mm/damon/sysfs: move unsigned long range directory to common module

The implementation of unsigned long type range directories can be reused
by multiple DAMON sysfs directories including those for DAMON-based
Operation Schemes and the range of number of monitoring regions.  Move the
code into the files for DAMON sysfs common logics.

Link: https://lkml.kernel.org/r/20221026225943.100429-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 96 insertions, 0 deletions

diff --git a/mm/damon/sysfs-common.c b/mm/damon/sysfs-common.c
index 9dc743868d5b..52bebf242f74 100644
--- a/mm/damon/sysfs-common.c
+++ b/mm/damon/sysfs-common.c
@@ -5,7 +5,103 @@
  * Author: SeongJae Park <sj@kernel.org>
  */
 
+#include <linux/slab.h>
+
 #include "sysfs-common.h"
 
 DEFINE_MUTEX(damon_sysfs_lock);
 
+/*
+ * unsigned long range directory
+ */
+
+struct damon_sysfs_ul_range *damon_sysfs_ul_range_alloc(
+		unsigned long min,
+		unsigned long max)
+{
+	struct damon_sysfs_ul_range *range = kmalloc(sizeof(*range),
+			GFP_KERNEL);
+
+	if (!range)
+		return NULL;
+	range->kobj = (struct kobject){};
+	range->min = min;
+	range->max = max;
+
+	return range;
+}
+
+static ssize_t min_show(struct kobject *kobj, struct kobj_attribute *attr,
+		char *buf)
+{
+	struct damon_sysfs_ul_range *range = container_of(kobj,
+			struct damon_sysfs_ul_range, kobj);
+
+	return sysfs_emit(buf, "%lu\n", range->min);
+}
+
+static ssize_t min_store(struct kobject *kobj, struct kobj_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct damon_sysfs_ul_range *range = container_of(kobj,
+			struct damon_sysfs_ul_range, kobj);
+	unsigned long min;
+	int err;
+
+	err = kstrtoul(buf, 0, &min);
+	if (err)
+		return err;
+
+	range->min = min;
+	return count;
+}
+
+static ssize_t max_show(struct kobject *kobj, struct kobj_attribute *attr,
+		char *buf)
+{
+	struct damon_sysfs_ul_range *range = container_of(kobj,
+			struct damon_sysfs_ul_range, kobj);
+
+	return sysfs_emit(buf, "%lu\n", range->max);
+}
+
+static ssize_t max_store(struct kobject *kobj, struct kobj_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct damon_sysfs_ul_range *range = container_of(kobj,
+			struct damon_sysfs_ul_range, kobj);
+	unsigned long max;
+	int err;
+
+	err = kstrtoul(buf, 0, &max);
+	if (err)
+		return err;
+
+	range->max = max;
+	return count;
+}
+
+void damon_sysfs_ul_range_release(struct kobject *kobj)
+{
+	kfree(container_of(kobj, struct damon_sysfs_ul_range, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_ul_range_min_attr =
+		__ATTR_RW_MODE(min, 0600);
+
+static struct kobj_attribute damon_sysfs_ul_range_max_attr =
+		__ATTR_RW_MODE(max, 0600);
+
+static struct attribute *damon_sysfs_ul_range_attrs[] = {
+	&damon_sysfs_ul_range_min_attr.attr,
+	&damon_sysfs_ul_range_max_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_ul_range);
+
+struct kobj_type damon_sysfs_ul_range_ktype = {
+	.release = damon_sysfs_ul_range_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.default_groups = damon_sysfs_ul_range_groups,
+};
+