scsi_pass.c

来自「基于组件方式开发操作系统的OSKIT源代码」· C语言 代码 · 共 861 行 · 第 1/2 页

		return (error);
	}

	splx(s);

	if ((softc->flags & PASS_FLAG_OPEN) == 0) {
		if (cam_periph_acquire(periph) != CAM_REQ_CMP)
			return(ENXIO);
		softc->flags |= PASS_FLAG_OPEN;
	}

	cam_periph_unlock(periph);

	return (error);
}

static int
passclose(dev_t dev, int flag, int fmt, struct proc *p)
{
	struct 	cam_periph *periph;
	struct	pass_softc *softc;
	int	unit, error;

	/* unit = dkunit(dev); */
	/* XXX KDM fix this */
	unit = minor(dev) & 0xff;

	periph = cam_extend_get(passperiphs, unit);
	if (periph == NULL)
		return (ENXIO);	

	softc = (struct pass_softc *)periph->softc;

	if ((error = cam_periph_lock(periph, PRIBIO)) != 0)
		return (error);

	softc->flags &= ~PASS_FLAG_OPEN;

	cam_periph_unlock(periph);
	cam_periph_release(periph);

	return (0);
}

static int
passread(dev_t dev, struct uio *uio, int ioflag)
{
	return(physio(passstrategy, NULL, dev, 1, minphys, uio));
}

static int
passwrite(dev_t dev, struct uio *uio, int ioflag)
{
	return(physio(passstrategy, NULL, dev, 0, minphys, uio));
}

/*
 * Actually translate the requested transfer into one the physical driver
 * can understand.  The transfer is described by a buf and will include
 * only one physical transfer.
 */
static void
passstrategy(struct buf *bp)
{
	struct cam_periph *periph;
	struct pass_softc *softc;
	u_int  unit;
	int    s;

	/*
	 * The read/write interface for the passthrough driver doesn't
	 * really work right now.  So, we just pass back EINVAL to tell the
	 * user to go away.
	 */
	bp->b_error = EINVAL;
	goto bad;

	/* unit = dkunit(bp->b_dev); */
	/* XXX KDM fix this */
	unit = minor(bp->b_dev) & 0xff;

	periph = cam_extend_get(passperiphs, unit);
	if (periph == NULL) {
		bp->b_error = ENXIO;
		goto bad;
	}
	softc = (struct pass_softc *)periph->softc;

	/*
	 * Odd number of bytes or negative offset
	 */
	/* valid request?  */
	if (bp->b_blkno < 0) {
		bp->b_error = EINVAL;
		goto bad;
        }
	
	/*
	 * Mask interrupts so that the pack cannot be invalidated until
	 * after we are in the queue.  Otherwise, we might not properly
	 * clean up one of the buffers.
	 */
	s = splbio();
	
	bufq_insert_tail(&softc->buf_queue, bp);

	splx(s);
	
	/*
	 * Schedule ourselves for performing the work.
	 */
	xpt_schedule(periph, /* XXX priority */1);

	return;
bad:
	bp->b_flags |= B_ERROR;

	/*
	 * Correctly set the buf to indicate a completed xfer
	 */
	bp->b_resid = bp->b_bcount;
	biodone(bp);
	return;
}

static void
passstart(struct cam_periph *periph, union ccb *start_ccb)
{
	struct pass_softc *softc;
	int s;

	softc = (struct pass_softc *)periph->softc;

	switch (softc->state) {
	case PASS_STATE_NORMAL:
	{
		struct buf *bp;

		s = splbio();
		bp = bufq_first(&softc->buf_queue);
		if (periph->immediate_priority <= periph->pinfo.priority) {
			start_ccb->ccb_h.ccb_type = PASS_CCB_WAITING;			
			SLIST_INSERT_HEAD(&periph->ccb_list, &start_ccb->ccb_h,
					  periph_links.sle);
			periph->immediate_priority = CAM_PRIORITY_NONE;
			splx(s);
			wakeup(&periph->ccb_list);
		} else if (bp == NULL) {
			splx(s);
			xpt_release_ccb(start_ccb);
		} else {

			bufq_remove(&softc->buf_queue, bp);

			devstat_start_transaction(&softc->device_stats);

			/*
			 * XXX JGibbs -
			 * Interpret the contents of the bp as a CCB
			 * and pass it to a routine shared by our ioctl
			 * code and passtart.
			 * For now, just biodone it with EIO so we don't
			 * hang.
			 */
			bp->b_error = EIO;
			bp->b_flags |= B_ERROR;
			bp->b_resid = bp->b_bcount;
			biodone(bp);
			bp = bufq_first(&softc->buf_queue);
			splx(s);
  
			xpt_action(start_ccb);

		}
		if (bp != NULL) {
			/* Have more work to do, so ensure we stay scheduled */
			xpt_schedule(periph, /* XXX priority */1);
		}
		break;
	}
	}
}
static void
passdone(struct cam_periph *periph, union ccb *done_ccb)
{ 
	struct pass_softc *softc;
	struct ccb_scsiio *csio;

	softc = (struct pass_softc *)periph->softc;
	csio = &done_ccb->csio;
	switch (csio->ccb_h.ccb_type) {
	case PASS_CCB_BUFFER_IO:
	{
		struct buf		*bp;
		cam_status		status;
		u_int8_t		scsi_status;
		devstat_trans_flags	ds_flags;

		status = done_ccb->ccb_h.status;
		scsi_status = done_ccb->csio.scsi_status;
		bp = (struct buf *)done_ccb->ccb_h.ccb_bp;
		/* XXX handle errors */
		if (!(((status & CAM_STATUS_MASK) == CAM_REQ_CMP)
		  && (scsi_status == SCSI_STATUS_OK))) {
			int error;
			
			if ((error = passerror(done_ccb, 0, 0)) == ERESTART) {
				/*
				 * A retry was scheuled, so
				 * just return.
				 */
				return;
			}

			/*
			 * XXX unfreeze the queue after we complete
			 * the abort process
			 */
			bp->b_error = error;
			bp->b_flags |= B_ERROR;
		}

		if ((done_ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN)
			ds_flags = DEVSTAT_READ;
		else if ((done_ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT)
			ds_flags = DEVSTAT_WRITE;
		else
			ds_flags = DEVSTAT_NO_DATA;

		devstat_end_transaction(&softc->device_stats, bp->b_bcount, 
					done_ccb->csio.tag_action & 0xf, 
					ds_flags);

		biodone(bp);
		break;
	}
	case PASS_CCB_WAITING:
	{
		/* Caller will release the CCB */
		wakeup(&done_ccb->ccb_h.cbfcnp);
		return;
	}
	}
	xpt_release_ccb(done_ccb);
}

static int
passioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
{
	struct 	cam_periph *periph;
	struct	pass_softc *softc;
	u_int8_t unit;
	int      error;


	/* unit = dkunit(dev); */
	/* XXX KDM fix this */
	unit = minor(dev) & 0xff;

	periph = cam_extend_get(passperiphs, unit);

	if (periph == NULL)
		return(ENXIO);

	softc = (struct pass_softc *)periph->softc;

	error = 0;

	switch (cmd) {

	case CAMIOCOMMAND:
	{
		union ccb *inccb;
		union ccb *ccb;
		int ccb_malloced;

		inccb = (union ccb *)addr;

		/*
		 * Some CCB types, like scan bus and scan lun can only go
		 * through the transport layer device.
		 */
		if (inccb->ccb_h.func_code & XPT_FC_XPT_ONLY) {
			xpt_print_path(periph->path);
			printf("CCB function code %#x is restricted to the "
			       "XPT device\n", inccb->ccb_h.func_code);
			error = ENODEV;
			break;
		}

		/*
		 * Non-immediate CCBs need a CCB from the per-device pool
		 * of CCBs, which is scheduled by the transport layer.
		 * Immediate CCBs and user-supplied CCBs should just be
		 * malloced.
		 */
		if ((inccb->ccb_h.func_code & XPT_FC_QUEUED)
		 && ((inccb->ccb_h.func_code & XPT_FC_USER_CCB) == 0)) {
			ccb = cam_periph_getccb(periph,
						inccb->ccb_h.pinfo.priority);
			ccb_malloced = 0;
		} else {
			ccb = xpt_alloc_ccb();

			if (ccb != NULL)
				xpt_setup_ccb(&ccb->ccb_h, periph->path,
					      inccb->ccb_h.pinfo.priority);
			ccb_malloced = 1;
		}

		if (ccb == NULL) {
			xpt_print_path(periph->path);
			printf("unable to allocate CCB\n");
			error = ENOMEM;
			break;
		}

		error = passsendccb(periph, ccb, inccb);

		if (ccb_malloced)
			xpt_free_ccb(ccb);
		else
			xpt_release_ccb(ccb);

		break;
	}
	default:
		error = cam_periph_ioctl(periph, cmd, addr, passerror);
		break;
	}

	return(error);
}

/*
 * Generally, "ccb" should be the CCB supplied by the kernel.  "inccb"
 * should be the CCB that is copied in from the user.
 */
static int
passsendccb(struct cam_periph *periph, union ccb *ccb, union ccb *inccb)
{
	struct pass_softc *softc;
	struct cam_periph_map_info mapinfo;
	int error, need_unmap;

	softc = (struct pass_softc *)periph->softc;

	need_unmap = 0;

	/*
	 * There are some fields in the CCB header that need to be
	 * preserved, the rest we get from the user.
	 */
	xpt_merge_ccb(ccb, inccb);

	/*
	 * There's no way for the user to have a completion
	 * function, so we put our own completion function in here.
	 */
	ccb->ccb_h.cbfcnp = passdone;

	/*
	 * We only attempt to map the user memory into kernel space
	 * if they haven't passed in a physical memory pointer,
	 * and if there is actually an I/O operation to perform.
	 * Right now cam_periph_mapmem() only supports SCSI and device
	 * match CCBs.  For the SCSI CCBs, we only pass the CCB in if
	 * there's actually data to map.  cam_periph_mapmem() will do the
	 * right thing, even if there isn't data to map, but since CCBs
	 * without data are a reasonably common occurance (e.g. test unit
	 * ready), it will save a few cycles if we check for it here.
	 */
	if (((ccb->ccb_h.flags & CAM_DATA_PHYS) == 0)
	 && (((ccb->ccb_h.func_code == XPT_SCSI_IO)
	    && ((ccb->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_NONE))
	  || (ccb->ccb_h.func_code == XPT_DEV_MATCH))) {

		bzero(&mapinfo, sizeof(mapinfo));

		error = cam_periph_mapmem(ccb, &mapinfo); 

		/*
		 * cam_periph_mapmem returned an error, we can't continue.
		 * Return the error to the user.
		 */
		if (error)
			return(error);

		/*
		 * We successfully mapped the memory in, so we need to
		 * unmap it when the transaction is done.
		 */
		need_unmap = 1;
	}

	/*
	 * If the user wants us to perform any error recovery, then honor
	 * that request.  Otherwise, it's up to the user to perform any
	 * error recovery.
	 */
	error = cam_periph_runccb(ccb,
				  (ccb->ccb_h.flags & CAM_PASS_ERR_RECOVER) ?
				  passerror : NULL,
				  /* cam_flags */ 0,
				  /* sense_flags */SF_RETRY_UA | SF_RETRY_SELTO,
				  &softc->device_stats);

	if (need_unmap != 0)
		cam_periph_unmapmem(ccb, &mapinfo);

	ccb->ccb_h.cbfcnp = NULL;
	ccb->ccb_h.periph_priv = inccb->ccb_h.periph_priv;
	bcopy(ccb, inccb, sizeof(union ccb));

	return(error);
}

static int
passerror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
{
	struct cam_periph *periph;
	struct pass_softc *softc;

	periph = xpt_path_periph(ccb->ccb_h.path);
	softc = (struct pass_softc *)periph->softc;
	
	return(cam_periph_error(ccb, cam_flags, sense_flags, 
				 &softc->saved_ccb));
}