net/mlx5: Introduce VHCA tunnel device capability

When using the device emulation feature (introduced in Bluefield-1 SOC),
a privileged function (the device emulation manager) will be able to
create a channel to execute commands on behalf of the emulated function.

This channel will be a general object of type VHCA_TUNNEL that will have
a unique ID for each emulated function. This ID will be passed in each
cmd that will be issued by the emulation SW in a well known offset in
the command header.

This channel is needed since the emulated function doesn't have a normal
command interface to the HCA HW, but some basic configuration for that
function is needed (e.g. initialize and enable the HCA). For that matter,
a specific command-set was defined and only those commands will be issued
by the HCA.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

include/linux/mlx5/mlx5_ifc.h

@@ -1390,7 +1390,9 @@ struct mlx5_ifc_cmd_hca_cap_bits {
 	u8	   reserved_at_6c8[0x28];
 	u8	   sf_base_id[0x10];
 
-	u8	   reserved_at_700[0x100];
+	u8	   reserved_at_700[0x80];
+	u8	   vhca_tunnel_commands[0x40];
+	u8	   reserved_at_7c0[0x40];
 };
 
 enum mlx5_flow_destination_type {
@@ -9694,7 +9696,7 @@ struct mlx5_ifc_general_obj_in_cmd_hdr_bits {
 	u8         opcode[0x10];
 	u8         uid[0x10];
 
-	u8         reserved_at_20[0x10];
+	u8         vhca_tunnel_id[0x10];
 	u8         obj_type[0x10];
 
 	u8         obj_id[0x20];