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

* Purpose : interrupt handler                                           *
*                                                                       *
* Inputs : irq - interrupt line, regs - ?                               *
*                                                                       *
* Returns : nothing                                                     *
************************************************************************/
static void AM53C974_intr(int irq, void *dev_id, struct pt_regs *regs)
{
AM53C974_local_declare(); 
struct Scsi_Host         *instance;
struct AM53C974_hostdata *hostdata;
unsigned char            cmdreg, dmastatus, statreg, isreg, instreg, cfifo;

/* find AM53C974 hostadapter responsible for this interrupt */
for (instance = first_instance; instance; instance = instance->next)
    if ((instance->irq == irq) && (instance->hostt == the_template)) goto FOUND;
sti();
return;

/* found; now decode and process */
FOUND:
hostdata = (struct AM53C974_hostdata *)instance->hostdata;
AM53C974_setio(instance);
dmastatus = AM53C974_read_8(DMASTATUS);

DEB_INTR(printk(SEPARATOR_LINE));
DEB_INTR(printk("AM53C974 interrupt; dmastatus=0x%02x\n", dmastatus));
KEYWAIT();

/*** DMA related interrupts ***/
if (hostdata->connected && (dmastatus & (DMASTATUS_ERROR | DMASTATUS_PWDN | 
                                         DMASTATUS_ABORT))) {
   /* DMA error or POWERDOWN */
   printk("scsi%d: DMA error or powerdown; dmastatus: 0x%02x\n",
          instance->host_no, dmastatus);
#ifdef AM53C974_DEBUG
   deb_stop = 1;
#endif
   panic("scsi%d: cannot recover\n", instance->host_no); }

if (hostdata->connected && (dmastatus & DMASTATUS_DONE)) {     
   /* DMA transfer done */
   unsigned long residual;
   cli();
   if (!(AM53C974_read_8(DMACMD) & DMACMD_DIR)) {
      do {
         dmastatus = AM53C974_read_8(DMASTATUS);
         residual  = AM53C974_read_8(CTCLREG) | (AM53C974_read_8(CTCMREG) << 8) |
                    (AM53C974_read_8(CTCHREG) << 16);
         residual += AM53C974_read_8(CFIREG) & CFIREG_CF;
         } while (!(dmastatus & DMASTATUS_SCSIINT) && residual);
      residual = AM53C974_read_8(CTCLREG) | (AM53C974_read_8(CTCMREG) << 8) |
                 (AM53C974_read_8(CTCHREG) << 16);
      residual += AM53C974_read_8(CFIREG) & CFIREG_CF;
      }
     else
      residual = 0;
   hostdata->connected->SCp.ptr += hostdata->connected->SCp.this_residual - residual;
   hostdata->connected->SCp.this_residual = residual;

   AM53C974_write_8(DMACMD, DMACMD_IDLE);

   /* if service request missed before, process it now (ugly) */
   if (hostdata->dma_busy) {
      hostdata->dma_busy = 0;
      cmdreg = AM53C974_read_8(CMDREG);
      statreg = AM53C974_read_8(STATREG);
      isreg = AM53C974_read_8(ISREG);
      instreg = AM53C974_read_8(INSTREG);
      cfifo = AM53C974_cfifo();
      AM53C974_information_transfer(instance, statreg, isreg, instreg, cfifo,
                                    dmastatus); }
   sti();
   }
   
if (!(dmastatus & DMASTATUS_SCSIINT)) {
   sti();
   return; }

/*** SCSI related interrupts ***/
cmdreg = AM53C974_read_8(CMDREG);
statreg = AM53C974_read_8(STATREG);
isreg = AM53C974_read_8(ISREG);
instreg = AM53C974_read_8(INSTREG);
cfifo = AM53C974_cfifo();

DEB_INTR(printk("scsi%d: statreg: 0x%02x; isreg: 0x%02x; instreg: 0x%02x; cfifo: 0x%02x\n",
                instance->host_no, statreg, isreg, instreg, cfifo));

if (statreg & STATREG_PE) {
   /* parity error */
#ifdef AM53C974_DEBUG
   deb_stop = 1;
#endif
   printk("scsi%d : PARITY error\n", instance->host_no);
   if (hostdata->connected) hostdata->sync_off[hostdata->connected->target] = 0; /* setup asynchronous transfer */
   hostdata->aborted = 1; }

if (statreg & STATREG_IOE) {
   /* illegal operation error */
#ifdef AM53C974_DEBUG
   deb_stop = 1;
#endif
   printk("scsi%d : ILLEGAL OPERATION error\n", instance->host_no);
   printk("cmdreg:  0x%02x; dmacmd:  0x%02x; statreg: 0x%02x; \n"
          "isreg:   0x%02x; instreg: 0x%02x; cfifo:   0x%02x\n",
           cmdreg, AM53C974_read_8(DMACMD), statreg, isreg, instreg, cfifo); }
if (hostdata->in_reset && (instreg & INSTREG_SRST)) {
   /* RESET INTERRUPT */
#ifdef AM53C974_DEBUG
   deb_stop = 1;
#endif
   DEB(printk("Bus reset interrupt received\n"));
   AM53C974_intr_bus_reset(instance);
   cli();
   if (hostdata->connected) {
      hostdata->connected->result = DID_RESET << 16;
      hostdata->connected->scsi_done((Scsi_Cmnd *)hostdata->connected);
      hostdata->connected = NULL; }
     else { 
      if (hostdata->sel_cmd) {
         hostdata->sel_cmd->result = DID_RESET << 16;
         hostdata->sel_cmd->scsi_done((Scsi_Cmnd *)hostdata->sel_cmd);
         hostdata->sel_cmd = NULL; }
      }
   sti();
   if (hostdata->in_reset == 1) goto EXIT;
     else return;
   }

if (instreg & INSTREG_ICMD) {
   /* INVALID COMMAND INTERRUPT */
#ifdef AM53C974_DEBUG
   deb_stop = 1;
#endif
   printk("scsi%d: Invalid command interrupt\n", instance->host_no);
   printk("cmdreg:  0x%02x; dmacmd:  0x%02x; statreg: 0x%02x; dmastatus: 0x%02x; \n"
          "isreg:   0x%02x; instreg: 0x%02x; cfifo:   0x%02x\n",
           cmdreg, AM53C974_read_8(DMACMD), statreg, dmastatus, isreg, instreg, cfifo);
   panic("scsi%d: cannot recover\n", instance->host_no); }

if (instreg & INSTREG_DIS) {
   /* DISCONNECT INTERRUPT */
   DEB_INTR(printk("Disconnect interrupt received; "));
   cli();
   AM53C974_intr_disconnect(instance);
   sti();
   goto EXIT; }

if (instreg & INSTREG_RESEL) {
   /* RESELECTION INTERRUPT */
   DEB_INTR(printk("Reselection interrupt received\n"));
   cli();
   AM53C974_intr_reselect(instance, statreg);
   sti();
   goto EXIT; }

if (instreg & INSTREG_SO) {
   DEB_INTR(printk("Successful operation interrupt received\n"));
   if (hostdata->selecting) {
      DEB_INTR(printk("DSR completed, starting select\n"));
      cli();
      AM53C974_select(instance, (Scsi_Cmnd *)hostdata->sel_cmd,
                          (hostdata->sel_cmd->cmnd[0] == REQUEST_SENSE) ? 
                                                  TAG_NONE : TAG_NEXT);
      hostdata->selecting = 0;
      AM53C974_set_sync(instance, hostdata->sel_cmd->target);
      sti();
      return; }

   if (hostdata->sel_cmd != NULL) {
      if ( ((isreg & ISREG_IS) != ISREG_OK_NO_STOP) &&
           ((isreg & ISREG_IS) != ISREG_OK_STOP) ) {
         /* UNSUCCESSFUL SELECTION */
         DEB_INTR(printk("unsuccessful selection\n"));
         cli();
         hostdata->dma_busy = 0;
	 LIST(hostdata->sel_cmd, hostdata->issue_queue);
	 hostdata->sel_cmd->host_scribble = (unsigned char *)hostdata->issue_queue;
         hostdata->issue_queue = hostdata->sel_cmd;
         hostdata->sel_cmd = NULL;
         hostdata->selecting = 0;
         sti();
         goto EXIT; }
        else {
         /* SUCCESSFUL SELECTION */
         DEB(printk("successful selection; cmd=0x%02lx\n", (long)hostdata->sel_cmd));
         cli();
         hostdata->dma_busy = 0;
         hostdata->disconnecting = 0;
         hostdata->connected = hostdata->sel_cmd;
         hostdata->sel_cmd = NULL;
         hostdata->selecting = 0;
#ifdef SCSI2
         if (!hostdata->connected->device->tagged_queue)
#endif    
            hostdata->busy[hostdata->connected->target] |= (1 << hostdata->connected->lun);
         /* very strange -- use_sg is sometimes nonzero for request sense commands !! */
         if ((hostdata->connected->cmnd[0] == REQUEST_SENSE) && hostdata->connected->use_sg) {
            DEB(printk("scsi%d: REQUEST_SENSE command with nonzero use_sg\n", instance->host_no));
            KEYWAIT();
            hostdata->connected->use_sg = 0; }
         initialize_SCp((Scsi_Cmnd *)hostdata->connected);
         hostdata->connected->SCp.phase = PHASE_CMDOUT;
         AM53C974_information_transfer(instance, statreg, isreg, instreg, cfifo, dmastatus);
         sti();
         return; }
      }
     else {
      cli();
      AM53C974_information_transfer(instance, statreg, isreg, instreg, cfifo, dmastatus);
      sti();
      return; }
   }
    
if (instreg & INSTREG_SR) {
   DEB_INTR(printk("Service request interrupt received, "));
   if (hostdata->connected) {
      DEB_INTR(printk("calling information_transfer\n"));
      cli();
      AM53C974_information_transfer(instance, statreg, isreg, instreg, cfifo, dmastatus);
      sti(); }
     else {
      printk("scsi%d: weird: service request when no command connected\n", instance->host_no);
      AM53C974_write_8(CMDREG, CMDREG_CFIFO); }   /* clear FIFO */
   return;
   }

EXIT:
  DEB_INTR(printk("intr: starting main\n"));
  run_main();
  DEB_INTR(printk("end of intr\n"));
}

/************************************************************************** 
* Function : AM53C974_intr_disconnect(struct Scsi_Host *instance)
*
* Purpose : manage target disconnection
*
* Inputs : instance -- which AM53C974
* 
* Returns : nothing
**************************************************************************/
static void AM53C974_intr_disconnect(struct Scsi_Host *instance) 
{
AM53C974_local_declare(); 
struct AM53C974_hostdata *hostdata = (struct AM53C974_hostdata *)instance->hostdata;
Scsi_Cmnd                *cmd;
AM53C974_setio(instance);

if (hostdata->sel_cmd != NULL) {
   /* normal selection timeout, typical for nonexisting targets */
   cmd = (Scsi_Cmnd *)hostdata->sel_cmd;
   DEB_INTR(printk("bad target\n"));
   cmd->result = DID_BAD_TARGET << 16;
   goto EXIT_FINISHED; }

if (!hostdata->connected) {
   /* can happen if controller was reset, a device tried to reconnect,
      failed and disconnects now */
   AM53C974_write_8(CMDREG, CMDREG_CFIFO);
   return; }

if (hostdata->disconnecting) {
   /* target sent disconnect message, so we are prepared */
   cmd = (Scsi_Cmnd *)hostdata->connected;
   AM53C974_set_async(instance, cmd->target);
   DEB_INTR(printk("scsi%d : disc. from cmnd %d for ta %d, lun %d\n",
   	           instance->host_no, cmd->cmnd[0], cmd->target, cmd->lun));
   if (cmd->device->disconnect) {
      /* target wants to reselect later */
      DEB_INTR(printk("ok, re-enabling selection\n"));
      LIST(cmd,hostdata->disconnected_queue);
      cmd->host_scribble = (unsigned char *)hostdata->disconnected_queue;
      hostdata->disconnected_queue = cmd;
      DEB_QUEUE(printk("scsi%d : command for target %d lun %d this %d was moved from connected to"
   	               "  the disconnected_queue\n", instance->host_no, cmd->target,
                        cmd->lun, hostdata->disconnected_queue->SCp.this_residual));
      DEB_QUEUE(AM53C974_print_queues(instance));
      goto EXIT_UNFINISHED; }
     else {
      /* target does not want to reselect later, we are really finished */
#ifdef AM53C974_DEBUG
      if (cmd->cmnd[0] == REQUEST_SENSE) {
        int i;
        printk("Request sense data dump:\n");
        for (i = 0; i < cmd->request_bufflen; i++) {
             printk("%02x ", *((char *)(cmd->request_buffer) + i));
             if (i && !(i % 16)) printk("\n"); }
        printk("\n"); }
#endif
      goto EXIT_FINISHED; } /* !cmd->device->disconnect */
   } /* if (hostdata->disconnecting) */

/* no disconnect message received; unexpected disconnection */
cmd = (Scsi_Cmnd *)hostdata->connected;
if (cmd) {
#ifdef AM53C974_DEBUG
   deb_stop = 1;
#endif
   AM53C974_set_async(instance, cmd->target);
   printk("scsi%d: Unexpected disconnect; phase: %d; target: %d; this_residual: %d; buffers_residual: %d; message: %d\n",
           instance->host_no, cmd->SCp.phase, cmd->target, cmd->SCp.this_residual, cmd->SCp.buffers_residual,
           cmd->SCp.Message);
   printk("cmdreg: 0x%02x; statreg: 0x%02x; isreg: 0x%02x; cfifo: 0x%02x\n",
          AM53C974_read_8(CMDREG), AM53C974_read_8(STATREG), AM53C974_read_8(ISREG),
           AM53C974_read_8(CFIREG) & CFIREG_CF);

    if ((hostdata->last_message[0] == EXTENDED_MESSAGE) && 
        (hostdata->last_message[2] == EXTENDED_SDTR)) {
        /* sync. negotiation was aborted, setup asynchronous transfer with target */
        hostdata->sync_off[cmd->target] = 0; }
   if (hostdata->aborted || hostdata->msgout[0] == ABORT)
      cmd->result = DID_ABORT << 16;
     else
      cmd->result = DID_ERROR << 16;
   goto EXIT_FINISHED; }

EXIT_FINISHED:
hostdata->aborted = 0;
hostdata->msgout[0] = NOP;
hostdata->sel_cmd = NULL;
hostdata->connected = NULL;
hostdata->selecting = 0;