FreeBSD/Linux Kernel Cross Reference
sys/dev/mps/mps.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2009 Yahoo! Inc.
      * Copyright (c) 2011-2015 LSI Corp.
      * Copyright (c) 2013-2015 Avago Technologies
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     * Avago Technologies (LSI) MPT-Fusion Host Adapter FreeBSD
     *
     * $FreeBSD: releng/12.0/sys/dev/mps/mps.c 330789 2018-03-12 05:02:22Z scottl $
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/12.0/sys/dev/mps/mps.c 330789 2018-03-12 05:02:22Z scottl $");
    
    /* Communications core for Avago Technologies (LSI) MPT2 */
    
    /* TODO Move headers to mpsvar */
    #include <sys/types.h>
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/selinfo.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    #include <sys/module.h>
    #include <sys/bus.h>
    #include <sys/conf.h>
    #include <sys/bio.h>
    #include <sys/malloc.h>
    #include <sys/uio.h>
    #include <sys/sysctl.h>
    #include <sys/smp.h>
    #include <sys/queue.h>
    #include <sys/kthread.h>
    #include <sys/taskqueue.h>
    #include <sys/endian.h>
    #include <sys/eventhandler.h>
    #include <sys/sbuf.h>
    #include <sys/priv.h>
    
    #include <machine/bus.h>
    #include <machine/resource.h>
    #include <sys/rman.h>
    #include <sys/proc.h>
    
    #include <dev/pci/pcivar.h>
    
    #include <cam/cam.h>
    #include <cam/scsi/scsi_all.h>
    
    #include <dev/mps/mpi/mpi2_type.h>
    #include <dev/mps/mpi/mpi2.h>
    #include <dev/mps/mpi/mpi2_ioc.h>
    #include <dev/mps/mpi/mpi2_sas.h>
    #include <dev/mps/mpi/mpi2_cnfg.h>
    #include <dev/mps/mpi/mpi2_init.h>
    #include <dev/mps/mpi/mpi2_tool.h>
    #include <dev/mps/mps_ioctl.h>
    #include <dev/mps/mpsvar.h>
    #include <dev/mps/mps_table.h>
    
    static int mps_diag_reset(struct mps_softc *sc, int sleep_flag);
    static int mps_init_queues(struct mps_softc *sc);
    static void mps_resize_queues(struct mps_softc *sc);
    static int mps_message_unit_reset(struct mps_softc *sc, int sleep_flag);
    static int mps_transition_operational(struct mps_softc *sc);
    static int mps_iocfacts_allocate(struct mps_softc *sc, uint8_t attaching);
    static void mps_iocfacts_free(struct mps_softc *sc);
    static void mps_startup(void *arg);
    static int mps_send_iocinit(struct mps_softc *sc);
    static int mps_alloc_queues(struct mps_softc *sc);
    static int mps_alloc_hw_queues(struct mps_softc *sc);
    static int mps_alloc_replies(struct mps_softc *sc);
    static int mps_alloc_requests(struct mps_softc *sc);
    static int mps_attach_log(struct mps_softc *sc);
    static __inline void mps_complete_command(struct mps_softc *sc,
       struct mps_command *cm);
   static void mps_dispatch_event(struct mps_softc *sc, uintptr_t data,
       MPI2_EVENT_NOTIFICATION_REPLY *reply);
   static void mps_config_complete(struct mps_softc *sc, struct mps_command *cm);
   static void mps_periodic(void *);
   static int mps_reregister_events(struct mps_softc *sc);
   static void mps_enqueue_request(struct mps_softc *sc, struct mps_command *cm);
   static int mps_get_iocfacts(struct mps_softc *sc, MPI2_IOC_FACTS_REPLY *facts);
   static int mps_wait_db_ack(struct mps_softc *sc, int timeout, int sleep_flag);
   static int mps_debug_sysctl(SYSCTL_HANDLER_ARGS);
   static int mps_dump_reqs(SYSCTL_HANDLER_ARGS);
   static void mps_parse_debug(struct mps_softc *sc, char *list);
   
   SYSCTL_NODE(_hw, OID_AUTO, mps, CTLFLAG_RD, 0, "MPS Driver Parameters");
   
   MALLOC_DEFINE(M_MPT2, "mps", "mpt2 driver memory");
   MALLOC_DECLARE(M_MPSUSER);
   
   /*
    * Do a "Diagnostic Reset" aka a hard reset.  This should get the chip out of
    * any state and back to its initialization state machine.
    */
   static char mpt2_reset_magic[] = { 0x00, 0x0f, 0x04, 0x0b, 0x02, 0x07, 0x0d };
   
   /* Added this union to smoothly convert le64toh cm->cm_desc.Words.
    * Compiler only support unint64_t to be passed as argument.
    * Otherwise it will throw below error
    * "aggregate value used where an integer was expected"
    */
   
   typedef union _reply_descriptor {
           u64 word;
           struct {
                   u32 low;
                   u32 high;
           } u;
   }reply_descriptor,address_descriptor;
   
   /* Rate limit chain-fail messages to 1 per minute */
   static struct timeval mps_chainfail_interval = { 60, 0 };
   
   /* 
    * sleep_flag can be either CAN_SLEEP or NO_SLEEP.
    * If this function is called from process context, it can sleep
    * and there is no harm to sleep, in case if this fuction is called
    * from Interrupt handler, we can not sleep and need NO_SLEEP flag set.
    * based on sleep flags driver will call either msleep, pause or DELAY.
    * msleep and pause are of same variant, but pause is used when mps_mtx
    * is not hold by driver.
    *
    */
   static int
   mps_diag_reset(struct mps_softc *sc,int sleep_flag)
   {
           uint32_t reg;
           int i, error, tries = 0;
           uint8_t first_wait_done = FALSE;
   
           mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);
   
           /* Clear any pending interrupts */
           mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
   
           /*
            * Force NO_SLEEP for threads prohibited to sleep
            * e.a Thread from interrupt handler are prohibited to sleep.
            */
           if (curthread->td_no_sleeping != 0)
                   sleep_flag = NO_SLEEP;
   
           mps_dprint(sc, MPS_INIT, "sequence start, sleep_flag= %d\n", sleep_flag);
    
           /* Push the magic sequence */
           error = ETIMEDOUT;
           while (tries++ < 20) {
                   for (i = 0; i < sizeof(mpt2_reset_magic); i++)
                           mps_regwrite(sc, MPI2_WRITE_SEQUENCE_OFFSET,
                               mpt2_reset_magic[i]);
                   /* wait 100 msec */
                   if (mtx_owned(&sc->mps_mtx) && sleep_flag == CAN_SLEEP)
                           msleep(&sc->msleep_fake_chan, &sc->mps_mtx, 0,
                               "mpsdiag", hz/10);
                   else if (sleep_flag == CAN_SLEEP)
                           pause("mpsdiag", hz/10);
                   else
                           DELAY(100 * 1000);
   
                   reg = mps_regread(sc, MPI2_HOST_DIAGNOSTIC_OFFSET);
                   if (reg & MPI2_DIAG_DIAG_WRITE_ENABLE) {
                           error = 0;
                           break;
                   }
           }
           if (error) {
                   mps_dprint(sc, MPS_INIT, "sequence failed, error=%d, exit\n",
                       error);
                   return (error);
           }
   
           /* Send the actual reset.  XXX need to refresh the reg? */
           reg |= MPI2_DIAG_RESET_ADAPTER;
           mps_dprint(sc, MPS_INIT, "sequence success, sending reset, reg= 0x%x\n",
                   reg);
           mps_regwrite(sc, MPI2_HOST_DIAGNOSTIC_OFFSET, reg);
   
           /* Wait up to 300 seconds in 50ms intervals */
           error = ETIMEDOUT;
           for (i = 0; i < 6000; i++) {
                   /*
                    * Wait 50 msec. If this is the first time through, wait 256
                    * msec to satisfy Diag Reset timing requirements.
                    */
                   if (first_wait_done) {
                           if (mtx_owned(&sc->mps_mtx) && sleep_flag == CAN_SLEEP)
                                   msleep(&sc->msleep_fake_chan, &sc->mps_mtx, 0,
                                       "mpsdiag", hz/20);
                           else if (sleep_flag == CAN_SLEEP)
                                   pause("mpsdiag", hz/20);
                           else
                                   DELAY(50 * 1000);
                   } else {
                           DELAY(256 * 1000);
                           first_wait_done = TRUE;
                   }
                   /*
                    * Check for the RESET_ADAPTER bit to be cleared first, then
                    * wait for the RESET state to be cleared, which takes a little
                    * longer.
                    */
                   reg = mps_regread(sc, MPI2_HOST_DIAGNOSTIC_OFFSET);
                   if (reg & MPI2_DIAG_RESET_ADAPTER) {
                           continue;
                   }
                   reg = mps_regread(sc, MPI2_DOORBELL_OFFSET);
                   if ((reg & MPI2_IOC_STATE_MASK) != MPI2_IOC_STATE_RESET) {
                           error = 0;
                           break;
                   }
           }
           if (error) {
                   mps_dprint(sc, MPS_INIT, "reset failed, error= %d, exit\n",
                       error);
                   return (error);
           }
   
           mps_regwrite(sc, MPI2_WRITE_SEQUENCE_OFFSET, 0x0);
           mps_dprint(sc, MPS_INIT, "diag reset success, exit\n");
   
           return (0);
   }
   
   static int
   mps_message_unit_reset(struct mps_softc *sc, int sleep_flag)
   {
           int error;
   
           MPS_FUNCTRACE(sc);
   
           mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);
   
           error = 0;
           mps_regwrite(sc, MPI2_DOORBELL_OFFSET,
               MPI2_FUNCTION_IOC_MESSAGE_UNIT_RESET <<
               MPI2_DOORBELL_FUNCTION_SHIFT);
   
           if (mps_wait_db_ack(sc, 5, sleep_flag) != 0) {
                   mps_dprint(sc, MPS_INIT|MPS_FAULT,
                       "Doorbell handshake failed\n");
                   error = ETIMEDOUT;
           }
   
           mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
           return (error);
   }
   
   static int
   mps_transition_ready(struct mps_softc *sc)
   {
           uint32_t reg, state;
           int error, tries = 0;
           int sleep_flags;
   
           MPS_FUNCTRACE(sc);
           /* If we are in attach call, do not sleep */
           sleep_flags = (sc->mps_flags & MPS_FLAGS_ATTACH_DONE)
                                           ? CAN_SLEEP:NO_SLEEP;
           error = 0;
   
           mps_dprint(sc, MPS_INIT, "%s entered, sleep_flags= %d\n",
              __func__, sleep_flags);
   
           while (tries++ < 1200) {
                   reg = mps_regread(sc, MPI2_DOORBELL_OFFSET);
                   mps_dprint(sc, MPS_INIT, "  Doorbell= 0x%x\n", reg);
   
                   /*
                    * Ensure the IOC is ready to talk.  If it's not, try
                    * resetting it.
                    */
                   if (reg & MPI2_DOORBELL_USED) {
                           mps_dprint(sc, MPS_INIT, "  Not ready, sending diag "
                               "reset\n");
                           mps_diag_reset(sc, sleep_flags);
                           DELAY(50000);
                           continue;
                   }
   
                   /* Is the adapter owned by another peer? */
                   if ((reg & MPI2_DOORBELL_WHO_INIT_MASK) ==
                       (MPI2_WHOINIT_PCI_PEER << MPI2_DOORBELL_WHO_INIT_SHIFT)) {
                           mps_dprint(sc, MPS_INIT|MPS_FAULT, "IOC is under the "
                               "control of another peer host, aborting "
                               "initialization.\n");
                           error = ENXIO;
                           break;
                   }
                   
                   state = reg & MPI2_IOC_STATE_MASK;
                   if (state == MPI2_IOC_STATE_READY) {
                           /* Ready to go! */
                           error = 0;
                           break;
                   } else if (state == MPI2_IOC_STATE_FAULT) {
                           mps_dprint(sc, MPS_INIT|MPS_FAULT, "IOC in fault "
                               "state 0x%x, resetting\n",
                               state & MPI2_DOORBELL_FAULT_CODE_MASK);
                           mps_diag_reset(sc, sleep_flags);
                   } else if (state == MPI2_IOC_STATE_OPERATIONAL) {
                           /* Need to take ownership */
                           mps_message_unit_reset(sc, sleep_flags);
                   } else if (state == MPI2_IOC_STATE_RESET) {
                           /* Wait a bit, IOC might be in transition */
                           mps_dprint(sc, MPS_INIT|MPS_FAULT,
                               "IOC in unexpected reset state\n");
                   } else {
                           mps_dprint(sc, MPS_INIT|MPS_FAULT,
                               "IOC in unknown state 0x%x\n", state);
                           error = EINVAL;
                           break;
                   }
           
                   /* Wait 50ms for things to settle down. */
                   DELAY(50000);
           }
   
           if (error)
                   mps_dprint(sc, MPS_INIT|MPS_FAULT,
                       "Cannot transition IOC to ready\n");
           mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
   
           return (error);
   }
   
   static int
   mps_transition_operational(struct mps_softc *sc)
   {
           uint32_t reg, state;
           int error;
   
           MPS_FUNCTRACE(sc);
   
           error = 0;
           reg = mps_regread(sc, MPI2_DOORBELL_OFFSET);
           mps_dprint(sc, MPS_INIT, "%s entered, Doorbell= 0x%x\n", __func__, reg);
   
           state = reg & MPI2_IOC_STATE_MASK;
           if (state != MPI2_IOC_STATE_READY) {
                   mps_dprint(sc, MPS_INIT, "IOC not ready\n");
                   if ((error = mps_transition_ready(sc)) != 0) {
                           mps_dprint(sc, MPS_INIT|MPS_FAULT, 
                               "failed to transition ready, exit\n");
                           return (error);
                   }
           }
   
           error = mps_send_iocinit(sc);
           mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
   
           return (error);
   }
   
   static void
   mps_resize_queues(struct mps_softc *sc)
   {
           u_int reqcr, prireqcr, maxio, sges_per_frame;
   
           /*
            * Size the queues. Since the reply queues always need one free
            * entry, we'll deduct one reply message here.  The LSI documents
            * suggest instead to add a count to the request queue, but I think
            * that it's better to deduct from reply queue.
            */
           prireqcr = MAX(1, sc->max_prireqframes);
           prireqcr = MIN(prireqcr, sc->facts->HighPriorityCredit);
   
           reqcr = MAX(2, sc->max_reqframes);
           reqcr = MIN(reqcr, sc->facts->RequestCredit);
   
           sc->num_reqs = prireqcr + reqcr;
           sc->num_prireqs = prireqcr;
           sc->num_replies = MIN(sc->max_replyframes + sc->max_evtframes,
               sc->facts->MaxReplyDescriptorPostQueueDepth) - 1;
   
           /* Store the request frame size in bytes rather than as 32bit words */
           sc->reqframesz = sc->facts->IOCRequestFrameSize * 4;
   
           /*
            * Max IO Size is Page Size * the following:
            * ((SGEs per frame - 1 for chain element) * Max Chain Depth)
            * + 1 for no chain needed in last frame
            *
            * If user suggests a Max IO size to use, use the smaller of the
            * user's value and the calculated value as long as the user's
            * value is larger than 0. The user's value is in pages.
            */
           sges_per_frame = sc->reqframesz / sizeof(MPI2_SGE_SIMPLE64) - 1;
           maxio = (sges_per_frame * sc->facts->MaxChainDepth + 1) * PAGE_SIZE;
   
           /*
            * If I/O size limitation requested, then use it and pass up to CAM.
            * If not, use MAXPHYS as an optimization hint, but report HW limit.
            */
           if (sc->max_io_pages > 0) {
                   maxio = min(maxio, sc->max_io_pages * PAGE_SIZE);
                   sc->maxio = maxio;
           } else {
                   sc->maxio = maxio;
                   maxio = min(maxio, MAXPHYS);
           }
   
           sc->num_chains = (maxio / PAGE_SIZE + sges_per_frame - 2) /
               sges_per_frame * reqcr;
           if (sc->max_chains > 0 && sc->max_chains < sc->num_chains)
                   sc->num_chains = sc->max_chains;
   
           /*
            * Figure out the number of MSIx-based queues.  If the firmware or
            * user has done something crazy and not allowed enough credit for
            * the queues to be useful then don't enable multi-queue.
            */
           if (sc->facts->MaxMSIxVectors < 2)
                   sc->msi_msgs = 1;
   
           if (sc->msi_msgs > 1) {
                   sc->msi_msgs = MIN(sc->msi_msgs, mp_ncpus);
                   sc->msi_msgs = MIN(sc->msi_msgs, sc->facts->MaxMSIxVectors);
                   if (sc->num_reqs / sc->msi_msgs < 2)
                           sc->msi_msgs = 1;
           }
   
           mps_dprint(sc, MPS_INIT, "Sized queues to q=%d reqs=%d replies=%d\n",
               sc->msi_msgs, sc->num_reqs, sc->num_replies);
   }
   
   /*
    * This is called during attach and when re-initializing due to a Diag Reset.
    * IOC Facts is used to allocate many of the structures needed by the driver.
    * If called from attach, de-allocation is not required because the driver has
    * not allocated any structures yet, but if called from a Diag Reset, previously
    * allocated structures based on IOC Facts will need to be freed and re-
    * allocated bases on the latest IOC Facts.
    */
   static int
   mps_iocfacts_allocate(struct mps_softc *sc, uint8_t attaching)
   {
           int error;
           Mpi2IOCFactsReply_t saved_facts;
           uint8_t saved_mode, reallocating;
   
           mps_dprint(sc, MPS_INIT|MPS_TRACE, "%s entered\n", __func__);
   
           /* Save old IOC Facts and then only reallocate if Facts have changed */
           if (!attaching) {
                   bcopy(sc->facts, &saved_facts, sizeof(MPI2_IOC_FACTS_REPLY));
           }
   
           /*
            * Get IOC Facts.  In all cases throughout this function, panic if doing
            * a re-initialization and only return the error if attaching so the OS
            * can handle it.
            */
           if ((error = mps_get_iocfacts(sc, sc->facts)) != 0) {
                   if (attaching) {
                           mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to get "
                               "IOC Facts with error %d, exit\n", error);
                           return (error);
                   } else {
                           panic("%s failed to get IOC Facts with error %d\n",
                               __func__, error);
                   }
           }
   
           MPS_DPRINT_PAGE(sc, MPS_XINFO, iocfacts, sc->facts);
   
           snprintf(sc->fw_version, sizeof(sc->fw_version), 
               "%02d.%02d.%02d.%02d", 
               sc->facts->FWVersion.Struct.Major,
               sc->facts->FWVersion.Struct.Minor,
               sc->facts->FWVersion.Struct.Unit,
               sc->facts->FWVersion.Struct.Dev);
   
           mps_dprint(sc, MPS_INFO, "Firmware: %s, Driver: %s\n", sc->fw_version,
               MPS_DRIVER_VERSION);
           mps_dprint(sc, MPS_INFO, "IOCCapabilities: %b\n",
                sc->facts->IOCCapabilities,
               "\2" "\3ScsiTaskFull" "\4DiagTrace" "\5SnapBuf" "\6ExtBuf"
               "\7EEDP" "\10BiDirTarg" "\11Multicast" "\14TransRetry" "\15IR"
               "\16EventReplay" "\17RaidAccel" "\20MSIXIndex" "\21HostDisc");
   
           /*
            * If the chip doesn't support event replay then a hard reset will be
            * required to trigger a full discovery.  Do the reset here then
            * retransition to Ready.  A hard reset might have already been done,
            * but it doesn't hurt to do it again.  Only do this if attaching, not
            * for a Diag Reset.
            */
           if (attaching && ((sc->facts->IOCCapabilities &
               MPI2_IOCFACTS_CAPABILITY_EVENT_REPLAY) == 0)) {
                   mps_dprint(sc, MPS_INIT, "No event replay, reseting\n");
                   mps_diag_reset(sc, NO_SLEEP);
                   if ((error = mps_transition_ready(sc)) != 0) {
                           mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to "
                               "transition to ready with error %d, exit\n",
                               error);
                           return (error);
                   }
           }
   
           /*
            * Set flag if IR Firmware is loaded.  If the RAID Capability has
            * changed from the previous IOC Facts, log a warning, but only if
            * checking this after a Diag Reset and not during attach.
            */
           saved_mode = sc->ir_firmware;
           if (sc->facts->IOCCapabilities &
               MPI2_IOCFACTS_CAPABILITY_INTEGRATED_RAID)
                   sc->ir_firmware = 1;
           if (!attaching) {
                   if (sc->ir_firmware != saved_mode) {
                           mps_dprint(sc, MPS_INIT|MPS_FAULT, "new IR/IT mode "
                               "in IOC Facts does not match previous mode\n");
                   }
           }
   
           /* Only deallocate and reallocate if relevant IOC Facts have changed */
           reallocating = FALSE;
           sc->mps_flags &= ~MPS_FLAGS_REALLOCATED;
   
           if ((!attaching) &&
               ((saved_facts.MsgVersion != sc->facts->MsgVersion) ||
               (saved_facts.HeaderVersion != sc->facts->HeaderVersion) ||
               (saved_facts.MaxChainDepth != sc->facts->MaxChainDepth) ||
               (saved_facts.RequestCredit != sc->facts->RequestCredit) ||
               (saved_facts.ProductID != sc->facts->ProductID) ||
               (saved_facts.IOCCapabilities != sc->facts->IOCCapabilities) ||
               (saved_facts.IOCRequestFrameSize !=
               sc->facts->IOCRequestFrameSize) ||
               (saved_facts.MaxTargets != sc->facts->MaxTargets) ||
               (saved_facts.MaxSasExpanders != sc->facts->MaxSasExpanders) ||
               (saved_facts.MaxEnclosures != sc->facts->MaxEnclosures) ||
               (saved_facts.HighPriorityCredit != sc->facts->HighPriorityCredit) ||
               (saved_facts.MaxReplyDescriptorPostQueueDepth !=
               sc->facts->MaxReplyDescriptorPostQueueDepth) ||
               (saved_facts.ReplyFrameSize != sc->facts->ReplyFrameSize) ||
               (saved_facts.MaxVolumes != sc->facts->MaxVolumes) ||
               (saved_facts.MaxPersistentEntries !=
               sc->facts->MaxPersistentEntries))) {
                   reallocating = TRUE;
   
                   /* Record that we reallocated everything */
                   sc->mps_flags |= MPS_FLAGS_REALLOCATED;
           }
   
           /*
            * Some things should be done if attaching or re-allocating after a Diag
            * Reset, but are not needed after a Diag Reset if the FW has not
            * changed.
            */
           if (attaching || reallocating) {
                   /*
                    * Check if controller supports FW diag buffers and set flag to
                    * enable each type.
                    */
                   if (sc->facts->IOCCapabilities &
                       MPI2_IOCFACTS_CAPABILITY_DIAG_TRACE_BUFFER)
                           sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_TRACE].
                               enabled = TRUE;
                   if (sc->facts->IOCCapabilities &
                       MPI2_IOCFACTS_CAPABILITY_SNAPSHOT_BUFFER)
                           sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_SNAPSHOT].
                               enabled = TRUE;
                   if (sc->facts->IOCCapabilities &
                       MPI2_IOCFACTS_CAPABILITY_EXTENDED_BUFFER)
                           sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_EXTENDED].
                               enabled = TRUE;
   
                   /*
                    * Set flag if EEDP is supported and if TLR is supported.
                    */
                   if (sc->facts->IOCCapabilities & MPI2_IOCFACTS_CAPABILITY_EEDP)
                           sc->eedp_enabled = TRUE;
                   if (sc->facts->IOCCapabilities & MPI2_IOCFACTS_CAPABILITY_TLR)
                           sc->control_TLR = TRUE;
   
                   mps_resize_queues(sc);
   
                   /*
                    * Initialize all Tail Queues
                    */
                   TAILQ_INIT(&sc->req_list);
                   TAILQ_INIT(&sc->high_priority_req_list);
                   TAILQ_INIT(&sc->chain_list);
                   TAILQ_INIT(&sc->tm_list);
           }
   
           /*
            * If doing a Diag Reset and the FW is significantly different
            * (reallocating will be set above in IOC Facts comparison), then all
            * buffers based on the IOC Facts will need to be freed before they are
            * reallocated.
            */
           if (reallocating) {
                   mps_iocfacts_free(sc);
                   mpssas_realloc_targets(sc, saved_facts.MaxTargets +
                       saved_facts.MaxVolumes);
           }
   
           /*
            * Any deallocation has been completed.  Now start reallocating
            * if needed.  Will only need to reallocate if attaching or if the new
            * IOC Facts are different from the previous IOC Facts after a Diag
            * Reset. Targets have already been allocated above if needed.
            */
           error = 0;
           while (attaching || reallocating) {
                   if ((error = mps_alloc_hw_queues(sc)) != 0)
                           break;
                   if ((error = mps_alloc_replies(sc)) != 0)
                           break;
                   if ((error = mps_alloc_requests(sc)) != 0)
                           break;
                   if ((error = mps_alloc_queues(sc)) != 0)
                           break;
   
                   break;
           }
           if (error) {
                   mps_dprint(sc, MPS_INIT|MPS_FAULT,
                       "Failed to alloc queues with error %d\n", error);
                   mps_free(sc);
                   return (error);
           }
   
           /* Always initialize the queues */
           bzero(sc->free_queue, sc->fqdepth * 4);
           mps_init_queues(sc);
   
           /*
            * Always get the chip out of the reset state, but only panic if not
            * attaching.  If attaching and there is an error, that is handled by
            * the OS.
            */
           error = mps_transition_operational(sc);
           if (error != 0) {
                   mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to "
                       "transition to operational with error %d\n", error);
                   mps_free(sc);
                   return (error);
           }
   
           /*
            * Finish the queue initialization.
            * These are set here instead of in mps_init_queues() because the
            * IOC resets these values during the state transition in
            * mps_transition_operational().  The free index is set to 1
            * because the corresponding index in the IOC is set to 0, and the
            * IOC treats the queues as full if both are set to the same value.
            * Hence the reason that the queue can't hold all of the possible
            * replies.
            */
           sc->replypostindex = 0;
           mps_regwrite(sc, MPI2_REPLY_FREE_HOST_INDEX_OFFSET, sc->replyfreeindex);
           mps_regwrite(sc, MPI2_REPLY_POST_HOST_INDEX_OFFSET, 0);
   
           /*
            * Attach the subsystems so they can prepare their event masks.
            * XXX Should be dynamic so that IM/IR and user modules can attach
            */
           error = 0;
           while (attaching) {
                   mps_dprint(sc, MPS_INIT, "Attaching subsystems\n");
                   if ((error = mps_attach_log(sc)) != 0)
                           break;
                   if ((error = mps_attach_sas(sc)) != 0)
                           break;
                   if ((error = mps_attach_user(sc)) != 0)
                           break;
                   break;
           }
           if (error) {
                   mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to attach all "
                       "subsystems: error %d\n", error);
                   mps_free(sc);
                   return (error);
           }
   
           /*
            * XXX If the number of MSI-X vectors changes during re-init, this
            * won't see it and adjust.
            */
           if (attaching && (error = mps_pci_setup_interrupts(sc)) != 0) {
                   mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to setup "
                       "interrupts\n");
                   mps_free(sc);
                   return (error);
           }
   
           /*
            * Set flag if this is a WD controller.  This shouldn't ever change, but
            * reset it after a Diag Reset, just in case.
            */
           sc->WD_available = FALSE;
           if (pci_get_device(sc->mps_dev) == MPI2_MFGPAGE_DEVID_SSS6200)
                   sc->WD_available = TRUE;
   
           return (error);
   }
   
   /*
    * This is called if memory is being free (during detach for example) and when
    * buffers need to be reallocated due to a Diag Reset.
    */
   static void
   mps_iocfacts_free(struct mps_softc *sc)
   {
           struct mps_command *cm;
           int i;
   
           mps_dprint(sc, MPS_TRACE, "%s\n", __func__);
   
           if (sc->free_busaddr != 0)
                   bus_dmamap_unload(sc->queues_dmat, sc->queues_map);
           if (sc->free_queue != NULL)
                   bus_dmamem_free(sc->queues_dmat, sc->free_queue,
                       sc->queues_map);
           if (sc->queues_dmat != NULL)
                   bus_dma_tag_destroy(sc->queues_dmat);
   
           if (sc->chain_frames != NULL) {
                   bus_dmamap_unload(sc->chain_dmat, sc->chain_map);
                   bus_dmamem_free(sc->chain_dmat, sc->chain_frames,
                       sc->chain_map);
           }
           if (sc->chain_dmat != NULL)
                   bus_dma_tag_destroy(sc->chain_dmat);
   
           if (sc->sense_busaddr != 0)
                   bus_dmamap_unload(sc->sense_dmat, sc->sense_map);
           if (sc->sense_frames != NULL)
                   bus_dmamem_free(sc->sense_dmat, sc->sense_frames,
                       sc->sense_map);
           if (sc->sense_dmat != NULL)
                   bus_dma_tag_destroy(sc->sense_dmat);
   
           if (sc->reply_busaddr != 0)
                   bus_dmamap_unload(sc->reply_dmat, sc->reply_map);
           if (sc->reply_frames != NULL)
                   bus_dmamem_free(sc->reply_dmat, sc->reply_frames,
                       sc->reply_map);
           if (sc->reply_dmat != NULL)
                   bus_dma_tag_destroy(sc->reply_dmat);
   
           if (sc->req_busaddr != 0)
                   bus_dmamap_unload(sc->req_dmat, sc->req_map);
           if (sc->req_frames != NULL)
                   bus_dmamem_free(sc->req_dmat, sc->req_frames, sc->req_map);
           if (sc->req_dmat != NULL)
                   bus_dma_tag_destroy(sc->req_dmat);
   
           if (sc->chains != NULL)
                   free(sc->chains, M_MPT2);
           if (sc->commands != NULL) {
                   for (i = 1; i < sc->num_reqs; i++) {
                           cm = &sc->commands[i];
                           bus_dmamap_destroy(sc->buffer_dmat, cm->cm_dmamap);
                   }
                   free(sc->commands, M_MPT2);
           }
           if (sc->buffer_dmat != NULL)
                   bus_dma_tag_destroy(sc->buffer_dmat);
   
           mps_pci_free_interrupts(sc);
           free(sc->queues, M_MPT2);
           sc->queues = NULL;
   }
   
   /* 
    * The terms diag reset and hard reset are used interchangeably in the MPI
    * docs to mean resetting the controller chip.  In this code diag reset
    * cleans everything up, and the hard reset function just sends the reset
    * sequence to the chip.  This should probably be refactored so that every
    * subsystem gets a reset notification of some sort, and can clean up
    * appropriately.
    */
   int
   mps_reinit(struct mps_softc *sc)
   {
           int error;
           struct mpssas_softc *sassc;
   
           sassc = sc->sassc;
   
           MPS_FUNCTRACE(sc);
   
           mtx_assert(&sc->mps_mtx, MA_OWNED);
   
           mps_dprint(sc, MPS_INIT|MPS_INFO, "Reinitializing controller\n");
           if (sc->mps_flags & MPS_FLAGS_DIAGRESET) {
                   mps_dprint(sc, MPS_INIT, "Reset already in progress\n");
                   return 0;
           }
   
           /* make sure the completion callbacks can recognize they're getting
            * a NULL cm_reply due to a reset.
            */
           sc->mps_flags |= MPS_FLAGS_DIAGRESET;
   
           /*
            * Mask interrupts here.
            */
           mps_dprint(sc, MPS_INIT, "masking interrupts and resetting\n");
           mps_mask_intr(sc);
   
           error = mps_diag_reset(sc, CAN_SLEEP);
           if (error != 0) {
                   /* XXXSL No need to panic here */
                   panic("%s hard reset failed with error %d\n",
                       __func__, error);
           }
   
           /* Restore the PCI state, including the MSI-X registers */
           mps_pci_restore(sc);
   
           /* Give the I/O subsystem special priority to get itself prepared */
           mpssas_handle_reinit(sc);
   
           /*
            * Get IOC Facts and allocate all structures based on this information.
            * The attach function will also call mps_iocfacts_allocate at startup.
            * If relevant values have changed in IOC Facts, this function will free
            * all of the memory based on IOC Facts and reallocate that memory.
            */
           if ((error = mps_iocfacts_allocate(sc, FALSE)) != 0) {
                   panic("%s IOC Facts based allocation failed with error %d\n",
                       __func__, error);
           }
   
           /*
            * Mapping structures will be re-allocated after getting IOC Page8, so
            * free these structures here.
            */
           mps_mapping_exit(sc);
   
           /*
            * The static page function currently read is IOC Page8.  Others can be
            * added in future.  It's possible that the values in IOC Page8 have
            * changed after a Diag Reset due to user modification, so always read
            * these.  Interrupts are masked, so unmask them before getting config
            * pages.
            */
           mps_unmask_intr(sc);
           sc->mps_flags &= ~MPS_FLAGS_DIAGRESET;
           mps_base_static_config_pages(sc);
   
           /*
            * Some mapping info is based in IOC Page8 data, so re-initialize the
            * mapping tables.
            */
           mps_mapping_initialize(sc);
   
           /*
            * Restart will reload the event masks clobbered by the reset, and
            * then enable the port.
            */
           mps_reregister_events(sc);
   
           /* the end of discovery will release the simq, so we're done. */
           mps_dprint(sc, MPS_INIT|MPS_XINFO, "Finished sc %p post %u free %u\n", 
               sc, sc->replypostindex, sc->replyfreeindex);
   
           mpssas_release_simq_reinit(sassc);
           mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
   
           return 0;
   }
   
   /* Wait for the chip to ACK a word that we've put into its FIFO 
    * Wait for <timeout> seconds. In single loop wait for busy loop
    * for 500 microseconds.
    * Total is [ 0.5 * (2000 * <timeout>) ] in miliseconds.
    * */
   static int
   mps_wait_db_ack(struct mps_softc *sc, int timeout, int sleep_flag)
   {
   
           u32 cntdn, count;
           u32 int_status;
           u32 doorbell;
   
           count = 0;
           cntdn = (sleep_flag == CAN_SLEEP) ? 1000*timeout : 2000*timeout;
           do {
                   int_status = mps_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET);
                   if (!(int_status & MPI2_HIS_SYS2IOC_DB_STATUS)) {
                           mps_dprint(sc, MPS_TRACE, 
                           "%s: successful count(%d), timeout(%d)\n",
                           __func__, count, timeout);
                   return 0;
                   } else if (int_status & MPI2_HIS_IOC2SYS_DB_STATUS) {
                           doorbell = mps_regread(sc, MPI2_DOORBELL_OFFSET);
                           if ((doorbell & MPI2_IOC_STATE_MASK) ==
                                   MPI2_IOC_STATE_FAULT) {
                                   mps_dprint(sc, MPS_FAULT, 
                                           "fault_state(0x%04x)!\n", doorbell);
                                   return (EFAULT);
                           }
                   } else if (int_status == 0xFFFFFFFF)
                           goto out;
   
                   /* If it can sleep, sleep for 1 milisecond, else busy loop for 
                   * 0.5 milisecond */
                   if (mtx_owned(&sc->mps_mtx) && sleep_flag == CAN_SLEEP)
                           msleep(&sc->msleep_fake_chan, &sc->mps_mtx, 0, 
                           "mpsdba", hz/1000);
                   else if (sleep_flag == CAN_SLEEP)
                           pause("mpsdba", hz/1000);
                   else
                           DELAY(500);
                   count++;
           } while (--cntdn);
   
           out:
           mps_dprint(sc, MPS_FAULT, "%s: failed due to timeout count(%d), "
                   "int_status(%x)!\n", __func__, count, int_status);
           return (ETIMEDOUT);
   
   }
   
   /* Wait for the chip to signal that the next word in its FIFO can be fetched */
   static int
   mps_wait_db_int(struct mps_softc *sc)
   {
           int retry;
   
           for (retry = 0; retry < MPS_DB_MAX_WAIT; retry++) {
                   if ((mps_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET) &
                       MPI2_HIS_IOC2SYS_DB_STATUS) != 0)
                           return (0);
                   DELAY(2000);
           }
           return (ETIMEDOUT);
   }
   
   /* Step through the synchronous command state machine, i.e. "Doorbell mode" */
   static int
   mps_request_sync(struct mps_softc *sc, void *req, MPI2_DEFAULT_REPLY *reply,
       int req_sz, int reply_sz, int timeout)
   {
           uint32_t *data32;
           uint16_t *data16;
           int i, count, ioc_sz, residual;
           int sleep_flags = CAN_SLEEP;
   
           if (curthread->td_no_sleeping != 0)
                   sleep_flags = NO_SLEEP;
   
           /* Step 1 */
           mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
   
           /* Step 2 */
           if (mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED)
                   return (EBUSY);
   
           /* Step 3
            * Announce that a message is coming through the doorbell.  Messages
            * are pushed at 32bit words, so round up if needed.
            */
           count = (req_sz + 3) / 4;
           mps_regwrite(sc, MPI2_DOORBELL_OFFSET,
               (MPI2_FUNCTION_HANDSHAKE << MPI2_DOORBELL_FUNCTION_SHIFT) |
               (count << MPI2_DOORBELL_ADD_DWORDS_SHIFT));
   
           /* Step 4 */
           if (mps_wait_db_int(sc) ||
               (mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED) == 0) {
                   mps_dprint(sc, MPS_FAULT, "Doorbell failed to activate\n");
                   return (ENXIO);
           }
           mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
           if (mps_wait_db_ack(sc, 5, sleep_flags) != 0) {
                  mps_dprint(sc, MPS_FAULT, "Doorbell handshake failed\n");
                  return (ENXIO);
          }
  
          /* Step 5 */
          /* Clock out the message data synchronously in 32-bit dwords*/
          data32 = (uint32_t *)req;
          for (i = 0; i < count; i++) {
                  mps_regwrite(sc, MPI2_DOORBELL_OFFSET, htole32(data32[i]));
                  if (mps_wait_db_ack(sc, 5, sleep_flags) != 0) {
                          mps_dprint(sc, MPS_FAULT,
                              "Timeout while writing doorbell\n");
                          return (ENXIO);
                  }
          }
  
          /* Step 6 */
          /* Clock in the reply in 16-bit words.  The total length of the
           * message is always in the 4th byte, so clock out the first 2 words
           * manually, then loop the rest.
           */
          data16 = (uint16_t *)reply;
          if (mps_wait_db_int(sc) != 0) {
                  mps_dprint(sc, MPS_FAULT, "Timeout reading doorbell 0\n");
                  return (ENXIO);
          }
          data16[0] =
              mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_DATA_MASK;
          mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
          if (mps_wait_db_int(sc) != 0) {
                  mps_dprint(sc, MPS_FAULT, "Timeout reading doorbell 1\n");
                  return (ENXIO);
          }
          data16[1] =
              mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_DATA_MASK;
          mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
  
          /* Number of 32bit words in the message */
          ioc_sz = reply->MsgLength;
  
          /*
           * Figure out how many 16bit words to clock in without overrunning.
           * The precision loss with dividing reply_sz can safely be
           * ignored because the messages can only be multiples of 32bits.
           */
          residual = 0;
          count = MIN((reply_sz / 4), ioc_sz) * 2;
          if (count < ioc_sz * 2) {
                  residual = ioc_sz * 2 - count;
                  mps_dprint(sc, MPS_ERROR, "Driver error, throwing away %d "
                      "residual message words\n", residual);
          }
  
          for (i = 2; i < count; i++) {
                  if (mps_wait_db_int(sc) != 0) {
                          mps_dprint(sc, MPS_FAULT,
                              "Timeout reading doorbell %d\n", i);
                          return (ENXIO);
                  }
                  data16[i] = mps_regread(sc, MPI2_DOORBELL_OFFSET) &
                      MPI2_DOORBELL_DATA_MASK;
                  mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
          }
  
          /*
           * Pull out residual words that won't fit into the provided buffer.
           * This keeps the chip from hanging due to a driver programming
           * error.
           */
          while (residual--) {
                  if (mps_wait_db_int(sc) != 0) {
                          mps_dprint(sc, MPS_FAULT,
                              "Timeout reading doorbell\n");
                          return (ENXIO);
                  }
                  (void)mps_regread(sc, MPI2_DOORBELL_OFFSET);
                  mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
          }
  
          /* Step 7 */
          if (mps_wait_db_int(sc) != 0) {
                  mps_dprint(sc, MPS_FAULT, "Timeout waiting to exit doorbell\n");
                  return (ENXIO);
          }
          if (mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED)
                  mps_dprint(sc, MPS_FAULT, "Warning, doorbell still active\n");
          mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
  
          return (0);
  }
  
  static void
  mps_enqueue_request(struct mps_softc *sc, struct mps_command *cm)
  {
          reply_descriptor rd;
          MPS_FUNCTRACE(sc);
          mps_dprint(sc, MPS_TRACE, "SMID %u cm %p ccb %p\n",
              cm->cm_desc.Default.SMID, cm, cm->cm_ccb);
  
          if (sc->mps_flags & MPS_FLAGS_ATTACH_DONE && !(sc->mps_flags & MPS_FLAGS_SHUTDOWN))
                  mtx_assert(&sc->mps_mtx, MA_OWNED);
  
          if (++sc->io_cmds_active > sc->io_cmds_highwater)
                  sc->io_cmds_highwater++;
          rd.u.low = cm->cm_desc.Words.Low;
          rd.u.high = cm->cm_desc.Words.High;
          rd.word = htole64(rd.word);
  
          KASSERT(cm->cm_state == MPS_CM_STATE_BUSY, ("command not busy\n"));
          cm->cm_state = MPS_CM_STATE_INQUEUE;
  
          /* TODO-We may need to make below regwrite atomic */
          mps_regwrite(sc, MPI2_REQUEST_DESCRIPTOR_POST_LOW_OFFSET,
              rd.u.low);
          mps_regwrite(sc, MPI2_REQUEST_DESCRIPTOR_POST_HIGH_OFFSET,
              rd.u.high);
  }
  
  /*
   * Just the FACTS, ma'am.
   */
  static int
  mps_get_iocfacts(struct mps_softc *sc, MPI2_IOC_FACTS_REPLY *facts)
  {
          MPI2_DEFAULT_REPLY *reply;
          MPI2_IOC_FACTS_REQUEST request;
          int error, req_sz, reply_sz;
  
          MPS_FUNCTRACE(sc);
          mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);
  
          req_sz = sizeof(MPI2_IOC_FACTS_REQUEST);
          reply_sz = sizeof(MPI2_IOC_FACTS_REPLY);
          reply = (MPI2_DEFAULT_REPLY *)facts;
  
          bzero(&request, req_sz);
          request.Function = MPI2_FUNCTION_IOC_FACTS;
          error = mps_request_sync(sc, &request, reply, req_sz, reply_sz, 5);
          mps_dprint(sc, MPS_INIT, "%s exit error= %d\n", __func__, error);
  
          return (error);
  }
  
  static int
  mps_send_iocinit(struct mps_softc *sc)
  {
          MPI2_IOC_INIT_REQUEST   init;
          MPI2_DEFAULT_REPLY      reply;
          int req_sz, reply_sz, error;
          struct timeval now;
          uint64_t time_in_msec;
  
          MPS_FUNCTRACE(sc);
          mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);
  
          /* Do a quick sanity check on proper initialization */
          if ((sc->pqdepth == 0) || (sc->fqdepth == 0) || (sc->reqframesz == 0)
              || (sc->replyframesz == 0)) {
                  mps_dprint(sc, MPS_INIT|MPS_ERROR,
                      "Driver not fully initialized for IOCInit\n");
                  return (EINVAL);
          }
  
          req_sz = sizeof(MPI2_IOC_INIT_REQUEST);
          reply_sz = sizeof(MPI2_IOC_INIT_REPLY);
          bzero(&init, req_sz);
          bzero(&reply, reply_sz);
  
          /*
           * Fill in the init block.  Note that most addresses are
           * deliberately in the lower 32bits of memory.  This is a micro-
           * optimzation for PCI/PCIX, though it's not clear if it helps PCIe.
           */
          init.Function = MPI2_FUNCTION_IOC_INIT;
          init.WhoInit = MPI2_WHOINIT_HOST_DRIVER;
          init.MsgVersion = htole16(MPI2_VERSION);
          init.HeaderVersion = htole16(MPI2_HEADER_VERSION);
          init.SystemRequestFrameSize = htole16((uint16_t)(sc->reqframesz / 4));
          init.ReplyDescriptorPostQueueDepth = htole16(sc->pqdepth);
          init.ReplyFreeQueueDepth = htole16(sc->fqdepth);
          init.SenseBufferAddressHigh = 0;
          init.SystemReplyAddressHigh = 0;
          init.SystemRequestFrameBaseAddress.High = 0;
          init.SystemRequestFrameBaseAddress.Low = htole32((uint32_t)sc->req_busaddr);
          init.ReplyDescriptorPostQueueAddress.High = 0;
          init.ReplyDescriptorPostQueueAddress.Low = htole32((uint32_t)sc->post_busaddr);
          init.ReplyFreeQueueAddress.High = 0;
          init.ReplyFreeQueueAddress.Low = htole32((uint32_t)sc->free_busaddr);
          getmicrotime(&now);
          time_in_msec = (now.tv_sec * 1000 + now.tv_usec/1000);
          init.TimeStamp.High = htole32((time_in_msec >> 32) & 0xFFFFFFFF);
          init.TimeStamp.Low = htole32(time_in_msec & 0xFFFFFFFF);
  
          error = mps_request_sync(sc, &init, &reply, req_sz, reply_sz, 5);
          if ((reply.IOCStatus & MPI2_IOCSTATUS_MASK) != MPI2_IOCSTATUS_SUCCESS)
                  error = ENXIO;
  
          mps_dprint(sc, MPS_INIT, "IOCInit status= 0x%x\n", reply.IOCStatus);
          mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
          return (error);
  }
  
  void
  mps_memaddr_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
  {
          bus_addr_t *addr;
  
          addr = arg;
          *addr = segs[0].ds_addr;
  }
  
  void
  mps_memaddr_wait_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
  {
          struct mps_busdma_context *ctx;
          int need_unload, need_free;
  
          ctx = (struct mps_busdma_context *)arg;
          need_unload = 0;
          need_free = 0;
  
          mps_lock(ctx->softc);
          ctx->error = error;
          ctx->completed = 1;
          if ((error == 0) && (ctx->abandoned == 0)) {
                  *ctx->addr = segs[0].ds_addr;
          } else {
                  if (nsegs != 0)
                          need_unload = 1;
                  if (ctx->abandoned != 0)
                          need_free = 1;
          }
          if (need_free == 0)
                  wakeup(ctx);
  
          mps_unlock(ctx->softc);
  
          if (need_unload != 0) {
                  bus_dmamap_unload(ctx->buffer_dmat,
                                    ctx->buffer_dmamap);
                  *ctx->addr = 0;
          }
  
          if (need_free != 0)
                  free(ctx, M_MPSUSER);
  }
  
  static int
  mps_alloc_queues(struct mps_softc *sc)
  {
          struct mps_queue *q;
          u_int nq, i;
  
          nq = sc->msi_msgs;
          mps_dprint(sc, MPS_INIT|MPS_XINFO, "Allocating %d I/O queues\n", nq);
  
          sc->queues = malloc(sizeof(struct mps_queue) * nq, M_MPT2,
              M_NOWAIT|M_ZERO);
          if (sc->queues == NULL)
                  return (ENOMEM);
  
          for (i = 0; i < nq; i++) {
                  q = &sc->queues[i];
                  mps_dprint(sc, MPS_INIT, "Configuring queue %d %p\n", i, q);
                  q->sc = sc;
                  q->qnum = i;
          }
  
          return (0);
  }
  
  static int
  mps_alloc_hw_queues(struct mps_softc *sc)
  {
          bus_addr_t queues_busaddr;
          uint8_t *queues;
          int qsize, fqsize, pqsize;
  
          /*
           * The reply free queue contains 4 byte entries in multiples of 16 and
           * aligned on a 16 byte boundary. There must always be an unused entry.
           * This queue supplies fresh reply frames for the firmware to use.
           *
           * The reply descriptor post queue contains 8 byte entries in
           * multiples of 16 and aligned on a 16 byte boundary.  This queue
           * contains filled-in reply frames sent from the firmware to the host.
           *
           * These two queues are allocated together for simplicity.
           */
          sc->fqdepth = roundup2(sc->num_replies + 1, 16);
          sc->pqdepth = roundup2(sc->num_replies + 1, 16);
          fqsize= sc->fqdepth * 4;
          pqsize = sc->pqdepth * 8;
          qsize = fqsize + pqsize;
  
          if (bus_dma_tag_create( sc->mps_parent_dmat,    /* parent */
                                  16, 0,                  /* algnmnt, boundary */
                                  BUS_SPACE_MAXADDR_32BIT,/* lowaddr */
                                  BUS_SPACE_MAXADDR,      /* highaddr */
                                  NULL, NULL,             /* filter, filterarg */
                                  qsize,                  /* maxsize */
                                  1,                      /* nsegments */
                                  qsize,                  /* maxsegsize */
                                  0,                      /* flags */
                                  NULL, NULL,             /* lockfunc, lockarg */
                                  &sc->queues_dmat)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate queues DMA tag\n");
                  return (ENOMEM);
          }
          if (bus_dmamem_alloc(sc->queues_dmat, (void **)&queues, BUS_DMA_NOWAIT,
              &sc->queues_map)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate queues memory\n");
                  return (ENOMEM);
          }
          bzero(queues, qsize);
          bus_dmamap_load(sc->queues_dmat, sc->queues_map, queues, qsize,
              mps_memaddr_cb, &queues_busaddr, 0);
  
          sc->free_queue = (uint32_t *)queues;
          sc->free_busaddr = queues_busaddr;
          sc->post_queue = (MPI2_REPLY_DESCRIPTORS_UNION *)(queues + fqsize);
          sc->post_busaddr = queues_busaddr + fqsize;
          mps_dprint(sc, MPS_INIT, "free queue busaddr= %#016jx size= %d\n",
              (uintmax_t)sc->free_busaddr, fqsize);
          mps_dprint(sc, MPS_INIT, "reply queue busaddr= %#016jx size= %d\n",
              (uintmax_t)sc->post_busaddr, pqsize);
  
          return (0);
  }
  
  static int
  mps_alloc_replies(struct mps_softc *sc)
  {
          int rsize, num_replies;
  
          /* Store the reply frame size in bytes rather than as 32bit words */
          sc->replyframesz = sc->facts->ReplyFrameSize * 4;
  
          /*
           * sc->num_replies should be one less than sc->fqdepth.  We need to
           * allocate space for sc->fqdepth replies, but only sc->num_replies
           * replies can be used at once.
           */
          num_replies = max(sc->fqdepth, sc->num_replies);
  
          rsize = sc->replyframesz * num_replies; 
          if (bus_dma_tag_create( sc->mps_parent_dmat,    /* parent */
                                  4, 0,                   /* algnmnt, boundary */
                                  BUS_SPACE_MAXADDR_32BIT,/* lowaddr */
                                  BUS_SPACE_MAXADDR,      /* highaddr */
                                  NULL, NULL,             /* filter, filterarg */
                                  rsize,                  /* maxsize */
                                  1,                      /* nsegments */
                                  rsize,                  /* maxsegsize */
                                  0,                      /* flags */
                                  NULL, NULL,             /* lockfunc, lockarg */
                                  &sc->reply_dmat)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate replies DMA tag\n");
                  return (ENOMEM);
          }
          if (bus_dmamem_alloc(sc->reply_dmat, (void **)&sc->reply_frames,
              BUS_DMA_NOWAIT, &sc->reply_map)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate replies memory\n");
                  return (ENOMEM);
          }
          bzero(sc->reply_frames, rsize);
          bus_dmamap_load(sc->reply_dmat, sc->reply_map, sc->reply_frames, rsize,
              mps_memaddr_cb, &sc->reply_busaddr, 0);
  
          mps_dprint(sc, MPS_INIT, "reply frames busaddr= %#016jx size= %d\n",
              (uintmax_t)sc->reply_busaddr, rsize);
  
          return (0);
  }
  
  static void
  mps_load_chains_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
  {
          struct mps_softc *sc = arg;
          struct mps_chain *chain;
          bus_size_t bo;
          int i, o, s;
  
          if (error != 0)
                  return;
  
          for (i = 0, o = 0, s = 0; s < nsegs; s++) {
                  for (bo = 0; bo + sc->reqframesz <= segs[s].ds_len;
                      bo += sc->reqframesz) {
                          chain = &sc->chains[i++];
                          chain->chain =(MPI2_SGE_IO_UNION *)(sc->chain_frames+o);
                          chain->chain_busaddr = segs[s].ds_addr + bo;
                          o += sc->reqframesz;
                          mps_free_chain(sc, chain);
                  }
                  if (bo != segs[s].ds_len)
                          o += segs[s].ds_len - bo;
          }
          sc->chain_free_lowwater = i;
  }
  
  static int
  mps_alloc_requests(struct mps_softc *sc)
  {
          struct mps_command *cm;
          int i, rsize, nsegs;
  
          rsize = sc->reqframesz * sc->num_reqs;
          if (bus_dma_tag_create( sc->mps_parent_dmat,    /* parent */
                                  16, 0,                  /* algnmnt, boundary */
                                  BUS_SPACE_MAXADDR_32BIT,/* lowaddr */
                                  BUS_SPACE_MAXADDR,      /* highaddr */
                                  NULL, NULL,             /* filter, filterarg */
                                  rsize,                  /* maxsize */
                                  1,                      /* nsegments */
                                  rsize,                  /* maxsegsize */
                                  0,                      /* flags */
                                  NULL, NULL,             /* lockfunc, lockarg */
                                  &sc->req_dmat)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate request DMA tag\n");
                  return (ENOMEM);
          }
          if (bus_dmamem_alloc(sc->req_dmat, (void **)&sc->req_frames,
              BUS_DMA_NOWAIT, &sc->req_map)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate request memory\n");
                  return (ENOMEM);
          }
          bzero(sc->req_frames, rsize);
          bus_dmamap_load(sc->req_dmat, sc->req_map, sc->req_frames, rsize,
              mps_memaddr_cb, &sc->req_busaddr, 0);
          mps_dprint(sc, MPS_INIT, "request frames busaddr= %#016jx size= %d\n",
              (uintmax_t)sc->req_busaddr, rsize);
  
          sc->chains = malloc(sizeof(struct mps_chain) * sc->num_chains, M_MPT2,
              M_NOWAIT | M_ZERO);
          if (!sc->chains) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate chain memory\n");
                  return (ENOMEM);
          }
          rsize = sc->reqframesz * sc->num_chains;
          if (bus_dma_tag_create( sc->mps_parent_dmat,    /* parent */
                                  16, 0,                  /* algnmnt, boundary */
                                  BUS_SPACE_MAXADDR_32BIT,/* lowaddr */
                                  BUS_SPACE_MAXADDR,      /* highaddr */
                                  NULL, NULL,             /* filter, filterarg */
                                  rsize,                  /* maxsize */
                                  howmany(rsize, PAGE_SIZE), /* nsegments */
                                  rsize,                  /* maxsegsize */
                                  0,                      /* flags */
                                  NULL, NULL,             /* lockfunc, lockarg */
                                  &sc->chain_dmat)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate chain DMA tag\n");
                  return (ENOMEM);
          }
          if (bus_dmamem_alloc(sc->chain_dmat, (void **)&sc->chain_frames,
              BUS_DMA_NOWAIT | BUS_DMA_ZERO, &sc->chain_map)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate chain memory\n");
                  return (ENOMEM);
          }
          if (bus_dmamap_load(sc->chain_dmat, sc->chain_map, sc->chain_frames,
              rsize, mps_load_chains_cb, sc, BUS_DMA_NOWAIT)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot load chain memory\n");
                  bus_dmamem_free(sc->chain_dmat, sc->chain_frames,
                      sc->chain_map);
                  return (ENOMEM);
          }
  
          rsize = MPS_SENSE_LEN * sc->num_reqs;
          if (bus_dma_tag_create( sc->mps_parent_dmat,    /* parent */
                                  1, 0,                   /* algnmnt, boundary */
                                  BUS_SPACE_MAXADDR_32BIT,/* lowaddr */
                                  BUS_SPACE_MAXADDR,      /* highaddr */
                                  NULL, NULL,             /* filter, filterarg */
                                  rsize,                  /* maxsize */
                                  1,                      /* nsegments */
                                  rsize,                  /* maxsegsize */
                                  0,                      /* flags */
                                  NULL, NULL,             /* lockfunc, lockarg */
                                  &sc->sense_dmat)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate sense DMA tag\n");
                  return (ENOMEM);
          }
          if (bus_dmamem_alloc(sc->sense_dmat, (void **)&sc->sense_frames,
              BUS_DMA_NOWAIT, &sc->sense_map)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate sense memory\n");
                  return (ENOMEM);
          }
          bzero(sc->sense_frames, rsize);
          bus_dmamap_load(sc->sense_dmat, sc->sense_map, sc->sense_frames, rsize,
              mps_memaddr_cb, &sc->sense_busaddr, 0);
          mps_dprint(sc, MPS_INIT, "sense frames busaddr= %#016jx size= %d\n",
              (uintmax_t)sc->sense_busaddr, rsize);
  
          nsegs = (sc->maxio / PAGE_SIZE) + 1;
          if (bus_dma_tag_create( sc->mps_parent_dmat,    /* parent */
                                  1, 0,                   /* algnmnt, boundary */
                                  BUS_SPACE_MAXADDR,      /* lowaddr */
                                  BUS_SPACE_MAXADDR,      /* highaddr */
                                  NULL, NULL,             /* filter, filterarg */
                                  BUS_SPACE_MAXSIZE_32BIT,/* maxsize */
                                  nsegs,                  /* nsegments */
                                  BUS_SPACE_MAXSIZE_24BIT,/* maxsegsize */
                                  BUS_DMA_ALLOCNOW,       /* flags */
                                  busdma_lock_mutex,      /* lockfunc */
                                  &sc->mps_mtx,           /* lockarg */
                                  &sc->buffer_dmat)) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate buffer DMA tag\n");
                  return (ENOMEM);
          }
  
          /*
           * SMID 0 cannot be used as a free command per the firmware spec.
           * Just drop that command instead of risking accounting bugs.
           */
          sc->commands = malloc(sizeof(struct mps_command) * sc->num_reqs,
              M_MPT2, M_WAITOK | M_ZERO);
          if(!sc->commands) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate command memory\n");
                  return (ENOMEM);
          }
          for (i = 1; i < sc->num_reqs; i++) {
                  cm = &sc->commands[i];
                  cm->cm_req = sc->req_frames + i * sc->reqframesz;
                  cm->cm_req_busaddr = sc->req_busaddr + i * sc->reqframesz;
                  cm->cm_sense = &sc->sense_frames[i];
                  cm->cm_sense_busaddr = sc->sense_busaddr + i * MPS_SENSE_LEN;
                  cm->cm_desc.Default.SMID = i;
                  cm->cm_sc = sc;
                  cm->cm_state = MPS_CM_STATE_BUSY;
                  TAILQ_INIT(&cm->cm_chain_list);
                  callout_init_mtx(&cm->cm_callout, &sc->mps_mtx, 0);
  
                  /* XXX Is a failure here a critical problem? */
                  if (bus_dmamap_create(sc->buffer_dmat, 0, &cm->cm_dmamap) == 0)
                          if (i <= sc->num_prireqs)
                                  mps_free_high_priority_command(sc, cm);
                          else
                                  mps_free_command(sc, cm);
                  else {
                          panic("failed to allocate command %d\n", i);
                          sc->num_reqs = i;
                          break;
                  }
          }
  
          return (0);
  }
  
  static int
  mps_init_queues(struct mps_softc *sc)
  {
          int i;
  
          memset((uint8_t *)sc->post_queue, 0xff, sc->pqdepth * 8);
  
          /*
           * According to the spec, we need to use one less reply than we
           * have space for on the queue.  So sc->num_replies (the number we
           * use) should be less than sc->fqdepth (allocated size).
           */
          if (sc->num_replies >= sc->fqdepth)
                  return (EINVAL);
  
          /*
           * Initialize all of the free queue entries.
           */
          for (i = 0; i < sc->fqdepth; i++)
                  sc->free_queue[i] = sc->reply_busaddr + (i * sc->replyframesz);
          sc->replyfreeindex = sc->num_replies;
  
          return (0);
  }
  
  /* Get the driver parameter tunables.  Lowest priority are the driver defaults.
   * Next are the global settings, if they exist.  Highest are the per-unit
   * settings, if they exist.
   */
  void
  mps_get_tunables(struct mps_softc *sc)
  {
          char tmpstr[80], mps_debug[80];
  
          /* XXX default to some debugging for now */
          sc->mps_debug = MPS_INFO|MPS_FAULT;
          sc->disable_msix = 0;
          sc->disable_msi = 0;
          sc->max_msix = MPS_MSIX_MAX;
          sc->max_chains = MPS_CHAIN_FRAMES;
          sc->max_io_pages = MPS_MAXIO_PAGES;
          sc->enable_ssu = MPS_SSU_ENABLE_SSD_DISABLE_HDD;
          sc->spinup_wait_time = DEFAULT_SPINUP_WAIT;
          sc->use_phynum = 1;
          sc->max_reqframes = MPS_REQ_FRAMES;
          sc->max_prireqframes = MPS_PRI_REQ_FRAMES;
          sc->max_replyframes = MPS_REPLY_FRAMES;
          sc->max_evtframes = MPS_EVT_REPLY_FRAMES;
  
          /*
           * Grab the global variables.
           */
          bzero(mps_debug, 80);
          if (TUNABLE_STR_FETCH("hw.mps.debug_level", mps_debug, 80) != 0)
                  mps_parse_debug(sc, mps_debug);
          TUNABLE_INT_FETCH("hw.mps.disable_msix", &sc->disable_msix);
          TUNABLE_INT_FETCH("hw.mps.disable_msi", &sc->disable_msi);
          TUNABLE_INT_FETCH("hw.mps.max_msix", &sc->max_msix);
          TUNABLE_INT_FETCH("hw.mps.max_chains", &sc->max_chains);
          TUNABLE_INT_FETCH("hw.mps.max_io_pages", &sc->max_io_pages);
          TUNABLE_INT_FETCH("hw.mps.enable_ssu", &sc->enable_ssu);
          TUNABLE_INT_FETCH("hw.mps.spinup_wait_time", &sc->spinup_wait_time);
          TUNABLE_INT_FETCH("hw.mps.use_phy_num", &sc->use_phynum);
          TUNABLE_INT_FETCH("hw.mps.max_reqframes", &sc->max_reqframes);
          TUNABLE_INT_FETCH("hw.mps.max_prireqframes", &sc->max_prireqframes);
          TUNABLE_INT_FETCH("hw.mps.max_replyframes", &sc->max_replyframes);
          TUNABLE_INT_FETCH("hw.mps.max_evtframes", &sc->max_evtframes);
  
          /* Grab the unit-instance variables */
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.debug_level",
              device_get_unit(sc->mps_dev));
          bzero(mps_debug, 80);
          if (TUNABLE_STR_FETCH(tmpstr, mps_debug, 80) != 0)
                  mps_parse_debug(sc, mps_debug);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.disable_msix",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->disable_msix);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.disable_msi",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->disable_msi);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_msix",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->max_msix);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_chains",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->max_chains);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_io_pages",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->max_io_pages);
  
          bzero(sc->exclude_ids, sizeof(sc->exclude_ids));
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.exclude_ids",
              device_get_unit(sc->mps_dev));
          TUNABLE_STR_FETCH(tmpstr, sc->exclude_ids, sizeof(sc->exclude_ids));
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.enable_ssu",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->enable_ssu);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.spinup_wait_time",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->spinup_wait_time);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.use_phy_num",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->use_phynum);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_reqframes",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->max_reqframes);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_prireqframes",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->max_prireqframes);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_replyframes",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->max_replyframes);
  
          snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_evtframes",
              device_get_unit(sc->mps_dev));
          TUNABLE_INT_FETCH(tmpstr, &sc->max_evtframes);
  
  }
  
  static void
  mps_setup_sysctl(struct mps_softc *sc)
  {
          struct sysctl_ctx_list  *sysctl_ctx = NULL;
          struct sysctl_oid       *sysctl_tree = NULL;
          char tmpstr[80], tmpstr2[80];
  
          /*
           * Setup the sysctl variable so the user can change the debug level
           * on the fly.
           */
          snprintf(tmpstr, sizeof(tmpstr), "MPS controller %d",
              device_get_unit(sc->mps_dev));
          snprintf(tmpstr2, sizeof(tmpstr2), "%d", device_get_unit(sc->mps_dev));
  
          sysctl_ctx = device_get_sysctl_ctx(sc->mps_dev);
          if (sysctl_ctx != NULL)
                  sysctl_tree = device_get_sysctl_tree(sc->mps_dev);
  
          if (sysctl_tree == NULL) {
                  sysctl_ctx_init(&sc->sysctl_ctx);
                  sc->sysctl_tree = SYSCTL_ADD_NODE(&sc->sysctl_ctx,
                      SYSCTL_STATIC_CHILDREN(_hw_mps), OID_AUTO, tmpstr2,
                      CTLFLAG_RD, 0, tmpstr);
                  if (sc->sysctl_tree == NULL)
                          return;
                  sysctl_ctx = &sc->sysctl_ctx;
                  sysctl_tree = sc->sysctl_tree;
          }
  
          SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "debug_level", CTLTYPE_STRING | CTLFLAG_RW |CTLFLAG_MPSAFE,
              sc, 0, mps_debug_sysctl, "A", "mps debug level");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "disable_msix", CTLFLAG_RD, &sc->disable_msix, 0,
              "Disable the use of MSI-X interrupts");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "disable_msi", CTLFLAG_RD, &sc->disable_msi, 0,
              "Disable the use of MSI interrupts");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "max_msix", CTLFLAG_RD, &sc->max_msix, 0,
              "User-defined maximum number of MSIX queues");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "msix_msgs", CTLFLAG_RD, &sc->msi_msgs, 0,
              "Negotiated number of MSIX queues");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "max_reqframes", CTLFLAG_RD, &sc->max_reqframes, 0,
              "Total number of allocated request frames");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "max_prireqframes", CTLFLAG_RD, &sc->max_prireqframes, 0,
              "Total number of allocated high priority request frames");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "max_replyframes", CTLFLAG_RD, &sc->max_replyframes, 0,
              "Total number of allocated reply frames");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "max_evtframes", CTLFLAG_RD, &sc->max_evtframes, 0,
              "Total number of event frames allocated");
  
          SYSCTL_ADD_STRING(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "firmware_version", CTLFLAG_RW, sc->fw_version,
              strlen(sc->fw_version), "firmware version");
  
          SYSCTL_ADD_STRING(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "driver_version", CTLFLAG_RW, MPS_DRIVER_VERSION,
              strlen(MPS_DRIVER_VERSION), "driver version");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "io_cmds_active", CTLFLAG_RD,
              &sc->io_cmds_active, 0, "number of currently active commands");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "io_cmds_highwater", CTLFLAG_RD,
              &sc->io_cmds_highwater, 0, "maximum active commands seen");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "chain_free", CTLFLAG_RD,
              &sc->chain_free, 0, "number of free chain elements");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "chain_free_lowwater", CTLFLAG_RD,
              &sc->chain_free_lowwater, 0,"lowest number of free chain elements");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "max_chains", CTLFLAG_RD,
              &sc->max_chains, 0,"maximum chain frames that will be allocated");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "max_io_pages", CTLFLAG_RD,
              &sc->max_io_pages, 0,"maximum pages to allow per I/O (if <1 use "
              "IOCFacts)");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "enable_ssu", CTLFLAG_RW, &sc->enable_ssu, 0,
              "enable SSU to SATA SSD/HDD at shutdown");
  
          SYSCTL_ADD_UQUAD(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "chain_alloc_fail", CTLFLAG_RD,
              &sc->chain_alloc_fail, "chain allocation failures");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "spinup_wait_time", CTLFLAG_RD,
              &sc->spinup_wait_time, DEFAULT_SPINUP_WAIT, "seconds to wait for "
              "spinup after SATA ID error");
  
          SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "mapping_table_dump", CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
              mps_mapping_dump, "A", "Mapping Table Dump");
  
          SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "encl_table_dump", CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
              mps_mapping_encl_dump, "A", "Enclosure Table Dump");
  
          SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "dump_reqs", CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_SKIP, sc, 0,
              mps_dump_reqs, "I", "Dump Active Requests");
  
          SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
              OID_AUTO, "use_phy_num", CTLFLAG_RD, &sc->use_phynum, 0,
              "Use the phy number for enumeration");
  }
  
  static struct mps_debug_string {
          char    *name;
          int     flag;
  } mps_debug_strings[] = {
          {"info", MPS_INFO},
          {"fault", MPS_FAULT},
          {"event", MPS_EVENT},
          {"log", MPS_LOG},
          {"recovery", MPS_RECOVERY},
          {"error", MPS_ERROR},
          {"init", MPS_INIT},
          {"xinfo", MPS_XINFO},
          {"user", MPS_USER},
          {"mapping", MPS_MAPPING},
          {"trace", MPS_TRACE}
  };
  
  enum mps_debug_level_combiner {
          COMB_NONE,
          COMB_ADD,
          COMB_SUB
  };
  
  static int
  mps_debug_sysctl(SYSCTL_HANDLER_ARGS)
  {
          struct mps_softc *sc;
          struct mps_debug_string *string;
          struct sbuf *sbuf;
          char *buffer;
          size_t sz;
          int i, len, debug, error;
  
          sc = (struct mps_softc *)arg1;
  
          error = sysctl_wire_old_buffer(req, 0);
          if (error != 0)
                  return (error);
  
          sbuf = sbuf_new_for_sysctl(NULL, NULL, 128, req);
          debug = sc->mps_debug;
  
          sbuf_printf(sbuf, "%#x", debug);
  
          sz = sizeof(mps_debug_strings) / sizeof(mps_debug_strings[0]);
          for (i = 0; i < sz; i++) {
                  string = &mps_debug_strings[i];
                  if (debug & string->flag)
                          sbuf_printf(sbuf, ",%s", string->name);
          }
  
          error = sbuf_finish(sbuf);
          sbuf_delete(sbuf);
  
          if (error || req->newptr == NULL)
                  return (error);
  
          len = req->newlen - req->newidx;
          if (len == 0)
                  return (0);
  
          buffer = malloc(len, M_MPT2, M_ZERO|M_WAITOK);
          error = SYSCTL_IN(req, buffer, len);
  
          mps_parse_debug(sc, buffer);
  
          free(buffer, M_MPT2);
          return (error);
  }
  
  static void
  mps_parse_debug(struct mps_softc *sc, char *list)
  {
          struct mps_debug_string *string;
          enum mps_debug_level_combiner op;
          char *token, *endtoken;
          size_t sz;
          int flags, i;
  
          if (list == NULL || *list == '\0')
                  return;
  
          if (*list == '+') {
                  op = COMB_ADD;
                  list++;
          } else if (*list == '-') {
                  op = COMB_SUB;
                  list++;
          } else
                  op = COMB_NONE;
          if (*list == '\0')
                  return;
  
          flags = 0;
          sz = sizeof(mps_debug_strings) / sizeof(mps_debug_strings[0]);
          while ((token = strsep(&list, ":,")) != NULL) {
  
                  /* Handle integer flags */
                  flags |= strtol(token, &endtoken, 0);
                  if (token != endtoken)
                          continue;
  
                  /* Handle text flags */
                  for (i = 0; i < sz; i++) {
                          string = &mps_debug_strings[i];
                          if (strcasecmp(token, string->name) == 0) {
                                  flags |= string->flag;
                                  break;
                          }
                  }
          }
  
          switch (op) {
          case COMB_NONE:
                  sc->mps_debug = flags;
                  break;
          case COMB_ADD:
                  sc->mps_debug |= flags;
                  break;
          case COMB_SUB:
                  sc->mps_debug &= (~flags);
                  break;
          }
  
          return;
  }
  
  struct mps_dumpreq_hdr {
          uint32_t        smid;
          uint32_t        state;
          uint32_t        numframes;
          uint32_t        deschi;
          uint32_t        desclo;
  };
  
  static int
  mps_dump_reqs(SYSCTL_HANDLER_ARGS)
  {
          struct mps_softc *sc;
          struct mps_chain *chain, *chain1;
          struct mps_command *cm;
          struct mps_dumpreq_hdr hdr;
          struct sbuf *sb;
          uint32_t smid, state;
          int i, numreqs, error = 0;
  
          sc = (struct mps_softc *)arg1;
  
          if ((error = priv_check(curthread, PRIV_DRIVER)) != 0) {
                  printf("priv check error %d\n", error);
                  return (error);
          }
  
          state = MPS_CM_STATE_INQUEUE;
          smid = 1;
          numreqs = sc->num_reqs;
  
          if (req->newptr != NULL)
                  return (EINVAL);
  
          if (smid == 0 || smid > sc->num_reqs)
                  return (EINVAL);
          if (numreqs <= 0 || (numreqs + smid > sc->num_reqs))
                  numreqs = sc->num_reqs;
          sb = sbuf_new_for_sysctl(NULL, NULL, 4096, req);
  
          /* Best effort, no locking */
          for (i = smid; i < numreqs; i++) {
                  cm = &sc->commands[i];
                  if (cm->cm_state != state)
                          continue;
                  hdr.smid = i;
                  hdr.state = cm->cm_state;
                  hdr.numframes = 1;
                  hdr.deschi = cm->cm_desc.Words.High;
                  hdr.desclo = cm->cm_desc.Words.Low;
                  TAILQ_FOREACH_SAFE(chain, &cm->cm_chain_list, chain_link,
                     chain1)
                          hdr.numframes++;
                  sbuf_bcat(sb, &hdr, sizeof(hdr));
                  sbuf_bcat(sb, cm->cm_req, 128);
                  TAILQ_FOREACH_SAFE(chain, &cm->cm_chain_list, chain_link,
                      chain1)
                          sbuf_bcat(sb, chain->chain, 128);
          }
  
          error = sbuf_finish(sb);
          sbuf_delete(sb);
          return (error);
  }
  
  int
  mps_attach(struct mps_softc *sc)
  {
          int error;
  
          MPS_FUNCTRACE(sc);
          mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);
  
          mtx_init(&sc->mps_mtx, "MPT2SAS lock", NULL, MTX_DEF);
          callout_init_mtx(&sc->periodic, &sc->mps_mtx, 0);
          callout_init_mtx(&sc->device_check_callout, &sc->mps_mtx, 0);
          TAILQ_INIT(&sc->event_list);
          timevalclear(&sc->lastfail);
  
          if ((error = mps_transition_ready(sc)) != 0) {
                  mps_dprint(sc, MPS_INIT|MPS_FAULT, "failed to transition "
                      "ready\n");
                  return (error);
          }
  
          sc->facts = malloc(sizeof(MPI2_IOC_FACTS_REPLY), M_MPT2,
              M_ZERO|M_NOWAIT);
          if(!sc->facts) {
                  mps_dprint(sc, MPS_INIT|MPS_FAULT, "Cannot allocate memory, "
                      "exit\n");
                  return (ENOMEM);
          }
  
          /*
           * Get IOC Facts and allocate all structures based on this information.
           * A Diag Reset will also call mps_iocfacts_allocate and re-read the IOC
           * Facts. If relevant values have changed in IOC Facts, this function
           * will free all of the memory based on IOC Facts and reallocate that
           * memory.  If this fails, any allocated memory should already be freed.
           */
          if ((error = mps_iocfacts_allocate(sc, TRUE)) != 0) {
                  mps_dprint(sc, MPS_INIT|MPS_FAULT, "IOC Facts based allocation "
                      "failed with error %d, exit\n", error);
                  return (error);
          }
  
          /* Start the periodic watchdog check on the IOC Doorbell */
          mps_periodic(sc);
  
          /*
           * The portenable will kick off discovery events that will drive the
           * rest of the initialization process.  The CAM/SAS module will
           * hold up the boot sequence until discovery is complete.
           */
          sc->mps_ich.ich_func = mps_startup;
          sc->mps_ich.ich_arg = sc;
          if (config_intrhook_establish(&sc->mps_ich) != 0) {
                  mps_dprint(sc, MPS_INIT|MPS_ERROR,
                      "Cannot establish MPS config hook\n");
                  error = EINVAL;
          }
  
          /*
           * Allow IR to shutdown gracefully when shutdown occurs.
           */
          sc->shutdown_eh = EVENTHANDLER_REGISTER(shutdown_final,
              mpssas_ir_shutdown, sc, SHUTDOWN_PRI_DEFAULT);
  
          if (sc->shutdown_eh == NULL)
                  mps_dprint(sc, MPS_INIT|MPS_ERROR,
                      "shutdown event registration failed\n");
  
          mps_setup_sysctl(sc);
  
          sc->mps_flags |= MPS_FLAGS_ATTACH_DONE;
          mps_dprint(sc, MPS_INIT, "%s exit error= %d\n", __func__, error);
  
          return (error);
  }
  
  /* Run through any late-start handlers. */
  static void
  mps_startup(void *arg)
  {
          struct mps_softc *sc;
  
          sc = (struct mps_softc *)arg;
          mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);
  
          mps_lock(sc);
          mps_unmask_intr(sc);
  
          /* initialize device mapping tables */
          mps_base_static_config_pages(sc);
          mps_mapping_initialize(sc);
          mpssas_startup(sc);
          mps_unlock(sc);
  
          mps_dprint(sc, MPS_INIT, "disestablish config intrhook\n");
          config_intrhook_disestablish(&sc->mps_ich);
          sc->mps_ich.ich_arg = NULL;
  
          mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
  }
  
  /* Periodic watchdog.  Is called with the driver lock already held. */
  static void
  mps_periodic(void *arg)
  {
          struct mps_softc *sc;
          uint32_t db;
  
          sc = (struct mps_softc *)arg;
          if (sc->mps_flags & MPS_FLAGS_SHUTDOWN)
                  return;
  
          db = mps_regread(sc, MPI2_DOORBELL_OFFSET);
          if ((db & MPI2_IOC_STATE_MASK) == MPI2_IOC_STATE_FAULT) {
                  mps_dprint(sc, MPS_FAULT, "IOC Fault 0x%08x, Resetting\n", db);
                  mps_reinit(sc);
          }
  
          callout_reset(&sc->periodic, MPS_PERIODIC_DELAY * hz, mps_periodic, sc);
  }
  
  static void
  mps_log_evt_handler(struct mps_softc *sc, uintptr_t data,
      MPI2_EVENT_NOTIFICATION_REPLY *event)
  {
          MPI2_EVENT_DATA_LOG_ENTRY_ADDED *entry;
  
          MPS_DPRINT_EVENT(sc, generic, event);
  
          switch (event->Event) {
          case MPI2_EVENT_LOG_DATA:
                  mps_dprint(sc, MPS_EVENT, "MPI2_EVENT_LOG_DATA:\n");
                  if (sc->mps_debug & MPS_EVENT)
                          hexdump(event->EventData, event->EventDataLength, NULL, 0);
                  break;
          case MPI2_EVENT_LOG_ENTRY_ADDED:
                  entry = (MPI2_EVENT_DATA_LOG_ENTRY_ADDED *)event->EventData;
                  mps_dprint(sc, MPS_EVENT, "MPI2_EVENT_LOG_ENTRY_ADDED event "
                      "0x%x Sequence %d:\n", entry->LogEntryQualifier,
                       entry->LogSequence);
                  break;
          default:
                  break;
          }
          return;
  }
  
  static int
  mps_attach_log(struct mps_softc *sc)
  {
          u32 events[MPI2_EVENT_NOTIFY_EVENTMASK_WORDS];
  
          bzero(events, 16);
          setbit(events, MPI2_EVENT_LOG_DATA);
          setbit(events, MPI2_EVENT_LOG_ENTRY_ADDED);
  
          mps_register_events(sc, events, mps_log_evt_handler, NULL,
              &sc->mps_log_eh);
  
          return (0);
  }
  
  static int
  mps_detach_log(struct mps_softc *sc)
  {
  
          if (sc->mps_log_eh != NULL)
                  mps_deregister_events(sc, sc->mps_log_eh);
          return (0);
  }
  
  /*
   * Free all of the driver resources and detach submodules.  Should be called
   * without the lock held.
   */
  int
  mps_free(struct mps_softc *sc)
  {
          int error;
  
          mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);
          /* Turn off the watchdog */
          mps_lock(sc);
          sc->mps_flags |= MPS_FLAGS_SHUTDOWN;
          mps_unlock(sc);
          /* Lock must not be held for this */
          callout_drain(&sc->periodic);
          callout_drain(&sc->device_check_callout);
  
          if (((error = mps_detach_log(sc)) != 0) ||
              ((error = mps_detach_sas(sc)) != 0)) {
                  mps_dprint(sc, MPS_INIT|MPS_FAULT, "failed to detach "
                      "subsystems, exit\n");
                  return (error);
          }
  
          mps_detach_user(sc);
  
          /* Put the IOC back in the READY state. */
          mps_lock(sc);
          if ((error = mps_transition_ready(sc)) != 0) {
                  mps_unlock(sc);
                  return (error);
          }
          mps_unlock(sc);
  
          if (sc->facts != NULL)
                  free(sc->facts, M_MPT2);
  
          /*
           * Free all buffers that are based on IOC Facts.  A Diag Reset may need
           * to free these buffers too.
           */
          mps_iocfacts_free(sc);
  
          if (sc->sysctl_tree != NULL)
                  sysctl_ctx_free(&sc->sysctl_ctx);
  
          /* Deregister the shutdown function */
          if (sc->shutdown_eh != NULL)
                  EVENTHANDLER_DEREGISTER(shutdown_final, sc->shutdown_eh);
  
          mtx_destroy(&sc->mps_mtx);
          mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
  
          return (0);
  }
  
  static __inline void
  mps_complete_command(struct mps_softc *sc, struct mps_command *cm)
  {
          MPS_FUNCTRACE(sc);
  
          if (cm == NULL) {
                  mps_dprint(sc, MPS_ERROR, "Completing NULL command\n");
                  return;
          }
  
          if (cm->cm_flags & MPS_CM_FLAGS_POLLED)
                  cm->cm_flags |= MPS_CM_FLAGS_COMPLETE;
  
          if (cm->cm_complete != NULL) {
                  mps_dprint(sc, MPS_TRACE,
                             "%s cm %p calling cm_complete %p data %p reply %p\n",
                             __func__, cm, cm->cm_complete, cm->cm_complete_data,
                             cm->cm_reply);
                  cm->cm_complete(sc, cm);
          }
  
          if (cm->cm_flags & MPS_CM_FLAGS_WAKEUP) {
                  mps_dprint(sc, MPS_TRACE, "waking up %p\n", cm);
                  wakeup(cm);
          }
  
          if (cm->cm_sc->io_cmds_active != 0) {
                  cm->cm_sc->io_cmds_active--;
          } else {
                  mps_dprint(sc, MPS_ERROR, "Warning: io_cmds_active is "
                      "out of sync - resynching to 0\n");
          }
  }
  
  
  static void
  mps_sas_log_info(struct mps_softc *sc , u32 log_info)
  {
          union loginfo_type {
                  u32     loginfo;
                  struct {
                          u32     subcode:16;
                          u32     code:8;
                          u32     originator:4;
                          u32     bus_type:4;
                  } dw;
          };
          union loginfo_type sas_loginfo;
          char *originator_str = NULL;
  
          sas_loginfo.loginfo = log_info;
          if (sas_loginfo.dw.bus_type != 3 /*SAS*/)
                  return;
  
          /* each nexus loss loginfo */
          if (log_info == 0x31170000)
                  return;
  
          /* eat the loginfos associated with task aborts */
          if ((log_info == 30050000 || log_info ==
              0x31140000 || log_info == 0x31130000))
                  return;
  
          switch (sas_loginfo.dw.originator) {
          case 0:
                  originator_str = "IOP";
                  break;
          case 1:
                  originator_str = "PL";
                  break;
          case 2:
                  originator_str = "IR";
                  break;
  }
  
          mps_dprint(sc, MPS_LOG, "log_info(0x%08x): originator(%s), "
          "code(0x%02x), sub_code(0x%04x)\n", log_info,
          originator_str, sas_loginfo.dw.code,
          sas_loginfo.dw.subcode);
  }
  
  static void
  mps_display_reply_info(struct mps_softc *sc, uint8_t *reply)
  {
          MPI2DefaultReply_t *mpi_reply;
          u16 sc_status;
  
          mpi_reply = (MPI2DefaultReply_t*)reply;
          sc_status = le16toh(mpi_reply->IOCStatus);
          if (sc_status & MPI2_IOCSTATUS_FLAG_LOG_INFO_AVAILABLE)
                  mps_sas_log_info(sc, le32toh(mpi_reply->IOCLogInfo));
  }
  void
  mps_intr(void *data)
  {
          struct mps_softc *sc;
          uint32_t status;
  
          sc = (struct mps_softc *)data;
          mps_dprint(sc, MPS_TRACE, "%s\n", __func__);
  
          /*
           * Check interrupt status register to flush the bus.  This is
           * needed for both INTx interrupts and driver-driven polling
           */
          status = mps_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET);
          if ((status & MPI2_HIS_REPLY_DESCRIPTOR_INTERRUPT) == 0)
                  return;
  
          mps_lock(sc);
          mps_intr_locked(data);
          mps_unlock(sc);
          return;
  }
  
  /*
   * In theory, MSI/MSIX interrupts shouldn't need to read any registers on the
   * chip.  Hopefully this theory is correct.
   */
  void
  mps_intr_msi(void *data)
  {
          struct mps_softc *sc;
  
          sc = (struct mps_softc *)data;
          mps_dprint(sc, MPS_TRACE, "%s\n", __func__);
          mps_lock(sc);
          mps_intr_locked(data);
          mps_unlock(sc);
          return;
  }
  
  /*
   * The locking is overly broad and simplistic, but easy to deal with for now.
   */
  void
  mps_intr_locked(void *data)
  {
          MPI2_REPLY_DESCRIPTORS_UNION *desc;
          struct mps_softc *sc;
          struct mps_command *cm = NULL;
          uint8_t flags;
          u_int pq;
          MPI2_DIAG_RELEASE_REPLY *rel_rep;
          mps_fw_diagnostic_buffer_t *pBuffer;
  
          sc = (struct mps_softc *)data;
  
          pq = sc->replypostindex;
          mps_dprint(sc, MPS_TRACE,
              "%s sc %p starting with replypostindex %u\n", 
              __func__, sc, sc->replypostindex);
  
          for ( ;; ) {
                  cm = NULL;
                  desc = &sc->post_queue[sc->replypostindex];
                  flags = desc->Default.ReplyFlags &
                      MPI2_RPY_DESCRIPT_FLAGS_TYPE_MASK;
                  if ((flags == MPI2_RPY_DESCRIPT_FLAGS_UNUSED)
                   || (le32toh(desc->Words.High) == 0xffffffff))
                          break;
  
                  /* increment the replypostindex now, so that event handlers
                   * and cm completion handlers which decide to do a diag
                   * reset can zero it without it getting incremented again
                   * afterwards, and we break out of this loop on the next
                   * iteration since the reply post queue has been cleared to
                   * 0xFF and all descriptors look unused (which they are).
                   */
                  if (++sc->replypostindex >= sc->pqdepth)
                          sc->replypostindex = 0;
  
                  switch (flags) {
                  case MPI2_RPY_DESCRIPT_FLAGS_SCSI_IO_SUCCESS:
                          cm = &sc->commands[le16toh(desc->SCSIIOSuccess.SMID)];
                          KASSERT(cm->cm_state == MPS_CM_STATE_INQUEUE,
                              ("command not inqueue\n"));
                          cm->cm_state = MPS_CM_STATE_BUSY;
                          cm->cm_reply = NULL;
                          break;
                  case MPI2_RPY_DESCRIPT_FLAGS_ADDRESS_REPLY:
                  {
                          uint32_t baddr;
                          uint8_t *reply;
  
                          /*
                           * Re-compose the reply address from the address
                           * sent back from the chip.  The ReplyFrameAddress
                           * is the lower 32 bits of the physical address of
                           * particular reply frame.  Convert that address to
                           * host format, and then use that to provide the
                           * offset against the virtual address base
                           * (sc->reply_frames).
                           */
                          baddr = le32toh(desc->AddressReply.ReplyFrameAddress);
                          reply = sc->reply_frames +
                                  (baddr - ((uint32_t)sc->reply_busaddr));
                          /*
                           * Make sure the reply we got back is in a valid
                           * range.  If not, go ahead and panic here, since
                           * we'll probably panic as soon as we deference the
                           * reply pointer anyway.
                           */
                          if ((reply < sc->reply_frames)
                           || (reply > (sc->reply_frames +
                               (sc->fqdepth * sc->replyframesz)))) {
                                  printf("%s: WARNING: reply %p out of range!\n",
                                         __func__, reply);
                                  printf("%s: reply_frames %p, fqdepth %d, "
                                         "frame size %d\n", __func__,
                                         sc->reply_frames, sc->fqdepth,
                                         sc->replyframesz);
                                  printf("%s: baddr %#x,\n", __func__, baddr);
                                  /* LSI-TODO. See Linux Code for Graceful exit */
                                  panic("Reply address out of range");
                          }
                          if (le16toh(desc->AddressReply.SMID) == 0) {
                                  if (((MPI2_DEFAULT_REPLY *)reply)->Function ==
                                      MPI2_FUNCTION_DIAG_BUFFER_POST) {
                                          /*
                                           * If SMID is 0 for Diag Buffer Post,
                                           * this implies that the reply is due to
                                           * a release function with a status that
                                           * the buffer has been released.  Set
                                           * the buffer flags accordingly.
                                           */
                                          rel_rep =
                                              (MPI2_DIAG_RELEASE_REPLY *)reply;
                                          if ((le16toh(rel_rep->IOCStatus) &
                                              MPI2_IOCSTATUS_MASK) ==
                                              MPI2_IOCSTATUS_DIAGNOSTIC_RELEASED)
                                          {
                                                  pBuffer =
                                                      &sc->fw_diag_buffer_list[
                                                      rel_rep->BufferType];
                                                  pBuffer->valid_data = TRUE;
                                                  pBuffer->owned_by_firmware =
                                                      FALSE;
                                                  pBuffer->immediate = FALSE;
                                          }
                                  } else
                                          mps_dispatch_event(sc, baddr,
                                              (MPI2_EVENT_NOTIFICATION_REPLY *)
                                              reply);
                          } else {
                                  cm = &sc->commands[
                                      le16toh(desc->AddressReply.SMID)];
                                  KASSERT(cm->cm_state == MPS_CM_STATE_INQUEUE,
                                      ("command not inqueue\n"));
                                  cm->cm_state = MPS_CM_STATE_BUSY;
                                  cm->cm_reply = reply;
                                  cm->cm_reply_data = le32toh(
                                      desc->AddressReply.ReplyFrameAddress);
                          }
                          break;
                  }
                  case MPI2_RPY_DESCRIPT_FLAGS_TARGETASSIST_SUCCESS:
                  case MPI2_RPY_DESCRIPT_FLAGS_TARGET_COMMAND_BUFFER:
                  case MPI2_RPY_DESCRIPT_FLAGS_RAID_ACCELERATOR_SUCCESS:
                  default:
                          /* Unhandled */
                          mps_dprint(sc, MPS_ERROR, "Unhandled reply 0x%x\n",
                              desc->Default.ReplyFlags);
                          cm = NULL;
                          break;
                  }
                  
  
                  if (cm != NULL) {
                          // Print Error reply frame
                          if (cm->cm_reply)
                                  mps_display_reply_info(sc,cm->cm_reply);
                          mps_complete_command(sc, cm);
                  }
  
                  desc->Words.Low = 0xffffffff;
                  desc->Words.High = 0xffffffff;
          }
  
          if (pq != sc->replypostindex) {
                  mps_dprint(sc, MPS_TRACE, "%s sc %p writing postindex %d\n",
                      __func__, sc, sc->replypostindex);
                  mps_regwrite(sc, MPI2_REPLY_POST_HOST_INDEX_OFFSET,
                      sc->replypostindex);
          }
  
          return;
  }
  
  static void
  mps_dispatch_event(struct mps_softc *sc, uintptr_t data,
      MPI2_EVENT_NOTIFICATION_REPLY *reply)
  {
          struct mps_event_handle *eh;
          int event, handled = 0;
  
          event = le16toh(reply->Event);
          TAILQ_FOREACH(eh, &sc->event_list, eh_list) {
                  if (isset(eh->mask, event)) {
                          eh->callback(sc, data, reply);
                          handled++;
                  }
          }
  
          if (handled == 0)
                  mps_dprint(sc, MPS_EVENT, "Unhandled event 0x%x\n", le16toh(event));
  
          /*
           * This is the only place that the event/reply should be freed.
           * Anything wanting to hold onto the event data should have
           * already copied it into their own storage.
           */
          mps_free_reply(sc, data);
  }
  
  static void
  mps_reregister_events_complete(struct mps_softc *sc, struct mps_command *cm)
  {
          mps_dprint(sc, MPS_TRACE, "%s\n", __func__);
  
          if (cm->cm_reply)
                  MPS_DPRINT_EVENT(sc, generic,
                          (MPI2_EVENT_NOTIFICATION_REPLY *)cm->cm_reply);
  
          mps_free_command(sc, cm);
  
          /* next, send a port enable */
          mpssas_startup(sc);
  }
  
  /*
   * For both register_events and update_events, the caller supplies a bitmap
   * of events that it _wants_.  These functions then turn that into a bitmask
   * suitable for the controller.
   */
  int
  mps_register_events(struct mps_softc *sc, u32 *mask,
      mps_evt_callback_t *cb, void *data, struct mps_event_handle **handle)
  {
          struct mps_event_handle *eh;
          int error = 0;
  
          eh = malloc(sizeof(struct mps_event_handle), M_MPT2, M_WAITOK|M_ZERO);
          if(!eh) {
                  mps_dprint(sc, MPS_ERROR, "Cannot allocate event memory\n");
                  return (ENOMEM);
          }
          eh->callback = cb;
          eh->data = data;
          TAILQ_INSERT_TAIL(&sc->event_list, eh, eh_list);
          if (mask != NULL)
                  error = mps_update_events(sc, eh, mask);
          *handle = eh;
  
          return (error);
  }
  
  int
  mps_update_events(struct mps_softc *sc, struct mps_event_handle *handle,
      u32 *mask)
  {
          MPI2_EVENT_NOTIFICATION_REQUEST *evtreq;
          MPI2_EVENT_NOTIFICATION_REPLY *reply = NULL;
          struct mps_command *cm;
          int error, i;
  
          mps_dprint(sc, MPS_TRACE, "%s\n", __func__);
  
          if ((mask != NULL) && (handle != NULL))
                  bcopy(mask, &handle->mask[0], sizeof(u32) * 
                                  MPI2_EVENT_NOTIFY_EVENTMASK_WORDS);
      
          for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                  sc->event_mask[i] = -1;
  
          for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                  sc->event_mask[i] &= ~handle->mask[i];
  
  
          if ((cm = mps_alloc_command(sc)) == NULL)
                  return (EBUSY);
          evtreq = (MPI2_EVENT_NOTIFICATION_REQUEST *)cm->cm_req;
          evtreq->Function = MPI2_FUNCTION_EVENT_NOTIFICATION;
          evtreq->MsgFlags = 0;
          evtreq->SASBroadcastPrimitiveMasks = 0;
  #ifdef MPS_DEBUG_ALL_EVENTS
          {
                  u_char fullmask[16];
                  memset(fullmask, 0x00, 16);
                  bcopy(fullmask, &evtreq->EventMasks[0], sizeof(u32) * 
                                  MPI2_EVENT_NOTIFY_EVENTMASK_WORDS);
          }
  #else
          for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                  evtreq->EventMasks[i] =
                      htole32(sc->event_mask[i]);
  #endif
          cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
          cm->cm_data = NULL;
  
          error = mps_wait_command(sc, &cm, 60, 0);
          if (cm != NULL)
                  reply = (MPI2_EVENT_NOTIFICATION_REPLY *)cm->cm_reply;
          if ((reply == NULL) ||
              (reply->IOCStatus & MPI2_IOCSTATUS_MASK) != MPI2_IOCSTATUS_SUCCESS)
                  error = ENXIO;
  
          if (reply)
                  MPS_DPRINT_EVENT(sc, generic, reply);
  
          mps_dprint(sc, MPS_TRACE, "%s finished error %d\n", __func__, error);
  
          if (cm != NULL)
                  mps_free_command(sc, cm);
          return (error);
  }
  
  static int
  mps_reregister_events(struct mps_softc *sc)
  {
          MPI2_EVENT_NOTIFICATION_REQUEST *evtreq;
          struct mps_command *cm;
          struct mps_event_handle *eh;
          int error, i;
  
          mps_dprint(sc, MPS_TRACE, "%s\n", __func__);
  
          /* first, reregister events */
  
          for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                  sc->event_mask[i] = -1;
  
          TAILQ_FOREACH(eh, &sc->event_list, eh_list) {
                  for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                          sc->event_mask[i] &= ~eh->mask[i];
          }
  
          if ((cm = mps_alloc_command(sc)) == NULL)
                  return (EBUSY);
          evtreq = (MPI2_EVENT_NOTIFICATION_REQUEST *)cm->cm_req;
          evtreq->Function = MPI2_FUNCTION_EVENT_NOTIFICATION;
          evtreq->MsgFlags = 0;
          evtreq->SASBroadcastPrimitiveMasks = 0;
  #ifdef MPS_DEBUG_ALL_EVENTS
          {
                  u_char fullmask[16];
                  memset(fullmask, 0x00, 16);
                  bcopy(fullmask, &evtreq->EventMasks[0], sizeof(u32) *
                          MPI2_EVENT_NOTIFY_EVENTMASK_WORDS);
          }
  #else
          for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                  evtreq->EventMasks[i] =
                      htole32(sc->event_mask[i]);
  #endif
          cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
          cm->cm_data = NULL;
          cm->cm_complete = mps_reregister_events_complete;
  
          error = mps_map_command(sc, cm);
  
          mps_dprint(sc, MPS_TRACE, "%s finished with error %d\n", __func__,
              error);
          return (error);
  }
  
  void
  mps_deregister_events(struct mps_softc *sc, struct mps_event_handle *handle)
  {
  
          TAILQ_REMOVE(&sc->event_list, handle, eh_list);
          free(handle, M_MPT2);
  }
  
  /*
   * Add a chain element as the next SGE for the specified command.
   * Reset cm_sge and cm_sgesize to indicate all the available space.
   */
  static int
  mps_add_chain(struct mps_command *cm)
  {
          MPI2_SGE_CHAIN32 *sgc;
          struct mps_chain *chain;
          u_int space;
  
          if (cm->cm_sglsize < MPS_SGC_SIZE)
                  panic("MPS: Need SGE Error Code\n");
  
          chain = mps_alloc_chain(cm->cm_sc);
          if (chain == NULL)
                  return (ENOBUFS);
  
          space = cm->cm_sc->reqframesz;
  
          /*
           * Note: a double-linked list is used to make it easier to
           * walk for debugging.
           */
          TAILQ_INSERT_TAIL(&cm->cm_chain_list, chain, chain_link);
  
          sgc = (MPI2_SGE_CHAIN32 *)&cm->cm_sge->MpiChain;
          sgc->Length = htole16(space);
          sgc->NextChainOffset = 0;
          /* TODO Looks like bug in Setting sgc->Flags. 
           *      sgc->Flags = ( MPI2_SGE_FLAGS_CHAIN_ELEMENT | MPI2_SGE_FLAGS_64_BIT_ADDRESSING |
           *                  MPI2_SGE_FLAGS_SYSTEM_ADDRESS) << MPI2_SGE_FLAGS_SHIFT
           *      This is fine.. because we are not using simple element. In case of 
           *      MPI2_SGE_CHAIN32, we have separate Length and Flags feild.
           */
          sgc->Flags = MPI2_SGE_FLAGS_CHAIN_ELEMENT;
          sgc->Address = htole32(chain->chain_busaddr);
  
          cm->cm_sge = (MPI2_SGE_IO_UNION *)&chain->chain->MpiSimple;
          cm->cm_sglsize = space;
          return (0);
  }
  
  /*
   * Add one scatter-gather element (chain, simple, transaction context)
   * to the scatter-gather list for a command.  Maintain cm_sglsize and
   * cm_sge as the remaining size and pointer to the next SGE to fill
   * in, respectively.
   */
  int
  mps_push_sge(struct mps_command *cm, void *sgep, size_t len, int segsleft)
  {
          MPI2_SGE_TRANSACTION_UNION *tc = sgep;
          MPI2_SGE_SIMPLE64 *sge = sgep;
          int error, type;
          uint32_t saved_buf_len, saved_address_low, saved_address_high;
  
          type = (tc->Flags & MPI2_SGE_FLAGS_ELEMENT_MASK);
  
  #ifdef INVARIANTS
          switch (type) {
          case MPI2_SGE_FLAGS_TRANSACTION_ELEMENT: {
                  if (len != tc->DetailsLength + 4)
                          panic("TC %p length %u or %zu?", tc,
                              tc->DetailsLength + 4, len);
                  }
                  break;
          case MPI2_SGE_FLAGS_CHAIN_ELEMENT:
                  /* Driver only uses 32-bit chain elements */
                  if (len != MPS_SGC_SIZE)
                          panic("CHAIN %p length %u or %zu?", sgep,
                              MPS_SGC_SIZE, len);
                  break;
          case MPI2_SGE_FLAGS_SIMPLE_ELEMENT:
                  /* Driver only uses 64-bit SGE simple elements */
                  if (len != MPS_SGE64_SIZE)
                          panic("SGE simple %p length %u or %zu?", sge,
                              MPS_SGE64_SIZE, len);
                  if (((le32toh(sge->FlagsLength) >> MPI2_SGE_FLAGS_SHIFT) &
                      MPI2_SGE_FLAGS_ADDRESS_SIZE) == 0)
                          panic("SGE simple %p not marked 64-bit?", sge);
  
                  break;
          default:
                  panic("Unexpected SGE %p, flags %02x", tc, tc->Flags);
          }
  #endif
  
          /*
           * case 1: 1 more segment, enough room for it
           * case 2: 2 more segments, enough room for both
           * case 3: >=2 more segments, only enough room for 1 and a chain
           * case 4: >=1 more segment, enough room for only a chain
           * case 5: >=1 more segment, no room for anything (error)
           */
  
          /*
           * There should be room for at least a chain element, or this
           * code is buggy.  Case (5).
           */
          if (cm->cm_sglsize < MPS_SGC_SIZE)
                  panic("MPS: Need SGE Error Code\n");
  
          if (segsleft >= 1 && cm->cm_sglsize < len + MPS_SGC_SIZE) {
                  /*
                   * 1 or more segment, enough room for only a chain.
                   * Hope the previous element wasn't a Simple entry
                   * that needed to be marked with
                   * MPI2_SGE_FLAGS_LAST_ELEMENT.  Case (4).
                   */
                  if ((error = mps_add_chain(cm)) != 0)
                          return (error);
          }
  
          if (segsleft >= 2 &&
              cm->cm_sglsize < len + MPS_SGC_SIZE + MPS_SGE64_SIZE) {
                  /*
                   * There are 2 or more segments left to add, and only
                   * enough room for 1 and a chain.  Case (3).
                   *
                   * Mark as last element in this chain if necessary.
                   */
                  if (type == MPI2_SGE_FLAGS_SIMPLE_ELEMENT) {
                          sge->FlagsLength |= htole32(
                              MPI2_SGE_FLAGS_LAST_ELEMENT << MPI2_SGE_FLAGS_SHIFT);
                  }
  
                  /*
                   * Add the item then a chain.  Do the chain now,
                   * rather than on the next iteration, to simplify
                   * understanding the code.
                   */
                  cm->cm_sglsize -= len;
                  bcopy(sgep, cm->cm_sge, len);
                  cm->cm_sge = (MPI2_SGE_IO_UNION *)((uintptr_t)cm->cm_sge + len);
                  return (mps_add_chain(cm));
          }
  
  #ifdef INVARIANTS
          /* Case 1: 1 more segment, enough room for it. */
          if (segsleft == 1 && cm->cm_sglsize < len)
                  panic("1 seg left and no room? %u versus %zu",
                      cm->cm_sglsize, len);
  
          /* Case 2: 2 more segments, enough room for both */
          if (segsleft == 2 && cm->cm_sglsize < len + MPS_SGE64_SIZE)
                  panic("2 segs left and no room? %u versus %zu",
                      cm->cm_sglsize, len);
  #endif
  
          if (segsleft == 1 && type == MPI2_SGE_FLAGS_SIMPLE_ELEMENT) {
                  /*
                   * If this is a bi-directional request, need to account for that
                   * here.  Save the pre-filled sge values.  These will be used
                   * either for the 2nd SGL or for a single direction SGL.  If
                   * cm_out_len is non-zero, this is a bi-directional request, so
                   * fill in the OUT SGL first, then the IN SGL, otherwise just
                   * fill in the IN SGL.  Note that at this time, when filling in
                   * 2 SGL's for a bi-directional request, they both use the same
                   * DMA buffer (same cm command).
                   */
                  saved_buf_len = le32toh(sge->FlagsLength) & 0x00FFFFFF;
                  saved_address_low = sge->Address.Low;
                  saved_address_high = sge->Address.High;
                  if (cm->cm_out_len) {
                          sge->FlagsLength = htole32(cm->cm_out_len |
                              ((uint32_t)(MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
                              MPI2_SGE_FLAGS_END_OF_BUFFER |
                              MPI2_SGE_FLAGS_HOST_TO_IOC |
                              MPI2_SGE_FLAGS_64_BIT_ADDRESSING) <<
                              MPI2_SGE_FLAGS_SHIFT));
                          cm->cm_sglsize -= len;
                          bcopy(sgep, cm->cm_sge, len);
                          cm->cm_sge = (MPI2_SGE_IO_UNION *)((uintptr_t)cm->cm_sge
                              + len);
                  }
                  saved_buf_len |=
                      ((uint32_t)(MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
                      MPI2_SGE_FLAGS_END_OF_BUFFER |
                      MPI2_SGE_FLAGS_LAST_ELEMENT |
                      MPI2_SGE_FLAGS_END_OF_LIST |
                      MPI2_SGE_FLAGS_64_BIT_ADDRESSING) <<
                      MPI2_SGE_FLAGS_SHIFT);
                  if (cm->cm_flags & MPS_CM_FLAGS_DATAIN) {
                          saved_buf_len |=
                              ((uint32_t)(MPI2_SGE_FLAGS_IOC_TO_HOST) <<
                              MPI2_SGE_FLAGS_SHIFT);
                  } else {
                          saved_buf_len |=
                              ((uint32_t)(MPI2_SGE_FLAGS_HOST_TO_IOC) <<
                              MPI2_SGE_FLAGS_SHIFT);
                  }
                  sge->FlagsLength = htole32(saved_buf_len);
                  sge->Address.Low = saved_address_low;
                  sge->Address.High = saved_address_high;
          }
  
          cm->cm_sglsize -= len;
          bcopy(sgep, cm->cm_sge, len);
          cm->cm_sge = (MPI2_SGE_IO_UNION *)((uintptr_t)cm->cm_sge + len);
          return (0);
  }
  
  /*
   * Add one dma segment to the scatter-gather list for a command.
   */
  int
  mps_add_dmaseg(struct mps_command *cm, vm_paddr_t pa, size_t len, u_int flags,
      int segsleft)
  {
          MPI2_SGE_SIMPLE64 sge;
  
          /*
           * This driver always uses 64-bit address elements for simplicity.
           */
          bzero(&sge, sizeof(sge));
          flags |= MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
              MPI2_SGE_FLAGS_64_BIT_ADDRESSING;
          sge.FlagsLength = htole32(len | (flags << MPI2_SGE_FLAGS_SHIFT));
          mps_from_u64(pa, &sge.Address);
  
          return (mps_push_sge(cm, &sge, sizeof sge, segsleft));
  }
  
  static void
  mps_data_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
  {
          struct mps_softc *sc;
          struct mps_command *cm;
          u_int i, dir, sflags;
  
          cm = (struct mps_command *)arg;
          sc = cm->cm_sc;
  
          /*
           * In this case, just print out a warning and let the chip tell the
           * user they did the wrong thing.
           */
          if ((cm->cm_max_segs != 0) && (nsegs > cm->cm_max_segs)) {
                  mps_dprint(sc, MPS_ERROR,
                             "%s: warning: busdma returned %d segments, "
                             "more than the %d allowed\n", __func__, nsegs,
                             cm->cm_max_segs);
          }
  
          /*
           * Set up DMA direction flags.  Bi-directional requests are also handled
           * here.  In that case, both direction flags will be set.
           */
          sflags = 0;
          if (cm->cm_flags & MPS_CM_FLAGS_SMP_PASS) {
                  /*
                   * We have to add a special case for SMP passthrough, there
                   * is no easy way to generically handle it.  The first
                   * S/G element is used for the command (therefore the
                   * direction bit needs to be set).  The second one is used
                   * for the reply.  We'll leave it to the caller to make
                   * sure we only have two buffers.
                   */
                  /*
                   * Even though the busdma man page says it doesn't make
                   * sense to have both direction flags, it does in this case.
                   * We have one s/g element being accessed in each direction.
                   */
                  dir = BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD;
  
                  /*
                   * Set the direction flag on the first buffer in the SMP
                   * passthrough request.  We'll clear it for the second one.
                   */
                  sflags |= MPI2_SGE_FLAGS_DIRECTION |
                            MPI2_SGE_FLAGS_END_OF_BUFFER;
          } else if (cm->cm_flags & MPS_CM_FLAGS_DATAOUT) {
                  sflags |= MPI2_SGE_FLAGS_HOST_TO_IOC;
                  dir = BUS_DMASYNC_PREWRITE;
          } else
                  dir = BUS_DMASYNC_PREREAD;
  
          for (i = 0; i < nsegs; i++) {
                  if ((cm->cm_flags & MPS_CM_FLAGS_SMP_PASS) && (i != 0)) {
                          sflags &= ~MPI2_SGE_FLAGS_DIRECTION;
                  }
                  error = mps_add_dmaseg(cm, segs[i].ds_addr, segs[i].ds_len,
                      sflags, nsegs - i);
                  if (error != 0) {
                          /* Resource shortage, roll back! */
                          if (ratecheck(&sc->lastfail, &mps_chainfail_interval))
                                  mps_dprint(sc, MPS_INFO, "Out of chain frames, "
                                      "consider increasing hw.mps.max_chains.\n");
                          cm->cm_flags |= MPS_CM_FLAGS_CHAIN_FAILED;
                          mps_complete_command(sc, cm);
                          return;
                  }
          }
  
          bus_dmamap_sync(sc->buffer_dmat, cm->cm_dmamap, dir);
          mps_enqueue_request(sc, cm);
  
          return;
  }
  
  static void
  mps_data_cb2(void *arg, bus_dma_segment_t *segs, int nsegs, bus_size_t mapsize,
               int error)
  {
          mps_data_cb(arg, segs, nsegs, error);
  }
  
  /*
   * This is the routine to enqueue commands ansynchronously.
   * Note that the only error path here is from bus_dmamap_load(), which can
   * return EINPROGRESS if it is waiting for resources.  Other than this, it's
   * assumed that if you have a command in-hand, then you have enough credits
   * to use it.
   */
  int
  mps_map_command(struct mps_softc *sc, struct mps_command *cm)
  {
          int error = 0;
  
          if (cm->cm_flags & MPS_CM_FLAGS_USE_UIO) {
                  error = bus_dmamap_load_uio(sc->buffer_dmat, cm->cm_dmamap,
                      &cm->cm_uio, mps_data_cb2, cm, 0);
          } else if (cm->cm_flags & MPS_CM_FLAGS_USE_CCB) {
                  error = bus_dmamap_load_ccb(sc->buffer_dmat, cm->cm_dmamap,
                      cm->cm_data, mps_data_cb, cm, 0);
          } else if ((cm->cm_data != NULL) && (cm->cm_length != 0)) {
                  error = bus_dmamap_load(sc->buffer_dmat, cm->cm_dmamap,
                      cm->cm_data, cm->cm_length, mps_data_cb, cm, 0);
          } else {
                  /* Add a zero-length element as needed */
                  if (cm->cm_sge != NULL)
                          mps_add_dmaseg(cm, 0, 0, 0, 1);
                  mps_enqueue_request(sc, cm);    
          }
  
          return (error);
  }
  
  /*
   * This is the routine to enqueue commands synchronously.  An error of
   * EINPROGRESS from mps_map_command() is ignored since the command will
   * be executed and enqueued automatically.  Other errors come from msleep().
   */
  int
  mps_wait_command(struct mps_softc *sc, struct mps_command **cmp, int timeout,
      int sleep_flag)
  {
          int error, rc;
          struct timeval cur_time, start_time;
          struct mps_command *cm = *cmp;
  
          if (sc->mps_flags & MPS_FLAGS_DIAGRESET) 
                  return  EBUSY;
  
          cm->cm_complete = NULL;
          cm->cm_flags |= MPS_CM_FLAGS_POLLED;
          error = mps_map_command(sc, cm);
          if ((error != 0) && (error != EINPROGRESS))
                  return (error);
  
          /*
           * Check for context and wait for 50 mSec at a time until time has
           * expired or the command has finished.  If msleep can't be used, need
           * to poll.
           */
          if (curthread->td_no_sleeping != 0)
                  sleep_flag = NO_SLEEP;
          getmicrouptime(&start_time);
          if (mtx_owned(&sc->mps_mtx) && sleep_flag == CAN_SLEEP) {
                  cm->cm_flags |= MPS_CM_FLAGS_WAKEUP;
                  error = msleep(cm, &sc->mps_mtx, 0, "mpswait", timeout*hz);
                  if (error == EWOULDBLOCK) {
                          /*
                           * Record the actual elapsed time in the case of a
                           * timeout for the message below.
                           */
                          getmicrouptime(&cur_time);
                          timevalsub(&cur_time, &start_time);
                  }
          } else {
                  while ((cm->cm_flags & MPS_CM_FLAGS_COMPLETE) == 0) {
                          mps_intr_locked(sc);
                          if (sleep_flag == CAN_SLEEP)
                                  pause("mpswait", hz/20);
                          else
                                  DELAY(50000);
                  
                          getmicrouptime(&cur_time);
                          timevalsub(&cur_time, &start_time);
                          if (cur_time.tv_sec > timeout) {
                                  error = EWOULDBLOCK;
                                  break;
                          }
                  }
          }
  
          if (error == EWOULDBLOCK) {
                  mps_dprint(sc, MPS_FAULT, "Calling Reinit from %s, timeout=%d,"
                      " elapsed=%jd\n", __func__, timeout,
                      (intmax_t)cur_time.tv_sec);
                  rc = mps_reinit(sc);
                  mps_dprint(sc, MPS_FAULT, "Reinit %s\n", (rc == 0) ? "success" :
                      "failed");
                  if (sc->mps_flags & MPS_FLAGS_REALLOCATED) {
                          /*
                           * Tell the caller that we freed the command in a
                           * reinit.
                           */
                          *cmp = NULL;
                  }
                  error = ETIMEDOUT;
          }
          return (error);
  }
  
  /*
   * The MPT driver had a verbose interface for config pages.  In this driver,
   * reduce it to much simpler terms, similar to the Linux driver.
   */
  int
  mps_read_config_page(struct mps_softc *sc, struct mps_config_params *params)
  {
          MPI2_CONFIG_REQUEST *req;
          struct mps_command *cm;
          int error;
  
          if (sc->mps_flags & MPS_FLAGS_BUSY) {
                  return (EBUSY);
          }
  
          cm = mps_alloc_command(sc);
          if (cm == NULL) {
                  return (EBUSY);
          }
  
          req = (MPI2_CONFIG_REQUEST *)cm->cm_req;
          req->Function = MPI2_FUNCTION_CONFIG;
          req->Action = params->action;
          req->SGLFlags = 0;
          req->ChainOffset = 0;
          req->PageAddress = params->page_address;
          if (params->hdr.Struct.PageType == MPI2_CONFIG_PAGETYPE_EXTENDED) {
                  MPI2_CONFIG_EXTENDED_PAGE_HEADER *hdr;
  
                  hdr = &params->hdr.Ext;
                  req->ExtPageType = hdr->ExtPageType;
                  req->ExtPageLength = hdr->ExtPageLength;
                  req->Header.PageType = MPI2_CONFIG_PAGETYPE_EXTENDED;
                  req->Header.PageLength = 0; /* Must be set to zero */
                  req->Header.PageNumber = hdr->PageNumber;
                  req->Header.PageVersion = hdr->PageVersion;
          } else {
                  MPI2_CONFIG_PAGE_HEADER *hdr;
  
                  hdr = &params->hdr.Struct;
                  req->Header.PageType = hdr->PageType;
                  req->Header.PageNumber = hdr->PageNumber;
                  req->Header.PageLength = hdr->PageLength;
                  req->Header.PageVersion = hdr->PageVersion;
          }
  
          cm->cm_data = params->buffer;
          cm->cm_length = params->length;
          if (cm->cm_data != NULL) {
                  cm->cm_sge = &req->PageBufferSGE;
                  cm->cm_sglsize = sizeof(MPI2_SGE_IO_UNION);
                  cm->cm_flags = MPS_CM_FLAGS_SGE_SIMPLE | MPS_CM_FLAGS_DATAIN;
          } else
                  cm->cm_sge = NULL;
          cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
  
          cm->cm_complete_data = params;
          if (params->callback != NULL) {
                  cm->cm_complete = mps_config_complete;
                  return (mps_map_command(sc, cm));
          } else {
                  error = mps_wait_command(sc, &cm, 0, CAN_SLEEP);
                  if (error) {
                          mps_dprint(sc, MPS_FAULT,
                              "Error %d reading config page\n", error);
                          if (cm != NULL)
                                  mps_free_command(sc, cm);
                          return (error);
                  }
                  mps_config_complete(sc, cm);
          }
  
          return (0);
  }
  
  int
  mps_write_config_page(struct mps_softc *sc, struct mps_config_params *params)
  {
          return (EINVAL);
  }
  
  static void
  mps_config_complete(struct mps_softc *sc, struct mps_command *cm)
  {
          MPI2_CONFIG_REPLY *reply;
          struct mps_config_params *params;
  
          MPS_FUNCTRACE(sc);
          params = cm->cm_complete_data;
  
          if (cm->cm_data != NULL) {
                  bus_dmamap_sync(sc->buffer_dmat, cm->cm_dmamap,
                      BUS_DMASYNC_POSTREAD);
                  bus_dmamap_unload(sc->buffer_dmat, cm->cm_dmamap);
          }
  
          /*
           * XXX KDM need to do more error recovery?  This results in the
           * device in question not getting probed.
           */
          if ((cm->cm_flags & MPS_CM_FLAGS_ERROR_MASK) != 0) {
                  params->status = MPI2_IOCSTATUS_BUSY;
                  goto done;
          }
  
          reply = (MPI2_CONFIG_REPLY *)cm->cm_reply;
          if (reply == NULL) {
                  params->status = MPI2_IOCSTATUS_BUSY;
                  goto done;
          }
          params->status = reply->IOCStatus;
          if (params->hdr.Struct.PageType == MPI2_CONFIG_PAGETYPE_EXTENDED) {
                  params->hdr.Ext.ExtPageType = reply->ExtPageType;
                  params->hdr.Ext.ExtPageLength = reply->ExtPageLength;
                  params->hdr.Ext.PageType = reply->Header.PageType;
                  params->hdr.Ext.PageNumber = reply->Header.PageNumber;
                  params->hdr.Ext.PageVersion = reply->Header.PageVersion;
          } else {
                  params->hdr.Struct.PageType = reply->Header.PageType;
                  params->hdr.Struct.PageNumber = reply->Header.PageNumber;
                  params->hdr.Struct.PageLength = reply->Header.PageLength;
                  params->hdr.Struct.PageVersion = reply->Header.PageVersion;
          }
  
  done:
          mps_free_command(sc, cm);
          if (params->callback != NULL)
                  params->callback(sc, params);
  
          return;
  }