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 * @offset: The current GPU offset, which can have different meanings
98 * depending on the memory type. For SYSTEM type memory, it should be 0.
99 * @cur_placement: Hint of current placement.
101 * Base class for TTM buffer object, that deals with data placement and CPU
102 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
103 * the driver can usually use the placement offset @offset directly as the
104 * GPU virtual address. For drivers implementing multiple
105 * GPU memory manager contexts, the driver should manage the address space
106 * in these contexts separately and use these objects to get the correct
107 * placement and caching for these GPU maps. This makes it possible to use
108 * these objects for even quite elaborate memory management schemes.
109 * The destroy member, the API visibility of this object makes it possible
110 * to derive driver specific types.
113 struct ttm_buffer_object {
114 struct drm_gem_object base;
117 * Members constant at init.
120 struct ttm_device *bdev;
121 enum ttm_bo_type type;
122 uint32_t page_alignment;
123 void (*destroy) (struct ttm_buffer_object *);
126 * Members not needing protection.
131 * Members protected by the bo::resv::reserved lock.
134 struct ttm_resource *resource;
137 struct ttm_lru_bulk_move *bulk_move;
140 * Members protected by the bdev::lru_lock.
143 struct list_head ddestroy;
146 * Members protected by a bo reservation.
153 * Special members that are protected by the reserve lock
154 * and the bo::lock when written to. Can be read with
155 * either of these locks held.
162 * struct ttm_bo_kmap_obj
164 * @virtual: The current kernel virtual address.
165 * @page: The page when kmap'ing a single page.
166 * @bo_kmap_type: Type of bo_kmap.
168 * Object describing a kernel mapping. Since a TTM bo may be located
169 * in various memory types with various caching policies, the
170 * mapping can either be an ioremap, a vmap, a kmap or part of a
174 #define TTM_BO_MAP_IOMEM_MASK 0x80
175 struct ttm_bo_kmap_obj {
179 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
182 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
184 struct ttm_buffer_object *bo;
188 * struct ttm_operation_ctx
190 * @interruptible: Sleep interruptible if sleeping.
191 * @no_wait_gpu: Return immediately if the GPU is busy.
192 * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages.
193 * @allow_res_evict: Allow eviction of reserved BOs. Can be used when multiple
194 * BOs share the same reservation object.
195 * @force_alloc: Don't check the memory account during suspend or CPU page
196 * faults. Should only be used by TTM internally.
197 * @resv: Reservation object to allow reserved evictions with.
199 * Context for TTM operations like changing buffer placement or general memory
202 struct ttm_operation_ctx {
205 bool gfp_retry_mayfail;
206 bool allow_res_evict;
208 struct dma_resv *resv;
209 uint64_t bytes_moved;
213 * ttm_bo_get - reference a struct ttm_buffer_object
215 * @bo: The buffer object.
217 static inline void ttm_bo_get(struct ttm_buffer_object *bo)
223 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
224 * its refcount has already reached zero.
225 * @bo: The buffer object.
227 * Used to reference a TTM buffer object in lookups where the object is removed
228 * from the lookup structure during the destructor and for RCU lookups.
230 * Returns: @bo if the referencing was successful, NULL otherwise.
232 static inline __must_check struct ttm_buffer_object *
233 ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
235 if (!kref_get_unless_zero(&bo->kref))
241 * ttm_bo_wait - wait for buffer idle.
243 * @bo: The buffer object.
244 * @interruptible: Use interruptible wait.
245 * @no_wait: Return immediately if buffer is busy.
247 * This function must be called with the bo::mutex held, and makes
248 * sure any previous rendering to the buffer is completed.
249 * Note: It might be necessary to block validations before the
250 * wait by reserving the buffer.
251 * Returns -EBUSY if no_wait is true and the buffer is busy.
252 * Returns -ERESTARTSYS if interrupted by a signal.
254 int ttm_bo_wait(struct ttm_buffer_object *bo, bool interruptible, bool no_wait);
256 static inline int ttm_bo_wait_ctx(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx)
258 return ttm_bo_wait(bo, ctx->interruptible, ctx->no_wait_gpu);
264 * @bo: The buffer object.
265 * @placement: Proposed placement for the buffer object.
266 * @ctx: validation parameters.
268 * Changes placement and caching policy of the buffer object
269 * according proposed placement.
271 * -EINVAL on invalid proposed placement.
272 * -ENOMEM on out-of-memory condition.
273 * -EBUSY if no_wait is true and buffer busy.
274 * -ERESTARTSYS if interrupted by a signal.
276 int ttm_bo_validate(struct ttm_buffer_object *bo,
277 struct ttm_placement *placement,
278 struct ttm_operation_ctx *ctx);
283 * @bo: The buffer object.
285 * Unreference a buffer object.
287 void ttm_bo_put(struct ttm_buffer_object *bo);
289 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
290 void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
291 struct ttm_lru_bulk_move *bulk);
294 * ttm_bo_lock_delayed_workqueue
296 * Prevent the delayed workqueue from running.
298 * True if the workqueue was queued at the time
300 int ttm_bo_lock_delayed_workqueue(struct ttm_device *bdev);
303 * ttm_bo_unlock_delayed_workqueue
305 * Allows the delayed workqueue to run.
307 void ttm_bo_unlock_delayed_workqueue(struct ttm_device *bdev, int resched);
310 * ttm_bo_eviction_valuable
312 * @bo: The buffer object to evict
313 * @place: the placement we need to make room for
315 * Check if it is valuable to evict the BO to make room for the given placement.
317 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
318 const struct ttm_place *place);
321 * ttm_bo_init_reserved
323 * @bdev: Pointer to a ttm_device struct.
324 * @bo: Pointer to a ttm_buffer_object to be initialized.
325 * @size: Requested size of buffer object.
326 * @type: Requested type of buffer object.
327 * @placement: Initial placement for buffer object.
328 * @page_alignment: Data alignment in pages.
329 * @ctx: TTM operation context for memory allocation.
330 * @sg: Scatter-gather table.
331 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
332 * @destroy: Destroy function. Use NULL for kfree().
334 * This function initializes a pre-allocated struct ttm_buffer_object.
335 * As this object may be part of a larger structure, this function,
336 * together with the @destroy function,
337 * enables driver-specific objects derived from a ttm_buffer_object.
339 * On successful return, the caller owns an object kref to @bo. The kref and
340 * list_kref are usually set to 1, but note that in some situations, other
341 * tasks may already be holding references to @bo as well.
342 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
343 * and it is the caller's responsibility to call ttm_bo_unreserve.
345 * If a failure occurs, the function will call the @destroy function, or
346 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
347 * illegal and will likely cause memory corruption.
350 * -ENOMEM: Out of memory.
351 * -EINVAL: Invalid placement flags.
352 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
355 int ttm_bo_init_reserved(struct ttm_device *bdev,
356 struct ttm_buffer_object *bo,
357 size_t size, enum ttm_bo_type type,
358 struct ttm_placement *placement,
359 uint32_t page_alignment,
360 struct ttm_operation_ctx *ctx,
361 struct sg_table *sg, struct dma_resv *resv,
362 void (*destroy) (struct ttm_buffer_object *));
367 * @bdev: Pointer to a ttm_device struct.
368 * @bo: Pointer to a ttm_buffer_object to be initialized.
369 * @size: Requested size of buffer object.
370 * @type: Requested type of buffer object.
371 * @placement: Initial placement for buffer object.
372 * @page_alignment: Data alignment in pages.
373 * @interruptible: If needing to sleep to wait for GPU resources,
374 * sleep interruptible.
375 * pinned in physical memory. If this behaviour is not desired, this member
376 * holds a pointer to a persistent shmem object. Typically, this would
377 * point to the shmem object backing a GEM object if TTM is used to back a
378 * GEM user interface.
379 * @sg: Scatter-gather table.
380 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
381 * @destroy: Destroy function. Use NULL for kfree().
383 * This function initializes a pre-allocated struct ttm_buffer_object.
384 * As this object may be part of a larger structure, this function,
385 * together with the @destroy function,
386 * enables driver-specific objects derived from a ttm_buffer_object.
388 * On successful return, the caller owns an object kref to @bo. The kref and
389 * list_kref are usually set to 1, but note that in some situations, other
390 * tasks may already be holding references to @bo as well.
392 * If a failure occurs, the function will call the @destroy function, or
393 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
394 * illegal and will likely cause memory corruption.
397 * -ENOMEM: Out of memory.
398 * -EINVAL: Invalid placement flags.
399 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
401 int ttm_bo_init(struct ttm_device *bdev, struct ttm_buffer_object *bo,
402 size_t size, enum ttm_bo_type type,
403 struct ttm_placement *placement,
404 uint32_t page_alignment, bool interrubtible,
405 struct sg_table *sg, struct dma_resv *resv,
406 void (*destroy) (struct ttm_buffer_object *));
409 * ttm_kmap_obj_virtual
411 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
412 * @is_iomem: Pointer to an integer that on return indicates 1 if the
413 * virtual map is io memory, 0 if normal memory.
415 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
416 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
417 * that should strictly be accessed by the iowriteXX() and similar functions.
419 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
422 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
429 * @bo: The buffer object.
430 * @start_page: The first page to map.
431 * @num_pages: Number of pages to map.
432 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
434 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
435 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
436 * used to obtain a virtual address to the data.
439 * -ENOMEM: Out of memory.
440 * -EINVAL: Invalid range.
442 int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
443 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
448 * @map: Object describing the map to unmap.
450 * Unmaps a kernel map set up by ttm_bo_kmap.
452 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
457 * @bo: The buffer object.
458 * @map: pointer to a struct iosys_map representing the map.
460 * Sets up a kernel virtual mapping, using ioremap or vmap to the
461 * data in the buffer object. The parameter @map returns the virtual
462 * address as struct iosys_map. Unmap the buffer with ttm_bo_vunmap().
465 * -ENOMEM: Out of memory.
466 * -EINVAL: Invalid range.
468 int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map);
473 * @bo: The buffer object.
474 * @map: Object describing the map to unmap.
476 * Unmaps a kernel map set up by ttm_bo_vmap().
478 void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map);
481 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
483 * @vma: vma as input from the fbdev mmap method.
484 * @bo: The bo backing the address space.
486 * Maps a buffer object.
488 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
493 * @bdev: Pointer to the struct ttm_device.
494 * @filp: Pointer to the struct file attempting to read / write.
495 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
496 * @rbuf: User-space pointer to address of buffer to read into.
498 * @count: Number of bytes to read / write.
499 * @f_pos: Pointer to current file position.
500 * @write: 1 for read, 0 for write.
502 * This function implements read / write into ttm buffer objects, and is
504 * be called from the fops::read and fops::write method.
506 * See man (2) write, man(2) read. In particular,
507 * the function may return -ERESTARTSYS if
508 * interrupted by a signal.
510 ssize_t ttm_bo_io(struct ttm_device *bdev, struct file *filp,
511 const char __user *wbuf, char __user *rbuf,
512 size_t count, loff_t *f_pos, bool write);
514 int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
517 void ttm_bo_pin(struct ttm_buffer_object *bo);
518 void ttm_bo_unpin(struct ttm_buffer_object *bo);
520 int ttm_mem_evict_first(struct ttm_device *bdev,
521 struct ttm_resource_manager *man,
522 const struct ttm_place *place,
523 struct ttm_operation_ctx *ctx,
524 struct ww_acquire_ctx *ticket);
526 /* Default number of pre-faulted pages in the TTM fault handler */
527 #define TTM_BO_VM_NUM_PREFAULT 16
529 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
530 struct vm_fault *vmf);
532 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
534 pgoff_t num_prefault);
536 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf);
538 void ttm_bo_vm_open(struct vm_area_struct *vma);
540 void ttm_bo_vm_close(struct vm_area_struct *vma);
542 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
543 void *buf, int len, int write);
544 bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all);
546 vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot);