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