[v2,05/13] mm/damon/sysfs: Support the physical address space monitoring

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 9221c93db6cc..968a4ba8e81b 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -113,12 +113,220 @@  static struct kobj_type damon_sysfs_ul_range_ktype = {
 	.default_groups = damon_sysfs_ul_range_groups,
 };
 
+/*
+ * init region directory
+ */
+
+struct damon_sysfs_region {
+	struct kobject kobj;
+	unsigned long start;
+	unsigned long end;
+};
+
+static struct damon_sysfs_region *damon_sysfs_region_alloc(
+		unsigned long start,
+		unsigned long end)
+{
+	struct damon_sysfs_region *region = kmalloc(sizeof(*region),
+			GFP_KERNEL);
+
+	if (!region)
+		return NULL;
+	region->kobj = (struct kobject){};
+	region->start = start;
+	region->end = end;
+	return region;
+}
+
+static ssize_t start_show(struct kobject *kobj, struct kobj_attribute *attr,
+		char *buf)
+{
+	struct damon_sysfs_region *region = container_of(kobj,
+			struct damon_sysfs_region, kobj);
+
+	return sysfs_emit(buf, "%lu\n", region->start);
+}
+
+static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct damon_sysfs_region *region = container_of(kobj,
+			struct damon_sysfs_region, kobj);
+	int err = kstrtoul(buf, 0, &region->start);
+
+	if (err)
+		return -EINVAL;
+	return count;
+}
+
+static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,
+		char *buf)
+{
+	struct damon_sysfs_region *region = container_of(kobj,
+			struct damon_sysfs_region, kobj);
+
+	return sysfs_emit(buf, "%lu\n", region->end);
+}
+
+static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct damon_sysfs_region *region = container_of(kobj,
+			struct damon_sysfs_region, kobj);
+	int err = kstrtoul(buf, 0, &region->end);
+
+	if (err)
+		return -EINVAL;
+	return count;
+}
+
+static void damon_sysfs_region_release(struct kobject *kobj)
+{
+	kfree(container_of(kobj, struct damon_sysfs_region, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_region_start_attr =
+		__ATTR_RW_MODE(start, 0600);
+
+static struct kobj_attribute damon_sysfs_region_end_attr =
+		__ATTR_RW_MODE(end, 0600);
+
+static struct attribute *damon_sysfs_region_attrs[] = {
+	&damon_sysfs_region_start_attr.attr,
+	&damon_sysfs_region_end_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_region);
+
+static struct kobj_type damon_sysfs_region_ktype = {
+	.release = damon_sysfs_region_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.default_groups = damon_sysfs_region_groups,
+};
+
+/*
+ * init_regions directory
+ */
+
+struct damon_sysfs_regions {
+	struct kobject kobj;
+	struct damon_sysfs_region **regions_arr;
+	int nr;
+};
+
+static struct damon_sysfs_regions *damon_sysfs_regions_alloc(void)
+{
+	return kzalloc(sizeof(struct damon_sysfs_regions), GFP_KERNEL);
+}
+
+static void damon_sysfs_regions_rm_dirs(struct damon_sysfs_regions *regions)
+{
+	struct damon_sysfs_region **regions_arr = regions->regions_arr;
+	int i;
+
+	for (i = 0; i < regions->nr; i++)
+		kobject_put(&regions_arr[i]->kobj);
+	regions->nr = 0;
+	kfree(regions_arr);
+	regions->regions_arr = NULL;
+}
+
+static int damon_sysfs_regions_add_dirs(struct damon_sysfs_regions *regions,
+		int nr_regions)
+{
+	struct damon_sysfs_region **regions_arr, *region;
+	int err, i;
+
+	damon_sysfs_regions_rm_dirs(regions);
+	if (!nr_regions)
+		return 0;
+
+	regions_arr = kmalloc_array(nr_regions, sizeof(*regions_arr),
+			GFP_KERNEL | __GFP_NOWARN);
+	if (!regions_arr)
+		return -ENOMEM;
+	regions->regions_arr = regions_arr;
+
+	for (i = 0; i < nr_regions; i++) {
+		region = damon_sysfs_region_alloc(0, 0);
+		if (!region) {
+			damon_sysfs_regions_rm_dirs(regions);
+			return -ENOMEM;
+		}
+
+		err = kobject_init_and_add(&region->kobj,
+				&damon_sysfs_region_ktype, &regions->kobj,
+				"%d", i);
+		if (err) {
+			kobject_put(&region->kobj);
+			damon_sysfs_regions_rm_dirs(regions);
+			return err;
+		}
+
+		regions_arr[i] = region;
+		regions->nr++;
+	}
+	return 0;
+}
+
+static ssize_t nr_regions_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	struct damon_sysfs_regions *regions = container_of(kobj,
+			struct damon_sysfs_regions, kobj);
+
+	return sysfs_emit(buf, "%d\n", regions->nr);
+}
+
+static ssize_t nr_regions_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	struct damon_sysfs_regions *regions = container_of(kobj,
+			struct damon_sysfs_regions, kobj);
+	int nr, err = kstrtoint(buf, 0, &nr);
+
+	if (err)
+		return err;
+	if (nr < 0)
+		return -EINVAL;
+
+	if (!mutex_trylock(&damon_sysfs_lock))
+		return -EBUSY;
+	err = damon_sysfs_regions_add_dirs(regions, nr);
+	mutex_unlock(&damon_sysfs_lock);
+	if (err)
+		return err;
+
+	return count;
+}
+
+static void damon_sysfs_regions_release(struct kobject *kobj)
+{
+	kfree(container_of(kobj, struct damon_sysfs_regions, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_regions_nr_attr =
+		__ATTR_RW_MODE(nr_regions, 0600);
+
+static struct attribute *damon_sysfs_regions_attrs[] = {
+	&damon_sysfs_regions_nr_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_regions);
+
+static struct kobj_type damon_sysfs_regions_ktype = {
+	.release = damon_sysfs_regions_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.default_groups = damon_sysfs_regions_groups,
+};
+
 /*
  * target directory
  */
 
 struct damon_sysfs_target {
 	struct kobject kobj;
+	struct damon_sysfs_regions *regions;
 	int pid;
 };
 
@@ -127,6 +335,29 @@  static struct damon_sysfs_target *damon_sysfs_target_alloc(void)
 	return kzalloc(sizeof(struct damon_sysfs_target), GFP_KERNEL);
 }
 
+static int damon_sysfs_target_add_dirs(struct damon_sysfs_target *target)
+{
+	struct damon_sysfs_regions *regions = damon_sysfs_regions_alloc();
+	int err;
+
+	if (!regions)
+		return -ENOMEM;
+
+	err = kobject_init_and_add(&regions->kobj, &damon_sysfs_regions_ktype,
+			&target->kobj, "regions");
+	if (err)
+		kobject_put(&regions->kobj);
+	else
+		target->regions = regions;
+	return err;
+}
+
+static void damon_sysfs_target_rm_dirs(struct damon_sysfs_target *target)
+{
+	damon_sysfs_regions_rm_dirs(target->regions);
+	kobject_put(&target->regions->kobj);
+}
+
 static ssize_t pid_target_show(struct kobject *kobj,
 		struct kobj_attribute *attr, char *buf)
 {
@@ -188,8 +419,10 @@  static void damon_sysfs_targets_rm_dirs(struct damon_sysfs_targets *targets)
 	struct damon_sysfs_target **targets_arr = targets->targets_arr;
 	int i;
 
-	for (i = 0; i < targets->nr; i++)
+	for (i = 0; i < targets->nr; i++) {
+		damon_sysfs_target_rm_dirs(targets_arr[i]);
 		kobject_put(&targets_arr[i]->kobj);
+	}
 	targets->nr = 0;
 	kfree(targets_arr);
 	targets->targets_arr = NULL;
@@ -224,6 +457,10 @@  static int damon_sysfs_targets_add_dirs(struct damon_sysfs_targets *targets,
 		if (err)
 			goto out;
 
+		err = damon_sysfs_target_add_dirs(target);
+		if (err)
+			goto out;
+
 		targets_arr[i] = target;
 		targets->nr++;
 	}
@@ -608,9 +845,6 @@  static ssize_t operations_store(struct kobject *kobj,
 
 	for (id = 0; id < NR_DAMON_OPS; id++) {
 		if (sysfs_streq(buf, damon_sysfs_ops_strs[id])) {
-			/* Support only vaddr */
-			if (id != DAMON_OPS_VADDR)
-				return -EINVAL;
 			context->ops_id = id;
 			return count;
 		}
@@ -855,10 +1089,37 @@  static void damon_sysfs_destroy_targets(struct damon_ctx *ctx)
 	}
 }
 
+static int damon_sysfs_set_regions(struct damon_target *t,
+		struct damon_sysfs_regions *sysfs_regions)
+{
+	int i;
+
+	for (i = 0; i < sysfs_regions->nr; i++) {
+		struct damon_sysfs_region *sys_region =
+			sysfs_regions->regions_arr[i];
+		struct damon_region *prev, *r;
+
+		if (sys_region->start > sys_region->end)
+			return -EINVAL;
+		r = damon_new_region(sys_region->start, sys_region->end);
+		if (!r)
+			return -ENOMEM;
+		damon_add_region(r, t);
+		if (damon_nr_regions(t) > 1) {
+			prev = damon_prev_region(r);
+			if (prev->ar.end > r->ar.start) {
+				damon_destroy_region(r, t);
+				return -EINVAL;
+			}
+		}
+	}
+	return 0;
+}
+
 static int damon_sysfs_set_targets(struct damon_ctx *ctx,
 		struct damon_sysfs_targets *sysfs_targets)
 {
-	int i;
+	int i, err;
 
 	for (i = 0; i < sysfs_targets->nr; i++) {
 		struct damon_sysfs_target *sys_target =
@@ -877,6 +1138,11 @@  static int damon_sysfs_set_targets(struct damon_ctx *ctx,
 			}
 		}
 		damon_add_target(ctx, t);
+		err = damon_sysfs_set_regions(t, sys_target->regions);
+		if (err) {
+			damon_sysfs_destroy_targets(ctx);
+			return err;
+		}
 	}
 	return 0;
 }