1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/*
* SPDX-License-Identifier: MIT
*
* Copyright © 2016 Intel Corporation
*/
#include "i915_scatterlist.h"
#include "i915_buddy.h"
#include "i915_ttm_buddy_manager.h"
#include <drm/drm_mm.h>
#include <linux/slab.h>
bool i915_sg_trim(struct sg_table *orig_st)
{
struct sg_table new_st;
struct scatterlist *sg, *new_sg;
unsigned int i;
if (orig_st->nents == orig_st->orig_nents)
return false;
if (sg_alloc_table(&new_st, orig_st->nents, GFP_KERNEL | __GFP_NOWARN))
return false;
new_sg = new_st.sgl;
for_each_sg(orig_st->sgl, sg, orig_st->nents, i) {
sg_set_page(new_sg, sg_page(sg), sg->length, 0);
sg_dma_address(new_sg) = sg_dma_address(sg);
sg_dma_len(new_sg) = sg_dma_len(sg);
new_sg = sg_next(new_sg);
}
GEM_BUG_ON(new_sg); /* Should walk exactly nents and hit the end */
sg_free_table(orig_st);
*orig_st = new_st;
return true;
}
/**
* i915_sg_from_mm_node - Create an sg_table from a struct drm_mm_node
* @node: The drm_mm_node.
* @region_start: An offset to add to the dma addresses of the sg list.
*
* Create a struct sg_table, initializing it from a struct drm_mm_node,
* taking a maximum segment length into account, splitting into segments
* if necessary.
*
* Return: A pointer to a kmalloced struct sg_table on success, negative
* error code cast to an error pointer on failure.
*/
struct sg_table *i915_sg_from_mm_node(const struct drm_mm_node *node,
u64 region_start)
{
const u64 max_segment = SZ_1G; /* Do we have a limit on this? */
u64 segment_pages = max_segment >> PAGE_SHIFT;
u64 block_size, offset, prev_end;
struct sg_table *st;
struct scatterlist *sg;
st = kmalloc(sizeof(*st), GFP_KERNEL);
if (!st)
return ERR_PTR(-ENOMEM);
if (sg_alloc_table(st, DIV_ROUND_UP(node->size, segment_pages),
GFP_KERNEL)) {
kfree(st);
return ERR_PTR(-ENOMEM);
}
sg = st->sgl;
st->nents = 0;
prev_end = (resource_size_t)-1;
block_size = node->size << PAGE_SHIFT;
offset = node->start << PAGE_SHIFT;
while (block_size) {
u64 len;
if (offset != prev_end || sg->length >= max_segment) {
if (st->nents)
sg = __sg_next(sg);
sg_dma_address(sg) = region_start + offset;
sg_dma_len(sg) = 0;
sg->length = 0;
st->nents++;
}
len = min(block_size, max_segment - sg->length);
sg->length += len;
sg_dma_len(sg) += len;
offset += len;
block_size -= len;
prev_end = offset;
}
sg_mark_end(sg);
i915_sg_trim(st);
return st;
}
/**
* i915_sg_from_buddy_resource - Create an sg_table from a struct
* i915_buddy_block list
* @res: The struct i915_ttm_buddy_resource.
* @region_start: An offset to add to the dma addresses of the sg list.
*
* Create a struct sg_table, initializing it from struct i915_buddy_block list,
* taking a maximum segment length into account, splitting into segments
* if necessary.
*
* Return: A pointer to a kmalloced struct sg_table on success, negative
* error code cast to an error pointer on failure.
*/
struct sg_table *i915_sg_from_buddy_resource(struct ttm_resource *res,
u64 region_start)
{
struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
const u64 size = res->num_pages << PAGE_SHIFT;
const u64 max_segment = rounddown(UINT_MAX, PAGE_SIZE);
struct i915_buddy_mm *mm = bman_res->mm;
struct list_head *blocks = &bman_res->blocks;
struct i915_buddy_block *block;
struct scatterlist *sg;
struct sg_table *st;
resource_size_t prev_end;
GEM_BUG_ON(list_empty(blocks));
st = kmalloc(sizeof(*st), GFP_KERNEL);
if (!st)
return ERR_PTR(-ENOMEM);
if (sg_alloc_table(st, res->num_pages, GFP_KERNEL)) {
kfree(st);
return ERR_PTR(-ENOMEM);
}
sg = st->sgl;
st->nents = 0;
prev_end = (resource_size_t)-1;
list_for_each_entry(block, blocks, link) {
u64 block_size, offset;
block_size = min_t(u64, size, i915_buddy_block_size(mm, block));
offset = i915_buddy_block_offset(block);
while (block_size) {
u64 len;
if (offset != prev_end || sg->length >= max_segment) {
if (st->nents)
sg = __sg_next(sg);
sg_dma_address(sg) = region_start + offset;
sg_dma_len(sg) = 0;
sg->length = 0;
st->nents++;
}
len = min(block_size, max_segment - sg->length);
sg->length += len;
sg_dma_len(sg) += len;
offset += len;
block_size -= len;
prev_end = offset;
}
}
sg_mark_end(sg);
i915_sg_trim(st);
return st;
}
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftests/scatterlist.c"
#endif
|
