mrsas(4): Report more correct maximum I/O size.

Subtract one SGE for the case of misaligned address.  Also take into
account maximum number of sectors reported by firmware, that gives
nicer 256KB limit instead of 276KB calculated from the SGE limit.

While there, remove number of I/O size checks, duplicating what is
already checked by CAM and busdma(9).

MFC after:	1 month
Sponsored by:	iXsystems, Inc.

(cherry picked from commit fa3d57c256104649217b5022947de9c1c59a326e)

2 files changed, 7 insertions, 40 deletions

diff --git a/sys/dev/mrsas/mrsas.c b/sys/dev/mrsas/mrsas.c
index df4fb98c53eb..ff7dc765a3b4 100644
--- a/sys/dev/mrsas/mrsas.c
+++ b/sys/dev/mrsas/mrsas.c
@@ -1923,15 +1923,16 @@ mrsas_alloc_mem(struct mrsas_softc *sc)
 	/*
 	 * Allocate parent DMA tag
 	 */
-	if (bus_dma_tag_create(NULL,	/* parent */
+	if (bus_dma_tag_create(
+	    bus_get_dma_tag(sc->mrsas_dev),	/* parent */
 	    1,				/* alignment */
 	    0,				/* boundary */
 	    BUS_SPACE_MAXADDR,		/* lowaddr */
 	    BUS_SPACE_MAXADDR,		/* highaddr */
 	    NULL, NULL,			/* filter, filterarg */
-	    MAXPHYS,			/* maxsize */
-	    sc->max_num_sge,		/* nsegments */
-	    MAXPHYS,			/* maxsegsize */
+	    BUS_SPACE_MAXSIZE,		/* maxsize */
+	    BUS_SPACE_UNRESTRICTED,	/* nsegments */
+	    BUS_SPACE_MAXSIZE,		/* maxsegsize */
 	    0,				/* flags */
 	    NULL, NULL,			/* lockfunc, lockarg */
 	    &sc->mrsas_parent_tag	/* tag */
@@ -2543,7 +2544,7 @@ mrsas_init_fw(struct mrsas_softc *sc)
 	    sc->ctrl_info->max_strips_per_io;
 	max_sectors_2 = sc->ctrl_info->max_request_size;
 	tmp_sectors = min(max_sectors_1, max_sectors_2);
-	sc->max_sectors_per_req = sc->max_num_sge * MRSAS_PAGE_SIZE / 512;
+	sc->max_sectors_per_req = (sc->max_num_sge - 1) * MRSAS_PAGE_SIZE / 512;
 
 	if (tmp_sectors && (sc->max_sectors_per_req > tmp_sectors))
 		sc->max_sectors_per_req = tmp_sectors;
diff --git a/sys/dev/mrsas/mrsas_cam.c b/sys/dev/mrsas/mrsas_cam.c
index 0ff897a01aa8..c53fdbb4ea71 100644
--- a/sys/dev/mrsas/mrsas_cam.c
+++ b/sys/dev/mrsas/mrsas_cam.c
@@ -369,7 +369,7 @@ mrsas_action(struct cam_sim *sim, union ccb *ccb)
 			else
 				ccb->cpi.max_target = MRSAS_MAX_LD_IDS - 1;
 #if (__FreeBSD_version > 704000)
-			ccb->cpi.maxio = sc->max_num_sge * MRSAS_PAGE_SIZE;
+			ccb->cpi.maxio = sc->max_sectors_per_req * 512;
 #endif
 			ccb->ccb_h.status = CAM_REQ_CMP;
 			xpt_done(ccb);
@@ -513,21 +513,11 @@ mrsas_startio(struct mrsas_softc *sc, struct cam_sim *sim,
 		ccb_h->status = CAM_REQ_INVALID;
 		goto done;
 	case CAM_DATA_VADDR:
-		if (csio->dxfer_len > (sc->max_num_sge * MRSAS_PAGE_SIZE)) {
-			mrsas_release_mpt_cmd(cmd);
-			ccb_h->status = CAM_REQ_TOO_BIG;
-			goto done;
-		}
 		cmd->length = csio->dxfer_len;
 		if (cmd->length)
 			cmd->data = csio->data_ptr;
 		break;
 	case CAM_DATA_BIO:
-		if (csio->dxfer_len > (sc->max_num_sge * MRSAS_PAGE_SIZE)) {
-			mrsas_release_mpt_cmd(cmd);
-			ccb_h->status = CAM_REQ_TOO_BIG;
-			goto done;
-		}
 		cmd->length = csio->dxfer_len;
 		if (cmd->length)
 			cmd->data = csio->data_ptr;
@@ -539,11 +529,6 @@ mrsas_startio(struct mrsas_softc *sc, struct cam_sim *sim,
 #else
 	if (!(ccb_h->flags & CAM_DATA_PHYS)) {	/* Virtual data address */
 		if (!(ccb_h->flags & CAM_SCATTER_VALID)) {
-			if (csio->dxfer_len > (sc->max_num_sge * MRSAS_PAGE_SIZE)) {
-				mrsas_release_mpt_cmd(cmd);
-				ccb_h->status = CAM_REQ_TOO_BIG;
-				goto done;
-			}
 			cmd->length = csio->dxfer_len;
 			if (cmd->length)
 				cmd->data = csio->data_ptr;
@@ -871,11 +856,6 @@ mrsas_build_ldio_rw(struct mrsas_softc *sc, struct mrsas_mpt_cmd *cmd,
 	io_request->DataLength = cmd->length;
 
 	if (mrsas_map_request(sc, cmd, ccb) == SUCCESS) {
-		if (cmd->sge_count > sc->max_num_sge) {
-			device_printf(sc->mrsas_dev, "Error: sge_count (0x%x) exceeds"
-			    "max (0x%x) allowed\n", cmd->sge_count, sc->max_num_sge);
-			return (FAIL);
-		}
 		if (sc->is_ventura || sc->is_aero)
 			io_request->RaidContext.raid_context_g35.numSGE = cmd->sge_count;
 		else {
@@ -1239,11 +1219,6 @@ mrsas_build_ldio_nonrw(struct mrsas_softc *sc, struct mrsas_mpt_cmd *cmd,
 	io_request->DataLength = cmd->length;
 
 	if (mrsas_map_request(sc, cmd, ccb) == SUCCESS) {
-		if (cmd->sge_count > sc->max_num_sge) {
-			device_printf(sc->mrsas_dev, "Error: sge_count (0x%x) exceeds"
-			    "max (0x%x) allowed\n", cmd->sge_count, sc->max_num_sge);
-			return (1);
-		}
 		if (sc->is_ventura || sc->is_aero)
 			io_request->RaidContext.raid_context_g35.numSGE = cmd->sge_count;
 		else {
@@ -1369,11 +1344,6 @@ mrsas_build_syspdio(struct mrsas_softc *sc, struct mrsas_mpt_cmd *cmd,
 	io_request->DataLength = cmd->length;
 
 	if (mrsas_map_request(sc, cmd, ccb) == SUCCESS) {
-		if (cmd->sge_count > sc->max_num_sge) {
-			device_printf(sc->mrsas_dev, "Error: sge_count (0x%x) exceeds"
-			    "max (0x%x) allowed\n", cmd->sge_count, sc->max_num_sge);
-			return (1);
-		}
 		if (sc->is_ventura || sc->is_aero)
 			io_request->RaidContext.raid_context_g35.numSGE = cmd->sge_count;
 		else {
@@ -1724,10 +1694,6 @@ mrsas_data_load_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
 	if (cmd->flags & MRSAS_DIR_OUT)
 		bus_dmamap_sync(cmd->sc->data_tag, cmd->data_dmamap,
 		    BUS_DMASYNC_PREWRITE);
-	if (nseg > sc->max_num_sge) {
-		device_printf(sc->mrsas_dev, "SGE count is too large or 0.\n");
-		return;
-	}
 
 	/* Check for whether PRPs should be built or IEEE SGLs*/
 	if ((cmd->io_request->IoFlags & MPI25_SAS_DEVICE0_FLAGS_ENABLED_FAST_PATH) &&