tweak mpii_start.

on 64bit archs you can post the descriptor in one go, which is easy. on
32bit you have to post it in halves in the right order, which is not
atomic and requires barriers for ordering.

1 files changed, 26 insertions, 14 deletions

diff --git a/sys/dev/pci/mpii.c b/sys/dev/pci/mpii.c
index 040a75be412..31190cd9518 100644
--- a/sys/dev/pci/mpii.c
+++ b/sys/dev/pci/mpii.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mpii.c,v 1.87 2014/03/27 07:12:52 dlg Exp $	*/
+/*	$OpenBSD: mpii.c,v 1.88 2014/03/27 10:15:43 dlg Exp $	*/
 /*
  * Copyright (c) 2010, 2012 Mike Belopuhov
  * Copyright (c) 2009 James Giannoules
@@ -127,7 +127,6 @@ struct mpii_device {
 
 struct mpii_ccb {
 	struct mpii_softc	*ccb_sc;
-	int			ccb_smid;
 
 	void *			ccb_cookie;
 	bus_dmamap_t		ccb_dmamap;
@@ -136,6 +135,7 @@ struct mpii_ccb {
 	void			*ccb_cmd;
 	bus_addr_t		ccb_cmd_dva;
 	u_int16_t		ccb_dev_handle;
+	u_int16_t		ccb_smid;
 
 	volatile enum {
 		MPII_CCB_FREE,
@@ -2384,7 +2384,7 @@ mpii_alloc_ccbs(struct mpii_softc *sc)
 		}
 
 		ccb->ccb_sc = sc;
-		ccb->ccb_smid = i;
+		htolem16(&ccb->ccb_smid, i);
 		ccb->ccb_offset = sc->sc_request_size * i;
 
 		ccb->ccb_cmd = &cmd[ccb->ccb_offset];
@@ -2499,11 +2499,17 @@ mpii_start(struct mpii_softc *sc, struct mpii_ccb *ccb)
 {
 	struct mpii_request_header	*rhp;
 	struct mpii_request_descr	descr;
-	u_int32_t			*rdp = (u_int32_t *)&descr;
+	u_long				 *rdp = (u_long *)&descr;
 
 	DNPRINTF(MPII_D_RW, "%s: mpii_start %#x\n", DEVNAME(sc),
 	    ccb->ccb_cmd_dva);
 
+	bus_dmamap_sync(sc->sc_dmat, MPII_DMA_MAP(sc->sc_requests),
+	    ccb->ccb_offset, sc->sc_request_size,
+	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+
+	ccb->ccb_state = MPII_CCB_QUEUED;
+
 	rhp = ccb->ccb_cmd;
 
 	memset(&descr, 0, sizeof(descr));
@@ -2511,7 +2517,7 @@ mpii_start(struct mpii_softc *sc, struct mpii_ccb *ccb)
 	switch (rhp->function) {
 	case MPII_FUNCTION_SCSI_IO_REQUEST:
 		descr.request_flags = MPII_REQ_DESCR_SCSI_IO;
-		htolem16(&descr.dev_handle, ccb->ccb_dev_handle);
+		descr.dev_handle = htole16(ccb->ccb_dev_handle);
 		break;
 	case MPII_FUNCTION_SCSI_TASK_MGMT:
 		descr.request_flags = MPII_REQ_DESCR_HIGH_PRIORITY;
@@ -2521,13 +2527,7 @@ mpii_start(struct mpii_softc *sc, struct mpii_ccb *ccb)
 	}
 
 	descr.vf_id = sc->sc_vf_id;
-	htolem16(&descr.smid, ccb->ccb_smid);
-
-	bus_dmamap_sync(sc->sc_dmat, MPII_DMA_MAP(sc->sc_requests),
-	    ccb->ccb_offset, sc->sc_request_size,
-	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
-
-	ccb->ccb_state = MPII_CCB_QUEUED;
+	descr.smid = ccb->ccb_smid;
 
 	DNPRINTF(MPII_D_RW, "%s:   MPII_REQ_DESCR_POST_LOW (0x%08x) write "
 	    "0x%08x\n", DEVNAME(sc), MPII_REQ_DESCR_POST_LOW, *rdp);
@@ -2535,10 +2535,22 @@ mpii_start(struct mpii_softc *sc, struct mpii_ccb *ccb)
 	DNPRINTF(MPII_D_RW, "%s:   MPII_REQ_DESCR_POST_HIGH (0x%08x) write "
 	    "0x%08x\n", DEVNAME(sc), MPII_REQ_DESCR_POST_HIGH, *(rdp+1));
 
+#if defined(__LP64__)
+	bus_space_write_raw_8(sc->sc_iot, sc->sc_ioh,
+	    MPII_REQ_DESCR_POST_LOW, *rdp);
+#else
 	mtx_enter(&sc->sc_req_mtx);
-	mpii_write(sc, MPII_REQ_DESCR_POST_LOW, htole32(*rdp));
-	mpii_write(sc, MPII_REQ_DESCR_POST_HIGH, htole32(*(rdp+1)));
+	bus_space_write_raw_4(sc->sc_iot, sc->sc_ioh,
+	    MPII_REQ_DESCR_POST_LOW, rdp[0]);
+	bus_space_barrier(sc->sc_iot, sc->sc_ioh,
+	    MPII_REQ_DESCR_POST_LOW, 8, BUS_SPACE_BARRIER_WRITE);
+
+	bus_space_write_raw_4(sc->sc_iot, sc->sc_ioh,
+	    MPII_REQ_DESCR_POST_HIGH, rdp[1]);
+	bus_space_barrier(sc->sc_iot, sc->sc_ioh,
+	    MPII_REQ_DESCR_POST_LOW, 8, BUS_SPACE_BARRIER_WRITE);
 	mtx_leave(&sc->sc_req_mtx);
+#endif
 }
 
 int