mm: memcg: move cgroup v1 interface files to memcontrol-v1.c

Move legacy cgroup v1 memory controller interfaces and corresponding code
into memcontrol-v1.c.

[roman.gushchin@linux.dev: move two functions]
  Link: https://lkml.kernel.org/r/20240704002712.2077812-1-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20240625005906.106920-11-roman.gushchin@linux.devSigned-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memcontrol-v1.h

@@ -3,6 +3,8 @@
 #ifndef __MM_MEMCONTROL_V1_H
 #define __MM_MEMCONTROL_V1_H
 
+#include <linux/cgroup-defs.h>
+
 void memcg1_update_tree(struct mem_cgroup *memcg, int nid);
 void memcg1_remove_from_trees(struct mem_cgroup *memcg);
 
@@ -34,12 +36,6 @@ int memcg1_can_attach(struct cgroup_taskset *tset);
 void memcg1_cancel_attach(struct cgroup_taskset *tset);
 void memcg1_move_task(void);
 
-struct cftype;
-u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
-				struct cftype *cft);
-int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
-				 struct cftype *cft, u64 val);
-
 /*
  * Per memcg event counter is incremented at every pagein/pageout. With THP,
  * it will be incremented by the number of pages. This counter is used
@@ -86,11 +82,23 @@ enum res_type {
 bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
 				enum mem_cgroup_events_target target);
 unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap);
-ssize_t memcg_write_event_control(struct kernfs_open_file *of,
-				  char *buf, size_t nbytes, loff_t off);
 
 bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked);
 void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked);
 void memcg1_oom_recover(struct mem_cgroup *memcg);
 
+void drain_all_stock(struct mem_cgroup *root_memcg);
+
+unsigned long memcg_events(struct mem_cgroup *memcg, int event);
+unsigned long memcg_events_local(struct mem_cgroup *memcg, int event);
+unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx);
+unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item);
+unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item);
+int memory_stat_show(struct seq_file *m, void *v);
+
+void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
+
+extern struct cftype memsw_files[];
+extern struct cftype mem_cgroup_legacy_files[];
+
 #endif	/* __MM_MEMCONTROL_V1_H */