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_gem.h> 19 #include <drm/drm_mode.h> 20 #include <drm/drm_print.h> 21 #include <drm/drmP.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 * Currently it's only partially implemented, just enough to support fbdev. 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 EXPORT_SYMBOL(drm_client_close); 64 65 /** 66 * drm_client_init - Initialise a DRM client 67 * @dev: DRM device 68 * @client: DRM client 69 * @name: Client name 70 * @funcs: DRM client functions (optional) 71 * 72 * This initialises the client and opens a &drm_file. Use drm_client_add() 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) || 85 !dev->driver->dumb_create || !dev->driver->gem_prime_vmap) 86 return -EOPNOTSUPP; 87 88 if (funcs && !try_module_get(funcs->owner)) 89 return -ENODEV; 90 91 client->dev = dev; 92 client->name = name; 93 client->funcs = funcs; 94 95 ret = drm_client_open(client); 96 if (ret) 97 goto err_put_module; 98 99 drm_dev_get(dev); 100 101 return 0; 102 103 err_put_module: 104 if (funcs) 105 module_put(funcs->owner); 106 107 return ret; 108 } 109 EXPORT_SYMBOL(drm_client_init); 110 111 /** 112 * drm_client_add - Add client to the device list 113 * @client: DRM client 114 * 115 * Add the client to the &drm_device client list to activate its callbacks. 116 * @client must be initialized by a call to drm_client_init(). After 117 * drm_client_add() it is no longer permissible to call drm_client_release() 118 * directly (outside the unregister callback), instead cleanup will happen 119 * automatically on driver unload. 120 */ 121 void drm_client_add(struct drm_client_dev *client) 122 { 123 struct drm_device *dev = client->dev; 124 125 mutex_lock(&dev->clientlist_mutex); 126 list_add(&client->list, &dev->clientlist); 127 mutex_unlock(&dev->clientlist_mutex); 128 } 129 EXPORT_SYMBOL(drm_client_add); 130 131 /** 132 * drm_client_release - Release DRM client resources 133 * @client: DRM client 134 * 135 * Releases resources by closing the &drm_file that was opened by drm_client_init(). 136 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set. 137 * 138 * This function should only be called from the unregister callback. An exception 139 * is fbdev which cannot free the buffer if userspace has open file descriptors. 140 * 141 * Note: 142 * Clients cannot initiate a release by themselves. This is done to keep the code simple. 143 * The driver has to be unloaded before the client can be unloaded. 144 */ 145 void drm_client_release(struct drm_client_dev *client) 146 { 147 struct drm_device *dev = client->dev; 148 149 DRM_DEV_DEBUG_KMS(dev->dev, "%s\n", client->name); 150 151 drm_client_close(client); 152 drm_dev_put(dev); 153 if (client->funcs) 154 module_put(client->funcs->owner); 155 } 156 EXPORT_SYMBOL(drm_client_release); 157 158 void drm_client_dev_unregister(struct drm_device *dev) 159 { 160 struct drm_client_dev *client, *tmp; 161 162 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 163 return; 164 165 mutex_lock(&dev->clientlist_mutex); 166 list_for_each_entry_safe(client, tmp, &dev->clientlist, list) { 167 list_del(&client->list); 168 if (client->funcs && client->funcs->unregister) { 169 client->funcs->unregister(client); 170 } else { 171 drm_client_release(client); 172 kfree(client); 173 } 174 } 175 mutex_unlock(&dev->clientlist_mutex); 176 } 177 178 /** 179 * drm_client_dev_hotplug - Send hotplug event to clients 180 * @dev: DRM device 181 * 182 * This function calls the &drm_client_funcs.hotplug callback on the attached clients. 183 * 184 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it 185 * don't need to call this function themselves. 186 */ 187 void drm_client_dev_hotplug(struct drm_device *dev) 188 { 189 struct drm_client_dev *client; 190 int ret; 191 192 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 193 return; 194 195 mutex_lock(&dev->clientlist_mutex); 196 list_for_each_entry(client, &dev->clientlist, list) { 197 if (!client->funcs || !client->funcs->hotplug) 198 continue; 199 200 ret = client->funcs->hotplug(client); 201 DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret); 202 } 203 mutex_unlock(&dev->clientlist_mutex); 204 } 205 EXPORT_SYMBOL(drm_client_dev_hotplug); 206 207 void drm_client_dev_restore(struct drm_device *dev) 208 { 209 struct drm_client_dev *client; 210 int ret; 211 212 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 213 return; 214 215 mutex_lock(&dev->clientlist_mutex); 216 list_for_each_entry(client, &dev->clientlist, list) { 217 if (!client->funcs || !client->funcs->restore) 218 continue; 219 220 ret = client->funcs->restore(client); 221 DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret); 222 if (!ret) /* The first one to return zero gets the privilege to restore */ 223 break; 224 } 225 mutex_unlock(&dev->clientlist_mutex); 226 } 227 228 static void drm_client_buffer_delete(struct drm_client_buffer *buffer) 229 { 230 struct drm_device *dev = buffer->client->dev; 231 232 if (buffer->vaddr && dev->driver->gem_prime_vunmap) 233 dev->driver->gem_prime_vunmap(buffer->gem, buffer->vaddr); 234 235 if (buffer->gem) 236 drm_gem_object_put_unlocked(buffer->gem); 237 238 if (buffer->handle) 239 drm_mode_destroy_dumb(dev, buffer->handle, buffer->client->file); 240 241 kfree(buffer); 242 } 243 244 static struct drm_client_buffer * 245 drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format) 246 { 247 struct drm_mode_create_dumb dumb_args = { }; 248 struct drm_device *dev = client->dev; 249 struct drm_client_buffer *buffer; 250 struct drm_gem_object *obj; 251 void *vaddr; 252 int ret; 253 254 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); 255 if (!buffer) 256 return ERR_PTR(-ENOMEM); 257 258 buffer->client = client; 259 260 dumb_args.width = width; 261 dumb_args.height = height; 262 dumb_args.bpp = drm_format_plane_cpp(format, 0) * 8; 263 ret = drm_mode_create_dumb(dev, &dumb_args, client->file); 264 if (ret) 265 goto err_delete; 266 267 buffer->handle = dumb_args.handle; 268 buffer->pitch = dumb_args.pitch; 269 270 obj = drm_gem_object_lookup(client->file, dumb_args.handle); 271 if (!obj) { 272 ret = -ENOENT; 273 goto err_delete; 274 } 275 276 buffer->gem = obj; 277 278 /* 279 * FIXME: The dependency on GEM here isn't required, we could 280 * convert the driver handle to a dma-buf instead and use the 281 * backend-agnostic dma-buf vmap support instead. This would 282 * require that the handle2fd prime ioctl is reworked to pull the 283 * fd_install step out of the driver backend hooks, to make that 284 * final step optional for internal users. 285 */ 286 vaddr = dev->driver->gem_prime_vmap(obj); 287 if (!vaddr) { 288 ret = -ENOMEM; 289 goto err_delete; 290 } 291 292 buffer->vaddr = vaddr; 293 294 return buffer; 295 296 err_delete: 297 drm_client_buffer_delete(buffer); 298 299 return ERR_PTR(ret); 300 } 301 302 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer) 303 { 304 int ret; 305 306 if (!buffer->fb) 307 return; 308 309 ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file); 310 if (ret) 311 DRM_DEV_ERROR(buffer->client->dev->dev, 312 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret); 313 314 buffer->fb = NULL; 315 } 316 317 static int drm_client_buffer_addfb(struct drm_client_buffer *buffer, 318 u32 width, u32 height, u32 format) 319 { 320 struct drm_client_dev *client = buffer->client; 321 struct drm_mode_fb_cmd fb_req = { }; 322 const struct drm_format_info *info; 323 int ret; 324 325 info = drm_format_info(format); 326 fb_req.bpp = info->cpp[0] * 8; 327 fb_req.depth = info->depth; 328 fb_req.width = width; 329 fb_req.height = height; 330 fb_req.handle = buffer->handle; 331 fb_req.pitch = buffer->pitch; 332 333 ret = drm_mode_addfb(client->dev, &fb_req, client->file); 334 if (ret) 335 return ret; 336 337 buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id); 338 if (WARN_ON(!buffer->fb)) 339 return -ENOENT; 340 341 /* drop the reference we picked up in framebuffer lookup */ 342 drm_framebuffer_put(buffer->fb); 343 344 strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN); 345 346 return 0; 347 } 348 349 /** 350 * drm_client_framebuffer_create - Create a client framebuffer 351 * @client: DRM client 352 * @width: Framebuffer width 353 * @height: Framebuffer height 354 * @format: Buffer format 355 * 356 * This function creates a &drm_client_buffer which consists of a 357 * &drm_framebuffer backed by a dumb buffer. 358 * Call drm_client_framebuffer_delete() to free the buffer. 359 * 360 * Returns: 361 * Pointer to a client buffer or an error pointer on failure. 362 */ 363 struct drm_client_buffer * 364 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format) 365 { 366 struct drm_client_buffer *buffer; 367 int ret; 368 369 buffer = drm_client_buffer_create(client, width, height, format); 370 if (IS_ERR(buffer)) 371 return buffer; 372 373 ret = drm_client_buffer_addfb(buffer, width, height, format); 374 if (ret) { 375 drm_client_buffer_delete(buffer); 376 return ERR_PTR(ret); 377 } 378 379 return buffer; 380 } 381 EXPORT_SYMBOL(drm_client_framebuffer_create); 382 383 /** 384 * drm_client_framebuffer_delete - Delete a client framebuffer 385 * @buffer: DRM client buffer (can be NULL) 386 */ 387 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer) 388 { 389 if (!buffer) 390 return; 391 392 drm_client_buffer_rmfb(buffer); 393 drm_client_buffer_delete(buffer); 394 } 395 EXPORT_SYMBOL(drm_client_framebuffer_delete); 396 397 #ifdef CONFIG_DEBUG_FS 398 static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data) 399 { 400 struct drm_info_node *node = m->private; 401 struct drm_device *dev = node->minor->dev; 402 struct drm_printer p = drm_seq_file_printer(m); 403 struct drm_client_dev *client; 404 405 mutex_lock(&dev->clientlist_mutex); 406 list_for_each_entry(client, &dev->clientlist, list) 407 drm_printf(&p, "%s\n", client->name); 408 mutex_unlock(&dev->clientlist_mutex); 409 410 return 0; 411 } 412 413 static const struct drm_info_list drm_client_debugfs_list[] = { 414 { "internal_clients", drm_client_debugfs_internal_clients, 0 }, 415 }; 416 417 int drm_client_debugfs_init(struct drm_minor *minor) 418 { 419 return drm_debugfs_create_files(drm_client_debugfs_list, 420 ARRAY_SIZE(drm_client_debugfs_list), 421 minor->debugfs_root, minor); 422 } 423 #endif 424