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