asc.c

早期freebsd实现

		regs->asc_cmd = ASC_CMD_XFER_INFO;
		readback(regs->asc_cmd);
		goto done;
	}

	/* check for SCSI bus reset */
	if (ir & ASC_INT_RESET) {
		register int i;

		printf("asc%d: SCSI bus reset!!\n", asc - asc_softc);
		/* need to flush any pending commands */
		for (i = 0; i < ASC_NCMD; i++) {
			if (!asc->cmd[i])
				continue;
			asc->st[i].error = EIO;
			asc_end(asc, 0, 0, 0);
		}
		/* rearbitrate synchronous offset */
		for (i = 0; i < ASC_NCMD; i++) {
			asc->st[i].sync_offset = 0;
			asc->st[i].flags = 0;
		}
		asc->target = -1;
		return;
	}

	/* check for command errors */
	if (ir & ASC_INT_ILL)
		goto abort;

	/* check for disconnect */
	if (ir & ASC_INT_DISC) {
		state = &asc->st[asc->target];
		switch (ASC_SS(ss)) {
		case 0: /* device did not respond */
			/* check for one of the starting scripts */
			switch (asc->script - asc_scripts) {
			case SCRIPT_TRY_SYNC:
			case SCRIPT_SIMPLE:
			case SCRIPT_DATA_IN:
			case SCRIPT_DATA_OUT:
				if (regs->asc_flags & ASC_FLAGS_FIFO_CNT) {
					regs->asc_cmd = ASC_CMD_FLUSH;
					readback(regs->asc_cmd);
				}
				state->error = ENXIO;
				asc_end(asc, status, ss, ir);
				return;
			}
			/* FALLTHROUGH */

		default:
			printf("asc%d: SCSI device %d: unexpected disconnect\n",
				asc - asc_softc, asc->target);
			/*
			 * On rare occasions my RZ24 does a disconnect during
			 * data in phase and the following seems to keep it
			 * happy.
			 * XXX Should a scsi disk ever do this??
			 */
			asc->script = &asc_scripts[SCRIPT_RESEL];
			asc->state = ASC_STATE_RESEL;
			state->flags |= DISCONN;
			regs->asc_cmd = ASC_CMD_ENABLE_SEL;
			readback(regs->asc_cmd);
			return;
		}
	}

	/* check for reselect */
	if (ir & ASC_INT_RESEL) {
		unsigned fifo, id, msg;

		fifo = regs->asc_flags & ASC_FLAGS_FIFO_CNT;
		if (fifo < 2)
			goto abort;
		/* read unencoded SCSI ID and convert to binary */
		msg = regs->asc_fifo & asc->myidmask;
		for (id = 0; (msg & 1) == 0; id++)
			msg >>= 1;
		/* read identify message */
		msg = regs->asc_fifo;
#ifdef DEBUG
		if (asc_logp == asc_log)
			asc_log[NLOG - 1].msg = msg;
		else
			asc_logp[-1].msg = msg;
#endif
		asc->state = ASC_STATE_BUSY;
		asc->target = id;
		state = &asc->st[id];
		asc->script = state->script;
		state->script = (script_t *)0;
		if (!(state->flags & DISCONN))
			goto abort;
		state->flags &= ~DISCONN;
		regs->asc_syn_p = state->sync_period;
		regs->asc_syn_o = state->sync_offset;
		regs->asc_cmd = ASC_CMD_MSG_ACPT;
		readback(regs->asc_cmd);
		goto done;
	}

	/* check if we are being selected as a target */
	if (ir & (ASC_INT_SEL | ASC_INT_SEL_ATN))
		goto abort;

	/*
	 * 'ir' must be just ASC_INT_FC.
	 * This is normal if canceling an ASC_ENABLE_SEL.
	 */

done:
	MachEmptyWriteBuffer();
	/* watch out for HW race conditions and setup & hold time violations */
	ir = regs->asc_status;
	while (ir != (status = regs->asc_status))
		ir = status;
	if (status & ASC_CSR_INT)
		goto again;
	return;

abort:
#ifdef DEBUG
	asc_DumpLog("asc_intr");
#endif
#if 0
	panic("asc_intr");
#else
	for (;;);
#endif
}

/*
 * All the many little things that the interrupt
 * routine might switch to.
 */

/* ARGSUSED */
static int
script_nop(asc, status, ss, ir)
	register asc_softc_t asc;
	register int status, ss, ir;
{
	return (1);
}

/* ARGSUSED */
static int
asc_get_status(asc, status, ss, ir)
	register asc_softc_t asc;
	register int status, ss, ir;
{
	register asc_regmap_t *regs = asc->regs;
	register int data;

	/*
	 * Get the last two bytes in the FIFO.
	 */
	if ((data = regs->asc_flags & ASC_FLAGS_FIFO_CNT) != 2) {
		printf("asc_get_status: fifo cnt %d\n", data); /* XXX */
		asc_DumpLog("get_status"); /* XXX */
		if (data < 2) {
			asc->regs->asc_cmd = ASC_CMD_MSG_ACPT;
			readback(asc->regs->asc_cmd);
			return (0);
		}
		do {
			data = regs->asc_fifo;
		} while ((regs->asc_flags & ASC_FLAGS_FIFO_CNT) > 2);
	}

	/* save the status byte */
	asc->st[asc->target].statusByte = data = regs->asc_fifo;
#ifdef DEBUG
	if (asc_logp == asc_log)
		asc_log[NLOG - 1].msg = data;
	else
		asc_logp[-1].msg = data;
#endif

	/* get the (presumed) command_complete message */
	if ((data = regs->asc_fifo) == SCSI_COMMAND_COMPLETE)
		return (1);

#ifdef DEBUG
	printf("asc_get_status: status %x cmd %x\n",
		asc->st[asc->target].statusByte, data);
	asc_DumpLog("asc_get_status");
#endif
	return (0);
}

/* ARGSUSED */
static int
asc_end(asc, status, ss, ir)
	register asc_softc_t asc;
	register int status, ss, ir;
{
	register ScsiCmd *scsicmd;
	register State *state;
	register int i, target;

	asc->state = ASC_STATE_IDLE;
	target = asc->target;
	asc->target = -1;
	scsicmd = asc->cmd[target];
	asc->cmd[target] = (ScsiCmd *)0;
	state = &asc->st[target];

#ifdef DEBUG
	if (asc_debug > 1) {
		printf("asc_end: %s target %d cmd %x err %d resid %d\n",
			scsicmd->sd->sd_driver->d_name, target,
			scsicmd->cmd[0], state->error, state->buflen);
	}
#endif
#ifdef DIAGNOSTIC
	if (target < 0 || !scsicmd)
		panic("asc_end");
#endif

	/* look for disconnected devices */
	for (i = 0; i < ASC_NCMD; i++) {
		if (!asc->cmd[i] || !(asc->st[i].flags & DISCONN))
			continue;
		asc->regs->asc_cmd = ASC_CMD_ENABLE_SEL;
		readback(asc->regs->asc_cmd);
		asc->state = ASC_STATE_RESEL;
		asc->script = &asc_scripts[SCRIPT_RESEL];
		break;
	}

	/*
	 * Look for another device that is ready.
	 * May want to keep last one started and increment for fairness
	 * rather than always starting at zero.
	 */
	for (i = 0; i < ASC_NCMD; i++) {
		/* don't restart a disconnected command */
		if (!asc->cmd[i] || (asc->st[i].flags & DISCONN))
			continue;
		asc_startcmd(asc, i);
		break;
	}

	/* signal device driver that the command is done */
	(*scsicmd->sd->sd_driver->d_done)(scsicmd->unit, state->error,
		state->buflen, state->statusByte);

	return (0);
}

/* ARGSUSED */
static int
asc_dma_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 len;

	/* check for previous chunk in buffer */
	if (state->flags & DMA_IN_PROGRESS) {
		/*
		 * Only count bytes that have been copied to memory.
		 * There may be some bytes in the FIFO if synchonous transfers
		 * are in progress.
		 */
		(*asc->dma_end)(asc, state, ASCDMA_READ);
		ASC_TC_GET(regs, len);
		len = state->dmalen - len;
		bcopy(state->dmaBufAddr, state->buf, len);
		state->buf += len;
		state->buflen -= len;
	}

	/* setup to start reading the next chunk */
	len = state->buflen;
	if (len > state->dmaBufSize)
		len = state->dmaBufSize;
	state->dmalen = len;
	(*asc->dma_start)(asc, state, state->dmaBufAddr, ASCDMA_READ);
	ASC_TC_PUT(regs, len);
#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_dma_in: 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_IN];
		return (0);
	}
	return (1);
}

/* ARGSUSED */
static int
asc_last_dma_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 len, fifo;

	/* copy data from buffer to main memory */
	(*asc->dma_end)(asc, state, ASCDMA_READ);
	ASC_TC_GET(regs, len);
	fifo = regs->asc_flags & ASC_FLAGS_FIFO_CNT;
#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_last_dma_in: buflen %d dmalen %d tc %d fifo %d\n",
			state->buflen, state->dmalen, len, fifo);
#endif
	if (fifo) {
		/* device must be trying to send more than we expect */
		regs->asc_cmd = ASC_CMD_FLUSH;
		readback(regs->asc_cmd);
	}
	state->flags &= ~DMA_IN_PROGRESS;
	len = state->dmalen - len;
	state->buflen -= len;
	bcopy(state->dmaBufAddr, state->buf, len);

	return (1);
}

/* ARGSUSED */
static int
asc_resume_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 len;

	/* setup to start reading the next chunk */
	len = state->buflen;
	if (len > state->dmaBufSize)
		len = state->dmaBufSize;
	state->dmalen = len;
	(*asc->dma_start)(asc, state, state->dmaBufAddr, ASCDMA_READ);
	ASC_TC_PUT(regs, len);
#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_resume_in: 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_IN];
		return (0);
	}
	return (1);
}

/* ARGSUSED */
static int
asc_resume_dma_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 len, off;

	/* setup to finish reading the current chunk */
	len = state->dmaresid;
	off = state->dmalen - len;
	if ((off & 1) && state->sync_offset) {
		printf("asc_resume_dma_in: odd xfer dmalen %d len %d off %d\n",
			state->dmalen, len, off); /* XXX */
		regs->asc_res_fifo = state->dmaBufAddr[off];
	}
	(*asc->dma_start)(asc, state, state->dmaBufAddr + off, ASCDMA_READ);
	ASC_TC_PUT(regs, len);
#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_resume_dma_in: 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_IN];
		return (0);
	}
	return (1);
}

/* ARGSUSED */
static int
asc_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, fifo;

	if (state->flags & DMA_IN_PROGRESS) {
		/* check to be sure previous chunk was finished */
		ASC_TC_GET(regs, len);
		fifo = regs->asc_flags & ASC_FLAGS_FIFO_CNT;
		if (len || fifo)
			printf("asc_dma_out: buflen %d dmalen %d tc %d fifo %d\n",
				state->buflen, state->dmalen, len, fifo); /* XXX */
		len += fifo;
		len = state->dmalen - len;
		state->buf += len;
		state->buflen -= len;
	}

	/* 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_dma_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_last_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, fifo;

	ASC_TC_GET(regs, len);
	fifo = regs->asc_flags & ASC_FLAGS_FIFO_CNT;
#ifdef DEBUG
	if (asc_debug > 2)
		printf("asc_last_dma_out: buflen %d dmalen %d tc %d fifo %d\n",
			state->buflen, state->dmalen, len, fifo);
#endif
	if (fifo) {
		len += fifo;
		regs->asc_cmd = ASC_CMD_FLUSH;
		readback(regs->asc_cmd);
		printf("asc_last_dma_out: buflen %d dmalen %d tc %d fifo %d\n",
			state->buflen, state->dmalen, len, fifo);
	}
	state->flags &= ~DMA_IN_PROGRESS;
	len = state->dmalen - len;
	state->buflen -= len;
	return (1);
}

/* ARGSUSED */
static int
asc_resume_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;