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);
 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}