scsi.c

基于组件方式开发操作系统的OSKIT源代码

               "(n should be 0 or non-zero)\n");
    } else {
	scsi_logging_level = (ints[1])? ~0 : 0;
    }
}

#ifdef CONFIG_SCSI_MULTI_LUN
static int max_scsi_luns = 8;
#else
static int max_scsi_luns = 1;
#endif

__initfunc(void scsi_luns_setup(char *str, int *ints))
{
    if (ints[0] != 1)
	printk("scsi_luns_setup : usage max_scsi_luns=n (n should be between 1 and 8)\n");
    else
	max_scsi_luns = ints[1];
}

/*
 *  Detecting SCSI devices :
 *  We scan all present host adapter's busses,  from ID 0 to ID (max_id).
 *  We use the INQUIRY command, determine device type, and pass the ID /
 *  lun address of all sequential devices to the tape driver, all random
 *  devices to the disk driver.
 */
static void scan_scsis (struct Scsi_Host *shpnt, 
                        unchar hardcoded,
                        unchar hchannel, 
                        unchar hid, 
                        unchar hlun)
{
  int             channel;
  int             dev;
  int             lun;
  int             max_dev_lun;
  Scsi_Cmnd     * SCpnt;
  unsigned char * scsi_result;
  unsigned char   scsi_result0[256];
  Scsi_Device   * SDpnt;
  Scsi_Device   * SDtail;
  int             sparse_lun;

  scsi_result = NULL;
  SCpnt = (Scsi_Cmnd *) scsi_init_malloc (sizeof (Scsi_Cmnd), 
					  GFP_ATOMIC | GFP_DMA);
    if (SCpnt) {
	SDpnt = (Scsi_Device *) scsi_init_malloc(sizeof (Scsi_Device), 
						 GFP_ATOMIC);
	if (SDpnt) {
	    /* Make sure we have something that is valid for DMA purposes */
	    scsi_result = ( ( !shpnt->unchecked_isa_dma )
			? &scsi_result0[0] : scsi_init_malloc (512, GFP_DMA));
	}
    }

  if (scsi_result == NULL) 
  {
      printk ("Unable to obtain scsi_result buffer\n");
      goto leave;
  }

  /*
   * We must chain ourself in the host_queue, so commands can time out 
   */
  SCpnt->next = NULL;
  SDpnt->device_queue = SCpnt;
  SDpnt->host = shpnt;
  SDpnt->online = TRUE;

  /*
   * Next, hook the device to the host in question.
   */
  SDpnt->prev = NULL;
  SDpnt->next = NULL;
  if( shpnt->host_queue != NULL )
  {
      SDtail = shpnt->host_queue;
      while( SDtail->next != NULL )
          SDtail = SDtail->next;

      SDtail->next = SDpnt;
      SDpnt->prev = SDtail;
  }
  else
  {
      shpnt->host_queue = SDpnt;
  }

  /*
   * We need to increment the counter for this one device so we can track when
   * things are quiet.
   */
  atomic_inc(&shpnt->host_active); 

  if (hardcoded == 1) {
    Scsi_Device *oldSDpnt=SDpnt;
    struct Scsi_Device_Template * sdtpnt;
    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);

    /* See warning by (DB) in scsi_proc_info() towards end of
       'add-single-device' section. (dpg) */
    if (shpnt->select_queue_depths != NULL)
	(shpnt->select_queue_depths)(shpnt, shpnt->host_queue);

    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);
		    if (0 == oldSDpnt->has_cmdblocks) {
			printk("scan_scsis: DANGER, no command blocks\n");
			/* What to do now ?? */
		    }
		}
	    }
	}
	resize_dma_pool();

        for(sdtpnt = scsi_devicelist; sdtpnt; sdtpnt = sdtpnt->next) {
            if(sdtpnt->finish && sdtpnt->nr_dev)
                {(*sdtpnt->finish)();}
	}
    }

  }
  else {
    /* Actual LUN. PC ordering is 0->n IBM/spec ordering is n->0 */
    int order_dev;
    
    for (channel = 0; channel <= shpnt->max_channel; channel++) {
      for (dev = 0; dev < shpnt->max_id; ++dev) {
        if( shpnt->reverse_ordering)
        	/* Shift to scanning 15,14,13... or 7,6,5,4, */
        	order_dev = shpnt->max_id-dev-1;
        else
        	order_dev = dev;
        	
        if (shpnt->this_id != order_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, order_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 */

  /*
   * We need to decrement the counter for this one device
   * so we know when everything is quiet.
   */
  atomic_dec(&shpnt->host_active); 

  leave:

  {/* Unchain SCpnt from host_queue */
      Scsi_Device *prev, *next;
      Scsi_Device * dqptr;
      
      for(dqptr = shpnt->host_queue; dqptr != SDpnt; dqptr = dqptr->next) 
          continue;
      if(dqptr) 
      {
          prev = dqptr->prev;
          next = dqptr->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);
    }

    {
        Scsi_Device * sdev;
        Scsi_Cmnd   * scmd;

        SCSI_LOG_SCAN_BUS(4,printk("Host status for host %p:\n", shpnt));
        for(sdev = shpnt->host_queue; sdev; sdev = sdev->next)
        {
            SCSI_LOG_SCAN_BUS(4,printk("Device %d %p: ", sdev->id, sdev));
            for(scmd=sdev->device_queue; scmd; scmd = scmd->next)
            {
                SCSI_LOG_SCAN_BUS(4,printk("%p ", scmd));
            }
            SCSI_LOG_SCAN_BUS(4,printk("\n"));
        }
    }
}

/*
 * 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;

  SDpnt->host = shpnt;
  SDpnt->id = dev;
  SDpnt->lun = lun;
  SDpnt->channel = channel;
  SDpnt->online = TRUE;

  /* 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;
    spin_lock_irq(&io_request_lock);
    scsi_do_cmd (SCpnt, (void *) scsi_cmd,
                 (void *) scsi_result,
                 256, scan_scsis_done, SCSI_TIMEOUT + 4 * HZ, 5);
    spin_unlock_irq(&io_request_lock);
    down (&sem);
    SCpnt->request.sem = NULL;
  }

  SCSI_LOG_SCAN_BUS(3,  printk ("scsi: scan_scsis_single id %d lun %d. Return code 0x%08x\n",
          dev, lun, SCpnt->result));
  SCSI_LOG_SCAN_BUS(3,print_driverbyte(SCpnt->result));
  SCSI_LOG_SCAN_BUS(3,print_hostbyte(SCpnt->result));
  SCSI_LOG_SCAN_BUS(3,printk("\n"));

  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;
  }

  SCSI_LOG_SCAN_BUS(3,printk ("scsi: performing INQUIRY\n"));
  /*
   * 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;
    spin_lock_irq(&io_request_lock);
    scsi_do_cmd (SCpnt, (void *) scsi_cmd,
                 (void *) scsi_result,
                 256, scan_scsis_done, SCSI_TIMEOUT, 3);
    spin_unlock_irq(&io_request_lock);
    down (&sem);
    SCpnt->request.sem = NULL;
  }

  SCSI_LOG_SCAN_BUS(3,printk ("scsi: INQUIRY %s with code 0x%x\n",
                              SCpnt->result ? "failed" : "successful", SCpnt->result));

  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 */
  }

  /*
   * It would seem the Panasonic DVD-RAM is backwards too
   * If DVD-RAM or PD media used, it seems to function
   * as Direct-Access
   */
  if (!strncmp (scsi_result + 8, "MATSHITA", 7) &&
      !strncmp (scsi_result + 16, "PD-2 LF-D100", 12)) {
    scsi_result[0] = TYPE_DISK;
    scsi_result[1] |= 0x80;     /* removable */
  }

  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->online = TRUE;
  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:
  case TYPE_ENCLOSURE:
    SDpnt->writeable = 1;
    break;
  case TYPE_WORM:
  case TYPE_ROM:
    SDpnt->writeable = 0;
    break;
  default:
    printk ("scsi: unknown type %d\n", type);
  }

  SDpnt->device_blocked = FALSE;
  SDpnt->device_busy = 0;
  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 &&