huge_gem_object.c revision 1.2 
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 vm_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_NORETRY)
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 vm_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	.flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE,
93	.get_pages = huge_get_pages,
94	.put_pages = huge_put_pages,
95};
96
97struct drm_i915_gem_object *
98huge_gem_object(struct drm_i915_private *i915,
99		phys_addr_t phys_size,
100		dma_addr_t dma_size)
101{
102	static struct lock_class_key lock_class;
103	struct drm_i915_gem_object *obj;
104	unsigned int cache_level;
105
106	GEM_BUG_ON(!phys_size || phys_size > dma_size);
107	GEM_BUG_ON(!IS_ALIGNED(phys_size, PAGE_SIZE));
108	GEM_BUG_ON(!IS_ALIGNED(dma_size, I915_GTT_PAGE_SIZE));
109
110	if (overflows_type(dma_size, obj->base.size))
111		return ERR_PTR(-E2BIG);
112
113	obj = i915_gem_object_alloc();
114	if (!obj)
115		return ERR_PTR(-ENOMEM);
116
117	drm_gem_private_object_init(&i915->drm, &obj->base, dma_size);
118	i915_gem_object_init(obj, &huge_ops, &lock_class);
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}
128