selftests/damon/drgn_dump_damon_status: dump DAMOS filters

drgn_dump_damon_status.py is a script for dumping DAMON internal status in
json format.  It is being used for seeing if DAMON parameters that are set
using _damon_sysfs.py are actually passed to DAMON in the kernel space. 
It is, however, not dumping full DAMON internal status, and it makes
increasing test coverage difficult.  Add damos filters dumping for more
tests.

Link: https://lkml.kernel.org/r/20250720171652.92309-12-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: sjp38

tools/testing/selftests/damon/drgn_dump_damon_status.py

@@ -135,8 +135,37 @@ def damos_migrate_dests_to_dict(dests):
             'nr_dests': nr_dests,
             }
 
+def damos_filter_to_dict(damos_filter):
+    filter_type_keyword = {
+            0: 'anon',
+            1: 'active',
+            2: 'memcg',
+            3: 'young',
+            4: 'hugepage_size',
+            5: 'unmapped',
+            6: 'addr',
+            7: 'target'
+            }
+    dict_ = {
+            'type': filter_type_keyword[int(damos_filter.type)],
+            'matching': bool(damos_filter.matching),
+            'allow': bool(damos_filter.allow),
+            }
+    type_ = dict_['type']
+    if type_ == 'memcg':
+        dict_['memcg_id'] = int(damos_filter.memcg_id)
+    elif type_ == 'addr':
+        dict_['addr_range'] = [int(damos_filter.addr_range.start),
+                               int(damos_filter.addr_range.end)]
+    elif type_ == 'target':
+        dict_['target_idx'] = int(damos_filter.target_idx)
+    elif type_ == 'hugeapge_size':
+        dict_['sz_range'] = [int(damos_filter.sz_range.min),
+                             int(damos_filter.sz_range.max)]
+    return dict_
+
 def scheme_to_dict(scheme):
-    return to_dict(scheme, [
+    dict_ = to_dict(scheme, [
         ['pattern', damos_access_pattern_to_dict],
         ['action', int],
         ['apply_interval_us', int],
@@ -145,6 +174,18 @@ def scheme_to_dict(scheme):
         ['target_nid', int],
         ['migrate_dests', damos_migrate_dests_to_dict],
         ])
+    filters = []
+    for f in list_for_each_entry(
+            'struct damos_filter', scheme.filters.address_of_(), 'list'):
+        filters.append(damos_filter_to_dict(f))
+    dict_['filters'] = filters
+    ops_filters = []
+    for f in list_for_each_entry(
+            'struct damos_filter', scheme.ops_filters.address_of_(), 'list'):
+        ops_filters.append(damos_filter_to_dict(f))
+    dict_['ops_filters'] = ops_filters
+
+    return dict_
 
 def schemes_to_list(schemes):
     return [scheme_to_dict(s)