LXR linux/drivers/gpu/drm/i915/gem/selftests/huge_gem

   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
  11static 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
  24static 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
  71err:
  72        huge_free_pages(obj, pages);
  73
  74        return -ENOMEM;
  75#undef GFP
  76}
  77
  78static 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
  87static 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
  94struct drm_i915_gem_object *
  95huge_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}
 124