[Intel-gfx] [PATCH] drm/i915/selftests: Add a GuC doorbells selftest

[Michel Thierry]

Try to create multiple clients (one of each kind) and exercise the
doorbell alloc/dealloc code.

Since our usage mode require very few clients/doorbells, this code has
been exercised very lightly and it's good to have a simple test for it.

As reference, this test already helped identify the bug fixed by
commit 7f1ea2ac3017 ("drm/i915/guc: Fix doorbell id selection").

Signed-off-by: Michel Thierry <michel.thierry at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Michal Winiarski <michal.winiarski at intel.com>
---
 drivers/gpu/drm/i915/i915_guc_submission.c         |   4 +
 .../gpu/drm/i915/selftests/i915_live_selftests.h   |   1 +
 drivers/gpu/drm/i915/selftests/intel_guc.c         | 132 +++++++++++++++++++++
 3 files changed, 137 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/selftests/intel_guc.c

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 13d383cdc4c9..cb3139d9f4fe 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -1280,3 +1280,7 @@ void i915_guc_submission_disable(struct drm_i915_private *dev_priv)
 	guc_client_free(guc->execbuf_client);
 	guc->execbuf_client = NULL;
 }
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/intel_guc.c"
+#endif
diff --git a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
index 54a73534b37e..1b750e92dd08 100644
--- a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
+++ b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
@@ -19,3 +19,4 @@ selftest(evict, i915_gem_evict_live_selftests)
 selftest(hugepages, i915_gem_huge_page_live_selftests)
 selftest(contexts, i915_gem_context_live_selftests)
 selftest(hangcheck, intel_hangcheck_live_selftests)
+selftest(guc, intel_guc_live_selftest)
diff --git a/drivers/gpu/drm/i915/selftests/intel_guc.c b/drivers/gpu/drm/i915/selftests/intel_guc.c
new file mode 100644
index 000000000000..9f7be34acf83
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/intel_guc.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include "../i915_selftest.h"
+
+static int check_all_doorbells(struct intel_guc *guc)
+{
+	u16 db_id;
+
+	pr_info_once("Max number of doorbells: %d", GUC_NUM_DOORBELLS);
+	for (db_id = 0; db_id < GUC_NUM_DOORBELLS; ++db_id) {
+		if (!doorbell_ok(guc, db_id)) {
+			pr_err("doorbell %d, not ok\n", db_id);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+/* create a client of each type and their doorbells */
+static int igt_guc_doorbells(void *arg)
+{
+	struct drm_i915_private *dev_priv = arg;
+	struct intel_guc *guc;
+	struct i915_guc_client *clients[GUC_CLIENT_PRIORITY_NUM];
+	int i, err = 0;
+
+	DRM_INFO("GuC Doorbells selftest\n");
+	GEM_BUG_ON(!HAS_GUC(dev_priv));
+	mutex_lock(&dev_priv->drm.struct_mutex);
+
+	guc = &dev_priv->guc;
+	if (!guc) {
+		pr_err("No guc object!\n");
+		err = -EINVAL;
+		goto unlock;
+	}
+
+	err = check_all_doorbells(guc);
+	if (err)
+		goto unlock;
+
+	for (i = 0; i < GUC_CLIENT_PRIORITY_NUM; i++) {
+		clients[i] = guc_client_alloc(dev_priv,
+					      INTEL_INFO(dev_priv)->ring_mask,
+					      i % GUC_CLIENT_PRIORITY_NUM,
+					      dev_priv->kernel_context);
+
+		if (!clients[i]) {
+			pr_err("[%d] No guc client!\n", i);
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (i > 0 &&
+		    clients[i - 1]->doorbell_id == clients[i]->doorbell_id) {
+			pr_err("doorbell ids must be unique!\n");
+			err = -EINVAL;
+			goto out;
+		}
+
+		/*
+		 * Client alloc gives us a doorbell, but we want to exercise
+		 * this ourselves.
+		 */
+		destroy_doorbell(clients[i]);
+		if (clients[i]->doorbell_id != GUC_DOORBELL_INVALID) {
+			pr_err("[%d] destroy db did not work!\n", i);
+			err = -EINVAL;
+			goto out;
+		}
+
+		err = __reserve_doorbell(clients[i]);
+		if (err) {
+			pr_err("Failed to reserve a doorbell\n");
+			goto out;
+		}
+
+		__update_doorbell_desc(clients[i], clients[i]->doorbell_id);
+		err = __create_doorbell(clients[i]);
+		if (err) {
+			pr_err("Failed to create a doorbell\n");
+			goto out;
+		}
+
+		err = check_all_doorbells(guc);
+		if (err)
+			goto out;
+	}
+
+out:
+	for (i = 0; i < GUC_CLIENT_PRIORITY_NUM; i++)
+		if (clients[i])
+			guc_client_free(clients[i]);
+unlock:
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+	return err;
+}
+
+int intel_guc_live_selftest(struct drm_i915_private *dev_priv)
+{
+	static const struct i915_subtest tests[] = {
+		SUBTEST(igt_guc_doorbells),
+	};
+
+	if (!i915_modparams.enable_guc_submission)
+		return 0;
+
+	return i915_subtests(tests, dev_priv);
+}
-- 
2.14.2