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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11 * permit persons to whom the Software is furnished to do so, subject to
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14 * The above copyright notice and this permission notice (including the
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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
;
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
105 struct drm_mm_node
*mm_node
;
107 unsigned long num_pages
;
108 uint32_t page_alignment
;
111 struct ttm_bus_placement bus
;
117 * @ttm_bo_type_device: These are 'normal' buffers that can
118 * be mmapped by user space. Each of these bos occupy a slot in the
119 * device address space, that can be used for normal vm operations.
121 * @ttm_bo_type_user: These are user-space memory areas that are made
122 * available to the GPU by mapping the buffer pages into the GPU aperture
123 * space. These buffers cannot be mmaped from the device address space.
125 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
126 * but they cannot be accessed from user-space. For kernel-only use.
138 * struct ttm_buffer_object
140 * @bdev: Pointer to the buffer object device structure.
141 * @buffer_start: The virtual user-space start address of ttm_bo_type_user
143 * @type: The bo type.
144 * @destroy: Destruction function. If NULL, kfree is used.
145 * @num_pages: Actual number of pages.
146 * @addr_space_offset: Address space offset.
147 * @acc_size: Accounted size for this object.
148 * @kref: Reference count of this buffer object. When this refcount reaches
149 * zero, the object is put on the delayed delete list.
150 * @list_kref: List reference count of this buffer object. This member is
151 * used to avoid destruction while the buffer object is still on a list.
152 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
153 * keeps one refcount. When this refcount reaches zero,
154 * the object is destroyed.
155 * @event_queue: Queue for processes waiting on buffer object status change.
156 * @lock: spinlock protecting mostly synchronization members.
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
;
218 * Members protected by the bo::reserved lock.
221 struct ttm_mem_reg mem
;
222 struct file
*persistant_swap_storage
;
227 * Members protected by the bo::reserved lock only when written to.
230 atomic_t cpu_writers
;
233 * Members protected by the bdev::lru_lock.
236 struct list_head lru
;
237 struct list_head ddestroy
;
238 struct list_head swap
;
243 * Members protected by the bdev::lru_lock
244 * only when written to.
251 * Members protected by the bo::lock
256 unsigned long priv_flags
;
259 * Members protected by the bdev::vm_lock
262 struct rb_node vm_rb
;
263 struct drm_mm_node
*vm_node
;
267 * Special members that are protected by the reserve lock
268 * and the bo::lock when written to. Can be read with
269 * either of these locks held.
272 unsigned long offset
;
273 uint32_t cur_placement
;
277 * struct ttm_bo_kmap_obj
279 * @virtual: The current kernel virtual address.
280 * @page: The page when kmap'ing a single page.
281 * @bo_kmap_type: Type of bo_kmap.
283 * Object describing a kernel mapping. Since a TTM bo may be located
284 * in various memory types with various caching policies, the
285 * mapping can either be an ioremap, a vmap, a kmap or part of a
289 #define TTM_BO_MAP_IOMEM_MASK 0x80
290 struct ttm_bo_kmap_obj
{
294 ttm_bo_map_iomap
= 1 | TTM_BO_MAP_IOMEM_MASK
,
297 ttm_bo_map_premapped
= 4 | TTM_BO_MAP_IOMEM_MASK
,
299 struct ttm_buffer_object
*bo
;
303 * ttm_bo_reference - reference a struct ttm_buffer_object
305 * @bo: The buffer object.
307 * Returns a refcounted pointer to a buffer object.
310 static inline struct ttm_buffer_object
*
311 ttm_bo_reference(struct ttm_buffer_object
*bo
)
318 * ttm_bo_wait - wait for buffer idle.
320 * @bo: The buffer object.
321 * @interruptible: Use interruptible wait.
322 * @no_wait: Return immediately if buffer is busy.
324 * This function must be called with the bo::mutex held, and makes
325 * sure any previous rendering to the buffer is completed.
326 * Note: It might be necessary to block validations before the
327 * wait by reserving the buffer.
328 * Returns -EBUSY if no_wait is true and the buffer is busy.
329 * Returns -ERESTARTSYS if interrupted by a signal.
331 extern int ttm_bo_wait(struct ttm_buffer_object
*bo
, bool lazy
,
332 bool interruptible
, bool no_wait
);
336 * @bo: The buffer object.
337 * @placement: Proposed placement for the buffer object.
338 * @interruptible: Sleep interruptible if sleeping.
339 * @no_wait_reserve: Return immediately if other buffers are busy.
340 * @no_wait_gpu: Return immediately if the GPU is busy.
342 * Changes placement and caching policy of the buffer object
343 * according proposed placement.
345 * -EINVAL on invalid proposed placement.
346 * -ENOMEM on out-of-memory condition.
347 * -EBUSY if no_wait is true and buffer busy.
348 * -ERESTARTSYS if interrupted by a signal.
350 extern int ttm_bo_validate(struct ttm_buffer_object
*bo
,
351 struct ttm_placement
*placement
,
352 bool interruptible
, bool no_wait_reserve
,
358 * @bo: The buffer object.
360 * Unreference and clear a pointer to a buffer object.
362 extern void ttm_bo_unref(struct ttm_buffer_object
**bo
);
365 * ttm_bo_lock_delayed_workqueue
367 * Prevent the delayed workqueue from running.
369 * True if the workqueue was queued at the time
371 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device
*bdev
);
374 * ttm_bo_unlock_delayed_workqueue
376 * Allows the delayed workqueue to run.
378 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device
*bdev
,
382 * ttm_bo_synccpu_write_grab
384 * @bo: The buffer object:
385 * @no_wait: Return immediately if buffer is busy.
387 * Synchronizes a buffer object for CPU RW access. This means
388 * blocking command submission that affects the buffer and
389 * waiting for buffer idle. This lock is recursive.
391 * -EBUSY if the buffer is busy and no_wait is true.
392 * -ERESTARTSYS if interrupted by a signal.
396 ttm_bo_synccpu_write_grab(struct ttm_buffer_object
*bo
, bool no_wait
);
398 * ttm_bo_synccpu_write_release:
400 * @bo : The buffer object.
402 * Releases a synccpu lock.
404 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object
*bo
);
409 * @bdev: Pointer to a ttm_bo_device struct.
410 * @bo: Pointer to a ttm_buffer_object to be initialized.
411 * @size: Requested size of buffer object.
412 * @type: Requested type of buffer object.
413 * @flags: Initial placement flags.
414 * @page_alignment: Data alignment in pages.
415 * @buffer_start: Virtual address of user space data backing a
416 * user buffer object.
417 * @interruptible: If needing to sleep to wait for GPU resources,
418 * sleep interruptible.
419 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
420 * pinned in physical memory. If this behaviour is not desired, this member
421 * holds a pointer to a persistant shmem object. Typically, this would
422 * point to the shmem object backing a GEM object if TTM is used to back a
423 * GEM user interface.
424 * @acc_size: Accounted size for this object.
425 * @destroy: Destroy function. Use NULL for kfree().
427 * This function initializes a pre-allocated struct ttm_buffer_object.
428 * As this object may be part of a larger structure, this function,
429 * together with the @destroy function,
430 * enables driver-specific objects derived from a ttm_buffer_object.
431 * On successful return, the object kref and list_kref are set to 1.
433 * -ENOMEM: Out of memory.
434 * -EINVAL: Invalid placement flags.
435 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
438 extern int ttm_bo_init(struct ttm_bo_device
*bdev
,
439 struct ttm_buffer_object
*bo
,
441 enum ttm_bo_type type
,
442 struct ttm_placement
*placement
,
443 uint32_t page_alignment
,
444 unsigned long buffer_start
,
446 struct file
*persistant_swap_storage
,
448 void (*destroy
) (struct ttm_buffer_object
*));
450 * ttm_bo_synccpu_object_init
452 * @bdev: Pointer to a ttm_bo_device struct.
453 * @bo: Pointer to a ttm_buffer_object to be initialized.
454 * @size: Requested size of buffer object.
455 * @type: Requested type of buffer object.
456 * @flags: Initial placement flags.
457 * @page_alignment: Data alignment in pages.
458 * @buffer_start: Virtual address of user space data backing a
459 * user buffer object.
460 * @interruptible: If needing to sleep while waiting for GPU resources,
461 * sleep interruptible.
462 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
463 * pinned in physical memory. If this behaviour is not desired, this member
464 * holds a pointer to a persistant shmem object. Typically, this would
465 * point to the shmem object backing a GEM object if TTM is used to back a
466 * GEM user interface.
467 * @p_bo: On successful completion *p_bo points to the created object.
469 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
470 * on that object. The destroy function is set to kfree().
472 * -ENOMEM: Out of memory.
473 * -EINVAL: Invalid placement flags.
474 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
477 extern int ttm_bo_create(struct ttm_bo_device
*bdev
,
479 enum ttm_bo_type type
,
480 struct ttm_placement
*placement
,
481 uint32_t page_alignment
,
482 unsigned long buffer_start
,
484 struct file
*persistant_swap_storage
,
485 struct ttm_buffer_object
**p_bo
);
488 * ttm_bo_check_placement
490 * @bo: the buffer object.
491 * @placement: placements
493 * Performs minimal validity checking on an intended change of
496 * -EINVAL: Intended change is invalid or not allowed.
498 extern int ttm_bo_check_placement(struct ttm_buffer_object
*bo
,
499 struct ttm_placement
*placement
);
504 * @bdev: Pointer to a ttm_bo_device struct.
505 * @mem_type: The memory type.
506 * @p_size: size managed area in pages.
508 * Initialize a manager for a given memory type.
509 * Note: if part of driver firstopen, it must be protected from a
510 * potentially racing lastclose.
512 * -EINVAL: invalid size or memory type.
513 * -ENOMEM: Not enough memory.
514 * May also return driver-specified errors.
517 extern int ttm_bo_init_mm(struct ttm_bo_device
*bdev
, unsigned type
,
518 unsigned long p_size
);
522 * @bdev: Pointer to a ttm_bo_device struct.
523 * @mem_type: The memory type.
525 * Take down a manager for a given memory type after first walking
526 * the LRU list to evict any buffers left alive.
528 * Normally, this function is part of lastclose() or unload(), and at that
529 * point there shouldn't be any buffers left created by user-space, since
530 * there should've been removed by the file descriptor release() method.
531 * However, before this function is run, make sure to signal all sync objects,
532 * and verify that the delayed delete queue is empty. The driver must also
533 * make sure that there are no NO_EVICT buffers present in this memory type
534 * when the call is made.
536 * If this function is part of a VT switch, the caller must make sure that
537 * there are no appications currently validating buffers before this
538 * function is called. The caller can do that by first taking the
539 * struct ttm_bo_device::ttm_lock in write mode.
542 * -EINVAL: invalid or uninitialized memory type.
543 * -EBUSY: There are still buffers left in this memory type.
546 extern int ttm_bo_clean_mm(struct ttm_bo_device
*bdev
, unsigned mem_type
);
551 * @bdev: Pointer to a ttm_bo_device struct.
552 * @mem_type: The memory type.
554 * Evicts all buffers on the lru list of the memory type.
555 * This is normally part of a VT switch or an
556 * out-of-memory-space-due-to-fragmentation handler.
557 * The caller must make sure that there are no other processes
558 * currently validating buffers, and can do that by taking the
559 * struct ttm_bo_device::ttm_lock in write mode.
562 * -EINVAL: Invalid or uninitialized memory type.
563 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
567 extern int ttm_bo_evict_mm(struct ttm_bo_device
*bdev
, unsigned mem_type
);
570 * ttm_kmap_obj_virtual
572 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
573 * @is_iomem: Pointer to an integer that on return indicates 1 if the
574 * virtual map is io memory, 0 if normal memory.
576 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
577 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
578 * that should strictly be accessed by the iowriteXX() and similar functions.
581 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj
*map
,
584 *is_iomem
= !!(map
->bo_kmap_type
& TTM_BO_MAP_IOMEM_MASK
);
591 * @bo: The buffer object.
592 * @start_page: The first page to map.
593 * @num_pages: Number of pages to map.
594 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
596 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
597 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
598 * used to obtain a virtual address to the data.
601 * -ENOMEM: Out of memory.
602 * -EINVAL: Invalid range.
605 extern int ttm_bo_kmap(struct ttm_buffer_object
*bo
, unsigned long start_page
,
606 unsigned long num_pages
, struct ttm_bo_kmap_obj
*map
);
611 * @map: Object describing the map to unmap.
613 * Unmaps a kernel map set up by ttm_bo_kmap.
616 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj
*map
);
622 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
624 * @vma: vma as input from the fbdev mmap method.
625 * @bo: The bo backing the address space. The address space will
626 * have the same size as the bo, and start at offset 0.
628 * This function is intended to be called by the fbdev mmap method
629 * if the fbdev address space is to be backed by a bo.
632 extern int ttm_fbdev_mmap(struct vm_area_struct
*vma
,
633 struct ttm_buffer_object
*bo
);
636 * ttm_bo_mmap - mmap out of the ttm device address space.
638 * @filp: filp as input from the mmap method.
639 * @vma: vma as input from the mmap method.
640 * @bdev: Pointer to the ttm_bo_device with the address space manager.
642 * This function is intended to be called by the device mmap method.
643 * if the device address space is to be backed by the bo manager.
646 extern int ttm_bo_mmap(struct file
*filp
, struct vm_area_struct
*vma
,
647 struct ttm_bo_device
*bdev
);
652 * @bdev: Pointer to the struct ttm_bo_device.
653 * @filp: Pointer to the struct file attempting to read / write.
654 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
655 * @rbuf: User-space pointer to address of buffer to read into.
657 * @count: Number of bytes to read / write.
658 * @f_pos: Pointer to current file position.
659 * @write: 1 for read, 0 for write.
661 * This function implements read / write into ttm buffer objects, and is
663 * be called from the fops::read and fops::write method.
665 * See man (2) write, man(2) read. In particular,
666 * the function may return -ERESTARTSYS if
667 * interrupted by a signal.
670 extern ssize_t
ttm_bo_io(struct ttm_bo_device
*bdev
, struct file
*filp
,
671 const char __user
*wbuf
, char __user
*rbuf
,
672 size_t count
, loff_t
*f_pos
, bool write
);
674 extern void ttm_bo_swapout_all(struct ttm_bo_device
*bdev
);