xref: /openbmc/linux/lib/bitfield_kunit.c (revision 63705da3)
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 
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 
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
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