This patch implements driver support for 1MB IO size.

NOTE:
The FreeBSD system currently restricts the MAX IO size to MAXPHYS which
in turn is 128KB. We tested the 1MB IO by converting the MAXPHYS to 1MB.

Following is the mail reference:
http://lists.freebsd.org/pipermail/freebsd-scsi/2015-January/006568.html

Submitted by:   Sumit Saxena <sumit.saxena@broadcom.com>
Reviewed by:    Kashyap Desai <Kashyap.Desai@broadcom.com>
MFC after:  3 days
Sponsored by:   AVAGO Technologies

1 files changed, 27 insertions, 6 deletions

diff --git a/sys/dev/mrsas/mrsas_cam.c b/sys/dev/mrsas/mrsas_cam.c
index 4ab096e..74c8391 100644
--- a/sys/dev/mrsas/mrsas_cam.c
+++ b/sys/dev/mrsas/mrsas_cam.c
@@ -344,7 +344,7 @@ 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 = MRSAS_MAX_IO_SIZE;
+			ccb->cpi.maxio = sc->max_num_sge * MRSAS_PAGE_SIZE;
 #endif
 			ccb->ccb_h.status = CAM_REQ_CMP;
 			xpt_done(ccb);
@@ -462,7 +462,7 @@ 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 > MRSAS_MAX_IO_SIZE) {
+		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;
@@ -472,6 +472,11 @@ mrsas_startio(struct mrsas_softc *sc, struct cam_sim *sim,
 			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;
@@ -483,7 +488,7 @@ 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 > MRSAS_MAX_IO_SIZE) {
+			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;
@@ -730,12 +735,18 @@ 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 > MRSAS_MAX_SGL) {
+		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);
 		}
+		/*
+		 * numSGE store lower 8 bit of sge_count. numSGEExt store
+		 * higher 8 bit of sge_count
+		 */
 		io_request->RaidContext.numSGE = cmd->sge_count;
+		io_request->RaidContext.numSGEExt = (uint8_t)(cmd->sge_count >> 8);
+
 	} else {
 		device_printf(sc->mrsas_dev, "Data map/load failed.\n");
 		return (FAIL);
@@ -939,12 +950,17 @@ 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 > MRSAS_MAX_SGL) {
+		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);
 		}
+		/*
+		 * numSGE store lower 8 bit of sge_count. numSGEExt store
+		 * higher 8 bit of sge_count
+		 */
 		io_request->RaidContext.numSGE = cmd->sge_count;
+		io_request->RaidContext.numSGEExt = (uint8_t)(cmd->sge_count >> 8);
 	} else {
 		device_printf(sc->mrsas_dev, "Data map/load failed.\n");
 		return (1);
@@ -1042,12 +1058,17 @@ 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 > MRSAS_MAX_SGL) {
+		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);
 		}
+		/*
+		 * numSGE store lower 8 bit of sge_count. numSGEExt store
+		 * higher 8 bit of sge_count
+		 */
 		io_request->RaidContext.numSGE = cmd->sge_count;
+		io_request->RaidContext.numSGEExt = (uint8_t)(cmd->sge_count >> 8);
 	} else {
 		device_printf(sc->mrsas_dev, "Data map/load failed.\n");
 		return (1);