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	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
79err:
80	huge_free_pages(obj, pages);
81	return -ENOMEM;
82#undef GFP
83}
84
85static 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
94static 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
100struct drm_i915_gem_object *
101huge_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}
132