1 /**************************************************************************
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
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26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30 /* $FreeBSD: head/sys/dev/drm2/ttm/ttm_bo_api.h 247835 2013-03-05 09:49:34Z kib $ */
32 #ifndef _TTM_BO_API_H_
33 #define _TTM_BO_API_H_
36 #include <drm/drm_hashtab.h>
37 #include <linux/kref.h>
38 #include <linux/list.h>
39 #include <linux/wait.h>
40 #include <linux/mutex.h>
41 #include <linux/reservation.h>
50 * @fpfn: first valid page frame number to put the object
51 * @lpfn: last valid page frame number to put the object
52 * @flags: memory domain and caching flags for the object
54 * Structure indicating a possible place to put an object.
63 * struct ttm_placement
65 * @num_placement: number of preferred placements
66 * @placement: preferred placements
67 * @num_busy_placement: number of preferred placements when need to evict buffer
68 * @busy_placement: preferred placements when need to evict buffer
70 * Structure indicating the placement you request for an object.
72 struct ttm_placement {
73 unsigned num_placement;
74 const struct ttm_place *placement;
75 unsigned num_busy_placement;
76 const struct ttm_place *busy_placement;
80 * struct ttm_bus_placement
82 * @addr: mapped virtual address
83 * @base: bus base address
84 * @is_iomem: is this io memory ?
86 * @offset: offset from the base address
87 * @io_reserved_vm: The VM system has a refcount in @io_reserved_count
88 * @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
90 * Structure indicating the bus placement of an object.
92 struct ttm_bus_placement {
99 uint64_t io_reserved_count;
106 * @mm_node: Memory manager node.
107 * @size: Requested size of memory region.
108 * @num_pages: Actual size of memory region in pages.
109 * @page_alignment: Page alignment.
110 * @placement: Placement flags.
111 * @bus: Placement on io bus accessible to the CPU
113 * Structure indicating the placement and space resources used by a
121 unsigned long num_pages;
122 uint32_t page_alignment;
125 struct ttm_bus_placement bus;
131 * @ttm_bo_type_device: These are 'normal' buffers that can
132 * be mmapped by user space. Each of these bos occupy a slot in the
133 * device address space, that can be used for normal vm operations.
135 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
136 * but they cannot be accessed from user-space. For kernel-only use.
138 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
151 * struct ttm_buffer_object
153 * @bdev: Pointer to the buffer object device structure.
154 * @type: The bo type.
155 * @destroy: Destruction function. If NULL, kfree is used.
156 * @num_pages: Actual number of pages.
157 * @addr_space_offset: Address space offset.
158 * @acc_size: Accounted size for this object.
159 * @kref: Reference count of this buffer object. When this refcount reaches
160 * zero, the object is put on the delayed delete list.
161 * @list_kref: List reference count of this buffer object. This member is
162 * used to avoid destruction while the buffer object is still on a list.
163 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
164 * keeps one refcount. When this refcount reaches zero,
165 * the object is destroyed.
166 * @event_queue: Queue for processes waiting on buffer object status change.
167 * @mem: structure describing current placement.
168 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
169 * pinned in physical memory. If this behaviour is not desired, this member
170 * holds a pointer to a persistent shmem object.
171 * @ttm: TTM structure holding system pages.
172 * @evicted: Whether the object was evicted without user-space knowing.
173 * @cpu_writes: For synchronization. Number of cpu writers.
174 * @lru: List head for the lru list.
175 * @ddestroy: List head for the delayed destroy list.
176 * @swap: List head for swap LRU list.
177 * @val_seq: Sequence of the validation holding the @reserved lock.
178 * Used to avoid starvation when many processes compete to validate the
179 * buffer. This member is protected by the bo_device::lru_lock.
180 * @seq_valid: The value of @val_seq is valid. This value is protected by
181 * the bo_device::lru_lock.
182 * @reserved: Deadlock-free lock used for synchronization state transitions.
183 * @sync_obj: Pointer to a synchronization object.
184 * @priv_flags: Flags describing buffer object internal state.
185 * @vm_rb: Rb node for the vm rb tree.
186 * @vm_node: Address space manager node.
187 * @offset: The current GPU offset, which can have different meanings
188 * depending on the memory type. For SYSTEM type memory, it should be 0.
189 * @cur_placement: Hint of current placement.
191 * Base class for TTM buffer object, that deals with data placement and CPU
192 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
193 * the driver can usually use the placement offset @offset directly as the
194 * GPU virtual address. For drivers implementing multiple
195 * GPU memory manager contexts, the driver should manage the address space
196 * in these contexts separately and use these objects to get the correct
197 * placement and caching for these GPU maps. This makes it possible to use
198 * these objects for even quite elaborate memory management schemes.
199 * The destroy member, the API visibility of this object makes it possible
200 * to derive driver specific types.
203 struct ttm_buffer_object {
205 * Members constant at init.
208 struct ttm_bo_global *glob;
209 struct ttm_bo_device *bdev;
210 enum ttm_bo_type type;
211 void (*destroy) (struct ttm_buffer_object *);
212 unsigned long num_pages;
213 uint64_t addr_space_offset;
217 * Members not needing protection.
221 struct kref list_kref;
224 * Members protected by the bo::reserved lock.
227 struct ttm_mem_reg mem;
228 struct vm_object *persistent_swap_storage;
233 * Members protected by the bo::reserved lock only when written to.
236 atomic_t cpu_writers;
239 * Members protected by the bdev::lru_lock.
242 struct list_head lru;
243 struct list_head ddestroy;
244 struct list_head swap;
245 struct list_head io_reserve_lru;
248 * Members protected by struct buffer_object_device::fence_lock
249 * In addition, setting sync_obj to anything else
250 * than NULL requires bo::reserved to be held. This allows for
251 * checking NULL while reserved but not holding the mentioned lock.
255 unsigned long priv_flags;
258 * Members protected by the bdev::vm_lock
261 RB_ENTRY(ttm_buffer_object) vm_rb;
262 struct drm_mm_node *vm_node;
266 * Special members that are protected by the reserve lock
267 * and the bo::lock when written to. Can be read with
268 * either of these locks held.
271 unsigned long offset;
272 uint32_t cur_placement;
276 struct reservation_object *resv;
277 struct reservation_object ttm_resv;
281 * struct ttm_bo_kmap_obj
283 * @virtual: The current kernel virtual address.
284 * @page: The page when kmap'ing a single page.
285 * @bo_kmap_type: Type of bo_kmap.
287 * Object describing a kernel mapping. Since a TTM bo may be located
288 * in various memory types with various caching policies, the
289 * mapping can either be an ioremap, a vmap, a kmap or part of a
293 #define TTM_BO_MAP_IOMEM_MASK 0x80
294 struct ttm_bo_kmap_obj {
298 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
301 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
303 struct ttm_buffer_object *bo;
307 * ttm_bo_reference - reference a struct ttm_buffer_object
309 * @bo: The buffer object.
311 * Returns a refcounted pointer to a buffer object.
314 static inline struct ttm_buffer_object *
315 ttm_bo_reference(struct ttm_buffer_object *bo)
322 * ttm_bo_wait - wait for buffer idle.
324 * @bo: The buffer object.
325 * @interruptible: Use interruptible wait.
326 * @no_wait: Return immediately if buffer is busy.
328 * This function must be called with the bo::mutex held, and makes
329 * sure any previous rendering to the buffer is completed.
330 * Note: It might be necessary to block validations before the
331 * wait by reserving the buffer.
332 * Returns -EBUSY if no_wait is true and the buffer is busy.
333 * Returns -ERESTARTSYS if interrupted by a signal.
335 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
336 bool interruptible, bool no_wait);
340 * @bo: The buffer object.
341 * @placement: Proposed placement for the buffer object.
342 * @interruptible: Sleep interruptible if sleeping.
343 * @no_wait_gpu: Return immediately if the GPU is busy.
345 * Changes placement and caching policy of the buffer object
346 * according proposed placement.
348 * -EINVAL on invalid proposed placement.
349 * -ENOMEM on out-of-memory condition.
350 * -EBUSY if no_wait is true and buffer busy.
351 * -ERESTARTSYS if interrupted by a signal.
353 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
354 struct ttm_placement *placement,
361 * @bo: The buffer object.
363 * Unreference and clear a pointer to a buffer object.
365 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
369 * ttm_bo_list_ref_sub
371 * @bo: The buffer object.
372 * @count: The number of references with which to decrease @bo::list_kref;
373 * @never_free: The refcount should not reach zero with this operation.
375 * Release @count lru list references to this buffer object.
377 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
383 * @bo: The buffer object.
385 * Add this bo to the relevant mem type lru and, if it's backed by
386 * system pages (ttms) to the swap list.
387 * This function must be called with struct ttm_bo_global::lru_lock held, and
388 * is typically called immediately prior to unreserving a bo.
390 extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
393 * ttm_bo_del_from_lru
395 * @bo: The buffer object.
397 * Remove this bo from all lru lists used to lookup and reserve an object.
398 * This function must be called with struct ttm_bo_global::lru_lock held,
399 * and is usually called just immediately after the bo has been reserved to
400 * avoid recursive reservation from lru lists.
402 extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
406 * ttm_bo_lock_delayed_workqueue
408 * Prevent the delayed workqueue from running.
410 * True if the workqueue was queued at the time
412 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
415 * ttm_bo_unlock_delayed_workqueue
417 * Allows the delayed workqueue to run.
419 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
423 * ttm_bo_synccpu_write_grab
425 * @bo: The buffer object:
426 * @no_wait: Return immediately if buffer is busy.
428 * Synchronizes a buffer object for CPU RW access. This means
429 * command submission that affects the buffer will return -EBUSY
430 * until ttm_bo_synccpu_write_release is called.
433 * -EBUSY if the buffer is busy and no_wait is true.
434 * -ERESTARTSYS if interrupted by a signal.
437 ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
440 * ttm_bo_synccpu_write_release:
442 * @bo : The buffer object.
444 * Releases a synccpu lock.
446 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
451 * @bdev: Pointer to a ttm_bo_device struct.
452 * @bo_size: size of the buffer object in byte.
453 * @struct_size: size of the structure holding buffer object datas
455 * Returns size to account for a buffer object
457 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
458 unsigned long bo_size,
459 unsigned struct_size);
460 size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
461 unsigned long bo_size,
462 unsigned struct_size);
467 * @bdev: Pointer to a ttm_bo_device struct.
468 * @bo: Pointer to a ttm_buffer_object to be initialized.
469 * @size: Requested size of buffer object.
470 * @type: Requested type of buffer object.
471 * @flags: Initial placement flags.
472 * @page_alignment: Data alignment in pages.
473 * @interruptible: If needing to sleep to wait for GPU resources,
474 * sleep interruptible.
475 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
476 * pinned in physical memory. If this behaviour is not desired, this member
477 * holds a pointer to a persistent shmem object. Typically, this would
478 * point to the shmem object backing a GEM object if TTM is used to back a
479 * GEM user interface.
480 * @acc_size: Accounted size for this object.
481 * @destroy: Destroy function. Use NULL for kfree().
483 * This function initializes a pre-allocated struct ttm_buffer_object.
484 * As this object may be part of a larger structure, this function,
485 * together with the @destroy function,
486 * enables driver-specific objects derived from a ttm_buffer_object.
487 * On successful return, the object kref and list_kref are set to 1.
488 * If a failure occurs, the function will call the @destroy function, or
489 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
490 * illegal and will likely cause memory corruption.
493 * -ENOMEM: Out of memory.
494 * -EINVAL: Invalid placement flags.
495 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
498 extern int ttm_bo_init(struct ttm_bo_device *bdev,
499 struct ttm_buffer_object *bo,
501 enum ttm_bo_type type,
502 struct ttm_placement *placement,
503 uint32_t page_alignment,
505 struct vm_object *persistent_swap_storage,
508 void (*destroy) (struct ttm_buffer_object *));
513 * @bdev: Pointer to a ttm_bo_device struct.
514 * @size: Requested size of buffer object.
515 * @type: Requested type of buffer object.
516 * @placement: Initial placement.
517 * @page_alignment: Data alignment in pages.
518 * @interruptible: If needing to sleep while waiting for GPU resources,
519 * sleep interruptible.
520 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
521 * pinned in physical memory. If this behaviour is not desired, this member
522 * holds a pointer to a persistent shmem object. Typically, this would
523 * point to the shmem object backing a GEM object if TTM is used to back a
524 * GEM user interface.
525 * @p_bo: On successful completion *p_bo points to the created object.
527 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
528 * on that object. The destroy function is set to kfree().
530 * -ENOMEM: Out of memory.
531 * -EINVAL: Invalid placement flags.
532 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
535 extern int ttm_bo_create(struct ttm_bo_device *bdev,
537 enum ttm_bo_type type,
538 struct ttm_placement *placement,
539 uint32_t page_alignment,
541 struct vm_object *persistent_swap_storage,
542 struct ttm_buffer_object **p_bo);
547 * @bdev: Pointer to a ttm_bo_device struct.
548 * @mem_type: The memory type.
549 * @p_size: size managed area in pages.
551 * Initialize a manager for a given memory type.
552 * Note: if part of driver firstopen, it must be protected from a
553 * potentially racing lastclose.
555 * -EINVAL: invalid size or memory type.
556 * -ENOMEM: Not enough memory.
557 * May also return driver-specified errors.
560 extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
561 unsigned long p_size);
565 * @bdev: Pointer to a ttm_bo_device struct.
566 * @mem_type: The memory type.
568 * Take down a manager for a given memory type after first walking
569 * the LRU list to evict any buffers left alive.
571 * Normally, this function is part of lastclose() or unload(), and at that
572 * point there shouldn't be any buffers left created by user-space, since
573 * there should've been removed by the file descriptor release() method.
574 * However, before this function is run, make sure to signal all sync objects,
575 * and verify that the delayed delete queue is empty. The driver must also
576 * make sure that there are no NO_EVICT buffers present in this memory type
577 * when the call is made.
579 * If this function is part of a VT switch, the caller must make sure that
580 * there are no appications currently validating buffers before this
581 * function is called. The caller can do that by first taking the
582 * struct ttm_bo_device::ttm_lock in write mode.
585 * -EINVAL: invalid or uninitialized memory type.
586 * -EBUSY: There are still buffers left in this memory type.
589 extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
594 * @bdev: Pointer to a ttm_bo_device struct.
595 * @mem_type: The memory type.
597 * Evicts all buffers on the lru list of the memory type.
598 * This is normally part of a VT switch or an
599 * out-of-memory-space-due-to-fragmentation handler.
600 * The caller must make sure that there are no other processes
601 * currently validating buffers, and can do that by taking the
602 * struct ttm_bo_device::ttm_lock in write mode.
605 * -EINVAL: Invalid or uninitialized memory type.
606 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
610 extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
613 * ttm_kmap_obj_virtual
615 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
616 * @is_iomem: Pointer to an integer that on return indicates 1 if the
617 * virtual map is io memory, 0 if normal memory.
619 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
620 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
621 * that should strictly be accessed by the iowriteXX() and similar functions.
624 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
627 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
634 * @bo: The buffer object.
635 * @start_page: The first page to map.
636 * @num_pages: Number of pages to map.
637 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
639 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
640 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
641 * used to obtain a virtual address to the data.
644 * -ENOMEM: Out of memory.
645 * -EINVAL: Invalid range.
648 extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
649 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
654 * @map: Object describing the map to unmap.
656 * Unmaps a kernel map set up by ttm_bo_kmap.
659 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
662 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
664 * @vma: vma as input from the fbdev mmap method.
665 * @bo: The bo backing the address space. The address space will
666 * have the same size as the bo, and start at offset 0.
668 * This function is intended to be called by the fbdev mmap method
669 * if the fbdev address space is to be backed by a bo.
673 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
674 struct ttm_buffer_object *bo);
677 * ttm_bo_mmap - mmap out of the ttm device address space.
679 * @filp: filp as input from the mmap method.
680 * @vma: vma as input from the mmap method.
681 * @bdev: Pointer to the ttm_bo_device with the address space manager.
683 * This function is intended to be called by the device mmap method.
684 * if the device address space is to be backed by the bo manager.
687 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
688 struct ttm_bo_device *bdev);
693 * @bdev: Pointer to the struct ttm_bo_device.
694 * @filp: Pointer to the struct file attempting to read / write.
695 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
696 * @rbuf: User-space pointer to address of buffer to read into.
698 * @count: Number of bytes to read / write.
699 * @f_pos: Pointer to current file position.
700 * @write: 1 for read, 0 for write.
702 * This function implements read / write into ttm buffer objects, and is
704 * be called from the fops::read and fops::write method.
706 * See man (2) write, man(2) read. In particular,
707 * the function may return -ERESTARTSYS if
708 * interrupted by a signal.
711 extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
712 const char *wbuf, char *rbuf,
713 size_t count, off_t *f_pos, bool write);
715 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
718 * ttm_bo_is_reserved - return an indication if a ttm buffer object is reserved
720 * @bo: The buffer object to check.
722 * This function returns an indication if a bo is reserved or not, and should
723 * only be used to print an error when it is not from incorrect api usage, since
724 * there's no guarantee that it is the caller that is holding the reservation.
726 static inline bool ttm_bo_is_reserved(struct ttm_buffer_object *bo)
728 return ww_mutex_is_locked(&bo->resv->lock);