drivers/gpu/drm/drm_framebuffer.c

   1 /*
   2  * Copyright (c) 2016 Intel Corporation
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that copyright
   7  * notice and this permission notice appear in supporting documentation, and
   8  * that the name of the copyright holders not be used in advertising or
   9  * publicity pertaining to distribution of the software without specific,
  10  * written prior permission.  The copyright holders make no representations
  11  * about the suitability of this software for any purpose.  It is provided "as
  12  * is" without express or implied warranty.
  13  *
  14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  20  * OF THIS SOFTWARE.
  21  */
  22
  23 #include <linux/export.h>
  24 #include <drm/drmP.h>
  25 #include <drm/drm_auth.h>
  26 #include <drm/drm_framebuffer.h>
  27
  28 #include "drm_crtc_internal.h"
  29
  30 /**
  31  * DOC: overview
  32  *
  33  * Frame buffers are abstract memory objects that provide a source of pixels to
  34  * scanout to a CRTC. Applications explicitly request the creation of frame
  35  * buffers through the DRM_IOCTL_MODE_ADDFB(2) ioctls and receive an opaque
  36  * handle that can be passed to the KMS CRTC control, plane configuration and
  37  * page flip functions.
  38  *
  39  * Frame buffers rely on the underlying memory manager for allocating backing
  40  * storage. When creating a frame buffer applications pass a memory handle
  41  * (or a list of memory handles for multi-planar formats) through the
  42  * struct &drm_mode_fb_cmd2 argument. For drivers using GEM as their userspace
  43  * buffer management interface this would be a GEM handle.  Drivers are however
  44  * free to use their own backing storage object handles, e.g. vmwgfx directly
  45  * exposes special TTM handles to userspace and so expects TTM handles in the
  46  * create ioctl and not GEM handles.
  47  *
  48  * Framebuffers are tracked with struct &drm_framebuffer. They are published
  49  * using drm_framebuffer_init() - after calling that function userspace can use
  50  * and access the framebuffer object. The helper function
  51  * drm_helper_mode_fill_fb_struct() can be used to pre-fill the required
  52  * metadata fields.
  53  *
  54  * The lifetime of a drm framebuffer is controlled with a reference count,
  55  * drivers can grab additional references with drm_framebuffer_reference() and
  56  * drop them again with drm_framebuffer_unreference(). For driver-private
  57  * framebuffers for which the last reference is never dropped (e.g. for the
  58  * fbdev framebuffer when the struct struct &drm_framebuffer is embedded into
  59  * the fbdev helper struct) drivers can manually clean up a framebuffer at
  60  * module unload time with drm_framebuffer_unregister_private(). But doing this
  61  * is not recommended, and it's better to have a normal free-standing struct
  62  * &drm_framebuffer.
  63  */
  64
  65 /**
  66  * drm_mode_addfb - add an FB to the graphics configuration
  67  * @dev: drm device for the ioctl
  68  * @data: data pointer for the ioctl
  69  * @file_priv: drm file for the ioctl call
  70  *
  71  * Add a new FB to the specified CRTC, given a user request. This is the
  72  * original addfb ioctl which only supported RGB formats.
  73  *
  74  * Called by the user via ioctl.
  75  *
  76  * Returns:
  77  * Zero on success, negative errno on failure.
  78  */
  79 int drm_mode_addfb(struct drm_device *dev,
  80                    void *data, struct drm_file *file_priv)
  81 {
  82         struct drm_mode_fb_cmd *or = data;
  83         struct drm_mode_fb_cmd2 r = {};
  84         int ret;
  85
  86         /* convert to new format and call new ioctl */
  87         r.fb_id = or->fb_id;
  88         r.width = or->width;
  89         r.height = or->height;
  90         r.pitches[0] = or->pitch;
  91         r.pixel_format = drm_mode_legacy_fb_format(or->bpp, or->depth);
  92         r.handles[0] = or->handle;
  93
  94         ret = drm_mode_addfb2(dev, &r, file_priv);
  95         if (ret)
  96                 return ret;
  97
  98         or->fb_id = r.fb_id;
  99
 100         return 0;
 101 }
 102
 103 static int format_check(const struct drm_mode_fb_cmd2 *r)
 104 {
 105         uint32_t format = r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN;
 106         char *format_name;
 107
 108         switch (format) {
 109         case DRM_FORMAT_C8:
 110         case DRM_FORMAT_RGB332:
 111         case DRM_FORMAT_BGR233:
 112         case DRM_FORMAT_XRGB4444:
 113         case DRM_FORMAT_XBGR4444:
 114         case DRM_FORMAT_RGBX4444:
 115         case DRM_FORMAT_BGRX4444:
 116         case DRM_FORMAT_ARGB4444:
 117         case DRM_FORMAT_ABGR4444:
 118         case DRM_FORMAT_RGBA4444:
 119         case DRM_FORMAT_BGRA4444:
 120         case DRM_FORMAT_XRGB1555:
 121         case DRM_FORMAT_XBGR1555:
 122         case DRM_FORMAT_RGBX5551:
 123         case DRM_FORMAT_BGRX5551:
 124         case DRM_FORMAT_ARGB1555:
 125         case DRM_FORMAT_ABGR1555:
 126         case DRM_FORMAT_RGBA5551:
 127         case DRM_FORMAT_BGRA5551:
 128         case DRM_FORMAT_RGB565:
 129         case DRM_FORMAT_BGR565:
 130         case DRM_FORMAT_RGB888:
 131         case DRM_FORMAT_BGR888:
 132         case DRM_FORMAT_XRGB8888:
 133         case DRM_FORMAT_XBGR8888:
 134         case DRM_FORMAT_RGBX8888:
 135         case DRM_FORMAT_BGRX8888:
 136         case DRM_FORMAT_ARGB8888:
 137         case DRM_FORMAT_ABGR8888:
 138         case DRM_FORMAT_RGBA8888:
 139         case DRM_FORMAT_BGRA8888:
 140         case DRM_FORMAT_XRGB2101010:
 141         case DRM_FORMAT_XBGR2101010:
 142         case DRM_FORMAT_RGBX1010102:
 143         case DRM_FORMAT_BGRX1010102:
 144         case DRM_FORMAT_ARGB2101010:
 145         case DRM_FORMAT_ABGR2101010:
 146         case DRM_FORMAT_RGBA1010102:
 147         case DRM_FORMAT_BGRA1010102:
 148         case DRM_FORMAT_YUYV:
 149         case DRM_FORMAT_YVYU:
 150         case DRM_FORMAT_UYVY:
 151         case DRM_FORMAT_VYUY:
 152         case DRM_FORMAT_AYUV:
 153         case DRM_FORMAT_NV12:
 154         case DRM_FORMAT_NV21:
 155         case DRM_FORMAT_NV16:
 156         case DRM_FORMAT_NV61:
 157         case DRM_FORMAT_NV24:
 158         case DRM_FORMAT_NV42:
 159         case DRM_FORMAT_YUV410:
 160         case DRM_FORMAT_YVU410:
 161         case DRM_FORMAT_YUV411:
 162         case DRM_FORMAT_YVU411:
 163         case DRM_FORMAT_YUV420:
 164         case DRM_FORMAT_YVU420:
 165         case DRM_FORMAT_YUV422:
 166         case DRM_FORMAT_YVU422:
 167         case DRM_FORMAT_YUV444:
 168         case DRM_FORMAT_YVU444:
 169                 return 0;
 170         default:
 171                 format_name = drm_get_format_name(r->pixel_format);
 172                 DRM_DEBUG_KMS("invalid pixel format %s\n", format_name);
 173                 kfree(format_name);
 174                 return -EINVAL;
 175         }
 176 }
 177
 178 static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 179 {
 180         int ret, hsub, vsub, num_planes, i;
 181
 182         ret = format_check(r);
 183         if (ret) {
 184                 char *format_name = drm_get_format_name(r->pixel_format);
 185                 DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
 186                 kfree(format_name);
 187                 return ret;
 188         }
 189
 190         hsub = drm_format_horz_chroma_subsampling(r->pixel_format);
 191         vsub = drm_format_vert_chroma_subsampling(r->pixel_format);
 192         num_planes = drm_format_num_planes(r->pixel_format);
 193
 194         if (r->width == 0 || r->width % hsub) {
 195                 DRM_DEBUG_KMS("bad framebuffer width %u\n", r->width);
 196                 return -EINVAL;
 197         }
 198
 199         if (r->height == 0 || r->height % vsub) {
 200                 DRM_DEBUG_KMS("bad framebuffer height %u\n", r->height);
 201                 return -EINVAL;
 202         }
 203
 204         for (i = 0; i < num_planes; i++) {
 205                 unsigned int width = r->width / (i != 0 ? hsub : 1);
 206                 unsigned int height = r->height / (i != 0 ? vsub : 1);
 207                 unsigned int cpp = drm_format_plane_cpp(r->pixel_format, i);
 208
 209                 if (!r->handles[i]) {
 210                         DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
 211                         return -EINVAL;
 212                 }
 213
 214                 if ((uint64_t) width * cpp > UINT_MAX)
 215                         return -ERANGE;
 216
 217                 if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
 218                         return -ERANGE;
 219
 220                 if (r->pitches[i] < width * cpp) {
 221                         DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
 222                         return -EINVAL;
 223                 }
 224
 225                 if (r->modifier[i] && !(r->flags & DRM_MODE_FB_MODIFIERS)) {
 226                         DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
 227                                       r->modifier[i], i);
 228                         return -EINVAL;
 229                 }
 230
 231                 /* modifier specific checks: */
 232                 switch (r->modifier[i]) {
 233                 case DRM_FORMAT_MOD_SAMSUNG_64_32_TILE:
 234                         /* NOTE: the pitch restriction may be lifted later if it turns
 235                          * out that no hw has this restriction:
 236                          */
 237                         if (r->pixel_format != DRM_FORMAT_NV12 ||
 238                                         width % 128 || height % 32 ||
 239                                         r->pitches[i] % 128) {
 240                                 DRM_DEBUG_KMS("bad modifier data for plane %d\n", i);
 241                                 return -EINVAL;
 242                         }
 243                         break;
 244
 245                 default:
 246                         break;
 247                 }
 248         }
 249
 250         for (i = num_planes; i < 4; i++) {
 251                 if (r->modifier[i]) {
 252                         DRM_DEBUG_KMS("non-zero modifier for unused plane %d\n", i);
 253                         return -EINVAL;
 254                 }
 255
 256                 /* Pre-FB_MODIFIERS userspace didn't clear the structs properly. */
 257                 if (!(r->flags & DRM_MODE_FB_MODIFIERS))
 258                         continue;
 259
 260                 if (r->handles[i]) {
 261                         DRM_DEBUG_KMS("buffer object handle for unused plane %d\n", i);
 262                         return -EINVAL;
 263                 }
 264
 265                 if (r->pitches[i]) {
 266                         DRM_DEBUG_KMS("non-zero pitch for unused plane %d\n", i);
 267                         return -EINVAL;
 268                 }
 269
 270                 if (r->offsets[i]) {
 271                         DRM_DEBUG_KMS("non-zero offset for unused plane %d\n", i);
 272                         return -EINVAL;
 273                 }
 274         }
 275
 276         return 0;
 277 }
 278
 279 struct drm_framebuffer *
 280 drm_internal_framebuffer_create(struct drm_device *dev,
 281                                 const struct drm_mode_fb_cmd2 *r,
 282                                 struct drm_file *file_priv)
 283 {
 284         struct drm_mode_config *config = &dev->mode_config;
 285         struct drm_framebuffer *fb;
 286         int ret;
 287
 288         if (r->flags & ~(DRM_MODE_FB_INTERLACED | DRM_MODE_FB_MODIFIERS)) {
 289                 DRM_DEBUG_KMS("bad framebuffer flags 0x%08x\n", r->flags);
 290                 return ERR_PTR(-EINVAL);
 291         }
 292
 293         if ((config->min_width > r->width) || (r->width > config->max_width)) {
 294                 DRM_DEBUG_KMS("bad framebuffer width %d, should be >= %d && <= %d\n",
 295                           r->width, config->min_width, config->max_width);
 296                 return ERR_PTR(-EINVAL);
 297         }
 298         if ((config->min_height > r->height) || (r->height > config->max_height)) {
 299                 DRM_DEBUG_KMS("bad framebuffer height %d, should be >= %d && <= %d\n",
 300                           r->height, config->min_height, config->max_height);
 301                 return ERR_PTR(-EINVAL);
 302         }
 303
 304         if (r->flags & DRM_MODE_FB_MODIFIERS &&
 305             !dev->mode_config.allow_fb_modifiers) {
 306                 DRM_DEBUG_KMS("driver does not support fb modifiers\n");
 307                 return ERR_PTR(-EINVAL);
 308         }
 309
 310         ret = framebuffer_check(r);
 311         if (ret)
 312                 return ERR_PTR(ret);
 313
 314         fb = dev->mode_config.funcs->fb_create(dev, file_priv, r);
 315         if (IS_ERR(fb)) {
 316                 DRM_DEBUG_KMS("could not create framebuffer\n");
 317                 return fb;
 318         }
 319
 320         return fb;
 321 }
 322
 323 /**
 324  * drm_mode_addfb2 - add an FB to the graphics configuration
 325  * @dev: drm device for the ioctl
 326  * @data: data pointer for the ioctl
 327  * @file_priv: drm file for the ioctl call
 328  *
 329  * Add a new FB to the specified CRTC, given a user request with format. This is
 330  * the 2nd version of the addfb ioctl, which supports multi-planar framebuffers
 331  * and uses fourcc codes as pixel format specifiers.
 332  *
 333  * Called by the user via ioctl.
 334  *
 335  * Returns:
 336  * Zero on success, negative errno on failure.
 337  */
 338 int drm_mode_addfb2(struct drm_device *dev,
 339                     void *data, struct drm_file *file_priv)
 340 {
 341         struct drm_mode_fb_cmd2 *r = data;
 342         struct drm_framebuffer *fb;
 343
 344         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 345                 return -EINVAL;
 346
 347         fb = drm_internal_framebuffer_create(dev, r, file_priv);
 348         if (IS_ERR(fb))
 349                 return PTR_ERR(fb);
 350
 351         DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
 352         r->fb_id = fb->base.id;
 353
 354         /* Transfer ownership to the filp for reaping on close */
 355         mutex_lock(&file_priv->fbs_lock);
 356         list_add(&fb->filp_head, &file_priv->fbs);
 357         mutex_unlock(&file_priv->fbs_lock);
 358
 359         return 0;
 360 }
 361
 362 struct drm_mode_rmfb_work {
 363         struct work_struct work;
 364         struct list_head fbs;
 365 };
 366
 367 static void drm_mode_rmfb_work_fn(struct work_struct *w)
 368 {
 369         struct drm_mode_rmfb_work *arg = container_of(w, typeof(*arg), work);
 370
 371         while (!list_empty(&arg->fbs)) {
 372                 struct drm_framebuffer *fb =
 373                         list_first_entry(&arg->fbs, typeof(*fb), filp_head);
 374
 375                 list_del_init(&fb->filp_head);
 376                 drm_framebuffer_remove(fb);
 377         }
 378 }
 379
 380 /**
 381  * drm_mode_rmfb - remove an FB from the configuration
 382  * @dev: drm device for the ioctl
 383  * @data: data pointer for the ioctl
 384  * @file_priv: drm file for the ioctl call
 385  *
 386  * Remove the FB specified by the user.
 387  *
 388  * Called by the user via ioctl.
 389  *
 390  * Returns:
 391  * Zero on success, negative errno on failure.
 392  */
 393 int drm_mode_rmfb(struct drm_device *dev,
 394                    void *data, struct drm_file *file_priv)
 395 {
 396         struct drm_framebuffer *fb = NULL;
 397         struct drm_framebuffer *fbl = NULL;
 398         uint32_t *id = data;
 399         int found = 0;
 400
 401         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 402                 return -EINVAL;
 403
 404         fb = drm_framebuffer_lookup(dev, *id);
 405         if (!fb)
 406                 return -ENOENT;
 407
 408         mutex_lock(&file_priv->fbs_lock);
 409         list_for_each_entry(fbl, &file_priv->fbs, filp_head)
 410                 if (fb == fbl)
 411                         found = 1;
 412         if (!found) {
 413                 mutex_unlock(&file_priv->fbs_lock);
 414                 goto fail_unref;
 415         }
 416
 417         list_del_init(&fb->filp_head);
 418         mutex_unlock(&file_priv->fbs_lock);
 419
 420         /* drop the reference we picked up in framebuffer lookup */
 421         drm_framebuffer_unreference(fb);
 422
 423         /*
 424          * we now own the reference that was stored in the fbs list
 425          *
 426          * drm_framebuffer_remove may fail with -EINTR on pending signals,
 427          * so run this in a separate stack as there's no way to correctly
 428          * handle this after the fb is already removed from the lookup table.
 429          */
 430         if (drm_framebuffer_read_refcount(fb) > 1) {
 431                 struct drm_mode_rmfb_work arg;
 432
 433                 INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
 434                 INIT_LIST_HEAD(&arg.fbs);
 435                 list_add_tail(&fb->filp_head, &arg.fbs);
 436
 437                 schedule_work(&arg.work);
 438                 flush_work(&arg.work);
 439                 destroy_work_on_stack(&arg.work);
 440         } else
 441                 drm_framebuffer_unreference(fb);
 442
 443         return 0;
 444
 445 fail_unref:
 446         drm_framebuffer_unreference(fb);
 447         return -ENOENT;
 448 }
 449
 450 /**
 451  * drm_mode_getfb - get FB info
 452  * @dev: drm device for the ioctl
 453  * @data: data pointer for the ioctl
 454  * @file_priv: drm file for the ioctl call
 455  *
 456  * Lookup the FB given its ID and return info about it.
 457  *
 458  * Called by the user via ioctl.
 459  *
 460  * Returns:
 461  * Zero on success, negative errno on failure.
 462  */
 463 int drm_mode_getfb(struct drm_device *dev,
 464                    void *data, struct drm_file *file_priv)
 465 {
 466         struct drm_mode_fb_cmd *r = data;
 467         struct drm_framebuffer *fb;
 468         int ret;
 469
 470         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 471                 return -EINVAL;
 472
 473         fb = drm_framebuffer_lookup(dev, r->fb_id);
 474         if (!fb)
 475                 return -ENOENT;
 476
 477         r->height = fb->height;
 478         r->width = fb->width;
 479         r->depth = fb->depth;
 480         r->bpp = fb->bits_per_pixel;
 481         r->pitch = fb->pitches[0];
 482         if (fb->funcs->create_handle) {
 483                 if (drm_is_current_master(file_priv) || capable(CAP_SYS_ADMIN) ||
 484                     drm_is_control_client(file_priv)) {
 485                         ret = fb->funcs->create_handle(fb, file_priv,
 486                                                        &r->handle);
 487                 } else {
 488                         /* GET_FB() is an unprivileged ioctl so we must not
 489                          * return a buffer-handle to non-master processes! For
 490                          * backwards-compatibility reasons, we cannot make
 491                          * GET_FB() privileged, so just return an invalid handle
 492                          * for non-masters. */
 493                         r->handle = 0;
 494                         ret = 0;
 495                 }
 496         } else {
 497                 ret = -ENODEV;
 498         }
 499
 500         drm_framebuffer_unreference(fb);
 501
 502         return ret;
 503 }
 504
 505 /**
 506  * drm_mode_dirtyfb_ioctl - flush frontbuffer rendering on an FB
 507  * @dev: drm device for the ioctl
 508  * @data: data pointer for the ioctl
 509  * @file_priv: drm file for the ioctl call
 510  *
 511  * Lookup the FB and flush out the damaged area supplied by userspace as a clip
 512  * rectangle list. Generic userspace which does frontbuffer rendering must call
 513  * this ioctl to flush out the changes on manual-update display outputs, e.g.
 514  * usb display-link, mipi manual update panels or edp panel self refresh modes.
 515  *
 516  * Modesetting drivers which always update the frontbuffer do not need to
 517  * implement the corresponding ->dirty framebuffer callback.
 518  *
 519  * Called by the user via ioctl.
 520  *
 521  * Returns:
 522  * Zero on success, negative errno on failure.
 523  */
 524 int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
 525                            void *data, struct drm_file *file_priv)
 526 {
 527         struct drm_clip_rect __user *clips_ptr;
 528         struct drm_clip_rect *clips = NULL;
 529         struct drm_mode_fb_dirty_cmd *r = data;
 530         struct drm_framebuffer *fb;
 531         unsigned flags;
 532         int num_clips;
 533         int ret;
 534
 535         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 536                 return -EINVAL;
 537
 538         fb = drm_framebuffer_lookup(dev, r->fb_id);
 539         if (!fb)
 540                 return -ENOENT;
 541
 542         num_clips = r->num_clips;
 543         clips_ptr = (struct drm_clip_rect __user *)(unsigned long)r->clips_ptr;
 544
 545         if (!num_clips != !clips_ptr) {
 546                 ret = -EINVAL;
 547                 goto out_err1;
 548         }
 549
 550         flags = DRM_MODE_FB_DIRTY_FLAGS & r->flags;
 551
 552         /* If userspace annotates copy, clips must come in pairs */
 553         if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY && (num_clips % 2)) {
 554                 ret = -EINVAL;
 555                 goto out_err1;
 556         }
 557
 558         if (num_clips && clips_ptr) {
 559                 if (num_clips < 0 || num_clips > DRM_MODE_FB_DIRTY_MAX_CLIPS) {
 560                         ret = -EINVAL;
 561                         goto out_err1;
 562                 }
 563                 clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
 564                 if (!clips) {
 565                         ret = -ENOMEM;
 566                         goto out_err1;
 567                 }
 568
 569                 ret = copy_from_user(clips, clips_ptr,
 570                                      num_clips * sizeof(*clips));
 571                 if (ret) {
 572                         ret = -EFAULT;
 573                         goto out_err2;
 574                 }
 575         }
 576
 577         if (fb->funcs->dirty) {
 578                 ret = fb->funcs->dirty(fb, file_priv, flags, r->color,
 579                                        clips, num_clips);
 580         } else {
 581                 ret = -ENOSYS;
 582         }
 583
 584 out_err2:
 585         kfree(clips);
 586 out_err1:
 587         drm_framebuffer_unreference(fb);
 588
 589         return ret;
 590 }
 591
 592 /**
 593  * drm_fb_release - remove and free the FBs on this file
 594  * @priv: drm file for the ioctl
 595  *
 596  * Destroy all the FBs associated with @filp.
 597  *
 598  * Called by the user via ioctl.
 599  *
 600  * Returns:
 601  * Zero on success, negative errno on failure.
 602  */
 603 void drm_fb_release(struct drm_file *priv)
 604 {
 605         struct drm_framebuffer *fb, *tfb;
 606         struct drm_mode_rmfb_work arg;
 607
 608         INIT_LIST_HEAD(&arg.fbs);
 609
 610         /*
 611          * When the file gets released that means no one else can access the fb
 612          * list any more, so no need to grab fpriv->fbs_lock. And we need to
 613          * avoid upsetting lockdep since the universal cursor code adds a
 614          * framebuffer while holding mutex locks.
 615          *
 616          * Note that a real deadlock between fpriv->fbs_lock and the modeset
 617          * locks is impossible here since no one else but this function can get
 618          * at it any more.
 619          */
 620         list_for_each_entry_safe(fb, tfb, &priv->fbs, filp_head) {
 621                 if (drm_framebuffer_read_refcount(fb) > 1) {
 622                         list_move_tail(&fb->filp_head, &arg.fbs);
 623                 } else {
 624                         list_del_init(&fb->filp_head);
 625
 626                         /* This drops the fpriv->fbs reference. */
 627                         drm_framebuffer_unreference(fb);
 628                 }
 629         }
 630
 631         if (!list_empty(&arg.fbs)) {
 632                 INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
 633
 634                 schedule_work(&arg.work);
 635                 flush_work(&arg.work);
 636                 destroy_work_on_stack(&arg.work);
 637         }
 638 }
 639
 640 void drm_framebuffer_free(struct kref *kref)
 641 {
 642         struct drm_framebuffer *fb =
 643                         container_of(kref, struct drm_framebuffer, base.refcount);
 644         struct drm_device *dev = fb->dev;
 645
 646         /*
 647          * The lookup idr holds a weak reference, which has not necessarily been
 648          * removed at this point. Check for that.
 649          */
 650         drm_mode_object_unregister(dev, &fb->base);
 651
 652         fb->funcs->destroy(fb);
 653 }
 654
 655 /**
 656  * drm_framebuffer_init - initialize a framebuffer
 657  * @dev: DRM device
 658  * @fb: framebuffer to be initialized
 659  * @funcs: ... with these functions
 660  *
 661  * Allocates an ID for the framebuffer's parent mode object, sets its mode
 662  * functions & device file and adds it to the master fd list.
 663  *
 664  * IMPORTANT:
 665  * This functions publishes the fb and makes it available for concurrent access
 666  * by other users. Which means by this point the fb _must_ be fully set up -
 667  * since all the fb attributes are invariant over its lifetime, no further
 668  * locking but only correct reference counting is required.
 669  *
 670  * Returns:
 671  * Zero on success, error code on failure.
 672  */
 673 int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb,
 674                          const struct drm_framebuffer_funcs *funcs)
 675 {
 676         int ret;
 677
 678         INIT_LIST_HEAD(&fb->filp_head);
 679         fb->dev = dev;
 680         fb->funcs = funcs;
 681
 682         ret = drm_mode_object_get_reg(dev, &fb->base, DRM_MODE_OBJECT_FB,
 683                                       false, drm_framebuffer_free);
 684         if (ret)
 685                 goto out;
 686
 687         mutex_lock(&dev->mode_config.fb_lock);
 688         dev->mode_config.num_fb++;
 689         list_add(&fb->head, &dev->mode_config.fb_list);
 690         mutex_unlock(&dev->mode_config.fb_lock);
 691
 692         drm_mode_object_register(dev, &fb->base);
 693 out:
 694         return ret;
 695 }
 696 EXPORT_SYMBOL(drm_framebuffer_init);
 697
 698 /**
 699  * drm_framebuffer_lookup - look up a drm framebuffer and grab a reference
 700  * @dev: drm device
 701  * @id: id of the fb object
 702  *
 703  * If successful, this grabs an additional reference to the framebuffer -
 704  * callers need to make sure to eventually unreference the returned framebuffer
 705  * again, using @drm_framebuffer_unreference.
 706  */
 707 struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
 708                                                uint32_t id)
 709 {
 710         struct drm_mode_object *obj;
 711         struct drm_framebuffer *fb = NULL;
 712
 713         obj = __drm_mode_object_find(dev, id, DRM_MODE_OBJECT_FB);
 714         if (obj)
 715                 fb = obj_to_fb(obj);
 716         return fb;
 717 }
 718 EXPORT_SYMBOL(drm_framebuffer_lookup);
 719
 720 /**
 721  * drm_framebuffer_unregister_private - unregister a private fb from the lookup idr
 722  * @fb: fb to unregister
 723  *
 724  * Drivers need to call this when cleaning up driver-private framebuffers, e.g.
 725  * those used for fbdev. Note that the caller must hold a reference of it's own,
 726  * i.e. the object may not be destroyed through this call (since it'll lead to a
 727  * locking inversion).
 728  */
 729 void drm_framebuffer_unregister_private(struct drm_framebuffer *fb)
 730 {
 731         struct drm_device *dev;
 732
 733         if (!fb)
 734                 return;
 735
 736         dev = fb->dev;
 737
 738         /* Mark fb as reaped and drop idr ref. */
 739         drm_mode_object_unregister(dev, &fb->base);
 740 }
 741 EXPORT_SYMBOL(drm_framebuffer_unregister_private);
 742
 743 /**
 744  * drm_framebuffer_cleanup - remove a framebuffer object
 745  * @fb: framebuffer to remove
 746  *
 747  * Cleanup framebuffer. This function is intended to be used from the drivers
 748  * ->destroy callback. It can also be used to clean up driver private
 749  * framebuffers embedded into a larger structure.
 750  *
 751  * Note that this function does not remove the fb from active usuage - if it is
 752  * still used anywhere, hilarity can ensue since userspace could call getfb on
 753  * the id and get back -EINVAL. Obviously no concern at driver unload time.
 754  *
 755  * Also, the framebuffer will not be removed from the lookup idr - for
 756  * user-created framebuffers this will happen in in the rmfb ioctl. For
 757  * driver-private objects (e.g. for fbdev) drivers need to explicitly call
 758  * drm_framebuffer_unregister_private.
 759  */
 760 void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
 761 {
 762         struct drm_device *dev = fb->dev;
 763
 764         mutex_lock(&dev->mode_config.fb_lock);
 765         list_del(&fb->head);
 766         dev->mode_config.num_fb--;
 767         mutex_unlock(&dev->mode_config.fb_lock);
 768 }
 769 EXPORT_SYMBOL(drm_framebuffer_cleanup);
 770
 771 /**
 772  * drm_framebuffer_remove - remove and unreference a framebuffer object
 773  * @fb: framebuffer to remove
 774  *
 775  * Scans all the CRTCs and planes in @dev's mode_config.  If they're
 776  * using @fb, removes it, setting it to NULL. Then drops the reference to the
 777  * passed-in framebuffer. Might take the modeset locks.
 778  *
 779  * Note that this function optimizes the cleanup away if the caller holds the
 780  * last reference to the framebuffer. It is also guaranteed to not take the
 781  * modeset locks in this case.
 782  */
 783 void drm_framebuffer_remove(struct drm_framebuffer *fb)
 784 {
 785         struct drm_device *dev;
 786         struct drm_crtc *crtc;
 787         struct drm_plane *plane;
 788
 789         if (!fb)
 790                 return;
 791
 792         dev = fb->dev;
 793
 794         WARN_ON(!list_empty(&fb->filp_head));
 795
 796         /*
 797          * drm ABI mandates that we remove any deleted framebuffers from active
 798          * useage. But since most sane clients only remove framebuffers they no
 799          * longer need, try to optimize this away.
 800          *
 801          * Since we're holding a reference ourselves, observing a refcount of 1
 802          * means that we're the last holder and can skip it. Also, the refcount
 803          * can never increase from 1 again, so we don't need any barriers or
 804          * locks.
 805          *
 806          * Note that userspace could try to race with use and instate a new
 807          * usage _after_ we've cleared all current ones. End result will be an
 808          * in-use fb with fb-id == 0. Userspace is allowed to shoot its own foot
 809          * in this manner.
 810          */
 811         if (drm_framebuffer_read_refcount(fb) > 1) {
 812                 drm_modeset_lock_all(dev);
 813                 /* remove from any CRTC */
 814                 drm_for_each_crtc(crtc, dev) {
 815                         if (crtc->primary->fb == fb) {
 816                                 /* should turn off the crtc */
 817                                 if (drm_crtc_force_disable(crtc))
 818                                         DRM_ERROR("failed to reset crtc %p when fb was deleted\n", crtc);
 819                         }
 820                 }
 821
 822                 drm_for_each_plane(plane, dev) {
 823                         if (plane->fb == fb)
 824                                 drm_plane_force_disable(plane);
 825                 }
 826                 drm_modeset_unlock_all(dev);
 827         }
 828
 829         drm_framebuffer_unreference(fb);
 830 }
 831 EXPORT_SYMBOL(drm_framebuffer_remove);