siop.c

MIPS处理器的bootloader,龙芯就是用的修改过的PMON2

		TAILQ_REMOVE(&sc->ready_list, siop_cmd, next);
		TAILQ_INSERT_TAIL(&reset_list, siop_cmd, next);
	}

	for (siop_cmd = TAILQ_FIRST(&reset_list); siop_cmd != NULL;
	    siop_cmd = next_siop_cmd) {
		next_siop_cmd = TAILQ_NEXT(siop_cmd, next);
		siop_cmd->xs->error = (siop_cmd->flags & CMDFL_TIMEOUT) ?
		    XS_TIMEOUT : XS_RESET;
		siop_cmd->siop_tables.status = htole32(SCSI_SIOP_NOCHECK);
		printf("cmd %p (status %d) about to be processed\n", siop_cmd,
		    siop_cmd->status);
		if (siop_cmd->status == CMDST_SENSE ||
		    siop_cmd->status == CMDST_SENSE_ACTIVE) 
			siop_cmd->status = CMDST_SENSE_DONE;
		else
			siop_cmd->status = CMDST_DONE;
		TAILQ_REMOVE(&reset_list, siop_cmd, next);
		siop_scsicmd_end(siop_cmd);
		TAILQ_INSERT_TAIL(&sc->free_list, siop_cmd, next);
	}
}

int
siop_scsicmd(xs)
	struct scsi_xfer *xs;
{
	struct siop_softc *sc = (struct siop_softc *)xs->sc_link->adapter_softc;
	struct siop_cmd *siop_cmd;
	int s, error, i, j;
	const int target = xs->sc_link->target;
	const int lun = xs->sc_link->lun;

	s = splbio();
#ifdef SIOP_DEBUG_SCHED
	printf("starting cmd 0x%02x for %d:%d\n", xs->cmd->opcode, target, lun);
#endif
	siop_cmd = TAILQ_FIRST(&sc->free_list);
	if (siop_cmd != NULL) {
		TAILQ_REMOVE(&sc->free_list, siop_cmd, next);
	} else {
		xs->error = XS_DRIVER_STUFFUP;
		splx(s);
		return(TRY_AGAIN_LATER);
	}

#ifndef PMON
	/* Always reset xs->stimeout, lest we timeout_del() with trash */
	timeout_set(&xs->stimeout, siop_timeout, siop_cmd);
#endif

#ifdef DIAGNOSTIC
	if (siop_cmd->status != CMDST_FREE)
		panic("siop_scsicmd: new cmd not free");
#endif
	if (sc->targets[target] == NULL) {
#ifdef SIOP_DEBUG
		printf("%s: alloc siop_target for target %d\n",
			sc->sc_dev.dv_xname, target);
#endif
		sc->targets[target] =
		    malloc(sizeof(struct siop_target), M_DEVBUF, M_NOWAIT);
		if (sc->targets[target] == NULL) {
			printf("%s: can't malloc memory for target %d\n",
			    sc->sc_dev.dv_xname, target);
			xs->error = XS_DRIVER_STUFFUP;
			splx(s);
			return(TRY_AGAIN_LATER);
		}
		sc->targets[target]->status = TARST_PROBING;
		sc->targets[target]->flags  = 0;
		sc->targets[target]->id = sc->clock_div << 24; /* scntl3 */
		sc->targets[target]->id |=  target << 16; /* id */
		/* sc->targets[target]->id |= 0x0 << 8; scxfer is 0 */

		/* get a lun switch script */
		sc->targets[target]->lunsw = siop_get_lunsw(sc);
		if (sc->targets[target]->lunsw == NULL) {
			printf("%s: can't alloc lunsw for target %d\n",
			    sc->sc_dev.dv_xname, target);
			xs->error = XS_DRIVER_STUFFUP;
			splx(s);
			return(TRY_AGAIN_LATER);
		}
		for (i=0; i < 8; i++)
			sc->targets[target]->siop_lun[i] = NULL;
		siop_add_reselsw(sc, target);
	}

	if (sc->targets[target]->siop_lun[lun] == NULL) {
		sc->targets[target]->siop_lun[lun] =
		    malloc(sizeof(struct siop_lun), M_DEVBUF, M_NOWAIT);
		if (sc->targets[target]->siop_lun[lun] == NULL) {
			printf("%s: can't alloc siop_lun for target %d "
			    "lun %d\n", sc->sc_dev.dv_xname, target, lun);
			xs->error = XS_DRIVER_STUFFUP;
			splx(s);
			return(TRY_AGAIN_LATER);
		}
		memset(sc->targets[target]->siop_lun[lun], 0,
		    sizeof(struct siop_lun));
	}
	siop_cmd->siop_target = sc->targets[target];
	siop_cmd->xs = xs;
	siop_cmd->flags = 0;
	siop_cmd->status = CMDST_READY;

	/* load the DMA maps */
	error = bus_dmamap_load(sc->sc_dmat, siop_cmd->dmamap_cmd,
	    xs->cmd, xs->cmdlen, NULL, BUS_DMA_NOWAIT);
	if (error) {
		printf("%s: unable to load cmd DMA map: %d\n",
		    sc->sc_dev.dv_xname, error);
		xs->error = XS_DRIVER_STUFFUP;
		splx(s);
		return(TRY_AGAIN_LATER);
	}
	if (xs->flags & (SCSI_DATA_IN | SCSI_DATA_OUT)) {
		error = bus_dmamap_load(sc->sc_dmat, siop_cmd->dmamap_data,
		    xs->data, xs->datalen, NULL, BUS_DMA_NOWAIT);
		if (error) {
			printf("%s: unable to load cmd DMA map: %d\n",
			    sc->sc_dev.dv_xname, error);
			xs->error = XS_DRIVER_STUFFUP;
			bus_dmamap_unload(sc->sc_dmat, siop_cmd->dmamap_cmd);
			splx(s);
			return(TRY_AGAIN_LATER);
		}
		bus_dmamap_sync(sc->sc_dmat, siop_cmd->dmamap_data,
		    0, siop_cmd->dmamap_data->dm_mapsize,
		    (xs->flags & SCSI_DATA_IN) ?
		    BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
	}
	bus_dmamap_sync(sc->sc_dmat, siop_cmd->dmamap_cmd,
	    0, siop_cmd->dmamap_cmd->dm_mapsize,
	    BUS_DMASYNC_PREWRITE);

	siop_setuptables(siop_cmd);

	TAILQ_INSERT_TAIL(&sc->ready_list, siop_cmd, next);

	siop_start(sc);
	if (xs->flags & SCSI_POLL) {
		/* poll for command completion */
		for(i = xs->timeout; i > 0; i--) {
			siop_intr(sc);
			if (xs->flags & ITSDONE) {
				if ((xs->cmd->opcode == INQUIRY)
				    && (xs->error == XS_NOERROR)) {
					error = ((struct scsi_inquiry_data *)xs->data)->device & SID_QUAL;
					if (error != SID_QUAL_BAD_LU) {
						/* 
						 * Allocate enough commands to hold at least max openings
						 * worth of commands. Do this statically now 'cuz 
						 * a) We can't rely on the upper layers to ask for more
						 * b) Doing it dynamically in siop_startcmd may cause 
						 *    calls to bus_dma* functions in interrupt context
						 */
						for (j = 0; j < SIOP_NTAG; j += SIOP_NCMDPB)
							siop_morecbd(sc);
						if (sc->targets[target]->status == TARST_PROBING)
							sc->targets[target]->status = TARST_ASYNC;
						/* Can't do lun 0 here, because flags not set yet */
						if (lun > 0)
							siop_add_dev(sc, target, lun);
					}
				}
				break;
			}
			delay(1000);
		}
		splx(s);
		if (i == 0) {
			siop_timeout(siop_cmd);
			while ((xs->flags & ITSDONE) == 0)
				siop_intr(sc);
		}
		return (COMPLETE);
	}
	splx(s);
	return (SUCCESSFULLY_QUEUED);
}

void
siop_start(sc)
	struct siop_softc *sc;
{
	struct siop_cmd *siop_cmd, *next_siop_cmd;
	struct siop_lun *siop_lun;
	u_int32_t dsa;
#ifndef PMON
	int timeout;
#endif
	int target, lun, tag, slot;
	int newcmd = 0; 
	int doingready = 0;

	/*
	 * first make sure to read valid data
	 */
	siop_script_sync(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

	/*
	 * The queue management here is a bit tricky: the script always looks
	 * at the slots from first to last, so if we always use the first 
	 * free slot commands can stay at the tail of the queue ~forever.
	 * The algorithm used here is to restart from the head when we know
	 * that the queue is empty, and only add commands after the last one.
	 * When we're at the end of the queue wait for the script to clear it.
	 * The best thing to do here would be to implement a circular queue,
	 * but using only 53c720 features this can be "interesting".
	 * A mid-way solution could be to implement 2 queues and swap orders.
	 */
	slot = sc->sc_currschedslot;
	/*
	 * If the instruction is 0x80000000 (JUMP foo, IF FALSE) the slot is
	 * free. As this is the last used slot, all previous slots are free,
	 * we can restart from 1.
	 * slot 0 is reserved for request sense commands.
	 */
	if (siop_script_read(sc, (Ent_script_sched_slot0 / 4) + slot * 2) ==
	    0x80000000) {
		slot = sc->sc_currschedslot = 1;
	} else {
		slot++;
	}
	/* first handle commands from the urgent list */
	siop_cmd = TAILQ_FIRST(&sc->urgent_list);
again:
	for (; siop_cmd != NULL; siop_cmd = next_siop_cmd) {
		next_siop_cmd = TAILQ_NEXT(siop_cmd, next);
#ifdef DIAGNOSTIC
		if (siop_cmd->status != CMDST_READY &&
		    siop_cmd->status != CMDST_SENSE)
			panic("siop: non-ready cmd in ready list");
#endif	
		target = siop_cmd->xs->sc_link->target;
		lun = siop_cmd->xs->sc_link->lun;
		siop_lun = sc->targets[target]->siop_lun[lun];
		/* if non-tagged command active, wait */
		if (siop_lun->siop_tag[0].active != NULL)
			continue;
		/*
		 * if we're in a queue full condition don't start a new
		 * command, unless it's a request sense
		 */
		if ((siop_lun->lun_flags & SIOP_LUNF_FULL) &&
		    siop_cmd->status == CMDST_READY)
			continue;
		/* find a free tag if needed */
		if (siop_cmd->flags & CMDFL_TAG) {
			for (tag = 1; tag < SIOP_NTAG; tag++) {
				if (siop_lun->siop_tag[tag].active == NULL)
					break;
			}
			if (tag == SIOP_NTAG) /* no free tag */
				continue;
		} else {
			tag = 0;
		}
		siop_cmd->tag = tag;
		/*
		 * find a free scheduler slot and load it. If it's a request
		 * sense we need to use slot 0.
		 */
		if (siop_cmd->status != CMDST_SENSE) {
			for (; slot < SIOP_NSLOTS; slot++) {
				/*
				 * If cmd if 0x80000000 the slot is free
				 */
				if (siop_script_read(sc,
				    (Ent_script_sched_slot0 / 4) + slot * 2) ==
				    0x80000000)
					break;
			}
			/* no more free slots, no need to continue */
			if (slot == SIOP_NSLOTS) {
				goto end;
			}
		} else {
			slot = 0;
			if (siop_script_read(sc, Ent_script_sched_slot0 / 4)
			    != 0x80000000) 
				goto end;
		}

#ifdef SIOP_DEBUG_SCHED
		printf("using slot %d for DSA 0x%lx\n", slot,
		    (u_long)siop_cmd->dsa);
#endif
		/* Ok, we can add the tag message */
		if (tag > 0) {
#ifdef DIAGNOSTIC
			int msgcount =
			    letoh32(siop_cmd->siop_tables.t_msgout.count);
			if (msgcount != 1)
				printf("%s:%d:%d: tag %d with msgcount %d\n",
				    sc->sc_dev.dv_xname, target, lun, tag,
				    msgcount);
#endif
			if (siop_cmd->xs->bp != NULL &&
			    (siop_cmd->xs->bp->b_flags & B_ASYNC))
				siop_cmd->siop_tables.msg_out[1] =
				    MSG_SIMPLE_Q_TAG;
			else
				siop_cmd->siop_tables.msg_out[1] =
				    MSG_ORDERED_Q_TAG;
			siop_cmd->siop_tables.msg_out[2] = tag;
			siop_cmd->siop_tables.t_msgout.count = htole32(3);
		}
		/* note that we started a new command */
		newcmd = 1;
		/* mark command as active */
		if (siop_cmd->status == CMDST_READY) {
			siop_cmd->status = CMDST_ACTIVE;
		} else if (siop_cmd->status == CMDST_SENSE) {
			siop_cmd->status = CMDST_SENSE_ACTIVE;
		} else
			panic("siop_start: bad status");
		if (doingready)
			TAILQ_REMOVE(&sc->ready_list, siop_cmd, next);
		else
			TAILQ_REMOVE(&sc->urgent_list, siop_cmd, next);
		siop_lun->siop_tag[tag].active = siop_cmd;

		/* patch scripts with DSA addr */
		dsa = siop_cmd->dsa;
		/* first reselect switch, if we have an entry */
		if (siop_lun->siop_tag[tag].reseloff > 0)
			siop_script_write(sc,
			    siop_lun->siop_tag[tag].reseloff + 1,
			    dsa + sizeof(struct siop_xfer_common) +
			    Ent_ldsa_reload_dsa);
		/* CMD script: MOVE MEMORY addr */
		siop_cmd->siop_xfer->resel[E_ldsa_abs_slot_Used[0]] = 
		   htole32(sc->sc_scriptaddr + Ent_script_sched_slot0 +
		   slot * 8);
		siop_table_sync(siop_cmd, BUS_DMASYNC_PREWRITE);
		/* scheduler slot: JUMP ldsa_select */
		siop_script_write(sc,
		    (Ent_script_sched_slot0 / 4) + slot * 2 + 1,
		    dsa + sizeof(struct siop_xfer_common) + Ent_ldsa_select);
#ifndef PMON
		/* handle timeout */
		if (siop_cmd->status == CMDST_ACTIVE) {
			if ((siop_cmd->xs->flags & SCSI_POLL) == 0) {
				/* start expire timer */
				timeout = (u_int64_t) siop_cmd->xs->timeout *
				    (u_int64_t)hz / 1000;
				if (timeout == 0)
					timeout = 1;
				timeout_add(&siop_cmd->xs->stimeout, timeout);
			}
		}
#endif
		/*
		 * Change JUMP cmd so that this slot will be handled
		 */
		siop_script_write(sc, (Ent_script_sched_slot0 / 4) + slot * 2,
		    0x80080000);
		/* if we're using the request sense slot, stop here */
		if (slot == 0)
			goto end;
		sc->sc_currschedslot = slot;
		slot++;
	}
	if (doingready == 0) {
		/* now process ready list */
		doingready = 1;
		siop_cmd = TAILQ_FIRST(&sc->ready_list);
		goto again;
	}

end:
	/* if nothing changed no need to flush cache and wakeup script */
	if (newcmd == 0)
		return;
	/* make sure SCRIPT processor will read valid data */
	siop_script_sync(sc,BUS_DMASYNC_PREREAD |  BUS_DMASYNC_PREWRITE);
	/* Signal script it has some work to do */
	bus_space_write_1(sc->sc_rt, sc->sc_rh, SIOP_ISTAT, ISTAT_SIGP);
	/* and wait for IRQ */
	return;
}

void
siop_timeout(v)
	void *v;
{
	struct siop_cmd *siop_cmd = v;
	struct siop_softc *sc = siop_cmd->siop_sc;
	int s;

	sc_print_addr(siop_cmd->xs->sc_link);
	printf("timeout on SCSI command 0x%x\n", siop_cmd->xs->cmd->opcode);

	s = splbio();
	/* reset the scsi bus */
	siop_resetbus(sc);

#ifndef PMON
	/* deactivate callout */
	timeout_del(&siop_cmd->xs->stimeout);
#endif
	/*
	 * Mark command as being timed out and just return. The bus
	 * reset will generate an interrupt, which will be handled
	 * in siop_intr().
	 */
	siop_cmd->flags |= CMDFL_TIMEOUT;
	splx(s);
	return;

}

void
siop_dump_script(sc)
	struct siop_softc *sc;
{ 
	int i;
	printf("Dumping script @ 0x%08x:\n", sc->sc_script);
	for (i = 0; i < PAGE_SIZE / 4; i += 2) {
		printf("0x%04x: 0x%08x 0x%08x", i * 4,
		    siop_script_read(sc, i), siop_script_read(sc, i+1));
		if ((siop_script_read(sc, i) & 0xe0000000) == 0xc0000000) {
			i++;
			printf(" 0x%08x", siop_script_read(sc, i+1));
		}
		printf("\n");