fas216.c

linux-2.6.15.6

 *  for new implementations.  The correct method is to respond to an
 *  SDTR message with a MESSAGE REJECT message if the either the
 *  initiator or target devices does not support synchronous transfers
 *  or does not want to negotiate for synchronous transfers at the time.
 *  Using the correct method assures compatibility with wide data
 *  transfers and future enhancements.
 *
 * We will always initiate a synchronous transfer negotiation request on
 * every INQUIRY or REQUEST SENSE message, unless the target itself has
 * at some point performed a synchronous transfer negotiation request, or
 * we have synchronous transfers disabled for this device.
 */

/**
 * fas216_handlesync - Handle a synchronous transfer message
 * @info: state structure for interface
 * @msg: message from target
 *
 * Handle a synchronous transfer message from the target
 */
static void fas216_handlesync(FAS216_Info *info, char *msg)
{
	struct fas216_device *dev = &info->device[info->SCpnt->device->id];
	enum { sync, async, none, reject } res = none;

#ifdef SCSI2_SYNC
	switch (msg[0]) {
	case MESSAGE_REJECT:
		/* Synchronous transfer request failed.
		 * Note: SCSI II r10:
		 *
		 *  SCSI devices that are capable of synchronous
		 *  data transfers shall not respond to an SDTR
		 *  message with a MESSAGE REJECT message.
		 *
		 * Hence, if we get this condition, we disable
		 * negotiation for this device.
		 */
		if (dev->sync_state == neg_inprogress) {
			dev->sync_state = neg_invalid;
			res = async;
		}
		break;

	case EXTENDED_MESSAGE:
		switch (dev->sync_state) {
		/* We don't accept synchronous transfer requests.
		 * Respond with a MESSAGE_REJECT to prevent a
		 * synchronous transfer agreement from being reached.
		 */
		case neg_invalid:
			res = reject;
			break;

		/* We were not negotiating a synchronous transfer,
		 * but the device sent us a negotiation request.
		 * Honour the request by sending back a SDTR
		 * message containing our capability, limited by
		 * the targets capability.
		 */
		default:
			fas216_cmd(info, CMD_SETATN);
			if (msg[4] > info->ifcfg.sync_max_depth)
				msg[4] = info->ifcfg.sync_max_depth;
			if (msg[3] < 1000 / info->ifcfg.clockrate)
				msg[3] = 1000 / info->ifcfg.clockrate;

			msgqueue_flush(&info->scsi.msgs);
			msgqueue_addmsg(&info->scsi.msgs, 5,
					EXTENDED_MESSAGE, 3, EXTENDED_SDTR,
					msg[3], msg[4]);
			info->scsi.phase = PHASE_MSGOUT_EXPECT;

			/* This is wrong.  The agreement is not in effect
			 * until this message is accepted by the device
			 */
			dev->sync_state = neg_targcomplete;
			res = sync;
			break;

		/* We initiated the synchronous transfer negotiation,
		 * and have successfully received a response from the
		 * target.  The synchronous transfer agreement has been
		 * reached.  Note: if the values returned are out of our
		 * bounds, we must reject the message.
		 */
		case neg_inprogress:
			res = reject;
			if (msg[4] <= info->ifcfg.sync_max_depth &&
			    msg[3] >= 1000 / info->ifcfg.clockrate) {
				dev->sync_state = neg_complete;
				res = sync;
			}
			break;
		}
	}
#else
	res = reject;
#endif

	switch (res) {
	case sync:
		dev->period = msg[3];
		dev->sof    = msg[4];
		dev->stp    = fas216_syncperiod(info, msg[3] * 4);
		fas216_set_sync(info, info->SCpnt->device->id);
		break;

	case reject:
		fas216_cmd(info, CMD_SETATN);
		msgqueue_flush(&info->scsi.msgs);
		msgqueue_addmsg(&info->scsi.msgs, 1, MESSAGE_REJECT);
		info->scsi.phase = PHASE_MSGOUT_EXPECT;

	case async:
		dev->period = info->ifcfg.asyncperiod / 4;
		dev->sof    = 0;
		dev->stp    = info->scsi.async_stp;
		fas216_set_sync(info, info->SCpnt->device->id);
		break;

	case none:
		break;
	}
}

/**
 * fas216_updateptrs - update data pointers after transfer suspended/paused
 * @info: interface's local pointer to update
 * @bytes_transferred: number of bytes transferred
 *
 * Update data pointers after transfer suspended/paused
 */
static void fas216_updateptrs(FAS216_Info *info, int bytes_transferred)
{
	struct scsi_pointer *SCp = &info->scsi.SCp;

	fas216_checkmagic(info);

	BUG_ON(bytes_transferred < 0);

	info->SCpnt->request_bufflen -= bytes_transferred;

	while (bytes_transferred != 0) {
		if (SCp->this_residual > bytes_transferred)
			break;
		/*
		 * We have used up this buffer.  Move on to the
		 * next buffer.
		 */
		bytes_transferred -= SCp->this_residual;
		if (!next_SCp(SCp) && bytes_transferred) {
			printk(KERN_WARNING "scsi%d.%c: out of buffers\n",
				info->host->host_no, '0' + info->SCpnt->device->id);
			return;
		}
	}

	SCp->this_residual -= bytes_transferred;
	if (SCp->this_residual)
		SCp->ptr += bytes_transferred;
	else
		SCp->ptr = NULL;
}

/**
 * fas216_pio - transfer data off of/on to card using programmed IO
 * @info: interface to transfer data to/from
 * @direction: direction to transfer data (DMA_OUT/DMA_IN)
 *
 * Transfer data off of/on to card using programmed IO.
 * Notes: this is incredibly slow.
 */
static void fas216_pio(FAS216_Info *info, fasdmadir_t direction)
{
	struct scsi_pointer *SCp = &info->scsi.SCp;

	fas216_checkmagic(info);

	if (direction == DMA_OUT)
		fas216_writeb(info, REG_FF, get_next_SCp_byte(SCp));
	else
		put_next_SCp_byte(SCp, fas216_readb(info, REG_FF));

	if (SCp->this_residual == 0)
		next_SCp(SCp);
}

static void fas216_set_stc(FAS216_Info *info, unsigned int length)
{
	fas216_writeb(info, REG_STCL, length);
	fas216_writeb(info, REG_STCM, length >> 8);
	fas216_writeb(info, REG_STCH, length >> 16);
}

static unsigned int fas216_get_ctc(FAS216_Info *info)
{
	return fas216_readb(info, REG_CTCL) +
	       (fas216_readb(info, REG_CTCM) << 8) +
	       (fas216_readb(info, REG_CTCH) << 16);
}

/**
 * fas216_cleanuptransfer - clean up after a transfer has completed.
 * @info: interface to clean up
 *
 * Update the data pointers according to the number of bytes transferred
 * on the SCSI bus.
 */
static void fas216_cleanuptransfer(FAS216_Info *info)
{
	unsigned long total, residual, fifo;
	fasdmatype_t dmatype = info->dma.transfer_type;

	info->dma.transfer_type = fasdma_none;

	/*
	 * PIO transfers do not need to be cleaned up.
	 */
	if (dmatype == fasdma_pio || dmatype == fasdma_none)
		return;

	if (dmatype == fasdma_real_all)
		total = info->SCpnt->request_bufflen;
	else
		total = info->scsi.SCp.this_residual;

	residual = fas216_get_ctc(info);

	fifo = fas216_readb(info, REG_CFIS) & CFIS_CF;

	fas216_log(info, LOG_BUFFER, "cleaning up from previous "
		   "transfer: length 0x%06x, residual 0x%x, fifo %d",
		   total, residual, fifo);

	/*
	 * If we were performing Data-Out, the transfer counter
	 * counts down each time a byte is transferred by the
	 * host to the FIFO.  This means we must include the
	 * bytes left in the FIFO from the transfer counter.
	 */
	if (info->scsi.phase == PHASE_DATAOUT)
		residual += fifo;

	fas216_updateptrs(info, total - residual);
}

/**
 * fas216_transfer - Perform a DMA/PIO transfer off of/on to card
 * @info: interface from which device disconnected from
 *
 * Start a DMA/PIO transfer off of/on to card
 */
static void fas216_transfer(FAS216_Info *info)
{
	fasdmadir_t direction;
	fasdmatype_t dmatype;

	fas216_log(info, LOG_BUFFER,
		   "starttransfer: buffer %p length 0x%06x reqlen 0x%06x",
		   info->scsi.SCp.ptr, info->scsi.SCp.this_residual,
		   info->SCpnt->request_bufflen);

	if (!info->scsi.SCp.ptr) {
		fas216_log(info, LOG_ERROR, "null buffer passed to "
			   "fas216_starttransfer");
		print_SCp(&info->scsi.SCp, "SCp: ", "\n");
		print_SCp(&info->SCpnt->SCp, "Cmnd SCp: ", "\n");
		return;
	}

	/*
	 * If we have a synchronous transfer agreement in effect, we must
	 * use DMA mode.  If we are using asynchronous transfers, we may
	 * use DMA mode or PIO mode.
	 */
	if (info->device[info->SCpnt->device->id].sof)
		dmatype = fasdma_real_all;
	else
		dmatype = fasdma_pio;

	if (info->scsi.phase == PHASE_DATAOUT)
		direction = DMA_OUT;
	else
		direction = DMA_IN;

	if (info->dma.setup)
		dmatype = info->dma.setup(info->host, &info->scsi.SCp,
					  direction, dmatype);
	info->dma.transfer_type = dmatype;

	if (dmatype == fasdma_real_all)
		fas216_set_stc(info, info->SCpnt->request_bufflen);
	else
		fas216_set_stc(info, info->scsi.SCp.this_residual);

	switch (dmatype) {
	case fasdma_pio:
		fas216_log(info, LOG_BUFFER, "PIO transfer");
		fas216_writeb(info, REG_SOF, 0);
		fas216_writeb(info, REG_STP, info->scsi.async_stp);
		fas216_cmd(info, CMD_TRANSFERINFO);
		fas216_pio(info, direction);
		break;

	case fasdma_pseudo:
		fas216_log(info, LOG_BUFFER, "pseudo transfer");
		fas216_cmd(info, CMD_TRANSFERINFO | CMD_WITHDMA);
		info->dma.pseudo(info->host, &info->scsi.SCp,
				 direction, info->SCpnt->transfersize);
		break;

	case fasdma_real_block:
		fas216_log(info, LOG_BUFFER, "block dma transfer");
		fas216_cmd(info, CMD_TRANSFERINFO | CMD_WITHDMA);
		break;

	case fasdma_real_all:
		fas216_log(info, LOG_BUFFER, "total dma transfer");
		fas216_cmd(info, CMD_TRANSFERINFO | CMD_WITHDMA);
		break;

	default:
		fas216_log(info, LOG_BUFFER | LOG_ERROR,
			   "invalid FAS216 DMA type");
		break;
	}
}

/**
 * fas216_stoptransfer - Stop a DMA transfer onto / off of the card
 * @info: interface from which device disconnected from
 *
 * Called when we switch away from DATA IN or DATA OUT phases.
 */
static void fas216_stoptransfer(FAS216_Info *info)
{
	fas216_checkmagic(info);

	if (info->dma.transfer_type == fasdma_real_all ||
	    info->dma.transfer_type == fasdma_real_block)
		info->dma.stop(info->host, &info->scsi.SCp);

	fas216_cleanuptransfer(info);

	if (info->scsi.phase == PHASE_DATAIN) {
		unsigned int fifo;

		/*
		 * If we were performing Data-In, then the FIFO counter
		 * contains the number of bytes not transferred via DMA
		 * from the on-board FIFO.  Read them manually.
		 */
		fifo = fas216_readb(info, REG_CFIS) & CFIS_CF;
		while (fifo && info->scsi.SCp.ptr) {
			*info->scsi.SCp.ptr = fas216_readb(info, REG_FF);
			fas216_updateptrs(info, 1);
			fifo--;
		}
	} else {
		/*
		 * After a Data-Out phase, there may be unsent
		 * bytes left in the FIFO.  Flush them out.
		 */
		fas216_cmd(info, CMD_FLUSHFIFO);
	}
}

static void fas216_aborttransfer(FAS216_Info *info)
{
	fas216_checkmagic(info);

	if (info->dma.transfer_type == fasdma_real_all ||
	    info->dma.transfer_type == fasdma_real_block)
		info->dma.stop(info->host, &info->scsi.SCp);

	info->dma.transfer_type = fasdma_none;
	fas216_cmd(info, CMD_FLUSHFIFO);
}

static void fas216_kick(FAS216_Info *info);

/**
 * fas216_disconnected_intr - handle device disconnection
 * @info: interface from which device disconnected from
 *
 * Handle device disconnection
 */
static void fas216_disconnect_intr(FAS216_Info *info)
{
	unsigned long flags;

	fas216_checkmagic(info);

	fas216_log(info, LOG_CONNECT, "disconnect phase=%02x",
		   info->scsi.phase);

	msgqueue_flush(&info->scsi.msgs);

	switch (info->scsi.phase) {
	case PHASE_SELECTION:			/* while selecting - no target		*/
	case PHASE_SELSTEPS:
		fas216_done(info, DID_NO_CONNECT);
		break;

	case PHASE_MSGIN_DISCONNECT:		/* message in - disconnecting		*/
		info->scsi.disconnectable = 1;
		info->scsi.phase = PHASE_IDLE;
		info->stats.disconnects += 1;
		spin_lock_irqsave(&info->host_lock, flags);
		if (info->scsi.phase == PHASE_IDLE)
			fas216_kick(info);
		spin_unlock_irqrestore(&info->host_lock, flags);
		break;

	case PHASE_DONE:			/* at end of command - complete		*/
		fas216_done(info, DID_OK);
		break;

	case PHASE_MSGOUT:			/* message out - possible ABORT message	*/
		if (fas216_get_last_msg(info, info->scsi.msgin_fifo) == ABORT) {
			info->scsi.aborting = 0;
			fas216_done(info, DID_ABORT);
			break;
		}

	default:				/* huh?					*/
		printk(KERN_ERR "scsi%d.%c: unexpected disconnect in phase %s\n",
			info->host->host_no, fas216_target(info), fas216_drv_phase(info));
		print_debug_list();
		fas216_stoptransfer(info);
		fas216_done(info, DID_ERROR);
		break;
	}
}

/**
 * fas216_reselected_intr - start reconnection of a device
 * @info: interface which was reselected
 *
 * Start reconnection of a device
 */
static void
fas216_reselected_intr(FAS216_Info *info)
{
	unsigned int cfis, i;
	unsigned char msg[4];
	unsigned char target, lun, tag;

	fas216_checkmagic(info);

	WARN_ON(info->scsi.phase == PHASE_SELECTION ||
		info->scsi.phase == PHASE_SELSTEPS);

	cfis = fas216_readb(info, REG_CFIS);

	fas216_log(info, LOG_CONNECT, "reconnect phase=%02x cfis=%02x",
		   info->scsi.phase, cfis);

	cfis &= CFIS_CF;

	if (cfis < 2 || cfis > 4) {
		printk(KERN_ERR "scsi%d.H: incorrect number of bytes after reselect\n",
			info->host->host_no);
		goto bad_message;
	}

	for (i = 0; i < cfis; i++)
		msg[i] = fas216_readb(info, REG_FF);

	if (!(msg[0] & (1 << info->host->this_id)) ||
	    !(msg[1] & 0x80))
		goto initiator_error;

	target = msg[0] & ~(1 << info->host->this_id);
	target = ffs(target) - 1;
	lun = msg[1] & 7;
	tag = 0;

	if (cfis >= 3) {
		if (msg[2] != SIMPLE_QUEUE_TAG)
			goto initiator_error;

		tag = msg[3];
	}

	/* set up for synchronous transfers */
	fas216_writeb(info, REG_SDID, target);
	fas216_set_sync(info, target);
	msgqueue_flush(&info->scsi.msgs);

	fas216_log(info, LOG_CONNECT, "Reconnected: target %1x lun %1x tag %02x",
		   target, lun, tag);

	if (info->scsi.disconnectable && info->SCpnt) {