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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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_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>
55 * struct ttm_bus_placement
57 * @addr: mapped virtual address
58 * @base: bus base address
59 * @is_iomem: is this io memory ?
61 * @offset: offset from the base address
62 * @io_reserved_vm: The VM system has a refcount in @io_reserved_count
63 * @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
65 * Structure indicating the bus placement of an object.
67 struct ttm_bus_placement {
74 uint64_t io_reserved_count;
81 * @mm_node: Memory manager node.
82 * @size: Requested size of memory region.
83 * @num_pages: Actual size of memory region in pages.
84 * @page_alignment: Page alignment.
85 * @placement: Placement flags.
86 * @bus: Placement on io bus accessible to the CPU
88 * Structure indicating the placement and space resources used by a
96 unsigned long num_pages;
97 uint32_t page_alignment;
100 struct ttm_bus_placement bus;
106 * @ttm_bo_type_device: These are 'normal' buffers that can
107 * be mmapped by user space. Each of these bos occupy a slot in the
108 * device address space, that can be used for normal vm operations.
110 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
111 * but they cannot be accessed from user-space. For kernel-only use.
113 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
126 * struct ttm_buffer_object
128 * @bdev: Pointer to the buffer object device structure.
129 * @type: The bo type.
130 * @destroy: Destruction function. If NULL, kfree is used.
131 * @num_pages: Actual number of pages.
132 * @acc_size: Accounted size for this object.
133 * @kref: Reference count of this buffer object. When this refcount reaches
134 * zero, the object is put on the delayed delete list.
135 * @list_kref: List reference count of this buffer object. This member is
136 * used to avoid destruction while the buffer object is still on a list.
137 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
138 * keeps one refcount. When this refcount reaches zero,
139 * the object is destroyed.
140 * @mem: structure describing current placement.
141 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
142 * pinned in physical memory. If this behaviour is not desired, this member
143 * holds a pointer to a persistent shmem object.
144 * @ttm: TTM structure holding system pages.
145 * @evicted: Whether the object was evicted without user-space knowing.
146 * @cpu_writes: For synchronization. Number of cpu writers.
147 * @lru: List head for the lru list.
148 * @ddestroy: List head for the delayed destroy list.
149 * @swap: List head for swap LRU list.
150 * @moving: Fence set when BO is moving
151 * @vma_node: Address space manager node.
152 * @offset: The current GPU offset, which can have different meanings
153 * depending on the memory type. For SYSTEM type memory, it should be 0.
154 * @cur_placement: Hint of current placement.
155 * @wu_mutex: Wait unreserved mutex.
157 * Base class for TTM buffer object, that deals with data placement and CPU
158 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
159 * the driver can usually use the placement offset @offset directly as the
160 * GPU virtual address. For drivers implementing multiple
161 * GPU memory manager contexts, the driver should manage the address space
162 * in these contexts separately and use these objects to get the correct
163 * placement and caching for these GPU maps. This makes it possible to use
164 * these objects for even quite elaborate memory management schemes.
165 * The destroy member, the API visibility of this object makes it possible
166 * to derive driver specific types.
169 struct ttm_buffer_object {
171 * Members constant at init.
174 struct ttm_bo_device *bdev;
175 enum ttm_bo_type type;
176 void (*destroy) (struct ttm_buffer_object *);
177 unsigned long num_pages;
181 * Members not needing protection.
185 struct kref list_kref;
188 * Members protected by the bo::resv::reserved lock.
191 struct ttm_mem_reg mem;
192 struct file *persistent_swap_storage;
197 * Members protected by the bo::reserved lock only when written to.
200 atomic_t cpu_writers;
203 * Members protected by the bdev::lru_lock.
206 struct list_head lru;
207 struct list_head ddestroy;
208 struct list_head swap;
209 struct list_head io_reserve_lru;
212 * Members protected by a bo reservation.
215 struct dma_fence *moving;
217 struct drm_vma_offset_node vma_node;
222 * Special members that are protected by the reserve lock
223 * and the bo::lock when written to. Can be read with
224 * either of these locks held.
227 uint64_t offset; /* GPU address space is independent of CPU word size */
231 struct reservation_object *resv;
232 struct reservation_object ttm_resv;
233 struct mutex wu_mutex;
237 * struct ttm_bo_kmap_obj
239 * @virtual: The current kernel virtual address.
240 * @page: The page when kmap'ing a single page.
241 * @bo_kmap_type: Type of bo_kmap.
243 * Object describing a kernel mapping. Since a TTM bo may be located
244 * in various memory types with various caching policies, the
245 * mapping can either be an ioremap, a vmap, a kmap or part of a
249 #define TTM_BO_MAP_IOMEM_MASK 0x80
250 struct ttm_bo_kmap_obj {
254 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
257 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
259 struct ttm_buffer_object *bo;
263 * struct ttm_operation_ctx
265 * @interruptible: Sleep interruptible if sleeping.
266 * @no_wait_gpu: Return immediately if the GPU is busy.
267 * @resv: Reservation object to allow reserved evictions with.
268 * @flags: Including the following flags
270 * Context for TTM operations like changing buffer placement or general memory
273 struct ttm_operation_ctx {
276 struct reservation_object *resv;
277 uint64_t bytes_moved;
281 /* Allow eviction of reserved BOs */
282 #define TTM_OPT_FLAG_ALLOW_RES_EVICT 0x1
283 /* when serving page fault or suspend, allow alloc anyway */
284 #define TTM_OPT_FLAG_FORCE_ALLOC 0x2
287 * ttm_bo_reference - reference a struct ttm_buffer_object
289 * @bo: The buffer object.
291 * Returns a refcounted pointer to a buffer object.
294 static inline struct ttm_buffer_object *
295 ttm_bo_reference(struct ttm_buffer_object *bo)
302 * ttm_bo_wait - wait for buffer idle.
304 * @bo: The buffer object.
305 * @interruptible: Use interruptible wait.
306 * @no_wait: Return immediately if buffer is busy.
308 * This function must be called with the bo::mutex held, and makes
309 * sure any previous rendering to the buffer is completed.
310 * Note: It might be necessary to block validations before the
311 * wait by reserving the buffer.
312 * Returns -EBUSY if no_wait is true and the buffer is busy.
313 * Returns -ERESTARTSYS if interrupted by a signal.
315 int ttm_bo_wait(struct ttm_buffer_object *bo, bool interruptible, bool no_wait);
318 * ttm_bo_mem_compat - Check if proposed placement is compatible with a bo
320 * @placement: Return immediately if buffer is busy.
321 * @mem: The struct ttm_mem_reg indicating the region where the bo resides
322 * @new_flags: Describes compatible placement found
324 * Returns true if the placement is compatible
326 bool ttm_bo_mem_compat(struct ttm_placement *placement, struct ttm_mem_reg *mem,
327 uint32_t *new_flags);
332 * @bo: The buffer object.
333 * @placement: Proposed placement for the buffer object.
334 * @ctx: validation parameters.
336 * Changes placement and caching policy of the buffer object
337 * according proposed placement.
339 * -EINVAL on invalid proposed placement.
340 * -ENOMEM on out-of-memory condition.
341 * -EBUSY if no_wait is true and buffer busy.
342 * -ERESTARTSYS if interrupted by a signal.
344 int ttm_bo_validate(struct ttm_buffer_object *bo,
345 struct ttm_placement *placement,
346 struct ttm_operation_ctx *ctx);
351 * @bo: The buffer object.
353 * Unreference and clear a pointer to a buffer object.
355 void ttm_bo_unref(struct ttm_buffer_object **bo);
360 * @bo: The buffer object.
362 * Add this bo to the relevant mem type lru and, if it's backed by
363 * system pages (ttms) to the swap list.
364 * This function must be called with struct ttm_bo_global::lru_lock held, and
365 * is typically called immediately prior to unreserving a bo.
367 void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
370 * ttm_bo_del_from_lru
372 * @bo: The buffer object.
374 * Remove this bo from all lru lists used to lookup and reserve an object.
375 * This function must be called with struct ttm_bo_global::lru_lock held,
376 * and is usually called just immediately after the bo has been reserved to
377 * avoid recursive reservation from lru lists.
379 void ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
382 * ttm_bo_move_to_lru_tail
384 * @bo: The buffer object.
386 * Move this BO to the tail of all lru lists used to lookup and reserve an
387 * object. This function must be called with struct ttm_bo_global::lru_lock
388 * held, and is used to make a BO less likely to be considered for eviction.
390 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
393 * ttm_bo_lock_delayed_workqueue
395 * Prevent the delayed workqueue from running.
397 * True if the workqueue was queued at the time
399 int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
402 * ttm_bo_unlock_delayed_workqueue
404 * Allows the delayed workqueue to run.
406 void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev, int resched);
409 * ttm_bo_eviction_valuable
411 * @bo: The buffer object to evict
412 * @place: the placement we need to make room for
414 * Check if it is valuable to evict the BO to make room for the given placement.
416 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
417 const struct ttm_place *place);
420 * ttm_bo_synccpu_write_grab
422 * @bo: The buffer object:
423 * @no_wait: Return immediately if buffer is busy.
425 * Synchronizes a buffer object for CPU RW access. This means
426 * command submission that affects the buffer will return -EBUSY
427 * until ttm_bo_synccpu_write_release is called.
430 * -EBUSY if the buffer is busy and no_wait is true.
431 * -ERESTARTSYS if interrupted by a signal.
433 int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
436 * ttm_bo_synccpu_write_release:
438 * @bo : The buffer object.
440 * Releases a synccpu lock.
442 void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
447 * @bdev: Pointer to a ttm_bo_device struct.
448 * @bo_size: size of the buffer object in byte.
449 * @struct_size: size of the structure holding buffer object datas
451 * Returns size to account for a buffer object
453 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
454 unsigned long bo_size,
455 unsigned struct_size);
456 size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
457 unsigned long bo_size,
458 unsigned struct_size);
461 * ttm_bo_init_reserved
463 * @bdev: Pointer to a ttm_bo_device struct.
464 * @bo: Pointer to a ttm_buffer_object to be initialized.
465 * @size: Requested size of buffer object.
466 * @type: Requested type of buffer object.
467 * @flags: Initial placement flags.
468 * @page_alignment: Data alignment in pages.
469 * @ctx: TTM operation context for memory allocation.
470 * @acc_size: Accounted size for this object.
471 * @resv: Pointer to a reservation_object, or NULL to let ttm allocate one.
472 * @destroy: Destroy function. Use NULL for kfree().
474 * This function initializes a pre-allocated struct ttm_buffer_object.
475 * As this object may be part of a larger structure, this function,
476 * together with the @destroy function,
477 * enables driver-specific objects derived from a ttm_buffer_object.
479 * On successful return, the caller owns an object kref to @bo. The kref and
480 * list_kref are usually set to 1, but note that in some situations, other
481 * tasks may already be holding references to @bo as well.
482 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
483 * and it is the caller's responsibility to call ttm_bo_unreserve.
485 * If a failure occurs, the function will call the @destroy function, or
486 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
487 * illegal and will likely cause memory corruption.
490 * -ENOMEM: Out of memory.
491 * -EINVAL: Invalid placement flags.
492 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
495 int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
496 struct ttm_buffer_object *bo,
498 enum ttm_bo_type type,
499 struct ttm_placement *placement,
500 uint32_t page_alignment,
501 struct ttm_operation_ctx *ctx,
504 struct reservation_object *resv,
505 void (*destroy) (struct ttm_buffer_object *));
510 * @bdev: Pointer to a ttm_bo_device struct.
511 * @bo: Pointer to a ttm_buffer_object to be initialized.
512 * @size: Requested size of buffer object.
513 * @type: Requested type of buffer object.
514 * @flags: Initial placement flags.
515 * @page_alignment: Data alignment in pages.
516 * @interruptible: If needing to sleep to wait for GPU resources,
517 * sleep interruptible.
518 * pinned in physical memory. If this behaviour is not desired, this member
519 * holds a pointer to a persistent shmem object. Typically, this would
520 * point to the shmem object backing a GEM object if TTM is used to back a
521 * GEM user interface.
522 * @acc_size: Accounted size for this object.
523 * @resv: Pointer to a reservation_object, or NULL to let ttm allocate one.
524 * @destroy: Destroy function. Use NULL for kfree().
526 * This function initializes a pre-allocated struct ttm_buffer_object.
527 * As this object may be part of a larger structure, this function,
528 * together with the @destroy function,
529 * enables driver-specific objects derived from a ttm_buffer_object.
531 * On successful return, the caller owns an object kref to @bo. The kref and
532 * list_kref are usually set to 1, but note that in some situations, other
533 * tasks may already be holding references to @bo as well.
535 * If a failure occurs, the function will call the @destroy function, or
536 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
537 * illegal and will likely cause memory corruption.
540 * -ENOMEM: Out of memory.
541 * -EINVAL: Invalid placement flags.
542 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
544 int ttm_bo_init(struct ttm_bo_device *bdev, struct ttm_buffer_object *bo,
545 unsigned long size, enum ttm_bo_type type,
546 struct ttm_placement *placement,
547 uint32_t page_alignment, bool interrubtible, size_t acc_size,
548 struct sg_table *sg, struct reservation_object *resv,
549 void (*destroy) (struct ttm_buffer_object *));
554 * @bdev: Pointer to a ttm_bo_device struct.
555 * @size: Requested size of buffer object.
556 * @type: Requested type of buffer object.
557 * @placement: Initial placement.
558 * @page_alignment: Data alignment in pages.
559 * @interruptible: If needing to sleep while waiting for GPU resources,
560 * sleep interruptible.
561 * @p_bo: On successful completion *p_bo points to the created object.
563 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
564 * on that object. The destroy function is set to kfree().
566 * -ENOMEM: Out of memory.
567 * -EINVAL: Invalid placement flags.
568 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
570 int ttm_bo_create(struct ttm_bo_device *bdev, unsigned long size,
571 enum ttm_bo_type type, struct ttm_placement *placement,
572 uint32_t page_alignment, bool interruptible,
573 struct ttm_buffer_object **p_bo);
578 * @bdev: Pointer to a ttm_bo_device struct.
579 * @mem_type: The memory type.
580 * @p_size: size managed area in pages.
582 * Initialize a manager for a given memory type.
583 * Note: if part of driver firstopen, it must be protected from a
584 * potentially racing lastclose.
586 * -EINVAL: invalid size or memory type.
587 * -ENOMEM: Not enough memory.
588 * May also return driver-specified errors.
590 int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
591 unsigned long p_size);
596 * @bdev: Pointer to a ttm_bo_device struct.
597 * @mem_type: The memory type.
599 * Take down a manager for a given memory type after first walking
600 * the LRU list to evict any buffers left alive.
602 * Normally, this function is part of lastclose() or unload(), and at that
603 * point there shouldn't be any buffers left created by user-space, since
604 * there should've been removed by the file descriptor release() method.
605 * However, before this function is run, make sure to signal all sync objects,
606 * and verify that the delayed delete queue is empty. The driver must also
607 * make sure that there are no NO_EVICT buffers present in this memory type
608 * when the call is made.
610 * If this function is part of a VT switch, the caller must make sure that
611 * there are no appications currently validating buffers before this
612 * function is called. The caller can do that by first taking the
613 * struct ttm_bo_device::ttm_lock in write mode.
616 * -EINVAL: invalid or uninitialized memory type.
617 * -EBUSY: There are still buffers left in this memory type.
619 int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
624 * @bdev: Pointer to a ttm_bo_device struct.
625 * @mem_type: The memory type.
627 * Evicts all buffers on the lru list of the memory type.
628 * This is normally part of a VT switch or an
629 * out-of-memory-space-due-to-fragmentation handler.
630 * The caller must make sure that there are no other processes
631 * currently validating buffers, and can do that by taking the
632 * struct ttm_bo_device::ttm_lock in write mode.
635 * -EINVAL: Invalid or uninitialized memory type.
636 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
639 int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
642 * ttm_kmap_obj_virtual
644 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
645 * @is_iomem: Pointer to an integer that on return indicates 1 if the
646 * virtual map is io memory, 0 if normal memory.
648 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
649 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
650 * that should strictly be accessed by the iowriteXX() and similar functions.
652 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
655 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
662 * @bo: The buffer object.
663 * @start_page: The first page to map.
664 * @num_pages: Number of pages to map.
665 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
667 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
668 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
669 * used to obtain a virtual address to the data.
672 * -ENOMEM: Out of memory.
673 * -EINVAL: Invalid range.
675 int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
676 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
681 * @map: Object describing the map to unmap.
683 * Unmaps a kernel map set up by ttm_bo_kmap.
685 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
688 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
690 * @vma: vma as input from the fbdev mmap method.
691 * @bo: The bo backing the address space. The address space will
692 * have the same size as the bo, and start at offset 0.
694 * This function is intended to be called by the fbdev mmap method
695 * if the fbdev address space is to be backed by a bo.
697 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
700 * ttm_bo_mmap - mmap out of the ttm device address space.
702 * @filp: filp as input from the mmap method.
703 * @vma: vma as input from the mmap method.
704 * @bdev: Pointer to the ttm_bo_device with the address space manager.
706 * This function is intended to be called by the device mmap method.
707 * if the device address space is to be backed by the bo manager.
709 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
710 struct ttm_bo_device *bdev);
712 void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot);
714 void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot);
719 * @bdev: Pointer to the struct ttm_bo_device.
720 * @filp: Pointer to the struct file attempting to read / write.
721 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
722 * @rbuf: User-space pointer to address of buffer to read into.
724 * @count: Number of bytes to read / write.
725 * @f_pos: Pointer to current file position.
726 * @write: 1 for read, 0 for write.
728 * This function implements read / write into ttm buffer objects, and is
730 * be called from the fops::read and fops::write method.
732 * See man (2) write, man(2) read. In particular,
733 * the function may return -ERESTARTSYS if
734 * interrupted by a signal.
736 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
737 const char __user *wbuf, char __user *rbuf,
738 size_t count, loff_t *f_pos, bool write);
740 int ttm_bo_swapout(struct ttm_bo_global *glob,
741 struct ttm_operation_ctx *ctx);
742 void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
743 int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo);