asc.c

早期freebsd实现

	/* setup for this chunk */
	len = state->buflen;
	if (len > state->dmaBufSize)
		len = state->dmaBufSize;
	state->dmalen = len;
	bcopy(state->buf, state->dmaBufAddr, len);
	(*asc->dma_start)(asc, state, state->dmaBufAddr, ASCDMA_WRITE);
	ASC_TC_PUT(regs, len);
#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_resume_out: buflen %d, len %d\n", state->buflen,
			len);
#endif

	/* check for next chunk */
	state->flags |= DMA_IN_PROGRESS;
	if (len != state->buflen) {
		regs->asc_cmd = ASC_CMD_XFER_INFO | ASC_CMD_DMA;
		readback(regs->asc_cmd);
		asc->script = &asc_scripts[SCRIPT_CONTINUE_OUT];
		return (0);
	}
	return (1);
}

/* ARGSUSED */
static int
asc_resume_dma_out(asc, status, ss, ir)
	register asc_softc_t asc;
	register int status, ss, ir;
{
	register asc_regmap_t *regs = asc->regs;
	register State *state = &asc->st[asc->target];
	register int len, off;

	/* setup to finish writing this chunk */
	len = state->dmaresid;
	off = state->dmalen - len;
	if (off & 1) {
		printf("asc_resume_dma_out: odd xfer dmalen %d len %d off %d\n",
			state->dmalen, len, off); /* XXX */
		regs->asc_fifo = state->dmaBufAddr[off];
		off++;
		len--;
	}
	(*asc->dma_start)(asc, state, state->dmaBufAddr + off, ASCDMA_WRITE);
	ASC_TC_PUT(regs, len);
#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_resume_dma_out: buflen %d dmalen %d len %d off %d\n",
			state->dmalen, state->buflen, len, off);
#endif

	/* check for next chunk */
	state->flags |= DMA_IN_PROGRESS;
	if (state->dmalen != state->buflen) {
		regs->asc_cmd = ASC_CMD_XFER_INFO | ASC_CMD_DMA;
		readback(regs->asc_cmd);
		asc->script = &asc_scripts[SCRIPT_CONTINUE_OUT];
		return (0);
	}
	return (1);
}

/* ARGSUSED */
static int
asc_sendsync(asc, status, ss, ir)
	register asc_softc_t asc;
	register int status, ss, ir;
{
	register asc_regmap_t *regs = asc->regs;
	register State *state = &asc->st[asc->target];

	/* send the extended synchronous negotiation message */
	regs->asc_fifo = SCSI_EXTENDED_MSG;
	MachEmptyWriteBuffer();
	regs->asc_fifo = 3;
	MachEmptyWriteBuffer();
	regs->asc_fifo = SCSI_SYNCHRONOUS_XFER;
	MachEmptyWriteBuffer();
	regs->asc_fifo = SCSI_MIN_PERIOD;
	MachEmptyWriteBuffer();
	regs->asc_fifo = ASC_MAX_OFFSET;
	/* state to resume after we see the sync reply message */
	state->script = asc->script + 2;
	state->msglen = 0;
	return (1);
}

/* ARGSUSED */
static int
asc_replysync(asc, status, ss, ir)
	register asc_softc_t asc;
	register int status, ss, ir;
{
	register asc_regmap_t *regs = asc->regs;
	register State *state = &asc->st[asc->target];

#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_replysync: %x %x\n",
			asc_to_scsi_period[state->sync_period] * asc->tb_ticks,
			state->sync_offset);
#endif
	/* send synchronous transfer in response to a request */
	regs->asc_fifo = SCSI_EXTENDED_MSG;
	MachEmptyWriteBuffer();
	regs->asc_fifo = 3;
	MachEmptyWriteBuffer();
	regs->asc_fifo = SCSI_SYNCHRONOUS_XFER;
	MachEmptyWriteBuffer();
	regs->asc_fifo = asc_to_scsi_period[state->sync_period] * asc->tb_ticks;
	MachEmptyWriteBuffer();
	regs->asc_fifo = state->sync_offset;
	regs->asc_cmd = ASC_CMD_XFER_INFO;
	readback(regs->asc_cmd);

	/* return to the appropriate script */
	if (!state->script) {
#ifdef DEBUG
		asc_DumpLog("asc_replsync");
#endif
		panic("asc_replysync");
	}
	asc->script = state->script;
	state->script = (script_t *)0;
	return (0);
}

/* ARGSUSED */
static int
asc_msg_in(asc, status, ss, ir)
	register asc_softc_t asc;
	register int status, ss, ir;
{
	register asc_regmap_t *regs = asc->regs;
	register State *state = &asc->st[asc->target];
	register int msg;
	int i;

	/* read one message byte */
	msg = regs->asc_fifo;
#ifdef DEBUG
	if (asc_logp == asc_log)
		asc_log[NLOG - 1].msg = msg;
	else
		asc_logp[-1].msg = msg;
#endif

	/* check for multi-byte message */
	if (state->msglen != 0) {
		/* first byte is the message length */
		if (state->msglen < 0) {
			state->msglen = msg;
			return (1);
		}
		if (state->msgcnt >= state->msglen)
			goto abort;
		state->msg_in[state->msgcnt++] = msg;

		/* did we just read the last byte of the message? */
		if (state->msgcnt != state->msglen)
			return (1);

		/* process an extended message */
#ifdef DEBUG
		if (asc_debug > 2)
			printf("asc_msg_in: msg %x %x %x\n",
				state->msg_in[0],
				state->msg_in[1],
				state->msg_in[2]);
#endif
		switch (state->msg_in[0]) {
		case SCSI_SYNCHRONOUS_XFER:
			state->flags |= DID_SYNC;
			state->sync_offset = state->msg_in[2];

			/* convert SCSI period to ASC period */
			i = state->msg_in[1] / asc->tb_ticks;
			if (i < asc->min_period)
				i = asc->min_period;
			else if (i >= asc->max_period) {
				/* can't do sync transfer, period too long */
				printf("asc%d: SCSI device %d: sync xfer period too long (%d)\n",
					asc - asc_softc, asc->target, i);
				i = asc->max_period;
				state->sync_offset = 0;
			}
			if ((i * asc->tb_ticks) != state->msg_in[1])
				i++;
			state->sync_period = i & 0x1F;

			/*
			 * If this is a request, check minimums and
			 * send back an acknowledge.
			 */
			if (!(state->flags & TRY_SYNC)) {
				regs->asc_cmd = ASC_CMD_SET_ATN;
				readback(regs->asc_cmd);

				if (state->sync_period < asc->min_period)
					state->sync_period =
						asc->min_period;
				if (state->sync_offset > ASC_MAX_OFFSET)
					state->sync_offset =
						ASC_MAX_OFFSET;
				asc->script = &asc_scripts[SCRIPT_REPLY_SYNC];
				regs->asc_syn_p = state->sync_period;
				readback(regs->asc_syn_p);
				regs->asc_syn_o = state->sync_offset;
				readback(regs->asc_syn_o);
				regs->asc_cmd = ASC_CMD_MSG_ACPT;
				readback(regs->asc_cmd);
				return (0);
			}

			regs->asc_syn_p = state->sync_period;
			readback(regs->asc_syn_p);
			regs->asc_syn_o = state->sync_offset;
			readback(regs->asc_syn_o);
			goto done;

		default:
			printf("asc%d: SCSI device %d: rejecting extended message 0x%x\n",
				asc - asc_softc, asc->target,
				state->msg_in[0]);
			goto reject;
		}
	}

	/* process first byte of a message */
#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_msg_in: msg %x\n", msg);
#endif
	switch (msg) {
#if 0
	case SCSI_MESSAGE_REJECT:
		printf(" did not like SYNCH xfer "); /* XXX */
		state->flags |= DID_SYNC;
		regs->asc_cmd = ASC_CMD_MSG_ACPT;
		readback(regs->asc_cmd);
		status = asc_wait(regs, ASC_CSR_INT);
		ir = regs->asc_intr;
		/* some just break out here, some dont */
		if (ASC_PHASE(status) == ASC_PHASE_MSG_OUT) {
			regs->asc_fifo = SCSI_ABORT;
			regs->asc_cmd = ASC_CMD_XFER_INFO;
			readback(regs->asc_cmd);
			status = asc_wait(regs, ASC_CSR_INT);
			ir = regs->asc_intr;
		}
		if (ir & ASC_INT_DISC) {
			asc_end(asc, status, 0, ir);
			return (0);
		}
		goto status;
#endif

	case SCSI_EXTENDED_MSG: /* read an extended message */
		/* setup to read message length next */
		state->msglen = -1;
		state->msgcnt = 0;
		return (1);

	case SCSI_NO_OP:
		break;

	case SCSI_SAVE_DATA_POINTER:
		/* expect another message */
		return (1);

	case SCSI_RESTORE_POINTERS:
		/*
		 * Need to do the following if resuming synchonous data in
		 * on an odd byte boundary.
		regs->asc_cnfg2 |= ASC_CNFG2_RFB;
		 */
		break;

	case SCSI_DISCONNECT:
		if (state->flags & DISCONN)
			goto abort;
		state->flags |= DISCONN;
		regs->asc_cmd = ASC_CMD_MSG_ACPT;
		readback(regs->asc_cmd);
		asc->script = &asc_scripts[SCRIPT_DISCONNECT];
		return (0);

	default:
		printf("asc%d: SCSI device %d: rejecting message 0x%x\n",
			asc - asc_softc, asc->target, msg);
	reject:
		/* request a message out before acknowledging this message */
		state->msg_out = SCSI_MESSAGE_REJECT;
		regs->asc_cmd = ASC_CMD_SET_ATN;
		readback(regs->asc_cmd);
	}

done:
	/* return to original script */
	regs->asc_cmd = ASC_CMD_MSG_ACPT;
	readback(regs->asc_cmd);
	if (!state->script) {
	abort:
#ifdef DEBUG
		asc_DumpLog("asc_msg_in");
#endif
		panic("asc_msg_in");
	}
	asc->script = state->script;
	state->script = (script_t *)0;
	return (0);
}

/* ARGSUSED */
static int
asc_disconnect(asc, status, ss, ir)
	register asc_softc_t asc;
	register int status, ss, ir;
{
	register State *state = &asc->st[asc->target];

#ifdef DIAGNOSTIC
	if (!(state->flags & DISCONN)) {
		printf("asc_disconnect: device %d: DISCONN not set!\n",
			asc->target);
	}
#endif
	asc->target = -1;
	asc->state = ASC_STATE_RESEL;
	return (1);
}

/*
 * DMA handling routines. For a turbochannel device, just set the dmar.
 * For the I/O ASIC, handle the actual DMA interface.
 */
static void
tb_dma_start(asc, state, cp, flag)
	asc_softc_t asc;
	State *state;
	caddr_t cp;
	int flag;
{

	if (flag == ASCDMA_WRITE)
		*asc->dmar = ASC_DMAR_WRITE | ASC_DMA_ADDR(cp);
	else
		*asc->dmar = ASC_DMA_ADDR(cp);
}

static void
tb_dma_end(asc, state, flag)
	asc_softc_t asc;
	State *state;
	int flag;
{

}

static void
asic_dma_start(asc, state, cp, flag)
	asc_softc_t asc;
	State *state;
	caddr_t cp;
	int flag;
{
	register volatile u_int *ssr = (volatile u_int *)
		ASIC_REG_CSR(asic_base);
	u_int phys, nphys;

	/* stop DMA engine first */
	*ssr &= ~ASIC_CSR_DMAEN_SCSI;
	*((volatile int *)ASIC_REG_SCSI_SCR(asic_base)) = 0;

	phys = MACH_CACHED_TO_PHYS(cp);
	cp = (caddr_t)pmax_trunc_page(cp + NBPG);
	nphys = MACH_CACHED_TO_PHYS(cp);

	asc->dma_next = cp;
	asc->dma_xfer = state->dmalen - (nphys - phys);

	*(volatile int *)ASIC_REG_SCSI_DMAPTR(asic_base) =
		ASIC_DMA_ADDR(phys);
	*(volatile int *)ASIC_REG_SCSI_DMANPTR(asic_base) =
		ASIC_DMA_ADDR(nphys);
	if (flag == ASCDMA_READ)
		*ssr |= ASIC_CSR_SCSI_DIR | ASIC_CSR_DMAEN_SCSI;
	else
		*ssr = (*ssr & ~ASIC_CSR_SCSI_DIR) | ASIC_CSR_DMAEN_SCSI;
	MachEmptyWriteBuffer();
}

static void
asic_dma_end(asc, state, flag)
	asc_softc_t asc;
	State *state;
	int flag;
{
	register volatile u_int *ssr = (volatile u_int *)
		ASIC_REG_CSR(asic_base);
	register volatile u_int *dmap = (volatile u_int *)
		ASIC_REG_SCSI_DMAPTR(asic_base);
	register u_short *to;
	register int w;
	int nb;

	*ssr &= ~ASIC_CSR_DMAEN_SCSI;
	to = (u_short *)MACH_PHYS_TO_CACHED(*dmap >> 3);
	*dmap = -1;
	*((volatile int *)ASIC_REG_SCSI_DMANPTR(asic_base)) = -1;
	MachEmptyWriteBuffer();

	if (flag == ASCDMA_READ) {
		MachFlushDCache(MACH_PHYS_TO_CACHED(
		    MACH_UNCACHED_TO_PHYS(state->dmaBufAddr)), state->dmalen);
		if (nb = *((int *)ASIC_REG_SCSI_SCR(asic_base))) {
			/* pick up last upto6 bytes, sigh. */
	
			/* Last byte really xferred is.. */
			w = *(int *)ASIC_REG_SCSI_SDR0(asic_base);
			*to++ = w;
			if (--nb > 0) {
				w >>= 16;
				*to++ = w;
			}
			if (--nb > 0) {
				w = *(int *)ASIC_REG_SCSI_SDR1(asic_base);
				*to++ = w;
			}
		}
	}
}

#ifdef notdef
/*
 * Called by asic_intr() for scsi dma pointer update interrupts.
 */
void
asc_dma_intr()
{
	asc_softc_t asc = &asc_softc[0];
	u_int next_phys;

	asc->dma_xfer -= NBPG;
	if (asc->dma_xfer <= -NBPG) {
		volatile u_int *ssr = (volatile u_int *)
			ASIC_REG_CSR(asic_base);
		*ssr &= ~ASIC_CSR_DMAEN_SCSI;
	} else {
		asc->dma_next += NBPG;
		next_phys = MACH_CACHED_TO_PHYS(asc->dma_next);
	}
	*(volatile int *)ASIC_REG_SCSI_DMANPTR(asic_base) =
		ASIC_DMA_ADDR(next_phys);
	MachEmptyWriteBuffer();
}
#endif

#ifdef DEBUG
asc_DumpLog(str)
	char *str;
{
	register struct asc_log *lp;
	register u_int status;

	printf("asc: %s: cmd %x bn %d cnt %d\n", str, asc_debug_cmd,
		asc_debug_bn, asc_debug_sz);
	lp = asc_logp;
	do {
		status = lp->status;
		printf("asc%d tgt %d status %x ss %x ir %x cond %d:%x msg %x resid %d\n",
			status >> 24,
			lp->target,
			(status >> 16) & 0xFF,
			(status >> 8) & 0xFF,
			status & 0XFF,
			lp->state,
			asc_scripts[lp->state].condition,
			lp->msg, lp->resid);
		if (++lp >= &asc_log[NLOG])
			lp = asc_log;
	} while (lp != asc_logp);
}
#endif

#endif	/* NASC > 0 */