Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / scsi / esp_scsi.c
diff --git a/kernel/drivers/scsi/esp_scsi.c b/kernel/drivers/scsi/esp_scsi.c
new file mode 100644 (file)
index 0000000..065b25d
--- /dev/null
@@ -0,0 +1,2800 @@
+/* esp_scsi.c: ESP SCSI driver.
+ *
+ * Copyright (C) 2007 David S. Miller (davem@davemloft.net)
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/completion.h>
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/irqreturn.h>
+
+#include <asm/irq.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_transport_spi.h>
+
+#include "esp_scsi.h"
+
+#define DRV_MODULE_NAME                "esp"
+#define PFX DRV_MODULE_NAME    ": "
+#define DRV_VERSION            "2.000"
+#define DRV_MODULE_RELDATE     "April 19, 2007"
+
+/* SCSI bus reset settle time in seconds.  */
+static int esp_bus_reset_settle = 3;
+
+static u32 esp_debug;
+#define ESP_DEBUG_INTR         0x00000001
+#define ESP_DEBUG_SCSICMD      0x00000002
+#define ESP_DEBUG_RESET                0x00000004
+#define ESP_DEBUG_MSGIN                0x00000008
+#define ESP_DEBUG_MSGOUT       0x00000010
+#define ESP_DEBUG_CMDDONE      0x00000020
+#define ESP_DEBUG_DISCONNECT   0x00000040
+#define ESP_DEBUG_DATASTART    0x00000080
+#define ESP_DEBUG_DATADONE     0x00000100
+#define ESP_DEBUG_RECONNECT    0x00000200
+#define ESP_DEBUG_AUTOSENSE    0x00000400
+#define ESP_DEBUG_EVENT                0x00000800
+#define ESP_DEBUG_COMMAND      0x00001000
+
+#define esp_log_intr(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_INTR) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_reset(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_RESET) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_msgin(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_MSGIN) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_msgout(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_MSGOUT) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_cmddone(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_CMDDONE) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_disconnect(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_DISCONNECT) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_datastart(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_DATASTART) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_datadone(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_DATADONE) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_reconnect(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_RECONNECT) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_autosense(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_AUTOSENSE) \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_event(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_EVENT)        \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_log_command(f, a...) \
+do {   if (esp_debug & ESP_DEBUG_COMMAND)      \
+               shost_printk(KERN_DEBUG, esp->host, f, ## a);   \
+} while (0)
+
+#define esp_read8(REG)         esp->ops->esp_read8(esp, REG)
+#define esp_write8(VAL,REG)    esp->ops->esp_write8(esp, VAL, REG)
+
+static void esp_log_fill_regs(struct esp *esp,
+                             struct esp_event_ent *p)
+{
+       p->sreg = esp->sreg;
+       p->seqreg = esp->seqreg;
+       p->sreg2 = esp->sreg2;
+       p->ireg = esp->ireg;
+       p->select_state = esp->select_state;
+       p->event = esp->event;
+}
+
+void scsi_esp_cmd(struct esp *esp, u8 val)
+{
+       struct esp_event_ent *p;
+       int idx = esp->esp_event_cur;
+
+       p = &esp->esp_event_log[idx];
+       p->type = ESP_EVENT_TYPE_CMD;
+       p->val = val;
+       esp_log_fill_regs(esp, p);
+
+       esp->esp_event_cur = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
+
+       esp_log_command("cmd[%02x]\n", val);
+       esp_write8(val, ESP_CMD);
+}
+EXPORT_SYMBOL(scsi_esp_cmd);
+
+static void esp_send_dma_cmd(struct esp *esp, int len, int max_len, int cmd)
+{
+       if (esp->flags & ESP_FLAG_USE_FIFO) {
+               int i;
+
+               scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+               for (i = 0; i < len; i++)
+                       esp_write8(esp->command_block[i], ESP_FDATA);
+               scsi_esp_cmd(esp, cmd);
+       } else {
+               if (esp->rev == FASHME)
+                       scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+               cmd |= ESP_CMD_DMA;
+               esp->ops->send_dma_cmd(esp, esp->command_block_dma,
+                                      len, max_len, 0, cmd);
+       }
+}
+
+static void esp_event(struct esp *esp, u8 val)
+{
+       struct esp_event_ent *p;
+       int idx = esp->esp_event_cur;
+
+       p = &esp->esp_event_log[idx];
+       p->type = ESP_EVENT_TYPE_EVENT;
+       p->val = val;
+       esp_log_fill_regs(esp, p);
+
+       esp->esp_event_cur = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
+
+       esp->event = val;
+}
+
+static void esp_dump_cmd_log(struct esp *esp)
+{
+       int idx = esp->esp_event_cur;
+       int stop = idx;
+
+       shost_printk(KERN_INFO, esp->host, "Dumping command log\n");
+       do {
+               struct esp_event_ent *p = &esp->esp_event_log[idx];
+
+               shost_printk(KERN_INFO, esp->host,
+                            "ent[%d] %s val[%02x] sreg[%02x] seqreg[%02x] "
+                            "sreg2[%02x] ireg[%02x] ss[%02x] event[%02x]\n",
+                            idx,
+                            p->type == ESP_EVENT_TYPE_CMD ? "CMD" : "EVENT",
+                            p->val, p->sreg, p->seqreg,
+                            p->sreg2, p->ireg, p->select_state, p->event);
+
+               idx = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
+       } while (idx != stop);
+}
+
+static void esp_flush_fifo(struct esp *esp)
+{
+       scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+       if (esp->rev == ESP236) {
+               int lim = 1000;
+
+               while (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES) {
+                       if (--lim == 0) {
+                               shost_printk(KERN_ALERT, esp->host,
+                                            "ESP_FF_BYTES will not clear!\n");
+                               break;
+                       }
+                       udelay(1);
+               }
+       }
+}
+
+static void hme_read_fifo(struct esp *esp)
+{
+       int fcnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
+       int idx = 0;
+
+       while (fcnt--) {
+               esp->fifo[idx++] = esp_read8(ESP_FDATA);
+               esp->fifo[idx++] = esp_read8(ESP_FDATA);
+       }
+       if (esp->sreg2 & ESP_STAT2_F1BYTE) {
+               esp_write8(0, ESP_FDATA);
+               esp->fifo[idx++] = esp_read8(ESP_FDATA);
+               scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+       }
+       esp->fifo_cnt = idx;
+}
+
+static void esp_set_all_config3(struct esp *esp, u8 val)
+{
+       int i;
+
+       for (i = 0; i < ESP_MAX_TARGET; i++)
+               esp->target[i].esp_config3 = val;
+}
+
+/* Reset the ESP chip, _not_ the SCSI bus. */
+static void esp_reset_esp(struct esp *esp)
+{
+       u8 family_code, version;
+
+       /* Now reset the ESP chip */
+       scsi_esp_cmd(esp, ESP_CMD_RC);
+       scsi_esp_cmd(esp, ESP_CMD_NULL | ESP_CMD_DMA);
+       if (esp->rev == FAST)
+               esp_write8(ESP_CONFIG2_FENAB, ESP_CFG2);
+       scsi_esp_cmd(esp, ESP_CMD_NULL | ESP_CMD_DMA);
+
+       /* This is the only point at which it is reliable to read
+        * the ID-code for a fast ESP chip variants.
+        */
+       esp->max_period = ((35 * esp->ccycle) / 1000);
+       if (esp->rev == FAST) {
+               version = esp_read8(ESP_UID);
+               family_code = (version & 0xf8) >> 3;
+               if (family_code == 0x02)
+                       esp->rev = FAS236;
+               else if (family_code == 0x0a)
+                       esp->rev = FASHME; /* Version is usually '5'. */
+               else
+                       esp->rev = FAS100A;
+               esp->min_period = ((4 * esp->ccycle) / 1000);
+       } else {
+               esp->min_period = ((5 * esp->ccycle) / 1000);
+       }
+       if (esp->rev == FAS236) {
+               /*
+                * The AM53c974 chip returns the same ID as FAS236;
+                * try to configure glitch eater.
+                */
+               u8 config4 = ESP_CONFIG4_GE1;
+               esp_write8(config4, ESP_CFG4);
+               config4 = esp_read8(ESP_CFG4);
+               if (config4 & ESP_CONFIG4_GE1) {
+                       esp->rev = PCSCSI;
+                       esp_write8(esp->config4, ESP_CFG4);
+               }
+       }
+       esp->max_period = (esp->max_period + 3)>>2;
+       esp->min_period = (esp->min_period + 3)>>2;
+
+       esp_write8(esp->config1, ESP_CFG1);
+       switch (esp->rev) {
+       case ESP100:
+               /* nothing to do */
+               break;
+
+       case ESP100A:
+               esp_write8(esp->config2, ESP_CFG2);
+               break;
+
+       case ESP236:
+               /* Slow 236 */
+               esp_write8(esp->config2, ESP_CFG2);
+               esp->prev_cfg3 = esp->target[0].esp_config3;
+               esp_write8(esp->prev_cfg3, ESP_CFG3);
+               break;
+
+       case FASHME:
+               esp->config2 |= (ESP_CONFIG2_HME32 | ESP_CONFIG2_HMEFENAB);
+               /* fallthrough... */
+
+       case FAS236:
+       case PCSCSI:
+               /* Fast 236, AM53c974 or HME */
+               esp_write8(esp->config2, ESP_CFG2);
+               if (esp->rev == FASHME) {
+                       u8 cfg3 = esp->target[0].esp_config3;
+
+                       cfg3 |= ESP_CONFIG3_FCLOCK | ESP_CONFIG3_OBPUSH;
+                       if (esp->scsi_id >= 8)
+                               cfg3 |= ESP_CONFIG3_IDBIT3;
+                       esp_set_all_config3(esp, cfg3);
+               } else {
+                       u32 cfg3 = esp->target[0].esp_config3;
+
+                       cfg3 |= ESP_CONFIG3_FCLK;
+                       esp_set_all_config3(esp, cfg3);
+               }
+               esp->prev_cfg3 = esp->target[0].esp_config3;
+               esp_write8(esp->prev_cfg3, ESP_CFG3);
+               if (esp->rev == FASHME) {
+                       esp->radelay = 80;
+               } else {
+                       if (esp->flags & ESP_FLAG_DIFFERENTIAL)
+                               esp->radelay = 0;
+                       else
+                               esp->radelay = 96;
+               }
+               break;
+
+       case FAS100A:
+               /* Fast 100a */
+               esp_write8(esp->config2, ESP_CFG2);
+               esp_set_all_config3(esp,
+                                   (esp->target[0].esp_config3 |
+                                    ESP_CONFIG3_FCLOCK));
+               esp->prev_cfg3 = esp->target[0].esp_config3;
+               esp_write8(esp->prev_cfg3, ESP_CFG3);
+               esp->radelay = 32;
+               break;
+
+       default:
+               break;
+       }
+
+       /* Reload the configuration registers */
+       esp_write8(esp->cfact, ESP_CFACT);
+
+       esp->prev_stp = 0;
+       esp_write8(esp->prev_stp, ESP_STP);
+
+       esp->prev_soff = 0;
+       esp_write8(esp->prev_soff, ESP_SOFF);
+
+       esp_write8(esp->neg_defp, ESP_TIMEO);
+
+       /* Eat any bitrot in the chip */
+       esp_read8(ESP_INTRPT);
+       udelay(100);
+}
+
+static void esp_map_dma(struct esp *esp, struct scsi_cmnd *cmd)
+{
+       struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
+       struct scatterlist *sg = scsi_sglist(cmd);
+       int dir = cmd->sc_data_direction;
+       int total, i;
+
+       if (dir == DMA_NONE)
+               return;
+
+       spriv->u.num_sg = esp->ops->map_sg(esp, sg, scsi_sg_count(cmd), dir);
+       spriv->cur_residue = sg_dma_len(sg);
+       spriv->cur_sg = sg;
+
+       total = 0;
+       for (i = 0; i < spriv->u.num_sg; i++)
+               total += sg_dma_len(&sg[i]);
+       spriv->tot_residue = total;
+}
+
+static dma_addr_t esp_cur_dma_addr(struct esp_cmd_entry *ent,
+                                  struct scsi_cmnd *cmd)
+{
+       struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
+
+       if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+               return ent->sense_dma +
+                       (ent->sense_ptr - cmd->sense_buffer);
+       }
+
+       return sg_dma_address(p->cur_sg) +
+               (sg_dma_len(p->cur_sg) -
+                p->cur_residue);
+}
+
+static unsigned int esp_cur_dma_len(struct esp_cmd_entry *ent,
+                                   struct scsi_cmnd *cmd)
+{
+       struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
+
+       if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+               return SCSI_SENSE_BUFFERSIZE -
+                       (ent->sense_ptr - cmd->sense_buffer);
+       }
+       return p->cur_residue;
+}
+
+static void esp_advance_dma(struct esp *esp, struct esp_cmd_entry *ent,
+                           struct scsi_cmnd *cmd, unsigned int len)
+{
+       struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
+
+       if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+               ent->sense_ptr += len;
+               return;
+       }
+
+       p->cur_residue -= len;
+       p->tot_residue -= len;
+       if (p->cur_residue < 0 || p->tot_residue < 0) {
+               shost_printk(KERN_ERR, esp->host,
+                            "Data transfer overflow.\n");
+               shost_printk(KERN_ERR, esp->host,
+                            "cur_residue[%d] tot_residue[%d] len[%u]\n",
+                            p->cur_residue, p->tot_residue, len);
+               p->cur_residue = 0;
+               p->tot_residue = 0;
+       }
+       if (!p->cur_residue && p->tot_residue) {
+               p->cur_sg++;
+               p->cur_residue = sg_dma_len(p->cur_sg);
+       }
+}
+
+static void esp_unmap_dma(struct esp *esp, struct scsi_cmnd *cmd)
+{
+       struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
+       int dir = cmd->sc_data_direction;
+
+       if (dir == DMA_NONE)
+               return;
+
+       esp->ops->unmap_sg(esp, scsi_sglist(cmd), spriv->u.num_sg, dir);
+}
+
+static void esp_save_pointers(struct esp *esp, struct esp_cmd_entry *ent)
+{
+       struct scsi_cmnd *cmd = ent->cmd;
+       struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
+
+       if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+               ent->saved_sense_ptr = ent->sense_ptr;
+               return;
+       }
+       ent->saved_cur_residue = spriv->cur_residue;
+       ent->saved_cur_sg = spriv->cur_sg;
+       ent->saved_tot_residue = spriv->tot_residue;
+}
+
+static void esp_restore_pointers(struct esp *esp, struct esp_cmd_entry *ent)
+{
+       struct scsi_cmnd *cmd = ent->cmd;
+       struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
+
+       if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+               ent->sense_ptr = ent->saved_sense_ptr;
+               return;
+       }
+       spriv->cur_residue = ent->saved_cur_residue;
+       spriv->cur_sg = ent->saved_cur_sg;
+       spriv->tot_residue = ent->saved_tot_residue;
+}
+
+static void esp_check_command_len(struct esp *esp, struct scsi_cmnd *cmd)
+{
+       if (cmd->cmd_len == 6 ||
+           cmd->cmd_len == 10 ||
+           cmd->cmd_len == 12) {
+               esp->flags &= ~ESP_FLAG_DOING_SLOWCMD;
+       } else {
+               esp->flags |= ESP_FLAG_DOING_SLOWCMD;
+       }
+}
+
+static void esp_write_tgt_config3(struct esp *esp, int tgt)
+{
+       if (esp->rev > ESP100A) {
+               u8 val = esp->target[tgt].esp_config3;
+
+               if (val != esp->prev_cfg3) {
+                       esp->prev_cfg3 = val;
+                       esp_write8(val, ESP_CFG3);
+               }
+       }
+}
+
+static void esp_write_tgt_sync(struct esp *esp, int tgt)
+{
+       u8 off = esp->target[tgt].esp_offset;
+       u8 per = esp->target[tgt].esp_period;
+
+       if (off != esp->prev_soff) {
+               esp->prev_soff = off;
+               esp_write8(off, ESP_SOFF);
+       }
+       if (per != esp->prev_stp) {
+               esp->prev_stp = per;
+               esp_write8(per, ESP_STP);
+       }
+}
+
+static u32 esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
+{
+       if (esp->rev == FASHME) {
+               /* Arbitrary segment boundaries, 24-bit counts.  */
+               if (dma_len > (1U << 24))
+                       dma_len = (1U << 24);
+       } else {
+               u32 base, end;
+
+               /* ESP chip limits other variants by 16-bits of transfer
+                * count.  Actually on FAS100A and FAS236 we could get
+                * 24-bits of transfer count by enabling ESP_CONFIG2_FENAB
+                * in the ESP_CFG2 register but that causes other unwanted
+                * changes so we don't use it currently.
+                */
+               if (dma_len > (1U << 16))
+                       dma_len = (1U << 16);
+
+               /* All of the DMA variants hooked up to these chips
+                * cannot handle crossing a 24-bit address boundary.
+                */
+               base = dma_addr & ((1U << 24) - 1U);
+               end = base + dma_len;
+               if (end > (1U << 24))
+                       end = (1U <<24);
+               dma_len = end - base;
+       }
+       return dma_len;
+}
+
+static int esp_need_to_nego_wide(struct esp_target_data *tp)
+{
+       struct scsi_target *target = tp->starget;
+
+       return spi_width(target) != tp->nego_goal_width;
+}
+
+static int esp_need_to_nego_sync(struct esp_target_data *tp)
+{
+       struct scsi_target *target = tp->starget;
+
+       /* When offset is zero, period is "don't care".  */
+       if (!spi_offset(target) && !tp->nego_goal_offset)
+               return 0;
+
+       if (spi_offset(target) == tp->nego_goal_offset &&
+           spi_period(target) == tp->nego_goal_period)
+               return 0;
+
+       return 1;
+}
+
+static int esp_alloc_lun_tag(struct esp_cmd_entry *ent,
+                            struct esp_lun_data *lp)
+{
+       if (!ent->orig_tag[0]) {
+               /* Non-tagged, slot already taken?  */
+               if (lp->non_tagged_cmd)
+                       return -EBUSY;
+
+               if (lp->hold) {
+                       /* We are being held by active tagged
+                        * commands.
+                        */
+                       if (lp->num_tagged)
+                               return -EBUSY;
+
+                       /* Tagged commands completed, we can unplug
+                        * the queue and run this untagged command.
+                        */
+                       lp->hold = 0;
+               } else if (lp->num_tagged) {
+                       /* Plug the queue until num_tagged decreases
+                        * to zero in esp_free_lun_tag.
+                        */
+                       lp->hold = 1;
+                       return -EBUSY;
+               }
+
+               lp->non_tagged_cmd = ent;
+               return 0;
+       } else {
+               /* Tagged command, see if blocked by a
+                * non-tagged one.
+                */
+               if (lp->non_tagged_cmd || lp->hold)
+                       return -EBUSY;
+       }
+
+       BUG_ON(lp->tagged_cmds[ent->orig_tag[1]]);
+
+       lp->tagged_cmds[ent->orig_tag[1]] = ent;
+       lp->num_tagged++;
+
+       return 0;
+}
+
+static void esp_free_lun_tag(struct esp_cmd_entry *ent,
+                            struct esp_lun_data *lp)
+{
+       if (ent->orig_tag[0]) {
+               BUG_ON(lp->tagged_cmds[ent->orig_tag[1]] != ent);
+               lp->tagged_cmds[ent->orig_tag[1]] = NULL;
+               lp->num_tagged--;
+       } else {
+               BUG_ON(lp->non_tagged_cmd != ent);
+               lp->non_tagged_cmd = NULL;
+       }
+}
+
+/* When a contingent allegiance conditon is created, we force feed a
+ * REQUEST_SENSE command to the device to fetch the sense data.  I
+ * tried many other schemes, relying on the scsi error handling layer
+ * to send out the REQUEST_SENSE automatically, but this was difficult
+ * to get right especially in the presence of applications like smartd
+ * which use SG_IO to send out their own REQUEST_SENSE commands.
+ */
+static void esp_autosense(struct esp *esp, struct esp_cmd_entry *ent)
+{
+       struct scsi_cmnd *cmd = ent->cmd;
+       struct scsi_device *dev = cmd->device;
+       int tgt, lun;
+       u8 *p, val;
+
+       tgt = dev->id;
+       lun = dev->lun;
+
+
+       if (!ent->sense_ptr) {
+               esp_log_autosense("Doing auto-sense for tgt[%d] lun[%d]\n",
+                                 tgt, lun);
+
+               ent->sense_ptr = cmd->sense_buffer;
+               ent->sense_dma = esp->ops->map_single(esp,
+                                                     ent->sense_ptr,
+                                                     SCSI_SENSE_BUFFERSIZE,
+                                                     DMA_FROM_DEVICE);
+       }
+       ent->saved_sense_ptr = ent->sense_ptr;
+
+       esp->active_cmd = ent;
+
+       p = esp->command_block;
+       esp->msg_out_len = 0;
+
+       *p++ = IDENTIFY(0, lun);
+       *p++ = REQUEST_SENSE;
+       *p++ = ((dev->scsi_level <= SCSI_2) ?
+               (lun << 5) : 0);
+       *p++ = 0;
+       *p++ = 0;
+       *p++ = SCSI_SENSE_BUFFERSIZE;
+       *p++ = 0;
+
+       esp->select_state = ESP_SELECT_BASIC;
+
+       val = tgt;
+       if (esp->rev == FASHME)
+               val |= ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT;
+       esp_write8(val, ESP_BUSID);
+
+       esp_write_tgt_sync(esp, tgt);
+       esp_write_tgt_config3(esp, tgt);
+
+       val = (p - esp->command_block);
+
+       esp_send_dma_cmd(esp, val, 16, ESP_CMD_SELA);
+}
+
+static struct esp_cmd_entry *find_and_prep_issuable_command(struct esp *esp)
+{
+       struct esp_cmd_entry *ent;
+
+       list_for_each_entry(ent, &esp->queued_cmds, list) {
+               struct scsi_cmnd *cmd = ent->cmd;
+               struct scsi_device *dev = cmd->device;
+               struct esp_lun_data *lp = dev->hostdata;
+
+               if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+                       ent->tag[0] = 0;
+                       ent->tag[1] = 0;
+                       return ent;
+               }
+
+               if (!spi_populate_tag_msg(&ent->tag[0], cmd)) {
+                       ent->tag[0] = 0;
+                       ent->tag[1] = 0;
+               }
+               ent->orig_tag[0] = ent->tag[0];
+               ent->orig_tag[1] = ent->tag[1];
+
+               if (esp_alloc_lun_tag(ent, lp) < 0)
+                       continue;
+
+               return ent;
+       }
+
+       return NULL;
+}
+
+static void esp_maybe_execute_command(struct esp *esp)
+{
+       struct esp_target_data *tp;
+       struct esp_lun_data *lp;
+       struct scsi_device *dev;
+       struct scsi_cmnd *cmd;
+       struct esp_cmd_entry *ent;
+       int tgt, lun, i;
+       u32 val, start_cmd;
+       u8 *p;
+
+       if (esp->active_cmd ||
+           (esp->flags & ESP_FLAG_RESETTING))
+               return;
+
+       ent = find_and_prep_issuable_command(esp);
+       if (!ent)
+               return;
+
+       if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+               esp_autosense(esp, ent);
+               return;
+       }
+
+       cmd = ent->cmd;
+       dev = cmd->device;
+       tgt = dev->id;
+       lun = dev->lun;
+       tp = &esp->target[tgt];
+       lp = dev->hostdata;
+
+       list_move(&ent->list, &esp->active_cmds);
+
+       esp->active_cmd = ent;
+
+       esp_map_dma(esp, cmd);
+       esp_save_pointers(esp, ent);
+
+       esp_check_command_len(esp, cmd);
+
+       p = esp->command_block;
+
+       esp->msg_out_len = 0;
+       if (tp->flags & ESP_TGT_CHECK_NEGO) {
+               /* Need to negotiate.  If the target is broken
+                * go for synchronous transfers and non-wide.
+                */
+               if (tp->flags & ESP_TGT_BROKEN) {
+                       tp->flags &= ~ESP_TGT_DISCONNECT;
+                       tp->nego_goal_period = 0;
+                       tp->nego_goal_offset = 0;
+                       tp->nego_goal_width = 0;
+                       tp->nego_goal_tags = 0;
+               }
+
+               /* If the settings are not changing, skip this.  */
+               if (spi_width(tp->starget) == tp->nego_goal_width &&
+                   spi_period(tp->starget) == tp->nego_goal_period &&
+                   spi_offset(tp->starget) == tp->nego_goal_offset) {
+                       tp->flags &= ~ESP_TGT_CHECK_NEGO;
+                       goto build_identify;
+               }
+
+               if (esp->rev == FASHME && esp_need_to_nego_wide(tp)) {
+                       esp->msg_out_len =
+                               spi_populate_width_msg(&esp->msg_out[0],
+                                                      (tp->nego_goal_width ?
+                                                       1 : 0));
+                       tp->flags |= ESP_TGT_NEGO_WIDE;
+               } else if (esp_need_to_nego_sync(tp)) {
+                       esp->msg_out_len =
+                               spi_populate_sync_msg(&esp->msg_out[0],
+                                                     tp->nego_goal_period,
+                                                     tp->nego_goal_offset);
+                       tp->flags |= ESP_TGT_NEGO_SYNC;
+               } else {
+                       tp->flags &= ~ESP_TGT_CHECK_NEGO;
+               }
+
+               /* Process it like a slow command.  */
+               if (tp->flags & (ESP_TGT_NEGO_WIDE | ESP_TGT_NEGO_SYNC))
+                       esp->flags |= ESP_FLAG_DOING_SLOWCMD;
+       }
+
+build_identify:
+       /* If we don't have a lun-data struct yet, we're probing
+        * so do not disconnect.  Also, do not disconnect unless
+        * we have a tag on this command.
+        */
+       if (lp && (tp->flags & ESP_TGT_DISCONNECT) && ent->tag[0])
+               *p++ = IDENTIFY(1, lun);
+       else
+               *p++ = IDENTIFY(0, lun);
+
+       if (ent->tag[0] && esp->rev == ESP100) {
+               /* ESP100 lacks select w/atn3 command, use select
+                * and stop instead.
+                */
+               esp->flags |= ESP_FLAG_DOING_SLOWCMD;
+       }
+
+       if (!(esp->flags & ESP_FLAG_DOING_SLOWCMD)) {
+               start_cmd = ESP_CMD_SELA;
+               if (ent->tag[0]) {
+                       *p++ = ent->tag[0];
+                       *p++ = ent->tag[1];
+
+                       start_cmd = ESP_CMD_SA3;
+               }
+
+               for (i = 0; i < cmd->cmd_len; i++)
+                       *p++ = cmd->cmnd[i];
+
+               esp->select_state = ESP_SELECT_BASIC;
+       } else {
+               esp->cmd_bytes_left = cmd->cmd_len;
+               esp->cmd_bytes_ptr = &cmd->cmnd[0];
+
+               if (ent->tag[0]) {
+                       for (i = esp->msg_out_len - 1;
+                            i >= 0; i--)
+                               esp->msg_out[i + 2] = esp->msg_out[i];
+                       esp->msg_out[0] = ent->tag[0];
+                       esp->msg_out[1] = ent->tag[1];
+                       esp->msg_out_len += 2;
+               }
+
+               start_cmd = ESP_CMD_SELAS;
+               esp->select_state = ESP_SELECT_MSGOUT;
+       }
+       val = tgt;
+       if (esp->rev == FASHME)
+               val |= ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT;
+       esp_write8(val, ESP_BUSID);
+
+       esp_write_tgt_sync(esp, tgt);
+       esp_write_tgt_config3(esp, tgt);
+
+       val = (p - esp->command_block);
+
+       if (esp_debug & ESP_DEBUG_SCSICMD) {
+               printk("ESP: tgt[%d] lun[%d] scsi_cmd [ ", tgt, lun);
+               for (i = 0; i < cmd->cmd_len; i++)
+                       printk("%02x ", cmd->cmnd[i]);
+               printk("]\n");
+       }
+
+       esp_send_dma_cmd(esp, val, 16, start_cmd);
+}
+
+static struct esp_cmd_entry *esp_get_ent(struct esp *esp)
+{
+       struct list_head *head = &esp->esp_cmd_pool;
+       struct esp_cmd_entry *ret;
+
+       if (list_empty(head)) {
+               ret = kzalloc(sizeof(struct esp_cmd_entry), GFP_ATOMIC);
+       } else {
+               ret = list_entry(head->next, struct esp_cmd_entry, list);
+               list_del(&ret->list);
+               memset(ret, 0, sizeof(*ret));
+       }
+       return ret;
+}
+
+static void esp_put_ent(struct esp *esp, struct esp_cmd_entry *ent)
+{
+       list_add(&ent->list, &esp->esp_cmd_pool);
+}
+
+static void esp_cmd_is_done(struct esp *esp, struct esp_cmd_entry *ent,
+                           struct scsi_cmnd *cmd, unsigned int result)
+{
+       struct scsi_device *dev = cmd->device;
+       int tgt = dev->id;
+       int lun = dev->lun;
+
+       esp->active_cmd = NULL;
+       esp_unmap_dma(esp, cmd);
+       esp_free_lun_tag(ent, dev->hostdata);
+       cmd->result = result;
+
+       if (ent->eh_done) {
+               complete(ent->eh_done);
+               ent->eh_done = NULL;
+       }
+
+       if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+               esp->ops->unmap_single(esp, ent->sense_dma,
+                                      SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+               ent->sense_ptr = NULL;
+
+               /* Restore the message/status bytes to what we actually
+                * saw originally.  Also, report that we are providing
+                * the sense data.
+                */
+               cmd->result = ((DRIVER_SENSE << 24) |
+                              (DID_OK << 16) |
+                              (COMMAND_COMPLETE << 8) |
+                              (SAM_STAT_CHECK_CONDITION << 0));
+
+               ent->flags &= ~ESP_CMD_FLAG_AUTOSENSE;
+               if (esp_debug & ESP_DEBUG_AUTOSENSE) {
+                       int i;
+
+                       printk("esp%d: tgt[%d] lun[%d] AUTO SENSE[ ",
+                              esp->host->unique_id, tgt, lun);
+                       for (i = 0; i < 18; i++)
+                               printk("%02x ", cmd->sense_buffer[i]);
+                       printk("]\n");
+               }
+       }
+
+       cmd->scsi_done(cmd);
+
+       list_del(&ent->list);
+       esp_put_ent(esp, ent);
+
+       esp_maybe_execute_command(esp);
+}
+
+static unsigned int compose_result(unsigned int status, unsigned int message,
+                                  unsigned int driver_code)
+{
+       return (status | (message << 8) | (driver_code << 16));
+}
+
+static void esp_event_queue_full(struct esp *esp, struct esp_cmd_entry *ent)
+{
+       struct scsi_device *dev = ent->cmd->device;
+       struct esp_lun_data *lp = dev->hostdata;
+
+       scsi_track_queue_full(dev, lp->num_tagged - 1);
+}
+
+static int esp_queuecommand_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
+{
+       struct scsi_device *dev = cmd->device;
+       struct esp *esp = shost_priv(dev->host);
+       struct esp_cmd_priv *spriv;
+       struct esp_cmd_entry *ent;
+
+       ent = esp_get_ent(esp);
+       if (!ent)
+               return SCSI_MLQUEUE_HOST_BUSY;
+
+       ent->cmd = cmd;
+
+       cmd->scsi_done = done;
+
+       spriv = ESP_CMD_PRIV(cmd);
+       spriv->u.dma_addr = ~(dma_addr_t)0x0;
+
+       list_add_tail(&ent->list, &esp->queued_cmds);
+
+       esp_maybe_execute_command(esp);
+
+       return 0;
+}
+
+static DEF_SCSI_QCMD(esp_queuecommand)
+
+static int esp_check_gross_error(struct esp *esp)
+{
+       if (esp->sreg & ESP_STAT_SPAM) {
+               /* Gross Error, could be one of:
+                * - top of fifo overwritten
+                * - top of command register overwritten
+                * - DMA programmed with wrong direction
+                * - improper phase change
+                */
+               shost_printk(KERN_ERR, esp->host,
+                            "Gross error sreg[%02x]\n", esp->sreg);
+               /* XXX Reset the chip. XXX */
+               return 1;
+       }
+       return 0;
+}
+
+static int esp_check_spur_intr(struct esp *esp)
+{
+       switch (esp->rev) {
+       case ESP100:
+       case ESP100A:
+               /* The interrupt pending bit of the status register cannot
+                * be trusted on these revisions.
+                */
+               esp->sreg &= ~ESP_STAT_INTR;
+               break;
+
+       default:
+               if (!(esp->sreg & ESP_STAT_INTR)) {
+                       if (esp->ireg & ESP_INTR_SR)
+                               return 1;
+
+                       /* If the DMA is indicating interrupt pending and the
+                        * ESP is not, the only possibility is a DMA error.
+                        */
+                       if (!esp->ops->dma_error(esp)) {
+                               shost_printk(KERN_ERR, esp->host,
+                                            "Spurious irq, sreg=%02x.\n",
+                                            esp->sreg);
+                               return -1;
+                       }
+
+                       shost_printk(KERN_ERR, esp->host, "DMA error\n");
+
+                       /* XXX Reset the chip. XXX */
+                       return -1;
+               }
+               break;
+       }
+
+       return 0;
+}
+
+static void esp_schedule_reset(struct esp *esp)
+{
+       esp_log_reset("esp_schedule_reset() from %pf\n",
+                     __builtin_return_address(0));
+       esp->flags |= ESP_FLAG_RESETTING;
+       esp_event(esp, ESP_EVENT_RESET);
+}
+
+/* In order to avoid having to add a special half-reconnected state
+ * into the driver we just sit here and poll through the rest of
+ * the reselection process to get the tag message bytes.
+ */
+static struct esp_cmd_entry *esp_reconnect_with_tag(struct esp *esp,
+                                                   struct esp_lun_data *lp)
+{
+       struct esp_cmd_entry *ent;
+       int i;
+
+       if (!lp->num_tagged) {
+               shost_printk(KERN_ERR, esp->host,
+                            "Reconnect w/num_tagged==0\n");
+               return NULL;
+       }
+
+       esp_log_reconnect("reconnect tag, ");
+
+       for (i = 0; i < ESP_QUICKIRQ_LIMIT; i++) {
+               if (esp->ops->irq_pending(esp))
+                       break;
+       }
+       if (i == ESP_QUICKIRQ_LIMIT) {
+               shost_printk(KERN_ERR, esp->host,
+                            "Reconnect IRQ1 timeout\n");
+               return NULL;
+       }
+
+       esp->sreg = esp_read8(ESP_STATUS);
+       esp->ireg = esp_read8(ESP_INTRPT);
+
+       esp_log_reconnect("IRQ(%d:%x:%x), ",
+                         i, esp->ireg, esp->sreg);
+
+       if (esp->ireg & ESP_INTR_DC) {
+               shost_printk(KERN_ERR, esp->host,
+                            "Reconnect, got disconnect.\n");
+               return NULL;
+       }
+
+       if ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP) {
+               shost_printk(KERN_ERR, esp->host,
+                            "Reconnect, not MIP sreg[%02x].\n", esp->sreg);
+               return NULL;
+       }
+
+       /* DMA in the tag bytes... */
+       esp->command_block[0] = 0xff;
+       esp->command_block[1] = 0xff;
+       esp->ops->send_dma_cmd(esp, esp->command_block_dma,
+                              2, 2, 1, ESP_CMD_DMA | ESP_CMD_TI);
+
+       /* ACK the message.  */
+       scsi_esp_cmd(esp, ESP_CMD_MOK);
+
+       for (i = 0; i < ESP_RESELECT_TAG_LIMIT; i++) {
+               if (esp->ops->irq_pending(esp)) {
+                       esp->sreg = esp_read8(ESP_STATUS);
+                       esp->ireg = esp_read8(ESP_INTRPT);
+                       if (esp->ireg & ESP_INTR_FDONE)
+                               break;
+               }
+               udelay(1);
+       }
+       if (i == ESP_RESELECT_TAG_LIMIT) {
+               shost_printk(KERN_ERR, esp->host, "Reconnect IRQ2 timeout\n");
+               return NULL;
+       }
+       esp->ops->dma_drain(esp);
+       esp->ops->dma_invalidate(esp);
+
+       esp_log_reconnect("IRQ2(%d:%x:%x) tag[%x:%x]\n",
+                         i, esp->ireg, esp->sreg,
+                         esp->command_block[0],
+                         esp->command_block[1]);
+
+       if (esp->command_block[0] < SIMPLE_QUEUE_TAG ||
+           esp->command_block[0] > ORDERED_QUEUE_TAG) {
+               shost_printk(KERN_ERR, esp->host,
+                            "Reconnect, bad tag type %02x.\n",
+                            esp->command_block[0]);
+               return NULL;
+       }
+
+       ent = lp->tagged_cmds[esp->command_block[1]];
+       if (!ent) {
+               shost_printk(KERN_ERR, esp->host,
+                            "Reconnect, no entry for tag %02x.\n",
+                            esp->command_block[1]);
+               return NULL;
+       }
+
+       return ent;
+}
+
+static int esp_reconnect(struct esp *esp)
+{
+       struct esp_cmd_entry *ent;
+       struct esp_target_data *tp;
+       struct esp_lun_data *lp;
+       struct scsi_device *dev;
+       int target, lun;
+
+       BUG_ON(esp->active_cmd);
+       if (esp->rev == FASHME) {
+               /* FASHME puts the target and lun numbers directly
+                * into the fifo.
+                */
+               target = esp->fifo[0];
+               lun = esp->fifo[1] & 0x7;
+       } else {
+               u8 bits = esp_read8(ESP_FDATA);
+
+               /* Older chips put the lun directly into the fifo, but
+                * the target is given as a sample of the arbitration
+                * lines on the bus at reselection time.  So we should
+                * see the ID of the ESP and the one reconnecting target
+                * set in the bitmap.
+                */
+               if (!(bits & esp->scsi_id_mask))
+                       goto do_reset;
+               bits &= ~esp->scsi_id_mask;
+               if (!bits || (bits & (bits - 1)))
+                       goto do_reset;
+
+               target = ffs(bits) - 1;
+               lun = (esp_read8(ESP_FDATA) & 0x7);
+
+               scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+               if (esp->rev == ESP100) {
+                       u8 ireg = esp_read8(ESP_INTRPT);
+                       /* This chip has a bug during reselection that can
+                        * cause a spurious illegal-command interrupt, which
+                        * we simply ACK here.  Another possibility is a bus
+                        * reset so we must check for that.
+                        */
+                       if (ireg & ESP_INTR_SR)
+                               goto do_reset;
+               }
+               scsi_esp_cmd(esp, ESP_CMD_NULL);
+       }
+
+       esp_write_tgt_sync(esp, target);
+       esp_write_tgt_config3(esp, target);
+
+       scsi_esp_cmd(esp, ESP_CMD_MOK);
+
+       if (esp->rev == FASHME)
+               esp_write8(target | ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT,
+                          ESP_BUSID);
+
+       tp = &esp->target[target];
+       dev = __scsi_device_lookup_by_target(tp->starget, lun);
+       if (!dev) {
+               shost_printk(KERN_ERR, esp->host,
+                            "Reconnect, no lp tgt[%u] lun[%u]\n",
+                            target, lun);
+               goto do_reset;
+       }
+       lp = dev->hostdata;
+
+       ent = lp->non_tagged_cmd;
+       if (!ent) {
+               ent = esp_reconnect_with_tag(esp, lp);
+               if (!ent)
+                       goto do_reset;
+       }
+
+       esp->active_cmd = ent;
+
+       if (ent->flags & ESP_CMD_FLAG_ABORT) {
+               esp->msg_out[0] = ABORT_TASK_SET;
+               esp->msg_out_len = 1;
+               scsi_esp_cmd(esp, ESP_CMD_SATN);
+       }
+
+       esp_event(esp, ESP_EVENT_CHECK_PHASE);
+       esp_restore_pointers(esp, ent);
+       esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
+       return 1;
+
+do_reset:
+       esp_schedule_reset(esp);
+       return 0;
+}
+
+static int esp_finish_select(struct esp *esp)
+{
+       struct esp_cmd_entry *ent;
+       struct scsi_cmnd *cmd;
+       u8 orig_select_state;
+
+       orig_select_state = esp->select_state;
+
+       /* No longer selecting.  */
+       esp->select_state = ESP_SELECT_NONE;
+
+       esp->seqreg = esp_read8(ESP_SSTEP) & ESP_STEP_VBITS;
+       ent = esp->active_cmd;
+       cmd = ent->cmd;
+
+       if (esp->ops->dma_error(esp)) {
+               /* If we see a DMA error during or as a result of selection,
+                * all bets are off.
+                */
+               esp_schedule_reset(esp);
+               esp_cmd_is_done(esp, ent, cmd, (DID_ERROR << 16));
+               return 0;
+       }
+
+       esp->ops->dma_invalidate(esp);
+
+       if (esp->ireg == (ESP_INTR_RSEL | ESP_INTR_FDONE)) {
+               struct esp_target_data *tp = &esp->target[cmd->device->id];
+
+               /* Carefully back out of the selection attempt.  Release
+                * resources (such as DMA mapping & TAG) and reset state (such
+                * as message out and command delivery variables).
+                */
+               if (!(ent->flags & ESP_CMD_FLAG_AUTOSENSE)) {
+                       esp_unmap_dma(esp, cmd);
+                       esp_free_lun_tag(ent, cmd->device->hostdata);
+                       tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_NEGO_WIDE);
+                       esp->flags &= ~ESP_FLAG_DOING_SLOWCMD;
+                       esp->cmd_bytes_ptr = NULL;
+                       esp->cmd_bytes_left = 0;
+               } else {
+                       esp->ops->unmap_single(esp, ent->sense_dma,
+                                              SCSI_SENSE_BUFFERSIZE,
+                                              DMA_FROM_DEVICE);
+                       ent->sense_ptr = NULL;
+               }
+
+               /* Now that the state is unwound properly, put back onto
+                * the issue queue.  This command is no longer active.
+                */
+               list_move(&ent->list, &esp->queued_cmds);
+               esp->active_cmd = NULL;
+
+               /* Return value ignored by caller, it directly invokes
+                * esp_reconnect().
+                */
+               return 0;
+       }
+
+       if (esp->ireg == ESP_INTR_DC) {
+               struct scsi_device *dev = cmd->device;
+
+               /* Disconnect.  Make sure we re-negotiate sync and
+                * wide parameters if this target starts responding
+                * again in the future.
+                */
+               esp->target[dev->id].flags |= ESP_TGT_CHECK_NEGO;
+
+               scsi_esp_cmd(esp, ESP_CMD_ESEL);
+               esp_cmd_is_done(esp, ent, cmd, (DID_BAD_TARGET << 16));
+               return 1;
+       }
+
+       if (esp->ireg == (ESP_INTR_FDONE | ESP_INTR_BSERV)) {
+               /* Selection successful.  On pre-FAST chips we have
+                * to do a NOP and possibly clean out the FIFO.
+                */
+               if (esp->rev <= ESP236) {
+                       int fcnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
+
+                       scsi_esp_cmd(esp, ESP_CMD_NULL);
+
+                       if (!fcnt &&
+                           (!esp->prev_soff ||
+                            ((esp->sreg & ESP_STAT_PMASK) != ESP_DIP)))
+                               esp_flush_fifo(esp);
+               }
+
+               /* If we are doing a slow command, negotiation, etc.
+                * we'll do the right thing as we transition to the
+                * next phase.
+                */
+               esp_event(esp, ESP_EVENT_CHECK_PHASE);
+               return 0;
+       }
+
+       shost_printk(KERN_INFO, esp->host,
+                    "Unexpected selection completion ireg[%x]\n", esp->ireg);
+       esp_schedule_reset(esp);
+       return 0;
+}
+
+static int esp_data_bytes_sent(struct esp *esp, struct esp_cmd_entry *ent,
+                              struct scsi_cmnd *cmd)
+{
+       int fifo_cnt, ecount, bytes_sent, flush_fifo;
+
+       fifo_cnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
+       if (esp->prev_cfg3 & ESP_CONFIG3_EWIDE)
+               fifo_cnt <<= 1;
+
+       ecount = 0;
+       if (!(esp->sreg & ESP_STAT_TCNT)) {
+               ecount = ((unsigned int)esp_read8(ESP_TCLOW) |
+                         (((unsigned int)esp_read8(ESP_TCMED)) << 8));
+               if (esp->rev == FASHME)
+                       ecount |= ((unsigned int)esp_read8(FAS_RLO)) << 16;
+               if (esp->rev == PCSCSI && (esp->config2 & ESP_CONFIG2_FENAB))
+                       ecount |= ((unsigned int)esp_read8(ESP_TCHI)) << 16;
+       }
+
+       bytes_sent = esp->data_dma_len;
+       bytes_sent -= ecount;
+
+       /*
+        * The am53c974 has a DMA 'pecularity'. The doc states:
+        * In some odd byte conditions, one residual byte will
+        * be left in the SCSI FIFO, and the FIFO Flags will
+        * never count to '0 '. When this happens, the residual
+        * byte should be retrieved via PIO following completion
+        * of the BLAST operation.
+        */
+       if (fifo_cnt == 1 && ent->flags & ESP_CMD_FLAG_RESIDUAL) {
+               size_t count = 1;
+               size_t offset = bytes_sent;
+               u8 bval = esp_read8(ESP_FDATA);
+
+               if (ent->flags & ESP_CMD_FLAG_AUTOSENSE)
+                       ent->sense_ptr[bytes_sent] = bval;
+               else {
+                       struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
+                       u8 *ptr;
+
+                       ptr = scsi_kmap_atomic_sg(p->cur_sg, p->u.num_sg,
+                                                 &offset, &count);
+                       if (likely(ptr)) {
+                               *(ptr + offset) = bval;
+                               scsi_kunmap_atomic_sg(ptr);
+                       }
+               }
+               bytes_sent += fifo_cnt;
+               ent->flags &= ~ESP_CMD_FLAG_RESIDUAL;
+       }
+       if (!(ent->flags & ESP_CMD_FLAG_WRITE))
+               bytes_sent -= fifo_cnt;
+
+       flush_fifo = 0;
+       if (!esp->prev_soff) {
+               /* Synchronous data transfer, always flush fifo. */
+               flush_fifo = 1;
+       } else {
+               if (esp->rev == ESP100) {
+                       u32 fflags, phase;
+
+                       /* ESP100 has a chip bug where in the synchronous data
+                        * phase it can mistake a final long REQ pulse from the
+                        * target as an extra data byte.  Fun.
+                        *
+                        * To detect this case we resample the status register
+                        * and fifo flags.  If we're still in a data phase and
+                        * we see spurious chunks in the fifo, we return error
+                        * to the caller which should reset and set things up
+                        * such that we only try future transfers to this
+                        * target in synchronous mode.
+                        */
+                       esp->sreg = esp_read8(ESP_STATUS);
+                       phase = esp->sreg & ESP_STAT_PMASK;
+                       fflags = esp_read8(ESP_FFLAGS);
+
+                       if ((phase == ESP_DOP &&
+                            (fflags & ESP_FF_ONOTZERO)) ||
+                           (phase == ESP_DIP &&
+                            (fflags & ESP_FF_FBYTES)))
+                               return -1;
+               }
+               if (!(ent->flags & ESP_CMD_FLAG_WRITE))
+                       flush_fifo = 1;
+       }
+
+       if (flush_fifo)
+               esp_flush_fifo(esp);
+
+       return bytes_sent;
+}
+
+static void esp_setsync(struct esp *esp, struct esp_target_data *tp,
+                       u8 scsi_period, u8 scsi_offset,
+                       u8 esp_stp, u8 esp_soff)
+{
+       spi_period(tp->starget) = scsi_period;
+       spi_offset(tp->starget) = scsi_offset;
+       spi_width(tp->starget) = (tp->flags & ESP_TGT_WIDE) ? 1 : 0;
+
+       if (esp_soff) {
+               esp_stp &= 0x1f;
+               esp_soff |= esp->radelay;
+               if (esp->rev >= FAS236) {
+                       u8 bit = ESP_CONFIG3_FSCSI;
+                       if (esp->rev >= FAS100A)
+                               bit = ESP_CONFIG3_FAST;
+
+                       if (scsi_period < 50) {
+                               if (esp->rev == FASHME)
+                                       esp_soff &= ~esp->radelay;
+                               tp->esp_config3 |= bit;
+                       } else {
+                               tp->esp_config3 &= ~bit;
+                       }
+                       esp->prev_cfg3 = tp->esp_config3;
+                       esp_write8(esp->prev_cfg3, ESP_CFG3);
+               }
+       }
+
+       tp->esp_period = esp->prev_stp = esp_stp;
+       tp->esp_offset = esp->prev_soff = esp_soff;
+
+       esp_write8(esp_soff, ESP_SOFF);
+       esp_write8(esp_stp, ESP_STP);
+
+       tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_CHECK_NEGO);
+
+       spi_display_xfer_agreement(tp->starget);
+}
+
+static void esp_msgin_reject(struct esp *esp)
+{
+       struct esp_cmd_entry *ent = esp->active_cmd;
+       struct scsi_cmnd *cmd = ent->cmd;
+       struct esp_target_data *tp;
+       int tgt;
+
+       tgt = cmd->device->id;
+       tp = &esp->target[tgt];
+
+       if (tp->flags & ESP_TGT_NEGO_WIDE) {
+               tp->flags &= ~(ESP_TGT_NEGO_WIDE | ESP_TGT_WIDE);
+
+               if (!esp_need_to_nego_sync(tp)) {
+                       tp->flags &= ~ESP_TGT_CHECK_NEGO;
+                       scsi_esp_cmd(esp, ESP_CMD_RATN);
+               } else {
+                       esp->msg_out_len =
+                               spi_populate_sync_msg(&esp->msg_out[0],
+                                                     tp->nego_goal_period,
+                                                     tp->nego_goal_offset);
+                       tp->flags |= ESP_TGT_NEGO_SYNC;
+                       scsi_esp_cmd(esp, ESP_CMD_SATN);
+               }
+               return;
+       }
+
+       if (tp->flags & ESP_TGT_NEGO_SYNC) {
+               tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_CHECK_NEGO);
+               tp->esp_period = 0;
+               tp->esp_offset = 0;
+               esp_setsync(esp, tp, 0, 0, 0, 0);
+               scsi_esp_cmd(esp, ESP_CMD_RATN);
+               return;
+       }
+
+       esp->msg_out[0] = ABORT_TASK_SET;
+       esp->msg_out_len = 1;
+       scsi_esp_cmd(esp, ESP_CMD_SATN);
+}
+
+static void esp_msgin_sdtr(struct esp *esp, struct esp_target_data *tp)
+{
+       u8 period = esp->msg_in[3];
+       u8 offset = esp->msg_in[4];
+       u8 stp;
+
+       if (!(tp->flags & ESP_TGT_NEGO_SYNC))
+               goto do_reject;
+
+       if (offset > 15)
+               goto do_reject;
+
+       if (offset) {
+               int one_clock;
+
+               if (period > esp->max_period) {
+                       period = offset = 0;
+                       goto do_sdtr;
+               }
+               if (period < esp->min_period)
+                       goto do_reject;
+
+               one_clock = esp->ccycle / 1000;
+               stp = DIV_ROUND_UP(period << 2, one_clock);
+               if (stp && esp->rev >= FAS236) {
+                       if (stp >= 50)
+                               stp--;
+               }
+       } else {
+               stp = 0;
+       }
+
+       esp_setsync(esp, tp, period, offset, stp, offset);
+       return;
+
+do_reject:
+       esp->msg_out[0] = MESSAGE_REJECT;
+       esp->msg_out_len = 1;
+       scsi_esp_cmd(esp, ESP_CMD_SATN);
+       return;
+
+do_sdtr:
+       tp->nego_goal_period = period;
+       tp->nego_goal_offset = offset;
+       esp->msg_out_len =
+               spi_populate_sync_msg(&esp->msg_out[0],
+                                     tp->nego_goal_period,
+                                     tp->nego_goal_offset);
+       scsi_esp_cmd(esp, ESP_CMD_SATN);
+}
+
+static void esp_msgin_wdtr(struct esp *esp, struct esp_target_data *tp)
+{
+       int size = 8 << esp->msg_in[3];
+       u8 cfg3;
+
+       if (esp->rev != FASHME)
+               goto do_reject;
+
+       if (size != 8 && size != 16)
+               goto do_reject;
+
+       if (!(tp->flags & ESP_TGT_NEGO_WIDE))
+               goto do_reject;
+
+       cfg3 = tp->esp_config3;
+       if (size == 16) {
+               tp->flags |= ESP_TGT_WIDE;
+               cfg3 |= ESP_CONFIG3_EWIDE;
+       } else {
+               tp->flags &= ~ESP_TGT_WIDE;
+               cfg3 &= ~ESP_CONFIG3_EWIDE;
+       }
+       tp->esp_config3 = cfg3;
+       esp->prev_cfg3 = cfg3;
+       esp_write8(cfg3, ESP_CFG3);
+
+       tp->flags &= ~ESP_TGT_NEGO_WIDE;
+
+       spi_period(tp->starget) = 0;
+       spi_offset(tp->starget) = 0;
+       if (!esp_need_to_nego_sync(tp)) {
+               tp->flags &= ~ESP_TGT_CHECK_NEGO;
+               scsi_esp_cmd(esp, ESP_CMD_RATN);
+       } else {
+               esp->msg_out_len =
+                       spi_populate_sync_msg(&esp->msg_out[0],
+                                             tp->nego_goal_period,
+                                             tp->nego_goal_offset);
+               tp->flags |= ESP_TGT_NEGO_SYNC;
+               scsi_esp_cmd(esp, ESP_CMD_SATN);
+       }
+       return;
+
+do_reject:
+       esp->msg_out[0] = MESSAGE_REJECT;
+       esp->msg_out_len = 1;
+       scsi_esp_cmd(esp, ESP_CMD_SATN);
+}
+
+static void esp_msgin_extended(struct esp *esp)
+{
+       struct esp_cmd_entry *ent = esp->active_cmd;
+       struct scsi_cmnd *cmd = ent->cmd;
+       struct esp_target_data *tp;
+       int tgt = cmd->device->id;
+
+       tp = &esp->target[tgt];
+       if (esp->msg_in[2] == EXTENDED_SDTR) {
+               esp_msgin_sdtr(esp, tp);
+               return;
+       }
+       if (esp->msg_in[2] == EXTENDED_WDTR) {
+               esp_msgin_wdtr(esp, tp);
+               return;
+       }
+
+       shost_printk(KERN_INFO, esp->host,
+                    "Unexpected extended msg type %x\n", esp->msg_in[2]);
+
+       esp->msg_out[0] = ABORT_TASK_SET;
+       esp->msg_out_len = 1;
+       scsi_esp_cmd(esp, ESP_CMD_SATN);
+}
+
+/* Analyze msgin bytes received from target so far.  Return non-zero
+ * if there are more bytes needed to complete the message.
+ */
+static int esp_msgin_process(struct esp *esp)
+{
+       u8 msg0 = esp->msg_in[0];
+       int len = esp->msg_in_len;
+
+       if (msg0 & 0x80) {
+               /* Identify */
+               shost_printk(KERN_INFO, esp->host,
+                            "Unexpected msgin identify\n");
+               return 0;
+       }
+
+       switch (msg0) {
+       case EXTENDED_MESSAGE:
+               if (len == 1)
+                       return 1;
+               if (len < esp->msg_in[1] + 2)
+                       return 1;
+               esp_msgin_extended(esp);
+               return 0;
+
+       case IGNORE_WIDE_RESIDUE: {
+               struct esp_cmd_entry *ent;
+               struct esp_cmd_priv *spriv;
+               if (len == 1)
+                       return 1;
+
+               if (esp->msg_in[1] != 1)
+                       goto do_reject;
+
+               ent = esp->active_cmd;
+               spriv = ESP_CMD_PRIV(ent->cmd);
+
+               if (spriv->cur_residue == sg_dma_len(spriv->cur_sg)) {
+                       spriv->cur_sg--;
+                       spriv->cur_residue = 1;
+               } else
+                       spriv->cur_residue++;
+               spriv->tot_residue++;
+               return 0;
+       }
+       case NOP:
+               return 0;
+       case RESTORE_POINTERS:
+               esp_restore_pointers(esp, esp->active_cmd);
+               return 0;
+       case SAVE_POINTERS:
+               esp_save_pointers(esp, esp->active_cmd);
+               return 0;
+
+       case COMMAND_COMPLETE:
+       case DISCONNECT: {
+               struct esp_cmd_entry *ent = esp->active_cmd;
+
+               ent->message = msg0;
+               esp_event(esp, ESP_EVENT_FREE_BUS);
+               esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
+               return 0;
+       }
+       case MESSAGE_REJECT:
+               esp_msgin_reject(esp);
+               return 0;
+
+       default:
+       do_reject:
+               esp->msg_out[0] = MESSAGE_REJECT;
+               esp->msg_out_len = 1;
+               scsi_esp_cmd(esp, ESP_CMD_SATN);
+               return 0;
+       }
+}
+
+static int esp_process_event(struct esp *esp)
+{
+       int write, i;
+
+again:
+       write = 0;
+       esp_log_event("process event %d phase %x\n",
+                     esp->event, esp->sreg & ESP_STAT_PMASK);
+       switch (esp->event) {
+       case ESP_EVENT_CHECK_PHASE:
+               switch (esp->sreg & ESP_STAT_PMASK) {
+               case ESP_DOP:
+                       esp_event(esp, ESP_EVENT_DATA_OUT);
+                       break;
+               case ESP_DIP:
+                       esp_event(esp, ESP_EVENT_DATA_IN);
+                       break;
+               case ESP_STATP:
+                       esp_flush_fifo(esp);
+                       scsi_esp_cmd(esp, ESP_CMD_ICCSEQ);
+                       esp_event(esp, ESP_EVENT_STATUS);
+                       esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
+                       return 1;
+
+               case ESP_MOP:
+                       esp_event(esp, ESP_EVENT_MSGOUT);
+                       break;
+
+               case ESP_MIP:
+                       esp_event(esp, ESP_EVENT_MSGIN);
+                       break;
+
+               case ESP_CMDP:
+                       esp_event(esp, ESP_EVENT_CMD_START);
+                       break;
+
+               default:
+                       shost_printk(KERN_INFO, esp->host,
+                                    "Unexpected phase, sreg=%02x\n",
+                                    esp->sreg);
+                       esp_schedule_reset(esp);
+                       return 0;
+               }
+               goto again;
+               break;
+
+       case ESP_EVENT_DATA_IN:
+               write = 1;
+               /* fallthru */
+
+       case ESP_EVENT_DATA_OUT: {
+               struct esp_cmd_entry *ent = esp->active_cmd;
+               struct scsi_cmnd *cmd = ent->cmd;
+               dma_addr_t dma_addr = esp_cur_dma_addr(ent, cmd);
+               unsigned int dma_len = esp_cur_dma_len(ent, cmd);
+
+               if (esp->rev == ESP100)
+                       scsi_esp_cmd(esp, ESP_CMD_NULL);
+
+               if (write)
+                       ent->flags |= ESP_CMD_FLAG_WRITE;
+               else
+                       ent->flags &= ~ESP_CMD_FLAG_WRITE;
+
+               if (esp->ops->dma_length_limit)
+                       dma_len = esp->ops->dma_length_limit(esp, dma_addr,
+                                                            dma_len);
+               else
+                       dma_len = esp_dma_length_limit(esp, dma_addr, dma_len);
+
+               esp->data_dma_len = dma_len;
+
+               if (!dma_len) {
+                       shost_printk(KERN_ERR, esp->host,
+                                    "DMA length is zero!\n");
+                       shost_printk(KERN_ERR, esp->host,
+                                    "cur adr[%08llx] len[%08x]\n",
+                                    (unsigned long long)esp_cur_dma_addr(ent, cmd),
+                                    esp_cur_dma_len(ent, cmd));
+                       esp_schedule_reset(esp);
+                       return 0;
+               }
+
+               esp_log_datastart("start data addr[%08llx] len[%u] write(%d)\n",
+                                 (unsigned long long)dma_addr, dma_len, write);
+
+               esp->ops->send_dma_cmd(esp, dma_addr, dma_len, dma_len,
+                                      write, ESP_CMD_DMA | ESP_CMD_TI);
+               esp_event(esp, ESP_EVENT_DATA_DONE);
+               break;
+       }
+       case ESP_EVENT_DATA_DONE: {
+               struct esp_cmd_entry *ent = esp->active_cmd;
+               struct scsi_cmnd *cmd = ent->cmd;
+               int bytes_sent;
+
+               if (esp->ops->dma_error(esp)) {
+                       shost_printk(KERN_INFO, esp->host,
+                                    "data done, DMA error, resetting\n");
+                       esp_schedule_reset(esp);
+                       return 0;
+               }
+
+               if (ent->flags & ESP_CMD_FLAG_WRITE) {
+                       /* XXX parity errors, etc. XXX */
+
+                       esp->ops->dma_drain(esp);
+               }
+               esp->ops->dma_invalidate(esp);
+
+               if (esp->ireg != ESP_INTR_BSERV) {
+                       /* We should always see exactly a bus-service
+                        * interrupt at the end of a successful transfer.
+                        */
+                       shost_printk(KERN_INFO, esp->host,
+                                    "data done, not BSERV, resetting\n");
+                       esp_schedule_reset(esp);
+                       return 0;
+               }
+
+               bytes_sent = esp_data_bytes_sent(esp, ent, cmd);
+
+               esp_log_datadone("data done flgs[%x] sent[%d]\n",
+                                ent->flags, bytes_sent);
+
+               if (bytes_sent < 0) {
+                       /* XXX force sync mode for this target XXX */
+                       esp_schedule_reset(esp);
+                       return 0;
+               }
+
+               esp_advance_dma(esp, ent, cmd, bytes_sent);
+               esp_event(esp, ESP_EVENT_CHECK_PHASE);
+               goto again;
+       }
+
+       case ESP_EVENT_STATUS: {
+               struct esp_cmd_entry *ent = esp->active_cmd;
+
+               if (esp->ireg & ESP_INTR_FDONE) {
+                       ent->status = esp_read8(ESP_FDATA);
+                       ent->message = esp_read8(ESP_FDATA);
+                       scsi_esp_cmd(esp, ESP_CMD_MOK);
+               } else if (esp->ireg == ESP_INTR_BSERV) {
+                       ent->status = esp_read8(ESP_FDATA);
+                       ent->message = 0xff;
+                       esp_event(esp, ESP_EVENT_MSGIN);
+                       return 0;
+               }
+
+               if (ent->message != COMMAND_COMPLETE) {
+                       shost_printk(KERN_INFO, esp->host,
+                                    "Unexpected message %x in status\n",
+                                    ent->message);
+                       esp_schedule_reset(esp);
+                       return 0;
+               }
+
+               esp_event(esp, ESP_EVENT_FREE_BUS);
+               esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
+               break;
+       }
+       case ESP_EVENT_FREE_BUS: {
+               struct esp_cmd_entry *ent = esp->active_cmd;
+               struct scsi_cmnd *cmd = ent->cmd;
+
+               if (ent->message == COMMAND_COMPLETE ||
+                   ent->message == DISCONNECT)
+                       scsi_esp_cmd(esp, ESP_CMD_ESEL);
+
+               if (ent->message == COMMAND_COMPLETE) {
+                       esp_log_cmddone("Command done status[%x] message[%x]\n",
+                                       ent->status, ent->message);
+                       if (ent->status == SAM_STAT_TASK_SET_FULL)
+                               esp_event_queue_full(esp, ent);
+
+                       if (ent->status == SAM_STAT_CHECK_CONDITION &&
+                           !(ent->flags & ESP_CMD_FLAG_AUTOSENSE)) {
+                               ent->flags |= ESP_CMD_FLAG_AUTOSENSE;
+                               esp_autosense(esp, ent);
+                       } else {
+                               esp_cmd_is_done(esp, ent, cmd,
+                                               compose_result(ent->status,
+                                                              ent->message,
+                                                              DID_OK));
+                       }
+               } else if (ent->message == DISCONNECT) {
+                       esp_log_disconnect("Disconnecting tgt[%d] tag[%x:%x]\n",
+                                          cmd->device->id,
+                                          ent->tag[0], ent->tag[1]);
+
+                       esp->active_cmd = NULL;
+                       esp_maybe_execute_command(esp);
+               } else {
+                       shost_printk(KERN_INFO, esp->host,
+                                    "Unexpected message %x in freebus\n",
+                                    ent->message);
+                       esp_schedule_reset(esp);
+                       return 0;
+               }
+               if (esp->active_cmd)
+                       esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
+               break;
+       }
+       case ESP_EVENT_MSGOUT: {
+               scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+
+               if (esp_debug & ESP_DEBUG_MSGOUT) {
+                       int i;
+                       printk("ESP: Sending message [ ");
+                       for (i = 0; i < esp->msg_out_len; i++)
+                               printk("%02x ", esp->msg_out[i]);
+                       printk("]\n");
+               }
+
+               if (esp->rev == FASHME) {
+                       int i;
+
+                       /* Always use the fifo.  */
+                       for (i = 0; i < esp->msg_out_len; i++) {
+                               esp_write8(esp->msg_out[i], ESP_FDATA);
+                               esp_write8(0, ESP_FDATA);
+                       }
+                       scsi_esp_cmd(esp, ESP_CMD_TI);
+               } else {
+                       if (esp->msg_out_len == 1) {
+                               esp_write8(esp->msg_out[0], ESP_FDATA);
+                               scsi_esp_cmd(esp, ESP_CMD_TI);
+                       } else if (esp->flags & ESP_FLAG_USE_FIFO) {
+                               for (i = 0; i < esp->msg_out_len; i++)
+                                       esp_write8(esp->msg_out[i], ESP_FDATA);
+                               scsi_esp_cmd(esp, ESP_CMD_TI);
+                       } else {
+                               /* Use DMA. */
+                               memcpy(esp->command_block,
+                                      esp->msg_out,
+                                      esp->msg_out_len);
+
+                               esp->ops->send_dma_cmd(esp,
+                                                      esp->command_block_dma,
+                                                      esp->msg_out_len,
+                                                      esp->msg_out_len,
+                                                      0,
+                                                      ESP_CMD_DMA|ESP_CMD_TI);
+                       }
+               }
+               esp_event(esp, ESP_EVENT_MSGOUT_DONE);
+               break;
+       }
+       case ESP_EVENT_MSGOUT_DONE:
+               if (esp->rev == FASHME) {
+                       scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+               } else {
+                       if (esp->msg_out_len > 1)
+                               esp->ops->dma_invalidate(esp);
+               }
+
+               if (!(esp->ireg & ESP_INTR_DC)) {
+                       if (esp->rev != FASHME)
+                               scsi_esp_cmd(esp, ESP_CMD_NULL);
+               }
+               esp_event(esp, ESP_EVENT_CHECK_PHASE);
+               goto again;
+       case ESP_EVENT_MSGIN:
+               if (esp->ireg & ESP_INTR_BSERV) {
+                       if (esp->rev == FASHME) {
+                               if (!(esp_read8(ESP_STATUS2) &
+                                     ESP_STAT2_FEMPTY))
+                                       scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+                       } else {
+                               scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+                               if (esp->rev == ESP100)
+                                       scsi_esp_cmd(esp, ESP_CMD_NULL);
+                       }
+                       scsi_esp_cmd(esp, ESP_CMD_TI);
+                       esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
+                       return 1;
+               }
+               if (esp->ireg & ESP_INTR_FDONE) {
+                       u8 val;
+
+                       if (esp->rev == FASHME)
+                               val = esp->fifo[0];
+                       else
+                               val = esp_read8(ESP_FDATA);
+                       esp->msg_in[esp->msg_in_len++] = val;
+
+                       esp_log_msgin("Got msgin byte %x\n", val);
+
+                       if (!esp_msgin_process(esp))
+                               esp->msg_in_len = 0;
+
+                       if (esp->rev == FASHME)
+                               scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+
+                       scsi_esp_cmd(esp, ESP_CMD_MOK);
+
+                       if (esp->event != ESP_EVENT_FREE_BUS)
+                               esp_event(esp, ESP_EVENT_CHECK_PHASE);
+               } else {
+                       shost_printk(KERN_INFO, esp->host,
+                                    "MSGIN neither BSERV not FDON, resetting");
+                       esp_schedule_reset(esp);
+                       return 0;
+               }
+               break;
+       case ESP_EVENT_CMD_START:
+               memcpy(esp->command_block, esp->cmd_bytes_ptr,
+                      esp->cmd_bytes_left);
+               esp_send_dma_cmd(esp, esp->cmd_bytes_left, 16, ESP_CMD_TI);
+               esp_event(esp, ESP_EVENT_CMD_DONE);
+               esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
+               break;
+       case ESP_EVENT_CMD_DONE:
+               esp->ops->dma_invalidate(esp);
+               if (esp->ireg & ESP_INTR_BSERV) {
+                       esp_event(esp, ESP_EVENT_CHECK_PHASE);
+                       goto again;
+               }
+               esp_schedule_reset(esp);
+               return 0;
+               break;
+
+       case ESP_EVENT_RESET:
+               scsi_esp_cmd(esp, ESP_CMD_RS);
+               break;
+
+       default:
+               shost_printk(KERN_INFO, esp->host,
+                            "Unexpected event %x, resetting\n", esp->event);
+               esp_schedule_reset(esp);
+               return 0;
+               break;
+       }
+       return 1;
+}
+
+static void esp_reset_cleanup_one(struct esp *esp, struct esp_cmd_entry *ent)
+{
+       struct scsi_cmnd *cmd = ent->cmd;
+
+       esp_unmap_dma(esp, cmd);
+       esp_free_lun_tag(ent, cmd->device->hostdata);
+       cmd->result = DID_RESET << 16;
+
+       if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
+               esp->ops->unmap_single(esp, ent->sense_dma,
+                                      SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+               ent->sense_ptr = NULL;
+       }
+
+       cmd->scsi_done(cmd);
+       list_del(&ent->list);
+       esp_put_ent(esp, ent);
+}
+
+static void esp_clear_hold(struct scsi_device *dev, void *data)
+{
+       struct esp_lun_data *lp = dev->hostdata;
+
+       BUG_ON(lp->num_tagged);
+       lp->hold = 0;
+}
+
+static void esp_reset_cleanup(struct esp *esp)
+{
+       struct esp_cmd_entry *ent, *tmp;
+       int i;
+
+       list_for_each_entry_safe(ent, tmp, &esp->queued_cmds, list) {
+               struct scsi_cmnd *cmd = ent->cmd;
+
+               list_del(&ent->list);
+               cmd->result = DID_RESET << 16;
+               cmd->scsi_done(cmd);
+               esp_put_ent(esp, ent);
+       }
+
+       list_for_each_entry_safe(ent, tmp, &esp->active_cmds, list) {
+               if (ent == esp->active_cmd)
+                       esp->active_cmd = NULL;
+               esp_reset_cleanup_one(esp, ent);
+       }
+
+       BUG_ON(esp->active_cmd != NULL);
+
+       /* Force renegotiation of sync/wide transfers.  */
+       for (i = 0; i < ESP_MAX_TARGET; i++) {
+               struct esp_target_data *tp = &esp->target[i];
+
+               tp->esp_period = 0;
+               tp->esp_offset = 0;
+               tp->esp_config3 &= ~(ESP_CONFIG3_EWIDE |
+                                    ESP_CONFIG3_FSCSI |
+                                    ESP_CONFIG3_FAST);
+               tp->flags &= ~ESP_TGT_WIDE;
+               tp->flags |= ESP_TGT_CHECK_NEGO;
+
+               if (tp->starget)
+                       __starget_for_each_device(tp->starget, NULL,
+                                                 esp_clear_hold);
+       }
+       esp->flags &= ~ESP_FLAG_RESETTING;
+}
+
+/* Runs under host->lock */
+static void __esp_interrupt(struct esp *esp)
+{
+       int finish_reset, intr_done;
+       u8 phase;
+
+       /*
+       * Once INTRPT is read STATUS and SSTEP are cleared.
+       */
+       esp->sreg = esp_read8(ESP_STATUS);
+       esp->seqreg = esp_read8(ESP_SSTEP);
+       esp->ireg = esp_read8(ESP_INTRPT);
+
+       if (esp->flags & ESP_FLAG_RESETTING) {
+               finish_reset = 1;
+       } else {
+               if (esp_check_gross_error(esp))
+                       return;
+
+               finish_reset = esp_check_spur_intr(esp);
+               if (finish_reset < 0)
+                       return;
+       }
+
+       if (esp->ireg & ESP_INTR_SR)
+               finish_reset = 1;
+
+       if (finish_reset) {
+               esp_reset_cleanup(esp);
+               if (esp->eh_reset) {
+                       complete(esp->eh_reset);
+                       esp->eh_reset = NULL;
+               }
+               return;
+       }
+
+       phase = (esp->sreg & ESP_STAT_PMASK);
+       if (esp->rev == FASHME) {
+               if (((phase != ESP_DIP && phase != ESP_DOP) &&
+                    esp->select_state == ESP_SELECT_NONE &&
+                    esp->event != ESP_EVENT_STATUS &&
+                    esp->event != ESP_EVENT_DATA_DONE) ||
+                   (esp->ireg & ESP_INTR_RSEL)) {
+                       esp->sreg2 = esp_read8(ESP_STATUS2);
+                       if (!(esp->sreg2 & ESP_STAT2_FEMPTY) ||
+                           (esp->sreg2 & ESP_STAT2_F1BYTE))
+                               hme_read_fifo(esp);
+               }
+       }
+
+       esp_log_intr("intr sreg[%02x] seqreg[%02x] "
+                    "sreg2[%02x] ireg[%02x]\n",
+                    esp->sreg, esp->seqreg, esp->sreg2, esp->ireg);
+
+       intr_done = 0;
+
+       if (esp->ireg & (ESP_INTR_S | ESP_INTR_SATN | ESP_INTR_IC)) {
+               shost_printk(KERN_INFO, esp->host,
+                            "unexpected IREG %02x\n", esp->ireg);
+               if (esp->ireg & ESP_INTR_IC)
+                       esp_dump_cmd_log(esp);
+
+               esp_schedule_reset(esp);
+       } else {
+               if (!(esp->ireg & ESP_INTR_RSEL)) {
+                       /* Some combination of FDONE, BSERV, DC.  */
+                       if (esp->select_state != ESP_SELECT_NONE)
+                               intr_done = esp_finish_select(esp);
+               } else if (esp->ireg & ESP_INTR_RSEL) {
+                       if (esp->active_cmd)
+                               (void) esp_finish_select(esp);
+                       intr_done = esp_reconnect(esp);
+               }
+       }
+       while (!intr_done)
+               intr_done = esp_process_event(esp);
+}
+
+irqreturn_t scsi_esp_intr(int irq, void *dev_id)
+{
+       struct esp *esp = dev_id;
+       unsigned long flags;
+       irqreturn_t ret;
+
+       spin_lock_irqsave(esp->host->host_lock, flags);
+       ret = IRQ_NONE;
+       if (esp->ops->irq_pending(esp)) {
+               ret = IRQ_HANDLED;
+               for (;;) {
+                       int i;
+
+                       __esp_interrupt(esp);
+                       if (!(esp->flags & ESP_FLAG_QUICKIRQ_CHECK))
+                               break;
+                       esp->flags &= ~ESP_FLAG_QUICKIRQ_CHECK;
+
+                       for (i = 0; i < ESP_QUICKIRQ_LIMIT; i++) {
+                               if (esp->ops->irq_pending(esp))
+                                       break;
+                       }
+                       if (i == ESP_QUICKIRQ_LIMIT)
+                               break;
+               }
+       }
+       spin_unlock_irqrestore(esp->host->host_lock, flags);
+
+       return ret;
+}
+EXPORT_SYMBOL(scsi_esp_intr);
+
+static void esp_get_revision(struct esp *esp)
+{
+       u8 val;
+
+       esp->config1 = (ESP_CONFIG1_PENABLE | (esp->scsi_id & 7));
+       if (esp->config2 == 0) {
+               esp->config2 = (ESP_CONFIG2_SCSI2ENAB | ESP_CONFIG2_REGPARITY);
+               esp_write8(esp->config2, ESP_CFG2);
+
+               val = esp_read8(ESP_CFG2);
+               val &= ~ESP_CONFIG2_MAGIC;
+
+               esp->config2 = 0;
+               if (val != (ESP_CONFIG2_SCSI2ENAB | ESP_CONFIG2_REGPARITY)) {
+                       /*
+                        * If what we write to cfg2 does not come back,
+                        * cfg2 is not implemented.
+                        * Therefore this must be a plain esp100.
+                        */
+                       esp->rev = ESP100;
+                       return;
+               }
+       }
+
+       esp_set_all_config3(esp, 5);
+       esp->prev_cfg3 = 5;
+       esp_write8(esp->config2, ESP_CFG2);
+       esp_write8(0, ESP_CFG3);
+       esp_write8(esp->prev_cfg3, ESP_CFG3);
+
+       val = esp_read8(ESP_CFG3);
+       if (val != 5) {
+               /* The cfg2 register is implemented, however
+                * cfg3 is not, must be esp100a.
+                */
+               esp->rev = ESP100A;
+       } else {
+               esp_set_all_config3(esp, 0);
+               esp->prev_cfg3 = 0;
+               esp_write8(esp->prev_cfg3, ESP_CFG3);
+
+               /* All of cfg{1,2,3} implemented, must be one of
+                * the fas variants, figure out which one.
+                */
+               if (esp->cfact == 0 || esp->cfact > ESP_CCF_F5) {
+                       esp->rev = FAST;
+                       esp->sync_defp = SYNC_DEFP_FAST;
+               } else {
+                       esp->rev = ESP236;
+               }
+       }
+}
+
+static void esp_init_swstate(struct esp *esp)
+{
+       int i;
+
+       INIT_LIST_HEAD(&esp->queued_cmds);
+       INIT_LIST_HEAD(&esp->active_cmds);
+       INIT_LIST_HEAD(&esp->esp_cmd_pool);
+
+       /* Start with a clear state, domain validation (via ->slave_configure,
+        * spi_dv_device()) will attempt to enable SYNC, WIDE, and tagged
+        * commands.
+        */
+       for (i = 0 ; i < ESP_MAX_TARGET; i++) {
+               esp->target[i].flags = 0;
+               esp->target[i].nego_goal_period = 0;
+               esp->target[i].nego_goal_offset = 0;
+               esp->target[i].nego_goal_width = 0;
+               esp->target[i].nego_goal_tags = 0;
+       }
+}
+
+/* This places the ESP into a known state at boot time. */
+static void esp_bootup_reset(struct esp *esp)
+{
+       u8 val;
+
+       /* Reset the DMA */
+       esp->ops->reset_dma(esp);
+
+       /* Reset the ESP */
+       esp_reset_esp(esp);
+
+       /* Reset the SCSI bus, but tell ESP not to generate an irq */
+       val = esp_read8(ESP_CFG1);
+       val |= ESP_CONFIG1_SRRDISAB;
+       esp_write8(val, ESP_CFG1);
+
+       scsi_esp_cmd(esp, ESP_CMD_RS);
+       udelay(400);
+
+       esp_write8(esp->config1, ESP_CFG1);
+
+       /* Eat any bitrot in the chip and we are done... */
+       esp_read8(ESP_INTRPT);
+}
+
+static void esp_set_clock_params(struct esp *esp)
+{
+       int fhz;
+       u8 ccf;
+
+       /* This is getting messy but it has to be done correctly or else
+        * you get weird behavior all over the place.  We are trying to
+        * basically figure out three pieces of information.
+        *
+        * a) Clock Conversion Factor
+        *
+        *    This is a representation of the input crystal clock frequency
+        *    going into the ESP on this machine.  Any operation whose timing
+        *    is longer than 400ns depends on this value being correct.  For
+        *    example, you'll get blips for arbitration/selection during high
+        *    load or with multiple targets if this is not set correctly.
+        *
+        * b) Selection Time-Out
+        *
+        *    The ESP isn't very bright and will arbitrate for the bus and try
+        *    to select a target forever if you let it.  This value tells the
+        *    ESP when it has taken too long to negotiate and that it should
+        *    interrupt the CPU so we can see what happened.  The value is
+        *    computed as follows (from NCR/Symbios chip docs).
+        *
+        *          (Time Out Period) *  (Input Clock)
+        *    STO = ----------------------------------
+        *          (8192) * (Clock Conversion Factor)
+        *
+        *    We use a time out period of 250ms (ESP_BUS_TIMEOUT).
+        *
+        * c) Imperical constants for synchronous offset and transfer period
+         *    register values
+        *
+        *    This entails the smallest and largest sync period we could ever
+        *    handle on this ESP.
+        */
+       fhz = esp->cfreq;
+
+       ccf = ((fhz / 1000000) + 4) / 5;
+       if (ccf == 1)
+               ccf = 2;
+
+       /* If we can't find anything reasonable, just assume 20MHZ.
+        * This is the clock frequency of the older sun4c's where I've
+        * been unable to find the clock-frequency PROM property.  All
+        * other machines provide useful values it seems.
+        */
+       if (fhz <= 5000000 || ccf < 1 || ccf > 8) {
+               fhz = 20000000;
+               ccf = 4;
+       }
+
+       esp->cfact = (ccf == 8 ? 0 : ccf);
+       esp->cfreq = fhz;
+       esp->ccycle = ESP_HZ_TO_CYCLE(fhz);
+       esp->ctick = ESP_TICK(ccf, esp->ccycle);
+       esp->neg_defp = ESP_NEG_DEFP(fhz, ccf);
+       esp->sync_defp = SYNC_DEFP_SLOW;
+}
+
+static const char *esp_chip_names[] = {
+       "ESP100",
+       "ESP100A",
+       "ESP236",
+       "FAS236",
+       "FAS100A",
+       "FAST",
+       "FASHME",
+       "AM53C974",
+};
+
+static struct scsi_transport_template *esp_transport_template;
+
+int scsi_esp_register(struct esp *esp, struct device *dev)
+{
+       static int instance;
+       int err;
+
+       if (!esp->num_tags)
+               esp->num_tags = ESP_DEFAULT_TAGS;
+       esp->host->transportt = esp_transport_template;
+       esp->host->max_lun = ESP_MAX_LUN;
+       esp->host->cmd_per_lun = 2;
+       esp->host->unique_id = instance;
+
+       esp_set_clock_params(esp);
+
+       esp_get_revision(esp);
+
+       esp_init_swstate(esp);
+
+       esp_bootup_reset(esp);
+
+       dev_printk(KERN_INFO, dev, "esp%u: regs[%1p:%1p] irq[%u]\n",
+                  esp->host->unique_id, esp->regs, esp->dma_regs,
+                  esp->host->irq);
+       dev_printk(KERN_INFO, dev,
+                  "esp%u: is a %s, %u MHz (ccf=%u), SCSI ID %u\n",
+                  esp->host->unique_id, esp_chip_names[esp->rev],
+                  esp->cfreq / 1000000, esp->cfact, esp->scsi_id);
+
+       /* Let the SCSI bus reset settle. */
+       ssleep(esp_bus_reset_settle);
+
+       err = scsi_add_host(esp->host, dev);
+       if (err)
+               return err;
+
+       instance++;
+
+       scsi_scan_host(esp->host);
+
+       return 0;
+}
+EXPORT_SYMBOL(scsi_esp_register);
+
+void scsi_esp_unregister(struct esp *esp)
+{
+       scsi_remove_host(esp->host);
+}
+EXPORT_SYMBOL(scsi_esp_unregister);
+
+static int esp_target_alloc(struct scsi_target *starget)
+{
+       struct esp *esp = shost_priv(dev_to_shost(&starget->dev));
+       struct esp_target_data *tp = &esp->target[starget->id];
+
+       tp->starget = starget;
+
+       return 0;
+}
+
+static void esp_target_destroy(struct scsi_target *starget)
+{
+       struct esp *esp = shost_priv(dev_to_shost(&starget->dev));
+       struct esp_target_data *tp = &esp->target[starget->id];
+
+       tp->starget = NULL;
+}
+
+static int esp_slave_alloc(struct scsi_device *dev)
+{
+       struct esp *esp = shost_priv(dev->host);
+       struct esp_target_data *tp = &esp->target[dev->id];
+       struct esp_lun_data *lp;
+
+       lp = kzalloc(sizeof(*lp), GFP_KERNEL);
+       if (!lp)
+               return -ENOMEM;
+       dev->hostdata = lp;
+
+       spi_min_period(tp->starget) = esp->min_period;
+       spi_max_offset(tp->starget) = 15;
+
+       if (esp->flags & ESP_FLAG_WIDE_CAPABLE)
+               spi_max_width(tp->starget) = 1;
+       else
+               spi_max_width(tp->starget) = 0;
+
+       return 0;
+}
+
+static int esp_slave_configure(struct scsi_device *dev)
+{
+       struct esp *esp = shost_priv(dev->host);
+       struct esp_target_data *tp = &esp->target[dev->id];
+
+       if (dev->tagged_supported)
+               scsi_change_queue_depth(dev, esp->num_tags);
+
+       tp->flags |= ESP_TGT_DISCONNECT;
+
+       if (!spi_initial_dv(dev->sdev_target))
+               spi_dv_device(dev);
+
+       return 0;
+}
+
+static void esp_slave_destroy(struct scsi_device *dev)
+{
+       struct esp_lun_data *lp = dev->hostdata;
+
+       kfree(lp);
+       dev->hostdata = NULL;
+}
+
+static int esp_eh_abort_handler(struct scsi_cmnd *cmd)
+{
+       struct esp *esp = shost_priv(cmd->device->host);
+       struct esp_cmd_entry *ent, *tmp;
+       struct completion eh_done;
+       unsigned long flags;
+
+       /* XXX This helps a lot with debugging but might be a bit
+        * XXX much for the final driver.
+        */
+       spin_lock_irqsave(esp->host->host_lock, flags);
+       shost_printk(KERN_ERR, esp->host, "Aborting command [%p:%02x]\n",
+                    cmd, cmd->cmnd[0]);
+       ent = esp->active_cmd;
+       if (ent)
+               shost_printk(KERN_ERR, esp->host,
+                            "Current command [%p:%02x]\n",
+                            ent->cmd, ent->cmd->cmnd[0]);
+       list_for_each_entry(ent, &esp->queued_cmds, list) {
+               shost_printk(KERN_ERR, esp->host, "Queued command [%p:%02x]\n",
+                            ent->cmd, ent->cmd->cmnd[0]);
+       }
+       list_for_each_entry(ent, &esp->active_cmds, list) {
+               shost_printk(KERN_ERR, esp->host, " Active command [%p:%02x]\n",
+                            ent->cmd, ent->cmd->cmnd[0]);
+       }
+       esp_dump_cmd_log(esp);
+       spin_unlock_irqrestore(esp->host->host_lock, flags);
+
+       spin_lock_irqsave(esp->host->host_lock, flags);
+
+       ent = NULL;
+       list_for_each_entry(tmp, &esp->queued_cmds, list) {
+               if (tmp->cmd == cmd) {
+                       ent = tmp;
+                       break;
+               }
+       }
+
+       if (ent) {
+               /* Easiest case, we didn't even issue the command
+                * yet so it is trivial to abort.
+                */
+               list_del(&ent->list);
+
+               cmd->result = DID_ABORT << 16;
+               cmd->scsi_done(cmd);
+
+               esp_put_ent(esp, ent);
+
+               goto out_success;
+       }
+
+       init_completion(&eh_done);
+
+       ent = esp->active_cmd;
+       if (ent && ent->cmd == cmd) {
+               /* Command is the currently active command on
+                * the bus.  If we already have an output message
+                * pending, no dice.
+                */
+               if (esp->msg_out_len)
+                       goto out_failure;
+
+               /* Send out an abort, encouraging the target to
+                * go to MSGOUT phase by asserting ATN.
+                */
+               esp->msg_out[0] = ABORT_TASK_SET;
+               esp->msg_out_len = 1;
+               ent->eh_done = &eh_done;
+
+               scsi_esp_cmd(esp, ESP_CMD_SATN);
+       } else {
+               /* The command is disconnected.  This is not easy to
+                * abort.  For now we fail and let the scsi error
+                * handling layer go try a scsi bus reset or host
+                * reset.
+                *
+                * What we could do is put together a scsi command
+                * solely for the purpose of sending an abort message
+                * to the target.  Coming up with all the code to
+                * cook up scsi commands, special case them everywhere,
+                * etc. is for questionable gain and it would be better
+                * if the generic scsi error handling layer could do at
+                * least some of that for us.
+                *
+                * Anyways this is an area for potential future improvement
+                * in this driver.
+                */
+               goto out_failure;
+       }
+
+       spin_unlock_irqrestore(esp->host->host_lock, flags);
+
+       if (!wait_for_completion_timeout(&eh_done, 5 * HZ)) {
+               spin_lock_irqsave(esp->host->host_lock, flags);
+               ent->eh_done = NULL;
+               spin_unlock_irqrestore(esp->host->host_lock, flags);
+
+               return FAILED;
+       }
+
+       return SUCCESS;
+
+out_success:
+       spin_unlock_irqrestore(esp->host->host_lock, flags);
+       return SUCCESS;
+
+out_failure:
+       /* XXX This might be a good location to set ESP_TGT_BROKEN
+        * XXX since we know which target/lun in particular is
+        * XXX causing trouble.
+        */
+       spin_unlock_irqrestore(esp->host->host_lock, flags);
+       return FAILED;
+}
+
+static int esp_eh_bus_reset_handler(struct scsi_cmnd *cmd)
+{
+       struct esp *esp = shost_priv(cmd->device->host);
+       struct completion eh_reset;
+       unsigned long flags;
+
+       init_completion(&eh_reset);
+
+       spin_lock_irqsave(esp->host->host_lock, flags);
+
+       esp->eh_reset = &eh_reset;
+
+       /* XXX This is too simple... We should add lots of
+        * XXX checks here so that if we find that the chip is
+        * XXX very wedged we return failure immediately so
+        * XXX that we can perform a full chip reset.
+        */
+       esp->flags |= ESP_FLAG_RESETTING;
+       scsi_esp_cmd(esp, ESP_CMD_RS);
+
+       spin_unlock_irqrestore(esp->host->host_lock, flags);
+
+       ssleep(esp_bus_reset_settle);
+
+       if (!wait_for_completion_timeout(&eh_reset, 5 * HZ)) {
+               spin_lock_irqsave(esp->host->host_lock, flags);
+               esp->eh_reset = NULL;
+               spin_unlock_irqrestore(esp->host->host_lock, flags);
+
+               return FAILED;
+       }
+
+       return SUCCESS;
+}
+
+/* All bets are off, reset the entire device.  */
+static int esp_eh_host_reset_handler(struct scsi_cmnd *cmd)
+{
+       struct esp *esp = shost_priv(cmd->device->host);
+       unsigned long flags;
+
+       spin_lock_irqsave(esp->host->host_lock, flags);
+       esp_bootup_reset(esp);
+       esp_reset_cleanup(esp);
+       spin_unlock_irqrestore(esp->host->host_lock, flags);
+
+       ssleep(esp_bus_reset_settle);
+
+       return SUCCESS;
+}
+
+static const char *esp_info(struct Scsi_Host *host)
+{
+       return "esp";
+}
+
+struct scsi_host_template scsi_esp_template = {
+       .module                 = THIS_MODULE,
+       .name                   = "esp",
+       .info                   = esp_info,
+       .queuecommand           = esp_queuecommand,
+       .target_alloc           = esp_target_alloc,
+       .target_destroy         = esp_target_destroy,
+       .slave_alloc            = esp_slave_alloc,
+       .slave_configure        = esp_slave_configure,
+       .slave_destroy          = esp_slave_destroy,
+       .eh_abort_handler       = esp_eh_abort_handler,
+       .eh_bus_reset_handler   = esp_eh_bus_reset_handler,
+       .eh_host_reset_handler  = esp_eh_host_reset_handler,
+       .can_queue              = 7,
+       .this_id                = 7,
+       .sg_tablesize           = SG_ALL,
+       .use_clustering         = ENABLE_CLUSTERING,
+       .max_sectors            = 0xffff,
+       .skip_settle_delay      = 1,
+       .use_blk_tags           = 1,
+};
+EXPORT_SYMBOL(scsi_esp_template);
+
+static void esp_get_signalling(struct Scsi_Host *host)
+{
+       struct esp *esp = shost_priv(host);
+       enum spi_signal_type type;
+
+       if (esp->flags & ESP_FLAG_DIFFERENTIAL)
+               type = SPI_SIGNAL_HVD;
+       else
+               type = SPI_SIGNAL_SE;
+
+       spi_signalling(host) = type;
+}
+
+static void esp_set_offset(struct scsi_target *target, int offset)
+{
+       struct Scsi_Host *host = dev_to_shost(target->dev.parent);
+       struct esp *esp = shost_priv(host);
+       struct esp_target_data *tp = &esp->target[target->id];
+
+       if (esp->flags & ESP_FLAG_DISABLE_SYNC)
+               tp->nego_goal_offset = 0;
+       else
+               tp->nego_goal_offset = offset;
+       tp->flags |= ESP_TGT_CHECK_NEGO;
+}
+
+static void esp_set_period(struct scsi_target *target, int period)
+{
+       struct Scsi_Host *host = dev_to_shost(target->dev.parent);
+       struct esp *esp = shost_priv(host);
+       struct esp_target_data *tp = &esp->target[target->id];
+
+       tp->nego_goal_period = period;
+       tp->flags |= ESP_TGT_CHECK_NEGO;
+}
+
+static void esp_set_width(struct scsi_target *target, int width)
+{
+       struct Scsi_Host *host = dev_to_shost(target->dev.parent);
+       struct esp *esp = shost_priv(host);
+       struct esp_target_data *tp = &esp->target[target->id];
+
+       tp->nego_goal_width = (width ? 1 : 0);
+       tp->flags |= ESP_TGT_CHECK_NEGO;
+}
+
+static struct spi_function_template esp_transport_ops = {
+       .set_offset             = esp_set_offset,
+       .show_offset            = 1,
+       .set_period             = esp_set_period,
+       .show_period            = 1,
+       .set_width              = esp_set_width,
+       .show_width             = 1,
+       .get_signalling         = esp_get_signalling,
+};
+
+static int __init esp_init(void)
+{
+       BUILD_BUG_ON(sizeof(struct scsi_pointer) <
+                    sizeof(struct esp_cmd_priv));
+
+       esp_transport_template = spi_attach_transport(&esp_transport_ops);
+       if (!esp_transport_template)
+               return -ENODEV;
+
+       return 0;
+}
+
+static void __exit esp_exit(void)
+{
+       spi_release_transport(esp_transport_template);
+}
+
+MODULE_DESCRIPTION("ESP SCSI driver core");
+MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+module_param(esp_bus_reset_settle, int, 0);
+MODULE_PARM_DESC(esp_bus_reset_settle,
+                "ESP scsi bus reset delay in seconds");
+
+module_param(esp_debug, int, 0);
+MODULE_PARM_DESC(esp_debug,
+"ESP bitmapped debugging message enable value:\n"
+"      0x00000001      Log interrupt events\n"
+"      0x00000002      Log scsi commands\n"
+"      0x00000004      Log resets\n"
+"      0x00000008      Log message in events\n"
+"      0x00000010      Log message out events\n"
+"      0x00000020      Log command completion\n"
+"      0x00000040      Log disconnects\n"
+"      0x00000080      Log data start\n"
+"      0x00000100      Log data done\n"
+"      0x00000200      Log reconnects\n"
+"      0x00000400      Log auto-sense data\n"
+);
+
+module_init(esp_init);
+module_exit(esp_exit);