diff options
Diffstat (limited to 'lib/test_bitfield.c')
| -rw-r--r-- | lib/test_bitfield.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/lib/test_bitfield.c b/lib/test_bitfield.c new file mode 100644 index 000000000000..5b8f4108662d --- /dev/null +++ b/lib/test_bitfield.c @@ -0,0 +1,168 @@ +// 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 <[email protected]>"); +MODULE_LICENSE("GPL"); |