Re: [PATCH v2 net-next 6/6] net: switchdev: extract struct switchdev_obj_*

From: Scott Feldman
Date: Wed Sep 30 2015 - 10:59:08 EST


On Wed, Sep 30, 2015 at 3:36 AM, Jiri Pirko <jiri@xxxxxxxxxxx> wrote:
> Tue, Sep 29, 2015 at 06:07:18PM CEST, vivien.didelot@xxxxxxxxxxxxxxxxxxxx wrote:
>>Now that switchdev and its drivers directly use specific switchdev_obj_*
>>structures, move them out of the switchdev_obj union and get rif of this
>>outer structure.
>>
>>Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
>>---
>> include/net/switchdev.h | 53 ++++++++++++++++++++++++-------------------------
>> 1 file changed, 26 insertions(+), 27 deletions(-)
>>
>>diff --git a/include/net/switchdev.h b/include/net/switchdev.h
>>index bcadac3..e11425e 100644
>>--- a/include/net/switchdev.h
>>+++ b/include/net/switchdev.h
>>@@ -64,30 +64,29 @@ enum switchdev_obj_id {
>> SWITCHDEV_OBJ_PORT_FDB,
>> };
>>
>>-struct switchdev_obj {
>>- enum switchdev_obj_id id;
>>- int (*cb)(struct switchdev_obj *obj);
>>- union {
>>- struct switchdev_obj_vlan { /* PORT_VLAN */
>>- u16 flags;
>>- u16 vid_begin;
>>- u16 vid_end;
>>- } vlan;
>>- struct switchdev_obj_ipv4_fib { /* IPV4_FIB */
>>- u32 dst;
>>- int dst_len;
>>- struct fib_info *fi;
>>- u8 tos;
>>- u8 type;
>>- u32 nlflags;
>>- u32 tb_id;
>>- } ipv4_fib;
>>- struct switchdev_obj_fdb { /* PORT_FDB */
>>- const unsigned char *addr;
>>- u16 vid;
>>- u16 ndm_state;
>>- } fdb;
>>- } u;
>>+/* SWITCHDEV_OBJ_PORT_VLAN */
>>+struct switchdev_obj_vlan {
>>+ u16 flags;
>>+ u16 vid_begin;
>>+ u16 vid_end;
>>+};
>>+
>>+/* SWITCHDEV_OBJ_IPV4_FIB */
>>+struct switchdev_obj_ipv4_fib {
>>+ u32 dst;
>>+ int dst_len;
>>+ struct fib_info *fi;
>>+ u8 tos;
>>+ u8 type;
>>+ u32 nlflags;
>>+ u32 tb_id;
>>+};
>>+
>>+/* SWITCHDEV_OBJ_PORT_FDB */
>>+struct switchdev_obj_fdb {
>>+ const unsigned char *addr;
>>+ u16 vid;
>>+ u16 ndm_state;
>> };
>
>
> I don't like these structs being passed down as a "void *". I think that
> we should have some "common" struct for these objects, event if it would
> be empty and pass it down. "void *" does not look good at all, does not
> tell the reader what that param is about. How about:
>
> struct switchdev_obj {
> };
>
> struct switchdev_obj_vlan {
> struct switchdev_obj obj;
> u16 flags;
> u16 vid_begin;
> u16 vid_end;
> };
> #define SWITCHDEV_OBJ_VLAN(obj) \
> container_of(obj, struct switchdev_obj_vlan, obj)
>
> /* SWITCHDEV_OBJ_IPV4_FIB */
> struct switchdev_obj_ipv4_fib {
> struct switchdev_obj obj;
> u32 dst;
> int dst_len;
> struct fib_info *fi;
> u8 tos;
> u8 type;
> u32 nlflags;
> u32 tb_id;
> };
> #define SWITCHDEV_OBJ_IPV4_FIB(obj) \
> container_of(obj, struct switchdev_obj_ipv4_fib, obj)
>
> /* SWITCHDEV_OBJ_PORT_FDB */
> struct switchdev_obj_fdb {
> struct switchdev_obj obj;
> const unsigned char *addr;
> u16 vid;
> u16 ndm_state;
> };
> #define SWITCHDEV_OBJ_FDB(obj) \
> container_of(obj, struct switchdev_obj_fdb, obj)
>
>
> then pass struct switchdev_obj *obj down to drivers and in driver, get
> original object by SWITCHDEV_OBJ_* ?


Yes, I agree with Jiri, keep the struct switchdev_obj, use it within
each specific struct, and pass struct switchdev * in core funcs rather
than void *.
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