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From:   Wei Yang <richard.weiyang@gmail.com>
To:     akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com,
        christian.brauner@ubuntu.com
Cc:     linux-kernel@vger.kernel.org, Wei Yang <richard.weiyang@gmail.com>
Subject: [PATCH] lib: make a test module with get_count_order/long
Date:   Sat, 30 May 2020 00:43:28 +0000
Message-Id: <20200530004328.30530-1-richard.weiyang@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

A test module to make sure get_count_order/long returns the correct result.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
 lib/Kconfig.debug                  | 13 ++++++
 lib/Makefile                       |  2 +
 lib/test_getorder.c                | 64 ++++++++++++++++++++++++++++++
 tools/testing/selftests/lib/config |  1 +
 4 files changed, 80 insertions(+)
 create mode 100644 lib/test_getorder.c

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c0ef216bb803..01e671151f42 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1999,6 +1999,19 @@ config TEST_BITOPS
 
 	  If unsure, say N.
 
+config TEST_GETORDER
+	tristate "Test module for compilation of get_count_order operations"
+	depends on m
+	help
+	  This builds the "test_getorder" module that is much like the
+	  TEST_LKM module except that it does a basic exercise of the
+	  get_count_order and get_count_order_long to make sure there are no
+	  compiler warnings from C=1 sparse checker or -Wextra compilations.
+	  It has no dependencies and doesn't run or load unless explicitly
+	  requested by name. For example: modprobe test_getorder.
+
+	  If unsure, say N.
+
 config TEST_VMALLOC
 	tristate "Test module for stress/performance analysis of vmalloc allocator"
 	default n
diff --git a/lib/Makefile b/lib/Makefile
index 0d942f7c7478..806d4df8f7c7 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -81,6 +81,8 @@ obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
 obj-$(CONFIG_TEST_BITOPS) += test_bitops.o
 CFLAGS_test_bitops.o += -Werror
+obj-$(CONFIG_TEST_GETORDER) += test_getorder.o
+CFLAGS_test_getorder.o += -Werror
 obj-$(CONFIG_TEST_PRINTF) += test_printf.o
 obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
 obj-$(CONFIG_TEST_STRSCPY) += test_strscpy.o
diff --git a/lib/test_getorder.c b/lib/test_getorder.c
new file mode 100644
index 000000000000..6492abc793af
--- /dev/null
+++ b/lib/test_getorder.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Author: Wei Yang <richard.weiyang@gmail.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+
+/* a tiny module only meant to test get_count_order/long */
+unsigned int order_comb[][2] = {
+	{0x00000003,  2},
+	{0x00000004,  2},
+	{0x00001fff, 13},
+	{0x00002000, 13},
+	{0x50000000, 31},
+	{0x80000000, 31},
+	{0x80003000, 32},
+};
+
+unsigned long order_comb_long[][2] = {
+	{0x0000000300000000, 34},
+	{0x0000000400000000, 34},
+	{0x00001fff00000000, 45},
+	{0x0000200000000000, 45},
+	{0x5000000000000000, 63},
+	{0x8000000000000000, 63},
+	{0x8000300000000000, 64},
+};
+
+static int __init test_getorder_startup(void)
+{
+	int i;
+
+	pr_warn("Loaded test module\n");
+	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
+		if (order_comb[i][1] != get_count_order(order_comb[i][0]))
+			pr_warn("get_count_order wrong for %x\n",
+					order_comb[i][0]);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(order_comb_long); i++) {
+		if (order_comb_long[i][1] !=
+				get_count_order_long(order_comb_long[i][0]))
+			pr_warn("get_count_order_long wrong for %lx\n",
+					order_comb_long[i][0]);
+	}
+
+	return 0;
+}
+
+static void __exit test_getorder_unstartup(void)
+{
+	pr_warn("Unloaded test module\n");
+}
+
+module_init(test_getorder_startup);
+module_exit(test_getorder_unstartup);
+
+MODULE_AUTHOR("Wei Yang <richard.weiyang@gmail.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("get_count_order/long testing module");
diff --git a/tools/testing/selftests/lib/config b/tools/testing/selftests/lib/config
index b80ee3f6e265..2ad467d34648 100644
--- a/tools/testing/selftests/lib/config
+++ b/tools/testing/selftests/lib/config
@@ -3,3 +3,4 @@ CONFIG_TEST_BITMAP=m
 CONFIG_PRIME_NUMBERS=m
 CONFIG_TEST_STRSCPY=m
 CONFIG_TEST_BITOPS=m
+CONFIG_TEST_GETORDER=m
-- 
2.23.0