ib_packet.c

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/*
 * Copyright (C) 2008 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <byteswap.h>
#include <gpxe/iobuf.h>
#include <gpxe/infiniband.h>
#include <gpxe/ib_packet.h>

/**
 * @file
 *
 * Infiniband Packet Formats
 *
 */

/**
 * Add IB headers
 *
 * @v ibdev             Infiniband device
 * @v iobuf             I/O buffer to contain headers
 * @v qp                Queue pair
 * @v payload_len       Payload length
 * @v av                Address vector
 */
int ib_push ( struct ib_device *ibdev, struct io_buffer *iobuf,
              struct ib_queue_pair *qp, size_t payload_len,
              const struct ib_address_vector *av ) {
        struct ib_local_route_header *lrh;
        struct ib_global_route_header *grh;
        struct ib_base_transport_header *bth;
        struct ib_datagram_extended_transport_header *deth;
        size_t orig_iob_len = iob_len ( iobuf );
        size_t pad_len;
        size_t lrh_len;
        size_t grh_len;
        unsigned int vl;
        unsigned int lnh;

        DBGC2 ( ibdev, "IBDEV %p TX %04x:%08lx => %04x:%08lx (key %08lx)\n",
                ibdev, ibdev->lid, qp->ext_qpn, av->lid, av->qpn, av->qkey );

        /* Calculate packet length */
        pad_len = ( (-payload_len) & 0x3 );
        payload_len += pad_len;
        payload_len += 4; /* ICRC */

        /* Reserve space for headers */
        orig_iob_len = iob_len ( iobuf );
        deth = iob_push ( iobuf, sizeof ( *deth ) );
        bth = iob_push ( iobuf, sizeof ( *bth ) );
        grh_len = ( payload_len + iob_len ( iobuf ) - orig_iob_len );
        grh = ( av->gid_present ?
                iob_push ( iobuf, sizeof ( *grh ) ) : NULL );
        lrh = iob_push ( iobuf, sizeof ( *lrh ) );
        lrh_len = ( payload_len + iob_len ( iobuf ) - orig_iob_len );

        /* Construct LRH */
        vl = ( ( qp->ext_qpn == IB_QPN_SMI ) ? IB_VL_SMP : IB_VL_DEFAULT );
        lrh->vl__lver = ( vl << 4 );
        lnh = ( grh ? IB_LNH_GRH : IB_LNH_BTH );
        lrh->sl__lnh = ( ( av->sl << 4 ) | lnh );
        lrh->dlid = htons ( av->lid );
        lrh->length = htons ( lrh_len >> 2 );
        lrh->slid = htons ( ibdev->lid );

        /* Construct GRH, if required */
        if ( grh ) {
                grh->ipver__tclass__flowlabel =
                        htonl ( IB_GRH_IPVER_IPv6 << 28 );
                grh->paylen = htons ( grh_len );
                grh->nxthdr = IB_GRH_NXTHDR_IBA;
                grh->hoplmt = 0;
                memcpy ( &grh->sgid, &ibdev->gid, sizeof ( grh->sgid ) );
                memcpy ( &grh->dgid, &av->gid, sizeof ( grh->dgid ) );
        }

        /* Construct BTH */
        bth->opcode = BTH_OPCODE_UD_SEND;
        bth->se__m__padcnt__tver = ( pad_len << 4 );
        bth->pkey = htons ( ibdev->pkey );
        bth->dest_qp = htonl ( av->qpn );
        bth->ack__psn = htonl ( ( qp->send.psn++ ) & 0xffffffUL );

        /* Construct DETH */
        deth->qkey = htonl ( av->qkey );
        deth->src_qp = htonl ( qp->ext_qpn );

        DBGCP_HDA ( ibdev, 0, iobuf->data,
                    ( iob_len ( iobuf ) - orig_iob_len ) );

        return 0;
}

/**
 * Remove IB headers
 *
 * @v ibdev             Infiniband device
 * @v iobuf             I/O buffer containing headers
 * @v qp                Queue pair to fill in, or NULL
 * @v payload_len       Payload length to fill in, or NULL
 * @v av                Address vector to fill in
 */
int ib_pull ( struct ib_device *ibdev, struct io_buffer *iobuf,
              struct ib_queue_pair **qp, size_t *payload_len,
              struct ib_address_vector *av ) {
        struct ib_local_route_header *lrh;
        struct ib_global_route_header *grh;
        struct ib_base_transport_header *bth;
        struct ib_datagram_extended_transport_header *deth;
        size_t orig_iob_len = iob_len ( iobuf );
        unsigned int lnh;
        size_t pad_len;
        unsigned long qpn;
        unsigned int lid;

        /* Clear return values */
        if ( qp )
                *qp = NULL;
        if ( payload_len )
                *payload_len = 0;
        memset ( av, 0, sizeof ( *av ) );

        /* Extract LRH */
        if ( iob_len ( iobuf ) < sizeof ( *lrh ) ) {
                DBGC ( ibdev, "IBDEV %p RX too short (%zd bytes) for LRH\n",
                       ibdev, iob_len ( iobuf ) );
                return -EINVAL;
        }
        lrh = iobuf->data;
        iob_pull ( iobuf, sizeof ( *lrh ) );
        av->lid = ntohs ( lrh->slid );
        av->sl = ( lrh->sl__lnh >> 4 );
        lnh = ( lrh->sl__lnh & 0x3 );
        lid = ntohs ( lrh->dlid );

        /* Reject unsupported packets */
        if ( ! ( ( lnh == IB_LNH_BTH ) || ( lnh == IB_LNH_GRH ) ) ) {
                DBGC ( ibdev, "IBDEV %p RX unsupported LNH %x\n",
                       ibdev, lnh );
                return -ENOTSUP;
        }

        /* Extract GRH, if present */
        if ( lnh == IB_LNH_GRH ) {
                if ( iob_len ( iobuf ) < sizeof ( *grh ) ) {
                        DBGC ( ibdev, "IBDEV %p RX too short (%zd bytes) "
                               "for GRH\n", ibdev, iob_len ( iobuf ) );
                        return -EINVAL;
                }
                grh = iobuf->data;
                iob_pull ( iobuf, sizeof ( *grh ) );
                av->gid_present = 1;
                memcpy ( &av->gid, &grh->sgid, sizeof ( av->gid ) );
        } else {
                grh = NULL;
        }

        /* Extract BTH */
        if ( iob_len ( iobuf ) < sizeof ( *bth ) ) {
                DBGC ( ibdev, "IBDEV %p RX too short (%zd bytes) for BTH\n",
                       ibdev, iob_len ( iobuf ) );
                return -EINVAL;
        }
        bth = iobuf->data;
        iob_pull ( iobuf, sizeof ( *bth ) );
        if ( bth->opcode != BTH_OPCODE_UD_SEND ) {
                DBGC ( ibdev, "IBDEV %p unsupported BTH opcode %x\n",
                       ibdev, bth->opcode );
                return -ENOTSUP;
        }
        qpn = ntohl ( bth->dest_qp );

        /* Extract DETH */
        if ( iob_len ( iobuf ) < sizeof ( *deth ) ) {
                DBGC ( ibdev, "IBDEV %p RX too short (%zd bytes) for DETH\n",
                       ibdev, iob_len ( iobuf ) );
                return -EINVAL;
        }
        deth = iobuf->data;
        iob_pull ( iobuf, sizeof ( *deth ) );
        av->qpn = ntohl ( deth->src_qp );
        av->qkey = ntohl ( deth->qkey );

        /* Calculate payload length, if applicable */
        if ( payload_len ) {
                pad_len = ( ( bth->se__m__padcnt__tver >> 4 ) & 0x3 );
                *payload_len = ( ( ntohs ( lrh->length ) << 2 )
                                 - ( orig_iob_len - iob_len ( iobuf ) )
                                 - pad_len - 4 /* ICRC */ );
        }

        /* Determine destination QP, if applicable */
        if ( qp ) {
                if ( IB_LID_MULTICAST ( lid ) && grh ) {
                        if ( ! ( *qp = ib_find_qp_mgid ( ibdev, &grh->dgid ))){
                                DBGC ( ibdev, "IBDEV %p RX for unknown MGID "
                                       "%08x:%08x:%08x:%08x\n", ibdev,
                                       ntohl ( grh->dgid.u.dwords[0] ),
                                       ntohl ( grh->dgid.u.dwords[1] ),
                                       ntohl ( grh->dgid.u.dwords[2] ),
                                       ntohl ( grh->dgid.u.dwords[3] ) );
                                return -ENODEV;
                        }
                } else {
                        if ( ! ( *qp = ib_find_qp_qpn ( ibdev, qpn ) ) ) {
                                DBGC ( ibdev, "IBDEV %p RX for nonexistent "
                                       "QPN %lx\n", ibdev, qpn );
                                return -ENODEV;
                        }
                }
                assert ( *qp );
        }

        DBGC2 ( ibdev, "IBDEV %p RX %04x:%08lx <= %04x:%08lx (key %08x)\n",
                ibdev, lid, ( IB_LID_MULTICAST( lid ) ?
                              ( qp ? (*qp)->ext_qpn : -1UL ) : qpn ),
                av->lid, av->qpn, ntohl ( deth->qkey ) );
        DBGCP_HDA ( ibdev, 0,
                    ( iobuf->data - ( orig_iob_len - iob_len ( iobuf ) ) ),
                    ( orig_iob_len - iob_len ( iobuf ) ) );

        return 0;
}