isci: Callbacks to libsas occur under scic_lock and are synchronized.

This patch changes the callback mechanism to libsas to only occur while
the scic_lock is held; the abort path cleanup of I/Os also checks to make
sure IREQ_ABORT_PATH_ACTIVE is clear before proceding.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 40 insertions, 13 deletions

diff --git a/drivers/scsi/isci/host.c b/drivers/scsi/isci/host.c
index 25d537e2f5c4..53c3ad64c998 100644
--- a/drivers/scsi/isci/host.c
+++ b/drivers/scsi/isci/host.c
@@ -1105,8 +1105,6 @@ void isci_host_completion_routine(unsigned long data)
         list_splice_init(&ihost->requests_to_complete,
                          &completed_request_list);
 
-        spin_unlock_irq(&ihost->scic_lock);
-
         /* Process any completions in the list. */
         list_for_each_safe(current_position, next_position,
                            &completed_request_list) {
@@ -1115,7 +1113,6 @@ void isci_host_completion_routine(unsigned long data)
                                      completed_node);
                 task = isci_request_access_task(request);
 
-
                 /* Return the task to libsas */
                 if (task != NULL) {
 
@@ -1141,11 +1138,12 @@ void isci_host_completion_routine(unsigned long data)
                                 }
                         }
                 }
+                if (test_and_clear_bit(IREQ_ABORT_PATH_ACTIVE, &request->flags))
+                        wake_up_all(&ihost->eventq);
 
-                spin_lock_irq(&ihost->scic_lock);
                 isci_free_tag(ihost, request->io_tag);
-                spin_unlock_irq(&ihost->scic_lock);
         }
+        spin_unlock_irq(&ihost->scic_lock);
 
         /* the coalesence timeout doubles at each encoding step, so
          * update it based on the ilog2 value of the outstanding requests
@@ -2703,8 +2701,6 @@ enum sci_status sci_controller_complete_io(struct isci_host *ihost,
 
                 index = ISCI_TAG_TCI(ireq->io_tag);
                 clear_bit(IREQ_ACTIVE, &ireq->flags);
-                if (test_bit(IREQ_ABORT_PATH_ACTIVE, &ireq->flags))
-                        wake_up_all(&ihost->eventq);
                 return SCI_SUCCESS;
         default:
                 dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c
index d1c2a2294a32..21a9800a9bec 100644
--- a/drivers/scsi/isci/remote_device.c
+++ b/drivers/scsi/isci/remote_device.c
@@ -145,6 +145,39 @@ static bool isci_compare_suspendcount(
         return localcount != idev->rnc.suspend_count;
 }
 
+static bool isci_check_reqterm(
+        struct isci_host *ihost,
+        struct isci_remote_device *idev,
+        struct isci_request *ireq,
+        u32 localcount)
+{
+        unsigned long flags;
+        bool res;
+
+        spin_lock_irqsave(&ihost->scic_lock, flags);
+        res = isci_compare_suspendcount(idev, localcount)
+                && !test_bit(IREQ_ABORT_PATH_ACTIVE, &ireq->flags);
+        spin_unlock_irqrestore(&ihost->scic_lock, flags);
+
+        return res;
+}
+
+static bool isci_check_devempty(
+        struct isci_host *ihost,
+        struct isci_remote_device *idev,
+        u32 localcount)
+{
+        unsigned long flags;
+        bool res;
+
+        spin_lock_irqsave(&ihost->scic_lock, flags);
+        res = isci_compare_suspendcount(idev, localcount)
+                && idev->started_request_count == 0;
+        spin_unlock_irqrestore(&ihost->scic_lock, flags);
+
+        return res;
+}
+
 enum sci_status isci_remote_device_terminate_requests(
         struct isci_host *ihost,
         struct isci_remote_device *idev,
@@ -179,17 +212,15 @@ enum sci_status isci_remote_device_terminate_requests(
                         sci_remote_device_terminate_req(ihost, idev, 0, ireq);
                         spin_unlock_irqrestore(&ihost->scic_lock, flags);
                         wait_event(ihost->eventq,
-                                   (isci_compare_suspendcount(idev,
-                                                              rnc_suspend_count)
-                                    && !test_bit(IREQ_ACTIVE, &ireq->flags)));
+                                   isci_check_reqterm(ihost, idev, ireq,
+                                                      rnc_suspend_count));
                 } else {
                         /* Terminate all TCs. */
                         sci_remote_device_terminate_requests(idev);
                         spin_unlock_irqrestore(&ihost->scic_lock, flags);
                         wait_event(ihost->eventq,
-                                   (isci_compare_suspendcount(idev,
-                                                              rnc_suspend_count)
-                                    && idev->started_request_count == 0));
+                                   isci_check_devempty(ihost, idev,
+                                                       rnc_suspend_count));
                 }
                 dev_dbg(&ihost->pdev->dev, "%s: idev=%p, wait done\n",
                         __func__, idev);