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authorJohannes Berg <johannes@sipsolutions.net>2018-06-20 09:58:30 +0300
committerKalle Valo <kvalo@codeaurora.org>2018-06-27 18:58:49 +0300
commit0e2dc70e3d0d503b0cc9c5f74db3eb6db52c9e22 (patch)
tree58ea25d9c8ffb3fbc407ffce77823dccbc020af2 /lib
parent37a3862e1238262e9866d5d66e5f5f9069cee3a1 (diff)
downloadlinux-0e2dc70e3d0d503b0cc9c5f74db3eb6db52c9e22.tar.xz
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 <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>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug7
-rw-r--r--lib/Makefile1
-rw-r--r--lib/test_bitfield.c168
3 files changed, 176 insertions, 0 deletions
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 <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");