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
|
/*
* SPDX-License-Identifier: MIT
*
* Copyright © 2016 Intel Corporation
*/
#ifndef I915_SCATTERLIST_H
#define I915_SCATTERLIST_H
#include <linux/pfn.h>
#include <linux/scatterlist.h>
#include <linux/swiotlb.h>
#include "i915_gem.h"
/*
* Optimised SGL iterator for GEM objects
*/
static __always_inline struct sgt_iter {
struct scatterlist *sgp;
union {
unsigned long pfn;
dma_addr_t dma;
};
unsigned int curr;
unsigned int max;
} __sgt_iter(struct scatterlist *sgl, bool dma) {
struct sgt_iter s = { .sgp = sgl };
if (dma && s.sgp && sg_dma_len(s.sgp) == 0) {
s.sgp = NULL;
} else if (s.sgp) {
s.max = s.curr = s.sgp->offset;
if (dma) {
s.dma = sg_dma_address(s.sgp);
s.max += sg_dma_len(s.sgp);
} else {
s.pfn = page_to_pfn(sg_page(s.sgp));
s.max += s.sgp->length;
}
}
return s;
}
static inline int __sg_page_count(const struct scatterlist *sg)
{
return sg->length >> PAGE_SHIFT;
}
static inline int __sg_dma_page_count(const struct scatterlist *sg)
{
return sg_dma_len(sg) >> PAGE_SHIFT;
}
static inline struct scatterlist *____sg_next(struct scatterlist *sg)
{
++sg;
if (unlikely(sg_is_chain(sg)))
sg = sg_chain_ptr(sg);
return sg;
}
/**
* __sg_next - return the next scatterlist entry in a list
* @sg: The current sg entry
*
* Description:
* If the entry is the last, return NULL; otherwise, step to the next
* element in the array (@sg@+1). If that's a chain pointer, follow it;
* otherwise just return the pointer to the current element.
**/
static inline struct scatterlist *__sg_next(struct scatterlist *sg)
{
return sg_is_last(sg) ? NULL : ____sg_next(sg);
}
/**
* __for_each_sgt_daddr - iterate over the device addresses of the given sg_table
* @__dp: Device address (output)
* @__iter: 'struct sgt_iter' (iterator state, internal)
* @__sgt: sg_table to iterate over (input)
* @__step: step size
*/
#define __for_each_sgt_daddr(__dp, __iter, __sgt, __step) \
for ((__iter) = __sgt_iter((__sgt)->sgl, true); \
((__dp) = (__iter).dma + (__iter).curr), (__iter).sgp; \
(((__iter).curr += (__step)) >= (__iter).max) ? \
(__iter) = __sgt_iter(__sg_next((__iter).sgp), true), 0 : 0)
/**
* for_each_sgt_page - iterate over the pages of the given sg_table
* @__pp: page pointer (output)
* @__iter: 'struct sgt_iter' (iterator state, internal)
* @__sgt: sg_table to iterate over (input)
*/
#define for_each_sgt_page(__pp, __iter, __sgt) \
for ((__iter) = __sgt_iter((__sgt)->sgl, false); \
((__pp) = (__iter).pfn == 0 ? NULL : \
pfn_to_page((__iter).pfn + ((__iter).curr >> PAGE_SHIFT))); \
(((__iter).curr += PAGE_SIZE) >= (__iter).max) ? \
(__iter) = __sgt_iter(__sg_next((__iter).sgp), false), 0 : 0)
static inline unsigned int i915_sg_page_sizes(struct scatterlist *sg)
{
unsigned int page_sizes;
page_sizes = 0;
while (sg) {
GEM_BUG_ON(sg->offset);
GEM_BUG_ON(!IS_ALIGNED(sg->length, PAGE_SIZE));
page_sizes |= sg->length;
sg = __sg_next(sg);
}
return page_sizes;
}
static inline unsigned int i915_sg_segment_size(void)
{
unsigned int size = swiotlb_max_segment();
if (size == 0)
size = UINT_MAX;
size = rounddown(size, PAGE_SIZE);
/* swiotlb_max_segment_size can return 1 byte when it means one page. */
if (size < PAGE_SIZE)
size = PAGE_SIZE;
return size;
}
bool i915_sg_trim(struct sg_table *orig_st);
#endif
|
