[RFC PATCH v3 22/37] mm/damon/sysfs: implement cpumask file under sample filter dir

[SeongJae Park <sj@kernel.org>]

The DAON sample filter directory has files for only common properties.
Add a file to further specify the CPUs to filter in or out.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 74594e6e461c..d6b0b6513fd1 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -758,6 +758,7 @@ struct damon_sysfs_sample_filter {
 	enum damon_sample_filter_type type;
 	bool matching;
 	bool allow;
+	cpumask_t cpumask;
 };
 
 static struct damon_sysfs_sample_filter *damon_sysfs_sample_filter_alloc(void)
@@ -765,6 +766,19 @@ static struct damon_sysfs_sample_filter *damon_sysfs_sample_filter_alloc(void)
 	return kzalloc(sizeof(struct damon_sysfs_sample_filter), GFP_KERNEL);
 }
 
+struct damon_sysfs_sample_filter_type_name {
+	enum damon_sample_filter_type type;
+	char *name;
+};
+
+static const struct damon_sysfs_sample_filter_type_name
+damon_sysfs_sample_filter_type_names[] = {
+	{
+		.type = DAMON_FILTER_TYPE_CPUMASK,
+		.name = "cpumask",
+	},
+};
+
 static ssize_t type_show(struct kobject *kobj,
 		struct kobj_attribute *attr, char *buf)
 {
@@ -851,6 +865,29 @@ static ssize_t allow_store(struct kobject *kobj,
 	return count;
 }
 
+static ssize_t cpumask_show(struct kobject *kobj, struct kobj_attribute *attr,
+		char *buf)
+{
+	struct damon_sysfs_sample_filter *filter = container_of(kobj,
+			struct damon_sysfs_sample_filter, kobj);
+
+	return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(&filter->cpumask));
+}
+
+static ssize_t cpumask_store(struct kobject *kobj, struct kobj_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct damon_sysfs_sample_filter *filter = container_of(kobj,
+			struct damon_sysfs_sample_filter, kobj);
+	cpumask_t cpumask;
+	int err = cpulist_parse(buf, &cpumask);
+
+	if (err)
+		return err;
+	filter->cpumask = cpumask;
+	return count;
+}
+
 static void damon_sysfs_sample_filter_release(struct kobject *kobj)
 {
 	struct damon_sysfs_sample_filter *filter = container_of(kobj,
@@ -868,10 +905,14 @@ static struct kobj_attribute damon_sysfs_sample_filter_matching_attr =
 static struct kobj_attribute damon_sysfs_sample_filter_allow_attr =
 		__ATTR_RW_MODE(allow, 0600);
 
+static struct kobj_attribute damon_sysfs_sample_filter_cpumask_attr =
+		__ATTR_RW_MODE(cpumask, 0600);
+
 static struct attribute *damon_sysfs_sample_filter_attrs[] = {
 	&damon_sysfs_sample_filter_type_attr.attr,
 	&damon_sysfs_sample_filter_matching_attr.attr,
 	&damon_sysfs_sample_filter_allow_attr.attr,
+	&damon_sysfs_sample_filter_cpumask_attr.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(damon_sysfs_sample_filter);
-- 
2.47.3