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 #define AFBC_HEADER_SIZE 16
19 #define AFBC_TH_LAYOUT_ALIGNMENT 8
20 #define AFBC_HDR_ALIGN 64
21 #define AFBC_SUPERBLOCK_PIXELS 256
22 #define AFBC_SUPERBLOCK_ALIGNMENT 128
23 #define AFBC_TH_BODY_START_ALIGNMENT 4096
28 * This library provides helpers for drivers that don't subclass
29 * &drm_framebuffer and use &drm_gem_object for their backing storage.
31 * Drivers without additional needs to validate framebuffers can simply use
32 * drm_gem_fb_create() and everything is wired up automatically. Other drivers
33 * can use all parts independently.
37 * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer
41 * No additional reference is taken beyond the one that the &drm_frambuffer
45 * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL
46 * if it does not exist.
48 struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
54 return fb->obj[plane];
56 EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj);
59 drm_gem_fb_init(struct drm_device *dev,
60 struct drm_framebuffer *fb,
61 const struct drm_mode_fb_cmd2 *mode_cmd,
62 struct drm_gem_object **obj, unsigned int num_planes,
63 const struct drm_framebuffer_funcs *funcs)
67 drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);
69 for (i = 0; i < num_planes; i++)
72 ret = drm_framebuffer_init(dev, fb, funcs);
74 drm_err(dev, "Failed to init framebuffer: %d\n", ret);
80 * drm_gem_fb_destroy - Free GEM backed framebuffer
83 * Frees a GEM backed framebuffer with its backing buffer(s) and the structure
84 * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy
87 void drm_gem_fb_destroy(struct drm_framebuffer *fb)
91 for (i = 0; i < 4; i++)
92 drm_gem_object_put(fb->obj[i]);
94 drm_framebuffer_cleanup(fb);
97 EXPORT_SYMBOL(drm_gem_fb_destroy);
100 * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer
102 * @file: DRM file to register the handle for
103 * @handle: Pointer to return the created handle
105 * This function creates a handle for the GEM object backing the framebuffer.
106 * Drivers can use this as their &drm_framebuffer_funcs->create_handle
107 * callback. The GETFB IOCTL calls into this callback.
110 * 0 on success or a negative error code on failure.
112 int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
113 unsigned int *handle)
115 return drm_gem_handle_create(file, fb->obj[0], handle);
117 EXPORT_SYMBOL(drm_gem_fb_create_handle);
120 * drm_gem_fb_init_with_funcs() - Helper function for implementing
121 * &drm_mode_config_funcs.fb_create
122 * callback in cases when the driver
123 * allocates a subclass of
124 * struct drm_framebuffer
126 * @fb: framebuffer object
127 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
128 * @mode_cmd: Metadata from the userspace framebuffer creation request
129 * @funcs: vtable to be used for the new framebuffer object
131 * This function can be used to set &drm_framebuffer_funcs for drivers that need
132 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
133 * change &drm_framebuffer_funcs. The function does buffer size validation.
134 * The buffer size validation is for a general case, though, so users should
135 * pay attention to the checks being appropriate for them or, at least,
139 * Zero or a negative error code.
141 int drm_gem_fb_init_with_funcs(struct drm_device *dev,
142 struct drm_framebuffer *fb,
143 struct drm_file *file,
144 const struct drm_mode_fb_cmd2 *mode_cmd,
145 const struct drm_framebuffer_funcs *funcs)
147 const struct drm_format_info *info;
148 struct drm_gem_object *objs[4];
151 info = drm_get_format_info(dev, mode_cmd);
153 drm_dbg_kms(dev, "Failed to get FB format info\n");
157 for (i = 0; i < info->num_planes; i++) {
158 unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
159 unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
160 unsigned int min_size;
162 objs[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]);
164 drm_dbg_kms(dev, "Failed to lookup GEM object\n");
166 goto err_gem_object_put;
169 min_size = (height - 1) * mode_cmd->pitches[i]
170 + drm_format_info_min_pitch(info, i, width)
171 + mode_cmd->offsets[i];
173 if (objs[i]->size < min_size) {
175 "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n",
176 objs[i]->size, min_size, i);
177 drm_gem_object_put(objs[i]);
179 goto err_gem_object_put;
183 ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs);
185 goto err_gem_object_put;
190 for (i--; i >= 0; i--)
191 drm_gem_object_put(objs[i]);
195 EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs);
198 * drm_gem_fb_create_with_funcs() - Helper function for the
199 * &drm_mode_config_funcs.fb_create
202 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
203 * @mode_cmd: Metadata from the userspace framebuffer creation request
204 * @funcs: vtable to be used for the new framebuffer object
206 * This function can be used to set &drm_framebuffer_funcs for drivers that need
207 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
208 * change &drm_framebuffer_funcs. The function does buffer size validation.
211 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
213 struct drm_framebuffer *
214 drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
215 const struct drm_mode_fb_cmd2 *mode_cmd,
216 const struct drm_framebuffer_funcs *funcs)
218 struct drm_framebuffer *fb;
221 fb = kzalloc(sizeof(*fb), GFP_KERNEL);
223 return ERR_PTR(-ENOMEM);
225 ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs);
233 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs);
235 static const struct drm_framebuffer_funcs drm_gem_fb_funcs = {
236 .destroy = drm_gem_fb_destroy,
237 .create_handle = drm_gem_fb_create_handle,
241 * drm_gem_fb_create() - Helper function for the
242 * &drm_mode_config_funcs.fb_create callback
244 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
245 * @mode_cmd: Metadata from the userspace framebuffer creation request
247 * This function creates a new framebuffer object described by
248 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
249 * backing the framebuffer.
251 * If your hardware has special alignment or pitch requirements these should be
252 * checked before calling this function. The function does buffer size
253 * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer
256 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
257 * The ADDFB2 IOCTL calls into this callback.
260 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
262 struct drm_framebuffer *
263 drm_gem_fb_create(struct drm_device *dev, struct drm_file *file,
264 const struct drm_mode_fb_cmd2 *mode_cmd)
266 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
269 EXPORT_SYMBOL_GPL(drm_gem_fb_create);
271 static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb = {
272 .destroy = drm_gem_fb_destroy,
273 .create_handle = drm_gem_fb_create_handle,
274 .dirty = drm_atomic_helper_dirtyfb,
278 * drm_gem_fb_create_with_dirty() - Helper function for the
279 * &drm_mode_config_funcs.fb_create callback
281 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
282 * @mode_cmd: Metadata from the userspace framebuffer creation request
284 * This function creates a new framebuffer object described by
285 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
286 * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty
287 * callback giving framebuffer flushing through the atomic machinery. Use
288 * drm_gem_fb_create() if you don't need the dirty callback.
289 * The function does buffer size validation.
291 * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes
292 * to enable userspace to use damage clips also with the ATOMIC IOCTL.
294 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
295 * The ADDFB2 IOCTL calls into this callback.
298 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
300 struct drm_framebuffer *
301 drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file,
302 const struct drm_mode_fb_cmd2 *mode_cmd)
304 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
305 &drm_gem_fb_funcs_dirtyfb);
307 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty);
309 static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
310 const struct drm_mode_fb_cmd2 *mode_cmd)
312 const struct drm_format_info *info;
314 info = drm_get_format_info(dev, mode_cmd);
316 /* use whatever a driver has set */
318 return info->cpp[0] * 8;
320 /* guess otherwise */
321 switch (info->format) {
322 case DRM_FORMAT_YUV420_8BIT:
324 case DRM_FORMAT_YUV420_10BIT:
326 case DRM_FORMAT_VUY101010:
332 /* all attempts failed */
336 static int drm_gem_afbc_min_size(struct drm_device *dev,
337 const struct drm_mode_fb_cmd2 *mode_cmd,
338 struct drm_afbc_framebuffer *afbc_fb)
340 __u32 n_blocks, w_alignment, h_alignment, hdr_alignment;
341 /* remove bpp when all users properly encode cpp in drm_format_info */
344 switch (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) {
345 case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16:
346 afbc_fb->block_width = 16;
347 afbc_fb->block_height = 16;
349 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8:
350 afbc_fb->block_width = 32;
351 afbc_fb->block_height = 8;
353 /* no user exists yet - fall through */
354 case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4:
355 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4:
357 drm_dbg_kms(dev, "Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n",
358 mode_cmd->modifier[0]
359 & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK);
363 /* tiled header afbc */
364 w_alignment = afbc_fb->block_width;
365 h_alignment = afbc_fb->block_height;
366 hdr_alignment = AFBC_HDR_ALIGN;
367 if (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_TILED) {
368 w_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
369 h_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
370 hdr_alignment = AFBC_TH_BODY_START_ALIGNMENT;
373 afbc_fb->aligned_width = ALIGN(mode_cmd->width, w_alignment);
374 afbc_fb->aligned_height = ALIGN(mode_cmd->height, h_alignment);
375 afbc_fb->offset = mode_cmd->offsets[0];
377 bpp = drm_gem_afbc_get_bpp(dev, mode_cmd);
379 drm_dbg_kms(dev, "Invalid AFBC bpp value: %d\n", bpp);
383 n_blocks = (afbc_fb->aligned_width * afbc_fb->aligned_height)
384 / AFBC_SUPERBLOCK_PIXELS;
385 afbc_fb->afbc_size = ALIGN(n_blocks * AFBC_HEADER_SIZE, hdr_alignment);
386 afbc_fb->afbc_size += n_blocks * ALIGN(bpp * AFBC_SUPERBLOCK_PIXELS / 8,
387 AFBC_SUPERBLOCK_ALIGNMENT);
393 * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to
394 * fill and validate all the afbc-specific
395 * struct drm_afbc_framebuffer members
398 * @afbc_fb: afbc-specific framebuffer
399 * @mode_cmd: Metadata from the userspace framebuffer creation request
400 * @afbc_fb: afbc framebuffer
402 * This function can be used by drivers which support afbc to complete
403 * the preparation of struct drm_afbc_framebuffer. It must be called after
404 * allocating the said struct and calling drm_gem_fb_init_with_funcs().
405 * It is caller's responsibility to put afbc_fb->base.obj objects in case
406 * the call is unsuccessful.
409 * Zero on success or a negative error value on failure.
411 int drm_gem_fb_afbc_init(struct drm_device *dev,
412 const struct drm_mode_fb_cmd2 *mode_cmd,
413 struct drm_afbc_framebuffer *afbc_fb)
415 const struct drm_format_info *info;
416 struct drm_gem_object **objs;
419 objs = afbc_fb->base.obj;
420 info = drm_get_format_info(dev, mode_cmd);
424 ret = drm_gem_afbc_min_size(dev, mode_cmd, afbc_fb);
428 if (objs[0]->size < afbc_fb->afbc_size)
433 EXPORT_SYMBOL_GPL(drm_gem_fb_afbc_init);