Let damon_probe objects be able to be installed on a given damon_ctx, by
adding a linked list header for storing the objects.  Add initialization
and cleanup of the new field with helper functions, too.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 include/linux/damon.h |  9 +++++++++
 mm/damon/core.c       | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 4794931fa2ea3..dc53bc3da74b3 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -857,6 +857,7 @@ struct damon_ctx {
 
 /* public: */
 	struct damon_operations ops;
+	struct list_head probes;
 	unsigned long addr_unit;
 	unsigned long min_region_sz;
 	bool pause;
@@ -909,6 +910,11 @@ static inline unsigned long damon_sz_region(struct damon_region *r)
 	return r->ar.end - r->ar.start;
 }
 
+#define damon_for_each_probe(p, ctx) \
+	list_for_each_entry(p, &ctx->probes, list)
+
+#define damon_for_each_probe_safe(p, next, ctx) \
+	list_for_each_entry_safe(p, next, &ctx->probes, list)
 
 #define damon_for_each_region(r, t) \
 	list_for_each_entry(r, &t->regions_list, list)
@@ -951,6 +957,9 @@ static inline unsigned long damon_sz_region(struct damon_region *r)
 
 #ifdef CONFIG_DAMON
 
+struct damon_probe *damon_new_probe(void);
+void damon_add_probe(struct damon_ctx *ctx, struct damon_probe *probe);
+
 struct damon_region *damon_new_region(unsigned long start, unsigned long end);
 
 /*
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 3a8725e400c6b..8a55cc61d2972 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -113,6 +113,38 @@ int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id)
 	return err;
 }
 
+struct damon_probe *damon_new_probe(void)
+{
+	struct damon_probe *p;
+
+	p = kmalloc_obj(*p);
+	if (!p)
+		return NULL;
+	INIT_LIST_HEAD(&p->list);
+	return p;
+}
+
+void damon_add_probe(struct damon_ctx *ctx, struct damon_probe *probe)
+{
+	list_add_tail(&probe->list, &ctx->probes);
+}
+
+static void damon_del_probe(struct damon_probe *p)
+{
+	list_del(&p->list);
+}
+
+static void damon_free_probe(struct damon_probe *p)
+{
+	kfree(p);
+}
+
+static void damon_destroy_probe(struct damon_probe *p)
+{
+	damon_del_probe(p);
+	damon_free_probe(p);
+}
+
 #ifdef CONFIG_DAMON_DEBUG_SANITY
 static void damon_verify_new_region(unsigned long start, unsigned long end)
 {
@@ -605,6 +637,8 @@ struct damon_ctx *damon_new_ctx(void)
 	ctx->attrs.min_nr_regions = 10;
 	ctx->attrs.max_nr_regions = 1000;
 
+	INIT_LIST_HEAD(&ctx->probes);
+
 	ctx->addr_unit = 1;
 	ctx->min_region_sz = DAMON_MIN_REGION_SZ;
 
@@ -627,12 +661,16 @@ static void damon_destroy_targets(struct damon_ctx *ctx)
 void damon_destroy_ctx(struct damon_ctx *ctx)
 {
 	struct damos *s, *next_s;
+	struct damon_probe *p, *next_p;
 
 	damon_destroy_targets(ctx);
 
 	damon_for_each_scheme_safe(s, next_s, ctx)
 		damon_destroy_scheme(s);
 
+	damon_for_each_probe_safe(p, next_p, ctx)
+		damon_destroy_probe(p);
+
 	kfree(ctx);
 }
 
-- 
2.47.3