// 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");