1 // SPDX-License-Identifier: MIT 2 3 #include <linux/fb.h> 4 5 #include <drm/drm_crtc_helper.h> 6 #include <drm/drm_drv.h> 7 #include <drm/drm_fb_helper.h> 8 #include <drm/drm_framebuffer.h> 9 #include <drm/drm_gem_framebuffer_helper.h> 10 #include <drm/drm_gem_shmem_helper.h> 11 12 #include <drm/drm_fbdev_shmem.h> 13 14 /* 15 * struct fb_ops 16 */ 17 18 static int drm_fbdev_shmem_fb_open(struct fb_info *info, int user) 19 { 20 struct drm_fb_helper *fb_helper = info->par; 21 22 /* No need to take a ref for fbcon because it unbinds on unregister */ 23 if (user && !try_module_get(fb_helper->dev->driver->fops->owner)) 24 return -ENODEV; 25 26 return 0; 27 } 28 29 static int drm_fbdev_shmem_fb_release(struct fb_info *info, int user) 30 { 31 struct drm_fb_helper *fb_helper = info->par; 32 33 if (user) 34 module_put(fb_helper->dev->driver->fops->owner); 35 36 return 0; 37 } 38 39 FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_shmem, 40 drm_fb_helper_damage_range, 41 drm_fb_helper_damage_area); 42 43 static int drm_fbdev_shmem_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 44 { 45 struct drm_fb_helper *fb_helper = info->par; 46 struct drm_framebuffer *fb = fb_helper->fb; 47 struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0); 48 struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); 49 50 if (shmem->map_wc) 51 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 52 53 return fb_deferred_io_mmap(info, vma); 54 } 55 56 static void drm_fbdev_shmem_fb_destroy(struct fb_info *info) 57 { 58 struct drm_fb_helper *fb_helper = info->par; 59 60 if (!fb_helper->dev) 61 return; 62 63 fb_deferred_io_cleanup(info); 64 drm_fb_helper_fini(fb_helper); 65 66 drm_client_buffer_vunmap(fb_helper->buffer); 67 drm_client_framebuffer_delete(fb_helper->buffer); 68 drm_client_release(&fb_helper->client); 69 drm_fb_helper_unprepare(fb_helper); 70 kfree(fb_helper); 71 } 72 73 static const struct fb_ops drm_fbdev_shmem_fb_ops = { 74 .owner = THIS_MODULE, 75 .fb_open = drm_fbdev_shmem_fb_open, 76 .fb_release = drm_fbdev_shmem_fb_release, 77 __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_shmem), 78 DRM_FB_HELPER_DEFAULT_OPS, 79 __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_shmem), 80 .fb_mmap = drm_fbdev_shmem_fb_mmap, 81 .fb_destroy = drm_fbdev_shmem_fb_destroy, 82 }; 83 84 static struct page *drm_fbdev_shmem_get_page(struct fb_info *info, unsigned long offset) 85 { 86 struct drm_fb_helper *fb_helper = info->par; 87 struct drm_framebuffer *fb = fb_helper->fb; 88 struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0); 89 struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); 90 unsigned int i = offset >> PAGE_SHIFT; 91 struct page *page; 92 93 if (fb_WARN_ON_ONCE(info, offset > obj->size)) 94 return NULL; 95 96 page = shmem->pages[i]; // protected by active vmap 97 if (page) 98 get_page(page); 99 fb_WARN_ON_ONCE(info, !page); 100 101 return page; 102 } 103 104 /* 105 * struct drm_fb_helper 106 */ 107 108 static int drm_fbdev_shmem_helper_fb_probe(struct drm_fb_helper *fb_helper, 109 struct drm_fb_helper_surface_size *sizes) 110 { 111 return drm_fbdev_shmem_driver_fbdev_probe(fb_helper, sizes); 112 } 113 114 static int drm_fbdev_shmem_helper_fb_dirty(struct drm_fb_helper *helper, 115 struct drm_clip_rect *clip) 116 { 117 struct drm_device *dev = helper->dev; 118 int ret; 119 120 /* Call damage handlers only if necessary */ 121 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) 122 return 0; 123 124 if (helper->fb->funcs->dirty) { 125 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); 126 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) 127 return ret; 128 } 129 130 return 0; 131 } 132 133 static const struct drm_fb_helper_funcs drm_fbdev_shmem_helper_funcs = { 134 .fb_probe = drm_fbdev_shmem_helper_fb_probe, 135 .fb_dirty = drm_fbdev_shmem_helper_fb_dirty, 136 }; 137 138 /* 139 * struct drm_driver 140 */ 141 142 int drm_fbdev_shmem_driver_fbdev_probe(struct drm_fb_helper *fb_helper, 143 struct drm_fb_helper_surface_size *sizes) 144 { 145 struct drm_client_dev *client = &fb_helper->client; 146 struct drm_device *dev = fb_helper->dev; 147 struct drm_client_buffer *buffer; 148 struct drm_gem_shmem_object *shmem; 149 struct drm_framebuffer *fb; 150 struct fb_info *info; 151 u32 format; 152 struct iosys_map map; 153 int ret; 154 155 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 156 sizes->surface_width, sizes->surface_height, 157 sizes->surface_bpp); 158 159 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, sizes->surface_depth); 160 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 161 sizes->surface_height, format); 162 if (IS_ERR(buffer)) 163 return PTR_ERR(buffer); 164 shmem = to_drm_gem_shmem_obj(buffer->gem); 165 166 fb = buffer->fb; 167 168 ret = drm_client_buffer_vmap(buffer, &map); 169 if (ret) { 170 goto err_drm_client_buffer_delete; 171 } else if (drm_WARN_ON(dev, map.is_iomem)) { 172 ret = -ENODEV; /* I/O memory not supported; use generic emulation */ 173 goto err_drm_client_buffer_delete; 174 } 175 176 fb_helper->funcs = &drm_fbdev_shmem_helper_funcs; 177 fb_helper->buffer = buffer; 178 fb_helper->fb = fb; 179 180 info = drm_fb_helper_alloc_info(fb_helper); 181 if (IS_ERR(info)) { 182 ret = PTR_ERR(info); 183 goto err_drm_client_buffer_vunmap; 184 } 185 186 drm_fb_helper_fill_info(info, fb_helper, sizes); 187 188 info->fbops = &drm_fbdev_shmem_fb_ops; 189 190 /* screen */ 191 info->flags |= FBINFO_VIRTFB; /* system memory */ 192 if (!shmem->map_wc) 193 info->flags |= FBINFO_READS_FAST; /* signal caching */ 194 info->screen_size = sizes->surface_height * fb->pitches[0]; 195 info->screen_buffer = map.vaddr; 196 info->fix.smem_len = info->screen_size; 197 198 /* deferred I/O */ 199 fb_helper->fbdefio.delay = HZ / 20; 200 fb_helper->fbdefio.get_page = drm_fbdev_shmem_get_page; 201 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 202 203 info->fbdefio = &fb_helper->fbdefio; 204 ret = fb_deferred_io_init(info); 205 if (ret) 206 goto err_drm_fb_helper_release_info; 207 208 return 0; 209 210 err_drm_fb_helper_release_info: 211 drm_fb_helper_release_info(fb_helper); 212 err_drm_client_buffer_vunmap: 213 fb_helper->fb = NULL; 214 fb_helper->buffer = NULL; 215 drm_client_buffer_vunmap(buffer); 216 err_drm_client_buffer_delete: 217 drm_client_framebuffer_delete(buffer); 218 return ret; 219 } 220 EXPORT_SYMBOL(drm_fbdev_shmem_driver_fbdev_probe); 221 222 /* 223 * struct drm_client_funcs 224 */ 225 226 static void drm_fbdev_shmem_client_unregister(struct drm_client_dev *client) 227 { 228 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 229 230 if (fb_helper->info) { 231 drm_fb_helper_unregister_info(fb_helper); 232 } else { 233 drm_client_release(&fb_helper->client); 234 drm_fb_helper_unprepare(fb_helper); 235 kfree(fb_helper); 236 } 237 } 238 239 static int drm_fbdev_shmem_client_restore(struct drm_client_dev *client) 240 { 241 drm_fb_helper_lastclose(client->dev); 242 243 return 0; 244 } 245 246 static int drm_fbdev_shmem_client_hotplug(struct drm_client_dev *client) 247 { 248 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 249 struct drm_device *dev = client->dev; 250 int ret; 251 252 if (dev->fb_helper) 253 return drm_fb_helper_hotplug_event(dev->fb_helper); 254 255 ret = drm_fb_helper_init(dev, fb_helper); 256 if (ret) 257 goto err_drm_err; 258 259 if (!drm_drv_uses_atomic_modeset(dev)) 260 drm_helper_disable_unused_functions(dev); 261 262 ret = drm_fb_helper_initial_config(fb_helper); 263 if (ret) 264 goto err_drm_fb_helper_fini; 265 266 return 0; 267 268 err_drm_fb_helper_fini: 269 drm_fb_helper_fini(fb_helper); 270 err_drm_err: 271 drm_err(dev, "fbdev-shmem: Failed to setup emulation (ret=%d)\n", ret); 272 return ret; 273 } 274 275 static const struct drm_client_funcs drm_fbdev_shmem_client_funcs = { 276 .owner = THIS_MODULE, 277 .unregister = drm_fbdev_shmem_client_unregister, 278 .restore = drm_fbdev_shmem_client_restore, 279 .hotplug = drm_fbdev_shmem_client_hotplug, 280 }; 281 282 /** 283 * drm_fbdev_shmem_setup() - Setup fbdev emulation for GEM SHMEM helpers 284 * @dev: DRM device 285 * @preferred_bpp: Preferred bits per pixel for the device. 286 * 32 is used if this is zero. 287 * 288 * This function sets up fbdev emulation for GEM DMA drivers that support 289 * dumb buffers with a virtual address and that can be mmap'ed. 290 * drm_fbdev_shmem_setup() shall be called after the DRM driver registered 291 * the new DRM device with drm_dev_register(). 292 * 293 * Restore, hotplug events and teardown are all taken care of. Drivers that do 294 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. 295 * Simple drivers might use drm_mode_config_helper_suspend(). 296 * 297 * This function is safe to call even when there are no connectors present. 298 * Setup will be retried on the next hotplug event. 299 * 300 * The fbdev is destroyed by drm_dev_unregister(). 301 */ 302 void drm_fbdev_shmem_setup(struct drm_device *dev, unsigned int preferred_bpp) 303 { 304 struct drm_fb_helper *fb_helper; 305 int ret; 306 307 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 308 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 309 310 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 311 if (!fb_helper) 312 return; 313 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_shmem_helper_funcs); 314 315 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_shmem_client_funcs); 316 if (ret) { 317 drm_err(dev, "Failed to register client: %d\n", ret); 318 goto err_drm_client_init; 319 } 320 321 drm_client_register(&fb_helper->client); 322 323 return; 324 325 err_drm_client_init: 326 drm_fb_helper_unprepare(fb_helper); 327 kfree(fb_helper); 328 } 329 EXPORT_SYMBOL(drm_fbdev_shmem_setup); 330