Re: [PATCH v2] IB/rxe: Avoid implicit enum conversions in rxe_init functions

[Jason Gunthorpe]

On Wed, Sep 26, 2018 at 10:01:57PM -0700, Nathan Chancellor wrote:
> Clang warns when an emumerated type is implicitly converted to another.
> 
> drivers/infiniband/sw/rxe/rxe.c:106:27: warning: implicit conversion
> from enumeration type 'enum rxe_device_param' to different enumeration
> type 'enum ib_atomic_cap' [-Wenum-conversion]
>         rxe->attr.atomic_cap                    = RXE_ATOMIC_CAP;
>                                                 ~ ^~~~~~~~~~~~~~
> drivers/infiniband/sw/rxe/rxe.c:131:22: warning: implicit conversion
> from enumeration type 'enum rxe_port_param' to different enumeration
> type 'enum ib_port_state' [-Wenum-conversion]
>         port->attr.state                = RXE_PORT_STATE;
>                                         ~ ^~~~~~~~~~~~~~
> drivers/infiniband/sw/rxe/rxe.c:132:24: warning: implicit conversion
> from enumeration type 'enum rxe_port_param' to different enumeration
> type 'enum ib_mtu' [-Wenum-conversion]
>         port->attr.max_mtu              = RXE_PORT_MAX_MTU;
>                                         ~ ^~~~~~~~~~~~~~~~
> drivers/infiniband/sw/rxe/rxe.c:133:27: warning: implicit conversion
> from enumeration type 'enum rxe_port_param' to different enumeration
> type 'enum ib_mtu' [-Wenum-conversion]
>         port->attr.active_mtu           = RXE_PORT_ACTIVE_MTU;
>                                         ~ ^~~~~~~~~~~~~~~~~~~
> drivers/infiniband/sw/rxe/rxe.c:151:24: warning: implicit conversion
> from enumeration type 'enum rxe_port_param' to different enumeration
> type 'enum ib_mtu' [-Wenum-conversion]
>                                 ib_mtu_enum_to_int(RXE_PORT_ACTIVE_MTU);
>                                 ~~~~~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~
> 5 warnings generated.
> 
> Use the appropriate values from the expected enumerated type so no
> conversion needs to happen.
> 
> Reported-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> 
> v1 -> v2:
> 
> * Don't cast, just use the expecting enumerated value directly, per
>   Jason's request
> 
>  drivers/infiniband/sw/rxe/rxe.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c
> index 10999fa69281..2f4e57886b89 100644
> +++ b/drivers/infiniband/sw/rxe/rxe.c
> @@ -103,7 +103,7 @@ static void rxe_init_device_param(struct rxe_dev *rxe)
>  	rxe->attr.max_res_rd_atom		= RXE_MAX_RES_RD_ATOM;
>  	rxe->attr.max_qp_init_rd_atom		= RXE_MAX_QP_INIT_RD_ATOM;
>  	rxe->attr.max_ee_init_rd_atom		= RXE_MAX_EE_INIT_RD_ATOM;
> -	rxe->attr.atomic_cap			= RXE_ATOMIC_CAP;
> +	rxe->attr.atomic_cap			= IB_ATOMIC_HCA;
>  	rxe->attr.max_ee			= RXE_MAX_EE;
>  	rxe->attr.max_rdd			= RXE_MAX_RDD;
>  	rxe->attr.max_mw			= RXE_MAX_MW;
> @@ -128,9 +128,9 @@ static void rxe_init_device_param(struct rxe_dev *rxe)
>  /* initialize port attributes */
>  static int rxe_init_port_param(struct rxe_port *port)
>  {
> -	port->attr.state		= RXE_PORT_STATE;
> -	port->attr.max_mtu		= RXE_PORT_MAX_MTU;
> -	port->attr.active_mtu		= RXE_PORT_ACTIVE_MTU;
> +	port->attr.state		= IB_PORT_DOWN;
> +	port->attr.max_mtu		= IB_MTU_4096;
> +	port->attr.active_mtu		= IB_MTU_256;
>  	port->attr.gid_tbl_len		= RXE_PORT_GID_TBL_LEN;
>  	port->attr.port_cap_flags	= RXE_PORT_PORT_CAP_FLAGS;
>  	port->attr.max_msg_sz		= RXE_PORT_MAX_MSG_SZ;
> @@ -147,8 +147,7 @@ static int rxe_init_port_param(struct rxe_port *port)
>  	port->attr.active_width		= RXE_PORT_ACTIVE_WIDTH;
>  	port->attr.active_speed		= RXE_PORT_ACTIVE_SPEED;
>  	port->attr.phys_state		= RXE_PORT_PHYS_STATE;
> -	port->mtu_cap			=
> -				ib_mtu_enum_to_int(RXE_PORT_ACTIVE_MTU);
> +	port->mtu_cap			= ib_mtu_enum_to_int(IB_MTU_256);
>  	port->subnet_prefix		= cpu_to_be64(RXE_PORT_SUBNET_PREFIX);
>  
>  	return 0;

These are the only place some of these values are used, so declaration
should be eliminated as well.

Jason