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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * drm gem framebuffer helper functions
4 *
5 * Copyright (C) 2017 Noralf Trønnes
6 */
7
8#include <linux/slab.h>
9#include <linux/module.h>
10
11#include <drm/drm_damage_helper.h>
12#include <drm/drm_fourcc.h>
13#include <drm/drm_framebuffer.h>
14#include <drm/drm_gem.h>
15#include <drm/drm_gem_framebuffer_helper.h>
16#include <drm/drm_modeset_helper.h>
17
18#include "drm_internal.h"
19
20MODULE_IMPORT_NS(DMA_BUF);
21
22#define AFBC_HEADER_SIZE 16
23#define AFBC_TH_LAYOUT_ALIGNMENT 8
24#define AFBC_HDR_ALIGN 64
25#define AFBC_SUPERBLOCK_PIXELS 256
26#define AFBC_SUPERBLOCK_ALIGNMENT 128
27#define AFBC_TH_BODY_START_ALIGNMENT 4096
28
29/**
30 * DOC: overview
31 *
32 * This library provides helpers for drivers that don't subclass
33 * &drm_framebuffer and use &drm_gem_object for their backing storage.
34 *
35 * Drivers without additional needs to validate framebuffers can simply use
36 * drm_gem_fb_create() and everything is wired up automatically. Other drivers
37 * can use all parts independently.
38 */
39
40/**
41 * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer
42 * @fb: Framebuffer
43 * @plane: Plane index
44 *
45 * No additional reference is taken beyond the one that the &drm_frambuffer
46 * already holds.
47 *
48 * Returns:
49 * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL
50 * if it does not exist.
51 */
52struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
53 unsigned int plane)
54{
55 struct drm_device *dev = fb->dev;
56
57 if (drm_WARN_ON_ONCE(dev, plane >= ARRAY_SIZE(fb->obj)))
58 return NULL;
59 else if (drm_WARN_ON_ONCE(dev, !fb->obj[plane]))
60 return NULL;
61
62 return fb->obj[plane];
63}
64EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj);
65
66static int
67drm_gem_fb_init(struct drm_device *dev,
68 struct drm_framebuffer *fb,
69 const struct drm_mode_fb_cmd2 *mode_cmd,
70 struct drm_gem_object **obj, unsigned int num_planes,
71 const struct drm_framebuffer_funcs *funcs)
72{
73 unsigned int i;
74 int ret;
75
76 drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);
77
78 for (i = 0; i < num_planes; i++)
79 fb->obj[i] = obj[i];
80
81 ret = drm_framebuffer_init(dev, fb, funcs);
82 if (ret)
83 drm_err(dev, "Failed to init framebuffer: %d\n", ret);
84
85 return ret;
86}
87
88/**
89 * drm_gem_fb_destroy - Free GEM backed framebuffer
90 * @fb: Framebuffer
91 *
92 * Frees a GEM backed framebuffer with its backing buffer(s) and the structure
93 * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy
94 * callback.
95 */
96void drm_gem_fb_destroy(struct drm_framebuffer *fb)
97{
98 unsigned int i;
99
100 for (i = 0; i < fb->format->num_planes; i++)
101 drm_gem_object_put(fb->obj[i]);
102
103 drm_framebuffer_cleanup(fb);
104 kfree(fb);
105}
106EXPORT_SYMBOL(drm_gem_fb_destroy);
107
108/**
109 * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer
110 * @fb: Framebuffer
111 * @file: DRM file to register the handle for
112 * @handle: Pointer to return the created handle
113 *
114 * This function creates a handle for the GEM object backing the framebuffer.
115 * Drivers can use this as their &drm_framebuffer_funcs->create_handle
116 * callback. The GETFB IOCTL calls into this callback.
117 *
118 * Returns:
119 * 0 on success or a negative error code on failure.
120 */
121int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
122 unsigned int *handle)
123{
124 return drm_gem_handle_create(file, fb->obj[0], handle);
125}
126EXPORT_SYMBOL(drm_gem_fb_create_handle);
127
128/**
129 * drm_gem_fb_init_with_funcs() - Helper function for implementing
130 * &drm_mode_config_funcs.fb_create
131 * callback in cases when the driver
132 * allocates a subclass of
133 * struct drm_framebuffer
134 * @dev: DRM device
135 * @fb: framebuffer object
136 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
137 * @mode_cmd: Metadata from the userspace framebuffer creation request
138 * @funcs: vtable to be used for the new framebuffer object
139 *
140 * This function can be used to set &drm_framebuffer_funcs for drivers that need
141 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
142 * change &drm_framebuffer_funcs. The function does buffer size validation.
143 * The buffer size validation is for a general case, though, so users should
144 * pay attention to the checks being appropriate for them or, at least,
145 * non-conflicting.
146 *
147 * Returns:
148 * Zero or a negative error code.
149 */
150int drm_gem_fb_init_with_funcs(struct drm_device *dev,
151 struct drm_framebuffer *fb,
152 struct drm_file *file,
153 const struct drm_mode_fb_cmd2 *mode_cmd,
154 const struct drm_framebuffer_funcs *funcs)
155{
156 const struct drm_format_info *info;
157 struct drm_gem_object *objs[DRM_FORMAT_MAX_PLANES];
158 unsigned int i;
159 int ret;
160
161 info = drm_get_format_info(dev, mode_cmd);
162 if (!info) {
163 drm_dbg_kms(dev, "Failed to get FB format info\n");
164 return -EINVAL;
165 }
166
167 for (i = 0; i < info->num_planes; i++) {
168 unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
169 unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
170 unsigned int min_size;
171
172 objs[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]);
173 if (!objs[i]) {
174 drm_dbg_kms(dev, "Failed to lookup GEM object\n");
175 ret = -ENOENT;
176 goto err_gem_object_put;
177 }
178
179 min_size = (height - 1) * mode_cmd->pitches[i]
180 + drm_format_info_min_pitch(info, i, width)
181 + mode_cmd->offsets[i];
182
183 if (objs[i]->size < min_size) {
184 drm_dbg_kms(dev,
185 "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n",
186 objs[i]->size, min_size, i);
187 drm_gem_object_put(objs[i]);
188 ret = -EINVAL;
189 goto err_gem_object_put;
190 }
191 }
192
193 ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs);
194 if (ret)
195 goto err_gem_object_put;
196
197 return 0;
198
199err_gem_object_put:
200 while (i > 0) {
201 --i;
202 drm_gem_object_put(objs[i]);
203 }
204 return ret;
205}
206EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs);
207
208/**
209 * drm_gem_fb_create_with_funcs() - Helper function for the
210 * &drm_mode_config_funcs.fb_create
211 * callback
212 * @dev: DRM device
213 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
214 * @mode_cmd: Metadata from the userspace framebuffer creation request
215 * @funcs: vtable to be used for the new framebuffer object
216 *
217 * This function can be used to set &drm_framebuffer_funcs for drivers that need
218 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
219 * change &drm_framebuffer_funcs. The function does buffer size validation.
220 *
221 * Returns:
222 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
223 */
224struct drm_framebuffer *
225drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
226 const struct drm_mode_fb_cmd2 *mode_cmd,
227 const struct drm_framebuffer_funcs *funcs)
228{
229 struct drm_framebuffer *fb;
230 int ret;
231
232 fb = kzalloc(sizeof(*fb), GFP_KERNEL);
233 if (!fb)
234 return ERR_PTR(-ENOMEM);
235
236 ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs);
237 if (ret) {
238 kfree(fb);
239 return ERR_PTR(ret);
240 }
241
242 return fb;
243}
244EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs);
245
246static const struct drm_framebuffer_funcs drm_gem_fb_funcs = {
247 .destroy = drm_gem_fb_destroy,
248 .create_handle = drm_gem_fb_create_handle,
249};
250
251/**
252 * drm_gem_fb_create() - Helper function for the
253 * &drm_mode_config_funcs.fb_create callback
254 * @dev: DRM device
255 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
256 * @mode_cmd: Metadata from the userspace framebuffer creation request
257 *
258 * This function creates a new framebuffer object described by
259 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
260 * backing the framebuffer.
261 *
262 * If your hardware has special alignment or pitch requirements these should be
263 * checked before calling this function. The function does buffer size
264 * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer
265 * flushing.
266 *
267 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
268 * The ADDFB2 IOCTL calls into this callback.
269 *
270 * Returns:
271 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
272 */
273struct drm_framebuffer *
274drm_gem_fb_create(struct drm_device *dev, struct drm_file *file,
275 const struct drm_mode_fb_cmd2 *mode_cmd)
276{
277 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
278 &drm_gem_fb_funcs);
279}
280EXPORT_SYMBOL_GPL(drm_gem_fb_create);
281
282static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb = {
283 .destroy = drm_gem_fb_destroy,
284 .create_handle = drm_gem_fb_create_handle,
285 .dirty = drm_atomic_helper_dirtyfb,
286};
287
288/**
289 * drm_gem_fb_create_with_dirty() - Helper function for the
290 * &drm_mode_config_funcs.fb_create callback
291 * @dev: DRM device
292 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
293 * @mode_cmd: Metadata from the userspace framebuffer creation request
294 *
295 * This function creates a new framebuffer object described by
296 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
297 * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty
298 * callback giving framebuffer flushing through the atomic machinery. Use
299 * drm_gem_fb_create() if you don't need the dirty callback.
300 * The function does buffer size validation.
301 *
302 * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes
303 * to enable userspace to use damage clips also with the ATOMIC IOCTL.
304 *
305 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
306 * The ADDFB2 IOCTL calls into this callback.
307 *
308 * Returns:
309 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
310 */
311struct drm_framebuffer *
312drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file,
313 const struct drm_mode_fb_cmd2 *mode_cmd)
314{
315 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
316 &drm_gem_fb_funcs_dirtyfb);
317}
318EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty);
319
320/**
321 * drm_gem_fb_vmap - maps all framebuffer BOs into kernel address space
322 * @fb: the framebuffer
323 * @map: returns the mapping's address for each BO
324 * @data: returns the data address for each BO, can be NULL
325 *
326 * This function maps all buffer objects of the given framebuffer into
327 * kernel address space and stores them in struct iosys_map. If the
328 * mapping operation fails for one of the BOs, the function unmaps the
329 * already established mappings automatically.
330 *
331 * Callers that want to access a BO's stored data should pass @data.
332 * The argument returns the addresses of the data stored in each BO. This
333 * is different from @map if the framebuffer's offsets field is non-zero.
334 *
335 * Both, @map and @data, must each refer to arrays with at least
336 * fb->format->num_planes elements.
337 *
338 * See drm_gem_fb_vunmap() for unmapping.
339 *
340 * Returns:
341 * 0 on success, or a negative errno code otherwise.
342 */
343int drm_gem_fb_vmap(struct drm_framebuffer *fb, struct iosys_map *map,
344 struct iosys_map *data)
345{
346 struct drm_gem_object *obj;
347 unsigned int i;
348 int ret;
349
350 for (i = 0; i < fb->format->num_planes; ++i) {
351 obj = drm_gem_fb_get_obj(fb, i);
352 if (!obj) {
353 ret = -EINVAL;
354 goto err_drm_gem_vunmap;
355 }
356 ret = drm_gem_vmap_unlocked(obj, &map[i]);
357 if (ret)
358 goto err_drm_gem_vunmap;
359 }
360
361 if (data) {
362 for (i = 0; i < fb->format->num_planes; ++i) {
363 memcpy(&data[i], &map[i], sizeof(data[i]));
364 if (iosys_map_is_null(&data[i]))
365 continue;
366 iosys_map_incr(&data[i], fb->offsets[i]);
367 }
368 }
369
370 return 0;
371
372err_drm_gem_vunmap:
373 while (i) {
374 --i;
375 obj = drm_gem_fb_get_obj(fb, i);
376 if (!obj)
377 continue;
378 drm_gem_vunmap_unlocked(obj, &map[i]);
379 }
380 return ret;
381}
382EXPORT_SYMBOL(drm_gem_fb_vmap);
383
384/**
385 * drm_gem_fb_vunmap - unmaps framebuffer BOs from kernel address space
386 * @fb: the framebuffer
387 * @map: mapping addresses as returned by drm_gem_fb_vmap()
388 *
389 * This function unmaps all buffer objects of the given framebuffer.
390 *
391 * See drm_gem_fb_vmap() for more information.
392 */
393void drm_gem_fb_vunmap(struct drm_framebuffer *fb, struct iosys_map *map)
394{
395 unsigned int i = fb->format->num_planes;
396 struct drm_gem_object *obj;
397
398 while (i) {
399 --i;
400 obj = drm_gem_fb_get_obj(fb, i);
401 if (!obj)
402 continue;
403 if (iosys_map_is_null(&map[i]))
404 continue;
405 drm_gem_vunmap_unlocked(obj, &map[i]);
406 }
407}
408EXPORT_SYMBOL(drm_gem_fb_vunmap);
409
410static void __drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir,
411 unsigned int num_planes)
412{
413 struct dma_buf_attachment *import_attach;
414 struct drm_gem_object *obj;
415 int ret;
416
417 while (num_planes) {
418 --num_planes;
419 obj = drm_gem_fb_get_obj(fb, num_planes);
420 if (!obj)
421 continue;
422 import_attach = obj->import_attach;
423 if (!import_attach)
424 continue;
425 ret = dma_buf_end_cpu_access(import_attach->dmabuf, dir);
426 if (ret)
427 drm_err(fb->dev, "dma_buf_end_cpu_access(%u, %d) failed: %d\n",
428 ret, num_planes, dir);
429 }
430}
431
432/**
433 * drm_gem_fb_begin_cpu_access - prepares GEM buffer objects for CPU access
434 * @fb: the framebuffer
435 * @dir: access mode
436 *
437 * Prepares a framebuffer's GEM buffer objects for CPU access. This function
438 * must be called before accessing the BO data within the kernel. For imported
439 * BOs, the function calls dma_buf_begin_cpu_access().
440 *
441 * See drm_gem_fb_end_cpu_access() for signalling the end of CPU access.
442 *
443 * Returns:
444 * 0 on success, or a negative errno code otherwise.
445 */
446int drm_gem_fb_begin_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir)
447{
448 struct dma_buf_attachment *import_attach;
449 struct drm_gem_object *obj;
450 unsigned int i;
451 int ret;
452
453 for (i = 0; i < fb->format->num_planes; ++i) {
454 obj = drm_gem_fb_get_obj(fb, i);
455 if (!obj) {
456 ret = -EINVAL;
457 goto err___drm_gem_fb_end_cpu_access;
458 }
459 import_attach = obj->import_attach;
460 if (!import_attach)
461 continue;
462 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, dir);
463 if (ret)
464 goto err___drm_gem_fb_end_cpu_access;
465 }
466
467 return 0;
468
469err___drm_gem_fb_end_cpu_access:
470 __drm_gem_fb_end_cpu_access(fb, dir, i);
471 return ret;
472}
473EXPORT_SYMBOL(drm_gem_fb_begin_cpu_access);
474
475/**
476 * drm_gem_fb_end_cpu_access - signals end of CPU access to GEM buffer objects
477 * @fb: the framebuffer
478 * @dir: access mode
479 *
480 * Signals the end of CPU access to the given framebuffer's GEM buffer objects. This
481 * function must be paired with a corresponding call to drm_gem_fb_begin_cpu_access().
482 * For imported BOs, the function calls dma_buf_end_cpu_access().
483 *
484 * See also drm_gem_fb_begin_cpu_access().
485 */
486void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir)
487{
488 __drm_gem_fb_end_cpu_access(fb, dir, fb->format->num_planes);
489}
490EXPORT_SYMBOL(drm_gem_fb_end_cpu_access);
491
492// TODO Drop this function and replace by drm_format_info_bpp() once all
493// DRM_FORMAT_* provide proper block info in drivers/gpu/drm/drm_fourcc.c
494static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
495 const struct drm_mode_fb_cmd2 *mode_cmd)
496{
497 const struct drm_format_info *info;
498
499 info = drm_get_format_info(dev, mode_cmd);
500
501 switch (info->format) {
502 case DRM_FORMAT_YUV420_8BIT:
503 return 12;
504 case DRM_FORMAT_YUV420_10BIT:
505 return 15;
506 case DRM_FORMAT_VUY101010:
507 return 30;
508 default:
509 return drm_format_info_bpp(info, 0);
510 }
511}
512
513static int drm_gem_afbc_min_size(struct drm_device *dev,
514 const struct drm_mode_fb_cmd2 *mode_cmd,
515 struct drm_afbc_framebuffer *afbc_fb)
516{
517 __u32 n_blocks, w_alignment, h_alignment, hdr_alignment;
518 /* remove bpp when all users properly encode cpp in drm_format_info */
519 __u32 bpp;
520
521 switch (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) {
522 case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16:
523 afbc_fb->block_width = 16;
524 afbc_fb->block_height = 16;
525 break;
526 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8:
527 afbc_fb->block_width = 32;
528 afbc_fb->block_height = 8;
529 break;
530 /* no user exists yet - fall through */
531 case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4:
532 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4:
533 default:
534 drm_dbg_kms(dev, "Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n",
535 mode_cmd->modifier[0]
536 & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK);
537 return -EINVAL;
538 }
539
540 /* tiled header afbc */
541 w_alignment = afbc_fb->block_width;
542 h_alignment = afbc_fb->block_height;
543 hdr_alignment = AFBC_HDR_ALIGN;
544 if (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_TILED) {
545 w_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
546 h_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
547 hdr_alignment = AFBC_TH_BODY_START_ALIGNMENT;
548 }
549
550 afbc_fb->aligned_width = ALIGN(mode_cmd->width, w_alignment);
551 afbc_fb->aligned_height = ALIGN(mode_cmd->height, h_alignment);
552 afbc_fb->offset = mode_cmd->offsets[0];
553
554 bpp = drm_gem_afbc_get_bpp(dev, mode_cmd);
555 if (!bpp) {
556 drm_dbg_kms(dev, "Invalid AFBC bpp value: %d\n", bpp);
557 return -EINVAL;
558 }
559
560 n_blocks = (afbc_fb->aligned_width * afbc_fb->aligned_height)
561 / AFBC_SUPERBLOCK_PIXELS;
562 afbc_fb->afbc_size = ALIGN(n_blocks * AFBC_HEADER_SIZE, hdr_alignment);
563 afbc_fb->afbc_size += n_blocks * ALIGN(bpp * AFBC_SUPERBLOCK_PIXELS / 8,
564 AFBC_SUPERBLOCK_ALIGNMENT);
565
566 return 0;
567}
568
569/**
570 * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to
571 * fill and validate all the afbc-specific
572 * struct drm_afbc_framebuffer members
573 *
574 * @dev: DRM device
575 * @afbc_fb: afbc-specific framebuffer
576 * @mode_cmd: Metadata from the userspace framebuffer creation request
577 * @afbc_fb: afbc framebuffer
578 *
579 * This function can be used by drivers which support afbc to complete
580 * the preparation of struct drm_afbc_framebuffer. It must be called after
581 * allocating the said struct and calling drm_gem_fb_init_with_funcs().
582 * It is caller's responsibility to put afbc_fb->base.obj objects in case
583 * the call is unsuccessful.
584 *
585 * Returns:
586 * Zero on success or a negative error value on failure.
587 */
588int drm_gem_fb_afbc_init(struct drm_device *dev,
589 const struct drm_mode_fb_cmd2 *mode_cmd,
590 struct drm_afbc_framebuffer *afbc_fb)
591{
592 const struct drm_format_info *info;
593 struct drm_gem_object **objs;
594 int ret;
595
596 objs = afbc_fb->base.obj;
597 info = drm_get_format_info(dev, mode_cmd);
598 if (!info)
599 return -EINVAL;
600
601 ret = drm_gem_afbc_min_size(dev, mode_cmd, afbc_fb);
602 if (ret < 0)
603 return ret;
604
605 if (objs[0]->size < afbc_fb->afbc_size)
606 return -EINVAL;
607
608 return 0;
609}
610EXPORT_SYMBOL_GPL(drm_gem_fb_afbc_init);