drivers/gpu/drm/radeon/radeon_cs.c

   1 /*
   2  * Copyright 2008 Jerome Glisse.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Jerome Glisse <glisse@freedesktop.org>
  26  */
  27 #include "drmP.h"
  28 #include "radeon_drm.h"
  29 #include "radeon_reg.h"
  30 #include "radeon.h"
  31
  32 void r100_cs_dump_packet(struct radeon_cs_parser *p,
  33                          struct radeon_cs_packet *pkt);
  34
  35 int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
  36 {
  37         struct drm_device *ddev = p->rdev->ddev;
  38         struct radeon_cs_chunk *chunk;
  39         unsigned i, j;
  40         bool duplicate;
  41
  42         if (p->chunk_relocs_idx == -1) {
  43                 return 0;
  44         }
  45         chunk = &p->chunks[p->chunk_relocs_idx];
  46         /* FIXME: we assume that each relocs use 4 dwords */
  47         p->nrelocs = chunk->length_dw / 4;
  48         p->relocs_ptr = kcalloc(p->nrelocs, sizeof(void *), GFP_KERNEL);
  49         if (p->relocs_ptr == NULL) {
  50                 return -ENOMEM;
  51         }
  52         p->relocs = kcalloc(p->nrelocs, sizeof(struct radeon_cs_reloc), GFP_KERNEL);
  53         if (p->relocs == NULL) {
  54                 return -ENOMEM;
  55         }
  56         for (i = 0; i < p->nrelocs; i++) {
  57                 struct drm_radeon_cs_reloc *r;
  58
  59                 duplicate = false;
  60                 r = (struct drm_radeon_cs_reloc *)&chunk->kdata[i*4];
  61                 for (j = 0; j < i; j++) {
  62                         if (r->handle == p->relocs[j].handle) {
  63                                 p->relocs_ptr[i] = &p->relocs[j];
  64                                 duplicate = true;
  65                                 break;
  66                         }
  67                 }
  68                 if (!duplicate) {
  69                         p->relocs[i].gobj = drm_gem_object_lookup(ddev,
  70                                                                   p->filp,
  71                                                                   r->handle);
  72                         if (p->relocs[i].gobj == NULL) {
  73                                 DRM_ERROR("gem object lookup failed 0x%x\n",
  74                                           r->handle);
  75                                 return -ENOENT;
  76                         }
  77                         p->relocs_ptr[i] = &p->relocs[i];
  78                         p->relocs[i].robj = gem_to_radeon_bo(p->relocs[i].gobj);
  79                         p->relocs[i].lobj.bo = p->relocs[i].robj;
  80                         p->relocs[i].lobj.wdomain = r->write_domain;
  81                         p->relocs[i].lobj.rdomain = r->read_domains;
  82                         p->relocs[i].lobj.tv.bo = &p->relocs[i].robj->tbo;
  83                         p->relocs[i].handle = r->handle;
  84                         p->relocs[i].flags = r->flags;
  85                         radeon_bo_list_add_object(&p->relocs[i].lobj,
  86                                                   &p->validated);
  87
  88                 } else
  89                         p->relocs[i].handle = 0;
  90         }
  91         return radeon_bo_list_validate(&p->validated);
  92 }
  93
  94 static int radeon_cs_get_ring(struct radeon_cs_parser *p, u32 ring, s32 priority)
  95 {
  96         p->priority = priority;
  97
  98         switch (ring) {
  99         default:
 100                 DRM_ERROR("unknown ring id: %d\n", ring);
 101                 return -EINVAL;
 102         case RADEON_CS_RING_GFX:
 103                 p->ring = RADEON_RING_TYPE_GFX_INDEX;
 104                 break;
 105         case RADEON_CS_RING_COMPUTE:
 106                 /* for now */
 107                 p->ring = RADEON_RING_TYPE_GFX_INDEX;
 108                 break;
 109         }
 110         return 0;
 111 }
 112
 113 static int radeon_cs_sync_rings(struct radeon_cs_parser *p)
 114 {
 115         bool sync_to_ring[RADEON_NUM_RINGS] = { };
 116         int i, r;
 117
 118         for (i = 0; i < p->nrelocs; i++) {
 119                 if (!p->relocs[i].robj || !p->relocs[i].robj->tbo.sync_obj)
 120                         continue;
 121
 122                 if (!(p->relocs[i].flags & RADEON_RELOC_DONT_SYNC)) {
 123                         struct radeon_fence *fence = p->relocs[i].robj->tbo.sync_obj;
 124                         if (!radeon_fence_signaled(fence)) {
 125                                 sync_to_ring[fence->ring] = true;
 126                         }
 127                 }
 128         }
 129
 130         for (i = 0; i < RADEON_NUM_RINGS; ++i) {
 131                 /* no need to sync to our own or unused rings */
 132                 if (i == p->ring || !sync_to_ring[i] || !p->rdev->ring[i].ready)
 133                         continue;
 134
 135                 if (!p->ib->fence->semaphore) {
 136                         r = radeon_semaphore_create(p->rdev, &p->ib->fence->semaphore);
 137                         if (r)
 138                                 return r;
 139                 }
 140
 141                 r = radeon_ring_lock(p->rdev, &p->rdev->ring[i], 3);
 142                 if (r)
 143                         return r;
 144                 radeon_semaphore_emit_signal(p->rdev, i, p->ib->fence->semaphore);
 145                 radeon_ring_unlock_commit(p->rdev, &p->rdev->ring[i]);
 146
 147                 r = radeon_ring_lock(p->rdev, &p->rdev->ring[p->ring], 3);
 148                 if (r)
 149                         return r;
 150                 radeon_semaphore_emit_wait(p->rdev, p->ring, p->ib->fence->semaphore);
 151                 radeon_ring_unlock_commit(p->rdev, &p->rdev->ring[p->ring]);
 152         }
 153         return 0;
 154 }
 155
 156 int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
 157 {
 158         struct drm_radeon_cs *cs = data;
 159         uint64_t *chunk_array_ptr;
 160         unsigned size, i;
 161         u32 ring = RADEON_CS_RING_GFX;
 162         s32 priority = 0;
 163
 164         if (!cs->num_chunks) {
 165                 return 0;
 166         }
 167         /* get chunks */
 168         INIT_LIST_HEAD(&p->validated);
 169         p->idx = 0;
 170         p->chunk_ib_idx = -1;
 171         p->chunk_relocs_idx = -1;
 172         p->chunk_flags_idx = -1;
 173         p->chunks_array = kcalloc(cs->num_chunks, sizeof(uint64_t), GFP_KERNEL);
 174         if (p->chunks_array == NULL) {
 175                 return -ENOMEM;
 176         }
 177         chunk_array_ptr = (uint64_t *)(unsigned long)(cs->chunks);
 178         if (DRM_COPY_FROM_USER(p->chunks_array, chunk_array_ptr,
 179                                sizeof(uint64_t)*cs->num_chunks)) {
 180                 return -EFAULT;
 181         }
 182         p->cs_flags = 0;
 183         p->nchunks = cs->num_chunks;
 184         p->chunks = kcalloc(p->nchunks, sizeof(struct radeon_cs_chunk), GFP_KERNEL);
 185         if (p->chunks == NULL) {
 186                 return -ENOMEM;
 187         }
 188         for (i = 0; i < p->nchunks; i++) {
 189                 struct drm_radeon_cs_chunk __user **chunk_ptr = NULL;
 190                 struct drm_radeon_cs_chunk user_chunk;
 191                 uint32_t __user *cdata;
 192
 193                 chunk_ptr = (void __user*)(unsigned long)p->chunks_array[i];
 194                 if (DRM_COPY_FROM_USER(&user_chunk, chunk_ptr,
 195                                        sizeof(struct drm_radeon_cs_chunk))) {
 196                         return -EFAULT;
 197                 }
 198                 p->chunks[i].length_dw = user_chunk.length_dw;
 199                 p->chunks[i].kdata = NULL;
 200                 p->chunks[i].chunk_id = user_chunk.chunk_id;
 201
 202                 if (p->chunks[i].chunk_id == RADEON_CHUNK_ID_RELOCS) {
 203                         p->chunk_relocs_idx = i;
 204                 }
 205                 if (p->chunks[i].chunk_id == RADEON_CHUNK_ID_IB) {
 206                         p->chunk_ib_idx = i;
 207                         /* zero length IB isn't useful */
 208                         if (p->chunks[i].length_dw == 0)
 209                                 return -EINVAL;
 210                 }
 211                 if (p->chunks[i].chunk_id == RADEON_CHUNK_ID_FLAGS) {
 212                         p->chunk_flags_idx = i;
 213                         /* zero length flags aren't useful */
 214                         if (p->chunks[i].length_dw == 0)
 215                                 return -EINVAL;
 216                 }
 217
 218                 p->chunks[i].length_dw = user_chunk.length_dw;
 219                 p->chunks[i].user_ptr = (void __user *)(unsigned long)user_chunk.chunk_data;
 220
 221                 cdata = (uint32_t *)(unsigned long)user_chunk.chunk_data;
 222                 if ((p->chunks[i].chunk_id == RADEON_CHUNK_ID_RELOCS) ||
 223                     (p->chunks[i].chunk_id == RADEON_CHUNK_ID_FLAGS)) {
 224                         size = p->chunks[i].length_dw * sizeof(uint32_t);
 225                         p->chunks[i].kdata = kmalloc(size, GFP_KERNEL);
 226                         if (p->chunks[i].kdata == NULL) {
 227                                 return -ENOMEM;
 228                         }
 229                         if (DRM_COPY_FROM_USER(p->chunks[i].kdata,
 230                                                p->chunks[i].user_ptr, size)) {
 231                                 return -EFAULT;
 232                         }
 233                         if (p->chunks[i].chunk_id == RADEON_CHUNK_ID_FLAGS) {
 234                                 p->cs_flags = p->chunks[i].kdata[0];
 235                                 if (p->chunks[i].length_dw > 1)
 236                                         ring = p->chunks[i].kdata[1];
 237                                 if (p->chunks[i].length_dw > 2)
 238                                         priority = (s32)p->chunks[i].kdata[2];
 239                         }
 240                 }
 241         }
 242
 243         if ((p->cs_flags & RADEON_CS_USE_VM) &&
 244             !p->rdev->vm_manager.enabled) {
 245                 DRM_ERROR("VM not active on asic!\n");
 246                 if (p->chunk_relocs_idx != -1)
 247                         kfree(p->chunks[p->chunk_relocs_idx].kdata);
 248                 if (p->chunk_flags_idx != -1)
 249                         kfree(p->chunks[p->chunk_flags_idx].kdata);
 250                 return -EINVAL;
 251         }
 252
 253         if (radeon_cs_get_ring(p, ring, priority)) {
 254                 if (p->chunk_relocs_idx != -1)
 255                         kfree(p->chunks[p->chunk_relocs_idx].kdata);
 256                 if (p->chunk_flags_idx != -1)
 257                         kfree(p->chunks[p->chunk_flags_idx].kdata);
 258                 return -EINVAL;
 259         }
 260
 261
 262         /* deal with non-vm */
 263         if ((p->chunk_ib_idx != -1) &&
 264             ((p->cs_flags & RADEON_CS_USE_VM) == 0) &&
 265             (p->chunks[p->chunk_ib_idx].chunk_id == RADEON_CHUNK_ID_IB)) {
 266                 if (p->chunks[p->chunk_ib_idx].length_dw > (16 * 1024)) {
 267                         DRM_ERROR("cs IB too big: %d\n",
 268                                   p->chunks[p->chunk_ib_idx].length_dw);
 269                         return -EINVAL;
 270                 }
 271                 p->chunks[p->chunk_ib_idx].kpage[0] = kmalloc(PAGE_SIZE, GFP_KERNEL);
 272                 p->chunks[p->chunk_ib_idx].kpage[1] = kmalloc(PAGE_SIZE, GFP_KERNEL);
 273                 if (p->chunks[p->chunk_ib_idx].kpage[0] == NULL ||
 274                     p->chunks[p->chunk_ib_idx].kpage[1] == NULL) {
 275                         kfree(p->chunks[p->chunk_ib_idx].kpage[0]);
 276                         kfree(p->chunks[p->chunk_ib_idx].kpage[1]);
 277                         return -ENOMEM;
 278                 }
 279                 p->chunks[p->chunk_ib_idx].kpage_idx[0] = -1;
 280                 p->chunks[p->chunk_ib_idx].kpage_idx[1] = -1;
 281                 p->chunks[p->chunk_ib_idx].last_copied_page = -1;
 282                 p->chunks[p->chunk_ib_idx].last_page_index =
 283                         ((p->chunks[p->chunk_ib_idx].length_dw * 4) - 1) / PAGE_SIZE;
 284         }
 285
 286         return 0;
 287 }
 288
 289 /**
 290  * cs_parser_fini() - clean parser states
 291  * @parser:     parser structure holding parsing context.
 292  * @error:      error number
 293  *
 294  * If error is set than unvalidate buffer, otherwise just free memory
 295  * used by parsing context.
 296  **/
 297 static void radeon_cs_parser_fini(struct radeon_cs_parser *parser, int error)
 298 {
 299         unsigned i;
 300
 301
 302         if (!error && parser->ib)
 303                 ttm_eu_fence_buffer_objects(&parser->validated,
 304                                             parser->ib->fence);
 305         else
 306                 ttm_eu_backoff_reservation(&parser->validated);
 307
 308         if (parser->relocs != NULL) {
 309                 for (i = 0; i < parser->nrelocs; i++) {
 310                         if (parser->relocs[i].gobj)
 311                                 drm_gem_object_unreference_unlocked(parser->relocs[i].gobj);
 312                 }
 313         }
 314         kfree(parser->track);
 315         kfree(parser->relocs);
 316         kfree(parser->relocs_ptr);
 317         for (i = 0; i < parser->nchunks; i++) {
 318                 kfree(parser->chunks[i].kdata);
 319                 kfree(parser->chunks[i].kpage[0]);
 320                 kfree(parser->chunks[i].kpage[1]);
 321         }
 322         kfree(parser->chunks);
 323         kfree(parser->chunks_array);
 324         radeon_ib_free(parser->rdev, &parser->ib);
 325 }
 326
 327 static int radeon_cs_ib_chunk(struct radeon_device *rdev,
 328                               struct radeon_cs_parser *parser)
 329 {
 330         struct radeon_cs_chunk *ib_chunk;
 331         int r;
 332
 333         if (parser->chunk_ib_idx == -1)
 334                 return 0;
 335
 336         if (parser->cs_flags & RADEON_CS_USE_VM)
 337                 return 0;
 338
 339         ib_chunk = &parser->chunks[parser->chunk_ib_idx];
 340         /* Copy the packet into the IB, the parser will read from the
 341          * input memory (cached) and write to the IB (which can be
 342          * uncached).
 343          */
 344         r =  radeon_ib_get(rdev, parser->ring, &parser->ib,
 345                            ib_chunk->length_dw * 4);
 346         if (r) {
 347                 DRM_ERROR("Failed to get ib !\n");
 348                 return r;
 349         }
 350         parser->ib->length_dw = ib_chunk->length_dw;
 351         r = radeon_cs_parse(rdev, parser->ring, parser);
 352         if (r || parser->parser_error) {
 353                 DRM_ERROR("Invalid command stream !\n");
 354                 return r;
 355         }
 356         r = radeon_cs_finish_pages(parser);
 357         if (r) {
 358                 DRM_ERROR("Invalid command stream !\n");
 359                 return r;
 360         }
 361         r = radeon_cs_sync_rings(parser);
 362         if (r) {
 363                 DRM_ERROR("Failed to synchronize rings !\n");
 364         }
 365         parser->ib->vm_id = 0;
 366         r = radeon_ib_schedule(rdev, parser->ib);
 367         if (r) {
 368                 DRM_ERROR("Failed to schedule IB !\n");
 369         }
 370         return 0;
 371 }
 372
 373 static int radeon_bo_vm_update_pte(struct radeon_cs_parser *parser,
 374                                    struct radeon_vm *vm)
 375 {
 376         struct radeon_bo_list *lobj;
 377         struct radeon_bo *bo;
 378         int r;
 379
 380         list_for_each_entry(lobj, &parser->validated, tv.head) {
 381                 bo = lobj->bo;
 382                 r = radeon_vm_bo_update_pte(parser->rdev, vm, bo, &bo->tbo.mem);
 383                 if (r) {
 384                         return r;
 385                 }
 386         }
 387         return 0;
 388 }
 389
 390 static int radeon_cs_ib_vm_chunk(struct radeon_device *rdev,
 391                                  struct radeon_cs_parser *parser)
 392 {
 393         struct radeon_cs_chunk *ib_chunk;
 394         struct radeon_fpriv *fpriv = parser->filp->driver_priv;
 395         struct radeon_vm *vm = &fpriv->vm;
 396         int r;
 397
 398         if (parser->chunk_ib_idx == -1)
 399                 return 0;
 400
 401         if ((parser->cs_flags & RADEON_CS_USE_VM) == 0)
 402                 return 0;
 403
 404         ib_chunk = &parser->chunks[parser->chunk_ib_idx];
 405         if (ib_chunk->length_dw > RADEON_IB_VM_MAX_SIZE) {
 406                 DRM_ERROR("cs IB too big: %d\n", ib_chunk->length_dw);
 407                 return -EINVAL;
 408         }
 409         r =  radeon_ib_get(rdev, parser->ring, &parser->ib,
 410                            ib_chunk->length_dw * 4);
 411         if (r) {
 412                 DRM_ERROR("Failed to get ib !\n");
 413                 return r;
 414         }
 415         parser->ib->length_dw = ib_chunk->length_dw;
 416         /* Copy the packet into the IB */
 417         if (DRM_COPY_FROM_USER(parser->ib->ptr, ib_chunk->user_ptr,
 418                                ib_chunk->length_dw * 4)) {
 419                 return -EFAULT;
 420         }
 421         r = radeon_ring_ib_parse(rdev, parser->ring, parser->ib);
 422         if (r) {
 423                 return r;
 424         }
 425
 426         mutex_lock(&vm->mutex);
 427         r = radeon_vm_bind(rdev, vm);
 428         if (r) {
 429                 goto out;
 430         }
 431         r = radeon_bo_vm_update_pte(parser, vm);
 432         if (r) {
 433                 goto out;
 434         }
 435         r = radeon_cs_sync_rings(parser);
 436         if (r) {
 437                 DRM_ERROR("Failed to synchronize rings !\n");
 438         }
 439         parser->ib->vm_id = vm->id;
 440         /* ib pool is bind at 0 in virtual address space to gpu_addr is the
 441          * offset inside the pool bo
 442          */
 443         parser->ib->gpu_addr = parser->ib->sa_bo.offset;
 444         r = radeon_ib_schedule(rdev, parser->ib);
 445 out:
 446         if (!r) {
 447                 if (vm->fence) {
 448                         radeon_fence_unref(&vm->fence);
 449                 }
 450                 vm->fence = radeon_fence_ref(parser->ib->fence);
 451         }
 452         mutex_unlock(&fpriv->vm.mutex);
 453         return r;
 454 }
 455
 456 int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 457 {
 458         struct radeon_device *rdev = dev->dev_private;
 459         struct radeon_cs_parser parser;
 460         int r;
 461
 462         radeon_mutex_lock(&rdev->cs_mutex);
 463         if (!rdev->accel_working) {
 464                 radeon_mutex_unlock(&rdev->cs_mutex);
 465                 return -EBUSY;
 466         }
 467         /* initialize parser */
 468         memset(&parser, 0, sizeof(struct radeon_cs_parser));
 469         parser.filp = filp;
 470         parser.rdev = rdev;
 471         parser.dev = rdev->dev;
 472         parser.family = rdev->family;
 473         r = radeon_cs_parser_init(&parser, data);
 474         if (r) {
 475                 DRM_ERROR("Failed to initialize parser !\n");
 476                 radeon_cs_parser_fini(&parser, r);
 477                 radeon_mutex_unlock(&rdev->cs_mutex);
 478                 return r;
 479         }
 480         r = radeon_cs_parser_relocs(&parser);
 481         if (r) {
 482                 if (r != -ERESTARTSYS)
 483                         DRM_ERROR("Failed to parse relocation %d!\n", r);
 484                 radeon_cs_parser_fini(&parser, r);
 485                 radeon_mutex_unlock(&rdev->cs_mutex);
 486                 return r;
 487         }
 488         r = radeon_cs_ib_chunk(rdev, &parser);
 489         if (r) {
 490                 goto out;
 491         }
 492         r = radeon_cs_ib_vm_chunk(rdev, &parser);
 493         if (r) {
 494                 goto out;
 495         }
 496 out:
 497         radeon_cs_parser_fini(&parser, r);
 498         radeon_mutex_unlock(&rdev->cs_mutex);
 499         return r;
 500 }
 501
 502 int radeon_cs_finish_pages(struct radeon_cs_parser *p)
 503 {
 504         struct radeon_cs_chunk *ibc = &p->chunks[p->chunk_ib_idx];
 505         int i;
 506         int size = PAGE_SIZE;
 507
 508         for (i = ibc->last_copied_page + 1; i <= ibc->last_page_index; i++) {
 509                 if (i == ibc->last_page_index) {
 510                         size = (ibc->length_dw * 4) % PAGE_SIZE;
 511                         if (size == 0)
 512                                 size = PAGE_SIZE;
 513                 }
 514
 515                 if (DRM_COPY_FROM_USER(p->ib->ptr + (i * (PAGE_SIZE/4)),
 516                                        ibc->user_ptr + (i * PAGE_SIZE),
 517                                        size))
 518                         return -EFAULT;
 519         }
 520         return 0;
 521 }
 522
 523 int radeon_cs_update_pages(struct radeon_cs_parser *p, int pg_idx)
 524 {
 525         int new_page;
 526         struct radeon_cs_chunk *ibc = &p->chunks[p->chunk_ib_idx];
 527         int i;
 528         int size = PAGE_SIZE;
 529
 530         for (i = ibc->last_copied_page + 1; i < pg_idx; i++) {
 531                 if (DRM_COPY_FROM_USER(p->ib->ptr + (i * (PAGE_SIZE/4)),
 532                                        ibc->user_ptr + (i * PAGE_SIZE),
 533                                        PAGE_SIZE)) {
 534                         p->parser_error = -EFAULT;
 535                         return 0;
 536                 }
 537         }
 538
 539         new_page = ibc->kpage_idx[0] < ibc->kpage_idx[1] ? 0 : 1;
 540
 541         if (pg_idx == ibc->last_page_index) {
 542                 size = (ibc->length_dw * 4) % PAGE_SIZE;
 543                         if (size == 0)
 544                                 size = PAGE_SIZE;
 545         }
 546
 547         if (DRM_COPY_FROM_USER(ibc->kpage[new_page],
 548                                ibc->user_ptr + (pg_idx * PAGE_SIZE),
 549                                size)) {
 550                 p->parser_error = -EFAULT;
 551                 return 0;
 552         }
 553
 554         /* copy to IB here */
 555         memcpy((void *)(p->ib->ptr+(pg_idx*(PAGE_SIZE/4))), ibc->kpage[new_page], size);
 556
 557         ibc->last_copied_page = pg_idx;
 558         ibc->kpage_idx[new_page] = pg_idx;
 559
 560         return new_page;
 561 }