scsi_obsolete.c

基于组件方式开发操作系统的OSKIT源代码

		/* We do not know how to abort.  Try waiting another
		 * time increment and see if this helps. Set the
		 * WAS_TIMEDOUT flag set so we do not try this twice
		 */
	    case SCSI_ABORT_BUSY: /* Tough call - returning 1 from
				   * this is too severe
				   */
	    case SCSI_ABORT_SNOOZE:
		if(why == DID_TIME_OUT) {
		    SCpnt->internal_timeout &= ~IN_ABORT;
		    if(SCpnt->flags & WAS_TIMEDOUT) {
			return 1; /* Indicate we cannot handle this.
				   * We drop down into the reset handler
				   * and try again
				   */
		    } else {
			SCpnt->flags |= WAS_TIMEDOUT;
			oldto = SCpnt->timeout_per_command;
			update_timeout(SCpnt, oldto);
		    }
		}
		return 0;
	    case SCSI_ABORT_PENDING:
		if(why != DID_TIME_OUT) {
		    update_timeout(SCpnt, oldto);
		}
		return 0;
	    case SCSI_ABORT_SUCCESS:
		/* We should have already aborted this one.  No
		 * need to adjust timeout
		 */
                 SCpnt->internal_timeout &= ~IN_ABORT;
                 return 0;
	    case SCSI_ABORT_NOT_RUNNING:
		SCpnt->internal_timeout &= ~IN_ABORT;
		update_timeout(SCpnt, 0);
		return 0;
	    case SCSI_ABORT_ERROR:
	    default:
		SCpnt->internal_timeout &= ~IN_ABORT;
		return 1;
	    }
	}
    }
}


/* Mark a single SCSI Device as having been reset. */

static inline void scsi_mark_device_reset(Scsi_Device *Device)
{
  Device->was_reset = 1;
  Device->expecting_cc_ua = 1;
}


/* Mark all SCSI Devices on a specific Host as having been reset. */

void scsi_mark_host_reset(struct Scsi_Host *Host)
{
  Scsi_Cmnd   * SCpnt;
  Scsi_Device * SDpnt;

  for (SDpnt = Host->host_queue; SDpnt; SDpnt = SDpnt->next)
    {
      for (SCpnt = SDpnt->device_queue; SCpnt; SCpnt = SCpnt->next)
        scsi_mark_device_reset(SCpnt->device);
    }
}


/* Mark all SCSI Devices on a specific Host Bus as having been reset. */

static void scsi_mark_bus_reset(struct Scsi_Host *Host, int channel)
{
  Scsi_Cmnd *SCpnt;
  Scsi_Device * SDpnt;

  for (SDpnt = Host->host_queue; SDpnt; SDpnt = SDpnt->next)
    {
      for (SCpnt = SDpnt->device_queue; SCpnt; SCpnt = SCpnt->next)
        if (SCpnt->channel == channel)
	  scsi_mark_device_reset(SCpnt->device);
    }
}


static int scsi_reset (Scsi_Cmnd * SCpnt, unsigned int reset_flags)
{
    int temp;
    Scsi_Cmnd * SCpnt1;
    Scsi_Device * SDpnt;
    struct Scsi_Host * host = SCpnt->host;

    printk("SCSI bus is being reset for host %d channel %d.\n",
	   host->host_no, SCpnt->channel);

#if 0
    /*
     * First of all, we need to make a recommendation to the low-level
     * driver as to whether a BUS_DEVICE_RESET should be performed,
     * or whether we should do a full BUS_RESET.  There is no simple
     * algorithm here - we basically use a series of heuristics
     * to determine what we should do.
     */
    SCpnt->host->suggest_bus_reset = FALSE;

    /*
     * First see if all of the active devices on the bus have
     * been jammed up so that we are attempting resets.  If so,
     * then suggest a bus reset.  Forcing a bus reset could
     * result in some race conditions, but no more than
     * you would usually get with timeouts.  We will cross
     * that bridge when we come to it.
     *
     * This is actually a pretty bad idea, since a sequence of
     * commands will often timeout together and this will cause a
     * Bus Device Reset followed immediately by a SCSI Bus Reset.
     * If all of the active devices really are jammed up, the
     * Bus Device Reset will quickly timeout and scsi_times_out
     * will follow up with a SCSI Bus Reset anyway.
     */
    SCpnt1 = host->host_queue;
    while(SCpnt1) {
	if( SCpnt1->request.rq_status != RQ_INACTIVE
	    && (SCpnt1->flags & (WAS_RESET | IS_RESETTING)) == 0 )
            	break;
        SCpnt1 = SCpnt1->next;
 	}
    if( SCpnt1 == NULL ) {
        reset_flags |= SCSI_RESET_SUGGEST_BUS_RESET;
    }

    /*
     * If the code that called us is suggesting a hard reset, then
     * definitely request it.  This usually occurs because a
     * BUS_DEVICE_RESET times out.
     *
     * Passing reset_flags along takes care of this automatically.
     */
    if( reset_flags & SCSI_RESET_SUGGEST_BUS_RESET ) {
        SCpnt->host->suggest_bus_reset = TRUE;
    }
#endif

    while (1) {

	/*
	 * Protect against races here.  If the command is done, or we are
	 * on a different command forget it.
	 */
	if (reset_flags & SCSI_RESET_ASYNCHRONOUS)
	  if (SCpnt->serial_number != SCpnt->serial_number_at_timeout) {
	    return 0;
	  }

	if (SCpnt->internal_timeout & IN_RESET)
	{
	    spin_unlock_irq(&io_request_lock);
	    while (SCpnt->internal_timeout & IN_RESET)
		barrier();
	    spin_lock_irq(&io_request_lock);
	}
	else
	{
	    SCpnt->internal_timeout |= IN_RESET;
	    update_timeout(SCpnt, RESET_TIMEOUT);

	    if (reset_flags & SCSI_RESET_SYNCHRONOUS)
	      SCpnt->flags |= SYNC_RESET;
	    if (host->host_busy)
	    {
                for(SDpnt = host->host_queue; SDpnt; SDpnt = SDpnt->next)
                {
                    SCpnt1 = SDpnt->device_queue;
                    while(SCpnt1) {
                        if (SCpnt1->request.rq_status != RQ_INACTIVE) {
#if 0
                            if (!(SCpnt1->flags & IS_RESETTING) &&
                                !(SCpnt1->internal_timeout & IN_ABORT))
                                scsi_abort(SCpnt1, DID_RESET);
#endif
                            SCpnt1->flags |= (WAS_RESET | IS_RESETTING);
                        }
                        SCpnt1 = SCpnt1->next;
                    }
                }

		host->last_reset = jiffies;
		host->resetting = 1;
		/*
		 * I suppose that the host reset callback will not play
		 * with the resetting field. We have just set the resetting
		 * flag here. -arca
		 */
		temp = host->hostt->reset(SCpnt, reset_flags);
		/*
		  This test allows the driver to introduce an additional bus
		  settle time delay by setting last_reset up to 20 seconds in
		  the future.  In the normal case where the driver does not
		  modify last_reset, it must be assumed that the actual bus
		  reset occurred immediately prior to the return to this code,
		  and so last_reset must be updated to the current time, so
		  that the delay in internal_cmnd will guarantee at least a
		  MIN_RESET_DELAY bus settle time.
		*/
		if (host->last_reset - jiffies > 20UL * HZ)
		  host->last_reset = jiffies;
	    }
	    else
	    {
		if (!host->block) host->host_busy++;
		host->last_reset = jiffies;
		host->resetting = 1;
		SCpnt->flags |= (WAS_RESET | IS_RESETTING);
		/*
		 * I suppose that the host reset callback will not play
		 * with the resetting field. We have just set the resetting
		 * flag here. -arca
		 */
		temp = host->hostt->reset(SCpnt, reset_flags);
		if (time_before(host->last_reset, jiffies) ||
		    (time_after(host->last_reset, jiffies + 20 * HZ)))
		  host->last_reset = jiffies;
		if (!host->block) host->host_busy--;
	    }
	    if (reset_flags & SCSI_RESET_SYNCHRONOUS)
	      SCpnt->flags &= ~SYNC_RESET;

#ifdef DEBUG
	    printk("scsi reset function returned %d\n", temp);
#endif

            /*
             * Now figure out what we need to do, based upon
             * what the low level driver said that it did.
	     * If the result is SCSI_RESET_SUCCESS, SCSI_RESET_PENDING,
	     * or SCSI_RESET_WAKEUP, then the low level driver did a
	     * bus device reset or bus reset, so we should go through
	     * and mark one or all of the devices on that bus
	     * as having been reset.
             */
            switch(temp & SCSI_RESET_ACTION) {
	    case SCSI_RESET_SUCCESS:
	        if (temp & SCSI_RESET_HOST_RESET)
		  scsi_mark_host_reset(host);
	        else if (temp & SCSI_RESET_BUS_RESET)
		  scsi_mark_bus_reset(host, SCpnt->channel);
		else scsi_mark_device_reset(SCpnt->device);
		SCpnt->internal_timeout &= ~(IN_RESET|IN_RESET2|IN_RESET3);
		return 0;
	    case SCSI_RESET_PENDING:
	        if (temp & SCSI_RESET_HOST_RESET)
		  scsi_mark_host_reset(host);
	        else if (temp & SCSI_RESET_BUS_RESET)
		  scsi_mark_bus_reset(host, SCpnt->channel);
		else scsi_mark_device_reset(SCpnt->device);
	    case SCSI_RESET_NOT_RUNNING:
		return 0;
	    case SCSI_RESET_PUNT:
		SCpnt->internal_timeout &= ~(IN_RESET|IN_RESET2|IN_RESET3);
                scsi_request_sense (SCpnt);
                return 0;
	    case SCSI_RESET_WAKEUP:
	        if (temp & SCSI_RESET_HOST_RESET)
		  scsi_mark_host_reset(host);
	        else if (temp & SCSI_RESET_BUS_RESET)
		  scsi_mark_bus_reset(host, SCpnt->channel);
		else scsi_mark_device_reset(SCpnt->device);
		SCpnt->internal_timeout &= ~(IN_RESET|IN_RESET2|IN_RESET3);
		scsi_request_sense (SCpnt);
                /*
                 * If a bus reset was performed, we
                 * need to wake up each and every command
                 * that was active on the bus or if it was a HBA
                 * reset all active commands on all channels
                 */
                if( temp & SCSI_RESET_HOST_RESET )
                {
                    for(SDpnt = host->host_queue; SDpnt; SDpnt = SDpnt->next)
                    {
                        SCpnt1 = SDpnt->device_queue;
                        while(SCpnt1) {
                            if (SCpnt1->request.rq_status != RQ_INACTIVE
                                && SCpnt1 != SCpnt)
                                scsi_request_sense (SCpnt1);
                            SCpnt1 = SCpnt1->next;
                        }
                    }
                } else if( temp & SCSI_RESET_BUS_RESET ) {
                    for(SDpnt = host->host_queue; SDpnt; SDpnt = SDpnt->next)
                    {
                        SCpnt1 = SDpnt->device_queue;
                        while(SCpnt1) {
                            if(SCpnt1->request.rq_status != RQ_INACTIVE
                               && SCpnt1 != SCpnt
                               && SCpnt1->channel == SCpnt->channel)
                                scsi_request_sense (SCpnt);
                            SCpnt1 = SCpnt1->next;
                        }
                    }
                }
		return 0;
	    case SCSI_RESET_SNOOZE:
		/* In this case, we set the timeout field to 0
		 * so that this command does not time out any more,
		 * and we return 1 so that we get a message on the
		 * screen.
		 */
		SCpnt->internal_timeout &= ~(IN_RESET|IN_RESET2|IN_RESET3);
		update_timeout(SCpnt, 0);
		/* If you snooze, you lose... */
	    case SCSI_RESET_ERROR:
	    default:
		return 1;
	    }

	    return temp;
	}
    }
}

/*
 * The strategy is to cause the timer code to call scsi_times_out()
 * when the soonest timeout is pending.
 * The arguments are used when we are queueing a new command, because
 * we do not want to subtract the time used from this time, but when we
 * set the timer, we want to take this value into account.
 */

int update_timeout(Scsi_Cmnd * SCset, int timeout)
{
  int	rtn;

  /*
   * We are using the new error handling code to actually register/deregister
   * timers for timeout.
   */

  if( !timer_pending(&SCset->eh_timeout) )
    {
      rtn = 0;
    }
  else
    {
      rtn = SCset->eh_timeout.expires - jiffies;
    }

  if( timeout == 0 )
    {
      scsi_delete_timer(SCset);
    }
  else
    {
      scsi_add_timer(SCset, timeout, scsi_old_times_out);
    }

  return rtn;
}


/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-indent-level: 4
 * c-brace-imaginary-offset: 0
 * c-brace-offset: -4
 * c-argdecl-indent: 4
 * c-label-offset: -4
 * c-continued-statement-offset: 4
 * c-continued-brace-offset: 0
 * indent-tabs-mode: nil
 * tab-width: 8
 * End:
 */