drm/i915/selftest: Fix workarounds selftest for GuC submission

When GuC submission is enabled, the GuC controls engine resets. Rather
than explicitly triggering a reset, the driver must submit a hanging
context to GuC and wait for the reset to occur.

Signed-off-by: Rahul Kumar Singh <rahul.kumar.singh@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-28-matthew.brost@intel.com

2 files changed, 102 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.c b/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.c
new file mode 100644
index 000000000000..5cdee1378e98
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+//#include "gt/intel_engine_user.h"
+#include "gt/intel_gt.h"
+#include "i915_drv.h"
+#include "i915_selftest.h"
+
+#include "selftests/intel_scheduler_helpers.h"
+
+#define REDUCED_TIMESLICE	5
+#define REDUCED_PREEMPT		10
+#define WAIT_FOR_RESET_TIME	1000
+
+int intel_selftest_modify_policy(struct intel_engine_cs *engine,
+				 struct intel_selftest_saved_policy *saved)
+
+{
+	int err;
+
+	saved->reset = engine->i915->params.reset;
+	saved->flags = engine->flags;
+	saved->timeslice = engine->props.timeslice_duration_ms;
+	saved->preempt_timeout = engine->props.preempt_timeout_ms;
+
+	/*
+	 * Enable force pre-emption on time slice expiration
+	 * together with engine reset on pre-emption timeout.
+	 * This is required to make the GuC notice and reset
+	 * the single hanging context.
+	 * Also, reduce the preemption timeout to something
+	 * small to speed the test up.
+	 */
+	engine->i915->params.reset = 2;
+	engine->flags |= I915_ENGINE_WANT_FORCED_PREEMPTION;
+	engine->props.timeslice_duration_ms = REDUCED_TIMESLICE;
+	engine->props.preempt_timeout_ms = REDUCED_PREEMPT;
+
+	if (!intel_engine_uses_guc(engine))
+		return 0;
+
+	err = intel_guc_global_policies_update(&engine->gt->uc.guc);
+	if (err)
+		intel_selftest_restore_policy(engine, saved);
+
+	return err;
+}
+
+int intel_selftest_restore_policy(struct intel_engine_cs *engine,
+				  struct intel_selftest_saved_policy *saved)
+{
+	/* Restore the original policies */
+	engine->i915->params.reset = saved->reset;
+	engine->flags = saved->flags;
+	engine->props.timeslice_duration_ms = saved->timeslice;
+	engine->props.preempt_timeout_ms = saved->preempt_timeout;
+
+	if (!intel_engine_uses_guc(engine))
+		return 0;
+
+	return intel_guc_global_policies_update(&engine->gt->uc.guc);
+}
+
+int intel_selftest_wait_for_rq(struct i915_request *rq)
+{
+	long ret;
+
+	ret = i915_request_wait(rq, 0, WAIT_FOR_RESET_TIME);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.h b/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.h
new file mode 100644
index 000000000000..79605b14bc33
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#ifndef _INTEL_SELFTEST_SCHEDULER_HELPERS_H_
+#define _INTEL_SELFTEST_SCHEDULER_HELPERS_H_
+
+#include <linux/types.h>
+
+struct i915_request;
+struct intel_engine_cs;
+
+struct intel_selftest_saved_policy {
+	u32 flags;
+	u32 reset;
+	u64 timeslice;
+	u64 preempt_timeout;
+};
+
+int intel_selftest_modify_policy(struct intel_engine_cs *engine,
+				 struct intel_selftest_saved_policy *saved);
+int intel_selftest_restore_policy(struct intel_engine_cs *engine,
+				  struct intel_selftest_saved_policy *saved);
+int intel_selftest_wait_for_rq(struct i915_request *rq);
+
+#endif