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/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>
50 * struct ttm_placement
52 * @fpfn: first valid page frame number to put the object
53 * @lpfn: last valid page frame number to put the object
54 * @num_placement: number of preferred placements
55 * @placement: preferred placements
56 * @num_busy_placement: number of preferred placements when need to evict buffer
57 * @busy_placement: preferred placements when need to evict buffer
59 * Structure indicating the placement you request for an object.
61 struct ttm_placement {
64 unsigned num_placement;
65 const uint32_t *placement;
66 unsigned num_busy_placement;
67 const uint32_t *busy_placement;
71 * struct ttm_bus_placement
73 * @addr: mapped virtual address
74 * @base: bus base address
75 * @is_iomem: is this io memory ?
77 * @offset: offset from the base address
78 * @io_reserved_vm: The VM system has a refcount in @io_reserved_count
79 * @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
81 * Structure indicating the bus placement of an object.
83 struct ttm_bus_placement {
90 uint64_t io_reserved_count;
97 * @mm_node: Memory manager node.
98 * @size: Requested size of memory region.
99 * @num_pages: Actual size of memory region in pages.
100 * @page_alignment: Page alignment.
101 * @placement: Placement flags.
102 * @bus: Placement on io bus accessible to the CPU
104 * Structure indicating the placement and space resources used by a
112 unsigned long num_pages;
113 uint32_t page_alignment;
116 struct ttm_bus_placement bus;
122 * @ttm_bo_type_device: These are 'normal' buffers that can
123 * be mmapped by user space. Each of these bos occupy a slot in the
124 * device address space, that can be used for normal vm operations.
126 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
127 * but they cannot be accessed from user-space. For kernel-only use.
129 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
142 * struct ttm_buffer_object
144 * @bdev: Pointer to the buffer object device structure.
145 * @type: The bo type.
146 * @destroy: Destruction function. If NULL, kfree is used.
147 * @num_pages: Actual number of pages.
148 * @acc_size: Accounted size for this object.
149 * @kref: Reference count of this buffer object. When this refcount reaches
150 * zero, the object is put on the delayed delete list.
151 * @list_kref: List reference count of this buffer object. This member is
152 * used to avoid destruction while the buffer object is still on a list.
153 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
154 * keeps one refcount. When this refcount reaches zero,
155 * the object is destroyed.
156 * @mem: structure describing current placement.
157 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
158 * pinned in physical memory. If this behaviour is not desired, this member
159 * holds a pointer to a persistent shmem object.
160 * @ttm: TTM structure holding system pages.
161 * @evicted: Whether the object was evicted without user-space knowing.
162 * @cpu_writes: For synchronization. Number of cpu writers.
163 * @lru: List head for the lru list.
164 * @ddestroy: List head for the delayed destroy list.
165 * @swap: List head for swap LRU list.
166 * @sync_obj: Pointer to a synchronization object.
167 * @priv_flags: Flags describing buffer object internal state.
168 * @vma_node: Address space manager node.
169 * @offset: The current GPU offset, which can have different meanings
170 * depending on the memory type. For SYSTEM type memory, it should be 0.
171 * @cur_placement: Hint of current placement.
173 * Base class for TTM buffer object, that deals with data placement and CPU
174 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
175 * the driver can usually use the placement offset @offset directly as the
176 * GPU virtual address. For drivers implementing multiple
177 * GPU memory manager contexts, the driver should manage the address space
178 * in these contexts separately and use these objects to get the correct
179 * placement and caching for these GPU maps. This makes it possible to use
180 * these objects for even quite elaborate memory management schemes.
181 * The destroy member, the API visibility of this object makes it possible
182 * to derive driver specific types.
185 struct ttm_buffer_object {
187 * Members constant at init.
190 struct ttm_bo_global *glob;
191 struct ttm_bo_device *bdev;
192 enum ttm_bo_type type;
193 void (*destroy) (struct ttm_buffer_object *);
194 unsigned long num_pages;
198 * Members not needing protection.
202 struct kref list_kref;
205 * Members protected by the bo::resv::reserved lock.
208 struct ttm_mem_reg mem;
209 struct file *persistent_swap_storage;
214 * Members protected by the bo::reserved lock only when written to.
217 atomic_t cpu_writers;
220 * Members protected by the bdev::lru_lock.
223 struct list_head lru;
224 struct list_head ddestroy;
225 struct list_head swap;
226 struct list_head io_reserve_lru;
229 * Members protected by struct buffer_object_device::fence_lock
230 * In addition, setting sync_obj to anything else
231 * than NULL requires bo::reserved to be held. This allows for
232 * checking NULL while reserved but not holding the mentioned lock.
236 unsigned long priv_flags;
238 struct drm_vma_offset_node vma_node;
241 * Special members that are protected by the reserve lock
242 * and the bo::lock when written to. Can be read with
243 * either of these locks held.
246 unsigned long offset;
247 uint32_t cur_placement;
251 struct reservation_object *resv;
252 struct reservation_object ttm_resv;
256 * struct ttm_bo_kmap_obj
258 * @virtual: The current kernel virtual address.
259 * @page: The page when kmap'ing a single page.
260 * @bo_kmap_type: Type of bo_kmap.
262 * Object describing a kernel mapping. Since a TTM bo may be located
263 * in various memory types with various caching policies, the
264 * mapping can either be an ioremap, a vmap, a kmap or part of a
268 #define TTM_BO_MAP_IOMEM_MASK 0x80
269 struct ttm_bo_kmap_obj {
273 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
276 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
278 struct ttm_buffer_object *bo;
282 * ttm_bo_reference - reference a struct ttm_buffer_object
284 * @bo: The buffer object.
286 * Returns a refcounted pointer to a buffer object.
289 static inline struct ttm_buffer_object *
290 ttm_bo_reference(struct ttm_buffer_object *bo)
297 * ttm_bo_wait - wait for buffer idle.
299 * @bo: The buffer object.
300 * @interruptible: Use interruptible wait.
301 * @no_wait: Return immediately if buffer is busy.
303 * This function must be called with the bo::mutex held, and makes
304 * sure any previous rendering to the buffer is completed.
305 * Note: It might be necessary to block validations before the
306 * wait by reserving the buffer.
307 * Returns -EBUSY if no_wait is true and the buffer is busy.
308 * Returns -ERESTARTSYS if interrupted by a signal.
310 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
311 bool interruptible, bool no_wait);
315 * @bo: The buffer object.
316 * @placement: Proposed placement for the buffer object.
317 * @interruptible: Sleep interruptible if sleeping.
318 * @no_wait_gpu: Return immediately if the GPU is busy.
320 * Changes placement and caching policy of the buffer object
321 * according proposed placement.
323 * -EINVAL on invalid proposed placement.
324 * -ENOMEM on out-of-memory condition.
325 * -EBUSY if no_wait is true and buffer busy.
326 * -ERESTARTSYS if interrupted by a signal.
328 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
329 struct ttm_placement *placement,
336 * @bo: The buffer object.
338 * Unreference and clear a pointer to a buffer object.
340 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
344 * ttm_bo_list_ref_sub
346 * @bo: The buffer object.
347 * @count: The number of references with which to decrease @bo::list_kref;
348 * @never_free: The refcount should not reach zero with this operation.
350 * Release @count lru list references to this buffer object.
352 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
358 * @bo: The buffer object.
360 * Add this bo to the relevant mem type lru and, if it's backed by
361 * system pages (ttms) to the swap list.
362 * This function must be called with struct ttm_bo_global::lru_lock held, and
363 * is typically called immediately prior to unreserving a bo.
365 extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
368 * ttm_bo_del_from_lru
370 * @bo: The buffer object.
372 * Remove this bo from all lru lists used to lookup and reserve an object.
373 * This function must be called with struct ttm_bo_global::lru_lock held,
374 * and is usually called just immediately after the bo has been reserved to
375 * avoid recursive reservation from lru lists.
377 extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
381 * ttm_bo_lock_delayed_workqueue
383 * Prevent the delayed workqueue from running.
385 * True if the workqueue was queued at the time
387 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
390 * ttm_bo_unlock_delayed_workqueue
392 * Allows the delayed workqueue to run.
394 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
398 * ttm_bo_synccpu_write_grab
400 * @bo: The buffer object:
401 * @no_wait: Return immediately if buffer is busy.
403 * Synchronizes a buffer object for CPU RW access. This means
404 * command submission that affects the buffer will return -EBUSY
405 * until ttm_bo_synccpu_write_release is called.
408 * -EBUSY if the buffer is busy and no_wait is true.
409 * -ERESTARTSYS if interrupted by a signal.
412 ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
415 * ttm_bo_synccpu_write_release:
417 * @bo : The buffer object.
419 * Releases a synccpu lock.
421 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
426 * @bdev: Pointer to a ttm_bo_device struct.
427 * @bo_size: size of the buffer object in byte.
428 * @struct_size: size of the structure holding buffer object datas
430 * Returns size to account for a buffer object
432 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
433 unsigned long bo_size,
434 unsigned struct_size);
435 size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
436 unsigned long bo_size,
437 unsigned struct_size);
442 * @bdev: Pointer to a ttm_bo_device struct.
443 * @bo: Pointer to a ttm_buffer_object to be initialized.
444 * @size: Requested size of buffer object.
445 * @type: Requested type of buffer object.
446 * @flags: Initial placement flags.
447 * @page_alignment: Data alignment in pages.
448 * @interruptible: If needing to sleep to wait for GPU resources,
449 * sleep interruptible.
450 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
451 * pinned in physical memory. If this behaviour is not desired, this member
452 * holds a pointer to a persistent shmem object. Typically, this would
453 * point to the shmem object backing a GEM object if TTM is used to back a
454 * GEM user interface.
455 * @acc_size: Accounted size for this object.
456 * @destroy: Destroy function. Use NULL for kfree().
458 * This function initializes a pre-allocated struct ttm_buffer_object.
459 * As this object may be part of a larger structure, this function,
460 * together with the @destroy function,
461 * enables driver-specific objects derived from a ttm_buffer_object.
462 * On successful return, the object kref and list_kref are set to 1.
463 * If a failure occurs, the function will call the @destroy function, or
464 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
465 * illegal and will likely cause memory corruption.
468 * -ENOMEM: Out of memory.
469 * -EINVAL: Invalid placement flags.
470 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
473 extern int ttm_bo_init(struct ttm_bo_device *bdev,
474 struct ttm_buffer_object *bo,
476 enum ttm_bo_type type,
477 struct ttm_placement *placement,
478 uint32_t page_alignment,
480 struct file *persistent_swap_storage,
483 void (*destroy) (struct ttm_buffer_object *));
486 * ttm_bo_synccpu_object_init
488 * @bdev: Pointer to a ttm_bo_device struct.
489 * @bo: Pointer to a ttm_buffer_object to be initialized.
490 * @size: Requested size of buffer object.
491 * @type: Requested type of buffer object.
492 * @flags: Initial placement flags.
493 * @page_alignment: Data alignment in pages.
494 * @interruptible: If needing to sleep while waiting for GPU resources,
495 * sleep interruptible.
496 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
497 * pinned in physical memory. If this behaviour is not desired, this member
498 * holds a pointer to a persistent shmem object. Typically, this would
499 * point to the shmem object backing a GEM object if TTM is used to back a
500 * GEM user interface.
501 * @p_bo: On successful completion *p_bo points to the created object.
503 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
504 * on that object. The destroy function is set to kfree().
506 * -ENOMEM: Out of memory.
507 * -EINVAL: Invalid placement flags.
508 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
511 extern int ttm_bo_create(struct ttm_bo_device *bdev,
513 enum ttm_bo_type type,
514 struct ttm_placement *placement,
515 uint32_t page_alignment,
517 struct file *persistent_swap_storage,
518 struct ttm_buffer_object **p_bo);
521 * ttm_bo_check_placement
523 * @bo: the buffer object.
524 * @placement: placements
526 * Performs minimal validity checking on an intended change of
529 * -EINVAL: Intended change is invalid or not allowed.
531 extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
532 struct ttm_placement *placement);
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.
550 extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
551 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.
579 extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
584 * @bdev: Pointer to a ttm_bo_device struct.
585 * @mem_type: The memory type.
587 * Evicts all buffers on the lru list of the memory type.
588 * This is normally part of a VT switch or an
589 * out-of-memory-space-due-to-fragmentation handler.
590 * The caller must make sure that there are no other processes
591 * currently validating buffers, and can do that by taking the
592 * struct ttm_bo_device::ttm_lock in write mode.
595 * -EINVAL: Invalid or uninitialized memory type.
596 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
600 extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
603 * ttm_kmap_obj_virtual
605 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
606 * @is_iomem: Pointer to an integer that on return indicates 1 if the
607 * virtual map is io memory, 0 if normal memory.
609 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
610 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
611 * that should strictly be accessed by the iowriteXX() and similar functions.
614 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
617 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
624 * @bo: The buffer object.
625 * @start_page: The first page to map.
626 * @num_pages: Number of pages to map.
627 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
629 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
630 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
631 * used to obtain a virtual address to the data.
634 * -ENOMEM: Out of memory.
635 * -EINVAL: Invalid range.
638 extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
639 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
644 * @map: Object describing the map to unmap.
646 * Unmaps a kernel map set up by ttm_bo_kmap.
649 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
652 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
654 * @vma: vma as input from the fbdev mmap method.
655 * @bo: The bo backing the address space. The address space will
656 * have the same size as the bo, and start at offset 0.
658 * This function is intended to be called by the fbdev mmap method
659 * if the fbdev address space is to be backed by a bo.
662 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
663 struct ttm_buffer_object *bo);
666 * ttm_bo_mmap - mmap out of the ttm device address space.
668 * @filp: filp as input from the mmap method.
669 * @vma: vma as input from the mmap method.
670 * @bdev: Pointer to the ttm_bo_device with the address space manager.
672 * This function is intended to be called by the device mmap method.
673 * if the device address space is to be backed by the bo manager.
676 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
677 struct ttm_bo_device *bdev);
682 * @bdev: Pointer to the struct ttm_bo_device.
683 * @filp: Pointer to the struct file attempting to read / write.
684 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
685 * @rbuf: User-space pointer to address of buffer to read into.
687 * @count: Number of bytes to read / write.
688 * @f_pos: Pointer to current file position.
689 * @write: 1 for read, 0 for write.
691 * This function implements read / write into ttm buffer objects, and is
693 * be called from the fops::read and fops::write method.
695 * See man (2) write, man(2) read. In particular,
696 * the function may return -ERESTARTSYS if
697 * interrupted by a signal.
700 extern 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 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);