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Annotation of researchv8dc/sys/dev/mba.c, revision 1.1

1.1     ! root        1: /*     mba.c   4.20    81/05/09        */
        !             2: 
        !             3: #include "mba.h"
        !             4: #if NMBA > 0
        !             5: /*
        !             6:  * Massbus driver, arbitrates a massbus among attached devices.
        !             7:  */
        !             8: #include "../h/param.h"
        !             9: #include "../h/systm.h"
        !            10: #include "../h/dk.h"
        !            11: #include "../h/buf.h"
        !            12: #include "../h/conf.h"
        !            13: #include "../h/dir.h"
        !            14: #include "../h/user.h"
        !            15: #include "../h/proc.h"
        !            16: #include "../h/map.h"
        !            17: #include "../h/pte.h"
        !            18: #include "../h/mbareg.h"
        !            19: #include "../h/mbavar.h"
        !            20: #include "../h/mtpr.h"
        !            21: #include "../h/vm.h"
        !            22: 
        !            23: char   mbsr_bits[] = MBSR_BITS;
        !            24: 
        !            25: #define MTRDREV 1      /* enable mag tape read backwards error recovery */
        !            26: 
        !            27: /*
        !            28:  * Start activity on a massbus device.
        !            29:  * We are given the device's mba_device structure and activate
        !            30:  * the device via the unit start routine.  The unit start
        !            31:  * routine may indicate that it is finished (e.g. if the operation
        !            32:  * was a ``sense'' on a tape drive), that the (multi-ported) unit
        !            33:  * is busy (we will get an interrupt later), that it started the
        !            34:  * unit (e.g. for a non-data transfer operation), or that it has
        !            35:  * set up a data transfer operation and we should start the massbus adaptor.
        !            36:  */
        !            37: mbustart(mi)
        !            38:        register struct mba_device *mi;
        !            39: {
        !            40:        register struct buf *bp;        /* i/o operation at head of queue */
        !            41:        register struct mba_hd *mhp;    /* header for mba device is on */
        !            42: 
        !            43: loop:
        !            44:        /*
        !            45:         * Get the first thing to do off device queue.
        !            46:         */
        !            47:        bp = mi->mi_tab.b_actf;
        !            48:        if (bp == NULL)
        !            49:                return;
        !            50:        /*
        !            51:         * Let the drivers unit start routine have at it
        !            52:         * and then process the request further, per its instructions.
        !            53:         */
        !            54:        switch ((*mi->mi_driver->md_ustart)(mi)) {
        !            55: 
        !            56:        case MBU_NEXT:          /* request is complete (e.g. ``sense'') */
        !            57:                mi->mi_tab.b_active = 0;
        !            58:                mi->mi_tab.b_errcnt = 0;
        !            59:                mi->mi_tab.b_actf = bp->av_forw;
        !            60:                iodone(bp);
        !            61:                goto loop;
        !            62: 
        !            63:        case MBU_DODATA:        /* all ready to do data transfer */
        !            64:                /*
        !            65:                 * Queue the device mba_device structure on the massbus
        !            66:                 * mba_hd structure for processing as soon as the
        !            67:                 * data path is available.
        !            68:                 */
        !            69:                mhp = mi->mi_hd;
        !            70:                mi->mi_forw = NULL;
        !            71:                if (mhp->mh_actf == NULL)
        !            72:                        mhp->mh_actf = mi;
        !            73:                else
        !            74:                        mhp->mh_actl->mi_forw = mi;
        !            75:                mhp->mh_actl = mi;
        !            76:                /*
        !            77:                 * If data path is idle, start transfer now.
        !            78:                 * In any case the device is ``active'' waiting for the
        !            79:                 * data to transfer.
        !            80:                 */
        !            81:                mi->mi_tab.b_active = 1;
        !            82:                if (mhp->mh_active == 0)
        !            83:                        mbstart(mhp);
        !            84:                return;
        !            85: 
        !            86:        case MBU_STARTED:       /* driver started a non-data transfer */
        !            87:                /*
        !            88:                 * Mark device busy during non-data transfer
        !            89:                 * and count this as a ``seek'' on the device.
        !            90:                 */
        !            91:                if (mi->mi_dk >= 0) {
        !            92:                        dk_seek[mi->mi_dk]++;
        !            93:                        dk_busy |= (1 << mi->mi_dk);
        !            94:                }
        !            95:                mi->mi_tab.b_active = 1;
        !            96:                return;
        !            97: 
        !            98:        case MBU_BUSY:          /* dual port drive busy */
        !            99:                /*
        !           100:                 * We mark the device structure so that when an
        !           101:                 * interrupt occurs we will know to restart the unit.
        !           102:                 */
        !           103:                mi->mi_tab.b_flags |= B_BUSY;
        !           104:                return;
        !           105: 
        !           106:        default:
        !           107:                panic("mbustart");
        !           108:        }
        !           109: }
        !           110: 
        !           111: /*
        !           112:  * Start an i/o operation on the massbus specified by the argument.
        !           113:  * We peel the first operation off its queue and insure that the drive
        !           114:  * is present and on-line.  We then use the drivers start routine
        !           115:  * (if any) to prepare the drive, setup the massbus map for the transfer
        !           116:  * and start the transfer.
        !           117:  */
        !           118: mbstart(mhp)
        !           119:        register struct mba_hd *mhp;
        !           120: {
        !           121:        register struct mba_device *mi;
        !           122:        struct buf *bp;
        !           123:        register struct mba_regs *mbp;
        !           124:        register int com;
        !           125: 
        !           126: loop:
        !           127:        /*
        !           128:         * Look for an operation at the front of the queue.
        !           129:         */
        !           130:        if ((mi = mhp->mh_actf) == NULL) {
        !           131:                return;
        !           132:        }
        !           133:        if ((bp = mi->mi_tab.b_actf) == NULL) {
        !           134:                mhp->mh_actf = mi->mi_forw;
        !           135:                goto loop;
        !           136:        }
        !           137:        /*
        !           138:         * If this device isn't present and on-line, then
        !           139:         * we screwed up, and can't really do the operation.
        !           140:         * Check only for non-tape drives, as the tape drivers
        !           141:         * check ONLINE themselves.  Also, TU78 registers are different.
        !           142:         */
        !           143:        if ((mi->mi_drv->mbd_dt & MBDT_TAP) == 0)
        !           144:        if ((mi->mi_drv->mbd_ds & MBDS_DREADY) != MBDS_DREADY) {
        !           145:                printf("%s%d: not ready\n", mi->mi_driver->md_dname,
        !           146:                    dkunit(bp));
        !           147:                mi->mi_tab.b_actf = bp->av_forw;
        !           148:                mi->mi_tab.b_errcnt = 0;
        !           149:                mi->mi_tab.b_active = 0;
        !           150:                bp->b_flags |= B_ERROR;
        !           151:                iodone(bp);
        !           152:                goto loop;
        !           153:        }
        !           154:        /*
        !           155:         * We can do the operation; mark the massbus active
        !           156:         * and let the device start routine setup any necessary
        !           157:         * device state for the transfer (e.g. desired cylinder, etc
        !           158:         * on disks).
        !           159:         */
        !           160:        mhp->mh_active = 1;
        !           161:        if (mi->mi_driver->md_start) {
        !           162:                if ((com = (*mi->mi_driver->md_start)(mi)) == 0)
        !           163:                        com = (bp->b_flags & B_READ) ?
        !           164:                            MB_RCOM|MB_GO : MB_WCOM|MB_GO;
        !           165:        } else
        !           166:                com = (bp->b_flags & B_READ) ? MB_RCOM|MB_GO : MB_WCOM|MB_GO;
        !           167: 
        !           168:        /*
        !           169:         * Setup the massbus control and map registers and start
        !           170:         * the transfer.
        !           171:         */
        !           172:        mbp = mi->mi_mba;
        !           173:        mbp->mba_sr = -1;       /* conservative */
        !           174: #ifdef MTRDREV
        !           175:        if (bp->b_bcount >= 0) {
        !           176:                mbp->mba_var = mbasetup(mi);
        !           177:                mbp->mba_bcr = -bp->b_bcount;
        !           178:        } else {
        !           179:                mbp->mba_var = mbasetup(mi) - bp->b_bcount - 1;
        !           180:                mbp->mba_bcr = bp->b_bcount;
        !           181:        }
        !           182: #else
        !           183:        mbp->mba_var = mbasetup(mi);
        !           184:        mbp->mba_bcr = -bp->b_bcount;
        !           185: #endif
        !           186:        mi->mi_drv->mbd_cs1 = com;
        !           187:        if (mi->mi_dk >= 0) {
        !           188:                dk_busy |= 1 << mi->mi_dk;
        !           189:                dk_xfer[mi->mi_dk]++;
        !           190: #ifdef MTRDREV
        !           191:                if (bp->b_bcount >= 0)
        !           192:                        dk_wds[mi->mi_dk] += bp->b_bcount >> 6;
        !           193:                else
        !           194:                        dk_wds[mi->mi_dk] += -(bp->b_bcount) >> 6;
        !           195: #else
        !           196:                dk_wds[mi->mi_dk] += bp->b_bcount >> 6;
        !           197: #endif
        !           198:        }
        !           199: }
        !           200: 
        !           201: /*
        !           202:  * Take an interrupt off of massbus mbanum,
        !           203:  * and dispatch to drivers as appropriate.
        !           204:  */
        !           205: mbintr(mbanum)
        !           206:        int mbanum;
        !           207: {
        !           208:        register struct mba_hd *mhp = &mba_hd[mbanum];
        !           209:        register struct mba_regs *mbp = mhp->mh_mba;
        !           210:        register struct mba_device *mi;
        !           211:        register struct buf *bp;
        !           212:        register int drive;
        !           213:        int mbasr, as;
        !           214:        
        !           215:        /*
        !           216:         * Read out the massbus status register
        !           217:         * and attention status register and clear
        !           218:         * the bits in same by writing them back.
        !           219:         */
        !           220:        mbasr = mbp->mba_sr;
        !           221:        mbp->mba_sr = mbasr;
        !           222: #if VAX750
        !           223:        if (mbasr&MBSR_CBHUNG) {
        !           224:                printf("mba%d: control bus hung\n", mbanum);
        !           225:                panic("cbhung");
        !           226:        }
        !           227: #endif
        !           228:        /* note: the mbd_as register is shared between drives */
        !           229:        as = mbp->mba_drv[0].mbd_as & 0xff;
        !           230:        mbp->mba_drv[0].mbd_as = as;
        !           231: 
        !           232:        /*
        !           233:         * If the mba was active, process the data transfer
        !           234:         * complete interrupt; otherwise just process units which
        !           235:         * are now finished.
        !           236:         */
        !           237:        if (mhp->mh_active) {
        !           238:                /*
        !           239:                 * Clear attention status for drive whose data
        !           240:                 * transfer related operation completed,
        !           241:                 * and give the dtint driver
        !           242:                 * routine a chance to say what is next.
        !           243:                 */
        !           244:                mi = mhp->mh_actf;
        !           245:                as &= ~(1 << mi->mi_drive);
        !           246:                dk_busy &= ~(1 << mi->mi_dk);
        !           247:                bp = mi->mi_tab.b_actf;
        !           248:                switch ((*mi->mi_driver->md_dtint)(mi, mbasr)) {
        !           249: 
        !           250:                case MBD_DONE:          /* all done, for better or worse */
        !           251:                        /*
        !           252:                         * Flush request from drive queue.
        !           253:                         */
        !           254:                        mi->mi_tab.b_errcnt = 0;
        !           255:                        mi->mi_tab.b_actf = bp->av_forw;
        !           256:                        iodone(bp);
        !           257:                        /* fall into... */
        !           258:                case MBD_RETRY:         /* attempt the operation again */
        !           259:                        /*
        !           260:                         * Dequeue data transfer from massbus queue;
        !           261:                         * if there is still a i/o request on the device
        !           262:                         * queue then start the next operation on the device.
        !           263:                         * (Common code for DONE and RETRY).
        !           264:                         */
        !           265:                        mhp->mh_active = 0;
        !           266:                        mi->mi_tab.b_active = 0;
        !           267:                        mhp->mh_actf = mi->mi_forw;
        !           268:                        if (mi->mi_tab.b_actf)
        !           269:                                mbustart(mi);
        !           270:                        break;
        !           271: 
        !           272:                case MBD_RESTARTED:     /* driver restarted op (ecc, e.g.)
        !           273:                        /*
        !           274:                         * Note that mhp->mh_active is still on.
        !           275:                         */
        !           276:                        break;
        !           277: 
        !           278:                default:
        !           279:                        panic("mbintr");
        !           280:                }
        !           281:        }
        !           282:        /*
        !           283:         * Service drives which require attention
        !           284:         * after non-data-transfer operations.
        !           285:         */
        !           286:        while (drive = ffs(as)) {
        !           287:                drive--;                /* was 1 origin */
        !           288:                as &= ~(1 << drive);
        !           289:                mi = mhp->mh_mbip[drive];
        !           290:                if (mi == NULL)
        !           291:                        continue;
        !           292:                /*
        !           293:                 * If driver has a handler for non-data transfer
        !           294:                 * interrupts, give it a chance to tell us what to do.
        !           295:                 */
        !           296:                if (mi->mi_driver->md_ndint) {
        !           297:                        mi->mi_tab.b_active = 0;
        !           298:                        switch ((*mi->mi_driver->md_ndint)(mi)) {
        !           299: 
        !           300:                        case MBN_DONE:          /* operation completed */
        !           301:                                mi->mi_tab.b_errcnt = 0;
        !           302:                                bp = mi->mi_tab.b_actf;
        !           303:                                mi->mi_tab.b_actf = bp->av_forw;
        !           304:                                iodone(bp);
        !           305:                                /* fall into common code */
        !           306:                        case MBN_RETRY:         /* operation continues */
        !           307:                                if (mi->mi_tab.b_actf)
        !           308:                                        mbustart(mi);
        !           309:                                break;
        !           310:                        case MBN_SKIP:          /* ignore unsol. interrupt */
        !           311:                                break;
        !           312:                        default:
        !           313:                                panic("mbintr");
        !           314:                        }
        !           315:                } else
        !           316:                        /*
        !           317:                         * If there is no non-data transfer interrupt
        !           318:                         * routine, then we should just
        !           319:                         * restart the unit, leading to a mbstart() soon.
        !           320:                         */
        !           321:                        mbustart(mi);
        !           322:        }
        !           323:        /*
        !           324:         * If there is an operation available and
        !           325:         * the massbus isn't active, get it going.
        !           326:         */
        !           327:        if (mhp->mh_actf && !mhp->mh_active)
        !           328:                mbstart(mhp);
        !           329:        /* THHHHATS all folks... */
        !           330: }
        !           331: 
        !           332: /*
        !           333:  * Setup the mapping registers for a transfer.
        !           334:  */
        !           335: mbasetup(mi)
        !           336:        register struct mba_device *mi;
        !           337: {
        !           338:        register struct mba_regs *mbap = mi->mi_mba;
        !           339:        struct buf *bp = mi->mi_tab.b_actf;
        !           340:        register int i;
        !           341:        int npf;
        !           342:        unsigned v;
        !           343:        register struct pte *pte, *io;
        !           344:        int o;
        !           345:        int vaddr;
        !           346:        struct proc *rp;
        !           347: 
        !           348:        io = mbap->mba_map;
        !           349:        v = btop(bp->b_un.b_addr);
        !           350:        o = (int)bp->b_un.b_addr & PGOFSET;
        !           351: #ifdef MTRDREV
        !           352:        if (bp->b_bcount >= 0)
        !           353:                npf = btoc(bp->b_bcount + o);
        !           354:        else
        !           355:                npf = btoc(-(bp->b_bcount) + o);
        !           356: #else
        !           357:        npf = btoc(bp->b_bcount + o);
        !           358: #endif
        !           359:        rp = bp->b_flags&B_DIRTY ? &proc[2] : bp->b_proc;
        !           360:        vaddr = o;
        !           361:        if (bp->b_flags & B_UAREA) {
        !           362:                for (i = 0; i < UPAGES; i++) {
        !           363:                        if (rp->p_addr[i].pg_pfnum == 0)
        !           364:                                panic("mba: zero upage");
        !           365:                        *(int *)io++ = rp->p_addr[i].pg_pfnum | PG_V;
        !           366:                }
        !           367:        } else if ((bp->b_flags & B_PHYS) == 0) {
        !           368:                pte = &Sysmap[btop(((int)bp->b_un.b_addr)&0x7fffffff)];
        !           369:                while (--npf >= 0)
        !           370:                        *(int *)io++ = pte++->pg_pfnum | PG_V;
        !           371:        } else {
        !           372:                if (bp->b_flags & B_PAGET)
        !           373:                        pte = &Usrptmap[btokmx((struct pte *)bp->b_un.b_addr)];
        !           374:                else
        !           375:                        pte = vtopte(rp, v);
        !           376:                while (--npf >= 0) {
        !           377:                        if (pte->pg_pfnum == 0)
        !           378:                                panic("mba, zero entry");
        !           379:                        *(int *)io++ = pte++->pg_pfnum | PG_V;
        !           380:                }
        !           381:        }
        !           382:        *(int *)io++ = 0;
        !           383:        return (vaddr);
        !           384: }
        !           385: 
        !           386: /*
        !           387:  * Init and interrupt enable a massbus adapter.
        !           388:  */
        !           389: mbainit(mp)
        !           390:        struct mba_regs *mp;
        !           391: {
        !           392: 
        !           393:        mp->mba_cr = MBCR_INIT;
        !           394:        mp->mba_cr = MBCR_IE;
        !           395: }
        !           396: #endif

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