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
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
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_hashtab.h"
35 #include <linux/kref.h>
36 #include <linux/list.h>
37 #include <linux/wait.h>
38 #include <linux/mutex.h>
40 #include <linux/rbtree.h>
41 #include <linux/bitmap.h>
49 * struct ttm_placement
51 * @fpfn: first valid page frame number to put the object
52 * @lpfn: last valid page frame number to put the object
53 * @num_placement: number of prefered placements
54 * @placement: prefered placements
55 * @num_busy_placement: number of prefered placements when need to evict buffer
56 * @busy_placement: prefered placements when need to evict buffer
58 * Structure indicating the placement you request for an object.
60 struct ttm_placement {
63 unsigned num_placement;
64 const uint32_t *placement;
65 unsigned num_busy_placement;
66 const uint32_t *busy_placement;
73 * @mm_node: Memory manager node.
74 * @size: Requested size of memory region.
75 * @num_pages: Actual size of memory region in pages.
76 * @page_alignment: Page alignment.
77 * @placement: Placement flags.
79 * Structure indicating the placement and space resources used by a
84 struct drm_mm_node *mm_node;
86 unsigned long num_pages;
87 uint32_t page_alignment;
95 * @ttm_bo_type_device: These are 'normal' buffers that can
96 * be mmapped by user space. Each of these bos occupy a slot in the
97 * device address space, that can be used for normal vm operations.
99 * @ttm_bo_type_user: These are user-space memory areas that are made
100 * available to the GPU by mapping the buffer pages into the GPU aperture
101 * space. These buffers cannot be mmaped from the device address space.
103 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
104 * but they cannot be accessed from user-space. For kernel-only use.
116 * struct ttm_buffer_object
118 * @bdev: Pointer to the buffer object device structure.
119 * @buffer_start: The virtual user-space start address of ttm_bo_type_user
121 * @type: The bo type.
122 * @destroy: Destruction function. If NULL, kfree is used.
123 * @num_pages: Actual number of pages.
124 * @addr_space_offset: Address space offset.
125 * @acc_size: Accounted size for this object.
126 * @kref: Reference count of this buffer object. When this refcount reaches
127 * zero, the object is put on the delayed delete list.
128 * @list_kref: List reference count of this buffer object. This member is
129 * used to avoid destruction while the buffer object is still on a list.
130 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
131 * keeps one refcount. When this refcount reaches zero,
132 * the object is destroyed.
133 * @event_queue: Queue for processes waiting on buffer object status change.
134 * @lock: spinlock protecting mostly synchronization members.
135 * @mem: structure describing current placement.
136 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
137 * pinned in physical memory. If this behaviour is not desired, this member
138 * holds a pointer to a persistant shmem object.
139 * @ttm: TTM structure holding system pages.
140 * @evicted: Whether the object was evicted without user-space knowing.
141 * @cpu_writes: For synchronization. Number of cpu writers.
142 * @lru: List head for the lru list.
143 * @ddestroy: List head for the delayed destroy list.
144 * @swap: List head for swap LRU list.
145 * @val_seq: Sequence of the validation holding the @reserved lock.
146 * Used to avoid starvation when many processes compete to validate the
147 * buffer. This member is protected by the bo_device::lru_lock.
148 * @seq_valid: The value of @val_seq is valid. This value is protected by
149 * the bo_device::lru_lock.
150 * @reserved: Deadlock-free lock used for synchronization state transitions.
151 * @sync_obj_arg: Opaque argument to synchronization object function.
152 * @sync_obj: Pointer to a synchronization object.
153 * @priv_flags: Flags describing buffer object internal state.
154 * @vm_rb: Rb node for the vm rb tree.
155 * @vm_node: Address space manager node.
156 * @offset: The current GPU offset, which can have different meanings
157 * depending on the memory type. For SYSTEM type memory, it should be 0.
158 * @cur_placement: Hint of current placement.
160 * Base class for TTM buffer object, that deals with data placement and CPU
161 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
162 * the driver can usually use the placement offset @offset directly as the
163 * GPU virtual address. For drivers implementing multiple
164 * GPU memory manager contexts, the driver should manage the address space
165 * in these contexts separately and use these objects to get the correct
166 * placement and caching for these GPU maps. This makes it possible to use
167 * these objects for even quite elaborate memory management schemes.
168 * The destroy member, the API visibility of this object makes it possible
169 * to derive driver specific types.
172 struct ttm_buffer_object {
174 * Members constant at init.
177 struct ttm_bo_global *glob;
178 struct ttm_bo_device *bdev;
179 unsigned long buffer_start;
180 enum ttm_bo_type type;
181 void (*destroy) (struct ttm_buffer_object *);
182 unsigned long num_pages;
183 uint64_t addr_space_offset;
187 * Members not needing protection.
191 struct kref list_kref;
192 wait_queue_head_t event_queue;
196 * Members protected by the bo::reserved lock.
199 struct ttm_mem_reg mem;
200 struct file *persistant_swap_storage;
205 * Members protected by the bo::reserved lock only when written to.
208 atomic_t cpu_writers;
211 * Members protected by the bdev::lru_lock.
214 struct list_head lru;
215 struct list_head ddestroy;
216 struct list_head swap;
221 * Members protected by the bdev::lru_lock
222 * only when written to.
229 * Members protected by the bo::lock
234 unsigned long priv_flags;
237 * Members protected by the bdev::vm_lock
240 struct rb_node vm_rb;
241 struct drm_mm_node *vm_node;
245 * Special members that are protected by the reserve lock
246 * and the bo::lock when written to. Can be read with
247 * either of these locks held.
250 unsigned long offset;
251 uint32_t cur_placement;
255 * struct ttm_bo_kmap_obj
257 * @virtual: The current kernel virtual address.
258 * @page: The page when kmap'ing a single page.
259 * @bo_kmap_type: Type of bo_kmap.
261 * Object describing a kernel mapping. Since a TTM bo may be located
262 * in various memory types with various caching policies, the
263 * mapping can either be an ioremap, a vmap, a kmap or part of a
267 #define TTM_BO_MAP_IOMEM_MASK 0x80
268 struct ttm_bo_kmap_obj {
272 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
275 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
280 * ttm_bo_reference - reference a struct ttm_buffer_object
282 * @bo: The buffer object.
284 * Returns a refcounted pointer to a buffer object.
287 static inline struct ttm_buffer_object *
288 ttm_bo_reference(struct ttm_buffer_object *bo)
295 * ttm_bo_wait - wait for buffer idle.
297 * @bo: The buffer object.
298 * @interruptible: Use interruptible wait.
299 * @no_wait: Return immediately if buffer is busy.
301 * This function must be called with the bo::mutex held, and makes
302 * sure any previous rendering to the buffer is completed.
303 * Note: It might be necessary to block validations before the
304 * wait by reserving the buffer.
305 * Returns -EBUSY if no_wait is true and the buffer is busy.
306 * Returns -ERESTARTSYS if interrupted by a signal.
308 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
309 bool interruptible, bool no_wait);
313 * @bo: The buffer object.
314 * @placement: Proposed placement for the buffer object.
315 * @interruptible: Sleep interruptible if sleeping.
316 * @no_wait: Return immediately if the buffer is busy.
318 * Changes placement and caching policy of the buffer object
319 * according proposed placement.
321 * -EINVAL on invalid proposed placement.
322 * -ENOMEM on out-of-memory condition.
323 * -EBUSY if no_wait is true and buffer busy.
324 * -ERESTARTSYS if interrupted by a signal.
326 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
327 struct ttm_placement *placement,
328 bool interruptible, bool no_wait);
333 * @bo: The buffer object.
335 * Unreference and clear a pointer to a buffer object.
337 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
340 * ttm_bo_synccpu_write_grab
342 * @bo: The buffer object:
343 * @no_wait: Return immediately if buffer is busy.
345 * Synchronizes a buffer object for CPU RW access. This means
346 * blocking command submission that affects the buffer and
347 * waiting for buffer idle. This lock is recursive.
349 * -EBUSY if the buffer is busy and no_wait is true.
350 * -ERESTARTSYS if interrupted by a signal.
354 ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
356 * ttm_bo_synccpu_write_release:
358 * @bo : The buffer object.
360 * Releases a synccpu lock.
362 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
367 * @bdev: Pointer to a ttm_bo_device struct.
368 * @bo: Pointer to a ttm_buffer_object to be initialized.
369 * @size: Requested size of buffer object.
370 * @type: Requested type of buffer object.
371 * @flags: Initial placement flags.
372 * @page_alignment: Data alignment in pages.
373 * @buffer_start: Virtual address of user space data backing a
374 * user buffer object.
375 * @interruptible: If needing to sleep to wait for GPU resources,
376 * sleep interruptible.
377 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
378 * pinned in physical memory. If this behaviour is not desired, this member
379 * holds a pointer to a persistant shmem object. Typically, this would
380 * point to the shmem object backing a GEM object if TTM is used to back a
381 * GEM user interface.
382 * @acc_size: Accounted size for this object.
383 * @destroy: Destroy function. Use NULL for kfree().
385 * This function initializes a pre-allocated struct ttm_buffer_object.
386 * As this object may be part of a larger structure, this function,
387 * together with the @destroy function,
388 * enables driver-specific objects derived from a ttm_buffer_object.
389 * On successful return, the object kref and list_kref are set to 1.
391 * -ENOMEM: Out of memory.
392 * -EINVAL: Invalid placement flags.
393 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
396 extern int ttm_bo_init(struct ttm_bo_device *bdev,
397 struct ttm_buffer_object *bo,
399 enum ttm_bo_type type,
400 struct ttm_placement *placement,
401 uint32_t page_alignment,
402 unsigned long buffer_start,
404 struct file *persistant_swap_storage,
406 void (*destroy) (struct ttm_buffer_object *));
408 * ttm_bo_synccpu_object_init
410 * @bdev: Pointer to a ttm_bo_device struct.
411 * @bo: Pointer to a ttm_buffer_object to be initialized.
412 * @size: Requested size of buffer object.
413 * @type: Requested type of buffer object.
414 * @flags: Initial placement flags.
415 * @page_alignment: Data alignment in pages.
416 * @buffer_start: Virtual address of user space data backing a
417 * user buffer object.
418 * @interruptible: If needing to sleep while waiting for GPU resources,
419 * sleep interruptible.
420 * @persistant_swap_storage: Usually the swap storage is deleted for buffers
421 * pinned in physical memory. If this behaviour is not desired, this member
422 * holds a pointer to a persistant shmem object. Typically, this would
423 * point to the shmem object backing a GEM object if TTM is used to back a
424 * GEM user interface.
425 * @p_bo: On successful completion *p_bo points to the created object.
427 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
428 * on that object. The destroy function is set to kfree().
430 * -ENOMEM: Out of memory.
431 * -EINVAL: Invalid placement flags.
432 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
435 extern int ttm_bo_create(struct ttm_bo_device *bdev,
437 enum ttm_bo_type type,
438 struct ttm_placement *placement,
439 uint32_t page_alignment,
440 unsigned long buffer_start,
442 struct file *persistant_swap_storage,
443 struct ttm_buffer_object **p_bo);
446 * ttm_bo_check_placement
448 * @bo: the buffer object.
449 * @placement: placements
451 * Performs minimal validity checking on an intended change of
454 * -EINVAL: Intended change is invalid or not allowed.
456 extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
457 struct ttm_placement *placement);
462 * @bdev: Pointer to a ttm_bo_device struct.
463 * @mem_type: The memory type.
464 * @p_size: size managed area in pages.
466 * Initialize a manager for a given memory type.
467 * Note: if part of driver firstopen, it must be protected from a
468 * potentially racing lastclose.
470 * -EINVAL: invalid size or memory type.
471 * -ENOMEM: Not enough memory.
472 * May also return driver-specified errors.
475 extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
476 unsigned long p_size);
480 * @bdev: Pointer to a ttm_bo_device struct.
481 * @mem_type: The memory type.
483 * Take down a manager for a given memory type after first walking
484 * the LRU list to evict any buffers left alive.
486 * Normally, this function is part of lastclose() or unload(), and at that
487 * point there shouldn't be any buffers left created by user-space, since
488 * there should've been removed by the file descriptor release() method.
489 * However, before this function is run, make sure to signal all sync objects,
490 * and verify that the delayed delete queue is empty. The driver must also
491 * make sure that there are no NO_EVICT buffers present in this memory type
492 * when the call is made.
494 * If this function is part of a VT switch, the caller must make sure that
495 * there are no appications currently validating buffers before this
496 * function is called. The caller can do that by first taking the
497 * struct ttm_bo_device::ttm_lock in write mode.
500 * -EINVAL: invalid or uninitialized memory type.
501 * -EBUSY: There are still buffers left in this memory type.
504 extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
509 * @bdev: Pointer to a ttm_bo_device struct.
510 * @mem_type: The memory type.
512 * Evicts all buffers on the lru list of the memory type.
513 * This is normally part of a VT switch or an
514 * out-of-memory-space-due-to-fragmentation handler.
515 * The caller must make sure that there are no other processes
516 * currently validating buffers, and can do that by taking the
517 * struct ttm_bo_device::ttm_lock in write mode.
520 * -EINVAL: Invalid or uninitialized memory type.
521 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
525 extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
528 * ttm_kmap_obj_virtual
530 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
531 * @is_iomem: Pointer to an integer that on return indicates 1 if the
532 * virtual map is io memory, 0 if normal memory.
534 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
535 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
536 * that should strictly be accessed by the iowriteXX() and similar functions.
539 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
542 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
549 * @bo: The buffer object.
550 * @start_page: The first page to map.
551 * @num_pages: Number of pages to map.
552 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
554 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
555 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
556 * used to obtain a virtual address to the data.
559 * -ENOMEM: Out of memory.
560 * -EINVAL: Invalid range.
563 extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
564 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
569 * @map: Object describing the map to unmap.
571 * Unmaps a kernel map set up by ttm_bo_kmap.
574 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
580 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
582 * @vma: vma as input from the fbdev mmap method.
583 * @bo: The bo backing the address space. The address space will
584 * have the same size as the bo, and start at offset 0.
586 * This function is intended to be called by the fbdev mmap method
587 * if the fbdev address space is to be backed by a bo.
590 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
591 struct ttm_buffer_object *bo);
594 * ttm_bo_mmap - mmap out of the ttm device address space.
596 * @filp: filp as input from the mmap method.
597 * @vma: vma as input from the mmap method.
598 * @bdev: Pointer to the ttm_bo_device with the address space manager.
600 * This function is intended to be called by the device mmap method.
601 * if the device address space is to be backed by the bo manager.
604 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
605 struct ttm_bo_device *bdev);
610 * @bdev: Pointer to the struct ttm_bo_device.
611 * @filp: Pointer to the struct file attempting to read / write.
612 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
613 * @rbuf: User-space pointer to address of buffer to read into.
615 * @count: Number of bytes to read / write.
616 * @f_pos: Pointer to current file position.
617 * @write: 1 for read, 0 for write.
619 * This function implements read / write into ttm buffer objects, and is
621 * be called from the fops::read and fops::write method.
623 * See man (2) write, man(2) read. In particular,
624 * the function may return -ERESTARTSYS if
625 * interrupted by a signal.
628 extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
629 const char __user *wbuf, char __user *rbuf,
630 size_t count, loff_t *f_pos, bool write);
632 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);