revert 213 commits (to 56092) from the last month. 10 still need work to resolve...

[AROS.git] / rom / devs / ahci / ahci_cam_aros.c

/*
 * Copyright (C) 2012-2018, The AROS Development Team.  All rights reserved.
 * Author: Jason S. McMullan <jason.mcmullan@gmail.com>
 *
 * Licensed under the AROS PUBLIC LICENSE (APL) Version 1.1
 */

#include <aros/debug.h>

#include <proto/exec.h>

/* We want all other bases obtained from our base */
#define __NOLIBBASE__

#include <aros/atomic.h>

#include <proto/expansion.h>
#include <proto/dos.h>

#include <dos/filehandler.h>

#include <devices/trackdisk.h>
#include <devices/scsidisk.h>

#include <scsi/commands.h>
#include <scsi/values.h>

#include "ahci.h"
#include "ahci_scsi.h"
#include "timer.h"

#include LC_LIBDEFS_FILE

/*
 * Execute a SCSI TEST UNIT READY every 250ms, to see
 * if the medium has changed.
 */
static void ahci_PortMonitor(struct Task *parent, struct Device *device, struct cam_sim *unit)
{
    struct MsgPort *mp;
    struct IORequest *tmr;

    D(bug("%s %d: Monitor Start\n", ((struct Node *)device)->ln_Name, unit->sim_Unit)); 
    AROS_ATOMIC_INC(unit->sim_UseCount);
    Signal(parent, SIGBREAKF_CTRL_C);

    tmr = ahci_OpenTimer();
    if (!tmr)
        return;

    if ((mp = CreateMsgPort())) { 
        struct IORequest *io;
        if ((io = CreateIORequest(mp, sizeof(struct IOStdReq)))) {
            BOOL media_present = FALSE;

            struct scsi_generic test_unit_ready = { .opcode = SCSI_TEST_UNIT_READY, };
            struct scsi_sense_data sense = {};
            struct SCSICmd scsi = {};

            io->io_Device = device;
            io->io_Unit = (struct Unit *)unit;

            D(bug("%s %d: Monitoring\n", ((struct Node *)device)->ln_Name, unit->sim_Unit)); 
            do {
                BOOL is_present;

                io->io_Command = HD_SCSICMD;
                io->io_Flags   = 0;
                io->io_Error = 0;
                IOStdReq(io)->io_Data = &scsi;
                IOStdReq(io)->io_Length = sizeof(scsi);
                IOStdReq(io)->io_Actual = 0;
                scsi.scsi_Command = (UBYTE *)&test_unit_ready;
                scsi.scsi_CmdLength = sizeof(test_unit_ready);
                scsi.scsi_Actual = 0;
                scsi.scsi_Status = 0;
                scsi.scsi_Flags = SCSIF_AUTOSENSE;
                scsi.scsi_SenseData = (UBYTE *)&sense;
                scsi.scsi_SenseLength = sizeof(sense);
                scsi.scsi_SenseActual = 0;

                DoIO(io);

                is_present = (io->io_Error == 0) && (scsi.scsi_Status == SCSI_GOOD);
                // TODO: Check sense for additional information

                ObtainSemaphore(&unit->sim_Lock);
                if (is_present)
                    unit->sim_Flags |= SIMF_MediaPresent;
                else
                    unit->sim_Flags &= ~SIMF_MediaPresent;
                if (is_present != media_present)
                    unit->sim_ChangeNum++;
                ReleaseSemaphore(&unit->sim_Lock);

                if (is_present != media_present) {
                    struct IORequest *msg;

                    D(bug("%s: Media change detected on ahci.device %d (%s => %s)\n", __func__, unit->sim_Unit, media_present ? "TRUE" : "FALSE", is_present ? "TRUE" : "FALSE"));

                    Forbid();
                    ForeachNode((struct Node *)&unit->sim_IOs, msg) {
                        D(bug("%s %d: io_Command = 0x%04x\n", ((struct Node *)device)->ln_Name, unit->sim_Unit, msg->io_Command)); 
                        if (msg->io_Command == TD_ADDCHANGEINT) {
                            D(bug("%s %d: Interrupt = 0x%p\n", ((struct Node *)device)->ln_Name, unit->sim_Unit, IOStdReq(msg)->io_Data));
                            Cause((struct Interrupt *)IOStdReq(msg)->io_Data);
                        }
                    }
                    Permit();
                }
                media_present = is_present;

                /* Wait 1s to the next scan */
            } while ((ahci_WaitTO(tmr, 1, 0, SIGF_DOS) & SIGF_DOS) == 0);

            DeleteIORequest(io);
        }
        DeleteMsgPort(mp);
    }
    AROS_ATOMIC_DEC(unit->sim_UseCount);
    D(bug("%s %d: Monitor End\n", ((struct Node *)device)->ln_Name, unit->sim_Unit)); 
}

static int ahci_RegisterPort(struct ahci_port *ap)
{
    struct AHCIBase *AHCIBase = ap->ap_sc->sc_dev->dev_AHCIBase;
    struct cam_sim *unit;
    char name[64];
        D(bug("[AHCI] %s()\n", __PRETTY_FUNCTION__)); 

    unit = AllocPooled(AHCIBase->ahci_MemPool, sizeof(*unit));
    if (!unit)
        return ENOMEM;

    ap->ap_sim = unit;
    unit->sim_Port = ap;
    unit->sim_Unit = ap->ap_sc->sc_dev->dev_HostID * 32 + ap->ap_num;
    InitSemaphore(&unit->sim_Lock);
    NEWLIST(&unit->sim_IOs);

    AddTail((struct List *)&AHCIBase->ahci_Units, (struct Node *)unit);

    /* Now that this device is in the unit list, start the disk change monitor */
    snprintf(name, sizeof(name), "ahci.device %d [media]", unit->sim_Unit);
    unit->sim_Monitor = NewCreateTask(TASKTAG_NAME, name,
                                      TASKTAG_PC, ahci_PortMonitor,
                                      TASKTAG_ARG1, FindTask(NULL),
                                      TASKTAG_ARG2, AHCIBase,
                                      TASKTAG_ARG3, unit,
                                      TAG_END);

    Wait(SIGBREAKF_CTRL_C);

    return 0;
}

static int ahci_UnregisterPort(struct ahci_port *ap)
{
    struct ahci_softc *sc = ap->ap_sc;
    struct AHCIBase *AHCIBase;
    struct cam_sim *unit = ap->ap_sim;

    D(bug("[AHCI] ahci_UnregisterPort: %p\n", ap));

    if (sc == NULL) {
        D(bug("No softc?\n"));
        return 0;
    }

    AHCIBase = sc->sc_dev->dev_AHCIBase;

    /* Stop the monitor, and wait for IOs to drain,
     * and users to CloseDevice() the unit.
     */
    if (unit->sim_Monitor)
        Signal(unit->sim_Monitor, SIGF_DOS);
    ObtainSemaphore(&unit->sim_Lock);
    while (unit->sim_UseCount) {
        ReleaseSemaphore(&unit->sim_Lock);
        ahci_os_sleep(100);
        ObtainSemaphore(&unit->sim_Lock);
    }
    ReleaseSemaphore(&unit->sim_Lock);

    /* Remove from the unit list */
    Forbid();
    Remove((struct Node *)unit);
    Permit();

    FreePooled(AHCIBase->ahci_MemPool, unit, sizeof(*unit));

    return 0;
}

/* Add a bootnode using expansion.library,
 * but only when dos.library has not yet been initialized.
 * This way, we get BootNodes if ahci.device is linked in,
 * but don't if ahci.device is loaded after booting.
 */
static BOOL ahci_RegisterVolume(struct ahci_port *ap, struct ata_port *at, struct ahci_Unit *unit)
{
    struct ExpansionBase *ExpansionBase;
    BOOL dos_loaded;
    struct DeviceNode *devnode;
    TEXT dosdevname[4] = "HA0";
    const ULONG DOS_ID = AROS_MAKE_ID('D','O','S','\001');
    const ULONG CDROM_ID = AROS_MAKE_ID('C','D','V','D');

    unit->au_UnitNum = device_get_unit(ap->ap_sc->sc_dev) * 32 + ap->ap_num;

    D(bug("[AHCI>>] %s()\n", __PRETTY_FUNCTION__)); 
    D(bug("[AHCI>>] %s: ap = %p, at = %p, unit = %d\n", __func__, ap, at, ap->ap_sim ? ap->ap_sim->sim_Unit : -1));

    /* See if dos.library has run */
    Forbid();
    dos_loaded = (FindName (&SysBase->LibList, "dos.library") != NULL);
    Permit();

    if (dos_loaded) {
        D(bug("[AHCI>>] %s: refused to register as boot volume - dos.library already loaded\n", __func__));
        return FALSE;
    }

    if (at == NULL || ap->ap_type == ATA_PORT_T_NONE)
        return FALSE;

    /* This should be dealt with using some sort of volume manager or such. */
    switch (ap->ap_type)
    {
        case ATA_PORT_T_DISK:
            break;
        case ATA_PORT_T_ATAPI:
            dosdevname[0] = 'C';
            break;
        default:
            D(bug("[AHCI>>]:-ahci_RegisterVolume called on unknown devicetype\n"));
            return FALSE;
    }

    ExpansionBase = (struct ExpansionBase *)OpenLibrary("expansion.library",
                                                        40L);

    if (ExpansionBase)
    {
        IPTR pp[4 + DE_BOOTBLOCKS + 1];

        if (ap->ap_num < 10)
            dosdevname[2] += ap->ap_num;
        else
            dosdevname[2] = 'A' + (ap->ap_num - 10);
    
        pp[0]               = (IPTR)dosdevname;
        pp[1]               = (IPTR)MOD_NAME_STRING;
        pp[2]               = unit->au_UnitNum;
        pp[DE_TABLESIZE    + 4] = DE_BOOTBLOCKS;
        pp[DE_SIZEBLOCK    + 4] = at->at_identify.sector_size;
        pp[DE_NUMHEADS     + 4] = at->at_identify.nheads;
        pp[DE_SECSPERBLOCK + 4] = 1;
        pp[DE_BLKSPERTRACK + 4] = at->at_identify.nsectors;
        pp[DE_RESERVEDBLKS + 4] = 2;
        pp[DE_LOWCYL       + 4] = 0;
        pp[DE_HIGHCYL      + 4] = (ap->ap_type == ATA_PORT_T_DISK) ? (at->at_identify.ncyls-1) : 0;
        pp[DE_NUMBUFFERS   + 4] = 10;
        pp[DE_BUFMEMTYPE   + 4] = MEMF_PUBLIC;
        pp[DE_MAXTRANSFER  + 4] = 0x00200000;
        pp[DE_MASK         + 4] = ~3;
        pp[DE_BOOTPRI      + 4] = (ap->ap_type == ATA_PORT_T_DISK) ? 0 : 10;
        pp[DE_DOSTYPE      + 4] = (ap->ap_type == ATA_PORT_T_DISK) ? DOS_ID : CDROM_ID;
        pp[DE_BAUD         + 4] = 0;
        pp[DE_CONTROL      + 4] = 0;
        pp[DE_BOOTBLOCKS   + 4] = 2;
    
        devnode = MakeDosNode(pp);

        if (devnode) {
            D(bug("[AHCI>>]:-ahci_RegisterVolume: '%s' C/H/S=%d/%d/%d, %s unit->au_UnitNum %d\n",
                        AROS_BSTR_ADDR(devnode->dn_Name), at->at_identify.ncyls, at->at_identify.nheads,  at->at_identify.nsectors, MOD_NAME_STRING, unit->au_UnitNum));
            AddBootNode(pp[DE_BOOTPRI + 4], 0, devnode, 0);
            D(bug("[AHCI>>]:-ahci_RegisterVolume: done\n"));
            return TRUE;
        }

        CloseLibrary((struct Library *)ExpansionBase);
    }

    return FALSE;
}


int ahci_cam_attach(struct ahci_port *ap)
{
    int error;

    D(bug("[AHCI] ahci_cam_attach: port %p\n", ap));

    ahci_os_unlock_port(ap);
    lockmgr(&ap->ap_sim_lock, LK_EXCLUSIVE);
    error = ahci_RegisterPort(ap);
    lockmgr(&ap->ap_sim_lock, LK_RELEASE);
    ahci_os_lock_port(ap);
    if (error) {
            ahci_cam_detach(ap);
            return (EINVAL);
    }
    ap->ap_flags |= AP_F_BUS_REGISTERED;

    if (ap->ap_probe == ATA_PROBE_NEED_IDENT)
            error = ahci_cam_probe(ap, NULL);
    else
            error = 0;
    if (error) {
            ahci_cam_detach(ap);
            return (EIO);
    }

    ap->ap_flags |= AP_F_CAM_ATTACHED;

    return 0;
}

void ahci_cam_detach(struct ahci_port *ap)
{
    D(bug("[AHCI] ahci_cam_detach: port %p\n", ap));

    lockmgr(&ap->ap_sim_lock, LK_EXCLUSIVE);
    if (ap->ap_flags & AP_F_BUS_REGISTERED) {
            ap->ap_flags &= ~AP_F_BUS_REGISTERED;
    }
    if (ap->ap_sim) {
            ahci_UnregisterPort(ap);
    }
    lockmgr(&ap->ap_sim_lock, LK_RELEASE);
    ap->ap_flags &= ~AP_F_CAM_ATTACHED;
}

/*
 * The state of the port has changed.
 *
 * If atx is NULL the physical port has changed state.
 * If atx is non-NULL a particular target behind a PM has changed state.
 *
 * If found is -1 the target state must be queued to a non-interrupt context.
 * (only works with at == NULL).
 *
 * If found is 0 the target was removed.
 * If found is 1 the target was inserted.
 */
void ahci_cam_changed(struct ahci_port *ap, struct ata_port *atx, int found)
{
    D(bug("[AHCI] ahci_cam_changed: ap=%p, sim = %p, atx=%p, found=%d\n", ap, ap->ap_sim, atx, found));

    if (ap->ap_sim) {
        if (found == 0) {
                ap->ap_sim->sim_Flags |= SIMF_OffLine;
        } else {
                ap->ap_sim->sim_Flags &= ~SIMF_OffLine;
        }
    }

    /* Mark the port scan as completed */
    ap->ap_flags |= AP_F_SCAN_COMPLETED;
}

static void ahci_strip_string(const char **basep, int *lenp)
{
        const char *base = *basep;
        int len = *lenp;

        while (len && (*base == 0 || *base == ' ')) {
                --len;
                ++base;
        }
        while (len && (base[len-1] == 0 || base[len-1] == ' '))
                --len;
        *basep = base;
        *lenp = len;
}

static u_int16_t bswap16(u_int16_t word)
{
    return ((word << 8) & 0xff00) |
           ((word >> 8) & 0x00ff);
}

/*
 * Fix byte ordering so buffers can be accessed as
 * strings.
 */
static void
ata_fix_identify(struct ata_identify *id)
{
        u_int16_t       *swap;
        int             i;
        D(bug("[AHCI] %s()\n", __PRETTY_FUNCTION__)); 

        swap = (u_int16_t *)id->serial;
        for (i = 0; i < sizeof(id->serial) / sizeof(u_int16_t); i++)
                swap[i] = bswap16(swap[i]);

        swap = (u_int16_t *)id->firmware;
        for (i = 0; i < sizeof(id->firmware) / sizeof(u_int16_t); i++)
                swap[i] = bswap16(swap[i]);

        swap = (u_int16_t *)id->model;
        for (i = 0; i < sizeof(id->model) / sizeof(u_int16_t); i++)
                swap[i] = bswap16(swap[i]);
}

/*
 * Dummy done callback for xa.
 */
static void ahci_ata_dummy_done(struct ata_xfer *xa)
{
}

/*
 * Setting the transfer mode is irrelevant for the SATA transport
 * but some (atapi) devices seem to need it anyway.  In addition
 * if we are running through a SATA->PATA converter for some reason
 * beyond my comprehension we might have to set the mode.
 *
 * We only support DMA modes for SATA attached devices, so don't bother
 * with legacy modes.
 */
static int
ahci_set_xfer(struct ahci_port *ap, struct ata_port *atx)
{
        struct ata_port *at;
        struct ata_xfer *xa;
        u_int16_t mode;
        u_int16_t mask;
        D(bug("[AHCI] %s()\n", __PRETTY_FUNCTION__)); 

        at = atx ? atx : ap->ap_ata[0];

        /*
         * Figure out the supported UDMA mode.  Ignore other legacy modes.
         */
        mask = le16toh(at->at_identify.ultradma);
        if ((mask & 0xFF) == 0 || mask == 0xFFFF)
                return(0);
        mask &= 0xFF;
        mode = 0x4F;
        while ((mask & 0x8000) == 0) {
                mask <<= 1;
                --mode;
        }

        /*
         * SATA atapi devices often still report a dma mode, even though
         * it is irrelevant for SATA transport.  It is also possible that
         * we are running through a SATA->PATA converter and seeing the
         * PATA dma mode.
         *
         * In this case the device may require a (dummy) SETXFER to be
         * sent before it will work properly.
         */
        xa = ahci_ata_get_xfer(ap, atx);
        xa->complete = ahci_ata_dummy_done;
        xa->fis->command = ATA_C_SET_FEATURES;
        xa->fis->features = ATA_SF_SETXFER;
        xa->fis->flags = ATA_H2D_FLAGS_CMD | at->at_target;
        xa->fis->sector_count = mode;
        xa->flags = ATA_F_PIO | ATA_F_POLL;
        xa->timeout = 1000;
        xa->datalen = 0;
        if (ahci_ata_cmd(xa) != ATA_S_COMPLETE) {
                kprintf("%s: Unable to set dummy xfer mode \n",
                        ATANAME(ap, atx));
        } else if (bootverbose) {
                kprintf("%s: Set dummy xfer mode to %02x\n",
                        ATANAME(ap, atx), mode);
        }
        ahci_ata_put_xfer(xa);
        return(0);
}


/*
 * DISK-specific probe after initial ident
 */
static int
ahci_cam_probe_disk(struct ahci_port *ap, struct ata_port *atx)
{
        struct ata_port *at;
        struct ata_xfer *xa;
        D(bug("[AHCI] %s()\n", __PRETTY_FUNCTION__)); 

        at = atx ? atx : ap->ap_ata[0];

        /*
         * Set dummy xfer mode
         */
        ahci_set_xfer(ap, atx);

        /*
         * Enable write cache if supported
         *
         * NOTE: "WD My Book" external disk devices have a very poor
         *       daughter board between the the ESATA and the HD.  Sending
         *       any ATA_C_SET_FEATURES commands will break the hardware port
         *       with a fatal protocol error.  However, this device also
         *       indicates that WRITECACHE is already on and READAHEAD is
         *       not supported so we avoid the issue.
         */
        if ((at->at_identify.cmdset82 & ATA_IDENTIFY_WRITECACHE) &&
            (at->at_identify.features85 & ATA_IDENTIFY_WRITECACHE) == 0) {
                xa = ahci_ata_get_xfer(ap, atx);
                xa->complete = ahci_ata_dummy_done;
                xa->fis->command = ATA_C_SET_FEATURES;
                xa->fis->features = ATA_SF_WRITECACHE_EN;
                /* xa->fis->features = ATA_SF_LOOKAHEAD_EN; */
                xa->fis->flags = ATA_H2D_FLAGS_CMD | at->at_target;
                xa->fis->device = 0;
                xa->flags = ATA_F_PIO | ATA_F_POLL;
                xa->timeout = 1000;
                xa->datalen = 0;
                if (ahci_ata_cmd(xa) == ATA_S_COMPLETE)
                        at->at_features |= ATA_PORT_F_WCACHE;
                else
                        kprintf("%s: Unable to enable write-caching\n",
                                ATANAME(ap, atx));
                ahci_ata_put_xfer(xa);
        }

        /*
         * Enable readahead if supported
         */
        if ((at->at_identify.cmdset82 & ATA_IDENTIFY_LOOKAHEAD) &&
            (at->at_identify.features85 & ATA_IDENTIFY_LOOKAHEAD) == 0) {
                xa = ahci_ata_get_xfer(ap, atx);
                xa->complete = ahci_ata_dummy_done;
                xa->fis->command = ATA_C_SET_FEATURES;
                xa->fis->features = ATA_SF_LOOKAHEAD_EN;
                xa->fis->flags = ATA_H2D_FLAGS_CMD | at->at_target;
                xa->fis->device = 0;
                xa->flags = ATA_F_PIO | ATA_F_POLL;
                xa->timeout = 1000;
                xa->datalen = 0;
                if (ahci_ata_cmd(xa) == ATA_S_COMPLETE)
                        at->at_features |= ATA_PORT_F_RAHEAD;
                else
                        kprintf("%s: Unable to enable read-ahead\n",
                                ATANAME(ap, atx));
                ahci_ata_put_xfer(xa);
        }

        /*
         * FREEZE LOCK the device so malicious users can't lock it on us.
         * As there is no harm in issuing this to devices that don't
         * support the security feature set we just send it, and don't bother
         * checking if the device sends a command abort to tell us it doesn't
         * support it
         */
        if ((at->at_identify.cmdset82 & ATA_IDENTIFY_SECURITY) &&
            (at->at_identify.securestatus & ATA_SECURE_FROZEN) == 0 &&
            (AhciNoFeatures & (1 << ap->ap_num)) == 0) {
                xa = ahci_ata_get_xfer(ap, atx);
                xa->complete = ahci_ata_dummy_done;
                xa->fis->command = ATA_C_SEC_FREEZE_LOCK;
                xa->fis->flags = ATA_H2D_FLAGS_CMD | at->at_target;
                xa->flags = ATA_F_PIO | ATA_F_POLL;
                xa->timeout = 1000;
                xa->datalen = 0;
                if (ahci_ata_cmd(xa) == ATA_S_COMPLETE)
                        at->at_features |= ATA_PORT_F_FRZLCK;
                else
                        kprintf("%s: Unable to set security freeze\n",
                                ATANAME(ap, atx));
                ahci_ata_put_xfer(xa);
        }

        /* Fix up sector size, if the Word 106 is valid */
        if ((at->at_identify.phys_sect_sz & 0xc000) == 0x4000) {
                /* Physical sector size is longer than 256 16-bit words? */
                if (at->at_identify.phys_sect_sz & (1 << 12)) { 
                        ULONG logsize;
                        D(ULONG physize;)
                        logsize = at->at_identify.words_lsec[0]; 
                        logsize <<= 16;
                        logsize += at->at_identify.words_lsec[1];
                        D(physize = logsize >> (at->at_identify.phys_sect_sz & 3));
                        D(kprintf("%s: Logical  sector size: %d bytes\n",
                                    ATANAME(ap, atx), logsize * 2));
                        D(kprintf("%s: Physical sector size: %d bytes\n",
                                    ATANAME(ap, atx), physize * 2));
                        at->at_identify.sector_size = logsize * 2;
                } else {
                        D(kprintf("%s: Physical sector size == Logical sector size\n", ATANAME(ap, atx)));
                        at->at_identify.sector_size = 256 * 2;
                }
        } else {
                kprintf("%s: ATA IDENTIFY: Invalid Word 106: 0x%04x\n", ATANAME(ap, atx), at->at_identify.phys_sect_sz);
                at->at_identify.sector_size = 256 * 2;
        }
        D(kprintf("%s: Sector size: %d bytes\n", ATANAME(ap, atx), at->at_identify.sector_size));

#if 1 /* Temporary debugging... */
    int i;
    kprintf("%s: ATA IDENTIFY\n", ATANAME(ap, atx));
    for (i = 0; i < 128; i++) {
        if ((i%8) == 0) kprintf("%s %3d:", ATANAME(ap, atx), i);
        kprintf(" %04x", ((uint16_t *)(&at->at_identify))[i]);
        if ((i%8) == 7) kprintf("\n");
    }
#endif

        return (0);
}

/*
 * ATAPI-specific probe after initial ident
 */
static int
ahci_cam_probe_atapi(struct ahci_port *ap, struct ata_port *atx)
{
        D(bug("[AHCI] %s()\n", __PRETTY_FUNCTION__)); 
        ahci_set_xfer(ap, atx);
        return(0);
}


/*
 * Once the AHCI port has been attached we need to probe for a device or
 * devices on the port and setup various options.
 *
 * If at is NULL we are probing the direct-attached device on the port,
 * which may or may not be a port multiplier.
 */
int
ahci_cam_probe(struct ahci_port *ap, struct ata_port *atx)
{
        struct ata_port *at;
        struct ata_xfer *xa;
        u_int64_t       capacity;
        u_int64_t       capacity_bytes;
        int             model_len;
        int             firmware_len;
        int             serial_len;
        int             error;
        int             devncqdepth;
        int             i;
        const char      *model_id;
        const char      *firmware_id;
        const char      *serial_id;
        const char      *wcstr;
        const char      *rastr;
        const char      *scstr;
        const char      *type;

        D(bug("[AHCI] %s()\n", __PRETTY_FUNCTION__)); 
        error = EIO;

        /*
         * A NULL atx indicates a probe of the directly connected device.
         * A non-NULL atx indicates a device connected via a port multiplier.
         * We need to preserve atx for calls to ahci_ata_get_xfer().
         *
         * at is always non-NULL.  For directly connected devices we supply
         * an (at) pointing to target 0.
         */
        if (atx == NULL) {
                at = ap->ap_ata[0];     /* direct attached - device 0 */
                if (ap->ap_type == ATA_PORT_T_PM) {
                        kprintf("%s: Found Port Multiplier\n",
                                ATANAME(ap, atx));
                        return (0);
                }
                at->at_type = ap->ap_type;
        } else {
                at = atx;
                if (atx->at_type == ATA_PORT_T_PM) {
                        kprintf("%s: Bogus device, reducing port count to %d\n",
                                ATANAME(ap, atx), atx->at_target);
                        if (ap->ap_pmcount > atx->at_target)
                                ap->ap_pmcount = atx->at_target;
                        goto err;
                }
        }
        if (ap->ap_type == ATA_PORT_T_NONE)
                goto err;
        if (at->at_type == ATA_PORT_T_NONE)
                goto err;

        /*
         * Issue identify, saving the result
         */
        xa = ahci_ata_get_xfer(ap, atx);
        xa->complete = ahci_ata_dummy_done;
        xa->data = &at->at_identify;
        xa->datalen = sizeof(at->at_identify);
        xa->flags = ATA_F_READ | ATA_F_PIO | ATA_F_POLL;
        xa->fis->flags = ATA_H2D_FLAGS_CMD | at->at_target;

        switch(at->at_type) {
        case ATA_PORT_T_DISK:
                xa->fis->command = ATA_C_IDENTIFY;
                type = "DISK";
                break;
        case ATA_PORT_T_ATAPI:
                xa->fis->command = ATA_C_ATAPI_IDENTIFY;
                xa->flags |= ATA_F_AUTOSENSE;
                type = "ATAPI";
                break;
        default:
                xa->fis->command = ATA_C_ATAPI_IDENTIFY;
                type = "UNKNOWN(ATAPI?)";
                break;
        }
        xa->fis->features = 0;
        xa->fis->device = 0;
        xa->timeout = 1000;

        if (ahci_ata_cmd(xa) != ATA_S_COMPLETE) {
                kprintf("%s: Detected %s device but unable to IDENTIFY\n",
                        ATANAME(ap, atx), type);
                ahci_ata_put_xfer(xa);
                goto err;
        }
        ahci_ata_put_xfer(xa);

        ata_fix_identify(&at->at_identify);

        /*
         * Read capacity using SATA probe info.
         */
        if (le16toh(at->at_identify.cmdset83) & 0x0400) {
                /* LBA48 feature set supported */
                capacity = 0;
                for (i = 3; i >= 0; --i) {
                        capacity <<= 16;
                        capacity +=
                            le16toh(at->at_identify.addrsecxt[i]);
                }
        } else {
                capacity = le16toh(at->at_identify.addrsec[1]);
                capacity <<= 16;
                capacity += le16toh(at->at_identify.addrsec[0]);
        }
        if (capacity == 0)
                capacity = 1024 * 1024 / 512;
        at->at_capacity = capacity;
        if (atx == NULL)
                ap->ap_probe = ATA_PROBE_GOOD;

        capacity_bytes = capacity * 512;

        /*
         * Negotiate NCQ, throw away any ata_xfer's beyond the negotiated
         * number of slots and limit the number of CAM ccb's to one less
         * so we always have a slot available for recovery.
         *
         * NCQ is not used if ap_ncqdepth is 1 or the host controller does
         * not support it, and in that case the driver can handle extra
         * ccb's.
         *
         * NCQ is currently used only with direct-attached disks.  It is
         * not used with port multipliers or direct-attached ATAPI devices.
         *
         * Remember at least one extra CCB needs to be reserved for the
         * error ccb.
         */
        if ((ap->ap_sc->sc_cap & AHCI_REG_CAP_SNCQ) &&
            ap->ap_type == ATA_PORT_T_DISK &&
            (le16toh(at->at_identify.satacap) & (1 << 8))) {
                at->at_ncqdepth = (le16toh(at->at_identify.qdepth) & 0x1F) + 1;
                devncqdepth = at->at_ncqdepth;
                if (at->at_ncqdepth > ap->ap_sc->sc_ncmds)
                        at->at_ncqdepth = ap->ap_sc->sc_ncmds;
                if (at->at_ncqdepth > 1) {
                        for (i = 0; i < ap->ap_sc->sc_ncmds; ++i) {
                                xa = ahci_ata_get_xfer(ap, atx);
                                if (xa->tag < at->at_ncqdepth) {
                                        xa->state = ATA_S_COMPLETE;
                                        ahci_ata_put_xfer(xa);
                                }
                        }
#if 0
                        if (at->at_ncqdepth >= ap->ap_sc->sc_ncmds) {
                                cam_sim_set_max_tags(ap->ap_sim,
                                                     at->at_ncqdepth - 1);
                        }
#endif
                }
        } else {
                devncqdepth = 0;
        }

        model_len = sizeof(at->at_identify.model);
        model_id = at->at_identify.model;
        ahci_strip_string(&model_id, &model_len);

        firmware_len = sizeof(at->at_identify.firmware);
        firmware_id = at->at_identify.firmware;
        ahci_strip_string(&firmware_id, &firmware_len);

        serial_len = sizeof(at->at_identify.serial);
        serial_id = at->at_identify.serial;
        ahci_strip_string(&serial_id, &serial_len);

        /*
         * Generate informatiive strings.
         *
         * NOTE: We do not automatically set write caching, lookahead,
         *       or the security state for ATAPI devices.
         */
        if (at->at_identify.cmdset82 & ATA_IDENTIFY_WRITECACHE) {
                if (at->at_identify.features85 & ATA_IDENTIFY_WRITECACHE)
                        wcstr = "enabled";
                else if (at->at_type == ATA_PORT_T_ATAPI)
                        wcstr = "disabled";
                else
                        wcstr = "enabling";
        } else {
                    wcstr = "notsupp";
        }

        if (at->at_identify.cmdset82 & ATA_IDENTIFY_LOOKAHEAD) {
                if (at->at_identify.features85 & ATA_IDENTIFY_LOOKAHEAD)
                        rastr = "enabled";
                else if (at->at_type == ATA_PORT_T_ATAPI)
                        rastr = "disabled";
                else
                        rastr = "enabling";
        } else {
                    rastr = "notsupp";
        }

        if (at->at_identify.cmdset82 & ATA_IDENTIFY_SECURITY) {
                if (at->at_identify.securestatus & ATA_SECURE_FROZEN)
                        scstr = "frozen";
                else if (at->at_type == ATA_PORT_T_ATAPI)
                        scstr = "unfrozen";
                else if (AhciNoFeatures & (1 << ap->ap_num))
                        scstr = "<disabled>";
                else
                        scstr = "freezing";
        } else {
                    scstr = "notsupp";
        }

        kprintf("%s: Found %s \"%*.*s %*.*s\" serial=\"%*.*s\"\n"
                "%s: tags=%d/%d satacap=%04x satafea=%04x NCQ=%s "
                "capacity=%lld.%02dMB\n",

                ATANAME(ap, atx),
                type,
                model_len, model_len, model_id,
                firmware_len, firmware_len, firmware_id,
                serial_len, serial_len, serial_id,

                ATANAME(ap, atx),
                devncqdepth, ap->ap_sc->sc_ncmds,
                at->at_identify.satacap,
                at->at_identify.satafsup,
                (at->at_ncqdepth > 1 ? "YES" : "NO"),
                (long long)capacity_bytes / (1024 * 1024),
                (int)(capacity_bytes % (1024 * 1024)) * 100 / (1024 * 1024)
        );
        kprintf("%s: f85=%04x f86=%04x f87=%04x WC=%s RA=%s SEC=%s\n",
                ATANAME(ap, atx),
                at->at_identify.features85,
                at->at_identify.features86,
                at->at_identify.features87,
                wcstr,
                rastr,
                scstr
        );

        /*
         * Additional type-specific probing
         */
        switch(at->at_type) {
        case ATA_PORT_T_DISK:
                error = ahci_cam_probe_disk(ap, atx);
                break;
        case ATA_PORT_T_ATAPI:
                error = ahci_cam_probe_atapi(ap, atx);
                break;
        default:
                error = EIO;
                break;
        }
err:
        if (error) {
                at->at_probe = ATA_PROBE_FAILED;
                if (atx == NULL)
                        ap->ap_probe = at->at_probe;
        } else {
                struct AHCIBase *AHCIBase = ap->ap_sc->sc_dev->dev_AHCIBase;
                struct TagItem unitAttrs[] =
                {
                    {aHidd_DriverData   , (IPTR)OOP_INST_DATA(AHCIBase->busClass, ap->ap_Object)        },
                    {TAG_DONE           , 0                                                             }
                };
                OOP_Object *unitObj;
                struct ahci_Unit *unit;

                at->at_probe = ATA_PROBE_GOOD;
                if (atx == NULL)
                        ap->ap_probe = at->at_probe;

                unitObj = OOP_NewObject(AHCIBase->unitClass, NULL, unitAttrs);
                if (unitObj)
                {
                    unit = OOP_INST_DATA(AHCIBase->unitClass, unitObj);
                    ahci_RegisterVolume(ap, at, unit);
                }
        }
        return (error);
}