1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * drm gem framebuffer helper functions
5 * Copyright (C) 2017 Noralf Trønnes
8 #include <linux/slab.h>
10 #include <drm/drm_damage_helper.h>
11 #include <drm/drm_fb_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>
18 #include "drm_internal.h"
20 #define AFBC_HEADER_SIZE 16
21 #define AFBC_TH_LAYOUT_ALIGNMENT 8
22 #define AFBC_HDR_ALIGN 64
23 #define AFBC_SUPERBLOCK_PIXELS 256
24 #define AFBC_SUPERBLOCK_ALIGNMENT 128
25 #define AFBC_TH_BODY_START_ALIGNMENT 4096
30 * This library provides helpers for drivers that don't subclass
31 * &drm_framebuffer and use &drm_gem_object for their backing storage.
33 * Drivers without additional needs to validate framebuffers can simply use
34 * drm_gem_fb_create() and everything is wired up automatically. Other drivers
35 * can use all parts independently.
39 * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer
43 * No additional reference is taken beyond the one that the &drm_frambuffer
47 * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL
48 * if it does not exist.
50 struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
53 if (plane >= ARRAY_SIZE(fb->obj))
56 return fb->obj[plane];
58 EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj);
61 drm_gem_fb_init(struct drm_device *dev,
62 struct drm_framebuffer *fb,
63 const struct drm_mode_fb_cmd2 *mode_cmd,
64 struct drm_gem_object **obj, unsigned int num_planes,
65 const struct drm_framebuffer_funcs *funcs)
70 drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);
72 for (i = 0; i < num_planes; i++)
75 ret = drm_framebuffer_init(dev, fb, funcs);
77 drm_err(dev, "Failed to init framebuffer: %d\n", ret);
83 * drm_gem_fb_destroy - Free GEM backed framebuffer
86 * Frees a GEM backed framebuffer with its backing buffer(s) and the structure
87 * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy
90 void drm_gem_fb_destroy(struct drm_framebuffer *fb)
94 for (i = 0; i < ARRAY_SIZE(fb->obj); i++)
95 drm_gem_object_put(fb->obj[i]);
97 drm_framebuffer_cleanup(fb);
100 EXPORT_SYMBOL(drm_gem_fb_destroy);
103 * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer
105 * @file: DRM file to register the handle for
106 * @handle: Pointer to return the created handle
108 * This function creates a handle for the GEM object backing the framebuffer.
109 * Drivers can use this as their &drm_framebuffer_funcs->create_handle
110 * callback. The GETFB IOCTL calls into this callback.
113 * 0 on success or a negative error code on failure.
115 int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
116 unsigned int *handle)
118 return drm_gem_handle_create(file, fb->obj[0], handle);
120 EXPORT_SYMBOL(drm_gem_fb_create_handle);
123 * drm_gem_fb_init_with_funcs() - Helper function for implementing
124 * &drm_mode_config_funcs.fb_create
125 * callback in cases when the driver
126 * allocates a subclass of
127 * struct drm_framebuffer
129 * @fb: framebuffer object
130 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
131 * @mode_cmd: Metadata from the userspace framebuffer creation request
132 * @funcs: vtable to be used for the new framebuffer object
134 * This function can be used to set &drm_framebuffer_funcs for drivers that need
135 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
136 * change &drm_framebuffer_funcs. The function does buffer size validation.
137 * The buffer size validation is for a general case, though, so users should
138 * pay attention to the checks being appropriate for them or, at least,
142 * Zero or a negative error code.
144 int drm_gem_fb_init_with_funcs(struct drm_device *dev,
145 struct drm_framebuffer *fb,
146 struct drm_file *file,
147 const struct drm_mode_fb_cmd2 *mode_cmd,
148 const struct drm_framebuffer_funcs *funcs)
150 const struct drm_format_info *info;
151 struct drm_gem_object *objs[DRM_FORMAT_MAX_PLANES];
155 info = drm_get_format_info(dev, mode_cmd);
157 drm_dbg_kms(dev, "Failed to get FB format info\n");
161 for (i = 0; i < info->num_planes; i++) {
162 unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
163 unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
164 unsigned int min_size;
166 objs[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]);
168 drm_dbg_kms(dev, "Failed to lookup GEM object\n");
170 goto err_gem_object_put;
173 min_size = (height - 1) * mode_cmd->pitches[i]
174 + drm_format_info_min_pitch(info, i, width)
175 + mode_cmd->offsets[i];
177 if (objs[i]->size < min_size) {
179 "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n",
180 objs[i]->size, min_size, i);
181 drm_gem_object_put(objs[i]);
183 goto err_gem_object_put;
187 ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs);
189 goto err_gem_object_put;
196 drm_gem_object_put(objs[i]);
200 EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs);
203 * drm_gem_fb_create_with_funcs() - Helper function for the
204 * &drm_mode_config_funcs.fb_create
207 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
208 * @mode_cmd: Metadata from the userspace framebuffer creation request
209 * @funcs: vtable to be used for the new framebuffer object
211 * This function can be used to set &drm_framebuffer_funcs for drivers that need
212 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
213 * change &drm_framebuffer_funcs. The function does buffer size validation.
216 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
218 struct drm_framebuffer *
219 drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
220 const struct drm_mode_fb_cmd2 *mode_cmd,
221 const struct drm_framebuffer_funcs *funcs)
223 struct drm_framebuffer *fb;
226 fb = kzalloc(sizeof(*fb), GFP_KERNEL);
228 return ERR_PTR(-ENOMEM);
230 ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs);
238 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs);
240 static const struct drm_framebuffer_funcs drm_gem_fb_funcs = {
241 .destroy = drm_gem_fb_destroy,
242 .create_handle = drm_gem_fb_create_handle,
246 * drm_gem_fb_create() - Helper function for the
247 * &drm_mode_config_funcs.fb_create callback
249 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
250 * @mode_cmd: Metadata from the userspace framebuffer creation request
252 * This function creates a new framebuffer object described by
253 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
254 * backing the framebuffer.
256 * If your hardware has special alignment or pitch requirements these should be
257 * checked before calling this function. The function does buffer size
258 * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer
261 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
262 * The ADDFB2 IOCTL calls into this callback.
265 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
267 struct drm_framebuffer *
268 drm_gem_fb_create(struct drm_device *dev, struct drm_file *file,
269 const struct drm_mode_fb_cmd2 *mode_cmd)
271 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
274 EXPORT_SYMBOL_GPL(drm_gem_fb_create);
276 static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb = {
277 .destroy = drm_gem_fb_destroy,
278 .create_handle = drm_gem_fb_create_handle,
279 .dirty = drm_atomic_helper_dirtyfb,
283 * drm_gem_fb_create_with_dirty() - Helper function for the
284 * &drm_mode_config_funcs.fb_create callback
286 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
287 * @mode_cmd: Metadata from the userspace framebuffer creation request
289 * This function creates a new framebuffer object described by
290 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
291 * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty
292 * callback giving framebuffer flushing through the atomic machinery. Use
293 * drm_gem_fb_create() if you don't need the dirty callback.
294 * The function does buffer size validation.
296 * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes
297 * to enable userspace to use damage clips also with the ATOMIC IOCTL.
299 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
300 * The ADDFB2 IOCTL calls into this callback.
303 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
305 struct drm_framebuffer *
306 drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file,
307 const struct drm_mode_fb_cmd2 *mode_cmd)
309 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
310 &drm_gem_fb_funcs_dirtyfb);
312 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty);
315 * drm_gem_fb_vmap - maps all framebuffer BOs into kernel address space
316 * @fb: the framebuffer
317 * @map: returns the mapping's address for each BO
318 * @data: returns the data address for each BO, can be NULL
320 * This function maps all buffer objects of the given framebuffer into
321 * kernel address space and stores them in struct dma_buf_map. If the
322 * mapping operation fails for one of the BOs, the function unmaps the
323 * already established mappings automatically.
325 * Callers that want to access a BO's stored data should pass @data.
326 * The argument returns the addresses of the data stored in each BO. This
327 * is different from @map if the framebuffer's offsets field is non-zero.
329 * See drm_gem_fb_vunmap() for unmapping.
332 * 0 on success, or a negative errno code otherwise.
334 int drm_gem_fb_vmap(struct drm_framebuffer *fb,
335 struct dma_buf_map map[static DRM_FORMAT_MAX_PLANES],
336 struct dma_buf_map data[DRM_FORMAT_MAX_PLANES])
338 struct drm_gem_object *obj;
342 for (i = 0; i < DRM_FORMAT_MAX_PLANES; ++i) {
343 obj = drm_gem_fb_get_obj(fb, i);
345 dma_buf_map_clear(&map[i]);
348 ret = drm_gem_vmap(obj, &map[i]);
350 goto err_drm_gem_vunmap;
354 for (i = 0; i < DRM_FORMAT_MAX_PLANES; ++i) {
355 memcpy(&data[i], &map[i], sizeof(data[i]));
356 if (dma_buf_map_is_null(&data[i]))
358 dma_buf_map_incr(&data[i], fb->offsets[i]);
367 obj = drm_gem_fb_get_obj(fb, i);
370 drm_gem_vunmap(obj, &map[i]);
374 EXPORT_SYMBOL(drm_gem_fb_vmap);
377 * drm_gem_fb_vunmap - unmaps framebuffer BOs from kernel address space
378 * @fb: the framebuffer
379 * @map: mapping addresses as returned by drm_gem_fb_vmap()
381 * This function unmaps all buffer objects of the given framebuffer.
383 * See drm_gem_fb_vmap() for more information.
385 void drm_gem_fb_vunmap(struct drm_framebuffer *fb,
386 struct dma_buf_map map[static DRM_FORMAT_MAX_PLANES])
388 unsigned int i = DRM_FORMAT_MAX_PLANES;
389 struct drm_gem_object *obj;
393 obj = drm_gem_fb_get_obj(fb, i);
396 if (dma_buf_map_is_null(&map[i]))
398 drm_gem_vunmap(obj, &map[i]);
401 EXPORT_SYMBOL(drm_gem_fb_vunmap);
404 * drm_gem_fb_begin_cpu_access - prepares GEM buffer objects for CPU access
405 * @fb: the framebuffer
408 * Prepares a framebuffer's GEM buffer objects for CPU access. This function
409 * must be called before accessing the BO data within the kernel. For imported
410 * BOs, the function calls dma_buf_begin_cpu_access().
412 * See drm_gem_fb_end_cpu_access() for signalling the end of CPU access.
415 * 0 on success, or a negative errno code otherwise.
417 int drm_gem_fb_begin_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir)
419 struct dma_buf_attachment *import_attach;
420 struct drm_gem_object *obj;
424 for (i = 0; i < ARRAY_SIZE(fb->obj); ++i) {
425 obj = drm_gem_fb_get_obj(fb, i);
428 import_attach = obj->import_attach;
431 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, dir);
433 goto err_dma_buf_end_cpu_access;
438 err_dma_buf_end_cpu_access:
441 obj = drm_gem_fb_get_obj(fb, i);
444 import_attach = obj->import_attach;
447 ret2 = dma_buf_end_cpu_access(import_attach->dmabuf, dir);
450 "dma_buf_end_cpu_access() failed during error handling: %d\n",
457 EXPORT_SYMBOL(drm_gem_fb_begin_cpu_access);
460 * drm_gem_fb_end_cpu_access - signals end of CPU access to GEM buffer objects
461 * @fb: the framebuffer
464 * Signals the end of CPU access to the given framebuffer's GEM buffer objects. This
465 * function must be paired with a corresponding call to drm_gem_fb_begin_cpu_access().
466 * For imported BOs, the function calls dma_buf_end_cpu_access().
468 * See also drm_gem_fb_begin_cpu_access().
470 void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir)
472 size_t i = ARRAY_SIZE(fb->obj);
473 struct dma_buf_attachment *import_attach;
474 struct drm_gem_object *obj;
479 obj = drm_gem_fb_get_obj(fb, i);
482 import_attach = obj->import_attach;
485 ret = dma_buf_end_cpu_access(import_attach->dmabuf, dir);
487 drm_err(fb->dev, "dma_buf_end_cpu_access() failed: %d\n", ret);
490 EXPORT_SYMBOL(drm_gem_fb_end_cpu_access);
492 static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
493 const struct drm_mode_fb_cmd2 *mode_cmd)
495 const struct drm_format_info *info;
497 info = drm_get_format_info(dev, mode_cmd);
499 /* use whatever a driver has set */
501 return info->cpp[0] * 8;
503 /* guess otherwise */
504 switch (info->format) {
505 case DRM_FORMAT_YUV420_8BIT:
507 case DRM_FORMAT_YUV420_10BIT:
509 case DRM_FORMAT_VUY101010:
515 /* all attempts failed */
519 static int drm_gem_afbc_min_size(struct drm_device *dev,
520 const struct drm_mode_fb_cmd2 *mode_cmd,
521 struct drm_afbc_framebuffer *afbc_fb)
523 __u32 n_blocks, w_alignment, h_alignment, hdr_alignment;
524 /* remove bpp when all users properly encode cpp in drm_format_info */
527 switch (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) {
528 case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16:
529 afbc_fb->block_width = 16;
530 afbc_fb->block_height = 16;
532 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8:
533 afbc_fb->block_width = 32;
534 afbc_fb->block_height = 8;
536 /* no user exists yet - fall through */
537 case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4:
538 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4:
540 drm_dbg_kms(dev, "Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n",
541 mode_cmd->modifier[0]
542 & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK);
546 /* tiled header afbc */
547 w_alignment = afbc_fb->block_width;
548 h_alignment = afbc_fb->block_height;
549 hdr_alignment = AFBC_HDR_ALIGN;
550 if (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_TILED) {
551 w_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
552 h_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
553 hdr_alignment = AFBC_TH_BODY_START_ALIGNMENT;
556 afbc_fb->aligned_width = ALIGN(mode_cmd->width, w_alignment);
557 afbc_fb->aligned_height = ALIGN(mode_cmd->height, h_alignment);
558 afbc_fb->offset = mode_cmd->offsets[0];
560 bpp = drm_gem_afbc_get_bpp(dev, mode_cmd);
562 drm_dbg_kms(dev, "Invalid AFBC bpp value: %d\n", bpp);
566 n_blocks = (afbc_fb->aligned_width * afbc_fb->aligned_height)
567 / AFBC_SUPERBLOCK_PIXELS;
568 afbc_fb->afbc_size = ALIGN(n_blocks * AFBC_HEADER_SIZE, hdr_alignment);
569 afbc_fb->afbc_size += n_blocks * ALIGN(bpp * AFBC_SUPERBLOCK_PIXELS / 8,
570 AFBC_SUPERBLOCK_ALIGNMENT);
576 * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to
577 * fill and validate all the afbc-specific
578 * struct drm_afbc_framebuffer members
581 * @afbc_fb: afbc-specific framebuffer
582 * @mode_cmd: Metadata from the userspace framebuffer creation request
583 * @afbc_fb: afbc framebuffer
585 * This function can be used by drivers which support afbc to complete
586 * the preparation of struct drm_afbc_framebuffer. It must be called after
587 * allocating the said struct and calling drm_gem_fb_init_with_funcs().
588 * It is caller's responsibility to put afbc_fb->base.obj objects in case
589 * the call is unsuccessful.
592 * Zero on success or a negative error value on failure.
594 int drm_gem_fb_afbc_init(struct drm_device *dev,
595 const struct drm_mode_fb_cmd2 *mode_cmd,
596 struct drm_afbc_framebuffer *afbc_fb)
598 const struct drm_format_info *info;
599 struct drm_gem_object **objs;
602 objs = afbc_fb->base.obj;
603 info = drm_get_format_info(dev, mode_cmd);
607 ret = drm_gem_afbc_min_size(dev, mode_cmd, afbc_fb);
611 if (objs[0]->size < afbc_fb->afbc_size)
616 EXPORT_SYMBOL_GPL(drm_gem_fb_afbc_init);