[infiniband] Allow MAD handlers to indicate response via return value

Now that MAD handlers no longer return a status code, we can allow
them to return a pointer to a MAD structure if and only if they want
to send a response.  This provides a more natural and flexible
approach than using a "response method" field within the handler's
descriptor.

diff --git a/src/include/gpxe/ib_gma.h b/src/include/gpxe/ib_gma.h
index c549dfc..1b33514 100644 (file)
--- a/src/include/gpxe/ib_gma.h
+++ b/src/include/gpxe/ib_gma.h
@@ -26,20 +26,15 @@ struct ib_gma_handler {
        uint8_t class_version;
        /** Method */
        uint8_t method;
-       /** Response method, or zero */
-       uint8_t resp_method;
        /** Attribute (in network byte order) */
        uint16_t attr_id;
        /** Handle attribute
         *
-        * @v gma       General management agent
-        * @v mad       MAD
-        *
-        * The handler should modify the MAD as applicable.  If the
-        * handler returns with a non-zero value in the MAD's @c
-        * method field, it will be sent as a response.
+        * @v gma               General management agent
+        * @v mad               MAD
+        * @ret response        MAD response, or NULL to send no response
         */
-       void ( * handle ) ( struct ib_gma *gma, union ib_mad *mad );
+       union ib_mad * ( * handle ) ( struct ib_gma *gma, union ib_mad *mad );
 };
 
 /** GMA attribute handlers */

diff --git a/src/net/infiniband/ib_gma.c b/src/net/infiniband/ib_gma.c
index 5e79fee..1bc9ba0 100644 (file)
--- a/src/net/infiniband/ib_gma.c
+++ b/src/net/infiniband/ib_gma.c
@@ -81,14 +81,48 @@ static unsigned int next_request_tid;
  *****************************************************************************
  */
 
+/**
+ * Construct directed route response, if necessary
+ *
+ * @v gma              General management agent
+ * @v mad              MAD response without DR fields filled in
+ * @ret mad            MAD response with DR fields filled in
+ */
+static union ib_mad * ib_sma_dr_response ( struct ib_gma *gma,
+                                          union ib_mad *mad ) {
+       struct ib_mad_hdr *hdr = &mad->hdr;
+       struct ib_mad_smp *smp = &mad->smp;
+       unsigned int hop_pointer;
+       unsigned int hop_count;
+
+       /* Set response fields for directed route SMPs */
+       if ( hdr->mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE ) {
+               hdr->status |= htons ( IB_SMP_STATUS_D_INBOUND );
+               hop_pointer = smp->mad_hdr.class_specific.smp.hop_pointer;
+               hop_count = smp->mad_hdr.class_specific.smp.hop_count;
+               assert ( hop_count == hop_pointer );
+               if ( hop_pointer < ( sizeof ( smp->return_path.hops ) /
+                                    sizeof ( smp->return_path.hops[0] ) ) ) {
+                       smp->return_path.hops[hop_pointer] = gma->ibdev->port;
+               } else {
+                       DBGC ( gma, "GMA %p invalid hop pointer %d\n",
+                              gma, hop_pointer );
+                       return NULL;
+               }
+       }
+
+       return mad;
+}
+
 /**
  * Get node information
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret response       MAD response
  */
-static void ib_sma_get_node_info ( struct ib_gma *gma,
-                                  union ib_mad *mad ) {
+static union ib_mad * ib_sma_get_node_info ( struct ib_gma *gma,
+                                            union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        struct ib_node_info *node_info = &mad->smp.smp_data.node_info;
 
@@ -103,6 +137,9 @@ static void ib_sma_get_node_info ( struct ib_gma *gma,
                 sizeof ( node_info->port_guid ) );
        node_info->partition_cap = htons ( 1 );
        node_info->local_port_num = ibdev->port;
+
+       mad->hdr.method = IB_MGMT_METHOD_GET_RESP;
+       return ib_sma_dr_response ( gma, mad );
 }
 
 /**
@@ -110,9 +147,10 @@ static void ib_sma_get_node_info ( struct ib_gma *gma,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret response       MAD response
  */
-static void ib_sma_get_node_desc ( struct ib_gma *gma,
-                                  union ib_mad *mad ) {
+static union ib_mad * ib_sma_get_node_desc ( struct ib_gma *gma,
+                                            union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        struct ib_node_desc *node_desc = &mad->smp.smp_data.node_desc;
        struct ib_gid_half *guid = &ibdev->gid.u.half[1];
@@ -123,6 +161,9 @@ static void ib_sma_get_node_desc ( struct ib_gma *gma,
                   guid->bytes[0], guid->bytes[1], guid->bytes[2],
                   guid->bytes[3], guid->bytes[4], guid->bytes[5],
                   guid->bytes[6], guid->bytes[7], ibdev->dev->name );
+
+       mad->hdr.method = IB_MGMT_METHOD_GET_RESP;
+       return ib_sma_dr_response ( gma, mad );
 }
 
 /**
@@ -130,15 +171,19 @@ static void ib_sma_get_node_desc ( struct ib_gma *gma,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret response       MAD response
  */
-static void ib_sma_get_guid_info ( struct ib_gma *gma,
-                                  union ib_mad *mad ) {
+static union ib_mad * ib_sma_get_guid_info ( struct ib_gma *gma,
+                                            union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        struct ib_guid_info *guid_info = &mad->smp.smp_data.guid_info;
 
        memset ( guid_info, 0, sizeof ( *guid_info ) );
        memcpy ( guid_info->guid[0], &ibdev->gid.u.half[1],
                 sizeof ( guid_info->guid[0] ) );
+
+       mad->hdr.method = IB_MGMT_METHOD_GET_RESP;
+       return ib_sma_dr_response ( gma, mad );
 }
 
 /**
@@ -146,9 +191,10 @@ static void ib_sma_get_guid_info ( struct ib_gma *gma,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret response       MAD response
  */
-static void ib_sma_get_port_info ( struct ib_gma *gma,
-                                  union ib_mad *mad ) {
+static union ib_mad * ib_sma_get_port_info ( struct ib_gma *gma,
+                                            union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        struct ib_port_info *port_info = &mad->smp.smp_data.port_info;
 
@@ -174,6 +220,9 @@ static void ib_sma_get_port_info ( struct ib_gma *gma,
        port_info->init_type_reply__mtu_cap = IB_MTU_2048;
        port_info->operational_vls__enforcement = ( IB_VL_0 << 4 );
        port_info->guid_cap = 1;
+
+       mad->hdr.method = IB_MGMT_METHOD_GET_RESP;
+       return ib_sma_dr_response ( gma, mad );
 }
 
 /**
@@ -181,9 +230,10 @@ static void ib_sma_get_port_info ( struct ib_gma *gma,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret response       MAD response
  */
-static void ib_sma_set_port_info ( struct ib_gma *gma,
-                                  union ib_mad *mad ) {
+static union ib_mad * ib_sma_set_port_info ( struct ib_gma *gma,
+                                            union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        const struct ib_port_info *port_info = &mad->smp.smp_data.port_info;
        int rc;
@@ -201,7 +251,7 @@ static void ib_sma_set_port_info ( struct ib_gma *gma,
                        htons ( IB_MGMT_STATUS_UNSUPPORTED_METHOD_ATTR );
        }
 
-       ib_sma_get_port_info ( gma, mad );
+       return ib_sma_get_port_info ( gma, mad );
 }
 
 /**
@@ -209,14 +259,19 @@ static void ib_sma_set_port_info ( struct ib_gma *gma,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret response       MAD response
  */
-static void ib_sma_get_pkey_table ( struct ib_gma *gma,
-                                   union ib_mad *mad ) {
+static union ib_mad * ib_sma_get_pkey_table ( struct ib_gma *gma,
+                                             union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        struct ib_pkey_table *pkey_table = &mad->smp.smp_data.pkey_table;
 
+       mad->hdr.method = IB_MGMT_METHOD_GET_RESP;
        memset ( pkey_table, 0, sizeof ( *pkey_table ) );
        pkey_table->pkey[0] = htons ( ibdev->pkey );
+
+       mad->hdr.method = IB_MGMT_METHOD_GET_RESP;
+       return ib_sma_dr_response ( gma, mad );
 }
 
 /**
@@ -224,15 +279,16 @@ static void ib_sma_get_pkey_table ( struct ib_gma *gma,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret response       MAD response
  */
-static void ib_sma_set_pkey_table ( struct ib_gma *gma,
-                                   union ib_mad *mad ) {
+static union ib_mad * ib_sma_set_pkey_table ( struct ib_gma *gma,
+                                             union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        struct ib_pkey_table *pkey_table = &mad->smp.smp_data.pkey_table;
 
        ibdev->pkey = ntohs ( pkey_table->pkey[0] );
 
-       ib_sma_get_pkey_table ( gma, mad );
+       return ib_sma_get_pkey_table ( gma, mad );
 }
 
 /** List of attribute handlers */
@@ -242,7 +298,6 @@ struct ib_gma_handler ib_sma_handlers[] __ib_gma_handler = {
                .mgmt_class_ignore = IB_SMP_CLASS_IGNORE,
                .class_version = IB_SMP_CLASS_VERSION,
                .method = IB_MGMT_METHOD_GET,
-               .resp_method = IB_MGMT_METHOD_GET_RESP,
                .attr_id = htons ( IB_SMP_ATTR_NODE_INFO ),
                .handle = ib_sma_get_node_info,
        },
@@ -251,7 +306,6 @@ struct ib_gma_handler ib_sma_handlers[] __ib_gma_handler = {
                .mgmt_class_ignore = IB_SMP_CLASS_IGNORE,
                .class_version = IB_SMP_CLASS_VERSION,
                .method = IB_MGMT_METHOD_GET,
-               .resp_method = IB_MGMT_METHOD_GET_RESP,
                .attr_id = htons ( IB_SMP_ATTR_NODE_DESC ),
                .handle = ib_sma_get_node_desc,
        },
@@ -260,7 +314,6 @@ struct ib_gma_handler ib_sma_handlers[] __ib_gma_handler = {
                .mgmt_class_ignore = IB_SMP_CLASS_IGNORE,
                .class_version = IB_SMP_CLASS_VERSION,
                .method = IB_MGMT_METHOD_GET,
-               .resp_method = IB_MGMT_METHOD_GET_RESP,
                .attr_id = htons ( IB_SMP_ATTR_GUID_INFO ),
                .handle = ib_sma_get_guid_info,
        },
@@ -269,7 +322,6 @@ struct ib_gma_handler ib_sma_handlers[] __ib_gma_handler = {
                .mgmt_class_ignore = IB_SMP_CLASS_IGNORE,
                .class_version = IB_SMP_CLASS_VERSION,
                .method = IB_MGMT_METHOD_GET,
-               .resp_method = IB_MGMT_METHOD_GET_RESP,
                .attr_id = htons ( IB_SMP_ATTR_PORT_INFO ),
                .handle = ib_sma_get_port_info,
        },
@@ -278,7 +330,6 @@ struct ib_gma_handler ib_sma_handlers[] __ib_gma_handler = {
                .mgmt_class_ignore = IB_SMP_CLASS_IGNORE,
                .class_version = IB_SMP_CLASS_VERSION,
                .method = IB_MGMT_METHOD_SET,
-               .resp_method = IB_MGMT_METHOD_GET_RESP,
                .attr_id = htons ( IB_SMP_ATTR_PORT_INFO ),
                .handle = ib_sma_set_port_info,
        },
@@ -287,7 +338,6 @@ struct ib_gma_handler ib_sma_handlers[] __ib_gma_handler = {
                .mgmt_class_ignore = IB_SMP_CLASS_IGNORE,
                .class_version = IB_SMP_CLASS_VERSION,
                .method = IB_MGMT_METHOD_GET,
-               .resp_method = IB_MGMT_METHOD_GET_RESP,
                .attr_id = htons ( IB_SMP_ATTR_PKEY_TABLE ),
                .handle = ib_sma_get_pkey_table,
        },
@@ -296,7 +346,6 @@ struct ib_gma_handler ib_sma_handlers[] __ib_gma_handler = {
                .mgmt_class_ignore = IB_SMP_CLASS_IGNORE,
                .class_version = IB_SMP_CLASS_VERSION,
                .method = IB_MGMT_METHOD_SET,
-               .resp_method = IB_MGMT_METHOD_GET_RESP,
                .attr_id = htons ( IB_SMP_ATTR_PKEY_TABLE ),
                .handle = ib_sma_set_pkey_table,
        },
@@ -314,8 +363,9 @@ struct ib_gma_handler ib_sma_handlers[] __ib_gma_handler = {
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret mad            MAD response
  */
-static void ib_handle_mad ( struct ib_gma *gma, union ib_mad *mad ) {
+static union ib_mad * ib_handle_mad ( struct ib_gma *gma, union ib_mad *mad ) {
        struct ib_mad_hdr *hdr = &mad->hdr;
        struct ib_gma_handler *handler;
 
@@ -325,14 +375,13 @@ static void ib_handle_mad ( struct ib_gma *gma, union ib_mad *mad ) {
                     ( handler->class_version == hdr->class_version ) &&
                     ( handler->method == hdr->method ) &&
                     ( handler->attr_id == hdr->attr_id ) ) {
-                       hdr->method = handler->resp_method;
-                       handler->handle ( gma, mad );
-                       return;
+                       return handler->handle ( gma, mad );
                }
        }
 
        hdr->method = IB_MGMT_METHOD_TRAP;
        hdr->status = htons ( IB_MGMT_STATUS_UNSUPPORTED_METHOD_ATTR );
+       return mad;
 }
 
 /**
@@ -353,8 +402,7 @@ static void ib_gma_complete_recv ( struct ib_device *ibdev,
        struct ib_mad_request *request;
        union ib_mad *mad;
        struct ib_mad_hdr *hdr;
-       unsigned int hop_pointer;
-       unsigned int hop_count;
+       union ib_mad *response;
 
        /* Ignore errors */
        if ( rc != 0 ) {
@@ -395,36 +443,17 @@ static void ib_gma_complete_recv ( struct ib_device *ibdev,
        }
 
        /* Handle MAD */
-       ib_handle_mad ( gma, mad );
-
-       /* Finish processing if we have no response to send */
-       if ( ! hdr->method )
+       if ( ( response = ib_handle_mad ( gma, mad ) ) == NULL )
                goto out;
 
+       /* Re-use I/O buffer for response */
+       memcpy ( mad, response, sizeof ( *mad ) );
        DBGC ( gma, "GMA %p TX TID %08x%08x (%02x,%02x,%02x,%04x) status "
               "%04x\n", gma, ntohl ( hdr->tid[0] ), ntohl ( hdr->tid[1] ),
               hdr->mgmt_class, hdr->class_version, hdr->method,
               ntohs ( hdr->attr_id ), ntohs ( hdr->status ) );
        DBGC2_HDA ( gma, 0, mad, sizeof ( *mad ) );
 
-       /* Set response fields for directed route SMPs */
-       if ( hdr->mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE ) {
-               struct ib_mad_smp *smp = &mad->smp;
-
-               hdr->status |= htons ( IB_SMP_STATUS_D_INBOUND );
-               hop_pointer = smp->mad_hdr.class_specific.smp.hop_pointer;
-               hop_count = smp->mad_hdr.class_specific.smp.hop_count;
-               assert ( hop_count == hop_pointer );
-               if ( hop_pointer < ( sizeof ( smp->return_path.hops ) /
-                                    sizeof ( smp->return_path.hops[0] ) ) ) {
-                       smp->return_path.hops[hop_pointer] = ibdev->port;
-               } else {
-                       DBGC ( gma, "GMA %p invalid hop pointer %d\n",
-                              gma, hop_pointer );
-                       goto out;
-               }
-       }
-
        /* Send MAD response, if applicable */
        if ( ( rc = ib_post_send ( ibdev, qp, av,
                                   iob_disown ( iobuf ) ) ) != 0 ) {

diff --git a/src/net/infiniband/ib_mcast.c b/src/net/infiniband/ib_mcast.c
index b7785e3..6e3026e 100644 (file)
--- a/src/net/infiniband/ib_mcast.c
+++ b/src/net/infiniband/ib_mcast.c
@@ -139,9 +139,10 @@ void ib_mcast_leave ( struct ib_device *ibdev, struct ib_queue_pair *qp,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret mad            MAD response
  */
-static void ib_handle_mc_member_join ( struct ib_gma *gma,
-                                      union ib_mad *mad ) {
+static union ib_mad * ib_handle_mc_member_join ( struct ib_gma *gma,
+                                                union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        struct ib_mc_member_record *mc_member_record =
                &mad->sa.sa_data.mc_member_record;
@@ -154,7 +155,7 @@ static void ib_handle_mc_member_join ( struct ib_gma *gma,
        if ( mad->hdr.status != htons ( IB_MGMT_STATUS_OK ) ) {
                DBGC ( gma, "GMA %p join failed with status %04x\n",
                       gma, ntohs ( mad->hdr.status ) );
-               return;
+               return NULL;
        }
 
        /* Extract MAD parameters */
@@ -169,7 +170,7 @@ static void ib_handle_mc_member_join ( struct ib_gma *gma,
                       ntohl ( gid->u.dwords[1] ),
                       ntohl ( gid->u.dwords[2] ),
                       ntohl ( gid->u.dwords[3] ) );
-               return;
+               return NULL;
        }
        DBGC ( gma, "GMA %p QPN %lx joined %08x:%08x:%08x:%08x qkey %lx\n",
               gma, qp->qpn, ntohl ( gid->u.dwords[0] ),
@@ -180,8 +181,10 @@ static void ib_handle_mc_member_join ( struct ib_gma *gma,
        if ( ( rc = ib_modify_qp ( ibdev, qp, IB_MODIFY_QKEY, qkey ) ) != 0 ) {
                DBGC ( gma, "GMA %p QPN %lx could not modify qkey: %s\n",
                       gma, qp->qpn, strerror ( rc ) );
-               return;
+               return NULL;
        }
+
+       return NULL;
 }
 
 /**
@@ -189,9 +192,10 @@ static void ib_handle_mc_member_join ( struct ib_gma *gma,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @v response         MAD response
  */
-static void ib_handle_mc_member_leave ( struct ib_gma *gma,
-                                       union ib_mad *mad ) {
+static union ib_mad * ib_handle_mc_member_leave ( struct ib_gma *gma,
+                                                 union ib_mad *mad ) {
        struct ib_mc_member_record *mc_member_record =
                &mad->sa.sa_data.mc_member_record;
        struct ib_gid *gid;
@@ -200,7 +204,7 @@ static void ib_handle_mc_member_leave ( struct ib_gma *gma,
        if ( mad->hdr.status != htons ( IB_MGMT_STATUS_OK ) ) {
                DBGC ( gma, "GMA %p leave failed with status %04x\n",
                       gma, ntohs ( mad->hdr.status ) );
-               return;
+               return NULL;
        }
 
        /* Extract MAD parameters */
@@ -208,6 +212,8 @@ static void ib_handle_mc_member_leave ( struct ib_gma *gma,
        DBGC ( gma, "GMA %p left %08x:%08x:%08x:%08x\n", gma,
               ntohl ( gid->u.dwords[0] ), ntohl ( gid->u.dwords[1] ),
               ntohl ( gid->u.dwords[2] ), ntohl ( gid->u.dwords[3] ) );
+
+       return NULL;
 }
 
 /** Multicast membership record response handler */

diff --git a/src/net/infiniband/ib_pathrec.c b/src/net/infiniband/ib_pathrec.c
index c3139dd..f0c7298 100644 (file)
--- a/src/net/infiniband/ib_pathrec.c
+++ b/src/net/infiniband/ib_pathrec.c
@@ -170,9 +170,10 @@ int ib_resolve_path ( struct ib_device *ibdev,
  *
  * @v gma              General management agent
  * @v mad              MAD
+ * @ret response       MAD response
  */
-static void ib_handle_path_record ( struct ib_gma *gma,
-                                   union ib_mad *mad ) {
+static union ib_mad * ib_handle_path_record ( struct ib_gma *gma,
+                                             union ib_mad *mad ) {
        struct ib_device *ibdev = gma->ibdev;
        struct ib_path_record *path_record = &mad->sa.sa_data.path_record;
        struct ib_gid *dgid = &path_record->dgid;
@@ -185,7 +186,7 @@ static void ib_handle_path_record ( struct ib_gma *gma,
        if ( mad->hdr.status != htons ( IB_MGMT_STATUS_OK ) ) {
                DBGC ( gma, "GMA %p path record lookup failed with status "
                       "%04x\n", gma, ntohs ( mad->hdr.status ) );
-               return;
+               return NULL;
        }
 
        /* Extract values from MAD */
@@ -208,6 +209,8 @@ static void ib_handle_path_record ( struct ib_gma *gma,
                cached->rate = rate;
                cached->sl = sl;
        }
+
+       return NULL;
 }
 
 /** Path record response handler */