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