am53c974.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

hostdata->disconnecting = 0;
hostdata->dma_busy = 0;
hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
AM53C974_write_8(CMDREG, CMDREG_CFIFO);
DEB(printk("disconnect; issue_queue: 0x%lx, disconnected_queue: 0x%lx\n", 
       (long)hostdata->issue_queue, (long)hostdata->disconnected_queue));
cmd->scsi_done(cmd);

if (!hostdata->selecting) {
   AM53C974_set_async(instance, cmd->target); 
   AM53C974_write_8(CMDREG, CMDREG_ESR); } /* allow reselect */
return;

EXIT_UNFINISHED:
hostdata->msgout[0] = NOP;
hostdata->sel_cmd = NULL;
hostdata->connected = NULL;
hostdata->aborted = 0;
hostdata->selecting = 0;
hostdata->disconnecting = 0;
hostdata->dma_busy = 0;
DEB(printk("disconnect; issue_queue: 0x%lx, disconnected_queue: 0x%lx\n", 
       (long)hostdata->issue_queue, (long)hostdata->disconnected_queue));
if (!hostdata->selecting) {
   AM53C974_set_async(instance, cmd->target); 
   AM53C974_write_8(CMDREG, CMDREG_ESR); } /* allow reselect */
return;
}

/************************************************************************** 
* Function : int AM53C974_sync_neg(struct Scsi_Host *instance, int target, unsigned char *msg)
*
* Purpose : setup message string for sync. negotiation
*
* Inputs : instance -- which AM53C974
*          target -- which SCSI target to deal with
*          msg -- input message string
* 
* Returns : 0 if parameters accepted or 1 if not accepted
*
* Side effects: hostdata is changed
*
* Note: we assume here that fastclk is enabled
**************************************************************************/
static int AM53C974_sync_neg(struct Scsi_Host *instance, int target, unsigned char *msg) 
{
AM53C974_local_declare(); 
struct AM53C974_hostdata *hostdata = (struct AM53C974_hostdata *)instance->hostdata;
int                      period, offset, i, rate, rate_rem;
AM53C974_setio(instance);

period = (DEF_CLK * msg[3] * 8 + 1000) / 2000;
if (period < MIN_PERIOD) {
    period = MIN_PERIOD;
    hostdata->msgout[3] = period / 4; }
   else
    if (period > MAX_PERIOD) {
       period = MAX_PERIOD;
       hostdata->msgout[3] = period / 4; }
      else
       hostdata->msgout[3] = msg[3];
offset = msg[4]; 
if (offset > MAX_OFFSET) offset = MAX_OFFSET;
hostdata->msgout[4] = offset;
hostdata->sync_per[target] = period;
hostdata->sync_off[target] = offset;
for (i = 0; i < 3; i++) hostdata->msgout[i] = msg[i];
if ((hostdata->msgout[3] != msg[3]) || (msg[4] != offset)) return(1);

rate = DEF_CLK / period;
rate_rem = 10 * (DEF_CLK - period * rate) / period;

if (offset)
   printk("\ntarget %d: rate=%d.%d Mhz, synchronous, sync offset=%d bytes\n",
          target, rate, rate_rem, offset);
  else
   printk("\ntarget %d: rate=%d.%d Mhz, asynchronous\n", target, rate, rate_rem);

return(0);
}

/************************************************************************** 
* Function : AM53C974_set_async(struct Scsi_Host *instance, int target)
*
* Purpose : put controller into async. mode
*
* Inputs : instance -- which AM53C974
*          target -- which SCSI target to deal with
* 
* Returns : nothing
**************************************************************************/
static __inline__ void AM53C974_set_async(struct Scsi_Host *instance, int target)
{
AM53C974_local_declare(); 
struct AM53C974_hostdata *hostdata = (struct AM53C974_hostdata *)instance->hostdata;
AM53C974_setio(instance);

AM53C974_write_8(STPREG, hostdata->sync_per[target]);
AM53C974_write_8(SOFREG, (DEF_SOF_RAD<<6) | (DEF_SOF_RAA<<4));
}

/************************************************************************** 
* Function : AM53C974_set_sync(struct Scsi_Host *instance, int target)
*
* Purpose : put controller into sync. mode
*
* Inputs : instance -- which AM53C974
*          target -- which SCSI target to deal with
* 
* Returns : nothing
**************************************************************************/
static __inline__ void AM53C974_set_sync(struct Scsi_Host *instance, int target)
{
AM53C974_local_declare(); 
struct AM53C974_hostdata *hostdata = (struct AM53C974_hostdata *)instance->hostdata;
AM53C974_setio(instance);

AM53C974_write_8(STPREG, hostdata->sync_per[target]);
AM53C974_write_8(SOFREG, (SOFREG_SO & hostdata->sync_off[target]) | 
                (DEF_SOF_RAD<<6) | (DEF_SOF_RAA<<4));
}

/***********************************************************************
* Function : AM53C974_information_transfer(struct Scsi_Host *instance, *
*                          unsigned char statreg, unsigned char isreg, *
*                         unsigned char instreg, unsigned char cfifo,  *
*                         unsigned char dmastatus)                     *
*                                                                      *
* Purpose : handle phase changes                                       *
*                                                                      *
* Inputs : instance - which AM53C974                                   *
*          statreg - status register                                     *
*          isreg - internal state register                             *
*          instreg - interrupt status register                         *
*          cfifo - number of bytes in FIFO                             *
*          dmastatus - dma status register                             *
*                                                                      *
* Returns : nothing                                                    *
************************************************************************/
static void AM53C974_information_transfer(struct Scsi_Host *instance, 
                                          unsigned char statreg, unsigned char isreg,
                                          unsigned char instreg, unsigned char cfifo,
                                          unsigned char dmastatus)
{
AM53C974_local_declare(); 
struct AM53C974_hostdata *hostdata = (struct AM53C974_hostdata *)instance->hostdata;
Scsi_Cmnd                *cmd = (Scsi_Cmnd *)hostdata->connected;
int                      ret, i, len, residual=-1;
AM53C974_setio(instance);

DEB_INFO(printk(SEPARATOR_LINE));
switch (statreg & STATREG_PHASE) {	/* scsi phase */
  case PHASE_DATAOUT:
    DEB_INFO(printk("Dataout phase; cmd=0x%lx, sel_cmd=0x%lx, this_residual=%d, buffers_residual=%d\n",
                    (long)hostdata->connected, (long)hostdata->sel_cmd, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
    cmd->SCp.phase = PHASE_DATAOUT;
    goto PHASE_DATA_IO;

  case PHASE_DATAIN:
    DEB_INFO(printk("Datain phase; cmd=0x%lx, sel_cmd=0x%lx, this_residual=%d, buffers_residual=%d\n",
                     (long)hostdata->connected, (long)hostdata->sel_cmd, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
    cmd->SCp.phase = PHASE_DATAIN;
    PHASE_DATA_IO:
    if (hostdata->aborted) {
       AM53C974_write_8(DMACMD, DMACMD_IDLE);
       AM53C974_write_8(CMDREG, CMDREG_CFIFO);
       AM53C974_write_8(CMDREG, CMDREG_SATN);
       return; }
    if ((!cmd->SCp.this_residual) && cmd->SCp.buffers_residual) {
       cmd->SCp.buffer++;
       cmd->SCp.buffers_residual--;
       cmd->SCp.ptr = (unsigned char *)cmd->SCp.buffer->address;
       cmd->SCp.this_residual = cmd->SCp.buffer->length; }
    if (cmd->SCp.this_residual) {
       if (!(AM53C974_read_8(DMACMD) & DMACMD_START)) {
          hostdata->dma_busy = 0;
          AM53C974_transfer_dma(instance, statreg & STATREG_IO,
                                (unsigned long)cmd->SCp.this_residual,
                                cmd->SCp.ptr); }
         else
          hostdata->dma_busy = 1;
       }
    return;

  case PHASE_MSGIN:
    DEB_INFO(printk("Message-In phase; cmd=0x%lx, sel_cmd=0x%lx\n",
                    (long)hostdata->connected, (long)hostdata->sel_cmd));
    AM53C974_set_async(instance, cmd->target);
    if (cmd->SCp.phase == PHASE_DATAIN)
       AM53C974_dma_blast(instance, dmastatus, statreg);
    if ((cmd->SCp.phase == PHASE_DATAOUT) && (AM53C974_read_8(DMACMD) & DMACMD_START)) {
       AM53C974_write_8(DMACMD, DMACMD_IDLE);
       residual = cfifo + (AM53C974_read_8(CTCLREG) | (AM53C974_read_8(CTCMREG) << 8) |
                          (AM53C974_read_8(CTCHREG) << 16));
       cmd->SCp.ptr += cmd->SCp.this_residual - residual;
       cmd->SCp.this_residual = residual;
       if (cfifo) { AM53C974_write_8(CMDREG, CMDREG_CFIFO); cfifo = 0; }
       }
    if (cmd->SCp.phase == PHASE_STATIN) {
       while ((AM53C974_read_8(CFIREG) & CFIREG_CF) < 2) ;
       cmd->SCp.Status = AM53C974_read_8(FFREG);
       cmd->SCp.Message = AM53C974_read_8(FFREG); 
       DEB_INFO(printk("Message-In phase; status=0x%02x, message=0x%02x\n",
                       cmd->SCp.Status, cmd->SCp.Message));
       ret = AM53C974_message(instance, cmd, cmd->SCp.Message); }
      else {
       if (!cfifo) {
          AM53C974_write_8(CMDREG, CMDREG_IT); 
          AM53C974_poll_int();
          cmd->SCp.Message = AM53C974_read_8(FFREG);
          }
       ret = AM53C974_message(instance, cmd, cmd->SCp.Message);
       }
    cmd->SCp.phase = PHASE_MSGIN;
    AM53C974_set_sync(instance, cmd->target);
    break;
  case PHASE_MSGOUT:
    DEB_INFO(printk("Message-Out phase; cfifo=%d; msgout[0]=0x%02x\n",
                    AM53C974_read_8(CFIREG) & CFIREG_CF, hostdata->msgout[0]));
    AM53C974_write_8(DMACMD, DMACMD_IDLE);
    AM53C974_set_async(instance, cmd->target);
    for (i = 0; i < sizeof(hostdata->last_message); i++) 
        hostdata->last_message[i] = hostdata->msgout[i];
    if ((hostdata->msgout[0] == 0) || INSIDE(hostdata->msgout[0], 0x02, 0x1F) || 
        INSIDE(hostdata->msgout[0], 0x80, 0xFF)) 
       len = 1;
      else {
       if (hostdata->msgout[0] == EXTENDED_MESSAGE) {
#ifdef AM53C974_DEBUG_INFO
          printk("Extended message dump:\n");
          for (i = 0; i < hostdata->msgout[1] + 2; i++) {
              printk("%02x ", hostdata->msgout[i]);
              if (i && !(i % 16)) printk("\n"); }
          printk("\n");
#endif
          len = hostdata->msgout[1] + 2; }
         else
          len = 2;
       }
    for (i = 0; i < len; i++) AM53C974_write_8(FFREG, hostdata->msgout[i]);
    AM53C974_write_8(CMDREG, CMDREG_IT);
    cmd->SCp.phase = PHASE_MSGOUT;
    hostdata->msgout[0] = NOP;
    AM53C974_set_sync(instance, cmd->target);
    break;

  case PHASE_CMDOUT:
    DEB_INFO(printk("Command-Out phase\n"));
    AM53C974_set_async(instance, cmd->target);
    for (i = 0; i < cmd->cmd_len; i++) AM53C974_write_8(FFREG, cmd->cmnd[i]);
    AM53C974_write_8(CMDREG, CMDREG_IT);
    cmd->SCp.phase = PHASE_CMDOUT;
    AM53C974_set_sync(instance, cmd->target);
    break;

  case PHASE_STATIN:
    DEB_INFO(printk("Status phase\n"));
    if (cmd->SCp.phase == PHASE_DATAIN)
       AM53C974_dma_blast(instance, dmastatus, statreg);
    AM53C974_set_async(instance, cmd->target);
    if (cmd->SCp.phase == PHASE_DATAOUT) {
       unsigned long residual;

       if (AM53C974_read_8(DMACMD) & DMACMD_START) {
          AM53C974_write_8(DMACMD, DMACMD_IDLE);
          residual = cfifo + (AM53C974_read_8(CTCLREG) | (AM53C974_read_8(CTCMREG) << 8) |
                              (AM53C974_read_8(CTCHREG) << 16));
          cmd->SCp.ptr += cmd->SCp.this_residual - residual;
          cmd->SCp.this_residual = residual; }
       if (cfifo) { AM53C974_write_8(CMDREG, CMDREG_CFIFO); cfifo = 0; }
       }
    cmd->SCp.phase = PHASE_STATIN;
    AM53C974_write_8(CMDREG, CMDREG_ICCS);  /* command complete */
    break;

  case PHASE_RES_0:
  case PHASE_RES_1:
#ifdef AM53C974_DEBUG
   deb_stop = 1;
#endif
    DEB_INFO(printk("Reserved phase\n"));
    break;
  }
KEYWAIT();
}

/******************************************************************************
* Function : int AM53C974_message(struct Scsi_Host *instance, Scsi_Cmnd *cmd,
*                                 unsigned char msg)                
*
* Purpose : handle SCSI messages
*
* Inputs : instance -- which AM53C974
*          cmd -- SCSI command the message belongs to
*          msg -- message id byte
* 
* Returns : 1 on success, 0 on failure.
**************************************************************************/
static int AM53C974_message(struct Scsi_Host *instance, Scsi_Cmnd *cmd,
                            unsigned char msg)
{
AM53C974_local_declare(); 
static unsigned char     extended_msg[10];
unsigned char            statreg;
int                      len, ret = 0;
unsigned char            *p;
#ifdef AM53C974_DEBUG_MSG
int                      j;
#endif
struct AM53C974_hostdata *hostdata = (struct AM53C974_hostdata *)instance->hostdata;
AM53C974_setio(instance);

DEB_MSG(printk(SEPARATOR_LINE));

/* Linking lets us reduce the time required to get the 
 * next command out to the device, hopefully this will
 * mean we don't waste another revolution due to the delays
 * required by ARBITRATION and another SELECTION.
 * In the current implementation proposal, low level drivers
 * merely have to start the next command, pointed to by 
 *