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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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 destroyed or put on the delayed delete list.
139 * @mem: structure describing current placement.
140 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
141 * pinned in physical memory. If this behaviour is not desired, this member
142 * holds a pointer to a persistent shmem object.
143 * @ttm: TTM structure holding system pages.
144 * @evicted: Whether the object was evicted without user-space knowing.
145 * @deleted: True if the object is only a zombie and already deleted.
146 * @lru: List head for the lru list.
147 * @ddestroy: List head for the delayed destroy list.
148 * @swap: List head for swap LRU list.
149 * @moving: Fence set when BO is moving
150 * @offset: The current GPU offset, which can have different meanings
151 * depending on the memory type. For SYSTEM type memory, it should be 0.
152 * @cur_placement: Hint of current placement.
154 * Base class for TTM buffer object, that deals with data placement and CPU
155 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
156 * the driver can usually use the placement offset @offset directly as the
157 * GPU virtual address. For drivers implementing multiple
158 * GPU memory manager contexts, the driver should manage the address space
159 * in these contexts separately and use these objects to get the correct
160 * placement and caching for these GPU maps. This makes it possible to use
161 * these objects for even quite elaborate memory management schemes.
162 * The destroy member, the API visibility of this object makes it possible
163 * to derive driver specific types.
166 struct ttm_buffer_object {
167 struct drm_gem_object base;
170 * Members constant at init.
173 struct ttm_bo_device *bdev;
174 enum ttm_bo_type type;
175 void (*destroy) (struct ttm_buffer_object *);
176 unsigned long num_pages;
180 * Members not needing protection.
185 * Members protected by the bo::resv::reserved lock.
188 struct ttm_mem_reg mem;
189 struct file *persistent_swap_storage;
195 * Members protected by the bdev::lru_lock.
198 struct list_head lru;
199 struct list_head ddestroy;
200 struct list_head swap;
201 struct list_head io_reserve_lru;
204 * Members protected by a bo reservation.
207 struct dma_fence *moving;
211 * Special members that are protected by the reserve lock
212 * and the bo::lock when written to. Can be read with
213 * either of these locks held.
220 * struct ttm_bo_kmap_obj
222 * @virtual: The current kernel virtual address.
223 * @page: The page when kmap'ing a single page.
224 * @bo_kmap_type: Type of bo_kmap.
226 * Object describing a kernel mapping. Since a TTM bo may be located
227 * in various memory types with various caching policies, the
228 * mapping can either be an ioremap, a vmap, a kmap or part of a
232 #define TTM_BO_MAP_IOMEM_MASK 0x80
233 struct ttm_bo_kmap_obj {
237 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
240 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
242 struct ttm_buffer_object *bo;
246 * struct ttm_operation_ctx
248 * @interruptible: Sleep interruptible if sleeping.
249 * @no_wait_gpu: Return immediately if the GPU is busy.
250 * @resv: Reservation object to allow reserved evictions with.
251 * @flags: Including the following flags
253 * Context for TTM operations like changing buffer placement or general memory
256 struct ttm_operation_ctx {
259 struct dma_resv *resv;
260 uint64_t bytes_moved;
264 /* Allow eviction of reserved BOs */
265 #define TTM_OPT_FLAG_ALLOW_RES_EVICT 0x1
266 /* when serving page fault or suspend, allow alloc anyway */
267 #define TTM_OPT_FLAG_FORCE_ALLOC 0x2
270 * ttm_bo_get - reference a struct ttm_buffer_object
272 * @bo: The buffer object.
274 static inline void ttm_bo_get(struct ttm_buffer_object *bo)
280 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
281 * its refcount has already reached zero.
282 * @bo: The buffer object.
284 * Used to reference a TTM buffer object in lookups where the object is removed
285 * from the lookup structure during the destructor and for RCU lookups.
287 * Returns: @bo if the referencing was successful, NULL otherwise.
289 static inline __must_check struct ttm_buffer_object *
290 ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
292 if (!kref_get_unless_zero(&bo->kref))
298 * ttm_bo_wait - wait for buffer idle.
300 * @bo: The buffer object.
301 * @interruptible: Use interruptible wait.
302 * @no_wait: Return immediately if buffer is busy.
304 * This function must be called with the bo::mutex held, and makes
305 * sure any previous rendering to the buffer is completed.
306 * Note: It might be necessary to block validations before the
307 * wait by reserving the buffer.
308 * Returns -EBUSY if no_wait is true and the buffer is busy.
309 * Returns -ERESTARTSYS if interrupted by a signal.
311 int ttm_bo_wait(struct ttm_buffer_object *bo, bool interruptible, bool no_wait);
314 * ttm_bo_mem_compat - Check if proposed placement is compatible with a bo
316 * @placement: Return immediately if buffer is busy.
317 * @mem: The struct ttm_mem_reg indicating the region where the bo resides
318 * @new_flags: Describes compatible placement found
320 * Returns true if the placement is compatible
322 bool ttm_bo_mem_compat(struct ttm_placement *placement, struct ttm_mem_reg *mem,
323 uint32_t *new_flags);
328 * @bo: The buffer object.
329 * @placement: Proposed placement for the buffer object.
330 * @ctx: validation parameters.
332 * Changes placement and caching policy of the buffer object
333 * according proposed placement.
335 * -EINVAL on invalid proposed placement.
336 * -ENOMEM on out-of-memory condition.
337 * -EBUSY if no_wait is true and buffer busy.
338 * -ERESTARTSYS if interrupted by a signal.
340 int ttm_bo_validate(struct ttm_buffer_object *bo,
341 struct ttm_placement *placement,
342 struct ttm_operation_ctx *ctx);
347 * @bo: The buffer object.
349 * Unreference a buffer object.
351 void ttm_bo_put(struct ttm_buffer_object *bo);
354 * ttm_bo_move_to_lru_tail
356 * @bo: The buffer object.
357 * @bulk: optional bulk move structure to remember BO positions
359 * Move this BO to the tail of all lru lists used to lookup and reserve an
360 * object. This function must be called with struct ttm_bo_global::lru_lock
361 * held, and is used to make a BO less likely to be considered for eviction.
363 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
364 struct ttm_lru_bulk_move *bulk);
367 * ttm_bo_bulk_move_lru_tail
369 * @bulk: bulk move structure
371 * Bulk move BOs to the LRU tail, only valid to use when driver makes sure that
372 * BO order never changes. Should be called with ttm_bo_global::lru_lock held.
374 void ttm_bo_bulk_move_lru_tail(struct ttm_lru_bulk_move *bulk);
377 * ttm_bo_lock_delayed_workqueue
379 * Prevent the delayed workqueue from running.
381 * True if the workqueue was queued at the time
383 int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
386 * ttm_bo_unlock_delayed_workqueue
388 * Allows the delayed workqueue to run.
390 void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev, int resched);
393 * ttm_bo_eviction_valuable
395 * @bo: The buffer object to evict
396 * @place: the placement we need to make room for
398 * Check if it is valuable to evict the BO to make room for the given placement.
400 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
401 const struct ttm_place *place);
406 * @bdev: Pointer to a ttm_bo_device struct.
407 * @bo_size: size of the buffer object in byte.
408 * @struct_size: size of the structure holding buffer object datas
410 * Returns size to account for a buffer object
412 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
413 unsigned long bo_size,
414 unsigned struct_size);
415 size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
416 unsigned long bo_size,
417 unsigned struct_size);
420 * ttm_bo_init_reserved
422 * @bdev: Pointer to a ttm_bo_device struct.
423 * @bo: Pointer to a ttm_buffer_object to be initialized.
424 * @size: Requested size of buffer object.
425 * @type: Requested type of buffer object.
426 * @flags: Initial placement flags.
427 * @page_alignment: Data alignment in pages.
428 * @ctx: TTM operation context for memory allocation.
429 * @acc_size: Accounted size for this object.
430 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
431 * @destroy: Destroy function. Use NULL for kfree().
433 * This function initializes a pre-allocated struct ttm_buffer_object.
434 * As this object may be part of a larger structure, this function,
435 * together with the @destroy function,
436 * enables driver-specific objects derived from a ttm_buffer_object.
438 * On successful return, the caller owns an object kref to @bo. The kref and
439 * list_kref are usually set to 1, but note that in some situations, other
440 * tasks may already be holding references to @bo as well.
441 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
442 * and it is the caller's responsibility to call ttm_bo_unreserve.
444 * If a failure occurs, the function will call the @destroy function, or
445 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
446 * illegal and will likely cause memory corruption.
449 * -ENOMEM: Out of memory.
450 * -EINVAL: Invalid placement flags.
451 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
454 int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
455 struct ttm_buffer_object *bo,
457 enum ttm_bo_type type,
458 struct ttm_placement *placement,
459 uint32_t page_alignment,
460 struct ttm_operation_ctx *ctx,
463 struct dma_resv *resv,
464 void (*destroy) (struct ttm_buffer_object *));
469 * @bdev: Pointer to a ttm_bo_device struct.
470 * @bo: Pointer to a ttm_buffer_object to be initialized.
471 * @size: Requested size of buffer object.
472 * @type: Requested type of buffer object.
473 * @flags: Initial placement flags.
474 * @page_alignment: Data alignment in pages.
475 * @interruptible: If needing to sleep to wait for GPU resources,
476 * sleep interruptible.
477 * pinned in physical memory. If this behaviour is not desired, this member
478 * holds a pointer to a persistent shmem object. Typically, this would
479 * point to the shmem object backing a GEM object if TTM is used to back a
480 * GEM user interface.
481 * @acc_size: Accounted size for this object.
482 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
483 * @destroy: Destroy function. Use NULL for kfree().
485 * This function initializes a pre-allocated struct ttm_buffer_object.
486 * As this object may be part of a larger structure, this function,
487 * together with the @destroy function,
488 * enables driver-specific objects derived from a ttm_buffer_object.
490 * On successful return, the caller owns an object kref to @bo. The kref and
491 * list_kref are usually set to 1, but note that in some situations, other
492 * tasks may already be holding references to @bo as well.
494 * If a failure occurs, the function will call the @destroy function, or
495 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
496 * illegal and will likely cause memory corruption.
499 * -ENOMEM: Out of memory.
500 * -EINVAL: Invalid placement flags.
501 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
503 int ttm_bo_init(struct ttm_bo_device *bdev, struct ttm_buffer_object *bo,
504 unsigned long size, enum ttm_bo_type type,
505 struct ttm_placement *placement,
506 uint32_t page_alignment, bool interrubtible, size_t acc_size,
507 struct sg_table *sg, struct dma_resv *resv,
508 void (*destroy) (struct ttm_buffer_object *));
513 * @bdev: Pointer to a ttm_bo_device struct.
514 * @size: Requested size of buffer object.
515 * @type: Requested type of buffer object.
516 * @placement: Initial placement.
517 * @page_alignment: Data alignment in pages.
518 * @interruptible: If needing to sleep while waiting for GPU resources,
519 * sleep interruptible.
520 * @p_bo: On successful completion *p_bo points to the created object.
522 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
523 * on that object. The destroy function is set to kfree().
525 * -ENOMEM: Out of memory.
526 * -EINVAL: Invalid placement flags.
527 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
529 int ttm_bo_create(struct ttm_bo_device *bdev, unsigned long size,
530 enum ttm_bo_type type, struct ttm_placement *placement,
531 uint32_t page_alignment, bool interruptible,
532 struct ttm_buffer_object **p_bo);
537 * @bdev: Pointer to a ttm_bo_device struct.
538 * @mem_type: The memory type.
539 * @p_size: size managed area in pages.
541 * Initialize a manager for a given memory type.
542 * Note: if part of driver firstopen, it must be protected from a
543 * potentially racing lastclose.
545 * -EINVAL: invalid size or memory type.
546 * -ENOMEM: Not enough memory.
547 * May also return driver-specified errors.
549 int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
550 unsigned long p_size);
555 * @bdev: Pointer to a ttm_bo_device struct.
556 * @mem_type: The memory type.
558 * Take down a manager for a given memory type after first walking
559 * the LRU list to evict any buffers left alive.
561 * Normally, this function is part of lastclose() or unload(), and at that
562 * point there shouldn't be any buffers left created by user-space, since
563 * there should've been removed by the file descriptor release() method.
564 * However, before this function is run, make sure to signal all sync objects,
565 * and verify that the delayed delete queue is empty. The driver must also
566 * make sure that there are no NO_EVICT buffers present in this memory type
567 * when the call is made.
569 * If this function is part of a VT switch, the caller must make sure that
570 * there are no appications currently validating buffers before this
571 * function is called. The caller can do that by first taking the
572 * struct ttm_bo_device::ttm_lock in write mode.
575 * -EINVAL: invalid or uninitialized memory type.
576 * -EBUSY: There are still buffers left in this memory type.
578 int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
583 * @bdev: Pointer to a ttm_bo_device struct.
584 * @mem_type: The memory type.
586 * Evicts all buffers on the lru list of the memory type.
587 * This is normally part of a VT switch or an
588 * out-of-memory-space-due-to-fragmentation handler.
589 * The caller must make sure that there are no other processes
590 * currently validating buffers, and can do that by taking the
591 * struct ttm_bo_device::ttm_lock in write mode.
594 * -EINVAL: Invalid or uninitialized memory type.
595 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
598 int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
601 * ttm_kmap_obj_virtual
603 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
604 * @is_iomem: Pointer to an integer that on return indicates 1 if the
605 * virtual map is io memory, 0 if normal memory.
607 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
608 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
609 * that should strictly be accessed by the iowriteXX() and similar functions.
611 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
614 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
621 * @bo: The buffer object.
622 * @start_page: The first page to map.
623 * @num_pages: Number of pages to map.
624 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
626 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
627 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
628 * used to obtain a virtual address to the data.
631 * -ENOMEM: Out of memory.
632 * -EINVAL: Invalid range.
634 int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
635 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
640 * @map: Object describing the map to unmap.
642 * Unmaps a kernel map set up by ttm_bo_kmap.
644 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
647 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
649 * @vma: vma as input from the fbdev mmap method.
650 * @bo: The bo backing the address space.
652 * Maps a buffer object.
654 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
657 * ttm_bo_mmap - mmap out of the ttm device address space.
659 * @filp: filp as input from the mmap method.
660 * @vma: vma as input from the mmap method.
661 * @bdev: Pointer to the ttm_bo_device with the address space manager.
663 * This function is intended to be called by the device mmap method.
664 * if the device address space is to be backed by the bo manager.
666 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
667 struct ttm_bo_device *bdev);
672 * @bdev: Pointer to the struct ttm_bo_device.
673 * @filp: Pointer to the struct file attempting to read / write.
674 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
675 * @rbuf: User-space pointer to address of buffer to read into.
677 * @count: Number of bytes to read / write.
678 * @f_pos: Pointer to current file position.
679 * @write: 1 for read, 0 for write.
681 * This function implements read / write into ttm buffer objects, and is
683 * be called from the fops::read and fops::write method.
685 * See man (2) write, man(2) read. In particular,
686 * the function may return -ERESTARTSYS if
687 * interrupted by a signal.
689 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
690 const char __user *wbuf, char __user *rbuf,
691 size_t count, loff_t *f_pos, bool write);
693 int ttm_bo_swapout(struct ttm_bo_global *glob,
694 struct ttm_operation_ctx *ctx);
695 void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
698 * ttm_bo_uses_embedded_gem_object - check if the given bo uses the
699 * embedded drm_gem_object.
701 * Most ttm drivers are using gem too, so the embedded
702 * ttm_buffer_object.base will be initialized by the driver (before
703 * calling ttm_bo_init). It is also possible to use ttm without gem
704 * though (vmwgfx does that).
706 * This helper will figure whenever a given ttm bo is a gem object too
709 * @bo: The bo to check.
711 static inline bool ttm_bo_uses_embedded_gem_object(struct ttm_buffer_object *bo)
713 return bo->base.dev != NULL;
716 /* Default number of pre-faulted pages in the TTM fault handler */
717 #define TTM_BO_VM_NUM_PREFAULT 16
719 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
720 struct vm_fault *vmf);
722 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
724 pgoff_t num_prefault,
725 pgoff_t fault_page_size);
727 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf);
729 void ttm_bo_vm_open(struct vm_area_struct *vma);
731 void ttm_bo_vm_close(struct vm_area_struct *vma);
733 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
734 void *buf, int len, int write);