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

   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 sgt_iter sgt_iter;
  16         struct page *page;
  17
  18         for_each_sgt_page(page, sgt_iter, pages) {
  19                 __free_page(page);
  20                 if (!--nreal)
  21                         break;
  22         }
  23
  24         sg_free_table(pages);
  25         kfree(pages);
  26 }
  27
  28 static int huge_get_pages(struct drm_i915_gem_object *obj)
  29 {
  30 #define GFP (GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL)
  31         const unsigned long nreal = obj->scratch / PAGE_SIZE;
  32         unsigned int npages; /* restricted by sg_alloc_table */
  33         struct scatterlist *sg, *src, *end;
  34         struct sg_table *pages;
  35         unsigned long n;
  36
  37         if (overflows_type(obj->base.size / PAGE_SIZE, npages))
  38                 return -E2BIG;
  39
  40         npages = obj->base.size / PAGE_SIZE;
  41         pages = kmalloc(sizeof(*pages), GFP);
  42         if (!pages)
  43                 return -ENOMEM;
  44
  45         if (sg_alloc_table(pages, npages, GFP)) {
  46                 kfree(pages);
  47                 return -ENOMEM;
  48         }
  49
  50         sg = pages->sgl;
  51         for (n = 0; n < nreal; n++) {
  52                 struct page *page;
  53
  54                 page = alloc_page(GFP | __GFP_HIGHMEM);
  55                 if (!page) {
  56                         sg_mark_end(sg);
  57                         goto err;
  58                 }
  59
  60                 sg_set_page(sg, page, PAGE_SIZE, 0);
  61                 sg = __sg_next(sg);
  62         }
  63         if (nreal < npages) {
  64                 for (end = sg, src = pages->sgl; sg; sg = __sg_next(sg)) {
  65                         sg_set_page(sg, sg_page(src), PAGE_SIZE, 0);
  66                         src = __sg_next(src);
  67                         if (src == end)
  68                                 src = pages->sgl;
  69                 }
  70         }
  71
  72         if (i915_gem_gtt_prepare_pages(obj, pages))
  73                 goto err;
  74
  75         __i915_gem_object_set_pages(obj, pages);
  76
  77         return 0;
  78
  79 err:
  80         huge_free_pages(obj, pages);
  81         return -ENOMEM;
  82 #undef GFP
  83 }
  84
  85 static void huge_put_pages(struct drm_i915_gem_object *obj,
  86                            struct sg_table *pages)
  87 {
  88         i915_gem_gtt_finish_pages(obj, pages);
  89         huge_free_pages(obj, pages);
  90
  91         obj->mm.dirty = false;
  92 }
  93
  94 static const struct drm_i915_gem_object_ops huge_ops = {
  95         .name = "huge-gem",
  96         .get_pages = huge_get_pages,
  97         .put_pages = huge_put_pages,
  98 };
  99
 100 struct drm_i915_gem_object *
 101 huge_gem_object(struct drm_i915_private *i915,
 102                 phys_addr_t phys_size,
 103                 dma_addr_t dma_size)
 104 {
 105         static struct lock_class_key lock_class;
 106         struct drm_i915_gem_object *obj;
 107         unsigned int cache_level;
 108
 109         GEM_BUG_ON(!phys_size || phys_size > dma_size);
 110         GEM_BUG_ON(!IS_ALIGNED(phys_size, PAGE_SIZE));
 111         GEM_BUG_ON(!IS_ALIGNED(dma_size, I915_GTT_PAGE_SIZE));
 112
 113         if (overflows_type(dma_size, obj->base.size))
 114                 return ERR_PTR(-E2BIG);
 115
 116         obj = i915_gem_object_alloc();
 117         if (!obj)
 118                 return ERR_PTR(-ENOMEM);
 119
 120         drm_gem_private_object_init(&i915->drm, &obj->base, dma_size);
 121         i915_gem_object_init(obj, &huge_ops, &lock_class, 0);
 122         obj->mem_flags |= I915_BO_FLAG_STRUCT_PAGE;
 123
 124         obj->read_domains = I915_GEM_DOMAIN_CPU;
 125         obj->write_domain = I915_GEM_DOMAIN_CPU;
 126         cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
 127         i915_gem_object_set_cache_coherency(obj, cache_level);
 128         obj->scratch = phys_size;
 129
 130         return obj;
 131 }