mm/damon/modules: deduplicate init steps for DAMON context setup

DAMON_RECLAIM and DAMON_LRU_SORT has duplicated code for DAMON context and
target initializations.  Deduplicate the part by implementing a function
for the initialization in 'modules-common.c' and using it.

Link: https://lkml.kernel.org/r/20221026225943.100429-12-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/mm/damon/modules-common.c b/mm/damon/modules-common.c
new file mode 100644
index 000000000000..b2381a8466ec
--- /dev/null
+++ b/mm/damon/modules-common.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common Primitives for DAMON Modules
+ *
+ * Author: SeongJae Park <sjpark@amazon.de>
+ */
+
+#include <linux/damon.h>
+
+#include "modules-common.h"
+
+/*
+ * Allocate, set, and return a DAMON context for the physical address space.
+ * @ctxp:	Pointer to save the point to the newly created context
+ * @targetp:	Pointer to save the point to the newly created target
+ */
+int damon_modules_new_paddr_ctx_target(struct damon_ctx **ctxp,
+		struct damon_target **targetp)
+{
+	struct damon_ctx *ctx;
+	struct damon_target *target;
+
+	ctx = damon_new_ctx();
+	if (!ctx)
+		return -ENOMEM;
+
+	if (damon_select_ops(ctx, DAMON_OPS_PADDR)) {
+		damon_destroy_ctx(ctx);
+		return -EINVAL;
+	}
+
+	target = damon_new_target();
+	if (!target) {
+		damon_destroy_ctx(ctx);
+		return -ENOMEM;
+	}
+	damon_add_target(ctx, target);
+
+	*ctxp = ctx;
+	*targetp = target;
+	return 0;
+}