root/drivers/gpu/drm/armada/armada_gem.c

DEFINITIONS

1. armada_gem_vm_fault
2. roundup_gem_size
3. armada_gem_free_object
4. armada_gem_linear_back
5. armada_gem_map_object
6. armada_gem_alloc_private_object
7. armada_gem_alloc_object
8. armada_gem_dumb_create
9. armada_gem_create_ioctl
10. armada_gem_mmap_ioctl
11. armada_gem_pwrite_ioctl
12. armada_gem_prime_map_dma_buf
13. armada_gem_prime_unmap_dma_buf
14. armada_gem_dmabuf_no_kmap
15. armada_gem_dmabuf_no_kunmap
16. armada_gem_dmabuf_mmap
17. armada_gem_prime_export
18. armada_gem_prime_import
19. armada_gem_map_import

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012 Russell King
   4  */
   5 
   6 #include <linux/dma-buf.h>
   7 #include <linux/dma-mapping.h>
   8 #include <linux/mman.h>
   9 #include <linux/shmem_fs.h>
  10 
  11 #include <drm/armada_drm.h>
  12 #include <drm/drm_prime.h>
  13 
  14 #include "armada_drm.h"
  15 #include "armada_gem.h"
  16 #include "armada_ioctlP.h"
  17 
  18 static vm_fault_t armada_gem_vm_fault(struct vm_fault *vmf)
  19 {
  20         struct drm_gem_object *gobj = vmf->vma->vm_private_data;
  21         struct armada_gem_object *obj = drm_to_armada_gem(gobj);
  22         unsigned long pfn = obj->phys_addr >> PAGE_SHIFT;
  23 
  24         pfn += (vmf->address - vmf->vma->vm_start) >> PAGE_SHIFT;
  25         return vmf_insert_pfn(vmf->vma, vmf->address, pfn);
  26 }
  27 
  28 const struct vm_operations_struct armada_gem_vm_ops = {
  29         .fault  = armada_gem_vm_fault,
  30         .open   = drm_gem_vm_open,
  31         .close  = drm_gem_vm_close,
  32 };
  33 
  34 static size_t roundup_gem_size(size_t size)
  35 {
  36         return roundup(size, PAGE_SIZE);
  37 }
  38 
  39 void armada_gem_free_object(struct drm_gem_object *obj)
  40 {
  41         struct armada_gem_object *dobj = drm_to_armada_gem(obj);
  42         struct armada_private *priv = obj->dev->dev_private;
  43 
  44         DRM_DEBUG_DRIVER("release obj %p\n", dobj);
  45 
  46         drm_gem_free_mmap_offset(&dobj->obj);
  47 
  48         might_lock(&priv->linear_lock);
  49 
  50         if (dobj->page) {
  51                 /* page backed memory */
  52                 unsigned int order = get_order(dobj->obj.size);
  53                 __free_pages(dobj->page, order);
  54         } else if (dobj->linear) {
  55                 /* linear backed memory */
  56                 mutex_lock(&priv->linear_lock);
  57                 drm_mm_remove_node(dobj->linear);
  58                 mutex_unlock(&priv->linear_lock);
  59                 kfree(dobj->linear);
  60                 if (dobj->addr)
  61                         iounmap(dobj->addr);
  62         }
  63 
  64         if (dobj->obj.import_attach) {
  65                 /* We only ever display imported data */
  66                 if (dobj->sgt)
  67                         dma_buf_unmap_attachment(dobj->obj.import_attach,
  68                                                  dobj->sgt, DMA_TO_DEVICE);
  69                 drm_prime_gem_destroy(&dobj->obj, NULL);
  70         }
  71 
  72         drm_gem_object_release(&dobj->obj);
  73 
  74         kfree(dobj);
  75 }
  76 
  77 int
  78 armada_gem_linear_back(struct drm_device *dev, struct armada_gem_object *obj)
  79 {
  80         struct armada_private *priv = dev->dev_private;
  81         size_t size = obj->obj.size;
  82 
  83         if (obj->page || obj->linear)
  84                 return 0;
  85 
  86         /*
  87          * If it is a small allocation (typically cursor, which will
  88          * be 32x64 or 64x32 ARGB pixels) try to get it from the system.
  89          * Framebuffers will never be this small (our minimum size for
  90          * framebuffers is larger than this anyway.)  Such objects are
  91          * only accessed by the CPU so we don't need any special handing
  92          * here.
  93          */
  94         if (size <= 8192) {
  95                 unsigned int order = get_order(size);
  96                 struct page *p = alloc_pages(GFP_KERNEL, order);
  97 
  98                 if (p) {
  99                         obj->addr = page_address(p);
 100                         obj->phys_addr = page_to_phys(p);
 101                         obj->page = p;
 102 
 103                         memset(obj->addr, 0, PAGE_ALIGN(size));
 104                 }
 105         }
 106 
 107         /*
 108          * We could grab something from CMA if it's enabled, but that
 109          * involves building in a problem:
 110          *
 111          * CMA's interface uses dma_alloc_coherent(), which provides us
 112          * with an CPU virtual address and a device address.
 113          *
 114          * The CPU virtual address may be either an address in the kernel
 115          * direct mapped region (for example, as it would be on x86) or
 116          * it may be remapped into another part of kernel memory space
 117          * (eg, as it would be on ARM.)  This means virt_to_phys() on the
 118          * returned virtual address is invalid depending on the architecture
 119          * implementation.
 120          *
 121          * The device address may also not be a physical address; it may
 122          * be that there is some kind of remapping between the device and
 123          * system RAM, which makes the use of the device address also
 124          * unsafe to re-use as a physical address.
 125          *
 126          * This makes DRM usage of dma_alloc_coherent() in a generic way
 127          * at best very questionable and unsafe.
 128          */
 129 
 130         /* Otherwise, grab it from our linear allocation */
 131         if (!obj->page) {
 132                 struct drm_mm_node *node;
 133                 unsigned align = min_t(unsigned, size, SZ_2M);
 134                 void __iomem *ptr;
 135                 int ret;
 136 
 137                 node = kzalloc(sizeof(*node), GFP_KERNEL);
 138                 if (!node)
 139                         return -ENOSPC;
 140 
 141                 mutex_lock(&priv->linear_lock);
 142                 ret = drm_mm_insert_node_generic(&priv->linear, node,
 143                                                  size, align, 0, 0);
 144                 mutex_unlock(&priv->linear_lock);
 145                 if (ret) {
 146                         kfree(node);
 147                         return ret;
 148                 }
 149 
 150                 obj->linear = node;
 151 
 152                 /* Ensure that the memory we're returning is cleared. */
 153                 ptr = ioremap_wc(obj->linear->start, size);
 154                 if (!ptr) {
 155                         mutex_lock(&priv->linear_lock);
 156                         drm_mm_remove_node(obj->linear);
 157                         mutex_unlock(&priv->linear_lock);
 158                         kfree(obj->linear);
 159                         obj->linear = NULL;
 160                         return -ENOMEM;
 161                 }
 162 
 163                 memset_io(ptr, 0, size);
 164                 iounmap(ptr);
 165 
 166                 obj->phys_addr = obj->linear->start;
 167                 obj->dev_addr = obj->linear->start;
 168                 obj->mapped = true;
 169         }
 170 
 171         DRM_DEBUG_DRIVER("obj %p phys %#llx dev %#llx\n", obj,
 172                          (unsigned long long)obj->phys_addr,
 173                          (unsigned long long)obj->dev_addr);
 174 
 175         return 0;
 176 }
 177 
 178 void *
 179 armada_gem_map_object(struct drm_device *dev, struct armada_gem_object *dobj)
 180 {
 181         /* only linear objects need to be ioremap'd */
 182         if (!dobj->addr && dobj->linear)
 183                 dobj->addr = ioremap_wc(dobj->phys_addr, dobj->obj.size);
 184         return dobj->addr;
 185 }
 186 
 187 struct armada_gem_object *
 188 armada_gem_alloc_private_object(struct drm_device *dev, size_t size)
 189 {
 190         struct armada_gem_object *obj;
 191 
 192         size = roundup_gem_size(size);
 193 
 194         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 195         if (!obj)
 196                 return NULL;
 197 
 198         drm_gem_private_object_init(dev, &obj->obj, size);
 199 
 200         DRM_DEBUG_DRIVER("alloc private obj %p size %zu\n", obj, size);
 201 
 202         return obj;
 203 }
 204 
 205 static struct armada_gem_object *armada_gem_alloc_object(struct drm_device *dev,
 206         size_t size)
 207 {
 208         struct armada_gem_object *obj;
 209         struct address_space *mapping;
 210 
 211         size = roundup_gem_size(size);
 212 
 213         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 214         if (!obj)
 215                 return NULL;
 216 
 217         if (drm_gem_object_init(dev, &obj->obj, size)) {
 218                 kfree(obj);
 219                 return NULL;
 220         }
 221 
 222         mapping = obj->obj.filp->f_mapping;
 223         mapping_set_gfp_mask(mapping, GFP_HIGHUSER | __GFP_RECLAIMABLE);
 224 
 225         DRM_DEBUG_DRIVER("alloc obj %p size %zu\n", obj, size);
 226 
 227         return obj;
 228 }
 229 
 230 /* Dumb alloc support */
 231 int armada_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 232         struct drm_mode_create_dumb *args)
 233 {
 234         struct armada_gem_object *dobj;
 235         u32 handle;
 236         size_t size;
 237         int ret;
 238 
 239         args->pitch = armada_pitch(args->width, args->bpp);
 240         args->size = size = args->pitch * args->height;
 241 
 242         dobj = armada_gem_alloc_private_object(dev, size);
 243         if (dobj == NULL)
 244                 return -ENOMEM;
 245 
 246         ret = armada_gem_linear_back(dev, dobj);
 247         if (ret)
 248                 goto err;
 249 
 250         ret = drm_gem_handle_create(file, &dobj->obj, &handle);
 251         if (ret)
 252                 goto err;
 253 
 254         args->handle = handle;
 255 
 256         /* drop reference from allocate - handle holds it now */
 257         DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
 258  err:
 259         drm_gem_object_put_unlocked(&dobj->obj);
 260         return ret;
 261 }
 262 
 263 /* Private driver gem ioctls */
 264 int armada_gem_create_ioctl(struct drm_device *dev, void *data,
 265         struct drm_file *file)
 266 {
 267         struct drm_armada_gem_create *args = data;
 268         struct armada_gem_object *dobj;
 269         size_t size;
 270         u32 handle;
 271         int ret;
 272 
 273         if (args->size == 0)
 274                 return -ENOMEM;
 275 
 276         size = args->size;
 277 
 278         dobj = armada_gem_alloc_object(dev, size);
 279         if (dobj == NULL)
 280                 return -ENOMEM;
 281 
 282         ret = drm_gem_handle_create(file, &dobj->obj, &handle);
 283         if (ret)
 284                 goto err;
 285 
 286         args->handle = handle;
 287 
 288         /* drop reference from allocate - handle holds it now */
 289         DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
 290  err:
 291         drm_gem_object_put_unlocked(&dobj->obj);
 292         return ret;
 293 }
 294 
 295 /* Map a shmem-backed object into process memory space */
 296 int armada_gem_mmap_ioctl(struct drm_device *dev, void *data,
 297         struct drm_file *file)
 298 {
 299         struct drm_armada_gem_mmap *args = data;
 300         struct armada_gem_object *dobj;
 301         unsigned long addr;
 302 
 303         dobj = armada_gem_object_lookup(file, args->handle);
 304         if (dobj == NULL)
 305                 return -ENOENT;
 306 
 307         if (!dobj->obj.filp) {
 308                 drm_gem_object_put_unlocked(&dobj->obj);
 309                 return -EINVAL;
 310         }
 311 
 312         addr = vm_mmap(dobj->obj.filp, 0, args->size, PROT_READ | PROT_WRITE,
 313                        MAP_SHARED, args->offset);
 314         drm_gem_object_put_unlocked(&dobj->obj);
 315         if (IS_ERR_VALUE(addr))
 316                 return addr;
 317 
 318         args->addr = addr;
 319 
 320         return 0;
 321 }
 322 
 323 int armada_gem_pwrite_ioctl(struct drm_device *dev, void *data,
 324         struct drm_file *file)
 325 {
 326         struct drm_armada_gem_pwrite *args = data;
 327         struct armada_gem_object *dobj;
 328         char __user *ptr;
 329         int ret;
 330 
 331         DRM_DEBUG_DRIVER("handle %u off %u size %u ptr 0x%llx\n",
 332                 args->handle, args->offset, args->size, args->ptr);
 333 
 334         if (args->size == 0)
 335                 return 0;
 336 
 337         ptr = (char __user *)(uintptr_t)args->ptr;
 338 
 339         if (!access_ok(ptr, args->size))
 340                 return -EFAULT;
 341 
 342         ret = fault_in_pages_readable(ptr, args->size);
 343         if (ret)
 344                 return ret;
 345 
 346         dobj = armada_gem_object_lookup(file, args->handle);
 347         if (dobj == NULL)
 348                 return -ENOENT;
 349 
 350         /* Must be a kernel-mapped object */
 351         if (!dobj->addr)
 352                 return -EINVAL;
 353 
 354         if (args->offset > dobj->obj.size ||
 355             args->size > dobj->obj.size - args->offset) {
 356                 DRM_ERROR("invalid size: object size %u\n", dobj->obj.size);
 357                 ret = -EINVAL;
 358                 goto unref;
 359         }
 360 
 361         if (copy_from_user(dobj->addr + args->offset, ptr, args->size)) {
 362                 ret = -EFAULT;
 363         } else if (dobj->update) {
 364                 dobj->update(dobj->update_data);
 365                 ret = 0;
 366         }
 367 
 368  unref:
 369         drm_gem_object_put_unlocked(&dobj->obj);
 370         return ret;
 371 }
 372 
 373 /* Prime support */
 374 static struct sg_table *
 375 armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
 376         enum dma_data_direction dir)
 377 {
 378         struct drm_gem_object *obj = attach->dmabuf->priv;
 379         struct armada_gem_object *dobj = drm_to_armada_gem(obj);
 380         struct scatterlist *sg;
 381         struct sg_table *sgt;
 382         int i, num;
 383 
 384         sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
 385         if (!sgt)
 386                 return NULL;
 387 
 388         if (dobj->obj.filp) {
 389                 struct address_space *mapping;
 390                 int count;
 391 
 392                 count = dobj->obj.size / PAGE_SIZE;
 393                 if (sg_alloc_table(sgt, count, GFP_KERNEL))
 394                         goto free_sgt;
 395 
 396                 mapping = dobj->obj.filp->f_mapping;
 397 
 398                 for_each_sg(sgt->sgl, sg, count, i) {
 399                         struct page *page;
 400 
 401                         page = shmem_read_mapping_page(mapping, i);
 402                         if (IS_ERR(page)) {
 403                                 num = i;
 404                                 goto release;
 405                         }
 406 
 407                         sg_set_page(sg, page, PAGE_SIZE, 0);
 408                 }
 409 
 410                 if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0) {
 411                         num = sgt->nents;
 412                         goto release;
 413                 }
 414         } else if (dobj->page) {
 415                 /* Single contiguous page */
 416                 if (sg_alloc_table(sgt, 1, GFP_KERNEL))
 417                         goto free_sgt;
 418 
 419                 sg_set_page(sgt->sgl, dobj->page, dobj->obj.size, 0);
 420 
 421                 if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
 422                         goto free_table;
 423         } else if (dobj->linear) {
 424                 /* Single contiguous physical region - no struct page */
 425                 if (sg_alloc_table(sgt, 1, GFP_KERNEL))
 426                         goto free_sgt;
 427                 sg_dma_address(sgt->sgl) = dobj->dev_addr;
 428                 sg_dma_len(sgt->sgl) = dobj->obj.size;
 429         } else {
 430                 goto free_sgt;
 431         }
 432         return sgt;
 433 
 434  release:
 435         for_each_sg(sgt->sgl, sg, num, i)
 436                 put_page(sg_page(sg));
 437  free_table:
 438         sg_free_table(sgt);
 439  free_sgt:
 440         kfree(sgt);
 441         return NULL;
 442 }
 443 
 444 static void armada_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
 445         struct sg_table *sgt, enum dma_data_direction dir)
 446 {
 447         struct drm_gem_object *obj = attach->dmabuf->priv;
 448         struct armada_gem_object *dobj = drm_to_armada_gem(obj);
 449         int i;
 450 
 451         if (!dobj->linear)
 452                 dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
 453 
 454         if (dobj->obj.filp) {
 455                 struct scatterlist *sg;
 456                 for_each_sg(sgt->sgl, sg, sgt->nents, i)
 457                         put_page(sg_page(sg));
 458         }
 459 
 460         sg_free_table(sgt);
 461         kfree(sgt);
 462 }
 463 
 464 static void *armada_gem_dmabuf_no_kmap(struct dma_buf *buf, unsigned long n)
 465 {
 466         return NULL;
 467 }
 468 
 469 static void
 470 armada_gem_dmabuf_no_kunmap(struct dma_buf *buf, unsigned long n, void *addr)
 471 {
 472 }
 473 
 474 static int
 475 armada_gem_dmabuf_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
 476 {
 477         return -EINVAL;
 478 }
 479 
 480 static const struct dma_buf_ops armada_gem_prime_dmabuf_ops = {
 481         .map_dma_buf    = armada_gem_prime_map_dma_buf,
 482         .unmap_dma_buf  = armada_gem_prime_unmap_dma_buf,
 483         .release        = drm_gem_dmabuf_release,
 484         .map            = armada_gem_dmabuf_no_kmap,
 485         .unmap          = armada_gem_dmabuf_no_kunmap,
 486         .mmap           = armada_gem_dmabuf_mmap,
 487 };
 488 
 489 struct dma_buf *
 490 armada_gem_prime_export(struct drm_gem_object *obj, int flags)
 491 {
 492         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 493 
 494         exp_info.ops = &armada_gem_prime_dmabuf_ops;
 495         exp_info.size = obj->size;
 496         exp_info.flags = O_RDWR;
 497         exp_info.priv = obj;
 498 
 499         return drm_gem_dmabuf_export(obj->dev, &exp_info);
 500 }
 501 
 502 struct drm_gem_object *
 503 armada_gem_prime_import(struct drm_device *dev, struct dma_buf *buf)
 504 {
 505         struct dma_buf_attachment *attach;
 506         struct armada_gem_object *dobj;
 507 
 508         if (buf->ops == &armada_gem_prime_dmabuf_ops) {
 509                 struct drm_gem_object *obj = buf->priv;
 510                 if (obj->dev == dev) {
 511                         /*
 512                          * Importing our own dmabuf(s) increases the
 513                          * refcount on the gem object itself.
 514                          */
 515                         drm_gem_object_get(obj);
 516                         return obj;
 517                 }
 518         }
 519 
 520         attach = dma_buf_attach(buf, dev->dev);
 521         if (IS_ERR(attach))
 522                 return ERR_CAST(attach);
 523 
 524         dobj = armada_gem_alloc_private_object(dev, buf->size);
 525         if (!dobj) {
 526                 dma_buf_detach(buf, attach);
 527                 return ERR_PTR(-ENOMEM);
 528         }
 529 
 530         dobj->obj.import_attach = attach;
 531         get_dma_buf(buf);
 532 
 533         /*
 534          * Don't call dma_buf_map_attachment() here - it maps the
 535          * scatterlist immediately for DMA, and this is not always
 536          * an appropriate thing to do.
 537          */
 538         return &dobj->obj;
 539 }
 540 
 541 int armada_gem_map_import(struct armada_gem_object *dobj)
 542 {
 543         int ret;
 544 
 545         dobj->sgt = dma_buf_map_attachment(dobj->obj.import_attach,
 546                                            DMA_TO_DEVICE);
 547         if (IS_ERR(dobj->sgt)) {
 548                 ret = PTR_ERR(dobj->sgt);
 549                 dobj->sgt = NULL;
 550                 DRM_ERROR("dma_buf_map_attachment() error: %d\n", ret);
 551                 return ret;
 552         }
 553         if (dobj->sgt->nents > 1) {
 554                 DRM_ERROR("dma_buf_map_attachment() returned an (unsupported) scattered list\n");
 555                 return -EINVAL;
 556         }
 557         if (sg_dma_len(dobj->sgt->sgl) < dobj->obj.size) {
 558                 DRM_ERROR("dma_buf_map_attachment() returned a small buffer\n");
 559                 return -EINVAL;
 560         }
 561         dobj->dev_addr = sg_dma_address(dobj->sgt->sgl);
 562         dobj->mapped = true;
 563         return 0;
 564 }