scsi: libsas: Add sas_execute_tmf()

Drivers using libsas have to issue their own TMFs, and the code to do this
is duplicated between drivers.

Add a common function to handle TMFs. This will be also used for sending
ATA commands, but use name "tmf" as the purpose is similar between SCSI and
ATA in the usage.

The force_phy_id argument will be used for a hisi_sas HW bug workaround.

We check the sas task status stat field against TMF codes, as according to
the SAS v1.1 spec 9.2.2.5.3, if response_data is in datapres, then the
response code should be a TMF code - see table 128.

Link: https://lore.kernel.org/r/1645112566-115804-10-git-send-email-john.garry@huawei.com
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 105 insertions, 0 deletions

diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 40dcb4e8a747..d04002180be3 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -917,6 +917,111 @@ void sas_task_internal_timedout(struct timer_list *t)
 		complete(&task->slow_task->completion);
 }
 
+#define TASK_TIMEOUT			(20 * HZ)
+#define TASK_RETRY			3
+
+int sas_execute_tmf(struct domain_device *device, void *parameter,
+		    int para_len, int force_phy_id,
+		    struct sas_tmf_task *tmf)
+{
+	struct sas_task *task;
+	struct sas_internal *i =
+		to_sas_internal(device->port->ha->core.shost->transportt);
+	int res, retry;
+
+	for (retry = 0; retry < TASK_RETRY; retry++) {
+		task = sas_alloc_slow_task(GFP_KERNEL);
+		if (!task)
+			return -ENOMEM;
+
+		task->dev = device;
+		task->task_proto = device->tproto;
+
+		task->task_done = sas_task_internal_done;
+		task->tmf = tmf;
+
+		task->slow_task->timer.function = sas_task_internal_timedout;
+		task->slow_task->timer.expires = jiffies + TASK_TIMEOUT;
+		add_timer(&task->slow_task->timer);
+
+		res = i->dft->lldd_execute_task(task, GFP_KERNEL);
+		if (res) {
+			del_timer_sync(&task->slow_task->timer);
+			pr_err("executing TMF task failed %016llx (%d)\n",
+			       SAS_ADDR(device->sas_addr), res);
+			break;
+		}
+
+		wait_for_completion(&task->slow_task->completion);
+
+		res = TMF_RESP_FUNC_FAILED;
+
+		if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
+			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
+				pr_err("TMF task timeout for %016llx and not done\n",
+				       SAS_ADDR(device->sas_addr));
+				break;
+			}
+			pr_warn("TMF task timeout for %016llx and done\n",
+				SAS_ADDR(device->sas_addr));
+		}
+
+		if (task->task_status.resp == SAS_TASK_COMPLETE &&
+		    task->task_status.stat == TMF_RESP_FUNC_COMPLETE) {
+			res = TMF_RESP_FUNC_COMPLETE;
+			break;
+		}
+
+		if (task->task_status.resp == SAS_TASK_COMPLETE &&
+		    task->task_status.stat == TMF_RESP_FUNC_SUCC) {
+			res = TMF_RESP_FUNC_SUCC;
+			break;
+		}
+
+		if (task->task_status.resp == SAS_TASK_COMPLETE &&
+		    task->task_status.stat == SAS_DATA_UNDERRUN) {
+			/* no error, but return the number of bytes of
+			 * underrun
+			 */
+			pr_warn("TMF task to dev %016llx resp: 0x%x sts 0x%x underrun\n",
+				SAS_ADDR(device->sas_addr),
+				task->task_status.resp,
+				task->task_status.stat);
+			res = task->task_status.residual;
+			break;
+		}
+
+		if (task->task_status.resp == SAS_TASK_COMPLETE &&
+		    task->task_status.stat == SAS_DATA_OVERRUN) {
+			pr_warn("TMF task blocked task error %016llx\n",
+				SAS_ADDR(device->sas_addr));
+			res = -EMSGSIZE;
+			break;
+		}
+
+		if (task->task_status.resp == SAS_TASK_COMPLETE &&
+		    task->task_status.stat == SAS_OPEN_REJECT) {
+			pr_warn("TMF task open reject failed  %016llx\n",
+				SAS_ADDR(device->sas_addr));
+			res = -EIO;
+		} else {
+			pr_warn("TMF task to dev %016llx resp: 0x%x status 0x%x\n",
+				SAS_ADDR(device->sas_addr),
+				task->task_status.resp,
+				task->task_status.stat);
+		}
+		sas_free_task(task);
+		task = NULL;
+	}
+
+	if (retry == TASK_RETRY)
+		pr_warn("executing TMF for %016llx failed after %d attempts!\n",
+			SAS_ADDR(device->sas_addr), TASK_RETRY);
+	sas_free_task(task);
+
+	return res;
+}
+
 /*
  * Tell an upper layer that it needs to initiate an abort for a given task.
  * This should only ever be called by an LLDD.