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
36 #include <linux/kref.h>
37 #include <linux/list.h>
38
39 #include "ttm_device.h"
40
41 /* Default number of pre-faulted pages in the TTM fault handler */
42 #if CONFIG_PGTABLE_LEVELS > 2
43 #define TTM_BO_VM_NUM_PREFAULT (1 << (PMD_SHIFT - PAGE_SHIFT))
44 #else
45 #define TTM_BO_VM_NUM_PREFAULT 16
46 #endif
47
48 struct iosys_map;
49
50 struct ttm_global;
51 struct ttm_device;
52 struct ttm_placement;
53 struct ttm_place;
54 struct ttm_resource;
55 struct ttm_resource_manager;
56 struct ttm_tt;
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 enum ttm_bo_type {
72 ttm_bo_type_device,
73 ttm_bo_type_kernel,
74 ttm_bo_type_sg
75 };
76
77 /**
78 * struct ttm_buffer_object
79 *
80 * @base: drm_gem_object superclass data.
81 * @bdev: Pointer to the buffer object device structure.
82 * @type: The bo type.
83 * @page_alignment: Page alignment.
84 * @destroy: Destruction function. If NULL, kfree is used.
85 * @kref: Reference count of this buffer object. When this refcount reaches
86 * zero, the object is destroyed or put on the delayed delete list.
87 * @resource: structure describing current placement.
88 * @ttm: TTM structure holding system pages.
89 * @deleted: True if the object is only a zombie and already deleted.
90 * @bulk_move: The bulk move object.
91 * @priority: Priority for LRU, BOs with lower priority are evicted first.
92 * @pin_count: Pin count.
93 *
94 * Base class for TTM buffer object, that deals with data placement and CPU
95 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
96 * the driver can usually use the placement offset @offset directly as the
97 * GPU virtual address. For drivers implementing multiple
98 * GPU memory manager contexts, the driver should manage the address space
99 * in these contexts separately and use these objects to get the correct
100 * placement and caching for these GPU maps. This makes it possible to use
101 * these objects for even quite elaborate memory management schemes.
102 * The destroy member, the API visibility of this object makes it possible
103 * to derive driver specific types.
104 */
105 struct ttm_buffer_object {
106 struct drm_gem_object base;
107
108 /*
109 * Members constant at init.
110 */
111 struct ttm_device *bdev;
112 enum ttm_bo_type type;
113 uint32_t page_alignment;
114 void (*destroy) (struct ttm_buffer_object *);
115
116 /*
117 * Members not needing protection.
118 */
119 struct kref kref;
120
121 /*
122 * Members protected by the bo::resv::reserved lock.
123 */
124 struct ttm_resource *resource;
125 struct ttm_tt *ttm;
126 bool deleted;
127 struct ttm_lru_bulk_move *bulk_move;
128 unsigned priority;
129 unsigned pin_count;
130
131 /**
132 * @delayed_delete: Work item used when we can't delete the BO
133 * immediately
134 */
135 struct work_struct delayed_delete;
136
137 /**
138 * @sg: external source of pages and DMA addresses, protected by the
139 * reservation lock.
140 */
141 struct sg_table *sg;
142 };
143
144 #define TTM_BO_MAP_IOMEM_MASK 0x80
145
146 /**
147 * struct ttm_bo_kmap_obj
148 *
149 * @virtual: The current kernel virtual address.
150 * @page: The page when kmap'ing a single page.
151 * @bo_kmap_type: Type of bo_kmap.
152 * @bo: The TTM BO.
153 *
154 * Object describing a kernel mapping. Since a TTM bo may be located
155 * in various memory types with various caching policies, the
156 * mapping can either be an ioremap, a vmap, a kmap or part of a
157 * premapped region.
158 */
159 struct ttm_bo_kmap_obj {
160 void *virtual;
161 struct page *page;
162 enum {
163 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
164 ttm_bo_map_vmap = 2,
165 ttm_bo_map_kmap = 3,
166 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
167 } bo_kmap_type;
168 struct ttm_buffer_object *bo;
169 };
170
171 /**
172 * struct ttm_operation_ctx
173 *
174 * @interruptible: Sleep interruptible if sleeping.
175 * @no_wait_gpu: Return immediately if the GPU is busy.
176 * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages.
177 * @allow_res_evict: Allow eviction of reserved BOs. Can be used when multiple
178 * BOs share the same reservation object.
179 * @force_alloc: Don't check the memory account during suspend or CPU page
180 * faults. Should only be used by TTM internally.
181 * @resv: Reservation object to allow reserved evictions with.
182 * @bytes_moved: Statistics on how many bytes have been moved.
183 *
184 * Context for TTM operations like changing buffer placement or general memory
185 * allocation.
186 */
187 struct ttm_operation_ctx {
188 bool interruptible;
189 bool no_wait_gpu;
190 bool gfp_retry_mayfail;
191 bool allow_res_evict;
192 bool force_alloc;
193 struct dma_resv *resv;
194 uint64_t bytes_moved;
195 };
196
197 /**
198 * ttm_bo_get - reference a struct ttm_buffer_object
199 *
200 * @bo: The buffer object.
201 */
202 static inline void ttm_bo_get(struct ttm_buffer_object *bo)
203 {
204 kref_get(&bo->kref);
205 }
206
207 /**
208 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
209 * its refcount has already reached zero.
210 * @bo: The buffer object.
211 *
212 * Used to reference a TTM buffer object in lookups where the object is removed
213 * from the lookup structure during the destructor and for RCU lookups.
214 *
215 * Returns: @bo if the referencing was successful, NULL otherwise.
216 */
217 static inline __must_check struct ttm_buffer_object *
218 ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
219 {
220 if (!kref_get_unless_zero(&bo->kref))
221 return NULL;
222 return bo;
223 }
224
225 /**
226 * ttm_bo_reserve:
227 *
228 * @bo: A pointer to a struct ttm_buffer_object.
229 * @interruptible: Sleep interruptible if waiting.
230 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
231 * @ticket: ticket used to acquire the ww_mutex.
232 *
233 * Locks a buffer object for validation. (Or prevents other processes from
234 * locking it for validation), while taking a number of measures to prevent
235 * deadlocks.
236 *
237 * Returns:
238 * -EDEADLK: The reservation may cause a deadlock.
239 * Release all buffer reservations, wait for @bo to become unreserved and
240 * try again.
241 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
242 * a signal. Release all buffer reservations and return to user-space.
243 * -EBUSY: The function needed to sleep, but @no_wait was true
244 * -EALREADY: Bo already reserved using @ticket. This error code will only
245 * be returned if @use_ticket is set to true.
246 */
247 static inline int ttm_bo_reserve(struct ttm_buffer_object *bo,
248 bool interruptible, bool no_wait,
249 struct ww_acquire_ctx *ticket)
250 {
251 int ret = 0;
252
253 if (no_wait) {
254 bool success;
255
256 if (WARN_ON(ticket))
257 return -EBUSY;
258
259 success = dma_resv_trylock(bo->base.resv);
260 return success ? 0 : -EBUSY;
261 }
262
263 if (interruptible)
264 ret = dma_resv_lock_interruptible(bo->base.resv, ticket);
265 else
266 ret = dma_resv_lock(bo->base.resv, ticket);
267 if (ret == -EINTR)
268 return -ERESTARTSYS;
269 return ret;
270 }
271
272 /**
273 * ttm_bo_reserve_slowpath:
274 * @bo: A pointer to a struct ttm_buffer_object.
275 * @interruptible: Sleep interruptible if waiting.
276 * @ticket: Ticket used to acquire the ww_mutex.
277 *
278 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
279 * from all our other reservations. Because there are no other reservations
280 * held by us, this function cannot deadlock any more.
281 */
282 static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
283 bool interruptible,
284 struct ww_acquire_ctx *ticket)
285 {
286 if (interruptible) {
287 int ret = dma_resv_lock_slow_interruptible(bo->base.resv,
288 ticket);
289 if (ret == -EINTR)
290 ret = -ERESTARTSYS;
291 return ret;
292 }
293 dma_resv_lock_slow(bo->base.resv, ticket);
294 return 0;
295 }
296
297 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
298
299 static inline void
300 ttm_bo_move_to_lru_tail_unlocked(struct ttm_buffer_object *bo)
301 {
302 spin_lock(&bo->bdev->lru_lock);
303 ttm_bo_move_to_lru_tail(bo);
304 spin_unlock(&bo->bdev->lru_lock);
305 }
306
307 static inline void ttm_bo_assign_mem(struct ttm_buffer_object *bo,
308 struct ttm_resource *new_mem)
309 {
310 WARN_ON(bo->resource);
311 bo->resource = new_mem;
312 }
313
314 /**
315 * ttm_bo_move_null - assign memory for a buffer object.
316 * @bo: The bo to assign the memory to
317 * @new_mem: The memory to be assigned.
318 *
319 * Assign the memory from new_mem to the memory of the buffer object bo.
320 */
321 static inline void ttm_bo_move_null(struct ttm_buffer_object *bo,
322 struct ttm_resource *new_mem)
323 {
324 ttm_resource_free(bo, &bo->resource);
325 ttm_bo_assign_mem(bo, new_mem);
326 }
327
328 /**
329 * ttm_bo_unreserve
330 *
331 * @bo: A pointer to a struct ttm_buffer_object.
332 *
333 * Unreserve a previous reservation of @bo.
334 */
335 static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo)
336 {
337 ttm_bo_move_to_lru_tail_unlocked(bo);
338 dma_resv_unlock(bo->base.resv);
339 }
340
341 /**
342 * ttm_kmap_obj_virtual
343 *
344 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
345 * @is_iomem: Pointer to an integer that on return indicates 1 if the
346 * virtual map is io memory, 0 if normal memory.
347 *
348 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
349 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
350 * that should strictly be accessed by the iowriteXX() and similar functions.
351 */
352 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
353 bool *is_iomem)
354 {
355 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
356 return map->virtual;
357 }
358
359 int ttm_bo_wait_ctx(struct ttm_buffer_object *bo,
360 struct ttm_operation_ctx *ctx);
361 int ttm_bo_validate(struct ttm_buffer_object *bo,
362 struct ttm_placement *placement,
363 struct ttm_operation_ctx *ctx);
364 void ttm_bo_put(struct ttm_buffer_object *bo);
365 void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
366 struct ttm_lru_bulk_move *bulk);
367 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
368 const struct ttm_place *place);
369 int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,
370 enum ttm_bo_type type, struct ttm_placement *placement,
371 uint32_t alignment, struct ttm_operation_ctx *ctx,
372 struct sg_table *sg, struct dma_resv *resv,
373 void (*destroy)(struct ttm_buffer_object *));
374 int ttm_bo_init_validate(struct ttm_device *bdev, struct ttm_buffer_object *bo,
375 enum ttm_bo_type type, struct ttm_placement *placement,
376 uint32_t alignment, bool interruptible,
377 struct sg_table *sg, struct dma_resv *resv,
378 void (*destroy)(struct ttm_buffer_object *));
379 int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
380 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
381 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
382 int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map);
383 void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map);
384 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
385 int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
386 gfp_t gfp_flags);
387 void ttm_bo_pin(struct ttm_buffer_object *bo);
388 void ttm_bo_unpin(struct ttm_buffer_object *bo);
389 int ttm_mem_evict_first(struct ttm_device *bdev,
390 struct ttm_resource_manager *man,
391 const struct ttm_place *place,
392 struct ttm_operation_ctx *ctx,
393 struct ww_acquire_ctx *ticket);
394 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
395 struct vm_fault *vmf);
396 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
397 pgprot_t prot,
398 pgoff_t num_prefault);
399 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf);
400 void ttm_bo_vm_open(struct vm_area_struct *vma);
401 void ttm_bo_vm_close(struct vm_area_struct *vma);
402 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
403 void *buf, int len, int write);
404 vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot);
405
406 int ttm_bo_mem_space(struct ttm_buffer_object *bo,
407 struct ttm_placement *placement,
408 struct ttm_resource **mem,
409 struct ttm_operation_ctx *ctx);
410
411 void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
412 /*
413 * ttm_bo_util.c
414 */
415 int ttm_mem_io_reserve(struct ttm_device *bdev,
416 struct ttm_resource *mem);
417 void ttm_mem_io_free(struct ttm_device *bdev,
418 struct ttm_resource *mem);
419 void ttm_move_memcpy(bool clear, u32 num_pages,
420 struct ttm_kmap_iter *dst_iter,
421 struct ttm_kmap_iter *src_iter);
422 int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
423 struct ttm_operation_ctx *ctx,
424 struct ttm_resource *new_mem);
425 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
426 struct dma_fence *fence, bool evict,
427 bool pipeline,
428 struct ttm_resource *new_mem);
429 void ttm_bo_move_sync_cleanup(struct ttm_buffer_object *bo,
430 struct ttm_resource *new_mem);
431 int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo);
432 pgprot_t ttm_io_prot(struct ttm_buffer_object *bo, struct ttm_resource *res,
433 pgprot_t tmp);
434 void ttm_bo_tt_destroy(struct ttm_buffer_object *bo);
435
436 #endif
437
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