[ofa-general] [PATCH V3] infiniband/core: Enable loopback of DR SMP responses from userspace

[Ralph Campbell]

Steve's patch plus the attached patch for ib_ipath allows loopback
to work and doesn't seem to obviously break anything.

I was wondering though about adding the code from
smi_check_local_returning_smp() to smi_check_local_smp()
instead of defining a separate function.
That got me thinking about what happens when a return path DR SMP
is received and ib_mad_recv_done_handler() calls smi_check_local_smp().
Now I'm trying to convince myself one way or the other whether
the same checks inib_mad_recv_done_handler() are needed or not.

On Wed, 2007-10-10 at 22:29 -0500, swelch at systemfabricworks.com wrote:
> 
>   Sean, Roland,
> 
>   This patch [v3] replaces the [v2] patch; it includes those changes but renames
>   the smi function testing returning SMP requests to the name Hal recommends.
> 
>   This patch allows userspace DR SMP responses to be looped back and delivered
>   to a local mad agent by the management stack.
> 
>   Thanks, Steve
> 
> Signed-off-by: Steve Welch <swelch at systemfabricworks.com>
> ---
>  drivers/infiniband/core/mad.c |    6 +++---
>  drivers/infiniband/core/smi.h |   18 +++++++++++++++++-
>  2 files changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
> index 6f42877..98148d6 100644
> --- a/drivers/infiniband/core/mad.c
> +++ b/drivers/infiniband/core/mad.c
> @@ -701,7 +701,8 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
>  	}
>  
>  	/* Check to post send on QP or process locally */
> -	if (smi_check_local_smp(smp, device) == IB_SMI_DISCARD)
> +	if (smi_check_local_smp(smp, device) == IB_SMI_DISCARD &&
> +	    smi_check_local_returning_smp(smp, device) == IB_SMI_DISCARD)
>  		goto out;
>  
>  	local = kmalloc(sizeof *local, GFP_ATOMIC);
> @@ -752,8 +753,7 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
>  		port_priv = ib_get_mad_port(mad_agent_priv->agent.device,
>  					    mad_agent_priv->agent.port_num);
>  		if (port_priv) {
> -			mad_priv->mad.mad.mad_hdr.tid =
> -				((struct ib_mad *)smp)->mad_hdr.tid;
> +			memcpy(&mad_priv->mad.mad, smp, sizeof(struct ib_mad));
>  			recv_mad_agent = find_mad_agent(port_priv,
>  						        &mad_priv->mad.mad);
>  		}
> diff --git a/drivers/infiniband/core/smi.h b/drivers/infiniband/core/smi.h
> index 1cfc298..aff96ba 100644
> --- a/drivers/infiniband/core/smi.h
> +++ b/drivers/infiniband/core/smi.h
> @@ -59,7 +59,8 @@ extern enum smi_action smi_handle_dr_smp_send(struct ib_smp *smp,
>  					      u8 node_type, int port_num);
>  
>  /*
> - * Return 1 if the SMP should be handled by the local SMA/SM via process_mad
> + * Return IB_SMI_HANDLE if the SMP should be handled by the local SMA/SM
> + * via process_mad
>   */
>  static inline enum smi_action smi_check_local_smp(struct ib_smp *smp,
>  						  struct ib_device *device)
> @@ -71,4 +72,19 @@ static inline enum smi_action smi_check_local_smp(struct ib_smp *smp,
>  		(smp->hop_ptr == smp->hop_cnt + 1)) ?
>  		IB_SMI_HANDLE : IB_SMI_DISCARD);
>  }
> +
> +/*
> + * Return IB_SMI_HANDLE if the SMP should be handled by the local SMA/SM
> + * via process_mad
> + */
> +static inline enum smi_action smi_check_local_returning_smp(struct ib_smp *smp,
> +						   struct ib_device *device)
> +{
> +	/* C14-13:3 -- We're at the end of the DR segment of path */
> +	/* C14-13:4 -- Hop Pointer == 0 -> give to SM */
> +	return ((device->process_mad &&
> +		ib_get_smp_direction(smp) &&
> +		!smp->hop_ptr) ? IB_SMI_HANDLE : IB_SMI_DISCARD);
> +}
> +
>  #endif	/* __SMI_H_ */



diff --git a/drivers/infiniband/hw/ipath/ipath_mad.c b/drivers/infiniband/hw/ipath/ipath_mad.c
index 3d1432d..1978c34 100644
--- a/drivers/infiniband/hw/ipath/ipath_mad.c
+++ b/drivers/infiniband/hw/ipath/ipath_mad.c
@@ -1434,7 +1434,7 @@ static int process_subn(struct ib_device *ibdev, int mad_flags,
 		 * before checking for other consumers.
 		 * Just tell the caller to process it normally.
 		 */
-		ret = IB_MAD_RESULT_FAILURE;
+		ret = IB_MAD_RESULT_SUCCESS;
 		goto bail;
 	default:
 		smp->status |= IB_SMP_UNSUP_METHOD;
@@ -1516,7 +1516,7 @@ static int process_perf(struct ib_device *ibdev, u8 port_num,
 		 * before checking for other consumers.
 		 * Just tell the caller to process it normally.
 		 */
-		ret = IB_MAD_RESULT_FAILURE;
+		ret = IB_MAD_RESULT_SUCCESS;
 		goto bail;
 	default:
 		pmp->status |= IB_SMP_UNSUP_METHOD;