Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / scsi / mesh.c
diff --git a/kernel/drivers/scsi/mesh.c b/kernel/drivers/scsi/mesh.c
new file mode 100644 (file)
index 0000000..555367f
--- /dev/null
@@ -0,0 +1,2074 @@
+/*
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/string.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/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(struct mesh_state *ms);
+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 tgt=%d cmd=", cmd, id);
+               for (i = 0; i < cmd->cmd_len; ++i)
+                       printk(" %x", cmd->cmnd[i]);
+               printk(" use_sg=%d buffer=%p bufflen=%u\n",
+                      scsi_sg_count(cmd), scsi_sglist(cmd), scsi_bufflen(cmd));
+       }
+#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(ms);
+                               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(ms);
+               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, 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);
+       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;
+               mesh_done(ms, 1);
+       } else if (exc == EXC_SELTO) {
+               /* selection timed out */
+               ms->stat = DID_BAD_TARGET;
+               mesh_done(ms, 1);
+       } else if (exc == EXC_PHASEMM) {
+               /* target wants to do something different:
+                  find out what it wants and do it. */
+               phase_mismatch(ms);
+       } else {
+               printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
+               mesh_dump_regs(ms);
+               dumplog(ms, ms->conn_tgt);
+               do_abort(ms);
+               phase_mismatch(ms);
+       }
+}
+
+static void handle_msgin(struct mesh_state *ms)
+{
+       int i, code;
+       struct scsi_cmnd *cmd = ms->current_req;
+       struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
+
+       if (ms->n_msgin == 0)
+               return;
+       code = ms->msgin[0];
+       if (ALLOW_DEBUG(ms->conn_tgt)) {
+               printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
+               for (i = 0; i < ms->n_msgin; ++i)
+                       printk(" %x", ms->msgin[i]);
+               printk("\n");
+       }
+       dlog(ms, "msgin msg=%.8x",
+            MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
+
+       ms->expect_reply = 0;
+       ms->n_msgout = 0;
+       if (ms->n_msgin < msgin_length(ms))
+               goto reject;
+       if (cmd)
+               cmd->SCp.Message = code;
+       switch (code) {
+       case COMMAND_COMPLETE:
+               break;
+       case EXTENDED_MESSAGE:
+               switch (ms->msgin[2]) {
+               case EXTENDED_MODIFY_DATA_POINTER:
+                       ms->data_ptr += (ms->msgin[3] << 24) + ms->msgin[6]
+                               + (ms->msgin[4] << 16) + (ms->msgin[5] << 8);
+                       break;
+               case EXTENDED_SDTR:
+                       if (tp->sdtr_state != sdtr_sent) {
+                               /* reply with an SDTR */
+                               add_sdtr_msg(ms);
+                               /* limit period to at least his value,
+                                  offset to no more than his */
+                               if (ms->msgout[3] < ms->msgin[3])
+                                       ms->msgout[3] = ms->msgin[3];
+                               if (ms->msgout[4] > ms->msgin[4])
+                                       ms->msgout[4] = ms->msgin[4];
+                               set_sdtr(ms, ms->msgout[3], ms->msgout[4]);
+                               ms->msgphase = msg_out;
+                       } else {
+                               set_sdtr(ms, ms->msgin[3], ms->msgin[4]);
+                       }
+                       break;
+               default:
+                       goto reject;
+               }
+               break;
+       case SAVE_POINTERS:
+               tp->saved_ptr = ms->data_ptr;
+               break;
+       case RESTORE_POINTERS:
+               ms->data_ptr = tp->saved_ptr;
+               break;
+       case DISCONNECT:
+               ms->phase = disconnecting;
+               break;
+       case ABORT:
+               break;
+       case MESSAGE_REJECT:
+               if (tp->sdtr_state == sdtr_sent)
+                       set_sdtr(ms, 0, 0);
+               break;
+       case NOP:
+               break;
+       default:
+               if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
+                       if (cmd == NULL) {
+                               do_abort(ms);
+                               ms->msgphase = msg_out;
+                       } else if (code != cmd->device->lun + IDENTIFY_BASE) {
+                               printk(KERN_WARNING "mesh: lun mismatch "
+                                      "(%d != %llu) on reselection from "
+                                      "target %d\n", code - IDENTIFY_BASE,
+                                      cmd->device->lun, ms->conn_tgt);
+                       }
+                       break;
+               }
+               goto reject;
+       }
+       return;
+
+ reject:
+       printk(KERN_WARNING "mesh: rejecting message from target %d:",
+              ms->conn_tgt);
+       for (i = 0; i < ms->n_msgin; ++i)
+               printk(" %x", ms->msgin[i]);
+       printk("\n");
+       ms->msgout[0] = MESSAGE_REJECT;
+       ms->n_msgout = 1;
+       ms->msgphase = msg_out;
+}
+
+/*
+ * Set up DMA commands for transferring data.
+ */
+static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
+{
+       int i, dma_cmd, total, off, dtot;
+       struct scatterlist *scl;
+       struct dbdma_cmd *dcmds;
+
+       dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
+               OUTPUT_MORE: INPUT_MORE;
+       dcmds = ms->dma_cmds;
+       dtot = 0;
+       if (cmd) {
+               int nseg;
+
+               cmd->SCp.this_residual = scsi_bufflen(cmd);
+
+               nseg = scsi_dma_map(cmd);
+               BUG_ON(nseg < 0);
+
+               if (nseg) {
+                       total = 0;
+                       off = ms->data_ptr;
+
+                       scsi_for_each_sg(cmd, scl, nseg, i) {
+                               u32 dma_addr = sg_dma_address(scl);
+                               u32 dma_len = sg_dma_len(scl);
+                               
+                               total += scl->length;
+                               if (off >= dma_len) {
+                                       off -= dma_len;
+                                       continue;
+                               }
+                               if (dma_len > 0xffff)
+                                       panic("mesh: scatterlist element >= 64k");
+                               dcmds->req_count = cpu_to_le16(dma_len - off);
+                               dcmds->command = cpu_to_le16(dma_cmd);
+                               dcmds->phy_addr = cpu_to_le32(dma_addr + off);
+                               dcmds->xfer_status = 0;
+                               ++dcmds;
+                               dtot += dma_len - off;
+                               off = 0;
+                       }
+               }
+       }
+       if (dtot == 0) {
+               /* Either the target has overrun our buffer,
+                  or the caller didn't provide a buffer. */
+               static char mesh_extra_buf[64];
+
+               dtot = sizeof(mesh_extra_buf);
+               dcmds->req_count = cpu_to_le16(dtot);
+               dcmds->phy_addr = cpu_to_le32(virt_to_phys(mesh_extra_buf));
+               dcmds->xfer_status = 0;
+               ++dcmds;
+       }
+       dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
+       dcmds[-1].command = cpu_to_le16(dma_cmd);
+       memset(dcmds, 0, sizeof(*dcmds));
+       dcmds->command = cpu_to_le16(DBDMA_STOP);
+       ms->dma_count = dtot;
+}
+
+static void halt_dma(struct mesh_state *ms)
+{
+       volatile struct dbdma_regs __iomem *md = ms->dma;
+       volatile struct mesh_regs __iomem *mr = ms->mesh;
+       struct scsi_cmnd *cmd = ms->current_req;
+       int t, nb;
+
+       if (!ms->tgts[ms->conn_tgt].data_goes_out) {
+               /* wait a little while until the fifo drains */
+               t = 50;
+               while (t > 0 && in_8(&mr->fifo_count) != 0
+                      && (in_le32(&md->status) & ACTIVE) != 0) {
+                       --t;
+                       udelay(1);
+               }
+       }
+       out_le32(&md->control, RUN << 16);      /* turn off RUN bit */
+       nb = (mr->count_hi << 8) + mr->count_lo;
+       dlog(ms, "halt_dma fc/count=%.6x",
+            MKWORD(0, mr->fifo_count, 0, nb));
+       if (ms->tgts[ms->conn_tgt].data_goes_out)
+               nb += mr->fifo_count;
+       /* nb is the number of bytes not yet transferred
+          to/from the target. */
+       ms->data_ptr -= nb;
+       dlog(ms, "data_ptr %x", ms->data_ptr);
+       if (ms->data_ptr < 0) {
+               printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
+                      ms->data_ptr, nb, ms);
+               ms->data_ptr = 0;
+#ifdef MESH_DBG
+               dumplog(ms, ms->conn_tgt);
+               dumpslog(ms);
+#endif /* MESH_DBG */
+       } else if (cmd && scsi_bufflen(cmd) &&
+                  ms->data_ptr > scsi_bufflen(cmd)) {
+               printk(KERN_DEBUG "mesh: target %d overrun, "
+                      "data_ptr=%x total=%x goes_out=%d\n",
+                      ms->conn_tgt, ms->data_ptr, scsi_bufflen(cmd),
+                      ms->tgts[ms->conn_tgt].data_goes_out);
+       }
+       scsi_dma_unmap(cmd);
+       ms->dma_started = 0;
+}
+
+static void phase_mismatch(struct mesh_state *ms)
+{
+       volatile struct mesh_regs __iomem *mr = ms->mesh;
+       int phase;
+
+       dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
+            MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
+       phase = in_8(&mr->bus_status0) & BS0_PHASE;
+       if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
+               /* output the last byte of the message, without ATN */
+               out_8(&mr->count_lo, 1);
+               out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
+               mesh_flush_io(mr);
+               udelay(1);
+               out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
+               ms->msgphase = msg_out_last;
+               return;
+       }
+
+       if (ms->msgphase == msg_in) {
+               get_msgin(ms);
+               if (ms->n_msgin)
+                       handle_msgin(ms);
+       }
+
+       if (ms->dma_started)
+               halt_dma(ms);
+       if (mr->fifo_count) {
+               out_8(&mr->sequence, SEQ_FLUSHFIFO);
+               mesh_flush_io(mr);
+               udelay(1);
+       }
+
+       ms->msgphase = msg_none;
+       switch (phase) {
+       case BP_DATAIN:
+               ms->tgts[ms->conn_tgt].data_goes_out = 0;
+               ms->phase = dataing;
+               break;
+       case BP_DATAOUT:
+               ms->tgts[ms->conn_tgt].data_goes_out = 1;
+               ms->phase = dataing;
+               break;
+       case BP_COMMAND:
+               ms->phase = commanding;
+               break;
+       case BP_STATUS:
+               ms->phase = statusing;
+               break;
+       case BP_MSGIN:
+               ms->msgphase = msg_in;
+               ms->n_msgin = 0;
+               break;
+       case BP_MSGOUT:
+               ms->msgphase = msg_out;
+               if (ms->n_msgout == 0) {
+                       if (ms->aborting) {
+                               do_abort(ms);
+                       } else {
+                               if (ms->last_n_msgout == 0) {
+                                       printk(KERN_DEBUG
+                                              "mesh: no msg to repeat\n");
+                                       ms->msgout[0] = NOP;
+                                       ms->last_n_msgout = 1;
+                               }
+                               ms->n_msgout = ms->last_n_msgout;
+                       }
+               }
+               break;
+       default:
+               printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
+               ms->stat = DID_ERROR;
+               mesh_done(ms, 1);
+               return;
+       }
+
+       start_phase(ms);
+}
+
+static void cmd_complete(struct mesh_state *ms)
+{
+       volatile struct mesh_regs __iomem *mr = ms->mesh;
+       struct scsi_cmnd *cmd = ms->current_req;
+       struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
+       int seq, n, t;
+
+       dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
+       seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
+       switch (ms->msgphase) {
+       case msg_out_xxx:
+               /* huh?  we expected a phase mismatch */
+               ms->n_msgin = 0;
+               ms->msgphase = msg_in;
+               /* fall through */
+
+       case msg_in:
+               /* should have some message bytes in fifo */
+               get_msgin(ms);
+               n = msgin_length(ms);
+               if (ms->n_msgin < n) {
+                       out_8(&mr->count_lo, n - ms->n_msgin);
+                       out_8(&mr->sequence, SEQ_MSGIN + seq);
+               } else {
+                       ms->msgphase = msg_none;
+                       handle_msgin(ms);
+                       start_phase(ms);
+               }
+               break;
+
+       case msg_in_bad:
+               out_8(&mr->sequence, SEQ_FLUSHFIFO);
+               mesh_flush_io(mr);
+               udelay(1);
+               out_8(&mr->count_lo, 1);
+               out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + use_active_neg);
+               break;
+
+       case msg_out:
+               /*
+                * To get the right timing on ATN wrt ACK, we have
+                * to get the MESH to drop ACK, wait until REQ gets
+                * asserted, then drop ATN.  To do this we first
+                * issue a SEQ_MSGOUT with ATN and wait for REQ,
+                * then change the command to a SEQ_MSGOUT w/o ATN.
+                * If we don't see REQ in a reasonable time, we
+                * change the command to SEQ_MSGIN with ATN,
+                * wait for the phase mismatch interrupt, then
+                * issue the SEQ_MSGOUT without ATN.
+                */
+               out_8(&mr->count_lo, 1);
+               out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg + SEQ_ATN);
+               t = 30;         /* wait up to 30us */
+               while ((in_8(&mr->bus_status0) & BS0_REQ) == 0 && --t >= 0)
+                       udelay(1);
+               dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
+                    MKWORD(mr->error, mr->exception,
+                           mr->fifo_count, mr->count_lo));
+               if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
+                       /* whoops, target didn't do what we expected */
+                       ms->last_n_msgout = ms->n_msgout;
+                       ms->n_msgout = 0;
+                       if (in_8(&mr->interrupt) & INT_ERROR) {
+                               printk(KERN_ERR "mesh: error %x in msg_out\n",
+                                      in_8(&mr->error));
+                               handle_error(ms);
+                               return;
+                       }
+                       if (in_8(&mr->exception) != EXC_PHASEMM)
+                               printk(KERN_ERR "mesh: exc %x in msg_out\n",
+                                      in_8(&mr->exception));
+                       else
+                               printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
+                                      in_8(&mr->bus_status0));
+                       handle_exception(ms);
+                       return;
+               }
+               if (in_8(&mr->bus_status0) & BS0_REQ) {
+                       out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
+                       mesh_flush_io(mr);
+                       udelay(1);
+                       out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
+                       ms->msgphase = msg_out_last;
+               } else {
+                       out_8(&mr->sequence, SEQ_MSGIN + use_active_neg + SEQ_ATN);
+                       ms->msgphase = msg_out_xxx;
+               }
+               break;
+
+       case msg_out_last:
+               ms->last_n_msgout = ms->n_msgout;
+               ms->n_msgout = 0;
+               ms->msgphase = ms->expect_reply? msg_in: msg_none;
+               start_phase(ms);
+               break;
+
+       case msg_none:
+               switch (ms->phase) {
+               case idle:
+                       printk(KERN_ERR "mesh: interrupt in idle phase?\n");
+                       dumpslog(ms);
+                       return;
+               case selecting:
+                       dlog(ms, "Selecting phase at command completion",0);
+                       ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
+                                                (cmd? cmd->device->lun: 0));
+                       ms->n_msgout = 1;
+                       ms->expect_reply = 0;
+                       if (ms->aborting) {
+                               ms->msgout[0] = ABORT;
+                               ms->n_msgout++;
+                       } else if (tp->sdtr_state == do_sdtr) {
+                               /* add SDTR message */
+                               add_sdtr_msg(ms);
+                               ms->expect_reply = 1;
+                               tp->sdtr_state = sdtr_sent;
+                       }
+                       ms->msgphase = msg_out;
+                       /*
+                        * We need to wait for REQ before dropping ATN.
+                        * We wait for at most 30us, then fall back to
+                        * a scheme where we issue a SEQ_COMMAND with ATN,
+                        * which will give us a phase mismatch interrupt
+                        * when REQ does come, and then we send the message.
+                        */
+                       t = 230;                /* wait up to 230us */
+                       while ((in_8(&mr->bus_status0) & BS0_REQ) == 0) {
+                               if (--t < 0) {
+                                       dlog(ms, "impatient for req", ms->n_msgout);
+                                       ms->msgphase = msg_none;
+                                       break;
+                               }
+                               udelay(1);
+                       }
+                       break;
+               case dataing:
+                       if (ms->dma_count != 0) {
+                               start_phase(ms);
+                               return;
+                       }
+                       /*
+                        * We can get a phase mismatch here if the target
+                        * changes to the status phase, even though we have
+                        * had a command complete interrupt.  Then, if we
+                        * issue the SEQ_STATUS command, we'll get a sequence
+                        * error interrupt.  Which isn't so bad except that
+                        * occasionally the mesh actually executes the
+                        * SEQ_STATUS *as well as* giving us the sequence
+                        * error and phase mismatch exception.
+                        */
+                       out_8(&mr->sequence, 0);
+                       out_8(&mr->interrupt,
+                             INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+                       halt_dma(ms);
+                       break;
+               case statusing:
+                       if (cmd) {
+                               cmd->SCp.Status = mr->fifo;
+                               if (DEBUG_TARGET(cmd))
+                                       printk(KERN_DEBUG "mesh: status is %x\n",
+                                              cmd->SCp.Status);
+                       }
+                       ms->msgphase = msg_in;
+                       break;
+               case busfreeing:
+                       mesh_done(ms, 1);
+                       return;
+               case disconnecting:
+                       ms->current_req = NULL;
+                       ms->phase = idle;
+                       mesh_start(ms);
+                       return;
+               default:
+                       break;
+               }
+               ++ms->phase;
+               start_phase(ms);
+               break;
+       }
+}
+
+
+/*
+ * Called by midlayer with host locked to queue a new
+ * request
+ */
+static int mesh_queue_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
+{
+       struct mesh_state *ms;
+
+       cmd->scsi_done = done;
+       cmd->host_scribble = NULL;
+
+       ms = (struct mesh_state *) cmd->device->host->hostdata;
+
+       if (ms->request_q == NULL)
+               ms->request_q = cmd;
+       else
+               ms->request_qtail->host_scribble = (void *) cmd;
+       ms->request_qtail = cmd;
+
+       if (ms->phase == idle)
+               mesh_start(ms);
+
+       return 0;
+}
+
+static DEF_SCSI_QCMD(mesh_queue)
+
+/*
+ * Called to handle interrupts, either call by the interrupt
+ * handler (do_mesh_interrupt) or by other functions in
+ * exceptional circumstances
+ */
+static void mesh_interrupt(struct mesh_state *ms)
+{
+       volatile struct mesh_regs __iomem *mr = ms->mesh;
+       int intr;
+
+#if 0
+       if (ALLOW_DEBUG(ms->conn_tgt))
+               printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
+                      "phase=%d msgphase=%d\n", mr->bus_status0,
+                      mr->interrupt, mr->exception, mr->error,
+                      ms->phase, ms->msgphase);
+#endif
+       while ((intr = in_8(&mr->interrupt)) != 0) {
+               dlog(ms, "interrupt intr/err/exc/seq=%.8x", 
+                    MKWORD(intr, mr->error, mr->exception, mr->sequence));
+               if (intr & INT_ERROR) {
+                       handle_error(ms);
+               } else if (intr & INT_EXCEPTION) {
+                       handle_exception(ms);
+               } else if (intr & INT_CMDDONE) {
+                       out_8(&mr->interrupt, INT_CMDDONE);
+                       cmd_complete(ms);
+               }
+       }
+}
+
+/* Todo: here we can at least try to remove the command from the
+ * queue if it isn't connected yet, and for pending command, assert
+ * ATN until the bus gets freed.
+ */
+static int mesh_abort(struct scsi_cmnd *cmd)
+{
+       struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
+
+       printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
+       mesh_dump_regs(ms);
+       dumplog(ms, cmd->device->id);
+       dumpslog(ms);
+       return FAILED;
+}
+
+/*
+ * Called by the midlayer with the lock held to reset the
+ * SCSI host and bus.
+ * The midlayer will wait for devices to come back, we don't need
+ * to do that ourselves
+ */
+static int mesh_host_reset(struct scsi_cmnd *cmd)
+{
+       struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
+       volatile struct mesh_regs __iomem *mr = ms->mesh;
+       volatile struct dbdma_regs __iomem *md = ms->dma;
+       unsigned long flags;
+
+       printk(KERN_DEBUG "mesh_host_reset\n");
+
+       spin_lock_irqsave(ms->host->host_lock, flags);
+
+       /* Reset the controller & dbdma channel */
+       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(1);
+       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);
+
+       /* Reset the 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 */
+
+       /* Complete pending commands */
+       handle_reset(ms);
+       
+       spin_unlock_irqrestore(ms->host->host_lock, flags);
+       return SUCCESS;
+}
+
+static void set_mesh_power(struct mesh_state *ms, int state)
+{
+       if (!machine_is(powermac))
+               return;
+       if (state) {
+               pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 1);
+               msleep(200);
+       } else {
+               pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
+               msleep(10);
+       }
+}
+
+
+#ifdef CONFIG_PM
+static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
+{
+       struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
+       unsigned long flags;
+
+       switch (mesg.event) {
+       case PM_EVENT_SUSPEND:
+       case PM_EVENT_HIBERNATE:
+       case PM_EVENT_FREEZE:
+               break;
+       default:
+               return 0;
+       }
+       if (ms->phase == sleeping)
+               return 0;
+
+       scsi_block_requests(ms->host);
+       spin_lock_irqsave(ms->host->host_lock, flags);
+       while(ms->phase != idle) {
+               spin_unlock_irqrestore(ms->host->host_lock, flags);
+               msleep(10);
+               spin_lock_irqsave(ms->host->host_lock, flags);
+       }
+       ms->phase = sleeping;
+       spin_unlock_irqrestore(ms->host->host_lock, flags);
+       disable_irq(ms->meshintr);
+       set_mesh_power(ms, 0);
+
+       return 0;
+}
+
+static int mesh_resume(struct macio_dev *mdev)
+{
+       struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
+       unsigned long flags;
+
+       if (ms->phase != sleeping)
+               return 0;
+
+       set_mesh_power(ms, 1);
+       mesh_init(ms);
+       spin_lock_irqsave(ms->host->host_lock, flags);
+       mesh_start(ms);
+       spin_unlock_irqrestore(ms->host->host_lock, flags);
+       enable_irq(ms->meshintr);
+       scsi_unblock_requests(ms->host);
+
+       return 0;
+}
+
+#endif /* CONFIG_PM */
+
+/*
+ * If we leave drives set for synchronous transfers (especially
+ * CDROMs), and reboot to MacOS, it gets confused, poor thing.
+ * So, on reboot we reset the SCSI bus.
+ */
+static int mesh_shutdown(struct macio_dev *mdev)
+{
+       struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
+       volatile struct mesh_regs __iomem *mr;
+       unsigned long flags;
+
+               printk(KERN_INFO "resetting MESH scsi bus(es)\n");
+       spin_lock_irqsave(ms->host->host_lock, flags);
+               mr = ms->mesh;
+       out_8(&mr->intr_mask, 0);
+       out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+       out_8(&mr->bus_status1, BS1_RST);
+       mesh_flush_io(mr);
+       udelay(30);
+       out_8(&mr->bus_status1, 0);
+       spin_unlock_irqrestore(ms->host->host_lock, flags);
+
+       return 0;
+}
+
+static struct scsi_host_template mesh_template = {
+       .proc_name                      = "mesh",
+       .name                           = "MESH",
+       .queuecommand                   = mesh_queue,
+       .eh_abort_handler               = mesh_abort,
+       .eh_host_reset_handler          = mesh_host_reset,
+       .can_queue                      = 20,
+       .this_id                        = 7,
+       .sg_tablesize                   = SG_ALL,
+       .cmd_per_lun                    = 2,
+       .use_clustering                 = DISABLE_CLUSTERING,
+};
+
+static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
+{
+       struct device_node *mesh = macio_get_of_node(mdev);
+       struct pci_dev* pdev = macio_get_pci_dev(mdev);
+       int tgt, minper;
+       const int *cfp;
+       struct mesh_state *ms;
+       struct Scsi_Host *mesh_host;
+       void *dma_cmd_space;
+       dma_addr_t dma_cmd_bus;
+
+       switch (mdev->bus->chip->type) {
+       case macio_heathrow:
+       case macio_gatwick:
+       case macio_paddington:
+               use_active_neg = 0;
+               break;
+       default:
+               use_active_neg = SEQ_ACTIVE_NEG;
+       }
+
+       if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
+                       printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
+                      " (got %d,%d)\n", macio_resource_count(mdev),
+                      macio_irq_count(mdev));
+               return -ENODEV;
+       }
+
+       if (macio_request_resources(mdev, "mesh") != 0) {
+                       printk(KERN_ERR "mesh: unable to request memory resources");
+               return -EBUSY;
+       }
+               mesh_host = scsi_host_alloc(&mesh_template, sizeof(struct mesh_state));
+       if (mesh_host == NULL) {
+               printk(KERN_ERR "mesh: couldn't register host");
+               goto out_release;
+       }
+       
+       /* Old junk for root discovery, that will die ultimately */
+#if !defined(MODULE)
+               note_scsi_host(mesh, mesh_host);
+#endif
+
+       mesh_host->base = macio_resource_start(mdev, 0);
+       mesh_host->irq = macio_irq(mdev, 0);
+               ms = (struct mesh_state *) mesh_host->hostdata;
+       macio_set_drvdata(mdev, ms);
+       ms->host = mesh_host;
+       ms->mdev = mdev;
+       ms->pdev = pdev;
+       
+       ms->mesh = ioremap(macio_resource_start(mdev, 0), 0x1000);
+       if (ms->mesh == NULL) {
+               printk(KERN_ERR "mesh: can't map registers\n");
+               goto out_free;
+       }               
+       ms->dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
+       if (ms->dma == NULL) {
+               printk(KERN_ERR "mesh: can't map registers\n");
+               iounmap(ms->mesh);
+               goto out_free;
+       }
+
+               ms->meshintr = macio_irq(mdev, 0);
+               ms->dmaintr = macio_irq(mdev, 1);
+
+               /* Space for dma command list: +1 for stop command,
+                * +1 to allow for aligning.
+        */
+       ms->dma_cmd_size = (mesh_host->sg_tablesize + 2) * sizeof(struct dbdma_cmd);
+
+       /* We use the PCI APIs for now until the generic one gets fixed
+        * enough or until we get some macio-specific versions
+        */
+       dma_cmd_space = pci_zalloc_consistent(macio_get_pci_dev(mdev),
+                                             ms->dma_cmd_size, &dma_cmd_bus);
+       if (dma_cmd_space == NULL) {
+               printk(KERN_ERR "mesh: can't allocate DMA table\n");
+               goto out_unmap;
+       }
+
+       ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
+               ms->dma_cmd_space = dma_cmd_space;
+       ms->dma_cmd_bus = dma_cmd_bus + ((unsigned long)ms->dma_cmds)
+               - (unsigned long)dma_cmd_space;
+       ms->current_req = NULL;
+               for (tgt = 0; tgt < 8; ++tgt) {
+               ms->tgts[tgt].sdtr_state = do_sdtr;
+               ms->tgts[tgt].sync_params = ASYNC_PARAMS;
+               ms->tgts[tgt].current_req = NULL;
+               }
+
+       if ((cfp = of_get_property(mesh, "clock-frequency", NULL)))
+                       ms->clk_freq = *cfp;
+       else {
+                       printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
+               ms->clk_freq = 50000000;
+               }
+
+               /* The maximum sync rate is clock / 5; increase
+                * mesh_sync_period if necessary.
+        */
+       minper = 1000000000 / (ms->clk_freq / 5); /* ns */
+       if (mesh_sync_period < minper)
+               mesh_sync_period = minper;
+
+       /* Power up the chip */
+       set_mesh_power(ms, 1);
+
+       /* Set it up */
+               mesh_init(ms);
+
+       /* Request interrupt */
+               if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
+               printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
+               goto out_shutdown;
+       }
+
+       /* Add scsi host & scan */
+       if (scsi_add_host(mesh_host, &mdev->ofdev.dev))
+               goto out_release_irq;
+       scsi_scan_host(mesh_host);
+
+       return 0;
+
+ out_release_irq:
+       free_irq(ms->meshintr, ms);
+ out_shutdown:
+       /* shutdown & reset bus in case of error or macos can be confused
+        * at reboot if the bus was set to synchronous mode already
+        */
+       mesh_shutdown(mdev);
+       set_mesh_power(ms, 0);
+       pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
+                           ms->dma_cmd_space, ms->dma_cmd_bus);
+ out_unmap:
+       iounmap(ms->dma);
+       iounmap(ms->mesh);
+ out_free:
+       scsi_host_put(mesh_host);
+ out_release:
+       macio_release_resources(mdev);
+
+       return -ENODEV;
+}
+
+static int mesh_remove(struct macio_dev *mdev)
+{
+       struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
+       struct Scsi_Host *mesh_host = ms->host;
+
+       scsi_remove_host(mesh_host);
+
+       free_irq(ms->meshintr, ms);
+
+       /* Reset scsi bus */
+       mesh_shutdown(mdev);
+
+       /* Shut down chip & termination */
+       set_mesh_power(ms, 0);
+
+       /* Unmap registers & dma controller */
+       iounmap(ms->mesh);
+               iounmap(ms->dma);
+
+       /* Free DMA commands memory */
+       pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
+                           ms->dma_cmd_space, ms->dma_cmd_bus);
+
+       /* Release memory resources */
+       macio_release_resources(mdev);
+
+       scsi_host_put(mesh_host);
+
+       return 0;
+}
+
+
+static struct of_device_id mesh_match[] = 
+{
+       {
+       .name           = "mesh",
+       },
+       {
+       .type           = "scsi",
+       .compatible     = "chrp,mesh0"
+       },
+       {},
+};
+MODULE_DEVICE_TABLE (of, mesh_match);
+
+static struct macio_driver mesh_driver = 
+{
+       .driver = {
+               .name           = "mesh",
+               .owner          = THIS_MODULE,
+               .of_match_table = mesh_match,
+       },
+       .probe          = mesh_probe,
+       .remove         = mesh_remove,
+       .shutdown       = mesh_shutdown,
+#ifdef CONFIG_PM
+       .suspend        = mesh_suspend,
+       .resume         = mesh_resume,
+#endif
+};
+
+
+static int __init init_mesh(void)
+{
+
+       /* Calculate sync rate from module parameters */
+       if (sync_rate > 10)
+               sync_rate = 10;
+       if (sync_rate > 0) {
+               printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
+               mesh_sync_period = 1000 / sync_rate;    /* ns */
+               mesh_sync_offset = 15;
+       } else
+               printk(KERN_INFO "mesh: configured for asynchronous\n");
+
+       return macio_register_driver(&mesh_driver);
+}
+
+static void __exit exit_mesh(void)
+{
+       return macio_unregister_driver(&mesh_driver);
+}
+
+module_init(init_mesh);
+module_exit(exit_mesh);