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_RESOURCE_H_
26 #define _TTM_RESOURCE_H_
27 
28 #include <linux/types.h>
29 #include <linux/list.h>
30 #include <linux/mutex.h>
31 #include <linux/iosys-map.h>
32 #include <linux/dma-fence.h>
33 
34 #include <drm/drm_print.h>
35 #include <drm/ttm/ttm_caching.h>
36 #include <drm/ttm/ttm_kmap_iter.h>
37 
38 #define TTM_MAX_BO_PRIORITY	4U
39 #define TTM_NUM_MEM_TYPES 8
40 
41 struct ttm_device;
42 struct ttm_resource_manager;
43 struct ttm_resource;
44 struct ttm_place;
45 struct ttm_buffer_object;
46 struct ttm_placement;
47 struct iosys_map;
48 struct io_mapping;
49 struct sg_table;
50 struct scatterlist;
51 
52 /**
53  * enum ttm_lru_item_type - enumerate ttm_lru_item subclasses
54  */
55 enum ttm_lru_item_type {
56 	/** @TTM_LRU_RESOURCE: The resource subclass */
57 	TTM_LRU_RESOURCE,
58 	/** @TTM_LRU_HITCH: The iterator hitch subclass */
59 	TTM_LRU_HITCH
60 };
61 
62 /**
63  * struct ttm_lru_item - The TTM lru list node base class
64  * @link: The list link
65  * @type: The subclass type
66  */
67 struct ttm_lru_item {
68 	struct list_head link;
69 	enum ttm_lru_item_type type;
70 };
71 
72 /**
73  * ttm_lru_item_init() - initialize a struct ttm_lru_item
74  * @item: The item to initialize
75  * @type: The subclass type
76  */
ttm_lru_item_init(struct ttm_lru_item * item,enum ttm_lru_item_type type)77 static inline void ttm_lru_item_init(struct ttm_lru_item *item,
78 				     enum ttm_lru_item_type type)
79 {
80 	item->type = type;
81 	INIT_LIST_HEAD(&item->link);
82 }
83 
ttm_lru_item_is_res(const struct ttm_lru_item * item)84 static inline bool ttm_lru_item_is_res(const struct ttm_lru_item *item)
85 {
86 	return item->type == TTM_LRU_RESOURCE;
87 }
88 
89 struct ttm_resource_manager_func {
90 	/**
91 	 * struct ttm_resource_manager_func member alloc
92 	 *
93 	 * @man: Pointer to a memory type manager.
94 	 * @bo: Pointer to the buffer object we're allocating space for.
95 	 * @place: Placement details.
96 	 * @res: Resulting pointer to the ttm_resource.
97 	 *
98 	 * This function should allocate space in the memory type managed
99 	 * by @man. Placement details if applicable are given by @place. If
100 	 * successful, a filled in ttm_resource object should be returned in
101 	 * @res. @res::start should be set to a value identifying the beginning
102 	 * of the range allocated, and the function should return zero.
103 	 * If the manager can't fulfill the request -ENOSPC should be returned.
104 	 * If a system error occurred, preventing the request to be fulfilled,
105 	 * the function should return a negative error code.
106 	 *
107 	 * This function may not be called from within atomic context and needs
108 	 * to take care of its own locking to protect any data structures
109 	 * managing the space.
110 	 */
111 	int  (*alloc)(struct ttm_resource_manager *man,
112 		      struct ttm_buffer_object *bo,
113 		      const struct ttm_place *place,
114 		      struct ttm_resource **res);
115 
116 	/**
117 	 * struct ttm_resource_manager_func member free
118 	 *
119 	 * @man: Pointer to a memory type manager.
120 	 * @res: Pointer to a struct ttm_resource to be freed.
121 	 *
122 	 * This function frees memory type resources previously allocated.
123 	 * May not be called from within atomic context.
124 	 */
125 	void (*free)(struct ttm_resource_manager *man,
126 		     struct ttm_resource *res);
127 
128 	/**
129 	 * struct ttm_resource_manager_func member intersects
130 	 *
131 	 * @man: Pointer to a memory type manager.
132 	 * @res: Pointer to a struct ttm_resource to be checked.
133 	 * @place: Placement to check against.
134 	 * @size: Size of the check.
135 	 *
136 	 * Test if @res intersects with @place + @size. Used to judge if
137 	 * evictions are valueable or not.
138 	 */
139 	bool (*intersects)(struct ttm_resource_manager *man,
140 			   struct ttm_resource *res,
141 			   const struct ttm_place *place,
142 			   size_t size);
143 
144 	/**
145 	 * struct ttm_resource_manager_func member compatible
146 	 *
147 	 * @man: Pointer to a memory type manager.
148 	 * @res: Pointer to a struct ttm_resource to be checked.
149 	 * @place: Placement to check against.
150 	 * @size: Size of the check.
151 	 *
152 	 * Test if @res compatible with @place + @size. Used to check of
153 	 * the need to move the backing store or not.
154 	 */
155 	bool (*compatible)(struct ttm_resource_manager *man,
156 			   struct ttm_resource *res,
157 			   const struct ttm_place *place,
158 			   size_t size);
159 
160 	/**
161 	 * struct ttm_resource_manager_func member debug
162 	 *
163 	 * @man: Pointer to a memory type manager.
164 	 * @printer: Prefix to be used in printout to identify the caller.
165 	 *
166 	 * This function is called to print out the state of the memory
167 	 * type manager to aid debugging of out-of-memory conditions.
168 	 * It may not be called from within atomic context.
169 	 */
170 	void (*debug)(struct ttm_resource_manager *man,
171 		      struct drm_printer *printer);
172 };
173 
174 /**
175  * struct ttm_resource_manager
176  *
177  * @use_type: The memory type is enabled.
178  * @use_tt: If a TT object should be used for the backing store.
179  * @size: Size of the managed region.
180  * @bdev: ttm device this manager belongs to
181  * @func: structure pointer implementing the range manager. See above
182  * @move_lock: lock for move fence
183  * @move: The fence of the last pipelined move operation.
184  * @lru: The lru list for this memory type.
185  *
186  * This structure is used to identify and manage memory types for a device.
187  */
188 struct ttm_resource_manager {
189 	/*
190 	 * No protection. Constant from start.
191 	 */
192 	bool use_type;
193 	bool use_tt;
194 	struct ttm_device *bdev;
195 	uint64_t size;
196 	const struct ttm_resource_manager_func *func;
197 	spinlock_t move_lock;
198 
199 	/*
200 	 * Protected by @move_lock.
201 	 */
202 	struct dma_fence *move;
203 
204 	/*
205 	 * Protected by the bdev->lru_lock.
206 	 */
207 	struct list_head lru[TTM_MAX_BO_PRIORITY];
208 
209 	/**
210 	 * @usage: How much of the resources are used, protected by the
211 	 * bdev->lru_lock.
212 	 */
213 	uint64_t usage;
214 };
215 
216 /**
217  * struct ttm_bus_placement
218  *
219  * @addr:		mapped virtual address
220  * @offset:		physical addr
221  * @is_iomem:		is this io memory ?
222  * @caching:		See enum ttm_caching
223  *
224  * Structure indicating the bus placement of an object.
225  */
226 struct ttm_bus_placement {
227 	void			*addr;
228 	phys_addr_t		offset;
229 	bool			is_iomem;
230 	enum ttm_caching	caching;
231 };
232 
233 /**
234  * struct ttm_resource
235  *
236  * @start: Start of the allocation.
237  * @size: Actual size of resource in bytes.
238  * @mem_type: Resource type of the allocation.
239  * @placement: Placement flags.
240  * @bus: Placement on io bus accessible to the CPU
241  * @bo: weak reference to the BO, protected by ttm_device::lru_lock
242  *
243  * Structure indicating the placement and space resources used by a
244  * buffer object.
245  */
246 struct ttm_resource {
247 	unsigned long start;
248 	size_t size;
249 	uint32_t mem_type;
250 	uint32_t placement;
251 	struct ttm_bus_placement bus;
252 	struct ttm_buffer_object *bo;
253 
254 	/**
255 	 * @lru: Least recently used list, see &ttm_resource_manager.lru
256 	 */
257 	struct ttm_lru_item lru;
258 };
259 
260 /**
261  * ttm_lru_item_to_res() - Downcast a struct ttm_lru_item to a struct ttm_resource
262  * @item: The struct ttm_lru_item to downcast
263  *
264  * Return: Pointer to the embedding struct ttm_resource
265  */
266 static inline struct ttm_resource *
ttm_lru_item_to_res(struct ttm_lru_item * item)267 ttm_lru_item_to_res(struct ttm_lru_item *item)
268 {
269 	return container_of(item, struct ttm_resource, lru);
270 }
271 
272 /**
273  * struct ttm_lru_bulk_move_pos
274  *
275  * @first: first res in the bulk move range
276  * @last: last res in the bulk move range
277  *
278  * Range of resources for a lru bulk move.
279  */
280 struct ttm_lru_bulk_move_pos {
281 	struct ttm_resource *first;
282 	struct ttm_resource *last;
283 };
284 
285 /**
286  * struct ttm_lru_bulk_move
287  * @pos: first/last lru entry for resources in the each domain/priority
288  * @cursor_list: The list of cursors currently traversing any of
289  * the sublists of @pos. Protected by the ttm device's lru_lock.
290  *
291  * Container for the current bulk move state. Should be used with
292  * ttm_lru_bulk_move_init() and ttm_bo_set_bulk_move().
293  * All BOs in a bulk_move structure need to share the same reservation object to
294  * ensure that the bulk as a whole is locked for eviction even if only one BO of
295  * the bulk is evicted.
296  */
297 struct ttm_lru_bulk_move {
298 	struct ttm_lru_bulk_move_pos pos[TTM_NUM_MEM_TYPES][TTM_MAX_BO_PRIORITY];
299 	struct list_head cursor_list;
300 };
301 
302 /**
303  * struct ttm_resource_cursor
304  * @man: The resource manager currently being iterated over
305  * @hitch: A hitch list node inserted before the next resource
306  * to iterate over.
307  * @bulk_link: A list link for the list of cursors traversing the
308  * bulk sublist of @bulk. Protected by the ttm device's lru_lock.
309  * @bulk: Pointer to struct ttm_lru_bulk_move whose subrange @hitch is
310  * inserted to. NULL if none. Never dereference this pointer since
311  * the struct ttm_lru_bulk_move object pointed to might have been
312  * freed. The pointer is only for comparison.
313  * @mem_type: The memory type of the LRU list being traversed.
314  * This field is valid iff @bulk != NULL.
315  * @priority: the current priority
316  *
317  * Cursor to iterate over the resources in a manager.
318  */
319 struct ttm_resource_cursor {
320 	struct ttm_resource_manager *man;
321 	struct ttm_lru_item hitch;
322 	struct list_head bulk_link;
323 	struct ttm_lru_bulk_move *bulk;
324 	unsigned int mem_type;
325 	unsigned int priority;
326 };
327 
328 void ttm_resource_cursor_fini(struct ttm_resource_cursor *cursor);
329 
330 /**
331  * struct ttm_kmap_iter_iomap - Specialization for a struct io_mapping +
332  * struct sg_table backed struct ttm_resource.
333  * @base: Embedded struct ttm_kmap_iter providing the usage interface.
334  * @iomap: struct io_mapping representing the underlying linear io_memory.
335  * @st: sg_table into @iomap, representing the memory of the struct ttm_resource.
336  * @start: Offset that needs to be subtracted from @st to make
337  * sg_dma_address(st->sgl) - @start == 0 for @iomap start.
338  * @cache: Scatterlist traversal cache for fast lookups.
339  * @cache.sg: Pointer to the currently cached scatterlist segment.
340  * @cache.i: First index of @sg. PAGE_SIZE granularity.
341  * @cache.end: Last index + 1 of @sg. PAGE_SIZE granularity.
342  * @cache.offs: First offset into @iomap of @sg. PAGE_SIZE granularity.
343  */
344 struct ttm_kmap_iter_iomap {
345 	struct ttm_kmap_iter base;
346 	struct io_mapping *iomap;
347 	struct sg_table *st;
348 	resource_size_t start;
349 	struct {
350 		struct scatterlist *sg;
351 		pgoff_t i;
352 		pgoff_t end;
353 		pgoff_t offs;
354 	} cache;
355 };
356 
357 /**
358  * struct ttm_kmap_iter_linear_io - Iterator specialization for linear io
359  * @base: The base iterator
360  * @dmap: Points to the starting address of the region
361  * @needs_unmap: Whether we need to unmap on fini
362  */
363 struct ttm_kmap_iter_linear_io {
364 	struct ttm_kmap_iter base;
365 	struct iosys_map dmap;
366 	bool needs_unmap;
367 };
368 
369 /**
370  * ttm_resource_manager_set_used
371  *
372  * @man: A memory manager object.
373  * @used: usage state to set.
374  *
375  * Set the manager in use flag. If disabled the manager is no longer
376  * used for object placement.
377  */
378 static inline void
ttm_resource_manager_set_used(struct ttm_resource_manager * man,bool used)379 ttm_resource_manager_set_used(struct ttm_resource_manager *man, bool used)
380 {
381 	int i;
382 
383 	for (i = 0; i < TTM_MAX_BO_PRIORITY; i++)
384 		WARN_ON(!list_empty(&man->lru[i]));
385 	man->use_type = used;
386 }
387 
388 /**
389  * ttm_resource_manager_used
390  *
391  * @man: Manager to get used state for
392  *
393  * Get the in use flag for a manager.
394  * Returns:
395  * true is used, false if not.
396  */
ttm_resource_manager_used(struct ttm_resource_manager * man)397 static inline bool ttm_resource_manager_used(struct ttm_resource_manager *man)
398 {
399 	return man->use_type;
400 }
401 
402 /**
403  * ttm_resource_manager_cleanup
404  *
405  * @man: A memory manager object.
406  *
407  * Cleanup the move fences from the memory manager object.
408  */
409 static inline void
ttm_resource_manager_cleanup(struct ttm_resource_manager * man)410 ttm_resource_manager_cleanup(struct ttm_resource_manager *man)
411 {
412 	dma_fence_put(man->move);
413 	man->move = NULL;
414 }
415 
416 void ttm_lru_bulk_move_init(struct ttm_lru_bulk_move *bulk);
417 void ttm_lru_bulk_move_tail(struct ttm_lru_bulk_move *bulk);
418 void ttm_lru_bulk_move_fini(struct ttm_device *bdev,
419 			    struct ttm_lru_bulk_move *bulk);
420 
421 void ttm_resource_add_bulk_move(struct ttm_resource *res,
422 				struct ttm_buffer_object *bo);
423 void ttm_resource_del_bulk_move(struct ttm_resource *res,
424 				struct ttm_buffer_object *bo);
425 void ttm_resource_move_to_lru_tail(struct ttm_resource *res);
426 
427 void ttm_resource_init(struct ttm_buffer_object *bo,
428                        const struct ttm_place *place,
429                        struct ttm_resource *res);
430 void ttm_resource_fini(struct ttm_resource_manager *man,
431 		       struct ttm_resource *res);
432 
433 int ttm_resource_alloc(struct ttm_buffer_object *bo,
434 		       const struct ttm_place *place,
435 		       struct ttm_resource **res);
436 void ttm_resource_free(struct ttm_buffer_object *bo, struct ttm_resource **res);
437 bool ttm_resource_intersects(struct ttm_device *bdev,
438 			     struct ttm_resource *res,
439 			     const struct ttm_place *place,
440 			     size_t size);
441 bool ttm_resource_compatible(struct ttm_resource *res,
442 			     struct ttm_placement *placement,
443 			     bool evicting);
444 void ttm_resource_set_bo(struct ttm_resource *res,
445 			 struct ttm_buffer_object *bo);
446 
447 void ttm_resource_manager_init(struct ttm_resource_manager *man,
448 			       struct ttm_device *bdev,
449 			       uint64_t size);
450 
451 int ttm_resource_manager_evict_all(struct ttm_device *bdev,
452 				   struct ttm_resource_manager *man);
453 
454 uint64_t ttm_resource_manager_usage(struct ttm_resource_manager *man);
455 void ttm_resource_manager_debug(struct ttm_resource_manager *man,
456 				struct drm_printer *p);
457 
458 struct ttm_resource *
459 ttm_resource_manager_first(struct ttm_resource_manager *man,
460 			   struct ttm_resource_cursor *cursor);
461 struct ttm_resource *
462 ttm_resource_manager_next(struct ttm_resource_cursor *cursor);
463 
464 struct ttm_resource *
465 ttm_lru_first_res_or_null(struct list_head *head);
466 
467 /**
468  * ttm_resource_manager_for_each_res - iterate over all resources
469  * @man: the resource manager
470  * @cursor: struct ttm_resource_cursor for the current position
471  * @res: the current resource
472  *
473  * Iterate over all the evictable resources in a resource manager.
474  */
475 #define ttm_resource_manager_for_each_res(man, cursor, res)		\
476 	for (res = ttm_resource_manager_first(man, cursor); res;	\
477 	     res = ttm_resource_manager_next(cursor))
478 
479 struct ttm_kmap_iter *
480 ttm_kmap_iter_iomap_init(struct ttm_kmap_iter_iomap *iter_io,
481 			 struct io_mapping *iomap,
482 			 struct sg_table *st,
483 			 resource_size_t start);
484 
485 struct ttm_kmap_iter_linear_io;
486 
487 struct ttm_kmap_iter *
488 ttm_kmap_iter_linear_io_init(struct ttm_kmap_iter_linear_io *iter_io,
489 			     struct ttm_device *bdev,
490 			     struct ttm_resource *mem);
491 
492 void ttm_kmap_iter_linear_io_fini(struct ttm_kmap_iter_linear_io *iter_io,
493 				  struct ttm_device *bdev,
494 				  struct ttm_resource *mem);
495 
496 void ttm_resource_manager_create_debugfs(struct ttm_resource_manager *man,
497 					 struct dentry * parent,
498 					 const char *name);
499 #endif
500