On Fri, 24 Oct 2025, Jouni Högander <[email protected]> wrote:
> From: Jani Nikula <[email protected]>
>
> Let's gradually start calling i915 and xe parent, or core, drivers from
> display via function pointers passed at display probe.
>
> Going forward, the struct intel_display_parent_interface is expected to
> include const pointers to sub-structs by functionality, for example:
>
> struct intel_display_rpm {
> struct ref_tracker *(*get)(struct drm_device *drm);
> /* ... */
> };
>
> struct intel_display_parent_interface {
> /* ... */
> const struct intel_display_rpm *rpm;
> };
>
> This is a baby step towards not building display as part of both i915
> and xe drivers, but rather making it an independent driver interfacing
> with the two.
>
> v2: unrelated include removal dropped
>
> Cc: Jouni Högander <[email protected]>
> Cc: Lucas De Marchi <[email protected]>
> Cc: Rodrigo Vivi <[email protected]>
> Cc: Ville Syrjälä <[email protected]>
> Signed-off-by: Jani Nikula <[email protected]>
> Signed-off-by: Jouni Högander <[email protected]>
> ---
> .../gpu/drm/i915/display/intel_display_core.h | 4 +++
> .../drm/i915/display/intel_display_device.c | 5 +++-
> .../drm/i915/display/intel_display_device.h | 4 ++-
> drivers/gpu/drm/i915/display/intel_fb.c | 1 +
> .../drm/i915/display/skl_universal_plane.c | 1 +
> drivers/gpu/drm/i915/i915_driver.c | 11 +++++++-
> drivers/gpu/drm/i915/i915_driver.h | 2 ++
> .../gpu/drm/i915/selftests/mock_gem_device.c | 4 ++-
> drivers/gpu/drm/xe/display/xe_display.c | 6 ++++-
> include/drm/intel/display_parent_interface.h | 26 +++++++++++++++++++
> 10 files changed, 59 insertions(+), 5 deletions(-)
> create mode 100644 include/drm/intel/display_parent_interface.h
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_core.h
> b/drivers/gpu/drm/i915/display/intel_display_core.h
> index 32664098b4078..893279be84091 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_core.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_core.h
> @@ -41,6 +41,7 @@ struct intel_cdclk_vals;
> struct intel_color_funcs;
> struct intel_crtc;
> struct intel_crtc_state;
> +struct intel_display_parent_interface;
> struct intel_dmc;
> struct intel_dpll_global_funcs;
> struct intel_dpll_mgr;
> @@ -291,6 +292,9 @@ struct intel_display {
> /* Intel PCH: where the south display engine lives */
> enum intel_pch pch_type;
>
> + /* Parent, or core, driver functions exposed to display */
> + const struct intel_display_parent_interface *parent;
> +
> /* Display functions */
> struct {
> /* Top level crtc-ish functions */
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c
> b/drivers/gpu/drm/i915/display/intel_display_device.c
> index f3f1f25b0f383..328447a5e5e8c 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -1647,7 +1647,8 @@ static void display_platforms_or(struct
> intel_display_platforms *dst,
> bitmap_or(dst->bitmap, dst->bitmap, src->bitmap,
> display_platforms_num_bits());
> }
>
> -struct intel_display *intel_display_device_probe(struct pci_dev *pdev)
> +struct intel_display *intel_display_device_probe(struct pci_dev *pdev,
> + const struct
> intel_display_parent_interface *parent)
> {
> struct intel_display *display;
> const struct intel_display_device_info *info;
> @@ -1663,6 +1664,8 @@ struct intel_display *intel_display_device_probe(struct
> pci_dev *pdev)
> /* Add drm device backpointer as early as possible. */
> display->drm = pci_get_drvdata(pdev);
>
> + display->parent = parent;
> +
> intel_display_params_copy(&display->params);
>
> if (has_no_display(pdev)) {
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h
> b/drivers/gpu/drm/i915/display/intel_display_device.h
> index 8fdb8a0a42821..a009082e3107b 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.h
> @@ -13,6 +13,7 @@
>
> struct drm_printer;
> struct intel_display;
> +struct intel_display_parent_interface;
> struct pci_dev;
>
> /*
> @@ -312,7 +313,8 @@ struct intel_display_device_info {
>
> bool intel_display_device_present(struct intel_display *display);
> bool intel_display_device_enabled(struct intel_display *display);
> -struct intel_display *intel_display_device_probe(struct pci_dev *pdev);
> +struct intel_display *intel_display_device_probe(struct pci_dev *pdev,
> + const struct
> intel_display_parent_interface *parent);
> void intel_display_device_remove(struct intel_display *display);
> void intel_display_device_info_runtime_init(struct intel_display *display);
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fb.c
> b/drivers/gpu/drm/i915/display/intel_fb.c
> index 6ade38198f396..f4512fb38a778 100644
> --- a/drivers/gpu/drm/i915/display/intel_fb.c
> +++ b/drivers/gpu/drm/i915/display/intel_fb.c
> @@ -9,6 +9,7 @@
> #include <drm/drm_blend.h>
> #include <drm/drm_gem.h>
> #include <drm/drm_modeset_helper.h>
> +#include <drm/intel/display_parent_interface.h>
Argh, I keep spotting rebase leftovers from my own patch. *facepalm*.
>
> #include "i915_utils.h"
> #include "intel_bo.h"
> diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c
> b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> index 765d288cce2b0..c70bde90b9a9e 100644
> --- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
> +++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> @@ -8,6 +8,7 @@
> #include <drm/drm_damage_helper.h>
> #include <drm/drm_fourcc.h>
> #include <drm/drm_print.h>
> +#include <drm/intel/display_parent_interface.h>
Ditto.
Obviously, I can't r-b this either, it being my code.
BR,
Jani.
>
> #include "pxp/intel_pxp.h"
> #include "i915_utils.h"
> diff --git a/drivers/gpu/drm/i915/i915_driver.c
> b/drivers/gpu/drm/i915/i915_driver.c
> index e19a08893b998..b295326eb4331 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -47,6 +47,7 @@
> #include <drm/drm_managed.h>
> #include <drm/drm_probe_helper.h>
> #include <drm/intel/display_member.h>
> +#include <drm/intel/display_parent_interface.h>
>
> #include "display/i9xx_display_sr.h"
> #include "display/intel_bw.h"
> @@ -738,6 +739,14 @@ static void i915_welcome_messages(struct
> drm_i915_private *dev_priv)
> "DRM_I915_DEBUG_RUNTIME_PM enabled\n");
> }
>
> +static const struct intel_display_parent_interface parent = {
> +};
> +
> +const struct intel_display_parent_interface
> *i915_driver_parent_interface(void)
> +{
> + return &parent;
> +}
> +
> /* Ensure drm and display members are placed properly. */
> INTEL_DISPLAY_MEMBER_STATIC_ASSERT(struct drm_i915_private, drm, display);
>
> @@ -762,7 +771,7 @@ i915_driver_create(struct pci_dev *pdev, const struct
> pci_device_id *ent)
> /* Set up device info and initial runtime info. */
> intel_device_info_driver_create(i915, pdev->device, match_info);
>
> - display = intel_display_device_probe(pdev);
> + display = intel_display_device_probe(pdev, &parent);
> if (IS_ERR(display))
> return ERR_CAST(display);
>
> diff --git a/drivers/gpu/drm/i915/i915_driver.h
> b/drivers/gpu/drm/i915/i915_driver.h
> index 1e95ecb2a163f..9551519ab4297 100644
> --- a/drivers/gpu/drm/i915/i915_driver.h
> +++ b/drivers/gpu/drm/i915/i915_driver.h
> @@ -12,6 +12,7 @@ struct pci_dev;
> struct pci_device_id;
> struct drm_i915_private;
> struct drm_printer;
> +struct intel_display_parent_interface;
>
> #define DRIVER_NAME "i915"
> #define DRIVER_DESC "Intel Graphics"
> @@ -24,6 +25,7 @@ void i915_driver_shutdown(struct drm_i915_private *i915);
>
> int i915_driver_resume_switcheroo(struct drm_i915_private *i915);
> int i915_driver_suspend_switcheroo(struct drm_i915_private *i915,
> pm_message_t state);
> +const struct intel_display_parent_interface
> *i915_driver_parent_interface(void);
>
> void
> i915_print_iommu_status(struct drm_i915_private *i915, struct drm_printer
> *p);
> diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
> b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
> index fb8751bd5df0a..b59626c4994cb 100644
> --- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
> +++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
> @@ -33,6 +33,7 @@
> #include "gt/intel_gt.h"
> #include "gt/intel_gt_requests.h"
> #include "gt/mock_engine.h"
> +#include "i915_driver.h"
> #include "intel_memory_region.h"
> #include "intel_region_ttm.h"
>
> @@ -183,7 +184,8 @@ struct drm_i915_private *mock_gem_device(void)
> /* Set up device info and initial runtime info. */
> intel_device_info_driver_create(i915, pdev->device, &mock_info);
>
> - display = intel_display_device_probe(pdev);
> + /* FIXME: Can we run selftests using a mock device without display? */
> + display = intel_display_device_probe(pdev,
> i915_driver_parent_interface());
> if (IS_ERR(display))
> goto err_device;
>
> diff --git a/drivers/gpu/drm/xe/display/xe_display.c
> b/drivers/gpu/drm/xe/display/xe_display.c
> index 5a02754d0610e..0e38c96eb6def 100644
> --- a/drivers/gpu/drm/xe/display/xe_display.c
> +++ b/drivers/gpu/drm/xe/display/xe_display.c
> @@ -14,6 +14,7 @@
> #include <drm/drm_managed.h>
> #include <drm/drm_probe_helper.h>
> #include <drm/intel/display_member.h>
> +#include <drm/intel/display_parent_interface.h>
> #include <uapi/drm/xe_drm.h>
>
> #include "soc/intel_dram.h"
> @@ -514,6 +515,9 @@ static void display_device_remove(struct drm_device *dev,
> void *arg)
> intel_display_device_remove(display);
> }
>
> +static const struct intel_display_parent_interface parent = {
> +};
> +
> /**
> * xe_display_probe - probe display and create display struct
> * @xe: XE device instance
> @@ -534,7 +538,7 @@ int xe_display_probe(struct xe_device *xe)
> if (!xe->info.probe_display)
> goto no_display;
>
> - display = intel_display_device_probe(pdev);
> + display = intel_display_device_probe(pdev, &parent);
> if (IS_ERR(display))
> return PTR_ERR(display);
>
> diff --git a/include/drm/intel/display_parent_interface.h
> b/include/drm/intel/display_parent_interface.h
> new file mode 100644
> index 0000000000000..28c976815327a
> --- /dev/null
> +++ b/include/drm/intel/display_parent_interface.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: MIT */
> +/* Copyright © 2025 Intel Corporation x*/
> +
> +#ifndef __DISPLAY_PARENT_INTERFACE_H__
> +#define __DISPLAY_PARENT_INTERFACE_H__
> +
> +#include <linux/types.h>
> +
> +struct drm_device;
> +
> +/**
> + * struct intel_display_parent_interface - services parent driver provides
> to display
> + *
> + * The parent, or core, driver provides a pointer to this structure to
> display
> + * driver when calling intel_display_device_probe(). The display driver uses
> it
> + * to access services provided by the parent driver. The structure may
> contain
> + * sub-struct pointers to group function pointers by functionality.
> + *
> + * All function and sub-struct pointers must be initialized and callable
> unless
> + * explicitly marked as "optional" below. The display driver will only NULL
> + * check the optional pointers.
> + */
> +struct intel_display_parent_interface {
> +};
> +
> +#endif
--
Jani Nikula, Intel
