1 files changed, 429 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c
new file mode 100644
index 0000000000..273d440a53
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c
@@ -0,0 +1,429 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2018 Intel Corporation
+ */
+
+#include <linux/sort.h>
+
+#include "i915_drv.h"
+
+#include "intel_gt_requests.h"
+#include "i915_selftest.h"
+#include "selftest_engine_heartbeat.h"
+
+static void reset_heartbeat(struct intel_engine_cs *engine)
+{
+	intel_engine_set_heartbeat(engine,
+				   engine->defaults.heartbeat_interval_ms);
+}
+
+static int timeline_sync(struct intel_timeline *tl)
+{
+	struct dma_fence *fence;
+	long timeout;
+
+	fence = i915_active_fence_get(&tl->last_request);
+	if (!fence)
+		return 0;
+
+	timeout = dma_fence_wait_timeout(fence, true, HZ / 2);
+	dma_fence_put(fence);
+	if (timeout < 0)
+		return timeout;
+
+	return 0;
+}
+
+static int engine_sync_barrier(struct intel_engine_cs *engine)
+{
+	return timeline_sync(engine->kernel_context->timeline);
+}
+
+struct pulse {
+	struct i915_active active;
+	struct kref kref;
+};
+
+static int pulse_active(struct i915_active *active)
+{
+	kref_get(&container_of(active, struct pulse, active)->kref);
+	return 0;
+}
+
+static void pulse_free(struct kref *kref)
+{
+	struct pulse *p = container_of(kref, typeof(*p), kref);
+
+	i915_active_fini(&p->active);
+	kfree(p);
+}
+
+static void pulse_put(struct pulse *p)
+{
+	kref_put(&p->kref, pulse_free);
+}
+
+static void pulse_retire(struct i915_active *active)
+{
+	pulse_put(container_of(active, struct pulse, active));
+}
+
+static struct pulse *pulse_create(void)
+{
+	struct pulse *p;
+
+	p = kmalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return p;
+
+	kref_init(&p->kref);
+	i915_active_init(&p->active, pulse_active, pulse_retire, 0);
+
+	return p;
+}
+
+static void pulse_unlock_wait(struct pulse *p)
+{
+	i915_active_unlock_wait(&p->active);
+}
+
+static int __live_idle_pulse(struct intel_engine_cs *engine,
+			     int (*fn)(struct intel_engine_cs *cs))
+{
+	struct pulse *p;
+	int err;
+
+	GEM_BUG_ON(!intel_engine_pm_is_awake(engine));
+
+	p = pulse_create();
+	if (!p)
+		return -ENOMEM;
+
+	err = i915_active_acquire(&p->active);
+	if (err)
+		goto out;
+
+	err = i915_active_acquire_preallocate_barrier(&p->active, engine);
+	if (err) {
+		i915_active_release(&p->active);
+		goto out;
+	}
+
+	i915_active_acquire_barrier(&p->active);
+	i915_active_release(&p->active);
+
+	GEM_BUG_ON(i915_active_is_idle(&p->active));
+	GEM_BUG_ON(llist_empty(&engine->barrier_tasks));
+
+	err = fn(engine);
+	if (err)
+		goto out;
+
+	GEM_BUG_ON(!llist_empty(&engine->barrier_tasks));
+
+	if (engine_sync_barrier(engine)) {
+		struct drm_printer m = drm_err_printer("pulse");
+
+		pr_err("%s: no heartbeat pulse?\n", engine->name);
+		intel_engine_dump(engine, &m, "%s", engine->name);
+
+		err = -ETIME;
+		goto out;
+	}
+
+	GEM_BUG_ON(READ_ONCE(engine->serial) != engine->wakeref_serial);
+
+	pulse_unlock_wait(p); /* synchronize with the retirement callback */
+
+	if (!i915_active_is_idle(&p->active)) {
+		struct drm_printer m = drm_err_printer("pulse");
+
+		pr_err("%s: heartbeat pulse did not flush idle tasks\n",
+		       engine->name);
+		i915_active_print(&p->active, &m);
+
+		err = -EINVAL;
+		goto out;
+	}
+
+out:
+	pulse_put(p);
+	return err;
+}
+
+static int live_idle_flush(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err = 0;
+
+	/* Check that we can flush the idle barriers */
+
+	for_each_engine(engine, gt, id) {
+		st_engine_heartbeat_disable(engine);
+		err = __live_idle_pulse(engine, intel_engine_flush_barriers);
+		st_engine_heartbeat_enable(engine);
+		if (err)
+			break;
+	}
+
+	return err;
+}
+
+static int live_idle_pulse(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err = 0;
+
+	/* Check that heartbeat pulses flush the idle barriers */
+
+	for_each_engine(engine, gt, id) {
+		st_engine_heartbeat_disable(engine);
+		err = __live_idle_pulse(engine, intel_engine_pulse);
+		st_engine_heartbeat_enable(engine);
+		if (err && err != -ENODEV)
+			break;
+
+		err = 0;
+	}
+
+	return err;
+}
+
+static int cmp_u32(const void *_a, const void *_b)
+{
+	const u32 *a = _a, *b = _b;
+
+	return *a - *b;
+}
+
+static int __live_heartbeat_fast(struct intel_engine_cs *engine)
+{
+	const unsigned int error_threshold = max(20000u, jiffies_to_usecs(6));
+	struct intel_context *ce;
+	struct i915_request *rq;
+	ktime_t t0, t1;
+	u32 times[5];
+	int err;
+	int i;
+
+	ce = intel_context_create(engine);
+	if (IS_ERR(ce))
+		return PTR_ERR(ce);
+
+	intel_engine_pm_get(engine);
+
+	err = intel_engine_set_heartbeat(engine, 1);
+	if (err)
+		goto err_pm;
+
+	for (i = 0; i < ARRAY_SIZE(times); i++) {
+		do {
+			/* Manufacture a tick */
+			intel_engine_park_heartbeat(engine);
+			GEM_BUG_ON(engine->heartbeat.systole);
+			engine->serial++; /*  pretend we are not idle! */
+			intel_engine_unpark_heartbeat(engine);
+
+			flush_delayed_work(&engine->heartbeat.work);
+			if (!delayed_work_pending(&engine->heartbeat.work)) {
+				pr_err("%s: heartbeat %d did not start\n",
+				       engine->name, i);
+				err = -EINVAL;
+				goto err_pm;
+			}
+
+			rcu_read_lock();
+			rq = READ_ONCE(engine->heartbeat.systole);
+			if (rq)
+				rq = i915_request_get_rcu(rq);
+			rcu_read_unlock();
+		} while (!rq);
+
+		t0 = ktime_get();
+		while (rq == READ_ONCE(engine->heartbeat.systole))
+			yield(); /* work is on the local cpu! */
+		t1 = ktime_get();
+
+		i915_request_put(rq);
+		times[i] = ktime_us_delta(t1, t0);
+	}
+
+	sort(times, ARRAY_SIZE(times), sizeof(times[0]), cmp_u32, NULL);
+
+	pr_info("%s: Heartbeat delay: %uus [%u, %u]\n",
+		engine->name,
+		times[ARRAY_SIZE(times) / 2],
+		times[0],
+		times[ARRAY_SIZE(times) - 1]);
+
+	/*
+	 * Ideally, the upper bound on min work delay would be something like
+	 * 2 * 2 (worst), +1 for scheduling, +1 for slack. In practice, we
+	 * are, even with system_wq_highpri, at the mercy of the CPU scheduler
+	 * and may be stuck behind some slow work for many millisecond. Such
+	 * as our very own display workers.
+	 */
+	if (times[ARRAY_SIZE(times) / 2] > error_threshold) {
+		pr_err("%s: Heartbeat delay was %uus, expected less than %dus\n",
+		       engine->name,
+		       times[ARRAY_SIZE(times) / 2],
+		       error_threshold);
+		err = -EINVAL;
+	}
+
+	reset_heartbeat(engine);
+err_pm:
+	intel_engine_pm_put(engine);
+	intel_context_put(ce);
+	return err;
+}
+
+static int live_heartbeat_fast(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err = 0;
+
+	/* Check that the heartbeat ticks at the desired rate. */
+	if (!CONFIG_DRM_I915_HEARTBEAT_INTERVAL)
+		return 0;
+
+	for_each_engine(engine, gt, id) {
+		err = __live_heartbeat_fast(engine);
+		if (err)
+			break;
+	}
+
+	return err;
+}
+
+static int __live_heartbeat_off(struct intel_engine_cs *engine)
+{
+	int err;
+
+	intel_engine_pm_get(engine);
+
+	engine->serial++;
+	flush_delayed_work(&engine->heartbeat.work);
+	if (!delayed_work_pending(&engine->heartbeat.work)) {
+		pr_err("%s: heartbeat not running\n",
+		       engine->name);
+		err = -EINVAL;
+		goto err_pm;
+	}
+
+	err = intel_engine_set_heartbeat(engine, 0);
+	if (err)
+		goto err_pm;
+
+	engine->serial++;
+	flush_delayed_work(&engine->heartbeat.work);
+	if (delayed_work_pending(&engine->heartbeat.work)) {
+		pr_err("%s: heartbeat still running\n",
+		       engine->name);
+		err = -EINVAL;
+		goto err_beat;
+	}
+
+	if (READ_ONCE(engine->heartbeat.systole)) {
+		pr_err("%s: heartbeat still allocated\n",
+		       engine->name);
+		err = -EINVAL;
+		goto err_beat;
+	}
+
+err_beat:
+	reset_heartbeat(engine);
+err_pm:
+	intel_engine_pm_put(engine);
+	return err;
+}
+
+static int live_heartbeat_off(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err = 0;
+
+	/* Check that we can turn off heartbeat and not interrupt VIP */
+	if (!CONFIG_DRM_I915_HEARTBEAT_INTERVAL)
+		return 0;
+
+	for_each_engine(engine, gt, id) {
+		if (!intel_engine_has_preemption(engine))
+			continue;
+
+		err = __live_heartbeat_off(engine);
+		if (err)
+			break;
+	}
+
+	return err;
+}
+
+int intel_heartbeat_live_selftests(struct drm_i915_private *i915)
+{
+	static const struct i915_subtest tests[] = {
+		SUBTEST(live_idle_flush),
+		SUBTEST(live_idle_pulse),
+		SUBTEST(live_heartbeat_fast),
+		SUBTEST(live_heartbeat_off),
+	};
+	int saved_hangcheck;
+	int err;
+
+	if (intel_gt_is_wedged(to_gt(i915)))
+		return 0;
+
+	saved_hangcheck = i915->params.enable_hangcheck;
+	i915->params.enable_hangcheck = INT_MAX;
+
+	err = intel_gt_live_subtests(tests, to_gt(i915));
+
+	i915->params.enable_hangcheck = saved_hangcheck;
+	return err;
+}
+
+void st_engine_heartbeat_disable(struct intel_engine_cs *engine)
+{
+	engine->props.heartbeat_interval_ms = 0;
+
+	intel_engine_pm_get(engine);
+	intel_engine_park_heartbeat(engine);
+}
+
+void st_engine_heartbeat_enable(struct intel_engine_cs *engine)
+{
+	intel_engine_pm_put(engine);
+
+	engine->props.heartbeat_interval_ms =
+		engine->defaults.heartbeat_interval_ms;
+}
+
+void st_engine_heartbeat_disable_no_pm(struct intel_engine_cs *engine)
+{
+	engine->props.heartbeat_interval_ms = 0;
+
+	/*
+	 * Park the heartbeat but without holding the PM lock as that
+	 * makes the engines appear not-idle. Note that if/when unpark
+	 * is called due to the PM lock being acquired later the
+	 * heartbeat still won't be enabled because of the above = 0.
+	 */
+	if (intel_engine_pm_get_if_awake(engine)) {
+		intel_engine_park_heartbeat(engine);
+		intel_engine_pm_put(engine);
+	}
+}
+
+void st_engine_heartbeat_enable_no_pm(struct intel_engine_cs *engine)
+{
+	engine->props.heartbeat_interval_ms =
+		engine->defaults.heartbeat_interval_ms;
+}