acornscsi.c.2

arm平台上的uclinux系统全部源代码

{
    unsigned int prev;
    do {
	signed int statptr;

	printk ("%c:", target == 8 ? 'H' : ('0' + target));
	statptr = status_ptr[target] - 10;

	if (statptr < 0)
	    statptr += 16;

	prev = status[target][statptr].when;

	for (; statptr != status_ptr[target]; statptr = (statptr + 1) & 15) {
	    if (status[target][statptr].when) {
#ifdef CONFIG_ACORNSCSI_CONSTANTS
		printk ("%c%02X:S=",
			status[target][statptr].irq ? '-' : ' ',
			status[target][statptr].ph);
		print_scsi_status (status[target][statptr].ssr);
#else
		printk ("%c%02X:%02X",
			status[target][statptr].irq ? '-' : ' ',
			status[target][statptr].ph,
			status[target][statptr].ssr);
#endif
		printk ("+%02ld",
			(status[target][statptr].when - prev) < 100 ?
				(status[target][statptr].when - prev) : 99);
		prev = status[target][statptr].when;
	    }
	}
	printk ("\n");
	if (target == 8)
	    break;
	target = 8;
    } while (1);
}

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

static
void acornscsi_dumpdma (AS_Host *host, char *where)
{
	unsigned int mode, addr, len;

	mode = dmac_read (host->dma.io_port, MODECON);
	addr = dmac_address (host->dma.io_port);
	len  = dmac_read (host->dma.io_port, TXCNTHI) << 8 |
	       dmac_read (host->dma.io_port, TXCNTLO);

	printk ("scsi%d: %s: DMAC %02x @%06x+%04x msk %02x, ",
		host->host->host_no, where,
		mode, addr, (len + 1) & 0xffff,
		dmac_read (host->dma.io_port, MASKREG));

	printk ("DMA @%06x, ", host->dma.start_addr);
	printk ("BH @%p +%04x, ", host->scsi.SCp.ptr,
		host->scsi.SCp.this_residual);
	printk ("DT @+%04x ST @+%04x", host->dma.transferred,
		host->scsi.SCp.have_data_in);
	printk ("\n");
}

/*
 * 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, ASR) & (ASR_INT|ASR_BSY|ASR_CIP))) {
	sbic_arm_write (host->scsi.io_port, DESTID, SCpnt->target);
	sbic_arm_write (host->scsi.io_port, 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;

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

    if (from_queue) {
#ifdef SCSI2_TAG
	/*
	 * tagged queueing - allocate a new tag to this command
	 */
	if (SCpnt->device->tagged_queue) {
	    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->target * 8 + SCpnt->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, 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 (host->scsi.SCp.ptr && result == DID_OK &&
		acornscsi_cmdtype (SCpnt->cmnd[0]) != CMD_MISC) {
	    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);
		print_command (SCpnt->cmnd);
		acornscsi_dumpdma (host, "done");
	 	acornscsi_dumplog (host, SCpnt->target);
		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->target * 8 + SCpnt->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
 */
/*
 * Purpose  : update SCSI Data Pointer
 * Notes    : this will only be one SG entry or less
 */
static
void acornscsi_data_updateptr (AS_Host *host, Scsi_Pointer *SCp, unsigned int length)
{
    SCp->ptr += length;
    SCp->this_residual -= length;

    if (!SCp->this_residual) {
	if (SCp->buffers_residual) {
	    SCp->buffer++;
	    SCp->buffers_residual--;
	    SCp->ptr = (char *)SCp->buffer->address;
	    SCp->this_residual = SCp->buffer->length;
	} else
	    SCp->ptr = NULL;
    }
}

/*
 * Prototype: void acornscsi_data_read (AS_Host *host, char *ptr,
 *				unsigned int start_addr, unsigned int length)
 * Purpose  : read data from DMA RAM
 * Params   : host - host to transfer from
 *	      ptr  - DRAM address
 *	      start_addr - host mem address
 *	      length - number of bytes to transfer
 * Notes    : this will only be one SG entry or less
 */
static
void acornscsi_data_read (AS_Host *host, char *ptr,
				 unsigned int start_addr, unsigned int length)
{
    extern void __acornscsi_in (int port, char *buf, int len);
    unsigned int page, offset, len = length;

    page = (start_addr >> 12);
    offset = start_addr & ((1 << 12) - 1);

    outb ((page & 0x3f) | host->card.page_reg, host->card.io_page);

    while (len > 0) {
	unsigned int this_len;

	if (len + offset > (1 << 12))
	    this_len = (1 << 12) - offset;
	else
	    this_len = len;

	__acornscsi_in (host->card.io_ram + (offset << 1), ptr, this_len);

	offset += this_len;
	ptr += this_len;
	len -= this_len;

	if (offset == (1 << 12)) {
	    offset = 0;
	    page ++;
	    outb ((page & 0x3f) | host->card.page_reg, host->card.io_page);
	}
    }
    outb (host->card.page_reg, host->card.io_page);
}

/*
 * Prototype: void acornscsi_data_write (AS_Host *host, char *ptr,
 *				unsigned int start_addr, unsigned int length)
 * Purpose  : write data to DMA RAM
 * Params   : host - host to transfer from
 *	      ptr  - DRAM address
 *	      start_addr - host mem address
 *	      length - number of bytes to transfer
 * Notes    : this will only be one SG entry or less
 */
static
void acornscsi_data_write (AS_Host *host, char *ptr,
				 unsigned int start_addr, unsigned int length)
{
    extern void __acornscsi_out (int port, char *buf, int len);
    unsigned int page, offset, len = length;

    page = (start_addr >> 12);
    offset = start_addr & ((1 << 12) - 1);

    outb ((page & 0x3f) | host->card.page_reg, host->card.io_page);

    while (len > 0) {
	unsigned int this_len;