From: Kashyap Desai Date: Fri, 21 Oct 2016 13:33:33 +0000 (-0700) Subject: scsi: megaraid_sas: Send SYNCHRONIZE_CACHE for VD to firmware X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d0fc91d67c59068ce6d42e41ce66a4c471e5bc74;p=linux-beck.git scsi: megaraid_sas: Send SYNCHRONIZE_CACHE for VD to firmware Until now the megaraid_sas driver has reported successful completion on SYNCHRONIZE_CACHE commands without sending them down to the controller. The controller firmware has been responsible for taking care of flushing disk caches for all drives that belong to a Virtual Disk at the time of system reboot/shutdown. There may have been a reason to avoid sending SYNCHRONIZE_CACHE to a VD in the past but that no longer appears to be valid. Older versions of MegaRaid firmware (Gen2 and Gen2.5) set the WCE bit for Virtual Disks but the firmware does not report correct completion status for a SYNCHRONIZE_CACHE command. As a result, we must use another method to identify whether it is safe to send the command to the controller. We use the canHandleSyncCache firmware flag in the scratch pad register at offset 0xB4. New SYNCHRONIZE_CACHE behavior: IF 'JBOD' Driver sends SYNCHRONIZE_CACHE command to the firmware Firmware sends SYNCHRONIZE_CACHE to drive Firmware obtains status from drive and returns same status back to driver ELSEIF 'VirtualDisk' IF firmware supports new API bit called canHandleSyncCache Driver sends SYNCHRONIZE_CACHE command to the firmware Firmware does not send SYNCHRONIZE_CACHE to drives Firmware returns SUCCESS ELSE Driver does not send SYNCHRONIZE_CACHE command to the firmware Driver return SUCCESS for that command ENDIF ENDIF [mkp: edited patch description] Signed-off-by: Kashyap Desai Signed-off-by: Sumit Saxena Reviewed-by: Tomas Henzl Reviewed-by: Hannes Reinecke Reviewed-by: Ewan D. Milne Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h index ca86c885dfaa..43fd14fad1a6 100644 --- a/drivers/scsi/megaraid/megaraid_sas.h +++ b/drivers/scsi/megaraid/megaraid_sas.h @@ -1429,6 +1429,8 @@ enum FW_BOOT_CONTEXT { #define MR_MAX_REPLY_QUEUES_EXT_OFFSET_SHIFT 14 #define MR_MAX_MSIX_REG_ARRAY 16 #define MR_RDPQ_MODE_OFFSET 0X00800000 +#define MR_CAN_HANDLE_SYNC_CACHE_OFFSET 0X01000000 + /* * register set for both 1068 and 1078 controllers * structure extended for 1078 registers @@ -2140,6 +2142,7 @@ struct megasas_instance { u8 is_imr; u8 is_rdpq; bool dev_handle; + bool fw_sync_cache_support; }; struct MR_LD_VF_MAP { u32 size; diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index d5410a39d956..f6db7abf150d 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -1700,11 +1700,8 @@ megasas_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scmd) goto out_done; } - /* - * FW takes care of flush cache on its own for Virtual Disk. - * No need to send it down for VD. For JBOD send SYNCHRONIZE_CACHE to FW. - */ - if ((scmd->cmnd[0] == SYNCHRONIZE_CACHE) && MEGASAS_IS_LOGICAL(scmd)) { + if ((scmd->cmnd[0] == SYNCHRONIZE_CACHE) && MEGASAS_IS_LOGICAL(scmd) && + (!instance->fw_sync_cache_support)) { scmd->result = DID_OK << 16; goto out_done; } diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c index 2159f6ae5a31..2e61306de9c8 100644 --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c @@ -748,6 +748,11 @@ megasas_ioc_init_fusion(struct megasas_instance *instance) goto fail_fw_init; } + instance->fw_sync_cache_support = (scratch_pad_2 & + MR_CAN_HANDLE_SYNC_CACHE_OFFSET) ? 1 : 0; + dev_info(&instance->pdev->dev, "FW supports sync cache\t: %s\n", + instance->fw_sync_cache_support ? "Yes" : "No"); + IOCInitMessage = dma_alloc_coherent(&instance->pdev->dev, sizeof(struct MPI2_IOC_INIT_REQUEST),