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1// SPDX-License-Identifier: GPL-2.0-or-later
2
3#include <drm/drm_gem_vram_helper.h>
4#include <drm/drm_device.h>
5#include <drm/drm_mode.h>
6#include <drm/drm_prime.h>
7#include <drm/drm_vram_mm_helper.h>
8#include <drm/ttm/ttm_page_alloc.h>
9
10static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
11
12/**
13 * DOC: overview
14 *
15 * This library provides a GEM buffer object that is backed by video RAM
16 * (VRAM). It can be used for framebuffer devices with dedicated memory.
17 */
18
19/*
20 * Buffer-objects helpers
21 */
22
23static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
24{
25 /* We got here via ttm_bo_put(), which means that the
26 * TTM buffer object in 'bo' has already been cleaned
27 * up; only release the GEM object.
28 */
29 drm_gem_object_release(&gbo->bo.base);
30}
31
32static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
33{
34 drm_gem_vram_cleanup(gbo);
35 kfree(gbo);
36}
37
38static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
39{
40 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
41
42 drm_gem_vram_destroy(gbo);
43}
44
45static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
46 unsigned long pl_flag)
47{
48 unsigned int i;
49 unsigned int c = 0;
50
51 gbo->placement.placement = gbo->placements;
52 gbo->placement.busy_placement = gbo->placements;
53
54 if (pl_flag & TTM_PL_FLAG_VRAM)
55 gbo->placements[c++].flags = TTM_PL_FLAG_WC |
56 TTM_PL_FLAG_UNCACHED |
57 TTM_PL_FLAG_VRAM;
58
59 if (pl_flag & TTM_PL_FLAG_SYSTEM)
60 gbo->placements[c++].flags = TTM_PL_MASK_CACHING |
61 TTM_PL_FLAG_SYSTEM;
62
63 if (!c)
64 gbo->placements[c++].flags = TTM_PL_MASK_CACHING |
65 TTM_PL_FLAG_SYSTEM;
66
67 gbo->placement.num_placement = c;
68 gbo->placement.num_busy_placement = c;
69
70 for (i = 0; i < c; ++i) {
71 gbo->placements[i].fpfn = 0;
72 gbo->placements[i].lpfn = 0;
73 }
74}
75
76static int drm_gem_vram_init(struct drm_device *dev,
77 struct ttm_bo_device *bdev,
78 struct drm_gem_vram_object *gbo,
79 size_t size, unsigned long pg_align,
80 bool interruptible)
81{
82 int ret;
83 size_t acc_size;
84
85 if (!gbo->bo.base.funcs)
86 gbo->bo.base.funcs = &drm_gem_vram_object_funcs;
87
88 ret = drm_gem_object_init(dev, &gbo->bo.base, size);
89 if (ret)
90 return ret;
91
92 acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo));
93
94 gbo->bo.bdev = bdev;
95 drm_gem_vram_placement(gbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
96
97 ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device,
98 &gbo->placement, pg_align, interruptible, acc_size,
99 NULL, NULL, ttm_buffer_object_destroy);
100 if (ret)
101 goto err_drm_gem_object_release;
102
103 return 0;
104
105err_drm_gem_object_release:
106 drm_gem_object_release(&gbo->bo.base);
107 return ret;
108}
109
110/**
111 * drm_gem_vram_create() - Creates a VRAM-backed GEM object
112 * @dev: the DRM device
113 * @bdev: the TTM BO device backing the object
114 * @size: the buffer size in bytes
115 * @pg_align: the buffer's alignment in multiples of the page size
116 * @interruptible: sleep interruptible if waiting for memory
117 *
118 * Returns:
119 * A new instance of &struct drm_gem_vram_object on success, or
120 * an ERR_PTR()-encoded error code otherwise.
121 */
122struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
123 struct ttm_bo_device *bdev,
124 size_t size,
125 unsigned long pg_align,
126 bool interruptible)
127{
128 struct drm_gem_vram_object *gbo;
129 int ret;
130
131 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
132 if (!gbo)
133 return ERR_PTR(-ENOMEM);
134
135 ret = drm_gem_vram_init(dev, bdev, gbo, size, pg_align, interruptible);
136 if (ret < 0)
137 goto err_kfree;
138
139 return gbo;
140
141err_kfree:
142 kfree(gbo);
143 return ERR_PTR(ret);
144}
145EXPORT_SYMBOL(drm_gem_vram_create);
146
147/**
148 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
149 * @gbo: the GEM VRAM object
150 *
151 * See ttm_bo_put() for more information.
152 */
153void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
154{
155 ttm_bo_put(&gbo->bo);
156}
157EXPORT_SYMBOL(drm_gem_vram_put);
158
159/**
160 * drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset
161 * @gbo: the GEM VRAM object
162 *
163 * See drm_vma_node_offset_addr() for more information.
164 *
165 * Returns:
166 * The buffer object's offset for userspace mappings on success, or
167 * 0 if no offset is allocated.
168 */
169u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo)
170{
171 return drm_vma_node_offset_addr(&gbo->bo.base.vma_node);
172}
173EXPORT_SYMBOL(drm_gem_vram_mmap_offset);
174
175/**
176 * drm_gem_vram_offset() - \
177 Returns a GEM VRAM object's offset in video memory
178 * @gbo: the GEM VRAM object
179 *
180 * This function returns the buffer object's offset in the device's video
181 * memory. The buffer object has to be pinned to %TTM_PL_VRAM.
182 *
183 * Returns:
184 * The buffer object's offset in video memory on success, or
185 * a negative errno code otherwise.
186 */
187s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
188{
189 if (WARN_ON_ONCE(!gbo->pin_count))
190 return (s64)-ENODEV;
191 return gbo->bo.offset;
192}
193EXPORT_SYMBOL(drm_gem_vram_offset);
194
195/**
196 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
197 * @gbo: the GEM VRAM object
198 * @pl_flag: a bitmask of possible memory regions
199 *
200 * Pinning a buffer object ensures that it is not evicted from
201 * a memory region. A pinned buffer object has to be unpinned before
202 * it can be pinned to another region. If the pl_flag argument is 0,
203 * the buffer is pinned at its current location (video RAM or system
204 * memory).
205 *
206 * Returns:
207 * 0 on success, or
208 * a negative error code otherwise.
209 */
210int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
211{
212 int i, ret;
213 struct ttm_operation_ctx ctx = { false, false };
214
215 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
216 if (ret < 0)
217 return ret;
218
219 if (gbo->pin_count)
220 goto out;
221
222 if (pl_flag)
223 drm_gem_vram_placement(gbo, pl_flag);
224
225 for (i = 0; i < gbo->placement.num_placement; ++i)
226 gbo->placements[i].flags |= TTM_PL_FLAG_NO_EVICT;
227
228 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
229 if (ret < 0)
230 goto err_ttm_bo_unreserve;
231
232out:
233 ++gbo->pin_count;
234 ttm_bo_unreserve(&gbo->bo);
235
236 return 0;
237
238err_ttm_bo_unreserve:
239 ttm_bo_unreserve(&gbo->bo);
240 return ret;
241}
242EXPORT_SYMBOL(drm_gem_vram_pin);
243
244/**
245 * drm_gem_vram_unpin() - Unpins a GEM VRAM object
246 * @gbo: the GEM VRAM object
247 *
248 * Returns:
249 * 0 on success, or
250 * a negative error code otherwise.
251 */
252int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
253{
254 int i, ret;
255 struct ttm_operation_ctx ctx = { false, false };
256
257 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
258 if (ret < 0)
259 return ret;
260
261 if (WARN_ON_ONCE(!gbo->pin_count))
262 goto out;
263
264 --gbo->pin_count;
265 if (gbo->pin_count)
266 goto out;
267
268 for (i = 0; i < gbo->placement.num_placement ; ++i)
269 gbo->placements[i].flags &= ~TTM_PL_FLAG_NO_EVICT;
270
271 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
272 if (ret < 0)
273 goto err_ttm_bo_unreserve;
274
275out:
276 ttm_bo_unreserve(&gbo->bo);
277
278 return 0;
279
280err_ttm_bo_unreserve:
281 ttm_bo_unreserve(&gbo->bo);
282 return ret;
283}
284EXPORT_SYMBOL(drm_gem_vram_unpin);
285
286/**
287 * drm_gem_vram_kmap() - Maps a GEM VRAM object into kernel address space
288 * @gbo: the GEM VRAM object
289 * @map: establish a mapping if necessary
290 * @is_iomem: returns true if the mapped memory is I/O memory, or false \
291 otherwise; can be NULL
292 *
293 * This function maps the buffer object into the kernel's address space
294 * or returns the current mapping. If the parameter map is false, the
295 * function only queries the current mapping, but does not establish a
296 * new one.
297 *
298 * Returns:
299 * The buffers virtual address if mapped, or
300 * NULL if not mapped, or
301 * an ERR_PTR()-encoded error code otherwise.
302 */
303void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
304 bool *is_iomem)
305{
306 int ret;
307 struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
308
309 if (kmap->virtual || !map)
310 goto out;
311
312 ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap);
313 if (ret)
314 return ERR_PTR(ret);
315
316out:
317 if (!is_iomem)
318 return kmap->virtual;
319 if (!kmap->virtual) {
320 *is_iomem = false;
321 return NULL;
322 }
323 return ttm_kmap_obj_virtual(kmap, is_iomem);
324}
325EXPORT_SYMBOL(drm_gem_vram_kmap);
326
327/**
328 * drm_gem_vram_kunmap() - Unmaps a GEM VRAM object
329 * @gbo: the GEM VRAM object
330 */
331void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo)
332{
333 struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
334
335 if (!kmap->virtual)
336 return;
337
338 ttm_bo_kunmap(kmap);
339 kmap->virtual = NULL;
340}
341EXPORT_SYMBOL(drm_gem_vram_kunmap);
342
343/**
344 * drm_gem_vram_fill_create_dumb() - \
345 Helper for implementing &struct drm_driver.dumb_create
346 * @file: the DRM file
347 * @dev: the DRM device
348 * @bdev: the TTM BO device managing the buffer object
349 * @pg_align: the buffer's alignment in multiples of the page size
350 * @interruptible: sleep interruptible if waiting for memory
351 * @args: the arguments as provided to \
352 &struct drm_driver.dumb_create
353 *
354 * This helper function fills &struct drm_mode_create_dumb, which is used
355 * by &struct drm_driver.dumb_create. Implementations of this interface
356 * should forwards their arguments to this helper, plus the driver-specific
357 * parameters.
358 *
359 * Returns:
360 * 0 on success, or
361 * a negative error code otherwise.
362 */
363int drm_gem_vram_fill_create_dumb(struct drm_file *file,
364 struct drm_device *dev,
365 struct ttm_bo_device *bdev,
366 unsigned long pg_align,
367 bool interruptible,
368 struct drm_mode_create_dumb *args)
369{
370 size_t pitch, size;
371 struct drm_gem_vram_object *gbo;
372 int ret;
373 u32 handle;
374
375 pitch = args->width * ((args->bpp + 7) / 8);
376 size = pitch * args->height;
377
378 size = roundup(size, PAGE_SIZE);
379 if (!size)
380 return -EINVAL;
381
382 gbo = drm_gem_vram_create(dev, bdev, size, pg_align, interruptible);
383 if (IS_ERR(gbo))
384 return PTR_ERR(gbo);
385
386 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
387 if (ret)
388 goto err_drm_gem_object_put_unlocked;
389
390 drm_gem_object_put_unlocked(&gbo->bo.base);
391
392 args->pitch = pitch;
393 args->size = size;
394 args->handle = handle;
395
396 return 0;
397
398err_drm_gem_object_put_unlocked:
399 drm_gem_object_put_unlocked(&gbo->bo.base);
400 return ret;
401}
402EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
403
404/*
405 * Helpers for struct ttm_bo_driver
406 */
407
408static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
409{
410 return (bo->destroy == ttm_buffer_object_destroy);
411}
412
413/**
414 * drm_gem_vram_bo_driver_evict_flags() - \
415 Implements &struct ttm_bo_driver.evict_flags
416 * @bo: TTM buffer object. Refers to &struct drm_gem_vram_object.bo
417 * @pl: TTM placement information.
418 */
419void drm_gem_vram_bo_driver_evict_flags(struct ttm_buffer_object *bo,
420 struct ttm_placement *pl)
421{
422 struct drm_gem_vram_object *gbo;
423
424 /* TTM may pass BOs that are not GEM VRAM BOs. */
425 if (!drm_is_gem_vram(bo))
426 return;
427
428 gbo = drm_gem_vram_of_bo(bo);
429 drm_gem_vram_placement(gbo, TTM_PL_FLAG_SYSTEM);
430 *pl = gbo->placement;
431}
432EXPORT_SYMBOL(drm_gem_vram_bo_driver_evict_flags);
433
434/**
435 * drm_gem_vram_bo_driver_verify_access() - \
436 Implements &struct ttm_bo_driver.verify_access
437 * @bo: TTM buffer object. Refers to &struct drm_gem_vram_object.bo
438 * @filp: File pointer.
439 *
440 * Returns:
441 * 0 on success, or
442 * a negative errno code otherwise.
443 */
444int drm_gem_vram_bo_driver_verify_access(struct ttm_buffer_object *bo,
445 struct file *filp)
446{
447 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
448
449 return drm_vma_node_verify_access(&gbo->bo.base.vma_node,
450 filp->private_data);
451}
452EXPORT_SYMBOL(drm_gem_vram_bo_driver_verify_access);
453
454/*
455 * drm_gem_vram_mm_funcs - Functions for &struct drm_vram_mm
456 *
457 * Most users of @struct drm_gem_vram_object will also use
458 * @struct drm_vram_mm. This instance of &struct drm_vram_mm_funcs
459 * can be used to connect both.
460 */
461const struct drm_vram_mm_funcs drm_gem_vram_mm_funcs = {
462 .evict_flags = drm_gem_vram_bo_driver_evict_flags,
463 .verify_access = drm_gem_vram_bo_driver_verify_access
464};
465EXPORT_SYMBOL(drm_gem_vram_mm_funcs);
466
467/*
468 * Helpers for struct drm_gem_object_funcs
469 */
470
471/**
472 * drm_gem_vram_object_free() - \
473 Implements &struct drm_gem_object_funcs.free
474 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
475 */
476static void drm_gem_vram_object_free(struct drm_gem_object *gem)
477{
478 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
479
480 drm_gem_vram_put(gbo);
481}
482
483/*
484 * Helpers for dump buffers
485 */
486
487/**
488 * drm_gem_vram_driver_create_dumb() - \
489 Implements &struct drm_driver.dumb_create
490 * @file: the DRM file
491 * @dev: the DRM device
492 * @args: the arguments as provided to \
493 &struct drm_driver.dumb_create
494 *
495 * This function requires the driver to use @drm_device.vram_mm for its
496 * instance of VRAM MM.
497 *
498 * Returns:
499 * 0 on success, or
500 * a negative error code otherwise.
501 */
502int drm_gem_vram_driver_dumb_create(struct drm_file *file,
503 struct drm_device *dev,
504 struct drm_mode_create_dumb *args)
505{
506 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
507 return -EINVAL;
508
509 return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev, 0,
510 false, args);
511}
512EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
513
514/**
515 * drm_gem_vram_driver_dumb_mmap_offset() - \
516 Implements &struct drm_driver.dumb_mmap_offset
517 * @file: DRM file pointer.
518 * @dev: DRM device.
519 * @handle: GEM handle
520 * @offset: Returns the mapping's memory offset on success
521 *
522 * Returns:
523 * 0 on success, or
524 * a negative errno code otherwise.
525 */
526int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
527 struct drm_device *dev,
528 uint32_t handle, uint64_t *offset)
529{
530 struct drm_gem_object *gem;
531 struct drm_gem_vram_object *gbo;
532
533 gem = drm_gem_object_lookup(file, handle);
534 if (!gem)
535 return -ENOENT;
536
537 gbo = drm_gem_vram_of_gem(gem);
538 *offset = drm_gem_vram_mmap_offset(gbo);
539
540 drm_gem_object_put_unlocked(gem);
541
542 return 0;
543}
544EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset);
545
546/*
547 * PRIME helpers
548 */
549
550/**
551 * drm_gem_vram_object_pin() - \
552 Implements &struct drm_gem_object_funcs.pin
553 * @gem: The GEM object to pin
554 *
555 * Returns:
556 * 0 on success, or
557 * a negative errno code otherwise.
558 */
559static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
560{
561 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
562
563 /* Fbdev console emulation is the use case of these PRIME
564 * helpers. This may involve updating a hardware buffer from
565 * a shadow FB. We pin the buffer to it's current location
566 * (either video RAM or system memory) to prevent it from
567 * being relocated during the update operation. If you require
568 * the buffer to be pinned to VRAM, implement a callback that
569 * sets the flags accordingly.
570 */
571 return drm_gem_vram_pin(gbo, 0);
572}
573
574/**
575 * drm_gem_vram_object_unpin() - \
576 Implements &struct drm_gem_object_funcs.unpin
577 * @gem: The GEM object to unpin
578 */
579static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
580{
581 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
582
583 drm_gem_vram_unpin(gbo);
584}
585
586/**
587 * drm_gem_vram_object_vmap() - \
588 Implements &struct drm_gem_object_funcs.vmap
589 * @gem: The GEM object to map
590 *
591 * Returns:
592 * The buffers virtual address on success, or
593 * NULL otherwise.
594 */
595static void *drm_gem_vram_object_vmap(struct drm_gem_object *gem)
596{
597 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
598 int ret;
599 void *base;
600
601 ret = drm_gem_vram_pin(gbo, 0);
602 if (ret)
603 return NULL;
604 base = drm_gem_vram_kmap(gbo, true, NULL);
605 if (IS_ERR(base)) {
606 drm_gem_vram_unpin(gbo);
607 return NULL;
608 }
609 return base;
610}
611
612/**
613 * drm_gem_vram_object_vunmap() - \
614 Implements &struct drm_gem_object_funcs.vunmap
615 * @gem: The GEM object to unmap
616 * @vaddr: The mapping's base address
617 */
618static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem,
619 void *vaddr)
620{
621 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
622
623 drm_gem_vram_kunmap(gbo);
624 drm_gem_vram_unpin(gbo);
625}
626
627/*
628 * GEM object funcs
629 */
630
631static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
632 .free = drm_gem_vram_object_free,
633 .pin = drm_gem_vram_object_pin,
634 .unpin = drm_gem_vram_object_unpin,
635 .vmap = drm_gem_vram_object_vmap,
636 .vunmap = drm_gem_vram_object_vunmap
637};
1// SPDX-License-Identifier: GPL-2.0-or-later
2
3#include <linux/iosys-map.h>
4#include <linux/module.h>
5
6#include <drm/drm_debugfs.h>
7#include <drm/drm_device.h>
8#include <drm/drm_drv.h>
9#include <drm/drm_file.h>
10#include <drm/drm_framebuffer.h>
11#include <drm/drm_gem_atomic_helper.h>
12#include <drm/drm_gem_framebuffer_helper.h>
13#include <drm/drm_gem_ttm_helper.h>
14#include <drm/drm_gem_vram_helper.h>
15#include <drm/drm_managed.h>
16#include <drm/drm_mode.h>
17#include <drm/drm_plane.h>
18#include <drm/drm_prime.h>
19#include <drm/drm_simple_kms_helper.h>
20
21#include <drm/ttm/ttm_range_manager.h>
22#include <drm/ttm/ttm_tt.h>
23
24static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
25
26/**
27 * DOC: overview
28 *
29 * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM
30 * buffer object that is backed by video RAM (VRAM). It can be used for
31 * framebuffer devices with dedicated memory.
32 *
33 * The data structure &struct drm_vram_mm and its helpers implement a memory
34 * manager for simple framebuffer devices with dedicated video memory. GEM
35 * VRAM buffer objects are either placed in the video memory or remain evicted
36 * to system memory.
37 *
38 * With the GEM interface userspace applications create, manage and destroy
39 * graphics buffers, such as an on-screen framebuffer. GEM does not provide
40 * an implementation of these interfaces. It's up to the DRM driver to
41 * provide an implementation that suits the hardware. If the hardware device
42 * contains dedicated video memory, the DRM driver can use the VRAM helper
43 * library. Each active buffer object is stored in video RAM. Active
44 * buffer are used for drawing the current frame, typically something like
45 * the frame's scanout buffer or the cursor image. If there's no more space
46 * left in VRAM, inactive GEM objects can be moved to system memory.
47 *
48 * To initialize the VRAM helper library call drmm_vram_helper_init().
49 * The function allocates and initializes an instance of &struct drm_vram_mm
50 * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize
51 * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize
52 * &struct file_operations; as illustrated below.
53 *
54 * .. code-block:: c
55 *
56 * struct file_operations fops ={
57 * .owner = THIS_MODULE,
58 * DRM_VRAM_MM_FILE_OPERATION
59 * };
60 * struct drm_driver drv = {
61 * .driver_feature = DRM_ ... ,
62 * .fops = &fops,
63 * DRM_GEM_VRAM_DRIVER
64 * };
65 *
66 * int init_drm_driver()
67 * {
68 * struct drm_device *dev;
69 * uint64_t vram_base;
70 * unsigned long vram_size;
71 * int ret;
72 *
73 * // setup device, vram base and size
74 * // ...
75 *
76 * ret = drmm_vram_helper_init(dev, vram_base, vram_size);
77 * if (ret)
78 * return ret;
79 * return 0;
80 * }
81 *
82 * This creates an instance of &struct drm_vram_mm, exports DRM userspace
83 * interfaces for GEM buffer management and initializes file operations to
84 * allow for accessing created GEM buffers. With this setup, the DRM driver
85 * manages an area of video RAM with VRAM MM and provides GEM VRAM objects
86 * to userspace.
87 *
88 * You don't have to clean up the instance of VRAM MM.
89 * drmm_vram_helper_init() is a managed interface that installs a
90 * clean-up handler to run during the DRM device's release.
91 *
92 * For drawing or scanout operations, rsp. buffer objects have to be pinned
93 * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or
94 * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system
95 * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards.
96 *
97 * A buffer object that is pinned in video RAM has a fixed address within that
98 * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically
99 * it's used to program the hardware's scanout engine for framebuffers, set
100 * the cursor overlay's image for a mouse cursor, or use it as input to the
101 * hardware's drawing engine.
102 *
103 * To access a buffer object's memory from the DRM driver, call
104 * drm_gem_vram_vmap(). It maps the buffer into kernel address
105 * space and returns the memory address. Use drm_gem_vram_vunmap() to
106 * release the mapping.
107 */
108
109/*
110 * Buffer-objects helpers
111 */
112
113static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
114{
115 /* We got here via ttm_bo_put(), which means that the
116 * TTM buffer object in 'bo' has already been cleaned
117 * up; only release the GEM object.
118 */
119
120 WARN_ON(gbo->vmap_use_count);
121 WARN_ON(iosys_map_is_set(&gbo->map));
122
123 drm_gem_object_release(&gbo->bo.base);
124}
125
126static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
127{
128 drm_gem_vram_cleanup(gbo);
129 kfree(gbo);
130}
131
132static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
133{
134 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
135
136 drm_gem_vram_destroy(gbo);
137}
138
139static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
140 unsigned long pl_flag)
141{
142 u32 invariant_flags = 0;
143 unsigned int i;
144 unsigned int c = 0;
145
146 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_TOPDOWN)
147 invariant_flags = TTM_PL_FLAG_TOPDOWN;
148
149 gbo->placement.placement = gbo->placements;
150 gbo->placement.busy_placement = gbo->placements;
151
152 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_VRAM) {
153 gbo->placements[c].mem_type = TTM_PL_VRAM;
154 gbo->placements[c++].flags = invariant_flags;
155 }
156
157 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_SYSTEM || !c) {
158 gbo->placements[c].mem_type = TTM_PL_SYSTEM;
159 gbo->placements[c++].flags = invariant_flags;
160 }
161
162 gbo->placement.num_placement = c;
163 gbo->placement.num_busy_placement = c;
164
165 for (i = 0; i < c; ++i) {
166 gbo->placements[i].fpfn = 0;
167 gbo->placements[i].lpfn = 0;
168 }
169}
170
171/**
172 * drm_gem_vram_create() - Creates a VRAM-backed GEM object
173 * @dev: the DRM device
174 * @size: the buffer size in bytes
175 * @pg_align: the buffer's alignment in multiples of the page size
176 *
177 * GEM objects are allocated by calling struct drm_driver.gem_create_object,
178 * if set. Otherwise kzalloc() will be used. Drivers can set their own GEM
179 * object functions in struct drm_driver.gem_create_object. If no functions
180 * are set, the new GEM object will use the default functions from GEM VRAM
181 * helpers.
182 *
183 * Returns:
184 * A new instance of &struct drm_gem_vram_object on success, or
185 * an ERR_PTR()-encoded error code otherwise.
186 */
187struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
188 size_t size,
189 unsigned long pg_align)
190{
191 struct drm_gem_vram_object *gbo;
192 struct drm_gem_object *gem;
193 struct drm_vram_mm *vmm = dev->vram_mm;
194 struct ttm_device *bdev;
195 int ret;
196
197 if (WARN_ONCE(!vmm, "VRAM MM not initialized"))
198 return ERR_PTR(-EINVAL);
199
200 if (dev->driver->gem_create_object) {
201 gem = dev->driver->gem_create_object(dev, size);
202 if (IS_ERR(gem))
203 return ERR_CAST(gem);
204 gbo = drm_gem_vram_of_gem(gem);
205 } else {
206 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
207 if (!gbo)
208 return ERR_PTR(-ENOMEM);
209 gem = &gbo->bo.base;
210 }
211
212 if (!gem->funcs)
213 gem->funcs = &drm_gem_vram_object_funcs;
214
215 ret = drm_gem_object_init(dev, gem, size);
216 if (ret) {
217 kfree(gbo);
218 return ERR_PTR(ret);
219 }
220
221 bdev = &vmm->bdev;
222
223 gbo->bo.bdev = bdev;
224 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
225
226 /*
227 * A failing ttm_bo_init will call ttm_buffer_object_destroy
228 * to release gbo->bo.base and kfree gbo.
229 */
230 ret = ttm_bo_init_validate(bdev, &gbo->bo, ttm_bo_type_device,
231 &gbo->placement, pg_align, false, NULL, NULL,
232 ttm_buffer_object_destroy);
233 if (ret)
234 return ERR_PTR(ret);
235
236 return gbo;
237}
238EXPORT_SYMBOL(drm_gem_vram_create);
239
240/**
241 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
242 * @gbo: the GEM VRAM object
243 *
244 * See ttm_bo_put() for more information.
245 */
246void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
247{
248 ttm_bo_put(&gbo->bo);
249}
250EXPORT_SYMBOL(drm_gem_vram_put);
251
252static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo)
253{
254 /* Keep TTM behavior for now, remove when drivers are audited */
255 if (WARN_ON_ONCE(!gbo->bo.resource ||
256 gbo->bo.resource->mem_type == TTM_PL_SYSTEM))
257 return 0;
258
259 return gbo->bo.resource->start;
260}
261
262/**
263 * drm_gem_vram_offset() - \
264 Returns a GEM VRAM object's offset in video memory
265 * @gbo: the GEM VRAM object
266 *
267 * This function returns the buffer object's offset in the device's video
268 * memory. The buffer object has to be pinned to %TTM_PL_VRAM.
269 *
270 * Returns:
271 * The buffer object's offset in video memory on success, or
272 * a negative errno code otherwise.
273 */
274s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
275{
276 if (WARN_ON_ONCE(!gbo->bo.pin_count))
277 return (s64)-ENODEV;
278 return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT;
279}
280EXPORT_SYMBOL(drm_gem_vram_offset);
281
282static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo,
283 unsigned long pl_flag)
284{
285 struct ttm_operation_ctx ctx = { false, false };
286 int ret;
287
288 if (gbo->bo.pin_count)
289 goto out;
290
291 if (pl_flag)
292 drm_gem_vram_placement(gbo, pl_flag);
293
294 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
295 if (ret < 0)
296 return ret;
297
298out:
299 ttm_bo_pin(&gbo->bo);
300
301 return 0;
302}
303
304/**
305 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
306 * @gbo: the GEM VRAM object
307 * @pl_flag: a bitmask of possible memory regions
308 *
309 * Pinning a buffer object ensures that it is not evicted from
310 * a memory region. A pinned buffer object has to be unpinned before
311 * it can be pinned to another region. If the pl_flag argument is 0,
312 * the buffer is pinned at its current location (video RAM or system
313 * memory).
314 *
315 * Small buffer objects, such as cursor images, can lead to memory
316 * fragmentation if they are pinned in the middle of video RAM. This
317 * is especially a problem on devices with only a small amount of
318 * video RAM. Fragmentation can prevent the primary framebuffer from
319 * fitting in, even though there's enough memory overall. The modifier
320 * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned
321 * at the high end of the memory region to avoid fragmentation.
322 *
323 * Returns:
324 * 0 on success, or
325 * a negative error code otherwise.
326 */
327int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
328{
329 int ret;
330
331 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
332 if (ret)
333 return ret;
334 ret = drm_gem_vram_pin_locked(gbo, pl_flag);
335 ttm_bo_unreserve(&gbo->bo);
336
337 return ret;
338}
339EXPORT_SYMBOL(drm_gem_vram_pin);
340
341static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo)
342{
343 ttm_bo_unpin(&gbo->bo);
344}
345
346/**
347 * drm_gem_vram_unpin() - Unpins a GEM VRAM object
348 * @gbo: the GEM VRAM object
349 *
350 * Returns:
351 * 0 on success, or
352 * a negative error code otherwise.
353 */
354int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
355{
356 int ret;
357
358 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
359 if (ret)
360 return ret;
361
362 drm_gem_vram_unpin_locked(gbo);
363 ttm_bo_unreserve(&gbo->bo);
364
365 return 0;
366}
367EXPORT_SYMBOL(drm_gem_vram_unpin);
368
369static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
370 struct iosys_map *map)
371{
372 int ret;
373
374 if (gbo->vmap_use_count > 0)
375 goto out;
376
377 /*
378 * VRAM helpers unmap the BO only on demand. So the previous
379 * page mapping might still be around. Only vmap if the there's
380 * no mapping present.
381 */
382 if (iosys_map_is_null(&gbo->map)) {
383 ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
384 if (ret)
385 return ret;
386 }
387
388out:
389 ++gbo->vmap_use_count;
390 *map = gbo->map;
391
392 return 0;
393}
394
395static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo,
396 struct iosys_map *map)
397{
398 struct drm_device *dev = gbo->bo.base.dev;
399
400 if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
401 return;
402
403 if (drm_WARN_ON_ONCE(dev, !iosys_map_is_equal(&gbo->map, map)))
404 return; /* BUG: map not mapped from this BO */
405
406 if (--gbo->vmap_use_count > 0)
407 return;
408
409 /*
410 * Permanently mapping and unmapping buffers adds overhead from
411 * updating the page tables and creates debugging output. Therefore,
412 * we delay the actual unmap operation until the BO gets evicted
413 * from memory. See drm_gem_vram_bo_driver_move_notify().
414 */
415}
416
417/**
418 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
419 * space
420 * @gbo: The GEM VRAM object to map
421 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
422 * store.
423 *
424 * The vmap function pins a GEM VRAM object to its current location, either
425 * system or video memory, and maps its buffer into kernel address space.
426 * As pinned object cannot be relocated, you should avoid pinning objects
427 * permanently. Call drm_gem_vram_vunmap() with the returned address to
428 * unmap and unpin the GEM VRAM object.
429 *
430 * Returns:
431 * 0 on success, or a negative error code otherwise.
432 */
433int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct iosys_map *map)
434{
435 int ret;
436
437 dma_resv_assert_held(gbo->bo.base.resv);
438
439 ret = drm_gem_vram_pin_locked(gbo, 0);
440 if (ret)
441 return ret;
442 ret = drm_gem_vram_kmap_locked(gbo, map);
443 if (ret)
444 goto err_drm_gem_vram_unpin_locked;
445
446 return 0;
447
448err_drm_gem_vram_unpin_locked:
449 drm_gem_vram_unpin_locked(gbo);
450 return ret;
451}
452EXPORT_SYMBOL(drm_gem_vram_vmap);
453
454/**
455 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object
456 * @gbo: The GEM VRAM object to unmap
457 * @map: Kernel virtual address where the VRAM GEM object was mapped
458 *
459 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See
460 * the documentation for drm_gem_vram_vmap() for more information.
461 */
462void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo,
463 struct iosys_map *map)
464{
465 dma_resv_assert_held(gbo->bo.base.resv);
466
467 drm_gem_vram_kunmap_locked(gbo, map);
468 drm_gem_vram_unpin_locked(gbo);
469}
470EXPORT_SYMBOL(drm_gem_vram_vunmap);
471
472/**
473 * drm_gem_vram_fill_create_dumb() - \
474 Helper for implementing &struct drm_driver.dumb_create
475 * @file: the DRM file
476 * @dev: the DRM device
477 * @pg_align: the buffer's alignment in multiples of the page size
478 * @pitch_align: the scanline's alignment in powers of 2
479 * @args: the arguments as provided to \
480 &struct drm_driver.dumb_create
481 *
482 * This helper function fills &struct drm_mode_create_dumb, which is used
483 * by &struct drm_driver.dumb_create. Implementations of this interface
484 * should forwards their arguments to this helper, plus the driver-specific
485 * parameters.
486 *
487 * Returns:
488 * 0 on success, or
489 * a negative error code otherwise.
490 */
491int drm_gem_vram_fill_create_dumb(struct drm_file *file,
492 struct drm_device *dev,
493 unsigned long pg_align,
494 unsigned long pitch_align,
495 struct drm_mode_create_dumb *args)
496{
497 size_t pitch, size;
498 struct drm_gem_vram_object *gbo;
499 int ret;
500 u32 handle;
501
502 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
503 if (pitch_align) {
504 if (WARN_ON_ONCE(!is_power_of_2(pitch_align)))
505 return -EINVAL;
506 pitch = ALIGN(pitch, pitch_align);
507 }
508 size = pitch * args->height;
509
510 size = roundup(size, PAGE_SIZE);
511 if (!size)
512 return -EINVAL;
513
514 gbo = drm_gem_vram_create(dev, size, pg_align);
515 if (IS_ERR(gbo))
516 return PTR_ERR(gbo);
517
518 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
519 if (ret)
520 goto err_drm_gem_object_put;
521
522 drm_gem_object_put(&gbo->bo.base);
523
524 args->pitch = pitch;
525 args->size = size;
526 args->handle = handle;
527
528 return 0;
529
530err_drm_gem_object_put:
531 drm_gem_object_put(&gbo->bo.base);
532 return ret;
533}
534EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
535
536/*
537 * Helpers for struct ttm_device_funcs
538 */
539
540static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
541{
542 return (bo->destroy == ttm_buffer_object_destroy);
543}
544
545static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo,
546 struct ttm_placement *pl)
547{
548 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
549 *pl = gbo->placement;
550}
551
552static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo)
553{
554 struct ttm_buffer_object *bo = &gbo->bo;
555 struct drm_device *dev = bo->base.dev;
556
557 if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count))
558 return;
559
560 ttm_bo_vunmap(bo, &gbo->map);
561 iosys_map_clear(&gbo->map); /* explicitly clear mapping for next vmap call */
562}
563
564static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo,
565 bool evict,
566 struct ttm_operation_ctx *ctx,
567 struct ttm_resource *new_mem)
568{
569 drm_gem_vram_bo_driver_move_notify(gbo);
570 return ttm_bo_move_memcpy(&gbo->bo, ctx, new_mem);
571}
572
573/*
574 * Helpers for struct drm_gem_object_funcs
575 */
576
577/**
578 * drm_gem_vram_object_free() - \
579 Implements &struct drm_gem_object_funcs.free
580 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
581 */
582static void drm_gem_vram_object_free(struct drm_gem_object *gem)
583{
584 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
585
586 drm_gem_vram_put(gbo);
587}
588
589/*
590 * Helpers for dump buffers
591 */
592
593/**
594 * drm_gem_vram_driver_dumb_create() - \
595 Implements &struct drm_driver.dumb_create
596 * @file: the DRM file
597 * @dev: the DRM device
598 * @args: the arguments as provided to \
599 &struct drm_driver.dumb_create
600 *
601 * This function requires the driver to use @drm_device.vram_mm for its
602 * instance of VRAM MM.
603 *
604 * Returns:
605 * 0 on success, or
606 * a negative error code otherwise.
607 */
608int drm_gem_vram_driver_dumb_create(struct drm_file *file,
609 struct drm_device *dev,
610 struct drm_mode_create_dumb *args)
611{
612 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
613 return -EINVAL;
614
615 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args);
616}
617EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
618
619/*
620 * Helpers for struct drm_plane_helper_funcs
621 */
622
623static void __drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
624 struct drm_plane_state *state,
625 unsigned int num_planes)
626{
627 struct drm_gem_object *obj;
628 struct drm_gem_vram_object *gbo;
629 struct drm_framebuffer *fb = state->fb;
630
631 while (num_planes) {
632 --num_planes;
633 obj = drm_gem_fb_get_obj(fb, num_planes);
634 if (!obj)
635 continue;
636 gbo = drm_gem_vram_of_gem(obj);
637 drm_gem_vram_unpin(gbo);
638 }
639}
640
641/**
642 * drm_gem_vram_plane_helper_prepare_fb() - \
643 * Implements &struct drm_plane_helper_funcs.prepare_fb
644 * @plane: a DRM plane
645 * @new_state: the plane's new state
646 *
647 * During plane updates, this function sets the plane's fence and
648 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM.
649 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them.
650 *
651 * Returns:
652 * 0 on success, or
653 * a negative errno code otherwise.
654 */
655int
656drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
657 struct drm_plane_state *new_state)
658{
659 struct drm_framebuffer *fb = new_state->fb;
660 struct drm_gem_vram_object *gbo;
661 struct drm_gem_object *obj;
662 unsigned int i;
663 int ret;
664
665 if (!fb)
666 return 0;
667
668 for (i = 0; i < fb->format->num_planes; ++i) {
669 obj = drm_gem_fb_get_obj(fb, i);
670 if (!obj) {
671 ret = -EINVAL;
672 goto err_drm_gem_vram_unpin;
673 }
674 gbo = drm_gem_vram_of_gem(obj);
675 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
676 if (ret)
677 goto err_drm_gem_vram_unpin;
678 }
679
680 ret = drm_gem_plane_helper_prepare_fb(plane, new_state);
681 if (ret)
682 goto err_drm_gem_vram_unpin;
683
684 return 0;
685
686err_drm_gem_vram_unpin:
687 __drm_gem_vram_plane_helper_cleanup_fb(plane, new_state, i);
688 return ret;
689}
690EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb);
691
692/**
693 * drm_gem_vram_plane_helper_cleanup_fb() - \
694 * Implements &struct drm_plane_helper_funcs.cleanup_fb
695 * @plane: a DRM plane
696 * @old_state: the plane's old state
697 *
698 * During plane updates, this function unpins the GEM VRAM
699 * objects of the plane's old framebuffer from VRAM. Complements
700 * drm_gem_vram_plane_helper_prepare_fb().
701 */
702void
703drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
704 struct drm_plane_state *old_state)
705{
706 struct drm_framebuffer *fb = old_state->fb;
707
708 if (!fb)
709 return;
710
711 __drm_gem_vram_plane_helper_cleanup_fb(plane, old_state, fb->format->num_planes);
712}
713EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb);
714
715/*
716 * Helpers for struct drm_simple_display_pipe_funcs
717 */
718
719/**
720 * drm_gem_vram_simple_display_pipe_prepare_fb() - \
721 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb
722 * @pipe: a simple display pipe
723 * @new_state: the plane's new state
724 *
725 * During plane updates, this function pins the GEM VRAM
726 * objects of the plane's new framebuffer to VRAM. Call
727 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them.
728 *
729 * Returns:
730 * 0 on success, or
731 * a negative errno code otherwise.
732 */
733int drm_gem_vram_simple_display_pipe_prepare_fb(
734 struct drm_simple_display_pipe *pipe,
735 struct drm_plane_state *new_state)
736{
737 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state);
738}
739EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb);
740
741/**
742 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \
743 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb
744 * @pipe: a simple display pipe
745 * @old_state: the plane's old state
746 *
747 * During plane updates, this function unpins the GEM VRAM
748 * objects of the plane's old framebuffer from VRAM. Complements
749 * drm_gem_vram_simple_display_pipe_prepare_fb().
750 */
751void drm_gem_vram_simple_display_pipe_cleanup_fb(
752 struct drm_simple_display_pipe *pipe,
753 struct drm_plane_state *old_state)
754{
755 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state);
756}
757EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb);
758
759/*
760 * PRIME helpers
761 */
762
763/**
764 * drm_gem_vram_object_pin() - \
765 Implements &struct drm_gem_object_funcs.pin
766 * @gem: The GEM object to pin
767 *
768 * Returns:
769 * 0 on success, or
770 * a negative errno code otherwise.
771 */
772static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
773{
774 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
775
776 /* Fbdev console emulation is the use case of these PRIME
777 * helpers. This may involve updating a hardware buffer from
778 * a shadow FB. We pin the buffer to it's current location
779 * (either video RAM or system memory) to prevent it from
780 * being relocated during the update operation. If you require
781 * the buffer to be pinned to VRAM, implement a callback that
782 * sets the flags accordingly.
783 */
784 return drm_gem_vram_pin(gbo, 0);
785}
786
787/**
788 * drm_gem_vram_object_unpin() - \
789 Implements &struct drm_gem_object_funcs.unpin
790 * @gem: The GEM object to unpin
791 */
792static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
793{
794 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
795
796 drm_gem_vram_unpin(gbo);
797}
798
799/**
800 * drm_gem_vram_object_vmap() -
801 * Implements &struct drm_gem_object_funcs.vmap
802 * @gem: The GEM object to map
803 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
804 * store.
805 *
806 * Returns:
807 * 0 on success, or a negative error code otherwise.
808 */
809static int drm_gem_vram_object_vmap(struct drm_gem_object *gem,
810 struct iosys_map *map)
811{
812 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
813
814 return drm_gem_vram_vmap(gbo, map);
815}
816
817/**
818 * drm_gem_vram_object_vunmap() -
819 * Implements &struct drm_gem_object_funcs.vunmap
820 * @gem: The GEM object to unmap
821 * @map: Kernel virtual address where the VRAM GEM object was mapped
822 */
823static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem,
824 struct iosys_map *map)
825{
826 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
827
828 drm_gem_vram_vunmap(gbo, map);
829}
830
831/*
832 * GEM object funcs
833 */
834
835static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
836 .free = drm_gem_vram_object_free,
837 .pin = drm_gem_vram_object_pin,
838 .unpin = drm_gem_vram_object_unpin,
839 .vmap = drm_gem_vram_object_vmap,
840 .vunmap = drm_gem_vram_object_vunmap,
841 .mmap = drm_gem_ttm_mmap,
842 .print_info = drm_gem_ttm_print_info,
843};
844
845/*
846 * VRAM memory manager
847 */
848
849/*
850 * TTM TT
851 */
852
853static void bo_driver_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt)
854{
855 ttm_tt_fini(tt);
856 kfree(tt);
857}
858
859/*
860 * TTM BO device
861 */
862
863static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo,
864 uint32_t page_flags)
865{
866 struct ttm_tt *tt;
867 int ret;
868
869 tt = kzalloc(sizeof(*tt), GFP_KERNEL);
870 if (!tt)
871 return NULL;
872
873 ret = ttm_tt_init(tt, bo, page_flags, ttm_cached, 0);
874 if (ret < 0)
875 goto err_ttm_tt_init;
876
877 return tt;
878
879err_ttm_tt_init:
880 kfree(tt);
881 return NULL;
882}
883
884static void bo_driver_evict_flags(struct ttm_buffer_object *bo,
885 struct ttm_placement *placement)
886{
887 struct drm_gem_vram_object *gbo;
888
889 /* TTM may pass BOs that are not GEM VRAM BOs. */
890 if (!drm_is_gem_vram(bo))
891 return;
892
893 gbo = drm_gem_vram_of_bo(bo);
894
895 drm_gem_vram_bo_driver_evict_flags(gbo, placement);
896}
897
898static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo)
899{
900 struct drm_gem_vram_object *gbo;
901
902 /* TTM may pass BOs that are not GEM VRAM BOs. */
903 if (!drm_is_gem_vram(bo))
904 return;
905
906 gbo = drm_gem_vram_of_bo(bo);
907
908 drm_gem_vram_bo_driver_move_notify(gbo);
909}
910
911static int bo_driver_move(struct ttm_buffer_object *bo,
912 bool evict,
913 struct ttm_operation_ctx *ctx,
914 struct ttm_resource *new_mem,
915 struct ttm_place *hop)
916{
917 struct drm_gem_vram_object *gbo;
918
919 if (!bo->resource) {
920 if (new_mem->mem_type != TTM_PL_SYSTEM) {
921 hop->mem_type = TTM_PL_SYSTEM;
922 hop->flags = TTM_PL_FLAG_TEMPORARY;
923 return -EMULTIHOP;
924 }
925
926 ttm_bo_move_null(bo, new_mem);
927 return 0;
928 }
929
930 gbo = drm_gem_vram_of_bo(bo);
931
932 return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem);
933}
934
935static int bo_driver_io_mem_reserve(struct ttm_device *bdev,
936 struct ttm_resource *mem)
937{
938 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
939
940 switch (mem->mem_type) {
941 case TTM_PL_SYSTEM: /* nothing to do */
942 break;
943 case TTM_PL_VRAM:
944 mem->bus.offset = (mem->start << PAGE_SHIFT) + vmm->vram_base;
945 mem->bus.is_iomem = true;
946 mem->bus.caching = ttm_write_combined;
947 break;
948 default:
949 return -EINVAL;
950 }
951
952 return 0;
953}
954
955static struct ttm_device_funcs bo_driver = {
956 .ttm_tt_create = bo_driver_ttm_tt_create,
957 .ttm_tt_destroy = bo_driver_ttm_tt_destroy,
958 .eviction_valuable = ttm_bo_eviction_valuable,
959 .evict_flags = bo_driver_evict_flags,
960 .move = bo_driver_move,
961 .delete_mem_notify = bo_driver_delete_mem_notify,
962 .io_mem_reserve = bo_driver_io_mem_reserve,
963};
964
965/*
966 * struct drm_vram_mm
967 */
968
969static int drm_vram_mm_debugfs(struct seq_file *m, void *data)
970{
971 struct drm_debugfs_entry *entry = m->private;
972 struct drm_vram_mm *vmm = entry->dev->vram_mm;
973 struct ttm_resource_manager *man = ttm_manager_type(&vmm->bdev, TTM_PL_VRAM);
974 struct drm_printer p = drm_seq_file_printer(m);
975
976 ttm_resource_manager_debug(man, &p);
977 return 0;
978}
979
980static const struct drm_debugfs_info drm_vram_mm_debugfs_list[] = {
981 { "vram-mm", drm_vram_mm_debugfs, 0, NULL },
982};
983
984/**
985 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file.
986 *
987 * @minor: drm minor device.
988 *
989 */
990void drm_vram_mm_debugfs_init(struct drm_minor *minor)
991{
992 drm_debugfs_add_files(minor->dev, drm_vram_mm_debugfs_list,
993 ARRAY_SIZE(drm_vram_mm_debugfs_list));
994}
995EXPORT_SYMBOL(drm_vram_mm_debugfs_init);
996
997static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
998 uint64_t vram_base, size_t vram_size)
999{
1000 int ret;
1001
1002 vmm->vram_base = vram_base;
1003 vmm->vram_size = vram_size;
1004
1005 ret = ttm_device_init(&vmm->bdev, &bo_driver, dev->dev,
1006 dev->anon_inode->i_mapping,
1007 dev->vma_offset_manager,
1008 false, true);
1009 if (ret)
1010 return ret;
1011
1012 ret = ttm_range_man_init(&vmm->bdev, TTM_PL_VRAM,
1013 false, vram_size >> PAGE_SHIFT);
1014 if (ret)
1015 return ret;
1016
1017 return 0;
1018}
1019
1020static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm)
1021{
1022 ttm_range_man_fini(&vmm->bdev, TTM_PL_VRAM);
1023 ttm_device_fini(&vmm->bdev);
1024}
1025
1026/*
1027 * Helpers for integration with struct drm_device
1028 */
1029
1030static struct drm_vram_mm *drm_vram_helper_alloc_mm(struct drm_device *dev, uint64_t vram_base,
1031 size_t vram_size)
1032{
1033 int ret;
1034
1035 if (WARN_ON(dev->vram_mm))
1036 return dev->vram_mm;
1037
1038 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL);
1039 if (!dev->vram_mm)
1040 return ERR_PTR(-ENOMEM);
1041
1042 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size);
1043 if (ret)
1044 goto err_kfree;
1045
1046 return dev->vram_mm;
1047
1048err_kfree:
1049 kfree(dev->vram_mm);
1050 dev->vram_mm = NULL;
1051 return ERR_PTR(ret);
1052}
1053
1054static void drm_vram_helper_release_mm(struct drm_device *dev)
1055{
1056 if (!dev->vram_mm)
1057 return;
1058
1059 drm_vram_mm_cleanup(dev->vram_mm);
1060 kfree(dev->vram_mm);
1061 dev->vram_mm = NULL;
1062}
1063
1064static void drm_vram_mm_release(struct drm_device *dev, void *ptr)
1065{
1066 drm_vram_helper_release_mm(dev);
1067}
1068
1069/**
1070 * drmm_vram_helper_init - Initializes a device's instance of
1071 * &struct drm_vram_mm
1072 * @dev: the DRM device
1073 * @vram_base: the base address of the video memory
1074 * @vram_size: the size of the video memory in bytes
1075 *
1076 * Creates a new instance of &struct drm_vram_mm and stores it in
1077 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned
1078 * up as part of device cleanup. Calling this function multiple times
1079 * will generate an error message.
1080 *
1081 * Returns:
1082 * 0 on success, or a negative errno code otherwise.
1083 */
1084int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
1085 size_t vram_size)
1086{
1087 struct drm_vram_mm *vram_mm;
1088
1089 if (drm_WARN_ON_ONCE(dev, dev->vram_mm))
1090 return 0;
1091
1092 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size);
1093 if (IS_ERR(vram_mm))
1094 return PTR_ERR(vram_mm);
1095 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL);
1096}
1097EXPORT_SYMBOL(drmm_vram_helper_init);
1098
1099/*
1100 * Mode-config helpers
1101 */
1102
1103static enum drm_mode_status
1104drm_vram_helper_mode_valid_internal(struct drm_device *dev,
1105 const struct drm_display_mode *mode,
1106 unsigned long max_bpp)
1107{
1108 struct drm_vram_mm *vmm = dev->vram_mm;
1109 unsigned long fbsize, fbpages, max_fbpages;
1110
1111 if (WARN_ON(!dev->vram_mm))
1112 return MODE_BAD;
1113
1114 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT;
1115
1116 fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
1117 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE);
1118
1119 if (fbpages > max_fbpages)
1120 return MODE_MEM;
1121
1122 return MODE_OK;
1123}
1124
1125/**
1126 * drm_vram_helper_mode_valid - Tests if a display mode's
1127 * framebuffer fits into the available video memory.
1128 * @dev: the DRM device
1129 * @mode: the mode to test
1130 *
1131 * This function tests if enough video memory is available for using the
1132 * specified display mode. Atomic modesetting requires importing the
1133 * designated framebuffer into video memory before evicting the active
1134 * one. Hence, any framebuffer may consume at most half of the available
1135 * VRAM. Display modes that require a larger framebuffer can not be used,
1136 * even if the CRTC does support them. Each framebuffer is assumed to
1137 * have 32-bit color depth.
1138 *
1139 * Note:
1140 * The function can only test if the display mode is supported in
1141 * general. If there are too many framebuffers pinned to video memory,
1142 * a display mode may still not be usable in practice. The color depth of
1143 * 32-bit fits all current use case. A more flexible test can be added
1144 * when necessary.
1145 *
1146 * Returns:
1147 * MODE_OK if the display mode is supported, or an error code of type
1148 * enum drm_mode_status otherwise.
1149 */
1150enum drm_mode_status
1151drm_vram_helper_mode_valid(struct drm_device *dev,
1152 const struct drm_display_mode *mode)
1153{
1154 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */
1155
1156 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp);
1157}
1158EXPORT_SYMBOL(drm_vram_helper_mode_valid);
1159
1160MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
1161MODULE_LICENSE("GPL");