Fix residual length reporting in target mode.

This allows to properly handle cases when target wants to receive or send
more data then initiator wants to send or receive.  Previously in such
cases isp(4) returned CAM_DATA_RUN_ERR, while now it returns resid > 0.

MFC after:	2 weeks

2 files changed, 28 insertions, 28 deletions

diff --git a/sys/dev/isp/isp_freebsd.c b/sys/dev/isp/isp_freebsd.c
index e66fd46bced1..36561f5dec0e 100644
--- a/sys/dev/isp/isp_freebsd.c
+++ b/sys/dev/isp/isp_freebsd.c
@@ -1316,13 +1316,24 @@ isp_target_start_ctio(ispsoftc_t *isp, union ccb *ccb, enum Start_Ctio_How how)
 		/*
 		 * Check for overflow
 		 */
-		tmp = atp->bytes_xfered + atp->bytes_in_transit + xfrlen;
-		if (tmp > atp->orig_datalen) {
-			isp_prt(isp, ISP_LOGERR, "%s: [0x%x] data overflow by %u bytes", __func__, cso->tag_id, tmp - atp->orig_datalen);
+		tmp = atp->bytes_xfered + atp->bytes_in_transit;
+		if (xfrlen > 0 && tmp > atp->orig_datalen) {
+			isp_prt(isp, ISP_LOGERR,
+			    "%s: [0x%x] data overflow by %u bytes", __func__,
+			    cso->tag_id, tmp + xfrlen - atp->orig_datalen);
 			ccb->ccb_h.status = CAM_DATA_RUN_ERR;
 			xpt_done(ccb);
 			continue;
 		}
+		if (xfrlen > atp->orig_datalen - tmp) {
+			xfrlen = atp->orig_datalen - tmp;
+			if (xfrlen == 0 && !sendstatus) {
+				cso->resid = cso->dxfer_len;
+				ccb->ccb_h.status = CAM_REQ_CMP;
+				xpt_done(ccb);
+				continue;
+			}
+		}
 
 		if (IS_24XX(isp)) {
 			ct7_entry_t *cto = (ct7_entry_t *) local;
@@ -1352,16 +1363,13 @@ isp_target_start_ctio(ispsoftc_t *isp, union ccb *ccb, enum Start_Ctio_How how)
 				cto->ct_flags |= CT7_SENDSTATUS | CT7_NO_DATA;
 				resid = atp->orig_datalen - atp->bytes_xfered - atp->bytes_in_transit;
 				if (sense_length <= MAXRESPLEN_24XX) {
-					if (resid < 0) {
-						cto->ct_resid = -resid;
-					} else if (resid > 0) {
-						cto->ct_resid = resid;
-					}
 					cto->ct_flags |= CT7_FLAG_MODE1;
 					cto->ct_scsi_status = cso->scsi_status;
 					if (resid < 0) {
+						cto->ct_resid = -resid;
 						cto->ct_scsi_status |= (FCP_RESID_OVERFLOW << 8);
 					} else if (resid > 0) {
+						cto->ct_resid = resid;
 						cto->ct_scsi_status |= (FCP_RESID_UNDERFLOW << 8);
 					}
 					if (fctape) {
@@ -2238,10 +2246,10 @@ static void
 isp_handle_platform_ctio(ispsoftc_t *isp, void *arg)
 {
 	union ccb *ccb;
-	int sentstatus = 0, ok = 0, notify_cam = 0, resid = 0, failure = 0;
+	int sentstatus = 0, ok = 0, notify_cam = 0, failure = 0;
 	atio_private_data_t *atp = NULL;
 	int bus;
-	uint32_t handle, moved_data = 0, data_requested;
+	uint32_t handle, data_requested, resid;
 
 	handle = ((ct2_entry_t *)arg)->ct_syshandle;
 	ccb = isp_find_xs(isp, handle);
@@ -2250,7 +2258,7 @@ isp_handle_platform_ctio(ispsoftc_t *isp, void *arg)
 		return;
 	}
 	isp_destroy_handle(isp, handle);
-	data_requested = PISP_PCMD(ccb)->datalen;
+	resid = data_requested = PISP_PCMD(ccb)->datalen;
 	isp_free_pcmd(isp, ccb);
 	if (isp->isp_nactive) {
 		isp->isp_nactive--;
@@ -2296,10 +2304,8 @@ isp_handle_platform_ctio(ispsoftc_t *isp, void *arg)
 			sentstatus = ct->ct_flags & CT7_SENDSTATUS;
 			ok = (ct->ct_nphdl == CT7_OK);
 			notify_cam = (ct->ct_header.rqs_seqno & ATPD_SEQ_NOTIFY_CAM) != 0;
-			if ((ct->ct_flags & CT7_DATAMASK) != CT7_NO_DATA) {
+			if ((ct->ct_flags & CT7_DATAMASK) != CT7_NO_DATA)
 				resid = ct->ct_resid;
-				moved_data = data_requested - resid;
-			}
 		}
 		isp_prt(isp, ok? ISP_LOGTDEBUG0 : ISP_LOGWARN, "%s: CTIO7[%x] seq %u nc %d sts 0x%x flg 0x%x sns %d resid %d %s", __func__, ct->ct_rxid, ATPD_GET_SEQNO(ct),
 		   notify_cam, ct->ct_nphdl, ct->ct_flags, (ccb->ccb_h.status & CAM_SENT_SENSE) != 0, resid, sentstatus? "FIN" : "MID");
@@ -2320,22 +2326,20 @@ isp_handle_platform_ctio(ispsoftc_t *isp, void *arg)
 			sentstatus = ct->ct_flags & CT2_SENDSTATUS;
 			ok = (ct->ct_status & ~QLTM_SVALID) == CT_OK;
 			notify_cam = (ct->ct_header.rqs_seqno & ATPD_SEQ_NOTIFY_CAM) != 0;
-			if ((ct->ct_flags & CT2_DATAMASK) != CT2_NO_DATA) {
+			if ((ct->ct_flags & CT2_DATAMASK) != CT2_NO_DATA)
 				resid = ct->ct_resid;
-				moved_data = data_requested - resid;
-			}
 		}
 		isp_prt(isp, ok? ISP_LOGTDEBUG0 : ISP_LOGWARN, "%s: CTIO2[%x] seq %u nc %d sts 0x%x flg 0x%x sns %d resid %d %s", __func__, ct->ct_rxid, ATPD_GET_SEQNO(ct),
 		    notify_cam, ct->ct_status, ct->ct_flags, (ccb->ccb_h.status & CAM_SENT_SENSE) != 0, resid, sentstatus? "FIN" : "MID");
 	}
 	if (ok) {
-		if (moved_data) {
-			atp->bytes_xfered += moved_data;
-			ccb->csio.resid = atp->orig_datalen - atp->bytes_xfered - atp->bytes_in_transit;
+		if (data_requested > 0) {
+			atp->bytes_xfered += data_requested - resid;
+			ccb->csio.resid = ccb->csio.dxfer_len -
+			    (data_requested - resid);
 		}
-		if (sentstatus && (ccb->ccb_h.flags & CAM_SEND_SENSE)) {
+		if (sentstatus && (ccb->ccb_h.flags & CAM_SEND_SENSE))
 			ccb->ccb_h.status |= CAM_SENT_SENSE;
-		}
 		ccb->ccb_h.status |= CAM_REQ_CMP;
 	} else {
 		notify_cam = 1;
diff --git a/sys/dev/isp/isp_target.c b/sys/dev/isp/isp_target.c
index 5a31ea766540..f86792ec86fc 100644
--- a/sys/dev/isp/isp_target.c
+++ b/sys/dev/isp/isp_target.c
@@ -558,13 +558,9 @@ isp_endcmd(ispsoftc_t *isp, ...)
 		} else {
 			cto->ct_flags |= CT7_FLAG_MODE1 | CT7_SENDSTATUS;
 		}
-		if (aep->at_cmnd.cdb_dl.sf.fcp_cmnd_dl) {
+		if (aep->at_cmnd.cdb_dl.sf.fcp_cmnd_dl != 0) {
 			cto->ct_resid = aep->at_cmnd.cdb_dl.sf.fcp_cmnd_dl;
-			if (cto->ct_resid < 0) {
-				 cto->ct_scsi_status |= (FCP_RESID_OVERFLOW << 8);
-			} else if (cto->ct_resid > 0) {
-				 cto->ct_scsi_status |= (FCP_RESID_UNDERFLOW << 8);
-			}
+			cto->ct_scsi_status |= (FCP_RESID_UNDERFLOW << 8);
 		}
 		cto->ct_syshandle = hdl;
 	} else {