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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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>
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.
172 * @wu_mutex: Wait unreserved mutex.
174 * Base class for TTM buffer object, that deals with data placement and CPU
175 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
176 * the driver can usually use the placement offset @offset directly as the
177 * GPU virtual address. For drivers implementing multiple
178 * GPU memory manager contexts, the driver should manage the address space
179 * in these contexts separately and use these objects to get the correct
180 * placement and caching for these GPU maps. This makes it possible to use
181 * these objects for even quite elaborate memory management schemes.
182 * The destroy member, the API visibility of this object makes it possible
183 * to derive driver specific types.
186 struct ttm_buffer_object
{
188 * Members constant at init.
191 struct ttm_bo_global
*glob
;
192 struct ttm_bo_device
*bdev
;
193 enum ttm_bo_type type
;
194 void (*destroy
) (struct ttm_buffer_object
*);
195 unsigned long num_pages
;
199 * Members not needing protection.
203 struct kref list_kref
;
206 * Members protected by the bo::resv::reserved lock.
209 struct ttm_mem_reg mem
;
210 struct file
*persistent_swap_storage
;
215 * Members protected by the bo::reserved lock only when written to.
218 atomic_t cpu_writers
;
221 * Members protected by the bdev::lru_lock.
224 struct list_head lru
;
225 struct list_head ddestroy
;
226 struct list_head swap
;
227 struct list_head io_reserve_lru
;
230 * Members protected by struct buffer_object_device::fence_lock
231 * In addition, setting sync_obj to anything else
232 * than NULL requires bo::reserved to be held. This allows for
233 * checking NULL while reserved but not holding the mentioned lock.
237 unsigned long priv_flags
;
239 struct drm_vma_offset_node vma_node
;
242 * Special members that are protected by the reserve lock
243 * and the bo::lock when written to. Can be read with
244 * either of these locks held.
247 unsigned long offset
;
248 uint32_t cur_placement
;
252 struct reservation_object
*resv
;
253 struct reservation_object ttm_resv
;
254 struct mutex wu_mutex
;
258 * struct ttm_bo_kmap_obj
260 * @virtual: The current kernel virtual address.
261 * @page: The page when kmap'ing a single page.
262 * @bo_kmap_type: Type of bo_kmap.
264 * Object describing a kernel mapping. Since a TTM bo may be located
265 * in various memory types with various caching policies, the
266 * mapping can either be an ioremap, a vmap, a kmap or part of a
270 #define TTM_BO_MAP_IOMEM_MASK 0x80
271 struct ttm_bo_kmap_obj
{
275 ttm_bo_map_iomap
= 1 | TTM_BO_MAP_IOMEM_MASK
,
278 ttm_bo_map_premapped
= 4 | TTM_BO_MAP_IOMEM_MASK
,
280 struct ttm_buffer_object
*bo
;
284 * ttm_bo_reference - reference a struct ttm_buffer_object
286 * @bo: The buffer object.
288 * Returns a refcounted pointer to a buffer object.
291 static inline struct ttm_buffer_object
*
292 ttm_bo_reference(struct ttm_buffer_object
*bo
)
299 * ttm_bo_wait - wait for buffer idle.
301 * @bo: The buffer object.
302 * @interruptible: Use interruptible wait.
303 * @no_wait: Return immediately if buffer is busy.
305 * This function must be called with the bo::mutex held, and makes
306 * sure any previous rendering to the buffer is completed.
307 * Note: It might be necessary to block validations before the
308 * wait by reserving the buffer.
309 * Returns -EBUSY if no_wait is true and the buffer is busy.
310 * Returns -ERESTARTSYS if interrupted by a signal.
312 extern int ttm_bo_wait(struct ttm_buffer_object
*bo
, bool lazy
,
313 bool interruptible
, bool no_wait
);
317 * @bo: The buffer object.
318 * @placement: Proposed placement for the buffer object.
319 * @interruptible: Sleep interruptible if sleeping.
320 * @no_wait_gpu: Return immediately if the GPU is busy.
322 * Changes placement and caching policy of the buffer object
323 * according proposed placement.
325 * -EINVAL on invalid proposed placement.
326 * -ENOMEM on out-of-memory condition.
327 * -EBUSY if no_wait is true and buffer busy.
328 * -ERESTARTSYS if interrupted by a signal.
330 extern int ttm_bo_validate(struct ttm_buffer_object
*bo
,
331 struct ttm_placement
*placement
,
338 * @bo: The buffer object.
340 * Unreference and clear a pointer to a buffer object.
342 extern void ttm_bo_unref(struct ttm_buffer_object
**bo
);
346 * ttm_bo_list_ref_sub
348 * @bo: The buffer object.
349 * @count: The number of references with which to decrease @bo::list_kref;
350 * @never_free: The refcount should not reach zero with this operation.
352 * Release @count lru list references to this buffer object.
354 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object
*bo
, int count
,
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 extern 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 extern int ttm_bo_del_from_lru(struct ttm_buffer_object
*bo
);
383 * ttm_bo_lock_delayed_workqueue
385 * Prevent the delayed workqueue from running.
387 * True if the workqueue was queued at the time
389 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device
*bdev
);
392 * ttm_bo_unlock_delayed_workqueue
394 * Allows the delayed workqueue to run.
396 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device
*bdev
,
400 * ttm_bo_synccpu_write_grab
402 * @bo: The buffer object:
403 * @no_wait: Return immediately if buffer is busy.
405 * Synchronizes a buffer object for CPU RW access. This means
406 * command submission that affects the buffer will return -EBUSY
407 * until ttm_bo_synccpu_write_release is called.
410 * -EBUSY if the buffer is busy and no_wait is true.
411 * -ERESTARTSYS if interrupted by a signal.
414 ttm_bo_synccpu_write_grab(struct ttm_buffer_object
*bo
, bool no_wait
);
417 * ttm_bo_synccpu_write_release:
419 * @bo : The buffer object.
421 * Releases a synccpu lock.
423 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object
*bo
);
428 * @bdev: Pointer to a ttm_bo_device struct.
429 * @bo_size: size of the buffer object in byte.
430 * @struct_size: size of the structure holding buffer object datas
432 * Returns size to account for a buffer object
434 size_t ttm_bo_acc_size(struct ttm_bo_device
*bdev
,
435 unsigned long bo_size
,
436 unsigned struct_size
);
437 size_t ttm_bo_dma_acc_size(struct ttm_bo_device
*bdev
,
438 unsigned long bo_size
,
439 unsigned struct_size
);
444 * @bdev: Pointer to a ttm_bo_device struct.
445 * @bo: Pointer to a ttm_buffer_object to be initialized.
446 * @size: Requested size of buffer object.
447 * @type: Requested type of buffer object.
448 * @flags: Initial placement flags.
449 * @page_alignment: Data alignment in pages.
450 * @interruptible: If needing to sleep to wait for GPU resources,
451 * sleep interruptible.
452 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
453 * pinned in physical memory. If this behaviour is not desired, this member
454 * holds a pointer to a persistent shmem object. Typically, this would
455 * point to the shmem object backing a GEM object if TTM is used to back a
456 * GEM user interface.
457 * @acc_size: Accounted size for this object.
458 * @destroy: Destroy function. Use NULL for kfree().
460 * This function initializes a pre-allocated struct ttm_buffer_object.
461 * As this object may be part of a larger structure, this function,
462 * together with the @destroy function,
463 * enables driver-specific objects derived from a ttm_buffer_object.
464 * On successful return, the object kref and list_kref are set to 1.
465 * If a failure occurs, the function will call the @destroy function, or
466 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
467 * illegal and will likely cause memory corruption.
470 * -ENOMEM: Out of memory.
471 * -EINVAL: Invalid placement flags.
472 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
475 extern int ttm_bo_init(struct ttm_bo_device
*bdev
,
476 struct ttm_buffer_object
*bo
,
478 enum ttm_bo_type type
,
479 struct ttm_placement
*placement
,
480 uint32_t page_alignment
,
482 struct file
*persistent_swap_storage
,
485 void (*destroy
) (struct ttm_buffer_object
*));
490 * @bdev: Pointer to a ttm_bo_device struct.
491 * @size: Requested size of buffer object.
492 * @type: Requested type of buffer object.
493 * @placement: Initial placement.
494 * @page_alignment: Data alignment in pages.
495 * @interruptible: If needing to sleep while waiting for GPU resources,
496 * sleep interruptible.
497 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
498 * pinned in physical memory. If this behaviour is not desired, this member
499 * holds a pointer to a persistent shmem object. Typically, this would
500 * point to the shmem object backing a GEM object if TTM is used to back a
501 * GEM user interface.
502 * @p_bo: On successful completion *p_bo points to the created object.
504 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
505 * on that object. The destroy function is set to kfree().
507 * -ENOMEM: Out of memory.
508 * -EINVAL: Invalid placement flags.
509 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
512 extern int ttm_bo_create(struct ttm_bo_device
*bdev
,
514 enum ttm_bo_type type
,
515 struct ttm_placement
*placement
,
516 uint32_t page_alignment
,
518 struct file
*persistent_swap_storage
,
519 struct ttm_buffer_object
**p_bo
);
522 * ttm_bo_check_placement
524 * @bo: the buffer object.
525 * @placement: placements
527 * Performs minimal validity checking on an intended change of
530 * -EINVAL: Intended change is invalid or not allowed.
532 extern int ttm_bo_check_placement(struct ttm_buffer_object
*bo
,
533 struct ttm_placement
*placement
);
538 * @bdev: Pointer to a ttm_bo_device struct.
539 * @mem_type: The memory type.
540 * @p_size: size managed area in pages.
542 * Initialize a manager for a given memory type.
543 * Note: if part of driver firstopen, it must be protected from a
544 * potentially racing lastclose.
546 * -EINVAL: invalid size or memory type.
547 * -ENOMEM: Not enough memory.
548 * May also return driver-specified errors.
551 extern int ttm_bo_init_mm(struct ttm_bo_device
*bdev
, unsigned type
,
552 unsigned long p_size
);
556 * @bdev: Pointer to a ttm_bo_device struct.
557 * @mem_type: The memory type.
559 * Take down a manager for a given memory type after first walking
560 * the LRU list to evict any buffers left alive.
562 * Normally, this function is part of lastclose() or unload(), and at that
563 * point there shouldn't be any buffers left created by user-space, since
564 * there should've been removed by the file descriptor release() method.
565 * However, before this function is run, make sure to signal all sync objects,
566 * and verify that the delayed delete queue is empty. The driver must also
567 * make sure that there are no NO_EVICT buffers present in this memory type
568 * when the call is made.
570 * If this function is part of a VT switch, the caller must make sure that
571 * there are no appications currently validating buffers before this
572 * function is called. The caller can do that by first taking the
573 * struct ttm_bo_device::ttm_lock in write mode.
576 * -EINVAL: invalid or uninitialized memory type.
577 * -EBUSY: There are still buffers left in this memory type.
580 extern int ttm_bo_clean_mm(struct ttm_bo_device
*bdev
, unsigned mem_type
);
585 * @bdev: Pointer to a ttm_bo_device struct.
586 * @mem_type: The memory type.
588 * Evicts all buffers on the lru list of the memory type.
589 * This is normally part of a VT switch or an
590 * out-of-memory-space-due-to-fragmentation handler.
591 * The caller must make sure that there are no other processes
592 * currently validating buffers, and can do that by taking the
593 * struct ttm_bo_device::ttm_lock in write mode.
596 * -EINVAL: Invalid or uninitialized memory type.
597 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
601 extern int ttm_bo_evict_mm(struct ttm_bo_device
*bdev
, unsigned mem_type
);
604 * ttm_kmap_obj_virtual
606 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
607 * @is_iomem: Pointer to an integer that on return indicates 1 if the
608 * virtual map is io memory, 0 if normal memory.
610 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
611 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
612 * that should strictly be accessed by the iowriteXX() and similar functions.
615 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj
*map
,
618 *is_iomem
= !!(map
->bo_kmap_type
& TTM_BO_MAP_IOMEM_MASK
);
625 * @bo: The buffer object.
626 * @start_page: The first page to map.
627 * @num_pages: Number of pages to map.
628 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
630 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
631 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
632 * used to obtain a virtual address to the data.
635 * -ENOMEM: Out of memory.
636 * -EINVAL: Invalid range.
639 extern int ttm_bo_kmap(struct ttm_buffer_object
*bo
, unsigned long start_page
,
640 unsigned long num_pages
, struct ttm_bo_kmap_obj
*map
);
645 * @map: Object describing the map to unmap.
647 * Unmaps a kernel map set up by ttm_bo_kmap.
650 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj
*map
);
653 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
655 * @vma: vma as input from the fbdev mmap method.
656 * @bo: The bo backing the address space. The address space will
657 * have the same size as the bo, and start at offset 0.
659 * This function is intended to be called by the fbdev mmap method
660 * if the fbdev address space is to be backed by a bo.
663 extern int ttm_fbdev_mmap(struct vm_area_struct
*vma
,
664 struct ttm_buffer_object
*bo
);
667 * ttm_bo_mmap - mmap out of the ttm device address space.
669 * @filp: filp as input from the mmap method.
670 * @vma: vma as input from the mmap method.
671 * @bdev: Pointer to the ttm_bo_device with the address space manager.
673 * This function is intended to be called by the device mmap method.
674 * if the device address space is to be backed by the bo manager.
677 extern int ttm_bo_mmap(struct file
*filp
, struct vm_area_struct
*vma
,
678 struct ttm_bo_device
*bdev
);
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.
701 extern ssize_t
ttm_bo_io(struct ttm_bo_device
*bdev
, struct file
*filp
,
702 const char __user
*wbuf
, char __user
*rbuf
,
703 size_t count
, loff_t
*f_pos
, bool write
);
705 extern void ttm_bo_swapout_all(struct ttm_bo_device
*bdev
);
706 extern int ttm_bo_wait_unreserved(struct ttm_buffer_object
*bo
);