acornscsi.c

linux-2.6.15.6

    "reset - advanced mode",	/* 01 */

    /* 2 */
    "sel",			/* 11 */
    "sel+xfer", 		/* 16 */
    "data-out", 		/* 18 */
    "data-in",			/* 19 */
    "cmd",			/* 1A */
    "stat",			/* 1B */
    "??-out",			/* 1C */
    "??-in",			/* 1D */
    "msg-out",			/* 1E */
    "msg-in",			/* 1F */

    /* 12 */
    "/ACK asserted",		/* 20 */
    "save-data-ptr",		/* 21 */
    "{re}sel",			/* 22 */

    /* 15 */
    "inv cmd",			/* 40 */
    "unexpected disconnect",	/* 41 */
    "sel timeout",		/* 42 */
    "P err",			/* 43 */
    "P err+ATN",		/* 44 */
    "bad status byte",		/* 47 */

    /* 21 */
    "resel, no id",		/* 80 */
    "resel",			/* 81 */
    "discon",			/* 85 */
};

static
void print_scsi_status(unsigned int ssr)
{
    if (acornscsi_map[ssr] != -1)
	printk("%s:%s",
		acornscsi_interrupttype[(ssr >> 4)],
		acornscsi_interruptcode[acornscsi_map[ssr]]);
    else
	printk("%X:%X", ssr >> 4, ssr & 0x0f);    
}    
#endif

static
void print_sbic_status(int asr, int ssr, int cmdphase)
{
#ifdef CONFIG_ACORNSCSI_CONSTANTS
    printk("sbic: %c%c%c%c%c%c ",
	    asr & ASR_INT ? 'I' : 'i',
	    asr & ASR_LCI ? 'L' : 'l',
	    asr & ASR_BSY ? 'B' : 'b',
	    asr & ASR_CIP ? 'C' : 'c',
	    asr & ASR_PE  ? 'P' : 'p',
	    asr & ASR_DBR ? 'D' : 'd');
    printk("scsi: ");
    print_scsi_status(ssr);
    printk(" ph %02X\n", cmdphase);
#else
    printk("sbic: %02X scsi: %X:%X ph: %02X\n",
	    asr, (ssr & 0xf0)>>4, ssr & 0x0f, cmdphase);
#endif
}

static void
acornscsi_dumplogline(AS_Host *host, int target, int line)
{
	unsigned long prev;
	signed int ptr;

	ptr = host->status_ptr[target] - STATUS_BUFFER_TO_PRINT;
	if (ptr < 0)
		ptr += STATUS_BUFFER_SIZE;

	printk("%c: %3s:", target == 8 ? 'H' : '0' + target,
		line == 0 ? "ph" : line == 1 ? "ssr" : "int");

	prev = host->status[target][ptr].when;

	for (; ptr != host->status_ptr[target]; ptr = (ptr + 1) & (STATUS_BUFFER_SIZE - 1)) {
		unsigned long time_diff;

		if (!host->status[target][ptr].when)
			continue;

		switch (line) {
		case 0:
			printk("%c%02X", host->status[target][ptr].irq ? '-' : ' ',
					 host->status[target][ptr].ph);
			break;

		case 1:
			printk(" %02X", host->status[target][ptr].ssr);
			break;

		case 2:
			time_diff = host->status[target][ptr].when - prev;
			prev = host->status[target][ptr].when;
			if (time_diff == 0)
				printk("==^");
			else if (time_diff >= 100)
				printk("   ");
			else
				printk(" %02ld", time_diff);
			break;
		}
	}

	printk("\n");
}

static
void acornscsi_dumplog(AS_Host *host, int target)
{
    do {
	acornscsi_dumplogline(host, target, 0);
	acornscsi_dumplogline(host, target, 1);
	acornscsi_dumplogline(host, target, 2);

	if (target == 8)
	    break;

	target = 8;
    } while (1);
}

static
char acornscsi_target(AS_Host *host)
{
	if (host->SCpnt)
		return '0' + host->SCpnt->device->id;
	return 'H';
}

/*
 * Prototype: cmdtype_t acornscsi_cmdtype(int command)
 * Purpose  : differentiate READ from WRITE from other commands
 * Params   : command - command to interpret
 * Returns  : CMD_READ	- command reads data,
 *	      CMD_WRITE - command writes data,
 *	      CMD_MISC	- everything else
 */
static inline
cmdtype_t acornscsi_cmdtype(int command)
{
    switch (command) {
    case WRITE_6:  case WRITE_10:  case WRITE_12:
	return CMD_WRITE;
    case READ_6:   case READ_10:   case READ_12:
	return CMD_READ;
    default:
	return CMD_MISC;
    }
}

/*
 * Prototype: int acornscsi_datadirection(int command)
 * Purpose  : differentiate between commands that have a DATA IN phase
 *	      and a DATA OUT phase
 * Params   : command - command to interpret
 * Returns  : DATADIR_OUT - data out phase expected
 *	      DATADIR_IN  - data in phase expected
 */
static
datadir_t acornscsi_datadirection(int command)
{
    switch (command) {
    case CHANGE_DEFINITION:	case COMPARE:		case COPY:
    case COPY_VERIFY:		case LOG_SELECT:	case MODE_SELECT:
    case MODE_SELECT_10:	case SEND_DIAGNOSTIC:	case WRITE_BUFFER:
    case FORMAT_UNIT:		case REASSIGN_BLOCKS:	case RESERVE:
    case SEARCH_EQUAL:		case SEARCH_HIGH:	case SEARCH_LOW:
    case WRITE_6:		case WRITE_10:		case WRITE_VERIFY:
    case UPDATE_BLOCK:		case WRITE_LONG:	case WRITE_SAME:
    case SEARCH_HIGH_12:	case SEARCH_EQUAL_12:	case SEARCH_LOW_12:
    case WRITE_12:		case WRITE_VERIFY_12:	case SET_WINDOW:
    case MEDIUM_SCAN:		case SEND_VOLUME_TAG:	case 0xea:
	return DATADIR_OUT;
    default:
	return DATADIR_IN;
    }
}

/*
 * Purpose  : provide values for synchronous transfers with 33C93.
 * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
 *	Modified by Russell King for 8MHz WD33C93A
 */
static struct sync_xfer_tbl {
    unsigned int period_ns;
    unsigned char reg_value;
} sync_xfer_table[] = {
    {	1, 0x20 },    { 249, 0x20 },	{ 374, 0x30 },
    { 499, 0x40 },    { 624, 0x50 },	{ 749, 0x60 },
    { 874, 0x70 },    { 999, 0x00 },	{   0,	  0 }
};

/*
 * Prototype: int acornscsi_getperiod(unsigned char syncxfer)
 * Purpose  : period for the synchronous transfer setting
 * Params   : syncxfer SYNCXFER register value
 * Returns  : period in ns.
 */
static
int acornscsi_getperiod(unsigned char syncxfer)
{
    int i;

    syncxfer &= 0xf0;
    if (syncxfer == 0x10)
	syncxfer = 0;

    for (i = 1; sync_xfer_table[i].period_ns; i++)
	if (syncxfer == sync_xfer_table[i].reg_value)
	    return sync_xfer_table[i].period_ns;
    return 0;
}

/*
 * Prototype: int round_period(unsigned int period)
 * Purpose  : return index into above table for a required REQ period
 * Params   : period - time (ns) for REQ
 * Returns  : table index
 * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
 */
static inline
int round_period(unsigned int period)
{
    int i;

    for (i = 1; sync_xfer_table[i].period_ns; i++) {
	if ((period <= sync_xfer_table[i].period_ns) &&
	    (period > sync_xfer_table[i - 1].period_ns))
	    return i;
    }
    return 7;
}

/*
 * Prototype: unsigned char calc_sync_xfer(unsigned int period, unsigned int offset)
 * Purpose  : calculate value for 33c93s SYNC register
 * Params   : period - time (ns) for REQ
 *	      offset - offset in bytes between REQ/ACK
 * Returns  : value for SYNC register
 * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
 */
static
unsigned char calc_sync_xfer(unsigned int period, unsigned int offset)
{
    return sync_xfer_table[round_period(period)].reg_value |
		((offset < SDTR_SIZE) ? offset : SDTR_SIZE);
}

/* ====================================================================================
 * Command functions
 */
/*
 * Function: acornscsi_kick(AS_Host *host)
 * Purpose : kick next command to interface
 * Params  : host - host to send command to
 * Returns : INTR_IDLE if idle, otherwise INTR_PROCESSING
 * Notes   : interrupts are always disabled!
 */
static
intr_ret_t acornscsi_kick(AS_Host *host)
{
    int from_queue = 0;
    Scsi_Cmnd *SCpnt;

    /* first check to see if a command is waiting to be executed */
    SCpnt = host->origSCpnt;
    host->origSCpnt = NULL;

    /* retrieve next command */
    if (!SCpnt) {
	SCpnt = queue_remove_exclude(&host->queues.issue, host->busyluns);
	if (!SCpnt)
	    return INTR_IDLE;

	from_queue = 1;
    }

    if (host->scsi.disconnectable && host->SCpnt) {
	queue_add_cmd_tail(&host->queues.disconnected, host->SCpnt);
	host->scsi.disconnectable = 0;
#if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
	DBG(host->SCpnt, printk("scsi%d.%c: moved command to disconnected queue\n",
		host->host->host_no, acornscsi_target(host)));
#endif
	host->SCpnt = NULL;
    }

    /*
     * If we have an interrupt pending, then we may have been reselected.
     * In this case, we don't want to write to the registers
     */
    if (!(sbic_arm_read(host->scsi.io_port, SBIC_ASR) & (ASR_INT|ASR_BSY|ASR_CIP))) {
	sbic_arm_write(host->scsi.io_port, SBIC_DESTID, SCpnt->device->id);
	sbic_arm_write(host->scsi.io_port, SBIC_CMND, CMND_SELWITHATN);
    }

    /*
     * claim host busy - all of these must happen atomically wrt
     * our interrupt routine.  Failure means command loss.
     */
    host->scsi.phase = PHASE_CONNECTING;
    host->SCpnt = SCpnt;
    host->scsi.SCp = SCpnt->SCp;
    host->dma.xfer_setup = 0;
    host->dma.xfer_required = 0;
    host->dma.xfer_done = 0;

#if (DEBUG & (DEBUG_ABORT|DEBUG_CONNECT))
    DBG(SCpnt,printk("scsi%d.%c: starting cmd %02X\n",
	    host->host->host_no, '0' + SCpnt->device->id,
	    SCpnt->cmnd[0]));
#endif

    if (from_queue) {
#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
	/*
	 * tagged queueing - allocate a new tag to this command
	 */
	if (SCpnt->device->simple_tags) {
	    SCpnt->device->current_tag += 1;
	    if (SCpnt->device->current_tag == 0)
		SCpnt->device->current_tag = 1;
	    SCpnt->tag = SCpnt->device->current_tag;
	} else
#endif
	    set_bit(SCpnt->device->id * 8 + SCpnt->device->lun, host->busyluns);

	host->stats.removes += 1;

	switch (acornscsi_cmdtype(SCpnt->cmnd[0])) {
	case CMD_WRITE:
	    host->stats.writes += 1;
	    break;
	case CMD_READ:
	    host->stats.reads += 1;
	    break;
	case CMD_MISC:
	    host->stats.miscs += 1;
	    break;
	}
    }

    return INTR_PROCESSING;
}    

/*
 * Function: void acornscsi_done(AS_Host *host, Scsi_Cmnd **SCpntp, unsigned int result)
 * Purpose : complete processing for command
 * Params  : host   - interface that completed
 *	     result - driver byte of result
 */
static
void acornscsi_done(AS_Host *host, Scsi_Cmnd **SCpntp, unsigned int result)
{
    Scsi_Cmnd *SCpnt = *SCpntp;

    /* clean up */
    sbic_arm_write(host->scsi.io_port, SBIC_SOURCEID, SOURCEID_ER | SOURCEID_DSP);

    host->stats.fins += 1;

    if (SCpnt) {
	*SCpntp = NULL;

	acornscsi_dma_cleanup(host);

	SCpnt->result = result << 16 | host->scsi.SCp.Message << 8 | host->scsi.SCp.Status;

	/*
	 * In theory, this should not happen.  In practice, it seems to.
	 * Only trigger an error if the device attempts to report all happy
	 * but with untransferred buffers...  If we don't do something, then
	 * data loss will occur.  Should we check SCpnt->underflow here?
	 * It doesn't appear to be set to something meaningful by the higher
	 * levels all the time.
	 */
	if (result == DID_OK) {
		int xfer_warn = 0;

		if (SCpnt->underflow == 0) {
			if (host->scsi.SCp.ptr &&
			    acornscsi_cmdtype(SCpnt->cmnd[0]) != CMD_MISC)
				xfer_warn = 1;
		} else {
			if (host->scsi.SCp.scsi_xferred < SCpnt->underflow ||
			    host->scsi.SCp.scsi_xferred != host->dma.transferred)
				xfer_warn = 1;
		}

		/* ANSI standard says: (SCSI-2 Rev 10c Sect 5.6.6)
		 *  Targets which break data transfers into multiple
		 *  connections shall end each successful connection
		 *  (except possibly the last) with a SAVE DATA
		 *  POINTER - DISCONNECT message sequence.
		 *
		 * This makes it difficult to ensure that a transfer has
		 * completed.  If we reach the end of a transfer during
		 * the command, then we can only have finished the transfer.
		 * therefore, if we seem to have some data remaining, this
		 * is not a problem.
		 */
		if (host->dma.xfer_done)
			xfer_warn = 0;

		if (xfer_warn) {
		    switch (status_byte(SCpnt->result)) {
		    case CHECK_CONDITION:
		    case COMMAND_TERMINATED:
		    case BUSY:
		    case QUEUE_FULL:
		    case RESERVATION_CONFLICT:
			break;

		    default:
			printk(KERN_ERR "scsi%d.H: incomplete data transfer detected: result=%08X command=",
				host->host->host_no, SCpnt->result);
			__scsi_print_command(SCpnt->cmnd);
			acornscsi_dumpdma(host, "done");
		 	acornscsi_dumplog(host, SCpnt->device->id);
			SCpnt->result &= 0xffff;
			SCpnt->result |= DID_ERROR << 16;
		    }
		}
	}

	if (!SCpnt->scsi_done)
	    panic("scsi%d.H: null scsi_done function in acornscsi_done", host->host->host_no);

	clear_bit(SCpnt->device->id * 8 + SCpnt->device->lun, host->busyluns);

	SCpnt->scsi_done(SCpnt);
    } else
	printk("scsi%d: null command in acornscsi_done", host->host->host_no);

    host->scsi.phase = PHASE_IDLE;
}

/* ====================================================================================
 * DMA routines
 */
/*