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
9 * without limitation the rights to use, copy, modify, merge, publish,
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_
34 #include <drm/drm_hashtab.h>
35 #include <drm/drm_vma_manager.h>
36 #include <linux/kref.h>
37 #include <linux/list.h>
38 #include <linux/wait.h>
39 #include <linux/mutex.h>
41 #include <linux/bitmap.h>
42 #include <linux/reservation.h>
51 * @fpfn: first valid page frame number to put the object
52 * @lpfn: last valid page frame number to put the object
53 * @flags: memory domain and caching flags for the object
55 * Structure indicating a possible place to put an object.
64 * struct ttm_placement
66 * @num_placement: number of preferred placements
67 * @placement: preferred placements
68 * @num_busy_placement: number of preferred placements when need to evict buffer
69 * @busy_placement: preferred placements when need to evict buffer
71 * Structure indicating the placement you request for an object.
73 struct ttm_placement
{
74 unsigned num_placement
;
75 const struct ttm_place
*placement
;
76 unsigned num_busy_placement
;
77 const struct ttm_place
*busy_placement
;
81 * struct ttm_bus_placement
83 * @addr: mapped virtual address
84 * @base: bus base address
85 * @is_iomem: is this io memory ?
87 * @offset: offset from the base address
88 * @io_reserved_vm: The VM system has a refcount in @io_reserved_count
89 * @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
91 * Structure indicating the bus placement of an object.
93 struct ttm_bus_placement
{
100 uint64_t io_reserved_count
;
107 * @mm_node: Memory manager node.
108 * @size: Requested size of memory region.
109 * @num_pages: Actual size of memory region in pages.
110 * @page_alignment: Page alignment.
111 * @placement: Placement flags.
112 * @bus: Placement on io bus accessible to the CPU
114 * Structure indicating the placement and space resources used by a
122 unsigned long num_pages
;
123 uint32_t page_alignment
;
126 struct ttm_bus_placement bus
;
132 * @ttm_bo_type_device: These are 'normal' buffers that can
133 * be mmapped by user space. Each of these bos occupy a slot in the
134 * device address space, that can be used for normal vm operations.
136 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
137 * but they cannot be accessed from user-space. For kernel-only use.
139 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
152 * struct ttm_buffer_object
154 * @bdev: Pointer to the buffer object device structure.
155 * @type: The bo type.
156 * @destroy: Destruction function. If NULL, kfree is used.
157 * @num_pages: Actual number of pages.
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 * @mem: structure describing current placement.
167 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
168 * pinned in physical memory. If this behaviour is not desired, this member
169 * holds a pointer to a persistent shmem object.
170 * @ttm: TTM structure holding system pages.
171 * @evicted: Whether the object was evicted without user-space knowing.
172 * @cpu_writes: For synchronization. Number of cpu writers.
173 * @lru: List head for the lru list.
174 * @ddestroy: List head for the delayed destroy list.
175 * @swap: List head for swap LRU list.
176 * @priv_flags: Flags describing buffer object internal state.
177 * @vma_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.
181 * @wu_mutex: Wait unreserved mutex.
183 * Base class for TTM buffer object, that deals with data placement and CPU
184 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
185 * the driver can usually use the placement offset @offset directly as the
186 * GPU virtual address. For drivers implementing multiple
187 * GPU memory manager contexts, the driver should manage the address space
188 * in these contexts separately and use these objects to get the correct
189 * placement and caching for these GPU maps. This makes it possible to use
190 * these objects for even quite elaborate memory management schemes.
191 * The destroy member, the API visibility of this object makes it possible
192 * to derive driver specific types.
195 struct ttm_buffer_object
{
197 * Members constant at init.
200 struct ttm_bo_global
*glob
;
201 struct ttm_bo_device
*bdev
;
202 enum ttm_bo_type type
;
203 void (*destroy
) (struct ttm_buffer_object
*);
204 unsigned long num_pages
;
208 * Members not needing protection.
212 struct kref list_kref
;
215 * Members protected by the bo::resv::reserved lock.
218 struct ttm_mem_reg mem
;
219 struct file
*persistent_swap_storage
;
224 * Members protected by the bo::reserved lock only when written to.
227 atomic_t cpu_writers
;
230 * Members protected by the bdev::lru_lock.
233 struct list_head lru
;
234 struct list_head ddestroy
;
235 struct list_head swap
;
236 struct list_head io_reserve_lru
;
239 * Members protected by a bo reservation.
242 unsigned long priv_flags
;
244 struct drm_vma_offset_node vma_node
;
247 * Special members that are protected by the reserve lock
248 * and the bo::lock when written to. Can be read with
249 * either of these locks held.
252 uint64_t offset
; /* GPU address space is independent of CPU word size */
253 uint32_t cur_placement
;
257 struct reservation_object
*resv
;
258 struct reservation_object ttm_resv
;
259 struct mutex wu_mutex
;
263 * struct ttm_bo_kmap_obj
265 * @virtual: The current kernel virtual address.
266 * @page: The page when kmap'ing a single page.
267 * @bo_kmap_type: Type of bo_kmap.
269 * Object describing a kernel mapping. Since a TTM bo may be located
270 * in various memory types with various caching policies, the
271 * mapping can either be an ioremap, a vmap, a kmap or part of a
275 #define TTM_BO_MAP_IOMEM_MASK 0x80
276 struct ttm_bo_kmap_obj
{
280 ttm_bo_map_iomap
= 1 | TTM_BO_MAP_IOMEM_MASK
,
283 ttm_bo_map_premapped
= 4 | TTM_BO_MAP_IOMEM_MASK
,
285 struct ttm_buffer_object
*bo
;
289 * ttm_bo_reference - reference a struct ttm_buffer_object
291 * @bo: The buffer object.
293 * Returns a refcounted pointer to a buffer object.
296 static inline struct ttm_buffer_object
*
297 ttm_bo_reference(struct ttm_buffer_object
*bo
)
304 * ttm_bo_wait - wait for buffer idle.
306 * @bo: The buffer object.
307 * @interruptible: Use interruptible wait.
308 * @no_wait: Return immediately if buffer is busy.
310 * This function must be called with the bo::mutex held, and makes
311 * sure any previous rendering to the buffer is completed.
312 * Note: It might be necessary to block validations before the
313 * wait by reserving the buffer.
314 * Returns -EBUSY if no_wait is true and the buffer is busy.
315 * Returns -ERESTARTSYS if interrupted by a signal.
317 extern int ttm_bo_wait(struct ttm_buffer_object
*bo
, bool lazy
,
318 bool interruptible
, bool no_wait
);
322 * @bo: The buffer object.
323 * @placement: Proposed placement for the buffer object.
324 * @interruptible: Sleep interruptible if sleeping.
325 * @no_wait_gpu: Return immediately if the GPU is busy.
327 * Changes placement and caching policy of the buffer object
328 * according proposed placement.
330 * -EINVAL on invalid proposed placement.
331 * -ENOMEM on out-of-memory condition.
332 * -EBUSY if no_wait is true and buffer busy.
333 * -ERESTARTSYS if interrupted by a signal.
335 extern int ttm_bo_validate(struct ttm_buffer_object
*bo
,
336 struct ttm_placement
*placement
,
343 * @bo: The buffer object.
345 * Unreference and clear a pointer to a buffer object.
347 extern void ttm_bo_unref(struct ttm_buffer_object
**bo
);
351 * ttm_bo_list_ref_sub
353 * @bo: The buffer object.
354 * @count: The number of references with which to decrease @bo::list_kref;
355 * @never_free: The refcount should not reach zero with this operation.
357 * Release @count lru list references to this buffer object.
359 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object
*bo
, int count
,
365 * @bo: The buffer object.
367 * Add this bo to the relevant mem type lru and, if it's backed by
368 * system pages (ttms) to the swap list.
369 * This function must be called with struct ttm_bo_global::lru_lock held, and
370 * is typically called immediately prior to unreserving a bo.
372 extern void ttm_bo_add_to_lru(struct ttm_buffer_object
*bo
);
375 * ttm_bo_del_from_lru
377 * @bo: The buffer object.
379 * Remove this bo from all lru lists used to lookup and reserve an object.
380 * This function must be called with struct ttm_bo_global::lru_lock held,
381 * and is usually called just immediately after the bo has been reserved to
382 * avoid recursive reservation from lru lists.
384 extern int ttm_bo_del_from_lru(struct ttm_buffer_object
*bo
);
387 * ttm_bo_move_to_lru_tail
389 * @bo: The buffer object.
391 * Move this BO to the tail of all lru lists used to lookup and reserve an
392 * object. This function must be called with struct ttm_bo_global::lru_lock
393 * held, and is used to make a BO less likely to be considered for eviction.
395 extern void ttm_bo_move_to_lru_tail(struct ttm_buffer_object
*bo
);
398 * ttm_bo_lock_delayed_workqueue
400 * Prevent the delayed workqueue from running.
402 * True if the workqueue was queued at the time
404 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device
*bdev
);
407 * ttm_bo_unlock_delayed_workqueue
409 * Allows the delayed workqueue to run.
411 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device
*bdev
,
415 * ttm_bo_synccpu_write_grab
417 * @bo: The buffer object:
418 * @no_wait: Return immediately if buffer is busy.
420 * Synchronizes a buffer object for CPU RW access. This means
421 * command submission that affects the buffer will return -EBUSY
422 * until ttm_bo_synccpu_write_release is called.
425 * -EBUSY if the buffer is busy and no_wait is true.
426 * -ERESTARTSYS if interrupted by a signal.
429 ttm_bo_synccpu_write_grab(struct ttm_buffer_object
*bo
, bool no_wait
);
432 * ttm_bo_synccpu_write_release:
434 * @bo : The buffer object.
436 * Releases a synccpu lock.
438 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object
*bo
);
443 * @bdev: Pointer to a ttm_bo_device struct.
444 * @bo_size: size of the buffer object in byte.
445 * @struct_size: size of the structure holding buffer object datas
447 * Returns size to account for a buffer object
449 size_t ttm_bo_acc_size(struct ttm_bo_device
*bdev
,
450 unsigned long bo_size
,
451 unsigned struct_size
);
452 size_t ttm_bo_dma_acc_size(struct ttm_bo_device
*bdev
,
453 unsigned long bo_size
,
454 unsigned struct_size
);
459 * @bdev: Pointer to a ttm_bo_device struct.
460 * @bo: Pointer to a ttm_buffer_object to be initialized.
461 * @size: Requested size of buffer object.
462 * @type: Requested type of buffer object.
463 * @flags: Initial placement flags.
464 * @page_alignment: Data alignment in pages.
465 * @interruptible: If needing to sleep to wait for GPU resources,
466 * sleep interruptible.
467 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
468 * pinned in physical memory. If this behaviour is not desired, this member
469 * holds a pointer to a persistent shmem object. Typically, this would
470 * point to the shmem object backing a GEM object if TTM is used to back a
471 * GEM user interface.
472 * @acc_size: Accounted size for this object.
473 * @resv: Pointer to a reservation_object, or NULL to let ttm allocate one.
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 file
*persistent_swap_storage
,
501 struct reservation_object
*resv
,
502 void (*destroy
) (struct ttm_buffer_object
*));
507 * @bdev: Pointer to a ttm_bo_device struct.
508 * @size: Requested size of buffer object.
509 * @type: Requested type of buffer object.
510 * @placement: Initial placement.
511 * @page_alignment: Data alignment in pages.
512 * @interruptible: If needing to sleep while waiting for GPU resources,
513 * sleep interruptible.
514 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
515 * pinned in physical memory. If this behaviour is not desired, this member
516 * holds a pointer to a persistent shmem object. Typically, this would
517 * point to the shmem object backing a GEM object if TTM is used to back a
518 * GEM user interface.
519 * @p_bo: On successful completion *p_bo points to the created object.
521 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
522 * on that object. The destroy function is set to kfree().
524 * -ENOMEM: Out of memory.
525 * -EINVAL: Invalid placement flags.
526 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
529 extern int ttm_bo_create(struct ttm_bo_device
*bdev
,
531 enum ttm_bo_type type
,
532 struct ttm_placement
*placement
,
533 uint32_t page_alignment
,
535 struct file
*persistent_swap_storage
,
536 struct ttm_buffer_object
**p_bo
);
541 * @bdev: Pointer to a ttm_bo_device struct.
542 * @mem_type: The memory type.
543 * @p_size: size managed area in pages.
545 * Initialize a manager for a given memory type.
546 * Note: if part of driver firstopen, it must be protected from a
547 * potentially racing lastclose.
549 * -EINVAL: invalid size or memory type.
550 * -ENOMEM: Not enough memory.
551 * May also return driver-specified errors.
554 extern int ttm_bo_init_mm(struct ttm_bo_device
*bdev
, unsigned type
,
555 unsigned long p_size
);
559 * @bdev: Pointer to a ttm_bo_device struct.
560 * @mem_type: The memory type.
562 * Take down a manager for a given memory type after first walking
563 * the LRU list to evict any buffers left alive.
565 * Normally, this function is part of lastclose() or unload(), and at that
566 * point there shouldn't be any buffers left created by user-space, since
567 * there should've been removed by the file descriptor release() method.
568 * However, before this function is run, make sure to signal all sync objects,
569 * and verify that the delayed delete queue is empty. The driver must also
570 * make sure that there are no NO_EVICT buffers present in this memory type
571 * when the call is made.
573 * If this function is part of a VT switch, the caller must make sure that
574 * there are no appications currently validating buffers before this
575 * function is called. The caller can do that by first taking the
576 * struct ttm_bo_device::ttm_lock in write mode.
579 * -EINVAL: invalid or uninitialized memory type.
580 * -EBUSY: There are still buffers left in this memory type.
583 extern int ttm_bo_clean_mm(struct ttm_bo_device
*bdev
, unsigned mem_type
);
588 * @bdev: Pointer to a ttm_bo_device struct.
589 * @mem_type: The memory type.
591 * Evicts all buffers on the lru list of the memory type.
592 * This is normally part of a VT switch or an
593 * out-of-memory-space-due-to-fragmentation handler.
594 * The caller must make sure that there are no other processes
595 * currently validating buffers, and can do that by taking the
596 * struct ttm_bo_device::ttm_lock in write mode.
599 * -EINVAL: Invalid or uninitialized memory type.
600 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
604 extern int ttm_bo_evict_mm(struct ttm_bo_device
*bdev
, unsigned mem_type
);
607 * ttm_kmap_obj_virtual
609 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
610 * @is_iomem: Pointer to an integer that on return indicates 1 if the
611 * virtual map is io memory, 0 if normal memory.
613 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
614 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
615 * that should strictly be accessed by the iowriteXX() and similar functions.
618 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj
*map
,
621 *is_iomem
= !!(map
->bo_kmap_type
& TTM_BO_MAP_IOMEM_MASK
);
628 * @bo: The buffer object.
629 * @start_page: The first page to map.
630 * @num_pages: Number of pages to map.
631 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
633 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
634 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
635 * used to obtain a virtual address to the data.
638 * -ENOMEM: Out of memory.
639 * -EINVAL: Invalid range.
642 extern int ttm_bo_kmap(struct ttm_buffer_object
*bo
, unsigned long start_page
,
643 unsigned long num_pages
, struct ttm_bo_kmap_obj
*map
);
648 * @map: Object describing the map to unmap.
650 * Unmaps a kernel map set up by ttm_bo_kmap.
653 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj
*map
);
656 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
658 * @vma: vma as input from the fbdev mmap method.
659 * @bo: The bo backing the address space. The address space will
660 * have the same size as the bo, and start at offset 0.
662 * This function is intended to be called by the fbdev mmap method
663 * if the fbdev address space is to be backed by a bo.
666 extern int ttm_fbdev_mmap(struct vm_area_struct
*vma
,
667 struct ttm_buffer_object
*bo
);
670 * ttm_bo_mmap - mmap out of the ttm device address space.
672 * @filp: filp as input from the mmap method.
673 * @vma: vma as input from the mmap method.
674 * @bdev: Pointer to the ttm_bo_device with the address space manager.
676 * This function is intended to be called by the device mmap method.
677 * if the device address space is to be backed by the bo manager.
680 extern int ttm_bo_mmap(struct file
*filp
, struct vm_area_struct
*vma
,
681 struct ttm_bo_device
*bdev
);
686 * @bdev: Pointer to the struct ttm_bo_device.
687 * @filp: Pointer to the struct file attempting to read / write.
688 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
689 * @rbuf: User-space pointer to address of buffer to read into.
691 * @count: Number of bytes to read / write.
692 * @f_pos: Pointer to current file position.
693 * @write: 1 for read, 0 for write.
695 * This function implements read / write into ttm buffer objects, and is
697 * be called from the fops::read and fops::write method.
699 * See man (2) write, man(2) read. In particular,
700 * the function may return -ERESTARTSYS if
701 * interrupted by a signal.
704 extern ssize_t
ttm_bo_io(struct ttm_bo_device
*bdev
, struct file
*filp
,
705 const char __user
*wbuf
, char __user
*rbuf
,
706 size_t count
, loff_t
*f_pos
, bool write
);
708 extern void ttm_bo_swapout_all(struct ttm_bo_device
*bdev
);
709 extern int ttm_bo_wait_unreserved(struct ttm_buffer_object
*bo
);