Messages in this thread | | | From | Andy Shevchenko <> | Date | Mon, 18 Jun 2018 23:44:46 +0300 | Subject | Re: [PATCH v4 3/3] bitfield: add tests |
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On Mon, Jun 18, 2018 at 11:37 PM, Johannes Berg <johannes@sipsolutions.net> wrote: > 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.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Though license mismatch. Either GPL-2.0+ for SPDX, or "GPL v2" for _LICENSE().
> > Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Signed-off-by: Johannes Berg <johannes@sipsolutions.net> > --- > 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 eb885942eb0f..b0870377b4d1 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -1799,6 +1799,13 @@ 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 84c6dcb31fbb..02ab4c1a64d1 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..c9bf2d542244 > --- /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 <johannes@sipsolutions.net>"); > +MODULE_LICENSE("GPL"); > -- > 2.14.4 >
-- With Best Regards, Andy Shevchenko
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