This source file includes following definitions.
- sg_dwiter_next
- sg_dwiter_is_at_end
- sg_dwiter_read_buffer
- needs_unaligned_copy
- sg_dwiter_get_next_block
- cb710_sg_dwiter_read_next_block
- sg_dwiter_write_slow
- cb710_sg_dwiter_write_next_block
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7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/cb710.h>
10
11 static bool sg_dwiter_next(struct sg_mapping_iter *miter)
12 {
13 if (sg_miter_next(miter)) {
14 miter->consumed = 0;
15 return true;
16 } else
17 return false;
18 }
19
20 static bool sg_dwiter_is_at_end(struct sg_mapping_iter *miter)
21 {
22 return miter->length == miter->consumed && !sg_dwiter_next(miter);
23 }
24
25 static uint32_t sg_dwiter_read_buffer(struct sg_mapping_iter *miter)
26 {
27 size_t len, left = 4;
28 uint32_t data;
29 void *addr = &data;
30
31 do {
32 len = min(miter->length - miter->consumed, left);
33 memcpy(addr, miter->addr + miter->consumed, len);
34 miter->consumed += len;
35 left -= len;
36 if (!left)
37 return data;
38 addr += len;
39 } while (sg_dwiter_next(miter));
40
41 memset(addr, 0, left);
42 return data;
43 }
44
45 static inline bool needs_unaligned_copy(const void *ptr)
46 {
47 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
48 return false;
49 #else
50 return ((ptr - NULL) & 3) != 0;
51 #endif
52 }
53
54 static bool sg_dwiter_get_next_block(struct sg_mapping_iter *miter, uint32_t **ptr)
55 {
56 size_t len;
57
58 if (sg_dwiter_is_at_end(miter))
59 return true;
60
61 len = miter->length - miter->consumed;
62
63 if (likely(len >= 4 && !needs_unaligned_copy(
64 miter->addr + miter->consumed))) {
65 *ptr = miter->addr + miter->consumed;
66 miter->consumed += 4;
67 return true;
68 }
69
70 return false;
71 }
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90 uint32_t cb710_sg_dwiter_read_next_block(struct sg_mapping_iter *miter)
91 {
92 uint32_t *ptr = NULL;
93
94 if (likely(sg_dwiter_get_next_block(miter, &ptr)))
95 return ptr ? *ptr : 0;
96
97 return sg_dwiter_read_buffer(miter);
98 }
99 EXPORT_SYMBOL_GPL(cb710_sg_dwiter_read_next_block);
100
101 static void sg_dwiter_write_slow(struct sg_mapping_iter *miter, uint32_t data)
102 {
103 size_t len, left = 4;
104 void *addr = &data;
105
106 do {
107 len = min(miter->length - miter->consumed, left);
108 memcpy(miter->addr, addr, len);
109 miter->consumed += len;
110 left -= len;
111 if (!left)
112 return;
113 addr += len;
114 } while (sg_dwiter_next(miter));
115 }
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130 void cb710_sg_dwiter_write_next_block(struct sg_mapping_iter *miter, uint32_t data)
131 {
132 uint32_t *ptr = NULL;
133
134 if (likely(sg_dwiter_get_next_block(miter, &ptr))) {
135 if (ptr)
136 *ptr = data;
137 else
138 return;
139 } else
140 sg_dwiter_write_slow(miter, data);
141 }
142 EXPORT_SYMBOL_GPL(cb710_sg_dwiter_write_next_block);
143