tools: ynl-gen: generate alloc and free helpers for req

We expect user to allocate requests with calloc(),
make things a bit more consistent and provide helpers.
Generate free calls, too.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/net/ynl/ynl-gen-c.py

@@ -1476,6 +1476,14 @@ def free_arg_name(direction):
     return 'obj'
 
 
+def print_alloc_wrapper(ri, direction):
+    name = op_prefix(ri, direction)
+    ri.cw.write_func_prot(f'static inline struct {name} *', f"{name}_alloc", [f"void"])
+    ri.cw.block_start()
+    ri.cw.p(f'return calloc(1, sizeof(struct {name}));')
+    ri.cw.block_end()
+
+
 def print_free_prototype(ri, direction, suffix=';'):
     name = op_prefix(ri, direction)
     arg = free_arg_name(direction)
@@ -1523,6 +1531,7 @@ def print_type_full(ri, struct):
 
 def print_type_helpers(ri, direction, deref=False):
     print_free_prototype(ri, direction)
+    ri.cw.nl()
 
     if ri.ku_space == 'user' and direction == 'request':
         for _, attr in ri.struct[direction].member_list():
@@ -1531,6 +1540,7 @@ def print_type_helpers(ri, direction, deref=False):
 
 
 def print_req_type_helpers(ri):
+    print_alloc_wrapper(ri, "request")
     print_type_helpers(ri, "request")
 
 
@@ -1554,6 +1564,12 @@ def print_req_type(ri):
     print_type(ri, "request")
 
 
+def print_req_free(ri):
+    if 'request' not in ri.op[ri.op_mode]:
+        return
+    _free_type(ri, 'request', ri.struct['request'])
+
+
 def print_rsp_type(ri):
     if (ri.op_mode == 'do' or ri.op_mode == 'dump') and 'reply' in ri.op[ri.op_mode]:
         direction = 'reply'
@@ -2344,6 +2360,7 @@ def main():
                 if 'do' in op and 'event' not in op:
                     cw.p(f"/* {op.enum_name} - do */")
                     ri = RenderInfo(cw, parsed, args.mode, op, op_name, "do")
+                    print_req_free(ri)
                     print_rsp_free(ri)
                     parse_rsp_msg(ri)
                     print_req(ri)