lib/bitfield_kunit.c

   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_DESCRIPTION("Test cases for bitfield helpers");
 155 MODULE_LICENSE("GPL");