[PATCH v2 1/5] drm/xe/gt: Use GT ordered workqueue for wedging

[Raag Jadav <raag.jadav@intel.com>]

Currently, xe_gt_declare_wedged() stops GuC CT and initiates exec queue
teardown synchronously. This is problematic in cases where the jobs are
still in-flight when the device is declated wedged.

Introduce a worker for GT specific wedge handling and queue the teardown
on GT ordered workqueue, so we don't disrupt the scheduler while jobs
are still in-flight.

Fixes: c9474b726b93 ("drm/xe: Wedge the entire device")
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
---
 drivers/gpu/drm/xe/xe_gt.c       | 15 +++++++++++++--
 drivers/gpu/drm/xe/xe_gt_types.h |  9 +++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
index 478e047031f4..5c201327a747 100644
--- a/drivers/gpu/drm/xe/xe_gt.c
+++ b/drivers/gpu/drm/xe/xe_gt.c
@@ -173,6 +173,7 @@ static void xe_gt_enable_comp_1wcoh(struct xe_gt *gt)
 }
 
 static void gt_reset_worker(struct work_struct *w);
+static void gt_wedge_worker(struct work_struct *w);
 
 static int emit_job_sync(struct xe_exec_queue *q, struct xe_bb *bb,
 			 long timeout_jiffies, bool force_reset)
@@ -704,6 +705,8 @@ static void xe_gt_fini(void *arg)
 	struct xe_gt *gt = arg;
 	int i;
 
+	disable_work_sync(&gt->wedge.worker);
+
 	if (disable_work_sync(&gt->reset.worker))
 		/*
 		 * If gt_reset_worker was halted from executing, take care of
@@ -723,6 +726,7 @@ int xe_gt_init(struct xe_gt *gt)
 	int i;
 
 	INIT_WORK(&gt->reset.worker, gt_reset_worker);
+	INIT_WORK(&gt->wedge.worker, gt_wedge_worker);
 
 	for (i = 0; i < XE_ENGINE_CLASS_MAX; ++i) {
 		gt->ring_ops[i] = xe_ring_ops_get(gt, i);
@@ -1005,6 +1009,14 @@ void xe_gt_reset_async(struct xe_gt *gt)
 		xe_pm_runtime_put(xe);
 }
 
+static void gt_wedge_worker(struct work_struct *w)
+{
+	struct xe_gt *gt = container_of(w, typeof(*gt), wedge.worker);
+
+	xe_uc_declare_wedged(&gt->uc);
+	xe_tlb_inval_reset(&gt->tlb_inval);
+}
+
 void xe_gt_suspend_prepare(struct xe_gt *gt)
 {
 	xe_uc_suspend_prepare(&gt->uc);
@@ -1195,6 +1207,5 @@ void xe_gt_declare_wedged(struct xe_gt *gt)
 {
 	xe_gt_assert(gt, gt_to_xe(gt)->wedged.mode);
 
-	xe_uc_declare_wedged(&gt->uc);
-	xe_tlb_inval_reset(&gt->tlb_inval);
+	queue_work(gt->ordered_wq, &gt->wedge.worker);
 }
diff --git a/drivers/gpu/drm/xe/xe_gt_types.h b/drivers/gpu/drm/xe/xe_gt_types.h
index 628911346455..ca1e2f82470d 100644
--- a/drivers/gpu/drm/xe/xe_gt_types.h
+++ b/drivers/gpu/drm/xe/xe_gt_types.h
@@ -233,6 +233,15 @@ struct xe_gt {
 		struct work_struct worker;
 	} reset;
 
+	/** @wedge: state for GT wedge */
+	struct {
+		/**
+		 * @wedge.worker: work so GT wedge to be done async allowing the wedge
+		 * code to safely flush all code paths
+		 */
+		struct work_struct worker;
+	} wedge;
+
 	/** @tlb_inval: TLB invalidation state */
 	struct xe_tlb_inval tlb_inval;
 
-- 
2.43.0