1 /*
2 * Copyright © 2014-2016 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 */
24
25 #include <drm/drmP.h>
26 #include <drm/i915_drm.h>
27 #include "i915_drv.h"
28
29 #define QUIET (__GFP_NORETRY | __GFP_NOWARN)
30
31 /* convert swiotlb segment size into sensible units (pages)! */
32 #define IO_TLB_SEGPAGES (IO_TLB_SEGSIZE << IO_TLB_SHIFT >> PAGE_SHIFT)
33
internal_free_pages(struct sg_table * st)34 static void internal_free_pages(struct sg_table *st)
35 {
36 struct scatterlist *sg;
37
38 for (sg = st->sgl; sg; sg = __sg_next(sg)) {
39 if (sg_page(sg))
40 __free_pages(sg_page(sg), get_order(sg->length));
41 }
42
43 sg_free_table(st);
44 kfree(st);
45 }
46
47 static struct sg_table *
i915_gem_object_get_pages_internal(struct drm_i915_gem_object * obj)48 i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj)
49 {
50 struct drm_i915_private *i915 = to_i915(obj->base.dev);
51 struct sg_table *st;
52 struct scatterlist *sg;
53 unsigned int npages;
54 int max_order;
55 gfp_t gfp;
56
57 max_order = MAX_ORDER;
58 #ifdef CONFIG_SWIOTLB
59 if (swiotlb_nr_tbl()) {
60 unsigned int max_segment;
61
62 max_segment = swiotlb_max_segment();
63 if (max_segment) {
64 max_segment = max_t(unsigned int, max_segment,
65 PAGE_SIZE) >> PAGE_SHIFT;
66 max_order = min(max_order, ilog2(max_segment));
67 }
68 }
69 #endif
70
71 gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE;
72 if (IS_I965GM(i915) || IS_I965G(i915)) {
73 /* 965gm cannot relocate objects above 4GiB. */
74 gfp &= ~__GFP_HIGHMEM;
75 gfp |= __GFP_DMA32;
76 }
77
78 create_st:
79 st = kmalloc(sizeof(*st), GFP_KERNEL);
80 if (!st)
81 return ERR_PTR(-ENOMEM);
82
83 npages = obj->base.size / PAGE_SIZE;
84 if (sg_alloc_table(st, npages, GFP_KERNEL)) {
85 kfree(st);
86 return ERR_PTR(-ENOMEM);
87 }
88
89 sg = st->sgl;
90 st->nents = 0;
91
92 do {
93 int order = min(fls(npages) - 1, max_order);
94 struct page *page;
95
96 do {
97 page = alloc_pages(gfp | (order ? QUIET : 0), order);
98 if (page)
99 break;
100 if (!order--)
101 goto err;
102
103 /* Limit subsequent allocations as well */
104 max_order = order;
105 } while (1);
106
107 sg_set_page(sg, page, PAGE_SIZE << order, 0);
108 st->nents++;
109
110 npages -= 1 << order;
111 if (!npages) {
112 sg_mark_end(sg);
113 break;
114 }
115
116 sg = __sg_next(sg);
117 } while (1);
118
119 if (i915_gem_gtt_prepare_pages(obj, st)) {
120 /* Failed to dma-map try again with single page sg segments */
121 if (get_order(st->sgl->length)) {
122 internal_free_pages(st);
123 max_order = 0;
124 goto create_st;
125 }
126 goto err;
127 }
128
129 /* Mark the pages as dontneed whilst they are still pinned. As soon
130 * as they are unpinned they are allowed to be reaped by the shrinker,
131 * and the caller is expected to repopulate - the contents of this
132 * object are only valid whilst active and pinned.
133 */
134 obj->mm.madv = I915_MADV_DONTNEED;
135 return st;
136
137 err:
138 sg_set_page(sg, NULL, 0, 0);
139 sg_mark_end(sg);
140 internal_free_pages(st);
141 return ERR_PTR(-ENOMEM);
142 }
143
i915_gem_object_put_pages_internal(struct drm_i915_gem_object * obj,struct sg_table * pages)144 static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj,
145 struct sg_table *pages)
146 {
147 i915_gem_gtt_finish_pages(obj, pages);
148 internal_free_pages(pages);
149
150 obj->mm.dirty = false;
151 obj->mm.madv = I915_MADV_WILLNEED;
152 }
153
154 static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {
155 .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE |
156 I915_GEM_OBJECT_IS_SHRINKABLE,
157 .get_pages = i915_gem_object_get_pages_internal,
158 .put_pages = i915_gem_object_put_pages_internal,
159 };
160
161 /**
162 * Creates a new object that wraps some internal memory for private use.
163 * This object is not backed by swappable storage, and as such its contents
164 * are volatile and only valid whilst pinned. If the object is reaped by the
165 * shrinker, its pages and data will be discarded. Equally, it is not a full
166 * GEM object and so not valid for access from userspace. This makes it useful
167 * for hardware interfaces like ringbuffers (which are pinned from the time
168 * the request is written to the time the hardware stops accessing it), but
169 * not for contexts (which need to be preserved when not active for later
170 * reuse). Note that it is not cleared upon allocation.
171 */
172 struct drm_i915_gem_object *
i915_gem_object_create_internal(struct drm_i915_private * i915,phys_addr_t size)173 i915_gem_object_create_internal(struct drm_i915_private *i915,
174 phys_addr_t size)
175 {
176 struct drm_i915_gem_object *obj;
177 unsigned int cache_level;
178
179 GEM_BUG_ON(!size);
180 GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
181
182 if (overflows_type(size, obj->base.size))
183 return ERR_PTR(-E2BIG);
184
185 obj = i915_gem_object_alloc(i915);
186 if (!obj)
187 return ERR_PTR(-ENOMEM);
188
189 drm_gem_private_object_init(&i915->drm, &obj->base, size);
190 i915_gem_object_init(obj, &i915_gem_object_internal_ops);
191
192 obj->base.read_domains = I915_GEM_DOMAIN_CPU;
193 obj->base.write_domain = I915_GEM_DOMAIN_CPU;
194
195 cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
196 i915_gem_object_set_cache_coherency(obj, cache_level);
197
198 return obj;
199 }
200