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
|
// SPDX-License-Identifier: GPL-2.0+
/*
* Test cases for bitfield helpers.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/bitfield.h>
#define CHECK_ENC_GET_U(tp, v, field, res) do { \
{ \
u##tp _res; \
\
_res = u##tp##_encode_bits(v, field); \
if (_res != res) { \
pr_warn("u" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != " #res "\n",\
(u64)_res); \
return -EINVAL; \
} \
if (u##tp##_get_bits(_res, field) != v) \
return -EINVAL; \
} \
} while (0)
#define CHECK_ENC_GET_LE(tp, v, field, res) do { \
{ \
__le##tp _res; \
\
_res = le##tp##_encode_bits(v, field); \
if (_res != cpu_to_le##tp(res)) { \
pr_warn("le" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx\n",\
(u64)le##tp##_to_cpu(_res), \
(u64)(res)); \
return -EINVAL; \
} \
if (le##tp##_get_bits(_res, field) != v) \
return -EINVAL; \
} \
} while (0)
#define CHECK_ENC_GET_BE(tp, v, field, res) do { \
{ \
__be##tp _res; \
\
_res = be##tp##_encode_bits(v, field); \
if (_res != cpu_to_be##tp(res)) { \
pr_warn("be" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx\n",\
(u64)be##tp##_to_cpu(_res), \
(u64)(res)); \
return -EINVAL; \
} \
if (be##tp##_get_bits(_res, field) != v) \
return -EINVAL; \
} \
} while (0)
#define CHECK_ENC_GET(tp, v, field, res) do { \
CHECK_ENC_GET_U(tp, v, field, res); \
CHECK_ENC_GET_LE(tp, v, field, res); \
CHECK_ENC_GET_BE(tp, v, field, res); \
} while (0)
static int test_constants(void)
{
/*
* NOTE
* This whole function compiles (or at least should, if everything
* is going according to plan) to nothing after optimisation.
*/
CHECK_ENC_GET(16, 1, 0x000f, 0x0001);
CHECK_ENC_GET(16, 3, 0x00f0, 0x0030);
CHECK_ENC_GET(16, 5, 0x0f00, 0x0500);
CHECK_ENC_GET(16, 7, 0xf000, 0x7000);
CHECK_ENC_GET(16, 14, 0x000f, 0x000e);
CHECK_ENC_GET(16, 15, 0x00f0, 0x00f0);
CHECK_ENC_GET_U(8, 1, 0x0f, 0x01);
CHECK_ENC_GET_U(8, 3, 0xf0, 0x30);
CHECK_ENC_GET_U(8, 14, 0x0f, 0x0e);
CHECK_ENC_GET_U(8, 15, 0xf0, 0xf0);
CHECK_ENC_GET(32, 1, 0x00000f00, 0x00000100);
CHECK_ENC_GET(32, 3, 0x0000f000, 0x00003000);
CHECK_ENC_GET(32, 5, 0x000f0000, 0x00050000);
CHECK_ENC_GET(32, 7, 0x00f00000, 0x00700000);
CHECK_ENC_GET(32, 14, 0x0f000000, 0x0e000000);
CHECK_ENC_GET(32, 15, 0xf0000000, 0xf0000000);
CHECK_ENC_GET(64, 1, 0x00000f0000000000ull, 0x0000010000000000ull);
CHECK_ENC_GET(64, 3, 0x0000f00000000000ull, 0x0000300000000000ull);
CHECK_ENC_GET(64, 5, 0x000f000000000000ull, 0x0005000000000000ull);
CHECK_ENC_GET(64, 7, 0x00f0000000000000ull, 0x0070000000000000ull);
CHECK_ENC_GET(64, 14, 0x0f00000000000000ull, 0x0e00000000000000ull);
CHECK_ENC_GET(64, 15, 0xf000000000000000ull, 0xf000000000000000ull);
return 0;
}
#define CHECK(tp, mask) do { \
u64 v; \
\
for (v = 0; v < 1 << hweight32(mask); v++) \
if (tp##_encode_bits(v, mask) != v << __ffs64(mask)) \
return -EINVAL; \
} while (0)
static int test_variables(void)
{
CHECK(u8, 0x0f);
CHECK(u8, 0xf0);
CHECK(u8, 0x38);
CHECK(u16, 0x0038);
CHECK(u16, 0x0380);
CHECK(u16, 0x3800);
CHECK(u16, 0x8000);
CHECK(u32, 0x80000000);
CHECK(u32, 0x7f000000);
CHECK(u32, 0x07e00000);
CHECK(u32, 0x00018000);
CHECK(u64, 0x8000000000000000ull);
CHECK(u64, 0x7f00000000000000ull);
CHECK(u64, 0x0001800000000000ull);
CHECK(u64, 0x0000000080000000ull);
CHECK(u64, 0x000000007f000000ull);
CHECK(u64, 0x0000000018000000ull);
CHECK(u64, 0x0000001f8000000ull);
return 0;
}
static int __init test_bitfields(void)
{
int ret = test_constants();
if (ret) {
pr_warn("constant tests failed!\n");
return ret;
}
ret = test_variables();
if (ret) {
pr_warn("variable tests failed!\n");
return ret;
}
#ifdef TEST_BITFIELD_COMPILE
/* these should fail compilation */
CHECK_ENC_GET(16, 16, 0x0f00, 0x1000);
u32_encode_bits(7, 0x06000000);
/* this should at least give a warning */
u16_encode_bits(0, 0x60000);
#endif
pr_info("tests passed\n");
return 0;
}
module_init(test_bitfields)
MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
MODULE_LICENSE("GPL");
|
