scsi: mpt3sas: Postprocessing of target and LUN reset

If driver has not received the interrupt for the aborted SCSI command
before processing the TM reply, driver polls all the reply descriptor pools
looking for the reply for the aborted SCSI command before marking TM as
FAILED. If it finds the reply, then it marks the TM as SUCCESS otherwise it
marks it FAILED.

scsih_tm_cmd_map_status() checks whether TM has aborted the timed out SCSI
command or not. If TM has aborted the IO, then it returns SUCCESS else it
returns FAILED.

Link: https://lore.kernel.org/r/1596096229-3341-7-git-send-email-suganath-prabu.subramani@broadcom.com
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_base.c

@@ -1785,12 +1785,14 @@ _base_is_controller_msix_enabled(struct MPT3SAS_ADAPTER *ioc)
 /**
  * mpt3sas_base_sync_reply_irqs - flush pending MSIX interrupts
  * @ioc: per adapter object
+ * @poll: poll over reply descriptor pools incase interrupt for
+ *		timed-out SCSI command got delayed
  * Context: non ISR conext
  *
  * Called when a Task Management request has completed.
  */
 void
-mpt3sas_base_sync_reply_irqs(struct MPT3SAS_ADAPTER *ioc)
+mpt3sas_base_sync_reply_irqs(struct MPT3SAS_ADAPTER *ioc, u8 poll)
 {
 	struct adapter_reply_queue *reply_q;
 
@@ -1820,6 +1822,8 @@ mpt3sas_base_sync_reply_irqs(struct MPT3SAS_ADAPTER *ioc)
 		}
 		synchronize_irq(pci_irq_vector(ioc->pdev, reply_q->msix_index));
 	}
+	if (poll)
+		_base_process_reply_queue(reply_q);
 }
 
 /**

drivers/scsi/mpt3sas/mpt3sas_base.h

@@ -1528,7 +1528,7 @@ __le32 mpt3sas_base_get_sense_buffer_dma(struct MPT3SAS_ADAPTER *ioc,
 	u16 smid);
 void *mpt3sas_base_get_pcie_sgl(struct MPT3SAS_ADAPTER *ioc, u16 smid);
 dma_addr_t mpt3sas_base_get_pcie_sgl_dma(struct MPT3SAS_ADAPTER *ioc, u16 smid);
-void mpt3sas_base_sync_reply_irqs(struct MPT3SAS_ADAPTER *ioc);
+void mpt3sas_base_sync_reply_irqs(struct MPT3SAS_ADAPTER *ioc, u8 poll);
 void mpt3sas_base_mask_interrupts(struct MPT3SAS_ADAPTER *ioc);
 void mpt3sas_base_unmask_interrupts(struct MPT3SAS_ADAPTER *ioc);
 

drivers/scsi/mpt3sas/mpt3sas_scsih.c

@@ -2760,6 +2760,96 @@ mpt3sas_scsih_clear_tm_flag(struct MPT3SAS_ADAPTER *ioc, u16 handle)
 	}
 }
 
+/**
+ * scsih_tm_cmd_map_status - map the target reset & LUN reset TM status
+ * @ioc - per adapter object
+ * @channel - the channel assigned by the OS
+ * @id: the id assigned by the OS
+ * @lun: lun number
+ * @type: MPI2_SCSITASKMGMT_TASKTYPE__XXX (defined in mpi2_init.h)
+ * @smid_task: smid assigned to the task
+ *
+ * Look whether TM has aborted the timed out SCSI command, if
+ * TM has aborted the IO then return SUCCESS else return FAILED.
+ */
+static int
+scsih_tm_cmd_map_status(struct MPT3SAS_ADAPTER *ioc, uint channel,
+	uint id, uint lun, u8 type, u16 smid_task)
+{
+
+	if (smid_task <= ioc->shost->can_queue) {
+		switch (type) {
+		case MPI2_SCSITASKMGMT_TASKTYPE_TARGET_RESET:
+			if (!(_scsih_scsi_lookup_find_by_target(ioc,
+			    id, channel)))
+				return SUCCESS;
+			break;
+		case MPI2_SCSITASKMGMT_TASKTYPE_ABRT_TASK_SET:
+		case MPI2_SCSITASKMGMT_TASKTYPE_LOGICAL_UNIT_RESET:
+			if (!(_scsih_scsi_lookup_find_by_lun(ioc, id,
+			    lun, channel)))
+				return SUCCESS;
+			break;
+		default:
+			return SUCCESS;
+		}
+	} else if (smid_task == ioc->scsih_cmds.smid) {
+		if ((ioc->scsih_cmds.status & MPT3_CMD_COMPLETE) ||
+		    (ioc->scsih_cmds.status & MPT3_CMD_NOT_USED))
+			return SUCCESS;
+	} else if (smid_task == ioc->ctl_cmds.smid) {
+		if ((ioc->ctl_cmds.status & MPT3_CMD_COMPLETE) ||
+		    (ioc->ctl_cmds.status & MPT3_CMD_NOT_USED))
+			return SUCCESS;
+	}
+
+	return FAILED;
+}
+
+/**
+ * scsih_tm_post_processing - post processing of target & LUN reset
+ * @ioc - per adapter object
+ * @handle: device handle
+ * @channel - the channel assigned by the OS
+ * @id: the id assigned by the OS
+ * @lun: lun number
+ * @type: MPI2_SCSITASKMGMT_TASKTYPE__XXX (defined in mpi2_init.h)
+ * @smid_task: smid assigned to the task
+ *
+ * Post processing of target & LUN reset. Due to interrupt latency
+ * issue it possible that interrupt for aborted IO might not be
+ * received yet. So before returning failure status, poll the
+ * reply descriptor pools for the reply of timed out SCSI command.
+ * Return FAILED status if reply for timed out is not received
+ * otherwise return SUCCESS.
+ */
+static int
+scsih_tm_post_processing(struct MPT3SAS_ADAPTER *ioc, u16 handle,
+	uint channel, uint id, uint lun, u8 type, u16 smid_task)
+{
+	int rc;
+
+	rc = scsih_tm_cmd_map_status(ioc, channel, id, lun, type, smid_task);
+	if (rc == SUCCESS)
+		return rc;
+
+	ioc_info(ioc,
+	    "Poll ReplyDescriptor queues for completion of"
+	    " smid(%d), task_type(0x%02x), handle(0x%04x)\n",
+	    smid_task, type, handle);
+
+	/*
+	 * Due to interrupt latency issues, driver may receive interrupt for
+	 * TM first and then for aborted SCSI IO command. So, poll all the
+	 * ReplyDescriptor pools before returning the FAILED status to SML.
+	 */
+	mpt3sas_base_mask_interrupts(ioc);
+	mpt3sas_base_sync_reply_irqs(ioc, 1);
+	mpt3sas_base_unmask_interrupts(ioc);
+
+	return scsih_tm_cmd_map_status(ioc, channel, id, lun, type, smid_task);
+}
+
 /**
  * mpt3sas_scsih_issue_tm - main routine for sending tm requests
  * @ioc: per adapter struct
@@ -2788,6 +2878,7 @@ mpt3sas_scsih_issue_tm(struct MPT3SAS_ADAPTER *ioc, u16 handle, uint channel,
 {
 	Mpi2SCSITaskManagementRequest_t *mpi_request;
 	Mpi2SCSITaskManagementReply_t *mpi_reply;
+	Mpi25SCSIIORequest_t *request;
 	u16 smid = 0;
 	u32 ioc_state;
 	int rc;
@@ -2843,7 +2934,9 @@ mpt3sas_scsih_issue_tm(struct MPT3SAS_ADAPTER *ioc, u16 handle, uint channel,
 	mpi_request->Function = MPI2_FUNCTION_SCSI_TASK_MGMT;
 	mpi_request->DevHandle = cpu_to_le16(handle);
 	mpi_request->TaskType = type;
-	mpi_request->MsgFlags = tr_method;
+	if (type == MPI2_SCSITASKMGMT_TASKTYPE_ABORT_TASK ||
+	    type == MPI2_SCSITASKMGMT_TASKTYPE_QUERY_TASK)
+		mpi_request->MsgFlags = tr_method;
 	mpi_request->TaskMID = cpu_to_le16(smid_task);
 	int_to_scsilun(lun, (struct scsi_lun *)mpi_request->LUN);
 	mpt3sas_scsih_set_tm_flag(ioc, handle);
@@ -2863,7 +2956,7 @@ mpt3sas_scsih_issue_tm(struct MPT3SAS_ADAPTER *ioc, u16 handle, uint channel,
 	}
 
 	/* sync IRQs in case those were busy during flush. */
-	mpt3sas_base_sync_reply_irqs(ioc);
+	mpt3sas_base_sync_reply_irqs(ioc, 0);
 
 	if (ioc->tm_cmds.status & MPT3_CMD_REPLY_VALID) {
 		mpt3sas_trigger_master(ioc, MASTER_TRIGGER_TASK_MANAGMENT);
@@ -2880,7 +2973,44 @@ mpt3sas_scsih_issue_tm(struct MPT3SAS_ADAPTER *ioc, u16 handle, uint channel,
 				    sizeof(Mpi2SCSITaskManagementRequest_t)/4);
 		}
 	}
-	rc = SUCCESS;
+
+	switch (type) {
+	case MPI2_SCSITASKMGMT_TASKTYPE_ABORT_TASK:
+		rc = SUCCESS;
+		/*
+		 * If DevHandle filed in smid_task's entry of request pool
+		 * doesn't match with device handle on which this task abort
+		 * TM is received then it means that TM has successfully
+		 * aborted the timed out command. Since smid_task's entry in
+		 * request pool will be memset to zero once the timed out
+		 * command is returned to the SML. If the command is not
+		 * aborted then smid_task’s entry won’t be cleared and it
+		 * will have same DevHandle value on which this task abort TM
+		 * is received and driver will return the TM status as FAILED.
+		 */
+		request = mpt3sas_base_get_msg_frame(ioc, smid_task);
+		if (le16_to_cpu(request->DevHandle) != handle)
+			break;
+
+		ioc_info(ioc, "Task abort tm failed: handle(0x%04x),"
+		    "timeout(%d) tr_method(0x%x) smid(%d) msix_index(%d)\n",
+		    handle, timeout, tr_method, smid_task, msix_task);
+		rc = FAILED;
+		break;
+
+	case MPI2_SCSITASKMGMT_TASKTYPE_TARGET_RESET:
+	case MPI2_SCSITASKMGMT_TASKTYPE_ABRT_TASK_SET:
+	case MPI2_SCSITASKMGMT_TASKTYPE_LOGICAL_UNIT_RESET:
+		rc = scsih_tm_post_processing(ioc, handle, channel, id, lun,
+		    type, smid_task);
+		break;
+	case MPI2_SCSITASKMGMT_TASKTYPE_QUERY_TASK:
+		rc = SUCCESS;
+		break;
+	default:
+		rc = FAILED;
+		break;
+	}
 
 out:
 	mpt3sas_scsih_clear_tm_flag(ioc, handle);