mesh.c

linux 内核源代码

	}
	dlog(ms, "after arb, intr/exc/err/fc=%.8x",
	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
	if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
	    && (in_8(&mr->bus_status0) & BS0_IO)) {
		/* looks like a reselection - try resetting the mesh */
		dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
		out_8(&mr->sequence, SEQ_RESETMESH);
		mesh_flush_io(mr);
		udelay(10);
		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
		out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
		out_8(&mr->sequence, SEQ_ENBRESEL);
		mesh_flush_io(mr);
		for (t = 10; t > 0 && in_8(&mr->interrupt) == 0; --t)
			udelay(1);
		dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
#ifndef MESH_MULTIPLE_HOSTS
		if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
		    && (in_8(&mr->bus_status0) & BS0_IO)) {
			printk(KERN_ERR "mesh: controller not responding"
			       " to reselection!\n");
			/*
			 * If this is a target reselecting us, and the
			 * mesh isn't responding, the higher levels of
			 * the scsi code will eventually time out and
			 * reset the bus.
			 */
		}
#endif
	}
}

/*
 * Start the next command for a MESH.
 * Should be called with interrupts disabled.
 */
static void mesh_start(struct mesh_state *ms)
{
	struct scsi_cmnd *cmd, *prev, *next;

	if (ms->phase != idle || ms->current_req != NULL) {
		printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
		       ms->phase, ms);
		return;
	}

	while (ms->phase == idle) {
		prev = NULL;
		for (cmd = ms->request_q; ; cmd = (struct scsi_cmnd *) cmd->host_scribble) {
			if (cmd == NULL)
				return;
			if (ms->tgts[cmd->device->id].current_req == NULL)
				break;
			prev = cmd;
		}
		next = (struct scsi_cmnd *) cmd->host_scribble;
		if (prev == NULL)
			ms->request_q = next;
		else
			prev->host_scribble = (void *) next;
		if (next == NULL)
			ms->request_qtail = prev;

		mesh_start_cmd(ms, cmd);
	}
}

static void mesh_done(struct mesh_state *ms, int start_next)
{
	struct scsi_cmnd *cmd;
	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];

	cmd = ms->current_req;
	ms->current_req = NULL;
	tp->current_req = NULL;
	if (cmd) {
		cmd->result = (ms->stat << 16) + cmd->SCp.Status;
		if (ms->stat == DID_OK)
			cmd->result += (cmd->SCp.Message << 8);
		if (DEBUG_TARGET(cmd)) {
			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
			       cmd->result, ms->data_ptr, scsi_bufflen(cmd));
#if 0
			/* needs to use sg? */
			if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
			    && cmd->request_buffer != 0) {
				unsigned char *b = cmd->request_buffer;
				printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
				       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
			}
#endif
		}
		cmd->SCp.this_residual -= ms->data_ptr;
		mesh_completed(ms, cmd);
	}
	if (start_next) {
		out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
		mesh_flush_io(ms->mesh);
		udelay(1);
		ms->phase = idle;
		mesh_start(ms);
	}
}

static inline void add_sdtr_msg(struct mesh_state *ms)
{
	int i = ms->n_msgout;

	ms->msgout[i] = EXTENDED_MESSAGE;
	ms->msgout[i+1] = 3;
	ms->msgout[i+2] = EXTENDED_SDTR;
	ms->msgout[i+3] = mesh_sync_period/4;
	ms->msgout[i+4] = (ALLOW_SYNC(ms->conn_tgt)? mesh_sync_offset: 0);
	ms->n_msgout = i + 5;
}

static void set_sdtr(struct mesh_state *ms, int period, int offset)
{
	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
	volatile struct mesh_regs __iomem *mr = ms->mesh;
	int v, tr;

	tp->sdtr_state = sdtr_done;
	if (offset == 0) {
		/* asynchronous */
		if (SYNC_OFF(tp->sync_params))
			printk(KERN_INFO "mesh: target %d now asynchronous\n",
			       ms->conn_tgt);
		tp->sync_params = ASYNC_PARAMS;
		out_8(&mr->sync_params, ASYNC_PARAMS);
		return;
	}
	/*
	 * We need to compute ceil(clk_freq * period / 500e6) - 2
	 * without incurring overflow.
	 */
	v = (ms->clk_freq / 5000) * period;
	if (v <= 250000) {
		/* special case: sync_period == 5 * clk_period */
		v = 0;
		/* units of tr are 100kB/s */
		tr = (ms->clk_freq + 250000) / 500000;
	} else {
		/* sync_period == (v + 2) * 2 * clk_period */
		v = (v + 99999) / 100000 - 2;
		if (v > 15)
			v = 15;	/* oops */
		tr = ((ms->clk_freq / (v + 2)) + 199999) / 200000;
	}
	if (offset > 15)
		offset = 15;	/* can't happen */
	tp->sync_params = SYNC_PARAMS(offset, v);
	out_8(&mr->sync_params, tp->sync_params);
	printk(KERN_INFO "mesh: target %d synchronous at %d.%d MB/s\n",
	       ms->conn_tgt, tr/10, tr%10);
}

static void start_phase(struct mesh_state *ms)
{
	int i, seq, nb;
	volatile struct mesh_regs __iomem *mr = ms->mesh;
	volatile struct dbdma_regs __iomem *md = ms->dma;
	struct scsi_cmnd *cmd = ms->current_req;
	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];

	dlog(ms, "start_phase nmo/exc/fc/seq = %.8x",
	     MKWORD(ms->n_msgout, mr->exception, mr->fifo_count, mr->sequence));
	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
	switch (ms->msgphase) {
	case msg_none:
		break;

	case msg_in:
		out_8(&mr->count_hi, 0);
		out_8(&mr->count_lo, 1);
		out_8(&mr->sequence, SEQ_MSGIN + seq);
		ms->n_msgin = 0;
		return;

	case msg_out:
		/*
		 * To make sure ATN drops before we assert ACK for
		 * the last byte of the message, we have to do the
		 * last byte specially.
		 */
		if (ms->n_msgout <= 0) {
			printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
			       ms->n_msgout);
			mesh_dump_regs(ms);
			ms->msgphase = msg_none;
			break;
		}
		if (ALLOW_DEBUG(ms->conn_tgt)) {
			printk(KERN_DEBUG "mesh: sending %d msg bytes:",
			       ms->n_msgout);
			for (i = 0; i < ms->n_msgout; ++i)
				printk(" %x", ms->msgout[i]);
			printk("\n");
		}
		dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
						ms->msgout[1], ms->msgout[2]));
		out_8(&mr->count_hi, 0);
		out_8(&mr->sequence, SEQ_FLUSHFIFO);
		mesh_flush_io(mr);
		udelay(1);
		/*
		 * If ATN is not already asserted, we assert it, then
		 * issue a SEQ_MSGOUT to get the mesh to drop ACK.
		 */
		if ((in_8(&mr->bus_status0) & BS0_ATN) == 0) {
			dlog(ms, "bus0 was %.2x explicitly asserting ATN", mr->bus_status0);
			out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
			mesh_flush_io(mr);
			udelay(1);
			out_8(&mr->count_lo, 1);
			out_8(&mr->sequence, SEQ_MSGOUT + seq);
			out_8(&mr->bus_status0, 0); /* release explicit ATN */
			dlog(ms,"hace: after explicit ATN bus0=%.2x",mr->bus_status0);
		}
		if (ms->n_msgout == 1) {
			/*
			 * We can't issue the SEQ_MSGOUT without ATN
			 * until the target has asserted REQ.  The logic
			 * in cmd_complete handles both situations:
			 * REQ already asserted or not.
			 */
			cmd_complete(ms);
		} else {
			out_8(&mr->count_lo, ms->n_msgout - 1);
			out_8(&mr->sequence, SEQ_MSGOUT + seq);
			for (i = 0; i < ms->n_msgout - 1; ++i)
				out_8(&mr->fifo, ms->msgout[i]);
		}
		return;

	default:
		printk(KERN_ERR "mesh bug: start_phase msgphase=%d\n",
		       ms->msgphase);
	}

	switch (ms->phase) {
	case selecting:
		out_8(&mr->dest_id, ms->conn_tgt);
		out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
		break;
	case commanding:
		out_8(&mr->sync_params, tp->sync_params);
		out_8(&mr->count_hi, 0);
		if (cmd) {
			out_8(&mr->count_lo, cmd->cmd_len);
			out_8(&mr->sequence, SEQ_COMMAND + seq);
			for (i = 0; i < cmd->cmd_len; ++i)
				out_8(&mr->fifo, cmd->cmnd[i]);
		} else {
			out_8(&mr->count_lo, 6);
			out_8(&mr->sequence, SEQ_COMMAND + seq);
			for (i = 0; i < 6; ++i)
				out_8(&mr->fifo, 0);
		}
		break;
	case dataing:
		/* transfer data, if any */
		if (!ms->dma_started) {
			set_dma_cmds(ms, cmd);
			out_le32(&md->cmdptr, virt_to_phys(ms->dma_cmds));
			out_le32(&md->control, (RUN << 16) | RUN);
			ms->dma_started = 1;
		}
		nb = ms->dma_count;
		if (nb > 0xfff0)
			nb = 0xfff0;
		ms->dma_count -= nb;
		ms->data_ptr += nb;
		out_8(&mr->count_lo, nb);
		out_8(&mr->count_hi, nb >> 8);
		out_8(&mr->sequence, (tp->data_goes_out?
				SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
		break;
	case statusing:
		out_8(&mr->count_hi, 0);
		out_8(&mr->count_lo, 1);
		out_8(&mr->sequence, SEQ_STATUS + seq);
		break;
	case busfreeing:
	case disconnecting:
		out_8(&mr->sequence, SEQ_ENBRESEL);
		mesh_flush_io(mr);
		udelay(1);
		dlog(ms, "enbresel intr/exc/err/fc=%.8x",
		     MKWORD(mr->interrupt, mr->exception, mr->error,
			    mr->fifo_count));
		out_8(&mr->sequence, SEQ_BUSFREE);
		break;
	default:
		printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
		       ms->phase);
		dumpslog(ms);
	}

}

static inline void get_msgin(struct mesh_state *ms)
{
	volatile struct mesh_regs __iomem *mr = ms->mesh;
	int i, n;

	n = mr->fifo_count;
	if (n != 0) {
		i = ms->n_msgin;
		ms->n_msgin = i + n;
		for (; n > 0; --n)
			ms->msgin[i++] = in_8(&mr->fifo);
	}
}

static inline int msgin_length(struct mesh_state *ms)
{
	int b, n;

	n = 1;
	if (ms->n_msgin > 0) {
		b = ms->msgin[0];
		if (b == 1) {
			/* extended message */
			n = ms->n_msgin < 2? 2: ms->msgin[1] + 2;
		} else if (0x20 <= b && b <= 0x2f) {
			/* 2-byte message */
			n = 2;
		}
	}
	return n;
}

static void reselected(struct mesh_state *ms)
{
	volatile struct mesh_regs __iomem *mr = ms->mesh;
	struct scsi_cmnd *cmd;
	struct mesh_target *tp;
	int b, t, prev;

	switch (ms->phase) {
	case idle:
		break;
	case arbitrating:
		if ((cmd = ms->current_req) != NULL) {
			/* put the command back on the queue */
			cmd->host_scribble = (void *) ms->request_q;
			if (ms->request_q == NULL)
				ms->request_qtail = cmd;
			ms->request_q = cmd;
			tp = &ms->tgts[cmd->device->id];
			tp->current_req = NULL;
		}
		break;
	case busfreeing:
		ms->phase = reselecting;
		mesh_done(ms, 0);
		break;
	case disconnecting:
		break;
	default:
		printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
		       ms->msgphase, ms->phase, ms->conn_tgt);
		dumplog(ms, ms->conn_tgt);
		dumpslog(ms);
	}

	if (ms->dma_started) {
		printk(KERN_ERR "mesh: reselected with DMA started !\n");
		halt_dma(ms);
	}
	ms->current_req = NULL;
	ms->phase = dataing;
	ms->msgphase = msg_in;
	ms->n_msgout = 0;
	ms->last_n_msgout = 0;
	prev = ms->conn_tgt;

	/*
	 * We seem to get abortive reselections sometimes.
	 */
	while ((in_8(&mr->bus_status1) & BS1_BSY) == 0) {
		static int mesh_aborted_resels;
		mesh_aborted_resels++;
		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
		mesh_flush_io(mr);
		udelay(1);
		out_8(&mr->sequence, SEQ_ENBRESEL);
		mesh_flush_io(mr);
		udelay(5);
		dlog(ms, "extra resel err/exc/fc = %.6x",
		     MKWORD(0, mr->error, mr->exception, mr->fifo_count));
	}
	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
       	mesh_flush_io(mr);
	udelay(1);
	out_8(&mr->sequence, SEQ_ENBRESEL);
       	mesh_flush_io(mr);
	udelay(1);
	out_8(&mr->sync_params, ASYNC_PARAMS);

	/*
	 * Find out who reselected us.
	 */
	if (in_8(&mr->fifo_count) == 0) {
		printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
		ms->conn_tgt = ms->host->this_id;
		goto bogus;
	}
	/* get the last byte in the fifo */
	do {
		b = in_8(&mr->fifo);
		dlog(ms, "reseldata %x", b);
	} while (in_8(&mr->fifo_count));
	for (t = 0; t < 8; ++t)
		if ((b & (1 << t)) != 0 && t != ms->host->this_id)
			break;
	if (b != (1 << t) + (1 << ms->host->this_id)) {
		printk(KERN_ERR "mesh: bad reselection data %x\n", b);
		ms->conn_tgt = ms->host->this_id;
		goto bogus;
	}


	/*
	 * Set up to continue with that target's transfer.
	 */
	ms->conn_tgt = t;
	tp = &ms->tgts[t];
	out_8(&mr->sync_params, tp->sync_params);
	if (ALLOW_DEBUG(t)) {
		printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
		printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
		       tp->saved_ptr, tp->data_goes_out, tp->current_req);
	}
	ms->current_req = tp->current_req;
	if (tp->current_req == NULL) {
		printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
		goto bogus;
	}
	ms->data_ptr = tp->saved_ptr;
	dlog(ms, "resel prev tgt=%d", prev);
	dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
	start_phase(ms);
	return;

bogus:
	dumplog(ms, ms->conn_tgt);
	dumpslog(ms);
	ms->data_ptr = 0;
	ms->aborting = 1;
	start_phase(ms);
}

static void do_abort(struct mesh_state *ms)
{
	ms->msgout[0] = ABORT;
	ms->n_msgout = 1;
	ms->aborting = 1;
	ms->stat = DID_ABORT;
	dlog(ms, "abort", 0);
}

static void handle_reset(struct mesh_state *ms)
{
	int tgt;
	struct mesh_target *tp;
	struct scsi_cmnd *cmd;
	volatile struct mesh_regs __iomem *mr = ms->mesh;

	for (tgt = 0; tgt < 8; ++tgt) {
		tp = &ms->tgts[tgt];
		if ((cmd = tp->current_req) != NULL) {
			cmd->result = DID_RESET << 16;
			tp->current_req = NULL;
			mesh_completed(ms, cmd);
		}
		ms->tgts[tgt].sdtr_state = do_sdtr;
		ms->tgts[tgt].sync_params = ASYNC_PARAMS;
	}
	ms->current_req = NULL;
	while ((cmd = ms->request_q) != NULL) {
		ms->request_q = (struct scsi_cmnd *) cmd->host_scribble;
		cmd->result = DID_RESET << 16;
		mesh_completed(ms, cmd);
	}
	ms->phase = idle;
	ms->msgphase = msg_none;
	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
	out_8(&mr->sequence, SEQ_FLUSHFIFO);
       	mesh_flush_io(mr);
	udelay(1);
	out_8(&mr->sync_params, ASYNC_PARAMS);
	out_8(&mr->sequence, SEQ_ENBRESEL);
}

static irqreturn_t do_mesh_interrupt(int irq, void *dev_id)
{
	unsigned long flags;
	struct mesh_state *ms = dev_id;
	struct Scsi_Host *dev = ms->host;
	
	spin_lock_irqsave(dev->host_lock, flags);
	mesh_interrupt(ms);
	spin_unlock_irqrestore(dev->host_lock, flags);
	return IRQ_HANDLED;
}

static void handle_error(struct mesh_state *ms)
{
	int err, exc, count;
	volatile struct mesh_regs __iomem *mr = ms->mesh;

	err = in_8(&mr->error);
	exc = in_8(&mr->exception);
	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);