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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 v2] lib: test get_count_order/long in test_bitops.c
Date:   Tue,  2 Jun 2020 22:37:28 +0000
Message-Id: <20200602223728.32722-1-richard.weiyang@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add some test for get_count_order/long in test_bitops.c.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>

---
v2: merge the test into test_bitops.c
---
 lib/Kconfig.debug | 10 +++++-----
 lib/test_bitops.c | 40 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index f80d5609798f..512111a72e34 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1987,15 +1987,15 @@ config TEST_LKM
 	  If unsure, say N.
 
 config TEST_BITOPS
-	tristate "Test module for compilation of clear_bit/set_bit operations"
+	tristate "Test module for compilation of bitops operations"
 	depends on m
 	help
 	  This builds the "test_bitops" module that is much like the
 	  TEST_LKM module except that it does a basic exercise of the
-	  clear_bit and set_bit macros 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_bitops.
+	  set/clear_bit macros 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_bitops.
 
 	  If unsure, say N.
 
diff --git a/lib/test_bitops.c b/lib/test_bitops.c
index fd50b3ae4a14..702d5973a5b6 100644
--- a/lib/test_bitops.c
+++ b/lib/test_bitops.c
@@ -9,7 +9,11 @@
 #include <linux/module.h>
 #include <linux/printk.h>
 
-/* a tiny module only meant to test set/clear_bit */
+/* a tiny module only meant to test
+ *
+ *   set/clear_bit
+ *   get_count_order/long
+ */
 
 /* use an enum because thats the most common BITMAP usage */
 enum bitops_fun {
@@ -24,6 +28,26 @@ enum bitops_fun {
 
 static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH);
 
+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_bitops_startup(void)
 {
 	pr_warn("Loaded test module\n");
@@ -32,6 +56,18 @@ static int __init test_bitops_startup(void)
 	set_bit(BITOPS_11, g_bitmap);
 	set_bit(BITOPS_31, g_bitmap);
 	set_bit(BITOPS_88, g_bitmap);
+
+	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;
 }
 
@@ -55,6 +91,6 @@ static void __exit test_bitops_unstartup(void)
 module_init(test_bitops_startup);
 module_exit(test_bitops_unstartup);
 
-MODULE_AUTHOR("Jesse Brandeburg <jesse.brandeburg@intel.com>");
+MODULE_AUTHOR("Jesse Brandeburg <jesse.brandeburg@intel.com>, Wei Yang <richard.weiyang@gmail.com>");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Bit testing module");
-- 
2.23.0