acornscsi.c

h内核

 * 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 == 0 && next_SCp(SCp) == 0)
	host->dma.xfer_done = 1;
}

/*
 * 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;

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

	__acornscsi_out(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);
}

/* =========================================================================================
 * On-board DMA routines
 */
#ifdef USE_DMAC
/*
 * Prototype: void acornscsi_dmastop(AS_Host *host)
 * Purpose  : stop all DMA
 * Params   : host - host on which to stop DMA
 * Notes    : This is called when leaving DATA IN/OUT phase,
 *	      or when interface is RESET
 */
static inline
void acornscsi_dma_stop(AS_Host *host)
{
    dmac_write(host->dma.io_port, DMAC_MASKREG, MASK_ON);
    dmac_clearintr(host->dma.io_intr_clear);

#if (DEBUG & DEBUG_DMA)
    DBG(host->SCpnt, acornscsi_dumpdma(host, "stop"));
#endif
}

/*
 * Function: void acornscsi_dma_setup(AS_Host *host, dmadir_t direction)
 * Purpose : setup DMA controller for data transfer
 * Params  : host - host to setup
 *	     direction - data transfer direction
 * Notes   : This is called when entering DATA I/O phase, not
 *	     while we're in a DATA I/O phase
 */
static
void acornscsi_dma_setup(AS_Host *host, dmadir_t direction)
{
    unsigned int address, length, mode;

    host->dma.direction = direction;

    dmac_write(host->dma.io_port, DMAC_MASKREG, MASK_ON);

    if (direction == DMA_OUT) {
#if (DEBUG & DEBUG_NO_WRITE)
	if (NO_WRITE & (1 << host->SCpnt->device->id)) {
	    printk(KERN_CRIT "scsi%d.%c: I can't handle DMA_OUT!\n",
		    host->host->host_no, acornscsi_target(host));
	    return;
	}
#endif
	mode = DMAC_WRITE;
    } else
	mode = DMAC_READ;

    /*
     * Allocate some buffer space, limited to half the buffer size
     */
    length = min_t(unsigned int, host->scsi.SCp.this_residual, DMAC_BUFFER_SIZE / 2);
    if (length) {
	host->dma.start_addr = address = host->dma.free_addr;
	host->dma.free_addr = (host->dma.free_addr + length) &
				(DMAC_BUFFER_SIZE - 1);

	/*
	 * Transfer data to DMA memory
	 */
	if (direction == DMA_OUT)
	    acornscsi_data_write(host, host->scsi.SCp.ptr, host->dma.start_addr,
				length);

	length -= 1;
	dmac_write(host->dma.io_port, DMAC_TXCNTLO, length);
	dmac_write(host->dma.io_port, DMAC_TXCNTHI, length >> 8);
	dmac_write(host->dma.io_port, DMAC_TXADRLO, address);
	dmac_write(host->dma.io_port, DMAC_TXADRMD, address >> 8);
	dmac_write(host->dma.io_port, DMAC_TXADRHI, 0);
	dmac_write(host->dma.io_port, DMAC_MODECON, mode);
	dmac_write(host->dma.io_port, DMAC_MASKREG, MASK_OFF);

#if (DEBUG & DEBUG_DMA)
	DBG(host->SCpnt, acornscsi_dumpdma(host, "strt"));
#endif
	host->dma.xfer_setup = 1;
    }
}

/*
 * Function: void acornscsi_dma_cleanup(AS_Host *host)
 * Purpose : ensure that all DMA transfers are up-to-date & host->scsi.SCp is correct
 * Params  : host - host to finish
 * Notes   : This is called when a command is:
 *		terminating, RESTORE_POINTERS, SAVE_POINTERS, DISCONECT
 *	   : This must not return until all transfers are completed.
 */
static
void acornscsi_dma_cleanup(AS_Host *host)
{
    dmac_write(host->dma.io_port, DMAC_MASKREG, MASK_ON);
    dmac_clearintr(host->dma.io_intr_clear);

    /*
     * Check for a pending transfer
     */
    if (host->dma.xfer_required) {
	host->dma.xfer_required = 0;
	if (host->dma.direction == DMA_IN)
	    acornscsi_data_read(host, host->dma.xfer_ptr,
				 host->dma.xfer_start, host->dma.xfer_length);
    }

    /*
     * Has a transfer been setup?
     */
    if (host->dma.xfer_setup) {
	unsigned int transferred;

	host->dma.xfer_setup = 0;

#if (DEBUG & DEBUG_DMA)
	DBG(host->SCpnt, acornscsi_dumpdma(host, "cupi"));
#endif

	/*
	 * Calculate number of bytes transferred from DMA.
	 */
	transferred = dmac_address(host->dma.io_port) - host->dma.start_addr;
	host->dma.transferred += transferred;

	if (host->dma.direction == DMA_IN)
	    acornscsi_data_read(host, host->scsi.SCp.ptr,
				 host->dma.start_addr, transferred);

	/*
	 * Update SCSI pointers
	 */
	acornscsi_data_updateptr(host, &host->scsi.SCp, transferred);
#if (DEBUG & DEBUG_DMA)
	DBG(host->SCpnt, acornscsi_dumpdma(host, "cupo"));
#endif
    }
}

/*
 * Function: void acornscsi_dmacintr(AS_Host *host)
 * Purpose : handle interrupts from DMAC device
 * Params  : host - host to process
 * Notes   : If reading, we schedule the read to main memory &
 *	     allow the transfer to continue.
 *	   : If writing, we fill the onboard DMA memory from main
 *	     memory.
 *	   : Called whenever DMAC finished it's current transfer.
 */
static
void acornscsi_dma_intr(AS_Host *host)
{
    unsigned int address, length, transferred;

#if (DEBUG & DEBUG_DMA)
    DBG(host->SCpnt, acornscsi_dumpdma(host, "inti"));
#endif

    dmac_write(host->dma.io_port, DMAC_MASKREG, MASK_ON);
    dmac_clearintr(host->dma.io_intr_clear);

    /*
     * Calculate amount transferred via DMA
     */
    transferred = dmac_address(host->dma.io_port) - host->dma.start_addr;
    host->dma.transferred += transferred;

    /*
     * Schedule DMA transfer off board
     */
    if (host->dma.direction == DMA_IN) {
	host->dma.xfer_start = host->dma.start_addr;
	host->dma.xfer_length = transferred;
	host->dma.xfer_ptr = host->scsi.SCp.ptr;
	host->dma.xfer_required = 1;
    }

    acornscsi_data_updateptr(host, &host->scsi.SCp, transferred);

    /*
     * Allocate some buffer space, limited to half the on-board RAM size
     */
    length = min_t(unsigned int, host->scsi.SCp.this_residual, DMAC_BUFFER_SIZE / 2);
    if (length) {
	host->dma.start_addr = address = host->dma.free_addr;
	host->dma.free_addr = (host->dma.free_addr + length) &
				(DMAC_BUFFER_SIZE - 1);

	/*
	 * Transfer data to DMA memory
	 */
	if (host->dma.direction == DMA_OUT)
	    acornscsi_data_write(host, host->scsi.SCp.ptr, host->dma.start_addr,
				length);

	length -= 1;
	dmac_write(host->dma.io_port, DMAC_TXCNTLO, length);
	dmac_write(host->dma.io_port, DMAC_TXCNTHI, length >> 8);
	dmac_write(host->dma.io_port, DMAC_TXADRLO, address);
	dmac_write(host->dma.io_port, DMAC_TXADRMD, address >> 8);
	dmac_write(host->dma.io_port, DMAC_TXADRHI, 0);
	dmac_write(host->dma.io_port, DMAC_MASKREG, MASK_OFF);

#if (DEBUG & DEBUG_DMA)
	DBG(host->SCpnt, acornscsi_dumpdma(host, "into"));
#endif
    } else {
	host->dma.xfer_setup = 0;
#if 0
	/*
	 * If the interface still wants more, then this is an error.
	 * We give it another byte, but we also attempt to raise an
	 * attention condition.  We continue giving one byte until
	 * the device recognises the attention.
	 */
	if (dmac_read(host->dma.io_port, DMAC_STATUS) & STATUS_RQ0) {
	    acornscsi_abortcmd(host, host->SCpnt->tag);

	    dmac_write(host->dma.io_port, DMAC_TXCNTLO, 0);
	    dmac_write(host->dma.io_port, DMAC_TXCNTHI, 0);
	    dmac_write(host->dma.io_port, DMAC_TXADRLO, 0);
	    dmac_write(host->dma.io_port, DMAC_TXADRMD, 0);
	    dmac_write(host->dma.io_port, DMAC_TXADRHI, 0);
	    dmac_write(host->dma.io_port, DMAC_MASKREG, MASK_OFF);
	}
#endif
    }
}

/*
 * Function: void acornscsi_dma_xfer(AS_Host *host)
 * Purpose : transfer data between AcornSCSI and memory
 * Params  : host - host to process
 */
static
void acornscsi_dma_xfer(AS_Host *host)
{
    host->dma.xfer_required = 0;

    if (host->dma.direction == DMA_IN)
	acornscsi_data_read(host, host->dma.xfer_ptr,
				host->dma.xfer_start, host->dma.xfer_length);
}

/*
 * Function: void acornscsi_dma_adjust(AS_Host *host)
 * Purpose : adjust DMA pointers & count for bytes transferred to
 *	     SBIC but not SCSI bus.
 * Params  : host - host to adjust DMA count for
 */
static
void acornscsi_dma_adjust(AS_Host *host)
{
    if (host->dma.xfer_setup) {
	signed long transferred;
#if (DEBUG & (DEBUG_DMA|DEBUG_WRITE))
	DBG(host->SCpnt, acornscsi_dumpdma(host, "adji"));
#endif
	/*
	 * Calculate correct DMA address - DMA is ahead of SCSI bus while
	 * writing.
	 *  host->scsi.SCp.scsi_xferred is the number of bytes
	 *  actually transferred to/from the SCSI bus.
	 *  host->dma.transferred is the number of bytes transferred
	 *  over DMA since host->dma.start_addr was last set.
	 *
	 * real_dma_addr = host->dma.start_addr + host->scsi.SCp.scsi_xferred
	 *		   - host->dma.transferred
	 */
	transferred = host->scsi.SCp.scsi_xferred - host->dma.transferred;
	if (transferred < 0)
	    printk("scsi%d.%c: Ack! DMA write correction %ld < 0!\n",
		    host->host->host_no, acornscsi_target(host), transferred);
	else if (transferred == 0)
	    host->dma.xfer_setup = 0;
	else {
	    transferred += host->dma.start_addr;
	    dmac_write(host->dma.io_port, DMAC_TXADRLO, transferred);
	    dmac_write(host->dma.io_port, DMAC_TXADRMD, transferred >> 8);
	    dmac_write(host->dma.io_port, DMAC_TXADRHI, transferred >> 16);
#if (DEBUG & (DEBUG_DMA|DEBUG_WRITE))
	    DBG(host->SCpnt, acornscsi_dumpdma(host, "adjo"));
#endif
	}
    }
}
#endif

/* =========================================================================================
 * Data I/O
 */
static int
acornscsi_write_pio(AS_Host *host, char *bytes, int *ptr, int len, unsigned int max_timeout)
{
	unsigned int asr, timeout = max_timeout;
	int my_ptr = *ptr;

	while (my_ptr < len) {
		asr = sbic_arm_read(host->scsi.io_port, SBIC_ASR);

		if (asr & ASR_DBR) {
			timeout = max_timeout;

			sbic_arm_write(host->scsi.io_port, SBIC_DATA, bytes[my_ptr++]);
		} else if (asr & ASR_INT)
			break;
		else if (--timeout == 0)
			break;
		udelay(1);
	}

	*ptr = my_ptr;

	return (timeout == 0) ? -1 : 0;
}

/*
 * Function: void acornscsi_sendcommand(AS_Host *host)
 * Purpose : send a command to a target
 * Params  : host - host which is connected to target
 */
static void
acornscsi_sendcommand(AS_Host *host)
{
    Scsi_Cmnd *SCpnt = host->SCpnt;

    sbic_arm_write(host->scsi.io_port, SBIC_TRANSCNTH, 0);
    sbic_arm_writenext(host->scsi.io_port, 0);
    sbic_arm_writenext(host->scsi.io_port, SCpnt->cmd_len - host->scsi.SCp.sent_command);

    acornscsi_sbic_issuecmd(host, CMND_XFERINFO);

    if (acornscsi_write_pio(host, SCpnt->cmnd,
	(int *)&host->scsi.SCp.sent_command, SCpnt->cmd_len, 1000000))
	printk("scsi%d: timeout while sending command\n", host->host->host_no);

    host->scsi.phase = PHASE_COMMAND;
}

static
void acornscsi_sendmessage(AS_Host *host)
{
    unsigned int message_length = msgqueue_msglength(&host->scsi.msgs);
    unsigned int msgnr;
    struct message *msg;