// 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 <johannes@sipsolutions.net>");
MODULE_LICENSE("GPL");
