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
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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/drm_gem.h>
35 #include <drm/drm_hashtab.h>
36 #include <drm/drm_vma_manager.h>
37 #include <linux/kref.h>
38 #include <linux/list.h>
39 #include <linux/wait.h>
40 #include <linux/mutex.h>
42 #include <linux/bitmap.h>
43 #include <linux/dma-resv.h>
55 struct ttm_lru_bulk_move
;
58 * struct ttm_bus_placement
60 * @addr: mapped virtual address
61 * @base: bus base address
62 * @is_iomem: is this io memory ?
64 * @offset: offset from the base address
65 * @io_reserved_vm: The VM system has a refcount in @io_reserved_count
66 * @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
68 * Structure indicating the bus placement of an object.
70 struct ttm_bus_placement
{
77 uint64_t io_reserved_count
;
84 * @mm_node: Memory manager node.
85 * @size: Requested size of memory region.
86 * @num_pages: Actual size of memory region in pages.
87 * @page_alignment: Page alignment.
88 * @placement: Placement flags.
89 * @bus: Placement on io bus accessible to the CPU
91 * Structure indicating the placement and space resources used by a
99 unsigned long num_pages
;
100 uint32_t page_alignment
;
103 struct ttm_bus_placement bus
;
109 * @ttm_bo_type_device: These are 'normal' buffers that can
110 * be mmapped by user space. Each of these bos occupy a slot in the
111 * device address space, that can be used for normal vm operations.
113 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
114 * but they cannot be accessed from user-space. For kernel-only use.
116 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
129 * struct ttm_buffer_object
131 * @base: drm_gem_object superclass data.
132 * @bdev: Pointer to the buffer object device structure.
133 * @type: The bo type.
134 * @destroy: Destruction function. If NULL, kfree is used.
135 * @num_pages: Actual number of pages.
136 * @acc_size: Accounted size for this object.
137 * @kref: Reference count of this buffer object. When this refcount reaches
138 * zero, the object is put on the delayed delete list.
139 * @list_kref: List reference count of this buffer object. This member is
140 * used to avoid destruction while the buffer object is still on a list.
141 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
142 * keeps one refcount. When this refcount reaches zero,
143 * the object is destroyed.
144 * @mem: structure describing current placement.
145 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
146 * pinned in physical memory. If this behaviour is not desired, this member
147 * holds a pointer to a persistent shmem object.
148 * @ttm: TTM structure holding system pages.
149 * @evicted: Whether the object was evicted without user-space knowing.
150 * @lru: List head for the lru list.
151 * @ddestroy: List head for the delayed destroy list.
152 * @swap: List head for swap LRU list.
153 * @moving: Fence set when BO is moving
154 * @offset: The current GPU offset, which can have different meanings
155 * depending on the memory type. For SYSTEM type memory, it should be 0.
156 * @cur_placement: Hint of current placement.
158 * Base class for TTM buffer object, that deals with data placement and CPU
159 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
160 * the driver can usually use the placement offset @offset directly as the
161 * GPU virtual address. For drivers implementing multiple
162 * GPU memory manager contexts, the driver should manage the address space
163 * in these contexts separately and use these objects to get the correct
164 * placement and caching for these GPU maps. This makes it possible to use
165 * these objects for even quite elaborate memory management schemes.
166 * The destroy member, the API visibility of this object makes it possible
167 * to derive driver specific types.
170 struct ttm_buffer_object
{
171 struct drm_gem_object base
;
174 * Members constant at init.
177 struct ttm_bo_device
*bdev
;
178 enum ttm_bo_type type
;
179 void (*destroy
) (struct ttm_buffer_object
*);
180 unsigned long num_pages
;
184 * Members not needing protection.
188 struct kref list_kref
;
191 * Members protected by the bo::resv::reserved lock.
194 struct ttm_mem_reg mem
;
195 struct file
*persistent_swap_storage
;
200 * Members protected by the bdev::lru_lock.
203 struct list_head lru
;
204 struct list_head ddestroy
;
205 struct list_head swap
;
206 struct list_head io_reserve_lru
;
209 * Members protected by a bo reservation.
212 struct dma_fence
*moving
;
216 * Special members that are protected by the reserve lock
217 * and the bo::lock when written to. Can be read with
218 * either of these locks held.
221 uint64_t offset
; /* GPU address space is independent of CPU word size */
227 * struct ttm_bo_kmap_obj
229 * @virtual: The current kernel virtual address.
230 * @page: The page when kmap'ing a single page.
231 * @bo_kmap_type: Type of bo_kmap.
233 * Object describing a kernel mapping. Since a TTM bo may be located
234 * in various memory types with various caching policies, the
235 * mapping can either be an ioremap, a vmap, a kmap or part of a
239 #define TTM_BO_MAP_IOMEM_MASK 0x80
240 struct ttm_bo_kmap_obj
{
244 ttm_bo_map_iomap
= 1 | TTM_BO_MAP_IOMEM_MASK
,
247 ttm_bo_map_premapped
= 4 | TTM_BO_MAP_IOMEM_MASK
,
249 struct ttm_buffer_object
*bo
;
253 * struct ttm_operation_ctx
255 * @interruptible: Sleep interruptible if sleeping.
256 * @no_wait_gpu: Return immediately if the GPU is busy.
257 * @resv: Reservation object to allow reserved evictions with.
258 * @flags: Including the following flags
260 * Context for TTM operations like changing buffer placement or general memory
263 struct ttm_operation_ctx
{
266 struct dma_resv
*resv
;
267 uint64_t bytes_moved
;
271 /* Allow eviction of reserved BOs */
272 #define TTM_OPT_FLAG_ALLOW_RES_EVICT 0x1
273 /* when serving page fault or suspend, allow alloc anyway */
274 #define TTM_OPT_FLAG_FORCE_ALLOC 0x2
277 * ttm_bo_get - reference a struct ttm_buffer_object
279 * @bo: The buffer object.
281 static inline void ttm_bo_get(struct ttm_buffer_object
*bo
)
287 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
288 * its refcount has already reached zero.
289 * @bo: The buffer object.
291 * Used to reference a TTM buffer object in lookups where the object is removed
292 * from the lookup structure during the destructor and for RCU lookups.
294 * Returns: @bo if the referencing was successful, NULL otherwise.
296 static inline __must_check
struct ttm_buffer_object
*
297 ttm_bo_get_unless_zero(struct ttm_buffer_object
*bo
)
299 if (!kref_get_unless_zero(&bo
->kref
))
305 * ttm_bo_wait - wait for buffer idle.
307 * @bo: The buffer object.
308 * @interruptible: Use interruptible wait.
309 * @no_wait: Return immediately if buffer is busy.
311 * This function must be called with the bo::mutex held, and makes
312 * sure any previous rendering to the buffer is completed.
313 * Note: It might be necessary to block validations before the
314 * wait by reserving the buffer.
315 * Returns -EBUSY if no_wait is true and the buffer is busy.
316 * Returns -ERESTARTSYS if interrupted by a signal.
318 int ttm_bo_wait(struct ttm_buffer_object
*bo
, bool interruptible
, bool no_wait
);
321 * ttm_bo_mem_compat - Check if proposed placement is compatible with a bo
323 * @placement: Return immediately if buffer is busy.
324 * @mem: The struct ttm_mem_reg indicating the region where the bo resides
325 * @new_flags: Describes compatible placement found
327 * Returns true if the placement is compatible
329 bool ttm_bo_mem_compat(struct ttm_placement
*placement
, struct ttm_mem_reg
*mem
,
330 uint32_t *new_flags
);
335 * @bo: The buffer object.
336 * @placement: Proposed placement for the buffer object.
337 * @ctx: validation parameters.
339 * Changes placement and caching policy of the buffer object
340 * according proposed placement.
342 * -EINVAL on invalid proposed placement.
343 * -ENOMEM on out-of-memory condition.
344 * -EBUSY if no_wait is true and buffer busy.
345 * -ERESTARTSYS if interrupted by a signal.
347 int ttm_bo_validate(struct ttm_buffer_object
*bo
,
348 struct ttm_placement
*placement
,
349 struct ttm_operation_ctx
*ctx
);
354 * @bo: The buffer object.
356 * Unreference a buffer object.
358 void ttm_bo_put(struct ttm_buffer_object
*bo
);
361 * ttm_bo_move_to_lru_tail
363 * @bo: The buffer object.
364 * @bulk: optional bulk move structure to remember BO positions
366 * Move this BO to the tail of all lru lists used to lookup and reserve an
367 * object. This function must be called with struct ttm_bo_global::lru_lock
368 * held, and is used to make a BO less likely to be considered for eviction.
370 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object
*bo
,
371 struct ttm_lru_bulk_move
*bulk
);
374 * ttm_bo_bulk_move_lru_tail
376 * @bulk: bulk move structure
378 * Bulk move BOs to the LRU tail, only valid to use when driver makes sure that
379 * BO order never changes. Should be called with ttm_bo_global::lru_lock held.
381 void ttm_bo_bulk_move_lru_tail(struct ttm_lru_bulk_move
*bulk
);
384 * ttm_bo_lock_delayed_workqueue
386 * Prevent the delayed workqueue from running.
388 * True if the workqueue was queued at the time
390 int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device
*bdev
);
393 * ttm_bo_unlock_delayed_workqueue
395 * Allows the delayed workqueue to run.
397 void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device
*bdev
, int resched
);
400 * ttm_bo_eviction_valuable
402 * @bo: The buffer object to evict
403 * @place: the placement we need to make room for
405 * Check if it is valuable to evict the BO to make room for the given placement.
407 bool ttm_bo_eviction_valuable(struct ttm_buffer_object
*bo
,
408 const struct ttm_place
*place
);
413 * @bdev: Pointer to a ttm_bo_device struct.
414 * @bo_size: size of the buffer object in byte.
415 * @struct_size: size of the structure holding buffer object datas
417 * Returns size to account for a buffer object
419 size_t ttm_bo_acc_size(struct ttm_bo_device
*bdev
,
420 unsigned long bo_size
,
421 unsigned struct_size
);
422 size_t ttm_bo_dma_acc_size(struct ttm_bo_device
*bdev
,
423 unsigned long bo_size
,
424 unsigned struct_size
);
427 * ttm_bo_init_reserved
429 * @bdev: Pointer to a ttm_bo_device struct.
430 * @bo: Pointer to a ttm_buffer_object to be initialized.
431 * @size: Requested size of buffer object.
432 * @type: Requested type of buffer object.
433 * @flags: Initial placement flags.
434 * @page_alignment: Data alignment in pages.
435 * @ctx: TTM operation context for memory allocation.
436 * @acc_size: Accounted size for this object.
437 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
438 * @destroy: Destroy function. Use NULL for kfree().
440 * This function initializes a pre-allocated struct ttm_buffer_object.
441 * As this object may be part of a larger structure, this function,
442 * together with the @destroy function,
443 * enables driver-specific objects derived from a ttm_buffer_object.
445 * On successful return, the caller owns an object kref to @bo. The kref and
446 * list_kref are usually set to 1, but note that in some situations, other
447 * tasks may already be holding references to @bo as well.
448 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
449 * and it is the caller's responsibility to call ttm_bo_unreserve.
451 * If a failure occurs, the function will call the @destroy function, or
452 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
453 * illegal and will likely cause memory corruption.
456 * -ENOMEM: Out of memory.
457 * -EINVAL: Invalid placement flags.
458 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
461 int ttm_bo_init_reserved(struct ttm_bo_device
*bdev
,
462 struct ttm_buffer_object
*bo
,
464 enum ttm_bo_type type
,
465 struct ttm_placement
*placement
,
466 uint32_t page_alignment
,
467 struct ttm_operation_ctx
*ctx
,
470 struct dma_resv
*resv
,
471 void (*destroy
) (struct ttm_buffer_object
*));
476 * @bdev: Pointer to a ttm_bo_device struct.
477 * @bo: Pointer to a ttm_buffer_object to be initialized.
478 * @size: Requested size of buffer object.
479 * @type: Requested type of buffer object.
480 * @flags: Initial placement flags.
481 * @page_alignment: Data alignment in pages.
482 * @interruptible: If needing to sleep to wait for GPU resources,
483 * sleep interruptible.
484 * pinned in physical memory. If this behaviour is not desired, this member
485 * holds a pointer to a persistent shmem object. Typically, this would
486 * point to the shmem object backing a GEM object if TTM is used to back a
487 * GEM user interface.
488 * @acc_size: Accounted size for this object.
489 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
490 * @destroy: Destroy function. Use NULL for kfree().
492 * This function initializes a pre-allocated struct ttm_buffer_object.
493 * As this object may be part of a larger structure, this function,
494 * together with the @destroy function,
495 * enables driver-specific objects derived from a ttm_buffer_object.
497 * On successful return, the caller owns an object kref to @bo. The kref and
498 * list_kref are usually set to 1, but note that in some situations, other
499 * tasks may already be holding references to @bo as well.
501 * If a failure occurs, the function will call the @destroy function, or
502 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
503 * illegal and will likely cause memory corruption.
506 * -ENOMEM: Out of memory.
507 * -EINVAL: Invalid placement flags.
508 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
510 int ttm_bo_init(struct ttm_bo_device
*bdev
, struct ttm_buffer_object
*bo
,
511 unsigned long size
, enum ttm_bo_type type
,
512 struct ttm_placement
*placement
,
513 uint32_t page_alignment
, bool interrubtible
, size_t acc_size
,
514 struct sg_table
*sg
, struct dma_resv
*resv
,
515 void (*destroy
) (struct ttm_buffer_object
*));
520 * @bdev: Pointer to a ttm_bo_device struct.
521 * @size: Requested size of buffer object.
522 * @type: Requested type of buffer object.
523 * @placement: Initial placement.
524 * @page_alignment: Data alignment in pages.
525 * @interruptible: If needing to sleep while waiting for GPU resources,
526 * sleep interruptible.
527 * @p_bo: On successful completion *p_bo points to the created object.
529 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
530 * on that object. The destroy function is set to kfree().
532 * -ENOMEM: Out of memory.
533 * -EINVAL: Invalid placement flags.
534 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
536 int ttm_bo_create(struct ttm_bo_device
*bdev
, unsigned long size
,
537 enum ttm_bo_type type
, struct ttm_placement
*placement
,
538 uint32_t page_alignment
, bool interruptible
,
539 struct ttm_buffer_object
**p_bo
);
544 * @bdev: Pointer to a ttm_bo_device struct.
545 * @mem_type: The memory type.
546 * @p_size: size managed area in pages.
548 * Initialize a manager for a given memory type.
549 * Note: if part of driver firstopen, it must be protected from a
550 * potentially racing lastclose.
552 * -EINVAL: invalid size or memory type.
553 * -ENOMEM: Not enough memory.
554 * May also return driver-specified errors.
556 int ttm_bo_init_mm(struct ttm_bo_device
*bdev
, unsigned type
,
557 unsigned long p_size
);
562 * @bdev: Pointer to a ttm_bo_device struct.
563 * @mem_type: The memory type.
565 * Take down a manager for a given memory type after first walking
566 * the LRU list to evict any buffers left alive.
568 * Normally, this function is part of lastclose() or unload(), and at that
569 * point there shouldn't be any buffers left created by user-space, since
570 * there should've been removed by the file descriptor release() method.
571 * However, before this function is run, make sure to signal all sync objects,
572 * and verify that the delayed delete queue is empty. The driver must also
573 * make sure that there are no NO_EVICT buffers present in this memory type
574 * when the call is made.
576 * If this function is part of a VT switch, the caller must make sure that
577 * there are no appications currently validating buffers before this
578 * function is called. The caller can do that by first taking the
579 * struct ttm_bo_device::ttm_lock in write mode.
582 * -EINVAL: invalid or uninitialized memory type.
583 * -EBUSY: There are still buffers left in this memory type.
585 int ttm_bo_clean_mm(struct ttm_bo_device
*bdev
, unsigned mem_type
);
590 * @bdev: Pointer to a ttm_bo_device struct.
591 * @mem_type: The memory type.
593 * Evicts all buffers on the lru list of the memory type.
594 * This is normally part of a VT switch or an
595 * out-of-memory-space-due-to-fragmentation handler.
596 * The caller must make sure that there are no other processes
597 * currently validating buffers, and can do that by taking the
598 * struct ttm_bo_device::ttm_lock in write mode.
601 * -EINVAL: Invalid or uninitialized memory type.
602 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
605 int ttm_bo_evict_mm(struct ttm_bo_device
*bdev
, unsigned mem_type
);
608 * ttm_kmap_obj_virtual
610 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
611 * @is_iomem: Pointer to an integer that on return indicates 1 if the
612 * virtual map is io memory, 0 if normal memory.
614 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
615 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
616 * 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.
641 int ttm_bo_kmap(struct ttm_buffer_object
*bo
, unsigned long start_page
,
642 unsigned long num_pages
, struct ttm_bo_kmap_obj
*map
);
647 * @map: Object describing the map to unmap.
649 * Unmaps a kernel map set up by ttm_bo_kmap.
651 void ttm_bo_kunmap(struct ttm_bo_kmap_obj
*map
);
654 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
656 * @vma: vma as input from the fbdev mmap method.
657 * @bo: The bo backing the address space.
659 * Maps a buffer object.
661 int ttm_bo_mmap_obj(struct vm_area_struct
*vma
, struct ttm_buffer_object
*bo
);
664 * ttm_bo_mmap - mmap out of the ttm device address space.
666 * @filp: filp as input from the mmap method.
667 * @vma: vma as input from the mmap method.
668 * @bdev: Pointer to the ttm_bo_device with the address space manager.
670 * This function is intended to be called by the device mmap method.
671 * if the device address space is to be backed by the bo manager.
673 int ttm_bo_mmap(struct file
*filp
, struct vm_area_struct
*vma
,
674 struct ttm_bo_device
*bdev
);
676 void *ttm_kmap_atomic_prot(struct page
*page
, pgprot_t prot
);
678 void ttm_kunmap_atomic_prot(void *addr
, pgprot_t prot
);
683 * @bdev: Pointer to the struct ttm_bo_device.
684 * @filp: Pointer to the struct file attempting to read / write.
685 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
686 * @rbuf: User-space pointer to address of buffer to read into.
688 * @count: Number of bytes to read / write.
689 * @f_pos: Pointer to current file position.
690 * @write: 1 for read, 0 for write.
692 * This function implements read / write into ttm buffer objects, and is
694 * be called from the fops::read and fops::write method.
696 * See man (2) write, man(2) read. In particular,
697 * the function may return -ERESTARTSYS if
698 * interrupted by a signal.
700 ssize_t
ttm_bo_io(struct ttm_bo_device
*bdev
, struct file
*filp
,
701 const char __user
*wbuf
, char __user
*rbuf
,
702 size_t count
, loff_t
*f_pos
, bool write
);
704 int ttm_bo_swapout(struct ttm_bo_global
*glob
,
705 struct ttm_operation_ctx
*ctx
);
706 void ttm_bo_swapout_all(struct ttm_bo_device
*bdev
);
709 * ttm_bo_uses_embedded_gem_object - check if the given bo uses the
710 * embedded drm_gem_object.
712 * Most ttm drivers are using gem too, so the embedded
713 * ttm_buffer_object.base will be initialized by the driver (before
714 * calling ttm_bo_init). It is also possible to use ttm without gem
715 * though (vmwgfx does that).
717 * This helper will figure whenever a given ttm bo is a gem object too
720 * @bo: The bo to check.
722 static inline bool ttm_bo_uses_embedded_gem_object(struct ttm_buffer_object
*bo
)
724 return bo
->base
.dev
!= NULL
;
727 /* Default number of pre-faulted pages in the TTM fault handler */
728 #define TTM_BO_VM_NUM_PREFAULT 16
730 vm_fault_t
ttm_bo_vm_reserve(struct ttm_buffer_object
*bo
,
731 struct vm_fault
*vmf
);
733 vm_fault_t
ttm_bo_vm_fault_reserved(struct vm_fault
*vmf
,
735 pgoff_t num_prefault
);
737 vm_fault_t
ttm_bo_vm_fault(struct vm_fault
*vmf
);
739 void ttm_bo_vm_open(struct vm_area_struct
*vma
);
741 void ttm_bo_vm_close(struct vm_area_struct
*vma
);
743 int ttm_bo_vm_access(struct vm_area_struct
*vma
, unsigned long addr
,
744 void *buf
, int len
, int write
);