IB/mlx4: Create slave AH's directly

Since slave GID's do not exist in the core gid table we can no longer use
the core code to help do this without creating inconsistencies. Directly
create the AH using mlx4 internal APIs.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

drivers/infiniband/hw/mlx4/ah.c

@@ -96,19 +96,29 @@ static struct ib_ah *create_iboe_ah(struct ib_pd *pd,
 
 	memcpy(ah->av.eth.mac, ah_attr->roce.dmac, ETH_ALEN);
 	eth_zero_addr(ah->av.eth.s_mac);
+
+	/*
+	 * If sgid_attr is NULL we are being called by mlx4_ib_create_ah_slave
+	 * and we are directly creating an AV for a slave's gid_index.
+	 */
 	gid_attr = ah_attr->grh.sgid_attr;
-	if (is_vlan_dev(gid_attr->ndev))
-		vlan_tag = vlan_dev_vlan_id(gid_attr->ndev);
-	memcpy(ah->av.eth.s_mac, gid_attr->ndev->dev_addr, ETH_ALEN);
+	if (gid_attr) {
+		if (is_vlan_dev(gid_attr->ndev))
+			vlan_tag = vlan_dev_vlan_id(gid_attr->ndev);
+		memcpy(ah->av.eth.s_mac, gid_attr->ndev->dev_addr, ETH_ALEN);
+		ret = mlx4_ib_gid_index_to_real_index(ibdev, gid_attr);
+		if (ret < 0)
+			return ERR_PTR(ret);
+		ah->av.eth.gid_index = ret;
+	} else {
+		/* mlx4_ib_create_ah_slave fills in the s_mac and the vlan */
+		ah->av.eth.gid_index = ah_attr->grh.sgid_index;
+	}
 
 	if (vlan_tag < 0x1000)
 		vlan_tag |= (rdma_ah_get_sl(ah_attr) & 7) << 13;
 	ah->av.eth.port_pd = cpu_to_be32(to_mpd(pd)->pdn |
 					 (rdma_ah_get_port_num(ah_attr) << 24));
-	ret = mlx4_ib_gid_index_to_real_index(ibdev, gid_attr);
-	if (ret < 0)
-		return ERR_PTR(ret);
-	ah->av.eth.gid_index = ret;
 	ah->av.eth.vlan = cpu_to_be16(vlan_tag);
 	ah->av.eth.hop_limit = grh->hop_limit;
 	if (rdma_ah_get_static_rate(ah_attr)) {
@@ -167,6 +177,40 @@ struct ib_ah *mlx4_ib_create_ah(struct ib_pd *pd, struct rdma_ah_attr *ah_attr,
 		return create_ib_ah(pd, ah_attr, ah); /* never fails */
 }
 
+/* AH's created via this call must be free'd by mlx4_ib_destroy_ah. */
+struct ib_ah *mlx4_ib_create_ah_slave(struct ib_pd *pd,
+				      struct rdma_ah_attr *ah_attr,
+				      int slave_sgid_index, u8 *s_mac,
+				      u16 vlan_tag)
+{
+	struct rdma_ah_attr slave_attr = *ah_attr;
+	struct mlx4_ib_ah *mah;
+	struct ib_ah *ah;
+
+	slave_attr.grh.sgid_attr = NULL;
+	slave_attr.grh.sgid_index = slave_sgid_index;
+	ah = mlx4_ib_create_ah(pd, &slave_attr, NULL);
+	if (IS_ERR(ah))
+		return ah;
+
+	ah->device = pd->device;
+	ah->pd = pd;
+	ah->type = ah_attr->type;
+	mah = to_mah(ah);
+
+	/* get rid of force-loopback bit */
+	mah->av.ib.port_pd &= cpu_to_be32(0x7FFFFFFF);
+
+	if (ah_attr->type == RDMA_AH_ATTR_TYPE_ROCE)
+		memcpy(mah->av.eth.s_mac, s_mac, 6);
+
+	if (vlan_tag < 0x1000)
+		vlan_tag |= (rdma_ah_get_sl(ah_attr) & 7) << 13;
+	mah->av.eth.vlan = cpu_to_be16(vlan_tag);
+
+	return ah;
+}
+
 int mlx4_ib_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr)
 {
 	struct mlx4_ib_ah *ah = to_mah(ibah);