1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Test cases for bitfield helpers.
4 */
5
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8 #include <kunit/test.h>
9 #include <linux/bitfield.h>
10
11 #define CHECK_ENC_GET_U(tp, v, field, res) do { \
12 { \
13 u##tp _res; \
14 \
15 _res = u##tp##_encode_bits(v, field); \
16 KUNIT_ASSERT_FALSE_MSG(context, _res != res, \
17 "u" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != " #res "\n", \
18 (u64)_res); \
19 KUNIT_ASSERT_FALSE(context, \
20 u##tp##_get_bits(_res, field) != v); \
21 } \
22 } while (0)
23
24 #define CHECK_ENC_GET_LE(tp, v, field, res) do { \
25 { \
26 __le##tp _res; \
27 \
28 _res = le##tp##_encode_bits(v, field); \
29 KUNIT_ASSERT_FALSE_MSG(context, \
30 _res != cpu_to_le##tp(res), \
31 "le" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx",\
32 (u64)le##tp##_to_cpu(_res), \
33 (u64)(res)); \
34 KUNIT_ASSERT_FALSE(context, \
35 le##tp##_get_bits(_res, field) != v);\
36 } \
37 } while (0)
38
39 #define CHECK_ENC_GET_BE(tp, v, field, res) do { \
40 { \
41 __be##tp _res; \
42 \
43 _res = be##tp##_encode_bits(v, field); \
44 KUNIT_ASSERT_FALSE_MSG(context, \
45 _res != cpu_to_be##tp(res), \
46 "be" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx", \
47 (u64)be##tp##_to_cpu(_res), \
48 (u64)(res)); \
49 KUNIT_ASSERT_FALSE(context, \
50 be##tp##_get_bits(_res, field) != v);\
51 } \
52 } while (0)
53
54 #define CHECK_ENC_GET(tp, v, field, res) do { \
55 CHECK_ENC_GET_U(tp, v, field, res); \
56 CHECK_ENC_GET_LE(tp, v, field, res); \
57 CHECK_ENC_GET_BE(tp, v, field, res); \
58 } while (0)
59
test_bitfields_constants(struct kunit * context)60 static void __init test_bitfields_constants(struct kunit *context)
61 {
62 /*
63 * NOTE
64 * This whole function compiles (or at least should, if everything
65 * is going according to plan) to nothing after optimisation.
66 */
67
68 CHECK_ENC_GET(16, 1, 0x000f, 0x0001);
69 CHECK_ENC_GET(16, 3, 0x00f0, 0x0030);
70 CHECK_ENC_GET(16, 5, 0x0f00, 0x0500);
71 CHECK_ENC_GET(16, 7, 0xf000, 0x7000);
72 CHECK_ENC_GET(16, 14, 0x000f, 0x000e);
73 CHECK_ENC_GET(16, 15, 0x00f0, 0x00f0);
74
75 CHECK_ENC_GET_U(8, 1, 0x0f, 0x01);
76 CHECK_ENC_GET_U(8, 3, 0xf0, 0x30);
77 CHECK_ENC_GET_U(8, 14, 0x0f, 0x0e);
78 CHECK_ENC_GET_U(8, 15, 0xf0, 0xf0);
79
80 CHECK_ENC_GET(32, 1, 0x00000f00, 0x00000100);
81 CHECK_ENC_GET(32, 3, 0x0000f000, 0x00003000);
82 CHECK_ENC_GET(32, 5, 0x000f0000, 0x00050000);
83 CHECK_ENC_GET(32, 7, 0x00f00000, 0x00700000);
84 CHECK_ENC_GET(32, 14, 0x0f000000, 0x0e000000);
85 CHECK_ENC_GET(32, 15, 0xf0000000, 0xf0000000);
86
87 CHECK_ENC_GET(64, 1, 0x00000f0000000000ull, 0x0000010000000000ull);
88 CHECK_ENC_GET(64, 3, 0x0000f00000000000ull, 0x0000300000000000ull);
89 CHECK_ENC_GET(64, 5, 0x000f000000000000ull, 0x0005000000000000ull);
90 CHECK_ENC_GET(64, 7, 0x00f0000000000000ull, 0x0070000000000000ull);
91 CHECK_ENC_GET(64, 14, 0x0f00000000000000ull, 0x0e00000000000000ull);
92 CHECK_ENC_GET(64, 15, 0xf000000000000000ull, 0xf000000000000000ull);
93 }
94
95 #define CHECK(tp, mask) do { \
96 u64 v; \
97 \
98 for (v = 0; v < 1 << hweight32(mask); v++) \
99 KUNIT_ASSERT_FALSE(context, \
100 tp##_encode_bits(v, mask) != v << __ffs64(mask));\
101 } while (0)
102
test_bitfields_variables(struct kunit * context)103 static void __init test_bitfields_variables(struct kunit *context)
104 {
105 CHECK(u8, 0x0f);
106 CHECK(u8, 0xf0);
107 CHECK(u8, 0x38);
108
109 CHECK(u16, 0x0038);
110 CHECK(u16, 0x0380);
111 CHECK(u16, 0x3800);
112 CHECK(u16, 0x8000);
113
114 CHECK(u32, 0x80000000);
115 CHECK(u32, 0x7f000000);
116 CHECK(u32, 0x07e00000);
117 CHECK(u32, 0x00018000);
118
119 CHECK(u64, 0x8000000000000000ull);
120 CHECK(u64, 0x7f00000000000000ull);
121 CHECK(u64, 0x0001800000000000ull);
122 CHECK(u64, 0x0000000080000000ull);
123 CHECK(u64, 0x000000007f000000ull);
124 CHECK(u64, 0x0000000018000000ull);
125 CHECK(u64, 0x0000001f8000000ull);
126 }
127
128 #ifdef TEST_BITFIELD_COMPILE
test_bitfields_compile(struct kunit * context)129 static void __init test_bitfields_compile(struct kunit *context)
130 {
131 /* these should fail compilation */
132 CHECK_ENC_GET(16, 16, 0x0f00, 0x1000);
133 u32_encode_bits(7, 0x06000000);
134
135 /* this should at least give a warning */
136 u16_encode_bits(0, 0x60000);
137 }
138 #endif
139
140 static struct kunit_case __refdata bitfields_test_cases[] = {
141 KUNIT_CASE(test_bitfields_constants),
142 KUNIT_CASE(test_bitfields_variables),
143 {}
144 };
145
146 static struct kunit_suite bitfields_test_suite = {
147 .name = "bitfields",
148 .test_cases = bitfields_test_cases,
149 };
150
151 kunit_test_suites(&bitfields_test_suite);
152
153 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
154 MODULE_LICENSE("GPL");
155