Merge remote-tracking branch 'origin/master'

[unleashed/lotheac.git] / usr / src / uts / common / io / 1394 / adapters / hci1394_async.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1999-2000 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I%     %E% SMI"

/*
 * hci1394_async.c
 *    These routines manipulate the 1394 asynchronous dma engines.  This
 *    includes incoming and outgoing reads, writes, and locks and their
 *    associated responses.
 */

#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/modctl.h>
#include <sys/stat.h>
#include <sys/sunddi.h>
#include <sys/cmn_err.h>
#include <sys/kmem.h>
#include <sys/types.h>
#include <sys/note.h>

#include <sys/1394/h1394.h>
#include <sys/1394/adapters/hci1394.h>


/*
 * ASYNC_ARRESP_ACK_ERROR is or'd into the error status when we get an ACK error
 * on an ARRESP.  Since the 1394 response code overlaps with the OpenHCI ACK/EVT
 * errors, we use this to distinguish between the errors in process_arresp().
 */
#define ASYNC_ARRESP_ACK_ERROR          0x8000

/* Macro's to help extract 48-bit 1394 address into a uint64_t */
#define HCI1394_TO_ADDR_HI(data) (((uint64_t)((data) & 0xFFFF)) << 32)
#define HCI1394_TO_ADDR_LO(data) ((uint64_t)((data) & 0xFFFFFFFF))

/*
 * Macro to convert a byte stream into a big endian quadlet or octlet or back
 * the other way. 1394 arithmetic lock operations are done on big endian
 * quadlets or octlets. compare swaps and bit masks are done on a byte streams.
 * All data is treated as byte streams over the bus. These macros will convert
 * the data to a big endian "integer" on x86 plaforms if the operation is an
 * arithmetic lock operation.  It will do nothing if it is not on x86 or is not
 * an arithmetic lock operation.
 */
#ifdef _LITTLE_ENDIAN
#define HCI1394_ARITH_LOCK_SWAP32(tcode, data) \
        (((tcode) == CMD1394_LOCK_FETCH_ADD) || \
        ((tcode) == CMD1394_LOCK_BOUNDED_ADD) || \
        ((tcode) == CMD1394_LOCK_WRAP_ADD)) ? \
        (ddi_swap32(data)) : (data)
#define HCI1394_ARITH_LOCK_SWAP64(tcode, data) \
        (((tcode) == CMD1394_LOCK_FETCH_ADD) || \
        ((tcode) == CMD1394_LOCK_BOUNDED_ADD) || \
        ((tcode) == CMD1394_LOCK_WRAP_ADD)) ? \
        (ddi_swap64(data)) : (data)
#else
#define HCI1394_ARITH_LOCK_SWAP32(tcode, data) (data)
#define HCI1394_ARITH_LOCK_SWAP64(tcode, data) (data)
#endif



static int hci1394_async_arresp_read(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, uint_t *tcode, hci1394_async_cmd_t **hcicmd,
    uint_t *size);
static int hci1394_async_arresp_size_get(uint_t tcode, hci1394_q_handle_t q,
    uint32_t *addr, uint_t *size);

static int hci1394_async_arreq_read(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, uint_t *tcode, hci1394_async_cmd_t **hcicmd,
    uint_t *size);
static int hci1394_async_arreq_read_qrd(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size);
static int hci1394_async_arreq_read_qwr(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size);
static int hci1394_async_arreq_read_brd(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size);
static int hci1394_async_arreq_read_bwr(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size);
static int hci1394_async_arreq_read_lck(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size);
static int hci1394_async_arreq_read_phy(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size,
    boolean_t *bus_reset_token);

static void hci1394_async_hcicmd_init(hci1394_async_handle_t async_handle,
    cmd1394_cmd_t *cmd, h1394_cmd_priv_t *cmd_priv,
    hci1394_async_cmd_t **hcicmd);

static void hci1394_async_atreq_start(void *async, uint32_t command_ptr);
static void hci1394_async_arresp_start(void *async, uint32_t command_ptr);
static void hci1394_async_arreq_start(void *async, uint32_t command_ptr);
static void hci1394_async_atresp_start(void *async, uint32_t command_ptr);

static void hci1394_async_atreq_wake(void *async);
static void hci1394_async_arresp_wake(void *async);
static void hci1394_async_arreq_wake(void *async);
static void hci1394_async_atresp_wake(void *async);

static void hci1394_async_atreq_flush(hci1394_async_handle_t async_handle);
static void hci1394_async_arresp_flush(hci1394_async_handle_t async_handle);
static void hci1394_async_arreq_flush(hci1394_async_handle_t async_handle);
static void hci1394_async_atresp_flush(hci1394_async_handle_t async_handle);
static void hci1394_async_pending_list_flush(hci1394_async_handle_t
    async_handle);

static void hci1394_async_pending_timeout(hci1394_tlist_node_t *node,
    void *arg);
static uint_t hci1394_async_timeout_calc(hci1394_async_handle_t async_handle,
    uint_t current_time);

_NOTE(SCHEME_PROTECTS_DATA("unique", msgb))

/*
 * hci1394_async_init()
 *    Initialize the async DMA engines and state. We init the tlabels; ATREQ
 *    pending Q; and ATREQ, ARRESP, ARREQ, and ATRESP Q's. init() returns a
 *    handle to be used in rest of the functions.
 */
int
hci1394_async_init(hci1394_drvinfo_t *drvinfo,
    hci1394_ohci_handle_t ohci_handle, hci1394_csr_handle_t csr_handle,
    hci1394_async_handle_t *async_handle)
{
        hci1394_tlist_timer_t timer_info;
        hci1394_q_info_t qinfo;
        hci1394_async_t *async;
        int status;


        ASSERT(drvinfo != NULL);
        ASSERT(ohci_handle != NULL);
        ASSERT(csr_handle != NULL);
        ASSERT(async_handle != NULL);

        /* alloc the space to keep track of the list */
        async = kmem_alloc(sizeof (hci1394_async_t), KM_SLEEP);

        /* copy in parms to our local state */
        async->as_drvinfo = drvinfo;
        async->as_ohci = ohci_handle;
        async->as_csr = csr_handle;
        async->as_flushing_arreq = B_FALSE;
        async->as_phy_reset = 0xFFFFFFFF;
        mutex_init(&async->as_atomic_lookup, NULL, MUTEX_DRIVER,
            drvinfo->di_iblock_cookie);

        /*
         * Initialize the tlabels. Reclaim a bad tlabel after the split timeout
         * has gone by. This time is in reference to the point the transaction
         * has been marked as bad. Therefore the tlabel will be reclaimed at
         * twice the split_timeout. (i.e. if the split timeout was set to 100mS
         * and the transaction has timed out, 100mS has already gone by. We need
         * to wait for 100mS more before we can reuse the tlabel. Therefore, the
         * reclaim time is split_timeout and not split_timeout * 2. The split
         * timeout is stored as the number of bus cycles.  We need to convert
         * this to nS since the reclaim time is passed as nS.
         */
        hci1394_tlabel_init(drvinfo, OHCI_BUS_CYCLE_TO_nS(
            hci1394_csr_split_timeout_get(csr_handle)), &async->as_tlabel);

        /*
         * Initialize ATREQ pending list. A pended ATREQ will be timed out after
         * "split_timeout" has gone by. split timeout is in bus cycles so we
         * need to convert that to nS for the tlist timer info. We will set the
         * timer resolution to 1/2 of the timeout so that we will have a worst
         * case timeout of split timeout + (1/2 * split timeout).  See
         * hci1394_tlist.h for more information about this.
         */
        timer_info.tlt_timeout =
            OHCI_BUS_CYCLE_TO_nS(hci1394_csr_split_timeout_get(csr_handle));
        timer_info.tlt_timer_resolution = timer_info.tlt_timeout / 2;
        timer_info.tlt_callback = hci1394_async_pending_timeout;
        timer_info.tlt_callback_arg = async;
        hci1394_tlist_init(drvinfo, &timer_info, &async->as_pending_list);

        /* Initialize ATREQ Q */
        qinfo.qi_desc_size = ASYNC_ATREQ_DESC_SIZE;
        qinfo.qi_data_size = ASYNC_ATREQ_DATA_SIZE;
        qinfo.qi_mode = HCI1394_ATQ;
        qinfo.qi_start = hci1394_async_atreq_start;
        qinfo.qi_wake = hci1394_async_atreq_wake;
        qinfo.qi_callback_arg = async;
        status = hci1394_q_init(drvinfo, async->as_ohci, &qinfo,
            &async->as_atreq_q);
        if (status != DDI_SUCCESS) {
                mutex_destroy(&async->as_atomic_lookup);
                hci1394_tlist_fini(&async->as_pending_list);
                hci1394_tlabel_fini(&async->as_tlabel);
                kmem_free(async, sizeof (hci1394_async_t));
                *async_handle = NULL;
                return (DDI_FAILURE);
        }

        /* Initialize ARRESP Q */
        qinfo.qi_desc_size = ASYNC_ARRESP_DESC_SIZE;
        qinfo.qi_data_size = ASYNC_ARRESP_DATA_SIZE;
        qinfo.qi_mode = HCI1394_ARQ;
        qinfo.qi_start = hci1394_async_arresp_start;
        qinfo.qi_wake = hci1394_async_arresp_wake;
        qinfo.qi_callback_arg = async;
        status = hci1394_q_init(drvinfo, async->as_ohci, &qinfo,
            &async->as_arresp_q);
        if (status != DDI_SUCCESS) {
                mutex_destroy(&async->as_atomic_lookup);
                hci1394_tlist_fini(&async->as_pending_list);
                hci1394_tlabel_fini(&async->as_tlabel);
                hci1394_q_fini(&async->as_atreq_q);
                kmem_free(async, sizeof (hci1394_async_t));
                *async_handle = NULL;
                return (DDI_FAILURE);
        }

        /* Initialize ARREQ Q */
        qinfo.qi_desc_size = ASYNC_ARREQ_DESC_SIZE;
        qinfo.qi_data_size = ASYNC_ARREQ_DATA_SIZE;
        qinfo.qi_mode = HCI1394_ARQ;
        qinfo.qi_start = hci1394_async_arreq_start;
        qinfo.qi_wake = hci1394_async_arreq_wake;
        qinfo.qi_callback_arg = async;
        status = hci1394_q_init(drvinfo, async->as_ohci, &qinfo,
            &async->as_arreq_q);
        if (status != DDI_SUCCESS) {
                mutex_destroy(&async->as_atomic_lookup);
                hci1394_tlist_fini(&async->as_pending_list);
                hci1394_tlabel_fini(&async->as_tlabel);
                hci1394_q_fini(&async->as_atreq_q);
                hci1394_q_fini(&async->as_arresp_q);
                kmem_free(async, sizeof (hci1394_async_t));
                *async_handle = NULL;
                return (DDI_FAILURE);
        }

        /* Initialize ATRESP Q */
        qinfo.qi_desc_size = ASYNC_ATRESP_DESC_SIZE;
        qinfo.qi_data_size = ASYNC_ATRESP_DATA_SIZE;
        qinfo.qi_mode = HCI1394_ATQ;
        qinfo.qi_start = hci1394_async_atresp_start;
        qinfo.qi_wake = hci1394_async_atresp_wake;
        qinfo.qi_callback_arg = async;
        status = hci1394_q_init(drvinfo, async->as_ohci, &qinfo,
            &async->as_atresp_q);
        if (status != DDI_SUCCESS) {
                mutex_destroy(&async->as_atomic_lookup);
                hci1394_tlist_fini(&async->as_pending_list);
                hci1394_tlabel_fini(&async->as_tlabel);
                hci1394_q_fini(&async->as_atreq_q);
                hci1394_q_fini(&async->as_arresp_q);
                hci1394_q_fini(&async->as_arreq_q);
                kmem_free(async, sizeof (hci1394_async_t));
                *async_handle = NULL;
                return (DDI_FAILURE);
        }

        *async_handle = async;

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_fini()
 *    Free's up the space allocated in init().  Notice that a pointer to the
 *    handle is used for the parameter.  fini() will set your handle to NULL
 *    before returning.
 */
void
hci1394_async_fini(hci1394_async_handle_t *async_handle)
{
        hci1394_async_t *async;


        ASSERT(async_handle != NULL);

        async = (hci1394_async_t *)*async_handle;

        mutex_destroy(&async->as_atomic_lookup);
        hci1394_tlabel_fini(&async->as_tlabel);
        hci1394_tlist_fini(&async->as_pending_list);
        hci1394_q_fini(&async->as_atreq_q);
        hci1394_q_fini(&async->as_atresp_q);
        hci1394_q_fini(&async->as_arreq_q);
        hci1394_q_fini(&async->as_arresp_q);

        kmem_free(async, sizeof (hci1394_async_t));

        /* set handle to null.  This helps catch bugs. */
        *async_handle = NULL;
}


/*
 * hci1394_async_suspend()
 *    The system is getting ready to be suspended.  Make sure that all of
 *    the Q's are clean and that the there are no scheduled timeouts in the
 *    pending Q.
 */
void
hci1394_async_suspend(hci1394_async_handle_t async_handle)
{
        ASSERT(async_handle != NULL);

        /* Flush out async DMA Q's */
        hci1394_async_flush(async_handle);

        /* Cancel any scheduled pending timeouts */
        hci1394_tlist_timeout_cancel(async_handle->as_pending_list);
}


/*
 * hci1394_async_resume()
 *    Re-setup the DMA Q's during a resume after a successful suspend. The
 *    tlabels will be re-initialized during the bus reset and the pending Q will
 *    be flushed during the suspend.
 */
int
hci1394_async_resume(hci1394_async_handle_t async_handle)
{
        ASSERT(async_handle != NULL);

        hci1394_q_resume(async_handle->as_atreq_q);
        hci1394_q_resume(async_handle->as_atresp_q);
        hci1394_q_resume(async_handle->as_arreq_q);
        hci1394_q_resume(async_handle->as_arresp_q);

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_cmd_overhead()
 *    Return the size of the HAL private area to attach to every alloced 1394
 *    framework command.  This allows us to track command state without having
 *    to alloc memory every time a command comes down the pipe.
 */
uint_t
hci1394_async_cmd_overhead()
{
        return (sizeof (hci1394_async_cmd_t));
}


/*
 * hci1394_async_flush()
 *    Flush out the Async Q's and the ATREQ pending list.  This is called every
 *    bus reset so that we're sync'd up with the HW and when shutting down or
 *    suspending to make sure we cleanup after all commands.
 */
void
hci1394_async_flush(hci1394_async_handle_t async_handle)
{
        ASSERT(async_handle != NULL);

        hci1394_async_atreq_flush(async_handle);
        hci1394_async_arresp_flush(async_handle);
        hci1394_async_pending_list_flush(async_handle);
        hci1394_async_arreq_flush(async_handle);
        hci1394_async_atresp_flush(async_handle);
        hci1394_tlabel_reset(async_handle->as_tlabel);
}


/*
 * hci1394_async_pending_timeout_update()
 *    Update the timeout for the pending list. This updates both the pending
 *    list timeout and time we wait to reclaim  bad tlabels.  timeout is the
 *    time in nS so we do not have to do any conversions. This routine will be
 *    called when the CSR split timeout registers are updated.
 */
void
hci1394_async_pending_timeout_update(hci1394_async_handle_t async_handle,
    hrtime_t timeout)
{
        ASSERT(async_handle != NULL);
        hci1394_tlist_timeout_update(async_handle->as_pending_list, timeout);
        hci1394_tlabel_set_reclaim_time(async_handle->as_tlabel, timeout);
}


/*
 * hci1394_async_atreq_process()
 *    Process an atreq, if one has completed. This is called during interrupt
 *    processing and will process a completed atreq. It returns status if an
 *    atreq was processed so that the ISR knows that it needs to be called
 *    again to see if another ATREQ has completed. flush_q set to B_TRUE tells
 *    this routine to process all commands regardless of their completion
 *    status.  This is used during bus reset processing to remove all commands
 *    from the Q.
 *
 *    There are a few race conditions that we have to watch for in atreq/arresp.
 *    They all have to do with pended responses so they are not applicable in
 *    the ARREQ/ATRESP engine (since ATRESP's can't be pended).
 *
 *    Since the race conditions only exist for pended responses, we will only
 *    talk about that sequence here. We're also going to simplify the discussion
 *    so what the code does, so it won't exactly match what we say (e.g. we
 *    don't always setup a timeout for every single command, etc.)
 *
 *    After Q'ing up an ATREQ, we will process the result of that command in
 *    one of a couple different paths. A normal condition would be that we Q up
 *    a command, we get an ATREQ complete interrupt and look at the ATREQ
 *    result. In the case it has been pended, we setup a timeout to wait for the
 *    response. If we receive the response before the timeout, the command is
 *    done and we send the response up the chain, if we do not, the command is
 *    done and we send a timeout notification up the chain.
 *
 *    The first race condition is when we get the timeout at the same time as
 *    the response. At first glance a mutex around the command state would
 *    solve this problem. But on a multi-processor machine, we may have the
 *    ARRESP interrupt handler(ISR) running on one processor and the timeout on
 *    another. This means that the command state could change between two
 *    reads while in the ISR. This means we need to have a little more complex
 *    logic around changing the command state and have to be careful how and
 *    when we do this.
 *
 *    The second race condition is that we could see the ARRESP before we
 *    process the ATREQ. We could be processing a few ARRESP from previous
 *    ATREQ's when the ATREQ completes and then the ARRESP comes in.  Since we
 *    already are in the interrupt handler, the ATREQ complete will not preempt
 *    us.
 *
 *    We will never see a race condition between the ATREQ interrupt for a
 *    command and the pending timeout since the command is not being timed until
 *    this routine is run for that command.
 */
int
hci1394_async_atreq_process(hci1394_async_handle_t async_handle,
    boolean_t flush_q, boolean_t *request_available)
{
        hci1394_async_cmd_t *hcicmd;
        hci1394_q_cmd_t *qcmd;
        int cmd_status;


        ASSERT(async_handle != NULL);
        ASSERT(request_available != NULL);

        /*
         * Get the next ATREQ that has completed (if one has). Space is free'd
         * up in atreq_q and atreq_data_q as part of this function call.
         */
        hci1394_q_at_next(async_handle->as_atreq_q, flush_q, &qcmd);

        /*
         * See if there were anymore requests on ATREQ Q. A NULL means there
         * were no completed commands left on the Q
         */
        if (qcmd == NULL) {
                *request_available = B_FALSE;
                return (DDI_SUCCESS);
        }

        /* There is a completed ATREQ, setup the HAL command pointer */
        *request_available = B_TRUE;
        hcicmd = (hci1394_async_cmd_t *)qcmd->qc_arg;

        /* save away the command completed timestamp for the services layer */
        hcicmd->ac_priv->ack_tstamp = qcmd->qc_timestamp;

        /*
         * Make sure this command has not already been processed. This command
         * may have already received a response.  If the ACK was not an ACK
         * pending, we have a HW error (i.e. The target HW sent a response to a
         * non-pended request). There is a race condition where the software
         * will see and complete a response before processing it's ACK Pending.
         * This can only happen for ACK pendings. We have seen this race
         * condition and response to a non-pended request during real-world
         * testing :-)
         */
        if (hcicmd->ac_state != HCI1394_CMD_STATE_IN_PROGRESS) {
                /*
                 * we already processed the ARRESP in arresp_process(), it
                 * better have been ACK pended. Otherwise the target device
                 * performed an illegal action.
                 */
                if (qcmd->qc_status == OHCI_ACK_PENDING) {
                        /*
                         * Tell source that their command has completed. We're
                         * done with this command.
                         * NOTE: We use ac_status which was set in
                         * process_arresp()
                         */
                        h1394_cmd_is_complete(
                            async_handle->as_drvinfo->di_sl_private,
                            hcicmd->ac_cmd, H1394_AT_REQ,
                            hcicmd->ac_status);
                        return (DDI_SUCCESS);
                /*
                 * This is a HW error.  Process the ACK like we never saw the
                 * response. We will do this below.
                 */
                } else {
                }
        }

        /*
         * if we got an ack pending, add it to the pending list and leave. We
         * will either get an ARRESP or the pending list will timeout the
         * response.
         */
        if (qcmd->qc_status == OHCI_ACK_PENDING) {
                hcicmd->ac_state = HCI1394_CMD_STATE_PENDING;
                /* Add this command to the pending list */
                hcicmd->ac_plist_node.tln_addr = hcicmd;
                hci1394_tlist_add(async_handle->as_pending_list,
                    &hcicmd->ac_plist_node);
                return (DDI_SUCCESS);
        }

        /*
         * setup our return command status based on the ACK from the HW. See the
         * OpenHCI 1.0 spec (table 3.2 on pg. 18) for more information about
         * these ACK/EVT's.
         */
        switch (qcmd->qc_status) {
        case OHCI_ACK_COMPLETE:
                cmd_status = H1394_CMD_SUCCESS;
                break;

        /*
         * we can get a nostatus during a bus reset (i.e. we shutdown the AT
         * engine before it flushed all the commands)
         */
        case OHCI_EVT_FLUSHED:
        case OHCI_EVT_NO_STATUS:
                cmd_status = H1394_CMD_EBUSRESET;
                break;

        case OHCI_EVT_MISSING_ACK:
        case OHCI_EVT_TIMEOUT:
                cmd_status = H1394_CMD_ETIMEOUT;
                break;

        case OHCI_ACK_BUSY_X:
        case OHCI_ACK_BUSY_A:
        case OHCI_ACK_BUSY_B:
                cmd_status = H1394_CMD_EDEVICE_BUSY;
                break;

        case OHCI_ACK_TARDY:
                cmd_status = H1394_CMD_EDEVICE_POWERUP;
                break;

        case OHCI_ACK_DATA_ERROR:
                cmd_status = H1394_CMD_EDATA_ERROR;
                break;

        case OHCI_ACK_TYPE_ERROR:
                cmd_status = H1394_CMD_ETYPE_ERROR;
                break;

        case OHCI_ACK_CONFLICT_ERROR:
                cmd_status = H1394_CMD_ERSRC_CONFLICT;
                break;

        case OHCI_ACK_ADDRESS_ERROR:
                cmd_status = H1394_CMD_EADDR_ERROR;
                break;

        case OHCI_EVT_UNDERRUN:
        case OHCI_EVT_DATA_READ:
        case OHCI_EVT_TCODE_ERR:
        case OHCI_EVT_DESCRIPTOR_READ:
        case OHCI_EVT_UNKNOWN:
        default:
                cmd_status = H1394_CMD_EUNKNOWN_ERROR;
                break;
        }

        /*
         * Free the tlabel that was used for this transfer. We will not try and
         * free the tlabel in the case that we already received a response or if
         * we did not allocate one (PHY packet). If we already received a
         * response, the tlabel would have been free'd in
         * hci1394_async_arresp_process().
         */
        if ((hcicmd->ac_state == HCI1394_CMD_STATE_IN_PROGRESS) &&
            (hcicmd->ac_tlabel_alloc == B_TRUE)) {
                hci1394_tlabel_free(async_handle->as_tlabel,
                    &hcicmd->ac_tlabel);
        }

        /*
         * if we got anything other than and ACK pending, we are done w/ this
         * transaction.
         */
        hcicmd->ac_state = HCI1394_CMD_STATE_COMPLETED;

        /* tell the services layer that the command has completed */
        h1394_cmd_is_complete(async_handle->as_drvinfo->di_sl_private,
            hcicmd->ac_cmd, H1394_AT_REQ, cmd_status);

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arresp_process()
 *    Process an arresp, if one has completed. This is called during interrupt
 *    processing and will process a completed arresp. It returns status if an
 *    arresp was processed so that the ISR knows that it needs to be called
 *    again to see if another ARRESP has completed.
 */
int
hci1394_async_arresp_process(hci1394_async_handle_t async_handle,
    boolean_t *response_available)
{
        hci1394_async_cmd_t *hcicmd;
        uint32_t *addr;
        int cmd_status;
        uint_t tcode;
        uint_t size;
        int status;


        ASSERT(async_handle != NULL);
        ASSERT(response_available != NULL);

        /*
         * See if there were any responses on ARRESP Q. A NULL means there
         * were no responses on the Q. This call does NOT free up space. We
         * need to do that later after we figure out how much space the
         * response takes up.
         */
        hci1394_q_ar_next(async_handle->as_arresp_q, &addr);
        if (addr == NULL) {
                *response_available = B_FALSE;
                return (DDI_SUCCESS);
        }

        /*
         * We got a response. Lock out pending timeout callback from marking
         * tlabel bad.
         */
        *response_available = B_TRUE;
        mutex_enter(&async_handle->as_atomic_lookup);

        /*
         * Read in the response into the 1394 framework command. We could get a
         * NULL for a command if we got a response with an error (i.e. tlabel
         * that didn't match a request) This would be a successful read but with
         * a NULL hcicmd returned. If we ever get a DDI_FAILURE, we will
         * shutdown.
         */
        status = hci1394_async_arresp_read(async_handle,
            (hci1394_basic_pkt_t *)addr, &tcode, &hcicmd, &size);
        if (status != DDI_SUCCESS) {
                mutex_exit(&async_handle->as_atomic_lookup);
                h1394_error_detected(async_handle->as_drvinfo->di_sl_private,
                    H1394_SELF_INITIATED_SHUTDOWN, NULL);
                cmn_err(CE_WARN, "hci1394(%d): driver shutdown: "
                    "unrecoverable error interrupt detected",
                    async_handle->as_drvinfo->di_instance);
                hci1394_shutdown(async_handle->as_drvinfo->di_dip);
                return (DDI_FAILURE);
        }

        /* Free up the arresp Q space, we are done with the data */
        hci1394_q_ar_free(async_handle->as_arresp_q, size);

        /*
         * if we did not get a valid command response (i.e. we got a bad tlabel
         * or something like that) we don't have anything else to do.  We will
         * say that we processed a response and will return successfully. We
         * still may have other responses on the Q.
         */
        if (hcicmd == NULL) {
                mutex_exit(&async_handle->as_atomic_lookup);
                return (DDI_SUCCESS);
        }

        /*
         * Make sure this is in the pending list. There is a small chance that
         * we will see the response before we see the ACK PENDING. If it is the
         * expected case, it is in the pending list.  We will remove it since
         * we are done with the command.
         *
         * NOTE: there is a race condition here with the pending timeout.  Look
         * at the comments before hci1394_async_atreq_process() for more info.
         */
        if (hcicmd->ac_state == HCI1394_CMD_STATE_PENDING) {
                /* remove this transfer from our the pending list */
                status = hci1394_tlist_delete(async_handle->as_pending_list,
                    &hcicmd->ac_plist_node);
                if (status != DDI_SUCCESS) {
                        mutex_exit(&async_handle->as_atomic_lookup);
                        return (DDI_SUCCESS);
                }
        }

        /* allow pending timeout callback to mark tlabel as bad */
        mutex_exit(&async_handle->as_atomic_lookup);

        /*
         * We got a valid response that we were able to read in. Free the tlabel
         * that was used for this transfer.
         */
        hci1394_tlabel_free(async_handle->as_tlabel, &hcicmd->ac_tlabel);

        /*
         * Setup our return command status based on the RESP or ACK or SW error.
         * See the IEEE1394-1995 spec (6.2.4.10 on pg. 159) for more information
         * on response codes. See the OpenHCI 1.0 spec (table 3.2 on pg. 18) for
         * more information about ACK/EVT's. ac_status could have an IEEE1394
         * response in it, a 1394 EVT/ACK, or a special cmd1394 error for a
         * device error caught in SW (e.g. for a block read request that got a
         * quadlet read response). We use a special mask to separate the
         * ACK/EVT's from the responses (ASYNC_ARRESP_ACK_ERROR).
         */
        switch (hcicmd->ac_status) {
        case IEEE1394_RESP_COMPLETE:
                cmd_status = H1394_CMD_SUCCESS;
                break;
        case IEEE1394_RESP_DATA_ERROR:
                cmd_status = H1394_CMD_EDATA_ERROR;
                break;
        case IEEE1394_RESP_TYPE_ERROR:
                cmd_status = H1394_CMD_ETYPE_ERROR;
                break;
        case IEEE1394_RESP_CONFLICT_ERROR:
                cmd_status = H1394_CMD_ERSRC_CONFLICT;
                break;
        case IEEE1394_RESP_ADDRESS_ERROR:
                cmd_status = H1394_CMD_EADDR_ERROR;
                break;
        case H1394_CMD_EDEVICE_ERROR:
                cmd_status = H1394_CMD_EDEVICE_ERROR;
                break;
        case OHCI_ACK_DATA_ERROR | ASYNC_ARRESP_ACK_ERROR:
                cmd_status = H1394_CMD_EDATA_ERROR;
                break;
        case OHCI_ACK_TYPE_ERROR | ASYNC_ARRESP_ACK_ERROR:
                cmd_status = H1394_CMD_ETYPE_ERROR;
                break;
        case OHCI_EVT_UNDERRUN | ASYNC_ARRESP_ACK_ERROR:
        case OHCI_EVT_DATA_READ | ASYNC_ARRESP_ACK_ERROR:
        case OHCI_EVT_TCODE_ERR | ASYNC_ARRESP_ACK_ERROR:
                cmd_status = H1394_CMD_EUNKNOWN_ERROR;
                break;
        default:
                cmd_status = H1394_CMD_EUNKNOWN_ERROR;
                break;
        }

        /*
         * if we have already processed the atreq and put it on the pending Q
         * (normal case), tell the services layer it completed.
         */
        if (hcicmd->ac_state == HCI1394_CMD_STATE_PENDING) {
                /* Set state indicating that we are done with this cmd */
                hcicmd->ac_state = HCI1394_CMD_STATE_COMPLETED;

                /* tell the services lyaer the command has completed */
                h1394_cmd_is_complete(async_handle->as_drvinfo->di_sl_private,
                    hcicmd->ac_cmd, H1394_AT_REQ, cmd_status);

        /*
         * We have not seen the atreq status yet.  We will call
         * h1394_command_is_complete() in atreq_process() in case we did not get
         * an ack pending (target HW error -> this is based on real world
         * experience :-))
         */
        } else {
                /* Set state indicating that we are done with this cmd */
                hcicmd->ac_state = HCI1394_CMD_STATE_COMPLETED;

                /* save away the status for atreq_process() */
                hcicmd->ac_status = cmd_status;
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arreq_process()
 *    Process an arreq, if one has arrived. This is called during interrupt
 *    processing and will process an arreq that has arrived. It returns status
 *    if an arreq was processed so that the ISR knows that it needs to be
 *    called again to see if another ARREQ has arrived.
 */
int
hci1394_async_arreq_process(hci1394_async_handle_t async_handle,
    boolean_t *request_available)
{
        hci1394_async_cmd_t *hcicmd;
        uint32_t *addr;
        uint_t tcode;
        uint_t size;
        int status;


        ASSERT(async_handle != NULL);
        ASSERT(request_available != NULL);

        /*
         * See if there were any requests on ARREQ Q. A NULL means there
         * were no requests on the Q. This call does NOT free up space. We
         * need to do that later after we figure out how much space the
         * request takes up.
         */
        hci1394_q_ar_next(async_handle->as_arreq_q, &addr);
        if (addr == NULL) {
                *request_available = B_FALSE;
                return (DDI_SUCCESS);
        }

        /*
         * We got a request. Read the request into a 1394 framework command.
         * We could get a NULL for a command if we got a request with an error
         * (i.e. ARREQ ACK was not ack pending or ack complete). This would be a
         * successful read but with a NULL hcicmd returned. If we ever get a
         * DDI_FAILURE, we will shutdown.
         */
        *request_available = B_TRUE;
        status = hci1394_async_arreq_read(async_handle,
            (hci1394_basic_pkt_t *)addr, &tcode, &hcicmd, &size);
        if (status != DDI_SUCCESS) {
                h1394_error_detected(async_handle->as_drvinfo->di_sl_private,
                    H1394_SELF_INITIATED_SHUTDOWN, NULL);
                cmn_err(CE_WARN, "hci1394(%d): driver shutdown: "
                    "unrecoverable error interrupt detected",
                    async_handle->as_drvinfo->di_instance);
                hci1394_shutdown(async_handle->as_drvinfo->di_dip);
                return (DDI_FAILURE);
        }

        /* Free up the arreq Q space, we are done with the data */
        hci1394_q_ar_free(async_handle->as_arreq_q, size);

        /*
         * if we did not get a valid request (i.e. The ARREQ had a bad ACK
         * or something like that) we don't have anything else to do.  We will
         * say that we processed a request and will return successfully. We
         * still may have other requests on the Q.
         */
        if (hcicmd == NULL) {
                return (DDI_SUCCESS);
        }

        /*
         * If as_flushing_arreq is set, we do not want to send any requests up
         * to the Services Layer. We are flushing the ARREQ until we see a bus
         * reset token that matches the current bus generation. Free up the
         * alloc'd command and return success.
         */
        if (async_handle->as_flushing_arreq == B_TRUE) {
                hci1394_async_response_complete(async_handle, hcicmd->ac_cmd,
                    hcicmd->ac_priv);
                return (DDI_SUCCESS);
        }

        /*
         * We got a valid request that we were able to read in. Call into the
         * services layer based on the type of request.
         */
        switch (tcode) {
        case IEEE1394_TCODE_READ_QUADLET:
        case IEEE1394_TCODE_READ_BLOCK:
                h1394_read_request(async_handle->as_drvinfo->di_sl_private,
                    hcicmd->ac_cmd);
                break;
        case IEEE1394_TCODE_WRITE_QUADLET:
        case IEEE1394_TCODE_WRITE_BLOCK:
                h1394_write_request(async_handle->as_drvinfo->di_sl_private,
                    hcicmd->ac_cmd);
                break;
        case IEEE1394_TCODE_LOCK:
                h1394_lock_request(async_handle->as_drvinfo->di_sl_private,
                    hcicmd->ac_cmd);
                break;
        case IEEE1394_TCODE_PHY:
                /*
                 * OpenHCI only handles 1 PHY quadlet at a time. If a selfid
                 * packet was received with multiple quadlets, we will treat
                 * each quadlet as a separate call.  We do not notify the
                 * services layer through the normal command interface, we will
                 * treat it like a command internally and then free up the
                 * command ourselves when we are done with it.
                 */
                h1394_phy_packet(async_handle->as_drvinfo->di_sl_private,
                    &hcicmd->ac_cmd->cmd_u.q.quadlet_data, 1,
                    hcicmd->ac_priv->recv_tstamp);
                /* free alloc'd command */
                hci1394_async_response_complete(async_handle, hcicmd->ac_cmd,
                    hcicmd->ac_priv);
                break;
        default:
                /* free alloc'd command */
                hci1394_async_response_complete(async_handle, hcicmd->ac_cmd,
                    hcicmd->ac_priv);
                break;
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_atresp_process()
 *    Process an atresp, if one has completed. This is called during interrupt
 *    processing and will process a completed atresp. It returns status if an
 *    atresp was processed so that the ISR knows that it needs to be called
 *    again to see if another ATRESP has completed. flush_q set to B_TRUE tells
 *    this routine to process all commands regardless of their completion
 *    status.  This is used during bus reset processing to remove all commands
 *    from the Q.
 */
int
hci1394_async_atresp_process(hci1394_async_handle_t async_handle,
    boolean_t flush_q, boolean_t *response_available)
{
        hci1394_async_cmd_t *hcicmd;
        hci1394_q_cmd_t *qcmd;
        int cmd_status;


        ASSERT(async_handle != NULL);
        ASSERT(response_available != NULL);

        /*
         * Get the next ATRESP that has completed (if one has). Space is free'd
         * up in atresp_q and atresp_data_q as part of this function call.
         */
        hci1394_q_at_next(async_handle->as_atresp_q, flush_q, &qcmd);

        /*
         * See if there were anymore requests on ATRESP Q. A NULL means there
         * were no completed commands left on the Q.
         */
        if (qcmd == NULL) {
                *response_available = B_FALSE;
                return (DDI_SUCCESS);
        }

        /* There is a completed ATRESP, setup the HAL command pointer */
        *response_available = B_TRUE;
        hcicmd = (hci1394_async_cmd_t *)qcmd->qc_arg;

        /* save away the command completed timestamp for the services layer */
        hcicmd->ac_priv->ack_tstamp = qcmd->qc_timestamp;

        /*
         * setup our return command status based on the ACK from the HW. See the
         * OpenHCI 1.0 spec (table 3.2 on pg. 18) for more information about
         * these ACK/EVT's.
         */
        switch (qcmd->qc_status) {
        case OHCI_ACK_COMPLETE:
                cmd_status = H1394_CMD_SUCCESS;
                break;

        /*
         * we can get a nostatus during a bus reset (i.e. we shutdown the AT
         * engine before it flushed all the commands)
         */
        case OHCI_EVT_FLUSHED:
        case OHCI_EVT_NO_STATUS:
                cmd_status = H1394_CMD_EBUSRESET;
                break;

        case OHCI_EVT_MISSING_ACK:
        case OHCI_EVT_TIMEOUT:
                cmd_status = H1394_CMD_ETIMEOUT;
                break;

        case OHCI_ACK_BUSY_X:
        case OHCI_ACK_BUSY_A:
        case OHCI_ACK_BUSY_B:
                cmd_status = H1394_CMD_EDEVICE_BUSY;
                break;

        case OHCI_ACK_TARDY:
                cmd_status = H1394_CMD_EDEVICE_POWERUP;
                break;

        case OHCI_ACK_DATA_ERROR:
                cmd_status = H1394_CMD_EDATA_ERROR;
                break;

        case OHCI_ACK_TYPE_ERROR:
                cmd_status = H1394_CMD_ETYPE_ERROR;
                break;

        case OHCI_ACK_CONFLICT_ERROR:
                cmd_status = H1394_CMD_ERSRC_CONFLICT;
                break;

        case OHCI_ACK_ADDRESS_ERROR:
                cmd_status = H1394_CMD_EADDR_ERROR;
                break;

        case OHCI_EVT_UNKNOWN:
                cmd_status = H1394_CMD_EUNKNOWN_ERROR;
                break;

        case OHCI_EVT_UNDERRUN:
        case OHCI_EVT_DATA_READ:
        case OHCI_EVT_TCODE_ERR:
        case OHCI_EVT_DESCRIPTOR_READ:
        default:
                cmd_status = H1394_CMD_EUNKNOWN_ERROR;
                break;
        }

        /* tell the services layer that the command has completed */
        h1394_cmd_is_complete(async_handle->as_drvinfo->di_sl_private,
            hcicmd->ac_cmd, H1394_AT_RESP, cmd_status);

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arresp_read()
 *    Read ARRESP in from memory into 1394 Framework command. We read the tcode
 *    which tells us which kind of arresp the packet is, get the size of the
 *    response, read in the sender, tlabel, and response code, and then
 *    lookup the command based on the sender and tlabel. Once we get the command
 *    (corresponding to the ATREQ), we will copy the rest of the response into
 *    that command.
 *
 *    The only time this routine should return DDI_FAILURE is if it was unable
 *    to maintain a good state in the ARRESP Q (i.e. an unknown response was
 *    received and we can not cleanup after it.)  If we detect a recoverable
 *    error, and it doesn't make sense to pass the response up to the Services
 *    Layer, we should return DDI_SUCCESS with hcicmd = NULL.
 */
static int
hci1394_async_arresp_read(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt,  uint_t *tcode, hci1394_async_cmd_t **hcicmd,
    uint_t *size)
{
        hci1394_tlabel_info_t ac_tlabel;
        h1394_cmd_priv_t *cmd_priv;
        cmd1394_cmd_t *cmd;
        uint32_t *status_addr;
        uint_t data_length;
        uint32_t quadlet;
        void *command;
        uint_t rcode;
        uint_t ack;
        int status;


        ASSERT(async_handle != NULL);
        ASSERT(pkt != NULL);
        ASSERT(tcode != NULL);
        ASSERT(hcicmd != NULL);
        ASSERT(size != NULL);

        /* read in the arresp tcode */
        quadlet = hci1394_q_ar_get32(async_handle->as_arresp_q, &pkt->q1);
        *tcode = HCI1394_DESC_TCODE_GET(quadlet);

        /* Get the size of the arresp */
        status = hci1394_async_arresp_size_get(*tcode,
            async_handle->as_arresp_q, &pkt->q1, size);
        if (status != DDI_SUCCESS) {
                return (DDI_FAILURE);
        }

        /* Read in the tlabel, destination, and rcode (response code) */
        quadlet = hci1394_q_ar_get32(async_handle->as_arresp_q, &pkt->q1);
        ac_tlabel.tbi_tlabel = HCI1394_DESC_TLABEL_GET(quadlet);
        quadlet = hci1394_q_ar_get32(async_handle->as_arresp_q, &pkt->q2);
        ac_tlabel.tbi_destination = HCI1394_DESC_DESTID_GET(quadlet);
        rcode = HCI1394_DESC_RCODE_GET(quadlet);

        /* Lookup the ATREQ framework command this response goes with */
        hci1394_tlabel_lookup(async_handle->as_tlabel, &ac_tlabel, &command);

        /*
         * If there is not a cooresponding ATREQ command, this is an error. We
         * will ignore this response but still return success so we cleanup
         * after it and go on with other arresp's. This could happend if a
         * response was sent after the command has timed out or if the target
         * device is misbehaving. (we have seen both cases)
         */
        *hcicmd = (hci1394_async_cmd_t *)command;
        if ((*hcicmd) == NULL) {
                return (DDI_SUCCESS);
        }

        /*
         * copy the response code into the hal private command space. Setup
         * shortcuts to the 1394 framework command (cmd) and the HAL/SL private
         * area (cmd_priv). A command is made up of 4 parts. There is the public
         * part which is accessable to the target driver, there is the Services
         * Layer private part which is only accessible to the services layer,
         * there is the SL/HAL private area which is where the SL and HAL share
         * information about a particular command, and there is the HAL private
         * area where we keep track of our command specific state information.
         */
        (*hcicmd)->ac_status = rcode;
        cmd = (*hcicmd)->ac_cmd;
        cmd_priv = (*hcicmd)->ac_priv;

        /*
         * Calculate the address where the status of the ARRESP and timestamp is
         * kept at.  It is the last quadlet in the response. Save away the
         * timestamp.
         */
        status_addr = (uint32_t *)((uintptr_t)pkt + (uintptr_t)*size -
            (uintptr_t)IEEE1394_QUADLET);
        quadlet = hci1394_q_ar_get32(async_handle->as_arresp_q, status_addr);
        cmd_priv->recv_tstamp = HCI1394_DESC_TIMESTAMP_GET(quadlet);

        /*
         * if we did not get an ACK_COMPLETE, we will use the ack error instead
         * of the response in the packet for our status. We use special mask to
         * separate the reponses from the ACKs (ASYNC_ARRESP_ACK_ERROR). We will
         * return success with hcicmd set to the command so that this error gets
         * sent up to the Services Layer.
         */
        ack = HCI1394_DESC_EVT_GET(quadlet);
        if (ack != OHCI_ACK_COMPLETE) {
                /* use the ack error instead of rcode for the command status */
                (*hcicmd)->ac_status = ack | ASYNC_ARRESP_ACK_ERROR;
                return (DDI_SUCCESS);
        }

        /*
         * If we get to this point we have gotten a valid ACK on the response
         * and have matched up the response with an ATREQ. Now we check the
         * response code. If it is not resp_complete, we do not have anything
         * left to look at in the response. Return successfully.
         */
        if (rcode != IEEE1394_RESP_COMPLETE) {
                return (DDI_SUCCESS);
        }

        /*
         * Read the rest of the response (based on which kind of response it is)
         * into the 1394 framework command. In all of the different responses,
         * we check to make sure the response matches the original request. We
         * originally did not have this check but found a device or two which
         * did not behave very well and would cause us to corrupt our commands.
         * Now we check :-) We will return success when we get this error since
         * we can recover from it.
         */
        switch (*tcode) {
        case IEEE1394_TCODE_WRITE_RESP:
                /*
                 * make sure the ATREQ was a quadlet/block write. The same
                 * response is sent back for those two type of ATREQs.
                 */
                if ((cmd->cmd_type != CMD1394_ASYNCH_WR_QUAD) &&
                    (cmd->cmd_type != CMD1394_ASYNCH_WR_BLOCK)) {
                        (*hcicmd)->ac_status = H1394_CMD_EDEVICE_ERROR;
                        return (DDI_SUCCESS);
                }
                break;

        case IEEE1394_TCODE_READ_QUADLET_RESP:
                /* make sure the ATREQ was a quadlet read */
                if (cmd->cmd_type != CMD1394_ASYNCH_RD_QUAD) {
                        (*hcicmd)->ac_status = H1394_CMD_EDEVICE_ERROR;
                        return (DDI_SUCCESS);
                }

                /*
                 * read the quadlet read response in.  Data is treated as a byte
                 * stream.
                 */
                hci1394_q_ar_rep_get8(async_handle->as_arresp_q,
                    (uint8_t *)&cmd->cmd_u.q.quadlet_data,
                    (uint8_t *)&pkt->q4, IEEE1394_QUADLET);
                break;

        case IEEE1394_TCODE_READ_BLOCK_RESP:
                /* make sure the ATREQ was a block read */
                if (cmd->cmd_type != CMD1394_ASYNCH_RD_BLOCK) {
                        (*hcicmd)->ac_status = H1394_CMD_EDEVICE_ERROR;
                        return (DDI_SUCCESS);
                }

                /*
                 * read in the data length.  Make sure the data length is the
                 * same size as the read block request size that went out.
                 */
                quadlet = hci1394_q_ar_get32(async_handle->as_arresp_q,
                    &pkt->q4);
                data_length = HCI1394_DESC_DATALEN_GET(quadlet);
                if (data_length != cmd_priv->mblk.length) {
                        (*hcicmd)->ac_status = H1394_CMD_EDEVICE_ERROR;
                        return (DDI_SUCCESS);
                }

                /* Copy the read block data into the command mblk */
                hci1394_q_ar_copy_to_mblk(async_handle->as_arresp_q,
                    (uint8_t *)&pkt->q5, &cmd_priv->mblk);
                break;

        case IEEE1394_TCODE_LOCK_RESP:
                /* read in the data length */
                quadlet = hci1394_q_ar_get32(async_handle->as_arresp_q,
                    &pkt->q4);
                data_length = HCI1394_DESC_DATALEN_GET(quadlet);

                if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_32) {
                        /*
                         * read in the data length.  Make sure the data length
                         * is the valid for a lock32 response (1 quadlet)
                         */
                        if (data_length != IEEE1394_QUADLET) {
                                (*hcicmd)->ac_status = H1394_CMD_EDEVICE_ERROR;
                                return (DDI_SUCCESS);
                        }

                        /*
                         * read the lock32 response in. Data is treated as a
                         * byte stream unless it is an arithmetic lock
                         * operation. In that case we treat data like a 32-bit
                         * word.
                         */
                        hci1394_q_ar_rep_get8(async_handle->as_arresp_q,
                            (uint8_t *)&cmd->cmd_u.l32.old_value,
                            (uint8_t *)&pkt->q5, IEEE1394_QUADLET);
                        cmd->cmd_u.l32.old_value = HCI1394_ARITH_LOCK_SWAP32(
                            cmd->cmd_u.l32.lock_type, cmd->cmd_u.l32.old_value);

                } else if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_64) {
                        /*
                         * read in the data length.  Make sure the data length
                         * is the valid for a lock64 response (1 octlet)
                         */
                        if (data_length != IEEE1394_OCTLET) {
                                (*hcicmd)->ac_status = H1394_CMD_EDEVICE_ERROR;
                                return (DDI_SUCCESS);
                        }

                        /*
                         * read the lock64 response in. Data is treated as a
                         * byte stream unless it is an arithmetic lock
                         * operation. In that case we treat data like a 64-bit
                         * word.
                         */
                        hci1394_q_ar_rep_get8(async_handle->as_arresp_q,
                            (uint8_t *)&cmd->cmd_u.l64.old_value,
                            (uint8_t *)&pkt->q5, IEEE1394_OCTLET);
                        cmd->cmd_u.l64.old_value = HCI1394_ARITH_LOCK_SWAP64(
                            cmd->cmd_u.l64.lock_type, cmd->cmd_u.l64.old_value);

                /*
                 * we sent out a request that was NOT a lock request and got
                 * back a lock response.
                 */
                } else {
                        (*hcicmd)->ac_status = H1394_CMD_EDEVICE_ERROR;
                        return (DDI_SUCCESS);
                }
                break;

        default:
                /* we got a tcode that we don't know about. Return error */
                return (DDI_FAILURE);
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arreq_read()
 *    Read ARREQ in from memory into a 1394 Framework command. Allocate a 1394
 *    framework command, read in the ARREQ, and before passing it up to the
 *    services layer, see if it was a valid broadcast request.
 *
 *    The only time this routine should return DDI_FAILURE is if it was unable
 *    to maintain a good state in the ARREQ Q (i.e. an unknown request was
 *    received and we can not cleanup after it.)  If we detect a recoverable
 *    error we should return DDI_SUCCESS with hcicmd = NULL.
 */
static int
hci1394_async_arreq_read(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, uint_t *tcode, hci1394_async_cmd_t **hcicmd,
    uint_t *size)
{
        h1394_cmd_priv_t *cmd_priv;
        boolean_t is_reset_token;
        cmd1394_cmd_t *cmd;
        uint32_t quadlet;
        int status;


        ASSERT(async_handle != NULL);
        ASSERT(pkt != NULL);
        ASSERT(tcode != NULL);
        ASSERT(hcicmd != NULL);
        ASSERT(size != NULL);

        /* read in the arresp tcode */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q1);
        *tcode = HCI1394_DESC_TCODE_GET(quadlet);

        /*
         * Allocated 1394 framework command.  The Services layer takes care of
         * cacheing commands. This is called during interrupt processing so we
         * do not want to sleep.
         */
        status = h1394_alloc_cmd(async_handle->as_drvinfo->di_sl_private,
            H1394_ALLOC_CMD_NOSLEEP, &cmd, &cmd_priv);
        if (status != DDI_SUCCESS) {
                return (DDI_FAILURE);
        }

        /* Initialize the HAL private command info */
        hci1394_async_hcicmd_init(async_handle, cmd, cmd_priv, hcicmd);

        /*
         * There are two generations in the command structure, one in the public
         * space and one in the HAL/SL private shared space. We need to fill in
         * both.  We only use the private one internally.
         */
        cmd_priv->bus_generation = async_handle->as_drvinfo->di_gencnt;
        cmd->bus_generation = async_handle->as_drvinfo->di_gencnt;

        /*
         * Read the request (based on which kind of request it is) into the 1394
         * framework command.
         */
        switch (*tcode) {
        case IEEE1394_TCODE_READ_QUADLET:
                /*
                 * We got a ARREQ quadlet read request. Read in the packet.
                 * If there is a problem with the packet (i.e. we don't get
                 * DDI_SUCCESS), we will free up the command and return NULL in
                 * hcicmd to indicate that we did not get a valid ARREQ to
                 * process.
                 */
                status = hci1394_async_arreq_read_qrd(async_handle, pkt,
                    *hcicmd, size);
                if (status != DDI_SUCCESS) {
                        hci1394_async_response_complete(async_handle, cmd,
                            cmd_priv);
                        *hcicmd = NULL;
                        return (DDI_SUCCESS);
                }
                break;

        case IEEE1394_TCODE_WRITE_QUADLET:
                /*
                 * We got a ARREQ quadlet write request. Read in the packet.
                 * If there is a problem with the packet (i.e. we don't get
                 * DDI_SUCCESS), we will free up the command and return NULL in
                 * hcicmd to indicate that we did not get a valid ARREQ to
                 * process.
                 */
                status = hci1394_async_arreq_read_qwr(async_handle, pkt,
                    *hcicmd, size);
                if (status != DDI_SUCCESS) {
                        hci1394_async_response_complete(async_handle, cmd,
                            cmd_priv);
                        *hcicmd = NULL;
                        return (DDI_SUCCESS);
                }
                break;

        case IEEE1394_TCODE_READ_BLOCK:
                /*
                 * We got a ARREQ block read request. Read in the packet.
                 * If there is a problem with the packet (i.e. we don't get
                 * DDI_SUCCESS), we will free up the command and return NULL in
                 * hcicmd to indicate that we did not get a valid ARREQ to
                 * process.
                 */
                status = hci1394_async_arreq_read_brd(async_handle, pkt,
                    *hcicmd, size);
                if (status != DDI_SUCCESS) {
                        hci1394_async_response_complete(async_handle, cmd,
                            cmd_priv);
                        *hcicmd = NULL;
                        return (DDI_SUCCESS);
                }
                break;

        case IEEE1394_TCODE_WRITE_BLOCK:
                /*
                 * We got a ARREQ block write request. Read in the packet.
                 * If there is a problem with the packet (i.e. we don't get
                 * DDI_SUCCESS), we will free up the command and return NULL in
                 * hcicmd to indicate that we did not get a valid ARREQ to
                 * process.
                 */
                status = hci1394_async_arreq_read_bwr(async_handle, pkt,
                    *hcicmd, size);
                if (status != DDI_SUCCESS) {
                        hci1394_async_response_complete(async_handle, cmd,
                            cmd_priv);
                        *hcicmd = NULL;
                        return (DDI_SUCCESS);
                }
                break;

        case IEEE1394_TCODE_LOCK:
                /*
                 * We got a ARREQ lock request. Read in the packet.
                 * If there is a problem with the packet (i.e. we don't get
                 * DDI_SUCCESS), we will free up the command and return NULL in
                 * hcicmd to indicate that we did not get a valid ARREQ to
                 * process.
                 */
                status = hci1394_async_arreq_read_lck(async_handle, pkt,
                    *hcicmd, size);
                if (status != DDI_SUCCESS) {
                        hci1394_async_response_complete(async_handle, cmd,
                            cmd_priv);
                        *hcicmd = NULL;
                        return (DDI_SUCCESS);
                }
                break;

        case IEEE1394_TCODE_PHY:
                /*
                 * We got a PHY packet in the ARREQ buffer. Read in the packet.
                 * If there is a problem with the packet (i.e. we don't get
                 * DDI_SUCCESS), we will free up the command and return NULL in
                 * hcicmd to indicate that we did not get a valid ARREQ to
                 * process.
                 */
                status = hci1394_async_arreq_read_phy(async_handle, pkt,
                    *hcicmd, size, &is_reset_token);
                if (status != DDI_SUCCESS) {
                        hci1394_async_response_complete(async_handle, cmd,
                            cmd_priv);
                        *hcicmd = NULL;
                        return (DDI_SUCCESS);
                }

                /*
                 * If we got a bus reset token, free up the command and return
                 * NULL in hcicmd to indicate that we did not get a valid ARREQ
                 * to process.
                 */
                if (is_reset_token == B_TRUE) {
                        hci1394_async_response_complete(async_handle, cmd,
                            cmd_priv);
                        *hcicmd = NULL;
                        return (DDI_SUCCESS);
                }
                break;

        default:
                /* we got a tcode that we don't know about. Return error */
                return (DDI_FAILURE);
        }

        /*
         * If this command was broadcast and it was not a write, drop the
         * command since it's an invalid request. We will free up the command
         * and return NULL in hcicmd to indicate that we did not get a valid
         * ARREQ to process.
         */
        if ((((*hcicmd)->ac_dest & IEEE1394_NODE_NUM_MASK) ==
            IEEE1394_BROADCAST_NODEID) && ((*tcode !=
            IEEE1394_TCODE_WRITE_QUADLET) && (*tcode !=
            IEEE1394_TCODE_WRITE_BLOCK))) {
                hci1394_async_response_complete(async_handle, cmd, cmd_priv);
                *hcicmd = NULL;
                return (DDI_SUCCESS);

        /*
         * It is a valid broadcast command, set that field in the public
         * command structure.
         */
        } else if ((((*hcicmd)->ac_dest & IEEE1394_NODE_NUM_MASK) ==
            IEEE1394_BROADCAST_NODEID)) {
                cmd->broadcast = 1;
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arreq_read_qrd()
 *    Read ARREQ quadlet read into the 1394 Framework command. This routine will
 *    return DDI_FAILURE if it was not able to read the request succesfully.
 */
static int
hci1394_async_arreq_read_qrd(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size)
{
        h1394_cmd_priv_t *cmd_priv;
        cmd1394_cmd_t *cmd;
        uint32_t quadlet;


        ASSERT(async_handle != NULL);
        ASSERT(pkt != NULL);
        ASSERT(hcicmd != NULL);
        ASSERT(size != NULL);

        /* Setup shortcuts, command type, and size of request */
        cmd = hcicmd->ac_cmd;
        cmd_priv = hcicmd->ac_priv;
        cmd->cmd_type = CMD1394_ASYNCH_RD_QUAD;
        *size = DESC_SZ_AR_READQUAD_REQ;

        /*
         * read in the ARREQ ACK/EVT, the speed, the time we received it, and
         * calculate the ATRESP timeout for when we send it.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q4);
        hcicmd->ac_status = HCI1394_DESC_EVT_GET(quadlet);
        cmd_priv->speed = HCI1394_DESC_AR_SPD_GET(quadlet);
        cmd_priv->recv_tstamp = HCI1394_DESC_TIMESTAMP_GET(quadlet);
        hcicmd->ac_qcmd.qc_timestamp = hci1394_async_timeout_calc(async_handle,
            cmd_priv->recv_tstamp);

        /*
         * if the ARREQ ACK was bad, we were unable to successfully read in this
         * request.  Return failure.
         */
        if ((hcicmd->ac_status != OHCI_ACK_COMPLETE) &&
            (hcicmd->ac_status != OHCI_ACK_PENDING)) {
                return (DDI_FAILURE);
        }

        /*
         * Read in the tlabel and destination. We don't use an mblk for this
         * request.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q1);
        hcicmd->ac_dest = HCI1394_DESC_DESTID_GET(quadlet);
        hcicmd->ac_tlabel.tbi_tlabel = HCI1394_DESC_TLABEL_GET(quadlet);
        hcicmd->ac_mblk_alloc = B_FALSE;

        /*
         * Read in the sender so we know who to send the ATRESP to and read in
         * the 1394 48-bit address for this request.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q2);
        cmd->nodeID = HCI1394_DESC_SRCID_GET(quadlet);
        cmd->cmd_addr = HCI1394_TO_ADDR_HI(quadlet);
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q3);
        cmd->cmd_addr |= HCI1394_TO_ADDR_LO(quadlet);

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arreq_read_qwr()
 *    Read ARREQ quadlet write into the 1394 Framework command. This routine
 *    will return DDI_FAILURE if it was not able to read the request
 *    succesfully.
 */
static int
hci1394_async_arreq_read_qwr(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size)
{
        h1394_cmd_priv_t *cmd_priv;
        cmd1394_cmd_t *cmd;
        uint32_t quadlet;


        ASSERT(async_handle != NULL);
        ASSERT(pkt != NULL);
        ASSERT(hcicmd != NULL);
        ASSERT(size != NULL);

        /* Setup shortcuts, command type, and size of request */
        cmd = hcicmd->ac_cmd;
        cmd_priv = hcicmd->ac_priv;
        cmd->cmd_type = CMD1394_ASYNCH_WR_QUAD;
        *size = DESC_SZ_AR_WRITEQUAD_REQ;

        /*
         * read in the ARREQ ACK/EVT, the speed, the time we received it, and
         * calculate the ATRESP timeout for when we send it.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q5);
        hcicmd->ac_status = HCI1394_DESC_EVT_GET(quadlet);
        cmd_priv->speed = HCI1394_DESC_AR_SPD_GET(quadlet);
        cmd_priv->recv_tstamp = HCI1394_DESC_TIMESTAMP_GET(quadlet);
        hcicmd->ac_qcmd.qc_timestamp = hci1394_async_timeout_calc(async_handle,
            cmd_priv->recv_tstamp);

        /*
         * if the ARREQ ACK was bad, we were unable to successfully read in this
         * request.  Return failure.
         */
        if ((hcicmd->ac_status != OHCI_ACK_COMPLETE) &&
            (hcicmd->ac_status != OHCI_ACK_PENDING)) {
                return (DDI_FAILURE);
        }

        /*
         * Read in the tlabel and destination. We don't use an mblk for this
         * request.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q1);
        hcicmd->ac_dest = HCI1394_DESC_DESTID_GET(quadlet);
        hcicmd->ac_tlabel.tbi_tlabel = HCI1394_DESC_TLABEL_GET(quadlet);
        hcicmd->ac_mblk_alloc = B_FALSE;

        /*
         * Read in the sender so we know who to send the ATRESP to. Read in
         * the 1394 48-bit address for this request. Copy the data quadlet into
         * the command.  The data quadlet is treated like a byte stream.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q2);
        cmd->nodeID = HCI1394_DESC_SRCID_GET(quadlet);
        cmd->cmd_addr = HCI1394_TO_ADDR_HI(quadlet);
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q3);
        cmd->cmd_addr |= HCI1394_TO_ADDR_LO(quadlet);
        hci1394_q_ar_rep_get8(async_handle->as_arreq_q,
            (uint8_t *)&cmd->cmd_u.q.quadlet_data, (uint8_t *)&pkt->q4,
            IEEE1394_QUADLET);

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arreq_read_brd()
 *    Read ARREQ block read into the 1394 Framework command. This routine will
 *    return DDI_FAILURE if it was not able to read the request succesfully.
 */
static int
hci1394_async_arreq_read_brd(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size)
{
        h1394_cmd_priv_t *cmd_priv;
        cmd1394_cmd_t *cmd;
        uint32_t quadlet;


        ASSERT(async_handle != NULL);
        ASSERT(pkt != NULL);
        ASSERT(hcicmd != NULL);
        ASSERT(size != NULL);

        /* Setup shortcuts, command type, and size of request */
        cmd = hcicmd->ac_cmd;
        cmd_priv = hcicmd->ac_priv;
        cmd->cmd_type = CMD1394_ASYNCH_RD_BLOCK;
        *size = DESC_SZ_AR_READBLOCK_REQ;

        /*
         * read in the ARREQ ACK/EVT, the speed, the time we received it, and
         * calculate the ATRESP timeout for when we send it.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q5);
        hcicmd->ac_status = HCI1394_DESC_EVT_GET(quadlet);
        cmd_priv->speed = HCI1394_DESC_AR_SPD_GET(quadlet);
        cmd_priv->recv_tstamp = HCI1394_DESC_TIMESTAMP_GET(quadlet);
        hcicmd->ac_qcmd.qc_timestamp = hci1394_async_timeout_calc(async_handle,
            cmd_priv->recv_tstamp);

        /*
         * if the ARREQ ACK was bad, we were unable to successfully read in this
         * request.  Return failure.
         */
        if ((hcicmd->ac_status != OHCI_ACK_COMPLETE) &&
            (hcicmd->ac_status != OHCI_ACK_PENDING)) {
                return (DDI_FAILURE);
        }

        /* Read in the tlabel and destination */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q1);
        hcicmd->ac_dest = HCI1394_DESC_DESTID_GET(quadlet);
        hcicmd->ac_tlabel.tbi_tlabel = HCI1394_DESC_TLABEL_GET(quadlet);

        /*
         * Read in the sender so we know who to send the ATRESP to. Read in
         * the 1394 48-bit address for this request. Read in the block data size
         * and allocate an mblk of that size.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q2);
        cmd->nodeID = HCI1394_DESC_SRCID_GET(quadlet);
        cmd->cmd_addr = HCI1394_TO_ADDR_HI(quadlet);
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q3);
        cmd->cmd_addr |= HCI1394_TO_ADDR_LO(quadlet);
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q4);
        cmd->cmd_u.b.blk_length = HCI1394_DESC_DATALEN_GET(quadlet);
        cmd->cmd_u.b.data_block = allocb(cmd->cmd_u.b.blk_length, 0);
        if (cmd->cmd_u.b.data_block == NULL) {
                return (DDI_FAILURE);
        }
        hcicmd->ac_mblk_alloc = B_TRUE;

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arreq_read_bwr()
 *    Read ARREQ block write into the 1394 Framework command. This routine will
 *    return DDI_FAILURE if it was not able to read the request succesfully.
 */
static int
hci1394_async_arreq_read_bwr(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size)
{
        h1394_cmd_priv_t *cmd_priv;
        uint32_t *local_addr;
        cmd1394_cmd_t *cmd;
        uint32_t quadlet;


        ASSERT(async_handle != NULL);
        ASSERT(pkt != NULL);
        ASSERT(hcicmd != NULL);
        ASSERT(size != NULL);

        /*
         * Setup shortcuts, command type, and size of request. The size of the
         * request is in quadlets, therefore we need to make sure we count in
         * the padding when figureing out the size (i.e. data may be in bytes
         * but the HW always pads to quadlets)
         */
        cmd = hcicmd->ac_cmd;
        cmd_priv = hcicmd->ac_priv;
        cmd->cmd_type = CMD1394_ASYNCH_WR_BLOCK;
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q4);
        cmd->cmd_u.b.blk_length = HCI1394_DESC_DATALEN_GET(quadlet);
        *size = DESC_SZ_AR_WRITEBLOCK_REQ +
            HCI1394_ALIGN_QUAD(cmd->cmd_u.b.blk_length);

        /*
         * read in the ARREQ ACK/EVT, the speed, the time we received it, and
         * calculate the ATRESP timeout for when we send it. The status word is
         * the last quadlet in the packet.
         */
        local_addr = (uint32_t *)(((uintptr_t)(&pkt->q5)) +
            ((uintptr_t)HCI1394_ALIGN_QUAD(cmd->cmd_u.b.blk_length)));
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, local_addr);
        hcicmd->ac_status = HCI1394_DESC_EVT_GET(quadlet);
        cmd_priv->speed = HCI1394_DESC_AR_SPD_GET(quadlet);
        cmd_priv->recv_tstamp = HCI1394_DESC_TIMESTAMP_GET(quadlet);
        hcicmd->ac_qcmd.qc_timestamp = hci1394_async_timeout_calc(async_handle,
            cmd_priv->recv_tstamp);

        /*
         * if the ARREQ ACK was bad, we were unable to successfully read in this
         * request.  Return failure.
         */
        if ((hcicmd->ac_status != OHCI_ACK_COMPLETE) &&
            (hcicmd->ac_status != OHCI_ACK_PENDING)) {
                return (DDI_FAILURE);
        }

        /* Read in the tlabel and destination */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q1);
        hcicmd->ac_dest = HCI1394_DESC_DESTID_GET(quadlet);
        hcicmd->ac_tlabel.tbi_tlabel = HCI1394_DESC_TLABEL_GET(quadlet);

        /*
         * Read in the sender so we know who to send the ATRESP to. Read in
         * the 1394 48-bit address for this request. Read in the block data size
         * and allocate an mblk of that size.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q2);
        cmd->nodeID = HCI1394_DESC_SRCID_GET(quadlet);
        cmd->cmd_addr = HCI1394_TO_ADDR_HI(quadlet);
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q3);
        cmd->cmd_addr |= HCI1394_TO_ADDR_LO(quadlet);
        cmd->cmd_u.b.data_block = allocb(cmd->cmd_u.b.blk_length, 0);
        if (cmd->cmd_u.b.data_block == NULL) {
                return (DDI_FAILURE);
        }
        hcicmd->ac_mblk_alloc = B_TRUE;

        /* Copy ARREQ write data into mblk_t */
        hci1394_q_ar_rep_get8(async_handle->as_arreq_q,
            (uint8_t *)cmd->cmd_u.b.data_block->b_wptr,
            (uint8_t *)&pkt->q5, cmd->cmd_u.b.blk_length);

        /* Update mblk_t wptr */
        cmd->cmd_u.b.data_block->b_wptr += cmd->cmd_u.b.blk_length;

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arreq_read_lck()
 *    Read ARREQ lock request into the 1394 Framework command. This routine will
 *    return DDI_FAILURE if it was not able to read the request succesfully.
 */
static int
hci1394_async_arreq_read_lck(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size)
{
        h1394_cmd_priv_t *cmd_priv;
        uint32_t *local_addr;
        cmd1394_cmd_t *cmd;
        uint8_t *data_addr;
        uint32_t quadlet;
        uint32_t length;


        ASSERT(async_handle != NULL);
        ASSERT(pkt != NULL);
        ASSERT(hcicmd != NULL);
        ASSERT(size != NULL);

        /*
         * Setup shortcuts, command type, and size of request. The size of the
         * request is in quadlets, therefore we need to make sure we count in
         * the padding when figuring out the size (i.e. data may be in bytes
         * but the HW always pads to quadlets)
         */
        cmd = hcicmd->ac_cmd;
        cmd_priv = hcicmd->ac_priv;
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q4);
        length = HCI1394_DESC_DATALEN_GET(quadlet);
        *size = DESC_SZ_AR_LOCK_REQ + HCI1394_ALIGN_QUAD(length);

        /* make sure the length is a valid lock request length */
        if (length == DESC_TWO_QUADS) {
                cmd->cmd_type = CMD1394_ASYNCH_LOCK_32;
                cmd->cmd_u.l32.lock_type = HCI1394_DESC_EXTTCODE_GET(quadlet);
        } else if (length == DESC_TWO_OCTLETS) {
                cmd->cmd_type = CMD1394_ASYNCH_LOCK_64;
                cmd->cmd_u.l64.lock_type = HCI1394_DESC_EXTTCODE_GET(quadlet);
        } else {
                return (DDI_FAILURE);
        }

        /*
         * read in the ARREQ ACK/EVT, the speed, the time we received it, and
         * calculate the ATRESP timeout for when we send it. The status word is
         * the last quadlet in the packet.
         */
        local_addr = (uint32_t *)(((uintptr_t)(&pkt->q5)) +
            ((uintptr_t)HCI1394_ALIGN_QUAD(length)));
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, local_addr);
        hcicmd->ac_status = HCI1394_DESC_EVT_GET(quadlet);
        cmd_priv->speed = HCI1394_DESC_AR_SPD_GET(quadlet);
        cmd_priv->recv_tstamp = HCI1394_DESC_TIMESTAMP_GET(quadlet);
        hcicmd->ac_qcmd.qc_timestamp = hci1394_async_timeout_calc(async_handle,
            cmd_priv->recv_tstamp);

        /*
         * if the ARREQ ACK was bad, we were unable to successfully read in this
         * request.  Return failure.
         */
        if ((hcicmd->ac_status != OHCI_ACK_COMPLETE) &&
            (hcicmd->ac_status != OHCI_ACK_PENDING)) {
                return (DDI_FAILURE);
        }

        /* Read in the tlabel and destination */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q1);
        hcicmd->ac_dest = HCI1394_DESC_DESTID_GET(quadlet);
        hcicmd->ac_tlabel.tbi_tlabel = HCI1394_DESC_TLABEL_GET(quadlet);
        hcicmd->ac_mblk_alloc = B_FALSE;

        /*
         * Read in the sender so we know who to send the ATRESP to. Read in
         * the 1394 48-bit address for this request.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q2);
        cmd->nodeID = HCI1394_DESC_SRCID_GET(quadlet);
        cmd->cmd_addr = HCI1394_TO_ADDR_HI(quadlet);
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q3);
        cmd->cmd_addr |= HCI1394_TO_ADDR_LO(quadlet);

        /* Copy ARREQ lock data into 1394 framework command */
        if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_32) {
                data_addr = (uint8_t *)&pkt->q5;
                hci1394_q_ar_rep_get8(async_handle->as_arreq_q,
                    (uint8_t *)&cmd->cmd_u.l32.arg_value, data_addr,
                    IEEE1394_QUADLET);
                data_addr = (uint8_t *)((uintptr_t)data_addr +
                    (uintptr_t)IEEE1394_QUADLET);
                hci1394_q_ar_rep_get8(async_handle->as_arreq_q,
                    (uint8_t *)&cmd->cmd_u.l32.data_value, data_addr,
                    IEEE1394_QUADLET);
                /*
                 * swap these for our correct architecture if we are doing
                 * arithmetic lock operations
                 */
                cmd->cmd_u.l32.arg_value = HCI1394_ARITH_LOCK_SWAP32(
                    cmd->cmd_u.l32.lock_type, cmd->cmd_u.l32.arg_value);
                cmd->cmd_u.l32.data_value = HCI1394_ARITH_LOCK_SWAP32(
                    cmd->cmd_u.l32.lock_type, cmd->cmd_u.l32.data_value);
        } else if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_64) {
                data_addr = (uint8_t *)&pkt->q5;
                hci1394_q_ar_rep_get8(async_handle->as_arreq_q,
                    (uint8_t *)&cmd->cmd_u.l64.arg_value, data_addr,
                    IEEE1394_OCTLET);
                data_addr = (uint8_t *)((uintptr_t)data_addr +
                    (uintptr_t)IEEE1394_OCTLET);
                hci1394_q_ar_rep_get8(async_handle->as_arreq_q,
                    (uint8_t *)&cmd->cmd_u.l64.data_value, data_addr,
                    IEEE1394_OCTLET);

                /*
                 * swap these for our correct architecture if we are doing
                 * arithmetic lock operations
                 */
                cmd->cmd_u.l64.arg_value = HCI1394_ARITH_LOCK_SWAP64(
                    cmd->cmd_u.l64.lock_type, cmd->cmd_u.l64.arg_value);
                cmd->cmd_u.l64.data_value = HCI1394_ARITH_LOCK_SWAP64(
                    cmd->cmd_u.l64.lock_type, cmd->cmd_u.l64.data_value);
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_arreq_read_phy()
 *    Read ARREQ PHY quadlet into the 1394 Framework command. This routine will
 *    return DDI_FAILURE if it was not able to read the request succesfully.
 */
static int
hci1394_async_arreq_read_phy(hci1394_async_handle_t async_handle,
    hci1394_basic_pkt_t *pkt, hci1394_async_cmd_t *hcicmd, uint_t *size,
    boolean_t *bus_reset_token)
{
        cmd1394_cmd_t *cmd;
        uint32_t quadlet;
        uint32_t data1;
        uint32_t data2;


        ASSERT(async_handle != NULL);
        ASSERT(pkt != NULL);
        ASSERT(hcicmd != NULL);
        ASSERT(size != NULL);

        /* Setup shortcuts, command type, and size of request */
        cmd = hcicmd->ac_cmd;
        cmd->cmd_type = CMD1394_ASYNCH_WR_QUAD;
        *size = DESC_SZ_AR_PHY;

        /*
         * read in the ARREQ ACK/EVT, the speed, the time we received it, and
         * set state that we do not use an mblk for this request.
         */
        quadlet = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q4);
        hcicmd->ac_status = HCI1394_DESC_EVT_GET(quadlet);
        hcicmd->ac_priv->speed = HCI1394_DESC_AR_SPD_GET(quadlet);
        hcicmd->ac_priv->recv_tstamp = HCI1394_DESC_TIMESTAMP_GET(quadlet);
        hcicmd->ac_mblk_alloc = B_FALSE;

        /* Read in the PHY packet quadlet and its check quadlet */
        data1 = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q2);
        data2 = hci1394_q_ar_get32(async_handle->as_arreq_q, &pkt->q3);

        /*
         * if this is a bus reset token, save away the generation. If the bus
         * reset token is for the current generation, we do not need to flush
         * the ARREQ Q anymore.
         */
        if (hcicmd->ac_status == OHCI_EVT_BUS_RESET) {
                *bus_reset_token = B_TRUE;
                async_handle->as_phy_reset = HCI1394_DESC_PHYGEN_GET(data2);
                if (async_handle->as_phy_reset == hci1394_ohci_current_busgen(
                    async_handle->as_ohci)) {
                        async_handle->as_flushing_arreq = B_FALSE;
                }
                return (DDI_SUCCESS);
        }

        *bus_reset_token = B_FALSE;

        /* if there is a data error in the PHY packet, return failure */
        if (data1 != ~data2) {
                return (DDI_FAILURE);
        }

        /* Copy the PHY quadlet to the command */
        cmd->cmd_u.q.quadlet_data = data1;

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_phy()
 *    Queue up ATREQ phy packet.
 */
int
hci1394_async_phy(hci1394_async_handle_t async_handle, cmd1394_cmd_t *cmd,
    h1394_cmd_priv_t *cmd_priv, int *result)
{
        hci1394_basic_pkt_t header;
        hci1394_async_cmd_t *hcicmd;
        int status;


        ASSERT(async_handle != NULL);
        ASSERT(cmd != NULL);
        ASSERT(cmd_priv != NULL);
        ASSERT(result != NULL);

        /*
         * make sure this call is during the current bus generation (i.e. no
         * bus resets have occured since this request was made.
         */
        if (cmd_priv->bus_generation != hci1394_ohci_current_busgen(
            async_handle->as_ohci)) {
                *result = H1394_STATUS_INVALID_BUSGEN;
                return (DDI_FAILURE);
        }

        /* Initialize the private HAL command structure */
        hci1394_async_hcicmd_init(async_handle, cmd, cmd_priv, &hcicmd);

        /* We do not allocate a tlabel for a PHY packet */
        hcicmd->ac_tlabel_alloc = B_FALSE;

        /*
         * Setup the packet header information for a ATREQ PHY packet Add in
         * the tcode, phy quadlet, and it's 1's complement.
         */
        header.q1 = DESC_ATREQ_Q1_PHY;
        header.q2 = cmd->cmd_u.q.quadlet_data;
        header.q3 = ~header.q2;

        /* Write request into the ATREQ Q. If we fail, we're out of space */
        status = hci1394_q_at(async_handle->as_atreq_q, &hcicmd->ac_qcmd,
            &header, DESC_PKT_HDRLEN_AT_PHY, result);
        if (status != DDI_SUCCESS) {
                return (DDI_FAILURE);
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_write()
 *    Queue up ATREQ write. This could be either a block write or a quadlet
 *    write.
 */
int
hci1394_async_write(hci1394_async_handle_t async_handle, cmd1394_cmd_t *cmd,
    h1394_cmd_priv_t *cmd_priv, int *result)
{
        hci1394_async_cmd_t *hcicmd;
        hci1394_basic_pkt_t header;
        int status;


        ASSERT(async_handle != NULL);
        ASSERT(cmd != NULL);
        ASSERT(cmd_priv != NULL);
        ASSERT(result != NULL);

        /*
         * make sure this call is during the current bus generation (i.e. no
         * bus resets have occured since this request was made.
         */
        if (cmd_priv->bus_generation != hci1394_ohci_current_busgen(
            async_handle->as_ohci)) {
                *result = H1394_STATUS_INVALID_BUSGEN;
                return (DDI_FAILURE);
        }

        /* Initialize the private HAL command structure */
        hci1394_async_hcicmd_init(async_handle, cmd, cmd_priv, &hcicmd);
        hcicmd->ac_dest = (uint_t)(cmd->cmd_addr >> IEEE1394_ADDR_PHY_ID_SHIFT);

        /* allocate a tlabel for this request */
        status = hci1394_tlabel_alloc(async_handle->as_tlabel, hcicmd->ac_dest,
            &hcicmd->ac_tlabel);
        if (status != DDI_SUCCESS) {
                *result = H1394_STATUS_EMPTY_TLABEL;
                return (DDI_FAILURE);
        }

        /*
         * Setup the packet header information for a ATREQ write packet. We
         * will set the tcode later on since this could be a block write or
         * a quadlet write. Set SRCBusId if this write is not a local bus
         * access. Copy in the speed, tlabel, and destination address.
         */
        header.q1 = 0;
        if ((hcicmd->ac_dest & IEEE1394_BUS_NUM_MASK) !=
            IEEE1394_BUS_NUM_MASK) {
                header.q1 |= DESC_AT_SRCBUSID;
        }
        header.q1 |= HCI1394_DESC_AT_SPD_SET(cmd_priv->speed) |
            HCI1394_DESC_TLABEL_SET(hcicmd->ac_tlabel.tbi_tlabel);
        header.q2 = (uint32_t)(cmd->cmd_addr >> 32);
        header.q3 = (uint32_t)(cmd->cmd_addr & DESC_PKT_DESTOFFLO_MASK);

        /* Register this command w/ its tlabel */
        hci1394_tlabel_register(async_handle->as_tlabel, &hcicmd->ac_tlabel,
            hcicmd);

        /* If this is a quadlet write ATREQ */
        if (cmd->cmd_type == CMD1394_ASYNCH_WR_QUAD) {
                /*
                 * setup the tcode for a quadlet write request and copy in
                 * the quadlet data. Endian issues will be taken care of in
                 * hci1394_q_at().
                 */
                header.q1 |= DESC_ATREQ_Q1_QWR;
                header.q4 = cmd->cmd_u.q.quadlet_data;

                /*
                 * Write the request into the ATREQ Q. If we fail, we are out
                 * of space.
                 */
                status = hci1394_q_at(async_handle->as_atreq_q,
                    &hcicmd->ac_qcmd, &header, DESC_PKT_HDRLEN_AT_WRITEQUAD,
                    result);
                if (status != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }

        /* This is a block write ATREQ */
        } else {
                /* setup the tcode and the length of the block write */
                header.q1 |= DESC_ATREQ_Q1_BWR;
                header.q4 = HCI1394_DESC_DATALEN_SET(cmd_priv->mblk.length);

                /*
                 * Write the request into the ATREQ Q. If we fail, we are out
                 * of space. The data is in a mblk(s). We use a special
                 * interface in the HAL/SL private command block to handle
                 * partial transfers out of the mblk due to packet size
                 * restrictions.
                 */
                status = hci1394_q_at_with_mblk(async_handle->as_atreq_q,
                    &hcicmd->ac_qcmd, &header, DESC_PKT_HDRLEN_AT_WRITEBLOCK,
                    &cmd_priv->mblk, result);
                if (status != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_read()
 *    Queue up ATREQ read. This could be either a block read or a quadlet
 *    read.
 */
int
hci1394_async_read(hci1394_async_handle_t async_handle, cmd1394_cmd_t *cmd,
    h1394_cmd_priv_t *cmd_priv, int *result)
{
        hci1394_basic_pkt_t header;
        int status;
        hci1394_async_cmd_t *hcicmd;


        ASSERT(async_handle != NULL);
        ASSERT(cmd != NULL);
        ASSERT(cmd_priv != NULL);
        ASSERT(result != NULL);

        /*
         * make sure this call is during the current bus generation (i.e. no
         * bus resets have occured since this request was made.
         */
        if (cmd_priv->bus_generation != hci1394_ohci_current_busgen(
            async_handle->as_ohci)) {
                *result = H1394_STATUS_INVALID_BUSGEN;
                return (DDI_FAILURE);
        }

        /* Initialize the private HAL command structure */
        hci1394_async_hcicmd_init(async_handle, cmd, cmd_priv, &hcicmd);
        hcicmd->ac_dest = (uint_t)(cmd->cmd_addr >> IEEE1394_ADDR_PHY_ID_SHIFT);

        /* allocate a tlabel for this request */
        status = hci1394_tlabel_alloc(async_handle->as_tlabel, hcicmd->ac_dest,
            &hcicmd->ac_tlabel);
        if (status != DDI_SUCCESS) {
                *result = H1394_STATUS_EMPTY_TLABEL;
                return (DDI_FAILURE);
        }

        /*
         * Setup the packet header information for a ATREQ read packet. We
         * will set the tcode later on since this could be a block read or
         * a quadlet read. Set SRCBusId if this read is not a local bus
         * access. Copy in the speed, tlabel, and destination address.
         */
        header.q1 = 0;
        if ((hcicmd->ac_dest & IEEE1394_BUS_NUM_MASK) !=
            IEEE1394_BUS_NUM_MASK) {
                header.q1 |= DESC_AT_SRCBUSID;
        }
        header.q1 |= HCI1394_DESC_AT_SPD_SET(cmd_priv->speed) |
            HCI1394_DESC_TLABEL_SET(hcicmd->ac_tlabel.tbi_tlabel);
        header.q2 = (uint32_t)(cmd->cmd_addr >> 32);
        header.q3 = (uint32_t)(cmd->cmd_addr & DESC_PKT_DESTOFFLO_MASK);

        /* Register this command w/ its tlabel */
        hci1394_tlabel_register(async_handle->as_tlabel, &hcicmd->ac_tlabel,
            hcicmd);

        /* If this is a quadlet read ATREQ */
        if (cmd->cmd_type == CMD1394_ASYNCH_RD_QUAD) {
                /* setup the tcode for a quadlet read request */
                header.q1 |= DESC_ATREQ_Q1_QRD;
                header.q4 = 0;

                /*
                 * Write the request into the ATREQ Q. If we fail, we are out
                 * of space.
                 */
                status = hci1394_q_at(async_handle->as_atreq_q,
                    &hcicmd->ac_qcmd, &header, DESC_PKT_HDRLEN_AT_READQUAD,
                    result);
                if (status != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }

        } else {
                /* setup the tcode and the length of the block read */
                header.q1 |= DESC_ATREQ_Q1_BRD;
                header.q4 = HCI1394_DESC_DATALEN_SET(cmd_priv->mblk.length);

                /*
                 * Write the request into the ATREQ Q. If we fail, we are out
                 * of space.
                 */
                status = hci1394_q_at(async_handle->as_atreq_q,
                    &hcicmd->ac_qcmd, &header, DESC_PKT_HDRLEN_AT_READBLOCK,
                    result);
                if (status != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_lock()
 *    Queue up ATREQ lock. This could be either a 32-bit or 64-bit lock
 *    request.
 */
int
hci1394_async_lock(hci1394_async_handle_t async_handle, cmd1394_cmd_t *cmd,
    h1394_cmd_priv_t *cmd_priv, int *result)
{
        hci1394_basic_pkt_t header;
        hci1394_async_cmd_t *hcicmd;
        uint32_t data32[2];
        uint64_t data64[2];
        uint8_t *datap;
        uint_t size;
        int status;


        ASSERT(async_handle != NULL);
        ASSERT(cmd != NULL);
        ASSERT(cmd_priv != NULL);
        ASSERT(result != NULL);

        /*
         * make sure this call is during the current bus generation (i.e. no
         * bus resets have occured since this request was made.
         */
        if (cmd_priv->bus_generation != hci1394_ohci_current_busgen(
            async_handle->as_ohci)) {
                *result = H1394_STATUS_INVALID_BUSGEN;
                return (DDI_FAILURE);
        }

        /* Initialize the private HAL command structure */
        hci1394_async_hcicmd_init(async_handle, cmd, cmd_priv, &hcicmd);
        hcicmd->ac_dest = (uint_t)(cmd->cmd_addr >> IEEE1394_ADDR_PHY_ID_SHIFT);

        /* allocate a tlabel for this request */
        status = hci1394_tlabel_alloc(async_handle->as_tlabel, hcicmd->ac_dest,
            &hcicmd->ac_tlabel);
        if (status != DDI_SUCCESS) {
                *result = H1394_STATUS_EMPTY_TLABEL;
                return (DDI_FAILURE);
        }

        /* Register this command w/ its tlabel */
        hci1394_tlabel_register(async_handle->as_tlabel, &hcicmd->ac_tlabel,
            hcicmd);

        /*
         * Setup the packet header information for a ATREQ lock packet. Set
         * the tcode up as a lock request. Set SRCBusId if this lock is not a
         * local bus access. Copy in the speed, tlabel, and destination
         * address.
         */
        header.q1 = DESC_ATREQ_Q1_LCK;
        if ((hcicmd->ac_dest & IEEE1394_BUS_NUM_MASK) !=
            IEEE1394_BUS_NUM_MASK) {
                header.q1 |= DESC_AT_SRCBUSID;
        }
        header.q1 |= HCI1394_DESC_AT_SPD_SET(cmd_priv->speed) |
            HCI1394_DESC_TLABEL_SET(hcicmd->ac_tlabel.tbi_tlabel);
        header.q2 = (uint32_t)(cmd->cmd_addr >> 32);
        header.q3 = (uint32_t)(cmd->cmd_addr & DESC_PKT_DESTOFFLO_MASK);

        /*
         * Setup the lock length based on what size lock operation we are
         * performing. If it isn't a lock32 or lock64, we have encountered an
         * internal error. Copy the lock data into a local data buffer. Perform
         * a byte swap if it is an arithmetic lock operation and we are on a
         * little endian machine.
         */
        if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_32) {
                size = DESC_TWO_QUADS;
                header.q4 = HCI1394_DESC_DATALEN_SET(size) |
                    HCI1394_DESC_EXTTCODE_SET(cmd->cmd_u.l32.lock_type);
                data32[0] = HCI1394_ARITH_LOCK_SWAP32(
                    cmd->cmd_u.l32.lock_type, cmd->cmd_u.l32.arg_value);
                data32[1] = HCI1394_ARITH_LOCK_SWAP32(
                    cmd->cmd_u.l32.lock_type, cmd->cmd_u.l32.data_value);
                datap = (uint8_t *)data32;
        } else if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_64) {
                size = DESC_TWO_OCTLETS;
                header.q4 = HCI1394_DESC_DATALEN_SET(size) |
                    HCI1394_DESC_EXTTCODE_SET(cmd->cmd_u.l64.lock_type);
                data64[0] = HCI1394_ARITH_LOCK_SWAP64(
                    cmd->cmd_u.l64.lock_type, cmd->cmd_u.l64.arg_value);
                data64[1] = HCI1394_ARITH_LOCK_SWAP64(
                    cmd->cmd_u.l64.lock_type, cmd->cmd_u.l64.data_value);
                datap = (uint8_t *)data64;
        } else {
                *result = H1394_STATUS_INTERNAL_ERROR;
                return (DDI_FAILURE);
        }

        /* Write request into the ATREQ Q. If we fail, we're out of space */
        status = hci1394_q_at_with_data(async_handle->as_atreq_q,
            &hcicmd->ac_qcmd, &header, DESC_PKT_HDRLEN_AT_LOCK, datap, size,
            result);
        if (status != DDI_SUCCESS) {
                return (DDI_FAILURE);
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_write_response()
 *    Send a write ATRESP. This routine should be called from the Services
 *    layer to send a response to a received write request (ARREQ). The same
 *    response is sent to a quadlet and block write request.
 */
int
hci1394_async_write_response(hci1394_async_handle_t async_handle,
    cmd1394_cmd_t *cmd, h1394_cmd_priv_t *cmd_priv, int *result)
{
        hci1394_basic_pkt_t header;
        int status;
        hci1394_async_cmd_t *hcicmd;


        ASSERT(async_handle != NULL);
        ASSERT(cmd != NULL);
        ASSERT(cmd_priv != NULL);
        ASSERT(result != NULL);

        /*
         * make sure this call is during the current bus generation (i.e. no
         * bus resets have occured since this request was made.
         */
        if (cmd_priv->bus_generation != hci1394_ohci_current_busgen(
            async_handle->as_ohci)) {
                *result = H1394_STATUS_INVALID_BUSGEN;
                return (DDI_FAILURE);
        }

        /*
         * setup a shortcut to the hal private command area. Copy the generation
         * to the Q area so that we can check the generation when the AT Q is
         * locked. This prevents us from loosing commands due to race
         * conditions.
         */
        hcicmd = (hci1394_async_cmd_t *)cmd_priv->hal_overhead;
        hcicmd->ac_qcmd.qc_generation = cmd_priv->bus_generation;

        /*
         * Setup the packet header information for a ATRESP write packet. Set
         * the tcode for a write response. Set SRCBusId if the addr is not a
         * local bus address. Copy in the speed, tlabel, and response code.
         */
        header.q1 = DESC_ATRESP_Q1_WR;
        if ((cmd->nodeID & IEEE1394_BUS_NUM_MASK) != IEEE1394_BUS_NUM_MASK) {
                header.q1 |= DESC_AT_SRCBUSID;
        }
        header.q1 |= HCI1394_DESC_AT_SPD_SET(cmd_priv->speed) |
            HCI1394_DESC_TLABEL_SET(hcicmd->ac_tlabel.tbi_tlabel);
        header.q2 = (HCI1394_DESC_DESTID_SET(cmd->nodeID) |
            HCI1394_DESC_RCODE_SET(cmd->cmd_result));
        header.q3 = 0;

        /* Write response into the ATRESP Q. If we fail, we're out of space */
        status = hci1394_q_at(async_handle->as_atresp_q, &hcicmd->ac_qcmd,
            &header, DESC_PKT_HDRLEN_AT_WRITE_RESP, result);
        if (status != DDI_SUCCESS) {
                return (DDI_FAILURE);
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_read_response()
 *    Send a read ATRESP. This routine should be called from the Services
 *    layer to send a response to a received read request (ARREQ). The
 *    response will differ between quadlet/block read requests.
 */
int
hci1394_async_read_response(hci1394_async_handle_t async_handle,
    cmd1394_cmd_t *cmd, h1394_cmd_priv_t *cmd_priv, int *result)
{
        hci1394_basic_pkt_t header;
        int status;
        hci1394_async_cmd_t *hcicmd;


        ASSERT(async_handle != NULL);
        ASSERT(cmd != NULL);
        ASSERT(cmd_priv != NULL);
        ASSERT(result != NULL);

        /*
         * make sure this call is during the current bus generation (i.e. no
         * bus resets have occured since this request was made.
         */
        if (cmd_priv->bus_generation != hci1394_ohci_current_busgen(
            async_handle->as_ohci)) {
                *result = H1394_STATUS_INVALID_BUSGEN;
                return (DDI_FAILURE);
        }

        /*
         * setup a shortcut to the hal private command area. Copy the generation
         * to the Q area so that we can check the generation when the AT Q is
         * locked. This prevents us from loosing commands due to race
         * conditions.
         */
        hcicmd = (hci1394_async_cmd_t *)cmd_priv->hal_overhead;
        hcicmd->ac_qcmd.qc_generation = cmd_priv->bus_generation;

        /*
         * Setup the packet header information for a ATRESP read packet. we
         * will set the tcode later based on type of read response. Set
         * SRCBusId if the addr is not a local bus address. Copy in the
         * speed, tlabel, and response code.
         */
        header.q1 = 0;
        if ((cmd->nodeID & IEEE1394_BUS_NUM_MASK) != IEEE1394_BUS_NUM_MASK) {
                header.q1 |= DESC_AT_SRCBUSID;
        }
        header.q1 |= HCI1394_DESC_AT_SPD_SET(cmd_priv->speed) |
            HCI1394_DESC_TLABEL_SET(hcicmd->ac_tlabel.tbi_tlabel);
        header.q2 = (uint32_t)(HCI1394_DESC_DESTID_SET(cmd->nodeID) |
            HCI1394_DESC_RCODE_SET(cmd->cmd_result));
        header.q3 = 0;

        /* if the response is a read quadlet response */
        if (cmd->cmd_type == CMD1394_ASYNCH_RD_QUAD) {
                /*
                 * setup the tcode for a quadlet read response, If the
                 * response code is not resp complete.
                 */
                header.q1 |= DESC_ATRESP_Q1_QRD;
                if (cmd->cmd_result == IEEE1394_RESP_COMPLETE) {
                        header.q4 = cmd->cmd_u.q.quadlet_data;
                } else {
                        header.q4 = 0x0;
                }

                /*
                 * Write response into the ATRESP Q. If we fail, we're out of
                 * space.
                 */
                status = hci1394_q_at(async_handle->as_atresp_q,
                    &hcicmd->ac_qcmd, &header, DESC_PKT_HDRLEN_AT_READQUAD_RESP,
                    result);
                if (status != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }

        /*
         * the response is a block read response. If the result is not a
         * resp complete, we are not going to send any data back.
         */
        } else if ((cmd->cmd_type == CMD1394_ASYNCH_RD_BLOCK) &&
            (cmd->cmd_result != IEEE1394_RESP_COMPLETE)) {
                /*
                 * Setup the tcode for a block read response, set the data
                 * length to zero since we had an error.
                 */
                header.q1 |= DESC_ATRESP_Q1_BRD;
                header.q4 = 0x0;

                /*
                 * Write response into the ATRESP Q. If we fail, we're out of
                 * space.
                 */
                status = hci1394_q_at(async_handle->as_atresp_q,
                    &hcicmd->ac_qcmd, &header,
                    DESC_PKT_HDRLEN_AT_READBLOCK_RESP, result);
                if (status != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }

        /*
         * the response is a block read response with a resp complete for the
         * response code. Send back the read data.
         */
        } else {
                /*
                 * Setup the tcode for a block read response, setup the data
                 * length.
                 */
                header.q1 |= DESC_ATRESP_Q1_BRD;
                header.q4 = HCI1394_DESC_DATALEN_SET(cmd->cmd_u.b.blk_length);

                /*
                 * Write response into the ATRESP Q. If we fail, we're out of
                 * space. Use the data in the mblk.
                 */
                status = hci1394_q_at_with_mblk(async_handle->as_atresp_q,
                    &hcicmd->ac_qcmd, &header,
                    DESC_PKT_HDRLEN_AT_READBLOCK_RESP, &cmd_priv->mblk, result);
                if (status != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_lock_response()
 *    Send a lock ATRESP. This routine should be called from the Services
 *    layer to send a response to a received lock request (ARREQ). The
 *    response will differ between 32-bit/64-bit lock requests.
 */
int
hci1394_async_lock_response(hci1394_async_handle_t async_handle,
    cmd1394_cmd_t *cmd, h1394_cmd_priv_t *cmd_priv, int *result)
{
        hci1394_basic_pkt_t header;
        hci1394_async_cmd_t *hcicmd;
        uint32_t data32;
        uint64_t data64;
        uint8_t *datap;
        uint_t size;
        int status;


        ASSERT(async_handle != NULL);
        ASSERT(cmd != NULL);
        ASSERT(cmd_priv != NULL);
        ASSERT(result != NULL);

        /*
         * make sure this call is during the current bus generation (i.e. no
         * bus resets have occured since this request was made.
         */
        if (cmd_priv->bus_generation != hci1394_ohci_current_busgen(
            async_handle->as_ohci)) {
                *result = H1394_STATUS_INVALID_BUSGEN;
                return (DDI_FAILURE);
        }

        /*
         * setup a shortcut to the hal private command area. Copy the generation
         * to the Q area so that we can check the generation when the AT Q is
         * locked. This prevents us from loosing commands due to race
         * conditions.
         */
        hcicmd = (hci1394_async_cmd_t *)cmd_priv->hal_overhead;
        hcicmd->ac_qcmd.qc_generation = cmd_priv->bus_generation;

        /*
         * Setup the packet header information for a ATRESP lock packet. Set
         * the tcode for a lock response. Set SRCBusId if the addr is not a
         * local bus address. Copy in the speed, tlabel, and response code.
         */
        header.q1 = DESC_ATRESP_Q1_LCK;
        if ((cmd->nodeID & IEEE1394_BUS_NUM_MASK) != IEEE1394_BUS_NUM_MASK) {
                header.q1 |= DESC_AT_SRCBUSID;
        }
        header.q1 |= HCI1394_DESC_AT_SPD_SET(cmd_priv->speed) |
            HCI1394_DESC_TLABEL_SET(hcicmd->ac_tlabel.tbi_tlabel);
        header.q2 = (uint32_t)(HCI1394_DESC_DESTID_SET(cmd->nodeID) |
            HCI1394_DESC_RCODE_SET(cmd->cmd_result));
        header.q3 = 0;

        /*
         * If the lock result is not a resp complete, we are not going to send
         * any data back.with the response.
         */
        if (cmd->cmd_result != IEEE1394_RESP_COMPLETE) {
                /* set response size to 0 for error. Set the extended tcode */
                size = 0;
                if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_32) {
                        header.q4 = HCI1394_DESC_DATALEN_SET(size) |
                            HCI1394_DESC_EXTTCODE_SET(cmd->cmd_u.l32.lock_type);
                } else {
                        header.q4 = HCI1394_DESC_DATALEN_SET(size) |
                            HCI1394_DESC_EXTTCODE_SET(cmd->cmd_u.l64.lock_type);
                }

                /*
                 * Write response into the ATRESP Q. If we fail, we're out of
                 * space.
                 */
                status = hci1394_q_at(async_handle->as_atresp_q,
                    &hcicmd->ac_qcmd, &header, DESC_PKT_HDRLEN_AT_LOCK_RESP,
                    result);
                if (status != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }
                return (DDI_SUCCESS);
        }

        /*
         * if the lock result is resp complete, setup the size of the response
         * depending on the lock size and copy the lock response data into a
         * local buffer. If the lock response is an arithmetic operation, swap
         * the data on little endian machines. If we don't know what type of
         * lock operation it is, someone has corrupted the command since we
         * had received the ARREQ.
         */
        if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_32) {
                size = IEEE1394_QUADLET;
                header.q4 = HCI1394_DESC_DATALEN_SET(size) |
                    HCI1394_DESC_EXTTCODE_SET(cmd->cmd_u.l32.lock_type);
                data32 = HCI1394_ARITH_LOCK_SWAP32(
                    cmd->cmd_u.l32.lock_type, cmd->cmd_u.l32.old_value);
                datap = (uint8_t *)&data32;
        } else if (cmd->cmd_type == CMD1394_ASYNCH_LOCK_64) {
                size = IEEE1394_OCTLET;
                header.q4 = HCI1394_DESC_DATALEN_SET(size) |
                    HCI1394_DESC_EXTTCODE_SET(cmd->cmd_u.l64.lock_type);
                data64 = HCI1394_ARITH_LOCK_SWAP64(
                    cmd->cmd_u.l64.lock_type, cmd->cmd_u.l64.old_value);
                datap = (uint8_t *)&data64;
        } else {
                *result = H1394_STATUS_INTERNAL_ERROR;
                return (DDI_FAILURE);
        }

        /*
         * Write response into the ATRESP Q. If we fail, we're out of space.
         * Use the local data buffer that we copied the data to above.
         */
        status = hci1394_q_at_with_data(async_handle->as_atresp_q,
            &hcicmd->ac_qcmd, &header, DESC_PKT_HDRLEN_AT_LOCK_RESP, datap,
            size, result);
        if (status != DDI_SUCCESS) {
                return (DDI_FAILURE);
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_response_complete()
 *    Free up space allocted during an ARREQ.  This is called when the target
 *    driver and Services Layer are done with a command which was by the HAL
 *    during ARREQ processing.  This routine will also free up any allocated
 *    mblks.
 *
 *    NOTE: a target driver can hold on to a block write ARREQ mblk by setting
 *    the mblk pointer to NULL.  This ONLY applies to block write ARREQs. The
 *    HAL will no longer track the mblk for this case.
 */
void
hci1394_async_response_complete(hci1394_async_handle_t async_handle,
    cmd1394_cmd_t *cmd, h1394_cmd_priv_t *cmd_priv)
{
        hci1394_async_cmd_t *hcicmd;


        ASSERT(async_handle != NULL);
        ASSERT(cmd != NULL);
        ASSERT(cmd_priv != NULL);

        hcicmd = (hci1394_async_cmd_t *)cmd_priv->hal_overhead;

        /* If we allocated an mblk for this command */
        if (hcicmd->ac_mblk_alloc == B_TRUE) {
                /*
                 * Don't free mblk if it is set to NULL. This allows a target
                 * driver to hold on to it in the case of a block write ARREQ.
                 */
                if (cmd->cmd_u.b.data_block != NULL) {
                        freeb(cmd->cmd_u.b.data_block);
                }
        }

        /* free up the 1394 framework command */
        (void) h1394_free_cmd((void *)async_handle->as_drvinfo->di_sl_private,
            &cmd);
}


/*
 * hci1394_async_pending_timeout()
 *    This is the ARREQ Pending timeout callback routine.  It is called from
 *    the tlist code. There is a race condition with the ARRESP interrupt
 *    handler (hci1394_async_arresp_process) which requires a mutex to
 *    lock around the mark of the bad tlabel.
 *
 *    Once we enter this routine, the command has timed out. If the command is
 *    in both the ARRESP handler and here, we will consider it to have timed
 *    out. That code path handles the race condition more easily.
 */
static void
hci1394_async_pending_timeout(hci1394_tlist_node_t *node, void *arg)
{
        hci1394_async_handle_t async_handle;
        hci1394_async_cmd_t *hcicmd;


        async_handle = (hci1394_async_handle_t)arg;
        ASSERT(async_handle != NULL);
        ASSERT(node != NULL);

        hcicmd = (hci1394_async_cmd_t *)node->tln_addr;

        /*
         * We do NOT want to set the command state here. That should only be
         * done in the ISR. The state does nothing for us here.
         */

        /*
         * We want a lock around tlabel_lookup/reading data into the cmd in the
         * ARRESP ISR processing and a lock around the tlabel_bad in this
         * routine. This ensures that we will not be touching the command
         * structure after we pass it up to the Services Layer. If we mark it as
         * bad first, the lookup will fail. If we get to the lookup first, the
         * pending list delete will fail in arresp_process() which will tell
         * that guy that we are in the middle of doing the timeout processing
         * for this command.  The ARRESP logic will just drop the response and
         * continue on.
         */
        mutex_enter(&hcicmd->ac_async->as_atomic_lookup);
        hci1394_tlabel_bad(async_handle->as_tlabel, &hcicmd->ac_tlabel);
        mutex_exit(&hcicmd->ac_async->as_atomic_lookup);

        /* Tell the Services Layer that the command has timed out */
        h1394_cmd_is_complete(async_handle->as_drvinfo->di_sl_private,
            hcicmd->ac_cmd, H1394_AT_REQ, H1394_CMD_ETIMEOUT);
}


/*
 * hci1394_async_timeout_calc()
 *    Calculate the timeout for an ATRESP. When an ARREQ is received, this
 *    routine is called with the time the ARREQ was received. It returns the
 *    time when the ATRESP is considered to have timed out. We timeout after
 *    split_timeout has gone by. Split timeout and the returned value are in bus
 *    cycles.
 */
static uint_t
hci1394_async_timeout_calc(hci1394_async_handle_t async_handle,
    uint_t current_time)
{
        uint_t split_timeout;
        uint_t temp;
        uint_t carry;
        uint_t z;

        /* Get the current split timeout */
        split_timeout = hci1394_csr_split_timeout_get(async_handle->as_csr);

        /*
         * The cycle count is broken up into two sections, the 3-bit seconds
         * field and the 13-bit cycle count. The cycle count is in 125uS
         * increments.  The maximum value of cycle count is 7999 (8000 is one
         * second). With 13-bits, we could store up to 8191. Therefore, we don't
         * have a simple 16-bit addition. Hence, the code we see below.
         */

        /*
         * calculate the new cycle count based on the cycle count from current
         * time and the split timeout. If this new value is not greater than the
         * maximum cycle count, we don't have a carry. Go to the next step.
         */
        temp = (current_time & OHCI_CYCLE_CNT_MASK) + (split_timeout &
            OHCI_CYCLE_CNT_MASK);
        if (temp < OHCI_MAX_CYCLE_CNT) {
                carry = 0;

        /*
         * the new cycle count adds up to more than the maximum cycle count,
         * set the carry state and adjust the total accordingly.
         */
        } else {
                temp = temp - OHCI_MAX_CYCLE_CNT;
                carry = 1;
        }

        /*
         * The timeout time equals the seconds added with the carry (1 or 0
         * seconds), added with the adjusted (if necessary) cycle count.
         * Mask the final value to get rid of any second rollovers.
         */
        z = (current_time & OHCI_CYCLE_SEC_MASK) + (split_timeout &
            OHCI_CYCLE_SEC_MASK) + (carry << OHCI_CYCLE_SEC_SHIFT) + temp;
        z = z & OHCI_TIMESTAMP_MASK;

        return (z);
}


/*
 * hci1394_async_arresp_size_get()
 *    Return the size of the arresp that was received in q_handle at addr.
 */
static int
hci1394_async_arresp_size_get(uint_t tcode, hci1394_q_handle_t q_handle,
    uint32_t *addr, uint_t *size)
{
        uint_t data_length;
        uint32_t quadlet;


        ASSERT(q_handle != NULL);
        ASSERT(addr != NULL);
        ASSERT(size != NULL);

        if (tcode == IEEE1394_TCODE_WRITE_RESP) {
                *size = DESC_PKT_HDRLEN_AT_WRITE_RESP + IEEE1394_QUADLET;
        } else if (tcode == IEEE1394_TCODE_READ_QUADLET_RESP) {
                *size = DESC_PKT_HDRLEN_AT_READQUAD_RESP + IEEE1394_QUADLET;
        } else if (tcode == IEEE1394_TCODE_READ_BLOCK_RESP) {
                quadlet = hci1394_q_ar_get32(q_handle, &addr[3]);
                data_length = HCI1394_DESC_DATALEN_GET(quadlet);
                /*
                 * response size is in quadlets, therefore we need to
                 * make sure we count in the padding when figuring out
                 * the size used up for this response
                 */
                *size = DESC_PKT_HDRLEN_AT_READBLOCK_RESP +
                    HCI1394_ALIGN_QUAD(data_length) + IEEE1394_QUADLET;
        } else if (tcode == IEEE1394_TCODE_LOCK_RESP) {
                quadlet = hci1394_q_ar_get32(q_handle, &addr[3]);
                data_length = HCI1394_DESC_DATALEN_GET(quadlet);
                /*
                 * response size is in quadlets, therefore we need to
                 * make sure we count in the padding when figuring out
                 * the size used up for this response
                 */
                *size = DESC_PKT_HDRLEN_AT_LOCK_RESP +
                    HCI1394_ALIGN_QUAD(data_length) + IEEE1394_QUADLET;
        } else {
                return (DDI_FAILURE);
        }

        return (DDI_SUCCESS);
}


/*
 * hci1394_async_pending_list_flush()
 *    Flush out the ATREQ pending list. All commands still on the ATREQ pending
 *    list are considered to be completed due to a bus reset. The ATREQ and
 *    ARRESP Q's should be flushed before the pending Q is flushed. The ATREQ
 *    could have more ACK pendings and the ARRESP could have valid responses to
 *    pended requests.
 */
void
hci1394_async_pending_list_flush(hci1394_async_handle_t async_handle)
{
        hci1394_tlist_node_t *node;
        hci1394_async_cmd_t *hcicmd;


        ASSERT(async_handle != NULL);

        do {
                /*
                 * get the first node on the pending list. This routine also
                 * removes the node from the list.
                 */
                hci1394_tlist_get(async_handle->as_pending_list, &node);
                if (node != NULL) {
                        /* set the command state to completed */
                        hcicmd = (hci1394_async_cmd_t *)node->tln_addr;
                        hcicmd->ac_state = HCI1394_CMD_STATE_COMPLETED;

                        /*
                         * Send the command up to the Services Layer with
                         * completed due to the bus reset for status.
                         */
                        h1394_cmd_is_complete(
                            async_handle->as_drvinfo->di_sl_private,
                            hcicmd->ac_cmd, H1394_AT_REQ,
                            H1394_CMD_EBUSRESET);
                }
        } while (node != NULL);
}


/*
 * hci1394_async_atreq_start()
 *    Setup the command pointer for the first descriptor to be fetched and
 *    then set the run bit. This routine will be called the first time
 *    a descriptor is added to the Q.
 */
static void
hci1394_async_atreq_start(void *async, uint32_t command_ptr)
{
        hci1394_async_handle_t async_handle;
        ASSERT(async != NULL);
        async_handle = (hci1394_async_handle_t)async;
        hci1394_ohci_atreq_start(async_handle->as_ohci, command_ptr);
}


/*
 * hci1394_async_atreq_wake()
 *    Set the wake bit for the ATREQ DMA engine. This routine will be called
 *    from the Q logic after placing a descriptor on the Q.
 */
static void
hci1394_async_atreq_wake(void *async)
{
        hci1394_async_handle_t async_handle;
        ASSERT(async != NULL);
        async_handle = (hci1394_async_handle_t)async;
        hci1394_ohci_atreq_wake(async_handle->as_ohci);
}


/*
 * hci1394_async_atreq_reset()
 *    Reset the atreq Q.  The AT DMA engines must be stopped every bus reset.
 *    They will restart when the next descriptor is added to the Q. We will stop
 *    the DMA engine and then notify the Q logic that it has been stopped so it
 *    knows to do a start next time it puts a descriptor on the Q.
 */
void
hci1394_async_atreq_reset(hci1394_async_handle_t async_handle)
{
        ASSERT(async_handle != NULL);
        hci1394_ohci_atreq_stop(async_handle->as_ohci);
        hci1394_q_stop(async_handle->as_atreq_q);
}


/*
 * hci1394_async_atreq_flush()
 *    Flush out the atreq Q. This routine is called during bus reset processing.
 *    it should be called before arresp_flush() and pending_list_flush().
 */
static void
hci1394_async_atreq_flush(hci1394_async_handle_t async_handle)
{
        boolean_t request_available;
        int status;

        ASSERT(async_handle != NULL);

        /* Clear reqTxComplete interrupt */
        hci1394_ohci_intr_clear(async_handle->as_ohci, OHCI_INTR_REQ_TX_CMPLT);

        /*
         * Processes all Q'd AT requests.  If the request is pended, it is
         * considered complete relative the the atreq engine.
         * flush_pending_list() will finish up the required processing for
         * pended requests.
         */
        do {
                /* Flush the atreq Q. Process all Q'd commands */
                status = hci1394_async_atreq_process(async_handle,
                    B_TRUE, &request_available);
                if (status != DDI_SUCCESS) {
                }
        } while (request_available == B_TRUE);
}


/*
 * hci1394_async_arresp_start()
 *    Setup the command pointer for the first descriptor to be fetched and
 *    then set the run bit. This routine will be called the first time
 *    a descriptor is added to the Q.
 */
static void
hci1394_async_arresp_start(void *async, uint32_t command_ptr)
{
        hci1394_async_handle_t async_handle;
        ASSERT(async != NULL);
        async_handle = (hci1394_async_handle_t)async;
        hci1394_ohci_arresp_start(async_handle->as_ohci, command_ptr);
}


/*
 * hci1394_async_arresp_wake()
 *    Set the wake bit for the ARRESP DMA engine. This routine will be called
 *    from the Q logic after placing a descriptor on the Q.
 */
static void
hci1394_async_arresp_wake(void *async)
{
        hci1394_async_handle_t async_handle;
        ASSERT(async != NULL);
        async_handle = (hci1394_async_handle_t)async;
        hci1394_ohci_arresp_wake(async_handle->as_ohci);
}


/*
 * hci1394_async_arresp_flush()
 *    Flush out the arresp Q. This routine is called during bus reset
 *    processing. This should be called before pending_list_flush(). All
 *    receive responses will be processed normally. The tlabels should
 *    not be reset until after the ARRESP Q has been flushed. Otherwise
 *    we would reject valid responses.
 */
static void
hci1394_async_arresp_flush(hci1394_async_handle_t async_handle)
{
        boolean_t response_available;
        int status;


        ASSERT(async_handle != NULL);

        /* Clear reqTxComplete interrupt */
        hci1394_ohci_intr_clear(async_handle->as_ohci, OHCI_INTR_RSPKT);

        do {
                /* Flush the arresp Q. Process all received commands */
                status = hci1394_async_arresp_process(async_handle,
                    &response_available);
                if (status != DDI_SUCCESS) {
                }
        } while (response_available == B_TRUE);
}


/*
 * hci1394_async_arreq_start()
 *    Setup the command pointer for the first descriptor to be fetched and
 *    then set the run bit. This routine will be called the first time
 *    a descriptor is added to the Q.
 */
static void
hci1394_async_arreq_start(void *async, uint32_t command_ptr)
{
        hci1394_async_handle_t async_handle;
        ASSERT(async != NULL);
        async_handle = (hci1394_async_handle_t)async;
        hci1394_ohci_arreq_start(async_handle->as_ohci, command_ptr);
}


/*
 * hci1394_async_arreq_wake()
 *    Set the wake bit for the ARREQ DMA engine. This routine will be called
 *    from the Q logic after placing a descriptor on the Q.
 */
static void
hci1394_async_arreq_wake(void *async)
{
        hci1394_async_handle_t async_handle;
        ASSERT(async != NULL);
        async_handle = (hci1394_async_handle_t)async;
        hci1394_ohci_arreq_wake(async_handle->as_ohci);
}


/*
 * hci1394_async_arreq_flush()
 *    Flush the ARREQ Q. This will flush up to the bus reset token in the
 *    ARREQ. There is no order dependency for when routine should get called
 *    (relative to the other Q flushing routines)
 */
static void
hci1394_async_arreq_flush(hci1394_async_handle_t async_handle)
{
        boolean_t request_available;
        int status;


        ASSERT(async_handle != NULL);

        /*
         * If the last bus reset token we have seen in
         * hci1394_async_arreq_read_phy() matches the current generation, the
         * ARREQ is already flushed.  We have nothing further to do here so
         * return. This can happen if we are processing ARREQ's and a bus reset
         * occurs. Since we are already in the ISR, we will see the token before
         * the bus reset handler gets to run.
         */
        if (async_handle->as_phy_reset == hci1394_ohci_current_busgen(
            async_handle->as_ohci)) {
                return;
        }

        /*
         * set flag to tell hci1394_async_arreq_process() that we should not
         * pass ARREQ's up to the Services Layer.  This will be set to B_FALSE
         * in hci1394_async_arreq_read_phy() when a bus reset token matching
         * the current generation is found.
         */
        async_handle->as_flushing_arreq = B_TRUE;

        /*
         * Process all requests that have been received or until we find the
         * correct bus reset token.
         */
        do {
                status = hci1394_async_arreq_process(async_handle,
                    &request_available);
                if (status != DDI_SUCCESS) {
                }
        } while ((request_available == B_TRUE) &&
            (async_handle->as_flushing_arreq == B_TRUE));

        /*
         * Clear the asserted interrupt if there are no more ARREQ's to process.
         * We could have ARREQ's in the Q after the bus reset token since we
         * will set as_flushing_arreq to FALSE when we see the correct bus reset
         * token in hci1394_async_arreq_read_phy(). If there are more ARREQ's,
         * we will process them later after finishing the reset of bus reset
         * processing.  That is why we will leave the interrupt asserted.
         */
        if (request_available == B_FALSE) {
                hci1394_ohci_intr_clear(async_handle->as_ohci, OHCI_INTR_RQPKT);
        }
}


/*
 * hci1394_async_atresp_start()
 *    Setup the command pointer for the first descriptor to be fetched and
 *    then set the run bit. This routine will be called the first time
 *    a descriptor is added to the Q.
 */
static void
hci1394_async_atresp_start(void *async, uint32_t command_ptr)
{
        hci1394_async_handle_t async_handle;
        ASSERT(async != NULL);
        async_handle = (hci1394_async_handle_t)async;
        hci1394_ohci_atresp_start(async_handle->as_ohci, command_ptr);
}


/*
 * hci1394_async_atresp_wake()
 *    Set the wake bit for the ATRESP DMA engine. This routine will be called
 *    from the Q logic after placing a descriptor on the Q.
 */
static void
hci1394_async_atresp_wake(void *async)
{
        hci1394_async_handle_t async_handle;
        ASSERT(async != NULL);
        async_handle = (hci1394_async_handle_t)async;
        hci1394_ohci_atresp_wake(async_handle->as_ohci);
}


/*
 * hci1394_async_atresp_reset()
 *    Reset the atresp Q.  The AT DMA engines must be stopped every bus reset.
 *    They will restart when the next descriptor is added to the Q. We will stop
 *    the DMA engine and then notify the Q logic that it has been stopped so it
 *    knows to do a start next time it puts a descriptor on the Q.
 */
void
hci1394_async_atresp_reset(hci1394_async_handle_t async_handle)
{
        ASSERT(async_handle != NULL);
        hci1394_ohci_atresp_stop(async_handle->as_ohci);
        hci1394_q_stop(async_handle->as_atresp_q);
}


/*
 * hci1394_async_atresp_flush()
 *    Flush all commands out of the atresp Q. This routine will be called
 *    during bus reset processing. There is no order dependency for when
 *    routine should get called (relative to the other Q flushing routines)
 */
static void
hci1394_async_atresp_flush(hci1394_async_handle_t async_handle)
{
        boolean_t response_available;
        int status;

        ASSERT(async_handle != NULL);

        /* Clear respTxComplete interrupt */
        hci1394_ohci_intr_clear(async_handle->as_ohci, OHCI_INTR_RESP_TX_CMPLT);

        /* Processes all AT responses */
        do {
                /* Flush the atresp Q. Process all Q'd commands */
                status = hci1394_async_atresp_process(async_handle,
                    B_TRUE, &response_available);
        } while (response_available == B_TRUE);
}

/*
 * hci1394_async_hcicmd_init()
 *    Initialize the private HAL command structure. This should be called from
 *    ATREQ and ARREQ routines.
 */
static void
hci1394_async_hcicmd_init(hci1394_async_handle_t async_handle,
    cmd1394_cmd_t *cmd, h1394_cmd_priv_t *cmd_priv,
    hci1394_async_cmd_t **hcicmd)
{
        *hcicmd = (hci1394_async_cmd_t *)cmd_priv->hal_overhead;
        (*hcicmd)->ac_cmd = cmd;
        (*hcicmd)->ac_priv = cmd_priv;
        (*hcicmd)->ac_async = async_handle;
        (*hcicmd)->ac_state = HCI1394_CMD_STATE_IN_PROGRESS;
        (*hcicmd)->ac_dest = 0;
        (*hcicmd)->ac_tlabel_alloc = B_TRUE;
        (*hcicmd)->ac_tlabel.tbi_tlabel = 0;
        (*hcicmd)->ac_tlabel.tbi_destination = 0;
        (*hcicmd)->ac_status = 0;
        (*hcicmd)->ac_qcmd.qc_timestamp = 0;
        (*hcicmd)->ac_qcmd.qc_arg = *hcicmd;
        (*hcicmd)->ac_qcmd.qc_generation = cmd_priv->bus_generation;
        (*hcicmd)->ac_mblk_alloc = B_FALSE;
}