commit 5aa4165c60aaade3aebe0c5278111781142a5636
author Shalom Toledo <shalomt@mellanox.com> Tue Nov 12 08:48:24 2019 +0200
committer David S. Miller <davem@davemloft.net> Tue Nov 12 10:54:02 2019 -0800
tree 1070fa41491f754cd3e28ac996b97efa77b51106
parent b2ef81dcdf3835bd55e5f97ff30131bb327be7fa

mlxsw: core: Parse TLVs' offsets of incoming EMADs

Until now the code assumes a fixed structure which makes it difficult to
support EMADs with and without new TLVs.

Make it more generic by parsing the TLVs when the EMADs are received and
store the offset to the different TLVs in the control block. Using these
offsets to extract information from the EMADs without relying on a specific
structure.

Signed-off-by: Shalom Toledo <shalomt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/core.c

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index 42e1ce3..698c7bc 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -361,20 +361,45 @@
 	mlxsw_emad_construct_eth_hdr(skb);
 }
 
+struct mlxsw_emad_tlv_offsets {
+	u16 op_tlv;
+	u16 reg_tlv;
+};
+
+static void mlxsw_emad_tlv_parse(struct sk_buff *skb)
+{
+	struct mlxsw_emad_tlv_offsets *offsets =
+		(struct mlxsw_emad_tlv_offsets *) skb->cb;
+
+	offsets->op_tlv = MLXSW_EMAD_ETH_HDR_LEN;
+	offsets->reg_tlv = MLXSW_EMAD_ETH_HDR_LEN +
+			   MLXSW_EMAD_OP_TLV_LEN * sizeof(u32);
+}
+
 static char *mlxsw_emad_op_tlv(const struct sk_buff *skb)
 {
-	return ((char *) (skb->data + MLXSW_EMAD_ETH_HDR_LEN));
+	struct mlxsw_emad_tlv_offsets *offsets =
+		(struct mlxsw_emad_tlv_offsets *) skb->cb;
+
+	return ((char *) (skb->data + offsets->op_tlv));
 }
 
 static char *mlxsw_emad_reg_tlv(const struct sk_buff *skb)
 {
-	return ((char *) (skb->data + MLXSW_EMAD_ETH_HDR_LEN +
-				      MLXSW_EMAD_OP_TLV_LEN * sizeof(u32)));
+	struct mlxsw_emad_tlv_offsets *offsets =
+		(struct mlxsw_emad_tlv_offsets *) skb->cb;
+
+	return ((char *) (skb->data + offsets->reg_tlv));
 }
 
-static char *mlxsw_emad_reg_payload(const char *op_tlv)
+static char *mlxsw_emad_reg_payload(const char *reg_tlv)
 {
-	return ((char *) (op_tlv + (MLXSW_EMAD_OP_TLV_LEN + 1) * sizeof(u32)));
+	return ((char *) (reg_tlv + sizeof(u32)));
+}
+
+static char *mlxsw_emad_reg_payload_cmd(const char *mbox)
+{
+	return ((char *) (mbox + (MLXSW_EMAD_OP_TLV_LEN + 1) * sizeof(u32)));
 }
 
 static u64 mlxsw_emad_get_tid(const struct sk_buff *skb)
@@ -535,11 +560,11 @@
 		mlxsw_emad_transmit_retry(mlxsw_core, trans);
 	} else {
 		if (err == 0) {
-			char *op_tlv = mlxsw_emad_op_tlv(skb);
+			char *reg_tlv = mlxsw_emad_reg_tlv(skb);
 
 			if (trans->cb)
 				trans->cb(mlxsw_core,
-					  mlxsw_emad_reg_payload(op_tlv),
+					  mlxsw_emad_reg_payload(reg_tlv),
 					  trans->reg->len, trans->cb_priv);
 		}
 		mlxsw_emad_trans_finish(trans, err);
@@ -556,6 +581,8 @@
 	trace_devlink_hwmsg(priv_to_devlink(mlxsw_core), true, 0,
 			    skb->data, skb->len);
 
+	mlxsw_emad_tlv_parse(skb);
+
 	if (!mlxsw_emad_is_resp(skb))
 		goto free_skb;
 
@@ -1395,12 +1422,16 @@
 	struct mlxsw_event_listener_item *event_listener_item = priv;
 	struct mlxsw_reg_info reg;
 	char *payload;
-	char *op_tlv = mlxsw_emad_op_tlv(skb);
-	char *reg_tlv = mlxsw_emad_reg_tlv(skb);
+	char *reg_tlv;
+	char *op_tlv;
+
+	mlxsw_emad_tlv_parse(skb);
+	op_tlv = mlxsw_emad_op_tlv(skb);
+	reg_tlv = mlxsw_emad_reg_tlv(skb);
 
 	reg.id = mlxsw_emad_op_tlv_register_id_get(op_tlv);
 	reg.len = (mlxsw_emad_reg_tlv_len_get(reg_tlv) - 1) * sizeof(u32);
-	payload = mlxsw_emad_reg_payload(op_tlv);
+	payload = mlxsw_emad_reg_payload(reg_tlv);
 	event_listener_item->el.func(&reg, payload, event_listener_item->priv);
 	dev_kfree_skb(skb);
 }
@@ -1713,7 +1744,7 @@
 	}
 
 	if (!err)
-		memcpy(payload, mlxsw_emad_reg_payload(out_mbox),
+		memcpy(payload, mlxsw_emad_reg_payload_cmd(out_mbox),
 		       reg->len);
 
 	mlxsw_cmd_mbox_free(out_mbox);