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
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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
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
44struct iosys_map;
45
46struct ttm_global;
47struct ttm_device;
48struct ttm_placement;
49struct ttm_place;
50struct ttm_resource;
51struct ttm_resource_manager;
52struct 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 */
67enum 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 * @bulk_move: The bulk move object.
87 * @priority: Priority for LRU, BOs with lower priority are evicted first.
88 * @pin_count: Pin count.
89 *
90 * Base class for TTM buffer object, that deals with data placement and CPU
91 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
92 * the driver can usually use the placement offset @offset directly as the
93 * GPU virtual address. For drivers implementing multiple
94 * GPU memory manager contexts, the driver should manage the address space
95 * in these contexts separately and use these objects to get the correct
96 * placement and caching for these GPU maps. This makes it possible to use
97 * these objects for even quite elaborate memory management schemes.
98 * The destroy member, the API visibility of this object makes it possible
99 * to derive driver specific types.
100 */
101struct ttm_buffer_object {
102 struct drm_gem_object base;
103
104 /*
105 * Members constant at init.
106 */
107 struct ttm_device *bdev;
108 enum ttm_bo_type type;
109 uint32_t page_alignment;
110 void (*destroy) (struct ttm_buffer_object *);
111
112 /*
113 * Members not needing protection.
114 */
115 struct kref kref;
116
117 /*
118 * Members protected by the bo::resv::reserved lock.
119 */
120 struct ttm_resource *resource;
121 struct ttm_tt *ttm;
122 bool deleted;
123 struct ttm_lru_bulk_move *bulk_move;
124 unsigned priority;
125 unsigned pin_count;
126
127 /**
128 * @delayed_delete: Work item used when we can't delete the BO
129 * immediately
130 */
131 struct work_struct delayed_delete;
132
133 /**
134 * @sg: external source of pages and DMA addresses, protected by the
135 * reservation lock.
136 */
137 struct sg_table *sg;
138};
139
140#define TTM_BO_MAP_IOMEM_MASK 0x80
141
142/**
143 * struct ttm_bo_kmap_obj
144 *
145 * @virtual: The current kernel virtual address.
146 * @page: The page when kmap'ing a single page.
147 * @bo_kmap_type: Type of bo_kmap.
148 * @bo: The TTM BO.
149 *
150 * Object describing a kernel mapping. Since a TTM bo may be located
151 * in various memory types with various caching policies, the
152 * mapping can either be an ioremap, a vmap, a kmap or part of a
153 * premapped region.
154 */
155struct ttm_bo_kmap_obj {
156 void *virtual;
157 struct page *page;
158 enum {
159 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
160 ttm_bo_map_vmap = 2,
161 ttm_bo_map_kmap = 3,
162 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
163 } bo_kmap_type;
164 struct ttm_buffer_object *bo;
165};
166
167/**
168 * struct ttm_operation_ctx
169 *
170 * @interruptible: Sleep interruptible if sleeping.
171 * @no_wait_gpu: Return immediately if the GPU is busy.
172 * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages.
173 * @allow_res_evict: Allow eviction of reserved BOs. Can be used when multiple
174 * BOs share the same reservation object.
175 * faults. Should only be used by TTM internally.
176 * @resv: Reservation object to allow reserved evictions with.
177 * @bytes_moved: Statistics on how many bytes have been moved.
178 *
179 * Context for TTM operations like changing buffer placement or general memory
180 * allocation.
181 */
182struct ttm_operation_ctx {
183 bool interruptible;
184 bool no_wait_gpu;
185 bool gfp_retry_mayfail;
186 bool allow_res_evict;
187 struct dma_resv *resv;
188 uint64_t bytes_moved;
189};
190
191struct ttm_lru_walk;
192
193/** struct ttm_lru_walk_ops - Operations for a LRU walk. */
194struct ttm_lru_walk_ops {
195 /**
196 * process_bo - Process this bo.
197 * @walk: struct ttm_lru_walk describing the walk.
198 * @bo: A locked and referenced buffer object.
199 *
200 * Return: Negative error code on error, User-defined positive value
201 * (typically, but not always, size of the processed bo) on success.
202 * On success, the returned values are summed by the walk and the
203 * walk exits when its target is met.
204 * 0 also indicates success, -EBUSY means this bo was skipped.
205 */
206 s64 (*process_bo)(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo);
207};
208
209/**
210 * struct ttm_lru_walk - Structure describing a LRU walk.
211 */
212struct ttm_lru_walk {
213 /** @ops: Pointer to the ops structure. */
214 const struct ttm_lru_walk_ops *ops;
215 /** @ctx: Pointer to the struct ttm_operation_ctx. */
216 struct ttm_operation_ctx *ctx;
217 /** @ticket: The struct ww_acquire_ctx if any. */
218 struct ww_acquire_ctx *ticket;
219 /** @trylock_only: Only use trylock for locking. */
220 bool trylock_only;
221};
222
223s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev,
224 struct ttm_resource_manager *man, s64 target);
225
226/**
227 * struct ttm_bo_shrink_flags - flags to govern the bo shrinking behaviour
228 * @purge: Purge the content rather than backing it up.
229 * @writeback: Attempt to immediately write content to swap space.
230 * @allow_move: Allow moving to system before shrinking. This is typically
231 * not desired for zombie- or ghost objects (with zombie object meaning
232 * objects with a zero gem object refcount)
233 */
234struct ttm_bo_shrink_flags {
235 u32 purge : 1;
236 u32 writeback : 1;
237 u32 allow_move : 1;
238};
239
240long ttm_bo_shrink(struct ttm_operation_ctx *ctx, struct ttm_buffer_object *bo,
241 const struct ttm_bo_shrink_flags flags);
242
243bool ttm_bo_shrink_suitable(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx);
244
245bool ttm_bo_shrink_avoid_wait(void);
246
247/**
248 * ttm_bo_get - reference a struct ttm_buffer_object
249 *
250 * @bo: The buffer object.
251 */
252static inline void ttm_bo_get(struct ttm_buffer_object *bo)
253{
254 kref_get(kref: &bo->kref);
255}
256
257/**
258 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
259 * its refcount has already reached zero.
260 * @bo: The buffer object.
261 *
262 * Used to reference a TTM buffer object in lookups where the object is removed
263 * from the lookup structure during the destructor and for RCU lookups.
264 *
265 * Returns: @bo if the referencing was successful, NULL otherwise.
266 */
267static inline __must_check struct ttm_buffer_object *
268ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
269{
270 if (!kref_get_unless_zero(kref: &bo->kref))
271 return NULL;
272 return bo;
273}
274
275/**
276 * ttm_bo_reserve:
277 *
278 * @bo: A pointer to a struct ttm_buffer_object.
279 * @interruptible: Sleep interruptible if waiting.
280 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
281 * @ticket: ticket used to acquire the ww_mutex.
282 *
283 * Locks a buffer object for validation. (Or prevents other processes from
284 * locking it for validation), while taking a number of measures to prevent
285 * deadlocks.
286 *
287 * Returns:
288 * -EDEADLK: The reservation may cause a deadlock.
289 * Release all buffer reservations, wait for @bo to become unreserved and
290 * try again.
291 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
292 * a signal. Release all buffer reservations and return to user-space.
293 * -EBUSY: The function needed to sleep, but @no_wait was true
294 * -EALREADY: Bo already reserved using @ticket. This error code will only
295 * be returned if @use_ticket is set to true.
296 */
297static inline int ttm_bo_reserve(struct ttm_buffer_object *bo,
298 bool interruptible, bool no_wait,
299 struct ww_acquire_ctx *ticket)
300{
301 int ret = 0;
302
303 if (no_wait) {
304 bool success;
305
306 if (WARN_ON(ticket))
307 return -EBUSY;
308
309 success = dma_resv_trylock(obj: bo->base.resv);
310 return success ? 0 : -EBUSY;
311 }
312
313 if (interruptible)
314 ret = dma_resv_lock_interruptible(obj: bo->base.resv, ctx: ticket);
315 else
316 ret = dma_resv_lock(obj: bo->base.resv, ctx: ticket);
317 if (ret == -EINTR)
318 return -ERESTARTSYS;
319 return ret;
320}
321
322/**
323 * ttm_bo_reserve_slowpath:
324 * @bo: A pointer to a struct ttm_buffer_object.
325 * @interruptible: Sleep interruptible if waiting.
326 * @ticket: Ticket used to acquire the ww_mutex.
327 *
328 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
329 * from all our other reservations. Because there are no other reservations
330 * held by us, this function cannot deadlock any more.
331 */
332static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
333 bool interruptible,
334 struct ww_acquire_ctx *ticket)
335{
336 if (interruptible) {
337 int ret = dma_resv_lock_slow_interruptible(obj: bo->base.resv,
338 ctx: ticket);
339 if (ret == -EINTR)
340 ret = -ERESTARTSYS;
341 return ret;
342 }
343 dma_resv_lock_slow(obj: bo->base.resv, ctx: ticket);
344 return 0;
345}
346
347void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
348
349static inline void
350ttm_bo_move_to_lru_tail_unlocked(struct ttm_buffer_object *bo)
351{
352 spin_lock(lock: &bo->bdev->lru_lock);
353 ttm_bo_move_to_lru_tail(bo);
354 spin_unlock(lock: &bo->bdev->lru_lock);
355}
356
357static inline void ttm_bo_assign_mem(struct ttm_buffer_object *bo,
358 struct ttm_resource *new_mem)
359{
360 WARN_ON(bo->resource);
361 bo->resource = new_mem;
362}
363
364/**
365 * ttm_bo_move_null - assign memory for a buffer object.
366 * @bo: The bo to assign the memory to
367 * @new_mem: The memory to be assigned.
368 *
369 * Assign the memory from new_mem to the memory of the buffer object bo.
370 */
371static inline void ttm_bo_move_null(struct ttm_buffer_object *bo,
372 struct ttm_resource *new_mem)
373{
374 ttm_resource_free(bo, res: &bo->resource);
375 ttm_bo_assign_mem(bo, new_mem);
376}
377
378/**
379 * ttm_bo_unreserve
380 *
381 * @bo: A pointer to a struct ttm_buffer_object.
382 *
383 * Unreserve a previous reservation of @bo.
384 */
385static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo)
386{
387 ttm_bo_move_to_lru_tail_unlocked(bo);
388 dma_resv_unlock(obj: bo->base.resv);
389}
390
391/**
392 * ttm_kmap_obj_virtual
393 *
394 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
395 * @is_iomem: Pointer to an integer that on return indicates 1 if the
396 * virtual map is io memory, 0 if normal memory.
397 *
398 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
399 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
400 * that should strictly be accessed by the iowriteXX() and similar functions.
401 */
402static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
403 bool *is_iomem)
404{
405 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
406 return map->virtual;
407}
408
409int ttm_bo_wait_ctx(struct ttm_buffer_object *bo,
410 struct ttm_operation_ctx *ctx);
411int ttm_bo_validate(struct ttm_buffer_object *bo,
412 struct ttm_placement *placement,
413 struct ttm_operation_ctx *ctx);
414void ttm_bo_put(struct ttm_buffer_object *bo);
415void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
416 struct ttm_lru_bulk_move *bulk);
417bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
418 const struct ttm_place *place);
419int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,
420 enum ttm_bo_type type, struct ttm_placement *placement,
421 uint32_t alignment, struct ttm_operation_ctx *ctx,
422 struct sg_table *sg, struct dma_resv *resv,
423 void (*destroy)(struct ttm_buffer_object *));
424int ttm_bo_init_validate(struct ttm_device *bdev, struct ttm_buffer_object *bo,
425 enum ttm_bo_type type, struct ttm_placement *placement,
426 uint32_t alignment, bool interruptible,
427 struct sg_table *sg, struct dma_resv *resv,
428 void (*destroy)(struct ttm_buffer_object *));
429int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
430 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
431void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
432int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map);
433void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map);
434int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
435s64 ttm_bo_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
436 struct ttm_resource_manager *man, gfp_t gfp_flags,
437 s64 target);
438void ttm_bo_pin(struct ttm_buffer_object *bo);
439void ttm_bo_unpin(struct ttm_buffer_object *bo);
440int ttm_bo_evict_first(struct ttm_device *bdev,
441 struct ttm_resource_manager *man,
442 struct ttm_operation_ctx *ctx);
443int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset,
444 void *buf, int len, int write);
445vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
446 struct vm_fault *vmf);
447vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
448 pgprot_t prot,
449 pgoff_t num_prefault);
450vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf);
451void ttm_bo_vm_open(struct vm_area_struct *vma);
452void ttm_bo_vm_close(struct vm_area_struct *vma);
453int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
454 void *buf, int len, int write);
455vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot);
456
457int ttm_bo_mem_space(struct ttm_buffer_object *bo,
458 struct ttm_placement *placement,
459 struct ttm_resource **mem,
460 struct ttm_operation_ctx *ctx);
461
462void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
463/*
464 * ttm_bo_util.c
465 */
466int ttm_mem_io_reserve(struct ttm_device *bdev,
467 struct ttm_resource *mem);
468void ttm_mem_io_free(struct ttm_device *bdev,
469 struct ttm_resource *mem);
470void ttm_move_memcpy(bool clear, u32 num_pages,
471 struct ttm_kmap_iter *dst_iter,
472 struct ttm_kmap_iter *src_iter);
473int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
474 struct ttm_operation_ctx *ctx,
475 struct ttm_resource *new_mem);
476int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
477 struct dma_fence *fence, bool evict,
478 bool pipeline,
479 struct ttm_resource *new_mem);
480void ttm_bo_move_sync_cleanup(struct ttm_buffer_object *bo,
481 struct ttm_resource *new_mem);
482int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo);
483pgprot_t ttm_io_prot(struct ttm_buffer_object *bo, struct ttm_resource *res,
484 pgprot_t tmp);
485void ttm_bo_tt_destroy(struct ttm_buffer_object *bo);
486int ttm_bo_populate(struct ttm_buffer_object *bo,
487 struct ttm_operation_ctx *ctx);
488
489/* Driver LRU walk helpers initially targeted for shrinking. */
490
491/**
492 * struct ttm_bo_lru_cursor - Iterator cursor for TTM LRU list looping
493 */
494struct ttm_bo_lru_cursor {
495 /** @res_curs: Embedded struct ttm_resource_cursor. */
496 struct ttm_resource_cursor res_curs;
497 /**
498 * @ctx: The struct ttm_operation_ctx used while looping.
499 * governs the locking mode.
500 */
501 struct ttm_operation_ctx *ctx;
502 /**
503 * @bo: Buffer object pointer if a buffer object is refcounted,
504 * NULL otherwise.
505 */
506 struct ttm_buffer_object *bo;
507 /**
508 * @needs_unlock: Valid iff @bo != NULL. The bo resv needs
509 * unlock before the next iteration or after loop exit.
510 */
511 bool needs_unlock;
512};
513
514void ttm_bo_lru_cursor_fini(struct ttm_bo_lru_cursor *curs);
515
516struct ttm_bo_lru_cursor *
517ttm_bo_lru_cursor_init(struct ttm_bo_lru_cursor *curs,
518 struct ttm_resource_manager *man,
519 struct ttm_operation_ctx *ctx);
520
521struct ttm_buffer_object *ttm_bo_lru_cursor_first(struct ttm_bo_lru_cursor *curs);
522
523struct ttm_buffer_object *ttm_bo_lru_cursor_next(struct ttm_bo_lru_cursor *curs);
524
525/*
526 * Defines needed to use autocleanup (linux/cleanup.h) with struct ttm_bo_lru_cursor.
527 */
528DEFINE_CLASS(ttm_bo_lru_cursor, struct ttm_bo_lru_cursor *,
529 if (_T) {ttm_bo_lru_cursor_fini(_T); },
530 ttm_bo_lru_cursor_init(curs, man, ctx),
531 struct ttm_bo_lru_cursor *curs, struct ttm_resource_manager *man,
532 struct ttm_operation_ctx *ctx);
533static inline void *
534class_ttm_bo_lru_cursor_lock_ptr(class_ttm_bo_lru_cursor_t *_T)
535{ return *_T; }
536#define class_ttm_bo_lru_cursor_is_conditional false
537
538/**
539 * ttm_bo_lru_for_each_reserved_guarded() - Iterate over buffer objects owning
540 * resources on LRU lists.
541 * @_cursor: struct ttm_bo_lru_cursor to use for the iteration.
542 * @_man: The resource manager whose LRU lists to iterate over.
543 * @_ctx: The struct ttm_operation_context to govern the @_bo locking.
544 * @_bo: The struct ttm_buffer_object pointer pointing to the buffer object
545 * for the current iteration.
546 *
547 * Iterate over all resources of @_man and for each resource, attempt to
548 * reference and lock (using the locking mode detailed in @_ctx) the buffer
549 * object it points to. If successful, assign @_bo to the address of the
550 * buffer object and update @_cursor. The iteration is guarded in the
551 * sense that @_cursor will be initialized before looping start and cleaned
552 * up at looping termination, even if terminated prematurely by, for
553 * example a return or break statement. Exiting the loop will also unlock
554 * (if needed) and unreference @_bo.
555 */
556#define ttm_bo_lru_for_each_reserved_guarded(_cursor, _man, _ctx, _bo) \
557 scoped_guard(ttm_bo_lru_cursor, _cursor, _man, _ctx) \
558 for ((_bo) = ttm_bo_lru_cursor_first(_cursor); (_bo); \
559 (_bo) = ttm_bo_lru_cursor_next(_cursor))
560
561#endif
562

source code of linux/include/drm/ttm/ttm_bo.h