1/**************************************************************************
  2 *
  3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
  4 * All Rights Reserved.
  5 *
  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:
 13 *
 14 * The above copyright notice and this permission notice (including the
 15 * next paragraph) shall be included in all copies or substantial portions
 16 * of the Software.
 17 *
 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.
 25 *
 26 **************************************************************************/
 27/*
 28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 29 */
 30
 31#ifndef _TTM_BO_API_H_
 32#define _TTM_BO_API_H_
 33
 34#include <drm/drm_gem.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>
 40#include <linux/mm.h>
 41#include <linux/bitmap.h>
 42#include <linux/dma-resv.h>
 43
 44#include "ttm_resource.h"
 45
 46struct ttm_global;
 47
 48struct ttm_device;
 49
 50struct iosys_map;
 51
 52struct drm_mm_node;
 53
 54struct ttm_placement;
 55
 56struct ttm_place;
 57
 58/**
 59 * enum ttm_bo_type
 60 *
 61 * @ttm_bo_type_device:	These are 'normal' buffers that can
 62 * be mmapped by user space. Each of these bos occupy a slot in the
 63 * device address space, that can be used for normal vm operations.
 64 *
 65 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
 66 * but they cannot be accessed from user-space. For kernel-only use.
 67 *
 68 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
 69 * driver.
 70 */
 71
 72enum ttm_bo_type {
 73	ttm_bo_type_device,
 74	ttm_bo_type_kernel,
 75	ttm_bo_type_sg
 76};
 77
 78struct ttm_tt;
 79
 80/**
 81 * struct ttm_buffer_object
 82 *
 83 * @base: drm_gem_object superclass data.
 84 * @bdev: Pointer to the buffer object device structure.
 85 * @type: The bo type.
 86 * @page_alignment: Page alignment.
 87 * @destroy: Destruction function. If NULL, kfree is used.
 88 * @num_pages: Actual number of pages.
 89 * @kref: Reference count of this buffer object. When this refcount reaches
 90 * zero, the object is destroyed or put on the delayed delete list.
 91 * @mem: structure describing current placement.
 92 * @ttm: TTM structure holding system pages.
 93 * @evicted: Whether the object was evicted without user-space knowing.
 94 * @deleted: True if the object is only a zombie and already deleted.
 95 * @ddestroy: List head for the delayed destroy list.
 96 * @swap: List head for swap LRU list.
 97 * @offset: The current GPU offset, which can have different meanings
 98 * depending on the memory type. For SYSTEM type memory, it should be 0.
 99 * @cur_placement: Hint of current placement.
100 *
101 * Base class for TTM buffer object, that deals with data placement and CPU
102 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
103 * the driver can usually use the placement offset @offset directly as the
104 * GPU virtual address. For drivers implementing multiple
105 * GPU memory manager contexts, the driver should manage the address space
106 * in these contexts separately and use these objects to get the correct
107 * placement and caching for these GPU maps. This makes it possible to use
108 * these objects for even quite elaborate memory management schemes.
109 * The destroy member, the API visibility of this object makes it possible
110 * to derive driver specific types.
111 */
112
113struct ttm_buffer_object {
114	struct drm_gem_object base;
115
116	/**
117	 * Members constant at init.
118	 */
119
120	struct ttm_device *bdev;
121	enum ttm_bo_type type;
122	uint32_t page_alignment;
123	void (*destroy) (struct ttm_buffer_object *);
124
125	/**
126	* Members not needing protection.
127	*/
128	struct kref kref;
129
130	/**
131	 * Members protected by the bo::resv::reserved lock.
132	 */
133
134	struct ttm_resource *resource;
135	struct ttm_tt *ttm;
136	bool deleted;
137	struct ttm_lru_bulk_move *bulk_move;
138
139	/**
140	 * Members protected by the bdev::lru_lock.
141	 */
142
143	struct list_head ddestroy;
144
145	/**
146	 * Members protected by a bo reservation.
147	 */
148
149	unsigned priority;
150	unsigned pin_count;
151
152	/**
153	 * Special members that are protected by the reserve lock
154	 * and the bo::lock when written to. Can be read with
155	 * either of these locks held.
156	 */
157
158	struct sg_table *sg;
159};
160
161/**
162 * struct ttm_bo_kmap_obj
163 *
164 * @virtual: The current kernel virtual address.
165 * @page: The page when kmap'ing a single page.
166 * @bo_kmap_type: Type of bo_kmap.
167 *
168 * Object describing a kernel mapping. Since a TTM bo may be located
169 * in various memory types with various caching policies, the
170 * mapping can either be an ioremap, a vmap, a kmap or part of a
171 * premapped region.
172 */
173
174#define TTM_BO_MAP_IOMEM_MASK 0x80
175struct ttm_bo_kmap_obj {
176	void *virtual;
177	struct page *page;
178	enum {
179		ttm_bo_map_iomap        = 1 | TTM_BO_MAP_IOMEM_MASK,
180		ttm_bo_map_vmap         = 2,
181		ttm_bo_map_kmap         = 3,
182		ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
183	} bo_kmap_type;
184	struct ttm_buffer_object *bo;
185};
186
187/**
188 * struct ttm_operation_ctx
189 *
190 * @interruptible: Sleep interruptible if sleeping.
191 * @no_wait_gpu: Return immediately if the GPU is busy.
192 * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages.
193 * @allow_res_evict: Allow eviction of reserved BOs. Can be used when multiple
194 * BOs share the same reservation object.
195 * @force_alloc: Don't check the memory account during suspend or CPU page
196 * faults. Should only be used by TTM internally.
197 * @resv: Reservation object to allow reserved evictions with.
198 *
199 * Context for TTM operations like changing buffer placement or general memory
200 * allocation.
201 */
202struct ttm_operation_ctx {
203	bool interruptible;
204	bool no_wait_gpu;
205	bool gfp_retry_mayfail;
206	bool allow_res_evict;
207	bool force_alloc;
208	struct dma_resv *resv;
209	uint64_t bytes_moved;
210};
211
212/**
213 * ttm_bo_get - reference a struct ttm_buffer_object
214 *
215 * @bo: The buffer object.
216 */
217static inline void ttm_bo_get(struct ttm_buffer_object *bo)
218{
219	kref_get(&bo->kref);
220}
221
222/**
223 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
224 * its refcount has already reached zero.
225 * @bo: The buffer object.
226 *
227 * Used to reference a TTM buffer object in lookups where the object is removed
228 * from the lookup structure during the destructor and for RCU lookups.
229 *
230 * Returns: @bo if the referencing was successful, NULL otherwise.
231 */
232static inline __must_check struct ttm_buffer_object *
233ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
234{
235	if (!kref_get_unless_zero(&bo->kref))
236		return NULL;
237	return bo;
238}
239
240/**
241 * ttm_bo_wait - wait for buffer idle.
242 *
243 * @bo:  The buffer object.
244 * @interruptible:  Use interruptible wait.
245 * @no_wait:  Return immediately if buffer is busy.
246 *
247 * This function must be called with the bo::mutex held, and makes
248 * sure any previous rendering to the buffer is completed.
249 * Note: It might be necessary to block validations before the
250 * wait by reserving the buffer.
251 * Returns -EBUSY if no_wait is true and the buffer is busy.
252 * Returns -ERESTARTSYS if interrupted by a signal.
253 */
254int ttm_bo_wait(struct ttm_buffer_object *bo, bool interruptible, bool no_wait);
255
256static inline int ttm_bo_wait_ctx(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx)
257{
258	return ttm_bo_wait(bo, ctx->interruptible, ctx->no_wait_gpu);
259}
260
261/**
262 * ttm_bo_validate
263 *
264 * @bo: The buffer object.
265 * @placement: Proposed placement for the buffer object.
266 * @ctx: validation parameters.
267 *
268 * Changes placement and caching policy of the buffer object
269 * according proposed placement.
270 * Returns
271 * -EINVAL on invalid proposed placement.
272 * -ENOMEM on out-of-memory condition.
273 * -EBUSY if no_wait is true and buffer busy.
274 * -ERESTARTSYS if interrupted by a signal.
275 */
276int ttm_bo_validate(struct ttm_buffer_object *bo,
277		    struct ttm_placement *placement,
278		    struct ttm_operation_ctx *ctx);
279
280/**
281 * ttm_bo_put
282 *
283 * @bo: The buffer object.
284 *
285 * Unreference a buffer object.
286 */
287void ttm_bo_put(struct ttm_buffer_object *bo);
288
289void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
290void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
291			  struct ttm_lru_bulk_move *bulk);
292
293/**
294 * ttm_bo_lock_delayed_workqueue
295 *
296 * Prevent the delayed workqueue from running.
297 * Returns
298 * True if the workqueue was queued at the time
299 */
300int ttm_bo_lock_delayed_workqueue(struct ttm_device *bdev);
301
302/**
303 * ttm_bo_unlock_delayed_workqueue
304 *
305 * Allows the delayed workqueue to run.
306 */
307void ttm_bo_unlock_delayed_workqueue(struct ttm_device *bdev, int resched);
308
309/**
310 * ttm_bo_eviction_valuable
311 *
312 * @bo: The buffer object to evict
313 * @place: the placement we need to make room for
314 *
315 * Check if it is valuable to evict the BO to make room for the given placement.
316 */
317bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
318			      const struct ttm_place *place);
319
320int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,
321			 enum ttm_bo_type type, struct ttm_placement *placement,
322			 uint32_t alignment, struct ttm_operation_ctx *ctx,
323			 struct sg_table *sg, struct dma_resv *resv,
324			 void (*destroy) (struct ttm_buffer_object *));
325int ttm_bo_init_validate(struct ttm_device *bdev, struct ttm_buffer_object *bo,
326			 enum ttm_bo_type type, struct ttm_placement *placement,
327			 uint32_t alignment, bool interruptible,
328			 struct sg_table *sg, struct dma_resv *resv,
329			 void (*destroy) (struct ttm_buffer_object *));
330
331/**
332 * ttm_kmap_obj_virtual
333 *
334 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
335 * @is_iomem: Pointer to an integer that on return indicates 1 if the
336 * virtual map is io memory, 0 if normal memory.
337 *
338 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
339 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
340 * that should strictly be accessed by the iowriteXX() and similar functions.
341 */
342static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
343					 bool *is_iomem)
344{
345	*is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
346	return map->virtual;
347}
348
349/**
350 * ttm_bo_kmap
351 *
352 * @bo: The buffer object.
353 * @start_page: The first page to map.
354 * @num_pages: Number of pages to map.
355 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
356 *
357 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
358 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
359 * used to obtain a virtual address to the data.
360 *
361 * Returns
362 * -ENOMEM: Out of memory.
363 * -EINVAL: Invalid range.
364 */
365int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
366		unsigned long num_pages, struct ttm_bo_kmap_obj *map);
367
368/**
369 * ttm_bo_kunmap
370 *
371 * @map: Object describing the map to unmap.
372 *
373 * Unmaps a kernel map set up by ttm_bo_kmap.
374 */
375void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
376
377/**
378 * ttm_bo_vmap
379 *
380 * @bo: The buffer object.
381 * @map: pointer to a struct iosys_map representing the map.
382 *
383 * Sets up a kernel virtual mapping, using ioremap or vmap to the
384 * data in the buffer object. The parameter @map returns the virtual
385 * address as struct iosys_map. Unmap the buffer with ttm_bo_vunmap().
386 *
387 * Returns
388 * -ENOMEM: Out of memory.
389 * -EINVAL: Invalid range.
390 */
391int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map);
392
393/**
394 * ttm_bo_vunmap
395 *
396 * @bo: The buffer object.
397 * @map: Object describing the map to unmap.
398 *
399 * Unmaps a kernel map set up by ttm_bo_vmap().
400 */
401void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map);
402
403/**
404 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
405 *
406 * @vma:       vma as input from the fbdev mmap method.
407 * @bo:        The bo backing the address space.
408 *
409 * Maps a buffer object.
410 */
411int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
412
413/**
414 * ttm_bo_io
415 *
416 * @bdev:      Pointer to the struct ttm_device.
417 * @filp:      Pointer to the struct file attempting to read / write.
418 * @wbuf:      User-space pointer to address of buffer to write. NULL on read.
419 * @rbuf:      User-space pointer to address of buffer to read into.
420 * Null on write.
421 * @count:     Number of bytes to read / write.
422 * @f_pos:     Pointer to current file position.
423 * @write:     1 for read, 0 for write.
424 *
425 * This function implements read / write into ttm buffer objects, and is
426 * intended to
427 * be called from the fops::read and fops::write method.
428 * Returns:
429 * See man (2) write, man(2) read. In particular,
430 * the function may return -ERESTARTSYS if
431 * interrupted by a signal.
432 */
433ssize_t ttm_bo_io(struct ttm_device *bdev, struct file *filp,
434		  const char __user *wbuf, char __user *rbuf,
435		  size_t count, loff_t *f_pos, bool write);
436
437int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
438		   gfp_t gfp_flags);
439
440void ttm_bo_pin(struct ttm_buffer_object *bo);
441void ttm_bo_unpin(struct ttm_buffer_object *bo);
442
443int ttm_mem_evict_first(struct ttm_device *bdev,
444			struct ttm_resource_manager *man,
445			const struct ttm_place *place,
446			struct ttm_operation_ctx *ctx,
447			struct ww_acquire_ctx *ticket);
448
449/* Default number of pre-faulted pages in the TTM fault handler */
450#define TTM_BO_VM_NUM_PREFAULT 16
451
452vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
453			     struct vm_fault *vmf);
454
455vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
456				    pgprot_t prot,
457				    pgoff_t num_prefault);
458
459vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf);
460
461void ttm_bo_vm_open(struct vm_area_struct *vma);
462
463void ttm_bo_vm_close(struct vm_area_struct *vma);
464
465int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
466		     void *buf, int len, int write);
467bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all);
468
469vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot);
470
471#endif