/*
 * Core routines and tables shareable across OS platforms.
 *
 * Copyright (c) 1994-2002 Justin T. Gibbs.
 * Copyright (c) 2000-2003 Adaptec Inc.
 * 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,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
 *
 * $Id: //depot/aic7xxx/aic7xxx/aic79xx.c#250 $
 */

#include "aic79xx_osm.h"
#include "aic79xx_inline.h"
#include "aicasm/aicasm_insformat.h"

/***************************** Lookup Tables **********************************/
static const char *const ahd_chip_names[] =
{
        "NONE",
        "aic7901",
        "aic7902",
        "aic7901A"
};

/*
 * Hardware error codes.
 */
struct ahd_hard_error_entry {
        uint8_t errno;
        const char *errmesg;
};

static const struct ahd_hard_error_entry ahd_hard_errors[] = {
        { DSCTMOUT,     "Discard Timer has timed out" },
        { ILLOPCODE,    "Illegal Opcode in sequencer program" },
        { SQPARERR,     "Sequencer Parity Error" },
        { DPARERR,      "Data-path Parity Error" },
        { MPARERR,      "Scratch or SCB Memory Parity Error" },
        { CIOPARERR,    "CIOBUS Parity Error" },
};
static const u_int num_errors = ARRAY_SIZE(ahd_hard_errors);

static const struct ahd_phase_table_entry ahd_phase_table[] =
{
        { P_DATAOUT,    NOP,                    "in Data-out phase"     },
        { P_DATAIN,     INITIATOR_ERROR,        "in Data-in phase"      },
        { P_DATAOUT_DT, NOP,                    "in DT Data-out phase"  },
        { P_DATAIN_DT,  INITIATOR_ERROR,        "in DT Data-in phase"   },
        { P_COMMAND,    NOP,                    "in Command phase"      },
        { P_MESGOUT,    NOP,                    "in Message-out phase"  },
        { P_STATUS,     INITIATOR_ERROR,        "in Status phase"       },
        { P_MESGIN,     MSG_PARITY_ERROR,       "in Message-in phase"   },
        { P_BUSFREE,    NOP,                    "while idle"            },
        { 0,            NOP,                    "in unknown phase"      }
};

/*
 * In most cases we only wish to itterate over real phases, so
 * exclude the last element from the count.
 */
static const u_int num_phases = ARRAY_SIZE(ahd_phase_table) - 1;

/* Our Sequencer Program */
#include "aic79xx_seq.h"

/**************************** Function Declarations ***************************/
static void             ahd_handle_transmission_error(struct ahd_softc *ahd);
static void             ahd_handle_lqiphase_error(struct ahd_softc *ahd,
                                                  u_int lqistat1);
static int              ahd_handle_pkt_busfree(struct ahd_softc *ahd,
                                               u_int busfreetime);
static int              ahd_handle_nonpkt_busfree(struct ahd_softc *ahd);
static void             ahd_handle_proto_violation(struct ahd_softc *ahd);
static void             ahd_force_renegotiation(struct ahd_softc *ahd,
                                                struct ahd_devinfo *devinfo);

static struct ahd_tmode_tstate*
                        ahd_alloc_tstate(struct ahd_softc *ahd,
                                         u_int scsi_id, char channel);
#ifdef AHD_TARGET_MODE
static void             ahd_free_tstate(struct ahd_softc *ahd,
                                        u_int scsi_id, char channel, int force);
#endif
static void             ahd_devlimited_syncrate(struct ahd_softc *ahd,
                                                struct ahd_initiator_tinfo *,
                                                u_int *period,
                                                u_int *ppr_options,
                                                role_t role);
static void             ahd_update_neg_table(struct ahd_softc *ahd,
                                             struct ahd_devinfo *devinfo,
                                             struct ahd_transinfo *tinfo);
static void             ahd_update_pending_scbs(struct ahd_softc *ahd);
static void             ahd_fetch_devinfo(struct ahd_softc *ahd,
                                          struct ahd_devinfo *devinfo);
static void             ahd_scb_devinfo(struct ahd_softc *ahd,
                                        struct ahd_devinfo *devinfo,
                                        struct scb *scb);
static void             ahd_setup_initiator_msgout(struct ahd_softc *ahd,
                                                   struct ahd_devinfo *devinfo,
                                                   struct scb *scb);
static void             ahd_build_transfer_msg(struct ahd_softc *ahd,
                                               struct ahd_devinfo *devinfo);
static void             ahd_construct_sdtr(struct ahd_softc *ahd,
                                           struct ahd_devinfo *devinfo,
                                           u_int period, u_int offset);
static void             ahd_construct_wdtr(struct ahd_softc *ahd,
                                           struct ahd_devinfo *devinfo,
                                           u_int bus_width);
static void             ahd_construct_ppr(struct ahd_softc *ahd,
                                          struct ahd_devinfo *devinfo,
                                          u_int period, u_int offset,
                                          u_int bus_width, u_int ppr_options);
static void             ahd_clear_msg_state(struct ahd_softc *ahd);
static void             ahd_handle_message_phase(struct ahd_softc *ahd);
typedef enum {
        AHDMSG_1B,
        AHDMSG_2B,
        AHDMSG_EXT
} ahd_msgtype;
static int              ahd_sent_msg(struct ahd_softc *ahd, ahd_msgtype type,
                                     u_int msgval, int full);
static int              ahd_parse_msg(struct ahd_softc *ahd,
                                      struct ahd_devinfo *devinfo);
static int              ahd_handle_msg_reject(struct ahd_softc *ahd,
                                              struct ahd_devinfo *devinfo);
static void             ahd_handle_ign_wide_residue(struct ahd_softc *ahd,
                                                struct ahd_devinfo *devinfo);
static void             ahd_reinitialize_dataptrs(struct ahd_softc *ahd);
static void             ahd_handle_devreset(struct ahd_softc *ahd,
                                            struct ahd_devinfo *devinfo,
                                            u_int lun, cam_status status,
                                            char *message, int verbose_level);
#ifdef AHD_TARGET_MODE
static void             ahd_setup_target_msgin(struct ahd_softc *ahd,
                                               struct ahd_devinfo *devinfo,
                                               struct scb *scb);
#endif

static u_int            ahd_sglist_size(struct ahd_softc *ahd);
static u_int            ahd_sglist_allocsize(struct ahd_softc *ahd);
static bus_dmamap_callback_t
                        ahd_dmamap_cb;
static void             ahd_initialize_hscbs(struct ahd_softc *ahd);
static int              ahd_init_scbdata(struct ahd_softc *ahd);
static void             ahd_fini_scbdata(struct ahd_softc *ahd);
static void             ahd_setup_iocell_workaround(struct ahd_softc *ahd);
static void             ahd_iocell_first_selection(struct ahd_softc *ahd);
static void             ahd_add_col_list(struct ahd_softc *ahd,
                                         struct scb *scb, u_int col_idx);
static void             ahd_rem_col_list(struct ahd_softc *ahd,
                                         struct scb *scb);
static void             ahd_chip_init(struct ahd_softc *ahd);
static void             ahd_qinfifo_requeue(struct ahd_softc *ahd,
                                            struct scb *prev_scb,
                                            struct scb *scb);
static int              ahd_qinfifo_count(struct ahd_softc *ahd);
static int              ahd_search_scb_list(struct ahd_softc *ahd, int target,
                                            char channel, int lun, u_int tag,
                                            role_t role, uint32_t status,
                                            ahd_search_action action,
                                            u_int *list_head, u_int *list_tail,
                                            u_int tid);
static void             ahd_stitch_tid_list(struct ahd_softc *ahd,
                                            u_int tid_prev, u_int tid_cur,
                                            u_int tid_next);
static void             ahd_add_scb_to_free_list(struct ahd_softc *ahd,
                                                 u_int scbid);
static u_int            ahd_rem_wscb(struct ahd_softc *ahd, u_int scbid,
                                     u_int prev, u_int next, u_int tid);
static void             ahd_reset_current_bus(struct ahd_softc *ahd);
static void             ahd_stat_timer(struct timer_list *t);
#ifdef AHD_DUMP_SEQ
static void             ahd_dumpseq(struct ahd_softc *ahd);
#endif
static void             ahd_loadseq(struct ahd_softc *ahd);
static int              ahd_check_patch(struct ahd_softc *ahd,
                                        const struct patch **start_patch,
                                        u_int start_instr, u_int *skip_addr);
static u_int            ahd_resolve_seqaddr(struct ahd_softc *ahd,
                                            u_int address);
static void             ahd_download_instr(struct ahd_softc *ahd,
                                           u_int instrptr, uint8_t *dconsts);
static int              ahd_probe_stack_size(struct ahd_softc *ahd);
static int              ahd_scb_active_in_fifo(struct ahd_softc *ahd,
                                               struct scb *scb);
static void             ahd_run_data_fifo(struct ahd_softc *ahd,
                                          struct scb *scb);

#ifdef AHD_TARGET_MODE
static void             ahd_queue_lstate_event(struct ahd_softc *ahd,
                                               struct ahd_tmode_lstate *lstate,
                                               u_int initiator_id,
                                               u_int event_type,
                                               u_int event_arg);
static void             ahd_update_scsiid(struct ahd_softc *ahd,
                                          u_int targid_mask);
static int              ahd_handle_target_cmd(struct ahd_softc *ahd,
                                              struct target_cmd *cmd);
#endif

static int              ahd_abort_scbs(struct ahd_softc *ahd, int target,
                                       char channel, int lun, u_int tag,
                                       role_t role, uint32_t status);
static void             ahd_alloc_scbs(struct ahd_softc *ahd);
static void             ahd_busy_tcl(struct ahd_softc *ahd, u_int tcl,
                                     u_int scbid);
static void             ahd_calc_residual(struct ahd_softc *ahd,
                                          struct scb *scb);
static void             ahd_clear_critical_section(struct ahd_softc *ahd);
static void             ahd_clear_intstat(struct ahd_softc *ahd);
static void             ahd_enable_coalescing(struct ahd_softc *ahd,
                                              int enable);
static u_int            ahd_find_busy_tcl(struct ahd_softc *ahd, u_int tcl);
static void             ahd_freeze_devq(struct ahd_softc *ahd,
                                        struct scb *scb);
static void             ahd_handle_scb_status(struct ahd_softc *ahd,
                                              struct scb *scb);
static const struct ahd_phase_table_entry* ahd_lookup_phase_entry(int phase);
static void             ahd_shutdown(void *arg);
static void             ahd_update_coalescing_values(struct ahd_softc *ahd,
                                                     u_int timer,
                                                     u_int maxcmds,
                                                     u_int mincmds);
static int              ahd_verify_vpd_cksum(struct vpd_config *vpd);
static int              ahd_wait_seeprom(struct ahd_softc *ahd);
static int              ahd_match_scb(struct ahd_softc *ahd, struct scb *scb,
                                      int target, char channel, int lun,
                                      u_int tag, role_t role);

static void             ahd_reset_cmds_pending(struct ahd_softc *ahd);

/*************************** Interrupt Services *******************************/
static void             ahd_run_qoutfifo(struct ahd_softc *ahd);
#ifdef AHD_TARGET_MODE
static void             ahd_run_tqinfifo(struct ahd_softc *ahd, int paused);
#endif
static void             ahd_handle_hwerrint(struct ahd_softc *ahd);
static void             ahd_handle_seqint(struct ahd_softc *ahd, u_int intstat);
static void             ahd_handle_scsiint(struct ahd_softc *ahd,
                                           u_int intstat);

/************************ Sequencer Execution Control *************************/
void
ahd_set_modes(struct ahd_softc *ahd, ahd_mode src, ahd_mode dst)
{
        if (ahd->src_mode == src && ahd->dst_mode == dst)
                return;
#ifdef AHD_DEBUG
        if (ahd->src_mode == AHD_MODE_UNKNOWN
         || ahd->dst_mode == AHD_MODE_UNKNOWN)
                panic("Setting mode prior to saving it.\n");
        if ((ahd_debug & AHD_SHOW_MODEPTR) != 0)
                printk("%s: Setting mode 0x%x\n", ahd_name(ahd),
                       ahd_build_mode_state(ahd, src, dst));
#endif
        ahd_outb(ahd, MODE_PTR, ahd_build_mode_state(ahd, src, dst));
        ahd->src_mode = src;
        ahd->dst_mode = dst;
}

static void
ahd_update_modes(struct ahd_softc *ahd)
{
        ahd_mode_state mode_ptr;
        ahd_mode src;
        ahd_mode dst;

        mode_ptr = ahd_inb(ahd, MODE_PTR);
#ifdef AHD_DEBUG
        if ((ahd_debug & AHD_SHOW_MODEPTR) != 0)
                printk("Reading mode 0x%x\n", mode_ptr);
#endif
        ahd_extract_mode_state(ahd, mode_ptr, &src, &dst);
        ahd_known_modes(ahd, src, dst);
}

static void
ahd_assert_modes(struct ahd_softc *ahd, ahd_mode srcmode,
                 ahd_mode dstmode, const char *file, int line)
{
#ifdef AHD_DEBUG
        if ((srcmode & AHD_MK_MSK(ahd->src_mode)) == 0
         || (dstmode & AHD_MK_MSK(ahd->dst_mode)) == 0) {
                panic("%s:%s:%d: Mode assertion failed.\n",
                       ahd_name(ahd), file, line);
        }
#endif
}

#define AHD_ASSERT_MODES(ahd, source, dest) \
        ahd_assert_modes(ahd, source, dest, __FILE__, __LINE__);

ahd_mode_state
ahd_save_modes(struct ahd_softc *ahd)
{
        if (ahd->src_mode == AHD_MODE_UNKNOWN
         || ahd->dst_mode == AHD_MODE_UNKNOWN)
                ahd_update_modes(ahd);

        return (ahd_build_mode_state(ahd, ahd->src_mode, ahd->dst_mode));
}

void
ahd_restore_modes(struct ahd_softc *ahd, ahd_mode_state state)
{
        ahd_mode src;
        ahd_mode dst;

        ahd_extract_mode_state(ahd, state, &src, &dst);
        ahd_set_modes(ahd, src, dst);
}

/*
 * Determine whether the sequencer has halted code execution.
 * Returns non-zero status if the sequencer is stopped.
 */
int
ahd_is_paused(struct ahd_softc *ahd)
{
        return ((ahd_inb(ahd, HCNTRL) & PAUSE) != 0);
}

/*
 * Request that the sequencer stop and wait, indefinitely, for it
 * to stop.  The sequencer will only acknowledge that it is paused
 * once it has reached an instruction boundary and PAUSEDIS is
 * cleared in the SEQCTL register.  The sequencer may use PAUSEDIS
 * for critical sections.
 */
void
ahd_pause(struct ahd_softc *ahd)
{
        ahd_outb(ahd, HCNTRL, ahd->pause);

        /*
         * Since the sequencer can disable pausing in a critical section, we
         * must loop until it actually stops.
         */
        while (ahd_is_paused(ahd) == 0)
                ;
}

/*
 * Allow the sequencer to continue program execution.
 * We check here to ensure that no additional interrupt
 * sources that would cause the sequencer to halt have been
 * asserted.  If, for example, a SCSI bus reset is detected
 * while we are fielding a different, pausing, interrupt type,
 * we don't want to release the sequencer before going back
 * into our interrupt handler and dealing with this new
 * condition.
 */
void
ahd_unpause(struct ahd_softc *ahd)
{
        /*
         * Automatically restore our modes to those saved
         * prior to the first change of the mode.
         */
        if (ahd->saved_src_mode != AHD_MODE_UNKNOWN
         && ahd->saved_dst_mode != AHD_MODE_UNKNOWN) {
                if ((ahd->flags & AHD_UPDATE_PEND_CMDS) != 0)
                        ahd_reset_cmds_pending(ahd);
                ahd_set_modes(ahd, ahd->saved_src_mode, ahd->saved_dst_mode);
        }

        if ((ahd_inb(ahd, INTSTAT) & ~CMDCMPLT) == 0)
                ahd_outb(ahd, HCNTRL, ahd->unpause);

        ahd_known_modes(ahd, AHD_MODE_UNKNOWN, AHD_MODE_UNKNOWN);
}

/*********************** Scatter Gather List Handling *************************/
void *
ahd_sg_setup(struct ahd_softc *ahd, struct scb *scb,
             void *sgptr, dma_addr_t addr, bus_size_t len, int last)
{
        scb->sg_count++;
        if (sizeof(dma_addr_t) > 4
         && (ahd->flags & AHD_64BIT_ADDRESSING) != 0) {
                struct ahd_dma64_seg *sg;

                sg = (struct ahd_dma64_seg *)sgptr;
                sg->addr = ahd_htole64(addr);
                sg->len = ahd_htole32(len | (last ? AHD_DMA_LAST_SEG : 0));
                return (sg + 1);
        } else {
                struct ahd_dma_seg *sg;

                sg = (struct ahd_dma_seg *)sgptr;
                sg->addr = ahd_htole32(addr & 0xFFFFFFFF);
                sg->len = ahd_htole32(len | ((addr >> 8) & 0x7F000000)
                                    | (last ? AHD_DMA_LAST_SEG : 0));
                return (sg + 1);
        }
}

static void
ahd_setup_scb_common(struct ahd_softc *ahd, struct scb *scb)
{
        /* XXX Handle target mode SCBs. */
        scb->crc_retry_count = 0;
        if ((scb->flags & SCB_PACKETIZED) != 0) {
                /* XXX what about ACA??  It is type 4, but TAG_TYPE == 0x3. */
                scb->hscb->task_attribute = scb->hscb->control & SCB_TAG_TYPE;
        } else {
                if (ahd_get_transfer_length(scb) & 0x01)
                        scb->hscb->task_attribute = SCB_XFERLEN_ODD;
                else
                        scb->hscb->task_attribute = 0;
        }

        if (scb->hscb->cdb_len <= MAX_CDB_LEN_WITH_SENSE_ADDR
         || (scb->hscb->cdb_len & SCB_CDB_LEN_PTR) != 0)
                scb->hscb->shared_data.idata.cdb_plus_saddr.sense_addr =
                    ahd_htole32(scb->sense_busaddr);
}

static void
ahd_setup_data_scb(struct ahd_softc *ahd, struct scb *scb)
{
        /*
         * Copy the first SG into the "current" data ponter area.
         */
        if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) {
                struct ahd_dma64_seg *sg;

                sg = (struct ahd_dma64_seg *)scb->sg_list;
                scb->hscb->dataptr = sg->addr;
                scb->hscb->datacnt = sg->len;
        } else {
                struct ahd_dma_seg *sg;
                uint32_t *dataptr_words;

                sg = (struct ahd_dma_seg *)scb->sg_list;
                dataptr_words = (uint32_t*)&scb->hscb->dataptr;
                dataptr_words[0] = sg->addr;
                dataptr_words[1] = 0;
                if ((ahd->flags & AHD_39BIT_ADDRESSING) != 0) {
                        uint64_t high_addr;

                        high_addr = ahd_le32toh(sg->len) & 0x7F000000;
                        scb->hscb->dataptr |= ahd_htole64(high_addr << 8);
                }
                scb->hscb->datacnt = sg->len;
        }
        /*
         * Note where to find the SG entries in bus space.
         * We also set the full residual flag which the
         * sequencer will clear as soon as a data transfer
         * occurs.
         */
        scb->hscb->sgptr = ahd_htole32(scb->sg_list_busaddr|SG_FULL_RESID);
}

static void
ahd_setup_noxfer_scb(struct ahd_softc *ahd, struct scb *scb)
{
        scb->hscb->sgptr = ahd_htole32(SG_LIST_NULL);
        scb->hscb->dataptr = 0;
        scb->hscb->datacnt = 0;
}

/************************** Memory mapping routines ***************************/
static void *
ahd_sg_bus_to_virt(struct ahd_softc *ahd, struct scb *scb, uint32_t sg_busaddr)
{
        dma_addr_t sg_offset;

        /* sg_list_phys points to entry 1, not 0 */
        sg_offset = sg_busaddr - (scb->sg_list_busaddr - ahd_sg_size(ahd));
        return ((uint8_t *)scb->sg_list + sg_offset);
}

static uint32_t
ahd_sg_virt_to_bus(struct ahd_softc *ahd, struct scb *scb, void *sg)
{
        dma_addr_t sg_offset;

        /* sg_list_phys points to entry 1, not 0 */
        sg_offset = ((uint8_t *)sg - (uint8_t *)scb->sg_list)
                  - ahd_sg_size(ahd);

        return (scb->sg_list_busaddr + sg_offset);
}

static void
ahd_sync_scb(struct ahd_softc *ahd, struct scb *scb, int op)
{
        ahd_dmamap_sync(ahd, ahd->scb_data.hscb_dmat,
                        scb->hscb_map->dmamap,
                        /*offset*/(uint8_t*)scb->hscb - scb->hscb_map->vaddr,
                        /*len*/sizeof(*scb->hscb), op);
}

void
ahd_sync_sglist(struct ahd_softc *ahd, struct scb *scb, int op)
{
        if (scb->sg_count == 0)
                return;

        ahd_dmamap_sync(ahd, ahd->scb_data.sg_dmat,
                        scb->sg_map->dmamap,
                        /*offset*/scb->sg_list_busaddr - ahd_sg_size(ahd),
                        /*len*/ahd_sg_size(ahd) * scb->sg_count, op);
}

static void
ahd_sync_sense(struct ahd_softc *ahd, struct scb *scb, int op)
{
        ahd_dmamap_sync(ahd, ahd->scb_data.sense_dmat,
                        scb->sense_map->dmamap,
                        /*offset*/scb->sense_busaddr,
                        /*len*/AHD_SENSE_BUFSIZE, op);
}

#ifdef AHD_TARGET_MODE
static uint32_t
ahd_targetcmd_offset(struct ahd_softc *ahd, u_int index)
{
        return (((uint8_t *)&ahd->targetcmds[index])
               - (uint8_t *)ahd->qoutfifo);
}
#endif

/*********************** Miscellaneous Support Functions ***********************/
/*
 * Return pointers to the transfer negotiation information
 * for the specified our_id/remote_id pair.
 */
struct ahd_initiator_tinfo *
ahd_fetch_transinfo(struct ahd_softc *ahd, char channel, u_int our_id,
                    u_int remote_id, struct ahd_tmode_tstate **tstate)
{
        /*
         * Transfer data structures are stored from the perspective
         * of the target role.  Since the parameters for a connection
         * in the initiator role to a given target are the same as
         * when the roles are reversed, we pretend we are the target.
         */
        if (channel == 'B')
                our_id += 8;
        *tstate = ahd->enabled_targets[our_id];
        return (&(*tstate)->transinfo[remote_id]);
}

uint16_t
ahd_inw(struct ahd_softc *ahd, u_int port)
{
        /*
         * Read high byte first as some registers increment
         * or have other side effects when the low byte is
         * read.
         */
        uint16_t r = ahd_inb(ahd, port+1) << 8;
        return r | ahd_inb(ahd, port);
}

void
ahd_outw(struct ahd_softc *ahd, u_int port, u_int value)
{
        /*
         * Write low byte first to accommodate registers
         * such as PRGMCNT where the order maters.
         */
        ahd_outb(ahd, port, value & 0xFF);
        ahd_outb(ahd, port+1, (value >> 8) & 0xFF);
}

uint32_t
ahd_inl(struct ahd_softc *ahd, u_int port)
{
        return ((ahd_inb(ahd, port))
              | (ahd_inb(ahd, port+1) << 8)
              | (ahd_inb(ahd, port+2) << 16)
              | (ahd_inb(ahd, port+3) << 24));
}

void
ahd_outl(struct ahd_softc *ahd, u_int port, uint32_t value)
{
        ahd_outb(ahd, port, (value) & 0xFF);
        ahd_outb(ahd, port+1, ((value) >> 8) & 0xFF);
        ahd_outb(ahd, port+2, ((value) >> 16) & 0xFF);
        ahd_outb(ahd, port+3, ((value) >> 24) & 0xFF);
}

uint64_t
ahd_inq(struct ahd_softc *ahd, u_int port)
{
        return ((ahd_inb(ahd, port))
              | (ahd_inb(ahd, port+1) << 8)
              | (ahd_inb(ahd, port+2) << 16)
              | (ahd_inb(ahd, port+3) << 24)
              | (((uint64_t)ahd_inb(ahd, port+4)) << 32)
              | (((uint64_t)ahd_inb(ahd, port+5)) << 40)
              | (((uint64_t)ahd_inb(ahd, port+6)) << 48)
              | (((uint64_t)ahd_inb(ahd, port+7)) << 56));
}

void
ahd_outq(struct ahd_softc *ahd, u_int port, uint64_t value)
{
        ahd_outb(ahd, port, value & 0xFF);
        ahd_outb(ahd, port+1, (value >> 8) & 0xFF);
        ahd_outb(ahd, port+2, (value >> 16) & 0xFF);
        ahd_outb(ahd, port+3, (value >> 24) & 0xFF);
        ahd_outb(ahd, port+4, (value >> 32) & 0xFF);
        ahd_outb(ahd, port+5, (value >> 40) & 0xFF);
        ahd_outb(ahd, port+6, (value >> 48) & 0xFF);
        ahd_outb(ahd, port+7, (value >> 56) & 0xFF);
}

u_int
ahd_get_scbptr(struct ahd_softc *ahd)
{
        AHD_ASSERT_MODES(ahd, ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK),
                         ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK));
        return (ahd_inb(ahd, SCBPTR) | (ahd_inb(ahd, SCBPTR + 1) << 8));
}

void
ahd_set_scbptr(struct ahd_softc *ahd, u_int scbptr)
{
        AHD_ASSERT_MODES(ahd, ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK),
                         ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK));
        ahd_outb(ahd, SCBPTR, scbptr & 0xFF);
        ahd_outb(ahd, SCBPTR+1, (scbptr >> 8) & 0xFF);
}

#if 0 /* unused */
static u_int
ahd_get_hnscb_qoff(struct ahd_softc *ahd)
{
        return (ahd_inw_atomic(ahd, HNSCB_QOFF));
}
#endif

static void
ahd_set_hnscb_qoff(struct ahd_softc *ahd, u_int value)
{
        ahd_outw_atomic(ahd, HNSCB_QOFF, value);
}

#if 0 /* unused */
static u_int
ahd_get_hescb_qoff(struct ahd_softc *ahd)
{
        return (ahd_inb(ahd, HESCB_QOFF));
}
#endif

static void
ahd_set_hescb_qoff(struct ahd_softc *ahd, u_int value)
{
        ahd_outb(ahd, HESCB_QOFF, value);
}

static u_int
ahd_get_snscb_qoff(struct ahd_softc *ahd)
{
        u_int oldvalue;

        AHD_ASSERT_MODES(ahd, AHD_MODE_CCHAN_MSK, AHD_MODE_CCHAN_MSK);
        oldvalue = ahd_inw(ahd, SNSCB_QOFF);
        ahd_outw(ahd, SNSCB_QOFF, oldvalue);
        return (oldvalue);
}

static void
ahd_set_snscb_qoff(struct ahd_softc *ahd, u_int value)
{
        AHD_ASSERT_MODES(ahd, AHD_MODE_CCHAN_MSK, AHD_MODE_CCHAN_MSK);
        ahd_outw(ahd, SNSCB_QOFF, value);
}

#if 0 /* unused */
static u_int
ahd_get_sescb_qoff(struct ahd_softc *ahd)
{
        AHD_ASSERT_MODES(ahd, AHD_MODE_CCHAN_MSK, AHD_MODE_CCHAN_MSK);
        return (ahd_inb(ahd, SESCB_QOFF));
}
#endif

static void
ahd_set_sescb_qoff(struct ahd_softc *ahd, u_int value)
{
        AHD_ASSERT_MODES(ahd, AHD_MODE_CCHAN_MSK, AHD_MODE_CCHAN_MSK);
        ahd_outb(ahd, SESCB_QOFF, value);
}

#if 0 /* unused */
static u_int
ahd_get_sdscb_qoff(struct ahd_softc *ahd)
{
        AHD_ASSERT_MODES(ahd, AHD_MODE_CCHAN_MSK, AHD_MODE_CCHAN_MSK);
        return (ahd_inb(ahd, SDSCB_QOFF) | (ahd_inb(ahd, SDSCB_QOFF + 1) << 8));
}
#endif

static void
ahd_set_sdscb_qoff(struct ahd_softc *ahd, u_int value)
{
        AHD_ASSERT_MODES(ahd, AHD_MODE_CCHAN_MSK, AHD_MODE_CCHAN_MSK);
        ahd_outb(ahd, SDSCB_QOFF, value & 0xFF);
        ahd_outb(ahd, SDSCB_QOFF+1, (value >> 8) & 0xFF);
}

u_int
ahd_inb_scbram(struct ahd_softc *ahd, u_int offset)
{
        u_int value;

        /*
         * Workaround PCI-X Rev A. hardware bug.
         * After a host read of SCB memory, the chip
         * may become confused into thinking prefetch
         * was required.  This starts the discard timer
         * running and can cause an unexpected discard
         * timer interrupt.  The work around is to read
         * a normal register prior to the exhaustion of
         * the discard timer.  The mode pointer register
         * has no side effects and so serves well for
         * this purpose.
         *
         * Razor #528
         */
        value = ahd_inb(ahd, offset);
        if ((ahd->bugs & AHD_PCIX_SCBRAM_RD_BUG) != 0)
                ahd_inb(ahd, MODE_PTR);
        return (value);
}

u_int
ahd_inw_scbram(struct ahd_softc *ahd, u_int offset)
{
        return (ahd_inb_scbram(ahd, offset)
              | (ahd_inb_scbram(ahd, offset+1) << 8));
}

static uint32_t
ahd_inl_scbram(struct ahd_softc *ahd, u_int offset)
{
        return (ahd_inw_scbram(ahd, offset)
              | (ahd_inw_scbram(ahd, offset+2) << 16));
}

static uint64_t
ahd_inq_scbram(struct ahd_softc *ahd, u_int offset)
{
        return (ahd_inl_scbram(ahd, offset)
              | ((uint64_t)ahd_inl_scbram(ahd, offset+4)) << 32);
}

struct scb *
ahd_lookup_scb(struct ahd_softc *ahd, u_int tag)
{
        struct scb* scb;

        if (tag >= AHD_SCB_MAX)
                return (NULL);
        scb = ahd->scb_data.scbindex[tag];
        if (scb != NULL)
                ahd_sync_scb(ahd, scb,
                             BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
        return (scb);
}

static void
ahd_swap_with_next_hscb(struct ahd_softc *ahd, struct scb *scb)
{
        struct   hardware_scb *q_hscb;
        struct   map_node *q_hscb_map;
        uint32_t saved_hscb_busaddr;

        /*
         * Our queuing method is a bit tricky.  The card
         * knows in advance which HSCB (by address) to download,
         * and we can't disappoint it.  To achieve this, the next
         * HSCB to download is saved off in ahd->next_queued_hscb.
         * When we are called to queue "an arbitrary scb",
         * we copy the contents of the incoming HSCB to the one
         * the sequencer knows about, swap HSCB pointers and
         * finally assign the SCB to the tag indexed location
         * in the scb_array.  This makes sure that we can still
         * locate the correct SCB by SCB_TAG.
         */
        q_hscb = ahd->next_queued_hscb;
        q_hscb_map = ahd->next_queued_hscb_map;
        saved_hscb_busaddr = q_hscb->hscb_busaddr;
        memcpy(q_hscb, scb->hscb, sizeof(*scb->hscb));
        q_hscb->hscb_busaddr = saved_hscb_busaddr;
        q_hscb->next_hscb_busaddr = scb->hscb->hscb_busaddr;

        /* Now swap HSCB pointers. */
        ahd->next_queued_hscb = scb->hscb;
        ahd->next_queued_hscb_map = scb->hscb_map;
        scb->hscb = q_hscb;
        scb->hscb_map = q_hscb_map;

        /* Now define the mapping from tag to SCB in the scbindex */
        ahd->scb_data.scbindex[SCB_GET_TAG(scb)] = scb;
}

/*
 * Tell the sequencer about a new transaction to execute.
 */
void
ahd_queue_scb(struct ahd_softc *ahd, struct scb *scb)
{
        ahd_swap_with_next_hscb(ahd, scb);

        if (SCBID_IS_NULL(SCB_GET_TAG(scb)))
                panic("Attempt to queue invalid SCB tag %x\n",
                      SCB_GET_TAG(scb));

        /*
         * Keep a history of SCBs we've downloaded in the qinfifo.
         */
        ahd->qinfifo[AHD_QIN_WRAP(ahd->qinfifonext)] = SCB_GET_TAG(scb);
        ahd->qinfifonext++;

        if (scb->sg_count != 0)
                ahd_setup_data_scb(ahd, scb);
        else
                ahd_setup_noxfer_scb(ahd, scb);
        ahd_setup_scb_common(ahd, scb);

        /*
         * Make sure our data is consistent from the
         * perspective of the adapter.
         */
        ahd_sync_scb(ahd, scb, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);

#ifdef AHD_DEBUG
        if ((ahd_debug & AHD_SHOW_QUEUE) != 0) {
                uint64_t host_dataptr;

                host_dataptr = ahd_le64toh(scb->hscb->dataptr);
                printk("%s: Queueing SCB %d:0x%x bus addr 0x%x - 0x%x%x/0x%x\n",
                       ahd_name(ahd),
                       SCB_GET_TAG(scb), scb->hscb->scsiid,
                       ahd_le32toh(scb->hscb->hscb_busaddr),
                       (u_int)((host_dataptr >> 32) & 0xFFFFFFFF),
                       (u_int)(host_dataptr & 0xFFFFFFFF),
                       ahd_le32toh(scb->hscb->datacnt));
        }
#endif
        /* Tell the adapter about the newly queued SCB */
        ahd_set_hnscb_qoff(ahd, ahd->qinfifonext);
}

/************************** Interrupt Processing ******************************/
static void
ahd_sync_qoutfifo(struct ahd_softc *ahd, int op)
{
        ahd_dmamap_sync(ahd, ahd->shared_data_dmat, ahd->shared_data_map.dmamap,
                        /*offset*/0,
                        /*len*/AHD_SCB_MAX * sizeof(struct ahd_completion), op);
}

static void
ahd_sync_tqinfifo(struct ahd_softc *ahd, int op)
{
#ifdef AHD_TARGET_MODE
        if ((ahd->flags & AHD_TARGETROLE) != 0) {
                ahd_dmamap_sync(ahd, ahd->shared_data_dmat,
                                ahd->shared_data_map.dmamap,
                                ahd_targetcmd_offset(ahd, 0),
                                sizeof(struct target_cmd) * AHD_TMODE_CMDS,
                                op);
        }
#endif
}

/*
 * See if the firmware has posted any completed commands
 * into our in-core command complete fifos.
 */
#define AHD_RUN_QOUTFIFO 0x1
#define AHD_RUN_TQINFIFO 0x2
static u_int
ahd_check_cmdcmpltqueues(struct ahd_softc *ahd)
{
        u_int retval;

        retval = 0;
        ahd_dmamap_sync(ahd, ahd->shared_data_dmat, ahd->shared_data_map.dmamap,
                        /*offset*/ahd->qoutfifonext * sizeof(*ahd->qoutfifo),
                        /*len*/sizeof(*ahd->qoutfifo), BUS_DMASYNC_POSTREAD);
        if (ahd->qoutfifo[ahd->qoutfifonext].valid_tag
          == ahd->qoutfifonext_valid_tag)
                retval |= AHD_RUN_QOUTFIFO;
#ifdef AHD_TARGET_MODE
        if ((ahd->flags & AHD_TARGETROLE) != 0
         && (ahd->flags & AHD_TQINFIFO_BLOCKED) == 0) {
                ahd_dmamap_sync(ahd, ahd->shared_data_dmat,
                                ahd->shared_data_map.dmamap,
                                ahd_targetcmd_offset(ahd, ahd->tqinfifofnext),
                                /*len*/sizeof(struct target_cmd),
                                BUS_DMASYNC_POSTREAD);
                if (ahd->targetcmds[ahd->tqinfifonext].cmd_valid != 0)
                        retval |= AHD_RUN_TQINFIFO;
        }
#endif
        return (retval);
}

/*
 * Catch an interrupt from the adapter
 */
int
ahd_intr(struct ahd_softc *ahd)
{
        u_int   intstat;

        if ((ahd->pause & INTEN) == 0) {
                /*
                 * Our interrupt is not enabled on the chip
                 * and may be disabled for re-entrancy reasons,
                 * so just return.  This is likely just a shared
                 * interrupt.
                 */
                return (0);
        }

        /*
         * Instead of directly reading the interrupt status register,
         * infer the cause of the interrupt by checking our in-core
         * completion queues.  This avoids a costly PCI bus read in
         * most cases.
         */
        if ((ahd->flags & AHD_ALL_INTERRUPTS) == 0
         && (ahd_check_cmdcmpltqueues(ahd) != 0))
                intstat = CMDCMPLT;
        else
                intstat = ahd_inb(ahd, INTSTAT);

        if ((intstat & INT_PEND) == 0)
                return (0);

        if (intstat & CMDCMPLT) {
                ahd_outb(ahd, CLRINT, CLRCMDINT);

                /*
                 * Ensure that the chip sees that we've cleared
                 * this interrupt before we walk the output fifo.
                 * Otherwise, we may, due to posted bus writes,
                 * clear the interrupt after we finish the scan,
                 * and after the sequencer has added new entries
                 * and asserted the interrupt again.
                 */
                if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) {
                        if (ahd_is_paused(ahd)) {
                                /*
                                 * Potentially lost SEQINT.
                                 * If SEQINTCODE is non-zero,
                                 * simulate the SEQINT.
                                 */
                                if (ahd_inb(ahd, SEQINTCODE) != NO_SEQINT)
                                        intstat |= SEQINT;
                        }
                } else {
                        ahd_flush_device_writes(ahd);
                }
                ahd_run_qoutfifo(ahd);
                ahd->cmdcmplt_counts[ahd->cmdcmplt_bucket]++;
                ahd->cmdcmplt_total++;

#ifdef AHD_TARGET_MODE
                if ((ahd->flags & AHD_TARGETROLE) != 0)
                        ahd_run_tqinfifo(ahd, /*paused*/FALSE);
#endif
        }

        /*
         * Handle statuses that may invalidate our cached
         * copy of INTSTAT separately.
         */
        if (intstat == 0xFF && (ahd->features & AHD_REMOVABLE) != 0) {
                /* Hot eject.  Do nothing */
        } else if (intstat & HWERRINT) {
                ahd_handle_hwerrint(ahd);
        } else if ((intstat & (PCIINT|SPLTINT)) != 0) {
                ahd->bus_intr(ahd);
        } else {

                if ((intstat & SEQINT) != 0)
                        ahd_handle_seqint(ahd, intstat);

                if ((intstat & SCSIINT) != 0)
                        ahd_handle_scsiint(ahd, intstat);
        }
        return (1);
}

/******************************** Private Inlines *****************************/
static inline void
ahd_assert_atn(struct ahd_softc *ahd)
{
        ahd_outb(ahd, SCSISIGO, ATNO);
}

/*
 * Determine if the current connection has a packetized
 * agreement.  This does not necessarily mean that we
 * are currently in a packetized transfer.  We could
 * just as easily be sending or receiving a message.
 */
static int
ahd_currently_packetized(struct ahd_softc *ahd)
{
        ahd_mode_state   saved_modes;
        int              packetized;

        saved_modes = ahd_save_modes(ahd);
        if ((ahd->bugs & AHD_PKTIZED_STATUS_BUG) != 0) {
                /*
                 * The packetized bit refers to the last
                 * connection, not the current one.  Check
                 * for non-zero LQISTATE instead.
                 */
                ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
                packetized = ahd_inb(ahd, LQISTATE) != 0;
        } else {
                ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
                packetized = ahd_inb(ahd, LQISTAT2) & PACKETIZED;
        }
        ahd_restore_modes(ahd, saved_modes);
        return (packetized);
}

static inline int
ahd_set_active_fifo(struct ahd_softc *ahd)
{
        u_int active_fifo;

        AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
        active_fifo = ahd_inb(ahd, DFFSTAT) & CURRFIFO;
        switch (active_fifo) {
        case 0:
        case 1:
                ahd_set_modes(ahd, active_fifo, active_fifo);
                return (1);
        default:
                return (0);
        }
}

static inline void
ahd_unbusy_tcl(struct ahd_softc *ahd, u_int tcl)
{
        ahd_busy_tcl(ahd, tcl, SCB_LIST_NULL);
}

/*
 * Determine whether the sequencer reported a residual
 * for this SCB/transaction.
 */
static inline void
ahd_update_residual(struct ahd_softc *ahd, struct scb *scb)
{
        uint32_t sgptr;

        sgptr = ahd_le32toh(scb->hscb->sgptr);
        if ((sgptr & SG_STATUS_VALID) != 0)
                ahd_calc_residual(ahd, scb);
}

static inline void
ahd_complete_scb(struct ahd_softc *ahd, struct scb *scb)
{
        uint32_t sgptr;

        sgptr = ahd_le32toh(scb->hscb->sgptr);
        if ((sgptr & SG_STATUS_VALID) != 0)
                ahd_handle_scb_status(ahd, scb);
        else
                ahd_done(ahd, scb);
}


/************************* Sequencer Execution Control ************************/
/*
 * Restart the sequencer program from address zero
 */
static void
ahd_restart(struct ahd_softc *ahd)
{

        ahd_pause(ahd);

        ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

        /* No more pending messages */
        ahd_clear_msg_state(ahd);
        ahd_outb(ahd, SCSISIGO, 0);             /* De-assert BSY */
        ahd_outb(ahd, MSG_OUT, NOP);    /* No message to send */
        ahd_outb(ahd, SXFRCTL1, ahd_inb(ahd, SXFRCTL1) & ~BITBUCKET);
        ahd_outb(ahd, SEQINTCTL, 0);
        ahd_outb(ahd, LASTPHASE, P_BUSFREE);
        ahd_outb(ahd, SEQ_FLAGS, 0);
        ahd_outb(ahd, SAVED_SCSIID, 0xFF);
        ahd_outb(ahd, SAVED_LUN, 0xFF);

        /*
         * Ensure that the sequencer's idea of TQINPOS
         * matches our own.  The sequencer increments TQINPOS
         * only after it sees a DMA complete and a reset could
         * occur before the increment leaving the kernel to believe
         * the command arrived but the sequencer to not.
         */
        ahd_outb(ahd, TQINPOS, ahd->tqinfifonext);

        /* Always allow reselection */
        ahd_outb(ahd, SCSISEQ1,
                 ahd_inb(ahd, SCSISEQ_TEMPLATE) & (ENSELI|ENRSELI|ENAUTOATNP));
        ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);

        /*
         * Clear any pending sequencer interrupt.  It is no
         * longer relevant since we're resetting the Program
         * Counter.
         */
        ahd_outb(ahd, CLRINT, CLRSEQINT);

        ahd_outb(ahd, SEQCTL0, FASTMODE|SEQRESET);
        ahd_unpause(ahd);
}

static void
ahd_clear_fifo(struct ahd_softc *ahd, u_int fifo)
{
        ahd_mode_state   saved_modes;

#ifdef AHD_DEBUG
        if ((ahd_debug & AHD_SHOW_FIFOS) != 0)
                printk("%s: Clearing FIFO %d\n", ahd_name(ahd), fifo);
#endif
        saved_modes = ahd_save_modes(ahd);
        ahd_set_modes(ahd, fifo, fifo);
        ahd_outb(ahd, DFFSXFRCTL, RSTCHN|CLRSHCNT);
        if ((ahd_inb(ahd, SG_STATE) & FETCH_INPROG) != 0)
                ahd_outb(ahd, CCSGCTL, CCSGRESET);
        ahd_outb(ahd, LONGJMP_ADDR + 1, INVALID_ADDR);
        ahd_outb(ahd, SG_STATE, 0);
        ahd_restore_modes(ahd, saved_modes);
}

/************************* Input/Output Queues ********************************/
/*
 * Flush and completed commands that are sitting in the command
 * complete queues down on the chip but have yet to be dma'ed back up.
 */
static void
ahd_flush_qoutfifo(struct ahd_softc *ahd)
{
        struct          scb *scb;
        ahd_mode_state  saved_modes;
        u_int           saved_scbptr;
        u_int           ccscbctl;
        u_int           scbid;
        u_int           next_scbid;

        saved_modes = ahd_save_modes(ahd);

        /*
         * Flush the good status FIFO for completed packetized commands.
         */
        ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
        saved_scbptr = ahd_get_scbptr(ahd);
        while ((ahd_inb(ahd, LQISTAT2) & LQIGSAVAIL) != 0) {
                u_int fifo_mode;
                u_int i;

                scbid = ahd_inw(ahd, GSFIFO);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb == NULL) {
                        printk("%s: Warning - GSFIFO SCB %d invalid\n",
                               ahd_name(ahd), scbid);
                        continue;
                }
                /*
                 * Determine if this transaction is still active in
                 * any FIFO.  If it is, we must flush that FIFO to
                 * the host before completing the  command.
                 */
                fifo_mode = 0;
rescan_fifos:
                for (i = 0; i < 2; i++) {
                        /* Toggle to the other mode. */
                        fifo_mode ^= 1;
                        ahd_set_modes(ahd, fifo_mode, fifo_mode);

                        if (ahd_scb_active_in_fifo(ahd, scb) == 0)
                                continue;

                        ahd_run_data_fifo(ahd, scb);

                        /*
                         * Running this FIFO may cause a CFG4DATA for
                         * this same transaction to assert in the other
                         * FIFO or a new snapshot SAVEPTRS interrupt
                         * in this FIFO.  Even running a FIFO may not
                         * clear the transaction if we are still waiting
                         * for data to drain to the host. We must loop
                         * until the transaction is not active in either
                         * FIFO just to be sure.  Reset our loop counter
                         * so we will visit both FIFOs again before
                         * declaring this transaction finished.  We
                         * also delay a bit so that status has a chance
                         * to change before we look at this FIFO again.
                         */
                        ahd_delay(200);
                        goto rescan_fifos;
                }
                ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
                ahd_set_scbptr(ahd, scbid);
                if ((ahd_inb_scbram(ahd, SCB_SGPTR) & SG_LIST_NULL) == 0
                 && ((ahd_inb_scbram(ahd, SCB_SGPTR) & SG_FULL_RESID) != 0
                  || (ahd_inb_scbram(ahd, SCB_RESIDUAL_SGPTR)
                      & SG_LIST_NULL) != 0)) {
                        u_int comp_head;

                        /*
                         * The transfer completed with a residual.
                         * Place this SCB on the complete DMA list
                         * so that we update our in-core copy of the
                         * SCB before completing the command.
                         */
                        ahd_outb(ahd, SCB_SCSI_STATUS, 0);
                        ahd_outb(ahd, SCB_SGPTR,
                                 ahd_inb_scbram(ahd, SCB_SGPTR)
                                 | SG_STATUS_VALID);
                        ahd_outw(ahd, SCB_TAG, scbid);
                        ahd_outw(ahd, SCB_NEXT_COMPLETE, SCB_LIST_NULL);
                        comp_head = ahd_inw(ahd, COMPLETE_DMA_SCB_HEAD);
                        if (SCBID_IS_NULL(comp_head)) {
                                ahd_outw(ahd, COMPLETE_DMA_SCB_HEAD, scbid);
                                ahd_outw(ahd, COMPLETE_DMA_SCB_TAIL, scbid);
                        } else {
                                u_int tail;

                                tail = ahd_inw(ahd, COMPLETE_DMA_SCB_TAIL);
                                ahd_set_scbptr(ahd, tail);
                                ahd_outw(ahd, SCB_NEXT_COMPLETE, scbid);
                                ahd_outw(ahd, COMPLETE_DMA_SCB_TAIL, scbid);
                                ahd_set_scbptr(ahd, scbid);
                        }
                } else
                        ahd_complete_scb(ahd, scb);
        }
        ahd_set_scbptr(ahd, saved_scbptr);

        /*
         * Setup for command channel portion of flush.
         */
        ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);

        /*
         * Wait for any inprogress DMA to complete and clear DMA state
         * if this is for an SCB in the qinfifo.
         */
        while (((ccscbctl = ahd_inb(ahd, CCSCBCTL)) & (CCARREN|CCSCBEN)) != 0) {

                if ((ccscbctl & (CCSCBDIR|CCARREN)) == (CCSCBDIR|CCARREN)) {
                        if ((ccscbctl & ARRDONE) != 0)
                                break;
                } else if ((ccscbctl & CCSCBDONE) != 0)
                        break;
                ahd_delay(200);
        }
        /*
         * We leave the sequencer to cleanup in the case of DMA's to
         * update the qoutfifo.  In all other cases (DMA's to the
         * chip or a push of an SCB from the COMPLETE_DMA_SCB list),
         * we disable the DMA engine so that the sequencer will not
         * attempt to handle the DMA completion.
         */
        if ((ccscbctl & CCSCBDIR) != 0 || (ccscbctl & ARRDONE) != 0)
                ahd_outb(ahd, CCSCBCTL, ccscbctl & ~(CCARREN|CCSCBEN));

        /*
         * Complete any SCBs that just finished
         * being DMA'ed into the qoutfifo.
         */
        ahd_run_qoutfifo(ahd);

        saved_scbptr = ahd_get_scbptr(ahd);
        /*
         * Manually update/complete any completed SCBs that are waiting to be
         * DMA'ed back up to the host.
         */
        scbid = ahd_inw(ahd, COMPLETE_DMA_SCB_HEAD);
        while (!SCBID_IS_NULL(scbid)) {
                uint8_t *hscb_ptr;
                u_int    i;

                ahd_set_scbptr(ahd, scbid);
                next_scbid = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb == NULL) {
                        printk("%s: Warning - DMA-up and complete "
                               "SCB %d invalid\n", ahd_name(ahd), scbid);
                        continue;
                }
                hscb_ptr = (uint8_t *)scb->hscb;
                for (i = 0; i < sizeof(struct hardware_scb); i++)
                        *hscb_ptr++ = ahd_inb_scbram(ahd, SCB_BASE + i);

                ahd_complete_scb(ahd, scb);
                scbid = next_scbid;
        }
        ahd_outw(ahd, COMPLETE_DMA_SCB_HEAD, SCB_LIST_NULL);
        ahd_outw(ahd, COMPLETE_DMA_SCB_TAIL, SCB_LIST_NULL);

        scbid = ahd_inw(ahd, COMPLETE_ON_QFREEZE_HEAD);
        while (!SCBID_IS_NULL(scbid)) {

                ahd_set_scbptr(ahd, scbid);
                next_scbid = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb == NULL) {
                        printk("%s: Warning - Complete Qfrz SCB %d invalid\n",
                               ahd_name(ahd), scbid);
                        continue;
                }

                ahd_complete_scb(ahd, scb);
                scbid = next_scbid;
        }
        ahd_outw(ahd, COMPLETE_ON_QFREEZE_HEAD, SCB_LIST_NULL);

        scbid = ahd_inw(ahd, COMPLETE_SCB_HEAD);
        while (!SCBID_IS_NULL(scbid)) {

                ahd_set_scbptr(ahd, scbid);
                next_scbid = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb == NULL) {
                        printk("%s: Warning - Complete SCB %d invalid\n",
                               ahd_name(ahd), scbid);
                        continue;
                }

                ahd_complete_scb(ahd, scb);
                scbid = next_scbid;
        }
        ahd_outw(ahd, COMPLETE_SCB_HEAD, SCB_LIST_NULL);

        /*
         * Restore state.
         */
        ahd_set_scbptr(ahd, saved_scbptr);
        ahd_restore_modes(ahd, saved_modes);
        ahd->flags |= AHD_UPDATE_PEND_CMDS;
}

/*
 * Determine if an SCB for a packetized transaction
 * is active in a FIFO.
 */
static int
ahd_scb_active_in_fifo(struct ahd_softc *ahd, struct scb *scb)
{

        /*
         * The FIFO is only active for our transaction if
         * the SCBPTR matches the SCB's ID and the firmware
         * has installed a handler for the FIFO or we have
         * a pending SAVEPTRS or CFG4DATA interrupt.
         */
        if (ahd_get_scbptr(ahd) != SCB_GET_TAG(scb)
         || ((ahd_inb(ahd, LONGJMP_ADDR+1) & INVALID_ADDR) != 0
          && (ahd_inb(ahd, SEQINTSRC) & (CFG4DATA|SAVEPTRS)) == 0))
                return (0);

        return (1);
}

/*
 * Run a data fifo to completion for a transaction we know
 * has completed across the SCSI bus (good status has been
 * received).  We are already set to the correct FIFO mode
 * on entry to this routine.
 *
 * This function attempts to operate exactly as the firmware
 * would when running this FIFO.  Care must be taken to update
 * this routine any time the firmware's FIFO algorithm is
 * changed.
 */
static void
ahd_run_data_fifo(struct ahd_softc *ahd, struct scb *scb)
{
        u_int seqintsrc;

        seqintsrc = ahd_inb(ahd, SEQINTSRC);
        if ((seqintsrc & CFG4DATA) != 0) {
                uint32_t datacnt;
                uint32_t sgptr;

                /*
                 * Clear full residual flag.
                 */
                sgptr = ahd_inl_scbram(ahd, SCB_SGPTR) & ~SG_FULL_RESID;
                ahd_outb(ahd, SCB_SGPTR, sgptr);

                /*
                 * Load datacnt and address.
                 */
                datacnt = ahd_inl_scbram(ahd, SCB_DATACNT);
                if ((datacnt & AHD_DMA_LAST_SEG) != 0) {
                        sgptr |= LAST_SEG;
                        ahd_outb(ahd, SG_STATE, 0);
                } else
                        ahd_outb(ahd, SG_STATE, LOADING_NEEDED);
                ahd_outq(ahd, HADDR, ahd_inq_scbram(ahd, SCB_DATAPTR));
                ahd_outl(ahd, HCNT, datacnt & AHD_SG_LEN_MASK);
                ahd_outb(ahd, SG_CACHE_PRE, sgptr);
                ahd_outb(ahd, DFCNTRL, PRELOADEN|SCSIEN|HDMAEN);

                /*
                 * Initialize Residual Fields.
                 */
                ahd_outb(ahd, SCB_RESIDUAL_DATACNT+3, datacnt >> 24);
                ahd_outl(ahd, SCB_RESIDUAL_SGPTR, sgptr & SG_PTR_MASK);

                /*
                 * Mark the SCB as having a FIFO in use.
                 */
                ahd_outb(ahd, SCB_FIFO_USE_COUNT,
                         ahd_inb_scbram(ahd, SCB_FIFO_USE_COUNT) + 1);

                /*
                 * Install a "fake" handler for this FIFO.
                 */
                ahd_outw(ahd, LONGJMP_ADDR, 0);

                /*
                 * Notify the hardware that we have satisfied
                 * this sequencer interrupt.
                 */
                ahd_outb(ahd, CLRSEQINTSRC, CLRCFG4DATA);
        } else if ((seqintsrc & SAVEPTRS) != 0) {
                uint32_t sgptr;
                uint32_t resid;

                if ((ahd_inb(ahd, LONGJMP_ADDR+1)&INVALID_ADDR) != 0) {
                        /*
                         * Snapshot Save Pointers.  All that
                         * is necessary to clear the snapshot
                         * is a CLRCHN.
                         */
                        goto clrchn;
                }

                /*
                 * Disable S/G fetch so the DMA engine
                 * is available to future users.
                 */
                if ((ahd_inb(ahd, SG_STATE) & FETCH_INPROG) != 0)
                        ahd_outb(ahd, CCSGCTL, 0);
                ahd_outb(ahd, SG_STATE, 0);

                /*
                 * Flush the data FIFO.  Strickly only
                 * necessary for Rev A parts.
                 */
                ahd_outb(ahd, DFCNTRL, ahd_inb(ahd, DFCNTRL) | FIFOFLUSH);

                /*
                 * Calculate residual.
                 */
                sgptr = ahd_inl_scbram(ahd, SCB_RESIDUAL_SGPTR);
                resid = ahd_inl(ahd, SHCNT);
                resid |= ahd_inb_scbram(ahd, SCB_RESIDUAL_DATACNT+3) << 24;
                ahd_outl(ahd, SCB_RESIDUAL_DATACNT, resid);
                if ((ahd_inb(ahd, SG_CACHE_SHADOW) & LAST_SEG) == 0) {
                        /*
                         * Must back up to the correct S/G element.
                         * Typically this just means resetting our
                         * low byte to the offset in the SG_CACHE,
                         * but if we wrapped, we have to correct
                         * the other bytes of the sgptr too.
                         */
                        if ((ahd_inb(ahd, SG_CACHE_SHADOW) & 0x80) != 0
                         && (sgptr & 0x80) == 0)
                                sgptr -= 0x100;
                        sgptr &= ~0xFF;
                        sgptr |= ahd_inb(ahd, SG_CACHE_SHADOW)
                               & SG_ADDR_MASK;
                        ahd_outl(ahd, SCB_RESIDUAL_SGPTR, sgptr);
                        ahd_outb(ahd, SCB_RESIDUAL_DATACNT + 3, 0);
                } else if ((resid & AHD_SG_LEN_MASK) == 0) {
                        ahd_outb(ahd, SCB_RESIDUAL_SGPTR,
                                 sgptr | SG_LIST_NULL);
                }
                /*
                 * Save Pointers.
                 */
                ahd_outq(ahd, SCB_DATAPTR, ahd_inq(ahd, SHADDR));
                ahd_outl(ahd, SCB_DATACNT, resid);
                ahd_outl(ahd, SCB_SGPTR, sgptr);
                ahd_outb(ahd, CLRSEQINTSRC, CLRSAVEPTRS);
                ahd_outb(ahd, SEQIMODE,
                         ahd_inb(ahd, SEQIMODE) | ENSAVEPTRS);
                /*
                 * If the data is to the SCSI bus, we are
                 * done, otherwise wait for FIFOEMP.
                 */
                if ((ahd_inb(ahd, DFCNTRL) & DIRECTION) != 0)
                        goto clrchn;
        } else if ((ahd_inb(ahd, SG_STATE) & LOADING_NEEDED) != 0) {
                uint32_t sgptr;
                uint64_t data_addr;
                uint32_t data_len;
                u_int    dfcntrl;

                /*
                 * Disable S/G fetch so the DMA engine
                 * is available to future users.  We won't
                 * be using the DMA engine to load segments.
                 */
                if ((ahd_inb(ahd, SG_STATE) & FETCH_INPROG) != 0) {
                        ahd_outb(ahd, CCSGCTL, 0);
                        ahd_outb(ahd, SG_STATE, LOADING_NEEDED);
                }

                /*
                 * Wait for the DMA engine to notice that the
                 * host transfer is enabled and that there is
                 * space in the S/G FIFO for new segments before
                 * loading more segments.
                 */
                if ((ahd_inb(ahd, DFSTATUS) & PRELOAD_AVAIL) != 0
                 && (ahd_inb(ahd, DFCNTRL) & HDMAENACK) != 0) {

                        /*
                         * Determine the offset of the next S/G
                         * element to load.
                         */
                        sgptr = ahd_inl_scbram(ahd, SCB_RESIDUAL_SGPTR);
                        sgptr &= SG_PTR_MASK;
                        if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) {
                                struct ahd_dma64_seg *sg;

                                sg = ahd_sg_bus_to_virt(ahd, scb, sgptr);
                                data_addr = sg->addr;
                                data_len = sg->len;
                                sgptr += sizeof(*sg);
                        } else {
                                struct  ahd_dma_seg *sg;

                                sg = ahd_sg_bus_to_virt(ahd, scb, sgptr);
                                data_addr = sg->len & AHD_SG_HIGH_ADDR_MASK;
                                data_addr <<= 8;
                                data_addr |= sg->addr;
                                data_len = sg->len;
                                sgptr += sizeof(*sg);
                        }

                        /*
                         * Update residual information.
                         */
                        ahd_outb(ahd, SCB_RESIDUAL_DATACNT+3, data_len >> 24);
                        ahd_outl(ahd, SCB_RESIDUAL_SGPTR, sgptr);

                        /*
                         * Load the S/G.
                         */
                        if (data_len & AHD_DMA_LAST_SEG) {
                                sgptr |= LAST_SEG;
                                ahd_outb(ahd, SG_STATE, 0);
                        }
                        ahd_outq(ahd, HADDR, data_addr);
                        ahd_outl(ahd, HCNT, data_len & AHD_SG_LEN_MASK);
                        ahd_outb(ahd, SG_CACHE_PRE, sgptr & 0xFF);

                        /*
                         * Advertise the segment to the hardware.
                         */
                        dfcntrl = ahd_inb(ahd, DFCNTRL)|PRELOADEN|HDMAEN;
                        if ((ahd->features & AHD_NEW_DFCNTRL_OPTS) != 0) {
                                /*
                                 * Use SCSIENWRDIS so that SCSIEN
                                 * is never modified by this
                                 * operation.
                                 */
                                dfcntrl |= SCSIENWRDIS;
                        }
                        ahd_outb(ahd, DFCNTRL, dfcntrl);
                }
        } else if ((ahd_inb(ahd, SG_CACHE_SHADOW) & LAST_SEG_DONE) != 0) {

                /*
                 * Transfer completed to the end of SG list
                 * and has flushed to the host.
                 */
                ahd_outb(ahd, SCB_SGPTR,
                         ahd_inb_scbram(ahd, SCB_SGPTR) | SG_LIST_NULL);
                goto clrchn;
        } else if ((ahd_inb(ahd, DFSTATUS) & FIFOEMP) != 0) {
clrchn:
                /*
                 * Clear any handler for this FIFO, decrement
                 * the FIFO use count for the SCB, and release
                 * the FIFO.
                 */
                ahd_outb(ahd, LONGJMP_ADDR + 1, INVALID_ADDR);
                ahd_outb(ahd, SCB_FIFO_USE_COUNT,
                         ahd_inb_scbram(ahd, SCB_FIFO_USE_COUNT) - 1);
                ahd_outb(ahd, DFFSXFRCTL, CLRCHN);
        }
}

/*
 * Look for entries in the QoutFIFO that have completed.
 * The valid_tag completion field indicates the validity
 * of the entry - the valid value toggles each time through
 * the queue. We use the sg_status field in the completion
 * entry to avoid referencing the hscb if the completion
 * occurred with no errors and no residual.  sg_status is
 * a copy of the first byte (little endian) of the sgptr
 * hscb field.
 */
static void
ahd_run_qoutfifo(struct ahd_softc *ahd)
{
        struct ahd_completion *completion;
        struct scb *scb;
        u_int  scb_index;

        if ((ahd->flags & AHD_RUNNING_QOUTFIFO) != 0)
                panic("ahd_run_qoutfifo recursion");
        ahd->flags |= AHD_RUNNING_QOUTFIFO;
        ahd_sync_qoutfifo(ahd, BUS_DMASYNC_POSTREAD);
        for (;;) {
                completion = &ahd->qoutfifo[ahd->qoutfifonext];

                if (completion->valid_tag != ahd->qoutfifonext_valid_tag)
                        break;

                scb_index = ahd_le16toh(completion->tag);
                scb = ahd_lookup_scb(ahd, scb_index);
                if (scb == NULL) {
                        printk("%s: WARNING no command for scb %d "
                               "(cmdcmplt)\nQOUTPOS = %d\n",
                               ahd_name(ahd), scb_index,
                               ahd->qoutfifonext);
                        ahd_dump_card_state(ahd);
                } else if ((completion->sg_status & SG_STATUS_VALID) != 0) {
                        ahd_handle_scb_status(ahd, scb);
                } else {
                        ahd_done(ahd, scb);
                }

                ahd->qoutfifonext = (ahd->qoutfifonext+1) & (AHD_QOUT_SIZE-1);
                if (ahd->qoutfifonext == 0)
                        ahd->qoutfifonext_valid_tag ^= QOUTFIFO_ENTRY_VALID;
        }
        ahd->flags &= ~AHD_RUNNING_QOUTFIFO;
}

/************************* Interrupt Handling *********************************/
static void
ahd_handle_hwerrint(struct ahd_softc *ahd)
{
        /*
         * Some catastrophic hardware error has occurred.
         * Print it for the user and disable the controller.
         */
        int i;
        int error;

        error = ahd_inb(ahd, ERROR);
        for (i = 0; i < num_errors; i++) {
                if ((error & ahd_hard_errors[i].errno) != 0)
                        printk("%s: hwerrint, %s\n",
                               ahd_name(ahd), ahd_hard_errors[i].errmesg);
        }

        ahd_dump_card_state(ahd);
        panic("BRKADRINT");

        /* Tell everyone that this HBA is no longer available */
        ahd_abort_scbs(ahd, CAM_TARGET_WILDCARD, ALL_CHANNELS,
                       CAM_LUN_WILDCARD, SCB_LIST_NULL, ROLE_UNKNOWN,
                       CAM_NO_HBA);

        /* Tell the system that this controller has gone away. */
        ahd_free(ahd);
}

#ifdef AHD_DEBUG
static void
ahd_dump_sglist(struct scb *scb)
{
        int i;

        if (scb->sg_count > 0) {
                if ((scb->ahd_softc->flags & AHD_64BIT_ADDRESSING) != 0) {
                        struct ahd_dma64_seg *sg_list;

                        sg_list = (struct ahd_dma64_seg*)scb->sg_list;
                        for (i = 0; i < scb->sg_count; i++) {
                                uint64_t addr;

                                addr = ahd_le64toh(sg_list[i].addr);
                                printk("sg[%d] - Addr 0x%x%x : Length %d%s\n",
                                       i,
                                       (uint32_t)((addr >> 32) & 0xFFFFFFFF),
                                       (uint32_t)(addr & 0xFFFFFFFF),
                                       sg_list[i].len & AHD_SG_LEN_MASK,
                                       (sg_list[i].len & AHD_DMA_LAST_SEG)
                                     ? " Last" : "");
                        }
                } else {
                        struct ahd_dma_seg *sg_list;

                        sg_list = (struct ahd_dma_seg*)scb->sg_list;
                        for (i = 0; i < scb->sg_count; i++) {
                                uint32_t len;

                                len = ahd_le32toh(sg_list[i].len);
                                printk("sg[%d] - Addr 0x%x%x : Length %d%s\n",
                                       i,
                                       (len & AHD_SG_HIGH_ADDR_MASK) >> 24,
                                       ahd_le32toh(sg_list[i].addr),
                                       len & AHD_SG_LEN_MASK,
                                       len & AHD_DMA_LAST_SEG ? " Last" : "");
                        }
                }
        }
}
#endif  /*  AHD_DEBUG  */

static void
ahd_handle_seqint(struct ahd_softc *ahd, u_int intstat)
{
        u_int seqintcode;

        /*
         * Save the sequencer interrupt code and clear the SEQINT
         * bit. We will unpause the sequencer, if appropriate,
         * after servicing the request.
         */
        seqintcode = ahd_inb(ahd, SEQINTCODE);
        ahd_outb(ahd, CLRINT, CLRSEQINT);
        if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) {
                /*
                 * Unpause the sequencer and let it clear
                 * SEQINT by writing NO_SEQINT to it.  This
                 * will cause the sequencer to be paused again,
                 * which is the expected state of this routine.
                 */
                ahd_unpause(ahd);
                while (!ahd_is_paused(ahd))
                        ;
                ahd_outb(ahd, CLRINT, CLRSEQINT);
        }
        ahd_update_modes(ahd);
#ifdef AHD_DEBUG
        if ((ahd_debug & AHD_SHOW_MISC) != 0)
                printk("%s: Handle Seqint Called for code %d\n",
                       ahd_name(ahd), seqintcode);
#endif
        switch (seqintcode) {
        case ENTERING_NONPACK:
        {
                struct  scb *scb;
                u_int   scbid;

                AHD_ASSERT_MODES(ahd, ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK),
                                 ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK));
                scbid = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb == NULL) {
                        /*
                         * Somehow need to know if this
                         * is from a selection or reselection.
                         * From that, we can determine target
                         * ID so we at least have an I_T nexus.
                         */
                } else {
                        ahd_outb(ahd, SAVED_SCSIID, scb->hscb->scsiid);
                        ahd_outb(ahd, SAVED_LUN, scb->hscb->lun);
                        ahd_outb(ahd, SEQ_FLAGS, 0x0);
                }
                if ((ahd_inb(ahd, LQISTAT2) & LQIPHASE_OUTPKT) != 0
                 && (ahd_inb(ahd, SCSISIGO) & ATNO) != 0) {
                        /*
                         * Phase change after read stream with
                         * CRC error with P0 asserted on last
                         * packet.
                         */
#ifdef AHD_DEBUG
                        if ((ahd_debug & AHD_SHOW_RECOVERY) != 0)
                                printk("%s: Assuming LQIPHASE_NLQ with "
                                       "P0 assertion\n", ahd_name(ahd));
#endif
                }
#ifdef AHD_DEBUG
                if ((ahd_debug & AHD_SHOW_RECOVERY) != 0)
                        printk("%s: Entering NONPACK\n", ahd_name(ahd));
#endif
                break;
        }
        case INVALID_SEQINT:
                printk("%s: Invalid Sequencer interrupt occurred, "
                       "resetting channel.\n",
                       ahd_name(ahd));
#ifdef AHD_DEBUG
                if ((ahd_debug & AHD_SHOW_RECOVERY) != 0)
                        ahd_dump_card_state(ahd);
#endif
                ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                break;
        case STATUS_OVERRUN:
        {
                struct  scb *scb;
                u_int   scbid;

                scbid = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb != NULL)
                        ahd_print_path(ahd, scb);
                else
                        printk("%s: ", ahd_name(ahd));
                printk("SCB %d Packetized Status Overrun", scbid);
                ahd_dump_card_state(ahd);
                ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                break;
        }
        case CFG4ISTAT_INTR:
        {
                struct  scb *scb;
                u_int   scbid;

                scbid = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb == NULL) {
                        ahd_dump_card_state(ahd);
                        printk("CFG4ISTAT: Free SCB %d referenced", scbid);
                        panic("For safety");
                }
                ahd_outq(ahd, HADDR, scb->sense_busaddr);
                ahd_outw(ahd, HCNT, AHD_SENSE_BUFSIZE);
                ahd_outb(ahd, HCNT + 2, 0);
                ahd_outb(ahd, SG_CACHE_PRE, SG_LAST_SEG);
                ahd_outb(ahd, DFCNTRL, PRELOADEN|SCSIEN|HDMAEN);
                break;
        }
        case ILLEGAL_PHASE:
        {
                u_int bus_phase;

                bus_phase = ahd_inb(ahd, SCSISIGI) & PHASE_MASK;
                printk("%s: ILLEGAL_PHASE 0x%x\n",
                       ahd_name(ahd), bus_phase);

                switch (bus_phase) {
                case P_DATAOUT:
                case P_DATAIN:
                case P_DATAOUT_DT:
                case P_DATAIN_DT:
                case P_MESGOUT:
                case P_STATUS:
                case P_MESGIN:
                        ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                        printk("%s: Issued Bus Reset.\n", ahd_name(ahd));
                        break;
                case P_COMMAND:
                {
                        struct  ahd_devinfo devinfo;
                        struct  scb *scb;
                        u_int   scbid;

                        /*
                         * If a target takes us into the command phase
                         * assume that it has been externally reset and
                         * has thus lost our previous packetized negotiation
                         * agreement.  Since we have not sent an identify
                         * message and may not have fully qualified the
                         * connection, we change our command to TUR, assert
                         * ATN and ABORT the task when we go to message in
                         * phase.  The OSM will see the REQUEUE_REQUEST
                         * status and retry the command.
                         */
                        scbid = ahd_get_scbptr(ahd);
                        scb = ahd_lookup_scb(ahd, scbid);
                        if (scb == NULL) {
                                printk("Invalid phase with no valid SCB.  "
                                       "Resetting bus.\n");
                                ahd_reset_channel(ahd, 'A',
                                                  /*Initiate Reset*/TRUE);
                                break;
                        }
                        ahd_compile_devinfo(&devinfo, SCB_GET_OUR_ID(scb),
                                            SCB_GET_TARGET(ahd, scb),
                                            SCB_GET_LUN(scb),
                                            SCB_GET_CHANNEL(ahd, scb),
                                            ROLE_INITIATOR);
                        ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                                      AHD_TRANS_ACTIVE, /*paused*/TRUE);
                        ahd_set_syncrate(ahd, &devinfo, /*period*/0,
                                         /*offset*/0, /*ppr_options*/0,
                                         AHD_TRANS_ACTIVE, /*paused*/TRUE);
                        /* Hand-craft TUR command */
                        ahd_outb(ahd, SCB_CDB_STORE, 0);
                        ahd_outb(ahd, SCB_CDB_STORE+1, 0);
                        ahd_outb(ahd, SCB_CDB_STORE+2, 0);
                        ahd_outb(ahd, SCB_CDB_STORE+3, 0);
                        ahd_outb(ahd, SCB_CDB_STORE+4, 0);
                        ahd_outb(ahd, SCB_CDB_STORE+5, 0);
                        ahd_outb(ahd, SCB_CDB_LEN, 6);
                        scb->hscb->control &= ~(TAG_ENB|SCB_TAG_TYPE);
                        scb->hscb->control |= MK_MESSAGE;
                        ahd_outb(ahd, SCB_CONTROL, scb->hscb->control);
                        ahd_outb(ahd, MSG_OUT, HOST_MSG);
                        ahd_outb(ahd, SAVED_SCSIID, scb->hscb->scsiid);
                        /*
                         * The lun is 0, regardless of the SCB's lun
                         * as we have not sent an identify message.
                         */
                        ahd_outb(ahd, SAVED_LUN, 0);
                        ahd_outb(ahd, SEQ_FLAGS, 0);
                        ahd_assert_atn(ahd);
                        scb->flags &= ~SCB_PACKETIZED;
                        scb->flags |= SCB_ABORT|SCB_EXTERNAL_RESET;
                        ahd_freeze_devq(ahd, scb);
                        ahd_set_transaction_status(scb, CAM_REQUEUE_REQ);
                        ahd_freeze_scb(scb);

                        /* Notify XPT */
                        ahd_send_async(ahd, devinfo.channel, devinfo.target,
                                       CAM_LUN_WILDCARD, AC_SENT_BDR);

                        /*
                         * Allow the sequencer to continue with
                         * non-pack processing.
                         */
                        ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
                        ahd_outb(ahd, CLRLQOINT1, CLRLQOPHACHGINPKT);
                        if ((ahd->bugs & AHD_CLRLQO_AUTOCLR_BUG) != 0) {
                                ahd_outb(ahd, CLRLQOINT1, 0);
                        }
#ifdef AHD_DEBUG
                        if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                                ahd_print_path(ahd, scb);
                                printk("Unexpected command phase from "
                                       "packetized target\n");
                        }
#endif
                        break;
                }
                }
                break;
        }
        case CFG4OVERRUN:
        {
                struct  scb *scb;
                u_int   scb_index;

#ifdef AHD_DEBUG
                if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                        printk("%s: CFG4OVERRUN mode = %x\n", ahd_name(ahd),
                               ahd_inb(ahd, MODE_PTR));
                }
#endif

                scb_index = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scb_index);
                if (scb == NULL) {
                        /*
                         * Attempt to transfer to an SCB that is
                         * not outstanding.
                         */
                        ahd_assert_atn(ahd);
                        ahd_outb(ahd, MSG_OUT, HOST_MSG);
                        ahd->msgout_buf[0] = ABORT_TASK;
                        ahd->msgout_len = 1;
                        ahd->msgout_index = 0;
                        ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
                        /*
                         * Clear status received flag to prevent any
                         * attempt to complete this bogus SCB.
                         */
                        ahd_outb(ahd, SCB_CONTROL,
                                 ahd_inb_scbram(ahd, SCB_CONTROL)
                                 & ~STATUS_RCVD);
                }
                break;
        }
        case DUMP_CARD_STATE:
        {
                ahd_dump_card_state(ahd);
                break;
        }
        case PDATA_REINIT:
        {
#ifdef AHD_DEBUG
                if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                        printk("%s: PDATA_REINIT - DFCNTRL = 0x%x "
                               "SG_CACHE_SHADOW = 0x%x\n",
                               ahd_name(ahd), ahd_inb(ahd, DFCNTRL),
                               ahd_inb(ahd, SG_CACHE_SHADOW));
                }
#endif
                ahd_reinitialize_dataptrs(ahd);
                break;
        }
        case HOST_MSG_LOOP:
        {
                struct ahd_devinfo devinfo;

                /*
                 * The sequencer has encountered a message phase
                 * that requires host assistance for completion.
                 * While handling the message phase(s), we will be
                 * notified by the sequencer after each byte is
                 * transferred so we can track bus phase changes.
                 *
                 * If this is the first time we've seen a HOST_MSG_LOOP
                 * interrupt, initialize the state of the host message
                 * loop.
                 */
                ahd_fetch_devinfo(ahd, &devinfo);
                if (ahd->msg_type == MSG_TYPE_NONE) {
                        struct scb *scb;
                        u_int scb_index;
                        u_int bus_phase;

                        bus_phase = ahd_inb(ahd, SCSISIGI) & PHASE_MASK;
                        if (bus_phase != P_MESGIN
                         && bus_phase != P_MESGOUT) {
                                printk("ahd_intr: HOST_MSG_LOOP bad "
                                       "phase 0x%x\n", bus_phase);
                                /*
                                 * Probably transitioned to bus free before
                                 * we got here.  Just punt the message.
                                 */
                                ahd_dump_card_state(ahd);
                                ahd_clear_intstat(ahd);
                                ahd_restart(ahd);
                                return;
                        }

                        scb_index = ahd_get_scbptr(ahd);
                        scb = ahd_lookup_scb(ahd, scb_index);
                        if (devinfo.role == ROLE_INITIATOR) {
                                if (bus_phase == P_MESGOUT)
                                        ahd_setup_initiator_msgout(ahd,
                                                                   &devinfo,
                                                                   scb);
                                else {
                                        ahd->msg_type =
                                            MSG_TYPE_INITIATOR_MSGIN;
                                        ahd->msgin_index = 0;
                                }
                        }
#ifdef AHD_TARGET_MODE
                        else {
                                if (bus_phase == P_MESGOUT) {
                                        ahd->msg_type =
                                            MSG_TYPE_TARGET_MSGOUT;
                                        ahd->msgin_index = 0;
                                } else
                                        ahd_setup_target_msgin(ahd,
                                                               &devinfo,
                                                               scb);
                        }
#endif
                }

                ahd_handle_message_phase(ahd);
                break;
        }
        case NO_MATCH:
        {
                /* Ensure we don't leave the selection hardware on */
                AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
                ahd_outb(ahd, SCSISEQ0, ahd_inb(ahd, SCSISEQ0) & ~ENSELO);

                printk("%s:%c:%d: no active SCB for reconnecting "
                       "target - issuing BUS DEVICE RESET\n",
                       ahd_name(ahd), 'A', ahd_inb(ahd, SELID) >> 4);
                printk("SAVED_SCSIID == 0x%x, SAVED_LUN == 0x%x, "
                       "REG0 == 0x%x ACCUM = 0x%x\n",
                       ahd_inb(ahd, SAVED_SCSIID), ahd_inb(ahd, SAVED_LUN),
                       ahd_inw(ahd, REG0), ahd_inb(ahd, ACCUM));
                printk("SEQ_FLAGS == 0x%x, SCBPTR == 0x%x, BTT == 0x%x, "
                       "SINDEX == 0x%x\n",
                       ahd_inb(ahd, SEQ_FLAGS), ahd_get_scbptr(ahd),
                       ahd_find_busy_tcl(ahd,
                                         BUILD_TCL(ahd_inb(ahd, SAVED_SCSIID),
                                                   ahd_inb(ahd, SAVED_LUN))),
                       ahd_inw(ahd, SINDEX));
                printk("SELID == 0x%x, SCB_SCSIID == 0x%x, SCB_LUN == 0x%x, "
                       "SCB_CONTROL == 0x%x\n",
                       ahd_inb(ahd, SELID), ahd_inb_scbram(ahd, SCB_SCSIID),
                       ahd_inb_scbram(ahd, SCB_LUN),
                       ahd_inb_scbram(ahd, SCB_CONTROL));
                printk("SCSIBUS[0] == 0x%x, SCSISIGI == 0x%x\n",
                       ahd_inb(ahd, SCSIBUS), ahd_inb(ahd, SCSISIGI));
                printk("SXFRCTL0 == 0x%x\n", ahd_inb(ahd, SXFRCTL0));
                printk("SEQCTL0 == 0x%x\n", ahd_inb(ahd, SEQCTL0));
                ahd_dump_card_state(ahd);
                ahd->msgout_buf[0] = TARGET_RESET;
                ahd->msgout_len = 1;
                ahd->msgout_index = 0;
                ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
                ahd_outb(ahd, MSG_OUT, HOST_MSG);
                ahd_assert_atn(ahd);
                break;
        }
        case PROTO_VIOLATION:
        {
                ahd_handle_proto_violation(ahd);
                break;
        }
        case IGN_WIDE_RES:
        {
                struct ahd_devinfo devinfo;

                ahd_fetch_devinfo(ahd, &devinfo);
                ahd_handle_ign_wide_residue(ahd, &devinfo);
                break;
        }
        case BAD_PHASE:
        {
                u_int lastphase;

                lastphase = ahd_inb(ahd, LASTPHASE);
                printk("%s:%c:%d: unknown scsi bus phase %x, "
                       "lastphase = 0x%x.  Attempting to continue\n",
                       ahd_name(ahd), 'A',
                       SCSIID_TARGET(ahd, ahd_inb(ahd, SAVED_SCSIID)),
                       lastphase, ahd_inb(ahd, SCSISIGI));
                break;
        }
        case MISSED_BUSFREE:
        {
                u_int lastphase;

                lastphase = ahd_inb(ahd, LASTPHASE);
                printk("%s:%c:%d: Missed busfree. "
                       "Lastphase = 0x%x, Curphase = 0x%x\n",
                       ahd_name(ahd), 'A',
                       SCSIID_TARGET(ahd, ahd_inb(ahd, SAVED_SCSIID)),
                       lastphase, ahd_inb(ahd, SCSISIGI));
                ahd_restart(ahd);
                return;
        }
        case DATA_OVERRUN:
        {
                /*
                 * When the sequencer detects an overrun, it
                 * places the controller in "BITBUCKET" mode
                 * and allows the target to complete its transfer.
                 * Unfortunately, none of the counters get updated
                 * when the controller is in this mode, so we have
                 * no way of knowing how large the overrun was.
                 */
                struct  scb *scb;
                u_int   scbindex;
#ifdef AHD_DEBUG
                u_int   lastphase;
#endif

                scbindex = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbindex);
#ifdef AHD_DEBUG
                lastphase = ahd_inb(ahd, LASTPHASE);
                if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                        ahd_print_path(ahd, scb);
                        printk("data overrun detected %s.  Tag == 0x%x.\n",
                               ahd_lookup_phase_entry(lastphase)->phasemsg,
                               SCB_GET_TAG(scb));
                        ahd_print_path(ahd, scb);
                        printk("%s seen Data Phase.  Length = %ld.  "
                               "NumSGs = %d.\n",
                               ahd_inb(ahd, SEQ_FLAGS) & DPHASE
                               ? "Have" : "Haven't",
                               ahd_get_transfer_length(scb), scb->sg_count);
                        ahd_dump_sglist(scb);
                }
#endif

                /*
                 * Set this and it will take effect when the
                 * target does a command complete.
                 */
                ahd_freeze_devq(ahd, scb);
                ahd_set_transaction_status(scb, CAM_DATA_RUN_ERR);
                ahd_freeze_scb(scb);
                break;
        }
        case MKMSG_FAILED:
        {
                struct ahd_devinfo devinfo;
                struct scb *scb;
                u_int scbid;

                ahd_fetch_devinfo(ahd, &devinfo);
                printk("%s:%c:%d:%d: Attempt to issue message failed\n",
                       ahd_name(ahd), devinfo.channel, devinfo.target,
                       devinfo.lun);
                scbid = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb != NULL
                 && (scb->flags & SCB_RECOVERY_SCB) != 0)
                        /*
                         * Ensure that we didn't put a second instance of this
                         * SCB into the QINFIFO.
                         */
                        ahd_search_qinfifo(ahd, SCB_GET_TARGET(ahd, scb),
                                           SCB_GET_CHANNEL(ahd, scb),
                                           SCB_GET_LUN(scb), SCB_GET_TAG(scb),
                                           ROLE_INITIATOR, /*status*/0,
                                           SEARCH_REMOVE);
                ahd_outb(ahd, SCB_CONTROL,
                         ahd_inb_scbram(ahd, SCB_CONTROL) & ~MK_MESSAGE);
                break;
        }
        case TASKMGMT_FUNC_COMPLETE:
        {
                u_int   scbid;
                struct  scb *scb;

                scbid = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb != NULL) {
                        u_int      lun;
                        u_int      tag;
                        cam_status error;

                        ahd_print_path(ahd, scb);
                        printk("Task Management Func 0x%x Complete\n",
                               scb->hscb->task_management);
                        lun = CAM_LUN_WILDCARD;
                        tag = SCB_LIST_NULL;

                        switch (scb->hscb->task_management) {
                        case SIU_TASKMGMT_ABORT_TASK:
                                tag = SCB_GET_TAG(scb);
                                fallthrough;
                        case SIU_TASKMGMT_ABORT_TASK_SET:
                        case SIU_TASKMGMT_CLEAR_TASK_SET:
                                lun = scb->hscb->lun;
                                error = CAM_REQ_ABORTED;
                                ahd_abort_scbs(ahd, SCB_GET_TARGET(ahd, scb),
                                               'A', lun, tag, ROLE_INITIATOR,
                                               error);
                                break;
                        case SIU_TASKMGMT_LUN_RESET:
                                lun = scb->hscb->lun;
                                fallthrough;
                        case SIU_TASKMGMT_TARGET_RESET:
                        {
                                struct ahd_devinfo devinfo;

                                ahd_scb_devinfo(ahd, &devinfo, scb);
                                error = CAM_BDR_SENT;
                                ahd_handle_devreset(ahd, &devinfo, lun,
                                                    CAM_BDR_SENT,
                                                    lun != CAM_LUN_WILDCARD
                                                    ? "Lun Reset"
                                                    : "Target Reset",
                                                    /*verbose_level*/0);
                                break;
                        }
                        default:
                                panic("Unexpected TaskMgmt Func\n");
                                break;
                        }
                }
                break;
        }
        case TASKMGMT_CMD_CMPLT_OKAY:
        {
                u_int   scbid;
                struct  scb *scb;

                /*
                 * An ABORT TASK TMF failed to be delivered before
                 * the targeted command completed normally.
                 */
                scbid = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb != NULL) {
                        /*
                         * Remove the second instance of this SCB from
                         * the QINFIFO if it is still there.
                         */
                        ahd_print_path(ahd, scb);
                        printk("SCB completes before TMF\n");
                        /*
                         * Handle losing the race.  Wait until any
                         * current selection completes.  We will then
                         * set the TMF back to zero in this SCB so that
                         * the sequencer doesn't bother to issue another
                         * sequencer interrupt for its completion.
                         */
                        while ((ahd_inb(ahd, SCSISEQ0) & ENSELO) != 0
                            && (ahd_inb(ahd, SSTAT0) & SELDO) == 0
                            && (ahd_inb(ahd, SSTAT1) & SELTO) == 0)
                                ;
                        ahd_outb(ahd, SCB_TASK_MANAGEMENT, 0);
                        ahd_search_qinfifo(ahd, SCB_GET_TARGET(ahd, scb),
                                           SCB_GET_CHANNEL(ahd, scb),
                                           SCB_GET_LUN(scb), SCB_GET_TAG(scb),
                                           ROLE_INITIATOR, /*status*/0,
                                           SEARCH_REMOVE);
                }
                break;
        }
        case TRACEPOINT0:
        case TRACEPOINT1:
        case TRACEPOINT2:
        case TRACEPOINT3:
                printk("%s: Tracepoint %d\n", ahd_name(ahd),
                       seqintcode - TRACEPOINT0);
                break;
        case NO_SEQINT:
                break;
        case SAW_HWERR:
                ahd_handle_hwerrint(ahd);
                break;
        default:
                printk("%s: Unexpected SEQINTCODE %d\n", ahd_name(ahd),
                       seqintcode);
                break;
        }
        /*
         *  The sequencer is paused immediately on
         *  a SEQINT, so we should restart it when
         *  we're done.
         */
        ahd_unpause(ahd);
}

static void
ahd_handle_scsiint(struct ahd_softc *ahd, u_int intstat)
{
        struct scb      *scb;
        u_int            status0;
        u_int            status3;
        u_int            status;
        u_int            lqistat1;
        u_int            lqostat0;
        u_int            scbid;
        u_int            busfreetime;

        ahd_update_modes(ahd);
        ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

        status3 = ahd_inb(ahd, SSTAT3) & (NTRAMPERR|OSRAMPERR);
        status0 = ahd_inb(ahd, SSTAT0) & (IOERR|OVERRUN|SELDI|SELDO);
        status = ahd_inb(ahd, SSTAT1) & (SELTO|SCSIRSTI|BUSFREE|SCSIPERR);
        lqistat1 = ahd_inb(ahd, LQISTAT1);
        lqostat0 = ahd_inb(ahd, LQOSTAT0);
        busfreetime = ahd_inb(ahd, SSTAT2) & BUSFREETIME;

        /*
         * Ignore external resets after a bus reset.
         */
        if (((status & SCSIRSTI) != 0) && (ahd->flags & AHD_BUS_RESET_ACTIVE)) {
                ahd_outb(ahd, CLRSINT1, CLRSCSIRSTI);
                return;
        }

        /*
         * Clear bus reset flag
         */
        ahd->flags &= ~AHD_BUS_RESET_ACTIVE;

        if ((status0 & (SELDI|SELDO)) != 0) {
                u_int simode0;

                ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
                simode0 = ahd_inb(ahd, SIMODE0);
                status0 &= simode0 & (IOERR|OVERRUN|SELDI|SELDO);
                ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
        }
        scbid = ahd_get_scbptr(ahd);
        scb = ahd_lookup_scb(ahd, scbid);
        if (scb != NULL
         && (ahd_inb(ahd, SEQ_FLAGS) & NOT_IDENTIFIED) != 0)
                scb = NULL;

        if ((status0 & IOERR) != 0) {
                u_int now_lvd;

                now_lvd = ahd_inb(ahd, SBLKCTL) & ENAB40;
                printk("%s: Transceiver State Has Changed to %s mode\n",
                       ahd_name(ahd), now_lvd ? "LVD" : "SE");
                ahd_outb(ahd, CLRSINT0, CLRIOERR);
                /*
                 * A change in I/O mode is equivalent to a bus reset.
                 */
                ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                ahd_pause(ahd);
                ahd_setup_iocell_workaround(ahd);
                ahd_unpause(ahd);
        } else if ((status0 & OVERRUN) != 0) {

                printk("%s: SCSI offset overrun detected.  Resetting bus.\n",
                       ahd_name(ahd));
                ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
        } else if ((status & SCSIRSTI) != 0) {

                printk("%s: Someone reset channel A\n", ahd_name(ahd));
                ahd_reset_channel(ahd, 'A', /*Initiate Reset*/FALSE);
        } else if ((status & SCSIPERR) != 0) {

                /* Make sure the sequencer is in a safe location. */
                ahd_clear_critical_section(ahd);

                ahd_handle_transmission_error(ahd);
        } else if (lqostat0 != 0) {

                printk("%s: lqostat0 == 0x%x!\n", ahd_name(ahd), lqostat0);
                ahd_outb(ahd, CLRLQOINT0, lqostat0);
                if ((ahd->bugs & AHD_CLRLQO_AUTOCLR_BUG) != 0)
                        ahd_outb(ahd, CLRLQOINT1, 0);
        } else if ((status & SELTO) != 0) {
                /* Stop the selection */
                ahd_outb(ahd, SCSISEQ0, 0);

                /* Make sure the sequencer is in a safe location. */
                ahd_clear_critical_section(ahd);

                /* No more pending messages */
                ahd_clear_msg_state(ahd);

                /* Clear interrupt state */
                ahd_outb(ahd, CLRSINT1, CLRSELTIMEO|CLRBUSFREE|CLRSCSIPERR);

                /*
                 * Although the driver does not care about the
                 * 'Selection in Progress' status bit, the busy
                 * LED does.  SELINGO is only cleared by a successful
                 * selection, so we must manually clear it to insure
                 * the LED turns off just incase no future successful
                 * selections occur (e.g. no devices on the bus).
                 */
                ahd_outb(ahd, CLRSINT0, CLRSELINGO);

                scbid = ahd_inw(ahd, WAITING_TID_HEAD);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb == NULL) {
                        printk("%s: ahd_intr - referenced scb not "
                               "valid during SELTO scb(0x%x)\n",
                               ahd_name(ahd), scbid);
                        ahd_dump_card_state(ahd);
                } else {
                        struct ahd_devinfo devinfo;
#ifdef AHD_DEBUG
                        if ((ahd_debug & AHD_SHOW_SELTO) != 0) {
                                ahd_print_path(ahd, scb);
                                printk("Saw Selection Timeout for SCB 0x%x\n",
                                       scbid);
                        }
#endif
                        ahd_scb_devinfo(ahd, &devinfo, scb);
                        ahd_set_transaction_status(scb, CAM_SEL_TIMEOUT);
                        ahd_freeze_devq(ahd, scb);

                        /*
                         * Cancel any pending transactions on the device
                         * now that it seems to be missing.  This will
                         * also revert us to async/narrow transfers until
                         * we can renegotiate with the device.
                         */
                        ahd_handle_devreset(ahd, &devinfo,
                                            CAM_LUN_WILDCARD,
                                            CAM_SEL_TIMEOUT,
                                            "Selection Timeout",
                                            /*verbose_level*/1);
                }
                ahd_outb(ahd, CLRINT, CLRSCSIINT);
                ahd_iocell_first_selection(ahd);
                ahd_unpause(ahd);
        } else if ((status0 & (SELDI|SELDO)) != 0) {

                ahd_iocell_first_selection(ahd);
                ahd_unpause(ahd);
        } else if (status3 != 0) {
                printk("%s: SCSI Cell parity error SSTAT3 == 0x%x\n",
                       ahd_name(ahd), status3);
                ahd_outb(ahd, CLRSINT3, status3);
        } else if ((lqistat1 & (LQIPHASE_LQ|LQIPHASE_NLQ)) != 0) {

                /* Make sure the sequencer is in a safe location. */
                ahd_clear_critical_section(ahd);

                ahd_handle_lqiphase_error(ahd, lqistat1);
        } else if ((lqistat1 & LQICRCI_NLQ) != 0) {
                /*
                 * This status can be delayed during some
                 * streaming operations.  The SCSIPHASE
                 * handler has already dealt with this case
                 * so just clear the error.
                 */
                ahd_outb(ahd, CLRLQIINT1, CLRLQICRCI_NLQ);
        } else if ((status & BUSFREE) != 0
                || (lqistat1 & LQOBUSFREE) != 0) {
                u_int lqostat1;
                int   restart;
                int   clear_fifo;
                int   packetized;
                u_int mode;

                /*
                 * Clear our selection hardware as soon as possible.
                 * We may have an entry in the waiting Q for this target,
                 * that is affected by this busfree and we don't want to
                 * go about selecting the target while we handle the event.
                 */
                ahd_outb(ahd, SCSISEQ0, 0);

                /* Make sure the sequencer is in a safe location. */
                ahd_clear_critical_section(ahd);

                /*
                 * Determine what we were up to at the time of
                 * the busfree.
                 */
                mode = AHD_MODE_SCSI;
                busfreetime = ahd_inb(ahd, SSTAT2) & BUSFREETIME;
                lqostat1 = ahd_inb(ahd, LQOSTAT1);
                switch (busfreetime) {
                case BUSFREE_DFF0:
                case BUSFREE_DFF1:
                {
                        mode = busfreetime == BUSFREE_DFF0
                             ? AHD_MODE_DFF0 : AHD_MODE_DFF1;
                        ahd_set_modes(ahd, mode, mode);
                        scbid = ahd_get_scbptr(ahd);
                        scb = ahd_lookup_scb(ahd, scbid);
                        if (scb == NULL) {
                                printk("%s: Invalid SCB %d in DFF%d "
                                       "during unexpected busfree\n",
                                       ahd_name(ahd), scbid, mode);
                                packetized = 0;
                        } else
                                packetized = (scb->flags & SCB_PACKETIZED) != 0;
                        clear_fifo = 1;
                        break;
                }
                case BUSFREE_LQO:
                        clear_fifo = 0;
                        packetized = 1;
                        break;
                default:
                        clear_fifo = 0;
                        packetized =  (lqostat1 & LQOBUSFREE) != 0;
                        if (!packetized
                         && ahd_inb(ahd, LASTPHASE) == P_BUSFREE
                         && (ahd_inb(ahd, SSTAT0) & SELDI) == 0
                         && ((ahd_inb(ahd, SSTAT0) & SELDO) == 0
                          || (ahd_inb(ahd, SCSISEQ0) & ENSELO) == 0))
                                /*
                                 * Assume packetized if we are not
                                 * on the bus in a non-packetized
                                 * capacity and any pending selection
                                 * was a packetized selection.
                                 */
                                packetized = 1;
                        break;
                }

#ifdef AHD_DEBUG
                if ((ahd_debug & AHD_SHOW_MISC) != 0)
                        printk("Saw Busfree.  Busfreetime = 0x%x.\n",
                               busfreetime);
#endif
                /*
                 * Busfrees that occur in non-packetized phases are
                 * handled by the nonpkt_busfree handler.
                 */
                if (packetized && ahd_inb(ahd, LASTPHASE) == P_BUSFREE) {
                        restart = ahd_handle_pkt_busfree(ahd, busfreetime);
                } else {
                        packetized = 0;
                        restart = ahd_handle_nonpkt_busfree(ahd);
                }
                /*
                 * Clear the busfree interrupt status.  The setting of
                 * the interrupt is a pulse, so in a perfect world, we
                 * would not need to muck with the ENBUSFREE logic.  This
                 * would ensure that if the bus moves on to another
                 * connection, busfree protection is still in force.  If
                 * BUSFREEREV is broken, however, we must manually clear
                 * the ENBUSFREE if the busfree occurred during a non-pack
                 * connection so that we don't get false positives during
                 * future, packetized, connections.
                 */
                ahd_outb(ahd, CLRSINT1, CLRBUSFREE);
                if (packetized == 0
                 && (ahd->bugs & AHD_BUSFREEREV_BUG) != 0)
                        ahd_outb(ahd, SIMODE1,
                                 ahd_inb(ahd, SIMODE1) & ~ENBUSFREE);

                if (clear_fifo)
                        ahd_clear_fifo(ahd, mode);

                ahd_clear_msg_state(ahd);
                ahd_outb(ahd, CLRINT, CLRSCSIINT);
                if (restart) {
                        ahd_restart(ahd);
                } else {
                        ahd_unpause(ahd);
                }
        } else {
                printk("%s: Missing case in ahd_handle_scsiint. status = %x\n",
                       ahd_name(ahd), status);
                ahd_dump_card_state(ahd);
                ahd_clear_intstat(ahd);
                ahd_unpause(ahd);
        }
}

static void
ahd_handle_transmission_error(struct ahd_softc *ahd)
{
        struct  scb *scb;
        u_int   scbid;
        u_int   lqistat1;
        u_int   msg_out;
        u_int   curphase;
        u_int   lastphase;
        u_int   perrdiag;
        u_int   cur_col;
        int     silent;

        scb = NULL;
        ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
        lqistat1 = ahd_inb(ahd, LQISTAT1) & ~(LQIPHASE_LQ|LQIPHASE_NLQ);
        ahd_inb(ahd, LQISTAT2);
        if ((lqistat1 & (LQICRCI_NLQ|LQICRCI_LQ)) == 0
         && (ahd->bugs & AHD_NLQICRC_DELAYED_BUG) != 0) {
                u_int lqistate;

                ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
                lqistate = ahd_inb(ahd, LQISTATE);
                if ((lqistate >= 0x1E && lqistate <= 0x24)
                 || (lqistate == 0x29)) {
#ifdef AHD_DEBUG
                        if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                                printk("%s: NLQCRC found via LQISTATE\n",
                                       ahd_name(ahd));
                        }
#endif
                        lqistat1 |= LQICRCI_NLQ;
                }
                ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
        }

        ahd_outb(ahd, CLRLQIINT1, lqistat1);
        lastphase = ahd_inb(ahd, LASTPHASE);
        curphase = ahd_inb(ahd, SCSISIGI) & PHASE_MASK;
        perrdiag = ahd_inb(ahd, PERRDIAG);
        msg_out = INITIATOR_ERROR;
        ahd_outb(ahd, CLRSINT1, CLRSCSIPERR);

        /*
         * Try to find the SCB associated with this error.
         */
        silent = FALSE;
        if (lqistat1 == 0
         || (lqistat1 & LQICRCI_NLQ) != 0) {
                if ((lqistat1 & (LQICRCI_NLQ|LQIOVERI_NLQ)) != 0)
                        ahd_set_active_fifo(ahd);
                scbid = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb != NULL && SCB_IS_SILENT(scb))
                        silent = TRUE;
        }

        cur_col = 0;
        if (silent == FALSE) {
                printk("%s: Transmission error detected\n", ahd_name(ahd));
                ahd_lqistat1_print(lqistat1, &cur_col, 50);
                ahd_lastphase_print(lastphase, &cur_col, 50);
                ahd_scsisigi_print(curphase, &cur_col, 50);
                ahd_perrdiag_print(perrdiag, &cur_col, 50);
                printk("\n");
                ahd_dump_card_state(ahd);
        }

        if ((lqistat1 & (LQIOVERI_LQ|LQIOVERI_NLQ)) != 0) {
                if (silent == FALSE) {
                        printk("%s: Gross protocol error during incoming "
                               "packet.  lqistat1 == 0x%x.  Resetting bus.\n",
                               ahd_name(ahd), lqistat1);
                }
                ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                return;
        } else if ((lqistat1 & LQICRCI_LQ) != 0) {
                /*
                 * A CRC error has been detected on an incoming LQ.
                 * The bus is currently hung on the last ACK.
                 * Hit LQIRETRY to release the last ack, and
                 * wait for the sequencer to determine that ATNO
                 * is asserted while in message out to take us
                 * to our host message loop.  No NONPACKREQ or
                 * LQIPHASE type errors will occur in this
                 * scenario.  After this first LQIRETRY, the LQI
                 * manager will be in ISELO where it will
                 * happily sit until another packet phase begins.
                 * Unexpected bus free detection is enabled
                 * through any phases that occur after we release
                 * this last ack until the LQI manager sees a
                 * packet phase.  This implies we may have to
                 * ignore a perfectly valid "unexected busfree"
                 * after our "initiator detected error" message is
                 * sent.  A busfree is the expected response after
                 * we tell the target that it's L_Q was corrupted.
                 * (SPI4R09 10.7.3.3.3)
                 */
                ahd_outb(ahd, LQCTL2, LQIRETRY);
                printk("LQIRetry for LQICRCI_LQ to release ACK\n");
        } else if ((lqistat1 & LQICRCI_NLQ) != 0) {
                /*
                 * We detected a CRC error in a NON-LQ packet.
                 * The hardware has varying behavior in this situation
                 * depending on whether this packet was part of a
                 * stream or not.
                 *
                 * PKT by PKT mode:
                 * The hardware has already acked the complete packet.
                 * If the target honors our outstanding ATN condition,
                 * we should be (or soon will be) in MSGOUT phase.
                 * This will trigger the LQIPHASE_LQ status bit as the
                 * hardware was expecting another LQ.  Unexpected
                 * busfree detection is enabled.  Once LQIPHASE_LQ is
                 * true (first entry into host message loop is much
                 * the same), we must clear LQIPHASE_LQ and hit
                 * LQIRETRY so the hardware is ready to handle
                 * a future LQ.  NONPACKREQ will not be asserted again
                 * once we hit LQIRETRY until another packet is
                 * processed.  The target may either go busfree
                 * or start another packet in response to our message.
                 *
                 * Read Streaming P0 asserted:
                 * If we raise ATN and the target completes the entire
                 * stream (P0 asserted during the last packet), the
                 * hardware will ack all data and return to the ISTART
                 * state.  When the target reponds to our ATN condition,
                 * LQIPHASE_LQ will be asserted.  We should respond to
                 * this with an LQIRETRY to prepare for any future
                 * packets.  NONPACKREQ will not be asserted again
                 * once we hit LQIRETRY until another packet is
                 * processed.  The target may either go busfree or
                 * start another packet in response to our message.
                 * Busfree detection is enabled.
                 *
                 * Read Streaming P0 not asserted:
                 * If we raise ATN and the target transitions to
                 * MSGOUT in or after a packet where P0 is not
                 * asserted, the hardware will assert LQIPHASE_NLQ.
                 * We should respond to the LQIPHASE_NLQ with an
                 * LQIRETRY.  Should the target stay in a non-pkt
                 * phase after we send our message, the hardware
                 * will assert LQIPHASE_LQ.  Recovery is then just as
                 * listed above for the read streaming with P0 asserted.
                 * Busfree detection is enabled.
                 */
                if (silent == FALSE)
                        printk("LQICRC_NLQ\n");
                if (scb == NULL) {
                        printk("%s: No SCB valid for LQICRC_NLQ.  "
                               "Resetting bus\n", ahd_name(ahd));
                        ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                        return;
                }
        } else if ((lqistat1 & LQIBADLQI) != 0) {
                printk("Need to handle BADLQI!\n");
                ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                return;
        } else if ((perrdiag & (PARITYERR|PREVPHASE)) == PARITYERR) {
                if ((curphase & ~P_DATAIN_DT) != 0) {
                        /* Ack the byte.  So we can continue. */
                        if (silent == FALSE)
                                printk("Acking %s to clear perror\n",
                                    ahd_lookup_phase_entry(curphase)->phasemsg);
                        ahd_inb(ahd, SCSIDAT);
                }

                if (curphase == P_MESGIN)
                        msg_out = MSG_PARITY_ERROR;
        }

        /*
         * We've set the hardware to assert ATN if we
         * get a parity error on "in" phases, so all we
         * need to do is stuff the message buffer with
         * the appropriate message.  "In" phases have set
         * mesg_out to something other than NOP.
         */
        ahd->send_msg_perror = msg_out;
        if (scb != NULL && msg_out == INITIATOR_ERROR)
                scb->flags |= SCB_TRANSMISSION_ERROR;
        ahd_outb(ahd, MSG_OUT, HOST_MSG);
        ahd_outb(ahd, CLRINT, CLRSCSIINT);
        ahd_unpause(ahd);
}

static void
ahd_handle_lqiphase_error(struct ahd_softc *ahd, u_int lqistat1)
{
        /*
         * Clear the sources of the interrupts.
         */
        ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
        ahd_outb(ahd, CLRLQIINT1, lqistat1);

        /*
         * If the "illegal" phase changes were in response
         * to our ATN to flag a CRC error, AND we ended up
         * on packet boundaries, clear the error, restart the
         * LQI manager as appropriate, and go on our merry
         * way toward sending the message.  Otherwise, reset
         * the bus to clear the error.
         */
        ahd_set_active_fifo(ahd);
        if ((ahd_inb(ahd, SCSISIGO) & ATNO) != 0
         && (ahd_inb(ahd, MDFFSTAT) & DLZERO) != 0) {
                if ((lqistat1 & LQIPHASE_LQ) != 0) {
                        printk("LQIRETRY for LQIPHASE_LQ\n");
                        ahd_outb(ahd, LQCTL2, LQIRETRY);
                } else if ((lqistat1 & LQIPHASE_NLQ) != 0) {
                        printk("LQIRETRY for LQIPHASE_NLQ\n");
                        ahd_outb(ahd, LQCTL2, LQIRETRY);
                } else
                        panic("ahd_handle_lqiphase_error: No phase errors\n");
                ahd_dump_card_state(ahd);
                ahd_outb(ahd, CLRINT, CLRSCSIINT);
                ahd_unpause(ahd);
        } else {
                printk("Resetting Channel for LQI Phase error\n");
                ahd_dump_card_state(ahd);
                ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
        }
}

/*
 * Packetized unexpected or expected busfree.
 * Entered in mode based on busfreetime.
 */
static int
ahd_handle_pkt_busfree(struct ahd_softc *ahd, u_int busfreetime)
{
        u_int lqostat1;

        AHD_ASSERT_MODES(ahd, ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK),
                         ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK));
        lqostat1 = ahd_inb(ahd, LQOSTAT1);
        if ((lqostat1 & LQOBUSFREE) != 0) {
                struct scb *scb;
                u_int scbid;
                u_int saved_scbptr;
                u_int waiting_h;
                u_int waiting_t;
                u_int next;

                /*
                 * The LQO manager detected an unexpected busfree
                 * either:
                 *
                 * 1) During an outgoing LQ.
                 * 2) After an outgoing LQ but before the first
                 *    REQ of the command packet.
                 * 3) During an outgoing command packet.
                 *
                 * In all cases, CURRSCB is pointing to the
                 * SCB that encountered the failure.  Clean
                 * up the queue, clear SELDO and LQOBUSFREE,
                 * and allow the sequencer to restart the select
                 * out at its lesure.
                 */
                ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
                scbid = ahd_inw(ahd, CURRSCB);
                scb = ahd_lookup_scb(ahd, scbid);
                if (scb == NULL)
                       panic("SCB not valid during LQOBUSFREE");
                /*
                 * Clear the status.
                 */
                ahd_outb(ahd, CLRLQOINT1, CLRLQOBUSFREE);
                if ((ahd->bugs & AHD_CLRLQO_AUTOCLR_BUG) != 0)
                        ahd_outb(ahd, CLRLQOINT1, 0);
                ahd_outb(ahd, SCSISEQ0, ahd_inb(ahd, SCSISEQ0) & ~ENSELO);
                ahd_flush_device_writes(ahd);
                ahd_outb(ahd, CLRSINT0, CLRSELDO);

                /*
                 * Return the LQO manager to its idle loop.  It will
                 * not do this automatically if the busfree occurs
                 * after the first REQ of either the LQ or command
                 * packet or between the LQ and command packet.
                 */
                ahd_outb(ahd, LQCTL2, ahd_inb(ahd, LQCTL2) | LQOTOIDLE);

                /*
                 * Update the waiting for selection queue so
                 * we restart on the correct SCB.
                 */
                waiting_h = ahd_inw(ahd, WAITING_TID_HEAD);
                saved_scbptr = ahd_get_scbptr(ahd);
                if (waiting_h != scbid) {

                        ahd_outw(ahd, WAITING_TID_HEAD, scbid);
                        waiting_t = ahd_inw(ahd, WAITING_TID_TAIL);
                        if (waiting_t == waiting_h) {
                                ahd_outw(ahd, WAITING_TID_TAIL, scbid);
                                next = SCB_LIST_NULL;
                        } else {
                                ahd_set_scbptr(ahd, waiting_h);
                                next = ahd_inw_scbram(ahd, SCB_NEXT2);
                        }
                        ahd_set_scbptr(ahd, scbid);
                        ahd_outw(ahd, SCB_NEXT2, next);
                }
                ahd_set_scbptr(ahd, saved_scbptr);
                if (scb->crc_retry_count < AHD_MAX_LQ_CRC_ERRORS) {
                        if (SCB_IS_SILENT(scb) == FALSE) {
                                ahd_print_path(ahd, scb);
                                printk("Probable outgoing LQ CRC error.  "
                                       "Retrying command\n");
                        }
                        scb->crc_retry_count++;
                } else {
                        ahd_set_transaction_status(scb, CAM_UNCOR_PARITY);
                        ahd_freeze_scb(scb);
                        ahd_freeze_devq(ahd, scb);
                }
                /* Return unpausing the sequencer. */
                return (0);
        } else if ((ahd_inb(ahd, PERRDIAG) & PARITYERR) != 0) {
                /*
                 * Ignore what are really parity errors that
                 * occur on the last REQ of a free running
                 * clock prior to going busfree.  Some drives
                 * do not properly active negate just before
                 * going busfree resulting in a parity glitch.
                 */
                ahd_outb(ahd, CLRSINT1, CLRSCSIPERR|CLRBUSFREE);
#ifdef AHD_DEBUG
                if ((ahd_debug & AHD_SHOW_MASKED_ERRORS) != 0)
                        printk("%s: Parity on last REQ detected "
                               "during busfree phase.\n",
                               ahd_name(ahd));
#endif
                /* Return unpausing the sequencer. */
                return (0);
        }
        if (ahd->src_mode != AHD_MODE_SCSI) {
                u_int   scbid;
                struct  scb *scb;

                scbid = ahd_get_scbptr(ahd);
                scb = ahd_lookup_scb(ahd, scbid);
                ahd_print_path(ahd, scb);
                printk("Unexpected PKT busfree condition\n");
                ahd_dump_card_state(ahd);
                ahd_abort_scbs(ahd, SCB_GET_TARGET(ahd, scb), 'A',
                               SCB_GET_LUN(scb), SCB_GET_TAG(scb),
                               ROLE_INITIATOR, CAM_UNEXP_BUSFREE);