xref: /openbmc/linux/include/drm/ttm/ttm_bo.h (revision e65e175b)
1 /**************************************************************************
2  *
3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
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23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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25  *
26  **************************************************************************/
27 /*
28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29  */
30 
31 #ifndef _TTM_BO_API_H_
32 #define _TTM_BO_API_H_
33 
34 #include <drm/drm_gem.h>
35 
36 #include <linux/kref.h>
37 #include <linux/list.h>
38 
39 #include "ttm_device.h"
40 
41 /* Default number of pre-faulted pages in the TTM fault handler */
42 #define TTM_BO_VM_NUM_PREFAULT 16
43 
44 struct iosys_map;
45 
46 struct ttm_global;
47 struct ttm_device;
48 struct ttm_placement;
49 struct ttm_place;
50 struct ttm_resource;
51 struct ttm_resource_manager;
52 struct ttm_tt;
53 
54 /**
55  * enum ttm_bo_type
56  *
57  * @ttm_bo_type_device:	These are 'normal' buffers that can
58  * be mmapped by user space. Each of these bos occupy a slot in the
59  * device address space, that can be used for normal vm operations.
60  *
61  * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
62  * but they cannot be accessed from user-space. For kernel-only use.
63  *
64  * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
65  * driver.
66  */
67 enum ttm_bo_type {
68 	ttm_bo_type_device,
69 	ttm_bo_type_kernel,
70 	ttm_bo_type_sg
71 };
72 
73 /**
74  * struct ttm_buffer_object
75  *
76  * @base: drm_gem_object superclass data.
77  * @bdev: Pointer to the buffer object device structure.
78  * @type: The bo type.
79  * @page_alignment: Page alignment.
80  * @destroy: Destruction function. If NULL, kfree is used.
81  * @kref: Reference count of this buffer object. When this refcount reaches
82  * zero, the object is destroyed or put on the delayed delete list.
83  * @resource: structure describing current placement.
84  * @ttm: TTM structure holding system pages.
85  * @deleted: True if the object is only a zombie and already deleted.
86  *
87  * Base class for TTM buffer object, that deals with data placement and CPU
88  * mappings. GPU mappings are really up to the driver, but for simpler GPUs
89  * the driver can usually use the placement offset @offset directly as the
90  * GPU virtual address. For drivers implementing multiple
91  * GPU memory manager contexts, the driver should manage the address space
92  * in these contexts separately and use these objects to get the correct
93  * placement and caching for these GPU maps. This makes it possible to use
94  * these objects for even quite elaborate memory management schemes.
95  * The destroy member, the API visibility of this object makes it possible
96  * to derive driver specific types.
97  */
98 struct ttm_buffer_object {
99 	struct drm_gem_object base;
100 
101 	/*
102 	 * Members constant at init.
103 	 */
104 	struct ttm_device *bdev;
105 	enum ttm_bo_type type;
106 	uint32_t page_alignment;
107 	void (*destroy) (struct ttm_buffer_object *);
108 
109 	/*
110 	* Members not needing protection.
111 	*/
112 	struct kref kref;
113 
114 	/*
115 	 * Members protected by the bo::resv::reserved lock.
116 	 */
117 	struct ttm_resource *resource;
118 	struct ttm_tt *ttm;
119 	bool deleted;
120 	struct ttm_lru_bulk_move *bulk_move;
121 	unsigned priority;
122 	unsigned pin_count;
123 
124 	/**
125 	 * @delayed_delete: Work item used when we can't delete the BO
126 	 * immediately
127 	 */
128 	struct work_struct delayed_delete;
129 
130 	/**
131 	 * Special members that are protected by the reserve lock
132 	 * and the bo::lock when written to. Can be read with
133 	 * either of these locks held.
134 	 */
135 	struct sg_table *sg;
136 };
137 
138 /**
139  * struct ttm_bo_kmap_obj
140  *
141  * @virtual: The current kernel virtual address.
142  * @page: The page when kmap'ing a single page.
143  * @bo_kmap_type: Type of bo_kmap.
144  *
145  * Object describing a kernel mapping. Since a TTM bo may be located
146  * in various memory types with various caching policies, the
147  * mapping can either be an ioremap, a vmap, a kmap or part of a
148  * premapped region.
149  */
150 #define TTM_BO_MAP_IOMEM_MASK 0x80
151 struct ttm_bo_kmap_obj {
152 	void *virtual;
153 	struct page *page;
154 	enum {
155 		ttm_bo_map_iomap        = 1 | TTM_BO_MAP_IOMEM_MASK,
156 		ttm_bo_map_vmap         = 2,
157 		ttm_bo_map_kmap         = 3,
158 		ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
159 	} bo_kmap_type;
160 	struct ttm_buffer_object *bo;
161 };
162 
163 /**
164  * struct ttm_operation_ctx
165  *
166  * @interruptible: Sleep interruptible if sleeping.
167  * @no_wait_gpu: Return immediately if the GPU is busy.
168  * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages.
169  * @allow_res_evict: Allow eviction of reserved BOs. Can be used when multiple
170  * BOs share the same reservation object.
171  * @force_alloc: Don't check the memory account during suspend or CPU page
172  * faults. Should only be used by TTM internally.
173  * @resv: Reservation object to allow reserved evictions with.
174  *
175  * Context for TTM operations like changing buffer placement or general memory
176  * allocation.
177  */
178 struct ttm_operation_ctx {
179 	bool interruptible;
180 	bool no_wait_gpu;
181 	bool gfp_retry_mayfail;
182 	bool allow_res_evict;
183 	bool force_alloc;
184 	struct dma_resv *resv;
185 	uint64_t bytes_moved;
186 };
187 
188 /**
189  * ttm_bo_get - reference a struct ttm_buffer_object
190  *
191  * @bo: The buffer object.
192  */
193 static inline void ttm_bo_get(struct ttm_buffer_object *bo)
194 {
195 	kref_get(&bo->kref);
196 }
197 
198 /**
199  * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
200  * its refcount has already reached zero.
201  * @bo: The buffer object.
202  *
203  * Used to reference a TTM buffer object in lookups where the object is removed
204  * from the lookup structure during the destructor and for RCU lookups.
205  *
206  * Returns: @bo if the referencing was successful, NULL otherwise.
207  */
208 static inline __must_check struct ttm_buffer_object *
209 ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
210 {
211 	if (!kref_get_unless_zero(&bo->kref))
212 		return NULL;
213 	return bo;
214 }
215 
216 /**
217  * ttm_bo_reserve:
218  *
219  * @bo: A pointer to a struct ttm_buffer_object.
220  * @interruptible: Sleep interruptible if waiting.
221  * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
222  * @ticket: ticket used to acquire the ww_mutex.
223  *
224  * Locks a buffer object for validation. (Or prevents other processes from
225  * locking it for validation), while taking a number of measures to prevent
226  * deadlocks.
227  *
228  * Returns:
229  * -EDEADLK: The reservation may cause a deadlock.
230  * Release all buffer reservations, wait for @bo to become unreserved and
231  * try again.
232  * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
233  * a signal. Release all buffer reservations and return to user-space.
234  * -EBUSY: The function needed to sleep, but @no_wait was true
235  * -EALREADY: Bo already reserved using @ticket. This error code will only
236  * be returned if @use_ticket is set to true.
237  */
238 static inline int ttm_bo_reserve(struct ttm_buffer_object *bo,
239 				 bool interruptible, bool no_wait,
240 				 struct ww_acquire_ctx *ticket)
241 {
242 	int ret = 0;
243 
244 	if (no_wait) {
245 		bool success;
246 
247 		if (WARN_ON(ticket))
248 			return -EBUSY;
249 
250 		success = dma_resv_trylock(bo->base.resv);
251 		return success ? 0 : -EBUSY;
252 	}
253 
254 	if (interruptible)
255 		ret = dma_resv_lock_interruptible(bo->base.resv, ticket);
256 	else
257 		ret = dma_resv_lock(bo->base.resv, ticket);
258 	if (ret == -EINTR)
259 		return -ERESTARTSYS;
260 	return ret;
261 }
262 
263 /**
264  * ttm_bo_reserve_slowpath:
265  * @bo: A pointer to a struct ttm_buffer_object.
266  * @interruptible: Sleep interruptible if waiting.
267  * @sequence: Set (@bo)->sequence to this value after lock
268  *
269  * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
270  * from all our other reservations. Because there are no other reservations
271  * held by us, this function cannot deadlock any more.
272  */
273 static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
274 					  bool interruptible,
275 					  struct ww_acquire_ctx *ticket)
276 {
277 	if (interruptible) {
278 		int ret = dma_resv_lock_slow_interruptible(bo->base.resv,
279 							   ticket);
280 		if (ret == -EINTR)
281 			ret = -ERESTARTSYS;
282 		return ret;
283 	}
284 	dma_resv_lock_slow(bo->base.resv, ticket);
285 	return 0;
286 }
287 
288 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
289 
290 static inline void
291 ttm_bo_move_to_lru_tail_unlocked(struct ttm_buffer_object *bo)
292 {
293 	spin_lock(&bo->bdev->lru_lock);
294 	ttm_bo_move_to_lru_tail(bo);
295 	spin_unlock(&bo->bdev->lru_lock);
296 }
297 
298 static inline void ttm_bo_assign_mem(struct ttm_buffer_object *bo,
299 				     struct ttm_resource *new_mem)
300 {
301 	WARN_ON(bo->resource);
302 	bo->resource = new_mem;
303 }
304 
305 /**
306  * ttm_bo_move_null = assign memory for a buffer object.
307  * @bo: The bo to assign the memory to
308  * @new_mem: The memory to be assigned.
309  *
310  * Assign the memory from new_mem to the memory of the buffer object bo.
311  */
312 static inline void ttm_bo_move_null(struct ttm_buffer_object *bo,
313 				    struct ttm_resource *new_mem)
314 {
315 	ttm_resource_free(bo, &bo->resource);
316 	ttm_bo_assign_mem(bo, new_mem);
317 }
318 
319 /**
320  * ttm_bo_unreserve
321  *
322  * @bo: A pointer to a struct ttm_buffer_object.
323  *
324  * Unreserve a previous reservation of @bo.
325  */
326 static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo)
327 {
328 	ttm_bo_move_to_lru_tail_unlocked(bo);
329 	dma_resv_unlock(bo->base.resv);
330 }
331 
332 /**
333  * ttm_kmap_obj_virtual
334  *
335  * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
336  * @is_iomem: Pointer to an integer that on return indicates 1 if the
337  * virtual map is io memory, 0 if normal memory.
338  *
339  * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
340  * If *is_iomem is 1 on return, the virtual address points to an io memory area,
341  * that should strictly be accessed by the iowriteXX() and similar functions.
342  */
343 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
344 					 bool *is_iomem)
345 {
346 	*is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
347 	return map->virtual;
348 }
349 
350 int ttm_bo_wait_ctx(struct ttm_buffer_object *bo,
351 		    struct ttm_operation_ctx *ctx);
352 int ttm_bo_validate(struct ttm_buffer_object *bo,
353 		    struct ttm_placement *placement,
354 		    struct ttm_operation_ctx *ctx);
355 void ttm_bo_put(struct ttm_buffer_object *bo);
356 void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
357 			  struct ttm_lru_bulk_move *bulk);
358 int ttm_bo_lock_delayed_workqueue(struct ttm_device *bdev);
359 void ttm_bo_unlock_delayed_workqueue(struct ttm_device *bdev, int resched);
360 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
361 			      const struct ttm_place *place);
362 int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,
363 			 enum ttm_bo_type type, struct ttm_placement *placement,
364 			 uint32_t alignment, struct ttm_operation_ctx *ctx,
365 			 struct sg_table *sg, struct dma_resv *resv,
366 			 void (*destroy)(struct ttm_buffer_object *));
367 int ttm_bo_init_validate(struct ttm_device *bdev, struct ttm_buffer_object *bo,
368 			 enum ttm_bo_type type, struct ttm_placement *placement,
369 			 uint32_t alignment, bool interruptible,
370 			 struct sg_table *sg, struct dma_resv *resv,
371 			 void (*destroy)(struct ttm_buffer_object *));
372 int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
373 		unsigned long num_pages, struct ttm_bo_kmap_obj *map);
374 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
375 int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map);
376 void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map);
377 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
378 int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
379 		   gfp_t gfp_flags);
380 void ttm_bo_pin(struct ttm_buffer_object *bo);
381 void ttm_bo_unpin(struct ttm_buffer_object *bo);
382 int ttm_mem_evict_first(struct ttm_device *bdev,
383 			struct ttm_resource_manager *man,
384 			const struct ttm_place *place,
385 			struct ttm_operation_ctx *ctx,
386 			struct ww_acquire_ctx *ticket);
387 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
388 			     struct vm_fault *vmf);
389 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
390 				    pgprot_t prot,
391 				    pgoff_t num_prefault);
392 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf);
393 void ttm_bo_vm_open(struct vm_area_struct *vma);
394 void ttm_bo_vm_close(struct vm_area_struct *vma);
395 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
396 		     void *buf, int len, int write);
397 vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot);
398 
399 int ttm_bo_mem_space(struct ttm_buffer_object *bo,
400 		     struct ttm_placement *placement,
401 		     struct ttm_resource **mem,
402 		     struct ttm_operation_ctx *ctx);
403 
404 void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
405 /*
406  * ttm_bo_util.c
407  */
408 int ttm_mem_io_reserve(struct ttm_device *bdev,
409 		       struct ttm_resource *mem);
410 void ttm_mem_io_free(struct ttm_device *bdev,
411 		     struct ttm_resource *mem);
412 void ttm_move_memcpy(bool clear, u32 num_pages,
413 		     struct ttm_kmap_iter *dst_iter,
414 		     struct ttm_kmap_iter *src_iter);
415 int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
416 		       struct ttm_operation_ctx *ctx,
417 		       struct ttm_resource *new_mem);
418 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
419 			      struct dma_fence *fence, bool evict,
420 			      bool pipeline,
421 			      struct ttm_resource *new_mem);
422 void ttm_bo_move_sync_cleanup(struct ttm_buffer_object *bo,
423 			      struct ttm_resource *new_mem);
424 int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo);
425 pgprot_t ttm_io_prot(struct ttm_buffer_object *bo, struct ttm_resource *res,
426 		     pgprot_t tmp);
427 void ttm_bo_tt_destroy(struct ttm_buffer_object *bo);
428 
429 #endif
430