1 // SPDX-License-Identifier: GPL-2.0 or MIT 2 /* 3 * Copyright 2018 Noralf Trønnes 4 */ 5 6 #include <linux/iosys-map.h> 7 #include <linux/list.h> 8 #include <linux/module.h> 9 #include <linux/mutex.h> 10 #include <linux/seq_file.h> 11 #include <linux/slab.h> 12 13 #include <drm/drm_client.h> 14 #include <drm/drm_debugfs.h> 15 #include <drm/drm_device.h> 16 #include <drm/drm_drv.h> 17 #include <drm/drm_file.h> 18 #include <drm/drm_fourcc.h> 19 #include <drm/drm_framebuffer.h> 20 #include <drm/drm_gem.h> 21 #include <drm/drm_mode.h> 22 #include <drm/drm_print.h> 23 24 #include "drm_crtc_internal.h" 25 #include "drm_internal.h" 26 27 /** 28 * DOC: overview 29 * 30 * This library provides support for clients running in the kernel like fbdev and bootsplash. 31 * 32 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported. 33 */ 34 35 static int drm_client_open(struct drm_client_dev *client) 36 { 37 struct drm_device *dev = client->dev; 38 struct drm_file *file; 39 40 file = drm_file_alloc(dev->primary); 41 if (IS_ERR(file)) 42 return PTR_ERR(file); 43 44 mutex_lock(&dev->filelist_mutex); 45 list_add(&file->lhead, &dev->filelist_internal); 46 mutex_unlock(&dev->filelist_mutex); 47 48 client->file = file; 49 50 return 0; 51 } 52 53 static void drm_client_close(struct drm_client_dev *client) 54 { 55 struct drm_device *dev = client->dev; 56 57 mutex_lock(&dev->filelist_mutex); 58 list_del(&client->file->lhead); 59 mutex_unlock(&dev->filelist_mutex); 60 61 drm_file_free(client->file); 62 } 63 64 /** 65 * drm_client_init - Initialise a DRM client 66 * @dev: DRM device 67 * @client: DRM client 68 * @name: Client name 69 * @funcs: DRM client functions (optional) 70 * 71 * This initialises the client and opens a &drm_file. 72 * Use drm_client_register() to complete the process. 73 * The caller needs to hold a reference on @dev before calling this function. 74 * The client is freed when the &drm_device is unregistered. See drm_client_release(). 75 * 76 * Returns: 77 * Zero on success or negative error code on failure. 78 */ 79 int drm_client_init(struct drm_device *dev, struct drm_client_dev *client, 80 const char *name, const struct drm_client_funcs *funcs) 81 { 82 int ret; 83 84 if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create) 85 return -EOPNOTSUPP; 86 87 if (funcs && !try_module_get(funcs->owner)) 88 return -ENODEV; 89 90 client->dev = dev; 91 client->name = name; 92 client->funcs = funcs; 93 94 ret = drm_client_modeset_create(client); 95 if (ret) 96 goto err_put_module; 97 98 ret = drm_client_open(client); 99 if (ret) 100 goto err_free; 101 102 drm_dev_get(dev); 103 104 return 0; 105 106 err_free: 107 drm_client_modeset_free(client); 108 err_put_module: 109 if (funcs) 110 module_put(funcs->owner); 111 112 return ret; 113 } 114 EXPORT_SYMBOL(drm_client_init); 115 116 /** 117 * drm_client_register - Register client 118 * @client: DRM client 119 * 120 * Add the client to the &drm_device client list to activate its callbacks. 121 * @client must be initialized by a call to drm_client_init(). After 122 * drm_client_register() it is no longer permissible to call drm_client_release() 123 * directly (outside the unregister callback), instead cleanup will happen 124 * automatically on driver unload. 125 * 126 * Registering a client generates a hotplug event that allows the client 127 * to set up its display from pre-existing outputs. The client must have 128 * initialized its state to able to handle the hotplug event successfully. 129 */ 130 void drm_client_register(struct drm_client_dev *client) 131 { 132 struct drm_device *dev = client->dev; 133 int ret; 134 135 mutex_lock(&dev->clientlist_mutex); 136 list_add(&client->list, &dev->clientlist); 137 138 if (client->funcs && client->funcs->hotplug) { 139 /* 140 * Perform an initial hotplug event to pick up the 141 * display configuration for the client. This step 142 * has to be performed *after* registering the client 143 * in the list of clients, or a concurrent hotplug 144 * event might be lost; leaving the display off. 145 * 146 * Hold the clientlist_mutex as for a regular hotplug 147 * event. 148 */ 149 ret = client->funcs->hotplug(client); 150 if (ret) 151 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret); 152 } 153 mutex_unlock(&dev->clientlist_mutex); 154 } 155 EXPORT_SYMBOL(drm_client_register); 156 157 /** 158 * drm_client_release - Release DRM client resources 159 * @client: DRM client 160 * 161 * Releases resources by closing the &drm_file that was opened by drm_client_init(). 162 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set. 163 * 164 * This function should only be called from the unregister callback. An exception 165 * is fbdev which cannot free the buffer if userspace has open file descriptors. 166 * 167 * Note: 168 * Clients cannot initiate a release by themselves. This is done to keep the code simple. 169 * The driver has to be unloaded before the client can be unloaded. 170 */ 171 void drm_client_release(struct drm_client_dev *client) 172 { 173 struct drm_device *dev = client->dev; 174 175 drm_dbg_kms(dev, "%s\n", client->name); 176 177 drm_client_modeset_free(client); 178 drm_client_close(client); 179 drm_dev_put(dev); 180 if (client->funcs) 181 module_put(client->funcs->owner); 182 } 183 EXPORT_SYMBOL(drm_client_release); 184 185 void drm_client_dev_unregister(struct drm_device *dev) 186 { 187 struct drm_client_dev *client, *tmp; 188 189 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 190 return; 191 192 mutex_lock(&dev->clientlist_mutex); 193 list_for_each_entry_safe(client, tmp, &dev->clientlist, list) { 194 list_del(&client->list); 195 if (client->funcs && client->funcs->unregister) { 196 client->funcs->unregister(client); 197 } else { 198 drm_client_release(client); 199 kfree(client); 200 } 201 } 202 mutex_unlock(&dev->clientlist_mutex); 203 } 204 205 /** 206 * drm_client_dev_hotplug - Send hotplug event to clients 207 * @dev: DRM device 208 * 209 * This function calls the &drm_client_funcs.hotplug callback on the attached clients. 210 * 211 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it 212 * don't need to call this function themselves. 213 */ 214 void drm_client_dev_hotplug(struct drm_device *dev) 215 { 216 struct drm_client_dev *client; 217 int ret; 218 219 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 220 return; 221 222 if (!dev->mode_config.num_connector) { 223 drm_dbg_kms(dev, "No connectors found, will not send hotplug events!\n"); 224 return; 225 } 226 227 mutex_lock(&dev->clientlist_mutex); 228 list_for_each_entry(client, &dev->clientlist, list) { 229 if (!client->funcs || !client->funcs->hotplug) 230 continue; 231 232 if (client->hotplug_failed) 233 continue; 234 235 ret = client->funcs->hotplug(client); 236 drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret); 237 if (ret) 238 client->hotplug_failed = true; 239 } 240 mutex_unlock(&dev->clientlist_mutex); 241 } 242 EXPORT_SYMBOL(drm_client_dev_hotplug); 243 244 void drm_client_dev_restore(struct drm_device *dev) 245 { 246 struct drm_client_dev *client; 247 int ret; 248 249 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 250 return; 251 252 mutex_lock(&dev->clientlist_mutex); 253 list_for_each_entry(client, &dev->clientlist, list) { 254 if (!client->funcs || !client->funcs->restore) 255 continue; 256 257 ret = client->funcs->restore(client); 258 drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret); 259 if (!ret) /* The first one to return zero gets the privilege to restore */ 260 break; 261 } 262 mutex_unlock(&dev->clientlist_mutex); 263 } 264 265 static void drm_client_buffer_delete(struct drm_client_buffer *buffer) 266 { 267 if (buffer->gem) { 268 drm_gem_vunmap_unlocked(buffer->gem, &buffer->map); 269 drm_gem_object_put(buffer->gem); 270 } 271 272 kfree(buffer); 273 } 274 275 static struct drm_client_buffer * 276 drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, 277 u32 format, u32 *handle) 278 { 279 const struct drm_format_info *info = drm_format_info(format); 280 struct drm_mode_create_dumb dumb_args = { }; 281 struct drm_device *dev = client->dev; 282 struct drm_client_buffer *buffer; 283 struct drm_gem_object *obj; 284 int ret; 285 286 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); 287 if (!buffer) 288 return ERR_PTR(-ENOMEM); 289 290 buffer->client = client; 291 292 dumb_args.width = width; 293 dumb_args.height = height; 294 dumb_args.bpp = drm_format_info_bpp(info, 0); 295 ret = drm_mode_create_dumb(dev, &dumb_args, client->file); 296 if (ret) 297 goto err_delete; 298 299 obj = drm_gem_object_lookup(client->file, dumb_args.handle); 300 if (!obj) { 301 ret = -ENOENT; 302 goto err_delete; 303 } 304 305 buffer->pitch = dumb_args.pitch; 306 buffer->gem = obj; 307 *handle = dumb_args.handle; 308 309 return buffer; 310 311 err_delete: 312 drm_client_buffer_delete(buffer); 313 314 return ERR_PTR(ret); 315 } 316 317 /** 318 * drm_client_buffer_vmap - Map DRM client buffer into address space 319 * @buffer: DRM client buffer 320 * @map_copy: Returns the mapped memory's address 321 * 322 * This function maps a client buffer into kernel address space. If the 323 * buffer is already mapped, it returns the existing mapping's address. 324 * 325 * Client buffer mappings are not ref'counted. Each call to 326 * drm_client_buffer_vmap() should be followed by a call to 327 * drm_client_buffer_vunmap(); or the client buffer should be mapped 328 * throughout its lifetime. 329 * 330 * The returned address is a copy of the internal value. In contrast to 331 * other vmap interfaces, you don't need it for the client's vunmap 332 * function. So you can modify it at will during blit and draw operations. 333 * 334 * Returns: 335 * 0 on success, or a negative errno code otherwise. 336 */ 337 int 338 drm_client_buffer_vmap(struct drm_client_buffer *buffer, 339 struct iosys_map *map_copy) 340 { 341 struct iosys_map *map = &buffer->map; 342 int ret; 343 344 /* 345 * FIXME: The dependency on GEM here isn't required, we could 346 * convert the driver handle to a dma-buf instead and use the 347 * backend-agnostic dma-buf vmap support instead. This would 348 * require that the handle2fd prime ioctl is reworked to pull the 349 * fd_install step out of the driver backend hooks, to make that 350 * final step optional for internal users. 351 */ 352 ret = drm_gem_vmap_unlocked(buffer->gem, map); 353 if (ret) 354 return ret; 355 356 *map_copy = *map; 357 358 return 0; 359 } 360 EXPORT_SYMBOL(drm_client_buffer_vmap); 361 362 /** 363 * drm_client_buffer_vunmap - Unmap DRM client buffer 364 * @buffer: DRM client buffer 365 * 366 * This function removes a client buffer's memory mapping. Calling this 367 * function is only required by clients that manage their buffer mappings 368 * by themselves. 369 */ 370 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer) 371 { 372 struct iosys_map *map = &buffer->map; 373 374 drm_gem_vunmap_unlocked(buffer->gem, map); 375 } 376 EXPORT_SYMBOL(drm_client_buffer_vunmap); 377 378 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer) 379 { 380 int ret; 381 382 if (!buffer->fb) 383 return; 384 385 ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file); 386 if (ret) 387 drm_err(buffer->client->dev, 388 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret); 389 390 buffer->fb = NULL; 391 } 392 393 static int drm_client_buffer_addfb(struct drm_client_buffer *buffer, 394 u32 width, u32 height, u32 format, 395 u32 handle) 396 { 397 struct drm_client_dev *client = buffer->client; 398 struct drm_mode_fb_cmd2 fb_req = { }; 399 int ret; 400 401 fb_req.width = width; 402 fb_req.height = height; 403 fb_req.pixel_format = format; 404 fb_req.handles[0] = handle; 405 fb_req.pitches[0] = buffer->pitch; 406 407 ret = drm_mode_addfb2(client->dev, &fb_req, client->file); 408 if (ret) 409 return ret; 410 411 buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id); 412 if (WARN_ON(!buffer->fb)) 413 return -ENOENT; 414 415 /* drop the reference we picked up in framebuffer lookup */ 416 drm_framebuffer_put(buffer->fb); 417 418 strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN); 419 420 return 0; 421 } 422 423 /** 424 * drm_client_framebuffer_create - Create a client framebuffer 425 * @client: DRM client 426 * @width: Framebuffer width 427 * @height: Framebuffer height 428 * @format: Buffer format 429 * 430 * This function creates a &drm_client_buffer which consists of a 431 * &drm_framebuffer backed by a dumb buffer. 432 * Call drm_client_framebuffer_delete() to free the buffer. 433 * 434 * Returns: 435 * Pointer to a client buffer or an error pointer on failure. 436 */ 437 struct drm_client_buffer * 438 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format) 439 { 440 struct drm_client_buffer *buffer; 441 u32 handle; 442 int ret; 443 444 buffer = drm_client_buffer_create(client, width, height, format, 445 &handle); 446 if (IS_ERR(buffer)) 447 return buffer; 448 449 ret = drm_client_buffer_addfb(buffer, width, height, format, handle); 450 451 /* 452 * The handle is only needed for creating the framebuffer, destroy it 453 * again to solve a circular dependency should anybody export the GEM 454 * object as DMA-buf. The framebuffer and our buffer structure are still 455 * holding references to the GEM object to prevent its destruction. 456 */ 457 drm_mode_destroy_dumb(client->dev, handle, client->file); 458 459 if (ret) { 460 drm_client_buffer_delete(buffer); 461 return ERR_PTR(ret); 462 } 463 464 return buffer; 465 } 466 EXPORT_SYMBOL(drm_client_framebuffer_create); 467 468 /** 469 * drm_client_framebuffer_delete - Delete a client framebuffer 470 * @buffer: DRM client buffer (can be NULL) 471 */ 472 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer) 473 { 474 if (!buffer) 475 return; 476 477 drm_client_buffer_rmfb(buffer); 478 drm_client_buffer_delete(buffer); 479 } 480 EXPORT_SYMBOL(drm_client_framebuffer_delete); 481 482 /** 483 * drm_client_framebuffer_flush - Manually flush client framebuffer 484 * @buffer: DRM client buffer (can be NULL) 485 * @rect: Damage rectangle (if NULL flushes all) 486 * 487 * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes 488 * for drivers that need it. 489 * 490 * Returns: 491 * Zero on success or negative error code on failure. 492 */ 493 int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect) 494 { 495 if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty) 496 return 0; 497 498 if (rect) { 499 struct drm_clip_rect clip = { 500 .x1 = rect->x1, 501 .y1 = rect->y1, 502 .x2 = rect->x2, 503 .y2 = rect->y2, 504 }; 505 506 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file, 507 0, 0, &clip, 1); 508 } 509 510 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file, 511 0, 0, NULL, 0); 512 } 513 EXPORT_SYMBOL(drm_client_framebuffer_flush); 514 515 #ifdef CONFIG_DEBUG_FS 516 static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data) 517 { 518 struct drm_debugfs_entry *entry = m->private; 519 struct drm_device *dev = entry->dev; 520 struct drm_printer p = drm_seq_file_printer(m); 521 struct drm_client_dev *client; 522 523 mutex_lock(&dev->clientlist_mutex); 524 list_for_each_entry(client, &dev->clientlist, list) 525 drm_printf(&p, "%s\n", client->name); 526 mutex_unlock(&dev->clientlist_mutex); 527 528 return 0; 529 } 530 531 static const struct drm_debugfs_info drm_client_debugfs_list[] = { 532 { "internal_clients", drm_client_debugfs_internal_clients, 0 }, 533 }; 534 535 void drm_client_debugfs_init(struct drm_device *dev) 536 { 537 drm_debugfs_add_files(dev, drm_client_debugfs_list, 538 ARRAY_SIZE(drm_client_debugfs_list)); 539 } 540 #endif 541