From 0e2dc70e3d0d503b0cc9c5f74db3eb6db52c9e22 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 20 Jun 2018 08:58:30 +0200 Subject: [PATCH] bitfield: add tests 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 Reviewed-by: Andy Shevchenko Signed-off-by: Johannes Berg Signed-off-by: Kalle Valo --- lib/Kconfig.debug | 7 ++ lib/Makefile | 1 + lib/test_bitfield.c | 168 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 176 insertions(+) create mode 100644 lib/test_bitfield.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8838d1158d19..d3d82eccdfa5 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1802,6 +1802,13 @@ config TEST_BITMAP If unsure, say N. +config TEST_BITFIELD + tristate "Test bitfield functions at runtime" + help + Enable this option to test the bitfield functions at boot. + + If unsure, say N. + config TEST_UUID tristate "Test functions located in the uuid module at runtime" diff --git a/lib/Makefile b/lib/Makefile index 956b320292fe..701717a23d32 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -68,6 +68,7 @@ obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o obj-$(CONFIG_TEST_PRINTF) += test_printf.o obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o +obj-$(CONFIG_TEST_BITFIELD) += test_bitfield.o obj-$(CONFIG_TEST_UUID) += test_uuid.o obj-$(CONFIG_TEST_PARMAN) += test_parman.o obj-$(CONFIG_TEST_KMOD) += test_kmod.o 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 +#include +#include + +#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 "); +MODULE_LICENSE("GPL");