drm/i915: Generalise GPU activity tracking

We currently track GPU memory usage inside VMA, such that we never
release memory used by the GPU until after it has finished accessing it.
However, we may want to track other resources aside from VMA, or we may
want to split a VMA into multiple independent regions and track each
separately. For this purpose, generalise our request tracking (akin to
struct reservation_object) so that we can embed it into other objects.

v2: Tweak error handling during selftest setup.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205130005.2807-2-chris@chris-wilson.co.uk

1 files changed, 157 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/selftests/i915_active.c b/drivers/gpu/drm/i915/selftests/i915_active.c
new file mode 100644
index 000000000000..337b1f98b923
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/i915_active.c
@@ -0,0 +1,157 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2018 Intel Corporation
+ */
+
+#include "../i915_selftest.h"
+
+#include "igt_flush_test.h"
+#include "lib_sw_fence.h"
+
+struct live_active {
+	struct i915_active base;
+	bool retired;
+};
+
+static void __live_active_retire(struct i915_active *base)
+{
+	struct live_active *active = container_of(base, typeof(*active), base);
+
+	active->retired = true;
+}
+
+static int __live_active_setup(struct drm_i915_private *i915,
+			       struct live_active *active)
+{
+	struct intel_engine_cs *engine;
+	struct i915_sw_fence *submit;
+	enum intel_engine_id id;
+	unsigned int count = 0;
+	int err = 0;
+
+	submit = heap_fence_create(GFP_KERNEL);
+	if (!submit)
+		return -ENOMEM;
+
+	i915_active_init(i915, &active->base, __live_active_retire);
+	active->retired = false;
+
+	if (!i915_active_acquire(&active->base)) {
+		pr_err("First i915_active_acquire should report being idle\n");
+		err = -EINVAL;
+		goto out;
+	}
+
+	for_each_engine(engine, i915, id) {
+		struct i915_request *rq;
+
+		rq = i915_request_alloc(engine, i915->kernel_context);
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			break;
+		}
+
+		err = i915_sw_fence_await_sw_fence_gfp(&rq->submit,
+						       submit,
+						       GFP_KERNEL);
+		if (err >= 0)
+			err = i915_active_ref(&active->base,
+					      rq->fence.context, rq);
+		i915_request_add(rq);
+		if (err) {
+			pr_err("Failed to track active ref!\n");
+			break;
+		}
+
+		count++;
+	}
+
+	i915_active_release(&active->base);
+	if (active->retired && count) {
+		pr_err("i915_active retired before submission!\n");
+		err = -EINVAL;
+	}
+	if (active->base.count != count) {
+		pr_err("i915_active not tracking all requests, found %d, expected %d\n",
+		       active->base.count, count);
+		err = -EINVAL;
+	}
+
+out:
+	i915_sw_fence_commit(submit);
+	heap_fence_put(submit);
+
+	return err;
+}
+
+static int live_active_wait(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct live_active active;
+	intel_wakeref_t wakeref;
+	int err;
+
+	/* Check that we get a callback when requests retire upon waiting */
+
+	mutex_lock(&i915->drm.struct_mutex);
+	wakeref = intel_runtime_pm_get(i915);
+
+	err = __live_active_setup(i915, &active);
+
+	i915_active_wait(&active.base);
+	if (!active.retired) {
+		pr_err("i915_active not retired after waiting!\n");
+		err = -EINVAL;
+	}
+
+	i915_active_fini(&active.base);
+	if (igt_flush_test(i915, I915_WAIT_LOCKED))
+		err = -EIO;
+
+	intel_runtime_pm_put(i915, wakeref);
+	mutex_unlock(&i915->drm.struct_mutex);
+	return err;
+}
+
+static int live_active_retire(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct live_active active;
+	intel_wakeref_t wakeref;
+	int err;
+
+	/* Check that we get a callback when requests are indirectly retired */
+
+	mutex_lock(&i915->drm.struct_mutex);
+	wakeref = intel_runtime_pm_get(i915);
+
+	err = __live_active_setup(i915, &active);
+
+	/* waits for & retires all requests */
+	if (igt_flush_test(i915, I915_WAIT_LOCKED))
+		err = -EIO;
+
+	if (!active.retired) {
+		pr_err("i915_active not retired after flushing!\n");
+		err = -EINVAL;
+	}
+
+	i915_active_fini(&active.base);
+	intel_runtime_pm_put(i915, wakeref);
+	mutex_unlock(&i915->drm.struct_mutex);
+	return err;
+}
+
+int i915_active_live_selftests(struct drm_i915_private *i915)
+{
+	static const struct i915_subtest tests[] = {
+		SUBTEST(live_active_wait),
+		SUBTEST(live_active_retire),
+	};
+
+	if (i915_terminally_wedged(&i915->gpu_error))
+		return 0;
+
+	return i915_subtests(tests, i915);
+}