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

[Jiri Pirko <jiri@resnulli.us>]

Tue, Sep 29, 2015 at 06:07:18PM CEST, vivien.didelot@savoirfairelinux.com 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@savoirfairelinux.com>
>---
> 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_* ?