drivers/gpu/drm/msm/msm_gem.c

   1 /*
   2  * Copyright (C) 2013 Red Hat
   3  * Author: Rob Clark <robdclark@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/spinlock.h>
  19 #include <linux/shmem_fs.h>
  20 #include <linux/dma-buf.h>
  21
  22 #include "msm_drv.h"
  23 #include "msm_gem.h"
  24 #include "msm_gpu.h"
  25 #include "msm_mmu.h"
  26
  27 static dma_addr_t physaddr(struct drm_gem_object *obj)
  28 {
  29         struct msm_gem_object *msm_obj = to_msm_bo(obj);
  30         struct msm_drm_private *priv = obj->dev->dev_private;
  31         return (((dma_addr_t)msm_obj->vram_node->start) << PAGE_SHIFT) +
  32                         priv->vram.paddr;
  33 }
  34
  35 /* allocate pages from VRAM carveout, used when no IOMMU: */
  36 static struct page **get_pages_vram(struct drm_gem_object *obj,
  37                 int npages)
  38 {
  39         struct msm_gem_object *msm_obj = to_msm_bo(obj);
  40         struct msm_drm_private *priv = obj->dev->dev_private;
  41         dma_addr_t paddr;
  42         struct page **p;
  43         int ret, i;
  44
  45         p = drm_malloc_ab(npages, sizeof(struct page *));
  46         if (!p)
  47                 return ERR_PTR(-ENOMEM);
  48
  49         ret = drm_mm_insert_node(&priv->vram.mm, msm_obj->vram_node,
  50                         npages, 0, DRM_MM_SEARCH_DEFAULT);
  51         if (ret) {
  52                 drm_free_large(p);
  53                 return ERR_PTR(ret);
  54         }
  55
  56         paddr = physaddr(obj);
  57         for (i = 0; i < npages; i++) {
  58                 p[i] = phys_to_page(paddr);
  59                 paddr += PAGE_SIZE;
  60         }
  61
  62         return p;
  63 }
  64
  65 /* called with dev->struct_mutex held */
  66 static struct page **get_pages(struct drm_gem_object *obj)
  67 {
  68         struct msm_gem_object *msm_obj = to_msm_bo(obj);
  69
  70         if (!msm_obj->pages) {
  71                 struct drm_device *dev = obj->dev;
  72                 struct page **p;
  73                 int npages = obj->size >> PAGE_SHIFT;
  74
  75                 if (iommu_present(&platform_bus_type))
  76                         p = drm_gem_get_pages(obj, 0);
  77                 else
  78                         p = get_pages_vram(obj, npages);
  79
  80                 if (IS_ERR(p)) {
  81                         dev_err(dev->dev, "could not get pages: %ld\n",
  82                                         PTR_ERR(p));
  83                         return p;
  84                 }
  85
  86                 msm_obj->sgt = drm_prime_pages_to_sg(p, npages);
  87                 if (IS_ERR(msm_obj->sgt)) {
  88                         dev_err(dev->dev, "failed to allocate sgt\n");
  89                         return ERR_CAST(msm_obj->sgt);
  90                 }
  91
  92                 msm_obj->pages = p;
  93
  94                 /* For non-cached buffers, ensure the new pages are clean
  95                  * because display controller, GPU, etc. are not coherent:
  96                  */
  97                 if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
  98                         dma_map_sg(dev->dev, msm_obj->sgt->sgl,
  99                                         msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
 100         }
 101
 102         return msm_obj->pages;
 103 }
 104
 105 static void put_pages(struct drm_gem_object *obj)
 106 {
 107         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 108
 109         if (msm_obj->pages) {
 110                 /* For non-cached buffers, ensure the new pages are clean
 111                  * because display controller, GPU, etc. are not coherent:
 112                  */
 113                 if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
 114                         dma_unmap_sg(obj->dev->dev, msm_obj->sgt->sgl,
 115                                         msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
 116                 sg_free_table(msm_obj->sgt);
 117                 kfree(msm_obj->sgt);
 118
 119                 if (iommu_present(&platform_bus_type))
 120                         drm_gem_put_pages(obj, msm_obj->pages, true, false);
 121                 else
 122                         drm_mm_remove_node(msm_obj->vram_node);
 123
 124                 msm_obj->pages = NULL;
 125         }
 126 }
 127
 128 struct page **msm_gem_get_pages(struct drm_gem_object *obj)
 129 {
 130         struct drm_device *dev = obj->dev;
 131         struct page **p;
 132         mutex_lock(&dev->struct_mutex);
 133         p = get_pages(obj);
 134         mutex_unlock(&dev->struct_mutex);
 135         return p;
 136 }
 137
 138 void msm_gem_put_pages(struct drm_gem_object *obj)
 139 {
 140         /* when we start tracking the pin count, then do something here */
 141 }
 142
 143 int msm_gem_mmap_obj(struct drm_gem_object *obj,
 144                 struct vm_area_struct *vma)
 145 {
 146         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 147
 148         vma->vm_flags &= ~VM_PFNMAP;
 149         vma->vm_flags |= VM_MIXEDMAP;
 150
 151         if (msm_obj->flags & MSM_BO_WC) {
 152                 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 153         } else if (msm_obj->flags & MSM_BO_UNCACHED) {
 154                 vma->vm_page_prot = pgprot_noncached(vm_get_page_prot(vma->vm_flags));
 155         } else {
 156                 /*
 157                  * Shunt off cached objs to shmem file so they have their own
 158                  * address_space (so unmap_mapping_range does what we want,
 159                  * in particular in the case of mmap'd dmabufs)
 160                  */
 161                 fput(vma->vm_file);
 162                 get_file(obj->filp);
 163                 vma->vm_pgoff = 0;
 164                 vma->vm_file  = obj->filp;
 165
 166                 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 167         }
 168
 169         return 0;
 170 }
 171
 172 int msm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 173 {
 174         int ret;
 175
 176         ret = drm_gem_mmap(filp, vma);
 177         if (ret) {
 178                 DBG("mmap failed: %d", ret);
 179                 return ret;
 180         }
 181
 182         return msm_gem_mmap_obj(vma->vm_private_data, vma);
 183 }
 184
 185 int msm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 186 {
 187         struct drm_gem_object *obj = vma->vm_private_data;
 188         struct drm_device *dev = obj->dev;
 189         struct page **pages;
 190         unsigned long pfn;
 191         pgoff_t pgoff;
 192         int ret;
 193
 194         /* Make sure we don't parallel update on a fault, nor move or remove
 195          * something from beneath our feet
 196          */
 197         ret = mutex_lock_interruptible(&dev->struct_mutex);
 198         if (ret)
 199                 goto out;
 200
 201         /* make sure we have pages attached now */
 202         pages = get_pages(obj);
 203         if (IS_ERR(pages)) {
 204                 ret = PTR_ERR(pages);
 205                 goto out_unlock;
 206         }
 207
 208         /* We don't use vmf->pgoff since that has the fake offset: */
 209         pgoff = ((unsigned long)vmf->virtual_address -
 210                         vma->vm_start) >> PAGE_SHIFT;
 211
 212         pfn = page_to_pfn(pages[pgoff]);
 213
 214         VERB("Inserting %p pfn %lx, pa %lx", vmf->virtual_address,
 215                         pfn, pfn << PAGE_SHIFT);
 216
 217         ret = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address, pfn);
 218
 219 out_unlock:
 220         mutex_unlock(&dev->struct_mutex);
 221 out:
 222         switch (ret) {
 223         case -EAGAIN:
 224         case 0:
 225         case -ERESTARTSYS:
 226         case -EINTR:
 227         case -EBUSY:
 228                 /*
 229                  * EBUSY is ok: this just means that another thread
 230                  * already did the job.
 231                  */
 232                 return VM_FAULT_NOPAGE;
 233         case -ENOMEM:
 234                 return VM_FAULT_OOM;
 235         default:
 236                 return VM_FAULT_SIGBUS;
 237         }
 238 }
 239
 240 /** get mmap offset */
 241 static uint64_t mmap_offset(struct drm_gem_object *obj)
 242 {
 243         struct drm_device *dev = obj->dev;
 244         int ret;
 245
 246         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 247
 248         /* Make it mmapable */
 249         ret = drm_gem_create_mmap_offset(obj);
 250
 251         if (ret) {
 252                 dev_err(dev->dev, "could not allocate mmap offset\n");
 253                 return 0;
 254         }
 255
 256         return drm_vma_node_offset_addr(&obj->vma_node);
 257 }
 258
 259 uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj)
 260 {
 261         uint64_t offset;
 262         mutex_lock(&obj->dev->struct_mutex);
 263         offset = mmap_offset(obj);
 264         mutex_unlock(&obj->dev->struct_mutex);
 265         return offset;
 266 }
 267
 268 /* should be called under struct_mutex.. although it can be called
 269  * from atomic context without struct_mutex to acquire an extra
 270  * iova ref if you know one is already held.
 271  *
 272  * That means when I do eventually need to add support for unpinning
 273  * the refcnt counter needs to be atomic_t.
 274  */
 275 int msm_gem_get_iova_locked(struct drm_gem_object *obj, int id,
 276                 uint32_t *iova)
 277 {
 278         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 279         int ret = 0;
 280
 281         if (!msm_obj->domain[id].iova) {
 282                 struct msm_drm_private *priv = obj->dev->dev_private;
 283                 struct msm_mmu *mmu = priv->mmus[id];
 284                 struct page **pages = get_pages(obj);
 285
 286                 if (IS_ERR(pages))
 287                         return PTR_ERR(pages);
 288
 289                 if (iommu_present(&platform_bus_type)) {
 290                         uint32_t offset = (uint32_t)mmap_offset(obj);
 291                         ret = mmu->funcs->map(mmu, offset, msm_obj->sgt,
 292                                         obj->size, IOMMU_READ | IOMMU_WRITE);
 293                         msm_obj->domain[id].iova = offset;
 294                 } else {
 295                         msm_obj->domain[id].iova = physaddr(obj);
 296                 }
 297         }
 298
 299         if (!ret)
 300                 *iova = msm_obj->domain[id].iova;
 301
 302         return ret;
 303 }
 304
 305 int msm_gem_get_iova(struct drm_gem_object *obj, int id, uint32_t *iova)
 306 {
 307         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 308         int ret;
 309
 310         /* this is safe right now because we don't unmap until the
 311          * bo is deleted:
 312          */
 313         if (msm_obj->domain[id].iova) {
 314                 *iova = msm_obj->domain[id].iova;
 315                 return 0;
 316         }
 317
 318         mutex_lock(&obj->dev->struct_mutex);
 319         ret = msm_gem_get_iova_locked(obj, id, iova);
 320         mutex_unlock(&obj->dev->struct_mutex);
 321         return ret;
 322 }
 323
 324 void msm_gem_put_iova(struct drm_gem_object *obj, int id)
 325 {
 326         // XXX TODO ..
 327         // NOTE: probably don't need a _locked() version.. we wouldn't
 328         // normally unmap here, but instead just mark that it could be
 329         // unmapped (if the iova refcnt drops to zero), but then later
 330         // if another _get_iova_locked() fails we can start unmapping
 331         // things that are no longer needed..
 332 }
 333
 334 int msm_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 335                 struct drm_mode_create_dumb *args)
 336 {
 337         args->pitch = align_pitch(args->width, args->bpp);
 338         args->size  = PAGE_ALIGN(args->pitch * args->height);
 339         return msm_gem_new_handle(dev, file, args->size,
 340                         MSM_BO_SCANOUT | MSM_BO_WC, &args->handle);
 341 }
 342
 343 int msm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
 344                 uint32_t handle, uint64_t *offset)
 345 {
 346         struct drm_gem_object *obj;
 347         int ret = 0;
 348
 349         /* GEM does all our handle to object mapping */
 350         obj = drm_gem_object_lookup(dev, file, handle);
 351         if (obj == NULL) {
 352                 ret = -ENOENT;
 353                 goto fail;
 354         }
 355
 356         *offset = msm_gem_mmap_offset(obj);
 357
 358         drm_gem_object_unreference_unlocked(obj);
 359
 360 fail:
 361         return ret;
 362 }
 363
 364 void *msm_gem_vaddr_locked(struct drm_gem_object *obj)
 365 {
 366         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 367         WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
 368         if (!msm_obj->vaddr) {
 369                 struct page **pages = get_pages(obj);
 370                 if (IS_ERR(pages))
 371                         return ERR_CAST(pages);
 372                 msm_obj->vaddr = vmap(pages, obj->size >> PAGE_SHIFT,
 373                                 VM_MAP, pgprot_writecombine(PAGE_KERNEL));
 374         }
 375         return msm_obj->vaddr;
 376 }
 377
 378 void *msm_gem_vaddr(struct drm_gem_object *obj)
 379 {
 380         void *ret;
 381         mutex_lock(&obj->dev->struct_mutex);
 382         ret = msm_gem_vaddr_locked(obj);
 383         mutex_unlock(&obj->dev->struct_mutex);
 384         return ret;
 385 }
 386
 387 /* setup callback for when bo is no longer busy..
 388  * TODO probably want to differentiate read vs write..
 389  */
 390 int msm_gem_queue_inactive_cb(struct drm_gem_object *obj,
 391                 struct msm_fence_cb *cb)
 392 {
 393         struct drm_device *dev = obj->dev;
 394         struct msm_drm_private *priv = dev->dev_private;
 395         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 396         int ret = 0;
 397
 398         mutex_lock(&dev->struct_mutex);
 399         if (!list_empty(&cb->work.entry)) {
 400                 ret = -EINVAL;
 401         } else if (is_active(msm_obj)) {
 402                 cb->fence = max(msm_obj->read_fence, msm_obj->write_fence);
 403                 list_add_tail(&cb->work.entry, &priv->fence_cbs);
 404         } else {
 405                 queue_work(priv->wq, &cb->work);
 406         }
 407         mutex_unlock(&dev->struct_mutex);
 408
 409         return ret;
 410 }
 411
 412 void msm_gem_move_to_active(struct drm_gem_object *obj,
 413                 struct msm_gpu *gpu, bool write, uint32_t fence)
 414 {
 415         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 416         msm_obj->gpu = gpu;
 417         if (write)
 418                 msm_obj->write_fence = fence;
 419         else
 420                 msm_obj->read_fence = fence;
 421         list_del_init(&msm_obj->mm_list);
 422         list_add_tail(&msm_obj->mm_list, &gpu->active_list);
 423 }
 424
 425 void msm_gem_move_to_inactive(struct drm_gem_object *obj)
 426 {
 427         struct drm_device *dev = obj->dev;
 428         struct msm_drm_private *priv = dev->dev_private;
 429         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 430
 431         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 432
 433         msm_obj->gpu = NULL;
 434         msm_obj->read_fence = 0;
 435         msm_obj->write_fence = 0;
 436         list_del_init(&msm_obj->mm_list);
 437         list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
 438 }
 439
 440 int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op,
 441                 struct timespec *timeout)
 442 {
 443         struct drm_device *dev = obj->dev;
 444         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 445         int ret = 0;
 446
 447         if (is_active(msm_obj)) {
 448                 uint32_t fence = 0;
 449
 450                 if (op & MSM_PREP_READ)
 451                         fence = msm_obj->write_fence;
 452                 if (op & MSM_PREP_WRITE)
 453                         fence = max(fence, msm_obj->read_fence);
 454                 if (op & MSM_PREP_NOSYNC)
 455                         timeout = NULL;
 456
 457                 ret = msm_wait_fence_interruptable(dev, fence, timeout);
 458         }
 459
 460         /* TODO cache maintenance */
 461
 462         return ret;
 463 }
 464
 465 int msm_gem_cpu_fini(struct drm_gem_object *obj)
 466 {
 467         /* TODO cache maintenance */
 468         return 0;
 469 }
 470
 471 #ifdef CONFIG_DEBUG_FS
 472 void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 473 {
 474         struct drm_device *dev = obj->dev;
 475         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 476         uint64_t off = drm_vma_node_start(&obj->vma_node);
 477
 478         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 479         seq_printf(m, "%08x: %c(r=%u,w=%u) %2d (%2d) %08llx %p %d\n",
 480                         msm_obj->flags, is_active(msm_obj) ? 'A' : 'I',
 481                         msm_obj->read_fence, msm_obj->write_fence,
 482                         obj->name, obj->refcount.refcount.counter,
 483                         off, msm_obj->vaddr, obj->size);
 484 }
 485
 486 void msm_gem_describe_objects(struct list_head *list, struct seq_file *m)
 487 {
 488         struct msm_gem_object *msm_obj;
 489         int count = 0;
 490         size_t size = 0;
 491
 492         list_for_each_entry(msm_obj, list, mm_list) {
 493                 struct drm_gem_object *obj = &msm_obj->base;
 494                 seq_printf(m, "   ");
 495                 msm_gem_describe(obj, m);
 496                 count++;
 497                 size += obj->size;
 498         }
 499
 500         seq_printf(m, "Total %d objects, %zu bytes\n", count, size);
 501 }
 502 #endif
 503
 504 void msm_gem_free_object(struct drm_gem_object *obj)
 505 {
 506         struct drm_device *dev = obj->dev;
 507         struct msm_drm_private *priv = obj->dev->dev_private;
 508         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 509         int id;
 510
 511         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 512
 513         /* object should not be on active list: */
 514         WARN_ON(is_active(msm_obj));
 515
 516         list_del(&msm_obj->mm_list);
 517
 518         for (id = 0; id < ARRAY_SIZE(msm_obj->domain); id++) {
 519                 struct msm_mmu *mmu = priv->mmus[id];
 520                 if (mmu && msm_obj->domain[id].iova) {
 521                         uint32_t offset = (uint32_t)mmap_offset(obj);
 522                         mmu->funcs->unmap(mmu, offset, msm_obj->sgt, obj->size);
 523                 }
 524         }
 525
 526         drm_gem_free_mmap_offset(obj);
 527
 528         if (obj->import_attach) {
 529                 if (msm_obj->vaddr)
 530                         dma_buf_vunmap(obj->import_attach->dmabuf, msm_obj->vaddr);
 531
 532                 /* Don't drop the pages for imported dmabuf, as they are not
 533                  * ours, just free the array we allocated:
 534                  */
 535                 if (msm_obj->pages)
 536                         drm_free_large(msm_obj->pages);
 537
 538         } else {
 539                 if (msm_obj->vaddr)
 540                         vunmap(msm_obj->vaddr);
 541                 put_pages(obj);
 542         }
 543
 544         if (msm_obj->resv == &msm_obj->_resv)
 545                 reservation_object_fini(msm_obj->resv);
 546
 547         drm_gem_object_release(obj);
 548
 549         kfree(msm_obj);
 550 }
 551
 552 /* convenience method to construct a GEM buffer object, and userspace handle */
 553 int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
 554                 uint32_t size, uint32_t flags, uint32_t *handle)
 555 {
 556         struct drm_gem_object *obj;
 557         int ret;
 558
 559         ret = mutex_lock_interruptible(&dev->struct_mutex);
 560         if (ret)
 561                 return ret;
 562
 563         obj = msm_gem_new(dev, size, flags);
 564
 565         mutex_unlock(&dev->struct_mutex);
 566
 567         if (IS_ERR(obj))
 568                 return PTR_ERR(obj);
 569
 570         ret = drm_gem_handle_create(file, obj, handle);
 571
 572         /* drop reference from allocate - handle holds it now */
 573         drm_gem_object_unreference_unlocked(obj);
 574
 575         return ret;
 576 }
 577
 578 static int msm_gem_new_impl(struct drm_device *dev,
 579                 uint32_t size, uint32_t flags,
 580                 struct drm_gem_object **obj)
 581 {
 582         struct msm_drm_private *priv = dev->dev_private;
 583         struct msm_gem_object *msm_obj;
 584         unsigned sz;
 585
 586         switch (flags & MSM_BO_CACHE_MASK) {
 587         case MSM_BO_UNCACHED:
 588         case MSM_BO_CACHED:
 589         case MSM_BO_WC:
 590                 break;
 591         default:
 592                 dev_err(dev->dev, "invalid cache flag: %x\n",
 593                                 (flags & MSM_BO_CACHE_MASK));
 594                 return -EINVAL;
 595         }
 596
 597         sz = sizeof(*msm_obj);
 598         if (!iommu_present(&platform_bus_type))
 599                 sz += sizeof(struct drm_mm_node);
 600
 601         msm_obj = kzalloc(sz, GFP_KERNEL);
 602         if (!msm_obj)
 603                 return -ENOMEM;
 604
 605         if (!iommu_present(&platform_bus_type))
 606                 msm_obj->vram_node = (void *)&msm_obj[1];
 607
 608         msm_obj->flags = flags;
 609
 610         msm_obj->resv = &msm_obj->_resv;
 611         reservation_object_init(msm_obj->resv);
 612
 613         INIT_LIST_HEAD(&msm_obj->submit_entry);
 614         list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
 615
 616         *obj = &msm_obj->base;
 617
 618         return 0;
 619 }
 620
 621 struct drm_gem_object *msm_gem_new(struct drm_device *dev,
 622                 uint32_t size, uint32_t flags)
 623 {
 624         struct drm_gem_object *obj = NULL;
 625         int ret;
 626
 627         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 628
 629         size = PAGE_ALIGN(size);
 630
 631         ret = msm_gem_new_impl(dev, size, flags, &obj);
 632         if (ret)
 633                 goto fail;
 634
 635         if (iommu_present(&platform_bus_type)) {
 636                 ret = drm_gem_object_init(dev, obj, size);
 637                 if (ret)
 638                         goto fail;
 639         } else {
 640                 drm_gem_private_object_init(dev, obj, size);
 641         }
 642
 643         return obj;
 644
 645 fail:
 646         if (obj)
 647                 drm_gem_object_unreference(obj);
 648
 649         return ERR_PTR(ret);
 650 }
 651
 652 struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 653                 uint32_t size, struct sg_table *sgt)
 654 {
 655         struct msm_gem_object *msm_obj;
 656         struct drm_gem_object *obj;
 657         int ret, npages;
 658
 659         /* if we don't have IOMMU, don't bother pretending we can import: */
 660         if (!iommu_present(&platform_bus_type)) {
 661                 dev_err(dev->dev, "cannot import without IOMMU\n");
 662                 return ERR_PTR(-EINVAL);
 663         }
 664
 665         size = PAGE_ALIGN(size);
 666
 667         ret = msm_gem_new_impl(dev, size, MSM_BO_WC, &obj);
 668         if (ret)
 669                 goto fail;
 670
 671         drm_gem_private_object_init(dev, obj, size);
 672
 673         npages = size / PAGE_SIZE;
 674
 675         msm_obj = to_msm_bo(obj);
 676         msm_obj->sgt = sgt;
 677         msm_obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
 678         if (!msm_obj->pages) {
 679                 ret = -ENOMEM;
 680                 goto fail;
 681         }
 682
 683         ret = drm_prime_sg_to_page_addr_arrays(sgt, msm_obj->pages, NULL, npages);
 684         if (ret)
 685                 goto fail;
 686
 687         return obj;
 688
 689 fail:
 690         if (obj)
 691                 drm_gem_object_unreference_unlocked(obj);
 692
 693         return ERR_PTR(ret);
 694 }