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_dma_helper.h> 8 #include <drm/drm_fb_helper.h> 9 #include <drm/drm_framebuffer.h> 10 #include <drm/drm_gem_dma_helper.h> 11 12 #include <drm/drm_fbdev_dma.h> 13 14 /* 15 * struct fb_ops 16 */ 17 18 static int drm_fbdev_dma_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_dma_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 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 40 { 41 struct drm_fb_helper *fb_helper = info->par; 42 43 return drm_gem_prime_mmap(fb_helper->buffer->gem, vma); 44 } 45 46 static void drm_fbdev_dma_fb_destroy(struct fb_info *info) 47 { 48 struct drm_fb_helper *fb_helper = info->par; 49 50 if (!fb_helper->dev) 51 return; 52 53 fb_deferred_io_cleanup(info); 54 drm_fb_helper_fini(fb_helper); 55 56 drm_client_buffer_vunmap(fb_helper->buffer); 57 drm_client_framebuffer_delete(fb_helper->buffer); 58 drm_client_release(&fb_helper->client); 59 drm_fb_helper_unprepare(fb_helper); 60 kfree(fb_helper); 61 } 62 63 static const struct fb_ops drm_fbdev_dma_fb_ops = { 64 .owner = THIS_MODULE, 65 .fb_open = drm_fbdev_dma_fb_open, 66 .fb_release = drm_fbdev_dma_fb_release, 67 __FB_DEFAULT_DMAMEM_OPS_RDWR, 68 DRM_FB_HELPER_DEFAULT_OPS, 69 __FB_DEFAULT_DMAMEM_OPS_DRAW, 70 .fb_mmap = drm_fbdev_dma_fb_mmap, 71 .fb_destroy = drm_fbdev_dma_fb_destroy, 72 }; 73 74 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma, 75 drm_fb_helper_damage_range, 76 drm_fb_helper_damage_area); 77 78 static int drm_fbdev_dma_deferred_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 79 { 80 struct drm_fb_helper *fb_helper = info->par; 81 struct drm_framebuffer *fb = fb_helper->fb; 82 struct drm_gem_dma_object *dma = drm_fb_dma_get_gem_obj(fb, 0); 83 84 if (!dma->map_noncoherent) 85 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 86 87 return fb_deferred_io_mmap(info, vma); 88 } 89 90 static const struct fb_ops drm_fbdev_dma_deferred_fb_ops = { 91 .owner = THIS_MODULE, 92 .fb_open = drm_fbdev_dma_fb_open, 93 .fb_release = drm_fbdev_dma_fb_release, 94 __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_dma), 95 DRM_FB_HELPER_DEFAULT_OPS, 96 __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_dma), 97 .fb_mmap = drm_fbdev_dma_deferred_fb_mmap, 98 .fb_destroy = drm_fbdev_dma_fb_destroy, 99 }; 100 101 /* 102 * struct drm_fb_helper 103 */ 104 105 static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper, 106 struct drm_fb_helper_surface_size *sizes) 107 { 108 return drm_fbdev_dma_driver_fbdev_probe(fb_helper, sizes); 109 } 110 111 static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper, 112 struct drm_clip_rect *clip) 113 { 114 struct drm_device *dev = helper->dev; 115 int ret; 116 117 /* Call damage handlers only if necessary */ 118 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) 119 return 0; 120 121 if (helper->fb->funcs->dirty) { 122 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); 123 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) 124 return ret; 125 } 126 127 return 0; 128 } 129 130 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 131 .fb_probe = drm_fbdev_dma_helper_fb_probe, 132 .fb_dirty = drm_fbdev_dma_helper_fb_dirty, 133 }; 134 135 /* 136 * struct drm_fb_helper 137 */ 138 139 int drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper *fb_helper, 140 struct drm_fb_helper_surface_size *sizes) 141 { 142 struct drm_client_dev *client = &fb_helper->client; 143 struct drm_device *dev = fb_helper->dev; 144 bool use_deferred_io = false; 145 struct drm_client_buffer *buffer; 146 struct drm_gem_dma_object *dma_obj; 147 struct drm_framebuffer *fb; 148 struct fb_info *info; 149 u32 format; 150 struct iosys_map map; 151 int ret; 152 153 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 154 sizes->surface_width, sizes->surface_height, 155 sizes->surface_bpp); 156 157 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, 158 sizes->surface_depth); 159 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 160 sizes->surface_height, format); 161 if (IS_ERR(buffer)) 162 return PTR_ERR(buffer); 163 dma_obj = to_drm_gem_dma_obj(buffer->gem); 164 165 fb = buffer->fb; 166 167 /* 168 * Deferred I/O requires struct page for framebuffer memory, 169 * which is not guaranteed for all DMA ranges. We thus only 170 * install deferred I/O if we have a framebuffer that requires 171 * it. 172 */ 173 if (fb->funcs->dirty) 174 use_deferred_io = true; 175 176 ret = drm_client_buffer_vmap(buffer, &map); 177 if (ret) { 178 goto err_drm_client_buffer_delete; 179 } else if (drm_WARN_ON(dev, map.is_iomem)) { 180 ret = -ENODEV; /* I/O memory not supported; use generic emulation */ 181 goto err_drm_client_buffer_delete; 182 } 183 184 fb_helper->funcs = &drm_fbdev_dma_helper_funcs; 185 fb_helper->buffer = buffer; 186 fb_helper->fb = fb; 187 188 info = drm_fb_helper_alloc_info(fb_helper); 189 if (IS_ERR(info)) { 190 ret = PTR_ERR(info); 191 goto err_drm_client_buffer_vunmap; 192 } 193 194 drm_fb_helper_fill_info(info, fb_helper, sizes); 195 196 if (use_deferred_io) 197 info->fbops = &drm_fbdev_dma_deferred_fb_ops; 198 else 199 info->fbops = &drm_fbdev_dma_fb_ops; 200 201 /* screen */ 202 info->flags |= FBINFO_VIRTFB; /* system memory */ 203 if (dma_obj->map_noncoherent) 204 info->flags |= FBINFO_READS_FAST; /* signal caching */ 205 info->screen_size = sizes->surface_height * fb->pitches[0]; 206 info->screen_buffer = map.vaddr; 207 if (!(info->flags & FBINFO_HIDE_SMEM_START)) { 208 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer))) 209 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer)); 210 } 211 info->fix.smem_len = info->screen_size; 212 213 /* 214 * Only set up deferred I/O if the screen buffer supports 215 * it. If this disagrees with the previous test for ->dirty, 216 * mmap on the /dev/fb file might not work correctly. 217 */ 218 if (!is_vmalloc_addr(info->screen_buffer) && info->fix.smem_start) { 219 unsigned long pfn = info->fix.smem_start >> PAGE_SHIFT; 220 221 if (drm_WARN_ON(dev, !pfn_to_page(pfn))) 222 use_deferred_io = false; 223 } 224 225 /* deferred I/O */ 226 if (use_deferred_io) { 227 fb_helper->fbdefio.delay = HZ / 20; 228 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 229 230 info->fbdefio = &fb_helper->fbdefio; 231 ret = fb_deferred_io_init(info); 232 if (ret) 233 goto err_drm_fb_helper_release_info; 234 } 235 236 return 0; 237 238 err_drm_fb_helper_release_info: 239 drm_fb_helper_release_info(fb_helper); 240 err_drm_client_buffer_vunmap: 241 fb_helper->fb = NULL; 242 fb_helper->buffer = NULL; 243 drm_client_buffer_vunmap(buffer); 244 err_drm_client_buffer_delete: 245 drm_client_framebuffer_delete(buffer); 246 return ret; 247 } 248 EXPORT_SYMBOL(drm_fbdev_dma_driver_fbdev_probe); 249 250 /* 251 * struct drm_client_funcs 252 */ 253 254 static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client) 255 { 256 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 257 258 if (fb_helper->info) { 259 drm_fb_helper_unregister_info(fb_helper); 260 } else { 261 drm_client_release(&fb_helper->client); 262 drm_fb_helper_unprepare(fb_helper); 263 kfree(fb_helper); 264 } 265 } 266 267 static int drm_fbdev_dma_client_restore(struct drm_client_dev *client) 268 { 269 drm_fb_helper_lastclose(client->dev); 270 271 return 0; 272 } 273 274 static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client) 275 { 276 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 277 struct drm_device *dev = client->dev; 278 int ret; 279 280 if (dev->fb_helper) 281 return drm_fb_helper_hotplug_event(dev->fb_helper); 282 283 ret = drm_fb_helper_init(dev, fb_helper); 284 if (ret) 285 goto err_drm_err; 286 287 if (!drm_drv_uses_atomic_modeset(dev)) 288 drm_helper_disable_unused_functions(dev); 289 290 ret = drm_fb_helper_initial_config(fb_helper); 291 if (ret) 292 goto err_drm_fb_helper_fini; 293 294 return 0; 295 296 err_drm_fb_helper_fini: 297 drm_fb_helper_fini(fb_helper); 298 err_drm_err: 299 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret); 300 return ret; 301 } 302 303 static const struct drm_client_funcs drm_fbdev_dma_client_funcs = { 304 .owner = THIS_MODULE, 305 .unregister = drm_fbdev_dma_client_unregister, 306 .restore = drm_fbdev_dma_client_restore, 307 .hotplug = drm_fbdev_dma_client_hotplug, 308 }; 309 310 /** 311 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers 312 * @dev: DRM device 313 * @preferred_bpp: Preferred bits per pixel for the device. 314 * 32 is used if this is zero. 315 * 316 * This function sets up fbdev emulation for GEM DMA drivers that support 317 * dumb buffers with a virtual address and that can be mmap'ed. 318 * drm_fbdev_dma_setup() shall be called after the DRM driver registered 319 * the new DRM device with drm_dev_register(). 320 * 321 * Restore, hotplug events and teardown are all taken care of. Drivers that do 322 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. 323 * Simple drivers might use drm_mode_config_helper_suspend(). 324 * 325 * This function is safe to call even when there are no connectors present. 326 * Setup will be retried on the next hotplug event. 327 * 328 * The fbdev is destroyed by drm_dev_unregister(). 329 */ 330 void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp) 331 { 332 struct drm_fb_helper *fb_helper; 333 int ret; 334 335 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 336 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 337 338 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 339 if (!fb_helper) 340 return; 341 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_dma_helper_funcs); 342 343 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_dma_client_funcs); 344 if (ret) { 345 drm_err(dev, "Failed to register client: %d\n", ret); 346 goto err_drm_client_init; 347 } 348 349 drm_client_register(&fb_helper->client); 350 351 return; 352 353 err_drm_client_init: 354 drm_fb_helper_unprepare(fb_helper); 355 kfree(fb_helper); 356 } 357 EXPORT_SYMBOL(drm_fbdev_dma_setup); 358