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

drivers/gpu/drm/i915/Makefile

@@ -280,6 +280,7 @@ i915-$(CONFIG_DRM_I915_CAPTURE_ERROR) += i915_gpu_error.o
 i915-$(CONFIG_DRM_I915_SELFTEST) += \
 	gem/selftests/i915_gem_client_blt.o \
 	gem/selftests/igt_gem_utils.o \
+	selftests/intel_scheduler_helpers.o \
 	selftests/i915_random.o \
 	selftests/i915_selftest.o \
 	selftests/igt_atomic.o \

drivers/gpu/drm/i915/gt/intel_engine_types.h

@@ -443,6 +443,7 @@ struct intel_engine_cs {
 #define I915_ENGINE_IS_VIRTUAL       BIT(5)
 #define I915_ENGINE_HAS_RELATIVE_MMIO BIT(6)
 #define I915_ENGINE_REQUIRES_CMD_PARSER BIT(7)
+#define I915_ENGINE_WANT_FORCED_PREEMPTION BIT(8)
 	unsigned int flags;
 
 	/*

drivers/gpu/drm/i915/gt/selftest_workarounds.c

@@ -12,6 +12,7 @@
 #include "selftests/igt_flush_test.h"
 #include "selftests/igt_reset.h"
 #include "selftests/igt_spinner.h"
+#include "selftests/intel_scheduler_helpers.h"
 #include "selftests/mock_drm.h"
 
 #include "gem/selftests/igt_gem_utils.h"
@@ -261,28 +262,34 @@ static int do_engine_reset(struct intel_engine_cs *engine)
 	return intel_engine_reset(engine, "live_workarounds");
 }
 
+static int do_guc_reset(struct intel_engine_cs *engine)
+{
+	/* Currently a no-op as the reset is handled by GuC */
+	return 0;
+}
+
 static int
 switch_to_scratch_context(struct intel_engine_cs *engine,
-			  struct igt_spinner *spin)
+			  struct igt_spinner *spin,
+			  struct i915_request **rq)
 {
 	struct intel_context *ce;
-	struct i915_request *rq;
 	int err = 0;
 
 	ce = intel_context_create(engine);
 	if (IS_ERR(ce))
 		return PTR_ERR(ce);
 
-	rq = igt_spinner_create_request(spin, ce, MI_NOOP);
+	*rq = igt_spinner_create_request(spin, ce, MI_NOOP);
 	intel_context_put(ce);
 
-	if (IS_ERR(rq)) {
+	if (IS_ERR(*rq)) {
 		spin = NULL;
-		err = PTR_ERR(rq);
+		err = PTR_ERR(*rq);
 		goto err;
 	}
 
-	err = request_add_spin(rq, spin);
+	err = request_add_spin(*rq, spin);
 err:
 	if (err && spin)
 		igt_spinner_end(spin);
@@ -296,6 +303,7 @@ static int check_whitelist_across_reset(struct intel_engine_cs *engine,
 {
 	struct intel_context *ce, *tmp;
 	struct igt_spinner spin;
+	struct i915_request *rq;
 	intel_wakeref_t wakeref;
 	int err;
 
@@ -316,13 +324,24 @@ static int check_whitelist_across_reset(struct intel_engine_cs *engine,
 		goto out_spin;
 	}
 
-	err = switch_to_scratch_context(engine, &spin);
+	err = switch_to_scratch_context(engine, &spin, &rq);
 	if (err)
 		goto out_spin;
 
+	/* Ensure the spinner hasn't aborted */
+	if (i915_request_completed(rq)) {
+		pr_err("%s spinner failed to start\n", name);
+		err = -ETIMEDOUT;
+		goto out_spin;
+	}
+
 	with_intel_runtime_pm(engine->uncore->rpm, wakeref)
 		err = reset(engine);
 
+	/* Ensure the reset happens and kills the engine */
+	if (err == 0)
+		err = intel_selftest_wait_for_rq(rq);
+
 	igt_spinner_end(&spin);
 
 	if (err) {
@@ -787,9 +806,27 @@ static int live_reset_whitelist(void *arg)
 			continue;
 
 		if (intel_has_reset_engine(gt)) {
+			if (intel_engine_uses_guc(engine)) {
+				struct intel_selftest_saved_policy saved;
+				int err2;
+
+				err = intel_selftest_modify_policy(engine, &saved);
+				if (err)
+					goto out;
+
+				err = check_whitelist_across_reset(engine,
+								   do_guc_reset,
+								   "guc");
+
+				err2 = intel_selftest_restore_policy(engine, &saved);
+				if (err == 0)
+					err = err2;
+			} else {
 				err = check_whitelist_across_reset(engine,
 								   do_engine_reset,
 								   "engine");
+			}
+
 			if (err)
 				goto out;
 		}
@@ -1235,15 +1272,23 @@ live_engine_reset_workarounds(void *arg)
 	reference_lists_init(gt, lists);
 
 	for_each_engine(engine, gt, id) {
+		struct intel_selftest_saved_policy saved;
+		bool using_guc = intel_engine_uses_guc(engine);
 		bool ok;
+		int ret2;
 
 		pr_info("Verifying after %s reset...\n", engine->name);
+		ret = intel_selftest_modify_policy(engine, &saved);
+		if (ret)
+			break;
+
 		ce = intel_context_create(engine);
 		if (IS_ERR(ce)) {
 			ret = PTR_ERR(ce);
-			break;
+			goto restore;
 		}
 
+		if (!using_guc) {
 			ok = verify_wa_lists(gt, lists, "before reset");
 			if (!ok) {
 				ret = -ESRCH;
@@ -1261,6 +1306,7 @@ live_engine_reset_workarounds(void *arg)
 				ret = -ESRCH;
 				goto err;
 			}
+		}
 
 		ret = igt_spinner_init(&spin, engine->gt);
 		if (ret)
@@ -1280,6 +1326,13 @@ live_engine_reset_workarounds(void *arg)
 			goto err;
 		}
 
+		/* Ensure the spinner hasn't aborted */
+		if (i915_request_completed(rq)) {
+			ret = -ETIMEDOUT;
+			goto skip;
+		}
+
+		if (!using_guc) {
 			ret = intel_engine_reset(engine, "live_workarounds:active");
 			if (ret) {
 				pr_err("%s: Reset failed on an active spinner\n",
@@ -1287,18 +1340,27 @@ live_engine_reset_workarounds(void *arg)
 				igt_spinner_fini(&spin);
 				goto err;
 			}
+		}
 
+		/* Ensure the reset happens and kills the engine */
+		if (ret == 0)
+			ret = intel_selftest_wait_for_rq(rq);
+
+skip:
 		igt_spinner_end(&spin);
 		igt_spinner_fini(&spin);
 
 		ok = verify_wa_lists(gt, lists, "after busy reset");
-		if (!ok) {
+		if (!ok)
 			ret = -ESRCH;
-			goto err;
-		}
 
 err:
 		intel_context_put(ce);
+
+restore:
+		ret2 = intel_selftest_restore_policy(engine, &saved);
+		if (ret == 0)
+			ret = ret2;
 		if (ret)
 			break;
 	}

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -1252,6 +1252,9 @@ static void guc_context_policy_init(struct intel_engine_cs *engine,
 {
 	desc->policy_flags = 0;
 
+	if (engine->flags & I915_ENGINE_WANT_FORCED_PREEMPTION)
+		desc->policy_flags |= CONTEXT_POLICY_FLAG_PREEMPT_TO_IDLE;
+
 	/* NB: For both of these, zero means disabled. */
 	desc->execution_quantum = engine->props.timeslice_duration_ms * 1000;
 	desc->preemption_timeout = engine->props.preempt_timeout_ms * 1000;

drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.c

+// 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;
+}

drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.h

+/* 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