[Intel-gfx] [PATCH 2/3] drm/i915/guc: Add work queue to trigger a GT reset

Matthew Brost
2022-01-18T21:50:04Z

The G2H handler needs to be flushed during a GT reset but a G2H
indicating engine reset failure can trigger a GT reset. Add a worker to
trigger the GT when a engine reset failure is received to break this
circular dependency.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
drivers/gpu/drm/i915/gt/uc/intel_guc.h | 5 ++++
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 23 +++++++++++++++----
2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
index 9d26a86fe557a..60ea8deef5392 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
@@ -119,6 +119,11 @@ struct intel_guc {
* function as it might be in an atomic context (no sleeping)
*/
struct work_struct destroyed_worker;
+ /**
+ * @reset_worker: worker to trigger a GT reset after an engine
+ * reset fails
+ */
+ struct work_struct reset_worker;
} submission_state;

/**
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 23a40f10d376d..cdd8d691251ff 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -1746,6 +1746,7 @@ void intel_guc_submission_reset_finish(struct intel_guc *guc)
}

static void destroyed_worker_func(struct work_struct *w);
+static void reset_worker_func(struct work_struct *w);

/*
* Set up the memory resources to be shared with the GuC (via the GGTT)
@@ -1776,6 +1777,8 @@ int intel_guc_submission_init(struct intel_guc *guc)
INIT_LIST_HEAD(&guc->submission_state.destroyed_contexts);
INIT_WORK(&guc->submission_state.destroyed_worker,
destroyed_worker_func);
+ INIT_WORK(&guc->submission_state.reset_worker,
+ reset_worker_func);

guc->submission_state.guc_ids_bitmap =
bitmap_zalloc(NUMBER_MULTI_LRC_GUC_ID(guc), GFP_KERNEL);
@@ -4052,6 +4055,17 @@ guc_lookup_engine(struct intel_guc *guc, u8 guc_class, u8 instance)
return gt->engine_class[engine_class][instance];
}

+static void reset_worker_func(struct work_struct *w)
+{
+ struct intel_guc *guc = container_of(w, struct intel_guc,
+ submission_state.reset_worker);
+ struct intel_gt *gt = guc_to_gt(guc);
+
+ intel_gt_handle_error(gt, ALL_ENGINES,
+ I915_ERROR_CAPTURE,
+ "GuC failed to reset a engine\n");
+}
+
int intel_guc_engine_failure_process_msg(struct intel_guc *guc,
const u32 *msg, u32 len)
{
@@ -4083,10 +4097,11 @@ int intel_guc_engine_failure_process_msg(struct intel_guc *guc,
drm_err(&gt->i915->drm, "GuC engine reset request failed on %d:%d (%s) because 0x%08X",
guc_class, instance, engine->name, reason);

- intel_gt_handle_error(gt, engine->mask,
- I915_ERROR_CAPTURE,
- "GuC failed to reset %s (reason=0x%08x)\n",
- engine->name, reason);
+ /*
+ * A GT reset flushes this worker queue (G2H handler) so we must use
+ * another worker to trigger a GT reset.
+ */
+ queue_work(system_unbound_wq, &guc->submission_state.reset_worker);

return 0;
}
--
2.34.1