cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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huge_gem_object.c (2839B)

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