[Intel-gfx] [PATCH 2/4] drm/i915/selftests: align more to real device lifetimes

[Daniel Vetter]

The big change is device_add so that device_del can auto-cleanup
devres resources. This allows us to use devm_drm_dev_alloc, which
removes the last user of drm_dev_init.

v2: Rebased

v3: use devres_open/release_group so we can use devm without real
hacks in the driver core or having to create an entire fake bus for
testing drivers. Might want to extract this into helpers eventually,
maybe as a mock_drm_dev_alloc or test_drm_dev_alloc.

v4:
- Fix IS_ERR handling (Matt)
- Delete surplus put_device() in mock_device_release (intel-gfx-ci)

Cc: Matthew Auld <matthew.william.auld at gmail.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com> (v3)
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 .../gpu/drm/i915/selftests/mock_gem_device.c  | 44 +++++++++++--------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index ac600d395c8f..816f9af15fb3 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -79,8 +79,6 @@ static void mock_device_release(struct drm_device *dev)
 
 out:
 	i915_params_free(&i915->params);
-	put_device(&i915->drm.pdev->dev);
-	i915->drm.pdev = NULL;
 }
 
 static struct drm_driver mock_driver = {
@@ -128,12 +126,6 @@ struct drm_i915_private *mock_gem_device(void)
 	pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
 	if (!pdev)
 		return NULL;
-	i915 = kzalloc(sizeof(*i915), GFP_KERNEL);
-	if (!i915) {
-		kfree(pdev);
-		return NULL;
-	}
-
 	device_initialize(&pdev->dev);
 	pdev->class = PCI_BASE_CLASS_DISPLAY << 16;
 	pdev->dev.release = release_dev;
@@ -144,8 +136,29 @@ struct drm_i915_private *mock_gem_device(void)
 	/* HACK to disable iommu for the fake device; force identity mapping */
 	pdev->dev.iommu = &fake_iommu;
 #endif
+	err = device_add(&pdev->dev);
+	if (err) {
+		kfree(pdev);
+		return NULL;
+	}
+
+	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
+		device_del(&pdev->dev);
+		return NULL;
+	}
+
+	i915 = devm_drm_dev_alloc(&pdev->dev, &mock_driver,
+				  struct drm_i915_private, drm);
+	if (IS_ERR(i915)) {
+		pr_err("Failed to allocate mock GEM device: err=%d\n", err);
+		devres_release_group(&pdev->dev, NULL);
+		device_del(&pdev->dev);
+
+		return NULL;
+	}
 
 	pci_set_drvdata(pdev, i915);
+	i915->drm.pdev = pdev;
 
 	dev_pm_domain_set(&pdev->dev, &pm_domain);
 	pm_runtime_enable(&pdev->dev);
@@ -153,16 +166,6 @@ struct drm_i915_private *mock_gem_device(void)
 	if (pm_runtime_enabled(&pdev->dev))
 		WARN_ON(pm_runtime_get_sync(&pdev->dev));
 
-	err = drm_dev_init(&i915->drm, &mock_driver, &pdev->dev);
-	if (err) {
-		pr_err("Failed to initialise mock GEM device: err=%d\n", err);
-		put_device(&pdev->dev);
-		kfree(i915);
-
-		return NULL;
-	}
-	i915->drm.pdev = pdev;
-	drmm_add_final_kfree(&i915->drm, i915);
 
 	i915_params_copy(&i915->params, &i915_modparams);
 
@@ -229,5 +232,8 @@ struct drm_i915_private *mock_gem_device(void)
 
 void mock_destroy_device(struct drm_i915_private *i915)
 {
-	drm_dev_put(&i915->drm);
+	struct device *dev = i915->drm.dev;
+
+	devres_release_group(dev, NULL);
+	device_del(dev);
 }
-- 
2.28.0