mpi3mr: Divert large WriteSame IOs to firmware if unmap and ndob bits are set

Firmware advertises the transfer lenght for writesame commands to driver during init.
So for any writesame IOs with ndob and unmap bit set and transfer lengh is greater
than the max write same length specified by the firmware, then direct those commands
to firmware instead of hardware otherwise hardware will break.

Reviewed by:            imp
Approved by:            imp
Differential revision:  https://reviews.freebsd.org/D44452

sys/dev/mpi3mr/mpi3mr.c

@@ -2176,6 +2176,8 @@ static int mpi3mr_issue_iocinit(struct mpi3mr_softc *sc)
 	time_in_msec = (now.tv_sec * 1000 + now.tv_usec/1000);
 	iocinit_req.TimeStamp = htole64(time_in_msec);
 
+	iocinit_req.MsgFlags |= MPI3_IOCINIT_MSGFLAGS_WRITESAMEDIVERT_SUPPORTED;
+
 	init_completion(&sc->init_cmds.completion);
 	retval = mpi3mr_submit_admin_cmd(sc, &iocinit_req,
 	    sizeof(iocinit_req));
@@ -3339,6 +3341,19 @@ void mpi3mr_update_device(struct mpi3mr_softc *sc,
 		break;
 	}
 
+	switch (flags & MPI3_DEVICE0_FLAGS_MAX_WRITE_SAME_MASK) {
+	case MPI3_DEVICE0_FLAGS_MAX_WRITE_SAME_256_LB:
+		tgtdev->ws_len = 256;
+		break;
+	case MPI3_DEVICE0_FLAGS_MAX_WRITE_SAME_2048_LB:
+		tgtdev->ws_len = 2048;
+		break;
+	case MPI3_DEVICE0_FLAGS_MAX_WRITE_SAME_NO_LIMIT:
+	default:
+		tgtdev->ws_len = 0;
+		break;
+	}
+
 	switch (tgtdev->dev_type) {
 	case MPI3_DEVICE_DEVFORM_SAS_SATA:
 	{
@@ -5648,6 +5663,7 @@ static void mpi3mr_invalidate_devhandles(struct mpi3mr_softc *sc)
 			target->io_throttle_enabled = 0;
 			target->io_divert = 0;
 			target->throttle_group = NULL;
+			target->ws_len = 0;
 		}
 	}
 	mtx_unlock_spin(&sc->target_lock);

sys/dev/mpi3mr/mpi3mr.h

@@ -231,6 +231,8 @@ extern char fmt_os_ver[16];
 
 #define MPI3MR_PERIODIC_DELAY	1	/* 1 second heartbeat/watchdog check */
 
+#define	WRITE_SAME_32	0x0d
+
 struct completion {
 	unsigned int done;
 	struct mtx lock;

sys/dev/mpi3mr/mpi3mr_cam.c

@@ -82,6 +82,7 @@
 #include "mpi3mr.h"
 #include <sys/time.h>			/* XXX for pcpu.h */
 #include <sys/pcpu.h>			/* XXX for PCPU_GET */
+#include <asm/unaligned.h>
 
 #define	smp_processor_id()  PCPU_GET(cpuid)
 
@@ -101,6 +102,37 @@ extern void mpi3mr_add_sg_single(void *paddr, U8 flags, U32 length,
 
 static U32 event_count;
 
+static
+inline void mpi3mr_divert_ws(Mpi3SCSIIORequest_t *req,
+			     struct ccb_scsiio *csio,
+			     U16 ws_len)
+{
+	U8 unmap = 0, ndob = 0;
+	U32 num_blocks = 0;
+	U8 opcode = scsiio_cdb_ptr(csio)[0];
+	U16 service_action = ((scsiio_cdb_ptr(csio)[8] << 8) | scsiio_cdb_ptr(csio)[9]);
+
+
+	if (opcode == WRITE_SAME_16 ||
+	   (opcode == VARIABLE_LEN_CDB &&
+	    service_action == WRITE_SAME_32)) {
+
+		int unmap_ndob_index = (opcode == WRITE_SAME_16) ? 1 : 10;
+
+		unmap = scsiio_cdb_ptr(csio)[unmap_ndob_index] & 0x08;
+		ndob = scsiio_cdb_ptr(csio)[unmap_ndob_index] & 0x01;
+		num_blocks = get_unaligned_be32(scsiio_cdb_ptr(csio) +
+						((opcode == WRITE_SAME_16) ? 10 : 28));
+
+		/* Check conditions for diversion to firmware */
+		if (unmap && ndob && num_blocks > ws_len) {
+			req->MsgFlags |= MPI3_SCSIIO_MSGFLAGS_DIVERT_TO_FIRMWARE;
+			req->Flags = htole32(le32toh(req->Flags) |
+					     MPI3_SCSIIO_FLAGS_DIVERT_REASON_WRITE_SAME_TOO_LARGE);
+		}
+	}
+}
+
 static void mpi3mr_prepare_sgls(void *arg,
 	bus_dma_segment_t *segs, int nsegs, int error)
 {
@@ -1079,6 +1111,9 @@ mpi3mr_action_scsiio(struct mpi3mr_cam_softc *cam_sc, union ccb *ccb)
 		break;
 	}
 
+	if (targ->ws_len)
+		mpi3mr_divert_ws(req, csio, targ->ws_len);
+
 	req->Flags = htole32(mpi_control);
 
 	if (csio->ccb_h.flags & CAM_CDB_POINTER)

sys/dev/mpi3mr/mpi3mr_cam.h

@@ -121,6 +121,7 @@ struct mpi3mr_target {
 	struct mpi3mr_throttle_group_info *throttle_group;
 	uint64_t	q_depth;
 	enum mpi3mr_target_state state;
+	uint16_t	ws_len;
 };
 
 struct mpi3mr_cam_softc {

sys/modules/mpi3mr/Makefile

@@ -6,6 +6,9 @@ SRCS=	mpi3mr_pci.c mpi3mr.c mpi3mr_cam.c mpi3mr_app.c
 SRCS+=	opt_cam.h
 SRCS+=	device_if.h bus_if.h pci_if.h
 
+CFLAGS+= -I${SRCTOP}/sys/compat/linuxkpi/common/include
+DEBUG_FLAGS= -g
+
 .include <bsd.kmod.mk>
 
 CWARNFLAGS.mpi3mr_sas.c=		${NO_WUNNEEDED_INTERNAL_DECL}