_populate
88 	 *
89 	 * @ttm: The struct ttm_tt to contain the backing pages.
90 	 *
91 	 * Allocate all backing pages
92 	 * Returns:
93 	 * -ENOMEM: Out of memory.
94 	 */
95 	int (*ttm_tt_populate)(struct ttm_device *bdev,
96 			       struct ttm_tt *ttm,
97 			       struct ttm_operation_ctx *ctx);
98 
99 	/**
100 	 * ttm_tt_unpopulate
101 	 *
102 	 * @ttm: The struct ttm_tt to contain the backing pages.
103 	 *
104 	 * Free all backing page
105 	 */
106 	void (*ttm_tt_unpopulate)(struct ttm_device *bdev,
107 				  struct ttm_tt *ttm);
108 
109 	/**
110 	 * ttm_tt_destroy
111 	 *
112 	 * @bdev: Pointer to a ttm device
113 	 * @ttm: Pointer to a struct ttm_tt.
114 	 *
115 	 * Destroy the backend. This will be call back from ttm_tt_destroy so
116 	 * don't call ttm_tt_destroy from the callback or infinite loop.
117 	 */
118 	void (*ttm_tt_destroy)(struct ttm_device *bdev, struct ttm_tt *ttm);
119 
120 	/**
121 	 * struct ttm_bo_driver member eviction_valuable
122 	 *
123 	 * @bo: the buffer object to be evicted
124 	 * @place: placement we need room for
125 	 *
126 	 * Check with the driver if it is valuable to evict a BO to make room
127 	 * for a certain placement.
128 	 */
129 	bool (*eviction_valuable)(struct ttm_buffer_object *bo,
130 				  const struct ttm_place *place);
131 	/**
132 	 * struct ttm_bo_driver member evict_flags:
133 	 *
134 	 * @bo: the buffer object to be evicted
135 	 *
136 	 * Return the bo flags for a buffer which is not mapped to the hardware.
137 	 * These will be placed in proposed_flags so that when the move is
138 	 * finished, they'll end up in bo->mem.flags
139 	 * This should not cause multihop evictions, and the core will warn
140 	 * if one is proposed.
141 	 */
142 
143 	void (*evict_flags)(struct ttm_buffer_object *bo,
144 			    struct ttm_placement *placement);
145 
146 	/**
147 	 * struct ttm_bo_driver member move:
148 	 *
149 	 * @bo: the buffer to move
150 	 * @evict: whether this motion is evicting the buffer from
151 	 * the graphics address space
152 	 * @ctx: context for this move with parameters
153 	 * @new_mem: the new memory region receiving the buffer
154 	 @ @hop: placement for driver directed intermediate hop
155 	 *
156 	 * Move a buffer between two memory regions.
157 	 * Returns errno -EMULTIHOP if driver requests a hop
158 	 */
159 	int (*move)(struct ttm_buffer_object *bo, bool evict,
160 		    struct ttm_operation_ctx *ctx,
161 		    struct ttm_resource *new_mem,
162 		    struct ttm_place *hop);
163 
164 	/**
165 	 * Hook to notify driver about a resource delete.
166 	 */
167 	void (*delete_mem_notify)(struct ttm_buffer_object *bo);
168 
169 	/**
170 	 * notify the driver that we're about to swap out this bo
171 	 */
172 	void (*swap_notify)(struct ttm_buffer_object *bo);
173 
174 	/**
175 	 * Driver callback on when mapping io memory (for bo_move_memcpy
176 	 * for instance). TTM will take care to call io_mem_free whenever
177 	 * the mapping is not use anymore. io_mem_reserve & io_mem_free
178 	 * are balanced.
179 	 */
180 	int (*io_mem_reserve)(struct ttm_device *bdev,
181 			      struct ttm_resource *mem);
182 	void (*io_mem_free)(struct ttm_device *bdev,
183 			    struct ttm_resource *mem);
184 
185 	/**
186 	 * Return the pfn for a given page_offset inside the BO.
187 	 *
188 	 * @bo: the BO to look up the pfn for
189 	 * @page_offset: the offset to look up
190 	 */
191 	unsigned long (*io_mem_pfn)(struct ttm_buffer_object *bo,
192 				    unsigned long page_offset);
193 
194 	/**
195 	 * Read/write memory buffers for ptrace access
196 	 *
197 	 * @bo: the BO to access
198 	 * @offset: the offset from the start of the BO
199 	 * @buf: pointer to source/destination buffer
200 	 * @len: number of bytes to copy
201 	 * @write: whether to read (0) from or write (non-0) to BO
202 	 *
203 	 * If successful, this function should return the number of
204 	 * bytes copied, -EIO otherwise. If the number of bytes
205 	 * returned is < len, the function may be called again with
206 	 * the remainder of the buffer to copy.
207 	 */
208 	int (*access_memory)(struct ttm_buffer_object *bo, unsigned long offset,
209 			     void *buf, int len, int write);
210 
211 	/**
212 	 * struct ttm_bo_driver member del_from_lru_notify
213 	 *
214 	 * @bo: the buffer object deleted from lru
215 	 *
216 	 * notify driver that a BO was deleted from LRU.
217 	 */
218 	void (*del_from_lru_notify)(struct ttm_buffer_object *bo);
219 
220 	/**
221 	 * Notify the driver that we're about to release a BO
222 	 *
223 	 * @bo: BO that is about to be released
224 	 *
225 	 * Gives the driver a chance to do any cleanup, including
226 	 * adding fences that may force a delayed delete
227 	 */
228 	void (*release_notify)(struct ttm_buffer_object *bo);
229 };
230 
231 /**
232  * struct ttm_device - Buffer object driver device-specific data.
233  *
234  * @device_list: Our entry in the global device list.
235  * @funcs: Function table for the device.
236  * @sysman: Resource manager for the system domain.
237  * @man_drv: An array of resource_managers.
238  * @vma_manager: Address space manager.
239  * @pool: page pool for the device.
240  * @dev_mapping: A pointer to the struct address_space representing the
241  * device address space.
242  * @wq: Work queue structure for the delayed delete workqueue.
243  */
244 struct ttm_device {
245 	/*
246 	 * Constant after bo device init
247 	 */
248 	struct list_head device_list;
249 	struct ttm_device_funcs *funcs;
250 
251 	/*
252 	 * Access via ttm_manager_type.
253 	 */
254 	struct ttm_resource_manager sysman;
255 	struct ttm_resource_manager *man_drv[TTM_NUM_MEM_TYPES];
256 
257 	/*
258 	 * Protected by internal locks.
259 	 */
260 	struct drm_vma_offset_manager *vma_manager;
261 	struct ttm_pool pool;
262 
263 	/*
264 	 * Protection for the per manager LRU and ddestroy lists.
265 	 */
266 	spinlock_t lru_lock;
267 	struct list_head ddestroy;
268 
269 	/*
270 	 * Protected by load / firstopen / lastclose /unload sync.
271 	 */
272 	struct address_space *dev_mapping;
273 
274 	/*
275 	 * Internal protection.
276 	 */
277 	struct delayed_work wq;
278 };
279 
280 int ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags);
281 int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
282 		       gfp_t gfp_flags);
283 
284 static inline struct ttm_resource_manager *
285 ttm_manager_type(struct ttm_device *bdev, int mem_type)
286 {
287 	return bdev->man_drv[mem_type];
288 }
289 
290 static inline void ttm_set_driver_manager(struct ttm_device *bdev, int type,
291 					  struct ttm_resource_manager *manager)
292 {
293 	bdev->man_drv[type] = manager;
294 }
295 
296 int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs,
297 		    struct device *dev, struct address_space *mapping,
298 		    struct drm_vma_offset_manager *vma_manager,
299 		    bool use_dma_alloc, bool use_dma32);
300 void ttm_device_fini(struct ttm_device *bdev);
301 
302 #endif
303