megaraid_sas: Fastpath region lock bypass

Firmware will fill out per-LD data to tell driver whether a particular
LD supports region lock bypass. If yes, then driver will send non-FP
LDIO to region lock bypass FIFO. With this change in driver, firmware
will optimize certain code to improve performance.
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/megaraid_sas.h

@@ -1528,7 +1528,9 @@ union megasas_sgl_frame {
 typedef union _MFI_CAPABILITIES {
 	struct {
 #if   defined(__BIG_ENDIAN_BITFIELD)
-		u32     reserved:23;
+		u32     reserved:21;
+		u32     support_fp_rlbypass:1;
+		u32     support_vfid_in_ioframe:1;
 		u32     support_ext_io_size:1;
 		u32	support_ext_queue_depth:1;
 		u32     security_protocol_cmds_fw:1;
@@ -1548,7 +1550,9 @@ typedef union _MFI_CAPABILITIES {
 		u32     security_protocol_cmds_fw:1;
 		u32	support_ext_queue_depth:1;
 		u32     support_ext_io_size:1;
-		u32     reserved:23;
+		u32     support_vfid_in_ioframe:1;
+		u32     support_fp_rlbypass:1;
+		u32     reserved:21;
 #endif
 	} mfi_capabilities;
 	__le32		reg;

drivers/scsi/megaraid/megaraid_sas_fp.c

@@ -1020,6 +1020,8 @@ MR_BuildRaidContext(struct megasas_instance *instance,
 	/* assume this IO needs the full row - we'll adjust if not true */
 	regSize             = stripSize;
 
+	io_info->do_fp_rlbypass = raid->capability.fpBypassRegionLock;
+
 	/* Check if we can send this I/O via FastPath */
 	if (raid->capability.fpCapable) {
 		if (isRead)

drivers/scsi/megaraid/megaraid_sas_fusion.c

@@ -666,6 +666,8 @@ megasas_ioc_init_fusion(struct megasas_instance *instance)
 	if (instance->max_chain_frame_sz > MEGASAS_CHAIN_FRAME_SZ_MIN)
 		drv_ops->mfi_capabilities.support_ext_io_size = 1;
 
+	drv_ops->mfi_capabilities.support_fp_rlbypass = 1;
+
 	/* Convert capability to LE32 */
 	cpu_to_le32s((u32 *)&init_frame->driver_operations.mfi_capabilities);
 
@@ -1710,8 +1712,8 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
 			(MEGASAS_REQ_DESCRIPT_FLAGS_LD_IO
 			 << MEGASAS_REQ_DESCRIPT_FLAGS_TYPE_SHIFT);
 		if (fusion->adapter_type == INVADER_SERIES) {
-			if (io_request->RaidContext.regLockFlags ==
-			    REGION_TYPE_UNUSED)
+			if (io_info.do_fp_rlbypass ||
+				(io_request->RaidContext.regLockFlags == REGION_TYPE_UNUSED))
 				cmd->request_desc->SCSIIO.RequestFlags =
 					(MEGASAS_REQ_DESCRIPT_FLAGS_NO_LOCK <<
 					MEGASAS_REQ_DESCRIPT_FLAGS_TYPE_SHIFT);

drivers/scsi/megaraid/megaraid_sas_fusion.h

@@ -643,7 +643,8 @@ struct MR_SPAN_BLOCK_INFO {
 struct MR_LD_RAID {
 	struct {
 #if   defined(__BIG_ENDIAN_BITFIELD)
-		u32     reserved4:6;
+		u32     reserved4:5;
+		u32     fpBypassRegionLock:1;
 		u32     tmCapable:1;
 		u32	fpNonRWCapable:1;
 		u32     fpReadAcrossStripe:1;
@@ -667,7 +668,8 @@ struct MR_LD_RAID {
 		u32     fpReadAcrossStripe:1;
 		u32	fpNonRWCapable:1;
 		u32     tmCapable:1;
-		u32     reserved4:6;
+		u32     fpBypassRegionLock:1;
+		u32     reserved4:5;
 #endif
 	} capability;
 	__le32     reserved6;
@@ -737,7 +739,7 @@ struct IO_REQUEST_INFO {
 	u8 fpOkForIo;
 	u8 IoforUnevenSpan;
 	u8 start_span;
-	u8 reserved;
+	u8 do_fp_rlbypass;
 	u64 start_row;
 	u8  span_arm;	/* span[7:5], arm[4:0] */
 	u8  pd_after_lb;