1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2018 Noralf Trønnes 4 */ 5 6 #include <linux/list.h> 7 #include <linux/module.h> 8 #include <linux/mutex.h> 9 #include <linux/seq_file.h> 10 #include <linux/slab.h> 11 12 #include <drm/drm_client.h> 13 #include <drm/drm_debugfs.h> 14 #include <drm/drm_device.h> 15 #include <drm/drm_drv.h> 16 #include <drm/drm_file.h> 17 #include <drm/drm_fourcc.h> 18 #include <drm/drm_framebuffer.h> 19 #include <drm/drm_gem.h> 20 #include <drm/drm_mode.h> 21 #include <drm/drm_print.h> 22 23 #include "drm_crtc_internal.h" 24 #include "drm_internal.h" 25 26 /** 27 * DOC: overview 28 * 29 * This library provides support for clients running in the kernel like fbdev and bootsplash. 30 * 31 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported. 32 */ 33 34 static int drm_client_open(struct drm_client_dev *client) 35 { 36 struct drm_device *dev = client->dev; 37 struct drm_file *file; 38 39 file = drm_file_alloc(dev->primary); 40 if (IS_ERR(file)) 41 return PTR_ERR(file); 42 43 mutex_lock(&dev->filelist_mutex); 44 list_add(&file->lhead, &dev->filelist_internal); 45 mutex_unlock(&dev->filelist_mutex); 46 47 client->file = file; 48 49 return 0; 50 } 51 52 static void drm_client_close(struct drm_client_dev *client) 53 { 54 struct drm_device *dev = client->dev; 55 56 mutex_lock(&dev->filelist_mutex); 57 list_del(&client->file->lhead); 58 mutex_unlock(&dev->filelist_mutex); 59 60 drm_file_free(client->file); 61 } 62 EXPORT_SYMBOL(drm_client_close); 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 void drm_client_register(struct drm_client_dev *client) 127 { 128 struct drm_device *dev = client->dev; 129 130 mutex_lock(&dev->clientlist_mutex); 131 list_add(&client->list, &dev->clientlist); 132 mutex_unlock(&dev->clientlist_mutex); 133 } 134 EXPORT_SYMBOL(drm_client_register); 135 136 /** 137 * drm_client_release - Release DRM client resources 138 * @client: DRM client 139 * 140 * Releases resources by closing the &drm_file that was opened by drm_client_init(). 141 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set. 142 * 143 * This function should only be called from the unregister callback. An exception 144 * is fbdev which cannot free the buffer if userspace has open file descriptors. 145 * 146 * Note: 147 * Clients cannot initiate a release by themselves. This is done to keep the code simple. 148 * The driver has to be unloaded before the client can be unloaded. 149 */ 150 void drm_client_release(struct drm_client_dev *client) 151 { 152 struct drm_device *dev = client->dev; 153 154 DRM_DEV_DEBUG_KMS(dev->dev, "%s\n", client->name); 155 156 drm_client_modeset_free(client); 157 drm_client_close(client); 158 drm_dev_put(dev); 159 if (client->funcs) 160 module_put(client->funcs->owner); 161 } 162 EXPORT_SYMBOL(drm_client_release); 163 164 void drm_client_dev_unregister(struct drm_device *dev) 165 { 166 struct drm_client_dev *client, *tmp; 167 168 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 169 return; 170 171 mutex_lock(&dev->clientlist_mutex); 172 list_for_each_entry_safe(client, tmp, &dev->clientlist, list) { 173 list_del(&client->list); 174 if (client->funcs && client->funcs->unregister) { 175 client->funcs->unregister(client); 176 } else { 177 drm_client_release(client); 178 kfree(client); 179 } 180 } 181 mutex_unlock(&dev->clientlist_mutex); 182 } 183 184 /** 185 * drm_client_dev_hotplug - Send hotplug event to clients 186 * @dev: DRM device 187 * 188 * This function calls the &drm_client_funcs.hotplug callback on the attached clients. 189 * 190 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it 191 * don't need to call this function themselves. 192 */ 193 void drm_client_dev_hotplug(struct drm_device *dev) 194 { 195 struct drm_client_dev *client; 196 int ret; 197 198 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 199 return; 200 201 mutex_lock(&dev->clientlist_mutex); 202 list_for_each_entry(client, &dev->clientlist, list) { 203 if (!client->funcs || !client->funcs->hotplug) 204 continue; 205 206 ret = client->funcs->hotplug(client); 207 DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret); 208 } 209 mutex_unlock(&dev->clientlist_mutex); 210 } 211 EXPORT_SYMBOL(drm_client_dev_hotplug); 212 213 void drm_client_dev_restore(struct drm_device *dev) 214 { 215 struct drm_client_dev *client; 216 int ret; 217 218 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 219 return; 220 221 mutex_lock(&dev->clientlist_mutex); 222 list_for_each_entry(client, &dev->clientlist, list) { 223 if (!client->funcs || !client->funcs->restore) 224 continue; 225 226 ret = client->funcs->restore(client); 227 DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret); 228 if (!ret) /* The first one to return zero gets the privilege to restore */ 229 break; 230 } 231 mutex_unlock(&dev->clientlist_mutex); 232 } 233 234 static void drm_client_buffer_delete(struct drm_client_buffer *buffer) 235 { 236 struct drm_device *dev = buffer->client->dev; 237 238 drm_gem_vunmap(buffer->gem, buffer->vaddr); 239 240 if (buffer->gem) 241 drm_gem_object_put_unlocked(buffer->gem); 242 243 if (buffer->handle) 244 drm_mode_destroy_dumb(dev, buffer->handle, buffer->client->file); 245 246 kfree(buffer); 247 } 248 249 static struct drm_client_buffer * 250 drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format) 251 { 252 const struct drm_format_info *info = drm_format_info(format); 253 struct drm_mode_create_dumb dumb_args = { }; 254 struct drm_device *dev = client->dev; 255 struct drm_client_buffer *buffer; 256 struct drm_gem_object *obj; 257 void *vaddr; 258 int ret; 259 260 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); 261 if (!buffer) 262 return ERR_PTR(-ENOMEM); 263 264 buffer->client = client; 265 266 dumb_args.width = width; 267 dumb_args.height = height; 268 dumb_args.bpp = info->cpp[0] * 8; 269 ret = drm_mode_create_dumb(dev, &dumb_args, client->file); 270 if (ret) 271 goto err_delete; 272 273 buffer->handle = dumb_args.handle; 274 buffer->pitch = dumb_args.pitch; 275 276 obj = drm_gem_object_lookup(client->file, dumb_args.handle); 277 if (!obj) { 278 ret = -ENOENT; 279 goto err_delete; 280 } 281 282 buffer->gem = obj; 283 284 /* 285 * FIXME: The dependency on GEM here isn't required, we could 286 * convert the driver handle to a dma-buf instead and use the 287 * backend-agnostic dma-buf vmap support instead. This would 288 * require that the handle2fd prime ioctl is reworked to pull the 289 * fd_install step out of the driver backend hooks, to make that 290 * final step optional for internal users. 291 */ 292 vaddr = drm_gem_vmap(obj); 293 if (IS_ERR(vaddr)) { 294 ret = PTR_ERR(vaddr); 295 goto err_delete; 296 } 297 298 buffer->vaddr = vaddr; 299 300 return buffer; 301 302 err_delete: 303 drm_client_buffer_delete(buffer); 304 305 return ERR_PTR(ret); 306 } 307 308 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer) 309 { 310 int ret; 311 312 if (!buffer->fb) 313 return; 314 315 ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file); 316 if (ret) 317 DRM_DEV_ERROR(buffer->client->dev->dev, 318 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret); 319 320 buffer->fb = NULL; 321 } 322 323 static int drm_client_buffer_addfb(struct drm_client_buffer *buffer, 324 u32 width, u32 height, u32 format) 325 { 326 struct drm_client_dev *client = buffer->client; 327 struct drm_mode_fb_cmd fb_req = { }; 328 const struct drm_format_info *info; 329 int ret; 330 331 info = drm_format_info(format); 332 fb_req.bpp = info->cpp[0] * 8; 333 fb_req.depth = info->depth; 334 fb_req.width = width; 335 fb_req.height = height; 336 fb_req.handle = buffer->handle; 337 fb_req.pitch = buffer->pitch; 338 339 ret = drm_mode_addfb(client->dev, &fb_req, client->file); 340 if (ret) 341 return ret; 342 343 buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id); 344 if (WARN_ON(!buffer->fb)) 345 return -ENOENT; 346 347 /* drop the reference we picked up in framebuffer lookup */ 348 drm_framebuffer_put(buffer->fb); 349 350 strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN); 351 352 return 0; 353 } 354 355 /** 356 * drm_client_framebuffer_create - Create a client framebuffer 357 * @client: DRM client 358 * @width: Framebuffer width 359 * @height: Framebuffer height 360 * @format: Buffer format 361 * 362 * This function creates a &drm_client_buffer which consists of a 363 * &drm_framebuffer backed by a dumb buffer. 364 * Call drm_client_framebuffer_delete() to free the buffer. 365 * 366 * Returns: 367 * Pointer to a client buffer or an error pointer on failure. 368 */ 369 struct drm_client_buffer * 370 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format) 371 { 372 struct drm_client_buffer *buffer; 373 int ret; 374 375 buffer = drm_client_buffer_create(client, width, height, format); 376 if (IS_ERR(buffer)) 377 return buffer; 378 379 ret = drm_client_buffer_addfb(buffer, width, height, format); 380 if (ret) { 381 drm_client_buffer_delete(buffer); 382 return ERR_PTR(ret); 383 } 384 385 return buffer; 386 } 387 EXPORT_SYMBOL(drm_client_framebuffer_create); 388 389 /** 390 * drm_client_framebuffer_delete - Delete a client framebuffer 391 * @buffer: DRM client buffer (can be NULL) 392 */ 393 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer) 394 { 395 if (!buffer) 396 return; 397 398 drm_client_buffer_rmfb(buffer); 399 drm_client_buffer_delete(buffer); 400 } 401 EXPORT_SYMBOL(drm_client_framebuffer_delete); 402 403 #ifdef CONFIG_DEBUG_FS 404 static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data) 405 { 406 struct drm_info_node *node = m->private; 407 struct drm_device *dev = node->minor->dev; 408 struct drm_printer p = drm_seq_file_printer(m); 409 struct drm_client_dev *client; 410 411 mutex_lock(&dev->clientlist_mutex); 412 list_for_each_entry(client, &dev->clientlist, list) 413 drm_printf(&p, "%s\n", client->name); 414 mutex_unlock(&dev->clientlist_mutex); 415 416 return 0; 417 } 418 419 static const struct drm_info_list drm_client_debugfs_list[] = { 420 { "internal_clients", drm_client_debugfs_internal_clients, 0 }, 421 }; 422 423 int drm_client_debugfs_init(struct drm_minor *minor) 424 { 425 return drm_debugfs_create_files(drm_client_debugfs_list, 426 ARRAY_SIZE(drm_client_debugfs_list), 427 minor->debugfs_root, minor); 428 } 429 #endif 430