[PATCH 3/4] debugfs: provide testing for the min/max simple debug files.

[chris hyser]

This patch contains a module and a bash script which tests the new simple
"unsigned min/max checking" files.

The module creates the debugfs files and encodes the test type and test
parameters in the file name which the script decodes and tests.

Currently the files were placed under testscripts though auto testing is
not yet enabled. The hope is that this eases testing of the patches.

Signed-off-by: Chris Hyser <chris.hyser@xxxxxxxxxx>
---
 tools/testing/selftests/debugfs/Makefile      |  15 ++
 tools/testing/selftests/debugfs/minmax_test.c | 140 +++++++++++++++++
 .../testing/selftests/debugfs/test_minmax.sh  | 147 ++++++++++++++++++
 3 files changed, 302 insertions(+)
 create mode 100644 tools/testing/selftests/debugfs/Makefile
 create mode 100644 tools/testing/selftests/debugfs/minmax_test.c
 create mode 100755 tools/testing/selftests/debugfs/test_minmax.sh

diff --git a/tools/testing/selftests/debugfs/Makefile b/tools/testing/selftests/debugfs/Makefile
new file mode 100644
index 000000000000..5dddaaf6c7a2
--- /dev/null
+++ b/tools/testing/selftests/debugfs/Makefile
@@ -0,0 +1,15 @@
+obj-m := minmax_test.o
+
+KDIR := ../../../..
+PWD := $(shell pwd)
+WARN_FLAGS += -Wall
+
+.PHONY: all
+all:
+	$(MAKE) -C $(KDIR) M=$(PWD) modules
+
+clean:
+	$(MAKE) -C $(KDIR) M=$(PWD) clean
+
+
+include ../lib.mk
diff --git a/tools/testing/selftests/debugfs/minmax_test.c b/tools/testing/selftests/debugfs/minmax_test.c
new file mode 100644
index 000000000000..0e0f6bcd6302
--- /dev/null
+++ b/tools/testing/selftests/debugfs/minmax_test.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test debugfs minmax simple files.
+ *
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ * Author: Chris Hyser <chris.hyser@xxxxxxxxxx>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, see <http://www.gnu.org/licenses>.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+MODULE_LICENSE("GPL");
+
+#define MIN_MAX 1
+
+static struct dentry *dir = NULL;
+
+#ifdef MIN_MAX
+u8 test_max_8 = 250;
+DEBUGFS_MAX_ATTRIBUTES(test_max_8_p, &test_max_8, 252);
+
+u8 test_min_8 = 250;
+DEBUGFS_MIN_ATTRIBUTES(test_min_8_p, &test_min_8, 25);
+
+u8 test_minmax_8 = 250;
+DEBUGFS_MINMAX_ATTRIBUTES(test_minmax_8_p, &test_minmax_8, 100, 253);
+
+
+u16 test_max_16 = 250;
+DEBUGFS_MAX_ATTRIBUTES(test_max_16_p, &test_max_16, 0x1fff);
+
+u16 test_min_16 = 250;
+DEBUGFS_MIN_ATTRIBUTES(test_min_16_p, &test_min_16, 100);
+
+u16 test_minmax_16 = 250;
+DEBUGFS_MINMAX_ATTRIBUTES(test_minmax_16_p, &test_minmax_16, 100, 300);
+
+
+u32 test_max_32 = 250;
+DEBUGFS_MAX_ATTRIBUTES(test_max_32_p, &test_max_32, 0x1fffffff);
+
+u32 test_min_32 = 250;
+DEBUGFS_MIN_ATTRIBUTES(test_min_32_p, &test_min_32, 100);
+
+u32 test_minmax_32 = 250;
+DEBUGFS_MINMAX_ATTRIBUTES(test_minmax_32_p, &test_minmax_32, 100, 0x1fffffff);
+
+/* test setting everything directly */
+u32 test_minmax_32_s = 250;
+static struct debugfs_minmax_params test_minmax_32_ps = {
+	.value = &test_minmax_32_s,
+	.min = 100,
+	.max = 0x1fffffff,
+	.flags = 3,
+};
+
+u64 test_max_64 = 250;
+DEBUGFS_MAX_ATTRIBUTES(test_max_64_p, &test_max_64, 0x1fffffff);
+
+u64 test_min_64 = 250;
+DEBUGFS_MIN_ATTRIBUTES(test_min_64_p, &test_min_64, 100);
+
+u64 test_minmax_64 = 250;
+DEBUGFS_MINMAX_ATTRIBUTES(test_minmax_64_p, &test_minmax_64, 100, 300);
+#endif
+
+u8 test_reg_8 = 250;
+u16 test_reg_16 = 250;
+u32 test_reg_32 = 250;
+u64 test_reg_64 = 250;
+
+u8 test_regx_8 = 250;
+u16 test_regx_16 = 250;
+u32 test_regx_32 = 250;
+u64 test_regx_64 = 250;
+
+
+/* File names consist of test_<test_type>_<1st param>_<optional sec
+ * param>_<storage size in bits>.
+ */
+
+int init_module(void)
+{
+	pr_err("minmax_test: init_module()\n");
+	dir = debugfs_create_dir("minmax_test", 0);
+	if (dir == NULL) {
+		printk(KERN_ALERT "minmax_test: can't create dir 'minmax_test'\n");
+		return -1;
+	}
+
+#ifdef MIN_MAX
+        debugfs_create_u8_minmax("test_max_252_8", 0644, dir, &test_max_8_p);
+        debugfs_create_u8_minmax("test_min_25_8", 0644, dir, &test_min_8_p);
+        debugfs_create_u8_minmax("test_minmax_100_253_8", 0644, dir, &test_minmax_8_p);
+
+        debugfs_create_u16_minmax("test_max_0x1fff_16", 0644, dir, &test_max_16_p);
+        debugfs_create_u16_minmax("test_min_100_16", 0644, dir, &test_min_16_p);
+        debugfs_create_u16_minmax("test_minmax_100_300_16", 0644, dir, &test_minmax_16_p);
+
+        debugfs_create_u32_minmax("test_max_0x1fffffff_32", 0644, dir, &test_max_32_p);
+        debugfs_create_u32_minmax("test_min_100_32", 0644, dir, &test_min_32_p);
+        debugfs_create_u32_minmax("test_minmax_100_0x1fffffff_32", 0644, dir, &test_minmax_32_p);
+        debugfs_create_u32_minmax("testss_minmax_100_0x1fffffff_32", 0644, dir, &test_minmax_32_ps);
+
+        debugfs_create_u64_minmax("test_max_0x1fffffff_64", 0644, dir, &test_max_64_p);
+        debugfs_create_u64_minmax("test_min_100_64", 0644, dir, &test_min_64_p);
+        debugfs_create_u64_minmax("test_minmax_100_300_64", 0644, dir, &test_minmax_64_p);
+#endif
+
+        debugfs_create_u8("test_reg_8", 0644, dir, &test_reg_8);
+        debugfs_create_u16("test_reg_16", 0644, dir, &test_reg_16);
+        debugfs_create_u32("test_reg_32", 0644, dir, &test_reg_32);
+        debugfs_create_u64("test_reg_64", 0644, dir, &test_reg_64);
+
+        debugfs_create_x8("test_regx_8", 0644, dir, &test_regx_8);
+        debugfs_create_x16("test_regx_16", 0644, dir, &test_regx_16);
+        debugfs_create_x32("test_regx_32", 0644, dir, &test_regx_32);
+        debugfs_create_x64("test_regx_64", 0644, dir, &test_regx_64);
+	return 0;
+}
+
+void cleanup_module(void)
+{
+	pr_err("minmax_test: cleanup_module()\n");
+	debugfs_remove_recursive(dir);
+}
diff --git a/tools/testing/selftests/debugfs/test_minmax.sh b/tools/testing/selftests/debugfs/test_minmax.sh
new file mode 100755
index 000000000000..67ed7b9abac2
--- /dev/null
+++ b/tools/testing/selftests/debugfs/test_minmax.sh
@@ -0,0 +1,147 @@
+#!/bin/bash
+
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Test debugfs minmax simple files.
+#
+# Copyright (c) 2023 Oracle and/or its affiliates.
+# Author: Chris Hyser <chris.hyser@xxxxxxxxxx>
+#
+# This library is free software; you can redistribute it and/or modify it
+# under the terms of version 2.1 of the GNU Lesser General Public License as
+# published by the Free Software Foundation.
+#
+# This library is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+# for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this library; if not, see <http://www.gnu.org/licenses>.
+
+rmmod minmax_test 2>/dev/null
+insmod minmax_test.ko
+
+cd /sys/kernel/debug/minmax_test
+pwd
+
+function split_wds()
+{
+    words=()
+    local IFS=_
+    for w in $1; do
+	words+=($w)
+    done
+}
+
+function test_max()
+{
+    echo $2 > $1
+    local res=$?
+    local rv=$(cat $1)
+    if ! (( res == 0 && $2 == rv )); then
+	return 1
+    fi
+
+    local max=$(($2 + 1))
+    echo $max > $1 2>/dev/null
+    res=$?
+    rv=$(cat $1)
+    if ! [[ $res -ne 0 && $2 -eq $rv ]]; then
+	return 1
+    fi
+    return 0
+}
+
+function test_min()
+{
+    echo $2 > $1
+    local res=$?
+    local rv=$(cat $1)
+    if ! [[ $res -eq 0 && $2 -eq $rv ]]; then
+	return 1
+    fi
+
+    local min=$(($2 - 1))
+    echo $min > $1 2>/dev/null
+    res=$?
+    rv=$(cat $1)
+    if ! [[ $res -ne 0 && $2 -eq $rv ]]; then
+	return 1
+    fi
+    return 0
+}
+
+function test_minmax()
+{
+    test_min $1 ${words[2]}
+    if [[ $? -ne 0 ]]; then
+	echo "$1: min error"
+        return 1
+    fi
+    test_max $1 ${words[3]}
+    if [[ $? -ne 0 ]]; then
+	echo "$1: max error"
+        return 1
+    fi
+    return 0
+}
+
+function test_reg()
+{
+    if [[ $2 -eq 64 ]]; then
+	local V=313
+
+	echo $V > $1 2>/dev/null
+
+	local rv=$(cat $1)
+	if ! (( rv == V )); then
+	    return 1
+	fi
+	return 0
+    fi
+
+    local max=$(((1 << $2) - 1))
+    test_max $1 $max
+    if [[ $? -ne 0 ]]; then
+	echo "$1: reg/x error"
+        return 1
+    fi
+    return 0
+}
+
+rc=0
+for f in *; do
+    split_wds $f
+    echo file: $f
+
+    if [[ ${words[1]} == "min" ]]; then
+	test_min $f ${words[2]}
+	if [[ $? -ne 0 ]]; then
+	    echo "$f: min error"
+	    rc=1
+	fi
+    elif [[ ${words[1]} == "max" ]]; then
+	test_max $f ${words[2]}
+	if [[ $? -ne 0 ]]; then
+	    echo "$f: max error"
+	    rc=1
+	fi
+    elif [[ ${words[1]} == "minmax" ]]; then
+	test_minmax $f ${words[2]} ${words[3]}
+	if [[ $? -ne 0 ]]; then
+	    echo "$f: minmax error"
+	    rc=1
+	fi
+    elif [[ ${words[1]} == "reg" || ${words[1]} == "regx" ]]; then
+	test_reg $f ${words[2]}
+	if [[ $? -ne 0 ]]; then
+	    echo "$f: reg/x error"
+	    rc=1
+	fi
+    fi
+done
+
+rmmod minmax_test
+
+exit $rc
-- 
2.31.1