scsi: megaraid_sas: SAS3.5 Generic Megaraid Controllers Stream Detection and IO Coalescing

Detect sequential Write IOs and pass the hint that it is part of sequential
stream to help HBA Firmware do the Full Stripe Writes. For read IOs on
certain RAID volumes like Read Ahead volumes,this will help driver to
send it to Firmware even if the IOs can potentially be sent to
hardware directly (called fast path) bypassing firmware.

Design: 8 streams are maintained per RAID volume as per the combined
firmware/driver design. When there is no stream detected the LRU stream
is used for next potential stream and LRU/MRU map is updated to make this
as MRU stream. Every time a stream is detected the MRU map
is updated to make the current stream as MRU stream.

Signed-off-by: Sasikumar Chandrasekaran <sasikumar.pc@broadcom.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 138 insertions, 27 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index fe69c4a0eb22..974fb3c37ad4 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -1704,6 +1704,90 @@ megasas_set_pd_lba(struct MPI2_RAID_SCSI_IO_REQUEST *io_request, u8 cdb_len,
 }
 
 /**
+ * megasas_stream_detect -	stream detection on read and and write IOs
+ * @instance:		Adapter soft state
+ * @cmd:		    Command to be prepared
+ * @io_info:		IO Request info
+ *
+ */
+
+/** stream detection on read and and write IOs */
+static void megasas_stream_detect(struct megasas_instance *instance,
+				struct megasas_cmd_fusion *cmd,
+				struct IO_REQUEST_INFO *io_info)
+{
+	struct fusion_context *fusion = instance->ctrl_context;
+	u32 device_id = io_info->ldTgtId;
+	struct LD_STREAM_DETECT *current_ld_sd
+		= fusion->stream_detect_by_ld[device_id];
+	u32 *track_stream = &current_ld_sd->mru_bit_map, stream_num;
+	u32 shifted_values, unshifted_values;
+	u32 index_value_mask, shifted_values_mask;
+	int i;
+	bool is_read_ahead = false;
+	struct STREAM_DETECT *current_sd;
+	/* find possible stream */
+	for (i = 0; i < MAX_STREAMS_TRACKED; ++i) {
+		stream_num =
+		(*track_stream >> (i * BITS_PER_INDEX_STREAM)) &
+			STREAM_MASK;
+		current_sd = &current_ld_sd->stream_track[stream_num];
+	/* if we found a stream, update the raid
+	 *  context and also update the mruBitMap
+	 */
+	/*	boundary condition */
+	if ((current_sd->next_seq_lba) &&
+		(io_info->ldStartBlock >= current_sd->next_seq_lba) &&
+		(io_info->ldStartBlock <= (current_sd->next_seq_lba+32)) &&
+		(current_sd->is_read == io_info->isRead)) {
+
+		if ((io_info->ldStartBlock != current_sd->next_seq_lba)
+			&& ((!io_info->isRead) || (!is_read_ahead)))
+			/*
+			 * Once the API availible we need to change this.
+			 * At this point we are not allowing any gap
+			 */
+			continue;
+
+		cmd->io_request->RaidContext.raid_context_g35.stream_detected = true;
+		current_sd->next_seq_lba =
+		io_info->ldStartBlock + io_info->numBlocks;
+		/*
+		 *	update the mruBitMap LRU
+		 */
+		shifted_values_mask =
+			(1 <<  i * BITS_PER_INDEX_STREAM) - 1;
+		shifted_values = ((*track_stream & shifted_values_mask)
+					<< BITS_PER_INDEX_STREAM);
+		index_value_mask =
+			STREAM_MASK << i * BITS_PER_INDEX_STREAM;
+		unshifted_values =
+			*track_stream & ~(shifted_values_mask |
+			index_value_mask);
+		*track_stream =
+			unshifted_values | shifted_values | stream_num;
+		return;
+
+		}
+
+	}
+	/*
+	 * if we did not find any stream, create a new one
+	 * from the least recently used
+	 */
+	stream_num =
+	(*track_stream >> ((MAX_STREAMS_TRACKED - 1) * BITS_PER_INDEX_STREAM)) &
+			STREAM_MASK;
+	current_sd = &current_ld_sd->stream_track[stream_num];
+	current_sd->is_read = io_info->isRead;
+	current_sd->next_seq_lba = io_info->ldStartBlock + io_info->numBlocks;
+	*track_stream =
+	(((*track_stream & ZERO_LAST_STREAM) << 4) | stream_num);
+	return;
+
+}
+
+/**
  * megasas_build_ldio_fusion -	Prepares IOs to devices
  * @instance:		Adapter soft state
  * @scp:		SCSI command
@@ -1725,15 +1809,17 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
 	struct fusion_context *fusion;
 	struct MR_DRV_RAID_MAP_ALL *local_map_ptr;
 	u8 *raidLUN;
+	unsigned long spinlock_flags;
 
 	device_id = MEGASAS_DEV_INDEX(scp);
 
 	fusion = instance->ctrl_context;
 
 	io_request = cmd->io_request;
-	io_request->RaidContext.VirtualDiskTgtId = cpu_to_le16(device_id);
-	io_request->RaidContext.status = 0;
-	io_request->RaidContext.exStatus = 0;
+	io_request->RaidContext.raid_context.VirtualDiskTgtId =
+		cpu_to_le16(device_id);
+	io_request->RaidContext.raid_context.status = 0;
+	io_request->RaidContext.raid_context.exStatus = 0;
 
 	req_desc = (union MEGASAS_REQUEST_DESCRIPTOR_UNION *)cmd->request_desc;
 
@@ -1804,11 +1890,11 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
 
 	if ((MR_TargetIdToLdGet(device_id, local_map_ptr) >=
 		instance->fw_supported_vd_count) || (!fusion->fast_path_io)) {
-		io_request->RaidContext.regLockFlags  = 0;
+		io_request->RaidContext.raid_context.regLockFlags  = 0;
 		fp_possible = 0;
 	} else {
 		if (MR_BuildRaidContext(instance, &io_info,
-					&io_request->RaidContext,
+					&io_request->RaidContext.raid_context,
 					local_map_ptr, &raidLUN))
 			fp_possible = io_info.fpOkForIo;
 	}
@@ -1819,6 +1905,18 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
 	cmd->request_desc->SCSIIO.MSIxIndex = instance->msix_vectors ?
 		raw_smp_processor_id() % instance->msix_vectors : 0;
 
+	if (instance->is_ventura) {
+		spin_lock_irqsave(&instance->stream_lock, spinlock_flags);
+		megasas_stream_detect(instance, cmd, &io_info);
+		spin_unlock_irqrestore(&instance->stream_lock, spinlock_flags);
+		/* In ventura if stream detected for a read and it is read ahead
+		 *  capable make this IO as LDIO
+		 */
+		if (io_request->RaidContext.raid_context_g35.stream_detected &&
+				io_info.isRead && io_info.ra_capable)
+			fp_possible = false;
+	}
+
 	if (fp_possible) {
 		megasas_set_pd_lba(io_request, scp->cmd_len, &io_info, scp,
 				   local_map_ptr, start_lba_lo);
@@ -1827,15 +1925,16 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
 			(MPI2_REQ_DESCRIPT_FLAGS_FP_IO
 			 << MEGASAS_REQ_DESCRIPT_FLAGS_TYPE_SHIFT);
 		if (fusion->adapter_type == INVADER_SERIES) {
-			if (io_request->RaidContext.regLockFlags ==
+			if (io_request->RaidContext.raid_context.regLockFlags ==
 			    REGION_TYPE_UNUSED)
 				cmd->request_desc->SCSIIO.RequestFlags =
 					(MEGASAS_REQ_DESCRIPT_FLAGS_NO_LOCK <<
 					MEGASAS_REQ_DESCRIPT_FLAGS_TYPE_SHIFT);
-			io_request->RaidContext.Type = MPI2_TYPE_CUDA;
-			io_request->RaidContext.nseg = 0x1;
+			io_request->RaidContext.raid_context.Type
+				= MPI2_TYPE_CUDA;
+			io_request->RaidContext.raid_context.nseg = 0x1;
 			io_request->IoFlags |= cpu_to_le16(MPI25_SAS_DEVICE0_FLAGS_ENABLED_FAST_PATH);
-			io_request->RaidContext.regLockFlags |=
+			io_request->RaidContext.raid_context.regLockFlags |=
 			  (MR_RL_FLAGS_GRANT_DESTINATION_CUDA |
 			   MR_RL_FLAGS_SEQ_NUM_ENABLE);
 		}
@@ -1862,22 +1961,24 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
 		/* populate the LUN field */
 		memcpy(io_request->LUN, raidLUN, 8);
 	} else {
-		io_request->RaidContext.timeoutValue =
+		io_request->RaidContext.raid_context.timeoutValue =
 			cpu_to_le16(local_map_ptr->raidMap.fpPdIoTimeoutSec);
 		cmd->request_desc->SCSIIO.RequestFlags =
 			(MEGASAS_REQ_DESCRIPT_FLAGS_LD_IO
 			 << MEGASAS_REQ_DESCRIPT_FLAGS_TYPE_SHIFT);
 		if (fusion->adapter_type == INVADER_SERIES) {
 			if (io_info.do_fp_rlbypass ||
-				(io_request->RaidContext.regLockFlags == REGION_TYPE_UNUSED))
+			(io_request->RaidContext.raid_context.regLockFlags
+					== REGION_TYPE_UNUSED))
 				cmd->request_desc->SCSIIO.RequestFlags =
 					(MEGASAS_REQ_DESCRIPT_FLAGS_NO_LOCK <<
 					MEGASAS_REQ_DESCRIPT_FLAGS_TYPE_SHIFT);
-			io_request->RaidContext.Type = MPI2_TYPE_CUDA;
-			io_request->RaidContext.regLockFlags |=
+			io_request->RaidContext.raid_context.Type
+				= MPI2_TYPE_CUDA;
+			io_request->RaidContext.raid_context.regLockFlags |=
 				(MR_RL_FLAGS_GRANT_DESTINATION_CPU0 |
 				 MR_RL_FLAGS_SEQ_NUM_ENABLE);
-			io_request->RaidContext.nseg = 0x1;
+			io_request->RaidContext.raid_context.nseg = 0x1;
 		}
 		io_request->Function = MEGASAS_MPI2_FUNCTION_LD_IO_REQUEST;
 		io_request->DevHandle = cpu_to_le16(device_id);
@@ -1913,7 +2014,7 @@ static void megasas_build_ld_nonrw_fusion(struct megasas_instance *instance,
 	local_map_ptr = fusion->ld_drv_map[(instance->map_id & 1)];
 	io_request->DataLength = cpu_to_le32(scsi_bufflen(scmd));
 	/* get RAID_Context pointer */
-	pRAID_Context = &io_request->RaidContext;
+	pRAID_Context = &io_request->RaidContext.raid_context;
 	/* Check with FW team */
 	pRAID_Context->VirtualDiskTgtId = cpu_to_le16(device_id);
 	pRAID_Context->regLockRowLBA    = 0;
@@ -2000,7 +2101,7 @@ megasas_build_syspd_fusion(struct megasas_instance *instance,
 
 	io_request = cmd->io_request;
 	/* get RAID_Context pointer */
-	pRAID_Context = &io_request->RaidContext;
+	pRAID_Context = &io_request->RaidContext.raid_context;
 	pRAID_Context->regLockFlags = 0;
 	pRAID_Context->regLockRowLBA = 0;
 	pRAID_Context->regLockLength = 0;
@@ -2094,9 +2195,9 @@ megasas_build_io_fusion(struct megasas_instance *instance,
 	io_request->Control = 0;
 	io_request->EEDPBlockSize = 0;
 	io_request->ChainOffset = 0;
-	io_request->RaidContext.RAIDFlags = 0;
-	io_request->RaidContext.Type = 0;
-	io_request->RaidContext.nseg = 0;
+	io_request->RaidContext.raid_context.RAIDFlags = 0;
+	io_request->RaidContext.raid_context.Type = 0;
+	io_request->RaidContext.raid_context.nseg = 0;
 
 	memcpy(io_request->CDB.CDB32, scp->cmnd, scp->cmd_len);
 	/*
@@ -2143,8 +2244,8 @@ megasas_build_io_fusion(struct megasas_instance *instance,
 	/* numSGE store lower 8 bit of sge_count.
 	 * numSGEExt store higher 8 bit of sge_count
 	 */
-	io_request->RaidContext.numSGE = sge_count;
-	io_request->RaidContext.numSGEExt = (u8)(sge_count >> 8);
+	io_request->RaidContext.raid_context.numSGE = sge_count;
+	io_request->RaidContext.raid_context.numSGEExt = (u8)(sge_count >> 8);
 
 	io_request->SGLFlags = cpu_to_le16(MPI2_SGE_FLAGS_64_BIT_ADDRESSING);
 
@@ -2303,8 +2404,8 @@ complete_cmd_fusion(struct megasas_instance *instance, u32 MSIxIndex)
 			cmd_fusion->scmd->SCp.ptr = NULL;
 
 		scmd_local = cmd_fusion->scmd;
-		status = scsi_io_req->RaidContext.status;
-		extStatus = scsi_io_req->RaidContext.exStatus;
+		status = scsi_io_req->RaidContext.raid_context.status;
+		extStatus = scsi_io_req->RaidContext.raid_context.exStatus;
 
 		switch (scsi_io_req->Function) {
 		case MPI2_FUNCTION_SCSI_TASK_MGMT:
@@ -2337,8 +2438,8 @@ complete_cmd_fusion(struct megasas_instance *instance, u32 MSIxIndex)
 		case MEGASAS_MPI2_FUNCTION_LD_IO_REQUEST: /* LD-IO Path */
 			/* Map the FW Cmd Status */
 			map_cmd_status(cmd_fusion, status, extStatus);
-			scsi_io_req->RaidContext.status = 0;
-			scsi_io_req->RaidContext.exStatus = 0;
+			scsi_io_req->RaidContext.raid_context.status = 0;
+			scsi_io_req->RaidContext.raid_context.exStatus = 0;
 			if (megasas_cmd_type(scmd_local) == READ_WRITE_LDIO)
 				atomic_dec(&instance->ldio_outstanding);
 			megasas_return_cmd_fusion(instance, cmd_fusion);
@@ -2905,7 +3006,7 @@ void megasas_refire_mgmt_cmd(struct megasas_instance *instance)
 				&& !(cmd_mfi->flags & DRV_DCMD_SKIP_REFIRE);
 		if (refire_cmd)
 			megasas_fire_cmd_fusion(instance, req_desc,
-							instance->is_ventura);
+				instance->is_ventura);
 		else
 			megasas_return_cmd(instance, cmd_mfi);
 	}
@@ -3394,7 +3495,7 @@ int megasas_check_mpio_paths(struct megasas_instance *instance,
 /* Core fusion reset function */
 int megasas_reset_fusion(struct Scsi_Host *shost, int reason)
 {
-	int retval = SUCCESS, i, convert = 0;
+	int retval = SUCCESS, i, j, convert = 0;
 	struct megasas_instance *instance;
 	struct megasas_cmd_fusion *cmd_fusion;
 	struct fusion_context *fusion;
@@ -3559,6 +3660,16 @@ transition_to_ready:
 			shost_for_each_device(sdev, shost)
 				megasas_update_sdev_properties(sdev);
 
+			/* reset stream detection array */
+			if (instance->is_ventura) {
+				for (j = 0; j < MAX_LOGICAL_DRIVES_EXT; ++j) {
+					memset(fusion->stream_detect_by_ld[j],
+					0, sizeof(struct LD_STREAM_DETECT));
+				 fusion->stream_detect_by_ld[j]->mru_bit_map
+						= MR_STREAM_BITMAP;
+				}
+			}
+
 			clear_bit(MEGASAS_FUSION_IN_RESET,
 				  &instance->reset_flags);
 			instance->instancet->enable_intr(instance);