SILI - Work around hardware LRAM bugs part 2/2.

[dragonfly.git] / sys / dev / disk / sili / sili.c

/*
 * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * 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 MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *
 * Copyright (c) 2006 David Gwynne <dlg@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *
 *
 * $OpenBSD: sili.c,v 1.147 2009/02/16 21:19:07 miod Exp $
 */

#include "sili.h"

void    sili_port_interrupt_enable(struct sili_port *ap);
void    sili_port_interrupt_redisable(struct sili_port *ap);
void    sili_port_interrupt_reenable(struct sili_port *ap);

int     sili_load_prb(struct sili_ccb *);
void    sili_unload_prb(struct sili_ccb *);
static void sili_load_prb_callback(void *info, bus_dma_segment_t *segs,
                                    int nsegs, int error);
void    sili_start(struct sili_ccb *);
int     sili_port_softreset(struct sili_port *ap);
int     sili_port_pmprobe(struct sili_port *ap);
int     sili_port_hardreset(struct sili_port *ap, int hard);
void    sili_port_hardstop(struct sili_port *ap);
void    sili_port_listen(struct sili_port *ap);

static void sili_ata_cmd_timeout_unserialized(void *);
static int sili_core_timeout(struct sili_ccb *ccb);
void    sili_quick_timeout(struct sili_ccb *ccb);
void    sili_check_active_timeouts(struct sili_port *ap);

#if 0
void    sili_beg_exclusive_access(struct sili_port *ap, struct ata_port *at);
void    sili_end_exclusive_access(struct sili_port *ap, struct ata_port *at);
#endif
void    sili_issue_pending_commands(struct sili_port *ap, struct sili_ccb *ccb);

int     sili_port_read_ncq_error(struct sili_port *, int);

struct sili_dmamem *sili_dmamem_alloc(struct sili_softc *, bus_dma_tag_t tag);
void    sili_dmamem_free(struct sili_softc *, struct sili_dmamem *);
static void sili_dmamem_saveseg(void *info, bus_dma_segment_t *segs, int nsegs, int error);

static void sili_dummy_done(struct ata_xfer *xa);
static void sili_empty_done(struct sili_ccb *ccb);
static void sili_ata_cmd_done(struct sili_ccb *ccb);

/* Wait for all bits in _b to be cleared */
#define sili_pwait_clr(_ap, _r, _b) \
        sili_pwait_eq((_ap), SILI_PWAIT_TIMEOUT, (_r), (_b), 0)
#define sili_pwait_clr_to(_ap, _to,  _r, _b) \
        sili_pwait_eq((_ap), _to, (_r), (_b), 0)

/* Wait for all bits in _b to be set */
#define sili_pwait_set(_ap, _r, _b) \
        sili_pwait_eq((_ap), SILI_PWAIT_TIMEOUT, (_r), (_b), (_b))
#define sili_pwait_set_to(_ap, _to, _r, _b) \
        sili_pwait_eq((_ap), _to, (_r), (_b), (_b))

#define SILI_PWAIT_TIMEOUT      1000

/*
 * Initialize the global SILI hardware.  This code does not set up any of
 * its ports.
 */
int
sili_init(struct sili_softc *sc)
{
        DPRINTF(SILI_D_VERBOSE, " GHC 0x%b",
                sili_read(sc, SILI_REG_GHC), SILI_FMT_GHC);

        /*
         * Reset the entire chip.  This also resets all ports.
         *
         * The spec doesn't say anything about how long we have to
         * wait, so wait 10ms.
         */
        sili_write(sc, SILI_REG_GCTL, SILI_REG_GCTL_GRESET);
        sili_os_sleep(10);
        sili_write(sc, SILI_REG_GCTL, 0);
        sili_os_sleep(10);

        return (0);
}

/*
 * Allocate and initialize an SILI port.
 */
int
sili_port_alloc(struct sili_softc *sc, u_int port)
{
        struct sili_port        *ap;
        struct ata_port         *at;
        struct sili_prb         *prb;
        struct sili_ccb         *ccb;
        int     rc = ENOMEM;
        int     error;
        int     i;

        ap = kmalloc(sizeof(*ap), M_DEVBUF, M_WAITOK | M_ZERO);

        ksnprintf(ap->ap_name, sizeof(ap->ap_name), "%s%d.%d",
                  device_get_name(sc->sc_dev),
                  device_get_unit(sc->sc_dev),
                  port);
        sc->sc_ports[port] = ap;
        kprintf("%s: allocate port\n", PORTNAME(ap));

        /*
         * Allocate enough so we never have to reallocate, it makes
         * it easier.
         *
         * ap_pmcount will be reduced by the scan if we encounter the
         * port multiplier port prior to target 15.
         */
        if (ap->ap_ata == NULL) {
                ap->ap_ata = kmalloc(sizeof(*ap->ap_ata) * SILI_MAX_PMPORTS,
                                     M_DEVBUF, M_INTWAIT | M_ZERO);
                for (i = 0; i < SILI_MAX_PMPORTS; ++i) {
                        at = &ap->ap_ata[i];
                        at->at_sili_port = ap;
                        at->at_target = i;
                        at->at_probe = ATA_PROBE_NEED_INIT;
                        at->at_features |= ATA_PORT_F_RESCAN;
                        ksnprintf(at->at_name, sizeof(at->at_name),
                                  "%s.%d", ap->ap_name, i);
                }
        }
        if (bus_space_subregion(sc->sc_piot, sc->sc_pioh,
                                SILI_PORT_REGION(port), SILI_PORT_SIZE,
                                &ap->ap_ioh) != 0) {
                device_printf(sc->sc_dev,
                              "unable to create register window for port %d\n",
                              port);
                goto freeport;
        }

        ap->ap_sc = sc;
        ap->ap_num = port;
        ap->ap_probe = ATA_PROBE_NEED_INIT;
        TAILQ_INIT(&ap->ap_ccb_free);
        TAILQ_INIT(&ap->ap_ccb_pending);
        lockinit(&ap->ap_ccb_lock, "silipo", 0, 0);

        /* Disable port interrupts */
        sili_pwrite(ap, SILI_PREG_INT_DISABLE, SILI_PREG_INT_MASK);

        /*
         * Reset the port.  This is similar to a Device Reset but far
         * more invasive.  We use Device Reset in our hardreset function.
         * This function also does the same OOB initialization sequence
         * that Device Reset does.
         *
         * NOTE: SILI_PREG_STATUS_READY will not be asserted unless and until
         *       a device is connected to the port, so we can't use it to
         *       verify that the port exists.
         */
        sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_RESET);
        if (sili_pread(ap, SILI_PREG_STATUS) & SILI_PREG_STATUS_READY) {
                device_printf(sc->sc_dev,
                              "Port %d will not go into reset\n", port);
                goto freeport;
        }
        sili_os_sleep(10);
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_RESUME);
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_RESET);

        /*
         * Adjust FIFO thresholds to improve PCI-e use.
         */
        sili_pwrite(ap, SILI_PREG_FIFO_CTL,
                SILI_PREG_FIFO_CTL_ENCODE(1024, 1024));

        /*
         * Allocate the SGE Table
         */
        ap->ap_dmamem_prbs = sili_dmamem_alloc(sc, sc->sc_tag_prbs);
        if (ap->ap_dmamem_prbs == NULL) {
                kprintf("%s: NOSGET\n", PORTNAME(ap));
                goto freeport;
        }

        /*
         * Set up the SGE table base address
         */
        ap->ap_prbs = (struct sili_prb *)SILI_DMA_KVA(ap->ap_dmamem_prbs);

        /*
         * Allocate a CCB for each command slot
         */
        ap->ap_ccbs = kmalloc(sizeof(struct sili_ccb) * sc->sc_ncmds, M_DEVBUF,
                              M_WAITOK | M_ZERO);
        if (ap->ap_ccbs == NULL) {
                device_printf(sc->sc_dev,
                              "unable to allocate command list for port %d\n",
                              port);
                goto freeport;
        }

        /*
         * Port control register setup.
         */
        sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_NOAUTOCC);
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_32BITDMA |
                                           SILI_PREG_CTL_PMA |
                                           SILI_PREG_CTL_NOAUTOCC);

        /*
         * Most structures are in the port BAR.  Assign convenient
         * pointers in the CCBs
         */

        for (i = 0; i < sc->sc_ncmds; i++) {
                ccb = &ap->ap_ccbs[i];

                error = bus_dmamap_create(sc->sc_tag_data, BUS_DMA_ALLOCNOW,
                                          &ccb->ccb_dmamap);
                if (error) {
                        device_printf(sc->sc_dev,
                                      "unable to create dmamap for port %d "
                                      "ccb %d\n", port, i);
                        goto freeport;
                }

                /*
                 * WARNING!!!  Access to the rfis is only allowed under very
                 *             carefully controlled circumstances because it
                 *             is located in the LRAM and reading from the
                 *             LRAM has hardware issues which can blow the
                 *             port up.  I kid you not (from Linux, and
                 *             verified by testing here).
                 */
                callout_init(&ccb->ccb_timeout);
                ccb->ccb_slot = i;
                ccb->ccb_port = ap;
                ccb->ccb_prb = &ap->ap_prbs[i];
                ccb->ccb_prb_paddr = SILI_DMA_DVA(ap->ap_dmamem_prbs) +
                                     sizeof(*ccb->ccb_prb) * i;
                ccb->ccb_xa.fis = &ccb->ccb_prb->prb_h2d;
                prb = bus_space_kva(ap->ap_sc->sc_iot, ap->ap_ioh,
                                    SILI_PREG_LRAM_SLOT(i));
                ccb->ccb_prb_lram = prb;
                /*
                 * Point our rfis to host-memory instead of the LRAM PRB.
                 * It will be copied back if ATA_F_AUTOSENSE is set.  The
                 * LRAM PRB is buggy.
                 */
                /*ccb->ccb_xa.rfis = &prb->prb_d2h;*/
                ccb->ccb_xa.rfis = (void *)ccb->ccb_xa.fis;

                ccb->ccb_xa.packetcmd = prb_packet(ccb->ccb_prb);
                ccb->ccb_xa.tag = i;

                ccb->ccb_xa.state = ATA_S_COMPLETE;

                /*
                 * Reserve CCB[1] as the error CCB.  It doesn't matter
                 * which one we use for the Sili controllers.
                 */
                if (i == 1)
                        ap->ap_err_ccb = ccb;
                else
                        sili_put_ccb(ccb);
        }
        kprintf("%s: start port\n", PORTNAME(ap));
        sili_os_start_port(ap);
        return(0);
freeport:
        sili_port_free(sc, port);
        return (rc);
}

/*
 * [re]initialize an idle port.  No CCBs should be active.
 *
 * If at is NULL we are initializing a directly connected port, otherwise
 * we are indirectly initializing a port multiplier port.
 *
 * This function is called during the initial port allocation sequence
 * and is also called on hot-plug insertion.  We take no chances and
 * use a hardreset instead of a softreset.
 *
 * This function is the only way to move a failed port back to active
 * status.
 *
 * Returns 0 if a device is successfully detected.
 */
int
sili_port_init(struct sili_port *ap, struct ata_port *atx)
{
        u_int32_t data;
        int rc;

        /*
         * Clear all notification bits
         */
        if (atx == NULL && (ap->ap_sc->sc_flags & SILI_F_SSNTF))
                sili_pwrite(ap, SILI_PREG_SNTF, -1);

        /*
         * Make sure the port is out of continuous COMRESET mode.
         */
        data = SILI_PREG_SCTL_SPM_NONE |
               SILI_PREG_SCTL_IPM_NONE |
               SILI_PREG_SCTL_SPD_NONE |
               SILI_PREG_SCTL_DET_NONE;
        if (SiliForceGen1 & (1 << ap->ap_num)) {
                data &= ~SILI_PREG_SCTL_SPD_NONE;
                data |= SILI_PREG_SCTL_SPD_GEN1;
        }
        sili_pwrite(ap, SILI_PREG_SCTL, data);

        /*
         * Hard-reset the port.  If a device is detected but it is busy
         * we try a second time, this time cycling the phy as well.
         *
         * XXX note: hard reset mode 2 (cycling the PHY) is not reliable.
         */
        if (atx)
                atx->at_probe = ATA_PROBE_NEED_HARD_RESET;
        else
                ap->ap_probe = ATA_PROBE_NEED_HARD_RESET;

        rc = sili_port_reset(ap, atx, 1);
#if 0
        rc = sili_port_reset(ap, atx, 1);
        if (rc == EBUSY) {
                rc = sili_port_reset(ap, atx, 2);
        }
#endif

        switch (rc) {
        case ENODEV:
                /*
                 * We had problems talking to the device on the port.
                 */
                if (atx) {
                        sili_pm_read(ap, atx->at_target,
                                     SATA_PMREG_SSTS, &data);

                        switch(data & SATA_PM_SSTS_DET) {
                        case SATA_PM_SSTS_DET_DEV_NE:
                                kprintf("%s: Device not communicating\n",
                                        ATANAME(ap, atx));
                                break;
                        case SATA_PM_SSTS_DET_PHYOFFLINE:
                                kprintf("%s: PHY offline\n",
                                        ATANAME(ap, atx));
                                break;
                        default:
                                kprintf("%s: No device detected\n",
                                        ATANAME(ap, atx));
                                break;
                        }
                } else {
                        data = sili_pread(ap, SILI_PREG_SSTS);

                        switch(data & SATA_PM_SSTS_DET) {
                        case SILI_PREG_SSTS_DET_DEV_NE:
                                kprintf("%s: Device not communicating\n",
                                        ATANAME(ap, atx));
                                break;
                        case SILI_PREG_SSTS_DET_OFFLINE:
                                kprintf("%s: PHY offline\n",
                                        ATANAME(ap, atx));
                                break;
                        default:
                                kprintf("%s: No device detected\n",
                                        ATANAME(ap, atx));
                                break;
                        }
                }
                break;

        case EBUSY:
                /*
                 * The device on the port is still telling us its busy,
                 * which means that it is not properly handling a SATA
                 * port COMRESET.
                 *
                 * It may be possible to softreset the device using CLO
                 * and a device reset command.
                 */
                if (atx) {
                        kprintf("%s: Device on port is bricked, giving up\n",
                                ATANAME(ap, atx));
                } else {
                        kprintf("%s: Device on port is bricked, "
                                "trying softreset\n", PORTNAME(ap));

                        rc = sili_port_reset(ap, atx, 0);
                        if (rc) {
                                kprintf("%s: Unable unbrick device\n",
                                        PORTNAME(ap));
                        } else {
                                kprintf("%s: Successfully unbricked\n",
                                        PORTNAME(ap));
                        }
                }
                break;

        default:
                break;
        }

        /*
         * Command transfers can only be enabled if a device was successfully
         * detected.
         *
         * Allocate or deallocate the ap_ata array here too.
         */
        if (atx == NULL) {
                switch(ap->ap_type) {
                case ATA_PORT_T_NONE:
                        ap->ap_pmcount = 0;
                        break;
                case ATA_PORT_T_PM:
                        /* already set */
                        break;
                default:
                        ap->ap_pmcount = 1;
                        break;
                }
        }

        /*
         * Flush interrupts on the port. XXX
         *
         * Enable interrupts on the port whether a device is sitting on
         * it or not, to handle hot-plug events.
         */
        if (atx == NULL) {
#if 0
                sili_pwrite(ap, SILI_PREG_IS, sili_pread(ap, SILI_PREG_IS));
                sili_write(ap->ap_sc, SILI_REG_IS, 1 << ap->ap_num);
#endif
                sili_port_interrupt_enable(ap);
        }
        return(rc);
}

/*
 * Handle an errored port.  This routine is called when the only
 * commands left on the queue are expired, meaning we can safely
 * go through a port init to clear its state.
 *
 * We complete the expired CCBs and then restart the queue.
 */
static
void
sili_port_reinit(struct sili_port *ap)
{
        struct sili_ccb *ccb;
        struct ata_port *at;
        int slot;
        int target;
        u_int32_t data;
        int reentrant;

        reentrant = (ap->ap_flags & AP_F_ERR_CCB_RESERVED) ? 1 : 0;

        kprintf("%s: PORT REINIT AFTER ERROR reentrant=%d\n",
                PORTNAME(ap), reentrant);

        /*
         * Clear port resume, clear bits 16:13 in the port device status
         * register.  This is from the data sheet.
         *
         * Data sheet does not specify a delay but it seems prudent.
         */
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_RESUME);
        sili_os_sleep(10);
        for (target = 0; target < SILI_MAX_PMPORTS; ++target) {
                data = sili_pread(ap, SILI_PREG_PM_STATUS(target));
                data &= ~(SILI_PREG_PM_STATUS_SERVICE |
                          SILI_PREG_PM_STATUS_LEGACY |
                          SILI_PREG_PM_STATUS_NATIVE |
                          SILI_PREG_PM_STATUS_VBSY);
                sili_pwrite(ap, SILI_PREG_PM_STATUS(target), data);
                sili_pwrite(ap, SILI_PREG_PM_QACTIVE(target), 0);
        }

        /*
         * Issue a Port Initialize and wait for it to clear.  This flushes
         * commands but does not reset the port.  Then wait for port ready.
         */
        sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_INIT);
        if (sili_pwait_clr(ap, SILI_PREG_STATUS, SILI_PREG_CTL_INIT)) {
                kprintf("%s: Unable to reinit, port failed\n",
                        PORTNAME(ap));
        }
        if (sili_pwait_set(ap, SILI_PREG_STATUS, SILI_PREG_STATUS_READY)) {
                kprintf("%s: Unable to reinit, port will not come ready\n",
                        PORTNAME(ap));
        }

        /*
         * Read the LOG ERROR page for targets that returned a specific
         * D2H FIS with ERR set.
         */
        if (reentrant == 0) {
                for (target = 0; target < SILI_MAX_PMPORTS; ++target) {
                        at = &ap->ap_ata[target];
                        if (at->at_features & ATA_PORT_F_READLOG) {
                                kprintf("%s: READ LOG ERROR PAGE\n",
                                        ATANAME(ap, at));
                                at->at_features &= ~ATA_PORT_F_READLOG;
                                sili_port_read_ncq_error(ap, target);
                        }
                }
        }

        /*
         * Finally clean out the expired commands, we've probed the error
         * status (or hopefully probed the error status).  Well, ok,
         * we probably didn't XXX.
         */
        while (ap->ap_expired) {
                slot = ffs(ap->ap_expired) - 1;
                ap->ap_expired &= ~(1 << slot);
                KKASSERT(ap->ap_active & (1 << slot));
                ap->ap_active &= ~(1 << slot);
                --ap->ap_active_cnt;
                ccb = &ap->ap_ccbs[slot];
                ccb->ccb_xa.state = ATA_S_TIMEOUT;
                kprintf("%s: reinit: kill slot %d\n",
                        ATANAME(ap, ccb->ccb_xa.at), ccb->ccb_slot);
                ccb->ccb_done(ccb);
                ccb->ccb_xa.complete(&ccb->ccb_xa);
        }

        /*
         * Wow.  All done.  We can get the port moving again.
         */
        if (reentrant) {
                kprintf("%s: reinit called reentrantly, skip end\n",
                        PORTNAME(ap));
        } else if (ap->ap_probe == ATA_PROBE_FAILED) {
                kprintf("%s: reinit failed, port is dead\n", PORTNAME(ap));
                while ((ccb = TAILQ_FIRST(&ap->ap_ccb_pending)) != NULL) {
                        TAILQ_REMOVE(&ap->ap_ccb_pending, ccb, ccb_entry);
                        ccb->ccb_xa.flags &= ~ATA_F_TIMEOUT_DESIRED;
                        ccb->ccb_xa.state = ATA_S_TIMEOUT;
                        ccb->ccb_done(ccb);
                        ccb->ccb_xa.complete(&ccb->ccb_xa);
                }
        } else {
                kprintf("%s: reinit succeeded probe=%d type=%d\n", PORTNAME(ap), ap->ap_probe, ap->ap_type);
                sili_issue_pending_commands(ap, NULL);
        }
        return;
}

/*
 * Enable or re-enable interrupts on a port.
 *
 * This routine is called from the port initialization code or from the
 * helper thread as the real interrupt may be forced to turn off certain
 * interrupt sources.
 */
void
sili_port_interrupt_enable(struct sili_port *ap)
{
        u_int32_t data;

        data =  SILI_PREG_INT_CCOMPLETE | SILI_PREG_INT_CERROR |
                SILI_PREG_INT_PHYRDYCHG | SILI_PREG_INT_DEVEXCHG |
                SILI_PREG_INT_DECODE | SILI_PREG_INT_CRC |
                SILI_PREG_INT_HANDSHK | SILI_PREG_INT_PMCHANGE;
        if (ap->ap_sc->sc_flags & SILI_F_SSNTF)
                data |= SILI_PREG_INT_SDB;
        sili_pwrite(ap, SILI_PREG_INT_ENABLE, data);
}

void
sili_port_interrupt_redisable(struct sili_port *ap)
{
        u_int32_t data;

        data = sili_read(ap->ap_sc, SILI_REG_GCTL);
        data &= SILI_REG_GINT_PORTMASK;
        data &= ~(1 << ap->ap_num);
        sili_write(ap->ap_sc, SILI_REG_GCTL, data);
}

void
sili_port_interrupt_reenable(struct sili_port *ap)
{
        u_int32_t data;

        data = sili_read(ap->ap_sc, SILI_REG_GCTL);
        data &= SILI_REG_GINT_PORTMASK;
        data |= (1 << ap->ap_num);
        sili_write(ap->ap_sc, SILI_REG_GCTL, data);
}

/*
 * Run the port / target state machine from a main context.
 *
 * The state machine for the port is always run.
 *
 * If atx is non-NULL run the state machine for a particular target.
 * If atx is NULL run the state machine for all targets.
 */
void
sili_port_state_machine(struct sili_port *ap, int initial)
{
        struct ata_port *at;
        u_int32_t data;
        int target;
        int didsleep;
        int loop;

        /*
         * State machine for port.  Note that CAM is not yet associated
         * during the initial parallel probe and the port's probe state
         * will not get past ATA_PROBE_NEED_IDENT.
         */
        {
                if (initial == 0 && ap->ap_probe <= ATA_PROBE_NEED_HARD_RESET) {
                        kprintf("%s: Waiting 10 seconds on insertion\n",
                                PORTNAME(ap));
                        sili_os_sleep(10000);
                        initial = 1;
                }
                if (ap->ap_probe == ATA_PROBE_NEED_INIT)
                        sili_port_init(ap, NULL);
                if (ap->ap_probe == ATA_PROBE_NEED_HARD_RESET)
                        sili_port_reset(ap, NULL, 1);
                if (ap->ap_probe == ATA_PROBE_NEED_SOFT_RESET)
                        sili_port_reset(ap, NULL, 0);
                if (ap->ap_probe == ATA_PROBE_NEED_IDENT)
                        sili_cam_probe(ap, NULL);
        }
        if (ap->ap_type != ATA_PORT_T_PM) {
                if (ap->ap_probe == ATA_PROBE_FAILED) {
                        sili_cam_changed(ap, NULL, 0);
                } else if (ap->ap_probe >= ATA_PROBE_NEED_IDENT) {
                        sili_cam_changed(ap, NULL, 1);
                }
                return;
        }

        /*
         * Port Multiplier state machine.
         *
         * Get a mask of changed targets and combine with any runnable
         * states already present.
         */
        for (loop = 0; ;++loop) {
                if (sili_pm_read(ap, 15, SATA_PMREG_EINFO, &data)) {
                        kprintf("%s: PM unable to read hot-plug bitmap\n",
                                PORTNAME(ap));
                        break;
                }

                /*
                 * Do at least one loop, then stop if no more state changes
                 * have occured.  The PM might not generate a new
                 * notification until we clear the entire bitmap.
                 */
                if (loop && data == 0)
                        break;

                /*
                 * New devices showing up in the bitmap require some spin-up
                 * time before we start probing them.  Reset didsleep.  The
                 * first new device we detect will sleep before probing.
                 *
                 * This only applies to devices whos change bit is set in
                 * the data, and does not apply to the initial boot-time
                 * probe.
                 */
                didsleep = 0;

                for (target = 0; target < ap->ap_pmcount; ++target) {
                        at = &ap->ap_ata[target];

                        /*
                         * Check the target state for targets behind the PM
                         * which have changed state.  This will adjust
                         * at_probe and set ATA_PORT_F_RESCAN
                         *
                         * We want to wait at least 10 seconds before probing
                         * a newly inserted device.  If the check status
                         * indicates a device is present and in need of a
                         * hard reset, we make sure we have slept before
                         * continuing.
                         *
                         * We also need to wait at least 1 second for the
                         * PHY state to change after insertion, if we
                         * haven't already waited the 10 seconds.
                         *
                         * NOTE: When pm_check_good finds a good port it
                         *       typically starts us in probe state
                         *       NEED_HARD_RESET rather than INIT.
                         */
                        if (data & (1 << target)) {
                                if (initial == 0 && didsleep == 0)
                                        sili_os_sleep(1000);
                                sili_pm_check_good(ap, target);
                                if (initial == 0 && didsleep == 0 &&
                                    at->at_probe <= ATA_PROBE_NEED_HARD_RESET
                                ) {
                                        didsleep = 1;
                                        kprintf("%s: Waiting 10 seconds on insertion\n", PORTNAME(ap));
                                        sili_os_sleep(10000);
                                }
                        }

                        /*
                         * Report hot-plug events before the probe state
                         * really gets hot.  Only actual events are reported
                         * here to reduce spew.
                         */
                        if (data & (1 << target)) {
                                kprintf("%s: HOTPLUG (PM) - ", ATANAME(ap, at));
                                switch(at->at_probe) {
                                case ATA_PROBE_NEED_INIT:
                                case ATA_PROBE_NEED_HARD_RESET:
                                        kprintf("Device inserted\n");
                                        break;
                                case ATA_PROBE_FAILED:
                                        kprintf("Device removed\n");
                                        break;
                                default:
                                        kprintf("Device probe in progress\n");
                                        break;
                                }
                        }

                        /*
                         * Run through the state machine as necessary if
                         * the port is not marked failed.
                         *
                         * The state machine may stop at NEED_IDENT if
                         * CAM is not yet attached.
                         *
                         * Acquire exclusive access to the port while we
                         * are doing this.  This prevents command-completion
                         * from queueing commands for non-polled targets
                         * inbetween our probe steps.  We need to do this
                         * because the reset probes can generate severe PHY
                         * and protocol errors and soft-brick the port.
                         */
                        if (at->at_probe != ATA_PROBE_FAILED &&
                            at->at_probe != ATA_PROBE_GOOD) {
#if 0
                                sili_beg_exclusive_access(ap, at);
#endif
                                if (at->at_probe == ATA_PROBE_NEED_INIT)
                                        sili_port_init(ap, at);
                                if (at->at_probe == ATA_PROBE_NEED_HARD_RESET)
                                        sili_port_reset(ap, at, 1);
                                if (at->at_probe == ATA_PROBE_NEED_SOFT_RESET)
                                        sili_port_reset(ap, at, 0);
                                if (at->at_probe == ATA_PROBE_NEED_IDENT)
                                        sili_cam_probe(ap, at);
#if 0
                                sili_end_exclusive_access(ap, at);
#endif
                        }

                        /*
                         * Add or remove from CAM
                         */
                        if (at->at_features & ATA_PORT_F_RESCAN) {
                                at->at_features &= ~ATA_PORT_F_RESCAN;
                                if (at->at_probe == ATA_PROBE_FAILED) {
                                        sili_cam_changed(ap, at, 0);
                                } else if (at->at_probe >= ATA_PROBE_NEED_IDENT) {
                                        sili_cam_changed(ap, at, 1);
                                }
                        }
                        data &= ~(1 << target);
                }
                if (data) {
                        kprintf("%s: WARNING (PM): extra bits set in "
                                "EINFO: %08x\n", PORTNAME(ap), data);
                        while (target < SILI_MAX_PMPORTS) {
                                sili_pm_check_good(ap, target);
                                ++target;
                        }
                }
        }
}

/*
 * De-initialize and detach a port.
 */
void
sili_port_free(struct sili_softc *sc, u_int port)
{
        struct sili_port                *ap = sc->sc_ports[port];
        struct sili_ccb                 *ccb;

        /*
         * Ensure port is disabled and its interrupts are all flushed.
         */
        if (ap->ap_sc) {
                sili_os_stop_port(ap);
                sili_pwrite(ap, SILI_PREG_INT_DISABLE, SILI_PREG_INT_MASK);
                sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_RESET);
                sili_write(ap->ap_sc, SILI_REG_GCTL,
                        sili_read(ap->ap_sc, SILI_REG_GCTL) &
                        ~SILI_REG_GINT_PORTST(ap->ap_num));
        }

        if (ap->ap_ccbs) {
                while ((ccb = sili_get_ccb(ap)) != NULL) {
                        if (ccb->ccb_dmamap) {
                                bus_dmamap_destroy(sc->sc_tag_data,
                                                   ccb->ccb_dmamap);
                                ccb->ccb_dmamap = NULL;
                        }
                }
                if ((ccb = ap->ap_err_ccb) != NULL) {
                        if (ccb->ccb_dmamap) {
                                bus_dmamap_destroy(sc->sc_tag_data,
                                                   ccb->ccb_dmamap);
                                ccb->ccb_dmamap = NULL;
                        }
                        ap->ap_err_ccb = NULL;
                }
                kfree(ap->ap_ccbs, M_DEVBUF);
                ap->ap_ccbs = NULL;
        }

        if (ap->ap_dmamem_prbs) {
                sili_dmamem_free(sc, ap->ap_dmamem_prbs);
                ap->ap_dmamem_prbs = NULL;
        }
        if (ap->ap_ata) {
                kfree(ap->ap_ata, M_DEVBUF);
                ap->ap_ata = NULL;
        }

        /* bus_space(9) says we dont free the subregions handle */

        kfree(ap, M_DEVBUF);
        sc->sc_ports[port] = NULL;
}

/*
 * Reset a port.
 *
 * If hard is 0 perform a softreset of the port.
 * If hard is 1 perform a hard reset of the port.
 * If hard is 2 perform a hard reset of the port and cycle the phy.
 *
 * If at is non-NULL an indirect port via a port-multiplier is being
 * reset, otherwise a direct port is being reset.
 *
 * NOTE: Indirect ports can only be soft-reset.
 */
int
sili_port_reset(struct sili_port *ap, struct ata_port *at, int hard)
{
        int rc;

        if (hard) {
                if (at)
                        rc = sili_pm_hardreset(ap, at->at_target, hard);
                else
                        rc = sili_port_hardreset(ap, hard);
        } else {
                if (at)
                        rc = sili_pm_softreset(ap, at->at_target);
                else
                        rc = sili_port_softreset(ap);
        }
        return(rc);
}

/*
 * SILI soft reset, Section 10.4.1
 *
 * (at) will be NULL when soft-resetting a directly-attached device, and
 * non-NULL when soft-resetting a device through a port multiplier.
 *
 * This function keeps port communications intact and attempts to generate
 * a reset to the connected device using device commands.
 */
int
sili_port_softreset(struct sili_port *ap)
{
        struct sili_ccb         *ccb = NULL;
        struct sili_prb         *prb;
        int                     error;
        u_int32_t               sig;

        error = EIO;

        kprintf("%s: START SOFTRESET\n", PORTNAME(ap));

        DPRINTF(SILI_D_VERBOSE, "%s: soft reset\n", PORTNAME(ap));

        crit_enter();
        ap->ap_state = AP_S_NORMAL;

        /*
         * Prep the special soft-reset SII command.
         */
        ccb = sili_get_err_ccb(ap);
        ccb->ccb_done = sili_empty_done;
        ccb->ccb_xa.flags = ATA_F_POLL | ATA_F_AUTOSENSE | ATA_F_EXCLUSIVE;
        ccb->ccb_xa.complete = sili_dummy_done;
        ccb->ccb_xa.at = NULL;

        prb = ccb->ccb_prb;
        bzero(&prb->prb_h2d, sizeof(prb->prb_h2d));
        prb->prb_h2d.flags = 0;
        prb->prb_control = SILI_PRB_CTRL_SOFTRESET;
        prb->prb_override = 0;

        ccb->ccb_xa.state = ATA_S_PENDING;
        ccb->ccb_xa.flags = 0;

                                /* XXX */
        if (sili_poll(ccb, 8000, sili_quick_timeout) != ATA_S_COMPLETE) {
                kprintf("%s: First FIS failed\n", PORTNAME(ap));
                goto err;
        }

        sig = (prb->prb_d2h.lba_high << 24) |
              (prb->prb_d2h.lba_mid << 16) |
              (prb->prb_d2h.lba_low << 8) |
              (prb->prb_d2h.sector_count);
        kprintf("%s: SOFTRESET SIGNATURE %08x\n", PORTNAME(ap), sig);

        /*
         * If the softreset is trying to clear a BSY condition after a
         * normal portreset we assign the port type.
         *
         * If the softreset is being run first as part of the ccb error
         * processing code then report if the device signature changed
         * unexpectedly.
         */
        if (ap->ap_type == ATA_PORT_T_NONE) {
                ap->ap_type = sili_port_signature(ap, NULL, sig);
        } else {
                if (sili_port_signature(ap, NULL, sig) != ap->ap_type) {
                        kprintf("%s: device signature unexpectedly "
                                "changed\n", PORTNAME(ap));
                        error = EBUSY; /* XXX */
                }
        }
        error = 0;
err:
        if (ccb != NULL) {
                sili_put_err_ccb(ccb);
        }

        /*
         * If we failed to softreset make the port quiescent, otherwise
         * make sure the port's start/stop state matches what it was on
         * entry.
         *
         * Don't kill the port if the softreset is on a port multiplier
         * target, that would kill all the targets!
         */
        kprintf("%s: END SOFTRESET %d prob=%d state=%d\n", PORTNAME(ap), error, ap->ap_probe, ap->ap_state);
        if (error) {
                sili_port_hardstop(ap);
                /* ap_probe set to failed */
        } else {
                ap->ap_probe = ATA_PROBE_NEED_IDENT;
        }
        crit_exit();

        if (bootverbose)
                kprintf("%s: END SOFTRESET\n", PORTNAME(ap));

        return (error);
}

/*
 * SILI port reset, Section 10.4.2
 *
 * This function does a hard reset of the port.  Note that the device
 * connected to the port could still end-up hung.
 */
int
sili_port_hardreset(struct sili_port *ap, int hard)
{
        u_int32_t r;
        int     error;
        int     loop;

        DPRINTF(SILI_D_VERBOSE, "%s: port reset\n", PORTNAME(ap));

        ap->ap_state = AP_S_NORMAL;
        error = 0;

        /*
         * Issue Device Reset.
         *
         * NOTE:  Unlike Port Reset, the port ready signal will not
         *        go active unless a device is established to be on
         *        the port.
         */
        sili_pwrite(ap, SILI_PREG_SERR, -1);
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_PMA);
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_RESUME);
        sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_DEVRESET);
        if (sili_pwait_clr(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_DEVRESET)) {
                kprintf("%s: hardreset failed to clear\n", PORTNAME(ap));
        }

        /*
         * Try to determine if there is a device on the port.
         *
         * Give the device 3/10 second to at least be detected.
         */
        loop = 300;
        while (loop > 0) {
                r = sili_pread(ap, SILI_PREG_SSTS);
                if (r & SILI_PREG_SSTS_DET)
                        break;
                loop -= sili_os_softsleep();
        }
        if (loop <= 0) {
                if (bootverbose) {
                        kprintf("%s: Port appears to be unplugged\n",
                                PORTNAME(ap));
                }
                error = ENODEV;
        }

        /*
         * There is something on the port.  Give the device 3 seconds
         * to fully negotiate.
         */
        if (error == 0 &&
            sili_pwait_eq(ap, 3000, SILI_PREG_SSTS,
                          SILI_PREG_SSTS_DET, SILI_PREG_SSTS_DET_DEV)) {
                if (bootverbose) {
                        kprintf("%s: Device may be powered down\n",
                                PORTNAME(ap));
                }
                error = ENODEV;
        }

        /*
         * Wait for the port to become ready.
         *
         * This can take more then a second, give it 3 seconds.  If we
         * succeed give the device another 3ms after that.
         *
         * NOTE: Port multipliers can do two things here.  First they can
         *       return device-ready if a device is on target 0 and also
         *       return the signature for that device.  If there is no
         *       device on target 0 then BSY/DRQ is never cleared and
         *       it never comes ready.
         */
        if (error == 0 && sili_pwait_set_to(ap, 3000, SILI_PREG_STATUS,
                                            SILI_PREG_STATUS_READY)) {
                /*
                 * The device is bricked or its a port multiplier and will
                 * not unbusy until we do the pmprobe CLO softreset sequence.
                 */
                error = sili_port_pmprobe(ap);
                if (error) {
                        kprintf("%s: Device will not come ready\n",
                                PORTNAME(ap));
                } else {
                        ap->ap_type = ATA_PORT_T_PM;
                }
        } else if (error == 0) {
                /*
                 * The sili's hardreset doesn't return a signature (does it)?
                 * In anycase, set the type so the signature gets set by
                 * the softreset stage.
                 */
                error = sili_port_pmprobe(ap);
                if (error) {
                        ap->ap_type = ATA_PORT_T_NONE;
                        error = 0;
                } else {
                        ap->ap_type = ATA_PORT_T_PM;
                        kprintf("%s: Port multiplier detected\n",
                                PORTNAME(ap));
                }
        }

        /*
         * hard-stop the port if we failed.  This will set ap_probe
         * to FAILED.
         */
        if (error) {
                sili_port_hardstop(ap);
                /* ap_probe set to failed */
        } else {
                if (ap->ap_type == ATA_PORT_T_PM)
                        ap->ap_probe = ATA_PROBE_GOOD;
                else
                        ap->ap_probe = ATA_PROBE_NEED_SOFT_RESET;
        }
        return (error);
}

/*
 * SILI port multiplier probe.  This routine is run by the hardreset code
 * if it gets past the device detect.
 *
 * All we do here is call sili_pm_softreset().  The Sili chip does all the
 * hard work for us.
 *
 * Return 0 on success, non-zero on failure.
 */
int
sili_port_pmprobe(struct sili_port *ap)
{
        struct ata_port *at;
        int error;
        int i;

        /*
         * If we don't support port multipliers don't try to detect one.
         */
        if ((ap->ap_sc->sc_flags & SILI_F_SPM) == 0)
                return (ENODEV);

        /*
         * The port may be unhappy from its hardreset if there's a PM
         * but no device at target 0.  If we try to shove the softreset
         * for target 15 down its throat it will pop a gasket.
         *
         * Reiniting the port.. kind of a soft reset of its command
         * processor which otherwise does not effect the port registers,
         * seems to fix the problem.
         */
        sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_PMA);
        sili_port_reinit(ap);
        ap->ap_state = AP_S_NORMAL;
        error = sili_pm_softreset(ap, 15);
        if (error == 0) {
                ap->ap_ata[15].at_probe = ATA_PROBE_GOOD;
        } else {
                error = EBUSY;
        }

        kprintf("PMPROBE3 %d\n", error);

        if (error == 0 && sili_pm_identify(ap)) {
                kprintf("%s: PM - cannot identify port multiplier\n",
                        PORTNAME(ap));
                error = EBUSY;
        }
        kprintf("PMPROBE3 %d %d %d\n", error, ap->ap_probe, ap->ap_state);

        /*
         * If we probed the PM reset the state for the targets behind
         * it so they get probed by the state machine.
         */
        if (error == 0) {
                for (i = 0; i < SILI_MAX_PMPORTS; ++i) {
                        at = &ap->ap_ata[i];
                        at->at_probe = ATA_PROBE_NEED_INIT;
                        at->at_features |= ATA_PORT_F_RESCAN;
                        at->at_features &= ~ATA_PORT_F_READLOG;
                }
        }

        /*
         * If we failed turn off PMA, otherwise identify the port multiplier.
         * CAM will iterate the devices.
         */
        if (error)
                sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_PMA);
        return(error);
}

/*
 * Hard-stop on hot-swap device removal.  See 10.10.1
 *
 * Place the port in a mode that will allow it to detect hot-swap insertions.
 * This is a bit imprecise because just setting-up SCTL to DET_INIT doesn't
 * seem to do the job.
 */
void
sili_port_hardstop(struct sili_port *ap)
{
        struct sili_ccb *ccb;
        struct ata_port *at;
        int i;
        int slot;

        ap->ap_state = AP_S_FATAL_ERROR;
        ap->ap_probe = ATA_PROBE_FAILED;
        ap->ap_type = ATA_PORT_T_NONE;

        /*
         * Clean up AT sub-ports on SATA port.
         */
        for (i = 0; ap->ap_ata && i < SILI_MAX_PMPORTS; ++i) {
                at = &ap->ap_ata[i];
                at->at_type = ATA_PORT_T_NONE;
                at->at_probe = ATA_PROBE_FAILED;
                at->at_features &= ~ATA_PORT_F_READLOG;
        }

        /*
         * Kill the port.  Don't bother waiting for it to transition
         * back up.
         */
        sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_RESET);
        if (sili_pread(ap, SILI_PREG_STATUS) & SILI_PREG_STATUS_READY) {
                kprintf("%s: Port will not go into reset\n",
                        PORTNAME(ap));
        }
        sili_os_sleep(10);
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_RESUME);
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_RESET);

        /*
         * Turn off port-multiplier control bit
         */
        sili_pwrite(ap, SILI_PREG_CTL_CLR, SILI_PREG_CTL_PMA);

        /*
         * Clean up the command list.
         */
        while (ap->ap_active) {
                slot = ffs(ap->ap_active) - 1;
                ap->ap_active &= ~(1 << slot);
                ap->ap_expired &= ~(1 << slot);
                --ap->ap_active_cnt;
                ccb = &ap->ap_ccbs[slot];
                if (ccb->ccb_xa.flags & ATA_F_TIMEOUT_RUNNING) {
                        callout_stop(&ccb->ccb_timeout);
                        ccb->ccb_xa.flags &= ~ATA_F_TIMEOUT_RUNNING;
                }
                ccb->ccb_xa.flags &= ~(ATA_F_TIMEOUT_DESIRED |
                                       ATA_F_TIMEOUT_EXPIRED);
                ccb->ccb_xa.state = ATA_S_TIMEOUT;
                ccb->ccb_done(ccb);
                ccb->ccb_xa.complete(&ccb->ccb_xa);
        }
        while ((ccb = TAILQ_FIRST(&ap->ap_ccb_pending)) != NULL) {
                TAILQ_REMOVE(&ap->ap_ccb_pending, ccb, ccb_entry);
                ccb->ccb_xa.state = ATA_S_TIMEOUT;
                ccb->ccb_xa.flags &= ~ATA_F_TIMEOUT_DESIRED;
                ccb->ccb_done(ccb);
                ccb->ccb_xa.complete(&ccb->ccb_xa);
        }
        KKASSERT(ap->ap_active_cnt == 0);

        /*
         * Put the port into a listen mode, we want to get insertion/removal
         * events.
         */
        sili_port_listen(ap);
}

/*
 * Place port into a listen mode for hotplug events only.  The port has
 * already been reset and the command processor may not be ready due
 * to the lack of a device.
 */
void
sili_port_listen(struct sili_port *ap)
{
        u_int32_t data;

#if 1
        data = SILI_PREG_SCTL_SPM_NONE |
               SILI_PREG_SCTL_IPM_NONE |
               SILI_PREG_SCTL_SPD_NONE |
               SILI_PREG_SCTL_DET_INIT;
        if (SiliForceGen1 & (1 << ap->ap_num)) {
                data &= ~SILI_PREG_SCTL_SPD_NONE;
                data |= SILI_PREG_SCTL_SPD_GEN1;
        }
#endif
        sili_pwrite(ap, SILI_PREG_SERR, -1);
        sili_pwrite(ap, SILI_PREG_INT_ENABLE, SILI_PREG_INT_PHYRDYCHG |
                                              SILI_PREG_INT_DEVEXCHG);
}

/*
 * Figure out what type of device is connected to the port, ATAPI or
 * DISK.
 */
int
sili_port_signature(struct sili_port *ap, struct ata_port *at, u_int32_t sig)
{
        if (bootverbose)
                kprintf("%s: sig %08x\n", ATANAME(ap, at), sig);
        if ((sig & 0xffff0000) == (SATA_SIGNATURE_ATAPI & 0xffff0000)) {
                return(ATA_PORT_T_ATAPI);
        } else if ((sig & 0xffff0000) ==
                 (SATA_SIGNATURE_PORT_MULTIPLIER & 0xffff0000)) {
                return(ATA_PORT_T_PM);
        } else {
                return(ATA_PORT_T_DISK);
        }
}

/*
 * Load the DMA descriptor table for a CCB's buffer.
 *
 * NOTE: ATA_F_PIO is auto-selected by sili part.
 */
int
sili_load_prb(struct sili_ccb *ccb)
{
        struct sili_port                *ap = ccb->ccb_port;
        struct sili_softc               *sc = ap->ap_sc;
        struct ata_xfer                 *xa = &ccb->ccb_xa;
        struct sili_prb                 *prb = ccb->ccb_prb;
        struct sili_sge                 *sge;
        bus_dmamap_t                    dmap = ccb->ccb_dmamap;
        int                             error;

        /*
         * Set up the PRB.  The PRB contains 2 SGE's (1 if it is an ATAPI
         * command).  The SGE must be set up to link to the rest of our
         * SGE array, in blocks of four SGEs (a SGE table) starting at
         */
        prb->prb_xfer_count = 0;
        prb->prb_control = 0;
        prb->prb_override = 0;
        sge = (ccb->ccb_xa.flags & ATA_F_PACKET) ?
                &prb->prb_sge_packet : &prb->prb_sge_normal;
        if (xa->datalen == 0) {
                sge->sge_flags = SILI_SGE_FLAGS_TRM | SILI_SGE_FLAGS_DRD;
                sge->sge_count = 0;
                return (0);
        }

        if (ccb->ccb_xa.flags & ATA_F_READ)
                prb->prb_control |= SILI_PRB_CTRL_READ;
        if (ccb->ccb_xa.flags & ATA_F_WRITE)
                prb->prb_control |= SILI_PRB_CTRL_WRITE;
        sge->sge_flags = SILI_SGE_FLAGS_LNK;
        sge->sge_count = 0;
        sge->sge_paddr = ccb->ccb_prb_paddr +
                         offsetof(struct sili_prb, prb_sge[0]);

        /*
         * Load our sge array.
         */
        error = bus_dmamap_load(sc->sc_tag_data, dmap,
                                xa->data, xa->datalen,
                                sili_load_prb_callback,
                                ccb,
                                ((xa->flags & ATA_F_NOWAIT) ?
                                    BUS_DMA_NOWAIT : BUS_DMA_WAITOK));
        if (error != 0) {
                kprintf("%s: error %d loading dmamap\n", PORTNAME(ap), error);
                return (1);
        }

        bus_dmamap_sync(sc->sc_tag_data, dmap,
                        (xa->flags & ATA_F_READ) ?
                            BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);

        return (0);

#ifdef DIAGNOSTIC
diagerr:
        bus_dmamap_unload(sc->sc_tag_data, dmap);
        return (1);
#endif
}

/*
 * Callback from BUSDMA system to load the segment list.
 *
 * The scatter/gather table is loaded by the sili chip in blocks of
 * four SGE's.  If a continuance is required the last entry in each
 * block must point to the next block.
 */
static
void
sili_load_prb_callback(void *info, bus_dma_segment_t *segs, int nsegs,
                        int error)
{
        struct sili_ccb *ccb = info;
        struct sili_sge *sge;
        int sgi;

        KKASSERT(nsegs <= SILI_MAX_SGET);

        sgi = 0;
        sge = &ccb->ccb_prb->prb_sge[0];
        while (nsegs) {
                if ((sgi & 3) == 3) {
                        sge->sge_paddr = htole64(ccb->ccb_prb_paddr +
                                                 offsetof(struct sili_prb,
                                                        prb_sge[sgi + 1]));
                        sge->sge_count = 0;
                        sge->sge_flags = SILI_SGE_FLAGS_LNK;
                } else {
                        sge->sge_paddr = htole64(segs->ds_addr);
                        sge->sge_count = htole32(segs->ds_len);
                        sge->sge_flags = 0;
                        --nsegs;
                        ++segs;
                }
                ++sge;
                ++sgi;
        }
        --sge;
        sge->sge_flags |= SILI_SGE_FLAGS_TRM;
}

void
sili_unload_prb(struct sili_ccb *ccb)
{
        struct sili_port                *ap = ccb->ccb_port;
        struct sili_softc               *sc = ap->ap_sc;
        struct ata_xfer                 *xa = &ccb->ccb_xa;
        bus_dmamap_t                    dmap = ccb->ccb_dmamap;

        if (xa->datalen != 0) {
                bus_dmamap_sync(sc->sc_tag_data, dmap,
                                (xa->flags & ATA_F_READ) ?
                                BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);

                bus_dmamap_unload(sc->sc_tag_data, dmap);

                if (ccb->ccb_xa.flags & ATA_F_NCQ)
                        xa->resid = 0;
                else
                        xa->resid = xa->datalen -
                                    le32toh(ccb->ccb_prb->prb_xfer_count);
        }
}

/*
 * Start a command and poll for completion.
 *
 * timeout is in ms and only counts once the command gets on-chip.
 *
 * Returns ATA_S_* state, compare against ATA_S_COMPLETE to determine
 * that no error occured.
 *
 * NOTE: If the caller specifies a NULL timeout function the caller is
 *       responsible for clearing hardware state on failure, but we will
 *       deal with removing the ccb from any pending queue.
 *
 * NOTE: NCQ should never be used with this function.
 *
 * NOTE: If the port is in a failed state and stopped we do not try
 *       to activate the ccb.
 */
int
sili_poll(struct sili_ccb *ccb, int timeout,
          void (*timeout_fn)(struct sili_ccb *))
{
        struct sili_port *ap = ccb->ccb_port;

        if (ccb->ccb_port->ap_state == AP_S_FATAL_ERROR) {
                ccb->ccb_xa.state = ATA_S_ERROR;
                return(ccb->ccb_xa.state);
        }

        sili_start(ccb);

        do {
                sili_port_intr(ap, 1);
                switch(ccb->ccb_xa.state) {
                case ATA_S_ONCHIP:
                        timeout -= sili_os_softsleep();
                        break;
                case ATA_S_PENDING:
                        /*
                         * The packet can get stuck on the pending queue
                         * if the port refuses to come ready.  XXX
                         */
#if 0
                        if (xxx AP_F_EXCLUSIVE_ACCESS)
                                timeout -= sili_os_softsleep();
                        else
#endif
                                sili_os_softsleep();
                        sili_check_active_timeouts(ap);
                        break;
                default:
                        return (ccb->ccb_xa.state);
                }
        } while (timeout > 0);

        kprintf("%s: Poll timeout slot %d\n",
                ATANAME(ap, ccb->ccb_xa.at),
                ccb->ccb_slot);

        timeout_fn(ccb);

        return(ccb->ccb_xa.state);
}

/*
 * When polling we have to check if the currently active CCB(s)
 * have timed out as the callout will be deadlocked while we
 * hold the port lock.
 */
void
sili_check_active_timeouts(struct sili_port *ap)
{
        struct sili_ccb *ccb;
        u_int32_t mask;
        int tag;

        mask = ap->ap_active;
        while (mask) {
                tag = ffs(mask) - 1;
                mask &= ~(1 << tag);
                ccb = &ap->ap_ccbs[tag];
                if (ccb->ccb_xa.flags & ATA_F_TIMEOUT_EXPIRED) {
                        sili_core_timeout(ccb);
                }
        }
}

static
__inline
void
sili_start_timeout(struct sili_ccb *ccb)
{
        if (ccb->ccb_xa.flags & ATA_F_TIMEOUT_DESIRED) {
                ccb->ccb_xa.flags |= ATA_F_TIMEOUT_RUNNING;
                callout_reset(&ccb->ccb_timeout,
                              (ccb->ccb_xa.timeout * hz + 999) / 1000,
                              sili_ata_cmd_timeout_unserialized, ccb);
        }
}

void
sili_start(struct sili_ccb *ccb)
{
        struct sili_port                *ap = ccb->ccb_port;
#if 0
        struct sili_softc               *sc = ap->ap_sc;
#endif

        KKASSERT(ccb->ccb_xa.state == ATA_S_PENDING);

        /*
         * Sync our SGE table and PRB
         */
        bus_dmamap_sync(ap->ap_dmamem_prbs->adm_tag,
                        ap->ap_dmamem_prbs->adm_map,
                        BUS_DMASYNC_PREWRITE);

        /*
         * XXX dmamap for PRB XXX  BUS_DMASYNC_PREWRITE
         */

        /*
         * Controller will update shared memory!
         * XXX bus_dmamap_sync ... BUS_DMASYNC_PREREAD ...
         */
        /* Prepare RFIS area for write by controller */

        /*
         * There's no point trying to optimize this, it only shaves a few
         * nanoseconds so just queue the command and call our generic issue.
         */
        sili_issue_pending_commands(ap, ccb);
}

#if 0
/*
 * While holding the port lock acquire exclusive access to the port.
 *
 * This is used when running the state machine to initialize and identify
 * targets over a port multiplier.  Setting exclusive access prevents
 * sili_port_intr() from activating any requests sitting on the pending
 * queue.
 */
void
sili_beg_exclusive_access(struct sili_port *ap, struct ata_port *at)
{
        KKASSERT((ap->ap_flags & AP_F_EXCLUSIVE_ACCESS) == 0);
        ap->ap_flags |= AP_F_EXCLUSIVE_ACCESS;
        while (ap->ap_active) {
                sili_port_intr(ap, 1);
                sili_os_softsleep();
        }
}

void
sili_end_exclusive_access(struct sili_port *ap, struct ata_port *at)
{
        KKASSERT((ap->ap_flags & AP_F_EXCLUSIVE_ACCESS) != 0);
        ap->ap_flags &= ~AP_F_EXCLUSIVE_ACCESS;
        sili_issue_pending_commands(ap, NULL);
}
#endif

/*
 * If ccb is not NULL enqueue and/or issue it.
 *
 * If ccb is NULL issue whatever we can from the queue.  However, nothing
 * new is issued if the exclusive access flag is set or expired ccb's are
 * present.
 *
 * If existing commands are still active (ap_active) we can only
 * issue matching new commands.
 */
void
sili_issue_pending_commands(struct sili_port *ap, struct sili_ccb *ccb)
{
        /*
         * Enqueue the ccb.
         *
         * If just running the queue and in exclusive access mode we
         * just return.  Also in this case if there are any expired ccb's
         * we want to clear the queue so the port can be safely stopped.
         *
         * XXX sili chip - expiration needs to be per-target if PM supports
         *      FBSS?
         */
        if (ccb) {
                TAILQ_INSERT_TAIL(&ap->ap_ccb_pending, ccb, ccb_entry);
        } else if (ap->ap_expired) {
                return;
        }

        /*
         * Pull the next ccb off the queue and run it if possible.
         * If the port is not ready to accept commands enable the
         * ready interrupt instead of starting a new command.
         *
         * XXX limit ncqdepth for attached devices behind PM
         */
        while ((ccb = TAILQ_FIRST(&ap->ap_ccb_pending)) != NULL) {
                /*
                 * Port may be wedged.
                 */
                if ((sili_pread(ap, SILI_PREG_STATUS) &
                    SILI_PREG_STATUS_READY) == 0) {
                        kprintf("%s: slot %d NOT READY\n",
                                ATANAME(ap, ccb->ccb_xa.at), ccb->ccb_slot);
                        sili_pwrite(ap, SILI_PREG_INT_ENABLE,
                                    SILI_PREG_INT_READY);
                        break;
                }

                /*
                 * Handle exclusivity requirements.  ATA_F_EXCLUSIVE is used
                 * when we may have to access the rfis which is stored in
                 * the LRAM PRB.  Unfortunately reading the LRAM PRB is
                 * highly problematic, so requests (like PM requests) which
                 * need to access the rfis use exclusive mode and then
                 * access the copy made by the port interrupt code back in
                 * host memory.
                 */
                if (ap->ap_active & ~ap->ap_expired) {
                        /*
                         * There may be multiple ccb's already running,
                         * but there will only be one if it is exclusive.
                         * We can't queue a new command in that case.
                         *
                         * XXX Current AUTOSENSE code forces exclusivity
                         *     to simplify the code.
                         */
                        KKASSERT(ap->ap_last_ccb);
                        KKASSERT(ap->ap_active &
                                 (1 << ap->ap_last_ccb->ccb_slot));
                        if (ap->ap_last_ccb->ccb_xa.flags &
                            (ATA_F_EXCLUSIVE | ATA_F_AUTOSENSE)) {
                                break;
                        }

                        /*
                         * If the ccb we want to run is exclusive and ccb's
                         * are still active on the port, we can't queue it
                         * yet.
                         *
                         * XXX Current AUTOSENSE code forces exclusivity
                         *     to simplify the code.
                         */
                        if (ccb->ccb_xa.flags &
                            (ATA_F_EXCLUSIVE | ATA_F_AUTOSENSE)) {
                                break;
                        }
                }

                TAILQ_REMOVE(&ap->ap_ccb_pending, ccb, ccb_entry);
                ccb->ccb_xa.state = ATA_S_ONCHIP;
                ap->ap_active |= 1 << ccb->ccb_slot;
                ap->ap_active_cnt++;
                ap->ap_last_ccb = ccb;

                /*
                 * We can't use the CMD_FIFO method because it requires us
                 * building the PRB in the LRAM, and the LRAM is buggy.  So
                 * we use host memory for the PRB.
                 */
                sili_pwrite(ap, SILI_PREG_CMDACT(ccb->ccb_slot),
                            (u_int32_t)ccb->ccb_prb_paddr);
                sili_pwrite(ap, SILI_PREG_CMDACT(ccb->ccb_slot) + 4,
                            (u_int32_t)(ccb->ccb_prb_paddr >> 32));
                /* sili_pwrite(ap, SILI_PREG_CMD_FIFO, ccb->ccb_slot); */
                sili_start_timeout(ccb);
        }
}

void
sili_intr(void *arg)
{
        struct sili_softc       *sc = arg;
        struct sili_port        *ap;
        u_int32_t               gint;
        int                     port;

        /*
         * Check if the master enable is up, and whether any interrupts are
         * pending.
         *
         * Clear the ints we got.
         */
        if ((sc->sc_flags & SILI_F_INT_GOOD) == 0)
                return;
        gint = sili_read(sc, SILI_REG_GINT);
        if (gint == 0 || gint == 0xffffffff)
                return;
        sili_write(sc, SILI_REG_GINT, gint);

        /*
         * Process interrupts for each port in a non-blocking fashion.
         */
        while (gint & SILI_REG_GINT_PORTMASK) {
                port = ffs(gint) - 1;
                ap = sc->sc_ports[port];
                if (ap) {
                        if (sili_os_lock_port_nb(ap) == 0) {
                                sili_port_intr(ap, 0);
                                sili_os_unlock_port(ap);
                        } else {
                                sili_port_interrupt_redisable(ap);
                                sili_os_signal_port_thread(ap, AP_SIGF_PORTINT);
                        }
                }
                gint &= ~(1 << port);
        }
}

/*
 * Core called from helper thread.
 */
void
sili_port_thread_core(struct sili_port *ap, int mask)
{
        /*
         * Process any expired timedouts.
         */
        sili_os_lock_port(ap);
        if (mask & AP_SIGF_TIMEOUT) {
                sili_check_active_timeouts(ap);
        }

        /*
         * Process port interrupts which require a higher level of
         * intervention.
         */
        if (mask & AP_SIGF_PORTINT) {
                sili_port_intr(ap, 1);
                sili_port_interrupt_reenable(ap);
                sili_os_unlock_port(ap);
        } else {
                sili_os_unlock_port(ap);
        }
}

/*
 * Core per-port interrupt handler.
 *
 * If blockable is 0 we cannot call sili_os_sleep() at all and we can only
 * deal with normal command completions which do not require blocking.
 */
void
sili_port_intr(struct sili_port *ap, int blockable)
{
        struct sili_softc       *sc = ap->ap_sc;
        u_int32_t               is;
        int                     slot;
        struct sili_ccb         *ccb = NULL;
        struct ata_port         *ccb_at = NULL;
#ifdef DIAGNOSTIC
        u_int32_t               tmp;
#endif
        u_int32_t               active;
        const u_int32_t         blockable_mask = SILI_PREG_IST_PHYRDYCHG |
                                                 SILI_PREG_IST_DEVEXCHG |
                                                 SILI_PREG_IST_CERROR |
                                                 SILI_PREG_IST_DECODE |
                                                 SILI_PREG_IST_CRC |
                                                 SILI_PREG_IST_HANDSHK;
        const u_int32_t         fatal_mask     = SILI_PREG_IST_PHYRDYCHG |
                                                 SILI_PREG_IST_DEVEXCHG |
                                                 SILI_PREG_IST_DECODE |
                                                 SILI_PREG_IST_CRC |
                                                 SILI_PREG_IST_HANDSHK;

        enum { NEED_NOTHING, NEED_HOTPLUG_INSERT,
               NEED_HOTPLUG_REMOVE } need = NEED_NOTHING;

        /*
         * NOTE: CCOMPLETE was automatically cleared when we read INT_STATUS.
         */
        is = sili_pread(ap, SILI_PREG_INT_STATUS);
        is &= SILI_PREG_IST_MASK;
        if (is & SILI_PREG_IST_CCOMPLETE)
                sili_pwrite(ap, SILI_PREG_INT_STATUS, SILI_PREG_IST_CCOMPLETE);

        /*
         * If we can't block then we can't handle these here.  Disable
         * the interrupts in question so we don't live-lock, the helper
         * thread will re-enable them.
         *
         * If the port is in a completely failed state we do not want
         * to drop through to failed-command-processing if blockable is 0,
         * just let the thread deal with it all.
         *
         * Otherwise we fall through and still handle DHRS and any commands
         * which completed normally.  Even if we are errored we haven't
         * stopped the port yet so CI/SACT are still good.
         */
        if (blockable == 0) {
                if (ap->ap_state == AP_S_FATAL_ERROR) {
                        sili_port_interrupt_redisable(ap);
                        sili_os_signal_port_thread(ap, AP_SIGF_PORTINT);
                        /*is &= ~blockable_mask;*/
                        return;
                }
                if (is & blockable_mask) {
                        sili_port_interrupt_redisable(ap);
                        sili_os_signal_port_thread(ap, AP_SIGF_PORTINT);
                        /*is &= ~blockable_mask;*/
                        return;
                }
        }

        if (is & SILI_PREG_IST_CERROR) {
                /*
                 * Command failed (blockable).
                 *
                 * This stops command processing.  We can extract the PM
                 * target from the PMP field in SILI_PREG_CONTEXT.  The
                 * tag is not necessarily valid so don't use that.
                 *
                 * We must then expire all CCB's for that target and resume
                 * processing if any other targets have active commands.
                 * Particular error codes can be recovered by reading the LOG
                 * page.
                 *
                 * The expire handling code will do the rest, which is
                 * basically to reset the port once the only active
                 * commands remaining are all expired.
                 */
                u_int32_t error;
                int       target;
                int       resume = 1;

                target = (sili_pread(ap, SILI_PREG_CONTEXT) >>
                          SILI_PREG_CONTEXT_PMPORT_SHIFT) &
                          SILI_PREG_CONTEXT_PMPORT_MASK;
                sili_pwrite(ap, SILI_PREG_INT_STATUS, SILI_PREG_IST_CERROR);
                active = ap->ap_active & ~ap->ap_expired;
                error = sili_pread(ap, SILI_PREG_CERROR);
                kprintf("%s.%d target error %d active=%08x hactive=%08x "
                        "SERR=%b\n",
                        PORTNAME(ap), target, error,
                        active, sili_pread(ap, SILI_PREG_SLOTST),
                        sili_pread(ap, SILI_PREG_SERR), SILI_PFMT_SERR);

                while (active) {
                        slot = ffs(active) - 1;
                        ccb = &ap->ap_ccbs[slot];
                        if ((ccb_at = ccb->ccb_xa.at) == NULL)
                                ccb_at = &ap->ap_ata[0];
                        if (target == ccb_at->at_target) {
                                kprintf("%s kill ccb slot %d\n",
                                        ATANAME(ap, ccb->ccb_xa.at), slot);
                                if (ccb->ccb_xa.flags & ATA_F_NCQ &&
                                    (error == SILI_PREG_CERROR_DEVICE ||
                                     error == SILI_PREG_CERROR_SDBERROR)) {
                                        ccb_at->at_features |= ATA_PORT_F_READLOG;
                                }
                                if (sili_core_timeout(ccb) == 0)
                                        resume = 0;
                        }
                        active &= ~(1 << slot);
                }

                /*
                 * Resume will be 0 if the timeout reinited and restarted
                 * the port.  Otherwise we resume the port to allow other
                 * commands to complete.
                 */
                kprintf("%s.%d remain=%08x resume=%d\n",
                        PORTNAME(ap), target,
                        ap->ap_active & ~ap->ap_expired, resume);
                if (resume)
                        sili_pwrite(ap, SILI_PREG_CTL_SET, SILI_PREG_CTL_RESUME);
        }

        /*
         * Device notification to us (non-blocking)
         *
         * This is interrupt status SILIPREG_IST_SDB
         *
         * NOTE!  On some parts notification bits can get set without
         *        generating an interrupt.  It is unclear whether this is
         *        a bug in the PM (sending a DTOH device setbits with 'N' set
         *        and 'I' not set), or a bug in the host controller.
         *
         *        It only seems to occur under load.
         */
        if (sc->sc_flags & SILI_F_SSNTF) {
                u_int32_t data;
                const char *xstr;

                data = sili_pread(ap, SILI_PREG_SNTF);
                if (is & SILI_PREG_IST_SDB) {
                        sili_pwrite(ap, SILI_PREG_INT_STATUS,
                                    SILI_PREG_IST_SDB);
                        is &= ~SILI_PREG_IST_SDB;
                        xstr = " (no SDBS!)";
                } else {
                        xstr = "";
                }
                if (data) {
                        kprintf("%s: NOTIFY %08x%s\n",
                                PORTNAME(ap), data, xstr);
                        sili_pwrite(ap, SILI_PREG_SNTF, data);
                        sili_cam_changed(ap, NULL, -1);
                }
        }

        /*
         * Port change (hot-plug) (blockable).
         *
         * A PCS interrupt will occur on hot-plug once communication is
         * established.
         *
         * A PRCS interrupt will occur on hot-unplug (and possibly also
         * on hot-plug).
         *
         * XXX We can then check the CPS (Cold Presence State) bit, if
         * supported, to determine if a device is plugged in or not and do
         * the right thing.
         *
         * WARNING:  A PCS interrupt is cleared by clearing DIAG_X, and
         *           can also occur if an unsolicited COMINIT is received.
         *           If this occurs command processing is automatically
         *           stopped (CR goes inactive) and the port must be stopped
         *           and restarted.
         */
        if (is & (SILI_PREG_IST_PHYRDYCHG | SILI_PREG_IST_DEVEXCHG)) {
                /* XXX */
                sili_pwrite(ap, SILI_PREG_SERR,
                        (SILI_PREG_SERR_DIAG_N | SILI_PREG_SERR_DIAG_X));
                sili_pwrite(ap, SILI_PREG_INT_STATUS,
                    is & (SILI_PREG_IST_PHYRDYCHG | SILI_PREG_IST_DEVEXCHG));

                is &= ~(SILI_PREG_IST_PHYRDYCHG | SILI_PREG_IST_DEVEXCHG);
                kprintf("%s: Port change\n", PORTNAME(ap));

                switch (sili_pread(ap, SILI_PREG_SSTS) & SILI_PREG_SSTS_DET) {
                case SILI_PREG_SSTS_DET_DEV:
                        if (ap->ap_type == ATA_PORT_T_NONE &&
                            ap->ap_probe == ATA_PROBE_FAILED) {
                                need = NEED_HOTPLUG_INSERT;
                                goto fatal;
                        }
                        break;
                default:
                        kprintf("%s: Device lost\n", PORTNAME(ap));
                        if (ap->ap_type != ATA_PORT_T_NONE) {
                                need = NEED_HOTPLUG_REMOVE;
                                goto fatal;
                        }
                        break;
                }
        }

        /*
         * Check for remaining errors - they are fatal. (blockable)
         */
        if (is & fatal_mask) {
                u_int32_t serr;

                sili_pwrite(ap, SILI_PREG_INT_STATUS, is & fatal_mask);

                serr = sili_pread(ap, SILI_PREG_SERR);
                kprintf("%s: Unrecoverable errors (IS: %b, SERR: %b), "
                        "disabling port.\n",
                        PORTNAME(ap),
                        is, SILI_PFMT_INT_STATUS,
                        serr, SILI_PFMT_SERR
                );
                is &= ~fatal_mask;
                /* XXX try recovery first */
                goto fatal;
        }

        /*
         * Fail all outstanding commands if we know the port won't recover.
         *
         * We may have a ccb_at if the failed command is known and was
         * being sent to a device over a port multiplier (PM).  In this
         * case if the port itself has not completely failed we fail just
         * the commands related to that target.
         */
        if (ap->ap_state == AP_S_FATAL_ERROR && ap->ap_active) {
fatal:
                kprintf("%s: Interrupt, fatal error\n", PORTNAME(ap));
                ap->ap_state = AP_S_FATAL_ERROR;
/*failall:*/
                /*
                 * Error all the active slots.  If running across a PM
                 * try to error out just the slots related to the target.
                 */
                active = ap->ap_active & ~ap->ap_expired;

                while (active) {
                        slot = ffs(active) - 1;
                        kprintf("%s: Killing slot %d\n", PORTNAME(ap), slot);
                        active &= ~(1 << slot);
                        ccb = &ap->ap_ccbs[slot];
                        sili_core_timeout(ccb);
                }
        }

        /*
         * CCB completion (non blocking).
         *
         * CCB completion is detected by noticing the slot bit in
         * the port slot status register has cleared while the bit
         * is still set in our ap_active variable.
         *
         * When completing expired events we must remember to reinit
         * the port once everything is clear.
         */
        active = ap->ap_active & ~sili_pread(ap, SILI_PREG_SLOTST);

        while (active) {
                slot = ffs(active) - 1;
                ccb = &ap->ap_ccbs[slot];

                DPRINTF(SILI_D_INTR, "%s: slot %d is complete%s\n",
                    PORTNAME(ap), slot, ccb->ccb_xa.state == ATA_S_ERROR ?
                    " (error)" : "");

                active &= ~(1 << slot);

                /*
                 * XXX sync POSTREAD for return data?
                 */
                ap->ap_active &= ~(1 << ccb->ccb_slot);
                --ap->ap_active_cnt;

                /*
                 * Complete the ccb.  If the ccb was marked expired it
                 * may or may not have been cleared from the port,
                 * make sure we mark it as having timed out.
                 *
                 * In a normal completion if AUTOSENSE is set we copy
                 * the PRB LRAM rfis back to the rfis in host-memory.
                 *
                 * XXX Currently AUTOSENSE also forces exclusivity so we
                 *     can safely work around a hardware bug when reading
                 *     the LRAM.
                 */
                if (ap->ap_expired & (1 << ccb->ccb_slot)) {
                        ap->ap_expired &= ~(1 << ccb->ccb_slot);
                        ccb->ccb_xa.state = ATA_S_TIMEOUT;
                        ccb->ccb_done(ccb);
                        ccb->ccb_xa.complete(&ccb->ccb_xa);
                } else {
                        if (ccb->ccb_xa.flags & ATA_F_AUTOSENSE) {
                                memcpy(ccb->ccb_xa.rfis,
                                       &ccb->ccb_prb_lram->prb_d2h,
                                       sizeof(ccb->ccb_prb_lram->prb_d2h));
                        }
                        if (ccb->ccb_xa.state == ATA_S_ONCHIP)
                                ccb->ccb_xa.state = ATA_S_COMPLETE;
                        ccb->ccb_done(ccb);
                }
        }
        if (is & SILI_PREG_IST_READY) {
                is &= ~SILI_PREG_IST_READY;
                sili_pwrite(ap, SILI_PREG_INT_DISABLE, SILI_PREG_INT_READY);
                sili_pwrite(ap, SILI_PREG_INT_STATUS, SILI_PREG_IST_READY);
        }

        /*
         * If we had expired commands and were waiting for
         * remaining commands to complete, and they have now
         * completed, we can reinit the port.
         *
         * This will also clean out the expired commands.
         * The timeout code also calls sili_port_reinit() if
         * the only commands remaining after a timeout are all
         * now expired commands.
         *
         * Otherwise just reissue.
         */
        if (ap->ap_expired && ap->ap_active == ap->ap_expired)
                sili_port_reinit(ap);
        else
                sili_issue_pending_commands(ap, NULL);

        /*
         * Cleanup.  Will not be set if non-blocking.
         */
        switch(need) {
        case NEED_HOTPLUG_INSERT:
                /*
                 * A hot-plug insertion event has occured and all
                 * outstanding commands have already been revoked.
                 *
                 * Don't recurse if this occurs while we are
                 * resetting the port.
                 *
                 * Place the port in a continuous COMRESET state
                 * until the INIT code gets to it.
                 */
                kprintf("%s: HOTPLUG - Device inserted\n",
                        PORTNAME(ap));
                ap->ap_probe = ATA_PROBE_NEED_INIT;
                sili_cam_changed(ap, NULL, -1);
                break;
        case NEED_HOTPLUG_REMOVE:
                /*
                 * A hot-plug removal event has occured and all
                 * outstanding commands have already been revoked.
                 *
                 * Don't recurse if this occurs while we are
                 * resetting the port.
                 */
                kprintf("%s: HOTPLUG - Device removed\n",
                        PORTNAME(ap));
                sili_port_hardstop(ap);
                /* ap_probe set to failed */
                sili_cam_changed(ap, NULL, -1);
                break;
        default:
                break;
        }
}

struct sili_ccb *
sili_get_ccb(struct sili_port *ap)
{
        struct sili_ccb                 *ccb;

        lockmgr(&ap->ap_ccb_lock, LK_EXCLUSIVE);
        ccb = TAILQ_FIRST(&ap->ap_ccb_free);
        if (ccb != NULL) {
                KKASSERT(ccb->ccb_xa.state == ATA_S_PUT);
                TAILQ_REMOVE(&ap->ap_ccb_free, ccb, ccb_entry);
                ccb->ccb_xa.state = ATA_S_SETUP;
                ccb->ccb_xa.at = NULL;
        }
        lockmgr(&ap->ap_ccb_lock, LK_RELEASE);

        return (ccb);
}

void
sili_put_ccb(struct sili_ccb *ccb)
{
        struct sili_port                *ap = ccb->ccb_port;

#ifdef DIAGNOSTIC
        if (ccb->ccb_xa.state != ATA_S_COMPLETE &&
            ccb->ccb_xa.state != ATA_S_TIMEOUT &&
            ccb->ccb_xa.state != ATA_S_ERROR) {
                kprintf("%s: invalid ata_xfer state %02x in sili_put_ccb, "
                        "slot %d\n",
                        PORTNAME(ccb->ccb_port), ccb->ccb_xa.state,
                        ccb->ccb_slot);
        }
#endif

        ccb->ccb_xa.state = ATA_S_PUT;
        lockmgr(&ap->ap_ccb_lock, LK_EXCLUSIVE);
        TAILQ_INSERT_TAIL(&ap->ap_ccb_free, ccb, ccb_entry);
        lockmgr(&ap->ap_ccb_lock, LK_RELEASE);
}

struct sili_ccb *
sili_get_err_ccb(struct sili_port *ap)
{
        struct sili_ccb *err_ccb;

        KKASSERT(sili_pread(ap, SILI_PREG_CI) == 0);
        KKASSERT((ap->ap_flags & AP_F_ERR_CCB_RESERVED) == 0);
        ap->ap_flags |= AP_F_ERR_CCB_RESERVED;

#ifdef DIAGNOSTIC
        KKASSERT(ap->ap_err_busy == 0);
        ap->ap_err_busy = 1;
#endif
        /*
         * Grab a CCB to use for error recovery.  This should never fail, as
         * we ask atascsi to reserve one for us at init time.
         */
        err_ccb = ap->ap_err_ccb;
        KKASSERT(err_ccb != NULL);
        err_ccb->ccb_xa.flags = 0;
        err_ccb->ccb_done = sili_empty_done;

        return err_ccb;
}

void
sili_put_err_ccb(struct sili_ccb *ccb)
{
        struct sili_port *ap = ccb->ccb_port;

#ifdef DIAGNOSTIC
        KKASSERT(ap->ap_err_busy);
#endif
        KKASSERT((ap->ap_flags & AP_F_ERR_CCB_RESERVED) != 0);

        KKASSERT(ccb == ap->ap_err_ccb);

#ifdef DIAGNOSTIC
        ap->ap_err_busy = 0;
#endif
        ap->ap_flags &= ~AP_F_ERR_CCB_RESERVED;
}

/*
 * Read log page to get NCQ error.
 */
int
sili_port_read_ncq_error(struct sili_port *ap, int target)
{
        struct sili_ccb         *ccb;
        struct ata_fis_h2d      *fis;
        int                     rc = EIO;

        DPRINTF(SILI_D_VERBOSE, "%s: read log page\n", PORTNAME(ap));

        /* Prep error CCB for READ LOG EXT, page 10h, 1 sector. */
        ccb = sili_get_err_ccb(ap);
        ccb->ccb_done = sili_empty_done;
        ccb->ccb_xa.flags = ATA_F_NOWAIT | ATA_F_READ | ATA_F_POLL;
        ccb->ccb_xa.data = ap->ap_err_scratch;
        ccb->ccb_xa.datalen = 512;
        ccb->ccb_xa.complete = sili_dummy_done;
        ccb->ccb_xa.at = &ap->ap_ata[target];
        fis = &ccb->ccb_prb->prb_h2d;
        bzero(fis, sizeof(*fis));

        fis->type = ATA_FIS_TYPE_H2D;
        fis->flags = ATA_H2D_FLAGS_CMD | target;
        fis->command = ATA_C_READ_LOG_EXT;
        fis->lba_low = 0x10;            /* queued error log page (10h) */
        fis->sector_count = 1;          /* number of sectors (1) */
        fis->sector_count_exp = 0;
        fis->lba_mid = 0;               /* starting offset */
        fis->lba_mid_exp = 0;
        fis->device = 0;

        if (sili_load_prb(ccb) != 0) {
                rc = ENOMEM;    /* XXX caller must abort all commands */
        } else {
                ccb->ccb_xa.state = ATA_S_PENDING;
                rc = sili_poll(ccb, 1000, sili_quick_timeout);
        }

        /* Abort our command, if it failed, by stopping command DMA. */
        if (rc) {
                kprintf("%s: log page read failed, slot %d was still active.\n",
                        ATANAME(ap, ccb->ccb_xa.at), ccb->ccb_slot);
        }

        /* Done with the error CCB now. */
        sili_unload_prb(ccb);
        sili_put_err_ccb(ccb);

        /* Extract failed register set and tags from the scratch space. */
        if (rc == 0) {
                struct ata_log_page_10h         *log;
                int                             err_slot;

                log = (struct ata_log_page_10h *)ap->ap_err_scratch;
                if (log->err_regs.type & ATA_LOG_10H_TYPE_NOTQUEUED) {
                        /* Not queued bit was set - wasn't an NCQ error? */
                        kprintf("%s: read NCQ error page, but not an NCQ "
                                "error?\n",
                                PORTNAME(ap));
                        rc = ESRCH;
                } else {
                        /* Copy back the log record as a D2H register FIS. */
                        err_slot = log->err_regs.type &
                                   ATA_LOG_10H_TYPE_TAG_MASK;
                        ccb = &ap->ap_ccbs[err_slot];
                        if (ap->ap_expired & (1 << ccb->ccb_slot)) {
                                kprintf("%s: read NCQ error page ok\n",
                                        ATANAME(ap, ccb->ccb_xa.at));
                                memcpy(&ccb->ccb_prb->prb_d2h, &log->err_regs,
                                        sizeof(struct ata_fis_d2h));
                                ccb->ccb_prb->prb_d2h.type = ATA_FIS_TYPE_D2H;
                                ccb->ccb_prb->prb_d2h.flags = 0;
                        } else {
                                kprintf("%s: error log slot %d did not match a failed ccb!\n", ATANAME(ccb->ccb_port, ccb->ccb_xa.at), err_slot);
                        }
                }
        }

        return (rc);
}

/*
 * Allocate memory for various structures DMAd by hardware.  The maximum
 * number of segments for these tags is 1 so the DMA memory will have a
 * single physical base address.
 */
struct sili_dmamem *
sili_dmamem_alloc(struct sili_softc *sc, bus_dma_tag_t tag)
{
        struct sili_dmamem *adm;
        int     error;

        adm = kmalloc(sizeof(*adm), M_DEVBUF, M_INTWAIT | M_ZERO);

        error = bus_dmamem_alloc(tag, (void **)&adm->adm_kva,
                                 BUS_DMA_ZERO, &adm->adm_map);
        if (error == 0) {
                adm->adm_tag = tag;
                error = bus_dmamap_load(tag, adm->adm_map,
                                        adm->adm_kva,
                                        bus_dma_tag_getmaxsize(tag),
                                        sili_dmamem_saveseg, &adm->adm_busaddr,
                                        0);
        }
        if (error) {
                if (adm->adm_map) {
                        bus_dmamap_destroy(tag, adm->adm_map);
                        adm->adm_map = NULL;
                        adm->adm_tag = NULL;
                        adm->adm_kva = NULL;
                }
                kfree(adm, M_DEVBUF);
                adm = NULL;
        }
        return (adm);
}

static
void
sili_dmamem_saveseg(void *info, bus_dma_segment_t *segs, int nsegs, int error)
{
        KKASSERT(error == 0);
        KKASSERT(nsegs == 1);
        *(bus_addr_t *)info = segs->ds_addr;
}


void
sili_dmamem_free(struct sili_softc *sc, struct sili_dmamem *adm)
{
        if (adm->adm_map) {
                bus_dmamap_unload(adm->adm_tag, adm->adm_map);
                bus_dmamap_destroy(adm->adm_tag, adm->adm_map);
                adm->adm_map = NULL;
                adm->adm_tag = NULL;
                adm->adm_kva = NULL;
        }
        kfree(adm, M_DEVBUF);
}

u_int32_t
sili_read(struct sili_softc *sc, bus_size_t r)
{
        bus_space_barrier(sc->sc_iot, sc->sc_ioh, r, 4,
                          BUS_SPACE_BARRIER_READ);
        return (bus_space_read_4(sc->sc_iot, sc->sc_ioh, r));
}

void
sili_write(struct sili_softc *sc, bus_size_t r, u_int32_t v)
{
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, r, v);
        bus_space_barrier(sc->sc_iot, sc->sc_ioh, r, 4,
                          BUS_SPACE_BARRIER_WRITE);
}

u_int32_t
sili_pread(struct sili_port *ap, bus_size_t r)
{
        bus_space_barrier(ap->ap_sc->sc_iot, ap->ap_ioh, r, 4,
                          BUS_SPACE_BARRIER_READ);
        return (bus_space_read_4(ap->ap_sc->sc_iot, ap->ap_ioh, r));
}

void
sili_pwrite(struct sili_port *ap, bus_size_t r, u_int32_t v)
{
        bus_space_write_4(ap->ap_sc->sc_iot, ap->ap_ioh, r, v);
        bus_space_barrier(ap->ap_sc->sc_iot, ap->ap_ioh, r, 4,
                          BUS_SPACE_BARRIER_WRITE);
}

/*
 * Wait up to (timeout) milliseconds for the masked port register to
 * match the target.
 *
 * Timeout is in milliseconds.
 */
int
sili_pwait_eq(struct sili_port *ap, int timeout,
              bus_size_t r, u_int32_t mask, u_int32_t target)
{
        int     t;

        /*
         * Loop hard up to 100uS
         */
        for (t = 0; t < 100; ++t) {
                if ((sili_pread(ap, r) & mask) == target)
                        return (0);
                sili_os_hardsleep(1);   /* us */
        }

        do {
                timeout -= sili_os_softsleep();
                if ((sili_pread(ap, r) & mask) == target)
                        return (0);
        } while (timeout > 0);
        return (1);
}

int
sili_wait_ne(struct sili_softc *sc, bus_size_t r, u_int32_t mask,
             u_int32_t target)
{
        int     t;

        /*
         * Loop hard up to 100uS
         */
        for (t = 0; t < 100; ++t) {
                if ((sili_read(sc, r) & mask) != target)
                        return (0);
                sili_os_hardsleep(1);   /* us */
        }

        /*
         * And one millisecond the slow way
         */
        t = 1000;
        do {
                t -= sili_os_softsleep();
                if ((sili_read(sc, r) & mask) != target)
                        return (0);
        } while (t > 0);

        return (1);
}


/*
 * Acquire an ata transfer.
 *
 * Pass a NULL at for direct-attached transfers, and a non-NULL at for
 * targets that go through the port multiplier.
 */
struct ata_xfer *
sili_ata_get_xfer(struct sili_port *ap, struct ata_port *at)
{
        struct sili_ccb         *ccb;

        ccb = sili_get_ccb(ap);
        if (ccb == NULL) {
                DPRINTF(SILI_D_XFER, "%s: sili_ata_get_xfer: NULL ccb\n",
                    PORTNAME(ap));
                return (NULL);
        }

        DPRINTF(SILI_D_XFER, "%s: sili_ata_get_xfer got slot %d\n",
            PORTNAME(ap), ccb->ccb_slot);

        bzero(ccb->ccb_xa.fis, sizeof(*ccb->ccb_xa.fis));
        ccb->ccb_xa.at = at;
        ccb->ccb_xa.fis->type = ATA_FIS_TYPE_H2D;

        return (&ccb->ccb_xa);
}

void
sili_ata_put_xfer(struct ata_xfer *xa)
{
        struct sili_ccb                 *ccb = (struct sili_ccb *)xa;

        DPRINTF(SILI_D_XFER, "sili_ata_put_xfer slot %d\n", ccb->ccb_slot);

        sili_put_ccb(ccb);
}

int
sili_ata_cmd(struct ata_xfer *xa)
{
        struct sili_ccb                 *ccb = (struct sili_ccb *)xa;

        KKASSERT(xa->state == ATA_S_SETUP);

        if (ccb->ccb_port->ap_state == AP_S_FATAL_ERROR)
                goto failcmd;
#if 0
        kprintf("%s: started std command %b ccb %d ccb_at %p %d\n",
                ATANAME(ccb->ccb_port, ccb->ccb_xa.at),
                sili_pread(ccb->ccb_port, SILI_PREG_CMD), SILI_PFMT_CMD,
                ccb->ccb_slot,
                ccb->ccb_xa.at,
                ccb->ccb_xa.at ? ccb->ccb_xa.at->at_target : -1);
#endif

        ccb->ccb_done = sili_ata_cmd_done;

        if (sili_load_prb(ccb) != 0)
                goto failcmd;

        xa->state = ATA_S_PENDING;

        if (xa->flags & ATA_F_POLL)
                return (sili_poll(ccb, xa->timeout, sili_ata_cmd_timeout));

        crit_enter();
        KKASSERT((xa->flags & ATA_F_TIMEOUT_EXPIRED) == 0);
        xa->flags |= ATA_F_TIMEOUT_DESIRED;
        sili_start(ccb);
        crit_exit();
        return (xa->state);

failcmd:
        crit_enter();
        xa->state = ATA_S_ERROR;
        xa->complete(xa);
        crit_exit();
        return (ATA_S_ERROR);
}

static void
sili_ata_cmd_done(struct sili_ccb *ccb)
{
        struct ata_xfer                 *xa = &ccb->ccb_xa;

        /*
         * NOTE: callout does not lock port and may race us modifying
         * the flags, so make sure its stopped.
         */
        if (xa->flags & ATA_F_TIMEOUT_RUNNING) {
                callout_stop(&ccb->ccb_timeout);
                xa->flags &= ~ATA_F_TIMEOUT_RUNNING;
        }
        xa->flags &= ~(ATA_F_TIMEOUT_DESIRED | ATA_F_TIMEOUT_EXPIRED);

        KKASSERT(xa->state != ATA_S_ONCHIP);
        sili_unload_prb(ccb);

#ifdef DIAGNOSTIC
        else if (xa->state != ATA_S_ERROR && xa->state != ATA_S_TIMEOUT)
                kprintf("%s: invalid ata_xfer state %02x in sili_ata_cmd_done, "
                        "slot %d\n",
                        PORTNAME(ccb->ccb_port), xa->state, ccb->ccb_slot);
#endif
        if (xa->state != ATA_S_TIMEOUT)
                xa->complete(xa);
}

/*
 * Timeout from callout, MPSAFE - nothing can mess with the CCB's flags
 * while the callout is runing.
 *
 * We can't safely get the port lock here or delay, we could block
 * the callout thread.
 */
static void
sili_ata_cmd_timeout_unserialized(void *arg)
{
        struct sili_ccb         *ccb = arg;
        struct sili_port        *ap = ccb->ccb_port;

        ccb->ccb_xa.flags &= ~ATA_F_TIMEOUT_RUNNING;
        ccb->ccb_xa.flags |= ATA_F_TIMEOUT_EXPIRED;
        sili_os_signal_port_thread(ap, AP_SIGF_TIMEOUT);
}

void
sili_ata_cmd_timeout(struct sili_ccb *ccb)
{
        sili_core_timeout(ccb);
}

/*
 * Timeout code, typically called when the port command processor is running.
 *
 * Returns 0 if all timeout processing completed, non-zero if it is still
 * in progress.
 */
static
int
sili_core_timeout(struct sili_ccb *ccb)
{
        struct ata_xfer         *xa = &ccb->ccb_xa;
        struct sili_port        *ap = ccb->ccb_port;
        struct ata_port         *at;

        at = ccb->ccb_xa.at;

        kprintf("%s: CMD TIMEOUT state=%d slot=%d\n"
                "\t active=%08x\n"
                "\texpired=%08x\n"
                "\thactive=%08x\n",
                ATANAME(ap, at),
                ccb->ccb_xa.state, ccb->ccb_slot,
                ap->ap_active,
                ap->ap_expired,
                sili_pread(ap, SILI_PREG_SLOTST)
        );

        /*
         * NOTE: Timeout will not be running if the command was polled.
         *       If we got here at least one of these flags should be set.
         *
         *       However, it might be running if we are called from the
         *       interrupt error handling code.
         */
        KKASSERT(xa->flags & (ATA_F_POLL | ATA_F_TIMEOUT_DESIRED |
                              ATA_F_TIMEOUT_RUNNING));
        if (xa->flags & ATA_F_TIMEOUT_RUNNING) {
                callout_stop(&ccb->ccb_timeout);
                xa->flags &= ~ATA_F_TIMEOUT_RUNNING;
        }
        xa->flags &= ~ATA_F_TIMEOUT_EXPIRED;

        if (ccb->ccb_xa.state == ATA_S_PENDING) {
                TAILQ_REMOVE(&ap->ap_ccb_pending, ccb, ccb_entry);
                ccb->ccb_xa.state = ATA_S_TIMEOUT;
                ccb->ccb_done(ccb);
                xa->complete(xa);
                sili_issue_pending_commands(ap, NULL);
                return(1);
        }
        if (ccb->ccb_xa.state != ATA_S_ONCHIP) {
                kprintf("%s: Unexpected state during timeout: %d\n",
                        ATANAME(ap, at), ccb->ccb_xa.state);
                return(1);
        }

        /*
         * We can't process timeouts while other commands are running.
         */
        ap->ap_expired |= 1 << ccb->ccb_slot;

        if (ap->ap_active != ap->ap_expired) {
                kprintf("%s: Deferred timeout until its safe, slot %d\n",
                        ATANAME(ap, at), ccb->ccb_slot);
                return(1);
        }

        /*
         * We have to issue a Port reinit.  We don't read an error log
         * page for timeouts.  Reiniting the port will clear all pending
         * commands.
         */
        sili_port_reinit(ap);
        return(0);
}

/*
 * Used by the softreset, pmprobe, and read_ncq_error only, in very
 * specialized, controlled circumstances.
 */
void
sili_quick_timeout(struct sili_ccb *ccb)
{
        struct sili_port *ap = ccb->ccb_port;

        switch (ccb->ccb_xa.state) {
        case ATA_S_PENDING:
                TAILQ_REMOVE(&ap->ap_ccb_pending, ccb, ccb_entry);
                ccb->ccb_xa.state = ATA_S_TIMEOUT;
                break;
        case ATA_S_ONCHIP:
                KKASSERT((ap->ap_active & ~ap->ap_expired) ==
                         (1 << ccb->ccb_slot));
                ccb->ccb_xa.state = ATA_S_TIMEOUT;
                ap->ap_active &= ~(1 << ccb->ccb_slot);
                KKASSERT(ap->ap_active_cnt > 0);
                --ap->ap_active_cnt;
                sili_port_reinit(ap);
                break;
        default:
                panic("%s: sili_quick_timeout: ccb in bad state %d",
                      ATANAME(ap, ccb->ccb_xa.at), ccb->ccb_xa.state);
        }
}

static void
sili_dummy_done(struct ata_xfer *xa)
{
}

static void
sili_empty_done(struct sili_ccb *ccb)
{
}