[arbel] Fix off-by-one error in the failure path in arbel_probe()

[gpxe/hramrach.git] / src / drivers / infiniband / arbel.c

/*
 * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * Based in part upon the original driver by Mellanox Technologies
 * Ltd.  Portions may be Copyright (c) Mellanox Technologies Ltd.
 *
 * 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.
 */

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <errno.h>
#include <byteswap.h>
#include <gpxe/pci.h>
#include <gpxe/malloc.h>
#include <gpxe/umalloc.h>
#include <gpxe/iobuf.h>
#include <gpxe/netdevice.h>
#include <gpxe/infiniband.h>
#include "arbel.h"

/**
 * @file
 *
 * Mellanox Arbel Infiniband HCA
 *
 */

/***************************************************************************
 *
 * Queue number allocation
 *
 ***************************************************************************
 */

/**
 * Allocate queue number
 *
 * @v q_inuse           Queue usage bitmask
 * @v max_inuse         Maximum number of in-use queues
 * @ret qn_offset       Free queue number offset, or negative error
 */
static int arbel_alloc_qn_offset ( arbel_bitmask_t *q_inuse,
                                   unsigned int max_inuse ) {
        unsigned int qn_offset = 0;
        arbel_bitmask_t mask = 1;

        while ( qn_offset < max_inuse ) {
                if ( ( mask & *q_inuse ) == 0 ) {
                        *q_inuse |= mask;
                        return qn_offset;
                }
                qn_offset++;
                mask <<= 1;
                if ( ! mask ) {
                        mask = 1;
                        q_inuse++;
                }
        }
        return -ENFILE;
}

/**
 * Free queue number
 *
 * @v q_inuse           Queue usage bitmask
 * @v qn_offset         Queue number offset
 */
static void arbel_free_qn_offset ( arbel_bitmask_t *q_inuse, int qn_offset ) {
        arbel_bitmask_t mask;

        mask = ( 1 << ( qn_offset % ( 8 * sizeof ( mask ) ) ) );
        q_inuse += ( qn_offset / ( 8 * sizeof ( mask ) ) );
        *q_inuse &= ~mask;
}

/***************************************************************************
 *
 * HCA commands
 *
 ***************************************************************************
 */

/**
 * Wait for Arbel command completion
 *
 * @v arbel             Arbel device
 * @ret rc              Return status code
 */
static int arbel_cmd_wait ( struct arbel *arbel,
                            struct arbelprm_hca_command_register *hcr ) {
        unsigned int wait;

        for ( wait = ARBEL_HCR_MAX_WAIT_MS ; wait ; wait-- ) {
                hcr->u.dwords[6] =
                        readl ( arbel->config + ARBEL_HCR_REG ( 6 ) );
                if ( MLX_GET ( hcr, go ) == 0 )
                        return 0;
                mdelay ( 1 );
        }
        return -EBUSY;
}

/**
 * Issue HCA command
 *
 * @v arbel             Arbel device
 * @v command           Command opcode, flags and input/output lengths
 * @v op_mod            Opcode modifier (0 if no modifier applicable)
 * @v in                Input parameters
 * @v in_mod            Input modifier (0 if no modifier applicable)
 * @v out               Output parameters
 * @ret rc              Return status code
 */
static int arbel_cmd ( struct arbel *arbel, unsigned long command,
                       unsigned int op_mod, const void *in,
                       unsigned int in_mod, void *out ) {
        struct arbelprm_hca_command_register hcr;
        unsigned int opcode = ARBEL_HCR_OPCODE ( command );
        size_t in_len = ARBEL_HCR_IN_LEN ( command );
        size_t out_len = ARBEL_HCR_OUT_LEN ( command );
        void *in_buffer;
        void *out_buffer;
        unsigned int status;
        unsigned int i;
        int rc;

        assert ( in_len <= ARBEL_MBOX_SIZE );
        assert ( out_len <= ARBEL_MBOX_SIZE );

        DBGC2 ( arbel, "Arbel %p command %02x in %zx%s out %zx%s\n",
                arbel, opcode, in_len,
                ( ( command & ARBEL_HCR_IN_MBOX ) ? "(mbox)" : "" ), out_len,
                ( ( command & ARBEL_HCR_OUT_MBOX ) ? "(mbox)" : "" ) );

        /* Check that HCR is free */
        if ( ( rc = arbel_cmd_wait ( arbel, &hcr ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p command interface locked\n", arbel );
                return rc;
        }

        /* Prepare HCR */
        memset ( &hcr, 0, sizeof ( hcr ) );
        in_buffer = &hcr.u.dwords[0];
        if ( in_len && ( command & ARBEL_HCR_IN_MBOX ) ) {
                in_buffer = arbel->mailbox_in;
                MLX_FILL_1 ( &hcr, 1, in_param_l, virt_to_bus ( in_buffer ) );
        }
        memcpy ( in_buffer, in, in_len );
        MLX_FILL_1 ( &hcr, 2, input_modifier, in_mod );
        out_buffer = &hcr.u.dwords[3];
        if ( out_len && ( command & ARBEL_HCR_OUT_MBOX ) ) {
                out_buffer = arbel->mailbox_out;
                MLX_FILL_1 ( &hcr, 4, out_param_l,
                             virt_to_bus ( out_buffer ) );
        }
        MLX_FILL_3 ( &hcr, 6,
                     opcode, opcode,
                     opcode_modifier, op_mod,
                     go, 1 );
        DBGC2_HD ( arbel, &hcr, sizeof ( hcr ) );
        if ( in_len ) {
                DBGC2 ( arbel, "Input:\n" );
                DBGC2_HD ( arbel, in, ( ( in_len < 512 ) ? in_len : 512 ) );
        }

        /* Issue command */
        for ( i = 0 ; i < ( sizeof ( hcr ) / sizeof ( hcr.u.dwords[0] ) ) ;
              i++ ) {
                writel ( hcr.u.dwords[i],
                         arbel->config + ARBEL_HCR_REG ( i ) );
                barrier();
        }

        /* Wait for command completion */
        if ( ( rc = arbel_cmd_wait ( arbel, &hcr ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p timed out waiting for command:\n",
                       arbel );
                DBGC_HD ( arbel, &hcr, sizeof ( hcr ) );
                return rc;
        }

        /* Check command status */
        status = MLX_GET ( &hcr, status );
        if ( status != 0 ) {
                DBGC ( arbel, "Arbel %p command failed with status %02x:\n",
                       arbel, status );
                DBGC_HD ( arbel, &hcr, sizeof ( hcr ) );
                return -EIO;
        }

        /* Read output parameters, if any */
        hcr.u.dwords[3] = readl ( arbel->config + ARBEL_HCR_REG ( 3 ) );
        hcr.u.dwords[4] = readl ( arbel->config + ARBEL_HCR_REG ( 4 ) );
        memcpy ( out, out_buffer, out_len );
        if ( out_len ) {
                DBGC2 ( arbel, "Output:\n" );
                DBGC2_HD ( arbel, out, ( ( out_len < 512 ) ? out_len : 512 ) );
        }

        return 0;
}

static inline int
arbel_cmd_query_dev_lim ( struct arbel *arbel,
                          struct arbelprm_query_dev_lim *dev_lim ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_OUT_CMD ( ARBEL_HCR_QUERY_DEV_LIM,
                                               1, sizeof ( *dev_lim ) ),
                           0, NULL, 0, dev_lim );
}

static inline int
arbel_cmd_query_fw ( struct arbel *arbel, struct arbelprm_query_fw *fw ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_OUT_CMD ( ARBEL_HCR_QUERY_FW, 
                                               1, sizeof ( *fw ) ),
                           0, NULL, 0, fw );
}

static inline int
arbel_cmd_init_hca ( struct arbel *arbel,
                     const struct arbelprm_init_hca *init_hca ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_INIT_HCA,
                                              1, sizeof ( *init_hca ) ),
                           0, init_hca, 0, NULL );
}

static inline int
arbel_cmd_close_hca ( struct arbel *arbel ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_VOID_CMD ( ARBEL_HCR_CLOSE_HCA ),
                           0, NULL, 0, NULL );
}

static inline int
arbel_cmd_init_ib ( struct arbel *arbel, unsigned int port,
                    const struct arbelprm_init_ib *init_ib ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_INIT_IB,
                                              1, sizeof ( *init_ib ) ),
                           0, init_ib, port, NULL );
}

static inline int
arbel_cmd_close_ib ( struct arbel *arbel, unsigned int port ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_VOID_CMD ( ARBEL_HCR_CLOSE_IB ),
                           0, NULL, port, NULL );
}

static inline int
arbel_cmd_sw2hw_mpt ( struct arbel *arbel, unsigned int index,
                      const struct arbelprm_mpt *mpt ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_SW2HW_MPT,
                                              1, sizeof ( *mpt ) ),
                           0, mpt, index, NULL );
}

static inline int
arbel_cmd_map_eq ( struct arbel *arbel, unsigned long index_map,
                   const struct arbelprm_event_mask *mask ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_MAP_EQ,
                                              0, sizeof ( *mask ) ),
                           0, mask, index_map, NULL );
}

static inline int
arbel_cmd_sw2hw_eq ( struct arbel *arbel, unsigned int index,
                     const struct arbelprm_eqc *eqctx ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_SW2HW_EQ,
                                              1, sizeof ( *eqctx ) ),
                           0, eqctx, index, NULL );
}

static inline int
arbel_cmd_hw2sw_eq ( struct arbel *arbel, unsigned int index,
                     struct arbelprm_eqc *eqctx ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_OUT_CMD ( ARBEL_HCR_HW2SW_EQ,
                                               1, sizeof ( *eqctx ) ),
                           1, NULL, index, eqctx );
}

static inline int
arbel_cmd_sw2hw_cq ( struct arbel *arbel, unsigned long cqn,
                     const struct arbelprm_completion_queue_context *cqctx ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_SW2HW_CQ,
                                              1, sizeof ( *cqctx ) ),
                           0, cqctx, cqn, NULL );
}

static inline int
arbel_cmd_hw2sw_cq ( struct arbel *arbel, unsigned long cqn,
                     struct arbelprm_completion_queue_context *cqctx) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_OUT_CMD ( ARBEL_HCR_HW2SW_CQ,
                                               1, sizeof ( *cqctx ) ),
                           0, NULL, cqn, cqctx );
}

static inline int
arbel_cmd_rst2init_qpee ( struct arbel *arbel, unsigned long qpn,
                          const struct arbelprm_qp_ee_state_transitions *ctx ){
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_RST2INIT_QPEE,
                                              1, sizeof ( *ctx ) ),
                           0, ctx, qpn, NULL );
}

static inline int
arbel_cmd_init2rtr_qpee ( struct arbel *arbel, unsigned long qpn,
                          const struct arbelprm_qp_ee_state_transitions *ctx ){
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_INIT2RTR_QPEE,
                                              1, sizeof ( *ctx ) ),
                           0, ctx, qpn, NULL );
}

static inline int
arbel_cmd_rtr2rts_qpee ( struct arbel *arbel, unsigned long qpn,
                         const struct arbelprm_qp_ee_state_transitions *ctx ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_RTR2RTS_QPEE,
                                              1, sizeof ( *ctx ) ),
                           0, ctx, qpn, NULL );
}

static inline int
arbel_cmd_rts2rts_qp ( struct arbel *arbel, unsigned long qpn,
                       const struct arbelprm_qp_ee_state_transitions *ctx ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_RTS2RTS_QPEE,
                                              1, sizeof ( *ctx ) ),
                           0, ctx, qpn, NULL );
}

static inline int
arbel_cmd_2rst_qpee ( struct arbel *arbel, unsigned long qpn ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_VOID_CMD ( ARBEL_HCR_2RST_QPEE ),
                           0x03, NULL, qpn, NULL );
}

static inline int
arbel_cmd_mad_ifc ( struct arbel *arbel, unsigned int port,
                    union arbelprm_mad *mad ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_INOUT_CMD ( ARBEL_HCR_MAD_IFC,
                                                 1, sizeof ( *mad ),
                                                 1, sizeof ( *mad ) ),
                           0x03, mad, port, mad );
}

static inline int
arbel_cmd_read_mgm ( struct arbel *arbel, unsigned int index,
                     struct arbelprm_mgm_entry *mgm ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_OUT_CMD ( ARBEL_HCR_READ_MGM,
                                               1, sizeof ( *mgm ) ),
                           0, NULL, index, mgm );
}

static inline int
arbel_cmd_write_mgm ( struct arbel *arbel, unsigned int index,
                      const struct arbelprm_mgm_entry *mgm ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_WRITE_MGM,
                                              1, sizeof ( *mgm ) ),
                           0, mgm, index, NULL );
}

static inline int
arbel_cmd_mgid_hash ( struct arbel *arbel, const struct ib_gid *gid,
                      struct arbelprm_mgm_hash *hash ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_INOUT_CMD ( ARBEL_HCR_MGID_HASH,
                                                 1, sizeof ( *gid ),
                                                 0, sizeof ( *hash ) ),
                           0, gid, 0, hash );
}

static inline int
arbel_cmd_run_fw ( struct arbel *arbel ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_VOID_CMD ( ARBEL_HCR_RUN_FW ),
                           0, NULL, 0, NULL );
}

static inline int
arbel_cmd_disable_lam ( struct arbel *arbel ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_VOID_CMD ( ARBEL_HCR_DISABLE_LAM ),
                           0, NULL, 0, NULL );
}

static inline int
arbel_cmd_enable_lam ( struct arbel *arbel, struct arbelprm_access_lam *lam ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_OUT_CMD ( ARBEL_HCR_ENABLE_LAM,
                                               1, sizeof ( *lam ) ),
                           1, NULL, 0, lam );
}

static inline int
arbel_cmd_unmap_icm ( struct arbel *arbel, unsigned int page_count ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_VOID_CMD ( ARBEL_HCR_UNMAP_ICM ),
                           0, NULL, page_count, NULL );
}

static inline int
arbel_cmd_map_icm ( struct arbel *arbel,
                    const struct arbelprm_virtual_physical_mapping *map ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_MAP_ICM,
                                              1, sizeof ( *map ) ),
                           0, map, 1, NULL );
}

static inline int
arbel_cmd_unmap_icm_aux ( struct arbel *arbel ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_VOID_CMD ( ARBEL_HCR_UNMAP_ICM_AUX ),
                           0, NULL, 0, NULL );
}

static inline int
arbel_cmd_map_icm_aux ( struct arbel *arbel,
                        const struct arbelprm_virtual_physical_mapping *map ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_MAP_ICM_AUX,
                                              1, sizeof ( *map ) ),
                           0, map, 1, NULL );
}

static inline int
arbel_cmd_set_icm_size ( struct arbel *arbel,
                         const struct arbelprm_scalar_parameter *icm_size,
                         struct arbelprm_scalar_parameter *icm_aux_size ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_INOUT_CMD ( ARBEL_HCR_SET_ICM_SIZE,
                                                 0, sizeof ( *icm_size ),
                                                 0, sizeof ( *icm_aux_size ) ),
                           0, icm_size, 0, icm_aux_size );
}

static inline int
arbel_cmd_unmap_fa ( struct arbel *arbel ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_VOID_CMD ( ARBEL_HCR_UNMAP_FA ),
                           0, NULL, 0, NULL );
}

static inline int
arbel_cmd_map_fa ( struct arbel *arbel,
                   const struct arbelprm_virtual_physical_mapping *map ) {
        return arbel_cmd ( arbel,
                           ARBEL_HCR_IN_CMD ( ARBEL_HCR_MAP_FA,
                                              1, sizeof ( *map ) ),
                           0, map, 1, NULL );
}

/***************************************************************************
 *
 * Completion queue operations
 *
 ***************************************************************************
 */

/**
 * Create completion queue
 *
 * @v ibdev             Infiniband device
 * @v cq                Completion queue
 * @ret rc              Return status code
 */
static int arbel_create_cq ( struct ib_device *ibdev,
                             struct ib_completion_queue *cq ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbel_completion_queue *arbel_cq;
        struct arbelprm_completion_queue_context cqctx;
        struct arbelprm_cq_ci_db_record *ci_db_rec;
        struct arbelprm_cq_arm_db_record *arm_db_rec;
        int cqn_offset;
        unsigned int i;
        int rc;

        /* Find a free completion queue number */
        cqn_offset = arbel_alloc_qn_offset ( arbel->cq_inuse, ARBEL_MAX_CQS );
        if ( cqn_offset < 0 ) {
                DBGC ( arbel, "Arbel %p out of completion queues\n", arbel );
                rc = cqn_offset;
                goto err_cqn_offset;
        }
        cq->cqn = ( arbel->limits.reserved_cqs + cqn_offset );

        /* Allocate control structures */
        arbel_cq = zalloc ( sizeof ( *arbel_cq ) );
        if ( ! arbel_cq ) {
                rc = -ENOMEM;
                goto err_arbel_cq;
        }
        arbel_cq->ci_doorbell_idx = arbel_cq_ci_doorbell_idx ( cqn_offset );
        arbel_cq->arm_doorbell_idx = arbel_cq_arm_doorbell_idx ( cqn_offset );

        /* Allocate completion queue itself */
        arbel_cq->cqe_size = ( cq->num_cqes * sizeof ( arbel_cq->cqe[0] ) );
        arbel_cq->cqe = malloc_dma ( arbel_cq->cqe_size,
                                     sizeof ( arbel_cq->cqe[0] ) );
        if ( ! arbel_cq->cqe ) {
                rc = -ENOMEM;
                goto err_cqe;
        }
        memset ( arbel_cq->cqe, 0, arbel_cq->cqe_size );
        for ( i = 0 ; i < cq->num_cqes ; i++ ) {
                MLX_FILL_1 ( &arbel_cq->cqe[i].normal, 7, owner, 1 );
        }
        barrier();

        /* Initialise doorbell records */
        ci_db_rec = &arbel->db_rec[arbel_cq->ci_doorbell_idx].cq_ci;
        MLX_FILL_1 ( ci_db_rec, 0, counter, 0 );
        MLX_FILL_2 ( ci_db_rec, 1,
                     res, ARBEL_UAR_RES_CQ_CI,
                     cq_number, cq->cqn );
        arm_db_rec = &arbel->db_rec[arbel_cq->arm_doorbell_idx].cq_arm;
        MLX_FILL_1 ( arm_db_rec, 0, counter, 0 );
        MLX_FILL_2 ( arm_db_rec, 1,
                     res, ARBEL_UAR_RES_CQ_ARM,
                     cq_number, cq->cqn );

        /* Hand queue over to hardware */
        memset ( &cqctx, 0, sizeof ( cqctx ) );
        MLX_FILL_1 ( &cqctx, 0, st, 0xa /* "Event fired" */ );
        MLX_FILL_1 ( &cqctx, 2, start_address_l,
                     virt_to_bus ( arbel_cq->cqe ) );
        MLX_FILL_2 ( &cqctx, 3,
                     usr_page, arbel->limits.reserved_uars,
                     log_cq_size, fls ( cq->num_cqes - 1 ) );
        MLX_FILL_1 ( &cqctx, 5, c_eqn, ARBEL_NO_EQ );
        MLX_FILL_1 ( &cqctx, 6, pd, ARBEL_GLOBAL_PD );
        MLX_FILL_1 ( &cqctx, 7, l_key, arbel->reserved_lkey );
        MLX_FILL_1 ( &cqctx, 12, cqn, cq->cqn );
        MLX_FILL_1 ( &cqctx, 13,
                     cq_ci_db_record, arbel_cq->ci_doorbell_idx );
        MLX_FILL_1 ( &cqctx, 14,
                     cq_state_db_record, arbel_cq->arm_doorbell_idx );
        if ( ( rc = arbel_cmd_sw2hw_cq ( arbel, cq->cqn, &cqctx ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p SW2HW_CQ failed: %s\n",
                       arbel, strerror ( rc ) );
                goto err_sw2hw_cq;
        }

        DBGC ( arbel, "Arbel %p CQN %#lx ring at [%p,%p)\n",
               arbel, cq->cqn, arbel_cq->cqe,
               ( ( ( void * ) arbel_cq->cqe ) + arbel_cq->cqe_size ) );
        ib_cq_set_drvdata ( cq, arbel_cq );
        return 0;

 err_sw2hw_cq:
        MLX_FILL_1 ( ci_db_rec, 1, res, ARBEL_UAR_RES_NONE );
        MLX_FILL_1 ( arm_db_rec, 1, res, ARBEL_UAR_RES_NONE );
        free_dma ( arbel_cq->cqe, arbel_cq->cqe_size );
 err_cqe:
        free ( arbel_cq );
 err_arbel_cq:
        arbel_free_qn_offset ( arbel->cq_inuse, cqn_offset );
 err_cqn_offset:
        return rc;
}

/**
 * Destroy completion queue
 *
 * @v ibdev             Infiniband device
 * @v cq                Completion queue
 */
static void arbel_destroy_cq ( struct ib_device *ibdev,
                               struct ib_completion_queue *cq ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbel_completion_queue *arbel_cq = ib_cq_get_drvdata ( cq );
        struct arbelprm_completion_queue_context cqctx;
        struct arbelprm_cq_ci_db_record *ci_db_rec;
        struct arbelprm_cq_arm_db_record *arm_db_rec;
        int cqn_offset;
        int rc;

        /* Take ownership back from hardware */
        if ( ( rc = arbel_cmd_hw2sw_cq ( arbel, cq->cqn, &cqctx ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p FATAL HW2SW_CQ failed on CQN %#lx: "
                       "%s\n", arbel, cq->cqn, strerror ( rc ) );
                /* Leak memory and return; at least we avoid corruption */
                return;
        }

        /* Clear doorbell records */
        ci_db_rec = &arbel->db_rec[arbel_cq->ci_doorbell_idx].cq_ci;
        arm_db_rec = &arbel->db_rec[arbel_cq->arm_doorbell_idx].cq_arm;
        MLX_FILL_1 ( ci_db_rec, 1, res, ARBEL_UAR_RES_NONE );
        MLX_FILL_1 ( arm_db_rec, 1, res, ARBEL_UAR_RES_NONE );

        /* Free memory */
        free_dma ( arbel_cq->cqe, arbel_cq->cqe_size );
        free ( arbel_cq );

        /* Mark queue number as free */
        cqn_offset = ( cq->cqn - arbel->limits.reserved_cqs );
        arbel_free_qn_offset ( arbel->cq_inuse, cqn_offset );

        ib_cq_set_drvdata ( cq, NULL );
}

/***************************************************************************
 *
 * Queue pair operations
 *
 ***************************************************************************
 */

/**
 * Create send work queue
 *
 * @v arbel_send_wq     Send work queue
 * @v num_wqes          Number of work queue entries
 * @ret rc              Return status code
 */
static int arbel_create_send_wq ( struct arbel_send_work_queue *arbel_send_wq,
                                  unsigned int num_wqes ) {
        struct arbelprm_ud_send_wqe *wqe;
        struct arbelprm_ud_send_wqe *next_wqe;
        unsigned int wqe_idx_mask;
        unsigned int i;

        /* Allocate work queue */
        arbel_send_wq->wqe_size = ( num_wqes *
                                    sizeof ( arbel_send_wq->wqe[0] ) );
        arbel_send_wq->wqe = malloc_dma ( arbel_send_wq->wqe_size,
                                          sizeof ( arbel_send_wq->wqe[0] ) );
        if ( ! arbel_send_wq->wqe )
                return -ENOMEM;
        memset ( arbel_send_wq->wqe, 0, arbel_send_wq->wqe_size );

        /* Link work queue entries */
        wqe_idx_mask = ( num_wqes - 1 );
        for ( i = 0 ; i < num_wqes ; i++ ) {
                wqe = &arbel_send_wq->wqe[i].ud;
                next_wqe = &arbel_send_wq->wqe[ ( i + 1 ) & wqe_idx_mask ].ud;
                MLX_FILL_1 ( &wqe->next, 0, nda_31_6,
                             ( virt_to_bus ( next_wqe ) >> 6 ) );
        }
        
        return 0;
}

/**
 * Create receive work queue
 *
 * @v arbel_recv_wq     Receive work queue
 * @v num_wqes          Number of work queue entries
 * @ret rc              Return status code
 */
static int arbel_create_recv_wq ( struct arbel_recv_work_queue *arbel_recv_wq,
                                  unsigned int num_wqes ) {
        struct arbelprm_recv_wqe *wqe;
        struct arbelprm_recv_wqe *next_wqe;
        unsigned int wqe_idx_mask;
        size_t nds;
        unsigned int i;
        unsigned int j;

        /* Allocate work queue */
        arbel_recv_wq->wqe_size = ( num_wqes *
                                    sizeof ( arbel_recv_wq->wqe[0] ) );
        arbel_recv_wq->wqe = malloc_dma ( arbel_recv_wq->wqe_size,
                                          sizeof ( arbel_recv_wq->wqe[0] ) );
        if ( ! arbel_recv_wq->wqe )
                return -ENOMEM;
        memset ( arbel_recv_wq->wqe, 0, arbel_recv_wq->wqe_size );

        /* Link work queue entries */
        wqe_idx_mask = ( num_wqes - 1 );
        nds = ( ( offsetof ( typeof ( *wqe ), data ) +
                  sizeof ( wqe->data[0] ) ) >> 4 );
        for ( i = 0 ; i < num_wqes ; i++ ) {
                wqe = &arbel_recv_wq->wqe[i].recv;
                next_wqe = &arbel_recv_wq->wqe[( i + 1 ) & wqe_idx_mask].recv;
                MLX_FILL_1 ( &wqe->next, 0, nda_31_6,
                             ( virt_to_bus ( next_wqe ) >> 6 ) );
                MLX_FILL_1 ( &wqe->next, 1, nds, ( sizeof ( *wqe ) / 16 ) );
                for ( j = 0 ; ( ( ( void * ) &wqe->data[j] ) <
                                ( ( void * ) ( wqe + 1 ) ) ) ; j++ ) {
                        MLX_FILL_1 ( &wqe->data[j], 1,
                                     l_key, ARBEL_INVALID_LKEY );
                }
        }
        
        return 0;
}

/**
 * Create queue pair
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 * @ret rc              Return status code
 */
static int arbel_create_qp ( struct ib_device *ibdev,
                             struct ib_queue_pair *qp ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbel_queue_pair *arbel_qp;
        struct arbelprm_qp_ee_state_transitions qpctx;
        struct arbelprm_qp_db_record *send_db_rec;
        struct arbelprm_qp_db_record *recv_db_rec;
        int qpn_offset;
        int rc;

        /* Find a free queue pair number */
        qpn_offset = arbel_alloc_qn_offset ( arbel->qp_inuse, ARBEL_MAX_QPS );
        if ( qpn_offset < 0 ) {
                DBGC ( arbel, "Arbel %p out of queue pairs\n", arbel );
                rc = qpn_offset;
                goto err_qpn_offset;
        }
        qp->qpn = ( ARBEL_QPN_BASE + arbel->limits.reserved_qps + qpn_offset );

        /* Allocate control structures */
        arbel_qp = zalloc ( sizeof ( *arbel_qp ) );
        if ( ! arbel_qp ) {
                rc = -ENOMEM;
                goto err_arbel_qp;
        }
        arbel_qp->send.doorbell_idx = arbel_send_doorbell_idx ( qpn_offset );
        arbel_qp->recv.doorbell_idx = arbel_recv_doorbell_idx ( qpn_offset );

        /* Create send and receive work queues */
        if ( ( rc = arbel_create_send_wq ( &arbel_qp->send,
                                           qp->send.num_wqes ) ) != 0 )
                goto err_create_send_wq;
        if ( ( rc = arbel_create_recv_wq ( &arbel_qp->recv,
                                           qp->recv.num_wqes ) ) != 0 )
                goto err_create_recv_wq;

        /* Initialise doorbell records */
        send_db_rec = &arbel->db_rec[arbel_qp->send.doorbell_idx].qp;
        MLX_FILL_1 ( send_db_rec, 0, counter, 0 );
        MLX_FILL_2 ( send_db_rec, 1,
                     res, ARBEL_UAR_RES_SQ,
                     qp_number, qp->qpn );
        recv_db_rec = &arbel->db_rec[arbel_qp->recv.doorbell_idx].qp;
        MLX_FILL_1 ( recv_db_rec, 0, counter, 0 );
        MLX_FILL_2 ( recv_db_rec, 1,
                     res, ARBEL_UAR_RES_RQ,
                     qp_number, qp->qpn );

        /* Hand queue over to hardware */
        memset ( &qpctx, 0, sizeof ( qpctx ) );
        MLX_FILL_3 ( &qpctx, 2,
                     qpc_eec_data.de, 1,
                     qpc_eec_data.pm_state, 0x03 /* Always 0x03 for UD */,
                     qpc_eec_data.st, ARBEL_ST_UD );
        MLX_FILL_6 ( &qpctx, 4,
                     qpc_eec_data.mtu, ARBEL_MTU_2048,
                     qpc_eec_data.msg_max, 11 /* 2^11 = 2048 */,
                     qpc_eec_data.log_rq_size, fls ( qp->recv.num_wqes - 1 ),
                     qpc_eec_data.log_rq_stride,
                     ( fls ( sizeof ( arbel_qp->recv.wqe[0] ) - 1 ) - 4 ),
                     qpc_eec_data.log_sq_size, fls ( qp->send.num_wqes - 1 ),
                     qpc_eec_data.log_sq_stride,
                     ( fls ( sizeof ( arbel_qp->send.wqe[0] ) - 1 ) - 4 ) );
        MLX_FILL_1 ( &qpctx, 5,
                     qpc_eec_data.usr_page, arbel->limits.reserved_uars );
        MLX_FILL_1 ( &qpctx, 10, qpc_eec_data.primary_address_path.port_number,
                     ibdev->port );
        MLX_FILL_1 ( &qpctx, 27, qpc_eec_data.pd, ARBEL_GLOBAL_PD );
        MLX_FILL_1 ( &qpctx, 29, qpc_eec_data.wqe_lkey, arbel->reserved_lkey );
        MLX_FILL_1 ( &qpctx, 30, qpc_eec_data.ssc, 1 );
        MLX_FILL_1 ( &qpctx, 33, qpc_eec_data.cqn_snd, qp->send.cq->cqn );
        MLX_FILL_1 ( &qpctx, 34, qpc_eec_data.snd_wqe_base_adr_l,
                     ( virt_to_bus ( arbel_qp->send.wqe ) >> 6 ) );
        MLX_FILL_1 ( &qpctx, 35, qpc_eec_data.snd_db_record_index,
                     arbel_qp->send.doorbell_idx );
        MLX_FILL_1 ( &qpctx, 38, qpc_eec_data.rsc, 1 );
        MLX_FILL_1 ( &qpctx, 41, qpc_eec_data.cqn_rcv, qp->recv.cq->cqn );
        MLX_FILL_1 ( &qpctx, 42, qpc_eec_data.rcv_wqe_base_adr_l,
                     ( virt_to_bus ( arbel_qp->recv.wqe ) >> 6 ) );
        MLX_FILL_1 ( &qpctx, 43, qpc_eec_data.rcv_db_record_index,
                     arbel_qp->recv.doorbell_idx );
        MLX_FILL_1 ( &qpctx, 44, qpc_eec_data.q_key, qp->qkey );
        if ( ( rc = arbel_cmd_rst2init_qpee ( arbel, qp->qpn, &qpctx )) != 0 ){
                DBGC ( arbel, "Arbel %p RST2INIT_QPEE failed: %s\n",
                       arbel, strerror ( rc ) );
                goto err_rst2init_qpee;
        }
        memset ( &qpctx, 0, sizeof ( qpctx ) );
        MLX_FILL_2 ( &qpctx, 4,
                     qpc_eec_data.mtu, ARBEL_MTU_2048,
                     qpc_eec_data.msg_max, 11 /* 2^11 = 2048 */ );
        if ( ( rc = arbel_cmd_init2rtr_qpee ( arbel, qp->qpn, &qpctx )) != 0 ){
                DBGC ( arbel, "Arbel %p INIT2RTR_QPEE failed: %s\n",
                       arbel, strerror ( rc ) );
                goto err_init2rtr_qpee;
        }
        memset ( &qpctx, 0, sizeof ( qpctx ) );
        if ( ( rc = arbel_cmd_rtr2rts_qpee ( arbel, qp->qpn, &qpctx ) ) != 0 ){
                DBGC ( arbel, "Arbel %p RTR2RTS_QPEE failed: %s\n",
                       arbel, strerror ( rc ) );
                goto err_rtr2rts_qpee;
        }

        DBGC ( arbel, "Arbel %p QPN %#lx send ring at [%p,%p)\n",
               arbel, qp->qpn, arbel_qp->send.wqe,
               ( ( (void *) arbel_qp->send.wqe ) + arbel_qp->send.wqe_size ) );
        DBGC ( arbel, "Arbel %p QPN %#lx receive ring at [%p,%p)\n",
               arbel, qp->qpn, arbel_qp->recv.wqe,
               ( ( (void *) arbel_qp->recv.wqe ) + arbel_qp->recv.wqe_size ) );
        ib_qp_set_drvdata ( qp, arbel_qp );
        return 0;

 err_rtr2rts_qpee:
 err_init2rtr_qpee:
        arbel_cmd_2rst_qpee ( arbel, qp->qpn );
 err_rst2init_qpee:
        MLX_FILL_1 ( send_db_rec, 1, res, ARBEL_UAR_RES_NONE );
        MLX_FILL_1 ( recv_db_rec, 1, res, ARBEL_UAR_RES_NONE );
        free_dma ( arbel_qp->recv.wqe, arbel_qp->recv.wqe_size );
 err_create_recv_wq:
        free_dma ( arbel_qp->send.wqe, arbel_qp->send.wqe_size );
 err_create_send_wq:
        free ( arbel_qp );
 err_arbel_qp:
        arbel_free_qn_offset ( arbel->qp_inuse, qpn_offset );
 err_qpn_offset:
        return rc;
}

/**
 * Modify queue pair
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 * @v mod_list          Modification list
 * @ret rc              Return status code
 */
static int arbel_modify_qp ( struct ib_device *ibdev,
                             struct ib_queue_pair *qp,
                             unsigned long mod_list ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbelprm_qp_ee_state_transitions qpctx;
        unsigned long optparammask = 0;
        int rc;

        /* Construct optparammask */
        if ( mod_list & IB_MODIFY_QKEY )
                optparammask |= ARBEL_QPEE_OPT_PARAM_QKEY;

        /* Issue RTS2RTS_QP */
        memset ( &qpctx, 0, sizeof ( qpctx ) );
        MLX_FILL_1 ( &qpctx, 0, opt_param_mask, optparammask );
        MLX_FILL_1 ( &qpctx, 44, qpc_eec_data.q_key, qp->qkey );
        if ( ( rc = arbel_cmd_rts2rts_qp ( arbel, qp->qpn, &qpctx ) ) != 0 ){
                DBGC ( arbel, "Arbel %p RTS2RTS_QP failed: %s\n",
                       arbel, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Destroy queue pair
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 */
static void arbel_destroy_qp ( struct ib_device *ibdev,
                               struct ib_queue_pair *qp ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbel_queue_pair *arbel_qp = ib_qp_get_drvdata ( qp );
        struct arbelprm_qp_db_record *send_db_rec;
        struct arbelprm_qp_db_record *recv_db_rec;
        int qpn_offset;
        int rc;

        /* Take ownership back from hardware */
        if ( ( rc = arbel_cmd_2rst_qpee ( arbel, qp->qpn ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p FATAL 2RST_QPEE failed on QPN %#lx: "
                       "%s\n", arbel, qp->qpn, strerror ( rc ) );
                /* Leak memory and return; at least we avoid corruption */
                return;
        }

        /* Clear doorbell records */
        send_db_rec = &arbel->db_rec[arbel_qp->send.doorbell_idx].qp;
        recv_db_rec = &arbel->db_rec[arbel_qp->recv.doorbell_idx].qp;
        MLX_FILL_1 ( send_db_rec, 1, res, ARBEL_UAR_RES_NONE );
        MLX_FILL_1 ( recv_db_rec, 1, res, ARBEL_UAR_RES_NONE );

        /* Free memory */
        free_dma ( arbel_qp->send.wqe, arbel_qp->send.wqe_size );
        free_dma ( arbel_qp->recv.wqe, arbel_qp->recv.wqe_size );
        free ( arbel_qp );

        /* Mark queue number as free */
        qpn_offset = ( qp->qpn - ARBEL_QPN_BASE - arbel->limits.reserved_qps );
        arbel_free_qn_offset ( arbel->qp_inuse, qpn_offset );

        ib_qp_set_drvdata ( qp, NULL );
}

/***************************************************************************
 *
 * Work request operations
 *
 ***************************************************************************
 */

/**
 * Ring doorbell register in UAR
 *
 * @v arbel             Arbel device
 * @v db_reg            Doorbell register structure
 * @v offset            Address of doorbell
 */
static void arbel_ring_doorbell ( struct arbel *arbel,
                                  union arbelprm_doorbell_register *db_reg,
                                  unsigned int offset ) {

        DBGC2 ( arbel, "Arbel %p ringing doorbell %08lx:%08lx at %lx\n",
                arbel, db_reg->dword[0], db_reg->dword[1],
                virt_to_phys ( arbel->uar + offset ) );

        barrier();
        writel ( db_reg->dword[0], ( arbel->uar + offset + 0 ) );
        barrier();
        writel ( db_reg->dword[1], ( arbel->uar + offset + 4 ) );
}

/** GID used for GID-less send work queue entries */
static const struct ib_gid arbel_no_gid = {
        { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0 } }
};

/**
 * Post send work queue entry
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 * @v av                Address vector
 * @v iobuf             I/O buffer
 * @ret rc              Return status code
 */
static int arbel_post_send ( struct ib_device *ibdev,
                             struct ib_queue_pair *qp,
                             struct ib_address_vector *av,
                             struct io_buffer *iobuf ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbel_queue_pair *arbel_qp = ib_qp_get_drvdata ( qp );
        struct ib_work_queue *wq = &qp->send;
        struct arbel_send_work_queue *arbel_send_wq = &arbel_qp->send;
        struct arbelprm_ud_send_wqe *prev_wqe;
        struct arbelprm_ud_send_wqe *wqe;
        struct arbelprm_qp_db_record *qp_db_rec;
        union arbelprm_doorbell_register db_reg;
        const struct ib_gid *gid;
        unsigned int wqe_idx_mask;
        size_t nds;

        /* Allocate work queue entry */
        wqe_idx_mask = ( wq->num_wqes - 1 );
        if ( wq->iobufs[wq->next_idx & wqe_idx_mask] ) {
                DBGC ( arbel, "Arbel %p send queue full", arbel );
                return -ENOBUFS;
        }
        wq->iobufs[wq->next_idx & wqe_idx_mask] = iobuf;
        prev_wqe = &arbel_send_wq->wqe[(wq->next_idx - 1) & wqe_idx_mask].ud;
        wqe = &arbel_send_wq->wqe[wq->next_idx & wqe_idx_mask].ud;

        /* Construct work queue entry */
        MLX_FILL_1 ( &wqe->next, 1, always1, 1 );
        memset ( &wqe->ctrl, 0, sizeof ( wqe->ctrl ) );
        MLX_FILL_1 ( &wqe->ctrl, 0, always1, 1 );
        memset ( &wqe->ud, 0, sizeof ( wqe->ud ) );
        MLX_FILL_2 ( &wqe->ud, 0,
                     ud_address_vector.pd, ARBEL_GLOBAL_PD,
                     ud_address_vector.port_number, ibdev->port );
        MLX_FILL_2 ( &wqe->ud, 1,
                     ud_address_vector.rlid, av->dlid,
                     ud_address_vector.g, av->gid_present );
        MLX_FILL_2 ( &wqe->ud, 2,
                     ud_address_vector.max_stat_rate,
                         ( ( av->rate >= 3 ) ? 0 : 1 ),
                     ud_address_vector.msg, 3 );
        MLX_FILL_1 ( &wqe->ud, 3, ud_address_vector.sl, av->sl );
        gid = ( av->gid_present ? &av->gid : &arbel_no_gid );
        memcpy ( &wqe->ud.u.dwords[4], gid, sizeof ( *gid ) );
        MLX_FILL_1 ( &wqe->ud, 8, destination_qp, av->dest_qp );
        MLX_FILL_1 ( &wqe->ud, 9, q_key, av->qkey );
        MLX_FILL_1 ( &wqe->data[0], 0, byte_count, iob_len ( iobuf ) );
        MLX_FILL_1 ( &wqe->data[0], 1, l_key, arbel->reserved_lkey );
        MLX_FILL_1 ( &wqe->data[0], 3,
                     local_address_l, virt_to_bus ( iobuf->data ) );

        /* Update previous work queue entry's "next" field */
        nds = ( ( offsetof ( typeof ( *wqe ), data ) +
                  sizeof ( wqe->data[0] ) ) >> 4 );
        MLX_SET ( &prev_wqe->next, nopcode, ARBEL_OPCODE_SEND );
        MLX_FILL_3 ( &prev_wqe->next, 1,
                     nds, nds,
                     f, 1,
                     always1, 1 );

        /* Update doorbell record */
        barrier();
        qp_db_rec = &arbel->db_rec[arbel_send_wq->doorbell_idx].qp;
        MLX_FILL_1 ( qp_db_rec, 0,
                     counter, ( ( wq->next_idx + 1 ) & 0xffff ) );

        /* Ring doorbell register */
        MLX_FILL_4 ( &db_reg.send, 0,
                     nopcode, ARBEL_OPCODE_SEND,
                     f, 1,
                     wqe_counter, ( wq->next_idx & 0xffff ),
                     wqe_cnt, 1 );
        MLX_FILL_2 ( &db_reg.send, 1,
                     nds, nds,
                     qpn, qp->qpn );
        arbel_ring_doorbell ( arbel, &db_reg, ARBEL_DB_POST_SND_OFFSET );

        /* Update work queue's index */
        wq->next_idx++;

        return 0;
}

/**
 * Post receive work queue entry
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 * @v iobuf             I/O buffer
 * @ret rc              Return status code
 */
static int arbel_post_recv ( struct ib_device *ibdev,
                             struct ib_queue_pair *qp,
                             struct io_buffer *iobuf ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbel_queue_pair *arbel_qp = ib_qp_get_drvdata ( qp );
        struct ib_work_queue *wq = &qp->recv;
        struct arbel_recv_work_queue *arbel_recv_wq = &arbel_qp->recv;
        struct arbelprm_recv_wqe *wqe;
        union arbelprm_doorbell_record *db_rec;
        unsigned int wqe_idx_mask;

        /* Allocate work queue entry */
        wqe_idx_mask = ( wq->num_wqes - 1 );
        if ( wq->iobufs[wq->next_idx & wqe_idx_mask] ) {
                DBGC ( arbel, "Arbel %p receive queue full", arbel );
                return -ENOBUFS;
        }
        wq->iobufs[wq->next_idx & wqe_idx_mask] = iobuf;
        wqe = &arbel_recv_wq->wqe[wq->next_idx & wqe_idx_mask].recv;

        /* Construct work queue entry */
        MLX_FILL_1 ( &wqe->data[0], 0, byte_count, iob_tailroom ( iobuf ) );
        MLX_FILL_1 ( &wqe->data[0], 1, l_key, arbel->reserved_lkey );
        MLX_FILL_1 ( &wqe->data[0], 3,
                     local_address_l, virt_to_bus ( iobuf->data ) );

        /* Update doorbell record */
        barrier();
        db_rec = &arbel->db_rec[arbel_recv_wq->doorbell_idx];
        MLX_FILL_1 ( &db_rec->qp, 0,
                     counter, ( ( wq->next_idx + 1 ) & 0xffff ) );      

        /* Update work queue's index */
        wq->next_idx++;

        return 0;       
}

/**
 * Handle completion
 *
 * @v ibdev             Infiniband device
 * @v cq                Completion queue
 * @v cqe               Hardware completion queue entry
 * @v complete_send     Send completion handler
 * @v complete_recv     Receive completion handler
 * @ret rc              Return status code
 */
static int arbel_complete ( struct ib_device *ibdev,
                            struct ib_completion_queue *cq,
                            union arbelprm_completion_entry *cqe,
                            ib_completer_t complete_send,
                            ib_completer_t complete_recv ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct ib_completion completion;
        struct ib_work_queue *wq;
        struct ib_queue_pair *qp;
        struct arbel_queue_pair *arbel_qp;
        struct arbel_send_work_queue *arbel_send_wq;
        struct arbel_recv_work_queue *arbel_recv_wq;
        struct arbelprm_recv_wqe *recv_wqe;
        struct io_buffer *iobuf;
        ib_completer_t complete;
        unsigned int opcode;
        unsigned long qpn;
        int is_send;
        unsigned long wqe_adr;
        unsigned int wqe_idx;
        int rc = 0;

        /* Parse completion */
        memset ( &completion, 0, sizeof ( completion ) );
        qpn = MLX_GET ( &cqe->normal, my_qpn );
        is_send = MLX_GET ( &cqe->normal, s );
        wqe_adr = ( MLX_GET ( &cqe->normal, wqe_adr ) << 6 );
        opcode = MLX_GET ( &cqe->normal, opcode );
        if ( opcode >= ARBEL_OPCODE_RECV_ERROR ) {
                /* "s" field is not valid for error opcodes */
                is_send = ( opcode == ARBEL_OPCODE_SEND_ERROR );
                completion.syndrome = MLX_GET ( &cqe->error, syndrome );
                DBGC ( arbel, "Arbel %p CPN %lx syndrome %x vendor %lx\n",
                       arbel, cq->cqn, completion.syndrome,
                       MLX_GET ( &cqe->error, vendor_code ) );
                rc = -EIO;
                /* Don't return immediately; propagate error to completer */
        }

        /* Identify work queue */
        wq = ib_find_wq ( cq, qpn, is_send );
        if ( ! wq ) {
                DBGC ( arbel, "Arbel %p CQN %lx unknown %s QPN %lx\n",
                       arbel, cq->cqn, ( is_send ? "send" : "recv" ), qpn );
                return -EIO;
        }
        qp = wq->qp;
        arbel_qp = ib_qp_get_drvdata ( qp );
        arbel_send_wq = &arbel_qp->send;
        arbel_recv_wq = &arbel_qp->recv;

        /* Identify work queue entry index */
        if ( is_send ) {
                wqe_idx = ( ( wqe_adr - virt_to_bus ( arbel_send_wq->wqe ) ) /
                            sizeof ( arbel_send_wq->wqe[0] ) );
                assert ( wqe_idx < qp->send.num_wqes );
        } else {
                wqe_idx = ( ( wqe_adr - virt_to_bus ( arbel_recv_wq->wqe ) ) /
                            sizeof ( arbel_recv_wq->wqe[0] ) );
                assert ( wqe_idx < qp->recv.num_wqes );
        }

        /* Identify I/O buffer */
        iobuf = wq->iobufs[wqe_idx];
        if ( ! iobuf ) {
                DBGC ( arbel, "Arbel %p CQN %lx QPN %lx empty WQE %x\n",
                       arbel, cq->cqn, qpn, wqe_idx );
                return -EIO;
        }
        wq->iobufs[wqe_idx] = NULL;

        /* Fill in length for received packets */
        if ( ! is_send ) {
                completion.len = MLX_GET ( &cqe->normal, byte_cnt );
                recv_wqe = &arbel_recv_wq->wqe[wqe_idx].recv;
                assert ( MLX_GET ( &recv_wqe->data[0], local_address_l ) ==
                         virt_to_bus ( iobuf->data ) );
                assert ( MLX_GET ( &recv_wqe->data[0], byte_count ) ==
                         iob_tailroom ( iobuf ) );
                MLX_FILL_1 ( &recv_wqe->data[0], 0, byte_count, 0 );
                MLX_FILL_1 ( &recv_wqe->data[0], 1,
                             l_key, ARBEL_INVALID_LKEY );
                if ( completion.len > iob_tailroom ( iobuf ) ) {
                        DBGC ( arbel, "Arbel %p CQN %lx QPN %lx IDX %x "
                               "overlength received packet length %zd\n",
                               arbel, cq->cqn, qpn, wqe_idx, completion.len );
                        return -EIO;
                }
        }

        /* Pass off to caller's completion handler */
        complete = ( is_send ? complete_send : complete_recv );
        complete ( ibdev, qp, &completion, iobuf );

        return rc;
}                            

/**
 * Poll completion queue
 *
 * @v ibdev             Infiniband device
 * @v cq                Completion queue
 * @v complete_send     Send completion handler
 * @v complete_recv     Receive completion handler
 */
static void arbel_poll_cq ( struct ib_device *ibdev,
                            struct ib_completion_queue *cq,
                            ib_completer_t complete_send,
                            ib_completer_t complete_recv ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbel_completion_queue *arbel_cq = ib_cq_get_drvdata ( cq );
        struct arbelprm_cq_ci_db_record *ci_db_rec;
        union arbelprm_completion_entry *cqe;
        unsigned int cqe_idx_mask;
        int rc;

        while ( 1 ) {
                /* Look for completion entry */
                cqe_idx_mask = ( cq->num_cqes - 1 );
                cqe = &arbel_cq->cqe[cq->next_idx & cqe_idx_mask];
                if ( MLX_GET ( &cqe->normal, owner ) != 0 ) {
                        /* Entry still owned by hardware; end of poll */
                        break;
                }

                /* Handle completion */
                if ( ( rc = arbel_complete ( ibdev, cq, cqe, complete_send,
                                             complete_recv ) ) != 0 ) {
                        DBGC ( arbel, "Arbel %p failed to complete: %s\n",
                               arbel, strerror ( rc ) );
                        DBGC_HD ( arbel, cqe, sizeof ( *cqe ) );
                }

                /* Return ownership to hardware */
                MLX_FILL_1 ( &cqe->normal, 7, owner, 1 );
                barrier();
                /* Update completion queue's index */
                cq->next_idx++;
                /* Update doorbell record */
                ci_db_rec = &arbel->db_rec[arbel_cq->ci_doorbell_idx].cq_ci;
                MLX_FILL_1 ( ci_db_rec, 0,
                             counter, ( cq->next_idx & 0xffffffffUL ) );
        }
}

/***************************************************************************
 *
 * Event queues
 *
 ***************************************************************************
 */

/**
 * Create event queue
 *
 * @v arbel             Arbel device
 * @ret rc              Return status code
 */
static int arbel_create_eq ( struct arbel *arbel ) {
        struct arbel_event_queue *arbel_eq = &arbel->eq;
        struct arbelprm_eqc eqctx;
        struct arbelprm_event_mask mask;
        unsigned int i;
        int rc;

        /* Select event queue number */
        arbel_eq->eqn = arbel->limits.reserved_eqs;

        /* Calculate doorbell address */
        arbel_eq->doorbell = ( arbel->eq_ci_doorbells +
                               ARBEL_DB_EQ_OFFSET ( arbel_eq->eqn ) );

        /* Allocate event queue itself */
        arbel_eq->eqe_size =
                ( ARBEL_NUM_EQES * sizeof ( arbel_eq->eqe[0] ) );
        arbel_eq->eqe = malloc_dma ( arbel_eq->eqe_size,
                                     sizeof ( arbel_eq->eqe[0] ) );
        if ( ! arbel_eq->eqe ) {
                rc = -ENOMEM;
                goto err_eqe;
        }
        memset ( arbel_eq->eqe, 0, arbel_eq->eqe_size );
        for ( i = 0 ; i < ARBEL_NUM_EQES ; i++ ) {
                MLX_FILL_1 ( &arbel_eq->eqe[i].generic, 7, owner, 1 );
        }
        barrier();

        /* Hand queue over to hardware */
        memset ( &eqctx, 0, sizeof ( eqctx ) );
        MLX_FILL_1 ( &eqctx, 0, st, 0xa /* "Fired" */ );
        MLX_FILL_1 ( &eqctx, 2,
                     start_address_l, virt_to_phys ( arbel_eq->eqe ) );
        MLX_FILL_1 ( &eqctx, 3, log_eq_size, fls ( ARBEL_NUM_EQES - 1 ) );
        MLX_FILL_1 ( &eqctx, 6, pd, ARBEL_GLOBAL_PD );
        MLX_FILL_1 ( &eqctx, 7, lkey, arbel->reserved_lkey );
        if ( ( rc = arbel_cmd_sw2hw_eq ( arbel, arbel_eq->eqn,
                                         &eqctx ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p SW2HW_EQ failed: %s\n",
                       arbel, strerror ( rc ) );
                goto err_sw2hw_eq;
        }

        /* Map events to this event queue */
        memset ( &mask, 0, sizeof ( mask ) );
        MLX_FILL_1 ( &mask, 1, port_state_change, 1 );
        if ( ( rc = arbel_cmd_map_eq ( arbel,
                                       ( ARBEL_MAP_EQ | arbel_eq->eqn ),
                                       &mask ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p MAP_EQ failed: %s\n",
                       arbel, strerror ( rc )  );
                goto err_map_eq;
        }

        DBGC ( arbel, "Arbel %p EQN %#lx ring at [%p,%p])\n",
               arbel, arbel_eq->eqn, arbel_eq->eqe,
               ( ( ( void * ) arbel_eq->eqe ) + arbel_eq->eqe_size ) );
        return 0;

 err_map_eq:
        arbel_cmd_hw2sw_eq ( arbel, arbel_eq->eqn, &eqctx );
 err_sw2hw_eq:
        free_dma ( arbel_eq->eqe, arbel_eq->eqe_size );
 err_eqe:
        memset ( arbel_eq, 0, sizeof ( *arbel_eq ) );
        return rc;
}

/**
 * Destroy event queue
 *
 * @v arbel             Arbel device
 */
static void arbel_destroy_eq ( struct arbel *arbel ) {
        struct arbel_event_queue *arbel_eq = &arbel->eq;
        struct arbelprm_eqc eqctx;
        struct arbelprm_event_mask mask;
        int rc;

        /* Unmap events from event queue */
        memset ( &mask, 0, sizeof ( mask ) );
        MLX_FILL_1 ( &mask, 1, port_state_change, 1 );
        if ( ( rc = arbel_cmd_map_eq ( arbel,
                                       ( ARBEL_UNMAP_EQ | arbel_eq->eqn ),
                                       &mask ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p FATAL MAP_EQ failed to unmap: %s\n",
                       arbel, strerror ( rc ) );
                /* Continue; HCA may die but system should survive */
        }

        /* Take ownership back from hardware */
        if ( ( rc = arbel_cmd_hw2sw_eq ( arbel, arbel_eq->eqn,
                                         &eqctx ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p FATAL HW2SW_EQ failed: %s\n",
                       arbel, strerror ( rc ) );
                /* Leak memory and return; at least we avoid corruption */
                return;
        }

        /* Free memory */
        free_dma ( arbel_eq->eqe, arbel_eq->eqe_size );
        memset ( arbel_eq, 0, sizeof ( *arbel_eq ) );
}

/**
 * Handle port state event
 *
 * @v arbel             Arbel device
 * @v eqe               Port state change event queue entry
 */
static void arbel_event_port_state_change ( struct arbel *arbel,
                                            union arbelprm_event_entry *eqe){
        unsigned int port;
        int link_up;

        /* Get port and link status */
        port = ( MLX_GET ( &eqe->port_state_change, data.p ) - 1 );
        link_up = ( MLX_GET ( &eqe->generic, event_sub_type ) & 0x04 );
        DBGC ( arbel, "Arbel %p port %d link %s\n", arbel, ( port + 1 ),
               ( link_up ? "up" : "down" ) );

        /* Sanity check */
        if ( port >= ARBEL_NUM_PORTS ) {
                DBGC ( arbel, "Arbel %p port %d does not exist!\n",
                       arbel, ( port + 1 ) );
                return;
        }

        /* Notify Infiniband core of link state change */
        ib_link_state_changed ( arbel->ibdev[port] );
}

/**
 * Poll event queue
 *
 * @v ibdev             Infiniband device
 */
static void arbel_poll_eq ( struct ib_device *ibdev ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbel_event_queue *arbel_eq = &arbel->eq;
        union arbelprm_event_entry *eqe;
        union arbelprm_eq_doorbell_register db_reg;
        unsigned int eqe_idx_mask;
        unsigned int event_type;

        while ( 1 ) {
                /* Look for event entry */
                eqe_idx_mask = ( ARBEL_NUM_EQES - 1 );
                eqe = &arbel_eq->eqe[arbel_eq->next_idx & eqe_idx_mask];
                if ( MLX_GET ( &eqe->generic, owner ) != 0 ) {
                        /* Entry still owned by hardware; end of poll */
                        break;
                }
                DBGCP ( arbel, "Arbel %p event:\n", arbel );
                DBGCP_HD ( arbel, eqe, sizeof ( *eqe ) );

                /* Handle event */
                event_type = MLX_GET ( &eqe->generic, event_type );
                switch ( event_type ) {
                case ARBEL_EV_PORT_STATE_CHANGE:
                        arbel_event_port_state_change ( arbel, eqe );
                        break;
                default:
                        DBGC ( arbel, "Arbel %p unrecognised event type "
                               "%#x:\n", arbel, event_type );
                        DBGC_HD ( arbel, eqe, sizeof ( *eqe ) );
                        break;
                }

                /* Return ownership to hardware */
                MLX_FILL_1 ( &eqe->generic, 7, owner, 1 );
                barrier();

                /* Update event queue's index */
                arbel_eq->next_idx++;

                /* Ring doorbell */
                MLX_FILL_1 ( &db_reg.ci, 0, ci, arbel_eq->next_idx );
                DBGCP ( arbel, "Ringing doorbell %08lx with %08lx\n",
                        virt_to_phys ( arbel_eq->doorbell ),
                        db_reg.dword[0] );
                writel ( db_reg.dword[0], arbel_eq->doorbell );
        }
}

/***************************************************************************
 *
 * Infiniband link-layer operations
 *
 ***************************************************************************
 */

/**
 * Initialise Infiniband link
 *
 * @v ibdev             Infiniband device
 * @ret rc              Return status code
 */
static int arbel_open ( struct ib_device *ibdev ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbelprm_init_ib init_ib;
        int rc;

        memset ( &init_ib, 0, sizeof ( init_ib ) );
        MLX_FILL_3 ( &init_ib, 0,
                     mtu_cap, ARBEL_MTU_2048,
                     port_width_cap, 3,
                     vl_cap, 1 );
        MLX_FILL_1 ( &init_ib, 1, max_gid, 1 );
        MLX_FILL_1 ( &init_ib, 2, max_pkey, 64 );
        if ( ( rc = arbel_cmd_init_ib ( arbel, ibdev->port,
                                        &init_ib ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not intialise IB: %s\n",
                       arbel, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Close Infiniband link
 *
 * @v ibdev             Infiniband device
 */
static void arbel_close ( struct ib_device *ibdev ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        int rc;

        if ( ( rc = arbel_cmd_close_ib ( arbel, ibdev->port ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not close IB: %s\n",
                       arbel, strerror ( rc ) );
                /* Nothing we can do about this */
        }
}

/***************************************************************************
 *
 * Multicast group operations
 *
 ***************************************************************************
 */

/**
 * Attach to multicast group
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 * @v gid               Multicast GID
 * @ret rc              Return status code
 */
static int arbel_mcast_attach ( struct ib_device *ibdev,
                                struct ib_queue_pair *qp,
                                struct ib_gid *gid ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbelprm_mgm_hash hash;
        struct arbelprm_mgm_entry mgm;
        unsigned int index;
        int rc;

        /* Generate hash table index */
        if ( ( rc = arbel_cmd_mgid_hash ( arbel, gid, &hash ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not hash GID: %s\n",
                       arbel, strerror ( rc ) );
                return rc;
        }
        index = MLX_GET ( &hash, hash );

        /* Check for existing hash table entry */
        if ( ( rc = arbel_cmd_read_mgm ( arbel, index, &mgm ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not read MGM %#x: %s\n",
                       arbel, index, strerror ( rc ) );
                return rc;
        }
        if ( MLX_GET ( &mgm, mgmqp_0.qi ) != 0 ) {
                /* FIXME: this implementation allows only a single QP
                 * per multicast group, and doesn't handle hash
                 * collisions.  Sufficient for IPoIB but may need to
                 * be extended in future.
                 */
                DBGC ( arbel, "Arbel %p MGID index %#x already in use\n",
                       arbel, index );
                return -EBUSY;
        }

        /* Update hash table entry */
        MLX_FILL_2 ( &mgm, 8,
                     mgmqp_0.qpn_i, qp->qpn,
                     mgmqp_0.qi, 1 );
        memcpy ( &mgm.u.dwords[4], gid, sizeof ( *gid ) );
        if ( ( rc = arbel_cmd_write_mgm ( arbel, index, &mgm ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not write MGM %#x: %s\n",
                       arbel, index, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Detach from multicast group
 *
 * @v ibdev             Infiniband device
 * @v qp                Queue pair
 * @v gid               Multicast GID
 */
static void arbel_mcast_detach ( struct ib_device *ibdev,
                                 struct ib_queue_pair *qp __unused,
                                 struct ib_gid *gid ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        struct arbelprm_mgm_hash hash;
        struct arbelprm_mgm_entry mgm;
        unsigned int index;
        int rc;

        /* Generate hash table index */
        if ( ( rc = arbel_cmd_mgid_hash ( arbel, gid, &hash ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not hash GID: %s\n",
                       arbel, strerror ( rc ) );
                return;
        }
        index = MLX_GET ( &hash, hash );

        /* Clear hash table entry */
        memset ( &mgm, 0, sizeof ( mgm ) );
        if ( ( rc = arbel_cmd_write_mgm ( arbel, index, &mgm ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not write MGM %#x: %s\n",
                       arbel, index, strerror ( rc ) );
                return;
        }
}

/***************************************************************************
 *
 * MAD operations
 *
 ***************************************************************************
 */

/**
 * Issue management datagram
 *
 * @v ibdev             Infiniband device
 * @v mad               Management datagram
 * @v len               Length of management datagram
 * @ret rc              Return status code
 */
static int arbel_mad ( struct ib_device *ibdev, struct ib_mad_hdr *mad,
                       size_t len ) {
        struct arbel *arbel = ib_get_drvdata ( ibdev );
        union arbelprm_mad mad_ifc;
        int rc;

        /* Copy in request packet */
        memset ( &mad_ifc, 0, sizeof ( mad_ifc ) );
        assert ( len <= sizeof ( mad_ifc.mad ) );
        memcpy ( &mad_ifc.mad, mad, len );

        /* Issue MAD */
        if ( ( rc = arbel_cmd_mad_ifc ( arbel, ibdev->port,
                                        &mad_ifc ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not issue MAD IFC: %s\n",
                       arbel, strerror ( rc ) );
                return rc;
        }

        /* Copy out reply packet */
        memcpy ( mad, &mad_ifc.mad, len );

        if ( mad->status != 0 ) {
                DBGC ( arbel, "Arbel %p MAD IFC status %04x\n",
                       arbel, ntohs ( mad->status ) );
                return -EIO;
        }
        return 0;
}

/** Arbel Infiniband operations */
static struct ib_device_operations arbel_ib_operations = {
        .create_cq      = arbel_create_cq,
        .destroy_cq     = arbel_destroy_cq,
        .create_qp      = arbel_create_qp,
        .modify_qp      = arbel_modify_qp,
        .destroy_qp     = arbel_destroy_qp,
        .post_send      = arbel_post_send,
        .post_recv      = arbel_post_recv,
        .poll_cq        = arbel_poll_cq,
        .poll_eq        = arbel_poll_eq,
        .open           = arbel_open,
        .close          = arbel_close,
        .mcast_attach   = arbel_mcast_attach,
        .mcast_detach   = arbel_mcast_detach,
        .mad            = arbel_mad,
};

/***************************************************************************
 *
 * Firmware control
 *
 ***************************************************************************
 */

/**
 * Start firmware running
 *
 * @v arbel             Arbel device
 * @ret rc              Return status code
 */
static int arbel_start_firmware ( struct arbel *arbel ) {
        struct arbelprm_query_fw fw;
        struct arbelprm_access_lam lam;
        struct arbelprm_virtual_physical_mapping map_fa;
        unsigned int fw_pages;
        unsigned int log2_fw_pages;
        size_t fw_size;
        physaddr_t fw_base;
        uint64_t eq_set_ci_base_addr;
        int rc;

        /* Get firmware parameters */
        if ( ( rc = arbel_cmd_query_fw ( arbel, &fw ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not query firmware: %s\n",
                       arbel, strerror ( rc ) );
                goto err_query_fw;
        }
        DBGC ( arbel, "Arbel %p firmware version %ld.%ld.%ld\n", arbel,
               MLX_GET ( &fw, fw_rev_major ), MLX_GET ( &fw, fw_rev_minor ),
               MLX_GET ( &fw, fw_rev_subminor ) );
        fw_pages = MLX_GET ( &fw, fw_pages );
        log2_fw_pages = fls ( fw_pages - 1 );
        fw_pages = ( 1 << log2_fw_pages );
        DBGC ( arbel, "Arbel %p requires %d kB for firmware\n",
               arbel, ( fw_pages * 4 ) );
        eq_set_ci_base_addr =
                ( ( (uint64_t) MLX_GET ( &fw, eq_set_ci_base_addr_h ) << 32 ) |
                  ( (uint64_t) MLX_GET ( &fw, eq_set_ci_base_addr_l ) ) );
        arbel->eq_ci_doorbells = ioremap ( eq_set_ci_base_addr, 0x200 );

        /* Enable locally-attached memory.  Ignore failure; there may
         * be no attached memory.
         */
        arbel_cmd_enable_lam ( arbel, &lam );

        /* Allocate firmware pages and map firmware area */
        fw_size = ( fw_pages * 4096 );
        arbel->firmware_area = umalloc ( fw_size * 2 );
        if ( ! arbel->firmware_area ) {
                rc = -ENOMEM;
                goto err_alloc_fa;
        }
        fw_base = ( user_to_phys ( arbel->firmware_area, fw_size ) &
                    ~( fw_size - 1 ) );
        DBGC ( arbel, "Arbel %p firmware area at physical [%lx,%lx)\n",
               arbel, fw_base, ( fw_base + fw_size ) );
        memset ( &map_fa, 0, sizeof ( map_fa ) );
        MLX_FILL_2 ( &map_fa, 3,
                     log2size, log2_fw_pages,
                     pa_l, ( fw_base >> 12 ) );
        if ( ( rc = arbel_cmd_map_fa ( arbel, &map_fa ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not map firmware: %s\n",
                       arbel, strerror ( rc ) );
                goto err_map_fa;
        }

        /* Start firmware */
        if ( ( rc = arbel_cmd_run_fw ( arbel ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not run firmware: %s\n",
                       arbel, strerror ( rc ) );
                goto err_run_fw;
        }

        DBGC ( arbel, "Arbel %p firmware started\n", arbel );
        return 0;

 err_run_fw:
        arbel_cmd_unmap_fa ( arbel );
 err_map_fa:
        ufree ( arbel->firmware_area );
        arbel->firmware_area = UNULL;
 err_alloc_fa:
 err_query_fw:
        return rc;
}

/**
 * Stop firmware running
 *
 * @v arbel             Arbel device
 */
static void arbel_stop_firmware ( struct arbel *arbel ) {
        int rc;

        if ( ( rc = arbel_cmd_unmap_fa ( arbel ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p FATAL could not stop firmware: %s\n",
                       arbel, strerror ( rc ) );
                /* Leak memory and return; at least we avoid corruption */
                return;
        }
        ufree ( arbel->firmware_area );
        arbel->firmware_area = UNULL;
}

/***************************************************************************
 *
 * Infinihost Context Memory management
 *
 ***************************************************************************
 */

/**
 * Get device limits
 *
 * @v arbel             Arbel device
 * @ret rc              Return status code
 */
static int arbel_get_limits ( struct arbel *arbel ) {
        struct arbelprm_query_dev_lim dev_lim;
        int rc;

        if ( ( rc = arbel_cmd_query_dev_lim ( arbel, &dev_lim ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not get device limits: %s\n",
                       arbel, strerror ( rc ) );
                return rc;
        }

        arbel->limits.reserved_qps =
                ( 1 << MLX_GET ( &dev_lim, log2_rsvd_qps ) );
        arbel->limits.qpc_entry_size = MLX_GET ( &dev_lim, qpc_entry_sz );
        arbel->limits.eqpc_entry_size = MLX_GET ( &dev_lim, eqpc_entry_sz );
        arbel->limits.reserved_srqs =
                ( 1 << MLX_GET ( &dev_lim, log2_rsvd_srqs ) );
        arbel->limits.srqc_entry_size = MLX_GET ( &dev_lim, srq_entry_sz );
        arbel->limits.reserved_ees =
                ( 1 << MLX_GET ( &dev_lim, log2_rsvd_ees ) );
        arbel->limits.eec_entry_size = MLX_GET ( &dev_lim, eec_entry_sz );
        arbel->limits.eeec_entry_size = MLX_GET ( &dev_lim, eeec_entry_sz );
        arbel->limits.reserved_cqs =
                ( 1 << MLX_GET ( &dev_lim, log2_rsvd_cqs ) );
        arbel->limits.cqc_entry_size = MLX_GET ( &dev_lim, cqc_entry_sz );
        arbel->limits.reserved_eqs = MLX_GET ( &dev_lim, num_rsvd_eqs );
        arbel->limits.reserved_mtts =
                ( 1 << MLX_GET ( &dev_lim, log2_rsvd_mtts ) );
        arbel->limits.mtt_entry_size = MLX_GET ( &dev_lim, mtt_entry_sz );
        arbel->limits.reserved_mrws =
                ( 1 << MLX_GET ( &dev_lim, log2_rsvd_mrws ) );
        arbel->limits.mpt_entry_size = MLX_GET ( &dev_lim, mpt_entry_sz );
        arbel->limits.reserved_rdbs =
                ( 1 << MLX_GET ( &dev_lim, log2_rsvd_rdbs ) );
        arbel->limits.eqc_entry_size = MLX_GET ( &dev_lim, eqc_entry_sz );
        arbel->limits.reserved_uars = MLX_GET ( &dev_lim, num_rsvd_uars );

        return 0;
}

/**
 * Get ICM usage
 *
 * @v log_num_entries   Log2 of the number of entries
 * @v entry_size        Entry size
 * @ret usage           Usage size in ICM
 */
static size_t icm_usage ( unsigned int log_num_entries, size_t entry_size ) {
        size_t usage;

        usage = ( ( 1 << log_num_entries ) * entry_size );
        usage = ( ( usage + 4095 ) & ~4095 );
        return usage;
}

/**
 * Allocate ICM
 *
 * @v arbel             Arbel device
 * @v init_hca          INIT_HCA structure to fill in
 * @ret rc              Return status code
 */
static int arbel_alloc_icm ( struct arbel *arbel,
                             struct arbelprm_init_hca *init_hca ) {
        struct arbelprm_scalar_parameter icm_size;
        struct arbelprm_scalar_parameter icm_aux_size;
        struct arbelprm_virtual_physical_mapping map_icm_aux;
        struct arbelprm_virtual_physical_mapping map_icm;
        union arbelprm_doorbell_record *db_rec;
        size_t icm_offset = 0;
        unsigned int log_num_qps, log_num_srqs, log_num_ees, log_num_cqs;
        unsigned int log_num_mtts, log_num_mpts, log_num_rdbs, log_num_eqs;
        int rc;

        icm_offset = ( ( arbel->limits.reserved_uars + 1 ) << 12 );

        /* Queue pair contexts */
        log_num_qps = fls ( arbel->limits.reserved_qps + ARBEL_MAX_QPS - 1 );
        MLX_FILL_2 ( init_hca, 13,
                     qpc_eec_cqc_eqc_rdb_parameters.qpc_base_addr_l,
                     ( icm_offset >> 7 ),
                     qpc_eec_cqc_eqc_rdb_parameters.log_num_of_qp,
                     log_num_qps );
        DBGC ( arbel, "Arbel %p ICM QPC base = %zx\n", arbel, icm_offset );
        icm_offset += icm_usage ( log_num_qps, arbel->limits.qpc_entry_size );

        /* Extended queue pair contexts */
        MLX_FILL_1 ( init_hca, 25,
                     qpc_eec_cqc_eqc_rdb_parameters.eqpc_base_addr_l,
                     icm_offset );
        DBGC ( arbel, "Arbel %p ICM EQPC base = %zx\n", arbel, icm_offset );
        //      icm_offset += icm_usage ( log_num_qps, arbel->limits.eqpc_entry_size );
        icm_offset += icm_usage ( log_num_qps, arbel->limits.qpc_entry_size );  

        /* Shared receive queue contexts */
        log_num_srqs = fls ( arbel->limits.reserved_srqs - 1 );
        MLX_FILL_2 ( init_hca, 19,
                     qpc_eec_cqc_eqc_rdb_parameters.srqc_base_addr_l,
                     ( icm_offset >> 5 ),
                     qpc_eec_cqc_eqc_rdb_parameters.log_num_of_srq,
                     log_num_srqs );
        DBGC ( arbel, "Arbel %p ICM SRQC base = %zx\n", arbel, icm_offset );
        icm_offset += icm_usage ( log_num_srqs, arbel->limits.srqc_entry_size );

        /* End-to-end contexts */
        log_num_ees = fls ( arbel->limits.reserved_ees - 1 );
        MLX_FILL_2 ( init_hca, 17,
                     qpc_eec_cqc_eqc_rdb_parameters.eec_base_addr_l,
                     ( icm_offset >> 7 ),
                     qpc_eec_cqc_eqc_rdb_parameters.log_num_of_ee,
                     log_num_ees );
        DBGC ( arbel, "Arbel %p ICM EEC base = %zx\n", arbel, icm_offset );
        icm_offset += icm_usage ( log_num_ees, arbel->limits.eec_entry_size );

        /* Extended end-to-end contexts */
        MLX_FILL_1 ( init_hca, 29,
                     qpc_eec_cqc_eqc_rdb_parameters.eeec_base_addr_l,
                     icm_offset );
        DBGC ( arbel, "Arbel %p ICM EEEC base = %zx\n", arbel, icm_offset );
        icm_offset += icm_usage ( log_num_ees, arbel->limits.eeec_entry_size );

        /* Completion queue contexts */
        log_num_cqs = fls ( arbel->limits.reserved_cqs + ARBEL_MAX_CQS - 1 );
        MLX_FILL_2 ( init_hca, 21,
                     qpc_eec_cqc_eqc_rdb_parameters.cqc_base_addr_l,
                     ( icm_offset >> 6 ),
                     qpc_eec_cqc_eqc_rdb_parameters.log_num_of_cq,
                     log_num_cqs );
        DBGC ( arbel, "Arbel %p ICM CQC base = %zx\n", arbel, icm_offset );
        icm_offset += icm_usage ( log_num_cqs, arbel->limits.cqc_entry_size );

        /* Memory translation table */
        log_num_mtts = fls ( arbel->limits.reserved_mtts - 1 );
        MLX_FILL_1 ( init_hca, 65,
                     tpt_parameters.mtt_base_addr_l, icm_offset );
        DBGC ( arbel, "Arbel %p ICM MTT base = %zx\n", arbel, icm_offset );
        icm_offset += icm_usage ( log_num_mtts, arbel->limits.mtt_entry_size );

        /* Memory protection table */
        log_num_mpts = fls ( arbel->limits.reserved_mrws + 1 - 1 );
        MLX_FILL_1 ( init_hca, 61,
                     tpt_parameters.mpt_base_adr_l, icm_offset );
        MLX_FILL_1 ( init_hca, 62,
                     tpt_parameters.log_mpt_sz, log_num_mpts );
        DBGC ( arbel, "Arbel %p ICM MTT base = %zx\n", arbel, icm_offset );
        icm_offset += icm_usage ( log_num_mpts, arbel->limits.mpt_entry_size );

        /* RDMA something or other */
        log_num_rdbs = fls ( arbel->limits.reserved_rdbs - 1 );
        MLX_FILL_1 ( init_hca, 37,
                     qpc_eec_cqc_eqc_rdb_parameters.rdb_base_addr_l,
                     icm_offset );
        DBGC ( arbel, "Arbel %p ICM RDB base = %zx\n", arbel, icm_offset );
        icm_offset += icm_usage ( log_num_rdbs, 32 );

        /* Event queue contexts */
        log_num_eqs =  fls ( arbel->limits.reserved_eqs + ARBEL_MAX_EQS - 1 );
        MLX_FILL_2 ( init_hca, 33,
                     qpc_eec_cqc_eqc_rdb_parameters.eqc_base_addr_l,
                     ( icm_offset >> 6 ),
                     qpc_eec_cqc_eqc_rdb_parameters.log_num_eq,
                     log_num_eqs );
        DBGC ( arbel, "Arbel %p ICM EQ base = %zx\n", arbel, icm_offset );
        icm_offset += ( ( 1 << log_num_eqs ) * arbel->limits.eqc_entry_size );

        /* Multicast table */
        MLX_FILL_1 ( init_hca, 49,
                     multicast_parameters.mc_base_addr_l, icm_offset );
        MLX_FILL_1 ( init_hca, 52,
                     multicast_parameters.log_mc_table_entry_sz,
                     fls ( sizeof ( struct arbelprm_mgm_entry ) - 1 ) );
        MLX_FILL_1 ( init_hca, 53,
                     multicast_parameters.mc_table_hash_sz, 8 );
        MLX_FILL_1 ( init_hca, 54,
                     multicast_parameters.log_mc_table_sz, 3 );
        DBGC ( arbel, "Arbel %p ICM MC base = %zx\n", arbel, icm_offset );
        icm_offset += ( 8 * sizeof ( struct arbelprm_mgm_entry ) );

        arbel->icm_len = icm_offset;
        arbel->icm_len = ( ( arbel->icm_len + 4095 ) & ~4095 );

        /* Get ICM auxiliary area size */
        memset ( &icm_size, 0, sizeof ( icm_size ) );
        MLX_FILL_1 ( &icm_size, 1, value, arbel->icm_len );
        if ( ( rc = arbel_cmd_set_icm_size ( arbel, &icm_size,
                                             &icm_aux_size ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not set ICM size: %s\n",
                       arbel, strerror ( rc ) );
                goto err_set_icm_size;
        }
        arbel->icm_aux_len = ( MLX_GET ( &icm_aux_size, value ) * 4096 );

        /* Allocate ICM data and auxiliary area */
        DBGC ( arbel, "Arbel %p requires %zd kB ICM and %zd kB AUX ICM\n",
               arbel, ( arbel->icm_len / 1024 ),
               ( arbel->icm_aux_len / 1024 ) );
        arbel->icm = umalloc ( arbel->icm_len + arbel->icm_aux_len );
        if ( ! arbel->icm ) {
                rc = -ENOMEM;
                goto err_alloc;
        }

        /* Map ICM auxiliary area */
        memset ( &map_icm_aux, 0, sizeof ( map_icm_aux ) );
        MLX_FILL_2 ( &map_icm_aux, 3,
                     log2size, fls ( ( arbel->icm_aux_len / 4096 ) - 1 ),
                     pa_l,
                     ( user_to_phys ( arbel->icm, arbel->icm_len ) >> 12 ) );
        if ( ( rc = arbel_cmd_map_icm_aux ( arbel, &map_icm_aux ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not map AUX ICM: %s\n",
                       arbel, strerror ( rc ) );
                goto err_map_icm_aux;
        }

        /* MAP ICM area */
        memset ( &map_icm, 0, sizeof ( map_icm ) );
        MLX_FILL_2 ( &map_icm, 3,
                     log2size, fls ( ( arbel->icm_len / 4096 ) - 1 ),
                     pa_l, ( user_to_phys ( arbel->icm, 0 ) >> 12 ) );
        if ( ( rc = arbel_cmd_map_icm ( arbel, &map_icm ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not map ICM: %s\n",
                       arbel, strerror ( rc ) );
                goto err_map_icm;
        }

        /* Initialise UAR context */
        arbel->db_rec = phys_to_virt ( user_to_phys ( arbel->icm, 0 ) +
                                       ( arbel->limits.reserved_uars *
                                         ARBEL_PAGE_SIZE ) );
        memset ( arbel->db_rec, 0, ARBEL_PAGE_SIZE );
        db_rec = &arbel->db_rec[ARBEL_GROUP_SEPARATOR_DOORBELL];
        MLX_FILL_1 ( &db_rec->qp, 1, res, ARBEL_UAR_RES_GROUP_SEP );

        return 0;

        arbel_cmd_unmap_icm ( arbel, ( arbel->icm_len / 4096 ) );
 err_map_icm:
        arbel_cmd_unmap_icm_aux ( arbel );
 err_map_icm_aux:
        ufree ( arbel->icm );
        arbel->icm = UNULL;
 err_alloc:
 err_set_icm_size:
        return rc;
}

/**
 * Free ICM
 *
 * @v arbel             Arbel device
 */
static void arbel_free_icm ( struct arbel *arbel ) {
        arbel_cmd_unmap_icm ( arbel, ( arbel->icm_len / 4096 ) );
        arbel_cmd_unmap_icm_aux ( arbel );
        ufree ( arbel->icm );
        arbel->icm = UNULL;
}

/***************************************************************************
 *
 * PCI interface
 *
 ***************************************************************************
 */

/**
 * Set up memory protection table
 *
 * @v arbel             Arbel device
 * @ret rc              Return status code
 */
static int arbel_setup_mpt ( struct arbel *arbel ) {
        struct arbelprm_mpt mpt;
        uint32_t key;
        int rc;

        /* Derive key */
        key = ( arbel->limits.reserved_mrws | ARBEL_MKEY_PREFIX );
        arbel->reserved_lkey = ( ( key << 8 ) | ( key >> 24 ) );

        /* Initialise memory protection table */
        memset ( &mpt, 0, sizeof ( mpt ) );
        MLX_FILL_4 ( &mpt, 0,
                     r_w, 1,
                     pa, 1,
                     lr, 1,
                     lw, 1 );
        MLX_FILL_1 ( &mpt, 2, mem_key, key );
        MLX_FILL_1 ( &mpt, 3, pd, ARBEL_GLOBAL_PD );
        MLX_FILL_1 ( &mpt, 6, reg_wnd_len_h, 0xffffffffUL );
        MLX_FILL_1 ( &mpt, 7, reg_wnd_len_l, 0xffffffffUL );
        if ( ( rc = arbel_cmd_sw2hw_mpt ( arbel, arbel->limits.reserved_mrws,
                                          &mpt ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not set up MPT: %s\n",
                       arbel, strerror ( rc ) );
                return rc;
        }

        return 0;
}
        
/**
 * Probe PCI device
 *
 * @v pci               PCI device
 * @v id                PCI ID
 * @ret rc              Return status code
 */
static int arbel_probe ( struct pci_device *pci,
                         const struct pci_device_id *id __unused ) {
        struct arbel *arbel;
        struct ib_device *ibdev;
        struct arbelprm_init_hca init_hca;
        int i;
        int rc;

        /* Allocate Arbel device */
        arbel = zalloc ( sizeof ( *arbel ) );
        if ( ! arbel ) {
                rc = -ENOMEM;
                goto err_alloc_arbel;
        }
        pci_set_drvdata ( pci, arbel );

        /* Allocate Infiniband devices */
        for ( i = 0 ; i < ARBEL_NUM_PORTS ; i++ ) {
                ibdev = alloc_ibdev ( 0 );
                if ( ! ibdev ) {
                        rc = -ENOMEM;
                        goto err_alloc_ibdev;
                }
                arbel->ibdev[i] = ibdev;
                ibdev->op = &arbel_ib_operations;
                ibdev->dev = &pci->dev;
                ibdev->port = ( ARBEL_PORT_BASE + i );
                ib_set_drvdata ( ibdev, arbel );
        }

        /* Fix up PCI device */
        adjust_pci_device ( pci );

        /* Get PCI BARs */
        arbel->config = ioremap ( pci_bar_start ( pci, ARBEL_PCI_CONFIG_BAR ),
                                  ARBEL_PCI_CONFIG_BAR_SIZE );
        arbel->uar = ioremap ( ( pci_bar_start ( pci, ARBEL_PCI_UAR_BAR ) +
                                 ARBEL_PCI_UAR_IDX * ARBEL_PCI_UAR_SIZE ),
                               ARBEL_PCI_UAR_SIZE );

        /* Allocate space for mailboxes */
        arbel->mailbox_in = malloc_dma ( ARBEL_MBOX_SIZE, ARBEL_MBOX_ALIGN );
        if ( ! arbel->mailbox_in ) {
                rc = -ENOMEM;
                goto err_mailbox_in;
        }
        arbel->mailbox_out = malloc_dma ( ARBEL_MBOX_SIZE, ARBEL_MBOX_ALIGN );
        if ( ! arbel->mailbox_out ) {
                rc = -ENOMEM;
                goto err_mailbox_out;
        }

        /* Start firmware */
        if ( ( rc = arbel_start_firmware ( arbel ) ) != 0 )
                goto err_start_firmware;

        /* Get device limits */
        if ( ( rc = arbel_get_limits ( arbel ) ) != 0 )
                goto err_get_limits;

        /* Allocate ICM */
        memset ( &init_hca, 0, sizeof ( init_hca ) );
        if ( ( rc = arbel_alloc_icm ( arbel, &init_hca ) ) != 0 )
                goto err_alloc_icm;

        /* Initialise HCA */
        MLX_FILL_1 ( &init_hca, 74, uar_parameters.log_max_uars, 1 );
        if ( ( rc = arbel_cmd_init_hca ( arbel, &init_hca ) ) != 0 ) {
                DBGC ( arbel, "Arbel %p could not initialise HCA: %s\n",
                       arbel, strerror ( rc ) );
                goto err_init_hca;
        }

        /* Set up memory protection */
        if ( ( rc = arbel_setup_mpt ( arbel ) ) != 0 )
                goto err_setup_mpt;

        /* Set up event queue */
        if ( ( rc = arbel_create_eq ( arbel ) ) != 0 )
                goto err_create_eq;

        /* Register Infiniband devices */
        for ( i = 0 ; i < ARBEL_NUM_PORTS ; i++ ) {
                if ( ( rc = register_ibdev ( arbel->ibdev[i] ) ) != 0 ) {
                        DBGC ( arbel, "Arbel %p could not register IB "
                               "device: %s\n", arbel, strerror ( rc ) );
                        goto err_register_ibdev;
                }
        }

        return 0;

        i = ARBEL_NUM_PORTS;
 err_register_ibdev:
        for ( i-- ; i >= 0 ; i-- )
                unregister_ibdev ( arbel->ibdev[i] );
        arbel_destroy_eq ( arbel );
 err_create_eq:
 err_setup_mpt:
        arbel_cmd_close_hca ( arbel );
 err_init_hca:
        arbel_free_icm ( arbel );
 err_alloc_icm:
 err_get_limits:
        arbel_stop_firmware ( arbel );
 err_start_firmware:
        free_dma ( arbel->mailbox_out, ARBEL_MBOX_SIZE );
 err_mailbox_out:
        free_dma ( arbel->mailbox_in, ARBEL_MBOX_SIZE );
 err_mailbox_in:
        i = ARBEL_NUM_PORTS;
 err_alloc_ibdev:
        for ( i-- ; i >= 0 ; i-- )
                ibdev_put ( arbel->ibdev[i] );
        free ( arbel );
 err_alloc_arbel:
        return rc;
}

/**
 * Remove PCI device
 *
 * @v pci               PCI device
 */
static void arbel_remove ( struct pci_device *pci ) {
        struct arbel *arbel = pci_get_drvdata ( pci );
        int i;

        for ( i = ( ARBEL_NUM_PORTS - 1 ) ; i >= 0 ; i-- )
                unregister_ibdev ( arbel->ibdev[i] );
        arbel_destroy_eq ( arbel );
        arbel_cmd_close_hca ( arbel );
        arbel_free_icm ( arbel );
        arbel_stop_firmware ( arbel );
        arbel_stop_firmware ( arbel );
        free_dma ( arbel->mailbox_out, ARBEL_MBOX_SIZE );
        free_dma ( arbel->mailbox_in, ARBEL_MBOX_SIZE );
        for ( i = ( ARBEL_NUM_PORTS - 1 ) ; i >= 0 ; i-- )
                ibdev_put ( arbel->ibdev[i] );
        free ( arbel );
}

static struct pci_device_id arbel_nics[] = {
        PCI_ROM ( 0x15b3, 0x6282, "mt25218", "MT25218 HCA driver" ),
        PCI_ROM ( 0x15b3, 0x6274, "mt25204", "MT25204 HCA driver" ),
};

struct pci_driver arbel_driver __pci_driver = {
        .ids = arbel_nics,
        .id_count = ( sizeof ( arbel_nics ) / sizeof ( arbel_nics[0] ) ),
        .probe = arbel_probe,
        .remove = arbel_remove,
};