/* 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]
  ", 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
  ");

  	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]
  ",
  			     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!
  ");

  				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.
  ");
  		shost_printk(KERN_ERR, esp->host,
  			     "cur_residue[%d] tot_residue[%d] len[%u]
  ",
  			     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]
  ",
  				  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("]
  ");
  	}

  	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("]
  ");
  		}
  	}
  
  	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]
  ", 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.
  ",
  					     esp->sreg);

  				return -1;
  			}

  			shost_printk(KERN_ERR, esp->host, "DMA error
  ");

  
  			/* 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
  ",

  		      __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
  ");

  		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
  ");

  		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.
  ");

  		return NULL;
  	}
  
  	if ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP) {

  		shost_printk(KERN_ERR, esp->host,
  			     "Reconnect, not MIP sreg[%02x].
  ", 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
  ");

  		return NULL;
  	}
  	esp->ops->dma_drain(esp);
  	esp->ops->dma_invalidate(esp);
  
  	esp_log_reconnect("IRQ2(%d:%x:%x) tag[%x:%x]
  ",
  			  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.
  ",
  			     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.
  ",
  			     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]
  ",
  			     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]
  ", 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
  ", 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
  ");

  		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
  ",
  		      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
  ",
  				     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!
  ");
  			shost_printk(KERN_ERR, esp->host,
  				     "cur adr[%08llx] len[%08x]
  ",
  				     (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)
  ",

  				  (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
  ");

  			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
  ");

  			esp_schedule_reset(esp);
  			return 0;
  		}
  
  		bytes_sent = esp_data_bytes_sent(esp, ent, cmd);

  		esp_log_datadone("data done flgs[%x] sent[%d]
  ",

  				 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
  ",
  				     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]
  ",

  					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]
  ",

  					   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
  ",
  				     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("]
  ");
  		}
  
  		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
  ", 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
  ", 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]
  ",
  		     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
  ", 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;
  	else if (esp->num_tags >= ESP_MAX_TAG)
  		esp->num_tags = ESP_MAX_TAG - 1;

  	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]
  ",
  		   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
  ",
  		   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]
  ",
  		     cmd, cmd->cmnd[0]);

  	ent = esp->active_cmd;
  	if (ent)

  		shost_printk(KERN_ERR, esp->host,
  			     "Current command [%p:%02x]
  ",
  			     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]
  ",
  			     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]
  ",
  			     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:
  "
  "	0x00000001	Log interrupt events
  "
  "	0x00000002	Log scsi commands
  "
  "	0x00000004	Log resets
  "
  "	0x00000008	Log message in events
  "
  "	0x00000010	Log message out events
  "
  "	0x00000020	Log command completion
  "
  "	0x00000040	Log disconnects
  "
  "	0x00000080	Log data start
  "
  "	0x00000100	Log data done
  "
  "	0x00000200	Log reconnects
  "
  "	0x00000400	Log auto-sense data
  "
  );
  
  module_init(esp_init);
  module_exit(esp_exit);