[RESEND 3/6] drm/i915/display: add intel_display_conversion.c to hide stuff better

[Jani Nikula]

The __to_intel_display() generics require the definition of struct
drm_i915_private i.e. inclusion of i915_drv.h. Add
intel_display_conversion.c with a __i915_to_display() function to do the
conversion without the intel_display_conversion.h having an implicit
dependency on i915_drv.h.

The long term goal is to remove __to_intel_display() and the
intel_display_conversion.[ch] files altoghether, and this is merely a
transitional step to make the dependencies on i915_drv.h explicit.

Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/Makefile                           | 1 +
 drivers/gpu/drm/i915/display/intel_display_conversion.c | 9 +++++++++
 drivers/gpu/drm/i915/display/intel_display_conversion.h | 9 +++++++--
 drivers/gpu/drm/xe/Makefile                             | 1 +
 4 files changed, 18 insertions(+), 2 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/display/intel_display_conversion.c

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index aa4494499324..1c4ebcb08a6d 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -237,6 +237,7 @@ i915-y += \
 	display/intel_crtc_state_dump.o \
 	display/intel_cursor.o \
 	display/intel_display.o \
+	display/intel_display_conversion.o \
 	display/intel_display_driver.o \
 	display/intel_display_irq.o \
 	display/intel_display_params.o \
diff --git a/drivers/gpu/drm/i915/display/intel_display_conversion.c b/drivers/gpu/drm/i915/display/intel_display_conversion.c
new file mode 100644
index 000000000000..bdd947f5ccd8
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_display_conversion.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: MIT
+/* Copyright © 2024 Intel Corporation */
+
+#include "i915_drv.h"
+
+struct intel_display *__i915_to_display(struct drm_i915_private *i915)
+{
+	return &i915->display;
+}
diff --git a/drivers/gpu/drm/i915/display/intel_display_conversion.h b/drivers/gpu/drm/i915/display/intel_display_conversion.h
index ad8545c8055d..790d0be698dc 100644
--- a/drivers/gpu/drm/i915/display/intel_display_conversion.h
+++ b/drivers/gpu/drm/i915/display/intel_display_conversion.h
@@ -8,14 +8,19 @@
 #ifndef __INTEL_DISPLAY_CONVERSION__
 #define __INTEL_DISPLAY_CONVERSION__
 
+struct drm_i915_private;
+struct intel_display;
+
+struct intel_display *__i915_to_display(struct drm_i915_private *i915);
+
 /*
  * Transitional macro to optionally convert struct drm_i915_private * to struct
  * intel_display *, also accepting the latter.
  */
 #define __to_intel_display(p)						\
 	_Generic(p,							\
-		 const struct drm_i915_private *: (&((const struct drm_i915_private *)(p))->display), \
-		 struct drm_i915_private *: (&((struct drm_i915_private *)(p))->display), \
+		 const struct drm_i915_private *: __i915_to_display((struct drm_i915_private *)(p)), \
+		 struct drm_i915_private *: __i915_to_display((struct drm_i915_private *)(p)), \
 		 const struct intel_display *: (p),			\
 		 struct intel_display *: (p))
 
diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index a93e6fcc0ad9..7358f45755b6 100644
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -208,6 +208,7 @@ xe-$(CONFIG_DRM_XE_DISPLAY) += \
 	i915-display/intel_ddi.o \
 	i915-display/intel_ddi_buf_trans.o \
 	i915-display/intel_display.o \
+	i915-display/intel_display_conversion.o \
 	i915-display/intel_display_device.o \
 	i915-display/intel_display_driver.o \
 	i915-display/intel_display_irq.o \
-- 
2.39.5