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,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
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 #include <drm/drm_hashtab.h>
36 #include <drm/drm_vma_manager.h>
37 #include <linux/kref.h>
38 #include <linux/list.h>
39 #include <linux/wait.h>
40 #include <linux/mutex.h>
41 #include <linux/mm.h>
42 #include <linux/bitmap.h>
43 #include <linux/dma-resv.h>
44
45 #include "ttm_resource.h"
46
47 struct ttm_global;
48
49 struct ttm_device;
50
51 struct dma_buf_map;
52
53 struct drm_mm_node;
54
55 struct ttm_placement;
56
57 struct ttm_place;
58
59 struct ttm_lru_bulk_move;
60
61 /**
62 * enum ttm_bo_type
63 *
64 * @ttm_bo_type_device: These are 'normal' buffers that can
65 * be mmapped by user space. Each of these bos occupy a slot in the
66 * device address space, that can be used for normal vm operations.
67 *
68 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
69 * but they cannot be accessed from user-space. For kernel-only use.
70 *
71 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
72 * driver.
73 */
74
75 enum ttm_bo_type {
76 ttm_bo_type_device,
77 ttm_bo_type_kernel,
78 ttm_bo_type_sg
79 };
80
81 struct ttm_tt;
82
83 /**
84 * struct ttm_buffer_object
85 *
86 * @base: drm_gem_object superclass data.
87 * @bdev: Pointer to the buffer object device structure.
88 * @type: The bo type.
89 * @page_alignment: Page alignment.
90 * @destroy: Destruction function. If NULL, kfree is used.
91 * @num_pages: Actual number of pages.
92 * @kref: Reference count of this buffer object. When this refcount reaches
93 * zero, the object is destroyed or put on the delayed delete list.
94 * @mem: structure describing current placement.
95 * @ttm: TTM structure holding system pages.
96 * @evicted: Whether the object was evicted without user-space knowing.
97 * @deleted: True if the object is only a zombie and already deleted.
98 * @lru: List head for the lru list.
99 * @ddestroy: List head for the delayed destroy list.
100 * @swap: List head for swap LRU list.
101 * @moving: Fence set when BO is moving
102 * @offset: The current GPU offset, which can have different meanings
103 * depending on the memory type. For SYSTEM type memory, it should be 0.
104 * @cur_placement: Hint of current placement.
105 *
106 * Base class for TTM buffer object, that deals with data placement and CPU
107 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
108 * the driver can usually use the placement offset @offset directly as the
109 * GPU virtual address. For drivers implementing multiple
110 * GPU memory manager contexts, the driver should manage the address space
111 * in these contexts separately and use these objects to get the correct
112 * placement and caching for these GPU maps. This makes it possible to use
113 * these objects for even quite elaborate memory management schemes.
114 * The destroy member, the API visibility of this object makes it possible
115 * to derive driver specific types.
116 */
117
118 struct ttm_buffer_object {
119 struct drm_gem_object base;
120
121 /**
122 * Members constant at init.
123 */
124
125 struct ttm_device *bdev;
126 enum ttm_bo_type type;
127 uint32_t page_alignment;
128 void (*destroy) (struct ttm_buffer_object *);
129
130 /**
131 * Members not needing protection.
132 */
133 struct kref kref;
134
135 /**
136 * Members protected by the bo::resv::reserved lock.
137 */
138
139 struct ttm_resource *resource;
140 struct ttm_tt *ttm;
141 bool deleted;
142
143 /**
144 * Members protected by the bdev::lru_lock.
145 */
146
147 struct list_head lru;
148 struct list_head ddestroy;
149
150 /**
151 * Members protected by a bo reservation.
152 */
153
154 struct dma_fence *moving;
155 unsigned priority;
156 unsigned pin_count;
157
158 /**
159 * Special members that are protected by the reserve lock
160 * and the bo::lock when written to. Can be read with
161 * either of these locks held.
162 */
163
164 struct sg_table *sg;
165 };
166
167 /**
168 * struct ttm_bo_kmap_obj
169 *
170 * @virtual: The current kernel virtual address.
171 * @page: The page when kmap'ing a single page.
172 * @bo_kmap_type: Type of bo_kmap.
173 *
174 * Object describing a kernel mapping. Since a TTM bo may be located
175 * in various memory types with various caching policies, the
176 * mapping can either be an ioremap, a vmap, a kmap or part of a
177 * premapped region.
178 */
179
180 #define TTM_BO_MAP_IOMEM_MASK 0x80
181 struct ttm_bo_kmap_obj {
182 void *virtual;
183 struct page *page;
184 enum {
185 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
186 ttm_bo_map_vmap = 2,
187 ttm_bo_map_kmap = 3,
188 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
189 } bo_kmap_type;
190 struct ttm_buffer_object *bo;
191 };
192
193 /**
194 * struct ttm_operation_ctx
195 *
196 * @interruptible: Sleep interruptible if sleeping.
197 * @no_wait_gpu: Return immediately if the GPU is busy.
198 * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages.
199 * @allow_res_evict: Allow eviction of reserved BOs. Can be used when multiple
200 * BOs share the same reservation object.
201 * @force_alloc: Don't check the memory account during suspend or CPU page
202 * faults. Should only be used by TTM internally.
203 * @resv: Reservation object to allow reserved evictions with.
204 *
205 * Context for TTM operations like changing buffer placement or general memory
206 * allocation.
207 */
208 struct ttm_operation_ctx {
209 bool interruptible;
210 bool no_wait_gpu;
211 bool gfp_retry_mayfail;
212 bool allow_res_evict;
213 bool force_alloc;
214 struct dma_resv *resv;
215 uint64_t bytes_moved;
216 };
217
218 /**
219 * ttm_bo_get - reference a struct ttm_buffer_object
220 *
221 * @bo: The buffer object.
222 */
ttm_bo_get(struct ttm_buffer_object * bo)223 static inline void ttm_bo_get(struct ttm_buffer_object *bo)
224 {
225 kref_get(&bo->kref);
226 }
227
228 /**
229 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
230 * its refcount has already reached zero.
231 * @bo: The buffer object.
232 *
233 * Used to reference a TTM buffer object in lookups where the object is removed
234 * from the lookup structure during the destructor and for RCU lookups.
235 *
236 * Returns: @bo if the referencing was successful, NULL otherwise.
237 */
238 static inline __must_check struct ttm_buffer_object *
ttm_bo_get_unless_zero(struct ttm_buffer_object * bo)239 ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
240 {
241 if (!kref_get_unless_zero(&bo->kref))
242 return NULL;
243 return bo;
244 }
245
246 /**
247 * ttm_bo_wait - wait for buffer idle.
248 *
249 * @bo: The buffer object.
250 * @interruptible: Use interruptible wait.
251 * @no_wait: Return immediately if buffer is busy.
252 *
253 * This function must be called with the bo::mutex held, and makes
254 * sure any previous rendering to the buffer is completed.
255 * Note: It might be necessary to block validations before the
256 * wait by reserving the buffer.
257 * Returns -EBUSY if no_wait is true and the buffer is busy.
258 * Returns -ERESTARTSYS if interrupted by a signal.
259 */
260 int ttm_bo_wait(struct ttm_buffer_object *bo, bool interruptible, bool no_wait);
261
ttm_bo_wait_ctx(struct ttm_buffer_object * bo,struct ttm_operation_ctx * ctx)262 static inline int ttm_bo_wait_ctx(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx)
263 {
264 return ttm_bo_wait(bo, ctx->interruptible, ctx->no_wait_gpu);
265 }
266
267 /**
268 * ttm_bo_mem_compat - Check if proposed placement is compatible with a bo
269 *
270 * @placement: Return immediately if buffer is busy.
271 * @mem: The struct ttm_resource indicating the region where the bo resides
272 * @new_flags: Describes compatible placement found
273 *
274 * Returns true if the placement is compatible
275 */
276 bool ttm_bo_mem_compat(struct ttm_placement *placement, struct ttm_resource *mem,
277 uint32_t *new_flags);
278
279 /**
280 * ttm_bo_validate
281 *
282 * @bo: The buffer object.
283 * @placement: Proposed placement for the buffer object.
284 * @ctx: validation parameters.
285 *
286 * Changes placement and caching policy of the buffer object
287 * according proposed placement.
288 * Returns
289 * -EINVAL on invalid proposed placement.
290 * -ENOMEM on out-of-memory condition.
291 * -EBUSY if no_wait is true and buffer busy.
292 * -ERESTARTSYS if interrupted by a signal.
293 */
294 int ttm_bo_validate(struct ttm_buffer_object *bo,
295 struct ttm_placement *placement,
296 struct ttm_operation_ctx *ctx);
297
298 /**
299 * ttm_bo_put
300 *
301 * @bo: The buffer object.
302 *
303 * Unreference a buffer object.
304 */
305 void ttm_bo_put(struct ttm_buffer_object *bo);
306
307 /**
308 * ttm_bo_move_to_lru_tail
309 *
310 * @bo: The buffer object.
311 * @mem: Resource object.
312 * @bulk: optional bulk move structure to remember BO positions
313 *
314 * Move this BO to the tail of all lru lists used to lookup and reserve an
315 * object. This function must be called with struct ttm_global::lru_lock
316 * held, and is used to make a BO less likely to be considered for eviction.
317 */
318 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
319 struct ttm_resource *mem,
320 struct ttm_lru_bulk_move *bulk);
321
322 /**
323 * ttm_bo_bulk_move_lru_tail
324 *
325 * @bulk: bulk move structure
326 *
327 * Bulk move BOs to the LRU tail, only valid to use when driver makes sure that
328 * BO order never changes. Should be called with ttm_global::lru_lock held.
329 */
330 void ttm_bo_bulk_move_lru_tail(struct ttm_lru_bulk_move *bulk);
331
332 /**
333 * ttm_bo_lock_delayed_workqueue
334 *
335 * Prevent the delayed workqueue from running.
336 * Returns
337 * True if the workqueue was queued at the time
338 */
339 int ttm_bo_lock_delayed_workqueue(struct ttm_device *bdev);
340
341 /**
342 * ttm_bo_unlock_delayed_workqueue
343 *
344 * Allows the delayed workqueue to run.
345 */
346 void ttm_bo_unlock_delayed_workqueue(struct ttm_device *bdev, int resched);
347
348 /**
349 * ttm_bo_eviction_valuable
350 *
351 * @bo: The buffer object to evict
352 * @place: the placement we need to make room for
353 *
354 * Check if it is valuable to evict the BO to make room for the given placement.
355 */
356 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
357 const struct ttm_place *place);
358
359 /**
360 * ttm_bo_init_reserved
361 *
362 * @bdev: Pointer to a ttm_device struct.
363 * @bo: Pointer to a ttm_buffer_object to be initialized.
364 * @size: Requested size of buffer object.
365 * @type: Requested type of buffer object.
366 * @flags: Initial placement flags.
367 * @page_alignment: Data alignment in pages.
368 * @ctx: TTM operation context for memory allocation.
369 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
370 * @destroy: Destroy function. Use NULL for kfree().
371 *
372 * This function initializes a pre-allocated struct ttm_buffer_object.
373 * As this object may be part of a larger structure, this function,
374 * together with the @destroy function,
375 * enables driver-specific objects derived from a ttm_buffer_object.
376 *
377 * On successful return, the caller owns an object kref to @bo. The kref and
378 * list_kref are usually set to 1, but note that in some situations, other
379 * tasks may already be holding references to @bo as well.
380 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
381 * and it is the caller's responsibility to call ttm_bo_unreserve.
382 *
383 * If a failure occurs, the function will call the @destroy function, or
384 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
385 * illegal and will likely cause memory corruption.
386 *
387 * Returns
388 * -ENOMEM: Out of memory.
389 * -EINVAL: Invalid placement flags.
390 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
391 */
392
393 int ttm_bo_init_reserved(struct ttm_device *bdev,
394 struct ttm_buffer_object *bo,
395 size_t size, enum ttm_bo_type type,
396 struct ttm_placement *placement,
397 uint32_t page_alignment,
398 struct ttm_operation_ctx *ctx,
399 struct sg_table *sg, struct dma_resv *resv,
400 void (*destroy) (struct ttm_buffer_object *));
401
402 /**
403 * ttm_bo_init
404 *
405 * @bdev: Pointer to a ttm_device struct.
406 * @bo: Pointer to a ttm_buffer_object to be initialized.
407 * @size: Requested size of buffer object.
408 * @type: Requested type of buffer object.
409 * @flags: Initial placement flags.
410 * @page_alignment: Data alignment in pages.
411 * @interruptible: If needing to sleep to wait for GPU resources,
412 * sleep interruptible.
413 * pinned in physical memory. If this behaviour is not desired, this member
414 * holds a pointer to a persistent shmem object. Typically, this would
415 * point to the shmem object backing a GEM object if TTM is used to back a
416 * GEM user interface.
417 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
418 * @destroy: Destroy function. Use NULL for kfree().
419 *
420 * This function initializes a pre-allocated struct ttm_buffer_object.
421 * As this object may be part of a larger structure, this function,
422 * together with the @destroy function,
423 * enables driver-specific objects derived from a ttm_buffer_object.
424 *
425 * On successful return, the caller owns an object kref to @bo. The kref and
426 * list_kref are usually set to 1, but note that in some situations, other
427 * tasks may already be holding references to @bo as well.
428 *
429 * If a failure occurs, the function will call the @destroy function, or
430 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
431 * illegal and will likely cause memory corruption.
432 *
433 * Returns
434 * -ENOMEM: Out of memory.
435 * -EINVAL: Invalid placement flags.
436 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
437 */
438 int ttm_bo_init(struct ttm_device *bdev, struct ttm_buffer_object *bo,
439 size_t size, enum ttm_bo_type type,
440 struct ttm_placement *placement,
441 uint32_t page_alignment, bool interrubtible,
442 struct sg_table *sg, struct dma_resv *resv,
443 void (*destroy) (struct ttm_buffer_object *));
444
445 /**
446 * ttm_kmap_obj_virtual
447 *
448 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
449 * @is_iomem: Pointer to an integer that on return indicates 1 if the
450 * virtual map is io memory, 0 if normal memory.
451 *
452 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
453 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
454 * that should strictly be accessed by the iowriteXX() and similar functions.
455 */
ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj * map,bool * is_iomem)456 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
457 bool *is_iomem)
458 {
459 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
460 return map->virtual;
461 }
462
463 /**
464 * ttm_bo_kmap
465 *
466 * @bo: The buffer object.
467 * @start_page: The first page to map.
468 * @num_pages: Number of pages to map.
469 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
470 *
471 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
472 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
473 * used to obtain a virtual address to the data.
474 *
475 * Returns
476 * -ENOMEM: Out of memory.
477 * -EINVAL: Invalid range.
478 */
479 int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
480 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
481
482 /**
483 * ttm_bo_kunmap
484 *
485 * @map: Object describing the map to unmap.
486 *
487 * Unmaps a kernel map set up by ttm_bo_kmap.
488 */
489 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
490
491 /**
492 * ttm_bo_vmap
493 *
494 * @bo: The buffer object.
495 * @map: pointer to a struct dma_buf_map representing the map.
496 *
497 * Sets up a kernel virtual mapping, using ioremap or vmap to the
498 * data in the buffer object. The parameter @map returns the virtual
499 * address as struct dma_buf_map. Unmap the buffer with ttm_bo_vunmap().
500 *
501 * Returns
502 * -ENOMEM: Out of memory.
503 * -EINVAL: Invalid range.
504 */
505 int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
506
507 /**
508 * ttm_bo_vunmap
509 *
510 * @bo: The buffer object.
511 * @map: Object describing the map to unmap.
512 *
513 * Unmaps a kernel map set up by ttm_bo_vmap().
514 */
515 void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
516
517 /**
518 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
519 *
520 * @vma: vma as input from the fbdev mmap method.
521 * @bo: The bo backing the address space.
522 *
523 * Maps a buffer object.
524 */
525 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
526
527 /**
528 * ttm_bo_io
529 *
530 * @bdev: Pointer to the struct ttm_device.
531 * @filp: Pointer to the struct file attempting to read / write.
532 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
533 * @rbuf: User-space pointer to address of buffer to read into.
534 * Null on write.
535 * @count: Number of bytes to read / write.
536 * @f_pos: Pointer to current file position.
537 * @write: 1 for read, 0 for write.
538 *
539 * This function implements read / write into ttm buffer objects, and is
540 * intended to
541 * be called from the fops::read and fops::write method.
542 * Returns:
543 * See man (2) write, man(2) read. In particular,
544 * the function may return -ERESTARTSYS if
545 * interrupted by a signal.
546 */
547 ssize_t ttm_bo_io(struct ttm_device *bdev, struct file *filp,
548 const char __user *wbuf, char __user *rbuf,
549 size_t count, loff_t *f_pos, bool write);
550
551 int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
552 gfp_t gfp_flags);
553
554 /**
555 * ttm_bo_pin - Pin the buffer object.
556 * @bo: The buffer object to pin
557 *
558 * Make sure the buffer is not evicted any more during memory pressure.
559 */
ttm_bo_pin(struct ttm_buffer_object * bo)560 static inline void ttm_bo_pin(struct ttm_buffer_object *bo)
561 {
562 dma_resv_assert_held(bo->base.resv);
563 WARN_ON_ONCE(!kref_read(&bo->kref));
564 ++bo->pin_count;
565 }
566
567 /**
568 * ttm_bo_unpin - Unpin the buffer object.
569 * @bo: The buffer object to unpin
570 *
571 * Allows the buffer object to be evicted again during memory pressure.
572 */
ttm_bo_unpin(struct ttm_buffer_object * bo)573 static inline void ttm_bo_unpin(struct ttm_buffer_object *bo)
574 {
575 dma_resv_assert_held(bo->base.resv);
576 WARN_ON_ONCE(!kref_read(&bo->kref));
577 if (bo->pin_count)
578 --bo->pin_count;
579 else
580 WARN_ON_ONCE(true);
581 }
582
583 int ttm_mem_evict_first(struct ttm_device *bdev,
584 struct ttm_resource_manager *man,
585 const struct ttm_place *place,
586 struct ttm_operation_ctx *ctx,
587 struct ww_acquire_ctx *ticket);
588
589 /* Default number of pre-faulted pages in the TTM fault handler */
590 #define TTM_BO_VM_NUM_PREFAULT 16
591
592 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
593 struct vm_fault *vmf);
594
595 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
596 pgprot_t prot,
597 pgoff_t num_prefault,
598 pgoff_t fault_page_size);
599
600 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf);
601
602 void ttm_bo_vm_open(struct vm_area_struct *vma);
603
604 void ttm_bo_vm_close(struct vm_area_struct *vma);
605
606 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
607 void *buf, int len, int write);
608 bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all);
609
610 vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot);
611
612 #endif
613