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                         drm_free_large(msm_obj->pages);
 124                 }
 125
 126                 msm_obj->pages = NULL;
 127         }
 128 }
 129
 130 struct page **msm_gem_get_pages(struct drm_gem_object *obj)
 131 {
 132         struct drm_device *dev = obj->dev;
 133         struct page **p;
 134         mutex_lock(&dev->struct_mutex);
 135         p = get_pages(obj);
 136         mutex_unlock(&dev->struct_mutex);
 137         return p;
 138 }
 139
 140 void msm_gem_put_pages(struct drm_gem_object *obj)
 141 {
 142         /* when we start tracking the pin count, then do something here */
 143 }
 144
 145 int msm_gem_mmap_obj(struct drm_gem_object *obj,
 146                 struct vm_area_struct *vma)
 147 {
 148         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 149
 150         vma->vm_flags &= ~VM_PFNMAP;
 151         vma->vm_flags |= VM_MIXEDMAP;
 152
 153         if (msm_obj->flags & MSM_BO_WC) {
 154                 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 155         } else if (msm_obj->flags & MSM_BO_UNCACHED) {
 156                 vma->vm_page_prot = pgprot_noncached(vm_get_page_prot(vma->vm_flags));
 157         } else {
 158                 /*
 159                  * Shunt off cached objs to shmem file so they have their own
 160                  * address_space (so unmap_mapping_range does what we want,
 161                  * in particular in the case of mmap'd dmabufs)
 162                  */
 163                 fput(vma->vm_file);
 164                 get_file(obj->filp);
 165                 vma->vm_pgoff = 0;
 166                 vma->vm_file  = obj->filp;
 167
 168                 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 169         }
 170
 171         return 0;
 172 }
 173
 174 int msm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 175 {
 176         int ret;
 177
 178         ret = drm_gem_mmap(filp, vma);
 179         if (ret) {
 180                 DBG("mmap failed: %d", ret);
 181                 return ret;
 182         }
 183
 184         return msm_gem_mmap_obj(vma->vm_private_data, vma);
 185 }
 186
 187 int msm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 188 {
 189         struct drm_gem_object *obj = vma->vm_private_data;
 190         struct drm_device *dev = obj->dev;
 191         struct page **pages;
 192         unsigned long pfn;
 193         pgoff_t pgoff;
 194         int ret;
 195
 196         /* Make sure we don't parallel update on a fault, nor move or remove
 197          * something from beneath our feet
 198          */
 199         ret = mutex_lock_interruptible(&dev->struct_mutex);
 200         if (ret)
 201                 goto out;
 202
 203         /* make sure we have pages attached now */
 204         pages = get_pages(obj);
 205         if (IS_ERR(pages)) {
 206                 ret = PTR_ERR(pages);
 207                 goto out_unlock;
 208         }
 209
 210         /* We don't use vmf->pgoff since that has the fake offset: */
 211         pgoff = ((unsigned long)vmf->virtual_address -
 212                         vma->vm_start) >> PAGE_SHIFT;
 213
 214         pfn = page_to_pfn(pages[pgoff]);
 215
 216         VERB("Inserting %p pfn %lx, pa %lx", vmf->virtual_address,
 217                         pfn, pfn << PAGE_SHIFT);
 218
 219         ret = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address, pfn);
 220
 221 out_unlock:
 222         mutex_unlock(&dev->struct_mutex);
 223 out:
 224         switch (ret) {
 225         case -EAGAIN:
 226         case 0:
 227         case -ERESTARTSYS:
 228         case -EINTR:
 229         case -EBUSY:
 230                 /*
 231                  * EBUSY is ok: this just means that another thread
 232                  * already did the job.
 233                  */
 234                 return VM_FAULT_NOPAGE;
 235         case -ENOMEM:
 236                 return VM_FAULT_OOM;
 237         default:
 238                 return VM_FAULT_SIGBUS;
 239         }
 240 }
 241
 242 /** get mmap offset */
 243 static uint64_t mmap_offset(struct drm_gem_object *obj)
 244 {
 245         struct drm_device *dev = obj->dev;
 246         int ret;
 247
 248         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 249
 250         /* Make it mmapable */
 251         ret = drm_gem_create_mmap_offset(obj);
 252
 253         if (ret) {
 254                 dev_err(dev->dev, "could not allocate mmap offset\n");
 255                 return 0;
 256         }
 257
 258         return drm_vma_node_offset_addr(&obj->vma_node);
 259 }
 260
 261 uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj)
 262 {
 263         uint64_t offset;
 264         mutex_lock(&obj->dev->struct_mutex);
 265         offset = mmap_offset(obj);
 266         mutex_unlock(&obj->dev->struct_mutex);
 267         return offset;
 268 }
 269
 270 /* should be called under struct_mutex.. although it can be called
 271  * from atomic context without struct_mutex to acquire an extra
 272  * iova ref if you know one is already held.
 273  *
 274  * That means when I do eventually need to add support for unpinning
 275  * the refcnt counter needs to be atomic_t.
 276  */
 277 int msm_gem_get_iova_locked(struct drm_gem_object *obj, int id,
 278                 uint32_t *iova)
 279 {
 280         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 281         struct drm_device *dev = obj->dev;
 282         int ret = 0;
 283
 284         if (!msm_obj->domain[id].iova) {
 285                 struct msm_drm_private *priv = obj->dev->dev_private;
 286                 struct msm_mmu *mmu = priv->mmus[id];
 287                 struct page **pages = get_pages(obj);
 288
 289                 if (!mmu) {
 290                         dev_err(dev->dev, "null MMU pointer\n");
 291                         return -EINVAL;
 292                 }
 293
 294                 if (IS_ERR(pages))
 295                         return PTR_ERR(pages);
 296
 297                 if (iommu_present(&platform_bus_type)) {
 298                         uint32_t offset = (uint32_t)mmap_offset(obj);
 299                         ret = mmu->funcs->map(mmu, offset, msm_obj->sgt,
 300                                         obj->size, IOMMU_READ | IOMMU_WRITE);
 301                         msm_obj->domain[id].iova = offset;
 302                 } else {
 303                         msm_obj->domain[id].iova = physaddr(obj);
 304                 }
 305         }
 306
 307         if (!ret)
 308                 *iova = msm_obj->domain[id].iova;
 309
 310         return ret;
 311 }
 312
 313 int msm_gem_get_iova(struct drm_gem_object *obj, int id, uint32_t *iova)
 314 {
 315         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 316         int ret;
 317
 318         /* this is safe right now because we don't unmap until the
 319          * bo is deleted:
 320          */
 321         if (msm_obj->domain[id].iova) {
 322                 *iova = msm_obj->domain[id].iova;
 323                 return 0;
 324         }
 325
 326         mutex_lock(&obj->dev->struct_mutex);
 327         ret = msm_gem_get_iova_locked(obj, id, iova);
 328         mutex_unlock(&obj->dev->struct_mutex);
 329         return ret;
 330 }
 331
 332 void msm_gem_put_iova(struct drm_gem_object *obj, int id)
 333 {
 334         // XXX TODO ..
 335         // NOTE: probably don't need a _locked() version.. we wouldn't
 336         // normally unmap here, but instead just mark that it could be
 337         // unmapped (if the iova refcnt drops to zero), but then later
 338         // if another _get_iova_locked() fails we can start unmapping
 339         // things that are no longer needed..
 340 }
 341
 342 int msm_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 343                 struct drm_mode_create_dumb *args)
 344 {
 345         args->pitch = align_pitch(args->width, args->bpp);
 346         args->size  = PAGE_ALIGN(args->pitch * args->height);
 347         return msm_gem_new_handle(dev, file, args->size,
 348                         MSM_BO_SCANOUT | MSM_BO_WC, &args->handle);
 349 }
 350
 351 int msm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
 352                 uint32_t handle, uint64_t *offset)
 353 {
 354         struct drm_gem_object *obj;
 355         int ret = 0;
 356
 357         /* GEM does all our handle to object mapping */
 358         obj = drm_gem_object_lookup(dev, file, handle);
 359         if (obj == NULL) {
 360                 ret = -ENOENT;
 361                 goto fail;
 362         }
 363
 364         *offset = msm_gem_mmap_offset(obj);
 365
 366         drm_gem_object_unreference_unlocked(obj);
 367
 368 fail:
 369         return ret;
 370 }
 371
 372 void *msm_gem_vaddr_locked(struct drm_gem_object *obj)
 373 {
 374         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 375         WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
 376         if (!msm_obj->vaddr) {
 377                 struct page **pages = get_pages(obj);
 378                 if (IS_ERR(pages))
 379                         return ERR_CAST(pages);
 380                 msm_obj->vaddr = vmap(pages, obj->size >> PAGE_SHIFT,
 381                                 VM_MAP, pgprot_writecombine(PAGE_KERNEL));
 382         }
 383         return msm_obj->vaddr;
 384 }
 385
 386 void *msm_gem_vaddr(struct drm_gem_object *obj)
 387 {
 388         void *ret;
 389         mutex_lock(&obj->dev->struct_mutex);
 390         ret = msm_gem_vaddr_locked(obj);
 391         mutex_unlock(&obj->dev->struct_mutex);
 392         return ret;
 393 }
 394
 395 /* setup callback for when bo is no longer busy..
 396  * TODO probably want to differentiate read vs write..
 397  */
 398 int msm_gem_queue_inactive_cb(struct drm_gem_object *obj,
 399                 struct msm_fence_cb *cb)
 400 {
 401         struct drm_device *dev = obj->dev;
 402         struct msm_drm_private *priv = dev->dev_private;
 403         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 404         int ret = 0;
 405
 406         mutex_lock(&dev->struct_mutex);
 407         if (!list_empty(&cb->work.entry)) {
 408                 ret = -EINVAL;
 409         } else if (is_active(msm_obj)) {
 410                 cb->fence = max(msm_obj->read_fence, msm_obj->write_fence);
 411                 list_add_tail(&cb->work.entry, &priv->fence_cbs);
 412         } else {
 413                 queue_work(priv->wq, &cb->work);
 414         }
 415         mutex_unlock(&dev->struct_mutex);
 416
 417         return ret;
 418 }
 419
 420 void msm_gem_move_to_active(struct drm_gem_object *obj,
 421                 struct msm_gpu *gpu, bool write, uint32_t fence)
 422 {
 423         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 424         msm_obj->gpu = gpu;
 425         if (write)
 426                 msm_obj->write_fence = fence;
 427         else
 428                 msm_obj->read_fence = fence;
 429         list_del_init(&msm_obj->mm_list);
 430         list_add_tail(&msm_obj->mm_list, &gpu->active_list);
 431 }
 432
 433 void msm_gem_move_to_inactive(struct drm_gem_object *obj)
 434 {
 435         struct drm_device *dev = obj->dev;
 436         struct msm_drm_private *priv = dev->dev_private;
 437         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 438
 439         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 440
 441         msm_obj->gpu = NULL;
 442         msm_obj->read_fence = 0;
 443         msm_obj->write_fence = 0;
 444         list_del_init(&msm_obj->mm_list);
 445         list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
 446 }
 447
 448 int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op,
 449                 struct timespec *timeout)
 450 {
 451         struct drm_device *dev = obj->dev;
 452         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 453         int ret = 0;
 454
 455         if (is_active(msm_obj)) {
 456                 uint32_t fence = 0;
 457
 458                 if (op & MSM_PREP_READ)
 459                         fence = msm_obj->write_fence;
 460                 if (op & MSM_PREP_WRITE)
 461                         fence = max(fence, msm_obj->read_fence);
 462                 if (op & MSM_PREP_NOSYNC)
 463                         timeout = NULL;
 464
 465                 ret = msm_wait_fence_interruptable(dev, fence, timeout);
 466         }
 467
 468         /* TODO cache maintenance */
 469
 470         return ret;
 471 }
 472
 473 int msm_gem_cpu_fini(struct drm_gem_object *obj)
 474 {
 475         /* TODO cache maintenance */
 476         return 0;
 477 }
 478
 479 #ifdef CONFIG_DEBUG_FS
 480 void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 481 {
 482         struct drm_device *dev = obj->dev;
 483         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 484         uint64_t off = drm_vma_node_start(&obj->vma_node);
 485
 486         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 487         seq_printf(m, "%08x: %c(r=%u,w=%u) %2d (%2d) %08llx %p %d\n",
 488                         msm_obj->flags, is_active(msm_obj) ? 'A' : 'I',
 489                         msm_obj->read_fence, msm_obj->write_fence,
 490                         obj->name, obj->refcount.refcount.counter,
 491                         off, msm_obj->vaddr, obj->size);
 492 }
 493
 494 void msm_gem_describe_objects(struct list_head *list, struct seq_file *m)
 495 {
 496         struct msm_gem_object *msm_obj;
 497         int count = 0;
 498         size_t size = 0;
 499
 500         list_for_each_entry(msm_obj, list, mm_list) {
 501                 struct drm_gem_object *obj = &msm_obj->base;
 502                 seq_printf(m, "   ");
 503                 msm_gem_describe(obj, m);
 504                 count++;
 505                 size += obj->size;
 506         }
 507
 508         seq_printf(m, "Total %d objects, %zu bytes\n", count, size);
 509 }
 510 #endif
 511
 512 void msm_gem_free_object(struct drm_gem_object *obj)
 513 {
 514         struct drm_device *dev = obj->dev;
 515         struct msm_drm_private *priv = obj->dev->dev_private;
 516         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 517         int id;
 518
 519         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 520
 521         /* object should not be on active list: */
 522         WARN_ON(is_active(msm_obj));
 523
 524         list_del(&msm_obj->mm_list);
 525
 526         for (id = 0; id < ARRAY_SIZE(msm_obj->domain); id++) {
 527                 struct msm_mmu *mmu = priv->mmus[id];
 528                 if (mmu && msm_obj->domain[id].iova) {
 529                         uint32_t offset = (uint32_t)mmap_offset(obj);
 530                         mmu->funcs->unmap(mmu, offset, msm_obj->sgt, obj->size);
 531                 }
 532         }
 533
 534         drm_gem_free_mmap_offset(obj);
 535
 536         if (obj->import_attach) {
 537                 if (msm_obj->vaddr)
 538                         dma_buf_vunmap(obj->import_attach->dmabuf, msm_obj->vaddr);
 539
 540                 /* Don't drop the pages for imported dmabuf, as they are not
 541                  * ours, just free the array we allocated:
 542                  */
 543                 if (msm_obj->pages)
 544                         drm_free_large(msm_obj->pages);
 545
 546         } else {
 547                 if (msm_obj->vaddr)
 548                         vunmap(msm_obj->vaddr);
 549                 put_pages(obj);
 550         }
 551
 552         if (msm_obj->resv == &msm_obj->_resv)
 553                 reservation_object_fini(msm_obj->resv);
 554
 555         drm_gem_object_release(obj);
 556
 557         kfree(msm_obj);
 558 }
 559
 560 /* convenience method to construct a GEM buffer object, and userspace handle */
 561 int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
 562                 uint32_t size, uint32_t flags, uint32_t *handle)
 563 {
 564         struct drm_gem_object *obj;
 565         int ret;
 566
 567         ret = mutex_lock_interruptible(&dev->struct_mutex);
 568         if (ret)
 569                 return ret;
 570
 571         obj = msm_gem_new(dev, size, flags);
 572
 573         mutex_unlock(&dev->struct_mutex);
 574
 575         if (IS_ERR(obj))
 576                 return PTR_ERR(obj);
 577
 578         ret = drm_gem_handle_create(file, obj, handle);
 579
 580         /* drop reference from allocate - handle holds it now */
 581         drm_gem_object_unreference_unlocked(obj);
 582
 583         return ret;
 584 }
 585
 586 static int msm_gem_new_impl(struct drm_device *dev,
 587                 uint32_t size, uint32_t flags,
 588                 struct drm_gem_object **obj)
 589 {
 590         struct msm_drm_private *priv = dev->dev_private;
 591         struct msm_gem_object *msm_obj;
 592         unsigned sz;
 593
 594         switch (flags & MSM_BO_CACHE_MASK) {
 595         case MSM_BO_UNCACHED:
 596         case MSM_BO_CACHED:
 597         case MSM_BO_WC:
 598                 break;
 599         default:
 600                 dev_err(dev->dev, "invalid cache flag: %x\n",
 601                                 (flags & MSM_BO_CACHE_MASK));
 602                 return -EINVAL;
 603         }
 604
 605         sz = sizeof(*msm_obj);
 606         if (!iommu_present(&platform_bus_type))
 607                 sz += sizeof(struct drm_mm_node);
 608
 609         msm_obj = kzalloc(sz, GFP_KERNEL);
 610         if (!msm_obj)
 611                 return -ENOMEM;
 612
 613         if (!iommu_present(&platform_bus_type))
 614                 msm_obj->vram_node = (void *)&msm_obj[1];
 615
 616         msm_obj->flags = flags;
 617
 618         msm_obj->resv = &msm_obj->_resv;
 619         reservation_object_init(msm_obj->resv);
 620
 621         INIT_LIST_HEAD(&msm_obj->submit_entry);
 622         list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
 623
 624         *obj = &msm_obj->base;
 625
 626         return 0;
 627 }
 628
 629 struct drm_gem_object *msm_gem_new(struct drm_device *dev,
 630                 uint32_t size, uint32_t flags)
 631 {
 632         struct drm_gem_object *obj = NULL;
 633         int ret;
 634
 635         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 636
 637         size = PAGE_ALIGN(size);
 638
 639         ret = msm_gem_new_impl(dev, size, flags, &obj);
 640         if (ret)
 641                 goto fail;
 642
 643         if (iommu_present(&platform_bus_type)) {
 644                 ret = drm_gem_object_init(dev, obj, size);
 645                 if (ret)
 646                         goto fail;
 647         } else {
 648                 drm_gem_private_object_init(dev, obj, size);
 649         }
 650
 651         return obj;
 652
 653 fail:
 654         if (obj)
 655                 drm_gem_object_unreference(obj);
 656
 657         return ERR_PTR(ret);
 658 }
 659
 660 struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 661                 uint32_t size, struct sg_table *sgt)
 662 {
 663         struct msm_gem_object *msm_obj;
 664         struct drm_gem_object *obj;
 665         int ret, npages;
 666
 667         /* if we don't have IOMMU, don't bother pretending we can import: */
 668         if (!iommu_present(&platform_bus_type)) {
 669                 dev_err(dev->dev, "cannot import without IOMMU\n");
 670                 return ERR_PTR(-EINVAL);
 671         }
 672
 673         size = PAGE_ALIGN(size);
 674
 675         ret = msm_gem_new_impl(dev, size, MSM_BO_WC, &obj);
 676         if (ret)
 677                 goto fail;
 678
 679         drm_gem_private_object_init(dev, obj, size);
 680
 681         npages = size / PAGE_SIZE;
 682
 683         msm_obj = to_msm_bo(obj);
 684         msm_obj->sgt = sgt;
 685         msm_obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
 686         if (!msm_obj->pages) {
 687                 ret = -ENOMEM;
 688                 goto fail;
 689         }
 690
 691         ret = drm_prime_sg_to_page_addr_arrays(sgt, msm_obj->pages, NULL, npages);
 692         if (ret)
 693                 goto fail;
 694
 695         return obj;
 696
 697 fail:
 698         if (obj)
 699                 drm_gem_object_unreference_unlocked(obj);
 700
 701         return ERR_PTR(ret);
 702 }