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1// SPDX-License-Identifier: GPL-2.0-or-later
2
3#include <linux/module.h>
4
5#include <drm/drm_debugfs.h>
6#include <drm/drm_device.h>
7#include <drm/drm_drv.h>
8#include <drm/drm_file.h>
9#include <drm/drm_framebuffer.h>
10#include <drm/drm_gem_framebuffer_helper.h>
11#include <drm/drm_gem_ttm_helper.h>
12#include <drm/drm_gem_vram_helper.h>
13#include <drm/drm_managed.h>
14#include <drm/drm_mode.h>
15#include <drm/drm_plane.h>
16#include <drm/drm_prime.h>
17#include <drm/drm_simple_kms_helper.h>
18#include <drm/ttm/ttm_page_alloc.h>
19
20static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
21
22/**
23 * DOC: overview
24 *
25 * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM
26 * buffer object that is backed by video RAM (VRAM). It can be used for
27 * framebuffer devices with dedicated memory.
28 *
29 * The data structure &struct drm_vram_mm and its helpers implement a memory
30 * manager for simple framebuffer devices with dedicated video memory. GEM
31 * VRAM buffer objects are either placed in the video memory or remain evicted
32 * to system memory.
33 *
34 * With the GEM interface userspace applications create, manage and destroy
35 * graphics buffers, such as an on-screen framebuffer. GEM does not provide
36 * an implementation of these interfaces. It's up to the DRM driver to
37 * provide an implementation that suits the hardware. If the hardware device
38 * contains dedicated video memory, the DRM driver can use the VRAM helper
39 * library. Each active buffer object is stored in video RAM. Active
40 * buffer are used for drawing the current frame, typically something like
41 * the frame's scanout buffer or the cursor image. If there's no more space
42 * left in VRAM, inactive GEM objects can be moved to system memory.
43 *
44 * To initialize the VRAM helper library call drmm_vram_helper_alloc_mm().
45 * The function allocates and initializes an instance of &struct drm_vram_mm
46 * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize
47 * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize
48 * &struct file_operations; as illustrated below.
49 *
50 * .. code-block:: c
51 *
52 * struct file_operations fops ={
53 * .owner = THIS_MODULE,
54 * DRM_VRAM_MM_FILE_OPERATION
55 * };
56 * struct drm_driver drv = {
57 * .driver_feature = DRM_ ... ,
58 * .fops = &fops,
59 * DRM_GEM_VRAM_DRIVER
60 * };
61 *
62 * int init_drm_driver()
63 * {
64 * struct drm_device *dev;
65 * uint64_t vram_base;
66 * unsigned long vram_size;
67 * int ret;
68 *
69 * // setup device, vram base and size
70 * // ...
71 *
72 * ret = drmm_vram_helper_alloc_mm(dev, vram_base, vram_size);
73 * if (ret)
74 * return ret;
75 * return 0;
76 * }
77 *
78 * This creates an instance of &struct drm_vram_mm, exports DRM userspace
79 * interfaces for GEM buffer management and initializes file operations to
80 * allow for accessing created GEM buffers. With this setup, the DRM driver
81 * manages an area of video RAM with VRAM MM and provides GEM VRAM objects
82 * to userspace.
83 *
84 * You don't have to clean up the instance of VRAM MM.
85 * drmm_vram_helper_alloc_mm() is a managed interface that installs a
86 * clean-up handler to run during the DRM device's release.
87 *
88 * For drawing or scanout operations, rsp. buffer objects have to be pinned
89 * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or
90 * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system
91 * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards.
92 *
93 * A buffer object that is pinned in video RAM has a fixed address within that
94 * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically
95 * it's used to program the hardware's scanout engine for framebuffers, set
96 * the cursor overlay's image for a mouse cursor, or use it as input to the
97 * hardware's draing engine.
98 *
99 * To access a buffer object's memory from the DRM driver, call
100 * drm_gem_vram_kmap(). It (optionally) maps the buffer into kernel address
101 * space and returns the memory address. Use drm_gem_vram_kunmap() to
102 * release the mapping.
103 */
104
105/*
106 * Buffer-objects helpers
107 */
108
109static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
110{
111 /* We got here via ttm_bo_put(), which means that the
112 * TTM buffer object in 'bo' has already been cleaned
113 * up; only release the GEM object.
114 */
115
116 WARN_ON(gbo->kmap_use_count);
117 WARN_ON(gbo->kmap.virtual);
118
119 drm_gem_object_release(&gbo->bo.base);
120}
121
122static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
123{
124 drm_gem_vram_cleanup(gbo);
125 kfree(gbo);
126}
127
128static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
129{
130 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
131
132 drm_gem_vram_destroy(gbo);
133}
134
135static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
136 unsigned long pl_flag)
137{
138 unsigned int i;
139 unsigned int c = 0;
140 u32 invariant_flags = pl_flag & TTM_PL_FLAG_TOPDOWN;
141
142 gbo->placement.placement = gbo->placements;
143 gbo->placement.busy_placement = gbo->placements;
144
145 if (pl_flag & TTM_PL_FLAG_VRAM)
146 gbo->placements[c++].flags = TTM_PL_FLAG_WC |
147 TTM_PL_FLAG_UNCACHED |
148 TTM_PL_FLAG_VRAM |
149 invariant_flags;
150
151 if (pl_flag & TTM_PL_FLAG_SYSTEM)
152 gbo->placements[c++].flags = TTM_PL_MASK_CACHING |
153 TTM_PL_FLAG_SYSTEM |
154 invariant_flags;
155
156 if (!c)
157 gbo->placements[c++].flags = TTM_PL_MASK_CACHING |
158 TTM_PL_FLAG_SYSTEM |
159 invariant_flags;
160
161 gbo->placement.num_placement = c;
162 gbo->placement.num_busy_placement = c;
163
164 for (i = 0; i < c; ++i) {
165 gbo->placements[i].fpfn = 0;
166 gbo->placements[i].lpfn = 0;
167 }
168}
169
170static int drm_gem_vram_init(struct drm_device *dev,
171 struct drm_gem_vram_object *gbo,
172 size_t size, unsigned long pg_align)
173{
174 struct drm_vram_mm *vmm = dev->vram_mm;
175 struct ttm_bo_device *bdev;
176 int ret;
177 size_t acc_size;
178
179 if (WARN_ONCE(!vmm, "VRAM MM not initialized"))
180 return -EINVAL;
181 bdev = &vmm->bdev;
182
183 gbo->bo.base.funcs = &drm_gem_vram_object_funcs;
184
185 ret = drm_gem_object_init(dev, &gbo->bo.base, size);
186 if (ret)
187 return ret;
188
189 acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo));
190
191 gbo->bo.bdev = bdev;
192 drm_gem_vram_placement(gbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
193
194 ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device,
195 &gbo->placement, pg_align, false, acc_size,
196 NULL, NULL, ttm_buffer_object_destroy);
197 if (ret)
198 goto err_drm_gem_object_release;
199
200 return 0;
201
202err_drm_gem_object_release:
203 drm_gem_object_release(&gbo->bo.base);
204 return ret;
205}
206
207/**
208 * drm_gem_vram_create() - Creates a VRAM-backed GEM object
209 * @dev: the DRM device
210 * @size: the buffer size in bytes
211 * @pg_align: the buffer's alignment in multiples of the page size
212 *
213 * Returns:
214 * A new instance of &struct drm_gem_vram_object on success, or
215 * an ERR_PTR()-encoded error code otherwise.
216 */
217struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
218 size_t size,
219 unsigned long pg_align)
220{
221 struct drm_gem_vram_object *gbo;
222 int ret;
223
224 if (dev->driver->gem_create_object) {
225 struct drm_gem_object *gem =
226 dev->driver->gem_create_object(dev, size);
227 if (!gem)
228 return ERR_PTR(-ENOMEM);
229 gbo = drm_gem_vram_of_gem(gem);
230 } else {
231 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
232 if (!gbo)
233 return ERR_PTR(-ENOMEM);
234 }
235
236 ret = drm_gem_vram_init(dev, gbo, size, pg_align);
237 if (ret < 0)
238 goto err_kfree;
239
240 return gbo;
241
242err_kfree:
243 kfree(gbo);
244 return ERR_PTR(ret);
245}
246EXPORT_SYMBOL(drm_gem_vram_create);
247
248/**
249 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
250 * @gbo: the GEM VRAM object
251 *
252 * See ttm_bo_put() for more information.
253 */
254void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
255{
256 ttm_bo_put(&gbo->bo);
257}
258EXPORT_SYMBOL(drm_gem_vram_put);
259
260/**
261 * drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset
262 * @gbo: the GEM VRAM object
263 *
264 * See drm_vma_node_offset_addr() for more information.
265 *
266 * Returns:
267 * The buffer object's offset for userspace mappings on success, or
268 * 0 if no offset is allocated.
269 */
270u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo)
271{
272 return drm_vma_node_offset_addr(&gbo->bo.base.vma_node);
273}
274EXPORT_SYMBOL(drm_gem_vram_mmap_offset);
275
276static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo)
277{
278 /* Keep TTM behavior for now, remove when drivers are audited */
279 if (WARN_ON_ONCE(!gbo->bo.mem.mm_node))
280 return 0;
281
282 return gbo->bo.mem.start;
283}
284
285/**
286 * drm_gem_vram_offset() - \
287 Returns a GEM VRAM object's offset in video memory
288 * @gbo: the GEM VRAM object
289 *
290 * This function returns the buffer object's offset in the device's video
291 * memory. The buffer object has to be pinned to %TTM_PL_VRAM.
292 *
293 * Returns:
294 * The buffer object's offset in video memory on success, or
295 * a negative errno code otherwise.
296 */
297s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
298{
299 if (WARN_ON_ONCE(!gbo->pin_count))
300 return (s64)-ENODEV;
301 return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT;
302}
303EXPORT_SYMBOL(drm_gem_vram_offset);
304
305static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo,
306 unsigned long pl_flag)
307{
308 int i, ret;
309 struct ttm_operation_ctx ctx = { false, false };
310
311 if (gbo->pin_count)
312 goto out;
313
314 if (pl_flag)
315 drm_gem_vram_placement(gbo, pl_flag);
316
317 for (i = 0; i < gbo->placement.num_placement; ++i)
318 gbo->placements[i].flags |= TTM_PL_FLAG_NO_EVICT;
319
320 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
321 if (ret < 0)
322 return ret;
323
324out:
325 ++gbo->pin_count;
326
327 return 0;
328}
329
330/**
331 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
332 * @gbo: the GEM VRAM object
333 * @pl_flag: a bitmask of possible memory regions
334 *
335 * Pinning a buffer object ensures that it is not evicted from
336 * a memory region. A pinned buffer object has to be unpinned before
337 * it can be pinned to another region. If the pl_flag argument is 0,
338 * the buffer is pinned at its current location (video RAM or system
339 * memory).
340 *
341 * Small buffer objects, such as cursor images, can lead to memory
342 * fragmentation if they are pinned in the middle of video RAM. This
343 * is especially a problem on devices with only a small amount of
344 * video RAM. Fragmentation can prevent the primary framebuffer from
345 * fitting in, even though there's enough memory overall. The modifier
346 * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned
347 * at the high end of the memory region to avoid fragmentation.
348 *
349 * Returns:
350 * 0 on success, or
351 * a negative error code otherwise.
352 */
353int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
354{
355 int ret;
356
357 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
358 if (ret)
359 return ret;
360 ret = drm_gem_vram_pin_locked(gbo, pl_flag);
361 ttm_bo_unreserve(&gbo->bo);
362
363 return ret;
364}
365EXPORT_SYMBOL(drm_gem_vram_pin);
366
367static int drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo)
368{
369 int i, ret;
370 struct ttm_operation_ctx ctx = { false, false };
371
372 if (WARN_ON_ONCE(!gbo->pin_count))
373 return 0;
374
375 --gbo->pin_count;
376 if (gbo->pin_count)
377 return 0;
378
379 for (i = 0; i < gbo->placement.num_placement ; ++i)
380 gbo->placements[i].flags &= ~TTM_PL_FLAG_NO_EVICT;
381
382 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
383 if (ret < 0)
384 return ret;
385
386 return 0;
387}
388
389/**
390 * drm_gem_vram_unpin() - Unpins a GEM VRAM object
391 * @gbo: the GEM VRAM object
392 *
393 * Returns:
394 * 0 on success, or
395 * a negative error code otherwise.
396 */
397int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
398{
399 int ret;
400
401 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
402 if (ret)
403 return ret;
404 ret = drm_gem_vram_unpin_locked(gbo);
405 ttm_bo_unreserve(&gbo->bo);
406
407 return ret;
408}
409EXPORT_SYMBOL(drm_gem_vram_unpin);
410
411static void *drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
412 bool map, bool *is_iomem)
413{
414 int ret;
415 struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
416
417 if (gbo->kmap_use_count > 0)
418 goto out;
419
420 if (kmap->virtual || !map)
421 goto out;
422
423 ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap);
424 if (ret)
425 return ERR_PTR(ret);
426
427out:
428 if (!kmap->virtual) {
429 if (is_iomem)
430 *is_iomem = false;
431 return NULL; /* not mapped; don't increment ref */
432 }
433 ++gbo->kmap_use_count;
434 if (is_iomem)
435 return ttm_kmap_obj_virtual(kmap, is_iomem);
436 return kmap->virtual;
437}
438
439/**
440 * drm_gem_vram_kmap() - Maps a GEM VRAM object into kernel address space
441 * @gbo: the GEM VRAM object
442 * @map: establish a mapping if necessary
443 * @is_iomem: returns true if the mapped memory is I/O memory, or false \
444 otherwise; can be NULL
445 *
446 * This function maps the buffer object into the kernel's address space
447 * or returns the current mapping. If the parameter map is false, the
448 * function only queries the current mapping, but does not establish a
449 * new one.
450 *
451 * Returns:
452 * The buffers virtual address if mapped, or
453 * NULL if not mapped, or
454 * an ERR_PTR()-encoded error code otherwise.
455 */
456void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
457 bool *is_iomem)
458{
459 int ret;
460 void *virtual;
461
462 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
463 if (ret)
464 return ERR_PTR(ret);
465 virtual = drm_gem_vram_kmap_locked(gbo, map, is_iomem);
466 ttm_bo_unreserve(&gbo->bo);
467
468 return virtual;
469}
470EXPORT_SYMBOL(drm_gem_vram_kmap);
471
472static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo)
473{
474 if (WARN_ON_ONCE(!gbo->kmap_use_count))
475 return;
476 if (--gbo->kmap_use_count > 0)
477 return;
478
479 /*
480 * Permanently mapping and unmapping buffers adds overhead from
481 * updating the page tables and creates debugging output. Therefore,
482 * we delay the actual unmap operation until the BO gets evicted
483 * from memory. See drm_gem_vram_bo_driver_move_notify().
484 */
485}
486
487/**
488 * drm_gem_vram_kunmap() - Unmaps a GEM VRAM object
489 * @gbo: the GEM VRAM object
490 */
491void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo)
492{
493 int ret;
494
495 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL);
496 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
497 return;
498 drm_gem_vram_kunmap_locked(gbo);
499 ttm_bo_unreserve(&gbo->bo);
500}
501EXPORT_SYMBOL(drm_gem_vram_kunmap);
502
503/**
504 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
505 * space
506 * @gbo: The GEM VRAM object to map
507 *
508 * The vmap function pins a GEM VRAM object to its current location, either
509 * system or video memory, and maps its buffer into kernel address space.
510 * As pinned object cannot be relocated, you should avoid pinning objects
511 * permanently. Call drm_gem_vram_vunmap() with the returned address to
512 * unmap and unpin the GEM VRAM object.
513 *
514 * If you have special requirements for the pinning or mapping operations,
515 * call drm_gem_vram_pin() and drm_gem_vram_kmap() directly.
516 *
517 * Returns:
518 * The buffer's virtual address on success, or
519 * an ERR_PTR()-encoded error code otherwise.
520 */
521void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo)
522{
523 int ret;
524 void *base;
525
526 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
527 if (ret)
528 return ERR_PTR(ret);
529
530 ret = drm_gem_vram_pin_locked(gbo, 0);
531 if (ret)
532 goto err_ttm_bo_unreserve;
533 base = drm_gem_vram_kmap_locked(gbo, true, NULL);
534 if (IS_ERR(base)) {
535 ret = PTR_ERR(base);
536 goto err_drm_gem_vram_unpin_locked;
537 }
538
539 ttm_bo_unreserve(&gbo->bo);
540
541 return base;
542
543err_drm_gem_vram_unpin_locked:
544 drm_gem_vram_unpin_locked(gbo);
545err_ttm_bo_unreserve:
546 ttm_bo_unreserve(&gbo->bo);
547 return ERR_PTR(ret);
548}
549EXPORT_SYMBOL(drm_gem_vram_vmap);
550
551/**
552 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object
553 * @gbo: The GEM VRAM object to unmap
554 * @vaddr: The mapping's base address as returned by drm_gem_vram_vmap()
555 *
556 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See
557 * the documentation for drm_gem_vram_vmap() for more information.
558 */
559void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr)
560{
561 int ret;
562
563 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL);
564 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
565 return;
566
567 drm_gem_vram_kunmap_locked(gbo);
568 drm_gem_vram_unpin_locked(gbo);
569
570 ttm_bo_unreserve(&gbo->bo);
571}
572EXPORT_SYMBOL(drm_gem_vram_vunmap);
573
574/**
575 * drm_gem_vram_fill_create_dumb() - \
576 Helper for implementing &struct drm_driver.dumb_create
577 * @file: the DRM file
578 * @dev: the DRM device
579 * @pg_align: the buffer's alignment in multiples of the page size
580 * @pitch_align: the scanline's alignment in powers of 2
581 * @args: the arguments as provided to \
582 &struct drm_driver.dumb_create
583 *
584 * This helper function fills &struct drm_mode_create_dumb, which is used
585 * by &struct drm_driver.dumb_create. Implementations of this interface
586 * should forwards their arguments to this helper, plus the driver-specific
587 * parameters.
588 *
589 * Returns:
590 * 0 on success, or
591 * a negative error code otherwise.
592 */
593int drm_gem_vram_fill_create_dumb(struct drm_file *file,
594 struct drm_device *dev,
595 unsigned long pg_align,
596 unsigned long pitch_align,
597 struct drm_mode_create_dumb *args)
598{
599 size_t pitch, size;
600 struct drm_gem_vram_object *gbo;
601 int ret;
602 u32 handle;
603
604 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
605 if (pitch_align) {
606 if (WARN_ON_ONCE(!is_power_of_2(pitch_align)))
607 return -EINVAL;
608 pitch = ALIGN(pitch, pitch_align);
609 }
610 size = pitch * args->height;
611
612 size = roundup(size, PAGE_SIZE);
613 if (!size)
614 return -EINVAL;
615
616 gbo = drm_gem_vram_create(dev, size, pg_align);
617 if (IS_ERR(gbo))
618 return PTR_ERR(gbo);
619
620 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
621 if (ret)
622 goto err_drm_gem_object_put;
623
624 drm_gem_object_put(&gbo->bo.base);
625
626 args->pitch = pitch;
627 args->size = size;
628 args->handle = handle;
629
630 return 0;
631
632err_drm_gem_object_put:
633 drm_gem_object_put(&gbo->bo.base);
634 return ret;
635}
636EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
637
638/*
639 * Helpers for struct ttm_bo_driver
640 */
641
642static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
643{
644 return (bo->destroy == ttm_buffer_object_destroy);
645}
646
647static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo,
648 struct ttm_placement *pl)
649{
650 drm_gem_vram_placement(gbo, TTM_PL_FLAG_SYSTEM);
651 *pl = gbo->placement;
652}
653
654static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo,
655 bool evict,
656 struct ttm_mem_reg *new_mem)
657{
658 struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
659
660 if (WARN_ON_ONCE(gbo->kmap_use_count))
661 return;
662
663 if (!kmap->virtual)
664 return;
665 ttm_bo_kunmap(kmap);
666 kmap->virtual = NULL;
667}
668
669/*
670 * Helpers for struct drm_gem_object_funcs
671 */
672
673/**
674 * drm_gem_vram_object_free() - \
675 Implements &struct drm_gem_object_funcs.free
676 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
677 */
678static void drm_gem_vram_object_free(struct drm_gem_object *gem)
679{
680 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
681
682 drm_gem_vram_put(gbo);
683}
684
685/*
686 * Helpers for dump buffers
687 */
688
689/**
690 * drm_gem_vram_driver_create_dumb() - \
691 Implements &struct drm_driver.dumb_create
692 * @file: the DRM file
693 * @dev: the DRM device
694 * @args: the arguments as provided to \
695 &struct drm_driver.dumb_create
696 *
697 * This function requires the driver to use @drm_device.vram_mm for its
698 * instance of VRAM MM.
699 *
700 * Returns:
701 * 0 on success, or
702 * a negative error code otherwise.
703 */
704int drm_gem_vram_driver_dumb_create(struct drm_file *file,
705 struct drm_device *dev,
706 struct drm_mode_create_dumb *args)
707{
708 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
709 return -EINVAL;
710
711 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args);
712}
713EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
714
715/**
716 * drm_gem_vram_driver_dumb_mmap_offset() - \
717 Implements &struct drm_driver.dumb_mmap_offset
718 * @file: DRM file pointer.
719 * @dev: DRM device.
720 * @handle: GEM handle
721 * @offset: Returns the mapping's memory offset on success
722 *
723 * Returns:
724 * 0 on success, or
725 * a negative errno code otherwise.
726 */
727int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
728 struct drm_device *dev,
729 uint32_t handle, uint64_t *offset)
730{
731 struct drm_gem_object *gem;
732 struct drm_gem_vram_object *gbo;
733
734 gem = drm_gem_object_lookup(file, handle);
735 if (!gem)
736 return -ENOENT;
737
738 gbo = drm_gem_vram_of_gem(gem);
739 *offset = drm_gem_vram_mmap_offset(gbo);
740
741 drm_gem_object_put(gem);
742
743 return 0;
744}
745EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset);
746
747/*
748 * Helpers for struct drm_plane_helper_funcs
749 */
750
751/**
752 * drm_gem_vram_plane_helper_prepare_fb() - \
753 * Implements &struct drm_plane_helper_funcs.prepare_fb
754 * @plane: a DRM plane
755 * @new_state: the plane's new state
756 *
757 * During plane updates, this function sets the plane's fence and
758 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM.
759 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them.
760 *
761 * Returns:
762 * 0 on success, or
763 * a negative errno code otherwise.
764 */
765int
766drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
767 struct drm_plane_state *new_state)
768{
769 size_t i;
770 struct drm_gem_vram_object *gbo;
771 int ret;
772
773 if (!new_state->fb)
774 return 0;
775
776 for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) {
777 if (!new_state->fb->obj[i])
778 continue;
779 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
780 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
781 if (ret)
782 goto err_drm_gem_vram_unpin;
783 }
784
785 ret = drm_gem_fb_prepare_fb(plane, new_state);
786 if (ret)
787 goto err_drm_gem_vram_unpin;
788
789 return 0;
790
791err_drm_gem_vram_unpin:
792 while (i) {
793 --i;
794 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
795 drm_gem_vram_unpin(gbo);
796 }
797 return ret;
798}
799EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb);
800
801/**
802 * drm_gem_vram_plane_helper_cleanup_fb() - \
803 * Implements &struct drm_plane_helper_funcs.cleanup_fb
804 * @plane: a DRM plane
805 * @old_state: the plane's old state
806 *
807 * During plane updates, this function unpins the GEM VRAM
808 * objects of the plane's old framebuffer from VRAM. Complements
809 * drm_gem_vram_plane_helper_prepare_fb().
810 */
811void
812drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
813 struct drm_plane_state *old_state)
814{
815 size_t i;
816 struct drm_gem_vram_object *gbo;
817
818 if (!old_state->fb)
819 return;
820
821 for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) {
822 if (!old_state->fb->obj[i])
823 continue;
824 gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]);
825 drm_gem_vram_unpin(gbo);
826 }
827}
828EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb);
829
830/*
831 * Helpers for struct drm_simple_display_pipe_funcs
832 */
833
834/**
835 * drm_gem_vram_simple_display_pipe_prepare_fb() - \
836 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb
837 * @pipe: a simple display pipe
838 * @new_state: the plane's new state
839 *
840 * During plane updates, this function pins the GEM VRAM
841 * objects of the plane's new framebuffer to VRAM. Call
842 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them.
843 *
844 * Returns:
845 * 0 on success, or
846 * a negative errno code otherwise.
847 */
848int drm_gem_vram_simple_display_pipe_prepare_fb(
849 struct drm_simple_display_pipe *pipe,
850 struct drm_plane_state *new_state)
851{
852 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state);
853}
854EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb);
855
856/**
857 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \
858 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb
859 * @pipe: a simple display pipe
860 * @old_state: the plane's old state
861 *
862 * During plane updates, this function unpins the GEM VRAM
863 * objects of the plane's old framebuffer from VRAM. Complements
864 * drm_gem_vram_simple_display_pipe_prepare_fb().
865 */
866void drm_gem_vram_simple_display_pipe_cleanup_fb(
867 struct drm_simple_display_pipe *pipe,
868 struct drm_plane_state *old_state)
869{
870 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state);
871}
872EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb);
873
874/*
875 * PRIME helpers
876 */
877
878/**
879 * drm_gem_vram_object_pin() - \
880 Implements &struct drm_gem_object_funcs.pin
881 * @gem: The GEM object to pin
882 *
883 * Returns:
884 * 0 on success, or
885 * a negative errno code otherwise.
886 */
887static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
888{
889 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
890
891 /* Fbdev console emulation is the use case of these PRIME
892 * helpers. This may involve updating a hardware buffer from
893 * a shadow FB. We pin the buffer to it's current location
894 * (either video RAM or system memory) to prevent it from
895 * being relocated during the update operation. If you require
896 * the buffer to be pinned to VRAM, implement a callback that
897 * sets the flags accordingly.
898 */
899 return drm_gem_vram_pin(gbo, 0);
900}
901
902/**
903 * drm_gem_vram_object_unpin() - \
904 Implements &struct drm_gem_object_funcs.unpin
905 * @gem: The GEM object to unpin
906 */
907static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
908{
909 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
910
911 drm_gem_vram_unpin(gbo);
912}
913
914/**
915 * drm_gem_vram_object_vmap() - \
916 Implements &struct drm_gem_object_funcs.vmap
917 * @gem: The GEM object to map
918 *
919 * Returns:
920 * The buffers virtual address on success, or
921 * NULL otherwise.
922 */
923static void *drm_gem_vram_object_vmap(struct drm_gem_object *gem)
924{
925 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
926 void *base;
927
928 base = drm_gem_vram_vmap(gbo);
929 if (IS_ERR(base))
930 return NULL;
931 return base;
932}
933
934/**
935 * drm_gem_vram_object_vunmap() - \
936 Implements &struct drm_gem_object_funcs.vunmap
937 * @gem: The GEM object to unmap
938 * @vaddr: The mapping's base address
939 */
940static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem,
941 void *vaddr)
942{
943 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
944
945 drm_gem_vram_vunmap(gbo, vaddr);
946}
947
948/*
949 * GEM object funcs
950 */
951
952static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
953 .free = drm_gem_vram_object_free,
954 .pin = drm_gem_vram_object_pin,
955 .unpin = drm_gem_vram_object_unpin,
956 .vmap = drm_gem_vram_object_vmap,
957 .vunmap = drm_gem_vram_object_vunmap,
958 .mmap = drm_gem_ttm_mmap,
959 .print_info = drm_gem_ttm_print_info,
960};
961
962/*
963 * VRAM memory manager
964 */
965
966/*
967 * TTM TT
968 */
969
970static void backend_func_destroy(struct ttm_tt *tt)
971{
972 ttm_tt_fini(tt);
973 kfree(tt);
974}
975
976static struct ttm_backend_func backend_func = {
977 .destroy = backend_func_destroy
978};
979
980/*
981 * TTM BO device
982 */
983
984static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo,
985 uint32_t page_flags)
986{
987 struct ttm_tt *tt;
988 int ret;
989
990 tt = kzalloc(sizeof(*tt), GFP_KERNEL);
991 if (!tt)
992 return NULL;
993
994 tt->func = &backend_func;
995
996 ret = ttm_tt_init(tt, bo, page_flags);
997 if (ret < 0)
998 goto err_ttm_tt_init;
999
1000 return tt;
1001
1002err_ttm_tt_init:
1003 kfree(tt);
1004 return NULL;
1005}
1006
1007static int bo_driver_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
1008 struct ttm_mem_type_manager *man)
1009{
1010 switch (type) {
1011 case TTM_PL_SYSTEM:
1012 man->flags = 0;
1013 man->available_caching = TTM_PL_MASK_CACHING;
1014 man->default_caching = TTM_PL_FLAG_CACHED;
1015 break;
1016 case TTM_PL_VRAM:
1017 man->func = &ttm_bo_manager_func;
1018 man->flags = TTM_MEMTYPE_FLAG_FIXED;
1019 man->available_caching = TTM_PL_FLAG_UNCACHED |
1020 TTM_PL_FLAG_WC;
1021 man->default_caching = TTM_PL_FLAG_WC;
1022 break;
1023 default:
1024 return -EINVAL;
1025 }
1026 return 0;
1027}
1028
1029static void bo_driver_evict_flags(struct ttm_buffer_object *bo,
1030 struct ttm_placement *placement)
1031{
1032 struct drm_gem_vram_object *gbo;
1033
1034 /* TTM may pass BOs that are not GEM VRAM BOs. */
1035 if (!drm_is_gem_vram(bo))
1036 return;
1037
1038 gbo = drm_gem_vram_of_bo(bo);
1039
1040 drm_gem_vram_bo_driver_evict_flags(gbo, placement);
1041}
1042
1043static void bo_driver_move_notify(struct ttm_buffer_object *bo,
1044 bool evict,
1045 struct ttm_mem_reg *new_mem)
1046{
1047 struct drm_gem_vram_object *gbo;
1048
1049 /* TTM may pass BOs that are not GEM VRAM BOs. */
1050 if (!drm_is_gem_vram(bo))
1051 return;
1052
1053 gbo = drm_gem_vram_of_bo(bo);
1054
1055 drm_gem_vram_bo_driver_move_notify(gbo, evict, new_mem);
1056}
1057
1058static int bo_driver_io_mem_reserve(struct ttm_bo_device *bdev,
1059 struct ttm_mem_reg *mem)
1060{
1061 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
1062
1063 mem->bus.addr = NULL;
1064 mem->bus.size = mem->num_pages << PAGE_SHIFT;
1065
1066 switch (mem->mem_type) {
1067 case TTM_PL_SYSTEM: /* nothing to do */
1068 mem->bus.offset = 0;
1069 mem->bus.base = 0;
1070 mem->bus.is_iomem = false;
1071 break;
1072 case TTM_PL_VRAM:
1073 mem->bus.offset = mem->start << PAGE_SHIFT;
1074 mem->bus.base = vmm->vram_base;
1075 mem->bus.is_iomem = true;
1076 break;
1077 default:
1078 return -EINVAL;
1079 }
1080
1081 return 0;
1082}
1083
1084static struct ttm_bo_driver bo_driver = {
1085 .ttm_tt_create = bo_driver_ttm_tt_create,
1086 .ttm_tt_populate = ttm_pool_populate,
1087 .ttm_tt_unpopulate = ttm_pool_unpopulate,
1088 .init_mem_type = bo_driver_init_mem_type,
1089 .eviction_valuable = ttm_bo_eviction_valuable,
1090 .evict_flags = bo_driver_evict_flags,
1091 .move_notify = bo_driver_move_notify,
1092 .io_mem_reserve = bo_driver_io_mem_reserve,
1093};
1094
1095/*
1096 * struct drm_vram_mm
1097 */
1098
1099static int drm_vram_mm_debugfs(struct seq_file *m, void *data)
1100{
1101 struct drm_info_node *node = (struct drm_info_node *) m->private;
1102 struct drm_vram_mm *vmm = node->minor->dev->vram_mm;
1103 struct drm_mm *mm = vmm->bdev.man[TTM_PL_VRAM].priv;
1104 struct drm_printer p = drm_seq_file_printer(m);
1105
1106 spin_lock(&ttm_bo_glob.lru_lock);
1107 drm_mm_print(mm, &p);
1108 spin_unlock(&ttm_bo_glob.lru_lock);
1109 return 0;
1110}
1111
1112static const struct drm_info_list drm_vram_mm_debugfs_list[] = {
1113 { "vram-mm", drm_vram_mm_debugfs, 0, NULL },
1114};
1115
1116/**
1117 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file.
1118 *
1119 * @minor: drm minor device.
1120 *
1121 */
1122void drm_vram_mm_debugfs_init(struct drm_minor *minor)
1123{
1124 drm_debugfs_create_files(drm_vram_mm_debugfs_list,
1125 ARRAY_SIZE(drm_vram_mm_debugfs_list),
1126 minor->debugfs_root, minor);
1127}
1128EXPORT_SYMBOL(drm_vram_mm_debugfs_init);
1129
1130static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
1131 uint64_t vram_base, size_t vram_size)
1132{
1133 int ret;
1134
1135 vmm->vram_base = vram_base;
1136 vmm->vram_size = vram_size;
1137
1138 ret = ttm_bo_device_init(&vmm->bdev, &bo_driver,
1139 dev->anon_inode->i_mapping,
1140 dev->vma_offset_manager,
1141 true);
1142 if (ret)
1143 return ret;
1144
1145 ret = ttm_bo_init_mm(&vmm->bdev, TTM_PL_VRAM, vram_size >> PAGE_SHIFT);
1146 if (ret)
1147 return ret;
1148
1149 return 0;
1150}
1151
1152static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm)
1153{
1154 ttm_bo_device_release(&vmm->bdev);
1155}
1156
1157/*
1158 * Helpers for integration with struct drm_device
1159 */
1160
1161/* deprecated; use drmm_vram_mm_init() */
1162struct drm_vram_mm *drm_vram_helper_alloc_mm(
1163 struct drm_device *dev, uint64_t vram_base, size_t vram_size)
1164{
1165 int ret;
1166
1167 if (WARN_ON(dev->vram_mm))
1168 return dev->vram_mm;
1169
1170 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL);
1171 if (!dev->vram_mm)
1172 return ERR_PTR(-ENOMEM);
1173
1174 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size);
1175 if (ret)
1176 goto err_kfree;
1177
1178 return dev->vram_mm;
1179
1180err_kfree:
1181 kfree(dev->vram_mm);
1182 dev->vram_mm = NULL;
1183 return ERR_PTR(ret);
1184}
1185EXPORT_SYMBOL(drm_vram_helper_alloc_mm);
1186
1187void drm_vram_helper_release_mm(struct drm_device *dev)
1188{
1189 if (!dev->vram_mm)
1190 return;
1191
1192 drm_vram_mm_cleanup(dev->vram_mm);
1193 kfree(dev->vram_mm);
1194 dev->vram_mm = NULL;
1195}
1196EXPORT_SYMBOL(drm_vram_helper_release_mm);
1197
1198static void drm_vram_mm_release(struct drm_device *dev, void *ptr)
1199{
1200 drm_vram_helper_release_mm(dev);
1201}
1202
1203/**
1204 * drmm_vram_helper_init - Initializes a device's instance of
1205 * &struct drm_vram_mm
1206 * @dev: the DRM device
1207 * @vram_base: the base address of the video memory
1208 * @vram_size: the size of the video memory in bytes
1209 *
1210 * Creates a new instance of &struct drm_vram_mm and stores it in
1211 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned
1212 * up as part of device cleanup. Calling this function multiple times
1213 * will generate an error message.
1214 *
1215 * Returns:
1216 * 0 on success, or a negative errno code otherwise.
1217 */
1218int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
1219 size_t vram_size)
1220{
1221 struct drm_vram_mm *vram_mm;
1222
1223 if (drm_WARN_ON_ONCE(dev, dev->vram_mm))
1224 return 0;
1225
1226 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size);
1227 if (IS_ERR(vram_mm))
1228 return PTR_ERR(vram_mm);
1229 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL);
1230}
1231EXPORT_SYMBOL(drmm_vram_helper_init);
1232
1233/*
1234 * Mode-config helpers
1235 */
1236
1237static enum drm_mode_status
1238drm_vram_helper_mode_valid_internal(struct drm_device *dev,
1239 const struct drm_display_mode *mode,
1240 unsigned long max_bpp)
1241{
1242 struct drm_vram_mm *vmm = dev->vram_mm;
1243 unsigned long fbsize, fbpages, max_fbpages;
1244
1245 if (WARN_ON(!dev->vram_mm))
1246 return MODE_BAD;
1247
1248 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT;
1249
1250 fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
1251 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE);
1252
1253 if (fbpages > max_fbpages)
1254 return MODE_MEM;
1255
1256 return MODE_OK;
1257}
1258
1259/**
1260 * drm_vram_helper_mode_valid - Tests if a display mode's
1261 * framebuffer fits into the available video memory.
1262 * @dev: the DRM device
1263 * @mode: the mode to test
1264 *
1265 * This function tests if enough video memory is available for using the
1266 * specified display mode. Atomic modesetting requires importing the
1267 * designated framebuffer into video memory before evicting the active
1268 * one. Hence, any framebuffer may consume at most half of the available
1269 * VRAM. Display modes that require a larger framebuffer can not be used,
1270 * even if the CRTC does support them. Each framebuffer is assumed to
1271 * have 32-bit color depth.
1272 *
1273 * Note:
1274 * The function can only test if the display mode is supported in
1275 * general. If there are too many framebuffers pinned to video memory,
1276 * a display mode may still not be usable in practice. The color depth of
1277 * 32-bit fits all current use case. A more flexible test can be added
1278 * when necessary.
1279 *
1280 * Returns:
1281 * MODE_OK if the display mode is supported, or an error code of type
1282 * enum drm_mode_status otherwise.
1283 */
1284enum drm_mode_status
1285drm_vram_helper_mode_valid(struct drm_device *dev,
1286 const struct drm_display_mode *mode)
1287{
1288 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */
1289
1290 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp);
1291}
1292EXPORT_SYMBOL(drm_vram_helper_mode_valid);
1293
1294MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
1295MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2
3#include <linux/dma-buf-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_ttm_helper.h>
13#include <drm/drm_gem_vram_helper.h>
14#include <drm/drm_managed.h>
15#include <drm/drm_mode.h>
16#include <drm/drm_plane.h>
17#include <drm/drm_prime.h>
18#include <drm/drm_simple_kms_helper.h>
19
20#include <drm/ttm/ttm_range_manager.h>
21
22static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
23
24/**
25 * DOC: overview
26 *
27 * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM
28 * buffer object that is backed by video RAM (VRAM). It can be used for
29 * framebuffer devices with dedicated memory.
30 *
31 * The data structure &struct drm_vram_mm and its helpers implement a memory
32 * manager for simple framebuffer devices with dedicated video memory. GEM
33 * VRAM buffer objects are either placed in the video memory or remain evicted
34 * to system memory.
35 *
36 * With the GEM interface userspace applications create, manage and destroy
37 * graphics buffers, such as an on-screen framebuffer. GEM does not provide
38 * an implementation of these interfaces. It's up to the DRM driver to
39 * provide an implementation that suits the hardware. If the hardware device
40 * contains dedicated video memory, the DRM driver can use the VRAM helper
41 * library. Each active buffer object is stored in video RAM. Active
42 * buffer are used for drawing the current frame, typically something like
43 * the frame's scanout buffer or the cursor image. If there's no more space
44 * left in VRAM, inactive GEM objects can be moved to system memory.
45 *
46 * To initialize the VRAM helper library call drmm_vram_helper_alloc_mm().
47 * The function allocates and initializes an instance of &struct drm_vram_mm
48 * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize
49 * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize
50 * &struct file_operations; as illustrated below.
51 *
52 * .. code-block:: c
53 *
54 * struct file_operations fops ={
55 * .owner = THIS_MODULE,
56 * DRM_VRAM_MM_FILE_OPERATION
57 * };
58 * struct drm_driver drv = {
59 * .driver_feature = DRM_ ... ,
60 * .fops = &fops,
61 * DRM_GEM_VRAM_DRIVER
62 * };
63 *
64 * int init_drm_driver()
65 * {
66 * struct drm_device *dev;
67 * uint64_t vram_base;
68 * unsigned long vram_size;
69 * int ret;
70 *
71 * // setup device, vram base and size
72 * // ...
73 *
74 * ret = drmm_vram_helper_alloc_mm(dev, vram_base, vram_size);
75 * if (ret)
76 * return ret;
77 * return 0;
78 * }
79 *
80 * This creates an instance of &struct drm_vram_mm, exports DRM userspace
81 * interfaces for GEM buffer management and initializes file operations to
82 * allow for accessing created GEM buffers. With this setup, the DRM driver
83 * manages an area of video RAM with VRAM MM and provides GEM VRAM objects
84 * to userspace.
85 *
86 * You don't have to clean up the instance of VRAM MM.
87 * drmm_vram_helper_alloc_mm() is a managed interface that installs a
88 * clean-up handler to run during the DRM device's release.
89 *
90 * For drawing or scanout operations, rsp. buffer objects have to be pinned
91 * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or
92 * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system
93 * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards.
94 *
95 * A buffer object that is pinned in video RAM has a fixed address within that
96 * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically
97 * it's used to program the hardware's scanout engine for framebuffers, set
98 * the cursor overlay's image for a mouse cursor, or use it as input to the
99 * hardware's draing engine.
100 *
101 * To access a buffer object's memory from the DRM driver, call
102 * drm_gem_vram_vmap(). It maps the buffer into kernel address
103 * space and returns the memory address. Use drm_gem_vram_vunmap() to
104 * release the mapping.
105 */
106
107/*
108 * Buffer-objects helpers
109 */
110
111static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
112{
113 /* We got here via ttm_bo_put(), which means that the
114 * TTM buffer object in 'bo' has already been cleaned
115 * up; only release the GEM object.
116 */
117
118 WARN_ON(gbo->vmap_use_count);
119 WARN_ON(dma_buf_map_is_set(&gbo->map));
120
121 drm_gem_object_release(&gbo->bo.base);
122}
123
124static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
125{
126 drm_gem_vram_cleanup(gbo);
127 kfree(gbo);
128}
129
130static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
131{
132 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
133
134 drm_gem_vram_destroy(gbo);
135}
136
137static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
138 unsigned long pl_flag)
139{
140 u32 invariant_flags = 0;
141 unsigned int i;
142 unsigned int c = 0;
143
144 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_TOPDOWN)
145 invariant_flags = TTM_PL_FLAG_TOPDOWN;
146
147 gbo->placement.placement = gbo->placements;
148 gbo->placement.busy_placement = gbo->placements;
149
150 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_VRAM) {
151 gbo->placements[c].mem_type = TTM_PL_VRAM;
152 gbo->placements[c++].flags = invariant_flags;
153 }
154
155 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_SYSTEM || !c) {
156 gbo->placements[c].mem_type = TTM_PL_SYSTEM;
157 gbo->placements[c++].flags = invariant_flags;
158 }
159
160 gbo->placement.num_placement = c;
161 gbo->placement.num_busy_placement = c;
162
163 for (i = 0; i < c; ++i) {
164 gbo->placements[i].fpfn = 0;
165 gbo->placements[i].lpfn = 0;
166 }
167}
168
169/**
170 * drm_gem_vram_create() - Creates a VRAM-backed GEM object
171 * @dev: the DRM device
172 * @size: the buffer size in bytes
173 * @pg_align: the buffer's alignment in multiples of the page size
174 *
175 * GEM objects are allocated by calling struct drm_driver.gem_create_object,
176 * if set. Otherwise kzalloc() will be used. Drivers can set their own GEM
177 * object functions in struct drm_driver.gem_create_object. If no functions
178 * are set, the new GEM object will use the default functions from GEM VRAM
179 * helpers.
180 *
181 * Returns:
182 * A new instance of &struct drm_gem_vram_object on success, or
183 * an ERR_PTR()-encoded error code otherwise.
184 */
185struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
186 size_t size,
187 unsigned long pg_align)
188{
189 struct drm_gem_vram_object *gbo;
190 struct drm_gem_object *gem;
191 struct drm_vram_mm *vmm = dev->vram_mm;
192 struct ttm_device *bdev;
193 int ret;
194
195 if (WARN_ONCE(!vmm, "VRAM MM not initialized"))
196 return ERR_PTR(-EINVAL);
197
198 if (dev->driver->gem_create_object) {
199 gem = dev->driver->gem_create_object(dev, size);
200 if (!gem)
201 return ERR_PTR(-ENOMEM);
202 gbo = drm_gem_vram_of_gem(gem);
203 } else {
204 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
205 if (!gbo)
206 return ERR_PTR(-ENOMEM);
207 gem = &gbo->bo.base;
208 }
209
210 if (!gem->funcs)
211 gem->funcs = &drm_gem_vram_object_funcs;
212
213 ret = drm_gem_object_init(dev, gem, size);
214 if (ret) {
215 kfree(gbo);
216 return ERR_PTR(ret);
217 }
218
219 bdev = &vmm->bdev;
220
221 gbo->bo.bdev = bdev;
222 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
223
224 /*
225 * A failing ttm_bo_init will call ttm_buffer_object_destroy
226 * to release gbo->bo.base and kfree gbo.
227 */
228 ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device,
229 &gbo->placement, pg_align, false, NULL, NULL,
230 ttm_buffer_object_destroy);
231 if (ret)
232 return ERR_PTR(ret);
233
234 return gbo;
235}
236EXPORT_SYMBOL(drm_gem_vram_create);
237
238/**
239 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
240 * @gbo: the GEM VRAM object
241 *
242 * See ttm_bo_put() for more information.
243 */
244void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
245{
246 ttm_bo_put(&gbo->bo);
247}
248EXPORT_SYMBOL(drm_gem_vram_put);
249
250static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo)
251{
252 /* Keep TTM behavior for now, remove when drivers are audited */
253 if (WARN_ON_ONCE(!gbo->bo.resource ||
254 gbo->bo.resource->mem_type == TTM_PL_SYSTEM))
255 return 0;
256
257 return gbo->bo.resource->start;
258}
259
260/**
261 * drm_gem_vram_offset() - \
262 Returns a GEM VRAM object's offset in video memory
263 * @gbo: the GEM VRAM object
264 *
265 * This function returns the buffer object's offset in the device's video
266 * memory. The buffer object has to be pinned to %TTM_PL_VRAM.
267 *
268 * Returns:
269 * The buffer object's offset in video memory on success, or
270 * a negative errno code otherwise.
271 */
272s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
273{
274 if (WARN_ON_ONCE(!gbo->bo.pin_count))
275 return (s64)-ENODEV;
276 return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT;
277}
278EXPORT_SYMBOL(drm_gem_vram_offset);
279
280static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo,
281 unsigned long pl_flag)
282{
283 struct ttm_operation_ctx ctx = { false, false };
284 int ret;
285
286 if (gbo->bo.pin_count)
287 goto out;
288
289 if (pl_flag)
290 drm_gem_vram_placement(gbo, pl_flag);
291
292 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
293 if (ret < 0)
294 return ret;
295
296out:
297 ttm_bo_pin(&gbo->bo);
298
299 return 0;
300}
301
302/**
303 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
304 * @gbo: the GEM VRAM object
305 * @pl_flag: a bitmask of possible memory regions
306 *
307 * Pinning a buffer object ensures that it is not evicted from
308 * a memory region. A pinned buffer object has to be unpinned before
309 * it can be pinned to another region. If the pl_flag argument is 0,
310 * the buffer is pinned at its current location (video RAM or system
311 * memory).
312 *
313 * Small buffer objects, such as cursor images, can lead to memory
314 * fragmentation if they are pinned in the middle of video RAM. This
315 * is especially a problem on devices with only a small amount of
316 * video RAM. Fragmentation can prevent the primary framebuffer from
317 * fitting in, even though there's enough memory overall. The modifier
318 * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned
319 * at the high end of the memory region to avoid fragmentation.
320 *
321 * Returns:
322 * 0 on success, or
323 * a negative error code otherwise.
324 */
325int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
326{
327 int ret;
328
329 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
330 if (ret)
331 return ret;
332 ret = drm_gem_vram_pin_locked(gbo, pl_flag);
333 ttm_bo_unreserve(&gbo->bo);
334
335 return ret;
336}
337EXPORT_SYMBOL(drm_gem_vram_pin);
338
339static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo)
340{
341 ttm_bo_unpin(&gbo->bo);
342}
343
344/**
345 * drm_gem_vram_unpin() - Unpins a GEM VRAM object
346 * @gbo: the GEM VRAM object
347 *
348 * Returns:
349 * 0 on success, or
350 * a negative error code otherwise.
351 */
352int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
353{
354 int ret;
355
356 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
357 if (ret)
358 return ret;
359
360 drm_gem_vram_unpin_locked(gbo);
361 ttm_bo_unreserve(&gbo->bo);
362
363 return 0;
364}
365EXPORT_SYMBOL(drm_gem_vram_unpin);
366
367static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
368 struct dma_buf_map *map)
369{
370 int ret;
371
372 if (gbo->vmap_use_count > 0)
373 goto out;
374
375 /*
376 * VRAM helpers unmap the BO only on demand. So the previous
377 * page mapping might still be around. Only vmap if the there's
378 * no mapping present.
379 */
380 if (dma_buf_map_is_null(&gbo->map)) {
381 ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
382 if (ret)
383 return ret;
384 }
385
386out:
387 ++gbo->vmap_use_count;
388 *map = gbo->map;
389
390 return 0;
391}
392
393static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo,
394 struct dma_buf_map *map)
395{
396 struct drm_device *dev = gbo->bo.base.dev;
397
398 if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
399 return;
400
401 if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map)))
402 return; /* BUG: map not mapped from this BO */
403
404 if (--gbo->vmap_use_count > 0)
405 return;
406
407 /*
408 * Permanently mapping and unmapping buffers adds overhead from
409 * updating the page tables and creates debugging output. Therefore,
410 * we delay the actual unmap operation until the BO gets evicted
411 * from memory. See drm_gem_vram_bo_driver_move_notify().
412 */
413}
414
415/**
416 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
417 * space
418 * @gbo: The GEM VRAM object to map
419 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
420 * store.
421 *
422 * The vmap function pins a GEM VRAM object to its current location, either
423 * system or video memory, and maps its buffer into kernel address space.
424 * As pinned object cannot be relocated, you should avoid pinning objects
425 * permanently. Call drm_gem_vram_vunmap() with the returned address to
426 * unmap and unpin the GEM VRAM object.
427 *
428 * Returns:
429 * 0 on success, or a negative error code otherwise.
430 */
431int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
432{
433 int ret;
434
435 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
436 if (ret)
437 return ret;
438
439 ret = drm_gem_vram_pin_locked(gbo, 0);
440 if (ret)
441 goto err_ttm_bo_unreserve;
442 ret = drm_gem_vram_kmap_locked(gbo, map);
443 if (ret)
444 goto err_drm_gem_vram_unpin_locked;
445
446 ttm_bo_unreserve(&gbo->bo);
447
448 return 0;
449
450err_drm_gem_vram_unpin_locked:
451 drm_gem_vram_unpin_locked(gbo);
452err_ttm_bo_unreserve:
453 ttm_bo_unreserve(&gbo->bo);
454 return ret;
455}
456EXPORT_SYMBOL(drm_gem_vram_vmap);
457
458/**
459 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object
460 * @gbo: The GEM VRAM object to unmap
461 * @map: Kernel virtual address where the VRAM GEM object was mapped
462 *
463 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See
464 * the documentation for drm_gem_vram_vmap() for more information.
465 */
466void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
467{
468 int ret;
469
470 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL);
471 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
472 return;
473
474 drm_gem_vram_kunmap_locked(gbo, map);
475 drm_gem_vram_unpin_locked(gbo);
476
477 ttm_bo_unreserve(&gbo->bo);
478}
479EXPORT_SYMBOL(drm_gem_vram_vunmap);
480
481/**
482 * drm_gem_vram_fill_create_dumb() - \
483 Helper for implementing &struct drm_driver.dumb_create
484 * @file: the DRM file
485 * @dev: the DRM device
486 * @pg_align: the buffer's alignment in multiples of the page size
487 * @pitch_align: the scanline's alignment in powers of 2
488 * @args: the arguments as provided to \
489 &struct drm_driver.dumb_create
490 *
491 * This helper function fills &struct drm_mode_create_dumb, which is used
492 * by &struct drm_driver.dumb_create. Implementations of this interface
493 * should forwards their arguments to this helper, plus the driver-specific
494 * parameters.
495 *
496 * Returns:
497 * 0 on success, or
498 * a negative error code otherwise.
499 */
500int drm_gem_vram_fill_create_dumb(struct drm_file *file,
501 struct drm_device *dev,
502 unsigned long pg_align,
503 unsigned long pitch_align,
504 struct drm_mode_create_dumb *args)
505{
506 size_t pitch, size;
507 struct drm_gem_vram_object *gbo;
508 int ret;
509 u32 handle;
510
511 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
512 if (pitch_align) {
513 if (WARN_ON_ONCE(!is_power_of_2(pitch_align)))
514 return -EINVAL;
515 pitch = ALIGN(pitch, pitch_align);
516 }
517 size = pitch * args->height;
518
519 size = roundup(size, PAGE_SIZE);
520 if (!size)
521 return -EINVAL;
522
523 gbo = drm_gem_vram_create(dev, size, pg_align);
524 if (IS_ERR(gbo))
525 return PTR_ERR(gbo);
526
527 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
528 if (ret)
529 goto err_drm_gem_object_put;
530
531 drm_gem_object_put(&gbo->bo.base);
532
533 args->pitch = pitch;
534 args->size = size;
535 args->handle = handle;
536
537 return 0;
538
539err_drm_gem_object_put:
540 drm_gem_object_put(&gbo->bo.base);
541 return ret;
542}
543EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
544
545/*
546 * Helpers for struct ttm_device_funcs
547 */
548
549static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
550{
551 return (bo->destroy == ttm_buffer_object_destroy);
552}
553
554static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo,
555 struct ttm_placement *pl)
556{
557 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
558 *pl = gbo->placement;
559}
560
561static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo)
562{
563 struct ttm_buffer_object *bo = &gbo->bo;
564 struct drm_device *dev = bo->base.dev;
565
566 if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count))
567 return;
568
569 ttm_bo_vunmap(bo, &gbo->map);
570 dma_buf_map_clear(&gbo->map); /* explicitly clear mapping for next vmap call */
571}
572
573static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo,
574 bool evict,
575 struct ttm_operation_ctx *ctx,
576 struct ttm_resource *new_mem)
577{
578 drm_gem_vram_bo_driver_move_notify(gbo);
579 return ttm_bo_move_memcpy(&gbo->bo, ctx, new_mem);
580}
581
582/*
583 * Helpers for struct drm_gem_object_funcs
584 */
585
586/**
587 * drm_gem_vram_object_free() - \
588 Implements &struct drm_gem_object_funcs.free
589 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
590 */
591static void drm_gem_vram_object_free(struct drm_gem_object *gem)
592{
593 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
594
595 drm_gem_vram_put(gbo);
596}
597
598/*
599 * Helpers for dump buffers
600 */
601
602/**
603 * drm_gem_vram_driver_dumb_create() - \
604 Implements &struct drm_driver.dumb_create
605 * @file: the DRM file
606 * @dev: the DRM device
607 * @args: the arguments as provided to \
608 &struct drm_driver.dumb_create
609 *
610 * This function requires the driver to use @drm_device.vram_mm for its
611 * instance of VRAM MM.
612 *
613 * Returns:
614 * 0 on success, or
615 * a negative error code otherwise.
616 */
617int drm_gem_vram_driver_dumb_create(struct drm_file *file,
618 struct drm_device *dev,
619 struct drm_mode_create_dumb *args)
620{
621 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
622 return -EINVAL;
623
624 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args);
625}
626EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
627
628/*
629 * Helpers for struct drm_plane_helper_funcs
630 */
631
632/**
633 * drm_gem_vram_plane_helper_prepare_fb() - \
634 * Implements &struct drm_plane_helper_funcs.prepare_fb
635 * @plane: a DRM plane
636 * @new_state: the plane's new state
637 *
638 * During plane updates, this function sets the plane's fence and
639 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM.
640 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them.
641 *
642 * Returns:
643 * 0 on success, or
644 * a negative errno code otherwise.
645 */
646int
647drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
648 struct drm_plane_state *new_state)
649{
650 size_t i;
651 struct drm_gem_vram_object *gbo;
652 int ret;
653
654 if (!new_state->fb)
655 return 0;
656
657 for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) {
658 if (!new_state->fb->obj[i])
659 continue;
660 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
661 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
662 if (ret)
663 goto err_drm_gem_vram_unpin;
664 }
665
666 ret = drm_gem_plane_helper_prepare_fb(plane, new_state);
667 if (ret)
668 goto err_drm_gem_vram_unpin;
669
670 return 0;
671
672err_drm_gem_vram_unpin:
673 while (i) {
674 --i;
675 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
676 drm_gem_vram_unpin(gbo);
677 }
678 return ret;
679}
680EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb);
681
682/**
683 * drm_gem_vram_plane_helper_cleanup_fb() - \
684 * Implements &struct drm_plane_helper_funcs.cleanup_fb
685 * @plane: a DRM plane
686 * @old_state: the plane's old state
687 *
688 * During plane updates, this function unpins the GEM VRAM
689 * objects of the plane's old framebuffer from VRAM. Complements
690 * drm_gem_vram_plane_helper_prepare_fb().
691 */
692void
693drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
694 struct drm_plane_state *old_state)
695{
696 size_t i;
697 struct drm_gem_vram_object *gbo;
698
699 if (!old_state->fb)
700 return;
701
702 for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) {
703 if (!old_state->fb->obj[i])
704 continue;
705 gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]);
706 drm_gem_vram_unpin(gbo);
707 }
708}
709EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb);
710
711/*
712 * Helpers for struct drm_simple_display_pipe_funcs
713 */
714
715/**
716 * drm_gem_vram_simple_display_pipe_prepare_fb() - \
717 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb
718 * @pipe: a simple display pipe
719 * @new_state: the plane's new state
720 *
721 * During plane updates, this function pins the GEM VRAM
722 * objects of the plane's new framebuffer to VRAM. Call
723 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them.
724 *
725 * Returns:
726 * 0 on success, or
727 * a negative errno code otherwise.
728 */
729int drm_gem_vram_simple_display_pipe_prepare_fb(
730 struct drm_simple_display_pipe *pipe,
731 struct drm_plane_state *new_state)
732{
733 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state);
734}
735EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb);
736
737/**
738 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \
739 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb
740 * @pipe: a simple display pipe
741 * @old_state: the plane's old state
742 *
743 * During plane updates, this function unpins the GEM VRAM
744 * objects of the plane's old framebuffer from VRAM. Complements
745 * drm_gem_vram_simple_display_pipe_prepare_fb().
746 */
747void drm_gem_vram_simple_display_pipe_cleanup_fb(
748 struct drm_simple_display_pipe *pipe,
749 struct drm_plane_state *old_state)
750{
751 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state);
752}
753EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb);
754
755/*
756 * PRIME helpers
757 */
758
759/**
760 * drm_gem_vram_object_pin() - \
761 Implements &struct drm_gem_object_funcs.pin
762 * @gem: The GEM object to pin
763 *
764 * Returns:
765 * 0 on success, or
766 * a negative errno code otherwise.
767 */
768static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
769{
770 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
771
772 /* Fbdev console emulation is the use case of these PRIME
773 * helpers. This may involve updating a hardware buffer from
774 * a shadow FB. We pin the buffer to it's current location
775 * (either video RAM or system memory) to prevent it from
776 * being relocated during the update operation. If you require
777 * the buffer to be pinned to VRAM, implement a callback that
778 * sets the flags accordingly.
779 */
780 return drm_gem_vram_pin(gbo, 0);
781}
782
783/**
784 * drm_gem_vram_object_unpin() - \
785 Implements &struct drm_gem_object_funcs.unpin
786 * @gem: The GEM object to unpin
787 */
788static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
789{
790 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
791
792 drm_gem_vram_unpin(gbo);
793}
794
795/**
796 * drm_gem_vram_object_vmap() -
797 * Implements &struct drm_gem_object_funcs.vmap
798 * @gem: The GEM object to map
799 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
800 * store.
801 *
802 * Returns:
803 * 0 on success, or a negative error code otherwise.
804 */
805static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, struct dma_buf_map *map)
806{
807 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
808
809 return drm_gem_vram_vmap(gbo, map);
810}
811
812/**
813 * drm_gem_vram_object_vunmap() -
814 * Implements &struct drm_gem_object_funcs.vunmap
815 * @gem: The GEM object to unmap
816 * @map: Kernel virtual address where the VRAM GEM object was mapped
817 */
818static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct dma_buf_map *map)
819{
820 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
821
822 drm_gem_vram_vunmap(gbo, map);
823}
824
825/*
826 * GEM object funcs
827 */
828
829static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
830 .free = drm_gem_vram_object_free,
831 .pin = drm_gem_vram_object_pin,
832 .unpin = drm_gem_vram_object_unpin,
833 .vmap = drm_gem_vram_object_vmap,
834 .vunmap = drm_gem_vram_object_vunmap,
835 .mmap = drm_gem_ttm_mmap,
836 .print_info = drm_gem_ttm_print_info,
837};
838
839/*
840 * VRAM memory manager
841 */
842
843/*
844 * TTM TT
845 */
846
847static void bo_driver_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt)
848{
849 ttm_tt_destroy_common(bdev, tt);
850 ttm_tt_fini(tt);
851 kfree(tt);
852}
853
854/*
855 * TTM BO device
856 */
857
858static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo,
859 uint32_t page_flags)
860{
861 struct ttm_tt *tt;
862 int ret;
863
864 tt = kzalloc(sizeof(*tt), GFP_KERNEL);
865 if (!tt)
866 return NULL;
867
868 ret = ttm_tt_init(tt, bo, page_flags, ttm_cached);
869 if (ret < 0)
870 goto err_ttm_tt_init;
871
872 return tt;
873
874err_ttm_tt_init:
875 kfree(tt);
876 return NULL;
877}
878
879static void bo_driver_evict_flags(struct ttm_buffer_object *bo,
880 struct ttm_placement *placement)
881{
882 struct drm_gem_vram_object *gbo;
883
884 /* TTM may pass BOs that are not GEM VRAM BOs. */
885 if (!drm_is_gem_vram(bo))
886 return;
887
888 gbo = drm_gem_vram_of_bo(bo);
889
890 drm_gem_vram_bo_driver_evict_flags(gbo, placement);
891}
892
893static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo)
894{
895 struct drm_gem_vram_object *gbo;
896
897 /* TTM may pass BOs that are not GEM VRAM BOs. */
898 if (!drm_is_gem_vram(bo))
899 return;
900
901 gbo = drm_gem_vram_of_bo(bo);
902
903 drm_gem_vram_bo_driver_move_notify(gbo);
904}
905
906static int bo_driver_move(struct ttm_buffer_object *bo,
907 bool evict,
908 struct ttm_operation_ctx *ctx,
909 struct ttm_resource *new_mem,
910 struct ttm_place *hop)
911{
912 struct drm_gem_vram_object *gbo;
913
914 gbo = drm_gem_vram_of_bo(bo);
915
916 return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem);
917}
918
919static int bo_driver_io_mem_reserve(struct ttm_device *bdev,
920 struct ttm_resource *mem)
921{
922 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
923
924 switch (mem->mem_type) {
925 case TTM_PL_SYSTEM: /* nothing to do */
926 break;
927 case TTM_PL_VRAM:
928 mem->bus.offset = (mem->start << PAGE_SHIFT) + vmm->vram_base;
929 mem->bus.is_iomem = true;
930 mem->bus.caching = ttm_write_combined;
931 break;
932 default:
933 return -EINVAL;
934 }
935
936 return 0;
937}
938
939static struct ttm_device_funcs bo_driver = {
940 .ttm_tt_create = bo_driver_ttm_tt_create,
941 .ttm_tt_destroy = bo_driver_ttm_tt_destroy,
942 .eviction_valuable = ttm_bo_eviction_valuable,
943 .evict_flags = bo_driver_evict_flags,
944 .move = bo_driver_move,
945 .delete_mem_notify = bo_driver_delete_mem_notify,
946 .io_mem_reserve = bo_driver_io_mem_reserve,
947};
948
949/*
950 * struct drm_vram_mm
951 */
952
953static int drm_vram_mm_debugfs(struct seq_file *m, void *data)
954{
955 struct drm_info_node *node = (struct drm_info_node *) m->private;
956 struct drm_vram_mm *vmm = node->minor->dev->vram_mm;
957 struct ttm_resource_manager *man = ttm_manager_type(&vmm->bdev, TTM_PL_VRAM);
958 struct drm_printer p = drm_seq_file_printer(m);
959
960 ttm_resource_manager_debug(man, &p);
961 return 0;
962}
963
964static const struct drm_info_list drm_vram_mm_debugfs_list[] = {
965 { "vram-mm", drm_vram_mm_debugfs, 0, NULL },
966};
967
968/**
969 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file.
970 *
971 * @minor: drm minor device.
972 *
973 */
974void drm_vram_mm_debugfs_init(struct drm_minor *minor)
975{
976 drm_debugfs_create_files(drm_vram_mm_debugfs_list,
977 ARRAY_SIZE(drm_vram_mm_debugfs_list),
978 minor->debugfs_root, minor);
979}
980EXPORT_SYMBOL(drm_vram_mm_debugfs_init);
981
982static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
983 uint64_t vram_base, size_t vram_size)
984{
985 int ret;
986
987 vmm->vram_base = vram_base;
988 vmm->vram_size = vram_size;
989
990 ret = ttm_device_init(&vmm->bdev, &bo_driver, dev->dev,
991 dev->anon_inode->i_mapping,
992 dev->vma_offset_manager,
993 false, true);
994 if (ret)
995 return ret;
996
997 ret = ttm_range_man_init(&vmm->bdev, TTM_PL_VRAM,
998 false, vram_size >> PAGE_SHIFT);
999 if (ret)
1000 return ret;
1001
1002 return 0;
1003}
1004
1005static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm)
1006{
1007 ttm_range_man_fini(&vmm->bdev, TTM_PL_VRAM);
1008 ttm_device_fini(&vmm->bdev);
1009}
1010
1011/*
1012 * Helpers for integration with struct drm_device
1013 */
1014
1015/* deprecated; use drmm_vram_mm_init() */
1016struct drm_vram_mm *drm_vram_helper_alloc_mm(
1017 struct drm_device *dev, uint64_t vram_base, size_t vram_size)
1018{
1019 int ret;
1020
1021 if (WARN_ON(dev->vram_mm))
1022 return dev->vram_mm;
1023
1024 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL);
1025 if (!dev->vram_mm)
1026 return ERR_PTR(-ENOMEM);
1027
1028 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size);
1029 if (ret)
1030 goto err_kfree;
1031
1032 return dev->vram_mm;
1033
1034err_kfree:
1035 kfree(dev->vram_mm);
1036 dev->vram_mm = NULL;
1037 return ERR_PTR(ret);
1038}
1039EXPORT_SYMBOL(drm_vram_helper_alloc_mm);
1040
1041void drm_vram_helper_release_mm(struct drm_device *dev)
1042{
1043 if (!dev->vram_mm)
1044 return;
1045
1046 drm_vram_mm_cleanup(dev->vram_mm);
1047 kfree(dev->vram_mm);
1048 dev->vram_mm = NULL;
1049}
1050EXPORT_SYMBOL(drm_vram_helper_release_mm);
1051
1052static void drm_vram_mm_release(struct drm_device *dev, void *ptr)
1053{
1054 drm_vram_helper_release_mm(dev);
1055}
1056
1057/**
1058 * drmm_vram_helper_init - Initializes a device's instance of
1059 * &struct drm_vram_mm
1060 * @dev: the DRM device
1061 * @vram_base: the base address of the video memory
1062 * @vram_size: the size of the video memory in bytes
1063 *
1064 * Creates a new instance of &struct drm_vram_mm and stores it in
1065 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned
1066 * up as part of device cleanup. Calling this function multiple times
1067 * will generate an error message.
1068 *
1069 * Returns:
1070 * 0 on success, or a negative errno code otherwise.
1071 */
1072int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
1073 size_t vram_size)
1074{
1075 struct drm_vram_mm *vram_mm;
1076
1077 if (drm_WARN_ON_ONCE(dev, dev->vram_mm))
1078 return 0;
1079
1080 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size);
1081 if (IS_ERR(vram_mm))
1082 return PTR_ERR(vram_mm);
1083 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL);
1084}
1085EXPORT_SYMBOL(drmm_vram_helper_init);
1086
1087/*
1088 * Mode-config helpers
1089 */
1090
1091static enum drm_mode_status
1092drm_vram_helper_mode_valid_internal(struct drm_device *dev,
1093 const struct drm_display_mode *mode,
1094 unsigned long max_bpp)
1095{
1096 struct drm_vram_mm *vmm = dev->vram_mm;
1097 unsigned long fbsize, fbpages, max_fbpages;
1098
1099 if (WARN_ON(!dev->vram_mm))
1100 return MODE_BAD;
1101
1102 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT;
1103
1104 fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
1105 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE);
1106
1107 if (fbpages > max_fbpages)
1108 return MODE_MEM;
1109
1110 return MODE_OK;
1111}
1112
1113/**
1114 * drm_vram_helper_mode_valid - Tests if a display mode's
1115 * framebuffer fits into the available video memory.
1116 * @dev: the DRM device
1117 * @mode: the mode to test
1118 *
1119 * This function tests if enough video memory is available for using the
1120 * specified display mode. Atomic modesetting requires importing the
1121 * designated framebuffer into video memory before evicting the active
1122 * one. Hence, any framebuffer may consume at most half of the available
1123 * VRAM. Display modes that require a larger framebuffer can not be used,
1124 * even if the CRTC does support them. Each framebuffer is assumed to
1125 * have 32-bit color depth.
1126 *
1127 * Note:
1128 * The function can only test if the display mode is supported in
1129 * general. If there are too many framebuffers pinned to video memory,
1130 * a display mode may still not be usable in practice. The color depth of
1131 * 32-bit fits all current use case. A more flexible test can be added
1132 * when necessary.
1133 *
1134 * Returns:
1135 * MODE_OK if the display mode is supported, or an error code of type
1136 * enum drm_mode_status otherwise.
1137 */
1138enum drm_mode_status
1139drm_vram_helper_mode_valid(struct drm_device *dev,
1140 const struct drm_display_mode *mode)
1141{
1142 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */
1143
1144 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp);
1145}
1146EXPORT_SYMBOL(drm_vram_helper_mode_valid);
1147
1148MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
1149MODULE_LICENSE("GPL");