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![Johannes Berg](/assets/img/avatar_default.png)
Add tests for the bitfield helpers. The constant ones will all be folded to nothing by the compiler (if everything is correct in the header file), and the variable ones do some tests against open-coding the necessary shifts. A few test cases that should fail/warn compilation are provided under ifdef. Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
168 lines
4.3 KiB
C
168 lines
4.3 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Test cases for bitfield helpers.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/bitfield.h>
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#define CHECK_ENC_GET_U(tp, v, field, res) do { \
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{ \
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u##tp _res; \
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\
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_res = u##tp##_encode_bits(v, field); \
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if (_res != res) { \
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pr_warn("u" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != " #res "\n",\
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(u64)_res); \
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return -EINVAL; \
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} \
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if (u##tp##_get_bits(_res, field) != v) \
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return -EINVAL; \
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} \
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} while (0)
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#define CHECK_ENC_GET_LE(tp, v, field, res) do { \
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{ \
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__le##tp _res; \
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\
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_res = le##tp##_encode_bits(v, field); \
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if (_res != cpu_to_le##tp(res)) { \
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pr_warn("le" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx\n",\
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(u64)le##tp##_to_cpu(_res), \
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(u64)(res)); \
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return -EINVAL; \
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} \
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if (le##tp##_get_bits(_res, field) != v) \
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return -EINVAL; \
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} \
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} while (0)
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#define CHECK_ENC_GET_BE(tp, v, field, res) do { \
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{ \
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__be##tp _res; \
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\
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_res = be##tp##_encode_bits(v, field); \
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if (_res != cpu_to_be##tp(res)) { \
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pr_warn("be" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx\n",\
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(u64)be##tp##_to_cpu(_res), \
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(u64)(res)); \
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return -EINVAL; \
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} \
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if (be##tp##_get_bits(_res, field) != v) \
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return -EINVAL; \
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} \
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} while (0)
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#define CHECK_ENC_GET(tp, v, field, res) do { \
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CHECK_ENC_GET_U(tp, v, field, res); \
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CHECK_ENC_GET_LE(tp, v, field, res); \
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CHECK_ENC_GET_BE(tp, v, field, res); \
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} while (0)
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static int test_constants(void)
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{
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/*
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* NOTE
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* This whole function compiles (or at least should, if everything
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* is going according to plan) to nothing after optimisation.
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*/
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CHECK_ENC_GET(16, 1, 0x000f, 0x0001);
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CHECK_ENC_GET(16, 3, 0x00f0, 0x0030);
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CHECK_ENC_GET(16, 5, 0x0f00, 0x0500);
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CHECK_ENC_GET(16, 7, 0xf000, 0x7000);
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CHECK_ENC_GET(16, 14, 0x000f, 0x000e);
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CHECK_ENC_GET(16, 15, 0x00f0, 0x00f0);
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CHECK_ENC_GET_U(8, 1, 0x0f, 0x01);
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CHECK_ENC_GET_U(8, 3, 0xf0, 0x30);
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CHECK_ENC_GET_U(8, 14, 0x0f, 0x0e);
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CHECK_ENC_GET_U(8, 15, 0xf0, 0xf0);
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CHECK_ENC_GET(32, 1, 0x00000f00, 0x00000100);
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CHECK_ENC_GET(32, 3, 0x0000f000, 0x00003000);
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CHECK_ENC_GET(32, 5, 0x000f0000, 0x00050000);
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CHECK_ENC_GET(32, 7, 0x00f00000, 0x00700000);
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CHECK_ENC_GET(32, 14, 0x0f000000, 0x0e000000);
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CHECK_ENC_GET(32, 15, 0xf0000000, 0xf0000000);
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CHECK_ENC_GET(64, 1, 0x00000f0000000000ull, 0x0000010000000000ull);
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CHECK_ENC_GET(64, 3, 0x0000f00000000000ull, 0x0000300000000000ull);
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CHECK_ENC_GET(64, 5, 0x000f000000000000ull, 0x0005000000000000ull);
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CHECK_ENC_GET(64, 7, 0x00f0000000000000ull, 0x0070000000000000ull);
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CHECK_ENC_GET(64, 14, 0x0f00000000000000ull, 0x0e00000000000000ull);
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CHECK_ENC_GET(64, 15, 0xf000000000000000ull, 0xf000000000000000ull);
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return 0;
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}
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#define CHECK(tp, mask) do { \
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u64 v; \
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\
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for (v = 0; v < 1 << hweight32(mask); v++) \
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if (tp##_encode_bits(v, mask) != v << __ffs64(mask)) \
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return -EINVAL; \
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} while (0)
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static int test_variables(void)
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{
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CHECK(u8, 0x0f);
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CHECK(u8, 0xf0);
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CHECK(u8, 0x38);
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CHECK(u16, 0x0038);
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CHECK(u16, 0x0380);
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CHECK(u16, 0x3800);
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CHECK(u16, 0x8000);
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CHECK(u32, 0x80000000);
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CHECK(u32, 0x7f000000);
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CHECK(u32, 0x07e00000);
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CHECK(u32, 0x00018000);
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CHECK(u64, 0x8000000000000000ull);
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CHECK(u64, 0x7f00000000000000ull);
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CHECK(u64, 0x0001800000000000ull);
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CHECK(u64, 0x0000000080000000ull);
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CHECK(u64, 0x000000007f000000ull);
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CHECK(u64, 0x0000000018000000ull);
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CHECK(u64, 0x0000001f8000000ull);
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return 0;
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}
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static int __init test_bitfields(void)
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{
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int ret = test_constants();
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if (ret) {
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pr_warn("constant tests failed!\n");
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return ret;
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}
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ret = test_variables();
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if (ret) {
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pr_warn("variable tests failed!\n");
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return ret;
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}
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#ifdef TEST_BITFIELD_COMPILE
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/* these should fail compilation */
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CHECK_ENC_GET(16, 16, 0x0f00, 0x1000);
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u32_encode_bits(7, 0x06000000);
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/* this should at least give a warning */
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u16_encode_bits(0, 0x60000);
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#endif
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pr_info("tests passed\n");
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return 0;
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}
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module_init(test_bitfields)
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MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
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MODULE_LICENSE("GPL");
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