root/drivers/gpu/drm/i915/gem/selftests/huge_gem_object.c

DEFINITIONS

1. huge_free_pages
2. huge_get_pages
3. huge_put_pages
4. huge_gem_object

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright © 2016 Intel Corporation
   5  */
   6 
   7 #include "i915_scatterlist.h"
   8 
   9 #include "huge_gem_object.h"
  10 
  11 static void huge_free_pages(struct drm_i915_gem_object *obj,
  12                             struct sg_table *pages)
  13 {
  14         unsigned long nreal = obj->scratch / PAGE_SIZE;
  15         struct scatterlist *sg;
  16 
  17         for (sg = pages->sgl; sg && nreal--; sg = __sg_next(sg))
  18                 __free_page(sg_page(sg));
  19 
  20         sg_free_table(pages);
  21         kfree(pages);
  22 }
  23 
  24 static int huge_get_pages(struct drm_i915_gem_object *obj)
  25 {
  26 #define GFP (GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY)
  27         const unsigned long nreal = obj->scratch / PAGE_SIZE;
  28         const unsigned long npages = obj->base.size / PAGE_SIZE;
  29         struct scatterlist *sg, *src, *end;
  30         struct sg_table *pages;
  31         unsigned long n;
  32 
  33         pages = kmalloc(sizeof(*pages), GFP);
  34         if (!pages)
  35                 return -ENOMEM;
  36 
  37         if (sg_alloc_table(pages, npages, GFP)) {
  38                 kfree(pages);
  39                 return -ENOMEM;
  40         }
  41 
  42         sg = pages->sgl;
  43         for (n = 0; n < nreal; n++) {
  44                 struct page *page;
  45 
  46                 page = alloc_page(GFP | __GFP_HIGHMEM);
  47                 if (!page) {
  48                         sg_mark_end(sg);
  49                         goto err;
  50                 }
  51 
  52                 sg_set_page(sg, page, PAGE_SIZE, 0);
  53                 sg = __sg_next(sg);
  54         }
  55         if (nreal < npages) {
  56                 for (end = sg, src = pages->sgl; sg; sg = __sg_next(sg)) {
  57                         sg_set_page(sg, sg_page(src), PAGE_SIZE, 0);
  58                         src = __sg_next(src);
  59                         if (src == end)
  60                                 src = pages->sgl;
  61                 }
  62         }
  63 
  64         if (i915_gem_gtt_prepare_pages(obj, pages))
  65                 goto err;
  66 
  67         __i915_gem_object_set_pages(obj, pages, PAGE_SIZE);
  68 
  69         return 0;
  70 
  71 err:
  72         huge_free_pages(obj, pages);
  73 
  74         return -ENOMEM;
  75 #undef GFP
  76 }
  77 
  78 static void huge_put_pages(struct drm_i915_gem_object *obj,
  79                            struct sg_table *pages)
  80 {
  81         i915_gem_gtt_finish_pages(obj, pages);
  82         huge_free_pages(obj, pages);
  83 
  84         obj->mm.dirty = false;
  85 }
  86 
  87 static const struct drm_i915_gem_object_ops huge_ops = {
  88         .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE |
  89                  I915_GEM_OBJECT_IS_SHRINKABLE,
  90         .get_pages = huge_get_pages,
  91         .put_pages = huge_put_pages,
  92 };
  93 
  94 struct drm_i915_gem_object *
  95 huge_gem_object(struct drm_i915_private *i915,
  96                 phys_addr_t phys_size,
  97                 dma_addr_t dma_size)
  98 {
  99         struct drm_i915_gem_object *obj;
 100         unsigned int cache_level;
 101 
 102         GEM_BUG_ON(!phys_size || phys_size > dma_size);
 103         GEM_BUG_ON(!IS_ALIGNED(phys_size, PAGE_SIZE));
 104         GEM_BUG_ON(!IS_ALIGNED(dma_size, I915_GTT_PAGE_SIZE));
 105 
 106         if (overflows_type(dma_size, obj->base.size))
 107                 return ERR_PTR(-E2BIG);
 108 
 109         obj = i915_gem_object_alloc();
 110         if (!obj)
 111                 return ERR_PTR(-ENOMEM);
 112 
 113         drm_gem_private_object_init(&i915->drm, &obj->base, dma_size);
 114         i915_gem_object_init(obj, &huge_ops);
 115 
 116         obj->read_domains = I915_GEM_DOMAIN_CPU;
 117         obj->write_domain = I915_GEM_DOMAIN_CPU;
 118         cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
 119         i915_gem_object_set_cache_coherency(obj, cache_level);
 120         obj->scratch = phys_size;
 121 
 122         return obj;
 123 }