[Intel-gfx] [PATCH 08/51] drm/i915: Use drmm_add_final_kfree

[Daniel Vetter]

With this we can drop the final kfree from the release function.

The mock device in the selftests needed it's pci_device split
up from the drm_device. In the future we could simplify this again
by allocating the pci_device as a managed allocation too.

v2: I overlooked that i915_driver_destroy is also called in the
unwind code of the error path. There we need a drm_dev_put.
Similar for the mock object.

Now the problem with that is that the drm_driver->release callbacks
for both the real driver and the mock one assume everything has been
set up. Hence going through that path for a partially set up driver
will result in issues. Quickest fix is to disable the ->release() hook
until the driver is fully initialized, and keep the onion unwinding.
Long term would be cleanest to move everything over to drmm_ release
actions, but that's a lot of work for a big driver like i915. Plus
more core work needed first anyway.

Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Matthew Auld <matthew.auld at intel.com>
Cc: Andi Shyti <andi.shyti at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
Cc: intel-gfx at lists.freedesktop.org
---
 drivers/gpu/drm/i915/i915_drv.c                |  9 ++++++++-
 drivers/gpu/drm/i915/i915_drv.h                |  3 +++
 .../gpu/drm/i915/selftests/mock_gem_device.c   | 18 +++++++++++++++++-
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 8b8a9c9a9b2a..ae81c74d0136 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -43,6 +43,7 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_ioctl.h>
 #include <drm/drm_irq.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/i915_drm.h>
 
@@ -1371,6 +1372,7 @@ i915_driver_create(struct pci_dev *pdev, const struct pci_device_id *ent)
 	}
 
 	i915->drm.dev_private = i915;
+	drmm_add_final_kfree(&i915->drm, i915);
 
 	i915->drm.pdev = pdev;
 	pci_set_drvdata(pdev, i915);
@@ -1390,7 +1392,6 @@ static void i915_driver_destroy(struct drm_i915_private *i915)
 	struct pci_dev *pdev = i915->drm.pdev;
 
 	drm_dev_fini(&i915->drm);
-	kfree(i915);
 }
 
 /**
@@ -1466,6 +1467,8 @@ int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	i915_welcome_messages(i915);
 
+	i915->do_release = true;
+
 	return 0;
 
 out_cleanup_hw:
@@ -1482,6 +1485,7 @@ int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 out_fini:
 	i915_probe_error(i915, "Device initialization failed (%d)\n", ret);
 	i915_driver_destroy(i915);
+	drm_dev_put(&i915->drm);
 	return ret;
 }
 
@@ -1528,6 +1532,9 @@ static void i915_driver_release(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_runtime_pm *rpm = &dev_priv->runtime_pm;
 
+	if (!dev_priv->do_release)
+		return;
+
 	disable_rpm_wakeref_asserts(rpm);
 
 	i915_gem_driver_release(dev_priv);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4305ccc4c683..6e88eae40a87 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -884,6 +884,9 @@ struct i915_selftest_stash {
 struct drm_i915_private {
 	struct drm_device drm;
 
+	/* FIXME: Device release actions should all be moved to drmm_ */
+	bool do_release;
+
 	const struct intel_device_info __info; /* Use INTEL_INFO() to access. */
 	struct intel_runtime_info __runtime; /* Use RUNTIME_INFO() to access. */
 	struct intel_driver_caps caps;
diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index 3b8986983afc..9b06d5ec889a 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -25,6 +25,8 @@
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 
+#include <drm/drm_managed.h>
+
 #include "gt/intel_gt.h"
 #include "gt/intel_gt_requests.h"
 #include "gt/mock_engine.h"
@@ -55,6 +57,9 @@ static void mock_device_release(struct drm_device *dev)
 {
 	struct drm_i915_private *i915 = to_i915(dev);
 
+	if (!i915->do_release)
+		return;
+
 	mock_device_flush(i915);
 	intel_gt_driver_remove(&i915->gt);
 
@@ -114,9 +119,14 @@ struct drm_i915_private *mock_gem_device(void)
 	struct pci_dev *pdev;
 	int err;
 
-	pdev = kzalloc(sizeof(*pdev) + sizeof(*i915), GFP_KERNEL);
+	pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
 	if (!pdev)
 		goto err;
+	i915 = kzalloc(sizeof(*i915), GFP_KERNEL);
+	if (!i915) {
+		kfree(pdev);
+		goto err;
+	}
 
 	device_initialize(&pdev->dev);
 	pdev->class = PCI_BASE_CLASS_DISPLAY << 16;
@@ -141,10 +151,13 @@ struct drm_i915_private *mock_gem_device(void)
 	err = drm_dev_init(&i915->drm, &mock_driver, &pdev->dev);
 	if (err) {
 		pr_err("Failed to initialise mock GEM device: err=%d\n", err);
+		kfree(i915);
+
 		goto put_device;
 	}
 	i915->drm.pdev = pdev;
 	i915->drm.dev_private = i915;
+	drmm_add_final_kfree(&i915->drm, i915);
 
 	intel_runtime_pm_init_early(&i915->runtime_pm);
 
@@ -189,6 +202,8 @@ struct drm_i915_private *mock_gem_device(void)
 	__clear_bit(I915_WEDGED, &i915->gt.reset.flags);
 	intel_engines_driver_register(i915);
 
+	i915->do_release = true;
+
 	return i915;
 
 err_context:
@@ -200,6 +215,7 @@ struct drm_i915_private *mock_gem_device(void)
 	intel_memory_regions_driver_release(i915);
 	drm_mode_config_cleanup(&i915->drm);
 	drm_dev_fini(&i915->drm);
+	drm_dev_put(&i915->drm);
 put_device:
 	put_device(&pdev->dev);
 err:
-- 
2.24.1