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
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
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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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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
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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
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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_
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>
42 #include <linux/bitmap.h>
43 #include <linux/reservation.h>
52 * @fpfn: first valid page frame number to put the object
53 * @lpfn: last valid page frame number to put the object
54 * @flags: memory domain and caching flags for the object
56 * Structure indicating a possible place to put an object.
65 * struct ttm_placement
67 * @fpfn: first valid page frame number to put the object
68 * @lpfn: last valid page frame number to put the object
69 * @num_placement: number of preferred placements
70 * @placement: preferred placements
71 * @num_busy_placement: number of preferred placements when need to evict buffer
72 * @busy_placement: preferred placements when need to evict buffer
74 * Structure indicating the placement you request for an object.
76 struct ttm_placement {
79 unsigned num_placement;
80 const struct ttm_place *placement;
81 unsigned num_busy_placement;
82 const struct ttm_place *busy_placement;
86 * struct ttm_bus_placement
88 * @addr: mapped virtual address
89 * @base: bus base address
90 * @is_iomem: is this io memory ?
92 * @offset: offset from the base address
93 * @io_reserved_vm: The VM system has a refcount in @io_reserved_count
94 * @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
96 * Structure indicating the bus placement of an object.
98 struct ttm_bus_placement {
102 unsigned long offset;
105 uint64_t io_reserved_count;
112 * @mm_node: Memory manager node.
113 * @size: Requested size of memory region.
114 * @num_pages: Actual size of memory region in pages.
115 * @page_alignment: Page alignment.
116 * @placement: Placement flags.
117 * @bus: Placement on io bus accessible to the CPU
119 * Structure indicating the placement and space resources used by a
127 unsigned long num_pages;
128 uint32_t page_alignment;
131 struct ttm_bus_placement bus;
137 * @ttm_bo_type_device: These are 'normal' buffers that can
138 * be mmapped by user space. Each of these bos occupy a slot in the
139 * device address space, that can be used for normal vm operations.
141 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
142 * but they cannot be accessed from user-space. For kernel-only use.
144 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
157 * struct ttm_buffer_object
159 * @bdev: Pointer to the buffer object device structure.
160 * @type: The bo type.
161 * @destroy: Destruction function. If NULL, kfree is used.
162 * @num_pages: Actual number of pages.
163 * @acc_size: Accounted size for this object.
164 * @kref: Reference count of this buffer object. When this refcount reaches
165 * zero, the object is put on the delayed delete list.
166 * @list_kref: List reference count of this buffer object. This member is
167 * used to avoid destruction while the buffer object is still on a list.
168 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
169 * keeps one refcount. When this refcount reaches zero,
170 * the object is destroyed.
171 * @mem: structure describing current placement.
172 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
173 * pinned in physical memory. If this behaviour is not desired, this member
174 * holds a pointer to a persistent shmem object.
175 * @ttm: TTM structure holding system pages.
176 * @evicted: Whether the object was evicted without user-space knowing.
177 * @cpu_writes: For synchronization. Number of cpu writers.
178 * @lru: List head for the lru list.
179 * @ddestroy: List head for the delayed destroy list.
180 * @swap: List head for swap LRU list.
181 * @sync_obj: Pointer to a synchronization object.
182 * @priv_flags: Flags describing buffer object internal state.
183 * @vma_node: Address space manager node.
184 * @offset: The current GPU offset, which can have different meanings
185 * depending on the memory type. For SYSTEM type memory, it should be 0.
186 * @cur_placement: Hint of current placement.
187 * @wu_mutex: Wait unreserved mutex.
189 * Base class for TTM buffer object, that deals with data placement and CPU
190 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
191 * the driver can usually use the placement offset @offset directly as the
192 * GPU virtual address. For drivers implementing multiple
193 * GPU memory manager contexts, the driver should manage the address space
194 * in these contexts separately and use these objects to get the correct
195 * placement and caching for these GPU maps. This makes it possible to use
196 * these objects for even quite elaborate memory management schemes.
197 * The destroy member, the API visibility of this object makes it possible
198 * to derive driver specific types.
201 struct ttm_buffer_object {
203 * Members constant at init.
206 struct ttm_bo_global *glob;
207 struct ttm_bo_device *bdev;
208 enum ttm_bo_type type;
209 void (*destroy) (struct ttm_buffer_object *);
210 unsigned long num_pages;
214 * Members not needing protection.
218 struct kref list_kref;
221 * Members protected by the bo::resv::reserved lock.
224 struct ttm_mem_reg mem;
225 struct vm_object *persistent_swap_storage;
230 * Members protected by the bo::reserved lock only when written to.
233 atomic_t cpu_writers;
236 * Members protected by the bdev::lru_lock.
239 struct list_head lru;
240 struct list_head ddestroy;
241 struct list_head swap;
242 struct list_head io_reserve_lru;
245 * Members protected by struct buffer_object_device::fence_lock
246 * In addition, setting sync_obj to anything else
247 * than NULL requires bo::reserved to be held. This allows for
248 * checking NULL while reserved but not holding the mentioned lock.
252 unsigned long priv_flags;
254 RB_ENTRY(ttm_buffer_object) vm_rb; /* DragonFly */
255 struct drm_vma_offset_node vma_node;
258 * Special members that are protected by the reserve lock
259 * and the bo::lock when written to. Can be read with
260 * either of these locks held.
263 unsigned long offset;
264 uint32_t cur_placement;
268 struct reservation_object *resv;
269 struct reservation_object ttm_resv;
270 struct lock wu_mutex;
274 * struct ttm_bo_kmap_obj
276 * @virtual: The current kernel virtual address.
277 * @page: The page when kmap'ing a single page.
278 * @bo_kmap_type: Type of bo_kmap.
280 * Object describing a kernel mapping. Since a TTM bo may be located
281 * in various memory types with various caching policies, the
282 * mapping can either be an ioremap, a vmap, a kmap or part of a
286 #define TTM_BO_MAP_IOMEM_MASK 0x80
287 struct ttm_bo_kmap_obj {
291 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
294 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
296 struct ttm_buffer_object *bo;
300 * ttm_bo_reference - reference a struct ttm_buffer_object
302 * @bo: The buffer object.
304 * Returns a refcounted pointer to a buffer object.
307 static inline struct ttm_buffer_object *
308 ttm_bo_reference(struct ttm_buffer_object *bo)
315 * ttm_bo_wait - wait for buffer idle.
317 * @bo: The buffer object.
318 * @interruptible: Use interruptible wait.
319 * @no_wait: Return immediately if buffer is busy.
321 * This function must be called with the bo::mutex held, and makes
322 * sure any previous rendering to the buffer is completed.
323 * Note: It might be necessary to block validations before the
324 * wait by reserving the buffer.
325 * Returns -EBUSY if no_wait is true and the buffer is busy.
326 * Returns -ERESTARTSYS if interrupted by a signal.
328 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
329 bool interruptible, bool no_wait);
333 * @bo: The buffer object.
334 * @placement: Proposed placement for the buffer object.
335 * @interruptible: Sleep interruptible if sleeping.
336 * @no_wait_gpu: Return immediately if the GPU is busy.
338 * Changes placement and caching policy of the buffer object
339 * according proposed placement.
341 * -EINVAL on invalid proposed placement.
342 * -ENOMEM on out-of-memory condition.
343 * -EBUSY if no_wait is true and buffer busy.
344 * -ERESTARTSYS if interrupted by a signal.
346 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
347 struct ttm_placement *placement,
354 * @bo: The buffer object.
356 * Unreference and clear a pointer to a buffer object.
358 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
362 * ttm_bo_list_ref_sub
364 * @bo: The buffer object.
365 * @count: The number of references with which to decrease @bo::list_kref;
366 * @never_free: The refcount should not reach zero with this operation.
368 * Release @count lru list references to this buffer object.
370 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
376 * @bo: The buffer object.
378 * Add this bo to the relevant mem type lru and, if it's backed by
379 * system pages (ttms) to the swap list.
380 * This function must be called with struct ttm_bo_global::lru_lock held, and
381 * is typically called immediately prior to unreserving a bo.
383 extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
386 * ttm_bo_del_from_lru
388 * @bo: The buffer object.
390 * Remove this bo from all lru lists used to lookup and reserve an object.
391 * This function must be called with struct ttm_bo_global::lru_lock held,
392 * and is usually called just immediately after the bo has been reserved to
393 * avoid recursive reservation from lru lists.
395 extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
399 * ttm_bo_lock_delayed_workqueue
401 * Prevent the delayed workqueue from running.
403 * True if the workqueue was queued at the time
405 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
408 * ttm_bo_unlock_delayed_workqueue
410 * Allows the delayed workqueue to run.
412 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
416 * ttm_bo_synccpu_write_grab
418 * @bo: The buffer object:
419 * @no_wait: Return immediately if buffer is busy.
421 * Synchronizes a buffer object for CPU RW access. This means
422 * command submission that affects the buffer will return -EBUSY
423 * until ttm_bo_synccpu_write_release is called.
426 * -EBUSY if the buffer is busy and no_wait is true.
427 * -ERESTARTSYS if interrupted by a signal.
430 ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
433 * ttm_bo_synccpu_write_release:
435 * @bo : The buffer object.
437 * Releases a synccpu lock.
439 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
444 * @bdev: Pointer to a ttm_bo_device struct.
445 * @bo_size: size of the buffer object in byte.
446 * @struct_size: size of the structure holding buffer object datas
448 * Returns size to account for a buffer object
450 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
451 unsigned long bo_size,
452 unsigned struct_size);
453 size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
454 unsigned long bo_size,
455 unsigned struct_size);
460 * @bdev: Pointer to a ttm_bo_device struct.
461 * @bo: Pointer to a ttm_buffer_object to be initialized.
462 * @size: Requested size of buffer object.
463 * @type: Requested type of buffer object.
464 * @flags: Initial placement flags.
465 * @page_alignment: Data alignment in pages.
466 * @interruptible: If needing to sleep to wait for GPU resources,
467 * sleep interruptible.
468 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
469 * pinned in physical memory. If this behaviour is not desired, this member
470 * holds a pointer to a persistent shmem object. Typically, this would
471 * point to the shmem object backing a GEM object if TTM is used to back a
472 * GEM user interface.
473 * @acc_size: Accounted size for this object.
474 * @destroy: Destroy function. Use NULL for kfree().
476 * This function initializes a pre-allocated struct ttm_buffer_object.
477 * As this object may be part of a larger structure, this function,
478 * together with the @destroy function,
479 * enables driver-specific objects derived from a ttm_buffer_object.
480 * On successful return, the object kref and list_kref are set to 1.
481 * If a failure occurs, the function will call the @destroy function, or
482 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
483 * illegal and will likely cause memory corruption.
486 * -ENOMEM: Out of memory.
487 * -EINVAL: Invalid placement flags.
488 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
491 extern int ttm_bo_init(struct ttm_bo_device *bdev,
492 struct ttm_buffer_object *bo,
494 enum ttm_bo_type type,
495 struct ttm_placement *placement,
496 uint32_t page_alignment,
498 struct vm_object *persistent_swap_storage,
501 void (*destroy) (struct ttm_buffer_object *));
506 * @bdev: Pointer to a ttm_bo_device struct.
507 * @size: Requested size of buffer object.
508 * @type: Requested type of buffer object.
509 * @placement: Initial placement.
510 * @page_alignment: Data alignment in pages.
511 * @interruptible: If needing to sleep while waiting for GPU resources,
512 * sleep interruptible.
513 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
514 * pinned in physical memory. If this behaviour is not desired, this member
515 * holds a pointer to a persistent shmem object. Typically, this would
516 * point to the shmem object backing a GEM object if TTM is used to back a
517 * GEM user interface.
518 * @p_bo: On successful completion *p_bo points to the created object.
520 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
521 * on that object. The destroy function is set to kfree().
523 * -ENOMEM: Out of memory.
524 * -EINVAL: Invalid placement flags.
525 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
528 extern int ttm_bo_create(struct ttm_bo_device *bdev,
530 enum ttm_bo_type type,
531 struct ttm_placement *placement,
532 uint32_t page_alignment,
534 struct vm_object *persistent_swap_storage,
535 struct ttm_buffer_object **p_bo);
538 * ttm_bo_check_placement
540 * @bo: the buffer object.
541 * @placement: placements
543 * Performs minimal validity checking on an intended change of
546 * -EINVAL: Intended change is invalid or not allowed.
548 extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
549 struct ttm_placement *placement);
554 * @bdev: Pointer to a ttm_bo_device struct.
555 * @mem_type: The memory type.
556 * @p_size: size managed area in pages.
558 * Initialize a manager for a given memory type.
559 * Note: if part of driver firstopen, it must be protected from a
560 * potentially racing lastclose.
562 * -EINVAL: invalid size or memory type.
563 * -ENOMEM: Not enough memory.
564 * May also return driver-specified errors.
567 extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
568 unsigned long p_size);
572 * @bdev: Pointer to a ttm_bo_device struct.
573 * @mem_type: The memory type.
575 * Take down a manager for a given memory type after first walking
576 * the LRU list to evict any buffers left alive.
578 * Normally, this function is part of lastclose() or unload(), and at that
579 * point there shouldn't be any buffers left created by user-space, since
580 * there should've been removed by the file descriptor release() method.
581 * However, before this function is run, make sure to signal all sync objects,
582 * and verify that the delayed delete queue is empty. The driver must also
583 * make sure that there are no NO_EVICT buffers present in this memory type
584 * when the call is made.
586 * If this function is part of a VT switch, the caller must make sure that
587 * there are no appications currently validating buffers before this
588 * function is called. The caller can do that by first taking the
589 * struct ttm_bo_device::ttm_lock in write mode.
592 * -EINVAL: invalid or uninitialized memory type.
593 * -EBUSY: There are still buffers left in this memory type.
596 extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
601 * @bdev: Pointer to a ttm_bo_device struct.
602 * @mem_type: The memory type.
604 * Evicts all buffers on the lru list of the memory type.
605 * This is normally part of a VT switch or an
606 * out-of-memory-space-due-to-fragmentation handler.
607 * The caller must make sure that there are no other processes
608 * currently validating buffers, and can do that by taking the
609 * struct ttm_bo_device::ttm_lock in write mode.
612 * -EINVAL: Invalid or uninitialized memory type.
613 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
617 extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
620 * ttm_kmap_obj_virtual
622 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
623 * @is_iomem: Pointer to an integer that on return indicates 1 if the
624 * virtual map is io memory, 0 if normal memory.
626 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
627 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
628 * that should strictly be accessed by the iowriteXX() and similar functions.
631 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
634 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
641 * @bo: The buffer object.
642 * @start_page: The first page to map.
643 * @num_pages: Number of pages to map.
644 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
646 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
647 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
648 * used to obtain a virtual address to the data.
651 * -ENOMEM: Out of memory.
652 * -EINVAL: Invalid range.
655 extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
656 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
661 * @map: Object describing the map to unmap.
663 * Unmaps a kernel map set up by ttm_bo_kmap.
666 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
669 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
671 * @vma: vma as input from the fbdev mmap method.
672 * @bo: The bo backing the address space. The address space will
673 * have the same size as the bo, and start at offset 0.
675 * This function is intended to be called by the fbdev mmap method
676 * if the fbdev address space is to be backed by a bo.
679 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
680 struct ttm_buffer_object *bo);
683 * ttm_bo_mmap - mmap out of the ttm device address space.
685 * @filp: filp as input from the mmap method.
686 * @vma: vma as input from the mmap method.
687 * @bdev: Pointer to the ttm_bo_device with the address space manager.
689 * This function is intended to be called by the device mmap method.
690 * if the device address space is to be backed by the bo manager.
693 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
694 struct ttm_bo_device *bdev);
699 * @bdev: Pointer to the struct ttm_bo_device.
700 * @filp: Pointer to the struct file attempting to read / write.
701 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
702 * @rbuf: User-space pointer to address of buffer to read into.
704 * @count: Number of bytes to read / write.
705 * @f_pos: Pointer to current file position.
706 * @write: 1 for read, 0 for write.
708 * This function implements read / write into ttm buffer objects, and is
710 * be called from the fops::read and fops::write method.
712 * See man (2) write, man(2) read. In particular,
713 * the function may return -ERESTARTSYS if
714 * interrupted by a signal.
717 extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
718 const char __user *wbuf, char __user *rbuf,
719 size_t count, loff_t *f_pos, bool write);
721 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
722 extern int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo);