[PATCH 20/28] drm/xe/vf: Stop and flush CTs in VF post migration recovery

[Matthew Brost <matthew.brost@intel.com>]

Flushing CTs (i.e., progressing all pending G2H messages) gives VF
post-migration recovery an accurate view of which H2G messages the GuC
has processed, enabling the GuC submission state machine to correctly
rebuild all state.

Also, stop all CT traffic, as the CT is not live during VF
post-migration recovery.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_sriov_vf.c |  2 ++
 drivers/gpu/drm/xe/xe_guc_ct.c      | 11 +++++++++++
 drivers/gpu/drm/xe/xe_guc_ct.h      |  1 +
 3 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
index d9e5654b289a..64c41056389c 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
@@ -23,6 +23,7 @@
 #include "xe_gt_sriov_vf.h"
 #include "xe_gt_sriov_vf_types.h"
 #include "xe_guc.h"
+#include "xe_guc_ct.h"
 #include "xe_guc_hxg_helpers.h"
 #include "xe_guc_relay.h"
 #include "xe_guc_submit.h"
@@ -1194,6 +1195,7 @@ static void vf_post_migration_shutdown(struct xe_gt *gt)
 	gt->sriov.vf.migration.recovery_queued = false;
 	spin_unlock(&gt->sriov.vf.migration.lock);
 
+	xe_guc_ct_flush(&gt->uc.guc.ct);
 	xe_guc_submit_pause(&gt->uc.guc);
 }
 
diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index 6a1baed934c2..fb4bf894de1c 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -574,6 +574,17 @@ void xe_guc_ct_disable(struct xe_guc_ct *ct)
 	stop_g2h_handler(ct);
 }
 
+/**
+ * xe_guc_ct_flush - Flush all processing of G2H / H2G
+ * @ct: the &xe_guc_ct
+ */
+void xe_guc_ct_flush(struct xe_guc_ct *ct)
+{
+	receive_g2h(ct);
+	wake_up_all(&ct->g2h_fence_wq);
+	xe_guc_ct_stop(ct);
+}
+
 /**
  * xe_guc_ct_stop - Set GuC to stopped state
  * @ct: the &xe_guc_ct
diff --git a/drivers/gpu/drm/xe/xe_guc_ct.h b/drivers/gpu/drm/xe/xe_guc_ct.h
index d6c81325a76c..1e32a59817cc 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.h
+++ b/drivers/gpu/drm/xe/xe_guc_ct.h
@@ -17,6 +17,7 @@ int xe_guc_ct_init_post_hwconfig(struct xe_guc_ct *ct);
 int xe_guc_ct_enable(struct xe_guc_ct *ct);
 void xe_guc_ct_disable(struct xe_guc_ct *ct);
 void xe_guc_ct_stop(struct xe_guc_ct *ct);
+void xe_guc_ct_flush(struct xe_guc_ct *ct);
 void xe_guc_ct_fast_path(struct xe_guc_ct *ct);
 
 struct xe_guc_ct_snapshot *xe_guc_ct_snapshot_capture(struct xe_guc_ct *ct);
-- 
2.34.1