Quoting Jani Nikula (2024-07-29 11:30:06-03:00)
>In the future, the display code shall not have any idea about struct
>xe_device or struct drm_i915_private, but will need to get at the struct
>drm_device via drvdata. Store the struct drm_device pointer to drvdata
>instead of the driver specific pointer.
>
>Even though struct drm_device is embedded in both struct xe_device and
>struct drm_i915_private at offset 0, take care to check for NULL before
>using container_of() to allow for other offsets.
I think the second half of this paragraph could be rephrased. One might
think that the text is suggesting that checking for NULL has something
to do with allowing other offsets.
I would jump directly to mention using container_of() and would assume
that it is implied that NULL check is necessary before using it. :-)
Reviewed-by: Gustavo Sousa <gustavo.sousa@xxxxxxxxx>
>
>Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>---
> drivers/gpu/drm/i915/i915_driver.c | 2 +-
> drivers/gpu/drm/i915/i915_drv.h | 8 ++++++--
> drivers/gpu/drm/i915/selftests/mock_gem_device.c | 2 +-
> drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h | 4 +++-
> drivers/gpu/drm/xe/xe_device.h | 8 ++++++--
> drivers/gpu/drm/xe/xe_pci.c | 2 +-
> 6 files changed, 18 insertions(+), 8 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
>index fb8e9c2fcea5..176c13c2e191 100644
>--- a/drivers/gpu/drm/i915/i915_driver.c
>+++ b/drivers/gpu/drm/i915/i915_driver.c
>@@ -723,7 +723,7 @@ i915_driver_create(struct pci_dev *pdev, const struct pci_device_id *ent)
> if (IS_ERR(i915))
> return i915;
>
>- pci_set_drvdata(pdev, i915);
>+ pci_set_drvdata(pdev, &i915->drm);
>
> /* Device parameters start as a copy of module parameters. */
> i915_params_copy(&i915->params, &i915_modparams);
>diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>index d7723dd11c80..f6edaef73db5 100644
>--- a/drivers/gpu/drm/i915/i915_drv.h
>+++ b/drivers/gpu/drm/i915/i915_drv.h
>@@ -365,12 +365,16 @@ static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
>
> static inline struct drm_i915_private *kdev_to_i915(struct device *kdev)
> {
>- return dev_get_drvdata(kdev);
>+ struct drm_device *drm = dev_get_drvdata(kdev);
>+
>+ return drm ? to_i915(drm) : NULL;
> }
>
> static inline struct drm_i915_private *pdev_to_i915(struct pci_dev *pdev)
> {
>- return pci_get_drvdata(pdev);
>+ struct drm_device *drm = pci_get_drvdata(pdev);
>+
>+ return drm ? to_i915(drm) : NULL;
> }
>
> static inline struct intel_gt *to_gt(const struct drm_i915_private *i915)
>diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
>index 0bd29846873b..91794ca17a58 100644
>--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
>+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
>@@ -172,7 +172,7 @@ struct drm_i915_private *mock_gem_device(void)
> return NULL;
> }
>
>- pci_set_drvdata(pdev, i915);
>+ pci_set_drvdata(pdev, &i915->drm);
>
> /* Device parameters start as a copy of module parameters. */
> i915_params_copy(&i915->params, &i915_modparams);
>diff --git a/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h b/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
>index 2feedddf1e40..766fba88a3c8 100644
>--- a/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
>+++ b/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
>@@ -23,7 +23,9 @@ static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
>
> static inline struct drm_i915_private *kdev_to_i915(struct device *kdev)
> {
>- return dev_get_drvdata(kdev);
>+ struct drm_device *drm = dev_get_drvdata(kdev);
>+
>+ return drm ? to_i915(drm) : NULL;
> }
>
> #define IS_PLATFORM(xe, x) ((xe)->info.platform == x)
>diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
>index 2c96f1b2aafd..022876eebfd5 100644
>--- a/drivers/gpu/drm/xe/xe_device.h
>+++ b/drivers/gpu/drm/xe/xe_device.h
>@@ -17,12 +17,16 @@ static inline struct xe_device *to_xe_device(const struct drm_device *dev)
>
> static inline struct xe_device *kdev_to_xe_device(struct device *kdev)
> {
>- return dev_get_drvdata(kdev);
>+ struct drm_device *drm = dev_get_drvdata(kdev);
>+
>+ return drm ? to_xe_device(drm) : NULL;
> }
>
> static inline struct xe_device *pdev_to_xe_device(struct pci_dev *pdev)
> {
>- return pci_get_drvdata(pdev);
>+ struct drm_device *drm = pci_get_drvdata(pdev);
>+
>+ return drm ? to_xe_device(drm) : NULL;
> }
>
> static inline struct xe_device *xe_device_const_cast(const struct xe_device *xe)
>diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
>index 7bb811b4a057..f861b8cf931a 100644
>--- a/drivers/gpu/drm/xe/xe_pci.c
>+++ b/drivers/gpu/drm/xe/xe_pci.c
>@@ -800,7 +800,7 @@ static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> if (IS_ERR(xe))
> return PTR_ERR(xe);
>
>- pci_set_drvdata(pdev, xe);
>+ pci_set_drvdata(pdev, &xe->drm);
>
> xe_pm_assert_unbounded_bridge(xe);
> subplatform_desc = find_subplatform(xe, desc);
>--
>2.39.2
>
