ib_cm.c

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/*
 * Copyright (C) 2009 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <byteswap.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/infiniband.h>
#include <ipxe/ib_mi.h>
#include <ipxe/ib_pathrec.h>
#include <ipxe/ib_cm.h>

/**
 * @file
 *
 * Infiniband communication management
 *
 */

/** List of connections */
static LIST_HEAD ( ib_cm_conns );

/**
 * Find connection by local communication ID
 *
 * @v local_id          Local communication ID
 * @ret conn            Connection, or NULL
 */
static struct ib_connection * ib_cm_find ( uint32_t local_id ) {
        struct ib_connection *conn;

        list_for_each_entry ( conn, &ib_cm_conns, list ) {
                if ( conn->local_id == local_id )
                        return conn;
        }
        return NULL;
}

/**
 * Send "ready to use" response
 *
 * @v ibdev             Infiniband device
 * @v mi                Management interface
 * @v tid               Transaction identifier
 * @v av                Address vector
 * @v local_id          Local communication ID
 * @v remote_id         Remote communication ID
 * @ret rc              Return status code
 */
static int ib_cm_send_rtu ( struct ib_device *ibdev,
                            struct ib_mad_interface *mi,
                            struct ib_mad_tid *tid,
                            struct ib_address_vector *av,
                            uint32_t local_id, uint32_t remote_id ) {
        union ib_mad mad;
        struct ib_cm_ready_to_use *rtu = &mad.cm.cm_data.ready_to_use;
        int rc;

        /* Construct "ready to use" response */
        memset ( &mad, 0, sizeof ( mad ) );
        mad.hdr.mgmt_class = IB_MGMT_CLASS_CM;
        mad.hdr.class_version = IB_CM_CLASS_VERSION;
        mad.hdr.method = IB_MGMT_METHOD_SEND;
        memcpy ( &mad.hdr.tid, tid, sizeof ( mad.hdr.tid ) );
        mad.hdr.attr_id = htons ( IB_CM_ATTR_READY_TO_USE );
        rtu->local_id = htonl ( local_id );
        rtu->remote_id = htonl ( remote_id );
        if ( ( rc = ib_mi_send ( ibdev, mi, &mad, av ) ) != 0 ) {
                DBGC ( local_id, "CM %08x could not send RTU: %s\n",
                       local_id, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Handle duplicate connection replies
 *
 * @v ibdev             Infiniband device
 * @v mi                Management interface
 * @v mad               Received MAD
 * @v av                Source address vector
 * @ret rc              Return status code
 *
 * If a "ready to use" MAD is lost, the peer may resend the connection
 * reply.  We have to respond to these with duplicate "ready to use"
 * MADs, otherwise the peer may time out and drop the connection.
 */
static void ib_cm_recv_rep ( struct ib_device *ibdev,
                             struct ib_mad_interface *mi,
                             union ib_mad *mad,
                             struct ib_address_vector *av ) {
        struct ib_cm_connect_reply *rep = &mad->cm.cm_data.connect_reply;
        struct ib_connection *conn;
        uint32_t local_id = ntohl ( rep->remote_id );
        int rc;

        /* Identify connection */
        conn = ib_cm_find ( local_id );
        if ( conn ) {
                /* Try to send "ready to use" reply */
                if ( ( rc = ib_cm_send_rtu ( ibdev, mi, &mad->hdr.tid, av,
                                             conn->local_id,
                                             conn->remote_id ) ) != 0 ) {
                        /* Ignore errors; the remote end will retry */
                }
        } else {
                DBGC ( local_id, "CM %08x unexpected REP\n", local_id );
        }
}

/**
 * Send reply to disconnection request
 *
 * @v ibdev             Infiniband device
 * @v mi                Management interface
 * @v tid               Transaction identifier
 * @v av                Address vector
 * @v local_id          Local communication ID
 * @v remote_id         Remote communication ID
 * @ret rc              Return status code
 */
static int ib_cm_send_drep ( struct ib_device *ibdev,
                             struct ib_mad_interface *mi,
                             struct ib_mad_tid *tid,
                             struct ib_address_vector *av,
                             uint32_t local_id, uint32_t remote_id ) {
        union ib_mad mad;
        struct ib_cm_disconnect_reply *drep = &mad.cm.cm_data.disconnect_reply;
        int rc;

        /* Construct reply to disconnection request */
        memset ( &mad, 0, sizeof ( mad ) );
        mad.hdr.mgmt_class = IB_MGMT_CLASS_CM;
        mad.hdr.class_version = IB_CM_CLASS_VERSION;
        mad.hdr.method = IB_MGMT_METHOD_SEND;
        memcpy ( &mad.hdr.tid, tid, sizeof ( mad.hdr.tid ) );
        mad.hdr.attr_id = htons ( IB_CM_ATTR_DISCONNECT_REPLY );
        drep->local_id = htonl ( local_id );
        drep->remote_id = htonl ( remote_id );
        if ( ( rc = ib_mi_send ( ibdev, mi, &mad, av ) ) != 0 ) {
                DBGC ( local_id, "CM %08x could not send DREP: %s\n",
                       local_id, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Handle disconnection requests
 *
 * @v ibdev             Infiniband device
 * @v mi                Management interface
 * @v mad               Received MAD
 * @v av                Source address vector
 * @ret rc              Return status code
 */
static void ib_cm_recv_dreq ( struct ib_device *ibdev,
                              struct ib_mad_interface *mi,
                              union ib_mad *mad,
                              struct ib_address_vector *av ) {
        struct ib_cm_disconnect_request *dreq =
                &mad->cm.cm_data.disconnect_request;
        struct ib_connection *conn;
        uint32_t local_id = ntohl ( dreq->remote_id );
        uint32_t remote_id = ntohl ( dreq->local_id );
        int rc;

        /* Identify connection */
        conn = ib_cm_find ( local_id );
        if ( conn ) {
                /* Notify upper layer */
                conn->op->changed ( ibdev, conn->qp, conn, -ENOTCONN,
                                    &dreq->private_data,
                                    sizeof ( dreq->private_data ) );
        } else {
                DBGC ( local_id, "CM %08x unexpected DREQ\n", local_id );
        }

        /* Send reply */
        if ( ( rc = ib_cm_send_drep ( ibdev, mi, &mad->hdr.tid, av, local_id,
                                      remote_id ) ) != 0 ) {
                /* Ignore errors; the remote end will retry */
        }
};

/** Communication management agents */
struct ib_mad_agent ib_cm_agent[] __ib_mad_agent = {
        {
                .mgmt_class = IB_MGMT_CLASS_CM,
                .class_version = IB_CM_CLASS_VERSION,
                .attr_id = htons ( IB_CM_ATTR_CONNECT_REPLY ),
                .handle = ib_cm_recv_rep,
        },
        {
                .mgmt_class = IB_MGMT_CLASS_CM,
                .class_version = IB_CM_CLASS_VERSION,
                .attr_id = htons ( IB_CM_ATTR_DISCONNECT_REQUEST ),
                .handle = ib_cm_recv_dreq,
        },
};

/**
 * Convert connection rejection reason to return status code
 *
 * @v reason            Rejection reason (in network byte order)
 * @ret rc              Return status code
 */
static int ib_cm_rejection_reason_to_rc ( uint16_t reason ) {
        switch ( reason ) {
        case htons ( IB_CM_REJECT_BAD_SERVICE_ID ) :
                return -ENODEV;
        case htons ( IB_CM_REJECT_STALE_CONN ) :
                return -EALREADY;
        case htons ( IB_CM_REJECT_CONSUMER ) :
                return -ENOTTY;
        default:
                return -EPERM;
        }
}

/**
 * Handle connection request transaction completion
 *
 * @v ibdev             Infiniband device
 * @v mi                Management interface
 * @v madx              Management transaction
 * @v rc                Status code
 * @v mad               Received MAD (or NULL on error)
 * @v av                Source address vector (or NULL on error)
 */
static void ib_cm_req_complete ( struct ib_device *ibdev,
                                 struct ib_mad_interface *mi,
                                 struct ib_mad_transaction *madx,
                                 int rc, union ib_mad *mad,
                                 struct ib_address_vector *av ) {
        struct ib_connection *conn = ib_madx_get_ownerdata ( madx );
        struct ib_queue_pair *qp = conn->qp;
        struct ib_cm_common *common = &mad->cm.cm_data.common;
        struct ib_cm_connect_reply *rep = &mad->cm.cm_data.connect_reply;
        struct ib_cm_connect_reject *rej = &mad->cm.cm_data.connect_reject;
        uint32_t local_id = conn->local_id;
        void *private_data = NULL;
        size_t private_data_len = 0;

        /* Report failures */
        if ( ( rc == 0 ) && ( mad->hdr.status != htons ( IB_MGMT_STATUS_OK ) ))
                rc = -EIO;
        if ( rc != 0 ) {
                DBGC ( local_id, "CM %08x connection request failed: %s\n",
                       local_id, strerror ( rc ) );
                goto out;
        }

        /* Record remote communication ID */
        conn->remote_id = ntohl ( common->local_id );

        /* Handle response */
        switch ( mad->hdr.attr_id ) {

        case htons ( IB_CM_ATTR_CONNECT_REPLY ) :
                /* Extract fields */
                qp->av.qpn = ( ntohl ( rep->local_qpn ) >> 8 );
                qp->send.psn = ( ntohl ( rep->starting_psn ) >> 8 );
                private_data = &rep->private_data;
                private_data_len = sizeof ( rep->private_data );
                DBGC ( local_id, "CM %08x connected to QPN %#lx PSN %#x\n",
                       local_id, qp->av.qpn, qp->send.psn );

                /* Modify queue pair */
                if ( ( rc = ib_modify_qp ( ibdev, qp ) ) != 0 ) {
                        DBGC ( local_id, "CM %08x could not modify queue "
                               "pair: %s\n", local_id, strerror ( rc ) );
                        goto out;
                }

                /* Send "ready to use" reply */
                if ( ( rc = ib_cm_send_rtu ( ibdev, mi, &mad->hdr.tid, av,
                                             conn->local_id,
                                             conn->remote_id ) ) != 0 ) {
                        /* Treat as non-fatal */
                        rc = 0;
                }
                break;

        case htons ( IB_CM_ATTR_CONNECT_REJECT ) :
                /* Extract fields */
                DBGC ( local_id, "CM %08x connection rejected (reason %d)\n",
                       local_id, ntohs ( rej->reason ) );
                /* Private data is valid only for a Consumer Reject */
                if ( rej->reason == htons ( IB_CM_REJECT_CONSUMER ) ) {
                        private_data = &rej->private_data;
                        private_data_len = sizeof ( rej->private_data );
                }
                rc = ib_cm_rejection_reason_to_rc ( rej->reason );
                break;

        default:
                DBGC ( local_id, "CM %08x unexpected response (attribute "
                       "%04x)\n", local_id, ntohs ( mad->hdr.attr_id ) );
                rc = -ENOTSUP;
                break;
        }

 out:
        /* Destroy the completed transaction */
        ib_destroy_madx ( ibdev, ibdev->gsi, madx );
        conn->madx = NULL;

        /* Hand off to the upper completion handler */
        conn->op->changed ( ibdev, qp, conn, rc, private_data,
                            private_data_len );
}

/** Connection request operations */
static struct ib_mad_transaction_operations ib_cm_req_op = {
        .complete = ib_cm_req_complete,
};

/**
 * Handle connection path transaction completion
 *
 * @v ibdev             Infiniband device
 * @v path              Path
 * @v rc                Status code
 * @v av                Address vector, or NULL on error
 */
static void ib_cm_path_complete ( struct ib_device *ibdev,
                                  struct ib_path *path, int rc,
                                  struct ib_address_vector *av ) {
        struct ib_connection *conn = ib_path_get_ownerdata ( path );
        struct ib_queue_pair *qp = conn->qp;
        union ib_mad mad;
        struct ib_cm_connect_request *req = &mad.cm.cm_data.connect_request;
        uint32_t local_id = conn->local_id;
        size_t private_data_len;

        /* Report failures */
        if ( rc != 0 ) {
                DBGC ( local_id, "CM %08x path lookup failed: %s\n",
                       local_id, strerror ( rc ) );
                conn->op->changed ( ibdev, qp, conn, rc, NULL, 0 );
                goto out;
        }

        /* Update queue pair peer path */
        memcpy ( &qp->av, av, sizeof ( qp->av ) );

        /* Construct connection request */
        memset ( &mad, 0, sizeof ( mad ) );
        mad.hdr.mgmt_class = IB_MGMT_CLASS_CM;
        mad.hdr.class_version = IB_CM_CLASS_VERSION;
        mad.hdr.method = IB_MGMT_METHOD_SEND;
        mad.hdr.attr_id = htons ( IB_CM_ATTR_CONNECT_REQUEST );
        req->local_id = htonl ( conn->local_id );
        memcpy ( &req->service_id, &conn->service_id,
                 sizeof ( req->service_id ) );
        memcpy ( &req->local_ca, &ibdev->node_guid, sizeof ( req->local_ca ) );
        req->local_qpn__responder_resources = htonl ( ( qp->qpn << 8 ) | 1 );
        req->local_eecn__initiator_depth = htonl ( ( 0 << 8 ) | 1 );
        req->remote_eecn__remote_timeout__service_type__ee_flow_ctrl =
                htonl ( ( 0x14 << 3 ) | ( IB_CM_TRANSPORT_RC << 1 ) |
                        ( 0 << 0 ) );
        req->starting_psn__local_timeout__retry_count =
                htonl ( ( qp->recv.psn << 8 ) | ( 0x14 << 3 ) |
                        ( 0x07 << 0 ) );
        req->pkey = htons ( ibdev->pkey );
        req->payload_mtu__rdc_exists__rnr_retry =
                ( ( IB_MTU_2048 << 4 ) | ( 1 << 3 ) | ( 0x07 << 0 ) );
        req->max_cm_retries__srq = ( ( 0x0f << 4 ) | ( 0 << 3 ) );
        req->primary.local_lid = htons ( ibdev->lid );
        req->primary.remote_lid = htons ( conn->qp->av.lid );
        memcpy ( &req->primary.local_gid, &ibdev->gid,
                 sizeof ( req->primary.local_gid ) );
        memcpy ( &req->primary.remote_gid, &conn->qp->av.gid,
                 sizeof ( req->primary.remote_gid ) );
        req->primary.flow_label__rate =
                htonl ( ( 0 << 12 ) | ( conn->qp->av.rate << 0 ) );
        req->primary.hop_limit = 0;
        req->primary.sl__subnet_local =
                ( ( conn->qp->av.sl << 4 ) | ( 1 << 3 ) );
        req->primary.local_ack_timeout = ( 0x13 << 3 );
        private_data_len = conn->private_data_len;
        if ( private_data_len > sizeof ( req->private_data ) )
                private_data_len = sizeof ( req->private_data );
        memcpy ( &req->private_data, &conn->private_data, private_data_len );

        /* Create connection request */
        av->qpn = IB_QPN_GSI;
        av->qkey = IB_QKEY_GSI;
        conn->madx = ib_create_madx ( ibdev, ibdev->gsi, &mad, av,
                                      &ib_cm_req_op );
        if ( ! conn->madx ) {
                DBGC ( local_id, "CM %08x could not create connection "
                       "request\n", local_id );
                conn->op->changed ( ibdev, qp, conn, rc, NULL, 0 );
                goto out;
        }
        ib_madx_set_ownerdata ( conn->madx, conn );

 out:
        /* Destroy the completed transaction */
        ib_destroy_path ( ibdev, path );
        conn->path = NULL;
}

/** Connection path operations */
static struct ib_path_operations ib_cm_path_op = {
        .complete = ib_cm_path_complete,
};

/**
 * Create connection to remote QP
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 * @v dgid              Target GID
 * @v service_id        Target service ID
 * @v private_data      Connection request private data
 * @v private_data_len  Length of connection request private data
 * @v op                Connection operations
 * @ret conn            Connection
 */
struct ib_connection *
ib_create_conn ( struct ib_device *ibdev, struct ib_queue_pair *qp,
                 union ib_gid *dgid, union ib_guid *service_id,
                 void *private_data, size_t private_data_len,
                 struct ib_connection_operations *op ) {
        struct ib_connection *conn;
        uint32_t local_id;

        /* Allocate and initialise request */
        conn = zalloc ( sizeof ( *conn ) + private_data_len );
        if ( ! conn )
                goto err_alloc_conn;
        conn->ibdev = ibdev;
        conn->qp = qp;
        memset ( &qp->av, 0, sizeof ( qp->av ) );
        qp->av.gid_present = 1;
        memcpy ( &qp->av.gid, dgid, sizeof ( qp->av.gid ) );
        conn->local_id = local_id = random();
        memcpy ( &conn->service_id, service_id, sizeof ( conn->service_id ) );
        conn->op = op;
        conn->private_data_len = private_data_len;
        memcpy ( &conn->private_data, private_data, private_data_len );

        /* Create path */
        conn->path = ib_create_path ( ibdev, &qp->av, &ib_cm_path_op );
        if ( ! conn->path )
                goto err_create_path;
        ib_path_set_ownerdata ( conn->path, conn );

        /* Add to list of connections */
        list_add ( &conn->list, &ib_cm_conns );

        DBGC ( local_id, "CM %08x created for IBDEV %s QPN %#lx\n",
               local_id, ibdev->name, qp->qpn );
        DBGC ( local_id, "CM %08x connecting to " IB_GID_FMT " "
               IB_GUID_FMT "\n", local_id, IB_GID_ARGS ( dgid ),
               IB_GUID_ARGS ( service_id ) );

        return conn;

        ib_destroy_path ( ibdev, conn->path );
 err_create_path:
        free ( conn );
 err_alloc_conn:
        return NULL;
}

/**
 * Destroy connection to remote QP
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 * @v conn              Connection
 */
void ib_destroy_conn ( struct ib_device *ibdev,
                       struct ib_queue_pair *qp __unused,
                       struct ib_connection *conn ) {

        list_del ( &conn->list );
        if ( conn->madx )
                ib_destroy_madx ( ibdev, ibdev->gsi, conn->madx );
        if ( conn->path )
                ib_destroy_path ( ibdev, conn->path );
        free ( conn );
}