mm/damon: deduplicate damon_{reclaim,lru_sort}_apply_parameters()

The bodies of damon_{reclaim,lru_sort}_apply_parameters() contain
duplicates.  This commit adds a common function
damon_set_region_biggest_system_ram_default() to remove the duplicates.

Link: https://lkml.kernel.org/r/6329f00d.a70a0220.9bb29.3678SMTPIN_ADDED_BROKEN@mx.google.com
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Suggested-by: SeongJae Park <sj@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 34 insertions, 1 deletions

diff --git a/mm/damon/core.c b/mm/damon/core.c
index 9c80c6eb00c2..4de8c7c52979 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -1245,7 +1245,8 @@ static int walk_system_ram(struct resource *res, void *arg)
  * Find biggest 'System RAM' resource and store its start and end address in
  * @start and @end, respectively.  If no System RAM is found, returns false.
  */
-bool damon_find_biggest_system_ram(unsigned long *start, unsigned long *end)
+static bool damon_find_biggest_system_ram(unsigned long *start,
+						unsigned long *end)
 
 {
 	struct damon_system_ram_region arg = {};
@@ -1259,6 +1260,38 @@ bool damon_find_biggest_system_ram(unsigned long *start, unsigned long *end)
 	return true;
 }
 
+/**
+ * damon_set_region_biggest_system_ram_default() - Set the region of the given
+ * monitoring target as requested, or biggest 'System RAM'.
+ * @t:		The monitoring target to set the region.
+ * @start:	The pointer to the start address of the region.
+ * @end:	The pointer to the end address of the region.
+ *
+ * This function sets the region of @t as requested by @start and @end.  If the
+ * values of @start and @end are zero, however, this function finds the biggest
+ * 'System RAM' resource and sets the region to cover the resource.  In the
+ * latter case, this function saves the start and end addresses of the resource
+ * in @start and @end, respectively.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_set_region_biggest_system_ram_default(struct damon_target *t,
+			unsigned long *start, unsigned long *end)
+{
+	struct damon_addr_range addr_range;
+
+	if (*start > *end)
+		return -EINVAL;
+
+	if (!*start && !*end &&
+		!damon_find_biggest_system_ram(start, end))
+		return -EINVAL;
+
+	addr_range.start = *start;
+	addr_range.end = *end;
+	return damon_set_regions(t, &addr_range, 1);
+}
+
 static int __init damon_init(void)
 {
 	damon_region_cache = KMEM_CACHE(damon_region, 0);