ahc(4)/ahd(4): fix target mode on ARM

One of the comments in ahc_execute_scb() notes that the CAM direction is
actually w.r.t. the initiator.  As a consequence, all of our sync ops
end up being wrong because the direction is flipped from that of the
transfer.  Fix it to do proper invalidation and avoid spewing random
garbage out on the SCSI bus.

Reported and tested by:	HP van Braam <hp@tmm.cx>
Reviewed by:	imp, mav
Differential Revision:	https://reviews.freebsd.org/D44860

2 files changed, 42 insertions, 28 deletions

diff --git a/sys/dev/aic7xxx/aic79xx_osm.c b/sys/dev/aic7xxx/aic79xx_osm.c
index df73b3fadfa4..4a1e3336fe5f 100644
--- a/sys/dev/aic7xxx/aic79xx_osm.c
+++ b/sys/dev/aic7xxx/aic79xx_osm.c
@@ -303,6 +303,25 @@ ahd_platform_intr(void *arg)
 	ahd_unlock(ahd);
 }
 
+static void
+ahd_sync_ccb(struct ahd_softc *ahd, struct scb *scb, union ccb *ccb, bool post)
+{
+	bus_dmasync_op_t op;
+	uint32_t rdmask;
+
+	if (ccb->ccb_h.func_code == XPT_CONT_TARGET_IO)
+		rdmask = CAM_DIR_OUT;
+	else
+		rdmask = CAM_DIR_IN;
+
+	if ((ccb->ccb_h.flags & CAM_DIR_MASK) == rdmask)
+		op = post ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_PREREAD;
+	else
+		op = post ? BUS_DMASYNC_POSTWRITE : BUS_DMASYNC_PREWRITE;
+
+	bus_dmamap_sync(ahd->buffer_dmat, scb->dmamap, op);
+}
+
 /*
  * We have an scb which has been processed by the
  * adaptor, now we look to see how the operation
@@ -324,13 +343,7 @@ ahd_done(struct ahd_softc *ahd, struct scb *scb)
 	callout_stop(&scb->io_timer);
 
 	if ((ccb->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_NONE) {
-		bus_dmasync_op_t op;
-
-		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN)
-			op = BUS_DMASYNC_POSTREAD;
-		else
-			op = BUS_DMASYNC_POSTWRITE;
-		bus_dmamap_sync(ahd->buffer_dmat, scb->dmamap, op);
+		ahd_sync_ccb(ahd, scb, ccb, true);
 		bus_dmamap_unload(ahd->buffer_dmat, scb->dmamap);
 	}
 
@@ -961,7 +974,6 @@ ahd_execute_scb(void *arg, bus_dma_segment_t *dm_segs, int nsegments,
 	scb->sg_count = 0;
 	if (nsegments != 0) {
 		void *sg;
-		bus_dmasync_op_t op;
 		u_int i;
 
 		/* Copy the segments into our SG list */
@@ -971,13 +983,8 @@ ahd_execute_scb(void *arg, bus_dma_segment_t *dm_segs, int nsegments,
 					  /*last*/i == 1);
 			dm_segs++;
 		}
-		
-		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN)
-			op = BUS_DMASYNC_PREREAD;
-		else
-			op = BUS_DMASYNC_PREWRITE;
 
-		bus_dmamap_sync(ahd->buffer_dmat, scb->dmamap, op);
+		ahd_sync_ccb(ahd, scb, ccb, false);
 
 		if (ccb->ccb_h.func_code == XPT_CONT_TARGET_IO) {
 			struct target_data *tdata;
diff --git a/sys/dev/aic7xxx/aic7xxx_osm.c b/sys/dev/aic7xxx/aic7xxx_osm.c
index 46c87defa3a5..04037773c528 100644
--- a/sys/dev/aic7xxx/aic7xxx_osm.c
+++ b/sys/dev/aic7xxx/aic7xxx_osm.c
@@ -302,6 +302,25 @@ ahc_platform_intr(void *arg)
 	ahc_unlock(ahc);
 }
 
+static void
+ahc_sync_ccb(struct ahc_softc *ahc, struct scb *scb, union ccb *ccb, bool post)
+{
+	bus_dmasync_op_t op;
+	uint32_t rdmask;
+
+	if (ccb->ccb_h.func_code == XPT_CONT_TARGET_IO)
+		rdmask = CAM_DIR_OUT;
+	else
+		rdmask = CAM_DIR_IN;
+
+	if ((ccb->ccb_h.flags & CAM_DIR_MASK) == rdmask)
+		op = post ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_PREREAD;
+	else
+		op = post ? BUS_DMASYNC_POSTWRITE : BUS_DMASYNC_PREWRITE;
+
+	bus_dmamap_sync(ahc->buffer_dmat, scb->dmamap, op);
+}
+
 /*
  * We have an scb which has been processed by the
  * adaptor, now we look to see how the operation
@@ -333,13 +352,7 @@ ahc_done(struct ahc_softc *ahc, struct scb *scb)
 	callout_stop(&scb->io_timer);
 
 	if ((ccb->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_NONE) {
-		bus_dmasync_op_t op;
-
-		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN)
-			op = BUS_DMASYNC_POSTREAD;
-		else
-			op = BUS_DMASYNC_POSTWRITE;
-		bus_dmamap_sync(ahc->buffer_dmat, scb->dmamap, op);
+		ahc_sync_ccb(ahc, scb, ccb, true);
 		bus_dmamap_unload(ahc->buffer_dmat, scb->dmamap);
 	}
 
@@ -943,7 +956,6 @@ ahc_execute_scb(void *arg, bus_dma_segment_t *dm_segs, int nsegments,
 	if (nsegments != 0) {
 		struct	  ahc_dma_seg *sg;
 		bus_dma_segment_t *end_seg;
-		bus_dmasync_op_t op;
 
 		end_seg = dm_segs + nsegments;
 
@@ -968,12 +980,7 @@ ahc_execute_scb(void *arg, bus_dma_segment_t *dm_segs, int nsegments,
 		 */
 		scb->hscb->sgptr = aic_htole32(scb->sg_list_phys|SG_FULL_RESID);
 
-		if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN)
-			op = BUS_DMASYNC_PREREAD;
-		else
-			op = BUS_DMASYNC_PREWRITE;
-
-		bus_dmamap_sync(ahc->buffer_dmat, scb->dmamap, op);
+		ahc_sync_ccb(ahc, scb, ccb, false);
 
 		if (ccb->ccb_h.func_code == XPT_CONT_TARGET_IO) {
 			struct target_data *tdata;