From: Johannes Berg <johannes@sipsolutions.net>
To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Andy Shevchenko <andy.shevchenko@gmail.com>
Subject: [PATCH v5 3/3] bitfield: add tests
Date: Mon, 18 Jun 2018 22:48:16 +0200 [thread overview]
Message-ID: <20180618204816.30806-3-johannes@sipsolutions.net> (raw)
In-Reply-To: <20180618204816.30806-1-johannes@sipsolutions.net>
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>
---
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..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");
--
2.14.4
prev parent reply other threads:[~2018-06-18 20:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-18 20:48 [PATCH v5 1/3] bitfield: fix *_encode_bits() Johannes Berg
2018-06-18 20:48 ` [PATCH v5 2/3] bitfield: add u8 helpers Johannes Berg
2018-06-18 20:48 ` Johannes Berg [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180618204816.30806-3-johannes@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=andy.shevchenko@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).