1/* $NetBSD: drm_framebuffer.h,v 1.2 2021/12/18 23:45:46 riastradh Exp $ */ 2 3/* 4 * Copyright (c) 2016 Intel Corporation 5 * 6 * Permission to use, copy, modify, distribute, and sell this software and its 7 * documentation for any purpose is hereby granted without fee, provided that 8 * the above copyright notice appear in all copies and that both that copyright 9 * notice and this permission notice appear in supporting documentation, and 10 * that the name of the copyright holders not be used in advertising or 11 * publicity pertaining to distribution of the software without specific, 12 * written prior permission. The copyright holders make no representations 13 * about the suitability of this software for any purpose. It is provided "as 14 * is" without express or implied warranty. 15 * 16 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 17 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO 18 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR 19 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, 20 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 21 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 22 * OF THIS SOFTWARE. 23 */ 24 25#ifndef __DRM_FRAMEBUFFER_H__ 26#define __DRM_FRAMEBUFFER_H__ 27 28#include <linux/ctype.h> 29#include <linux/list.h> 30#include <linux/sched.h> 31 32#include <drm/drm_mode_object.h> 33 34struct drm_clip_rect; 35struct drm_device; 36struct drm_file; 37struct drm_format_info; 38struct drm_framebuffer; 39struct drm_gem_object; 40 41/** 42 * struct drm_framebuffer_funcs - framebuffer hooks 43 */ 44struct drm_framebuffer_funcs { 45 /** 46 * @destroy: 47 * 48 * Clean up framebuffer resources, specifically also unreference the 49 * backing storage. The core guarantees to call this function for every 50 * framebuffer successfully created by calling 51 * &drm_mode_config_funcs.fb_create. Drivers must also call 52 * drm_framebuffer_cleanup() to release DRM core resources for this 53 * framebuffer. 54 */ 55 void (*destroy)(struct drm_framebuffer *framebuffer); 56 57 /** 58 * @create_handle: 59 * 60 * Create a buffer handle in the driver-specific buffer manager (either 61 * GEM or TTM) valid for the passed-in &struct drm_file. This is used by 62 * the core to implement the GETFB IOCTL, which returns (for 63 * sufficiently priviledged user) also a native buffer handle. This can 64 * be used for seamless transitions between modesetting clients by 65 * copying the current screen contents to a private buffer and blending 66 * between that and the new contents. 67 * 68 * GEM based drivers should call drm_gem_handle_create() to create the 69 * handle. 70 * 71 * RETURNS: 72 * 73 * 0 on success or a negative error code on failure. 74 */ 75 int (*create_handle)(struct drm_framebuffer *fb, 76 struct drm_file *file_priv, 77 unsigned int *handle); 78 /** 79 * @dirty: 80 * 81 * Optional callback for the dirty fb IOCTL. 82 * 83 * Userspace can notify the driver via this callback that an area of the 84 * framebuffer has changed and should be flushed to the display 85 * hardware. This can also be used internally, e.g. by the fbdev 86 * emulation, though that's not the case currently. 87 * 88 * See documentation in drm_mode.h for the struct drm_mode_fb_dirty_cmd 89 * for more information as all the semantics and arguments have a one to 90 * one mapping on this function. 91 * 92 * Atomic drivers should use drm_atomic_helper_dirtyfb() to implement 93 * this hook. 94 * 95 * RETURNS: 96 * 97 * 0 on success or a negative error code on failure. 98 */ 99 int (*dirty)(struct drm_framebuffer *framebuffer, 100 struct drm_file *file_priv, unsigned flags, 101 unsigned color, struct drm_clip_rect *clips, 102 unsigned num_clips); 103}; 104 105/** 106 * struct drm_framebuffer - frame buffer object 107 * 108 * Note that the fb is refcounted for the benefit of driver internals, 109 * for example some hw, disabling a CRTC/plane is asynchronous, and 110 * scanout does not actually complete until the next vblank. So some 111 * cleanup (like releasing the reference(s) on the backing GEM bo(s)) 112 * should be deferred. In cases like this, the driver would like to 113 * hold a ref to the fb even though it has already been removed from 114 * userspace perspective. See drm_framebuffer_get() and 115 * drm_framebuffer_put(). 116 * 117 * The refcount is stored inside the mode object @base. 118 */ 119struct drm_framebuffer { 120 /** 121 * @dev: DRM device this framebuffer belongs to 122 */ 123 struct drm_device *dev; 124 /** 125 * @head: Place on the &drm_mode_config.fb_list, access protected by 126 * &drm_mode_config.fb_lock. 127 */ 128 struct list_head head; 129 130 /** 131 * @base: base modeset object structure, contains the reference count. 132 */ 133 struct drm_mode_object base; 134 135 /** 136 * @comm: Name of the process allocating the fb, used for fb dumping. 137 */ 138 char comm[TASK_COMM_LEN]; 139 140 /** 141 * @format: framebuffer format information 142 */ 143 const struct drm_format_info *format; 144 /** 145 * @funcs: framebuffer vfunc table 146 */ 147 const struct drm_framebuffer_funcs *funcs; 148 /** 149 * @pitches: Line stride per buffer. For userspace created object this 150 * is copied from drm_mode_fb_cmd2. 151 */ 152 unsigned int pitches[4]; 153 /** 154 * @offsets: Offset from buffer start to the actual pixel data in bytes, 155 * per buffer. For userspace created object this is copied from 156 * drm_mode_fb_cmd2. 157 * 158 * Note that this is a linear offset and does not take into account 159 * tiling or buffer laytou per @modifier. It meant to be used when the 160 * actual pixel data for this framebuffer plane starts at an offset, 161 * e.g. when multiple planes are allocated within the same backing 162 * storage buffer object. For tiled layouts this generally means it 163 * @offsets must at least be tile-size aligned, but hardware often has 164 * stricter requirements. 165 * 166 * This should not be used to specifiy x/y pixel offsets into the buffer 167 * data (even for linear buffers). Specifying an x/y pixel offset is 168 * instead done through the source rectangle in &struct drm_plane_state. 169 */ 170 unsigned int offsets[4]; 171 /** 172 * @modifier: Data layout modifier. This is used to describe 173 * tiling, or also special layouts (like compression) of auxiliary 174 * buffers. For userspace created object this is copied from 175 * drm_mode_fb_cmd2. 176 */ 177 uint64_t modifier; 178 /** 179 * @width: Logical width of the visible area of the framebuffer, in 180 * pixels. 181 */ 182 unsigned int width; 183 /** 184 * @height: Logical height of the visible area of the framebuffer, in 185 * pixels. 186 */ 187 unsigned int height; 188 /** 189 * @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or 190 * DRM_MODE_FB_MODIFIERS. 191 */ 192 int flags; 193 /** 194 * @hot_x: X coordinate of the cursor hotspot. Used by the legacy cursor 195 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR 196 * universal plane. 197 */ 198 int hot_x; 199 /** 200 * @hot_y: Y coordinate of the cursor hotspot. Used by the legacy cursor 201 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR 202 * universal plane. 203 */ 204 int hot_y; 205 /** 206 * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock. 207 */ 208 struct list_head filp_head; 209 /** 210 * @obj: GEM objects backing the framebuffer, one per plane (optional). 211 * 212 * This is used by the GEM framebuffer helpers, see e.g. 213 * drm_gem_fb_create(). 214 */ 215 struct drm_gem_object *obj[4]; 216}; 217 218#define obj_to_fb(x) container_of(x, struct drm_framebuffer, base) 219 220int drm_framebuffer_init(struct drm_device *dev, 221 struct drm_framebuffer *fb, 222 const struct drm_framebuffer_funcs *funcs); 223struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev, 224 struct drm_file *file_priv, 225 uint32_t id); 226void drm_framebuffer_remove(struct drm_framebuffer *fb); 227void drm_framebuffer_cleanup(struct drm_framebuffer *fb); 228void drm_framebuffer_unregister_private(struct drm_framebuffer *fb); 229 230/** 231 * drm_framebuffer_get - acquire a framebuffer reference 232 * @fb: DRM framebuffer 233 * 234 * This function increments the framebuffer's reference count. 235 */ 236static inline void drm_framebuffer_get(struct drm_framebuffer *fb) 237{ 238 drm_mode_object_get(&fb->base); 239} 240 241/** 242 * drm_framebuffer_put - release a framebuffer reference 243 * @fb: DRM framebuffer 244 * 245 * This function decrements the framebuffer's reference count and frees the 246 * framebuffer if the reference count drops to zero. 247 */ 248static inline void drm_framebuffer_put(struct drm_framebuffer *fb) 249{ 250 drm_mode_object_put(&fb->base); 251} 252 253/** 254 * drm_framebuffer_read_refcount - read the framebuffer reference count. 255 * @fb: framebuffer 256 * 257 * This functions returns the framebuffer's reference count. 258 */ 259static inline uint32_t drm_framebuffer_read_refcount(const struct drm_framebuffer *fb) 260{ 261 return kref_read(&fb->base.refcount); 262} 263 264/** 265 * drm_framebuffer_assign - store a reference to the fb 266 * @p: location to store framebuffer 267 * @fb: new framebuffer (maybe NULL) 268 * 269 * This functions sets the location to store a reference to the framebuffer, 270 * unreferencing the framebuffer that was previously stored in that location. 271 */ 272static inline void drm_framebuffer_assign(struct drm_framebuffer **p, 273 struct drm_framebuffer *fb) 274{ 275 if (fb) 276 drm_framebuffer_get(fb); 277 if (*p) 278 drm_framebuffer_put(*p); 279 *p = fb; 280} 281 282/* 283 * drm_for_each_fb - iterate over all framebuffers 284 * @fb: the loop cursor 285 * @dev: the DRM device 286 * 287 * Iterate over all framebuffers of @dev. User must hold 288 * &drm_mode_config.fb_lock. 289 */ 290#define drm_for_each_fb(fb, dev) \ 291 for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)), \ 292 fb = list_first_entry(&(dev)->mode_config.fb_list, \ 293 struct drm_framebuffer, head); \ 294 &fb->head != (&(dev)->mode_config.fb_list); \ 295 fb = list_next_entry(fb, head)) 296 297int drm_framebuffer_plane_width(int width, 298 const struct drm_framebuffer *fb, int plane); 299int drm_framebuffer_plane_height(int height, 300 const struct drm_framebuffer *fb, int plane); 301 302#endif 303