[PATCH 07/13] drm/xe/kunit: Activate empty MMIO stubs in test_init()

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

Our fake xe_device created in test_init() will immediately crash
when test code attempts to reuse any function that is accessing
the xe_mmio structure. But in many cases we can simply ignore
writes and return some value on reads, to make the code happy.

Activate simple stubs that will just log the MMIO accesses and
allow to pass test specific value, if non-zero value is better.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
 drivers/gpu/drm/xe/tests/xe_kunit_helpers.c | 37 +++++++++++++++++++++
 drivers/gpu/drm/xe/tests/xe_pci_test.h      |  1 +
 2 files changed, 38 insertions(+)

diff --git a/drivers/gpu/drm/xe/tests/xe_kunit_helpers.c b/drivers/gpu/drm/xe/tests/xe_kunit_helpers.c
index 8276cabc4820..14271c4662d6 100644
--- a/drivers/gpu/drm/xe/tests/xe_kunit_helpers.c
+++ b/drivers/gpu/drm/xe/tests/xe_kunit_helpers.c
@@ -17,6 +17,7 @@
 #include "xe_device.h"
 #include "xe_device_types.h"
 #include "xe_ggtt.h"
+#include "xe_mmio.h"
 #include "xe_pm.h"
 
 /**
@@ -99,6 +100,28 @@ static struct xe_bo *fake_xe_managed_bo_create_pin_map(struct xe_device *xe,
 	return bo;
 }
 
+static u32 fake_xe_mmio_read32(struct xe_mmio *mmio, struct xe_reg reg)
+{
+	struct kunit *test = kunit_get_current_test();
+	struct kunit_resource *res;
+	u32 val = 0;
+
+	res = kunit_find_named_resource(test, "mmio_read");
+	if (res) {
+		val = *(u32 *)res->data;
+		kunit_put_resource(res);
+	}
+	kunit_info(test, "mmio[%#x] read %#x\n", reg.addr, val);
+	return val;
+}
+
+static void fake_xe_mmio_write32(struct xe_mmio *mmio, struct xe_reg reg, u32 val)
+{
+	struct kunit *test = kunit_get_current_test();
+
+	kunit_info(test, "mmio[%#x] write %#x\n", reg.addr, val);
+}
+
 /**
  * xe_kunit_helper_xe_device_test_init - Prepare a &xe_device for a KUnit test.
  * @test: the &kunit where this fake &xe_device will be used
@@ -116,6 +139,9 @@ static struct xe_bo *fake_xe_managed_bo_create_pin_map(struct xe_device *xe,
  * If xe_pci_fake_data->ggtt_size is set then this function will also do
  * a minimal GGTT initialization.
  *
+ * This function will also activate stubs for some xe_mmio operations.
+ * The xe_mmio reads will return value passed in xe_pci_fake_data->mmio_read.
+ *
  * This function uses KUNIT_ASSERT to detect any failures.
  *
  * Return: Always 0.
@@ -145,6 +171,17 @@ int xe_kunit_helper_xe_device_test_init(struct kunit *test)
 	kunit_activate_static_stub(test, xe_managed_bo_create_pin_map,
 				   fake_xe_managed_bo_create_pin_map);
 
+	if (data && data->mmio_read) {
+		struct kunit_resource *res = kunit_kzalloc(test, sizeof(*res), GFP_KERNEL);
+
+		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, res);
+		err = kunit_add_named_resource(test, NULL, NULL, res,
+					       "mmio_read", &data->mmio_read);
+		KUNIT_ASSERT_EQ(test, err, 0);
+	}
+	kunit_activate_static_stub(test, xe_mmio_read32, fake_xe_mmio_read32);
+	kunit_activate_static_stub(test, xe_mmio_write32, fake_xe_mmio_write32);
+
 	test->priv = xe;
 	return 0;
 }
diff --git a/drivers/gpu/drm/xe/tests/xe_pci_test.h b/drivers/gpu/drm/xe/tests/xe_pci_test.h
index e807585b88c2..0011b9e710e5 100644
--- a/drivers/gpu/drm/xe/tests/xe_pci_test.h
+++ b/drivers/gpu/drm/xe/tests/xe_pci_test.h
@@ -24,6 +24,7 @@ struct xe_pci_fake_data {
 	u32 media_verx100;
 	u64 ggtt_start;
 	u64 ggtt_size;
+	u32 mmio_read;
 };
 
 int xe_pci_fake_device_init(struct xe_device *xe);
-- 
2.47.1