the-tree/lib/bitfield_kunit.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Test cases for bitfield helpers.
0004  */
0005
0006 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0007
0008 #include <kunit/test.h>
0009 #include <linux/bitfield.h>
0010
0011 #define CHECK_ENC_GET_U(tp, v, field, res) do {             \
0012         {                           \
0013             u##tp _res;                 \
0014                                     \
0015             _res = u##tp##_encode_bits(v, field);       \
0016             KUNIT_ASSERT_FALSE_MSG(context, _res != res,    \
0017                        "u" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != " #res "\n",  \
0018                        (u64)_res);          \
0019             KUNIT_ASSERT_FALSE(context,         \
0020                    u##tp##_get_bits(_res, field) != v); \
0021         }                           \
0022     } while (0)
0023
0024 #define CHECK_ENC_GET_LE(tp, v, field, res) do {            \
0025         {                           \
0026             __le##tp _res;                  \
0027                                     \
0028             _res = le##tp##_encode_bits(v, field);      \
0029             KUNIT_ASSERT_FALSE_MSG(context,         \
0030                        _res != cpu_to_le##tp(res),  \
0031                        "le" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx",\
0032                        (u64)le##tp##_to_cpu(_res),  \
0033                        (u64)(res));         \
0034             KUNIT_ASSERT_FALSE(context,         \
0035                    le##tp##_get_bits(_res, field) != v);\
0036         }                           \
0037     } while (0)
0038
0039 #define CHECK_ENC_GET_BE(tp, v, field, res) do {            \
0040         {                           \
0041             __be##tp _res;                  \
0042                                     \
0043             _res = be##tp##_encode_bits(v, field);      \
0044             KUNIT_ASSERT_FALSE_MSG(context,         \
0045                        _res != cpu_to_be##tp(res),  \
0046                        "be" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx", \
0047                        (u64)be##tp##_to_cpu(_res),  \
0048                        (u64)(res));         \
0049             KUNIT_ASSERT_FALSE(context,         \
0050                    be##tp##_get_bits(_res, field) != v);\
0051         }                           \
0052     } while (0)
0053
0054 #define CHECK_ENC_GET(tp, v, field, res) do {               \
0055         CHECK_ENC_GET_U(tp, v, field, res);         \
0056         CHECK_ENC_GET_LE(tp, v, field, res);            \
0057         CHECK_ENC_GET_BE(tp, v, field, res);            \
0058     } while (0)
0059
0060 static void __init test_bitfields_constants(struct kunit *context)
0061 {
0062     /*
0063      * NOTE
0064      * This whole function compiles (or at least should, if everything
0065      * is going according to plan) to nothing after optimisation.
0066      */
0067
0068     CHECK_ENC_GET(16,  1, 0x000f, 0x0001);
0069     CHECK_ENC_GET(16,  3, 0x00f0, 0x0030);
0070     CHECK_ENC_GET(16,  5, 0x0f00, 0x0500);
0071     CHECK_ENC_GET(16,  7, 0xf000, 0x7000);
0072     CHECK_ENC_GET(16, 14, 0x000f, 0x000e);
0073     CHECK_ENC_GET(16, 15, 0x00f0, 0x00f0);
0074
0075     CHECK_ENC_GET_U(8,  1, 0x0f, 0x01);
0076     CHECK_ENC_GET_U(8,  3, 0xf0, 0x30);
0077     CHECK_ENC_GET_U(8, 14, 0x0f, 0x0e);
0078     CHECK_ENC_GET_U(8, 15, 0xf0, 0xf0);
0079
0080     CHECK_ENC_GET(32,  1, 0x00000f00, 0x00000100);
0081     CHECK_ENC_GET(32,  3, 0x0000f000, 0x00003000);
0082     CHECK_ENC_GET(32,  5, 0x000f0000, 0x00050000);
0083     CHECK_ENC_GET(32,  7, 0x00f00000, 0x00700000);
0084     CHECK_ENC_GET(32, 14, 0x0f000000, 0x0e000000);
0085     CHECK_ENC_GET(32, 15, 0xf0000000, 0xf0000000);
0086
0087     CHECK_ENC_GET(64,  1, 0x00000f0000000000ull, 0x0000010000000000ull);
0088     CHECK_ENC_GET(64,  3, 0x0000f00000000000ull, 0x0000300000000000ull);
0089     CHECK_ENC_GET(64,  5, 0x000f000000000000ull, 0x0005000000000000ull);
0090     CHECK_ENC_GET(64,  7, 0x00f0000000000000ull, 0x0070000000000000ull);
0091     CHECK_ENC_GET(64, 14, 0x0f00000000000000ull, 0x0e00000000000000ull);
0092     CHECK_ENC_GET(64, 15, 0xf000000000000000ull, 0xf000000000000000ull);
0093 }
0094
0095 #define CHECK(tp, mask) do {                        \
0096         u64 v;                          \
0097                                     \
0098         for (v = 0; v < 1 << hweight32(mask); v++)      \
0099             KUNIT_ASSERT_FALSE(context,         \
0100                 tp##_encode_bits(v, mask) != v << __ffs64(mask));\
0101     } while (0)
0102
0103 static void __init test_bitfields_variables(struct kunit *context)
0104 {
0105     CHECK(u8, 0x0f);
0106     CHECK(u8, 0xf0);
0107     CHECK(u8, 0x38);
0108
0109     CHECK(u16, 0x0038);
0110     CHECK(u16, 0x0380);
0111     CHECK(u16, 0x3800);
0112     CHECK(u16, 0x8000);
0113
0114     CHECK(u32, 0x80000000);
0115     CHECK(u32, 0x7f000000);
0116     CHECK(u32, 0x07e00000);
0117     CHECK(u32, 0x00018000);
0118
0119     CHECK(u64, 0x8000000000000000ull);
0120     CHECK(u64, 0x7f00000000000000ull);
0121     CHECK(u64, 0x0001800000000000ull);
0122     CHECK(u64, 0x0000000080000000ull);
0123     CHECK(u64, 0x000000007f000000ull);
0124     CHECK(u64, 0x0000000018000000ull);
0125     CHECK(u64, 0x0000001f8000000ull);
0126 }
0127
0128 #ifdef TEST_BITFIELD_COMPILE
0129 static void __init test_bitfields_compile(struct kunit *context)
0130 {
0131     /* these should fail compilation */
0132     CHECK_ENC_GET(16, 16, 0x0f00, 0x1000);
0133     u32_encode_bits(7, 0x06000000);
0134
0135     /* this should at least give a warning */
0136     u16_encode_bits(0, 0x60000);
0137 }
0138 #endif
0139
0140 static struct kunit_case __refdata bitfields_test_cases[] = {
0141     KUNIT_CASE(test_bitfields_constants),
0142     KUNIT_CASE(test_bitfields_variables),
0143     {}
0144 };
0145
0146 static struct kunit_suite bitfields_test_suite = {
0147     .name = "bitfields",
0148     .test_cases = bitfields_test_cases,
0149 };
0150
0151 kunit_test_suites(&bitfields_test_suite);
0152
0153 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
0154 MODULE_LICENSE("GPL");