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}