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_hashtab.h"
35 #include <linux/kref.h>
36 #include <linux/list.h>
37 #include <linux/wait.h>
38 #include <linux/mutex.h>
40 #include <linux/rbtree.h>
41 #include <linux/bitmap.h>
49 * struct ttm_placement
51 * @fpfn: first valid page frame number to put the object
52 * @lpfn: last valid page frame number to put the object
53 * @num_placement: number of prefered placements
54 * @placement: prefered placements
55 * @num_busy_placement: number of prefered placements when need to evict buffer
56 * @busy_placement: prefered placements when need to evict buffer
58 * Structure indicating the placement you request for an object.
60 struct ttm_placement {
63 unsigned num_placement;
64 const uint32_t *placement;
65 unsigned num_busy_placement;
66 const uint32_t *busy_placement;
70 * struct ttm_bus_placement
72 * @addr: mapped virtual address
73 * @base: bus base address
74 * @is_iomem: is this io memory ?
76 * @offset: offset from the base address
78 * Structure indicating the bus placement of an object.
80 struct ttm_bus_placement {
93 * @mm_node: Memory manager node.
94 * @size: Requested size of memory region.
95 * @num_pages: Actual size of memory region in pages.
96 * @page_alignment: Page alignment.
97 * @placement: Placement flags.
98 * @bus: Placement on io bus accessible to the CPU
100 * Structure indicating the placement and space resources used by a
108 unsigned long num_pages;
109 uint32_t page_alignment;
112 struct ttm_bus_placement bus;
118 * @ttm_bo_type_device: These are 'normal' buffers that can
119 * be mmapped by user space. Each of these bos occupy a slot in the
120 * device address space, that can be used for normal vm operations.
122 * @ttm_bo_type_user: These are user-space memory areas that are made
123 * available to the GPU by mapping the buffer pages into the GPU aperture
124 * space. These buffers cannot be mmaped from the device address space.
126 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
127 * but they cannot be accessed from user-space. For kernel-only use.
139 * struct ttm_buffer_object
141 * @bdev: Pointer to the buffer object device structure.
142 * @buffer_start: The virtual user-space start address of ttm_bo_type_user
144 * @type: The bo type.
145 * @destroy: Destruction function. If NULL, kfree is used.
146 * @num_pages: Actual number of pages.
147 * @addr_space_offset: Address space offset.
148 * @acc_size: Accounted size for this object.
149 * @kref: Reference count of this buffer object. When this refcount reaches
150 * zero, the object is put on the delayed delete list.
151 * @list_kref: List reference count of this buffer object. This member is
152 * used to avoid destruction while the buffer object is still on a list.
153 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
154 * keeps one refcount. When this refcount reaches zero,
155 * the object is destroyed.
156 * @event_queue: Queue for processes waiting on buffer object status change.
157 * @mem: structure describing current placement.
158 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
159 * pinned in physical memory. If this behaviour is not desired, this member
160 * holds a pointer to a persistant shmem object.
161 * @ttm: TTM structure holding system pages.
162 * @evicted: Whether the object was evicted without user-space knowing.
163 * @cpu_writes: For synchronization. Number of cpu writers.
164 * @lru: List head for the lru list.
165 * @ddestroy: List head for the delayed destroy list.
166 * @swap: List head for swap LRU list.
167 * @val_seq: Sequence of the validation holding the @reserved lock.
168 * Used to avoid starvation when many processes compete to validate the
169 * buffer. This member is protected by the bo_device::lru_lock.
170 * @seq_valid: The value of @val_seq is valid. This value is protected by
171 * the bo_device::lru_lock.
172 * @reserved: Deadlock-free lock used for synchronization state transitions.
173 * @sync_obj_arg: Opaque argument to synchronization object function.
174 * @sync_obj: Pointer to a synchronization object.
175 * @priv_flags: Flags describing buffer object internal state.
176 * @vm_rb: Rb node for the vm rb tree.
177 * @vm_node: Address space manager node.
178 * @offset: The current GPU offset, which can have different meanings
179 * depending on the memory type. For SYSTEM type memory, it should be 0.
180 * @cur_placement: Hint of current placement.
182 * Base class for TTM buffer object, that deals with data placement and CPU
183 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
184 * the driver can usually use the placement offset @offset directly as the
185 * GPU virtual address. For drivers implementing multiple
186 * GPU memory manager contexts, the driver should manage the address space
187 * in these contexts separately and use these objects to get the correct
188 * placement and caching for these GPU maps. This makes it possible to use
189 * these objects for even quite elaborate memory management schemes.
190 * The destroy member, the API visibility of this object makes it possible
191 * to derive driver specific types.
194 struct ttm_buffer_object {
196 * Members constant at init.
199 struct ttm_bo_global *glob;
200 struct ttm_bo_device *bdev;
201 unsigned long buffer_start;
202 enum ttm_bo_type type;
203 void (*destroy) (struct ttm_buffer_object *);
204 unsigned long num_pages;
205 uint64_t addr_space_offset;
209 * Members not needing protection.
213 struct kref list_kref;
214 wait_queue_head_t event_queue;
217 * Members protected by the bo::reserved lock.
220 struct ttm_mem_reg mem;
221 struct file *persistant_swap_storage;
226 * Members protected by the bo::reserved lock only when written to.
229 atomic_t cpu_writers;
232 * Members protected by the bdev::lru_lock.
235 struct list_head lru;
236 struct list_head ddestroy;
237 struct list_head swap;
242 * Members protected by the bdev::lru_lock
243 * only when written to.
249 * Members protected by struct buffer_object_device::fence_lock
250 * In addition, setting sync_obj to anything else
251 * than NULL requires bo::reserved to be held. This allows for
252 * checking NULL while reserved but not holding the mentioned lock.
257 unsigned long priv_flags;
260 * Members protected by the bdev::vm_lock
263 struct rb_node vm_rb;
264 struct drm_mm_node *vm_node;
268 * Special members that are protected by the reserve lock
269 * and the bo::lock when written to. Can be read with
270 * either of these locks held.
273 unsigned long offset;
274 uint32_t cur_placement;
278 * struct ttm_bo_kmap_obj
280 * @virtual: The current kernel virtual address.
281 * @page: The page when kmap'ing a single page.
282 * @bo_kmap_type: Type of bo_kmap.
284 * Object describing a kernel mapping. Since a TTM bo may be located
285 * in various memory types with various caching policies, the
286 * mapping can either be an ioremap, a vmap, a kmap or part of a
290 #define TTM_BO_MAP_IOMEM_MASK 0x80
291 struct ttm_bo_kmap_obj {
295 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
298 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
300 struct ttm_buffer_object *bo;
304 * ttm_bo_reference - reference a struct ttm_buffer_object
306 * @bo: The buffer object.
308 * Returns a refcounted pointer to a buffer object.
311 static inline struct ttm_buffer_object *
312 ttm_bo_reference(struct ttm_buffer_object *bo)
319 * ttm_bo_wait - wait for buffer idle.
321 * @bo: The buffer object.
322 * @interruptible: Use interruptible wait.
323 * @no_wait: Return immediately if buffer is busy.
325 * This function must be called with the bo::mutex held, and makes
326 * sure any previous rendering to the buffer is completed.
327 * Note: It might be necessary to block validations before the
328 * wait by reserving the buffer.
329 * Returns -EBUSY if no_wait is true and the buffer is busy.
330 * Returns -ERESTARTSYS if interrupted by a signal.
332 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
333 bool interruptible, bool no_wait);
337 * @bo: The buffer object.
338 * @placement: Proposed placement for the buffer object.
339 * @interruptible: Sleep interruptible if sleeping.
340 * @no_wait_reserve: Return immediately if other buffers are busy.
341 * @no_wait_gpu: Return immediately if the GPU is busy.
343 * Changes placement and caching policy of the buffer object
344 * according proposed placement.
346 * -EINVAL on invalid proposed placement.
347 * -ENOMEM on out-of-memory condition.
348 * -EBUSY if no_wait is true and buffer busy.
349 * -ERESTARTSYS if interrupted by a signal.
351 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
352 struct ttm_placement *placement,
353 bool interruptible, bool no_wait_reserve,
359 * @bo: The buffer object.
361 * Unreference and clear a pointer to a buffer object.
363 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
367 * ttm_bo_list_ref_sub
369 * @bo: The buffer object.
370 * @count: The number of references with which to decrease @bo::list_kref;
371 * @never_free: The refcount should not reach zero with this operation.
373 * Release @count lru list references to this buffer object.
375 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
381 * @bo: The buffer object.
383 * Add this bo to the relevant mem type lru and, if it's backed by
384 * system pages (ttms) to the swap list.
385 * This function must be called with struct ttm_bo_global::lru_lock held, and
386 * is typically called immediately prior to unreserving a bo.
388 extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
391 * ttm_bo_del_from_lru
393 * @bo: The buffer object.
395 * Remove this bo from all lru lists used to lookup and reserve an object.
396 * This function must be called with struct ttm_bo_global::lru_lock held,
397 * and is usually called just immediately after the bo has been reserved to
398 * avoid recursive reservation from lru lists.
400 extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
404 * ttm_bo_lock_delayed_workqueue
406 * Prevent the delayed workqueue from running.
408 * True if the workqueue was queued at the time
410 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
413 * ttm_bo_unlock_delayed_workqueue
415 * Allows the delayed workqueue to run.
417 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
421 * ttm_bo_synccpu_write_grab
423 * @bo: The buffer object:
424 * @no_wait: Return immediately if buffer is busy.
426 * Synchronizes a buffer object for CPU RW access. This means
427 * blocking command submission that affects the buffer and
428 * waiting for buffer idle. This lock is recursive.
430 * -EBUSY if the buffer is busy and no_wait is true.
431 * -ERESTARTSYS if interrupted by a signal.
435 ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
437 * ttm_bo_synccpu_write_release:
439 * @bo : The buffer object.
441 * Releases a synccpu lock.
443 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
448 * @bdev: Pointer to a ttm_bo_device struct.
449 * @bo: Pointer to a ttm_buffer_object to be initialized.
450 * @size: Requested size of buffer object.
451 * @type: Requested type of buffer object.
452 * @flags: Initial placement flags.
453 * @page_alignment: Data alignment in pages.
454 * @buffer_start: Virtual address of user space data backing a
455 * user buffer object.
456 * @interruptible: If needing to sleep to wait for GPU resources,
457 * sleep interruptible.
458 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
459 * pinned in physical memory. If this behaviour is not desired, this member
460 * holds a pointer to a persistant shmem object. Typically, this would
461 * point to the shmem object backing a GEM object if TTM is used to back a
462 * GEM user interface.
463 * @acc_size: Accounted size for this object.
464 * @destroy: Destroy function. Use NULL for kfree().
466 * This function initializes a pre-allocated struct ttm_buffer_object.
467 * As this object may be part of a larger structure, this function,
468 * together with the @destroy function,
469 * enables driver-specific objects derived from a ttm_buffer_object.
470 * On successful return, the object kref and list_kref are set to 1.
471 * If a failure occurs, the function will call the @destroy function, or
472 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
473 * illegal and will likely cause memory corruption.
476 * -ENOMEM: Out of memory.
477 * -EINVAL: Invalid placement flags.
478 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
481 extern int ttm_bo_init(struct ttm_bo_device *bdev,
482 struct ttm_buffer_object *bo,
484 enum ttm_bo_type type,
485 struct ttm_placement *placement,
486 uint32_t page_alignment,
487 unsigned long buffer_start,
489 struct file *persistant_swap_storage,
491 void (*destroy) (struct ttm_buffer_object *));
493 * ttm_bo_synccpu_object_init
495 * @bdev: Pointer to a ttm_bo_device struct.
496 * @bo: Pointer to a ttm_buffer_object to be initialized.
497 * @size: Requested size of buffer object.
498 * @type: Requested type of buffer object.
499 * @flags: Initial placement flags.
500 * @page_alignment: Data alignment in pages.
501 * @buffer_start: Virtual address of user space data backing a
502 * user buffer object.
503 * @interruptible: If needing to sleep while waiting for GPU resources,
504 * sleep interruptible.
505 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
506 * pinned in physical memory. If this behaviour is not desired, this member
507 * holds a pointer to a persistant shmem object. Typically, this would
508 * point to the shmem object backing a GEM object if TTM is used to back a
509 * GEM user interface.
510 * @p_bo: On successful completion *p_bo points to the created object.
512 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
513 * on that object. The destroy function is set to kfree().
515 * -ENOMEM: Out of memory.
516 * -EINVAL: Invalid placement flags.
517 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
520 extern int ttm_bo_create(struct ttm_bo_device *bdev,
522 enum ttm_bo_type type,
523 struct ttm_placement *placement,
524 uint32_t page_alignment,
525 unsigned long buffer_start,
527 struct file *persistant_swap_storage,
528 struct ttm_buffer_object **p_bo);
531 * ttm_bo_check_placement
533 * @bo: the buffer object.
534 * @placement: placements
536 * Performs minimal validity checking on an intended change of
539 * -EINVAL: Intended change is invalid or not allowed.
541 extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
542 struct ttm_placement *placement);
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);
665 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
667 * @vma: vma as input from the fbdev mmap method.
668 * @bo: The bo backing the address space. The address space will
669 * have the same size as the bo, and start at offset 0.
671 * This function is intended to be called by the fbdev mmap method
672 * if the fbdev address space is to be backed by a bo.
675 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
676 struct ttm_buffer_object *bo);
679 * ttm_bo_mmap - mmap out of the ttm device address space.
681 * @filp: filp as input from the mmap method.
682 * @vma: vma as input from the mmap method.
683 * @bdev: Pointer to the ttm_bo_device with the address space manager.
685 * This function is intended to be called by the device mmap method.
686 * if the device address space is to be backed by the bo manager.
689 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
690 struct ttm_bo_device *bdev);
695 * @bdev: Pointer to the struct ttm_bo_device.
696 * @filp: Pointer to the struct file attempting to read / write.
697 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
698 * @rbuf: User-space pointer to address of buffer to read into.
700 * @count: Number of bytes to read / write.
701 * @f_pos: Pointer to current file position.
702 * @write: 1 for read, 0 for write.
704 * This function implements read / write into ttm buffer objects, and is
706 * be called from the fops::read and fops::write method.
708 * See man (2) write, man(2) read. In particular,
709 * the function may return -ERESTARTSYS if
710 * interrupted by a signal.
713 extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
714 const char __user *wbuf, char __user *rbuf,
715 size_t count, loff_t *f_pos, bool write);
717 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);