Merge r268024, 268025:

 Fix a case in ndling ATA_PASSTHROUGH commands that have an unaligned buffer.
 This impacts some home-rolled SMART tools.

 In rare cases, a SATA drive can stop responding to commands and trigger a
 reset device task request from the driver.  If the drive fails to respond
 with a signature FIS, the driver would previously get into an endless retry
 loop, stalling all I/O to the drive and keeping user processes stranded.
 Instead, fail the i/o and invalidate the device if the task management
 command times out.  This is controllable with the sysctl and tunable
 hw.isci.fail_on_task_timeout
 dev.isci.0.fail_on_task_timeout

 The default for these is 1.

Obtained from:	Netflix, Inc.

5 files changed, 41 insertions, 3 deletions

diff --git a/sys/dev/isci/isci.h b/sys/dev/isci/isci.h
index 1dc8e93..ce0426a 100644
--- a/sys/dev/isci/isci.h
+++ b/sys/dev/isci/isci.h
@@ -164,6 +164,7 @@ struct ISCI_CONTROLLER
 	uint32_t		initial_discovery_mask;
 	BOOL			is_frozen;
 	BOOL			release_queued_ccbs;
+	BOOL			fail_on_task_timeout;
 	uint8_t			*remote_device_memory;
 	struct ISCI_MEMORY	cached_controller_memory;
 	struct ISCI_MEMORY	uncached_controller_memory;
diff --git a/sys/dev/isci/isci_controller.c b/sys/dev/isci/isci_controller.c
index 0760f34..f3ff082 100644
--- a/sys/dev/isci/isci_controller.c
+++ b/sys/dev/isci/isci_controller.c
@@ -300,6 +300,8 @@ SCI_STATUS isci_controller_initialize(struct ISCI_CONTROLLER *controller)
 	SCI_CONTROLLER_HANDLE_T scic_controller_handle;
 	char led_name[64];
 	unsigned long tunable;
+	uint32_t io_shortage;
+	uint32_t fail_on_timeout;
 	int i;
 
 	scic_controller_handle =
@@ -365,10 +367,12 @@ SCI_STATUS isci_controller_initialize(struct ISCI_CONTROLLER *controller)
 	 *  this io_shortage parameter, which will tell CAM that we have a
 	 *  large queue depth than we really do.
 	 */
-	uint32_t io_shortage = 0;
+	io_shortage = 0;
 	TUNABLE_INT_FETCH("hw.isci.io_shortage", &io_shortage);
 	controller->sim_queue_depth += io_shortage;
 
+	fail_on_timeout = 1;
+	TUNABLE_INT_FETCH("hw.isci.fail_on_task_timeout", &fail_on_timeout);
 	/* Attach to CAM using xpt_bus_register now, then immediately freeze
 	 *  the simq.  It will get released later when initial domain discovery
 	 *  is complete.
diff --git a/sys/dev/isci/isci_sysctl.c b/sys/dev/isci/isci_sysctl.c
index 4623a8a..62a10b9 100644
--- a/sys/dev/isci/isci_sysctl.c
+++ b/sys/dev/isci/isci_sysctl.c
@@ -222,6 +222,24 @@ isci_sysctl_log_frozen_lun_masks(SYSCTL_HANDLER_ARGS)
 	return (0);
 }
 
+static int
+isci_sysctl_fail_on_task_timeout(SYSCTL_HANDLER_ARGS)
+{
+	struct isci_softc	*isci = (struct isci_softc *)arg1;
+	int32_t			fail_on_timeout = 0;
+	int			error, i;
+
+	error = sysctl_handle_int(oidp, &fail_on_timeout, 0, req);
+
+	if (error || fail_on_timeout == 0)
+		return (error);
+
+	for (i = 0; i < isci->controller_count; i++)
+		isci->controllers[i].fail_on_task_timeout = fail_on_timeout;
+
+	return (0);
+}
+
 void isci_sysctl_initialize(struct isci_softc *isci)
 {
 	struct sysctl_ctx_list *sysctl_ctx = device_get_sysctl_ctx(isci->device);
@@ -259,5 +277,10 @@ void isci_sysctl_initialize(struct isci_softc *isci)
 	    "log_frozen_lun_masks", CTLTYPE_UINT| CTLFLAG_RW, isci, 0,
 	    isci_sysctl_log_frozen_lun_masks, "IU",
 	    "Log frozen lun masks to kernel log");
+
+	SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree), OID_AUTO,
+	    "fail_on_task_timeout", CTLTYPE_UINT | CTLFLAG_RW, isci, 0,
+	    isci_sysctl_fail_on_task_timeout, "IU",
+	    "Fail a command that has encountered a task management timeout");
 }
 
diff --git a/sys/dev/isci/isci_task_request.c b/sys/dev/isci/isci_task_request.c
index 5d7f63d..6c8be45 100644
--- a/sys/dev/isci/isci_task_request.c
+++ b/sys/dev/isci/isci_task_request.c
@@ -206,8 +206,17 @@ isci_task_request_complete(SCI_CONTROLLER_HANDLE_T scif_controller,
 		break;
 
 	case SCI_FAILURE_TIMEOUT:
-		retry_task = TRUE;
-		isci_log_message(0, "ISCI", "task timeout - retrying\n");
+		if (isci_controller->fail_on_task_timeout) {
+			retry_task = FALSE;
+			isci_log_message(0, "ISCI",
+			    "task timeout - not retrying\n");
+			scif_cb_domain_device_removed(isci_controller,
+			    isci_remote_device->domain, isci_remote_device);
+		} else {
+			retry_task = TRUE;
+			isci_log_message(0, "ISCI",
+			    "task timeout - retrying\n");
+		}
 		break;
 
 	case SCI_TASK_FAILURE:
diff --git a/sys/dev/isci/scil/scic_sds_stp_request.c b/sys/dev/isci/scil/scic_sds_stp_request.c
index ed597b1..f3fe28d 100644
--- a/sys/dev/isci/scil/scic_sds_stp_request.c
+++ b/sys/dev/isci/scil/scic_sds_stp_request.c
@@ -1222,6 +1222,7 @@ SCI_STATUS scic_sds_stp_request_pio_data_in_copy_data_buffer(
          length -= copy_length;
          sgl_offset += copy_length;
          data_offset += copy_length;
+         source_address += copy_length;
 #endif
       }
    }