isci: When in the abort path, defeat other resume calls until done.

Completion of I/Os during the one of the abort path interface calls
from libsas can drive remote device state changes and the resumption
of the device RNC.  This is a problem when the abort path is
attempting to cleanup outstanding I/O at the same time - the resumption
can prevent the termination from occuring correctly.

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

3 files changed, 83 insertions, 46 deletions

diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c
index acc94a454a1f..d1c2a2294a32 100644
--- a/drivers/scsi/isci/remote_device.c
+++ b/drivers/scsi/isci/remote_device.c
@@ -1266,6 +1266,7 @@ enum sci_status isci_remote_device_resume_from_abort(
         /* Preserve any current resume callbacks, for instance from other
          * resumptions.
          */
+        clear_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags);
         status = sci_remote_device_resume(idev, idev->rnc.user_callback,
                                           idev->rnc.user_cookie);
         spin_unlock_irqrestore(&ihost->scic_lock, flags);
@@ -1501,6 +1502,7 @@ enum sci_status isci_remote_device_suspend_terminate(
 
         /* Put the device into suspension. */
         spin_lock_irqsave(&ihost->scic_lock, flags);
+        set_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags);
         sci_remote_device_suspend(idev, SCI_SW_SUSPEND_LINKHANG_DETECT);
         spin_unlock_irqrestore(&ihost->scic_lock, flags);
 
diff --git a/drivers/scsi/isci/remote_device.h b/drivers/scsi/isci/remote_device.h
index d1d18925fbfc..53564c35cf24 100644
--- a/drivers/scsi/isci/remote_device.h
+++ b/drivers/scsi/isci/remote_device.h
@@ -86,6 +86,7 @@ struct isci_remote_device {
         #define IDEV_IO_READY 4
         #define IDEV_IO_NCQERROR 5
         #define IDEV_RNC_LLHANG_ENABLED 6
+        #define IDEV_ABORT_PATH_ACTIVE 7
         unsigned long flags;
         struct kref kref;
         struct isci_port *isci_port;
diff --git a/drivers/scsi/isci/remote_node_context.c b/drivers/scsi/isci/remote_node_context.c
index 77c8b5138b7e..faeae9554ee3 100644
--- a/drivers/scsi/isci/remote_node_context.c
+++ b/drivers/scsi/isci/remote_node_context.c
@@ -161,6 +161,14 @@ static void sci_remote_node_context_construct_buffer(struct sci_remote_node_cont
         rnc->ssp.oaf_more_compatibility_features = 0;
 }
 
+static void sci_remote_node_context_save_cbparams(
+        struct sci_remote_node_context *sci_rnc,
+        scics_sds_remote_node_context_callback callback,
+        void *callback_parameter)
+{
+        sci_rnc->user_callback = callback;
+        sci_rnc->user_cookie   = callback_parameter;
+}
 /**
  *
  * @sci_rnc:
@@ -179,10 +187,9 @@ static void sci_remote_node_context_setup_to_resume(
 {
         if (sci_rnc->destination_state != RNC_DEST_FINAL) {
                 sci_rnc->destination_state = dest_param;
-                if (callback != NULL) {
-                        sci_rnc->user_callback = callback;
-                        sci_rnc->user_cookie   = callback_parameter;
-                }
+                if (callback != NULL)
+                        sci_remote_node_context_save_cbparams(
+                                sci_rnc, callback, callback_parameter);
         }
 }
 
@@ -648,67 +655,94 @@ enum sci_status sci_remote_node_context_resume(struct sci_remote_node_context *s
                                                     void *cb_p)
 {
         enum scis_sds_remote_node_context_states state;
+        struct isci_remote_device *idev = rnc_to_dev(sci_rnc);
 
         state = sci_rnc->sm.current_state_id;
-        dev_dbg(scirdev_to_dev(rnc_to_dev(sci_rnc)),
-                 "%s: state %s, cb_fn = %p, cb_p = %p; dest_state = %d\n",
-                 __func__, rnc_state_name(state), cb_fn, cb_p,
-                 sci_rnc->destination_state);
+        dev_dbg(scirdev_to_dev(idev),
+                "%s: state %s, cb_fn = %p, cb_p = %p; dest_state = %d; "
+                        "dev resume path %s\n",
+                __func__, rnc_state_name(state), cb_fn, cb_p,
+                sci_rnc->destination_state,
+                test_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags)
+                        ? "<abort active>" : "<normal>");
 
         switch (state) {
         case SCI_RNC_INITIAL:
                 if (sci_rnc->remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
                         return SCI_FAILURE_INVALID_STATE;
 
-                sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p,
-                                                        RNC_DEST_READY);
-                sci_remote_node_context_construct_buffer(sci_rnc);
-                sci_change_state(&sci_rnc->sm, SCI_RNC_POSTING);
+                if (test_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags))
+                        sci_remote_node_context_save_cbparams(sci_rnc, cb_fn,
+                                                              cb_p);
+                else {
+                        sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn,
+                                                        cb_p, RNC_DEST_READY);
+                        sci_remote_node_context_construct_buffer(sci_rnc);
+                        sci_change_state(&sci_rnc->sm, SCI_RNC_POSTING);
+                }
                 return SCI_SUCCESS;
+
         case SCI_RNC_POSTING:
         case SCI_RNC_INVALIDATING:
         case SCI_RNC_RESUMING:
-                /* We are still waiting to post when a resume was requested. */
-                switch (sci_rnc->destination_state) {
-                case RNC_DEST_SUSPENDED:
-                case RNC_DEST_SUSPENDED_RESUME:
-                        /* Previously waiting to suspend after posting.  Now
-                         * continue onto resumption.
+                if (test_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags))
+                        sci_remote_node_context_save_cbparams(sci_rnc, cb_fn,
+                                                              cb_p);
+                else {
+                        /* We are still waiting to post when a resume was
+                         * requested.
                          */
-                        sci_remote_node_context_setup_to_resume(
-                                sci_rnc, cb_fn, cb_p,
-                                RNC_DEST_SUSPENDED_RESUME);
-                        break;
-                default:
-                        sci_remote_node_context_setup_to_resume(
-                                sci_rnc, cb_fn, cb_p,
-                                RNC_DEST_READY);
-                        break;
+                        switch (sci_rnc->destination_state) {
+                        case RNC_DEST_SUSPENDED:
+                        case RNC_DEST_SUSPENDED_RESUME:
+                                /* Previously waiting to suspend after posting.
+                                 * Now continue onto resumption.
+                                 */
+                                sci_remote_node_context_setup_to_resume(
+                                        sci_rnc, cb_fn, cb_p,
+                                        RNC_DEST_SUSPENDED_RESUME);
+                                break;
+                        default:
+                                sci_remote_node_context_setup_to_resume(
+                                        sci_rnc, cb_fn, cb_p,
+                                        RNC_DEST_READY);
+                                break;
+                        }
                 }
                 return SCI_SUCCESS;
+
         case SCI_RNC_TX_SUSPENDED:
-        case SCI_RNC_TX_RX_SUSPENDED: {
-                struct isci_remote_device *idev = rnc_to_dev(sci_rnc);
-                struct domain_device *dev = idev->domain_dev;
-
-                /* If this is an expander attached SATA device we must
-                 * invalidate and repost the RNC since this is the only way
-                 * to clear the TCi to NCQ tag mapping table for the RNi.
-                 * All other device types we can just resume.
-                 */
-                sci_remote_node_context_setup_to_resume(sci_rnc, cb_fn, cb_p,
-                                                        RNC_DEST_READY);
+        case SCI_RNC_TX_RX_SUSPENDED:
+                if (test_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags))
+                        sci_remote_node_context_save_cbparams(sci_rnc, cb_fn,
+                                                              cb_p);
+                else {
+                        struct domain_device *dev = idev->domain_dev;
+                        /* If this is an expander attached SATA device we must
+                         * invalidate and repost the RNC since this is the only
+                         * way to clear the TCi to NCQ tag mapping table for
+                         * the RNi. All other device types we can just resume.
+                         */
+                        sci_remote_node_context_setup_to_resume(
+                                sci_rnc, cb_fn, cb_p, RNC_DEST_READY);
 
-                if (dev_is_sata(dev) && dev->parent)
-                        sci_change_state(&sci_rnc->sm, SCI_RNC_INVALIDATING);
-                else
-                        sci_change_state(&sci_rnc->sm, SCI_RNC_RESUMING);
+                        if (dev_is_sata(dev) && dev->parent)
+                                sci_change_state(&sci_rnc->sm,
+                                                 SCI_RNC_INVALIDATING);
+                        else
+                                sci_change_state(&sci_rnc->sm,
+                                                 SCI_RNC_RESUMING);
+                }
                 return SCI_SUCCESS;
-        }
+
         case SCI_RNC_AWAIT_SUSPENSION:
-                sci_remote_node_context_setup_to_resume(
-                        sci_rnc, cb_fn, cb_p,
-                        RNC_DEST_SUSPENDED_RESUME);
+                if (test_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags))
+                        sci_remote_node_context_save_cbparams(sci_rnc, cb_fn,
+                                                              cb_p);
+                else
+                        sci_remote_node_context_setup_to_resume(
+                                sci_rnc, cb_fn, cb_p,
+                                RNC_DEST_SUSPENDED_RESUME);
                 return SCI_SUCCESS;
         default:
                 dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),