scsi.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

    channel = hchannel;
    if(channel > shpnt->max_channel) goto leave;
    dev = hid;
    if(dev >= shpnt->max_id) goto leave;
    lun = hlun;
    if(lun >= shpnt->max_lun) goto leave;
    scan_scsis_single (channel, dev, lun, &max_dev_lun, &sparse_lun,
		       &SDpnt, SCpnt, shpnt, scsi_result);
    if(SDpnt!=oldSDpnt) {

	/* it could happen the blockdevice hasn't yet been inited */
    for(sdtpnt = scsi_devicelist; sdtpnt; sdtpnt = sdtpnt->next)
        if(sdtpnt->init && sdtpnt->dev_noticed) (*sdtpnt->init)();

            oldSDpnt->scsi_request_fn = NULL;
            for(sdtpnt = scsi_devicelist; sdtpnt; sdtpnt = sdtpnt->next)
                if(sdtpnt->attach) {
		  (*sdtpnt->attach)(oldSDpnt);
                  if(oldSDpnt->attached) scsi_build_commandblocks(oldSDpnt);}
	    resize_dma_pool();
  
        for(sdtpnt = scsi_devicelist; sdtpnt; sdtpnt = sdtpnt->next) {
            if(sdtpnt->finish && sdtpnt->nr_dev)
                {(*sdtpnt->finish)();}
	}
    }

  }
  else {
    for (channel = 0; channel <= shpnt->max_channel; channel++) {
      for (dev = 0; dev < shpnt->max_id; ++dev) {
        if (shpnt->this_id != dev) {

          /*
           * We need the for so our continue, etc. work fine. We put this in
           * a variable so that we can override it during the scan if we
           * detect a device *KNOWN* to have multiple logical units.
           */
          max_dev_lun = (max_scsi_luns < shpnt->max_lun ?
                         max_scsi_luns : shpnt->max_lun);
	  sparse_lun = 0;
          for (lun = 0; lun < max_dev_lun; ++lun) {
            if (!scan_scsis_single (channel, dev, lun, &max_dev_lun,
				    &sparse_lun, &SDpnt, SCpnt, shpnt,
				    scsi_result)
		&& !sparse_lun)
              break; /* break means don't probe further for luns!=0 */
          }                     /* for lun ends */
        }                       /* if this_id != id ends */
      }                         /* for dev ends */
    }                           /* for channel ends */
  } 				/* if/else hardcoded */

  leave:

  {/* Unchain SCpnt from host_queue */
    Scsi_Cmnd *prev, *next, *hqptr;
    for(hqptr = shpnt->host_queue; hqptr != SCpnt; hqptr = hqptr->next) ;
    if(hqptr) {
      prev = hqptr->prev;
      next = hqptr->next;
      if(prev) 
     	prev->next = next;
      else 
     	shpnt->host_queue = next;
      if(next) next->prev = prev;
    }
  }
 
     /* Last device block does not exist.  Free memory. */
    if (SDpnt != NULL)
      scsi_init_free ((char *) SDpnt, sizeof (Scsi_Device));

    if (SCpnt != NULL)
      scsi_init_free ((char *) SCpnt, sizeof (Scsi_Cmnd));

    /* If we allocated a buffer so we could do DMA, free it now */
    if (scsi_result != &scsi_result0[0] && scsi_result != NULL)
      scsi_init_free (scsi_result, 512);

}

/*
 * The worker for scan_scsis.
 * Returning 0 means Please don't ask further for lun!=0, 1 means OK go on.
 * Global variables used : scsi_devices(linked list)
 */
int scan_scsis_single (int channel, int dev, int lun, int *max_dev_lun,
    int *sparse_lun, Scsi_Device **SDpnt2, Scsi_Cmnd * SCpnt,
    struct Scsi_Host * shpnt, char *scsi_result)
{
  unsigned char scsi_cmd[12];
  struct Scsi_Device_Template *sdtpnt;
  Scsi_Device * SDtail, *SDpnt=*SDpnt2;
  int bflags, type=-1;

  SDtail = scsi_devices;
  if (scsi_devices)
    while (SDtail->next)
      SDtail = SDtail->next;

  memset (SDpnt, 0, sizeof (Scsi_Device));
  SDpnt->host = shpnt;
  SDpnt->id = dev;
  SDpnt->lun = lun;
  SDpnt->channel = channel;

  /* Some low level driver could use device->type (DB) */
  SDpnt->type = -1;

  /*
   * Assume that the device will have handshaking problems, and then fix this
   * field later if it turns out it doesn't
   */
  SDpnt->borken = 1;
  SDpnt->was_reset = 0;
  SDpnt->expecting_cc_ua = 0;

  scsi_cmd[0] = TEST_UNIT_READY;
  scsi_cmd[1] = lun << 5;
  scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[4] = scsi_cmd[5] = 0;

  SCpnt->host = SDpnt->host;
  SCpnt->device = SDpnt;
  SCpnt->target = SDpnt->id;
  SCpnt->lun = SDpnt->lun;
  SCpnt->channel = SDpnt->channel;
  {
    struct semaphore sem = MUTEX_LOCKED;
    SCpnt->request.sem = &sem;
    SCpnt->request.rq_status = RQ_SCSI_BUSY;
    scsi_do_cmd (SCpnt, (void *) scsi_cmd,
                 (void *) scsi_result,
                 256, scan_scsis_done, SCSI_TIMEOUT + 4 * HZ, 5);
    down (&sem);
  }

#if defined(DEBUG) || defined(DEBUG_INIT)
  printk ("scsi: scan_scsis_single id %d lun %d. Return code 0x%08x\n",
          dev, lun, SCpnt->result);
  print_driverbyte(SCpnt->result); print_hostbyte(SCpnt->result);
  printk("\n");
#endif

  if (SCpnt->result) {
    if (((driver_byte (SCpnt->result) & DRIVER_SENSE) ||
         (status_byte (SCpnt->result) & CHECK_CONDITION)) &&
        ((SCpnt->sense_buffer[0] & 0x70) >> 4) == 7) {
      if (((SCpnt->sense_buffer[2] & 0xf) != NOT_READY) &&
          ((SCpnt->sense_buffer[2] & 0xf) != UNIT_ATTENTION) &&
          ((SCpnt->sense_buffer[2] & 0xf) != ILLEGAL_REQUEST || lun > 0))
        return 1;
    }
    else
      return 0;
  }

#if defined (DEBUG) || defined(DEBUG_INIT)
  printk ("scsi: performing INQUIRY\n");
#endif
  /*
   * Build an INQUIRY command block.
   */
  scsi_cmd[0] = INQUIRY;
  scsi_cmd[1] = (lun << 5) & 0xe0;
  scsi_cmd[2] = 0;
  scsi_cmd[3] = 0;
  scsi_cmd[4] = 255;
  scsi_cmd[5] = 0;
  SCpnt->cmd_len = 0;
  {
    struct semaphore sem = MUTEX_LOCKED;
    SCpnt->request.sem = &sem;
    SCpnt->request.rq_status = RQ_SCSI_BUSY;
    scsi_do_cmd (SCpnt, (void *) scsi_cmd,
                 (void *) scsi_result,
                 256, scan_scsis_done, SCSI_TIMEOUT, 3);
    down (&sem);
  }

#if defined(DEBUG) || defined(DEBUG_INIT)
  printk ("scsi: INQUIRY %s with code 0x%x\n",
          SCpnt->result ? "failed" : "successful", SCpnt->result);
#endif

  if (SCpnt->result)
    return 0;     /* assume no peripheral if any sort of error */

  /*
   * Check the peripheral qualifier field - this tells us whether LUNS
   * are supported here or not.
   */
  if( (scsi_result[0] >> 5) == 3 )
    {
      return 0;     /* assume no peripheral if any sort of error */
    }

  /*
   * It would seem some TOSHIBA CDROM gets things wrong
   */
  if (!strncmp (scsi_result + 8, "TOSHIBA", 7) &&
      !strncmp (scsi_result + 16, "CD-ROM", 6) &&
      scsi_result[0] == TYPE_DISK) {
    scsi_result[0] = TYPE_ROM;
    scsi_result[1] |= 0x80;     /* removable */
  }

  if (!strncmp (scsi_result + 8, "NEC", 3)) {
    if (!strncmp (scsi_result + 16, "CD-ROM DRIVE:84 ", 16) ||
        !strncmp (scsi_result + 16, "CD-ROM DRIVE:25", 15))
      SDpnt->manufacturer = SCSI_MAN_NEC_OLDCDR;
    else
      SDpnt->manufacturer = SCSI_MAN_NEC;
  }
  else if (!strncmp (scsi_result + 8, "TOSHIBA", 7))
    SDpnt->manufacturer = SCSI_MAN_TOSHIBA;
  else if (!strncmp (scsi_result + 8, "SONY", 4))
    SDpnt->manufacturer = SCSI_MAN_SONY;
  else if (!strncmp (scsi_result + 8, "PIONEER", 7))
    SDpnt->manufacturer = SCSI_MAN_PIONEER;
  else
    SDpnt->manufacturer = SCSI_MAN_UNKNOWN;

  memcpy (SDpnt->vendor, scsi_result + 8, 8);
  memcpy (SDpnt->model, scsi_result + 16, 16);
  memcpy (SDpnt->rev, scsi_result + 32, 4);

  SDpnt->removable = (0x80 & scsi_result[1]) >> 7;
  SDpnt->lockable = SDpnt->removable;
  SDpnt->changed = 0;
  SDpnt->access_count = 0;
  SDpnt->busy = 0;
  SDpnt->has_cmdblocks = 0;
  /*
   * Currently, all sequential devices are assumed to be tapes, all random
   * devices disk, with the appropriate read only flags set for ROM / WORM
   * treated as RO.
   */
  switch (type = (scsi_result[0] & 0x1f)) {
  case TYPE_TAPE:
  case TYPE_DISK:
  case TYPE_MOD:
  case TYPE_PROCESSOR:
  case TYPE_SCANNER:
  case TYPE_MEDIUM_CHANGER:
    SDpnt->writeable = 1;
    break;
  case TYPE_WORM:
  case TYPE_ROM:
    SDpnt->writeable = 0;
    break;
  default:
    printk ("scsi: unknown type %d\n", type);
  }

  SDpnt->single_lun = 0;
  SDpnt->soft_reset =
    (scsi_result[7] & 1) && ((scsi_result[3] & 7) == 2);
  SDpnt->random = (type == TYPE_TAPE) ? 0 : 1;
  SDpnt->type = (type & 0x1f);

  print_inquiry (scsi_result);

  for (sdtpnt = scsi_devicelist; sdtpnt;
       sdtpnt = sdtpnt->next)
    if (sdtpnt->detect)
      SDpnt->attached +=
        (*sdtpnt->detect) (SDpnt);

  SDpnt->scsi_level = scsi_result[2] & 0x07;
  if (SDpnt->scsi_level >= 2 ||
      (SDpnt->scsi_level == 1 &&
       (scsi_result[3] & 0x0f) == 1))
    SDpnt->scsi_level++;

  /*
   * Accommodate drivers that want to sleep when they should be in a polling
   * loop.
   */
  SDpnt->disconnect = 0;

  /*
   * Get any flags for this device.
   */
  bflags = get_device_flags (scsi_result);

  /*
   * Set the tagged_queue flag for SCSI-II devices that purport to support
   * tagged queuing in the INQUIRY data.
   */
  SDpnt->tagged_queue = 0;
  if ((SDpnt->scsi_level >= SCSI_2) &&
      (scsi_result[7] & 2) &&
      !(bflags & BLIST_NOTQ)) {
    SDpnt->tagged_supported = 1;
    SDpnt->current_tag = 0;
  }

  /*
   * Some revisions of the Texel CD ROM drives have handshaking problems when
   * used with the Seagate controllers.  Before we know what type of device
   * we're talking to, we assume it's borken and then change it here if it
   * turns out that it isn't a TEXEL drive.
   */
  if ((bflags & BLIST_BORKEN) == 0)
    SDpnt->borken = 0;

  /*
   * If we want to only allow I/O to one of the luns attached to this device
   * at a time, then we set this flag.
   */
  if (bflags & BLIST_SINGLELUN)
    SDpnt->single_lun = 1;

  /*
   * These devices need this "key" to unlock the devices so we can use it
   */
  if ((bflags & BLIST_KEY) != 0) {
    printk ("Unlocked floptical drive.\n");
    SDpnt->lockable = 0;
    scsi_cmd[0] = MODE_SENSE;
    scsi_cmd[1] = (lun << 5) & 0xe0;
    scsi_cmd[2] = 0x2e;
    scsi_cmd[3] = 0;
    scsi_cmd[4] = 0x2a;
    scsi_cmd[5] = 0;
    SCpnt->cmd_len = 0;
    {
      struct semaphore sem = MUTEX_LOCKED;
      SCpnt->request.rq_status = RQ_SCSI_BUSY;
      SCpnt->request.sem = &sem;
      scsi_do_cmd (SCpnt, (void *) scsi_cmd,
                   (void *) scsi_result, 0x2a,
                   scan_scsis_done, SCSI_TIMEOUT, 3);
      down (&sem);
    }
  }
  /* Add this device to the linked list at the end */
  if (SDtail)
    SDtail->next = SDpnt;
  else
    scsi_devices = SDpnt;
  SDtail = SDpnt;

  SDpnt = (Scsi_Device *) scsi_init_malloc (sizeof (Scsi_Device), GFP_ATOMIC);
  *SDpnt2=SDpnt;
  if (!SDpnt)
    printk ("scsi: scan_scsis_single: Cannot malloc\n");


  /*
   * Some scsi devices cannot be polled for lun != 0 due to firmware bugs
   */
  if (bflags & BLIST_NOLUN)
    return 0;                   /* break; */

  /*
   * If this device is known to support sparse multiple units, override the
   * other settings, and scan all of them.
   */
  if (bflags & BLIST_SPARSELUN) {
    *max_dev_lun = 8;
    *sparse_lun = 1;
    return 1;
  }

  /*
   * If this device is known to support multiple units, override the other
   * settings, and scan all of them.
   */
  if (bflags & BLIST_FORCELUN) {
    *max_dev_lun = 8;
    return 1;
  }

  /*
   * REGAL CDC-4X: avoid hang after LUN 4
   */
  if (bflags & BLIST_MAX5LUN) {
    *max_dev_lun = 5;
    return 1;
  }

  /*
   * We assume the device can't handle lun!=0 if: - it reports scsi-0 (ANSI
   * SCSI Revision 0) (old drives like MAXTOR XT-3280) or - it reports scsi-1
   * (ANSI SCSI Revision 1) and Response Data Format 0
   */
  if (((scsi_result[2] & 0x07) == 0)
      ||
      ((scsi_result[2] & 0x07) == 1 &&
       (scsi_result[3] & 0x0f) == 0))
    return 0;
  return 1;
}

/*
 *  Flag bits for the internal_timeout array
 */
#define NORMAL_TIMEOUT 0
#define IN_ABORT  1
#define IN_RESET  2
#define IN_RESET2 4
#define IN_RESET3 8

/*
 * This is our time out function, called when the timer expires for a
 * given host adapter.  It will attempt to abort the currently executing
 * command, that failing perform a kernel panic.
 */

static void scsi_times_out (Scsi_Cmnd * SCpnt)
{
    
    switch (SCpnt->internal_timeout & (IN_ABORT | IN_RESET | IN_RESET2 | IN_RESET3))
    {
    case NORMAL_TIMEOUT:
	{
#ifdef DEBUG_TIMEOUT
	    scsi_dump_status();
#endif
	}
	
	if (!scsi_abort (SCpnt, DID_TIME_OUT))
	    return;
    case IN_ABORT:
	printk("SCSI host %d abort (pid %ld) timed out - resetting\n",
	       SCpnt->host->host_no, SCpnt->pid);
	if (!scsi_reset (SCpnt, SCSI_RESET_ASYNCHRONOUS))
	    return;
    case IN_RESET:
    case (IN_ABORT | IN_RESET):
	/* This might be controversial, but if there is a bus hang,
	 * you might conceivably want the machine up and running
	 * esp if you have an ide disk. 
	 */
	printk("SCSI host %d channel %d reset (pid %ld) timed out - "
               "trying harder\n",
	       SCpnt->host->host_no, SCpnt->channel, SCpnt->pid);
	SCpnt->internal_timeout &= ~IN_RESET;
	SCpnt->internal_timeout |= IN_RESET2;
        scsi_reset (SCpnt,
		    SCSI_RESET_ASYNCHRONOUS | SCSI_RESET_SUGGEST_BUS_RESET);
        return;
    case IN_RESET2:
    case (IN_ABORT | IN_RESET2):