Revert "scsi: megaraid_sas: Enable or Disable Fast path based on the PCI Threshold Bandwidth"

This reverts commit "3e5eadb1" ("scsi: megaraid_sas: Enable or
Disable Fast path based on the PCI Threshold Bandwidth")

This patch was aimed to increase performance of R1 Write operation for
large IO size.  Since this method used timer approach, it turn on/off
fast path did not work as expected.  Patch 0013 describes new algorithm
and performance number.
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/megaraid_sas.h

@@ -1477,8 +1477,6 @@ enum FW_BOOT_CONTEXT {
 #define MFI_1068_FW_HANDSHAKE_OFFSET		0x64
 #define MFI_1068_FW_READY			0xDDDD0000
 
-#define MEGASAS_RAID1_FAST_PATH_STATUS_CHECK_INTERVAL HZ
-
 #define MR_MAX_REPLY_QUEUES_OFFSET              0X0000001F
 #define MR_MAX_REPLY_QUEUES_EXT_OFFSET          0X003FC000
 #define MR_MAX_REPLY_QUEUES_EXT_OFFSET_SHIFT    14
@@ -2154,10 +2152,6 @@ struct megasas_instance {
 	atomic_t ldio_outstanding;
 	atomic_t fw_reset_no_pci_access;
 
-	atomic64_t bytes_wrote; /* used for raid1 fast path enable or disable */
-	atomic_t r1_write_fp_capable;
-
-
 	struct megasas_instance_template *instancet;
 	struct tasklet_struct isr_tasklet;
 	struct work_struct work_init;
@@ -2199,7 +2193,6 @@ struct megasas_instance {
 	long reset_flags;
 	struct mutex reset_mutex;
 	struct timer_list sriov_heartbeat_timer;
-	struct timer_list r1_fp_hold_timer;
 	char skip_heartbeat_timer_del;
 	u8 requestorId;
 	char PlasmaFW111;
@@ -2216,7 +2209,6 @@ struct megasas_instance {
 	bool is_ventura;
 	bool msix_combined;
 	u16 max_raid_mapsize;
-	u64 pci_threshold_bandwidth; /* used to control the fp writes */
 };
 struct MR_LD_VF_MAP {
 	u32 size;

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -1940,9 +1940,6 @@ void megaraid_sas_kill_hba(struct megasas_instance *instance)
 	}
 	/* Complete outstanding ioctls when adapter is killed */
 	megasas_complete_outstanding_ioctls(instance);
-	if (instance->is_ventura)
-		del_timer_sync(&instance->r1_fp_hold_timer);
-
 }
 
  /**
@@ -2441,24 +2438,6 @@ void megasas_sriov_heartbeat_handler(unsigned long instance_addr)
 	}
 }
 
-/*Handler for disabling/enabling raid 1 fast paths*/
-void megasas_change_r1_fp_status(unsigned long instance_addr)
-{
-	struct megasas_instance *instance =
-			(struct megasas_instance *)instance_addr;
-	if (atomic64_read(&instance->bytes_wrote) >=
-					instance->pci_threshold_bandwidth) {
-
-		atomic64_set(&instance->bytes_wrote, 0);
-		atomic_set(&instance->r1_write_fp_capable, 0);
-	} else {
-		atomic64_set(&instance->bytes_wrote, 0);
-		atomic_set(&instance->r1_write_fp_capable, 1);
-	}
-	mod_timer(&instance->r1_fp_hold_timer,
-	 jiffies + MEGASAS_RAID1_FAST_PATH_STATUS_CHECK_INTERVAL);
-}
-
 /**
  * megasas_wait_for_outstanding -	Wait for all outstanding cmds
  * @instance:				Adapter soft state
@@ -5386,17 +5365,6 @@ static int megasas_init_fw(struct megasas_instance *instance)
 			instance->skip_heartbeat_timer_del = 1;
 	}
 
-	if (instance->is_ventura) {
-		atomic64_set(&instance->bytes_wrote, 0);
-		atomic_set(&instance->r1_write_fp_capable, 1);
-		megasas_start_timer(instance,
-			    &instance->r1_fp_hold_timer,
-			    megasas_change_r1_fp_status,
-			    MEGASAS_RAID1_FAST_PATH_STATUS_CHECK_INTERVAL);
-				dev_info(&instance->pdev->dev, "starting the raid 1 fp timer with interval %d\n",
-				MEGASAS_RAID1_FAST_PATH_STATUS_CHECK_INTERVAL);
-	}
-
 	return 0;
 
 fail_get_ld_pd_list:
@@ -6187,9 +6155,6 @@ megasas_suspend(struct pci_dev *pdev, pm_message_t state)
 	if (instance->requestorId && !instance->skip_heartbeat_timer_del)
 		del_timer_sync(&instance->sriov_heartbeat_timer);
 
-	if (instance->is_ventura)
-		del_timer_sync(&instance->r1_fp_hold_timer);
-
 	megasas_flush_cache(instance);
 	megasas_shutdown_controller(instance, MR_DCMD_HIBERNATE_SHUTDOWN);
 
@@ -6316,16 +6281,6 @@ megasas_resume(struct pci_dev *pdev)
 	megasas_setup_jbod_map(instance);
 	instance->unload = 0;
 
-	if (instance->is_ventura) {
-		atomic64_set(&instance->bytes_wrote, 0);
-		atomic_set(&instance->r1_write_fp_capable, 1);
-		megasas_start_timer(instance,
-			    &instance->r1_fp_hold_timer,
-			    megasas_change_r1_fp_status,
-			    MEGASAS_RAID1_FAST_PATH_STATUS_CHECK_INTERVAL);
-	}
-
-
 	/*
 	 * Initiate AEN (Asynchronous Event Notification)
 	 */
@@ -6414,9 +6369,6 @@ static void megasas_detach_one(struct pci_dev *pdev)
 	if (instance->requestorId && !instance->skip_heartbeat_timer_del)
 		del_timer_sync(&instance->sriov_heartbeat_timer);
 
-	if (instance->is_ventura)
-		del_timer_sync(&instance->r1_fp_hold_timer);
-
 	if (instance->fw_crash_state != UNAVAILABLE)
 		megasas_free_host_crash_buffer(instance);
 	scsi_remove_host(instance->host);

drivers/scsi/megaraid/megaraid_sas_fp.c

@@ -197,9 +197,6 @@ void MR_PopulateDrvRaidMap(struct megasas_instance *instance)
 
 	if (instance->max_raid_mapsize) {
 		fw_map_dyn = fusion->ld_map[(instance->map_id & 1)];
-		if (fw_map_dyn->pci_threshold_bandwidth)
-			instance->pci_threshold_bandwidth =
-			le64_to_cpu(fw_map_dyn->pci_threshold_bandwidth);
 #if VD_EXT_DEBUG
 		dev_dbg(&instance->pdev->dev, "raidMapSize 0x%x fw_map_dyn->descTableOffset 0x%x\n",
 			le32_to_cpu(fw_map_dyn->raid_map_size),
@@ -207,8 +204,6 @@ void MR_PopulateDrvRaidMap(struct megasas_instance *instance)
 		dev_dbg(&instance->pdev->dev, "descTableSize 0x%x descTableNumElements 0x%x\n",
 			le32_to_cpu(fw_map_dyn->desc_table_size),
 			le32_to_cpu(fw_map_dyn->desc_table_num_elements));
-		dev_dbg(&instance->pdev->dev, "PCIThreasholdBandwidth %llu\n",
-			instance->pci_threshold_bandwidth);
 		dev_dbg(&instance->pdev->dev, "drv map %p ldCount %d\n",
 			drv_map, fw_map_dyn->ld_count);
 #endif
@@ -439,8 +434,6 @@ void MR_PopulateDrvRaidMap(struct megasas_instance *instance)
 			sizeof(struct MR_DEV_HANDLE_INFO) *
 			MAX_RAIDMAP_PHYSICAL_DEVICES);
 	}
-	if (instance->is_ventura && !instance->pci_threshold_bandwidth)
-		instance->pci_threshold_bandwidth = ULLONG_MAX;
 }
 
 /*

drivers/scsi/megaraid/megaraid_sas_fusion.c

@@ -95,7 +95,6 @@ extern unsigned int resetwaittime;
 extern unsigned int dual_qdepth_disable;
 static void megasas_free_rdpq_fusion(struct megasas_instance *instance);
 static void megasas_free_reply_fusion(struct megasas_instance *instance);
-void megasas_change_r1_fp_status(unsigned long instance_addr);
 
 
 
@@ -2634,9 +2633,8 @@ megasas_build_and_issue_cmd_fusion(struct megasas_instance *instance,
 	 *	to get new command
 	 */
 	if (cmd->is_raid_1_fp_write &&
-		(atomic_inc_return(&instance->fw_outstanding) >
-			(instance->host->can_queue) ||
-		(!atomic_read(&instance->r1_write_fp_capable)))) {
+		atomic_inc_return(&instance->fw_outstanding) >
+			(instance->host->can_queue)) {
 		megasas_fpio_to_ldio(instance, cmd, cmd->scmd);
 		atomic_dec(&instance->fw_outstanding);
 	} else if (cmd->is_raid_1_fp_write) {
@@ -2645,19 +2643,17 @@ megasas_build_and_issue_cmd_fusion(struct megasas_instance *instance,
 		megasas_prepare_secondRaid1_IO(instance, cmd, r1_cmd);
 	}
 
+
 	/*
 	 * Issue the command to the FW
 	 */
-	if (scmd->sc_data_direction == PCI_DMA_TODEVICE && instance->is_ventura)
-		atomic64_add(scsi_bufflen(scmd), &instance->bytes_wrote);
 
 	megasas_fire_cmd_fusion(instance, req_desc, instance->is_ventura);
 
-	if (r1_cmd) {
-		atomic64_add(scsi_bufflen(scmd), &instance->bytes_wrote);
+	if (r1_cmd)
 		megasas_fire_cmd_fusion(instance, r1_cmd->request_desc,
 				instance->is_ventura);
-	}
+
 
 	return 0;
 }

drivers/scsi/megaraid/megaraid_sas_fusion.h

@@ -977,7 +977,7 @@ struct MR_FW_RAID_MAP_DYNAMIC {
 	u32 desc_table_size;  /* Total Size of desc table */
 	/* Total Number of elements in the desc table */
 	u32 desc_table_num_elements;
-	u64	pci_threshold_bandwidth;
+	u64	reserved1;
 	u32	reserved2[3];	/*future use */
 	/* timeout value used by driver in FP IOs */
 	u8 fp_pd_io_timeout_sec;