[RFC PATCH 07/18] mm/damon/sysfs: Use damon_addr_range for regions' start and end values

[SeongJae Park <sj@kernel.org>]

DAMON has a struct for each address range but DAMON sysfs interface is
using the low type (unsigned long) for storing the start and end
addresses of regions.  Use the dedicated struct for better type safety.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 9f1219a67e3f..b9183063bfea 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1062,13 +1062,11 @@ static struct kobj_type damon_sysfs_schemes_ktype = {
 
 struct damon_sysfs_region {
 	struct kobject kobj;
-	unsigned long start;
-	unsigned long end;
+	struct damon_addr_range ar;
 };
 
 static struct damon_sysfs_region *damon_sysfs_region_alloc(
-		unsigned long start,
-		unsigned long end)
+		struct damon_addr_range ar)
 {
 	struct damon_sysfs_region *region = kmalloc(sizeof(*region),
 			GFP_KERNEL);
@@ -1076,8 +1074,7 @@ static struct damon_sysfs_region *damon_sysfs_region_alloc(
 	if (!region)
 		return NULL;
 	region->kobj = (struct kobject){};
-	region->start = start;
-	region->end = end;
+	region->ar = ar;
 	return region;
 }
 
@@ -1087,7 +1084,7 @@ static ssize_t start_show(struct kobject *kobj, struct kobj_attribute *attr,
 	struct damon_sysfs_region *region = container_of(kobj,
 			struct damon_sysfs_region, kobj);
 
-	return sysfs_emit(buf, "%lu\n", region->start);
+	return sysfs_emit(buf, "%lu\n", region->ar.start);
 }
 
 static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -1095,7 +1092,7 @@ static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
 {
 	struct damon_sysfs_region *region = container_of(kobj,
 			struct damon_sysfs_region, kobj);
-	int err = kstrtoul(buf, 0, &region->start);
+	int err = kstrtoul(buf, 0, &region->ar.start);
 
 	return err ? err : count;
 }
@@ -1106,7 +1103,7 @@ static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,
 	struct damon_sysfs_region *region = container_of(kobj,
 			struct damon_sysfs_region, kobj);
 
-	return sysfs_emit(buf, "%lu\n", region->end);
+	return sysfs_emit(buf, "%lu\n", region->ar.end);
 }
 
 static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -1114,7 +1111,7 @@ static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
 {
 	struct damon_sysfs_region *region = container_of(kobj,
 			struct damon_sysfs_region, kobj);
-	int err = kstrtoul(buf, 0, &region->end);
+	int err = kstrtoul(buf, 0, &region->ar.end);
 
 	return err ? err : count;
 }
@@ -1187,7 +1184,7 @@ static int damon_sysfs_regions_add_dirs(struct damon_sysfs_regions *regions,
 	regions->regions_arr = regions_arr;
 
 	for (i = 0; i < nr_regions; i++) {
-		region = damon_sysfs_region_alloc(0, 0);
+		region = damon_sysfs_region_alloc((struct damon_addr_range){});
 		if (!region) {
 			damon_sysfs_regions_rm_dirs(regions);
 			return -ENOMEM;
@@ -2147,11 +2144,11 @@ static int damon_sysfs_set_regions(struct damon_target *t,
 		struct damon_sysfs_region *sys_region =
 			sysfs_regions->regions_arr[i];
 
-		if (sys_region->start > sys_region->end)
+		if (sys_region->ar.start > sys_region->ar.end)
 			goto out;
 
-		ranges[i].start = sys_region->start;
-		ranges[i].end = sys_region->end;
+		ranges[i].start = sys_region->ar.start;
+		ranges[i].end = sys_region->ar.end;
 		if (i == 0)
 			continue;
 		if (ranges[i - 1].end > ranges[i].start)
-- 
2.25.1