/*      $NetBSD: mscp.c,v 1.39 2024/01/11 06:19:49 mrg Exp $    */

/*
* Copyright (c) 1988 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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 University 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 REGENTS 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 REGENTS 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.
*
*      @(#)mscp.c      7.5 (Berkeley) 12/16/90
*/

/*
* Copyright (c) 1996 Ludd, University of Lule}, Sweden.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
*
*      @(#)mscp.c      7.5 (Berkeley) 12/16/90
*/

/*
* MSCP generic driver routines
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mscp.c,v 1.39 2024/01/11 06:19:49 mrg Exp $");

#include <sys/param.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/device.h>
#include <sys/proc.h>
#include <sys/systm.h>

#include <sys/bus.h>

#include <dev/mscp/mscp.h>
#include <dev/mscp/mscpreg.h>
#include <dev/mscp/mscpvar.h>

#define PCMD    PSWP            /* priority for command packet waits */

/*
* Get a command packet.  Second argument is true iff we are
* to wait if necessary.  Return NULL if none are available and
* we cannot wait.
*/
struct mscp *
mscp_getcp(struct mscp_softc *mi, int canwait)
{
#define mri     (&mi->mi_cmd)
       struct mscp *mp;
       int i;
       int s = spluba();

again:
       /*
        * Ensure that we have some command credits, and
        * that the next command packet is free.
        */
       if (mi->mi_credits <= MSCP_MINCREDITS) {
               if (!canwait) {
                       splx(s);
                       return (NULL);
               }
               mi->mi_wantcredits = 1;
               (void) tsleep(&mi->mi_wantcredits, PCMD, "mscpwcrd", 0);
               goto again;
       }
       i = mri->mri_next;
       if (mri->mri_desc[i] & MSCP_OWN) {
               if (!canwait) {
                       splx(s);
                       return (NULL);
               }
               mi->mi_wantcmd = 1;
               (void) tsleep(&mi->mi_wantcmd, PCMD, "mscpwcmd", 0);
               goto again;
       }
       mi->mi_credits--;
       mri->mri_desc[i] &= ~MSCP_INT;
       mri->mri_next = (mri->mri_next + 1) % mri->mri_size;
       splx(s);
       mp = &mri->mri_ring[i];

       /*
        * Initialise some often-zero fields.
        * ARE THE LAST TWO NECESSARY IN GENERAL?  IT SURE WOULD BE
        * NICE IF DEC SOLD DOCUMENTATION FOR THEIR OWN CONTROLLERS.
        */
       mp->mscp_msglen = MSCP_MSGLEN;
       mp->mscp_flags = 0;
       mp->mscp_modifier = 0;
       mp->mscp_seq.seq_bytecount = 0;
       mp->mscp_seq.seq_buffer = 0;
       mp->mscp_seq.seq_mapbase = 0;
/*???*/ mp->mscp_sccc.sccc_errlgfl = 0;
/*???*/ mp->mscp_sccc.sccc_copyspd = 0;
       return (mp);
#undef  mri
}

#ifdef AVOID_EMULEX_BUG
int     mscp_aeb_xor = 0x8000bb80;
#endif

/*
* Handle a response ring transition.
*/
void
mscp_dorsp(struct mscp_softc *mi)
{
       device_t drive;
       struct mscp_device *me = mi->mi_me;
       struct mscp_ctlr *mc = mi->mi_mc;
       struct buf *bp;
       struct mscp *mp;
       struct mscp_xi *mxi;
       int nextrsp;
       int st, error;
       extern struct mscp mscp_cold_reply;
       extern int mscp_cold_unit;

       nextrsp = mi->mi_rsp.mri_next;
loop:
       if (mi->mi_rsp.mri_desc[nextrsp] & MSCP_OWN) {
               /*
                * No more responses.  Remember the next expected
                * response index.  Check to see if we have some
                * credits back, and wake up sleepers if so.
                */
               mi->mi_rsp.mri_next = nextrsp;
               if (mi->mi_wantcredits && mi->mi_credits > MSCP_MINCREDITS) {
                       mi->mi_wantcredits = 0;
                       wakeup((void *) &mi->mi_wantcredits);
               }
               return;
       }

       mp = &mi->mi_rsp.mri_ring[nextrsp];
       mi->mi_credits += MSCP_CREDITS(mp->mscp_msgtc);
       /*
        * Controllers are allowed to interrupt as any drive, so we
        * must check the command before checking for a drive.
        */
       if (mp->mscp_opcode == (M_OP_SETCTLRC | M_OP_END)) {
               if ((mp->mscp_status & M_ST_MASK) == M_ST_SUCCESS) {
                       mi->mi_flags |= MSC_READY;
               } else {
                       printf("%s: SETCTLRC failed: %d ",
                           device_xname(mi->mi_dev), mp->mscp_status);
                       mscp_printevent(mp);
               }
               goto done;
       }

       /*
        * Found a response.  Update credit information.  If there is
        * nothing else to do, jump to `done' to get the next response.
        */
       if (mp->mscp_unit >= mi->mi_driveno) { /* Must expand drive table */
               int tmpno = (mp->mscp_unit + 32) & ~31;
               device_t *tmp = (device_t *)
                   malloc(tmpno * sizeof(tmp[0]), M_DEVBUF, M_NOWAIT|M_ZERO);
               /* XXX tmp should be checked for NULL */
               if (mi->mi_driveno) {
                       memcpy(tmp, mi->mi_dp, mi->mi_driveno * sizeof(tmp[0]));
                       free(mi->mi_dp, M_DEVBUF);
               }
               mi->mi_driveno = tmpno;
               mi->mi_dp = tmp;
       }

       drive = mi->mi_dp[mp->mscp_unit];

       switch (MSCP_MSGTYPE(mp->mscp_msgtc)) {

       case MSCPT_SEQ:
               break;

       case MSCPT_DATAGRAM:
               (*me->me_dgram)(drive, mp, mi);
               goto done;

       case MSCPT_CREDITS:
               goto done;

       case MSCPT_MAINTENANCE:
       default:
               printf("%s: unit %d: unknown message type 0x%x ignored\n",
                       device_xname(mi->mi_dev), mp->mscp_unit,
                       MSCP_MSGTYPE(mp->mscp_msgtc));
               goto done;
       }

       /*
        * Handle individual responses.
        */
       st = mp->mscp_status & M_ST_MASK;
       error = 0;
       switch (mp->mscp_opcode) {

       case M_OP_END:
               /*
                * The controller presents a bogus END packet when
                * a read/write command is given with an illegal
                * block number.  This is contrary to the MSCP
                * specification (ENDs are to be given only for
                * invalid commands), but that is the way of it.
                */
               if (st == M_ST_INVALCMD && mp->mscp_cmdref != 0) {
                       printf("%s: bad lbn (%d)?\n", device_xname(drive),
                               (int)mp->mscp_seq.seq_lbn);
                       error = EIO;
                       goto rwend;
               }
               goto unknown;

       case M_OP_ONLINE | M_OP_END:
               /*
                * Finished an ON LINE request.  Call the driver to
                * find out whether it succeeded.  If so, mark it on
                * line.
                */
               (*me->me_online)(drive, mp);
               break;

       case M_OP_GETUNITST | M_OP_END:
               /*
                * Got unit status.  If we are autoconfiguring, save
                * the mscp struct so that mscp_attach know what to do.
                * If the drive isn't configured, call config_found()
                * to set it up, otherwise it's just a "normal" unit
                * status.
                */
               if (cold) {
                       memcpy(&mscp_cold_reply, mp, sizeof(struct mscp));
                       /* Detect that we've reached the end of all units */
                       if (mp->mscp_unit < mscp_cold_unit)
                               break;
               }

               if (mp->mscp_status == (M_ST_OFFLINE|M_OFFLINE_UNKNOWN))
                       break;

               if (drive == 0) {
                       struct mscp_work *mw;

                       mutex_spin_enter(&mi->mi_mtx);

                       mw = SLIST_FIRST(&mi->mi_freelist);
                       if (mw == NULL) {
                               aprint_error_dev(mi->mi_dev,
                                   "couldn't attach drive (no free items)\n");
                               mutex_spin_exit(&mi->mi_mtx);
                       } else {
                               SLIST_REMOVE_HEAD(&mi->mi_freelist, mw_list);
                               mutex_spin_exit(&mi->mi_mtx);

                               mw->mw_mi = mi;
                               mw->mw_mp = *mp;
                               mw->mw_online = false;
                               workqueue_enqueue(mi->mi_wq,
                                   (struct work *)mw, NULL);
                       }
               } else
                       /* Hack to avoid complaints */
                       if (!(((mp->mscp_event & M_ST_MASK) == M_ST_AVAILABLE)
                           && cold))
                               (*me->me_gotstatus)(drive, mp);
               break;

       case M_OP_AVAILATTN:
               /*
                * The drive went offline and we did not notice.
                * Mark it off line now, to force an on line request
                * next, so we can make sure it is still the same
                * drive.
                *
                * IF THE UDA DRIVER HAS A COMMAND AWAITING UNIBUS
                * RESOURCES, THAT COMMAND MAY GO OUT BEFORE THE ON
                * LINE.  IS IT WORTH FIXING??
                */
#ifdef notyet
               (*md->md_offline)(ui, mp);
#endif
               break;

       case M_OP_POS | M_OP_END:
       case M_OP_WRITM | M_OP_END:
       case M_OP_AVAILABLE | M_OP_END:
               /*
                * A non-data transfer operation completed.
                */
               (*me->me_cmddone)(drive, mp);
               break;

       case M_OP_READ | M_OP_END:
       case M_OP_WRITE | M_OP_END:
               /*
                * A transfer finished.  Get the buffer, and release its
                * map registers via ubadone().  If the command finished
                * with an off line or available status, the drive went
                * off line (the idiot controller does not tell us until
                * it comes back *on* line, or until we try to use it).
                */
rwend:
#ifdef DIAGNOSTIC
               if (mp->mscp_cmdref >= NCMD) {
                       /*
                        * No buffer means there is a bug somewhere!
                        */
                       printf("%s: io done, but bad xfer number?\n",
                           device_xname(drive));
                       mscp_hexdump(mp);
                       break;
               }
#endif

               if (mp->mscp_cmdref == -1) {
                       (*me->me_cmddone)(drive, mp);
                       break;
               }
               mxi = &mi->mi_xi[mp->mscp_cmdref];
               if (mxi->mxi_inuse == 0)
                       panic("mxi not inuse");
               bp = mxi->mxi_bp;
               /*
                * Mark any error-due-to-bad-LBN (via `goto rwend').
                * WHAT STATUS WILL THESE HAVE?  IT SURE WOULD BE NICE
                * IF DEC SOLD DOCUMENTATION FOR THEIR OWN CONTROLLERS.
                */
               bp->b_error = error;
               if (st == M_ST_OFFLINE || st == M_ST_AVAILABLE) {
#ifdef notyet
                       (*md->md_offline)(ui, mp);
#endif
               }

               /*
                * If the transfer failed, give the driver a crack
                * at fixing things up.
                */
               if (st != M_ST_SUCCESS) {
                       switch ((*me->me_ioerr)(drive, mp, bp)) {

                       case MSCP_DONE:         /* fixed */
                               break;

                       case MSCP_RESTARTED:    /* still working on it */
                               goto out;

                       case MSCP_FAILED:       /* no luck */
                               /* XXX must move to ra.c */
                               mscp_printevent(mp);
                               break;
                       }
               }

               /*
                * Set the residual count and mark the transfer as
                * done.  If the I/O wait queue is now empty, release
                * the shared BDP, if any.
                */
               bp->b_resid = bp->b_bcount - mp->mscp_seq.seq_bytecount;
               bus_dmamap_unload(mi->mi_dmat, mxi->mxi_dmam);

               (*mc->mc_ctlrdone)(device_parent(mi->mi_dev));
               (*me->me_iodone)(drive, bp);
out:
               mxi->mxi_inuse = 0;
               mi->mi_mxiuse |= (1 << mp->mscp_cmdref);
               break;

       case M_OP_REPLACE | M_OP_END:
               /*
                * A replace operation finished.  Just let the driver
                * handle it (if it does replaces).
                */
               if (me->me_replace == NULL)
                       printf("%s: bogus REPLACE end\n", device_xname(drive));
               else
                       (*me->me_replace)(drive, mp);
               break;

       default:
               /*
                * If it is not one of the above, we cannot handle it.
                * (And we should not have received it, for that matter.)
                */
unknown:
               printf("%s: unknown opcode 0x%x status 0x%x ignored\n",
                       device_xname(drive), mp->mscp_opcode, mp->mscp_status);
#ifdef DIAGNOSTIC
               mscp_hexdump(mp);
#endif
               break;
       }

       /*
        * If the drive needs to be put back in the controller queue,
        * do that now.  (`bp' below ought to be `dp', but they are all
        * struct buf *.)  Note that b_active was cleared in the driver;
        * we presume that there is something to be done, hence reassert it.
        */
#ifdef notyet /* XXX */
       if (ui->ui_flags & UNIT_REQUEUE) {
               ...
       }
#endif
done:
       /*
        * Give back the response packet, and take a look at the next.
        */
       mp->mscp_msglen = MSCP_MSGLEN;
       mi->mi_rsp.mri_desc[nextrsp] |= MSCP_OWN;
       nextrsp = (nextrsp + 1) % mi->mi_rsp.mri_size;
       goto loop;
}

/*
* Requeue outstanding transfers, e.g., after bus reset.
* Also requeue any drives that have on line or unit status
* info pending.
*/
void
mscp_requeue(struct mscp_softc *mi)
{
       panic("mscp_requeue");
}

/*
* mscp_worker: Complete configuration and online events.
*
* If the new work mw_online is false, this is an autoconfiguration
* event, otherwise it is a online event that needs to be handled
* in a thread context.
*/
void
mscp_worker(struct work *wk, void *arg)
{
       struct mscp_work *mw = (struct mscp_work *)wk;
       struct mscp_softc *mi = mw->mw_mi;
       struct drive_attach_args da;

       /* This is an online event. */
       if (mw->mw_online) {
               struct mscp_device *me = mi->mi_me;

               if (me->me_online_cb)
                       return (*me->me_online_cb)(wk);
               /* Must be cb for this type. */
               panic("mscp_worker");
       }

       da.da_mp = &mw->mw_mp;
       da.da_typ = mi->mi_type;

       config_found(mi->mi_dev, (void *)&da, mscp_print, CFARGS_NONE);

       mutex_spin_enter(&mi->mi_mtx);
       SLIST_INSERT_HEAD(&mw->mw_mi->mi_freelist, mw, mw_list);
       mutex_spin_exit(&mi->mi_mtx);
}