Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 2062 insertions, 0 deletions

diff --git a/drivers/scsi/mesh.c b/drivers/scsi/mesh.c
new file mode 100644
index 00000000000..85f3a74ac42
--- /dev/null
+++ b/drivers/scsi/mesh.c
@@ -0,0 +1,2062 @@
+/*
+ * SCSI low-level driver for the MESH (Macintosh Enhanced SCSI Hardware)
+ * bus adaptor found on Power Macintosh computers.
+ * We assume the MESH is connected to a DBDMA (descriptor-based DMA)
+ * controller.
+ *
+ * Paul Mackerras, August 1996.
+ * Copyright (C) 1996 Paul Mackerras.
+ *
+ * Apr. 21 2002  - BenH		Rework bus reset code for new error handler
+ *                              Add delay after initial bus reset
+ *                              Add module parameters
+ *
+ * Sep. 27 2003  - BenH		Move to new driver model, fix some write posting
+ *				issues
+ * To do:
+ * - handle aborts correctly
+ * - retry arbitration if lost (unless higher levels do this for us)
+ * - power down the chip when no device is detected
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/interrupt.h>
+#include <linux/reboot.h>
+#include <linux/spinlock.h>
+#include <asm/dbdma.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/prom.h>
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/hydra.h>
+#include <asm/processor.h>
+#include <asm/machdep.h>
+#include <asm/pmac_feature.h>
+#include <asm/pci-bridge.h>
+#include <asm/macio.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+#include "mesh.h"
+
+#if 1
+#undef KERN_DEBUG
+#define KERN_DEBUG KERN_WARNING
+#endif
+
+MODULE_AUTHOR("Paul Mackerras (paulus@samba.org)");
+MODULE_DESCRIPTION("PowerMac MESH SCSI driver");
+MODULE_LICENSE("GPL");
+
+static int sync_rate = CONFIG_SCSI_MESH_SYNC_RATE;
+static int sync_targets = 0xff;
+static int resel_targets = 0xff;
+static int debug_targets = 0;	/* print debug for these targets */
+static int init_reset_delay = CONFIG_SCSI_MESH_RESET_DELAY_MS;
+
+module_param(sync_rate, int, 0);
+MODULE_PARM_DESC(sync_rate, "Synchronous rate (0..10, 0=async)");
+module_param(sync_targets, int, 0);
+MODULE_PARM_DESC(sync_targets, "Bitmask of targets allowed to set synchronous");
+module_param(resel_targets, int, 0);
+MODULE_PARM_DESC(resel_targets, "Bitmask of targets allowed to set disconnect");
+module_param(debug_targets, int, 0644);
+MODULE_PARM_DESC(debug_targets, "Bitmask of debugged targets");
+module_param(init_reset_delay, int, 0);
+MODULE_PARM_DESC(init_reset_delay, "Initial bus reset delay (0=no reset)");
+
+static int mesh_sync_period = 100;
+static int mesh_sync_offset = 0;
+static unsigned char use_active_neg = 0;  /* bit mask for SEQ_ACTIVE_NEG if used */
+
+#define ALLOW_SYNC(tgt)		((sync_targets >> (tgt)) & 1)
+#define ALLOW_RESEL(tgt)	((resel_targets >> (tgt)) & 1)
+#define ALLOW_DEBUG(tgt)	((debug_targets >> (tgt)) & 1)
+#define DEBUG_TARGET(cmd)	((cmd) && ALLOW_DEBUG((cmd)->device->id))
+
+#undef MESH_DBG
+#define N_DBG_LOG	50
+#define N_DBG_SLOG	20
+#define NUM_DBG_EVENTS	13
+#undef	DBG_USE_TB		/* bombs on 601 */
+
+struct dbglog {
+	char	*fmt;
+	u32	tb;
+	u8	phase;
+	u8	bs0;
+	u8	bs1;
+	u8	tgt;
+	int	d;
+};
+
+enum mesh_phase {
+	idle,
+	arbitrating,
+	selecting,
+	commanding,
+	dataing,
+	statusing,
+	busfreeing,
+	disconnecting,
+	reselecting,
+	sleeping
+};
+
+enum msg_phase {
+	msg_none,
+	msg_out,
+	msg_out_xxx,
+	msg_out_last,
+	msg_in,
+	msg_in_bad,
+};
+
+enum sdtr_phase {
+	do_sdtr,
+	sdtr_sent,
+	sdtr_done
+};
+
+struct mesh_target {
+	enum sdtr_phase sdtr_state;
+	int	sync_params;
+	int	data_goes_out;		/* guess as to data direction */
+	struct scsi_cmnd *current_req;
+	u32	saved_ptr;
+#ifdef MESH_DBG
+	int	log_ix;
+	int	n_log;
+	struct dbglog log[N_DBG_LOG];
+#endif
+};
+
+struct mesh_state {
+	volatile struct	mesh_regs __iomem *mesh;
+	int	meshintr;
+	volatile struct	dbdma_regs __iomem *dma;
+	int	dmaintr;
+	struct	Scsi_Host *host;
+	struct	mesh_state *next;
+	struct scsi_cmnd *request_q;
+	struct scsi_cmnd *request_qtail;
+	enum mesh_phase phase;		/* what we're currently trying to do */
+	enum msg_phase msgphase;
+	int	conn_tgt;		/* target we're connected to */
+	struct scsi_cmnd *current_req;		/* req we're currently working on */
+	int	data_ptr;
+	int	dma_started;
+	int	dma_count;
+	int	stat;
+	int	aborting;
+	int	expect_reply;
+	int	n_msgin;
+	u8	msgin[16];
+	int	n_msgout;
+	int	last_n_msgout;
+	u8	msgout[16];
+	struct dbdma_cmd *dma_cmds;	/* space for dbdma commands, aligned */
+	dma_addr_t dma_cmd_bus;
+	void	*dma_cmd_space;
+	int	dma_cmd_size;
+	int	clk_freq;
+	struct mesh_target tgts[8];
+	struct macio_dev *mdev;
+	struct pci_dev* pdev;
+#ifdef MESH_DBG
+	int	log_ix;
+	int	n_log;
+	struct dbglog log[N_DBG_SLOG];
+#endif
+};
+
+/*
+ * Driver is too messy, we need a few prototypes...
+ */
+static void mesh_done(struct mesh_state *ms, int start_next);
+static void mesh_interrupt(int irq, void *dev_id, struct pt_regs *ptregs);
+static void cmd_complete(struct mesh_state *ms);
+static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd);
+static void halt_dma(struct mesh_state *ms);
+static void phase_mismatch(struct mesh_state *ms);
+
+
+/*
+ * Some debugging & logging routines
+ */
+
+#ifdef MESH_DBG
+
+static inline u32 readtb(void)
+{
+	u32 tb;
+
+#ifdef DBG_USE_TB
+	/* Beware: if you enable this, it will crash on 601s. */
+	asm ("mftb %0" : "=r" (tb) : );
+#else
+	tb = 0;
+#endif
+	return tb;
+}
+
+static void dlog(struct mesh_state *ms, char *fmt, int a)
+{
+	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
+	struct dbglog *tlp, *slp;
+
+	tlp = &tp->log[tp->log_ix];
+	slp = &ms->log[ms->log_ix];
+	tlp->fmt = fmt;
+	tlp->tb = readtb();
+	tlp->phase = (ms->msgphase << 4) + ms->phase;
+	tlp->bs0 = ms->mesh->bus_status0;
+	tlp->bs1 = ms->mesh->bus_status1;
+	tlp->tgt = ms->conn_tgt;
+	tlp->d = a;
+	*slp = *tlp;
+	if (++tp->log_ix >= N_DBG_LOG)
+		tp->log_ix = 0;
+	if (tp->n_log < N_DBG_LOG)
+		++tp->n_log;
+	if (++ms->log_ix >= N_DBG_SLOG)
+		ms->log_ix = 0;
+	if (ms->n_log < N_DBG_SLOG)
+		++ms->n_log;
+}
+
+static void dumplog(struct mesh_state *ms, int t)
+{
+	struct mesh_target *tp = &ms->tgts[t];
+	struct dbglog *lp;
+	int i;
+
+	if (tp->n_log == 0)
+		return;
+	i = tp->log_ix - tp->n_log;
+	if (i < 0)
+		i += N_DBG_LOG;
+	tp->n_log = 0;
+	do {
+		lp = &tp->log[i];
+		printk(KERN_DEBUG "mesh log %d: bs=%.2x%.2x ph=%.2x ",
+		       t, lp->bs1, lp->bs0, lp->phase);
+#ifdef DBG_USE_TB
+		printk("tb=%10u ", lp->tb);
+#endif
+		printk(lp->fmt, lp->d);
+		printk("\n");
+		if (++i >= N_DBG_LOG)
+			i = 0;
+	} while (i != tp->log_ix);
+}
+
+static void dumpslog(struct mesh_state *ms)
+{
+	struct dbglog *lp;
+	int i;
+
+	if (ms->n_log == 0)
+		return;
+	i = ms->log_ix - ms->n_log;
+	if (i < 0)
+		i += N_DBG_SLOG;
+	ms->n_log = 0;
+	do {
+		lp = &ms->log[i];
+		printk(KERN_DEBUG "mesh log: bs=%.2x%.2x ph=%.2x t%d ",
+		       lp->bs1, lp->bs0, lp->phase, lp->tgt);
+#ifdef DBG_USE_TB
+		printk("tb=%10u ", lp->tb);
+#endif
+		printk(lp->fmt, lp->d);
+		printk("\n");
+		if (++i >= N_DBG_SLOG)
+			i = 0;
+	} while (i != ms->log_ix);
+}
+
+#else
+
+static inline void dlog(struct mesh_state *ms, char *fmt, int a)
+{}
+static inline void dumplog(struct mesh_state *ms, int tgt)
+{}
+static inline void dumpslog(struct mesh_state *ms)
+{}
+
+#endif /* MESH_DBG */
+
+#define MKWORD(a, b, c, d)	(((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
+
+static void
+mesh_dump_regs(struct mesh_state *ms)
+{
+	volatile struct mesh_regs __iomem *mr = ms->mesh;
+	volatile struct dbdma_regs __iomem *md = ms->dma;
+	int t;
+	struct mesh_target *tp;
+
+	printk(KERN_DEBUG "mesh: state at %p, regs at %p, dma at %p\n",
+	       ms, mr, md);
+	printk(KERN_DEBUG "    ct=%4x seq=%2x bs=%4x fc=%2x "
+	       "exc=%2x err=%2x im=%2x int=%2x sp=%2x\n",
+	       (mr->count_hi << 8) + mr->count_lo, mr->sequence,
+	       (mr->bus_status1 << 8) + mr->bus_status0, mr->fifo_count,
+	       mr->exception, mr->error, mr->intr_mask, mr->interrupt,
+	       mr->sync_params);
+	while(in_8(&mr->fifo_count))
+		printk(KERN_DEBUG " fifo data=%.2x\n",in_8(&mr->fifo));
+	printk(KERN_DEBUG "    dma stat=%x cmdptr=%x\n",
+	       in_le32(&md->status), in_le32(&md->cmdptr));
+	printk(KERN_DEBUG "    phase=%d msgphase=%d conn_tgt=%d data_ptr=%d\n",
+	       ms->phase, ms->msgphase, ms->conn_tgt, ms->data_ptr);
+	printk(KERN_DEBUG "    dma_st=%d dma_ct=%d n_msgout=%d\n",
+	       ms->dma_started, ms->dma_count, ms->n_msgout);
+	for (t = 0; t < 8; ++t) {
+		tp = &ms->tgts[t];
+		if (tp->current_req == NULL)
+			continue;
+		printk(KERN_DEBUG "    target %d: req=%p goes_out=%d saved_ptr=%d\n",
+		       t, tp->current_req, tp->data_goes_out, tp->saved_ptr);
+	}
+}
+
+
+/*
+ * Flush write buffers on the bus path to the mesh
+ */
+static inline void mesh_flush_io(volatile struct mesh_regs __iomem *mr)
+{
+	(void)in_8(&mr->mesh_id);
+}
+
+
+/*
+ * Complete a SCSI command
+ */
+static void mesh_completed(struct mesh_state *ms, struct scsi_cmnd *cmd)
+{
+	(*cmd->scsi_done)(cmd);
+}
+
+
+/* Called with  meshinterrupt disabled, initialize the chipset
+ * and eventually do the initial bus reset. The lock must not be
+ * held since we can schedule.
+ */
+static void mesh_init(struct mesh_state *ms)
+{
+	volatile struct mesh_regs __iomem *mr = ms->mesh;
+	volatile struct dbdma_regs __iomem *md = ms->dma;
+
+	mesh_flush_io(mr);
+	udelay(100);
+
+	/* Reset controller */
+	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
+	out_8(&mr->exception, 0xff);	/* clear all exception bits */
+	out_8(&mr->error, 0xff);	/* clear all error bits */
+	out_8(&mr->sequence, SEQ_RESETMESH);
+	mesh_flush_io(mr);
+	udelay(10);
+	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+	out_8(&mr->source_id, ms->host->this_id);
+	out_8(&mr->sel_timeout, 25);	/* 250ms */
+	out_8(&mr->sync_params, ASYNC_PARAMS);
+
+	if (init_reset_delay) {
+		printk(KERN_INFO "mesh: performing initial bus reset...\n");
+		
+		/* Reset bus */
+		out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
+		mesh_flush_io(mr);
+		udelay(30);			/* leave it on for >= 25us */
+		out_8(&mr->bus_status1, 0);	/* negate RST */
+		mesh_flush_io(mr);
+
+		/* Wait for bus to come back */
+		msleep(init_reset_delay);
+	}
+	
+	/* Reconfigure controller */
+	out_8(&mr->interrupt, 0xff);	/* clear all interrupt bits */
+	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);
+
+	ms->phase = idle;
+	ms->msgphase = msg_none;
+}
+
+
+static void mesh_start_cmd(struct mesh_state *ms, struct scsi_cmnd *cmd)
+{
+	volatile struct mesh_regs __iomem *mr = ms->mesh;
+	int t, id;
+
+	id = cmd->device->id;
+	ms->current_req = cmd;
+	ms->tgts[id].data_goes_out = cmd->sc_data_direction == DMA_TO_DEVICE;
+	ms->tgts[id].current_req = cmd;
+
+#if 1
+	if (DEBUG_TARGET(cmd)) {
+		int i;
+		printk(KERN_DEBUG "mesh_start: %p ser=%lu tgt=%d cmd=",
+		       cmd, cmd->serial_number, id);
+		for (i = 0; i < cmd->cmd_len; ++i)
+			printk(" %x", cmd->cmnd[i]);
+		printk(" use_sg=%d buffer=%p bufflen=%u\n",
+		       cmd->use_sg, cmd->request_buffer, cmd->request_bufflen);
+	}
+#endif
+	if (ms->dma_started)
+		panic("mesh: double DMA start !\n");
+
+	ms->phase = arbitrating;
+	ms->msgphase = msg_none;
+	ms->data_ptr = 0;
+	ms->dma_started = 0;
+	ms->n_msgout = 0;
+	ms->last_n_msgout = 0;
+	ms->expect_reply = 0;
+	ms->conn_tgt = id;
+	ms->tgts[id].saved_ptr = 0;
+	ms->stat = DID_OK;
+	ms->aborting = 0;
+#ifdef MESH_DBG
+	ms->tgts[id].n_log = 0;
+	dlog(ms, "start cmd=%x", (int) cmd);
+#endif
+
+	/* Off we go */
+	dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
+	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
+	out_8(&mr->interrupt, INT_CMDDONE);
+	out_8(&mr->sequence, SEQ_ENBRESEL);
+	mesh_flush_io(mr);
+	udelay(1);
+
+	if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
+		/*
+		 * Some other device has the bus or is arbitrating for it -
+		 * probably a target which is about to reselect us.
+		 */
+		dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception,
+			    mr->error, mr->fifo_count));
+		for (t = 100; t > 0; --t) {
+			if ((in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) == 0)
+				break;
+			if (in_8(&mr->interrupt) != 0) {
+				dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
+				     MKWORD(mr->interrupt, mr->exception,
+					    mr->error, mr->fifo_count));
+				mesh_interrupt(0, (void *)ms, NULL);
+				if (ms->phase != arbitrating)
+					return;
+			}
+			udelay(1);
+		}
+		if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
+			/* XXX should try again in a little while */
+			ms->stat = DID_BUS_BUSY;
+			ms->phase = idle;
+			mesh_done(ms, 0);
+			return;
+		}
+	}
+
+	/*
+	 * Apparently the mesh has a bug where it will assert both its
+	 * own bit and the target's bit on the bus during arbitration.
+	 */
+	out_8(&mr->dest_id, mr->source_id);
+
+	/*
+	 * There appears to be a race with reselection sometimes,
+	 * where a target reselects us just as we issue the
+	 * arbitrate command.  It seems that then the arbitrate
+	 * command just hangs waiting for the bus to be free
+	 * without giving us a reselection exception.
+	 * The only way I have found to get it to respond correctly
+	 * is this: disable reselection before issuing the arbitrate
+	 * command, then after issuing it, if it looks like a target
+	 * is trying to reselect us, reset the mesh and then enable
+	 * reselection.
+	 */
+	out_8(&mr->sequence, SEQ_DISRESEL);
+	if (in_8(&mr->interrupt) != 0) {
+		dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception,
+			    mr->error, mr->fifo_count));
+		mesh_interrupt(0, (void *)ms, NULL);
+		if (ms->phase != arbitrating)
+			return;
+		dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception,
+			    mr->error, mr->fifo_count));
+	}
+
+	out_8(&mr->sequence, SEQ_ARBITRATE);
+
+	for (t = 230; t > 0; --t) {
+		if (in_8(&mr->interrupt) != 0)
+			break;
+		udelay(1);
+	}
+	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, cmd->request_bufflen);
+			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]);
+			}
+		}
+		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 explictly 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, struct pt_regs *ptregs)
+{
+	unsigned long flags;
+	struct Scsi_Host *dev = ((struct mesh_state *)dev_id)->host;
+	
+	spin_lock_irqsave(dev->host_lock, flags);
+	mesh_interrupt(irq, dev_id, ptregs);
+	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);
+	dlog(ms, "error err/exc/fc/cl=%.8x",
+	     MKWORD(err, exc, mr->fifo_count, mr->count_lo));
+	if (err & ERR_SCSIRESET) {
+		/* SCSI bus was reset */
+		printk(KERN_INFO "mesh: SCSI bus reset detected: "
+		       "waiting for end...");
+		while ((in_8(&mr->bus_status1) & BS1_RST) != 0)
+			udelay(1);
+		printk("done\n");
+		handle_reset(ms);
+		/* request_q is empty, no point in mesh_start() */
+		return;
+	}
+	if (err & ERR_UNEXPDISC) {
+		/* Unexpected disconnect */
+		if (exc & EXC_RESELECTED) {
+			reselected(ms);
+			return;
+		}
+		if (!ms->aborting) {
+			printk(KERN_WARNING "mesh: target %d aborted\n",
+			       ms->conn_tgt);
+			dumplog(ms, ms->conn_tgt);
+			dumpslog(ms);
+		}
+		out_8(&mr->interrupt, INT_CMDDONE);
+		ms->stat = DID_ABORT;
+		mesh_done(ms, 1);
+		return;
+	}
+	if (err & ERR_PARITY) {
+		if (ms->msgphase == msg_in) {
+			printk(KERN_ERR "mesh: msg parity error, target %d\n",
+			       ms->conn_tgt);
+			ms->msgout[0] = MSG_PARITY_ERROR;
+			ms->n_msgout = 1;
+			ms->msgphase = msg_in_bad;
+			cmd_complete(ms);
+			return;
+		}
+		if (ms->stat == DID_OK) {
+			printk(KERN_ERR "mesh: parity error, target %d\n",
+			       ms->conn_tgt);
+			ms->stat = DID_PARITY;
+		}
+		count = (mr->count_hi << 8) + mr->count_lo;
+		if (count == 0) {
+			cmd_complete(ms);
+		} else {
+			/* reissue the data transfer command */
+			out_8(&mr->sequence, mr->sequence);
+		}
+		return;
+	}
+	if (err & ERR_SEQERR) {
+		if (exc & EXC_RESELECTED) {
+			/* This can happen if we issue a command to
+			   get the bus just after the target reselects us. */
+			static int mesh_resel_seqerr;
+			mesh_resel_seqerr++;
+			reselected(ms);
+			return;
+		}
+		if (exc == EXC_PHASEMM) {
+			static int mesh_phasemm_seqerr;
+			mesh_phasemm_seqerr++;
+			phase_mismatch(ms);
+			return;
+		}
+		printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
+		       err, exc);
+	} else {
+		printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
+	}
+	mesh_dump_regs(ms);
+	dumplog(ms, ms->conn_tgt);
+	if (ms->phase > selecting && (in_8(&mr->bus_status1) & BS1_BSY)) {
+		/* try to do what the target wants */
+		do_abort(ms);
+		phase_mismatch(ms);
+		return;
+	}
+	ms->stat = DID_ERROR;
+	mesh_done(ms, 1);
+}
+
+static void handle_exception(struct mesh_state *ms)
+{
+	int exc;
+	volatile struct mesh_regs __iomem *mr = ms->mesh;
+
+	exc = in_8(&mr->exception);
+	out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
+	if (exc & EXC_RESELECTED) {
+		static int mesh_resel_exc;
+		mesh_resel_exc++;
+		reselected(ms);
+	} else if (exc == EXC_ARBLOST) {
+		printk(KERN_DEBUG "mesh: lost arbitration\n");
+		ms->stat = DID_BUS_BUSY;