1 /**************************************************************************
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
6 * Permission is hereby granted, free of charge, to any person obtaining a
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26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
31 #ifndef _TTM_BO_API_H_
32 #define _TTM_BO_API_H_
34 #include <drm/drm_gem.h>
35 #include <drm/drm_vma_manager.h>
36 #include <linux/kref.h>
37 #include <linux/list.h>
38 #include <linux/wait.h>
39 #include <linux/mutex.h>
41 #include <linux/bitmap.h>
42 #include <linux/dma-resv.h>
44 #include "ttm_resource.h"
61 * @ttm_bo_type_device: These are 'normal' buffers that can
62 * be mmapped by user space. Each of these bos occupy a slot in the
63 * device address space, that can be used for normal vm operations.
65 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
66 * but they cannot be accessed from user-space. For kernel-only use.
68 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
81 * struct ttm_buffer_object
83 * @base: drm_gem_object superclass data.
84 * @bdev: Pointer to the buffer object device structure.
86 * @page_alignment: Page alignment.
87 * @destroy: Destruction function. If NULL, kfree is used.
88 * @num_pages: Actual number of pages.
89 * @kref: Reference count of this buffer object. When this refcount reaches
90 * zero, the object is destroyed or put on the delayed delete list.
91 * @mem: structure describing current placement.
92 * @ttm: TTM structure holding system pages.
93 * @evicted: Whether the object was evicted without user-space knowing.
94 * @deleted: True if the object is only a zombie and already deleted.
95 * @ddestroy: List head for the delayed destroy list.
96 * @swap: List head for swap LRU list.
97 * @moving: Fence set when BO is moving
98 * @offset: The current GPU offset, which can have different meanings
99 * depending on the memory type. For SYSTEM type memory, it should be 0.
100 * @cur_placement: Hint of current placement.
102 * Base class for TTM buffer object, that deals with data placement and CPU
103 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
104 * the driver can usually use the placement offset @offset directly as the
105 * GPU virtual address. For drivers implementing multiple
106 * GPU memory manager contexts, the driver should manage the address space
107 * in these contexts separately and use these objects to get the correct
108 * placement and caching for these GPU maps. This makes it possible to use
109 * these objects for even quite elaborate memory management schemes.
110 * The destroy member, the API visibility of this object makes it possible
111 * to derive driver specific types.
114 struct ttm_buffer_object {
115 struct drm_gem_object base;
118 * Members constant at init.
121 struct ttm_device *bdev;
122 enum ttm_bo_type type;
123 uint32_t page_alignment;
124 void (*destroy) (struct ttm_buffer_object *);
127 * Members not needing protection.
132 * Members protected by the bo::resv::reserved lock.
135 struct ttm_resource *resource;
138 struct ttm_lru_bulk_move *bulk_move;
141 * Members protected by the bdev::lru_lock.
144 struct list_head ddestroy;
147 * Members protected by a bo reservation.
150 struct dma_fence *moving;
155 * Special members that are protected by the reserve lock
156 * and the bo::lock when written to. Can be read with
157 * either of these locks held.
164 * struct ttm_bo_kmap_obj
166 * @virtual: The current kernel virtual address.
167 * @page: The page when kmap'ing a single page.
168 * @bo_kmap_type: Type of bo_kmap.
170 * Object describing a kernel mapping. Since a TTM bo may be located
171 * in various memory types with various caching policies, the
172 * mapping can either be an ioremap, a vmap, a kmap or part of a
176 #define TTM_BO_MAP_IOMEM_MASK 0x80
177 struct ttm_bo_kmap_obj {
181 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
184 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
186 struct ttm_buffer_object *bo;
190 * struct ttm_operation_ctx
192 * @interruptible: Sleep interruptible if sleeping.
193 * @no_wait_gpu: Return immediately if the GPU is busy.
194 * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages.
195 * @allow_res_evict: Allow eviction of reserved BOs. Can be used when multiple
196 * BOs share the same reservation object.
197 * @force_alloc: Don't check the memory account during suspend or CPU page
198 * faults. Should only be used by TTM internally.
199 * @resv: Reservation object to allow reserved evictions with.
201 * Context for TTM operations like changing buffer placement or general memory
204 struct ttm_operation_ctx {
207 bool gfp_retry_mayfail;
208 bool allow_res_evict;
210 struct dma_resv *resv;
211 uint64_t bytes_moved;
215 * ttm_bo_get - reference a struct ttm_buffer_object
217 * @bo: The buffer object.
219 static inline void ttm_bo_get(struct ttm_buffer_object *bo)
225 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
226 * its refcount has already reached zero.
227 * @bo: The buffer object.
229 * Used to reference a TTM buffer object in lookups where the object is removed
230 * from the lookup structure during the destructor and for RCU lookups.
232 * Returns: @bo if the referencing was successful, NULL otherwise.
234 static inline __must_check struct ttm_buffer_object *
235 ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
237 if (!kref_get_unless_zero(&bo->kref))
243 * ttm_bo_wait - wait for buffer idle.
245 * @bo: The buffer object.
246 * @interruptible: Use interruptible wait.
247 * @no_wait: Return immediately if buffer is busy.
249 * This function must be called with the bo::mutex held, and makes
250 * sure any previous rendering to the buffer is completed.
251 * Note: It might be necessary to block validations before the
252 * wait by reserving the buffer.
253 * Returns -EBUSY if no_wait is true and the buffer is busy.
254 * Returns -ERESTARTSYS if interrupted by a signal.
256 int ttm_bo_wait(struct ttm_buffer_object *bo, bool interruptible, bool no_wait);
258 static inline int ttm_bo_wait_ctx(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx)
260 return ttm_bo_wait(bo, ctx->interruptible, ctx->no_wait_gpu);
266 * @bo: The buffer object.
267 * @placement: Proposed placement for the buffer object.
268 * @ctx: validation parameters.
270 * Changes placement and caching policy of the buffer object
271 * according proposed placement.
273 * -EINVAL on invalid proposed placement.
274 * -ENOMEM on out-of-memory condition.
275 * -EBUSY if no_wait is true and buffer busy.
276 * -ERESTARTSYS if interrupted by a signal.
278 int ttm_bo_validate(struct ttm_buffer_object *bo,
279 struct ttm_placement *placement,
280 struct ttm_operation_ctx *ctx);
285 * @bo: The buffer object.
287 * Unreference a buffer object.
289 void ttm_bo_put(struct ttm_buffer_object *bo);
291 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
292 void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
293 struct ttm_lru_bulk_move *bulk);
296 * ttm_bo_lock_delayed_workqueue
298 * Prevent the delayed workqueue from running.
300 * True if the workqueue was queued at the time
302 int ttm_bo_lock_delayed_workqueue(struct ttm_device *bdev);
305 * ttm_bo_unlock_delayed_workqueue
307 * Allows the delayed workqueue to run.
309 void ttm_bo_unlock_delayed_workqueue(struct ttm_device *bdev, int resched);
312 * ttm_bo_eviction_valuable
314 * @bo: The buffer object to evict
315 * @place: the placement we need to make room for
317 * Check if it is valuable to evict the BO to make room for the given placement.
319 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
320 const struct ttm_place *place);
323 * ttm_bo_init_reserved
325 * @bdev: Pointer to a ttm_device struct.
326 * @bo: Pointer to a ttm_buffer_object to be initialized.
327 * @size: Requested size of buffer object.
328 * @type: Requested type of buffer object.
329 * @placement: Initial placement for buffer object.
330 * @page_alignment: Data alignment in pages.
331 * @ctx: TTM operation context for memory allocation.
332 * @sg: Scatter-gather table.
333 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
334 * @destroy: Destroy function. Use NULL for kfree().
336 * This function initializes a pre-allocated struct ttm_buffer_object.
337 * As this object may be part of a larger structure, this function,
338 * together with the @destroy function,
339 * enables driver-specific objects derived from a ttm_buffer_object.
341 * On successful return, the caller owns an object kref to @bo. The kref and
342 * list_kref are usually set to 1, but note that in some situations, other
343 * tasks may already be holding references to @bo as well.
344 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
345 * and it is the caller's responsibility to call ttm_bo_unreserve.
347 * If a failure occurs, the function will call the @destroy function, or
348 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
349 * illegal and will likely cause memory corruption.
352 * -ENOMEM: Out of memory.
353 * -EINVAL: Invalid placement flags.
354 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
357 int ttm_bo_init_reserved(struct ttm_device *bdev,
358 struct ttm_buffer_object *bo,
359 size_t size, enum ttm_bo_type type,
360 struct ttm_placement *placement,
361 uint32_t page_alignment,
362 struct ttm_operation_ctx *ctx,
363 struct sg_table *sg, struct dma_resv *resv,
364 void (*destroy) (struct ttm_buffer_object *));
369 * @bdev: Pointer to a ttm_device struct.
370 * @bo: Pointer to a ttm_buffer_object to be initialized.
371 * @size: Requested size of buffer object.
372 * @type: Requested type of buffer object.
373 * @placement: Initial placement for buffer object.
374 * @page_alignment: Data alignment in pages.
375 * @interruptible: If needing to sleep to wait for GPU resources,
376 * sleep interruptible.
377 * pinned in physical memory. If this behaviour is not desired, this member
378 * holds a pointer to a persistent shmem object. Typically, this would
379 * point to the shmem object backing a GEM object if TTM is used to back a
380 * GEM user interface.
381 * @sg: Scatter-gather table.
382 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
383 * @destroy: Destroy function. Use NULL for kfree().
385 * This function initializes a pre-allocated struct ttm_buffer_object.
386 * As this object may be part of a larger structure, this function,
387 * together with the @destroy function,
388 * enables driver-specific objects derived from a ttm_buffer_object.
390 * On successful return, the caller owns an object kref to @bo. The kref and
391 * list_kref are usually set to 1, but note that in some situations, other
392 * tasks may already be holding references to @bo as well.
394 * If a failure occurs, the function will call the @destroy function, or
395 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
396 * illegal and will likely cause memory corruption.
399 * -ENOMEM: Out of memory.
400 * -EINVAL: Invalid placement flags.
401 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
403 int ttm_bo_init(struct ttm_device *bdev, struct ttm_buffer_object *bo,
404 size_t size, enum ttm_bo_type type,
405 struct ttm_placement *placement,
406 uint32_t page_alignment, bool interrubtible,
407 struct sg_table *sg, struct dma_resv *resv,
408 void (*destroy) (struct ttm_buffer_object *));
411 * ttm_kmap_obj_virtual
413 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
414 * @is_iomem: Pointer to an integer that on return indicates 1 if the
415 * virtual map is io memory, 0 if normal memory.
417 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
418 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
419 * that should strictly be accessed by the iowriteXX() and similar functions.
421 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
424 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
431 * @bo: The buffer object.
432 * @start_page: The first page to map.
433 * @num_pages: Number of pages to map.
434 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
436 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
437 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
438 * used to obtain a virtual address to the data.
441 * -ENOMEM: Out of memory.
442 * -EINVAL: Invalid range.
444 int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
445 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
450 * @map: Object describing the map to unmap.
452 * Unmaps a kernel map set up by ttm_bo_kmap.
454 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
459 * @bo: The buffer object.
460 * @map: pointer to a struct iosys_map representing the map.
462 * Sets up a kernel virtual mapping, using ioremap or vmap to the
463 * data in the buffer object. The parameter @map returns the virtual
464 * address as struct iosys_map. Unmap the buffer with ttm_bo_vunmap().
467 * -ENOMEM: Out of memory.
468 * -EINVAL: Invalid range.
470 int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map);
475 * @bo: The buffer object.
476 * @map: Object describing the map to unmap.
478 * Unmaps a kernel map set up by ttm_bo_vmap().
480 void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map);
483 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
485 * @vma: vma as input from the fbdev mmap method.
486 * @bo: The bo backing the address space.
488 * Maps a buffer object.
490 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
495 * @bdev: Pointer to the struct ttm_device.
496 * @filp: Pointer to the struct file attempting to read / write.
497 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
498 * @rbuf: User-space pointer to address of buffer to read into.
500 * @count: Number of bytes to read / write.
501 * @f_pos: Pointer to current file position.
502 * @write: 1 for read, 0 for write.
504 * This function implements read / write into ttm buffer objects, and is
506 * be called from the fops::read and fops::write method.
508 * See man (2) write, man(2) read. In particular,
509 * the function may return -ERESTARTSYS if
510 * interrupted by a signal.
512 ssize_t ttm_bo_io(struct ttm_device *bdev, struct file *filp,
513 const char __user *wbuf, char __user *rbuf,
514 size_t count, loff_t *f_pos, bool write);
516 int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
519 void ttm_bo_pin(struct ttm_buffer_object *bo);
520 void ttm_bo_unpin(struct ttm_buffer_object *bo);
522 int ttm_mem_evict_first(struct ttm_device *bdev,
523 struct ttm_resource_manager *man,
524 const struct ttm_place *place,
525 struct ttm_operation_ctx *ctx,
526 struct ww_acquire_ctx *ticket);
528 /* Default number of pre-faulted pages in the TTM fault handler */
529 #define TTM_BO_VM_NUM_PREFAULT 16
531 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
532 struct vm_fault *vmf);
534 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
536 pgoff_t num_prefault);
538 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf);
540 void ttm_bo_vm_open(struct vm_area_struct *vma);
542 void ttm_bo_vm_close(struct vm_area_struct *vma);
544 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
545 void *buf, int len, int write);
546 bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all);
548 vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot);