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Annotation of 41BSD/4.0.upgrade/sys/dev/mba.c, revision 1.1

1.1     ! root        1: /*     mba.c   4.21    81/10/27        */
        !             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:  * Start activity on a massbus device.
        !            26:  * We are given the device's mba_device structure and activate
        !            27:  * the device via the unit start routine.  The unit start
        !            28:  * routine may indicate that it is finished (e.g. if the operation
        !            29:  * was a ``sense'' on a tape drive), that the (multi-ported) unit
        !            30:  * is busy (we will get an interrupt later), that it started the
        !            31:  * unit (e.g. for a non-data transfer operation), or that it has
        !            32:  * set up a data transfer operation and we should start the massbus adaptor.
        !            33:  */
        !            34: mbustart(mi)
        !            35:        register struct mba_device *mi;
        !            36: {
        !            37:        register struct buf *bp;        /* i/o operation at head of queue */
        !            38:        register struct mba_hd *mhp;    /* header for mba device is on */
        !            39: 
        !            40: loop:
        !            41:        /*
        !            42:         * Get the first thing to do off device queue.
        !            43:         */
        !            44:        bp = mi->mi_tab.b_actf;
        !            45:        if (bp == NULL)
        !            46:                return;
        !            47:        /*
        !            48:         * Let the drivers unit start routine have at it
        !            49:         * and then process the request further, per its instructions.
        !            50:         */
        !            51:        switch ((*mi->mi_driver->md_ustart)(mi)) {
        !            52: 
        !            53:        case MBU_NEXT:          /* request is complete (e.g. ``sense'') */
        !            54:                mi->mi_tab.b_active = 0;
        !            55:                mi->mi_tab.b_errcnt = 0;
        !            56:                mi->mi_tab.b_actf = bp->av_forw;
        !            57:                iodone(bp);
        !            58:                goto loop;
        !            59: 
        !            60:        case MBU_DODATA:        /* all ready to do data transfer */
        !            61:                /*
        !            62:                 * Queue the device mba_device structure on the massbus
        !            63:                 * mba_hd structure for processing as soon as the
        !            64:                 * data path is available.
        !            65:                 */
        !            66:                mhp = mi->mi_hd;
        !            67:                mi->mi_forw = NULL;
        !            68:                if (mhp->mh_actf == NULL)
        !            69:                        mhp->mh_actf = mi;
        !            70:                else
        !            71:                        mhp->mh_actl->mi_forw = mi;
        !            72:                mhp->mh_actl = mi;
        !            73:                /*
        !            74:                 * If data path is idle, start transfer now.
        !            75:                 * In any case the device is ``active'' waiting for the
        !            76:                 * data to transfer.
        !            77:                 */
        !            78:                mi->mi_tab.b_active = 1;
        !            79:                if (mhp->mh_active == 0)
        !            80:                        mbstart(mhp);
        !            81:                return;
        !            82: 
        !            83:        case MBU_STARTED:       /* driver started a non-data transfer */
        !            84:                /*
        !            85:                 * Mark device busy during non-data transfer
        !            86:                 * and count this as a ``seek'' on the device.
        !            87:                 */
        !            88:                if (mi->mi_dk >= 0) {
        !            89:                        dk_seek[mi->mi_dk]++;
        !            90:                        dk_busy |= (1 << mi->mi_dk);
        !            91:                }
        !            92:                mi->mi_tab.b_active = 1;
        !            93:                return;
        !            94: 
        !            95:        case MBU_BUSY:          /* dual port drive busy */
        !            96:                /*
        !            97:                 * We mark the device structure so that when an
        !            98:                 * interrupt occurs we will know to restart the unit.
        !            99:                 */
        !           100:                mi->mi_tab.b_flags |= B_BUSY;
        !           101:                return;
        !           102: 
        !           103:        default:
        !           104:                panic("mbustart");
        !           105:        }
        !           106: }
        !           107: 
        !           108: /*
        !           109:  * Start an i/o operation on the massbus specified by the argument.
        !           110:  * We peel the first operation off its queue and insure that the drive
        !           111:  * is present and on-line.  We then use the drivers start routine
        !           112:  * (if any) to prepare the drive, setup the massbus map for the transfer
        !           113:  * and start the transfer.
        !           114:  */
        !           115: mbstart(mhp)
        !           116:        register struct mba_hd *mhp;
        !           117: {
        !           118:        register struct mba_device *mi;
        !           119:        struct buf *bp;
        !           120:        register struct mba_regs *mbp;
        !           121:        register int com;
        !           122: 
        !           123: loop:
        !           124:        /*
        !           125:         * Look for an operation at the front of the queue.
        !           126:         */
        !           127:        if ((mi = mhp->mh_actf) == NULL) {
        !           128:                return;
        !           129:        }
        !           130:        if ((bp = mi->mi_tab.b_actf) == NULL) {
        !           131:                mhp->mh_actf = mi->mi_forw;
        !           132:                goto loop;
        !           133:        }
        !           134:        /*
        !           135:         * If this device isn't present and on-line, then
        !           136:         * we screwed up, and can't really do the operation.
        !           137:         * Only check for non-tapes because tape drivers check
        !           138:         * ONLINE themselves and because TU78 registers are
        !           139:         * different.
        !           140:         */
        !           141:        if ((mi->mi_drv->mbd_dt & MBDT_TAP) == 0)
        !           142:        if ((mi->mi_drv->mbd_ds & MBDS_DREADY) != MBDS_DREADY) {
        !           143:                printf("%s%d: not ready\n", mi->mi_driver->md_dname,
        !           144:                    dkunit(bp));
        !           145:                mi->mi_tab.b_actf = bp->av_forw;
        !           146:                mi->mi_tab.b_errcnt = 0;
        !           147:                mi->mi_tab.b_active = 0;
        !           148:                bp->b_flags |= B_ERROR;
        !           149:                iodone(bp);
        !           150:                goto loop;
        !           151:        }
        !           152:        /*
        !           153:         * We can do the operation; mark the massbus active
        !           154:         * and let the device start routine setup any necessary
        !           155:         * device state for the transfer (e.g. desired cylinder, etc
        !           156:         * on disks).
        !           157:         */
        !           158:        mhp->mh_active = 1;
        !           159:        if (mi->mi_driver->md_start) {
        !           160:                if ((com = (*mi->mi_driver->md_start)(mi)) == 0)
        !           161:                        com = (bp->b_flags & B_READ) ?
        !           162:                            MB_RCOM|MB_GO : MB_WCOM|MB_GO;
        !           163:        } else
        !           164:                com = (bp->b_flags & B_READ) ? MB_RCOM|MB_GO : MB_WCOM|MB_GO;
        !           165: 
        !           166:        /*
        !           167:         * Setup the massbus control and map registers and start
        !           168:         * the transfer.
        !           169:         */
        !           170:        mbp = mi->mi_mba;
        !           171:        mbp->mba_sr = -1;       /* conservative */
        !           172:        mbp->mba_var = mbasetup(mi);
        !           173:        mbp->mba_bcr = -bp->b_bcount;
        !           174:        mi->mi_drv->mbd_cs1 = com;
        !           175:        if (mi->mi_dk >= 0) {
        !           176:                dk_busy |= 1 << mi->mi_dk;
        !           177:                dk_xfer[mi->mi_dk]++;
        !           178:                dk_wds[mi->mi_dk] += bp->b_bcount >> 6;
        !           179:        }
        !           180: }
        !           181: 
        !           182: /*
        !           183:  * Take an interrupt off of massbus mbanum,
        !           184:  * and dispatch to drivers as appropriate.
        !           185:  */
        !           186: mbintr(mbanum)
        !           187:        int mbanum;
        !           188: {
        !           189:        register struct mba_hd *mhp = &mba_hd[mbanum];
        !           190:        register struct mba_regs *mbp = mhp->mh_mba;
        !           191:        register struct mba_device *mi;
        !           192:        register struct buf *bp;
        !           193:        register int drive;
        !           194:        int mbasr, as;
        !           195:        
        !           196:        /*
        !           197:         * Read out the massbus status register
        !           198:         * and attention status register and clear
        !           199:         * the bits in same by writing them back.
        !           200:         */
        !           201:        mbasr = mbp->mba_sr;
        !           202:        mbp->mba_sr = mbasr;
        !           203: #if VAX750
        !           204:        if (mbasr&MBSR_CBHUNG) {
        !           205:                printf("mba%d: control bus hung\n", mbanum);
        !           206:                panic("cbhung");
        !           207:        }
        !           208: #endif
        !           209:        /* note: the mbd_as register is shared between drives */
        !           210:        as = mbp->mba_drv[0].mbd_as & 0xff;
        !           211:        mbp->mba_drv[0].mbd_as = as;
        !           212: 
        !           213:        /*
        !           214:         * If the mba was active, process the data transfer
        !           215:         * complete interrupt; otherwise just process units which
        !           216:         * are now finished.
        !           217:         */
        !           218:        if (mhp->mh_active) {
        !           219:                /*
        !           220:                 * Clear attention status for drive whose data
        !           221:                 * transfer related operation completed,
        !           222:                 * and give the dtint driver
        !           223:                 * routine a chance to say what is next.
        !           224:                 */
        !           225:                mi = mhp->mh_actf;
        !           226:                as &= ~(1 << mi->mi_drive);
        !           227:                dk_busy &= ~(1 << mi->mi_dk);
        !           228:                bp = mi->mi_tab.b_actf;
        !           229:                switch ((*mi->mi_driver->md_dtint)(mi, mbasr)) {
        !           230: 
        !           231:                case MBD_DONE:          /* all done, for better or worse */
        !           232:                        /*
        !           233:                         * Flush request from drive queue.
        !           234:                         */
        !           235:                        mi->mi_tab.b_errcnt = 0;
        !           236:                        mi->mi_tab.b_actf = bp->av_forw;
        !           237:                        iodone(bp);
        !           238:                        /* fall into... */
        !           239:                case MBD_RETRY:         /* attempt the operation again */
        !           240:                        /*
        !           241:                         * Dequeue data transfer from massbus queue;
        !           242:                         * if there is still a i/o request on the device
        !           243:                         * queue then start the next operation on the device.
        !           244:                         * (Common code for DONE and RETRY).
        !           245:                         */
        !           246:                        mhp->mh_active = 0;
        !           247:                        mi->mi_tab.b_active = 0;
        !           248:                        mhp->mh_actf = mi->mi_forw;
        !           249:                        if (mi->mi_tab.b_actf)
        !           250:                                mbustart(mi);
        !           251:                        break;
        !           252: 
        !           253:                case MBD_RESTARTED:     /* driver restarted op (ecc, e.g.)
        !           254:                        /*
        !           255:                         * Note that mhp->mh_active is still on.
        !           256:                         */
        !           257:                        break;
        !           258: 
        !           259:                default:
        !           260:                        panic("mbintr");
        !           261:                }
        !           262:        }
        !           263:        /*
        !           264:         * Service drives which require attention
        !           265:         * after non-data-transfer operations.
        !           266:         */
        !           267:        while (drive = ffs(as)) {
        !           268:                drive--;                /* was 1 origin */
        !           269:                as &= ~(1 << drive);
        !           270:                mi = mhp->mh_mbip[drive];
        !           271:                if (mi == NULL)
        !           272:                        continue;
        !           273:                /*
        !           274:                 * If driver has a handler for non-data transfer
        !           275:                 * interrupts, give it a chance to tell us what to do.
        !           276:                 */
        !           277:                if (mi->mi_driver->md_ndint) {
        !           278:                        mi->mi_tab.b_active = 0;
        !           279:                        switch ((*mi->mi_driver->md_ndint)(mi)) {
        !           280: 
        !           281:                        case MBN_DONE:          /* operation completed */
        !           282:                                mi->mi_tab.b_errcnt = 0;
        !           283:                                bp = mi->mi_tab.b_actf;
        !           284:                                mi->mi_tab.b_actf = bp->av_forw;
        !           285:                                iodone(bp);
        !           286:                                /* fall into common code */
        !           287:                        case MBN_RETRY:         /* operation continues */
        !           288:                                if (mi->mi_tab.b_actf)
        !           289:                                        mbustart(mi);
        !           290:                                break;
        !           291:                        case MBN_SKIP:          /* ignore unsol. interrupt */
        !           292:                                break;
        !           293:                        default:
        !           294:                                panic("mbintr");
        !           295:                        }
        !           296:                } else
        !           297:                        /*
        !           298:                         * If there is no non-data transfer interrupt
        !           299:                         * routine, then we should just
        !           300:                         * restart the unit, leading to a mbstart() soon.
        !           301:                         */
        !           302:                        mbustart(mi);
        !           303:        }
        !           304:        /*
        !           305:         * If there is an operation available and
        !           306:         * the massbus isn't active, get it going.
        !           307:         */
        !           308:        if (mhp->mh_actf && !mhp->mh_active)
        !           309:                mbstart(mhp);
        !           310:        /* THHHHATS all folks... */
        !           311: }
        !           312: 
        !           313: /*
        !           314:  * Setup the mapping registers for a transfer.
        !           315:  */
        !           316: mbasetup(mi)
        !           317:        register struct mba_device *mi;
        !           318: {
        !           319:        register struct mba_regs *mbap = mi->mi_mba;
        !           320:        struct buf *bp = mi->mi_tab.b_actf;
        !           321:        register int i;
        !           322:        int npf;
        !           323:        unsigned v;
        !           324:        register struct pte *pte, *io;
        !           325:        int o;
        !           326:        int vaddr;
        !           327:        struct proc *rp;
        !           328: 
        !           329:        io = mbap->mba_map;
        !           330:        v = btop(bp->b_un.b_addr);
        !           331:        o = (int)bp->b_un.b_addr & PGOFSET;
        !           332:        npf = btoc(bp->b_bcount + o);
        !           333:        rp = bp->b_flags&B_DIRTY ? &proc[2] : bp->b_proc;
        !           334:        vaddr = o;
        !           335:        if (bp->b_flags & B_UAREA) {
        !           336:                for (i = 0; i < UPAGES; i++) {
        !           337:                        if (rp->p_addr[i].pg_pfnum == 0)
        !           338:                                panic("mba: zero upage");
        !           339:                        *(int *)io++ = rp->p_addr[i].pg_pfnum | PG_V;
        !           340:                }
        !           341:        } else if ((bp->b_flags & B_PHYS) == 0) {
        !           342:                pte = &Sysmap[btop(((int)bp->b_un.b_addr)&0x7fffffff)];
        !           343:                while (--npf >= 0)
        !           344:                        *(int *)io++ = pte++->pg_pfnum | PG_V;
        !           345:        } else {
        !           346:                if (bp->b_flags & B_PAGET)
        !           347:                        pte = &Usrptmap[btokmx((struct pte *)bp->b_un.b_addr)];
        !           348:                else
        !           349:                        pte = vtopte(rp, v);
        !           350:                while (--npf >= 0) {
        !           351:                        if (pte->pg_pfnum == 0)
        !           352:                                panic("mba, zero entry");
        !           353:                        *(int *)io++ = pte++->pg_pfnum | PG_V;
        !           354:                }
        !           355:        }
        !           356:        *(int *)io++ = 0;
        !           357:        return (vaddr);
        !           358: }
        !           359: 
        !           360: /*
        !           361:  * Init and interrupt enable a massbus adapter.
        !           362:  */
        !           363: mbainit(mp)
        !           364:        struct mba_regs *mp;
        !           365: {
        !           366: 
        !           367:        mp->mba_cr = MBCR_INIT;
        !           368:        mp->mba_cr = MBCR_IE;
        !           369: }
        !           370: #endif

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