esp.c 120.6 KB
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/* esp.c: ESP Sun SCSI driver.
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Linus Torvalds 已提交
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 *
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 * Copyright (C) 1995, 1998, 2006 David S. Miller (davem@davemloft.net)
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 */

/* TODO:
 *
 * 1) Maybe disable parity checking in config register one for SCSI1
 *    targets.  (Gilmore says parity error on the SBus can lock up
 *    old sun4c's)
 * 2) Add support for DMA2 pipelining.
 * 3) Add tagged queueing.
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/module.h>

#include "esp.h"

#include <asm/sbus.h>
#include <asm/dma.h>
#include <asm/system.h>
#include <asm/ptrace.h>
#include <asm/pgtable.h>
#include <asm/oplib.h>
#include <asm/io.h>
#include <asm/irq.h>
#ifndef __sparc_v9__
#include <asm/machines.h>
#include <asm/idprom.h>
#endif

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>

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#define DRV_VERSION "1.101"

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#define DEBUG_ESP
/* #define DEBUG_ESP_HME */
/* #define DEBUG_ESP_DATA */
/* #define DEBUG_ESP_QUEUE */
/* #define DEBUG_ESP_DISCONNECT */
/* #define DEBUG_ESP_STATUS */
/* #define DEBUG_ESP_PHASES */
/* #define DEBUG_ESP_WORKBUS */
/* #define DEBUG_STATE_MACHINE */
/* #define DEBUG_ESP_CMDS */
/* #define DEBUG_ESP_IRQS */
/* #define DEBUG_SDTR */
/* #define DEBUG_ESP_SG */

/* Use the following to sprinkle debugging messages in a way which
 * suits you if combinations of the above become too verbose when
 * trying to track down a specific problem.
 */
/* #define DEBUG_ESP_MISC */

#if defined(DEBUG_ESP)
#define ESPLOG(foo)  printk foo
#else
#define ESPLOG(foo)
#endif /* (DEBUG_ESP) */

#if defined(DEBUG_ESP_HME)
#define ESPHME(foo)  printk foo
#else
#define ESPHME(foo)
#endif

#if defined(DEBUG_ESP_DATA)
#define ESPDATA(foo)  printk foo
#else
#define ESPDATA(foo)
#endif

#if defined(DEBUG_ESP_QUEUE)
#define ESPQUEUE(foo)  printk foo
#else
#define ESPQUEUE(foo)
#endif

#if defined(DEBUG_ESP_DISCONNECT)
#define ESPDISC(foo)  printk foo
#else
#define ESPDISC(foo)
#endif

#if defined(DEBUG_ESP_STATUS)
#define ESPSTAT(foo)  printk foo
#else
#define ESPSTAT(foo)
#endif

#if defined(DEBUG_ESP_PHASES)
#define ESPPHASE(foo)  printk foo
#else
#define ESPPHASE(foo)
#endif

#if defined(DEBUG_ESP_WORKBUS)
#define ESPBUS(foo)  printk foo
#else
#define ESPBUS(foo)
#endif

#if defined(DEBUG_ESP_IRQS)
#define ESPIRQ(foo)  printk foo
#else
#define ESPIRQ(foo)
#endif

#if defined(DEBUG_SDTR)
#define ESPSDTR(foo)  printk foo
#else
#define ESPSDTR(foo)
#endif

#if defined(DEBUG_ESP_MISC)
#define ESPMISC(foo)  printk foo
#else
#define ESPMISC(foo)
#endif

/* Command phase enumeration. */
enum {
	not_issued    = 0x00,  /* Still in the issue_SC queue.          */

	/* Various forms of selecting a target. */
#define in_slct_mask    0x10
	in_slct_norm  = 0x10,  /* ESP is arbitrating, normal selection  */
	in_slct_stop  = 0x11,  /* ESP will select, then stop with IRQ   */
	in_slct_msg   = 0x12,  /* select, then send a message           */
	in_slct_tag   = 0x13,  /* select and send tagged queue msg      */
	in_slct_sneg  = 0x14,  /* select and acquire sync capabilities  */

	/* Any post selection activity. */
#define in_phases_mask  0x20
	in_datain     = 0x20,  /* Data is transferring from the bus     */
	in_dataout    = 0x21,  /* Data is transferring to the bus       */
	in_data_done  = 0x22,  /* Last DMA data operation done (maybe)  */
	in_msgin      = 0x23,  /* Eating message from target            */
	in_msgincont  = 0x24,  /* Eating more msg bytes from target     */
	in_msgindone  = 0x25,  /* Decide what to do with what we got    */
	in_msgout     = 0x26,  /* Sending message to target             */
	in_msgoutdone = 0x27,  /* Done sending msg out                  */
	in_cmdbegin   = 0x28,  /* Sending cmd after abnormal selection  */
	in_cmdend     = 0x29,  /* Done sending slow cmd                 */
	in_status     = 0x2a,  /* Was in status phase, finishing cmd    */
	in_freeing    = 0x2b,  /* freeing the bus for cmd cmplt or disc */
	in_the_dark   = 0x2c,  /* Don't know what bus phase we are in   */

	/* Special states, ie. not normal bus transitions... */
#define in_spec_mask    0x80
	in_abortone   = 0x80,  /* Aborting one command currently        */
	in_abortall   = 0x81,  /* Blowing away all commands we have     */
	in_resetdev   = 0x82,  /* SCSI target reset in progress         */
	in_resetbus   = 0x83,  /* SCSI bus reset in progress            */
	in_tgterror   = 0x84,  /* Target did something stupid           */
};

enum {
	/* Zero has special meaning, see skipahead[12]. */
/*0*/	do_never,

/*1*/	do_phase_determine,
/*2*/	do_reset_bus,
/*3*/	do_reset_complete,
/*4*/	do_work_bus,
/*5*/	do_intr_end
};

/* Forward declarations. */
static irqreturn_t esp_intr(int irq, void *dev_id, struct pt_regs *pregs);

/* Debugging routines */
struct esp_cmdstrings {
	u8 cmdchar;
	char *text;
} esp_cmd_strings[] = {
	/* Miscellaneous */
	{ ESP_CMD_NULL, "ESP_NOP", },
	{ ESP_CMD_FLUSH, "FIFO_FLUSH", },
	{ ESP_CMD_RC, "RSTESP", },
	{ ESP_CMD_RS, "RSTSCSI", },
	/* Disconnected State Group */
	{ ESP_CMD_RSEL, "RESLCTSEQ", },
	{ ESP_CMD_SEL, "SLCTNATN", },
	{ ESP_CMD_SELA, "SLCTATN", },
	{ ESP_CMD_SELAS, "SLCTATNSTOP", },
	{ ESP_CMD_ESEL, "ENSLCTRESEL", },
	{ ESP_CMD_DSEL, "DISSELRESEL", },
	{ ESP_CMD_SA3, "SLCTATN3", },
	{ ESP_CMD_RSEL3, "RESLCTSEQ", },
	/* Target State Group */
	{ ESP_CMD_SMSG, "SNDMSG", },
	{ ESP_CMD_SSTAT, "SNDSTATUS", },
	{ ESP_CMD_SDATA, "SNDDATA", },
	{ ESP_CMD_DSEQ, "DISCSEQ", },
	{ ESP_CMD_TSEQ, "TERMSEQ", },
	{ ESP_CMD_TCCSEQ, "TRGTCMDCOMPSEQ", },
	{ ESP_CMD_DCNCT, "DISC", },
	{ ESP_CMD_RMSG, "RCVMSG", },
	{ ESP_CMD_RCMD, "RCVCMD", },
	{ ESP_CMD_RDATA, "RCVDATA", },
	{ ESP_CMD_RCSEQ, "RCVCMDSEQ", },
	/* Initiator State Group */
	{ ESP_CMD_TI, "TRANSINFO", },
	{ ESP_CMD_ICCSEQ, "INICMDSEQCOMP", },
	{ ESP_CMD_MOK, "MSGACCEPTED", },
	{ ESP_CMD_TPAD, "TPAD", },
	{ ESP_CMD_SATN, "SATN", },
	{ ESP_CMD_RATN, "RATN", },
};
#define NUM_ESP_COMMANDS  ((sizeof(esp_cmd_strings)) / (sizeof(struct esp_cmdstrings)))

/* Print textual representation of an ESP command */
static inline void esp_print_cmd(u8 espcmd)
{
	u8 dma_bit = espcmd & ESP_CMD_DMA;
	int i;

	espcmd &= ~dma_bit;
	for (i = 0; i < NUM_ESP_COMMANDS; i++)
		if (esp_cmd_strings[i].cmdchar == espcmd)
			break;
	if (i == NUM_ESP_COMMANDS)
		printk("ESP_Unknown");
	else
		printk("%s%s", esp_cmd_strings[i].text,
		       ((dma_bit) ? "+DMA" : ""));
}

/* Print the status register's value */
static inline void esp_print_statreg(u8 statreg)
{
	u8 phase;

	printk("STATUS<");
	phase = statreg & ESP_STAT_PMASK;
	printk("%s,", (phase == ESP_DOP ? "DATA-OUT" :
		       (phase == ESP_DIP ? "DATA-IN" :
			(phase == ESP_CMDP ? "COMMAND" :
			 (phase == ESP_STATP ? "STATUS" :
			  (phase == ESP_MOP ? "MSG-OUT" :
			   (phase == ESP_MIP ? "MSG_IN" :
			    "unknown")))))));
	if (statreg & ESP_STAT_TDONE)
		printk("TRANS_DONE,");
	if (statreg & ESP_STAT_TCNT)
		printk("TCOUNT_ZERO,");
	if (statreg & ESP_STAT_PERR)
		printk("P_ERROR,");
	if (statreg & ESP_STAT_SPAM)
		printk("SPAM,");
	if (statreg & ESP_STAT_INTR)
		printk("IRQ,");
	printk(">");
}

/* Print the interrupt register's value */
static inline void esp_print_ireg(u8 intreg)
{
	printk("INTREG< ");
	if (intreg & ESP_INTR_S)
		printk("SLCT_NATN ");
	if (intreg & ESP_INTR_SATN)
		printk("SLCT_ATN ");
	if (intreg & ESP_INTR_RSEL)
		printk("RSLCT ");
	if (intreg & ESP_INTR_FDONE)
		printk("FDONE ");
	if (intreg & ESP_INTR_BSERV)
		printk("BSERV ");
	if (intreg & ESP_INTR_DC)
		printk("DISCNCT ");
	if (intreg & ESP_INTR_IC)
		printk("ILL_CMD ");
	if (intreg & ESP_INTR_SR)
		printk("SCSI_BUS_RESET ");
	printk(">");
}

/* Print the sequence step registers contents */
static inline void esp_print_seqreg(u8 stepreg)
{
	stepreg &= ESP_STEP_VBITS;
	printk("STEP<%s>",
	       (stepreg == ESP_STEP_ASEL ? "SLCT_ARB_CMPLT" :
		(stepreg == ESP_STEP_SID ? "1BYTE_MSG_SENT" :
		 (stepreg == ESP_STEP_NCMD ? "NOT_IN_CMD_PHASE" :
		  (stepreg == ESP_STEP_PPC ? "CMD_BYTES_LOST" :
		   (stepreg == ESP_STEP_FINI4 ? "CMD_SENT_OK" :
		    "UNKNOWN"))))));
}

static char *phase_string(int phase)
{
	switch (phase) {
	case not_issued:
		return "UNISSUED";
	case in_slct_norm:
		return "SLCTNORM";
	case in_slct_stop:
		return "SLCTSTOP";
	case in_slct_msg:
		return "SLCTMSG";
	case in_slct_tag:
		return "SLCTTAG";
	case in_slct_sneg:
		return "SLCTSNEG";
	case in_datain:
		return "DATAIN";
	case in_dataout:
		return "DATAOUT";
	case in_data_done:
		return "DATADONE";
	case in_msgin:
		return "MSGIN";
	case in_msgincont:
		return "MSGINCONT";
	case in_msgindone:
		return "MSGINDONE";
	case in_msgout:
		return "MSGOUT";
	case in_msgoutdone:
		return "MSGOUTDONE";
	case in_cmdbegin:
		return "CMDBEGIN";
	case in_cmdend:
		return "CMDEND";
	case in_status:
		return "STATUS";
	case in_freeing:
		return "FREEING";
	case in_the_dark:
		return "CLUELESS";
	case in_abortone:
		return "ABORTONE";
	case in_abortall:
		return "ABORTALL";
	case in_resetdev:
		return "RESETDEV";
	case in_resetbus:
		return "RESETBUS";
	case in_tgterror:
		return "TGTERROR";
	default:
		return "UNKNOWN";
	};
}

#ifdef DEBUG_STATE_MACHINE
static inline void esp_advance_phase(struct scsi_cmnd *s, int newphase)
{
	ESPLOG(("<%s>", phase_string(newphase)));
	s->SCp.sent_command = s->SCp.phase;
	s->SCp.phase = newphase;
}
#else
#define esp_advance_phase(__s, __newphase) \
	(__s)->SCp.sent_command = (__s)->SCp.phase; \
	(__s)->SCp.phase = (__newphase);
#endif

#ifdef DEBUG_ESP_CMDS
static inline void esp_cmd(struct esp *esp, u8 cmd)
{
	esp->espcmdlog[esp->espcmdent] = cmd;
	esp->espcmdent = (esp->espcmdent + 1) & 31;
	sbus_writeb(cmd, esp->eregs + ESP_CMD);
}
#else
#define esp_cmd(__esp, __cmd)	\
	sbus_writeb((__cmd), ((__esp)->eregs) + ESP_CMD)
#endif

#define ESP_INTSOFF(__dregs)	\
	sbus_writel(sbus_readl((__dregs)+DMA_CSR)&~(DMA_INT_ENAB), (__dregs)+DMA_CSR)
#define ESP_INTSON(__dregs)	\
	sbus_writel(sbus_readl((__dregs)+DMA_CSR)|DMA_INT_ENAB, (__dregs)+DMA_CSR)
#define ESP_IRQ_P(__dregs)	\
	(sbus_readl((__dregs)+DMA_CSR) & (DMA_HNDL_INTR|DMA_HNDL_ERROR))

/* How we use the various Linux SCSI data structures for operation.
 *
 * struct scsi_cmnd:
 *
 *   We keep track of the synchronous capabilities of a target
 *   in the device member, using sync_min_period and
 *   sync_max_offset.  These are the values we directly write
 *   into the ESP registers while running a command.  If offset
 *   is zero the ESP will use asynchronous transfers.
 *   If the borken flag is set we assume we shouldn't even bother
 *   trying to negotiate for synchronous transfer as this target
 *   is really stupid.  If we notice the target is dropping the
 *   bus, and we have been allowing it to disconnect, we clear
 *   the disconnect flag.
 */


/* Manipulation of the ESP command queues.  Thanks to the aha152x driver
 * and its author, Juergen E. Fischer, for the methods used here.
 * Note that these are per-ESP queues, not global queues like
 * the aha152x driver uses.
 */
static inline void append_SC(struct scsi_cmnd **SC, struct scsi_cmnd *new_SC)
{
	struct scsi_cmnd *end;

	new_SC->host_scribble = (unsigned char *) NULL;
	if (!*SC)
		*SC = new_SC;
	else {
		for (end=*SC;end->host_scribble;end=(struct scsi_cmnd *)end->host_scribble)
			;
		end->host_scribble = (unsigned char *) new_SC;
	}
}

static inline void prepend_SC(struct scsi_cmnd **SC, struct scsi_cmnd *new_SC)
{
	new_SC->host_scribble = (unsigned char *) *SC;
	*SC = new_SC;
}

static inline struct scsi_cmnd *remove_first_SC(struct scsi_cmnd **SC)
{
	struct scsi_cmnd *ptr;
	ptr = *SC;
	if (ptr)
		*SC = (struct scsi_cmnd *) (*SC)->host_scribble;
	return ptr;
}

static inline struct scsi_cmnd *remove_SC(struct scsi_cmnd **SC, int target, int lun)
{
	struct scsi_cmnd *ptr, *prev;

	for (ptr = *SC, prev = NULL;
	     ptr && ((ptr->device->id != target) || (ptr->device->lun != lun));
	     prev = ptr, ptr = (struct scsi_cmnd *) ptr->host_scribble)
		;
	if (ptr) {
		if (prev)
			prev->host_scribble=ptr->host_scribble;
		else
			*SC=(struct scsi_cmnd *)ptr->host_scribble;
	}
	return ptr;
}

/* Resetting various pieces of the ESP scsi driver chipset/buses. */
static void esp_reset_dma(struct esp *esp)
{
	int can_do_burst16, can_do_burst32, can_do_burst64;
	int can_do_sbus64;
	u32 tmp;

	can_do_burst16 = (esp->bursts & DMA_BURST16) != 0;
	can_do_burst32 = (esp->bursts & DMA_BURST32) != 0;
	can_do_burst64 = 0;
	can_do_sbus64 = 0;
	if (sbus_can_dma_64bit(esp->sdev))
		can_do_sbus64 = 1;
	if (sbus_can_burst64(esp->sdev))
		can_do_burst64 = (esp->bursts & DMA_BURST64) != 0;

	/* Punt the DVMA into a known state. */
	if (esp->dma->revision != dvmahme) {
		tmp = sbus_readl(esp->dregs + DMA_CSR);
		sbus_writel(tmp | DMA_RST_SCSI, esp->dregs + DMA_CSR);
		sbus_writel(tmp & ~DMA_RST_SCSI, esp->dregs + DMA_CSR);
	}
	switch (esp->dma->revision) {
	case dvmahme:
		/* This is the HME DVMA gate array. */

		sbus_writel(DMA_RESET_FAS366, esp->dregs + DMA_CSR);
		sbus_writel(DMA_RST_SCSI, esp->dregs + DMA_CSR);

		esp->prev_hme_dmacsr = (DMA_PARITY_OFF|DMA_2CLKS|DMA_SCSI_DISAB|DMA_INT_ENAB);
		esp->prev_hme_dmacsr &= ~(DMA_ENABLE|DMA_ST_WRITE|DMA_BRST_SZ);

		if (can_do_burst64)
			esp->prev_hme_dmacsr |= DMA_BRST64;
		else if (can_do_burst32)
			esp->prev_hme_dmacsr |= DMA_BRST32;

		if (can_do_sbus64) {
			esp->prev_hme_dmacsr |= DMA_SCSI_SBUS64;
			sbus_set_sbus64(esp->sdev, esp->bursts);
		}

		/* This chip is horrible. */
		while (sbus_readl(esp->dregs + DMA_CSR) & DMA_PEND_READ)
			udelay(1);

		sbus_writel(0, esp->dregs + DMA_CSR);
		sbus_writel(esp->prev_hme_dmacsr, esp->dregs + DMA_CSR);

		/* This is necessary to avoid having the SCSI channel
		 * engine lock up on us.
		 */
		sbus_writel(0, esp->dregs + DMA_ADDR);

		break;
	case dvmarev2:
		/* This is the gate array found in the sun4m
		 * NCR SBUS I/O subsystem.
		 */
		if (esp->erev != esp100) {
			tmp = sbus_readl(esp->dregs + DMA_CSR);
			sbus_writel(tmp | DMA_3CLKS, esp->dregs + DMA_CSR);
		}
		break;
	case dvmarev3:
		tmp = sbus_readl(esp->dregs + DMA_CSR);
		tmp &= ~DMA_3CLKS;
		tmp |= DMA_2CLKS;
		if (can_do_burst32) {
			tmp &= ~DMA_BRST_SZ;
			tmp |= DMA_BRST32;
		}
		sbus_writel(tmp, esp->dregs + DMA_CSR);
		break;
	case dvmaesc1:
		/* This is the DMA unit found on SCSI/Ether cards. */
		tmp = sbus_readl(esp->dregs + DMA_CSR);
		tmp |= DMA_ADD_ENABLE;
		tmp &= ~DMA_BCNT_ENAB;
		if (!can_do_burst32 && can_do_burst16) {
			tmp |= DMA_ESC_BURST;
		} else {
			tmp &= ~(DMA_ESC_BURST);
		}
		sbus_writel(tmp, esp->dregs + DMA_CSR);
		break;
	default:
		break;
	};
	ESP_INTSON(esp->dregs);
}

/* Reset the ESP chip, _not_ the SCSI bus. */
static void __init esp_reset_esp(struct esp *esp)
{
	u8 family_code, version;
	int i;

	/* Now reset the ESP chip */
	esp_cmd(esp, ESP_CMD_RC);
	esp_cmd(esp, ESP_CMD_NULL | ESP_CMD_DMA);
	esp_cmd(esp, ESP_CMD_NULL | ESP_CMD_DMA);

	/* Reload the configuration registers */
	sbus_writeb(esp->cfact, esp->eregs + ESP_CFACT);
	esp->prev_stp = 0;
	sbus_writeb(esp->prev_stp, esp->eregs + ESP_STP);
	esp->prev_soff = 0;
	sbus_writeb(esp->prev_soff, esp->eregs + ESP_SOFF);
	sbus_writeb(esp->neg_defp, esp->eregs + ESP_TIMEO);

	/* 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->erev == fast) {
		version = sbus_readb(esp->eregs + ESP_UID);
		family_code = (version & 0xf8) >> 3;
		if (family_code == 0x02)
			esp->erev = fas236;
		else if (family_code == 0x0a)
			esp->erev = fashme; /* Version is usually '5'. */
		else
			esp->erev = fas100a;
		ESPMISC(("esp%d: FAST chip is %s (family=%d, version=%d)\n",
			 esp->esp_id,
			 (esp->erev == fas236) ? "fas236" :
			 ((esp->erev == fas100a) ? "fas100a" :
			  "fasHME"), family_code, (version & 7)));

		esp->min_period = ((4 * esp->ccycle) / 1000);
	} else {
		esp->min_period = ((5 * esp->ccycle) / 1000);
	}
	esp->max_period = (esp->max_period + 3)>>2;
	esp->min_period = (esp->min_period + 3)>>2;

	sbus_writeb(esp->config1, esp->eregs + ESP_CFG1);
	switch (esp->erev) {
	case esp100:
		/* nothing to do */
		break;
	case esp100a:
		sbus_writeb(esp->config2, esp->eregs + ESP_CFG2);
		break;
	case esp236:
		/* Slow 236 */
		sbus_writeb(esp->config2, esp->eregs + ESP_CFG2);
		esp->prev_cfg3 = esp->config3[0];
		sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);
		break;
	case fashme:
		esp->config2 |= (ESP_CONFIG2_HME32 | ESP_CONFIG2_HMEFENAB);
		/* fallthrough... */
	case fas236:
		/* Fast 236 or HME */
		sbus_writeb(esp->config2, esp->eregs + ESP_CFG2);
		for (i = 0; i < 16; i++) {
			if (esp->erev == fashme) {
				u8 cfg3;

				cfg3 = ESP_CONFIG3_FCLOCK | ESP_CONFIG3_OBPUSH;
				if (esp->scsi_id >= 8)
					cfg3 |= ESP_CONFIG3_IDBIT3;
				esp->config3[i] |= cfg3;
			} else {
				esp->config3[i] |= ESP_CONFIG3_FCLK;
			}
		}
		esp->prev_cfg3 = esp->config3[0];
		sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);
		if (esp->erev == fashme) {
			esp->radelay = 80;
		} else {
			if (esp->diff)
				esp->radelay = 0;
			else
				esp->radelay = 96;
		}
		break;
	case fas100a:
		/* Fast 100a */
		sbus_writeb(esp->config2, esp->eregs + ESP_CFG2);
		for (i = 0; i < 16; i++)
			esp->config3[i] |= ESP_CONFIG3_FCLOCK;
		esp->prev_cfg3 = esp->config3[0];
		sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);
		esp->radelay = 32;
		break;
	default:
		panic("esp: what could it be... I wonder...");
		break;
	};

	/* Eat any bitrot in the chip */
	sbus_readb(esp->eregs + ESP_INTRPT);
	udelay(100);
}

/* This places the ESP into a known state at boot time. */
static void __init esp_bootup_reset(struct esp *esp)
{
	u8 tmp;

	/* Reset the DMA */
	esp_reset_dma(esp);

	/* Reset the ESP */
	esp_reset_esp(esp);

	/* Reset the SCSI bus, but tell ESP not to generate an irq */
	tmp = sbus_readb(esp->eregs + ESP_CFG1);
	tmp |= ESP_CONFIG1_SRRDISAB;
	sbus_writeb(tmp, esp->eregs + ESP_CFG1);

	esp_cmd(esp, ESP_CMD_RS);
	udelay(400);

	sbus_writeb(esp->config1, esp->eregs + ESP_CFG1);

	/* Eat any bitrot in the chip and we are done... */
	sbus_readb(esp->eregs + ESP_INTRPT);
}

static int __init esp_find_dvma(struct esp *esp, struct sbus_dev *dma_sdev)
{
	struct sbus_dev *sdev = esp->sdev;
	struct sbus_dma *dma;

	if (dma_sdev != NULL) {
		for_each_dvma(dma) {
			if (dma->sdev == dma_sdev)
				break;
		}
	} else {
		for_each_dvma(dma) {
			/* If allocated already, can't use it. */
			if (dma->allocated)
				continue;

			if (dma->sdev == NULL)
				break;

			/* If bus + slot are the same and it has the
			 * correct OBP name, it's ours.
			 */
			if (sdev->bus == dma->sdev->bus &&
			    sdev->slot == dma->sdev->slot &&
			    (!strcmp(dma->sdev->prom_name, "dma") ||
			     !strcmp(dma->sdev->prom_name, "espdma")))
				break;
		}
	}

	/* If we don't know how to handle the dvma,
	 * do not use this device.
	 */
	if (dma == NULL) {
		printk("Cannot find dvma for ESP%d's SCSI\n", esp->esp_id);
		return -1;
	}
	if (dma->allocated) {
		printk("esp%d: can't use my espdma\n", esp->esp_id);
		return -1;
	}
	dma->allocated = 1;
	esp->dma = dma;
	esp->dregs = dma->regs;

	return 0;
}

static int __init esp_map_regs(struct esp *esp, int hme)
{
	struct sbus_dev *sdev = esp->sdev;
	struct resource *res;

	/* On HME, two reg sets exist, first is DVMA,
	 * second is ESP registers.
	 */
	if (hme)
		res = &sdev->resource[1];
	else
		res = &sdev->resource[0];

	esp->eregs = sbus_ioremap(res, 0, ESP_REG_SIZE, "ESP Registers");

	if (esp->eregs == 0)
		return -1;
	return 0;
}

static int __init esp_map_cmdarea(struct esp *esp)
{
	struct sbus_dev *sdev = esp->sdev;

	esp->esp_command = sbus_alloc_consistent(sdev, 16,
						 &esp->esp_command_dvma);
	if (esp->esp_command == NULL ||
	    esp->esp_command_dvma == 0)
		return -1;
	return 0;
}

static int __init esp_register_irq(struct esp *esp)
{
	esp->ehost->irq = esp->irq = esp->sdev->irqs[0];

	/* We used to try various overly-clever things to
	 * reduce the interrupt processing overhead on
	 * sun4c/sun4m when multiple ESP's shared the
	 * same IRQ.  It was too complex and messy to
	 * sanely maintain.
	 */
	if (request_irq(esp->ehost->irq, esp_intr,
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			IRQF_SHARED, "ESP SCSI", esp)) {
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		printk("esp%d: Cannot acquire irq line\n",
		       esp->esp_id);
		return -1;
	}

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	printk("esp%d: IRQ %d ", esp->esp_id,
	       esp->ehost->irq);
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	return 0;
}

static void __init esp_get_scsi_id(struct esp *esp)
{
	struct sbus_dev *sdev = esp->sdev;
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	struct device_node *dp = sdev->ofdev.node;
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	esp->scsi_id = of_getintprop_default(dp,
					     "initiator-id",
					     -1);
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	if (esp->scsi_id == -1)
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		esp->scsi_id = of_getintprop_default(dp,
						     "scsi-initiator-id",
						     -1);
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	if (esp->scsi_id == -1)
		esp->scsi_id = (sdev->bus == NULL) ? 7 :
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			of_getintprop_default(sdev->bus->ofdev.node,
					      "scsi-initiator-id",
					      7);
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	esp->ehost->this_id = esp->scsi_id;
	esp->scsi_id_mask = (1 << esp->scsi_id);

}

static void __init esp_get_clock_params(struct esp *esp)
{
	struct sbus_dev *sdev = esp->sdev;
	int prom_node = esp->prom_node;
	int sbus_prom_node;
	unsigned int fmhz;
	u8 ccf;

	if (sdev != NULL && sdev->bus != NULL)
		sbus_prom_node = sdev->bus->prom_node;
	else
		sbus_prom_node = 0;

	/* 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)
	 *
	 *    You usually want the time out period to be
	 *    around 250ms, I think we'll set it a little
	 *    bit higher to account for fully loaded SCSI
	 *    bus's and slow devices that don't respond so
	 *    quickly to selection attempts. (yeah, I know
	 *    this is out of spec. but there is a lot of
	 *    buggy pieces of firmware out there so bite me)
	 *
	 * 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.
	 */

	fmhz = prom_getintdefault(prom_node, "clock-frequency", -1);
	if (fmhz == -1)
		fmhz = (!sbus_prom_node) ? 0 :
			prom_getintdefault(sbus_prom_node, "clock-frequency", -1);

	if (fmhz <= (5000000))
		ccf = 0;
	else
		ccf = (((5000000 - 1) + (fmhz))/(5000000));

	if (!ccf || ccf > 8) {
		/* 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.
		 */
		ccf = ESP_CCF_F4;
		fmhz = (20000000);
	}

	if (ccf == (ESP_CCF_F7 + 1))
		esp->cfact = ESP_CCF_F0;
	else if (ccf == ESP_CCF_NEVER)
		esp->cfact = ESP_CCF_F2;
	else
		esp->cfact = ccf;
	esp->raw_cfact = ccf;

	esp->cfreq = fmhz;
	esp->ccycle = ESP_MHZ_TO_CYCLE(fmhz);
	esp->ctick = ESP_TICK(ccf, esp->ccycle);
	esp->neg_defp = ESP_NEG_DEFP(fmhz, ccf);
	esp->sync_defp = SYNC_DEFP_SLOW;

	printk("SCSI ID %d Clk %dMHz CCYC=%d CCF=%d TOut %d ",
	       esp->scsi_id, (fmhz / 1000000),
	       (int)esp->ccycle, (int)ccf, (int) esp->neg_defp);
}

static void __init esp_get_bursts(struct esp *esp, struct sbus_dev *dma)
{
	struct sbus_dev *sdev = esp->sdev;
	u8 bursts;

	bursts = prom_getintdefault(esp->prom_node, "burst-sizes", 0xff);

	if (dma) {
		u8 tmp = prom_getintdefault(dma->prom_node,
					    "burst-sizes", 0xff);
		if (tmp != 0xff)
			bursts &= tmp;
	}

	if (sdev->bus) {
		u8 tmp = prom_getintdefault(sdev->bus->prom_node,
					    "burst-sizes", 0xff);
		if (tmp != 0xff)
			bursts &= tmp;
	}

	if (bursts == 0xff ||
	    (bursts & DMA_BURST16) == 0 ||
	    (bursts & DMA_BURST32) == 0)
		bursts = (DMA_BURST32 - 1);

	esp->bursts = bursts;
}

static void __init esp_get_revision(struct esp *esp)
{
	u8 tmp;

	esp->config1 = (ESP_CONFIG1_PENABLE | (esp->scsi_id & 7));
	esp->config2 = (ESP_CONFIG2_SCSI2ENAB | ESP_CONFIG2_REGPARITY);
	sbus_writeb(esp->config2, esp->eregs + ESP_CFG2);

	tmp = sbus_readb(esp->eregs + ESP_CFG2);
	tmp &= ~ESP_CONFIG2_MAGIC;
	if (tmp != (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->erev = esp100;
		printk("NCR53C90(esp100)\n");
	} else {
		esp->config2 = 0;
		esp->prev_cfg3 = esp->config3[0] = 5;
		sbus_writeb(esp->config2, esp->eregs + ESP_CFG2);
		sbus_writeb(0, esp->eregs + ESP_CFG3);
		sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);

		tmp = sbus_readb(esp->eregs + ESP_CFG3);
		if (tmp != 5) {
			/* The cfg2 register is implemented, however
			 * cfg3 is not, must be esp100a.
			 */
			esp->erev = esp100a;
			printk("NCR53C90A(esp100a)\n");
		} else {
			int target;

			for (target = 0; target < 16; target++)
				esp->config3[target] = 0;
			esp->prev_cfg3 = 0;
			sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);

			/* All of cfg{1,2,3} implemented, must be one of
			 * the fas variants, figure out which one.
			 */
			if (esp->raw_cfact > ESP_CCF_F5) {
				esp->erev = fast;
				esp->sync_defp = SYNC_DEFP_FAST;
				printk("NCR53C9XF(espfast)\n");
			} else {
				esp->erev = esp236;
				printk("NCR53C9x(esp236)\n");
			}
			esp->config2 = 0;
			sbus_writeb(esp->config2, esp->eregs + ESP_CFG2);
		}
	}
}

static void __init esp_init_swstate(struct esp *esp)
{
	int i;

	/* Command queues... */
	esp->current_SC = NULL;
	esp->disconnected_SC = NULL;
	esp->issue_SC = NULL;

	/* Target and current command state... */
	esp->targets_present = 0;
	esp->resetting_bus = 0;
	esp->snip = 0;

	init_waitqueue_head(&esp->reset_queue);

	/* Debugging... */
	for(i = 0; i < 32; i++)
		esp->espcmdlog[i] = 0;
	esp->espcmdent = 0;

	/* MSG phase state... */
	for(i = 0; i < 16; i++) {
		esp->cur_msgout[i] = 0;
		esp->cur_msgin[i] = 0;
	}
	esp->prevmsgout = esp->prevmsgin = 0;
	esp->msgout_len = esp->msgin_len = 0;

	/* Clear the one behind caches to hold unmatchable values. */
	esp->prev_soff = esp->prev_stp = esp->prev_cfg3 = 0xff;
	esp->prev_hme_dmacsr = 0xffffffff;
}

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static int __init detect_one_esp(struct scsi_host_template *tpnt,
				 struct device *dev,
				 struct sbus_dev *esp_dev,
				 struct sbus_dev *espdma,
				 struct sbus_bus *sbus,
				 int hme)
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{
1041 1042
	static int instance;
	struct Scsi_Host *esp_host = scsi_host_alloc(tpnt, sizeof(struct esp));
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	struct esp *esp;
	
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	if (!esp_host)
		return -ENOMEM;

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	if (hme)
		esp_host->max_id = 16;
	esp = (struct esp *) esp_host->hostdata;
	esp->ehost = esp_host;
	esp->sdev = esp_dev;
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	esp->esp_id = instance;
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	esp->prom_node = esp_dev->prom_node;
	prom_getstring(esp->prom_node, "name", esp->prom_name,
		       sizeof(esp->prom_name));

	if (esp_find_dvma(esp, espdma) < 0)
		goto fail_unlink;
	if (esp_map_regs(esp, hme) < 0) {
		printk("ESP registers unmappable");
		goto fail_dvma_release;
	}
	if (esp_map_cmdarea(esp) < 0) {
		printk("ESP DVMA transport area unmappable");
		goto fail_unmap_regs;
	}
	if (esp_register_irq(esp) < 0)
		goto fail_unmap_cmdarea;

	esp_get_scsi_id(esp);

	esp->diff = prom_getbool(esp->prom_node, "differential");
	if (esp->diff)
		printk("Differential ");

	esp_get_clock_params(esp);
	esp_get_bursts(esp, espdma);
	esp_get_revision(esp);
	esp_init_swstate(esp);

	esp_bootup_reset(esp);

1084 1085 1086 1087 1088 1089 1090 1091
	if (scsi_add_host(esp_host, dev))
		goto fail_free_irq;

	dev_set_drvdata(&esp_dev->ofdev.dev, esp);

	scsi_scan_host(esp_host);
	instance++;

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	return 0;

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fail_free_irq:
	free_irq(esp->ehost->irq, esp);

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fail_unmap_cmdarea:
	sbus_free_consistent(esp->sdev, 16,
			     (void *) esp->esp_command,
			     esp->esp_command_dvma);

fail_unmap_regs:
	sbus_iounmap(esp->eregs, ESP_REG_SIZE);

fail_dvma_release:
	esp->dma->allocated = 0;

fail_unlink:
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	scsi_host_put(esp_host);
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	return -1;
}

/* Detecting ESP chips on the machine.  This is the simple and easy
 * version.
 */
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static int __devexit esp_remove_common(struct esp *esp)
{
	unsigned int irq = esp->ehost->irq;

	scsi_remove_host(esp->ehost);

	ESP_INTSOFF(esp->dregs);
#if 0
	esp_reset_dma(esp);
	esp_reset_esp(esp);
#endif

	free_irq(irq, esp);
	sbus_free_consistent(esp->sdev, 16,
			     (void *) esp->esp_command, esp->esp_command_dvma);
	sbus_iounmap(esp->eregs, ESP_REG_SIZE);
	esp->dma->allocated = 0;

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	scsi_host_put(esp->ehost);
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	return 0;
}

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#ifdef CONFIG_SUN4

#include <asm/sun4paddr.h>

1144
static struct sbus_dev sun4_esp_dev;
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static int __init esp_sun4_probe(struct scsi_host_template *tpnt)
{
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	if (sun4_esp_physaddr) {
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		memset(&sun4_esp_dev, 0, sizeof(esp_dev));
		sun4_esp_dev.reg_addrs[0].phys_addr = sun4_esp_physaddr;
		sun4_esp_dev.irqs[0] = 4;
		sun4_esp_dev.resource[0].start = sun4_esp_physaddr;
		sun4_esp_dev.resource[0].end =
			sun4_esp_physaddr + ESP_REG_SIZE - 1;
		sun4_esp_dev.resource[0].flags = IORESOURCE_IO;

		return detect_one_esp(tpnt, NULL,
				      &sun4_esp_dev, NULL, NULL, 0);
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	}
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	return 0;
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}

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static int __devexit esp_sun4_remove(void)
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{
1165
	struct esp *esp = dev_get_drvdata(&dev->dev);
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	return esp_remove_common(esp);
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}

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#else /* !CONFIG_SUN4 */
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static int __devinit esp_sbus_probe(struct of_device *dev, const struct of_device_id *match)
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{
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	struct sbus_dev *sdev = to_sbus_device(&dev->dev);
	struct device_node *dp = dev->node;
	struct sbus_dev *dma_sdev = NULL;
	int hme = 0;

	if (dp->parent &&
	    (!strcmp(dp->parent->name, "espdma") ||
	     !strcmp(dp->parent->name, "dma")))
		dma_sdev = sdev->parent;
	else if (!strcmp(dp->name, "SUNW,fas")) {
		dma_sdev = sdev;
		hme = 1;
	}
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	return detect_one_esp(match->data, &dev->dev,
			      sdev, dma_sdev, sdev->bus, hme);
}
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static int __devexit esp_sbus_remove(struct of_device *dev)
{
	struct esp *esp = dev_get_drvdata(&dev->dev);
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	return esp_remove_common(esp);
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}

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#endif /* !CONFIG_SUN4 */

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/* The info function will return whatever useful
 * information the developer sees fit.  If not provided, then
 * the name field will be used instead.
 */
static const char *esp_info(struct Scsi_Host *host)
{
	struct esp *esp;

	esp = (struct esp *) host->hostdata;
	switch (esp->erev) {
	case esp100:
		return "Sparc ESP100 (NCR53C90)";
	case esp100a:
		return "Sparc ESP100A (NCR53C90A)";
	case esp236:
		return "Sparc ESP236";
	case fas236:
		return "Sparc ESP236-FAST";
	case fashme:
		return "Sparc ESP366-HME";
	case fas100a:
		return "Sparc ESP100A-FAST";
	default:
		return "Bogon ESP revision";
	};
}

/* From Wolfgang Stanglmeier's NCR scsi driver. */
struct info_str
{
	char *buffer;
	int length;
	int offset;
	int pos;
};

static void copy_mem_info(struct info_str *info, char *data, int len)
{
	if (info->pos + len > info->length)
		len = info->length - info->pos;

	if (info->pos + len < info->offset) {
		info->pos += len;
		return;
	}
	if (info->pos < info->offset) {
		data += (info->offset - info->pos);
		len  -= (info->offset - info->pos);
	}

	if (len > 0) {
		memcpy(info->buffer + info->pos, data, len);
		info->pos += len;
	}
}

static int copy_info(struct info_str *info, char *fmt, ...)
{
	va_list args;
	char buf[81];
	int len;

	va_start(args, fmt);
	len = vsprintf(buf, fmt, args);
	va_end(args);

	copy_mem_info(info, buf, len);
	return len;
}

static int esp_host_info(struct esp *esp, char *ptr, off_t offset, int len)
{
	struct scsi_device *sdev;
	struct info_str info;
	int i;

	info.buffer	= ptr;
	info.length	= len;
	info.offset	= offset;
	info.pos	= 0;

	copy_info(&info, "Sparc ESP Host Adapter:\n");
	copy_info(&info, "\tPROM node\t\t%08x\n", (unsigned int) esp->prom_node);
	copy_info(&info, "\tPROM name\t\t%s\n", esp->prom_name);
	copy_info(&info, "\tESP Model\t\t");
	switch (esp->erev) {
	case esp100:
		copy_info(&info, "ESP100\n");
		break;
	case esp100a:
		copy_info(&info, "ESP100A\n");
		break;
	case esp236:
		copy_info(&info, "ESP236\n");
		break;
	case fas236:
		copy_info(&info, "FAS236\n");
		break;
	case fas100a:
		copy_info(&info, "FAS100A\n");
		break;
	case fast:
		copy_info(&info, "FAST\n");
		break;
	case fashme:
		copy_info(&info, "Happy Meal FAS\n");
		break;
	case espunknown:
	default:
		copy_info(&info, "Unknown!\n");
		break;
	};
	copy_info(&info, "\tDMA Revision\t\t");
	switch (esp->dma->revision) {
	case dvmarev0:
		copy_info(&info, "Rev 0\n");
		break;
	case dvmaesc1:
		copy_info(&info, "ESC Rev 1\n");
		break;
	case dvmarev1:
		copy_info(&info, "Rev 1\n");
		break;
	case dvmarev2:
		copy_info(&info, "Rev 2\n");
		break;
	case dvmarev3:
		copy_info(&info, "Rev 3\n");
		break;
	case dvmarevplus:
		copy_info(&info, "Rev 1+\n");
		break;
	case dvmahme:
		copy_info(&info, "Rev HME/FAS\n");
		break;
	default:
		copy_info(&info, "Unknown!\n");
		break;
	};
	copy_info(&info, "\tLive Targets\t\t[ ");
	for (i = 0; i < 15; i++) {
		if (esp->targets_present & (1 << i))
			copy_info(&info, "%d ", i);
	}
	copy_info(&info, "]\n\n");
	
	/* Now describe the state of each existing target. */
	copy_info(&info, "Target #\tconfig3\t\tSync Capabilities\tDisconnect\tWide\n");

	shost_for_each_device(sdev, esp->ehost) {
		struct esp_device *esp_dev = sdev->hostdata;
		uint id = sdev->id;

		if (!(esp->targets_present & (1 << id)))
			continue;

		copy_info(&info, "%d\t\t", id);
		copy_info(&info, "%08lx\t", esp->config3[id]);
		copy_info(&info, "[%02lx,%02lx]\t\t\t",
			esp_dev->sync_max_offset,
			esp_dev->sync_min_period);
		copy_info(&info, "%s\t\t",
			esp_dev->disconnect ? "yes" : "no");
		copy_info(&info, "%s\n",
			(esp->config3[id] & ESP_CONFIG3_EWIDE) ? "yes" : "no");
	}
	return info.pos > info.offset? info.pos - info.offset : 0;
}

/* ESP proc filesystem code. */
static int esp_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset,
			 int length, int inout)
{
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	struct esp *esp = (struct esp *) host->hostdata;
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	if (inout)
		return -EINVAL; /* not yet */

	if (start)
		*start = buffer;

	return esp_host_info(esp, buffer, offset, length);
}

static void esp_get_dmabufs(struct esp *esp, struct scsi_cmnd *sp)
{
	if (sp->use_sg == 0) {
		sp->SCp.this_residual = sp->request_bufflen;
		sp->SCp.buffer = (struct scatterlist *) sp->request_buffer;
		sp->SCp.buffers_residual = 0;
		if (sp->request_bufflen) {
			sp->SCp.have_data_in = sbus_map_single(esp->sdev, sp->SCp.buffer,
							       sp->SCp.this_residual,
							       sp->sc_data_direction);
			sp->SCp.ptr = (char *) ((unsigned long)sp->SCp.have_data_in);
		} else {
			sp->SCp.ptr = NULL;
		}
	} else {
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		sp->SCp.buffer = (struct scatterlist *) sp->request_buffer;
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		sp->SCp.buffers_residual = sbus_map_sg(esp->sdev,
						       sp->SCp.buffer,
						       sp->use_sg,
						       sp->sc_data_direction);
		sp->SCp.this_residual = sg_dma_len(sp->SCp.buffer);
		sp->SCp.ptr = (char *) ((unsigned long)sg_dma_address(sp->SCp.buffer));
	}
}

static void esp_release_dmabufs(struct esp *esp, struct scsi_cmnd *sp)
{
	if (sp->use_sg) {
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		sbus_unmap_sg(esp->sdev, sp->request_buffer, sp->use_sg,
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			      sp->sc_data_direction);
	} else if (sp->request_bufflen) {
		sbus_unmap_single(esp->sdev,
				  sp->SCp.have_data_in,
				  sp->request_bufflen,
				  sp->sc_data_direction);
	}
}

static void esp_restore_pointers(struct esp *esp, struct scsi_cmnd *sp)
{
	struct esp_pointers *ep = &esp->data_pointers[sp->device->id];

	sp->SCp.ptr = ep->saved_ptr;
	sp->SCp.buffer = ep->saved_buffer;
	sp->SCp.this_residual = ep->saved_this_residual;
	sp->SCp.buffers_residual = ep->saved_buffers_residual;
}

static void esp_save_pointers(struct esp *esp, struct scsi_cmnd *sp)
{
	struct esp_pointers *ep = &esp->data_pointers[sp->device->id];

	ep->saved_ptr = sp->SCp.ptr;
	ep->saved_buffer = sp->SCp.buffer;
	ep->saved_this_residual = sp->SCp.this_residual;
	ep->saved_buffers_residual = sp->SCp.buffers_residual;
}

/* Some rules:
 *
 *   1) Never ever panic while something is live on the bus.
 *      If there is to be any chance of syncing the disks this
 *      rule is to be obeyed.
 *
 *   2) Any target that causes a foul condition will no longer
 *      have synchronous transfers done to it, no questions
 *      asked.
 *
 *   3) Keep register accesses to a minimum.  Think about some
 *      day when we have Xbus machines this is running on and
 *      the ESP chip is on the other end of the machine on a
 *      different board from the cpu where this is running.
 */

/* Fire off a command.  We assume the bus is free and that the only
 * case where we could see an interrupt is where we have disconnected
 * commands active and they are trying to reselect us.
 */
static inline void esp_check_cmd(struct esp *esp, struct scsi_cmnd *sp)
{
	switch (sp->cmd_len) {
	case 6:
	case 10:
	case 12:
		esp->esp_slowcmd = 0;
		break;

	default:
		esp->esp_slowcmd = 1;
		esp->esp_scmdleft = sp->cmd_len;
		esp->esp_scmdp = &sp->cmnd[0];
		break;
	};
}

static inline void build_sync_nego_msg(struct esp *esp, int period, int offset)
{
	esp->cur_msgout[0] = EXTENDED_MESSAGE;
	esp->cur_msgout[1] = 3;
	esp->cur_msgout[2] = EXTENDED_SDTR;
	esp->cur_msgout[3] = period;
	esp->cur_msgout[4] = offset;
	esp->msgout_len = 5;
}

/* SIZE is in bits, currently HME only supports 16 bit wide transfers. */
static inline void build_wide_nego_msg(struct esp *esp, int size)
{
	esp->cur_msgout[0] = EXTENDED_MESSAGE;
	esp->cur_msgout[1] = 2;
	esp->cur_msgout[2] = EXTENDED_WDTR;
	switch (size) {
	case 32:
		esp->cur_msgout[3] = 2;
		break;
	case 16:
		esp->cur_msgout[3] = 1;
		break;
	case 8:
	default:
		esp->cur_msgout[3] = 0;
		break;
	};

	esp->msgout_len = 4;
}

static void esp_exec_cmd(struct esp *esp)
{
	struct scsi_cmnd *SCptr;
	struct scsi_device *SDptr;
	struct esp_device *esp_dev;
	volatile u8 *cmdp = esp->esp_command;
	u8 the_esp_command;
	int lun, target;
	int i;

	/* Hold off if we have disconnected commands and
	 * an IRQ is showing...
	 */
	if (esp->disconnected_SC && ESP_IRQ_P(esp->dregs))
		return;

	/* Grab first member of the issue queue. */
	SCptr = esp->current_SC = remove_first_SC(&esp->issue_SC);

	/* Safe to panic here because current_SC is null. */
	if (!SCptr)
		panic("esp: esp_exec_cmd and issue queue is NULL");

	SDptr = SCptr->device;
	esp_dev = SDptr->hostdata;
	lun = SCptr->device->lun;
	target = SCptr->device->id;

	esp->snip = 0;
	esp->msgout_len = 0;

	/* Send it out whole, or piece by piece?   The ESP
	 * only knows how to automatically send out 6, 10,
	 * and 12 byte commands.  I used to think that the
	 * Linux SCSI code would never throw anything other
	 * than that to us, but then again there is the
	 * SCSI generic driver which can send us anything.
	 */
	esp_check_cmd(esp, SCptr);

	/* If arbitration/selection is successful, the ESP will leave
	 * ATN asserted, causing the target to go into message out
	 * phase.  The ESP will feed the target the identify and then
	 * the target can only legally go to one of command,
	 * datain/out, status, or message in phase, or stay in message
	 * out phase (should we be trying to send a sync negotiation
	 * message after the identify).  It is not allowed to drop
	 * BSY, but some buggy targets do and we check for this
	 * condition in the selection complete code.  Most of the time
	 * we'll make the command bytes available to the ESP and it
	 * will not interrupt us until it finishes command phase, we
	 * cannot do this for command sizes the ESP does not
	 * understand and in this case we'll get interrupted right
	 * when the target goes into command phase.
	 *
	 * It is absolutely _illegal_ in the presence of SCSI-2 devices
	 * to use the ESP select w/o ATN command.  When SCSI-2 devices are
	 * present on the bus we _must_ always go straight to message out
	 * phase with an identify message for the target.  Being that
	 * selection attempts in SCSI-1 w/o ATN was an option, doing SCSI-2
	 * selections should not confuse SCSI-1 we hope.
	 */

	if (esp_dev->sync) {
		/* this targets sync is known */
#ifndef __sparc_v9__
do_sync_known:
#endif
		if (esp_dev->disconnect)
			*cmdp++ = IDENTIFY(1, lun);
		else
			*cmdp++ = IDENTIFY(0, lun);

		if (esp->esp_slowcmd) {
			the_esp_command = (ESP_CMD_SELAS | ESP_CMD_DMA);
			esp_advance_phase(SCptr, in_slct_stop);
		} else {
			the_esp_command = (ESP_CMD_SELA | ESP_CMD_DMA);
			esp_advance_phase(SCptr, in_slct_norm);
		}
	} else if (!(esp->targets_present & (1<<target)) || !(esp_dev->disconnect)) {
		/* After the bootup SCSI code sends both the
		 * TEST_UNIT_READY and INQUIRY commands we want
		 * to at least attempt allowing the device to
		 * disconnect.
		 */
		ESPMISC(("esp: Selecting device for first time. target=%d "
			 "lun=%d\n", target, SCptr->device->lun));
		if (!SDptr->borken && !esp_dev->disconnect)
			esp_dev->disconnect = 1;

		*cmdp++ = IDENTIFY(0, lun);
		esp->prevmsgout = NOP;
		esp_advance_phase(SCptr, in_slct_norm);
		the_esp_command = (ESP_CMD_SELA | ESP_CMD_DMA);

		/* Take no chances... */
		esp_dev->sync_max_offset = 0;
		esp_dev->sync_min_period = 0;
	} else {
		/* Sorry, I have had way too many problems with
		 * various CDROM devices on ESP. -DaveM
		 */
		int cdrom_hwbug_wkaround = 0;

#ifndef __sparc_v9__
		/* Never allow disconnects or synchronous transfers on
		 * SparcStation1 and SparcStation1+.  Allowing those
		 * to be enabled seems to lockup the machine completely.
		 */
		if ((idprom->id_machtype == (SM_SUN4C | SM_4C_SS1)) ||
		    (idprom->id_machtype == (SM_SUN4C | SM_4C_SS1PLUS))) {
			/* But we are nice and allow tapes and removable
			 * disks (but not CDROMs) to disconnect.
			 */
			if(SDptr->type == TYPE_TAPE ||
			   (SDptr->type != TYPE_ROM && SDptr->removable))
				esp_dev->disconnect = 1;
			else
				esp_dev->disconnect = 0;
			esp_dev->sync_max_offset = 0;
			esp_dev->sync_min_period = 0;
			esp_dev->sync = 1;
			esp->snip = 0;
			goto do_sync_known;
		}
#endif /* !(__sparc_v9__) */

		/* We've talked to this guy before,
		 * but never negotiated.  Let's try,
		 * need to attempt WIDE first, before
		 * sync nego, as per SCSI 2 standard.
		 */
		if (esp->erev == fashme && !esp_dev->wide) {
			if (!SDptr->borken &&
			   SDptr->type != TYPE_ROM &&
			   SDptr->removable == 0) {
				build_wide_nego_msg(esp, 16);
				esp_dev->wide = 1;
				esp->wnip = 1;
				goto after_nego_msg_built;
			} else {
				esp_dev->wide = 1;
				/* Fall through and try sync. */
			}
		}

		if (!SDptr->borken) {
			if ((SDptr->type == TYPE_ROM)) {
				/* Nice try sucker... */
				ESPMISC(("esp%d: Disabling sync for buggy "
					 "CDROM.\n", esp->esp_id));
				cdrom_hwbug_wkaround = 1;
				build_sync_nego_msg(esp, 0, 0);
			} else if (SDptr->removable != 0) {
				ESPMISC(("esp%d: Not negotiating sync/wide but "
					 "allowing disconnect for removable media.\n",
					 esp->esp_id));
				build_sync_nego_msg(esp, 0, 0);
			} else {
				build_sync_nego_msg(esp, esp->sync_defp, 15);
			}
		} else {
			build_sync_nego_msg(esp, 0, 0);
		}
		esp_dev->sync = 1;
		esp->snip = 1;

after_nego_msg_built:
		/* A fix for broken SCSI1 targets, when they disconnect
		 * they lock up the bus and confuse ESP.  So disallow
		 * disconnects for SCSI1 targets for now until we
		 * find a better fix.
		 *
		 * Addendum: This is funny, I figured out what was going
		 *           on.  The blotzed SCSI1 target would disconnect,
		 *           one of the other SCSI2 targets or both would be
		 *           disconnected as well.  The SCSI1 target would
		 *           stay disconnected long enough that we start
		 *           up a command on one of the SCSI2 targets.  As
		 *           the ESP is arbitrating for the bus the SCSI1
		 *           target begins to arbitrate as well to reselect
		 *           the ESP.  The SCSI1 target refuses to drop it's
		 *           ID bit on the data bus even though the ESP is
		 *           at ID 7 and is the obvious winner for any
		 *           arbitration.  The ESP is a poor sport and refuses
		 *           to lose arbitration, it will continue indefinitely
		 *           trying to arbitrate for the bus and can only be
		 *           stopped via a chip reset or SCSI bus reset.
		 *           Therefore _no_ disconnects for SCSI1 targets
		 *           thank you very much. ;-)
		 */
		if(((SDptr->scsi_level < 3) &&
		    (SDptr->type != TYPE_TAPE) &&
		    SDptr->removable == 0) ||
		    cdrom_hwbug_wkaround || SDptr->borken) {
			ESPMISC((KERN_INFO "esp%d: Disabling DISCONNECT for target %d "
				 "lun %d\n", esp->esp_id, SCptr->device->id, SCptr->device->lun));
			esp_dev->disconnect = 0;
			*cmdp++ = IDENTIFY(0, lun);
		} else {
			*cmdp++ = IDENTIFY(1, lun);
		}

		/* ESP fifo is only so big...
		 * Make this look like a slow command.
		 */
		esp->esp_slowcmd = 1;
		esp->esp_scmdleft = SCptr->cmd_len;
		esp->esp_scmdp = &SCptr->cmnd[0];

		the_esp_command = (ESP_CMD_SELAS | ESP_CMD_DMA);
		esp_advance_phase(SCptr, in_slct_msg);
	}

	if (!esp->esp_slowcmd)
		for (i = 0; i < SCptr->cmd_len; i++)
			*cmdp++ = SCptr->cmnd[i];

	/* HME sucks... */
	if (esp->erev == fashme)
		sbus_writeb((target & 0xf) | (ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT),
			    esp->eregs + ESP_BUSID);
	else
		sbus_writeb(target & 7, esp->eregs + ESP_BUSID);
	if (esp->prev_soff != esp_dev->sync_max_offset ||
	    esp->prev_stp  != esp_dev->sync_min_period ||
	    (esp->erev > esp100a &&
	     esp->prev_cfg3 != esp->config3[target])) {
		esp->prev_soff = esp_dev->sync_max_offset;
		esp->prev_stp = esp_dev->sync_min_period;
		sbus_writeb(esp->prev_soff, esp->eregs + ESP_SOFF);
		sbus_writeb(esp->prev_stp, esp->eregs + ESP_STP);
		if (esp->erev > esp100a) {
			esp->prev_cfg3 = esp->config3[target];
			sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);
		}
	}
	i = (cmdp - esp->esp_command);

	if (esp->erev == fashme) {
		esp_cmd(esp, ESP_CMD_FLUSH); /* Grrr! */

		/* Set up the DMA and HME counters */
		sbus_writeb(i, esp->eregs + ESP_TCLOW);
		sbus_writeb(0, esp->eregs + ESP_TCMED);
		sbus_writeb(0, esp->eregs + FAS_RLO);
		sbus_writeb(0, esp->eregs + FAS_RHI);
		esp_cmd(esp, the_esp_command);

		/* Talk about touchy hardware... */
		esp->prev_hme_dmacsr = ((esp->prev_hme_dmacsr |
					 (DMA_SCSI_DISAB | DMA_ENABLE)) &
					~(DMA_ST_WRITE));
		sbus_writel(16, esp->dregs + DMA_COUNT);
		sbus_writel(esp->esp_command_dvma, esp->dregs + DMA_ADDR);
		sbus_writel(esp->prev_hme_dmacsr, esp->dregs + DMA_CSR);
	} else {
		u32 tmp;

		/* Set up the DMA and ESP counters */
		sbus_writeb(i, esp->eregs + ESP_TCLOW);
		sbus_writeb(0, esp->eregs + ESP_TCMED);
		tmp = sbus_readl(esp->dregs + DMA_CSR);
		tmp &= ~DMA_ST_WRITE;
		tmp |= DMA_ENABLE;
		sbus_writel(tmp, esp->dregs + DMA_CSR);
		if (esp->dma->revision == dvmaesc1) {
			if (i) /* Workaround ESC gate array SBUS rerun bug. */
				sbus_writel(PAGE_SIZE, esp->dregs + DMA_COUNT);
		}
		sbus_writel(esp->esp_command_dvma, esp->dregs + DMA_ADDR);

		/* Tell ESP to "go". */
		esp_cmd(esp, the_esp_command);
	}
}

/* Queue a SCSI command delivered from the mid-level Linux SCSI code. */
static int esp_queue(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
{
	struct esp *esp;

	/* Set up func ptr and initial driver cmd-phase. */
	SCpnt->scsi_done = done;
	SCpnt->SCp.phase = not_issued;

	/* We use the scratch area. */
	ESPQUEUE(("esp_queue: target=%d lun=%d ", SCpnt->device->id, SCpnt->device->lun));
	ESPDISC(("N<%02x,%02x>", SCpnt->device->id, SCpnt->device->lun));

	esp = (struct esp *) SCpnt->device->host->hostdata;
	esp_get_dmabufs(esp, SCpnt);
	esp_save_pointers(esp, SCpnt); /* FIXME for tag queueing */

	SCpnt->SCp.Status           = CHECK_CONDITION;
	SCpnt->SCp.Message          = 0xff;
	SCpnt->SCp.sent_command     = 0;

	/* Place into our queue. */
	if (SCpnt->cmnd[0] == REQUEST_SENSE) {
		ESPQUEUE(("RQSENSE\n"));
		prepend_SC(&esp->issue_SC, SCpnt);
	} else {
		ESPQUEUE(("\n"));
		append_SC(&esp->issue_SC, SCpnt);
	}

	/* Run it now if we can. */
	if (!esp->current_SC && !esp->resetting_bus)
		esp_exec_cmd(esp);

	return 0;
}

/* Dump driver state. */
static void esp_dump_cmd(struct scsi_cmnd *SCptr)
{
	ESPLOG(("[tgt<%02x> lun<%02x> "
		"pphase<%s> cphase<%s>]",
		SCptr->device->id, SCptr->device->lun,
		phase_string(SCptr->SCp.sent_command),
		phase_string(SCptr->SCp.phase)));
}

static void esp_dump_state(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
#ifdef DEBUG_ESP_CMDS
	int i;
#endif

	ESPLOG(("esp%d: dumping state\n", esp->esp_id));
	ESPLOG(("esp%d: dma -- cond_reg<%08x> addr<%08x>\n",
		esp->esp_id,
		sbus_readl(esp->dregs + DMA_CSR),
		sbus_readl(esp->dregs + DMA_ADDR)));
	ESPLOG(("esp%d: SW [sreg<%02x> sstep<%02x> ireg<%02x>]\n",
		esp->esp_id, esp->sreg, esp->seqreg, esp->ireg));
	ESPLOG(("esp%d: HW reread [sreg<%02x> sstep<%02x> ireg<%02x>]\n",
		esp->esp_id,
		sbus_readb(esp->eregs + ESP_STATUS),
		sbus_readb(esp->eregs + ESP_SSTEP),
		sbus_readb(esp->eregs + ESP_INTRPT)));
#ifdef DEBUG_ESP_CMDS
	printk("esp%d: last ESP cmds [", esp->esp_id);
	i = (esp->espcmdent - 1) & 31;
	printk("<"); esp_print_cmd(esp->espcmdlog[i]); printk(">");
	i = (i - 1) & 31;
	printk("<"); esp_print_cmd(esp->espcmdlog[i]); printk(">");
	i = (i - 1) & 31;
	printk("<"); esp_print_cmd(esp->espcmdlog[i]); printk(">");
	i = (i - 1) & 31;
	printk("<"); esp_print_cmd(esp->espcmdlog[i]); printk(">");
	printk("]\n");
#endif /* (DEBUG_ESP_CMDS) */

	if (SCptr) {
		ESPLOG(("esp%d: current command ", esp->esp_id));
		esp_dump_cmd(SCptr);
	}
	ESPLOG(("\n"));
	SCptr = esp->disconnected_SC;
	ESPLOG(("esp%d: disconnected ", esp->esp_id));
	while (SCptr) {
		esp_dump_cmd(SCptr);
		SCptr = (struct scsi_cmnd *) SCptr->host_scribble;
	}
	ESPLOG(("\n"));
}

/* Abort a command.  The host_lock is acquired by caller. */
static int esp_abort(struct scsi_cmnd *SCptr)
{
	struct esp *esp = (struct esp *) SCptr->device->host->hostdata;
	int don;

	ESPLOG(("esp%d: Aborting command\n", esp->esp_id));
	esp_dump_state(esp);

	/* Wheee, if this is the current command on the bus, the
	 * best we can do is assert ATN and wait for msgout phase.
	 * This should even fix a hung SCSI bus when we lose state
	 * in the driver and timeout because the eventual phase change
	 * will cause the ESP to (eventually) give an interrupt.
	 */
	if (esp->current_SC == SCptr) {
		esp->cur_msgout[0] = ABORT;
		esp->msgout_len = 1;
		esp->msgout_ctr = 0;
		esp_cmd(esp, ESP_CMD_SATN);
		return SUCCESS;
	}

	/* If it is still in the issue queue then we can safely
	 * call the completion routine and report abort success.
	 */
	don = (sbus_readl(esp->dregs + DMA_CSR) & DMA_INT_ENAB);
	if (don) {
		ESP_INTSOFF(esp->dregs);
	}
	if (esp->issue_SC) {
		struct scsi_cmnd **prev, *this;
		for (prev = (&esp->issue_SC), this = esp->issue_SC;
		     this != NULL;
		     prev = (struct scsi_cmnd **) &(this->host_scribble),
			     this = (struct scsi_cmnd *) this->host_scribble) {

			if (this == SCptr) {
				*prev = (struct scsi_cmnd *) this->host_scribble;
				this->host_scribble = NULL;

				esp_release_dmabufs(esp, this);
				this->result = DID_ABORT << 16;
				this->scsi_done(this);

				if (don)
					ESP_INTSON(esp->dregs);

				return SUCCESS;
			}
		}
	}

	/* Yuck, the command to abort is disconnected, it is not
	 * worth trying to abort it now if something else is live
	 * on the bus at this time.  So, we let the SCSI code wait
	 * a little bit and try again later.
	 */
	if (esp->current_SC) {
		if (don)
			ESP_INTSON(esp->dregs);
		return FAILED;
	}

	/* It's disconnected, we have to reconnect to re-establish
	 * the nexus and tell the device to abort.  However, we really
	 * cannot 'reconnect' per se.  Don't try to be fancy, just
	 * indicate failure, which causes our caller to reset the whole
	 * bus.
	 */

	if (don)
		ESP_INTSON(esp->dregs);

	return FAILED;
}

/* We've sent ESP_CMD_RS to the ESP, the interrupt had just
 * arrived indicating the end of the SCSI bus reset.  Our job
 * is to clean out the command queues and begin re-execution
 * of SCSI commands once more.
 */
static int esp_finish_reset(struct esp *esp)
{
	struct scsi_cmnd *sp = esp->current_SC;

	/* Clean up currently executing command, if any. */
	if (sp != NULL) {
		esp->current_SC = NULL;

		esp_release_dmabufs(esp, sp);
		sp->result = (DID_RESET << 16);

		sp->scsi_done(sp);
	}

	/* Clean up disconnected queue, they have been invalidated
	 * by the bus reset.
	 */
	if (esp->disconnected_SC) {
		while ((sp = remove_first_SC(&esp->disconnected_SC)) != NULL) {
			esp_release_dmabufs(esp, sp);
			sp->result = (DID_RESET << 16);

			sp->scsi_done(sp);
		}
	}

	/* SCSI bus reset is complete. */
	esp->resetting_bus = 0;
	wake_up(&esp->reset_queue);

	/* Ok, now it is safe to get commands going once more. */
	if (esp->issue_SC)
		esp_exec_cmd(esp);

	return do_intr_end;
}

static int esp_do_resetbus(struct esp *esp)
{
	ESPLOG(("esp%d: Resetting scsi bus\n", esp->esp_id));
	esp->resetting_bus = 1;
	esp_cmd(esp, ESP_CMD_RS);

	return do_intr_end;
}

/* Reset ESP chip, reset hanging bus, then kill active and
 * disconnected commands for targets without soft reset.
 *
 * The host_lock is acquired by caller.
 */
static int esp_reset(struct scsi_cmnd *SCptr)
{
	struct esp *esp = (struct esp *) SCptr->device->host->hostdata;

C
Christoph Hellwig 已提交
2020
	spin_lock_irq(esp->ehost->host_lock);
L
Linus Torvalds 已提交
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	(void) esp_do_resetbus(esp);
	spin_unlock_irq(esp->ehost->host_lock);

	wait_event(esp->reset_queue, (esp->resetting_bus == 0));

	return SUCCESS;
}

/* Internal ESP done function. */
static void esp_done(struct esp *esp, int error)
{
	struct scsi_cmnd *done_SC = esp->current_SC;

	esp->current_SC = NULL;

	esp_release_dmabufs(esp, done_SC);
	done_SC->result = error;

	done_SC->scsi_done(done_SC);

	/* Bus is free, issue any commands in the queue. */
	if (esp->issue_SC && !esp->current_SC)
		esp_exec_cmd(esp);

}

/* Wheee, ESP interrupt engine. */  

/* Forward declarations. */
static int esp_do_phase_determine(struct esp *esp);
static int esp_do_data_finale(struct esp *esp);
static int esp_select_complete(struct esp *esp);
static int esp_do_status(struct esp *esp);
static int esp_do_msgin(struct esp *esp);
static int esp_do_msgindone(struct esp *esp);
static int esp_do_msgout(struct esp *esp);
static int esp_do_cmdbegin(struct esp *esp);

#define sreg_datainp(__sreg)  (((__sreg) & ESP_STAT_PMASK) == ESP_DIP)
#define sreg_dataoutp(__sreg) (((__sreg) & ESP_STAT_PMASK) == ESP_DOP)

/* Read any bytes found in the FAS366 fifo, storing them into
 * the ESP driver software state structure.
 */
static void hme_fifo_read(struct esp *esp)
{
	u8 count = 0;
	u8 status = esp->sreg;

	/* Cannot safely frob the fifo for these following cases, but
	 * we must always read the fifo when the reselect interrupt
	 * is pending.
	 */
	if (((esp->ireg & ESP_INTR_RSEL) == 0)	&&
	    (sreg_datainp(status)		||
	     sreg_dataoutp(status)		||
	     (esp->current_SC &&
	      esp->current_SC->SCp.phase == in_data_done))) {
		ESPHME(("<wkaround_skipped>"));
	} else {
		unsigned long fcnt = sbus_readb(esp->eregs + ESP_FFLAGS) & ESP_FF_FBYTES;

		/* The HME stores bytes in multiples of 2 in the fifo. */
		ESPHME(("hme_fifo[fcnt=%d", (int)fcnt));
		while (fcnt) {
			esp->hme_fifo_workaround_buffer[count++] =
				sbus_readb(esp->eregs + ESP_FDATA);
			esp->hme_fifo_workaround_buffer[count++] =
				sbus_readb(esp->eregs + ESP_FDATA);
			ESPHME(("<%02x,%02x>", esp->hme_fifo_workaround_buffer[count-2], esp->hme_fifo_workaround_buffer[count-1]));
			fcnt--;
		}
		if (sbus_readb(esp->eregs + ESP_STATUS2) & ESP_STAT2_F1BYTE) {
			ESPHME(("<poke_byte>"));
			sbus_writeb(0, esp->eregs + ESP_FDATA);
			esp->hme_fifo_workaround_buffer[count++] =
				sbus_readb(esp->eregs + ESP_FDATA);
			ESPHME(("<%02x,0x00>", esp->hme_fifo_workaround_buffer[count-1]));
			ESPHME(("CMD_FLUSH"));
			esp_cmd(esp, ESP_CMD_FLUSH);
		} else {
			ESPHME(("no_xtra_byte"));
		}
	}
	ESPHME(("wkarnd_cnt=%d]", (int)count));
	esp->hme_fifo_workaround_count = count;
}

static inline void hme_fifo_push(struct esp *esp, u8 *bytes, u8 count)
{
	esp_cmd(esp, ESP_CMD_FLUSH);
	while (count) {
		u8 tmp = *bytes++;
		sbus_writeb(tmp, esp->eregs + ESP_FDATA);
		sbus_writeb(0, esp->eregs + ESP_FDATA);
		count--;
	}
}

/* We try to avoid some interrupts by jumping ahead and see if the ESP
 * has gotten far enough yet.  Hence the following.
 */
static inline int skipahead1(struct esp *esp, struct scsi_cmnd *scp,
			     int prev_phase, int new_phase)
{
	if (scp->SCp.sent_command != prev_phase)
		return 0;
	if (ESP_IRQ_P(esp->dregs)) {
		/* Yes, we are able to save an interrupt. */
		if (esp->erev == fashme)
			esp->sreg2 = sbus_readb(esp->eregs + ESP_STATUS2);
		esp->sreg = (sbus_readb(esp->eregs + ESP_STATUS) & ~(ESP_STAT_INTR));
		esp->ireg = sbus_readb(esp->eregs + ESP_INTRPT);
		if (esp->erev == fashme) {
			/* This chip is really losing. */
			ESPHME(("HME["));
			/* Must latch fifo before reading the interrupt
			 * register else garbage ends up in the FIFO
			 * which confuses the driver utterly.
			 * Happy Meal indeed....
			 */
			ESPHME(("fifo_workaround]"));
			if (!(esp->sreg2 & ESP_STAT2_FEMPTY) ||
			    (esp->sreg2 & ESP_STAT2_F1BYTE))
				hme_fifo_read(esp);
		}
		if (!(esp->ireg & ESP_INTR_SR))
			return 0;
		else
			return do_reset_complete;
	}
	/* Ho hum, target is taking forever... */
	scp->SCp.sent_command = new_phase; /* so we don't recurse... */
	return do_intr_end;
}

static inline int skipahead2(struct esp *esp, struct scsi_cmnd *scp,
			     int prev_phase1, int prev_phase2, int new_phase)
{
	if (scp->SCp.sent_command != prev_phase1 &&
	    scp->SCp.sent_command != prev_phase2)
		return 0;
	if (ESP_IRQ_P(esp->dregs)) {
		/* Yes, we are able to save an interrupt. */
		if (esp->erev == fashme)
			esp->sreg2 = sbus_readb(esp->eregs + ESP_STATUS2);
		esp->sreg = (sbus_readb(esp->eregs + ESP_STATUS) & ~(ESP_STAT_INTR));
		esp->ireg = sbus_readb(esp->eregs + ESP_INTRPT);
		if (esp->erev == fashme) {
			/* This chip is really losing. */
			ESPHME(("HME["));

			/* Must latch fifo before reading the interrupt
			 * register else garbage ends up in the FIFO
			 * which confuses the driver utterly.
			 * Happy Meal indeed....
			 */
			ESPHME(("fifo_workaround]"));
			if (!(esp->sreg2 & ESP_STAT2_FEMPTY) ||
			    (esp->sreg2 & ESP_STAT2_F1BYTE))
				hme_fifo_read(esp);
		}
		if (!(esp->ireg & ESP_INTR_SR))
			return 0;
		else
			return do_reset_complete;
	}
	/* Ho hum, target is taking forever... */
	scp->SCp.sent_command = new_phase; /* so we don't recurse... */
	return do_intr_end;
}

/* Now some dma helpers. */
static void dma_setup(struct esp *esp, __u32 addr, int count, int write)
{
	u32 nreg = sbus_readl(esp->dregs + DMA_CSR);

	if (write)
		nreg |= DMA_ST_WRITE;
	else
		nreg &= ~(DMA_ST_WRITE);
	nreg |= DMA_ENABLE;
	sbus_writel(nreg, esp->dregs + DMA_CSR);
	if (esp->dma->revision == dvmaesc1) {
		/* This ESC gate array sucks! */
		__u32 src = addr;
		__u32 dest = src + count;

		if (dest & (PAGE_SIZE - 1))
			count = PAGE_ALIGN(count);
		sbus_writel(count, esp->dregs + DMA_COUNT);
	}
	sbus_writel(addr, esp->dregs + DMA_ADDR);
}

static void dma_drain(struct esp *esp)
{
	u32 tmp;

	if (esp->dma->revision == dvmahme)
		return;
	if ((tmp = sbus_readl(esp->dregs + DMA_CSR)) & DMA_FIFO_ISDRAIN) {
		switch (esp->dma->revision) {
		default:
			tmp |= DMA_FIFO_STDRAIN;
			sbus_writel(tmp, esp->dregs + DMA_CSR);

		case dvmarev3:
		case dvmaesc1:
			while (sbus_readl(esp->dregs + DMA_CSR) & DMA_FIFO_ISDRAIN)
				udelay(1);
		};
	}
}

static void dma_invalidate(struct esp *esp)
{
	u32 tmp;

	if (esp->dma->revision == dvmahme) {
		sbus_writel(DMA_RST_SCSI, esp->dregs + DMA_CSR);

		esp->prev_hme_dmacsr = ((esp->prev_hme_dmacsr |
					 (DMA_PARITY_OFF | DMA_2CLKS |
					  DMA_SCSI_DISAB | DMA_INT_ENAB)) &
					~(DMA_ST_WRITE | DMA_ENABLE));

		sbus_writel(0, esp->dregs + DMA_CSR);
		sbus_writel(esp->prev_hme_dmacsr, esp->dregs + DMA_CSR);

		/* This is necessary to avoid having the SCSI channel
		 * engine lock up on us.
		 */
		sbus_writel(0, esp->dregs + DMA_ADDR);
	} else {
		while ((tmp = sbus_readl(esp->dregs + DMA_CSR)) & DMA_PEND_READ)
			udelay(1);

		tmp &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
		tmp |= DMA_FIFO_INV;
		sbus_writel(tmp, esp->dregs + DMA_CSR);
		tmp &= ~DMA_FIFO_INV;
		sbus_writel(tmp, esp->dregs + DMA_CSR);
	}
}

static inline void dma_flashclear(struct esp *esp)
{
	dma_drain(esp);
	dma_invalidate(esp);
}

static int dma_can_transfer(struct esp *esp, struct scsi_cmnd *sp)
{
	__u32 base, end, sz;

	if (esp->dma->revision == dvmarev3) {
		sz = sp->SCp.this_residual;
		if (sz > 0x1000000)
			sz = 0x1000000;
	} else {
		base = ((__u32)((unsigned long)sp->SCp.ptr));
		base &= (0x1000000 - 1);
		end = (base + sp->SCp.this_residual);
		if (end > 0x1000000)
			end = 0x1000000;
		sz = (end - base);
	}
	return sz;
}

/* Misc. esp helper macros. */
#define esp_setcount(__eregs, __cnt, __hme) \
	sbus_writeb(((__cnt)&0xff), (__eregs) + ESP_TCLOW); \
	sbus_writeb((((__cnt)>>8)&0xff), (__eregs) + ESP_TCMED); \
	if (__hme) { \
		sbus_writeb((((__cnt)>>16)&0xff), (__eregs) + FAS_RLO); \
		sbus_writeb(0, (__eregs) + FAS_RHI); \
	}

#define esp_getcount(__eregs, __hme) \
	((sbus_readb((__eregs) + ESP_TCLOW)&0xff) | \
	 ((sbus_readb((__eregs) + ESP_TCMED)&0xff) << 8) | \
         ((__hme) ? sbus_readb((__eregs) + FAS_RLO) << 16 : 0))

#define fcount(__esp) \
	(((__esp)->erev == fashme) ? \
	  (__esp)->hme_fifo_workaround_count : \
	  sbus_readb(((__esp)->eregs) + ESP_FFLAGS) & ESP_FF_FBYTES)

#define fnzero(__esp) \
	(((__esp)->erev == fashme) ? 0 : \
	 sbus_readb(((__esp)->eregs) + ESP_FFLAGS) & ESP_FF_ONOTZERO)

/* XXX speculative nops unnecessary when continuing amidst a data phase
 * XXX even on esp100!!!  another case of flooding the bus with I/O reg
 * XXX writes...
 */
#define esp_maybe_nop(__esp) \
	if ((__esp)->erev == esp100) \
		esp_cmd((__esp), ESP_CMD_NULL)

#define sreg_to_dataphase(__sreg) \
	((((__sreg) & ESP_STAT_PMASK) == ESP_DOP) ? in_dataout : in_datain)

/* The ESP100 when in synchronous data phase, can mistake a long final
 * REQ pulse from the target as an extra byte, it places whatever is on
 * the data lines into the fifo.  For now, we will assume when this
 * happens that the target is a bit quirky and we don't want to
 * be talking synchronously to it anyways.  Regardless, we need to
 * tell the ESP to eat the extraneous byte so that we can proceed
 * to the next phase.
 */
static int esp100_sync_hwbug(struct esp *esp, struct scsi_cmnd *sp, int fifocnt)
{
	/* Do not touch this piece of code. */
	if ((!(esp->erev == esp100)) ||
	    (!(sreg_datainp((esp->sreg = sbus_readb(esp->eregs + ESP_STATUS))) &&
	       !fifocnt) &&
	     !(sreg_dataoutp(esp->sreg) && !fnzero(esp)))) {
		if (sp->SCp.phase == in_dataout)
			esp_cmd(esp, ESP_CMD_FLUSH);
		return 0;
	} else {
		/* Async mode for this guy. */
		build_sync_nego_msg(esp, 0, 0);

		/* Ack the bogus byte, but set ATN first. */
		esp_cmd(esp, ESP_CMD_SATN);
		esp_cmd(esp, ESP_CMD_MOK);
		return 1;
	}
}

/* This closes the window during a selection with a reselect pending, because
 * we use DMA for the selection process the FIFO should hold the correct
 * contents if we get reselected during this process.  So we just need to
 * ack the possible illegal cmd interrupt pending on the esp100.
 */
static inline int esp100_reconnect_hwbug(struct esp *esp)
{
	u8 tmp;

	if (esp->erev != esp100)
		return 0;
	tmp = sbus_readb(esp->eregs + ESP_INTRPT);
	if (tmp & ESP_INTR_SR)
		return 1;
	return 0;
}

/* This verifies the BUSID bits during a reselection so that we know which
 * target is talking to us.
 */
static inline int reconnect_target(struct esp *esp)
{
	int it, me = esp->scsi_id_mask, targ = 0;

	if (2 != fcount(esp))
		return -1;
	if (esp->erev == fashme) {
		/* HME does not latch it's own BUS ID bits during
		 * a reselection.  Also the target number is given
		 * as an unsigned char, not as a sole bit number
		 * like the other ESP's do.
		 * Happy Meal indeed....
		 */
		targ = esp->hme_fifo_workaround_buffer[0];
	} else {
		it = sbus_readb(esp->eregs + ESP_FDATA);
		if (!(it & me))
			return -1;
		it &= ~me;
		if (it & (it - 1))
			return -1;
		while (!(it & 1))
			targ++, it >>= 1;
	}
	return targ;
}

/* This verifies the identify from the target so that we know which lun is
 * being reconnected.
 */
static inline int reconnect_lun(struct esp *esp)
{
	int lun;

	if ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP)
		return -1;
	if (esp->erev == fashme)
		lun = esp->hme_fifo_workaround_buffer[1];
	else
		lun = sbus_readb(esp->eregs + ESP_FDATA);

	/* Yes, you read this correctly.  We report lun of zero
	 * if we see parity error.  ESP reports parity error for
	 * the lun byte, and this is the only way to hope to recover
	 * because the target is connected.
	 */
	if (esp->sreg & ESP_STAT_PERR)
		return 0;

	/* Check for illegal bits being set in the lun. */
	if ((lun & 0x40) || !(lun & 0x80))
		return -1;

	return lun & 7;
}

/* This puts the driver in a state where it can revitalize a command that
 * is being continued due to reselection.
 */
static inline void esp_connect(struct esp *esp, struct scsi_cmnd *sp)
{
	struct esp_device *esp_dev = sp->device->hostdata;

	if (esp->prev_soff  != esp_dev->sync_max_offset ||
	    esp->prev_stp   != esp_dev->sync_min_period ||
	    (esp->erev > esp100a &&
	     esp->prev_cfg3 != esp->config3[sp->device->id])) {
		esp->prev_soff = esp_dev->sync_max_offset;
		esp->prev_stp = esp_dev->sync_min_period;
		sbus_writeb(esp->prev_soff, esp->eregs + ESP_SOFF);
		sbus_writeb(esp->prev_stp, esp->eregs + ESP_STP);
		if (esp->erev > esp100a) {
			esp->prev_cfg3 = esp->config3[sp->device->id];
			sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);
		}
	}
	esp->current_SC = sp;
}

/* This will place the current working command back into the issue queue
 * if we are to receive a reselection amidst a selection attempt.
 */
static inline void esp_reconnect(struct esp *esp, struct scsi_cmnd *sp)
{
	if (!esp->disconnected_SC)
		ESPLOG(("esp%d: Weird, being reselected but disconnected "
			"command queue is empty.\n", esp->esp_id));
	esp->snip = 0;
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	esp->current_SC = NULL;
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	sp->SCp.phase = not_issued;
	append_SC(&esp->issue_SC, sp);
}

/* Begin message in phase. */
static int esp_do_msgin(struct esp *esp)
{
	/* Must be very careful with the fifo on the HME */
	if ((esp->erev != fashme) ||
	    !(sbus_readb(esp->eregs + ESP_STATUS2) & ESP_STAT2_FEMPTY))
		esp_cmd(esp, ESP_CMD_FLUSH);
	esp_maybe_nop(esp);
	esp_cmd(esp, ESP_CMD_TI);
	esp->msgin_len = 1;
	esp->msgin_ctr = 0;
	esp_advance_phase(esp->current_SC, in_msgindone);
	return do_work_bus;
}

/* This uses various DMA csr fields and the fifo flags count value to
 * determine how many bytes were successfully sent/received by the ESP.
 */
static inline int esp_bytes_sent(struct esp *esp, int fifo_count)
{
	int rval = sbus_readl(esp->dregs + DMA_ADDR) - esp->esp_command_dvma;

	if (esp->dma->revision == dvmarev1)
		rval -= (4 - ((sbus_readl(esp->dregs + DMA_CSR) & DMA_READ_AHEAD)>>11));
	return rval - fifo_count;
}

static inline void advance_sg(struct scsi_cmnd *sp)
{
	++sp->SCp.buffer;
	--sp->SCp.buffers_residual;
	sp->SCp.this_residual = sg_dma_len(sp->SCp.buffer);
	sp->SCp.ptr = (char *)((unsigned long)sg_dma_address(sp->SCp.buffer));
}

/* Please note that the way I've coded these routines is that I _always_
 * check for a disconnect during any and all information transfer
 * phases.  The SCSI standard states that the target _can_ cause a BUS
 * FREE condition by dropping all MSG/CD/IO/BSY signals.  Also note
 * that during information transfer phases the target controls every
 * change in phase, the only thing the initiator can do is "ask" for
 * a message out phase by driving ATN true.  The target can, and sometimes
 * will, completely ignore this request so we cannot assume anything when
 * we try to force a message out phase to abort/reset a target.  Most of
 * the time the target will eventually be nice and go to message out, so
 * we may have to hold on to our state about what we want to tell the target
 * for some period of time.
 */

/* I think I have things working here correctly.  Even partial transfers
 * within a buffer or sub-buffer should not upset us at all no matter
 * how bad the target and/or ESP fucks things up.
 */
static int esp_do_data(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
	int thisphase, hmuch;

	ESPDATA(("esp_do_data: "));
	esp_maybe_nop(esp);
	thisphase = sreg_to_dataphase(esp->sreg);
	esp_advance_phase(SCptr, thisphase);
	ESPDATA(("newphase<%s> ", (thisphase == in_datain) ? "DATAIN" : "DATAOUT"));
	hmuch = dma_can_transfer(esp, SCptr);
	if (hmuch > (64 * 1024) && (esp->erev != fashme))
		hmuch = (64 * 1024);
	ESPDATA(("hmuch<%d> ", hmuch));
	esp->current_transfer_size = hmuch;

	if (esp->erev == fashme) {
		u32 tmp = esp->prev_hme_dmacsr;

		/* Always set the ESP count registers first. */
		esp_setcount(esp->eregs, hmuch, 1);

		/* Get the DMA csr computed. */
		tmp |= (DMA_SCSI_DISAB | DMA_ENABLE);
		if (thisphase == in_datain)
			tmp |= DMA_ST_WRITE;
		else
			tmp &= ~(DMA_ST_WRITE);
		esp->prev_hme_dmacsr = tmp;

		ESPDATA(("DMA|TI --> do_intr_end\n"));
		if (thisphase == in_datain) {
			sbus_writel(hmuch, esp->dregs + DMA_COUNT);
			esp_cmd(esp, ESP_CMD_DMA | ESP_CMD_TI);
		} else {
			esp_cmd(esp, ESP_CMD_DMA | ESP_CMD_TI);
			sbus_writel(hmuch, esp->dregs + DMA_COUNT);
		}
		sbus_writel((__u32)((unsigned long)SCptr->SCp.ptr), esp->dregs+DMA_ADDR);
		sbus_writel(esp->prev_hme_dmacsr, esp->dregs + DMA_CSR);
	} else {
		esp_setcount(esp->eregs, hmuch, 0);
		dma_setup(esp, ((__u32)((unsigned long)SCptr->SCp.ptr)),
			  hmuch, (thisphase == in_datain));
		ESPDATA(("DMA|TI --> do_intr_end\n"));
		esp_cmd(esp, ESP_CMD_DMA | ESP_CMD_TI);
	}
	return do_intr_end;
}

/* See how successful the data transfer was. */
static int esp_do_data_finale(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
	struct esp_device *esp_dev = SCptr->device->hostdata;
	int bogus_data = 0, bytes_sent = 0, fifocnt, ecount = 0;

	ESPDATA(("esp_do_data_finale: "));

	if (SCptr->SCp.phase == in_datain) {
		if (esp->sreg & ESP_STAT_PERR) {
			/* Yuck, parity error.  The ESP asserts ATN
			 * so that we can go to message out phase
			 * immediately and inform the target that
			 * something bad happened.
			 */
			ESPLOG(("esp%d: data bad parity detected.\n",
				esp->esp_id));
			esp->cur_msgout[0] = INITIATOR_ERROR;
			esp->msgout_len = 1;
		}
		dma_drain(esp);
	}
	dma_invalidate(esp);

	/* This could happen for the above parity error case. */
	if (esp->ireg != ESP_INTR_BSERV) {
		/* Please go to msgout phase, please please please... */
		ESPLOG(("esp%d: !BSERV after data, probably to msgout\n",
			esp->esp_id));
		return esp_do_phase_determine(esp);
	}	

	/* Check for partial transfers and other horrible events.
	 * Note, here we read the real fifo flags register even
	 * on HME broken adapters because we skip the HME fifo
	 * workaround code in esp_handle() if we are doing data
	 * phase things.  We don't want to fuck directly with
	 * the fifo like that, especially if doing synchronous
	 * transfers!  Also, will need to double the count on
	 * HME if we are doing wide transfers, as the HME fifo
	 * will move and count 16-bit quantities during wide data.
	 * SMCC _and_ Qlogic can both bite me.
	 */
	fifocnt = (sbus_readb(esp->eregs + ESP_FFLAGS) & ESP_FF_FBYTES);
	if (esp->erev != fashme)
		ecount = esp_getcount(esp->eregs, 0);
	bytes_sent = esp->current_transfer_size;

	ESPDATA(("trans_sz(%d), ", bytes_sent));
	if (esp->erev == fashme) {
		if (!(esp->sreg & ESP_STAT_TCNT)) {
			ecount = esp_getcount(esp->eregs, 1);
			bytes_sent -= ecount;
		}

		/* Always subtract any cruft remaining in the FIFO. */
		if (esp->prev_cfg3 & ESP_CONFIG3_EWIDE)
			fifocnt <<= 1;
		if (SCptr->SCp.phase == in_dataout)
			bytes_sent -= fifocnt;

		/* I have an IBM disk which exhibits the following
		 * behavior during writes to it.  It disconnects in
		 * the middle of a partial transfer, the current sglist
		 * buffer is 1024 bytes, the disk stops data transfer
		 * at 512 bytes.
		 *
		 * However the FAS366 reports that 32 more bytes were
		 * transferred than really were.  This is precisely
		 * the size of a fully loaded FIFO in wide scsi mode.
		 * The FIFO state recorded indicates that it is empty.
		 *
		 * I have no idea if this is a bug in the FAS366 chip
		 * or a bug in the firmware on this IBM disk.  In any
		 * event the following seems to be a good workaround.  -DaveM
		 */
		if (bytes_sent != esp->current_transfer_size &&
		    SCptr->SCp.phase == in_dataout) {
			int mask = (64 - 1);

			if ((esp->prev_cfg3 & ESP_CONFIG3_EWIDE) == 0)
				mask >>= 1;

			if (bytes_sent & mask)
				bytes_sent -= (bytes_sent & mask);
		}
	} else {
		if (!(esp->sreg & ESP_STAT_TCNT))
			bytes_sent -= ecount;
		if (SCptr->SCp.phase == in_dataout)
			bytes_sent -= fifocnt;
	}

	ESPDATA(("bytes_sent(%d), ", bytes_sent));

	/* If we were in synchronous mode, check for peculiarities. */
	if (esp->erev == fashme) {
		if (esp_dev->sync_max_offset) {
			if (SCptr->SCp.phase == in_dataout)
				esp_cmd(esp, ESP_CMD_FLUSH);
		} else {
			esp_cmd(esp, ESP_CMD_FLUSH);
		}
	} else {
		if (esp_dev->sync_max_offset)
			bogus_data = esp100_sync_hwbug(esp, SCptr, fifocnt);
		else
			esp_cmd(esp, ESP_CMD_FLUSH);
	}

	/* Until we are sure of what has happened, we are certainly
	 * in the dark.
	 */
	esp_advance_phase(SCptr, in_the_dark);

	if (bytes_sent < 0) {
		/* I've seen this happen due to lost state in this
		 * driver.  No idea why it happened, but allowing
		 * this value to be negative caused things to
		 * lock up.  This allows greater chance of recovery.
		 * In fact every time I've seen this, it has been
		 * a driver bug without question.
		 */
		ESPLOG(("esp%d: yieee, bytes_sent < 0!\n", esp->esp_id));
		ESPLOG(("esp%d: csz=%d fifocount=%d ecount=%d\n",
			esp->esp_id,
			esp->current_transfer_size, fifocnt, ecount));
		ESPLOG(("esp%d: use_sg=%d ptr=%p this_residual=%d\n",
			esp->esp_id,
			SCptr->use_sg, SCptr->SCp.ptr, SCptr->SCp.this_residual));
		ESPLOG(("esp%d: Forcing async for target %d\n", esp->esp_id, 
			SCptr->device->id));
		SCptr->device->borken = 1;
		esp_dev->sync = 0;
		bytes_sent = 0;
	}

	/* Update the state of our transfer. */
	SCptr->SCp.ptr += bytes_sent;
	SCptr->SCp.this_residual -= bytes_sent;
	if (SCptr->SCp.this_residual < 0) {
		/* shit */
		ESPLOG(("esp%d: Data transfer overrun.\n", esp->esp_id));
		SCptr->SCp.this_residual = 0;
	}

	/* Maybe continue. */
	if (!bogus_data) {
		ESPDATA(("!bogus_data, "));

		/* NO MATTER WHAT, we advance the scatterlist,
		 * if the target should decide to disconnect
		 * in between scatter chunks (which is common)
		 * we could die horribly!  I used to have the sg
		 * advance occur only if we are going back into
		 * (or are staying in) a data phase, you can
		 * imagine the hell I went through trying to
		 * figure this out.
		 */
		if (SCptr->use_sg && !SCptr->SCp.this_residual)
			advance_sg(SCptr);
		if (sreg_datainp(esp->sreg) || sreg_dataoutp(esp->sreg)) {
			ESPDATA(("to more data\n"));
			return esp_do_data(esp);
		}
		ESPDATA(("to new phase\n"));
		return esp_do_phase_determine(esp);
	}
	/* Bogus data, just wait for next interrupt. */
	ESPLOG(("esp%d: bogus_data during end of data phase\n",
		esp->esp_id));
	return do_intr_end;
}

/* We received a non-good status return at the end of
 * running a SCSI command.  This is used to decide if
 * we should clear our synchronous transfer state for
 * such a device when that happens.
 *
 * The idea is that when spinning up a disk or rewinding
 * a tape, we don't want to go into a loop re-negotiating
 * synchronous capabilities over and over.
 */
static int esp_should_clear_sync(struct scsi_cmnd *sp)
{
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	u8 cmd = sp->cmnd[0];
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	/* These cases are for spinning up a disk and
	 * waiting for that spinup to complete.
	 */
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	if (cmd == START_STOP)
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		return 0;

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	if (cmd == TEST_UNIT_READY)
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		return 0;

	/* One more special case for SCSI tape drives,
	 * this is what is used to probe the device for
	 * completion of a rewind or tape load operation.
	 */
	if (sp->device->type == TYPE_TAPE) {
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		if (cmd == MODE_SENSE)
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3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093
			return 0;
	}

	return 1;
}

/* Either a command is completing or a target is dropping off the bus
 * to continue the command in the background so we can do other work.
 */
static int esp_do_freebus(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
	struct esp_device *esp_dev = SCptr->device->hostdata;
	int rval;

	rval = skipahead2(esp, SCptr, in_status, in_msgindone, in_freeing);
	if (rval)
		return rval;
	if (esp->ireg != ESP_INTR_DC) {
		ESPLOG(("esp%d: Target will not disconnect\n", esp->esp_id));
		return do_reset_bus; /* target will not drop BSY... */
	}
	esp->msgout_len = 0;
	esp->prevmsgout = NOP;
	if (esp->prevmsgin == COMMAND_COMPLETE) {
		/* Normal end of nexus. */
		if (esp->disconnected_SC || (esp->erev == fashme))
			esp_cmd(esp, ESP_CMD_ESEL);

		if (SCptr->SCp.Status != GOOD &&
		    SCptr->SCp.Status != CONDITION_GOOD &&
		    ((1<<SCptr->device->id) & esp->targets_present) &&
		    esp_dev->sync &&
		    esp_dev->sync_max_offset) {
			/* SCSI standard says that the synchronous capabilities
			 * should be renegotiated at this point.  Most likely
			 * we are about to request sense from this target
			 * in which case we want to avoid using sync
			 * transfers until we are sure of the current target
			 * state.
			 */
			ESPMISC(("esp: Status <%d> for target %d lun %d\n",
				 SCptr->SCp.Status, SCptr->device->id, SCptr->device->lun));

			/* But don't do this when spinning up a disk at
			 * boot time while we poll for completion as it
			 * fills up the console with messages.  Also, tapes
			 * can report not ready many times right after
			 * loading up a tape.
			 */
			if (esp_should_clear_sync(SCptr) != 0)
				esp_dev->sync = 0;
		}
		ESPDISC(("F<%02x,%02x>", SCptr->device->id, SCptr->device->lun));
		esp_done(esp, ((SCptr->SCp.Status & 0xff) |
			       ((SCptr->SCp.Message & 0xff)<<8) |
			       (DID_OK << 16)));
	} else if (esp->prevmsgin == DISCONNECT) {
		/* Normal disconnect. */
		esp_cmd(esp, ESP_CMD_ESEL);
		ESPDISC(("D<%02x,%02x>", SCptr->device->id, SCptr->device->lun));
		append_SC(&esp->disconnected_SC, SCptr);
		esp->current_SC = NULL;
		if (esp->issue_SC)
			esp_exec_cmd(esp);
	} else {
		/* Driver bug, we do not expect a disconnect here
		 * and should not have advanced the state engine
		 * to in_freeing.
		 */
		ESPLOG(("esp%d: last msg not disc and not cmd cmplt.\n",
			esp->esp_id));
		return do_reset_bus;
	}
	return do_intr_end;
}

/* When a reselect occurs, and we cannot find the command to
 * reconnect to in our queues, we do this.
 */
static int esp_bad_reconnect(struct esp *esp)
{
	struct scsi_cmnd *sp;

	ESPLOG(("esp%d: Eieeee, reconnecting unknown command!\n",
		esp->esp_id));
	ESPLOG(("QUEUE DUMP\n"));
	sp = esp->issue_SC;
	ESPLOG(("esp%d: issue_SC[", esp->esp_id));
	while (sp) {
		ESPLOG(("<%02x,%02x>", sp->device->id, sp->device->lun));
		sp = (struct scsi_cmnd *) sp->host_scribble;
	}
	ESPLOG(("]\n"));
	sp = esp->current_SC;
	ESPLOG(("esp%d: current_SC[", esp->esp_id));
	if (sp)
		ESPLOG(("<%02x,%02x>", sp->device->id, sp->device->lun));
	else
		ESPLOG(("<NULL>"));
	ESPLOG(("]\n"));
	sp = esp->disconnected_SC;
	ESPLOG(("esp%d: disconnected_SC[", esp->esp_id));
	while (sp) {
		ESPLOG(("<%02x,%02x>", sp->device->id, sp->device->lun));
		sp = (struct scsi_cmnd *) sp->host_scribble;
	}
	ESPLOG(("]\n"));
	return do_reset_bus;
}

/* Do the needy when a target tries to reconnect to us. */
static int esp_do_reconnect(struct esp *esp)
{
	int lun, target;
	struct scsi_cmnd *SCptr;

	/* Check for all bogus conditions first. */
	target = reconnect_target(esp);
	if (target < 0) {
		ESPDISC(("bad bus bits\n"));
		return do_reset_bus;
	}
	lun = reconnect_lun(esp);
	if (lun < 0) {
		ESPDISC(("target=%2x, bad identify msg\n", target));
		return do_reset_bus;
	}

	/* Things look ok... */
	ESPDISC(("R<%02x,%02x>", target, lun));

	/* Must not flush FIFO or DVMA on HME. */
	if (esp->erev != fashme) {
		esp_cmd(esp, ESP_CMD_FLUSH);
		if (esp100_reconnect_hwbug(esp))
			return do_reset_bus;
		esp_cmd(esp, ESP_CMD_NULL);
	}

	SCptr = remove_SC(&esp->disconnected_SC, (u8) target, (u8) lun);
	if (!SCptr)
		return esp_bad_reconnect(esp);

	esp_connect(esp, SCptr);
	esp_cmd(esp, ESP_CMD_MOK);

	if (esp->erev == fashme)
		sbus_writeb(((SCptr->device->id & 0xf) |
			     (ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT)),
			    esp->eregs + ESP_BUSID);

	/* Reconnect implies a restore pointers operation. */
	esp_restore_pointers(esp, SCptr);

	esp->snip = 0;
	esp_advance_phase(SCptr, in_the_dark);
	return do_intr_end;
}

/* End of NEXUS (hopefully), pick up status + message byte then leave if
 * all goes well.
 */
static int esp_do_status(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
	int intr, rval;

	rval = skipahead1(esp, SCptr, in_the_dark, in_status);
	if (rval)
		return rval;
	intr = esp->ireg;
	ESPSTAT(("esp_do_status: "));
	if (intr != ESP_INTR_DC) {
		int message_out = 0; /* for parity problems */

		/* Ack the message. */
		ESPSTAT(("ack msg, "));
		esp_cmd(esp, ESP_CMD_MOK);

		if (esp->erev != fashme) {
			dma_flashclear(esp);

			/* Wait till the first bits settle. */
			while (esp->esp_command[0] == 0xff)
				udelay(1);
		} else {
			esp->esp_command[0] = esp->hme_fifo_workaround_buffer[0];
			esp->esp_command[1] = esp->hme_fifo_workaround_buffer[1];
		}

		ESPSTAT(("got something, "));
		/* ESP chimes in with one of
		 *
		 * 1) function done interrupt:
		 *	both status and message in bytes
		 *	are available
		 *
		 * 2) bus service interrupt:
		 *	only status byte was acquired
		 *
		 * 3) Anything else:
		 *	can't happen, but we test for it
		 *	anyways
		 *
		 * ALSO: If bad parity was detected on either
		 *       the status _or_ the message byte then
		 *       the ESP has asserted ATN on the bus
		 *       and we must therefore wait for the
		 *       next phase change.
		 */
		if (intr & ESP_INTR_FDONE) {
			/* We got it all, hallejulia. */
			ESPSTAT(("got both, "));
			SCptr->SCp.Status = esp->esp_command[0];
			SCptr->SCp.Message = esp->esp_command[1];
			esp->prevmsgin = SCptr->SCp.Message;
			esp->cur_msgin[0] = SCptr->SCp.Message;
			if (esp->sreg & ESP_STAT_PERR) {
				/* There was bad parity for the
				 * message byte, the status byte
				 * was ok.
				 */
				message_out = MSG_PARITY_ERROR;
			}
		} else if (intr == ESP_INTR_BSERV) {
			/* Only got status byte. */
			ESPLOG(("esp%d: got status only, ", esp->esp_id));
			if (!(esp->sreg & ESP_STAT_PERR)) {
				SCptr->SCp.Status = esp->esp_command[0];
				SCptr->SCp.Message = 0xff;
			} else {
				/* The status byte had bad parity.
				 * we leave the scsi_pointer Status
				 * field alone as we set it to a default
				 * of CHECK_CONDITION in esp_queue.
				 */
				message_out = INITIATOR_ERROR;
			}
		} else {
			/* This shouldn't happen ever. */
			ESPSTAT(("got bolixed\n"));
			esp_advance_phase(SCptr, in_the_dark);
			return esp_do_phase_determine(esp);
		}

		if (!message_out) {
			ESPSTAT(("status=%2x msg=%2x, ", SCptr->SCp.Status,
				SCptr->SCp.Message));
			if (SCptr->SCp.Message == COMMAND_COMPLETE) {
				ESPSTAT(("and was COMMAND_COMPLETE\n"));
				esp_advance_phase(SCptr, in_freeing);
				return esp_do_freebus(esp);
			} else {
				ESPLOG(("esp%d: and _not_ COMMAND_COMPLETE\n",
					esp->esp_id));
				esp->msgin_len = esp->msgin_ctr = 1;
				esp_advance_phase(SCptr, in_msgindone);
				return esp_do_msgindone(esp);
			}
		} else {
			/* With luck we'll be able to let the target
			 * know that bad parity happened, it will know
			 * which byte caused the problems and send it
			 * again.  For the case where the status byte
			 * receives bad parity, I do not believe most
			 * targets recover very well.  We'll see.
			 */
			ESPLOG(("esp%d: bad parity somewhere mout=%2x\n",
				esp->esp_id, message_out));
			esp->cur_msgout[0] = message_out;
			esp->msgout_len = esp->msgout_ctr = 1;
			esp_advance_phase(SCptr, in_the_dark);
			return esp_do_phase_determine(esp);
		}
	} else {
		/* If we disconnect now, all hell breaks loose. */
		ESPLOG(("esp%d: whoops, disconnect\n", esp->esp_id));
		esp_advance_phase(SCptr, in_the_dark);
		return esp_do_phase_determine(esp);
	}
}

static int esp_enter_status(struct esp *esp)
{
	u8 thecmd = ESP_CMD_ICCSEQ;

	esp_cmd(esp, ESP_CMD_FLUSH);
	if (esp->erev != fashme) {
		u32 tmp;

		esp->esp_command[0] = esp->esp_command[1] = 0xff;
		sbus_writeb(2, esp->eregs + ESP_TCLOW);
		sbus_writeb(0, esp->eregs + ESP_TCMED);
		tmp = sbus_readl(esp->dregs + DMA_CSR);
		tmp |= (DMA_ST_WRITE | DMA_ENABLE);
		sbus_writel(tmp, esp->dregs + DMA_CSR);
		if (esp->dma->revision == dvmaesc1)
			sbus_writel(0x100, esp->dregs + DMA_COUNT);
		sbus_writel(esp->esp_command_dvma, esp->dregs + DMA_ADDR);
		thecmd |= ESP_CMD_DMA;
	}
	esp_cmd(esp, thecmd);
	esp_advance_phase(esp->current_SC, in_status);

	return esp_do_status(esp);
}

static int esp_disconnect_amidst_phases(struct esp *esp)
{
	struct scsi_cmnd *sp = esp->current_SC;
	struct esp_device *esp_dev = sp->device->hostdata;

	/* This means real problems if we see this
	 * here.  Unless we were actually trying
	 * to force the device to abort/reset.
	 */
	ESPLOG(("esp%d Disconnect amidst phases, ", esp->esp_id));
	ESPLOG(("pphase<%s> cphase<%s>, ",
		phase_string(sp->SCp.phase),
		phase_string(sp->SCp.sent_command)));

	if (esp->disconnected_SC != NULL || (esp->erev == fashme))
		esp_cmd(esp, ESP_CMD_ESEL);

	switch (esp->cur_msgout[0]) {
	default:
		/* We didn't expect this to happen at all. */
		ESPLOG(("device is bolixed\n"));
		esp_advance_phase(sp, in_tgterror);
		esp_done(esp, (DID_ERROR << 16));
		break;

	case BUS_DEVICE_RESET:
		ESPLOG(("device reset successful\n"));
		esp_dev->sync_max_offset = 0;
		esp_dev->sync_min_period = 0;
		esp_dev->sync = 0;
		esp_advance_phase(sp, in_resetdev);
		esp_done(esp, (DID_RESET << 16));
		break;

	case ABORT:
		ESPLOG(("device abort successful\n"));
		esp_advance_phase(sp, in_abortone);
		esp_done(esp, (DID_ABORT << 16));
		break;

	};
	return do_intr_end;
}

static int esp_enter_msgout(struct esp *esp)
{
	esp_advance_phase(esp->current_SC, in_msgout);
	return esp_do_msgout(esp);
}

static int esp_enter_msgin(struct esp *esp)
{
	esp_advance_phase(esp->current_SC, in_msgin);
	return esp_do_msgin(esp);
}

static int esp_enter_cmd(struct esp *esp)
{
	esp_advance_phase(esp->current_SC, in_cmdbegin);
	return esp_do_cmdbegin(esp);
}

static int esp_enter_badphase(struct esp *esp)
{
	ESPLOG(("esp%d: Bizarre bus phase %2x.\n", esp->esp_id,
		esp->sreg & ESP_STAT_PMASK));
	return do_reset_bus;
}

typedef int (*espfunc_t)(struct esp *);

static espfunc_t phase_vector[] = {
	esp_do_data,		/* ESP_DOP */
	esp_do_data,		/* ESP_DIP */
	esp_enter_cmd,		/* ESP_CMDP */
	esp_enter_status,	/* ESP_STATP */
	esp_enter_badphase,	/* ESP_STAT_PMSG */
	esp_enter_badphase,	/* ESP_STAT_PMSG | ESP_STAT_PIO */
	esp_enter_msgout,	/* ESP_MOP */
	esp_enter_msgin,	/* ESP_MIP */
};

/* The target has control of the bus and we have to see where it has
 * taken us.
 */
static int esp_do_phase_determine(struct esp *esp)
{
	if ((esp->ireg & ESP_INTR_DC) != 0)
		return esp_disconnect_amidst_phases(esp);
	return phase_vector[esp->sreg & ESP_STAT_PMASK](esp);
}

/* First interrupt after exec'ing a cmd comes here. */
static int esp_select_complete(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
	struct esp_device *esp_dev = SCptr->device->hostdata;
	int cmd_bytes_sent, fcnt;

	if (esp->erev != fashme)
		esp->seqreg = (sbus_readb(esp->eregs + ESP_SSTEP) & ESP_STEP_VBITS);

	if (esp->erev == fashme)
		fcnt = esp->hme_fifo_workaround_count;
	else
		fcnt = (sbus_readb(esp->eregs + ESP_FFLAGS) & ESP_FF_FBYTES);

	cmd_bytes_sent = esp_bytes_sent(esp, fcnt);
	dma_invalidate(esp);

	/* Let's check to see if a reselect happened
	 * while we we're trying to select.  This must
	 * be checked first.
	 */
	if (esp->ireg == (ESP_INTR_RSEL | ESP_INTR_FDONE)) {
		esp_reconnect(esp, SCptr);
		return esp_do_reconnect(esp);
	}

	/* Looks like things worked, we should see a bus service &
	 * a function complete interrupt at this point.  Note we
	 * are doing a direct comparison because we don't want to
	 * be fooled into thinking selection was successful if
	 * ESP_INTR_DC is set, see below.
	 */
	if (esp->ireg == (ESP_INTR_FDONE | ESP_INTR_BSERV)) {
		/* target speaks... */
		esp->targets_present |= (1<<SCptr->device->id);

		/* What if the target ignores the sdtr? */
		if (esp->snip)
			esp_dev->sync = 1;

		/* See how far, if at all, we got in getting
		 * the information out to the target.
		 */
		switch (esp->seqreg) {
		default:

		case ESP_STEP_ASEL:
			/* Arbitration won, target selected, but
			 * we are in some phase which is not command
			 * phase nor is it message out phase.
			 *
			 * XXX We've confused the target, obviously.
			 * XXX So clear it's state, but we also end
			 * XXX up clearing everyone elses.  That isn't
			 * XXX so nice.  I'd like to just reset this
			 * XXX target, but if I cannot even get it's
			 * XXX attention and finish selection to talk
			 * XXX to it, there is not much more I can do.
			 * XXX If we have a loaded bus we're going to
			 * XXX spend the next second or so renegotiating
			 * XXX for synchronous transfers.
			 */
			ESPLOG(("esp%d: STEP_ASEL for tgt %d\n",
				esp->esp_id, SCptr->device->id));

		case ESP_STEP_SID:
			/* Arbitration won, target selected, went
			 * to message out phase, sent one message
			 * byte, then we stopped.  ATN is asserted
			 * on the SCSI bus and the target is still
			 * there hanging on.  This is a legal
			 * sequence step if we gave the ESP a select
			 * and stop command.
			 *
			 * XXX See above, I could set the borken flag
			 * XXX in the device struct and retry the
			 * XXX command.  But would that help for
			 * XXX tagged capable targets?
			 */

		case ESP_STEP_NCMD:
			/* Arbitration won, target selected, maybe
			 * sent the one message byte in message out
			 * phase, but we did not go to command phase
			 * in the end.  Actually, we could have sent
			 * only some of the message bytes if we tried
			 * to send out the entire identify and tag
			 * message using ESP_CMD_SA3.
			 */
			cmd_bytes_sent = 0;
			break;

		case ESP_STEP_PPC:
			/* No, not the powerPC pinhead.  Arbitration
			 * won, all message bytes sent if we went to
			 * message out phase, went to command phase
			 * but only part of the command was sent.
			 *
			 * XXX I've seen this, but usually in conjunction
			 * XXX with a gross error which appears to have
			 * XXX occurred between the time I told the
			 * XXX ESP to arbitrate and when I got the
			 * XXX interrupt.  Could I have misloaded the
			 * XXX command bytes into the fifo?  Actually,
			 * XXX I most likely missed a phase, and therefore
			 * XXX went into never never land and didn't even
			 * XXX know it.  That was the old driver though.
			 * XXX What is even more peculiar is that the ESP
			 * XXX showed the proper function complete and
			 * XXX bus service bits in the interrupt register.
			 */

		case ESP_STEP_FINI4:
		case ESP_STEP_FINI5:
		case ESP_STEP_FINI6:
		case ESP_STEP_FINI7:
			/* Account for the identify message */
			if (SCptr->SCp.phase == in_slct_norm)
				cmd_bytes_sent -= 1;
		};

		if (esp->erev != fashme)
			esp_cmd(esp, ESP_CMD_NULL);

		/* Be careful, we could really get fucked during synchronous
		 * data transfers if we try to flush the fifo now.
		 */
		if ((esp->erev != fashme) && /* not a Happy Meal and... */
		    !fcnt && /* Fifo is empty and... */
		    /* either we are not doing synchronous transfers or... */
		    (!esp_dev->sync_max_offset ||
		     /* We are not going into data in phase. */
		     ((esp->sreg & ESP_STAT_PMASK) != ESP_DIP)))
			esp_cmd(esp, ESP_CMD_FLUSH); /* flush is safe */

		/* See how far we got if this is not a slow command. */
		if (!esp->esp_slowcmd) {
			if (cmd_bytes_sent < 0)
				cmd_bytes_sent = 0;
			if (cmd_bytes_sent != SCptr->cmd_len) {
				/* Crapola, mark it as a slowcmd
				 * so that we have some chance of
				 * keeping the command alive with
				 * good luck.
				 *
				 * XXX Actually, if we didn't send it all
				 * XXX this means either we didn't set things
				 * XXX up properly (driver bug) or the target
				 * XXX or the ESP detected parity on one of
				 * XXX the command bytes.  This makes much
				 * XXX more sense, and therefore this code
				 * XXX should be changed to send out a
				 * XXX parity error message or if the status
				 * XXX register shows no parity error then
				 * XXX just expect the target to bring the
				 * XXX bus into message in phase so that it
				 * XXX can send us the parity error message.
				 * XXX SCSI sucks...
				 */
				esp->esp_slowcmd = 1;
				esp->esp_scmdp = &(SCptr->cmnd[cmd_bytes_sent]);
				esp->esp_scmdleft = (SCptr->cmd_len - cmd_bytes_sent);
			}
		}

		/* Now figure out where we went. */
		esp_advance_phase(SCptr, in_the_dark);
		return esp_do_phase_determine(esp);
	}

	/* Did the target even make it? */
	if (esp->ireg == ESP_INTR_DC) {
		/* wheee... nobody there or they didn't like
		 * what we told it to do, clean up.
		 */

		/* If anyone is off the bus, but working on
		 * a command in the background for us, tell
		 * the ESP to listen for them.
		 */
		if (esp->disconnected_SC)
			esp_cmd(esp, ESP_CMD_ESEL);

		if (((1<<SCptr->device->id) & esp->targets_present) &&
		    esp->seqreg != 0 &&
		    (esp->cur_msgout[0] == EXTENDED_MESSAGE) &&
		    (SCptr->SCp.phase == in_slct_msg ||
		     SCptr->SCp.phase == in_slct_stop)) {
			/* shit */
			esp->snip = 0;
			ESPLOG(("esp%d: Failed synchronous negotiation for target %d "
				"lun %d\n", esp->esp_id, SCptr->device->id, SCptr->device->lun));
			esp_dev->sync_max_offset = 0;
			esp_dev->sync_min_period = 0;
			esp_dev->sync = 1; /* so we don't negotiate again */

			/* Run the command again, this time though we
			 * won't try to negotiate for synchronous transfers.
			 *
			 * XXX I'd like to do something like send an
			 * XXX INITIATOR_ERROR or ABORT message to the
			 * XXX target to tell it, "Sorry I confused you,
			 * XXX please come back and I will be nicer next
			 * XXX time".  But that requires having the target
			 * XXX on the bus, and it has dropped BSY on us.
			 */
			esp->current_SC = NULL;
			esp_advance_phase(SCptr, not_issued);
			prepend_SC(&esp->issue_SC, SCptr);
			esp_exec_cmd(esp);
			return do_intr_end;
		}

		/* Ok, this is normal, this is what we see during boot
		 * or whenever when we are scanning the bus for targets.
		 * But first make sure that is really what is happening.
		 */
		if (((1<<SCptr->device->id) & esp->targets_present)) {
			ESPLOG(("esp%d: Warning, live target %d not responding to "
				"selection.\n", esp->esp_id, SCptr->device->id));

			/* This _CAN_ happen.  The SCSI standard states that
			 * the target is to _not_ respond to selection if
			 * _it_ detects bad parity on the bus for any reason.
			 * Therefore, we assume that if we've talked successfully
			 * to this target before, bad parity is the problem.
			 */
			esp_done(esp, (DID_PARITY << 16));
		} else {
			/* Else, there really isn't anyone there. */
			ESPMISC(("esp: selection failure, maybe nobody there?\n"));
			ESPMISC(("esp: target %d lun %d\n",
				 SCptr->device->id, SCptr->device->lun));
			esp_done(esp, (DID_BAD_TARGET << 16));
		}
		return do_intr_end;
	}

	ESPLOG(("esp%d: Selection failure.\n", esp->esp_id));
	printk("esp%d: Currently -- ", esp->esp_id);
	esp_print_ireg(esp->ireg); printk(" ");
	esp_print_statreg(esp->sreg); printk(" ");
	esp_print_seqreg(esp->seqreg); printk("\n");
	printk("esp%d: New -- ", esp->esp_id);
	esp->sreg = sbus_readb(esp->eregs + ESP_STATUS);
	esp->seqreg = sbus_readb(esp->eregs + ESP_SSTEP);
	esp->ireg = sbus_readb(esp->eregs + ESP_INTRPT);
	esp_print_ireg(esp->ireg); printk(" ");
	esp_print_statreg(esp->sreg); printk(" ");
	esp_print_seqreg(esp->seqreg); printk("\n");
	ESPLOG(("esp%d: resetting bus\n", esp->esp_id));
	return do_reset_bus; /* ugh... */
}

/* Continue reading bytes for msgin phase. */
static int esp_do_msgincont(struct esp *esp)
{
	if (esp->ireg & ESP_INTR_BSERV) {
		/* in the right phase too? */
		if ((esp->sreg & ESP_STAT_PMASK) == ESP_MIP) {
			/* phew... */
			esp_cmd(esp, ESP_CMD_TI);
			esp_advance_phase(esp->current_SC, in_msgindone);
			return do_intr_end;
		}

		/* We changed phase but ESP shows bus service,
		 * in this case it is most likely that we, the
		 * hacker who has been up for 20hrs straight
		 * staring at the screen, drowned in coffee
		 * smelling like retched cigarette ashes
		 * have miscoded something..... so, try to
		 * recover as best we can.
		 */
		ESPLOG(("esp%d: message in mis-carriage.\n", esp->esp_id));
	}
	esp_advance_phase(esp->current_SC, in_the_dark);
	return do_phase_determine;
}

static int check_singlebyte_msg(struct esp *esp)
{
	esp->prevmsgin = esp->cur_msgin[0];
	if (esp->cur_msgin[0] & 0x80) {
		/* wheee... */
		ESPLOG(("esp%d: target sends identify amidst phases\n",
			esp->esp_id));
		esp_advance_phase(esp->current_SC, in_the_dark);
		return 0;
	} else if (((esp->cur_msgin[0] & 0xf0) == 0x20) ||
		   (esp->cur_msgin[0] == EXTENDED_MESSAGE)) {
		esp->msgin_len = 2;
		esp_advance_phase(esp->current_SC, in_msgincont);
		return 0;
	}
	esp_advance_phase(esp->current_SC, in_the_dark);
	switch (esp->cur_msgin[0]) {
	default:
		/* We don't want to hear about it. */
		ESPLOG(("esp%d: msg %02x which we don't know about\n", esp->esp_id,
			esp->cur_msgin[0]));
		return MESSAGE_REJECT;

	case NOP:
		ESPLOG(("esp%d: target %d sends a nop\n", esp->esp_id,
			esp->current_SC->device->id));
		return 0;

	case RESTORE_POINTERS:
		/* In this case we might also have to backup the
		 * "slow command" pointer.  It is rare to get such
		 * a save/restore pointer sequence so early in the
		 * bus transition sequences, but cover it.
		 */
		if (esp->esp_slowcmd) {
			esp->esp_scmdleft = esp->current_SC->cmd_len;
			esp->esp_scmdp = &esp->current_SC->cmnd[0];
		}
		esp_restore_pointers(esp, esp->current_SC);
		return 0;

	case SAVE_POINTERS:
		esp_save_pointers(esp, esp->current_SC);
		return 0;

	case COMMAND_COMPLETE:
	case DISCONNECT:
		/* Freeing the bus, let it go. */
		esp->current_SC->SCp.phase = in_freeing;
		return 0;

	case MESSAGE_REJECT:
		ESPMISC(("msg reject, "));
		if (esp->prevmsgout == EXTENDED_MESSAGE) {
			struct esp_device *esp_dev = esp->current_SC->device->hostdata;

			/* Doesn't look like this target can
			 * do synchronous or WIDE transfers.
			 */
			ESPSDTR(("got reject, was trying nego, clearing sync/WIDE\n"));
			esp_dev->sync = 1;
			esp_dev->wide = 1;
			esp_dev->sync_min_period = 0;
			esp_dev->sync_max_offset = 0;
			return 0;
		} else {
			ESPMISC(("not sync nego, sending ABORT\n"));
			return ABORT;
		}
	};
}

/* Target negotiates for synchronous transfers before we do, this
 * is legal although very strange.  What is even funnier is that
 * the SCSI2 standard specifically recommends against targets doing
 * this because so many initiators cannot cope with this occurring.
 */
static int target_with_ants_in_pants(struct esp *esp,
				     struct scsi_cmnd *SCptr,
				     struct esp_device *esp_dev)
{
	if (esp_dev->sync || SCptr->device->borken) {
		/* sorry, no can do */
		ESPSDTR(("forcing to async, "));
		build_sync_nego_msg(esp, 0, 0);
		esp_dev->sync = 1;
		esp->snip = 1;
		ESPLOG(("esp%d: hoping for msgout\n", esp->esp_id));
		esp_advance_phase(SCptr, in_the_dark);
		return EXTENDED_MESSAGE;
	}

	/* Ok, we'll check them out... */
	return 0;
}

static void sync_report(struct esp *esp)
{
	int msg3, msg4;
	char *type;

	msg3 = esp->cur_msgin[3];
	msg4 = esp->cur_msgin[4];
	if (msg4) {
		int hz = 1000000000 / (msg3 * 4);
		int integer = hz / 1000000;
		int fraction = (hz - (integer * 1000000)) / 10000;
		if ((esp->erev == fashme) &&
		    (esp->config3[esp->current_SC->device->id] & ESP_CONFIG3_EWIDE)) {
			type = "FAST-WIDE";
			integer <<= 1;
			fraction <<= 1;
		} else if ((msg3 * 4) < 200) {
			type = "FAST";
		} else {
			type = "synchronous";
		}

		/* Do not transform this back into one big printk
		 * again, it triggers a bug in our sparc64-gcc272
		 * sibling call optimization.  -DaveM
		 */
		ESPLOG((KERN_INFO "esp%d: target %d ",
			esp->esp_id, esp->current_SC->device->id));
		ESPLOG(("[period %dns offset %d %d.%02dMHz ",
			(int) msg3 * 4, (int) msg4,
			integer, fraction));
		ESPLOG(("%s SCSI%s]\n", type,
			(((msg3 * 4) < 200) ? "-II" : "")));
	} else {
		ESPLOG((KERN_INFO "esp%d: target %d asynchronous\n",
			esp->esp_id, esp->current_SC->device->id));
	}
}

static int check_multibyte_msg(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
	struct esp_device *esp_dev = SCptr->device->hostdata;
	u8 regval = 0;
	int message_out = 0;

	ESPSDTR(("chk multibyte msg: "));
	if (esp->cur_msgin[2] == EXTENDED_SDTR) {
		int period = esp->cur_msgin[3];
		int offset = esp->cur_msgin[4];

		ESPSDTR(("is sync nego response, "));
		if (!esp->snip) {
			int rval;

			/* Target negotiates first! */
			ESPSDTR(("target jumps the gun, "));
			message_out = EXTENDED_MESSAGE; /* we must respond */
			rval = target_with_ants_in_pants(esp, SCptr, esp_dev);
			if (rval)
				return rval;
		}

		ESPSDTR(("examining sdtr, "));

		/* Offset cannot be larger than ESP fifo size. */
		if (offset > 15) {
			ESPSDTR(("offset too big %2x, ", offset));
			offset = 15;
			ESPSDTR(("sending back new offset\n"));
			build_sync_nego_msg(esp, period, offset);
			return EXTENDED_MESSAGE;
		}

		if (offset && period > esp->max_period) {
			/* Yeee, async for this slow device. */
			ESPSDTR(("period too long %2x, ", period));
			build_sync_nego_msg(esp, 0, 0);
			ESPSDTR(("hoping for msgout\n"));
			esp_advance_phase(esp->current_SC, in_the_dark);
			return EXTENDED_MESSAGE;
		} else if (offset && period < esp->min_period) {
			ESPSDTR(("period too short %2x, ", period));
			period = esp->min_period;
			if (esp->erev > esp236)
				regval = 4;
			else
				regval = 5;
		} else if (offset) {
			int tmp;

			ESPSDTR(("period is ok, "));
			tmp = esp->ccycle / 1000;
			regval = (((period << 2) + tmp - 1) / tmp);
			if (regval && ((esp->erev == fas100a ||
					esp->erev == fas236  ||
					esp->erev == fashme))) {
				if (period >= 50)
					regval--;
			}
		}

		if (offset) {
			u8 bit;

			esp_dev->sync_min_period = (regval & 0x1f);
			esp_dev->sync_max_offset = (offset | esp->radelay);
			if (esp->erev == fas100a || esp->erev == fas236 || esp->erev == fashme) {
				if ((esp->erev == fas100a) || (esp->erev == fashme))
					bit = ESP_CONFIG3_FAST;
				else
					bit = ESP_CONFIG3_FSCSI;
				if (period < 50) {
					/* On FAS366, if using fast-20 synchronous transfers
					 * we need to make sure the REQ/ACK assert/deassert
					 * control bits are clear.
					 */
					if (esp->erev == fashme)
						esp_dev->sync_max_offset &= ~esp->radelay;
					esp->config3[SCptr->device->id] |= bit;
				} else {
					esp->config3[SCptr->device->id] &= ~bit;
				}
				esp->prev_cfg3 = esp->config3[SCptr->device->id];
				sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);
			}
			esp->prev_soff = esp_dev->sync_max_offset;
			esp->prev_stp = esp_dev->sync_min_period;
			sbus_writeb(esp->prev_soff, esp->eregs + ESP_SOFF);
			sbus_writeb(esp->prev_stp, esp->eregs + ESP_STP);
			ESPSDTR(("soff=%2x stp=%2x cfg3=%2x\n",
				 esp_dev->sync_max_offset,
				 esp_dev->sync_min_period,
				 esp->config3[SCptr->device->id]));

			esp->snip = 0;
		} else if (esp_dev->sync_max_offset) {
			u8 bit;

			/* back to async mode */
			ESPSDTR(("unaccaptable sync nego, forcing async\n"));
			esp_dev->sync_max_offset = 0;
			esp_dev->sync_min_period = 0;
			esp->prev_soff = 0;
			esp->prev_stp = 0;
			sbus_writeb(esp->prev_soff, esp->eregs + ESP_SOFF);
			sbus_writeb(esp->prev_stp, esp->eregs + ESP_STP);
			if (esp->erev == fas100a || esp->erev == fas236 || esp->erev == fashme) {
				if ((esp->erev == fas100a) || (esp->erev == fashme))
					bit = ESP_CONFIG3_FAST;
				else
					bit = ESP_CONFIG3_FSCSI;
				esp->config3[SCptr->device->id] &= ~bit;
				esp->prev_cfg3 = esp->config3[SCptr->device->id];
				sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);
			}
		}

		sync_report(esp);

		ESPSDTR(("chk multibyte msg: sync is known, "));
		esp_dev->sync = 1;

		if (message_out) {
			ESPLOG(("esp%d: sending sdtr back, hoping for msgout\n",
				esp->esp_id));
			build_sync_nego_msg(esp, period, offset);
			esp_advance_phase(SCptr, in_the_dark);
			return EXTENDED_MESSAGE;
		}

		ESPSDTR(("returning zero\n"));
		esp_advance_phase(SCptr, in_the_dark); /* ...or else! */
		return 0;
	} else if (esp->cur_msgin[2] == EXTENDED_WDTR) {
		int size = 8 << esp->cur_msgin[3];

		esp->wnip = 0;
		if (esp->erev != fashme) {
			ESPLOG(("esp%d: AIEEE wide msg received and not HME.\n",
				esp->esp_id));
			message_out = MESSAGE_REJECT;
		} else if (size > 16) {
			ESPLOG(("esp%d: AIEEE wide transfer for %d size "
				"not supported.\n", esp->esp_id, size));
			message_out = MESSAGE_REJECT;
		} else {
			/* Things look good; let's see what we got. */
			if (size == 16) {
				/* Set config 3 register for this target. */
				esp->config3[SCptr->device->id] |= ESP_CONFIG3_EWIDE;
			} else {
				/* Just make sure it was one byte sized. */
				if (size != 8) {
					ESPLOG(("esp%d: Aieee, wide nego of %d size.\n",
						esp->esp_id, size));
					message_out = MESSAGE_REJECT;
					goto finish;
				}
				/* Pure paranoia. */
				esp->config3[SCptr->device->id] &= ~(ESP_CONFIG3_EWIDE);
			}
			esp->prev_cfg3 = esp->config3[SCptr->device->id];
			sbus_writeb(esp->prev_cfg3, esp->eregs + ESP_CFG3);

			/* Regardless, next try for sync transfers. */
			build_sync_nego_msg(esp, esp->sync_defp, 15);
			esp_dev->sync = 1;
			esp->snip = 1;
			message_out = EXTENDED_MESSAGE;
		}
	} else if (esp->cur_msgin[2] == EXTENDED_MODIFY_DATA_POINTER) {
		ESPLOG(("esp%d: rejecting modify data ptr msg\n", esp->esp_id));
		message_out = MESSAGE_REJECT;
	}
finish:
	esp_advance_phase(SCptr, in_the_dark);
	return message_out;
}

static int esp_do_msgindone(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
	int message_out = 0, it = 0, rval;

	rval = skipahead1(esp, SCptr, in_msgin, in_msgindone);
	if (rval)
		return rval;
	if (SCptr->SCp.sent_command != in_status) {
		if (!(esp->ireg & ESP_INTR_DC)) {
			if (esp->msgin_len && (esp->sreg & ESP_STAT_PERR)) {
				message_out = MSG_PARITY_ERROR;
				esp_cmd(esp, ESP_CMD_FLUSH);
			} else if (esp->erev != fashme &&
			  (it = (sbus_readb(esp->eregs + ESP_FFLAGS) & ESP_FF_FBYTES)) != 1) {
				/* We certainly dropped the ball somewhere. */
				message_out = INITIATOR_ERROR;
				esp_cmd(esp, ESP_CMD_FLUSH);
			} else if (!esp->msgin_len) {
				if (esp->erev == fashme)
					it = esp->hme_fifo_workaround_buffer[0];
				else
					it = sbus_readb(esp->eregs + ESP_FDATA);
				esp_advance_phase(SCptr, in_msgincont);
			} else {
				/* it is ok and we want it */
				if (esp->erev == fashme)
					it = esp->cur_msgin[esp->msgin_ctr] =
						esp->hme_fifo_workaround_buffer[0];
				else
					it = esp->cur_msgin[esp->msgin_ctr] =
						sbus_readb(esp->eregs + ESP_FDATA);
				esp->msgin_ctr++;
			}
		} else {
			esp_advance_phase(SCptr, in_the_dark);
			return do_work_bus;
		}
	} else {
		it = esp->cur_msgin[0];
	}
	if (!message_out && esp->msgin_len) {
		if (esp->msgin_ctr < esp->msgin_len) {
			esp_advance_phase(SCptr, in_msgincont);
		} else if (esp->msgin_len == 1) {
			message_out = check_singlebyte_msg(esp);
		} else if (esp->msgin_len == 2) {
			if (esp->cur_msgin[0] == EXTENDED_MESSAGE) {
				if ((it + 2) >= 15) {
					message_out = MESSAGE_REJECT;
				} else {
					esp->msgin_len = (it + 2);
					esp_advance_phase(SCptr, in_msgincont);
				}
			} else {
				message_out = MESSAGE_REJECT; /* foo on you */
			}
		} else {
			message_out = check_multibyte_msg(esp);
		}
	}
	if (message_out < 0) {
		return -message_out;
	} else if (message_out) {
		if (((message_out != 1) &&
		     ((message_out < 0x20) || (message_out & 0x80))))
			esp->msgout_len = 1;
		esp->cur_msgout[0] = message_out;
		esp_cmd(esp, ESP_CMD_SATN);
		esp_advance_phase(SCptr, in_the_dark);
		esp->msgin_len = 0;
	}
	esp->sreg = sbus_readb(esp->eregs + ESP_STATUS);
	esp->sreg &= ~(ESP_STAT_INTR);
	if ((esp->sreg & (ESP_STAT_PMSG|ESP_STAT_PCD)) == (ESP_STAT_PMSG|ESP_STAT_PCD))
		esp_cmd(esp, ESP_CMD_MOK);
	if ((SCptr->SCp.sent_command == in_msgindone) &&
	    (SCptr->SCp.phase == in_freeing))
		return esp_do_freebus(esp);
	return do_intr_end;
}

static int esp_do_cmdbegin(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;

	esp_advance_phase(SCptr, in_cmdend);
	if (esp->erev == fashme) {
		u32 tmp = sbus_readl(esp->dregs + DMA_CSR);
		int i;

		for (i = 0; i < esp->esp_scmdleft; i++)
			esp->esp_command[i] = *esp->esp_scmdp++;
		esp->esp_scmdleft = 0;
		esp_cmd(esp, ESP_CMD_FLUSH);
		esp_setcount(esp->eregs, i, 1);
		esp_cmd(esp, (ESP_CMD_DMA | ESP_CMD_TI));
		tmp |= (DMA_SCSI_DISAB | DMA_ENABLE);
		tmp &= ~(DMA_ST_WRITE);
		sbus_writel(i, esp->dregs + DMA_COUNT);
		sbus_writel(esp->esp_command_dvma, esp->dregs + DMA_ADDR);
		sbus_writel(tmp, esp->dregs + DMA_CSR);
	} else {
		u8 tmp;

		esp_cmd(esp, ESP_CMD_FLUSH);
		tmp = *esp->esp_scmdp++;
		esp->esp_scmdleft--;
		sbus_writeb(tmp, esp->eregs + ESP_FDATA);
		esp_cmd(esp, ESP_CMD_TI);
	}
	return do_intr_end;
}

static int esp_do_cmddone(struct esp *esp)
{
	if (esp->erev == fashme)
		dma_invalidate(esp);
	else
		esp_cmd(esp, ESP_CMD_NULL);

	if (esp->ireg & ESP_INTR_BSERV) {
		esp_advance_phase(esp->current_SC, in_the_dark);
		return esp_do_phase_determine(esp);
	}

	ESPLOG(("esp%d: in do_cmddone() but didn't get BSERV interrupt.\n",
		esp->esp_id));
	return do_reset_bus;
}

static int esp_do_msgout(struct esp *esp)
{
	esp_cmd(esp, ESP_CMD_FLUSH);
	switch (esp->msgout_len) {
	case 1:
		if (esp->erev == fashme)
			hme_fifo_push(esp, &esp->cur_msgout[0], 1);
		else
			sbus_writeb(esp->cur_msgout[0], esp->eregs + ESP_FDATA);

		esp_cmd(esp, ESP_CMD_TI);
		break;

	case 2:
		esp->esp_command[0] = esp->cur_msgout[0];
		esp->esp_command[1] = esp->cur_msgout[1];

		if (esp->erev == fashme) {
			hme_fifo_push(esp, &esp->cur_msgout[0], 2);
			esp_cmd(esp, ESP_CMD_TI);
		} else {
			dma_setup(esp, esp->esp_command_dvma, 2, 0);
			esp_setcount(esp->eregs, 2, 0);
			esp_cmd(esp, ESP_CMD_DMA | ESP_CMD_TI);
		}
		break;

	case 4:
		esp->esp_command[0] = esp->cur_msgout[0];
		esp->esp_command[1] = esp->cur_msgout[1];
		esp->esp_command[2] = esp->cur_msgout[2];
		esp->esp_command[3] = esp->cur_msgout[3];
		esp->snip = 1;

		if (esp->erev == fashme) {
			hme_fifo_push(esp, &esp->cur_msgout[0], 4);
			esp_cmd(esp, ESP_CMD_TI);
		} else {
			dma_setup(esp, esp->esp_command_dvma, 4, 0);
			esp_setcount(esp->eregs, 4, 0);
			esp_cmd(esp, ESP_CMD_DMA | ESP_CMD_TI);
		}
		break;

	case 5:
		esp->esp_command[0] = esp->cur_msgout[0];
		esp->esp_command[1] = esp->cur_msgout[1];
		esp->esp_command[2] = esp->cur_msgout[2];
		esp->esp_command[3] = esp->cur_msgout[3];
		esp->esp_command[4] = esp->cur_msgout[4];
		esp->snip = 1;

		if (esp->erev == fashme) {
			hme_fifo_push(esp, &esp->cur_msgout[0], 5);
			esp_cmd(esp, ESP_CMD_TI);
		} else {
			dma_setup(esp, esp->esp_command_dvma, 5, 0);
			esp_setcount(esp->eregs, 5, 0);
			esp_cmd(esp, ESP_CMD_DMA | ESP_CMD_TI);
		}
		break;

	default:
		/* whoops */
		ESPMISC(("bogus msgout sending NOP\n"));
		esp->cur_msgout[0] = NOP;

		if (esp->erev == fashme) {
			hme_fifo_push(esp, &esp->cur_msgout[0], 1);
		} else {
			sbus_writeb(esp->cur_msgout[0], esp->eregs + ESP_FDATA);
		}

		esp->msgout_len = 1;
		esp_cmd(esp, ESP_CMD_TI);
		break;
	};

	esp_advance_phase(esp->current_SC, in_msgoutdone);
	return do_intr_end;
}

static int esp_do_msgoutdone(struct esp *esp)
{
	if (esp->msgout_len > 1) {
		/* XXX HME/FAS ATN deassert workaround required,
		 * XXX no DMA flushing, only possible ESP_CMD_FLUSH
		 * XXX to kill the fifo.
		 */
		if (esp->erev != fashme) {
			u32 tmp;

			while ((tmp = sbus_readl(esp->dregs + DMA_CSR)) & DMA_PEND_READ)
				udelay(1);
			tmp &= ~DMA_ENABLE;
			sbus_writel(tmp, esp->dregs + DMA_CSR);
			dma_invalidate(esp);
		} else {
			esp_cmd(esp, ESP_CMD_FLUSH);
		}
	}
	if (!(esp->ireg & ESP_INTR_DC)) {
		if (esp->erev != fashme)
			esp_cmd(esp, ESP_CMD_NULL);
		switch (esp->sreg & ESP_STAT_PMASK) {
		case ESP_MOP:
			/* whoops, parity error */
			ESPLOG(("esp%d: still in msgout, parity error assumed\n",
				esp->esp_id));
			if (esp->msgout_len > 1)
				esp_cmd(esp, ESP_CMD_SATN);
			esp_advance_phase(esp->current_SC, in_msgout);
			return do_work_bus;

		case ESP_DIP:
			break;

		default:
			/* Happy Meal fifo is touchy... */
			if ((esp->erev != fashme) &&
			    !fcount(esp) &&
			    !(((struct esp_device *)esp->current_SC->device->hostdata)->sync_max_offset))
				esp_cmd(esp, ESP_CMD_FLUSH);
			break;

		};
	} else {
		ESPLOG(("esp%d: disconnect, resetting bus\n", esp->esp_id));
		return do_reset_bus;
	}

	/* If we sent out a synchronous negotiation message, update
	 * our state.
	 */
	if (esp->cur_msgout[2] == EXTENDED_MESSAGE &&
	    esp->cur_msgout[4] == EXTENDED_SDTR) {
		esp->snip = 1; /* anal retentiveness... */
	}

	esp->prevmsgout = esp->cur_msgout[0];
	esp->msgout_len = 0;
	esp_advance_phase(esp->current_SC, in_the_dark);
	return esp_do_phase_determine(esp);
}

static int esp_bus_unexpected(struct esp *esp)
{
	ESPLOG(("esp%d: command in weird state %2x\n",
		esp->esp_id, esp->current_SC->SCp.phase));
	return do_reset_bus;
}

static espfunc_t bus_vector[] = {
	esp_do_data_finale,
	esp_do_data_finale,
	esp_bus_unexpected,
	esp_do_msgin,
	esp_do_msgincont,
	esp_do_msgindone,
	esp_do_msgout,
	esp_do_msgoutdone,
	esp_do_cmdbegin,
	esp_do_cmddone,
	esp_do_status,
	esp_do_freebus,
	esp_do_phase_determine,
	esp_bus_unexpected,
	esp_bus_unexpected,
	esp_bus_unexpected,
};

/* This is the second tier in our dual-level SCSI state machine. */
static int esp_work_bus(struct esp *esp)
{
	struct scsi_cmnd *SCptr = esp->current_SC;
	unsigned int phase;

	ESPBUS(("esp_work_bus: "));
	if (!SCptr) {
		ESPBUS(("reconnect\n"));
		return esp_do_reconnect(esp);
	}
	phase = SCptr->SCp.phase;
	if ((phase & 0xf0) == in_phases_mask)
		return bus_vector[(phase & 0x0f)](esp);
	else if ((phase & 0xf0) == in_slct_mask)
		return esp_select_complete(esp);
	else
		return esp_bus_unexpected(esp);
}

static espfunc_t isvc_vector[] = {
4094
	NULL,
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	esp_do_phase_determine,
	esp_do_resetbus,
	esp_finish_reset,
	esp_work_bus
};

/* Main interrupt handler for an esp adapter. */
static void esp_handle(struct esp *esp)
{
	struct scsi_cmnd *SCptr;
	int what_next = do_intr_end;

	SCptr = esp->current_SC;

	/* Check for errors. */
	esp->sreg = sbus_readb(esp->eregs + ESP_STATUS);
	esp->sreg &= (~ESP_STAT_INTR);
	if (esp->erev == fashme) {
		esp->sreg2 = sbus_readb(esp->eregs + ESP_STATUS2);
		esp->seqreg = (sbus_readb(esp->eregs + ESP_SSTEP) & ESP_STEP_VBITS);
	}

	if (esp->sreg & (ESP_STAT_SPAM)) {
		/* Gross error, could be due to one of:
		 *
		 * - top of fifo overwritten, could be because
		 *   we tried to do a synchronous transfer with
		 *   an offset greater than ESP fifo size
		 *
		 * - top of command register overwritten
		 *
		 * - DMA setup to go in one direction, SCSI
		 *   bus points in the other, whoops
		 *
		 * - weird phase change during asynchronous
		 *   data phase while we are initiator
		 */
		ESPLOG(("esp%d: Gross error sreg=%2x\n", esp->esp_id, esp->sreg));

		/* If a command is live on the bus we cannot safely
		 * reset the bus, so we'll just let the pieces fall
		 * where they may.  Here we are hoping that the
		 * target will be able to cleanly go away soon
		 * so we can safely reset things.
		 */
		if (!SCptr) {
			ESPLOG(("esp%d: No current cmd during gross error, "
				"resetting bus\n", esp->esp_id));
			what_next = do_reset_bus;
			goto state_machine;
		}
	}

	if (sbus_readl(esp->dregs + DMA_CSR) & DMA_HNDL_ERROR) {
		/* A DMA gate array error.  Here we must
		 * be seeing one of two things.  Either the
		 * virtual to physical address translation
		 * on the SBUS could not occur, else the
		 * translation it did get pointed to a bogus
		 * page.  Ho hum...
		 */
		ESPLOG(("esp%d: DMA error %08x\n", esp->esp_id,
			sbus_readl(esp->dregs + DMA_CSR)));

		/* DMA gate array itself must be reset to clear the
		 * error condition.
		 */
		esp_reset_dma(esp);

		what_next = do_reset_bus;
		goto state_machine;
	}

	esp->ireg = sbus_readb(esp->eregs + ESP_INTRPT);   /* Unlatch intr reg */

	if (esp->erev == fashme) {
		/* This chip is really losing. */
		ESPHME(("HME["));

		ESPHME(("sreg2=%02x,", esp->sreg2));
		/* Must latch fifo before reading the interrupt
		 * register else garbage ends up in the FIFO
		 * which confuses the driver utterly.
		 */
		if (!(esp->sreg2 & ESP_STAT2_FEMPTY) ||
		    (esp->sreg2 & ESP_STAT2_F1BYTE)) {
			ESPHME(("fifo_workaround]"));
			hme_fifo_read(esp);
		} else {
			ESPHME(("no_fifo_workaround]"));
		}
	}

	/* No current cmd is only valid at this point when there are
	 * commands off the bus or we are trying a reset.
	 */
	if (!SCptr && !esp->disconnected_SC && !(esp->ireg & ESP_INTR_SR)) {
		/* Panic is safe, since current_SC is null. */
		ESPLOG(("esp%d: no command in esp_handle()\n", esp->esp_id));
		panic("esp_handle: current_SC == penguin within interrupt!");
	}

	if (esp->ireg & (ESP_INTR_IC)) {
		/* Illegal command fed to ESP.  Outside of obvious
		 * software bugs that could cause this, there is
		 * a condition with esp100 where we can confuse the
		 * ESP into an erroneous illegal command interrupt
		 * because it does not scrape the FIFO properly
		 * for reselection.  See esp100_reconnect_hwbug()
		 * to see how we try very hard to avoid this.
		 */
		ESPLOG(("esp%d: invalid command\n", esp->esp_id));

		esp_dump_state(esp);

		if (SCptr != NULL) {
			/* Devices with very buggy firmware can drop BSY
			 * during a scatter list interrupt when using sync
			 * mode transfers.  We continue the transfer as
			 * expected, the target drops the bus, the ESP
			 * gets confused, and we get a illegal command
			 * interrupt because the bus is in the disconnected
			 * state now and ESP_CMD_TI is only allowed when
			 * a nexus is alive on the bus.
			 */
			ESPLOG(("esp%d: Forcing async and disabling disconnect for "
				"target %d\n", esp->esp_id, SCptr->device->id));
			SCptr->device->borken = 1; /* foo on you */
		}

		what_next = do_reset_bus;
	} else if (!(esp->ireg & ~(ESP_INTR_FDONE | ESP_INTR_BSERV | ESP_INTR_DC))) {
		if (SCptr) {
			unsigned int phase = SCptr->SCp.phase;

			if (phase & in_phases_mask) {
				what_next = esp_work_bus(esp);
			} else if (phase & in_slct_mask) {
				what_next = esp_select_complete(esp);
			} else {
				ESPLOG(("esp%d: interrupt for no good reason...\n",
					esp->esp_id));
				what_next = do_intr_end;
			}
		} else {
			ESPLOG(("esp%d: BSERV or FDONE or DC while SCptr==NULL\n",
				esp->esp_id));
			what_next = do_reset_bus;
		}
	} else if (esp->ireg & ESP_INTR_SR) {
		ESPLOG(("esp%d: SCSI bus reset interrupt\n", esp->esp_id));
		what_next = do_reset_complete;
	} else if (esp->ireg & (ESP_INTR_S | ESP_INTR_SATN)) {
		ESPLOG(("esp%d: AIEEE we have been selected by another initiator!\n",
			esp->esp_id));
		what_next = do_reset_bus;
	} else if (esp->ireg & ESP_INTR_RSEL) {
		if (SCptr == NULL) {
			/* This is ok. */
			what_next = esp_do_reconnect(esp);
		} else if (SCptr->SCp.phase & in_slct_mask) {
			/* Only selection code knows how to clean
			 * up properly.
			 */
			ESPDISC(("Reselected during selection attempt\n"));
			what_next = esp_select_complete(esp);
		} else {
			ESPLOG(("esp%d: Reselected while bus is busy\n",
				esp->esp_id));
			what_next = do_reset_bus;
		}
	}

	/* This is tier-one in our dual level SCSI state machine. */
state_machine:
	while (what_next != do_intr_end) {
		if (what_next >= do_phase_determine &&
		    what_next < do_intr_end) {
			what_next = isvc_vector[what_next](esp);
		} else {
			/* state is completely lost ;-( */
			ESPLOG(("esp%d: interrupt engine loses state, resetting bus\n",
				esp->esp_id));
			what_next = do_reset_bus;
		}
	}
}

/* Service only the ESP described by dev_id. */
static irqreturn_t esp_intr(int irq, void *dev_id, struct pt_regs *pregs)
{
	struct esp *esp = dev_id;
	unsigned long flags;

	spin_lock_irqsave(esp->ehost->host_lock, flags);
	if (ESP_IRQ_P(esp->dregs)) {
		ESP_INTSOFF(esp->dregs);

		ESPIRQ(("I[%d:%d](", smp_processor_id(), esp->esp_id));
		esp_handle(esp);
		ESPIRQ((")"));

		ESP_INTSON(esp->dregs);
	}
	spin_unlock_irqrestore(esp->ehost->host_lock, flags);

	return IRQ_HANDLED;
}

static int esp_slave_alloc(struct scsi_device *SDptr)
{
	struct esp_device *esp_dev =
		kmalloc(sizeof(struct esp_device), GFP_ATOMIC);

	if (!esp_dev)
		return -ENOMEM;
	memset(esp_dev, 0, sizeof(struct esp_device));
	SDptr->hostdata = esp_dev;
	return 0;
}

static void esp_slave_destroy(struct scsi_device *SDptr)
{
	struct esp *esp = (struct esp *) SDptr->host->hostdata;

	esp->targets_present &= ~(1 << SDptr->id);
	kfree(SDptr->hostdata);
	SDptr->hostdata = NULL;
}

4325 4326 4327 4328
static struct scsi_host_template esp_template = {
	.module			= THIS_MODULE,
	.name			= "esp",
	.info			= esp_info,
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	.slave_alloc		= esp_slave_alloc,
	.slave_destroy		= esp_slave_destroy,
	.queuecommand		= esp_queue,
	.eh_abort_handler	= esp_abort,
	.eh_bus_reset_handler	= esp_reset,
	.can_queue		= 7,
	.this_id		= 7,
	.sg_tablesize		= SG_ALL,
	.cmd_per_lun		= 1,
	.use_clustering		= ENABLE_CLUSTERING,
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	.proc_name		= "esp",
	.proc_info		= esp_proc_info,
};

#ifndef CONFIG_SUN4
static struct of_device_id esp_match[] = {
	{
		.name = "SUNW,esp",
		.data = &esp_template,
	},
	{
		.name = "SUNW,fas",
		.data = &esp_template,
	},
	{
		.name = "esp",
		.data = &esp_template,
	},
	{},
};
MODULE_DEVICE_TABLE(of, esp_match);

static struct of_platform_driver esp_sbus_driver = {
	.name		= "esp",
	.match_table	= esp_match,
	.probe		= esp_sbus_probe,
	.remove		= __devexit_p(esp_sbus_remove),
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};
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#endif

static int __init esp_init(void)
{
#ifdef CONFIG_SUN4
	return esp_sun4_probe(&esp_template);
#else
	return of_register_driver(&esp_sbus_driver, &sbus_bus_type);
#endif
}
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static void __exit esp_exit(void)
{
#ifdef CONFIG_SUN4
	esp_sun4_remove();
#else
	of_unregister_driver(&esp_sbus_driver);
#endif
}
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MODULE_DESCRIPTION("ESP Sun SCSI driver");
MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
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MODULE_LICENSE("GPL");
4390
MODULE_VERSION(DRV_VERSION);
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module_init(esp_init);
module_exit(esp_exit);