drivers/gpu/drm/udl/udl_fb.c

   1 /*
   2  * Copyright (C) 2012 Red Hat
   3  *
   4  * based in parts on udlfb.c:
   5  * Copyright (C) 2009 Roberto De Ioris <[email protected]>
   6  * Copyright (C) 2009 Jaya Kumar <[email protected]>
   7  * Copyright (C) 2009 Bernie Thompson <[email protected]>
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License v2. See the file COPYING in the main directory of this archive for
  11  * more details.
  12  */
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/fb.h>
  16 #include <linux/dma-buf.h>
  17
  18 #include <drm/drmP.h>
  19 #include <drm/drm_crtc.h>
  20 #include <drm/drm_crtc_helper.h>
  21 #include "udl_drv.h"
  22
  23 #include <drm/drm_fb_helper.h>
  24
  25 #define DL_DEFIO_WRITE_DELAY    5 /* fb_deferred_io.delay in jiffies */
  26
  27 static int fb_defio = 1;  /* Optionally enable experimental fb_defio mmap support */
  28 static int fb_bpp = 16;
  29
  30 module_param(fb_bpp, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
  31 module_param(fb_defio, int, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
  32
  33 struct udl_fbdev {
  34         struct drm_fb_helper helper;
  35         struct udl_framebuffer ufb;
  36         struct list_head fbdev_list;
  37         int fb_count;
  38 };
  39
  40 #define DL_ALIGN_UP(x, a) ALIGN(x, a)
  41 #define DL_ALIGN_DOWN(x, a) ALIGN(x-(a-1), a)
  42
  43 /** Read the red component (0..255) of a 32 bpp colour. */
  44 #define DLO_RGB_GETRED(col) (uint8_t)((col) & 0xFF)
  45
  46 /** Read the green component (0..255) of a 32 bpp colour. */
  47 #define DLO_RGB_GETGRN(col) (uint8_t)(((col) >> 8) & 0xFF)
  48
  49 /** Read the blue component (0..255) of a 32 bpp colour. */
  50 #define DLO_RGB_GETBLU(col) (uint8_t)(((col) >> 16) & 0xFF)
  51
  52 /** Return red/green component of a 16 bpp colour number. */
  53 #define DLO_RG16(red, grn) (uint8_t)((((red) & 0xF8) | ((grn) >> 5)) & 0xFF)
  54
  55 /** Return green/blue component of a 16 bpp colour number. */
  56 #define DLO_GB16(grn, blu) (uint8_t)(((((grn) & 0x1C) << 3) | ((blu) >> 3)) & 0xFF)
  57
  58 /** Return 8 bpp colour number from red, green and blue components. */
  59 #define DLO_RGB8(red, grn, blu) ((((red) << 5) | (((grn) & 3) << 3) | ((blu) & 7)) & 0xFF)
  60
  61 #if 0
  62 static uint8_t rgb8(uint32_t col)
  63 {
  64         uint8_t red = DLO_RGB_GETRED(col);
  65         uint8_t grn = DLO_RGB_GETGRN(col);
  66         uint8_t blu = DLO_RGB_GETBLU(col);
  67
  68         return DLO_RGB8(red, grn, blu);
  69 }
  70
  71 static uint16_t rgb16(uint32_t col)
  72 {
  73         uint8_t red = DLO_RGB_GETRED(col);
  74         uint8_t grn = DLO_RGB_GETGRN(col);
  75         uint8_t blu = DLO_RGB_GETBLU(col);
  76
  77         return (DLO_RG16(red, grn) << 8) + DLO_GB16(grn, blu);
  78 }
  79 #endif
  80
  81 /*
  82  * NOTE: fb_defio.c is holding info->fbdefio.mutex
  83  *   Touching ANY framebuffer memory that triggers a page fault
  84  *   in fb_defio will cause a deadlock, when it also tries to
  85  *   grab the same mutex.
  86  */
  87 static void udlfb_dpy_deferred_io(struct fb_info *info,
  88                                   struct list_head *pagelist)
  89 {
  90         struct page *cur;
  91         struct fb_deferred_io *fbdefio = info->fbdefio;
  92         struct udl_fbdev *ufbdev = info->par;
  93         struct drm_device *dev = ufbdev->ufb.base.dev;
  94         struct udl_device *udl = dev->dev_private;
  95         struct urb *urb;
  96         char *cmd;
  97         cycles_t start_cycles, end_cycles;
  98         int bytes_sent = 0;
  99         int bytes_identical = 0;
 100         int bytes_rendered = 0;
 101
 102         if (!fb_defio)
 103                 return;
 104
 105         start_cycles = get_cycles();
 106
 107         urb = udl_get_urb(dev);
 108         if (!urb)
 109                 return;
 110
 111         cmd = urb->transfer_buffer;
 112
 113         /* walk the written page list and render each to device */
 114         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
 115
 116                 if (udl_render_hline(dev, (ufbdev->ufb.base.bits_per_pixel / 8),
 117                                   &urb, (char *) info->fix.smem_start,
 118                                   &cmd, cur->index << PAGE_SHIFT,
 119                                   PAGE_SIZE, &bytes_identical, &bytes_sent))
 120                         goto error;
 121                 bytes_rendered += PAGE_SIZE;
 122         }
 123
 124         if (cmd > (char *) urb->transfer_buffer) {
 125                 /* Send partial buffer remaining before exiting */
 126                 int len = cmd - (char *) urb->transfer_buffer;
 127                 udl_submit_urb(dev, urb, len);
 128                 bytes_sent += len;
 129         } else
 130                 udl_urb_completion(urb);
 131
 132 error:
 133         atomic_add(bytes_sent, &udl->bytes_sent);
 134         atomic_add(bytes_identical, &udl->bytes_identical);
 135         atomic_add(bytes_rendered, &udl->bytes_rendered);
 136         end_cycles = get_cycles();
 137         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 138                     >> 10)), /* Kcycles */
 139                    &udl->cpu_kcycles_used);
 140 }
 141
 142 int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
 143                       int width, int height)
 144 {
 145         struct drm_device *dev = fb->base.dev;
 146         struct udl_device *udl = dev->dev_private;
 147         int i, ret;
 148         char *cmd;
 149         cycles_t start_cycles, end_cycles;
 150         int bytes_sent = 0;
 151         int bytes_identical = 0;
 152         struct urb *urb;
 153         int aligned_x;
 154         int bpp = (fb->base.bits_per_pixel / 8);
 155
 156         if (!fb->active_16)
 157                 return 0;
 158
 159         if (!fb->obj->vmapping) {
 160                 ret = udl_gem_vmap(fb->obj);
 161                 if (ret == -ENOMEM) {
 162                         DRM_ERROR("failed to vmap fb\n");
 163                         return 0;
 164                 }
 165                 if (!fb->obj->vmapping) {
 166                         DRM_ERROR("failed to vmapping\n");
 167                         return 0;
 168                 }
 169         }
 170
 171         start_cycles = get_cycles();
 172
 173         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
 174         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
 175         x = aligned_x;
 176
 177         if ((width <= 0) ||
 178             (x + width > fb->base.width) ||
 179             (y + height > fb->base.height))
 180                 return -EINVAL;
 181
 182         urb = udl_get_urb(dev);
 183         if (!urb)
 184                 return 0;
 185         cmd = urb->transfer_buffer;
 186
 187         for (i = y; i < y + height ; i++) {
 188                 const int line_offset = fb->base.pitches[0] * i;
 189                 const int byte_offset = line_offset + (x * bpp);
 190
 191                 if (udl_render_hline(dev, bpp, &urb,
 192                                      (char *) fb->obj->vmapping,
 193                                      &cmd, byte_offset, width * bpp,
 194                                      &bytes_identical, &bytes_sent))
 195                         goto error;
 196         }
 197
 198         if (cmd > (char *) urb->transfer_buffer) {
 199                 /* Send partial buffer remaining before exiting */
 200                 int len = cmd - (char *) urb->transfer_buffer;
 201                 ret = udl_submit_urb(dev, urb, len);
 202                 bytes_sent += len;
 203         } else
 204                 udl_urb_completion(urb);
 205
 206 error:
 207         atomic_add(bytes_sent, &udl->bytes_sent);
 208         atomic_add(bytes_identical, &udl->bytes_identical);
 209         atomic_add(width*height*bpp, &udl->bytes_rendered);
 210         end_cycles = get_cycles();
 211         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 212                     >> 10)), /* Kcycles */
 213                    &udl->cpu_kcycles_used);
 214
 215         return 0;
 216 }
 217
 218 static int udl_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 219 {
 220         unsigned long start = vma->vm_start;
 221         unsigned long size = vma->vm_end - vma->vm_start;
 222         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 223         unsigned long page, pos;
 224
 225         if (offset + size > info->fix.smem_len)
 226                 return -EINVAL;
 227
 228         pos = (unsigned long)info->fix.smem_start + offset;
 229
 230         pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
 231                   pos, size);
 232
 233         while (size > 0) {
 234                 page = vmalloc_to_pfn((void *)pos);
 235                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 236                         return -EAGAIN;
 237
 238                 start += PAGE_SIZE;
 239                 pos += PAGE_SIZE;
 240                 if (size > PAGE_SIZE)
 241                         size -= PAGE_SIZE;
 242                 else
 243                         size = 0;
 244         }
 245
 246         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
 247         return 0;
 248 }
 249
 250 static void udl_fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
 251 {
 252         struct udl_fbdev *ufbdev = info->par;
 253
 254         sys_fillrect(info, rect);
 255
 256         udl_handle_damage(&ufbdev->ufb, rect->dx, rect->dy, rect->width,
 257                           rect->height);
 258 }
 259
 260 static void udl_fb_copyarea(struct fb_info *info, const struct fb_copyarea *region)
 261 {
 262         struct udl_fbdev *ufbdev = info->par;
 263
 264         sys_copyarea(info, region);
 265
 266         udl_handle_damage(&ufbdev->ufb, region->dx, region->dy, region->width,
 267                           region->height);
 268 }
 269
 270 static void udl_fb_imageblit(struct fb_info *info, const struct fb_image *image)
 271 {
 272         struct udl_fbdev *ufbdev = info->par;
 273
 274         sys_imageblit(info, image);
 275
 276         udl_handle_damage(&ufbdev->ufb, image->dx, image->dy, image->width,
 277                           image->height);
 278 }
 279
 280 /*
 281  * It's common for several clients to have framebuffer open simultaneously.
 282  * e.g. both fbcon and X. Makes things interesting.
 283  * Assumes caller is holding info->lock (for open and release at least)
 284  */
 285 static int udl_fb_open(struct fb_info *info, int user)
 286 {
 287         struct udl_fbdev *ufbdev = info->par;
 288         struct drm_device *dev = ufbdev->ufb.base.dev;
 289         struct udl_device *udl = dev->dev_private;
 290
 291         /* If the USB device is gone, we don't accept new opens */
 292         if (drm_device_is_unplugged(udl->ddev))
 293                 return -ENODEV;
 294
 295         ufbdev->fb_count++;
 296
 297         if (fb_defio && (info->fbdefio == NULL)) {
 298                 /* enable defio at last moment if not disabled by client */
 299
 300                 struct fb_deferred_io *fbdefio;
 301
 302                 fbdefio = kmalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
 303
 304                 if (fbdefio) {
 305                         fbdefio->delay = DL_DEFIO_WRITE_DELAY;
 306                         fbdefio->deferred_io = udlfb_dpy_deferred_io;
 307                 }
 308
 309                 info->fbdefio = fbdefio;
 310                 fb_deferred_io_init(info);
 311         }
 312
 313         pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 314                   info->node, user, info, ufbdev->fb_count);
 315
 316         return 0;
 317 }
 318
 319
 320 /*
 321  * Assumes caller is holding info->lock mutex (for open and release at least)
 322  */
 323 static int udl_fb_release(struct fb_info *info, int user)
 324 {
 325         struct udl_fbdev *ufbdev = info->par;
 326
 327         ufbdev->fb_count--;
 328
 329         if ((ufbdev->fb_count == 0) && (info->fbdefio)) {
 330                 fb_deferred_io_cleanup(info);
 331                 kfree(info->fbdefio);
 332                 info->fbdefio = NULL;
 333                 info->fbops->fb_mmap = udl_fb_mmap;
 334         }
 335
 336         pr_warn("released /dev/fb%d user=%d count=%d\n",
 337                 info->node, user, ufbdev->fb_count);
 338
 339         return 0;
 340 }
 341
 342 static struct fb_ops udlfb_ops = {
 343         .owner = THIS_MODULE,
 344         .fb_check_var = drm_fb_helper_check_var,
 345         .fb_set_par = drm_fb_helper_set_par,
 346         .fb_fillrect = udl_fb_fillrect,
 347         .fb_copyarea = udl_fb_copyarea,
 348         .fb_imageblit = udl_fb_imageblit,
 349         .fb_pan_display = drm_fb_helper_pan_display,
 350         .fb_blank = drm_fb_helper_blank,
 351         .fb_setcmap = drm_fb_helper_setcmap,
 352         .fb_debug_enter = drm_fb_helper_debug_enter,
 353         .fb_debug_leave = drm_fb_helper_debug_leave,
 354         .fb_mmap = udl_fb_mmap,
 355         .fb_open = udl_fb_open,
 356         .fb_release = udl_fb_release,
 357 };
 358
 359 static void udl_crtc_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
 360                            u16 blue, int regno)
 361 {
 362 }
 363
 364 static void udl_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
 365                              u16 *blue, int regno)
 366 {
 367         *red = 0;
 368         *green = 0;
 369         *blue = 0;
 370 }
 371
 372 static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,
 373                                       struct drm_file *file,
 374                                       unsigned flags, unsigned color,
 375                                       struct drm_clip_rect *clips,
 376                                       unsigned num_clips)
 377 {
 378         struct udl_framebuffer *ufb = to_udl_fb(fb);
 379         int i;
 380         int ret = 0;
 381
 382         if (!ufb->active_16)
 383                 return 0;
 384
 385         if (ufb->obj->base.import_attach) {
 386                 ret = dma_buf_begin_cpu_access(ufb->obj->base.import_attach->dmabuf,
 387                                                0, ufb->obj->base.size,
 388                                                DMA_FROM_DEVICE);
 389                 if (ret)
 390                         return ret;
 391         }
 392
 393         for (i = 0; i < num_clips; i++) {
 394                 ret = udl_handle_damage(ufb, clips[i].x1, clips[i].y1,
 395                                   clips[i].x2 - clips[i].x1,
 396                                   clips[i].y2 - clips[i].y1);
 397                 if (ret)
 398                         break;
 399         }
 400
 401         if (ufb->obj->base.import_attach) {
 402                 dma_buf_end_cpu_access(ufb->obj->base.import_attach->dmabuf,
 403                                        0, ufb->obj->base.size,
 404                                        DMA_FROM_DEVICE);
 405         }
 406         return ret;
 407 }
 408
 409 static void udl_user_framebuffer_destroy(struct drm_framebuffer *fb)
 410 {
 411         struct udl_framebuffer *ufb = to_udl_fb(fb);
 412
 413         if (ufb->obj)
 414                 drm_gem_object_unreference_unlocked(&ufb->obj->base);
 415
 416         drm_framebuffer_cleanup(fb);
 417         kfree(ufb);
 418 }
 419
 420 static const struct drm_framebuffer_funcs udlfb_funcs = {
 421         .destroy = udl_user_framebuffer_destroy,
 422         .dirty = udl_user_framebuffer_dirty,
 423         .create_handle = NULL,
 424 };
 425
 426
 427 static int
 428 udl_framebuffer_init(struct drm_device *dev,
 429                      struct udl_framebuffer *ufb,
 430                      struct drm_mode_fb_cmd2 *mode_cmd,
 431                      struct udl_gem_object *obj)
 432 {
 433         int ret;
 434
 435         ufb->obj = obj;
 436         ret = drm_framebuffer_init(dev, &ufb->base, &udlfb_funcs);
 437         drm_helper_mode_fill_fb_struct(&ufb->base, mode_cmd);
 438         return ret;
 439 }
 440
 441
 442 static int udlfb_create(struct udl_fbdev *ufbdev,
 443                         struct drm_fb_helper_surface_size *sizes)
 444 {
 445         struct drm_device *dev = ufbdev->helper.dev;
 446         struct fb_info *info;
 447         struct device *device = &dev->usbdev->dev;
 448         struct drm_framebuffer *fb;
 449         struct drm_mode_fb_cmd2 mode_cmd;
 450         struct udl_gem_object *obj;
 451         uint32_t size;
 452         int ret = 0;
 453
 454         if (sizes->surface_bpp == 24)
 455                 sizes->surface_bpp = 32;
 456
 457         mode_cmd.width = sizes->surface_width;
 458         mode_cmd.height = sizes->surface_height;
 459         mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7) / 8);
 460
 461         mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 462                                                           sizes->surface_depth);
 463
 464         size = mode_cmd.pitches[0] * mode_cmd.height;
 465         size = ALIGN(size, PAGE_SIZE);
 466
 467         obj = udl_gem_alloc_object(dev, size);
 468         if (!obj)
 469                 goto out;
 470
 471         ret = udl_gem_vmap(obj);
 472         if (ret) {
 473                 DRM_ERROR("failed to vmap fb\n");
 474                 goto out_gfree;
 475         }
 476
 477         info = framebuffer_alloc(0, device);
 478         if (!info) {
 479                 ret = -ENOMEM;
 480                 goto out_gfree;
 481         }
 482         info->par = ufbdev;
 483
 484         ret = udl_framebuffer_init(dev, &ufbdev->ufb, &mode_cmd, obj);
 485         if (ret)
 486                 goto out_gfree;
 487
 488         fb = &ufbdev->ufb.base;
 489
 490         ufbdev->helper.fb = fb;
 491         ufbdev->helper.fbdev = info;
 492
 493         strcpy(info->fix.id, "udldrmfb");
 494
 495         info->screen_base = ufbdev->ufb.obj->vmapping;
 496         info->fix.smem_len = size;
 497         info->fix.smem_start = (unsigned long)ufbdev->ufb.obj->vmapping;
 498
 499         info->flags = FBINFO_DEFAULT | FBINFO_CAN_FORCE_OUTPUT;
 500         info->fbops = &udlfb_ops;
 501         drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);
 502         drm_fb_helper_fill_var(info, &ufbdev->helper, sizes->fb_width, sizes->fb_height);
 503
 504         ret = fb_alloc_cmap(&info->cmap, 256, 0);
 505         if (ret) {
 506                 ret = -ENOMEM;
 507                 goto out_gfree;
 508         }
 509
 510
 511         DRM_DEBUG_KMS("allocated %dx%d vmal %p\n",
 512                       fb->width, fb->height,
 513                       ufbdev->ufb.obj->vmapping);
 514
 515         return ret;
 516 out_gfree:
 517         drm_gem_object_unreference(&ufbdev->ufb.obj->base);
 518 out:
 519         return ret;
 520 }
 521
 522 static int udl_fb_find_or_create_single(struct drm_fb_helper *helper,
 523                                         struct drm_fb_helper_surface_size *sizes)
 524 {
 525         struct udl_fbdev *ufbdev = (struct udl_fbdev *)helper;
 526         int new_fb = 0;
 527         int ret;
 528
 529         if (!helper->fb) {
 530                 ret = udlfb_create(ufbdev, sizes);
 531                 if (ret)
 532                         return ret;
 533
 534                 new_fb = 1;
 535         }
 536         return new_fb;
 537 }
 538
 539 static struct drm_fb_helper_funcs udl_fb_helper_funcs = {
 540         .gamma_set = udl_crtc_fb_gamma_set,
 541         .gamma_get = udl_crtc_fb_gamma_get,
 542         .fb_probe = udl_fb_find_or_create_single,
 543 };
 544
 545 static void udl_fbdev_destroy(struct drm_device *dev,
 546                               struct udl_fbdev *ufbdev)
 547 {
 548         struct fb_info *info;
 549         if (ufbdev->helper.fbdev) {
 550                 info = ufbdev->helper.fbdev;
 551                 unregister_framebuffer(info);
 552                 if (info->cmap.len)
 553                         fb_dealloc_cmap(&info->cmap);
 554                 framebuffer_release(info);
 555         }
 556         drm_fb_helper_fini(&ufbdev->helper);
 557         drm_framebuffer_cleanup(&ufbdev->ufb.base);
 558         drm_gem_object_unreference_unlocked(&ufbdev->ufb.obj->base);
 559 }
 560
 561 int udl_fbdev_init(struct drm_device *dev)
 562 {
 563         struct udl_device *udl = dev->dev_private;
 564         int bpp_sel = fb_bpp;
 565         struct udl_fbdev *ufbdev;
 566         int ret;
 567
 568         ufbdev = kzalloc(sizeof(struct udl_fbdev), GFP_KERNEL);
 569         if (!ufbdev)
 570                 return -ENOMEM;
 571
 572         udl->fbdev = ufbdev;
 573         ufbdev->helper.funcs = &udl_fb_helper_funcs;
 574
 575         ret = drm_fb_helper_init(dev, &ufbdev->helper,
 576                                  1, 1);
 577         if (ret) {
 578                 kfree(ufbdev);
 579                 return ret;
 580
 581         }
 582
 583         drm_fb_helper_single_add_all_connectors(&ufbdev->helper);
 584         drm_fb_helper_initial_config(&ufbdev->helper, bpp_sel);
 585         return 0;
 586 }
 587
 588 void udl_fbdev_cleanup(struct drm_device *dev)
 589 {
 590         struct udl_device *udl = dev->dev_private;
 591         if (!udl->fbdev)
 592                 return;
 593
 594         udl_fbdev_destroy(dev, udl->fbdev);
 595         kfree(udl->fbdev);
 596         udl->fbdev = NULL;
 597 }
 598
 599 void udl_fbdev_unplug(struct drm_device *dev)
 600 {
 601         struct udl_device *udl = dev->dev_private;
 602         struct udl_fbdev *ufbdev;
 603         if (!udl->fbdev)
 604                 return;
 605
 606         ufbdev = udl->fbdev;
 607         if (ufbdev->helper.fbdev) {
 608                 struct fb_info *info;
 609                 info = ufbdev->helper.fbdev;
 610                 unlink_framebuffer(info);
 611         }
 612 }
 613
 614 struct drm_framebuffer *
 615 udl_fb_user_fb_create(struct drm_device *dev,
 616                    struct drm_file *file,
 617                    struct drm_mode_fb_cmd2 *mode_cmd)
 618 {
 619         struct drm_gem_object *obj;
 620         struct udl_framebuffer *ufb;
 621         int ret;
 622         uint32_t size;
 623
 624         obj = drm_gem_object_lookup(dev, file, mode_cmd->handles[0]);
 625         if (obj == NULL)
 626                 return ERR_PTR(-ENOENT);
 627
 628         size = mode_cmd->pitches[0] * mode_cmd->height;
 629         size = ALIGN(size, PAGE_SIZE);
 630
 631         if (size > obj->size) {
 632                 DRM_ERROR("object size not sufficient for fb %d %zu %d %d\n", size, obj->size, mode_cmd->pitches[0], mode_cmd->height);
 633                 return ERR_PTR(-ENOMEM);
 634         }
 635
 636         ufb = kzalloc(sizeof(*ufb), GFP_KERNEL);
 637         if (ufb == NULL)
 638                 return ERR_PTR(-ENOMEM);
 639
 640         ret = udl_framebuffer_init(dev, ufb, mode_cmd, to_udl_bo(obj));
 641         if (ret) {
 642                 kfree(ufb);
 643                 return ERR_PTR(-EINVAL);
 644         }
 645         return &ufb->base;
 646 }