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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18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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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;
73 * @mm_node: Memory manager node.
74 * @size: Requested size of memory region.
75 * @num_pages: Actual size of memory region in pages.
76 * @page_alignment: Page alignment.
77 * @placement: Placement flags.
79 * Structure indicating the placement and space resources used by a
84 struct drm_mm_node *mm_node;
86 unsigned long num_pages;
87 uint32_t page_alignment;
95 * @ttm_bo_type_device: These are 'normal' buffers that can
96 * be mmapped by user space. Each of these bos occupy a slot in the
97 * device address space, that can be used for normal vm operations.
99 * @ttm_bo_type_user: These are user-space memory areas that are made
100 * available to the GPU by mapping the buffer pages into the GPU aperture
101 * space. These buffers cannot be mmaped from the device address space.
103 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
104 * but they cannot be accessed from user-space. For kernel-only use.
116 * struct ttm_buffer_object
118 * @bdev: Pointer to the buffer object device structure.
119 * @buffer_start: The virtual user-space start address of ttm_bo_type_user
121 * @type: The bo type.
122 * @destroy: Destruction function. If NULL, kfree is used.
123 * @num_pages: Actual number of pages.
124 * @addr_space_offset: Address space offset.
125 * @acc_size: Accounted size for this object.
126 * @kref: Reference count of this buffer object. When this refcount reaches
127 * zero, the object is put on the delayed delete list.
128 * @list_kref: List reference count of this buffer object. This member is
129 * used to avoid destruction while the buffer object is still on a list.
130 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
131 * keeps one refcount. When this refcount reaches zero,
132 * the object is destroyed.
133 * @event_queue: Queue for processes waiting on buffer object status change.
134 * @lock: spinlock protecting mostly synchronization members.
135 * @mem: structure describing current placement.
136 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
137 * pinned in physical memory. If this behaviour is not desired, this member
138 * holds a pointer to a persistant shmem object.
139 * @ttm: TTM structure holding system pages.
140 * @evicted: Whether the object was evicted without user-space knowing.
141 * @cpu_writes: For synchronization. Number of cpu writers.
142 * @lru: List head for the lru list.
143 * @ddestroy: List head for the delayed destroy list.
144 * @swap: List head for swap LRU list.
145 * @val_seq: Sequence of the validation holding the @reserved lock.
146 * Used to avoid starvation when many processes compete to validate the
147 * buffer. This member is protected by the bo_device::lru_lock.
148 * @seq_valid: The value of @val_seq is valid. This value is protected by
149 * the bo_device::lru_lock.
150 * @reserved: Deadlock-free lock used for synchronization state transitions.
151 * @sync_obj_arg: Opaque argument to synchronization object function.
152 * @sync_obj: Pointer to a synchronization object.
153 * @priv_flags: Flags describing buffer object internal state.
154 * @vm_rb: Rb node for the vm rb tree.
155 * @vm_node: Address space manager node.
156 * @offset: The current GPU offset, which can have different meanings
157 * depending on the memory type. For SYSTEM type memory, it should be 0.
158 * @cur_placement: Hint of current placement.
160 * Base class for TTM buffer object, that deals with data placement and CPU
161 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
162 * the driver can usually use the placement offset @offset directly as the
163 * GPU virtual address. For drivers implementing multiple
164 * GPU memory manager contexts, the driver should manage the address space
165 * in these contexts separately and use these objects to get the correct
166 * placement and caching for these GPU maps. This makes it possible to use
167 * these objects for even quite elaborate memory management schemes.
168 * The destroy member, the API visibility of this object makes it possible
169 * to derive driver specific types.
172 struct ttm_buffer_object {
174 * Members constant at init.
177 struct ttm_bo_global *glob;
178 struct ttm_bo_device *bdev;
179 unsigned long buffer_start;
180 enum ttm_bo_type type;
181 void (*destroy) (struct ttm_buffer_object *);
182 unsigned long num_pages;
183 uint64_t addr_space_offset;
187 * Members not needing protection.
191 struct kref list_kref;
192 wait_queue_head_t event_queue;
196 * Members protected by the bo::reserved lock.
199 struct ttm_mem_reg mem;
200 struct file *persistant_swap_storage;
205 * Members protected by the bo::reserved lock only when written to.
208 atomic_t cpu_writers;
211 * Members protected by the bdev::lru_lock.
214 struct list_head lru;
215 struct list_head ddestroy;
216 struct list_head swap;
221 * Members protected by the bdev::lru_lock
222 * only when written to.
229 * Members protected by the bo::lock
234 unsigned long priv_flags;
237 * Members protected by the bdev::vm_lock
240 struct rb_node vm_rb;
241 struct drm_mm_node *vm_node;
245 * Special members that are protected by the reserve lock
246 * and the bo::lock when written to. Can be read with
247 * either of these locks held.
250 unsigned long offset;
251 uint32_t cur_placement;
255 * struct ttm_bo_kmap_obj
257 * @virtual: The current kernel virtual address.
258 * @page: The page when kmap'ing a single page.
259 * @bo_kmap_type: Type of bo_kmap.
261 * Object describing a kernel mapping. Since a TTM bo may be located
262 * in various memory types with various caching policies, the
263 * mapping can either be an ioremap, a vmap, a kmap or part of a
267 #define TTM_BO_MAP_IOMEM_MASK 0x80
268 struct ttm_bo_kmap_obj {
272 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
275 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
280 * ttm_bo_reference - reference a struct ttm_buffer_object
282 * @bo: The buffer object.
284 * Returns a refcounted pointer to a buffer object.
287 static inline struct ttm_buffer_object *
288 ttm_bo_reference(struct ttm_buffer_object *bo)
295 * ttm_bo_wait - wait for buffer idle.
297 * @bo: The buffer object.
298 * @interruptible: Use interruptible wait.
299 * @no_wait: Return immediately if buffer is busy.
301 * This function must be called with the bo::mutex held, and makes
302 * sure any previous rendering to the buffer is completed.
303 * Note: It might be necessary to block validations before the
304 * wait by reserving the buffer.
305 * Returns -EBUSY if no_wait is true and the buffer is busy.
306 * Returns -ERESTARTSYS if interrupted by a signal.
308 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
309 bool interruptible, bool no_wait);
313 * @bo: The buffer object.
314 * @placement: Proposed placement for the buffer object.
315 * @interruptible: Sleep interruptible if sleeping.
316 * @no_wait_reserve: Return immediately if other buffers are busy.
317 * @no_wait_gpu: Return immediately if the GPU is busy.
319 * Changes placement and caching policy of the buffer object
320 * according proposed placement.
322 * -EINVAL on invalid proposed placement.
323 * -ENOMEM on out-of-memory condition.
324 * -EBUSY if no_wait is true and buffer busy.
325 * -ERESTARTSYS if interrupted by a signal.
327 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
328 struct ttm_placement *placement,
329 bool interruptible, bool no_wait_reserve,
335 * @bo: The buffer object.
337 * Unreference and clear a pointer to a buffer object.
339 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
342 * ttm_bo_synccpu_write_grab
344 * @bo: The buffer object:
345 * @no_wait: Return immediately if buffer is busy.
347 * Synchronizes a buffer object for CPU RW access. This means
348 * blocking command submission that affects the buffer and
349 * waiting for buffer idle. This lock is recursive.
351 * -EBUSY if the buffer is busy and no_wait is true.
352 * -ERESTARTSYS if interrupted by a signal.
356 ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
358 * ttm_bo_synccpu_write_release:
360 * @bo : The buffer object.
362 * Releases a synccpu lock.
364 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
369 * @bdev: Pointer to a ttm_bo_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 * @flags: Initial placement flags.
374 * @page_alignment: Data alignment in pages.
375 * @buffer_start: Virtual address of user space data backing a
376 * user buffer object.
377 * @interruptible: If needing to sleep to wait for GPU resources,
378 * sleep interruptible.
379 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
380 * pinned in physical memory. If this behaviour is not desired, this member
381 * holds a pointer to a persistant shmem object. Typically, this would
382 * point to the shmem object backing a GEM object if TTM is used to back a
383 * GEM user interface.
384 * @acc_size: Accounted size for this object.
385 * @destroy: Destroy function. Use NULL for kfree().
387 * This function initializes a pre-allocated struct ttm_buffer_object.
388 * As this object may be part of a larger structure, this function,
389 * together with the @destroy function,
390 * enables driver-specific objects derived from a ttm_buffer_object.
391 * On successful return, the object kref and list_kref are set to 1.
393 * -ENOMEM: Out of memory.
394 * -EINVAL: Invalid placement flags.
395 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
398 extern int ttm_bo_init(struct ttm_bo_device *bdev,
399 struct ttm_buffer_object *bo,
401 enum ttm_bo_type type,
402 struct ttm_placement *placement,
403 uint32_t page_alignment,
404 unsigned long buffer_start,
406 struct file *persistant_swap_storage,
408 void (*destroy) (struct ttm_buffer_object *));
410 * ttm_bo_synccpu_object_init
412 * @bdev: Pointer to a ttm_bo_device struct.
413 * @bo: Pointer to a ttm_buffer_object to be initialized.
414 * @size: Requested size of buffer object.
415 * @type: Requested type of buffer object.
416 * @flags: Initial placement flags.
417 * @page_alignment: Data alignment in pages.
418 * @buffer_start: Virtual address of user space data backing a
419 * user buffer object.
420 * @interruptible: If needing to sleep while waiting for GPU resources,
421 * sleep interruptible.
422 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
423 * pinned in physical memory. If this behaviour is not desired, this member
424 * holds a pointer to a persistant shmem object. Typically, this would
425 * point to the shmem object backing a GEM object if TTM is used to back a
426 * GEM user interface.
427 * @p_bo: On successful completion *p_bo points to the created object.
429 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
430 * on that object. The destroy function is set to kfree().
432 * -ENOMEM: Out of memory.
433 * -EINVAL: Invalid placement flags.
434 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
437 extern int ttm_bo_create(struct ttm_bo_device *bdev,
439 enum ttm_bo_type type,
440 struct ttm_placement *placement,
441 uint32_t page_alignment,
442 unsigned long buffer_start,
444 struct file *persistant_swap_storage,
445 struct ttm_buffer_object **p_bo);
448 * ttm_bo_check_placement
450 * @bo: the buffer object.
451 * @placement: placements
453 * Performs minimal validity checking on an intended change of
456 * -EINVAL: Intended change is invalid or not allowed.
458 extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
459 struct ttm_placement *placement);
464 * @bdev: Pointer to a ttm_bo_device struct.
465 * @mem_type: The memory type.
466 * @p_size: size managed area in pages.
468 * Initialize a manager for a given memory type.
469 * Note: if part of driver firstopen, it must be protected from a
470 * potentially racing lastclose.
472 * -EINVAL: invalid size or memory type.
473 * -ENOMEM: Not enough memory.
474 * May also return driver-specified errors.
477 extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
478 unsigned long p_size);
482 * @bdev: Pointer to a ttm_bo_device struct.
483 * @mem_type: The memory type.
485 * Take down a manager for a given memory type after first walking
486 * the LRU list to evict any buffers left alive.
488 * Normally, this function is part of lastclose() or unload(), and at that
489 * point there shouldn't be any buffers left created by user-space, since
490 * there should've been removed by the file descriptor release() method.
491 * However, before this function is run, make sure to signal all sync objects,
492 * and verify that the delayed delete queue is empty. The driver must also
493 * make sure that there are no NO_EVICT buffers present in this memory type
494 * when the call is made.
496 * If this function is part of a VT switch, the caller must make sure that
497 * there are no appications currently validating buffers before this
498 * function is called. The caller can do that by first taking the
499 * struct ttm_bo_device::ttm_lock in write mode.
502 * -EINVAL: invalid or uninitialized memory type.
503 * -EBUSY: There are still buffers left in this memory type.
506 extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
511 * @bdev: Pointer to a ttm_bo_device struct.
512 * @mem_type: The memory type.
514 * Evicts all buffers on the lru list of the memory type.
515 * This is normally part of a VT switch or an
516 * out-of-memory-space-due-to-fragmentation handler.
517 * The caller must make sure that there are no other processes
518 * currently validating buffers, and can do that by taking the
519 * struct ttm_bo_device::ttm_lock in write mode.
522 * -EINVAL: Invalid or uninitialized memory type.
523 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
527 extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
530 * ttm_kmap_obj_virtual
532 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
533 * @is_iomem: Pointer to an integer that on return indicates 1 if the
534 * virtual map is io memory, 0 if normal memory.
536 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
537 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
538 * that should strictly be accessed by the iowriteXX() and similar functions.
541 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
544 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
551 * @bo: The buffer object.
552 * @start_page: The first page to map.
553 * @num_pages: Number of pages to map.
554 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
556 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
557 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
558 * used to obtain a virtual address to the data.
561 * -ENOMEM: Out of memory.
562 * -EINVAL: Invalid range.
565 extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
566 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
571 * @map: Object describing the map to unmap.
573 * Unmaps a kernel map set up by ttm_bo_kmap.
576 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
582 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
584 * @vma: vma as input from the fbdev mmap method.
585 * @bo: The bo backing the address space. The address space will
586 * have the same size as the bo, and start at offset 0.
588 * This function is intended to be called by the fbdev mmap method
589 * if the fbdev address space is to be backed by a bo.
592 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
593 struct ttm_buffer_object *bo);
596 * ttm_bo_mmap - mmap out of the ttm device address space.
598 * @filp: filp as input from the mmap method.
599 * @vma: vma as input from the mmap method.
600 * @bdev: Pointer to the ttm_bo_device with the address space manager.
602 * This function is intended to be called by the device mmap method.
603 * if the device address space is to be backed by the bo manager.
606 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
607 struct ttm_bo_device *bdev);
612 * @bdev: Pointer to the struct ttm_bo_device.
613 * @filp: Pointer to the struct file attempting to read / write.
614 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
615 * @rbuf: User-space pointer to address of buffer to read into.
617 * @count: Number of bytes to read / write.
618 * @f_pos: Pointer to current file position.
619 * @write: 1 for read, 0 for write.
621 * This function implements read / write into ttm buffer objects, and is
623 * be called from the fops::read and fops::write method.
625 * See man (2) write, man(2) read. In particular,
626 * the function may return -ERESTARTSYS if
627 * interrupted by a signal.
630 extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
631 const char __user *wbuf, char __user *rbuf,
632 size_t count, loff_t *f_pos, bool write);
634 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);