Re: [PATCH 16/16] drm/i915: Consolidate the intel_plane_(un)pin_fb() implementations

[Jani Nikula <jani.nikula@linux.intel.com>]

On Thu, 23 Apr 2026, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Currently i915 and each implement their own versions of

and xe?

> intel_plane_(un)pin(). Now that we have the fb_pin parent
> interface we can consolidate this to a single implementation.
>
> The result is a mixture of the i915 and xe implementations.
> The reuse_vma() hack comes from xe (and i915 doesn't implement
> that part of the parent interface, and the pin_params are
> taken from i915 since the platforms supported by i915 need
> more things.

One somewhat complicated and spread out comment inline. Other than that,

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_cursor.c |   1 -
>  drivers/gpu/drm/i915/display/intel_fb_pin.h |  27 -----
>  drivers/gpu/drm/i915/display/intel_plane.c  | 118 +++++++++++++++++++-
>  drivers/gpu/drm/i915/display/intel_plane.h  |   3 +
>  drivers/gpu/drm/i915/i915_fb_pin.c          | 116 +------------------
>  drivers/gpu/drm/xe/display/xe_fb_pin.c      |  82 +-------------
>  6 files changed, 126 insertions(+), 221 deletions(-)
>  delete mode 100644 drivers/gpu/drm/i915/display/intel_fb_pin.h
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
> index 18d1014de361..52347668f27d 100644
> --- a/drivers/gpu/drm/i915/display/intel_cursor.c
> +++ b/drivers/gpu/drm/i915/display/intel_cursor.c
> @@ -21,7 +21,6 @@
>  #include "intel_display_utils.h"
>  #include "intel_display_wa.h"
>  #include "intel_fb.h"
> -#include "intel_fb_pin.h"
>  #include "intel_frontbuffer.h"
>  #include "intel_plane.h"
>  #include "intel_psr.h"
> diff --git a/drivers/gpu/drm/i915/display/intel_fb_pin.h b/drivers/gpu/drm/i915/display/intel_fb_pin.h
> deleted file mode 100644
> index 6ff17d3e2cf5..000000000000
> --- a/drivers/gpu/drm/i915/display/intel_fb_pin.h
> +++ /dev/null
> @@ -1,27 +0,0 @@
> -/* SPDX-License-Identifier: MIT */
> -/*
> - * Copyright © 2021 Intel Corporation
> - */
> -
> -#ifndef __INTEL_FB_PIN_H__
> -#define __INTEL_FB_PIN_H__
> -
> -#include <linux/types.h>
> -
> -struct drm_gem_object;
> -struct i915_vma;
> -struct intel_fb_pin_params;
> -struct intel_plane_state;
> -struct i915_gtt_view;
> -struct iosys_map;
> -
> -struct i915_vma *
> -intel_fb_pin_to_ggtt(struct drm_gem_object *obj,
> -		     const struct intel_fb_pin_params *pin_params,
> -		     int *out_fence_id);
> -
> -int intel_plane_pin_fb(struct intel_plane_state *new_plane_state,
> -		       const struct intel_plane_state *old_plane_state);
> -void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state);
> -
> -#endif
> diff --git a/drivers/gpu/drm/i915/display/intel_plane.c b/drivers/gpu/drm/i915/display/intel_plane.c
> index e50e1a15410a..f132fa955d21 100644
> --- a/drivers/gpu/drm/i915/display/intel_plane.c
> +++ b/drivers/gpu/drm/i915/display/intel_plane.c
> @@ -44,6 +44,7 @@
>  #include <drm/drm_gem_atomic_helper.h>
>  #include <drm/drm_panic.h>
>  #include <drm/drm_print.h>
> +#include <drm/intel/display_parent_interface.h>
>  
>  #include "i9xx_plane_regs.h"
>  #include "intel_cdclk.h"
> @@ -53,7 +54,6 @@
>  #include "intel_display_trace.h"
>  #include "intel_display_types.h"
>  #include "intel_fb.h"
> -#include "intel_fb_pin.h"
>  #include "intel_fbdev.h"
>  #include "intel_parent.h"
>  #include "intel_plane.h"
> @@ -1191,6 +1191,122 @@ int intel_plane_check_src_coordinates(struct intel_plane_state *plane_state)
>  	return 0;
>  }
>  
> +static unsigned int
> +intel_plane_fb_min_alignment(const struct intel_plane_state *plane_state)
> +{
> +	const struct intel_framebuffer *fb = to_intel_framebuffer(plane_state->hw.fb);
> +
> +	return fb->min_alignment;

(1)

> +}
> +
> +static unsigned int
> +intel_plane_fb_min_phys_alignment(const struct intel_plane_state *plane_state)
> +{
> +	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
> +	const struct drm_framebuffer *fb = plane_state->hw.fb;
> +
> +	if (!intel_plane_needs_physical(plane))
> +		return 0;
> +
> +	return plane->min_alignment(plane, fb, 0);
> +}
> +
> +static unsigned int
> +intel_plane_fb_vtd_guard(const struct intel_plane_state *plane_state)
> +{
> +	return intel_fb_view_vtd_guard(plane_state->hw.fb,
> +				       &plane_state->view,
> +				       plane_state->hw.rotation);
> +}
> +
> +int intel_plane_pin_fb(struct intel_plane_state *plane_state,
> +		       const struct intel_plane_state *old_plane_state)
> +{
> +	struct intel_display *display = to_intel_display(plane_state);
> +	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
> +	const struct intel_framebuffer *fb =
> +		to_intel_framebuffer(plane_state->hw.fb);
> +	const struct intel_framebuffer *old_fb =
> +		to_intel_framebuffer(old_plane_state->hw.fb);
> +	struct i915_vma *ggtt_vma = NULL;
> +	struct i915_vma *dpt_vma = NULL;
> +	int fence_id = -1;
> +	u32 offset = 0;
> +	int ret;
> +
> +	/* hack for xe since it can't keep track of vmas properly */
> +	ggtt_vma = intel_parent_fb_pin_reuse_vma(display,
> +						 old_plane_state->ggtt_vma,
> +						 intel_fb_bo(&old_fb->base),
> +						 &old_plane_state->view.gtt,
> +						 intel_fb_bo(&fb->base),
> +						 &plane_state->view.gtt,
> +						 &offset);
> +	if (ggtt_vma)
> +		goto got_vma;
> +
> +	if (!intel_fb_uses_dpt(&fb->base)) {
> +		struct intel_fb_pin_params pin_params = {
> +			.view = &plane_state->view.gtt,
> +			.alignment = intel_plane_fb_min_alignment(plane_state),

So this is equal to i915, and uses (1) above.

> +			.phys_alignment = intel_plane_fb_min_phys_alignment(plane_state),
> +			.vtd_guard = intel_plane_fb_vtd_guard(plane_state),
> +			.needs_cpu_lmem_access = intel_fb_needs_cpu_access(&fb->base),
> +			.needs_low_address = intel_plane_needs_low_address(display),
> +			.needs_physical = intel_plane_needs_physical(plane),
> +			.needs_fence = intel_plane_needs_fence(display),
> +		};
> +
> +		ret = intel_parent_fb_pin_ggtt_pin(display, intel_fb_bo(&fb->base),
> +						   &pin_params, &ggtt_vma, &offset,
> +						   intel_plane_uses_fence(plane_state) ? &fence_id : NULL);
> +	} else {
> +		struct intel_fb_pin_params pin_params = {
> +			.view = &plane_state->view.gtt,
> +			.alignment = intel_plane_fb_min_alignment(plane_state),
> +			.needs_cpu_lmem_access = intel_fb_needs_cpu_access(&fb->base),
> +		};
> +
> +		ret = intel_parent_fb_pin_dpt_pin(display, intel_fb_bo(&fb->base),
> +						  fb->dpt, &pin_params,
> +						  &dpt_vma, &ggtt_vma, &offset);
> +	}
> +	if (ret)
> +		return ret;
> +
> +got_vma:
> +	plane_state->dpt_vma = dpt_vma;
> +	plane_state->ggtt_vma = ggtt_vma;
> +	plane_state->fence_id = fence_id;
> +
> +	plane_state->surf = offset + plane->surf_offset(plane_state);
> +
> +	return 0;
> +}
> +
> +void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state)
> +{
> +	struct intel_display *display = to_intel_display(old_plane_state);
> +	const struct intel_framebuffer *fb =
> +		to_intel_framebuffer(old_plane_state->hw.fb);
> +
> +	if (!intel_fb_uses_dpt(&fb->base)) {
> +		intel_parent_fb_pin_ggtt_unpin(display,
> +					       old_plane_state->ggtt_vma,
> +					       old_plane_state->fence_id);
> +
> +		old_plane_state->ggtt_vma = NULL;
> +		old_plane_state->fence_id = -1;
> +	} else {
> +		intel_parent_fb_pin_dpt_unpin(display, fb->dpt,
> +					      old_plane_state->dpt_vma,
> +					      old_plane_state->ggtt_vma);
> +
> +		old_plane_state->dpt_vma = NULL;
> +		old_plane_state->ggtt_vma = NULL;
> +	}
> +}
> +
>  static int add_dma_resv_fences(struct dma_resv *resv,
>  			       struct drm_plane_state *new_plane_state)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_plane.h b/drivers/gpu/drm/i915/display/intel_plane.h
> index 7b5456f56f42..a6338bba72d9 100644
> --- a/drivers/gpu/drm/i915/display/intel_plane.h
> +++ b/drivers/gpu/drm/i915/display/intel_plane.h
> @@ -92,5 +92,8 @@ int intel_plane_atomic_check(struct intel_atomic_state *state);
>  bool intel_plane_format_mod_supported_async(struct drm_plane *plane,
>  					    u32 format,
>  					    u64 modifier);
> +int intel_plane_pin_fb(struct intel_plane_state *new_plane_state,
> +		       const struct intel_plane_state *old_plane_state);
> +void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state);
>  
>  #endif /* __INTEL_PLANE_H__ */
> diff --git a/drivers/gpu/drm/i915/i915_fb_pin.c b/drivers/gpu/drm/i915/i915_fb_pin.c
> index cedefee46fbf..1034cb767e9f 100644
> --- a/drivers/gpu/drm/i915/i915_fb_pin.c
> +++ b/drivers/gpu/drm/i915/i915_fb_pin.c
> @@ -3,20 +3,9 @@
>   * Copyright © 2021 Intel Corporation
>   */
>  
> -/**
> - * DOC: display pinning helpers
> - */
> -
>  #include <drm/drm_print.h>
>  #include <drm/intel/display_parent_interface.h>
>  
> -#include "display/intel_display_core.h"
> -#include "display/intel_display_types.h"
> -#include "display/intel_fb.h"
> -#include "display/intel_fb_pin.h"
> -#include "display/intel_parent.h"
> -#include "display/intel_plane.h"
> -
>  #include "gem/i915_gem_domain.h"
>  #include "gem/i915_gem_object.h"
>  
> @@ -114,7 +103,7 @@ intel_fb_pin_to_dpt(struct drm_gem_object *_obj, struct intel_dpt *dpt,
>  	return vma;
>  }
>  
> -struct i915_vma *
> +static struct i915_vma *
>  intel_fb_pin_to_ggtt(struct drm_gem_object *_obj,
>  		     const struct intel_fb_pin_params *pin_params,
>  		     int *out_fence_id)
> @@ -230,34 +219,6 @@ static void intel_fb_unpin_vma(struct i915_vma *vma, int fence_id)
>  	i915_vma_put(vma);
>  }
>  
> -static unsigned int
> -intel_plane_fb_min_alignment(const struct intel_plane_state *plane_state)
> -{
> -	const struct intel_framebuffer *fb = to_intel_framebuffer(plane_state->hw.fb);
> -
> -	return fb->min_alignment;
> -}
> -
> -static unsigned int
> -intel_plane_fb_min_phys_alignment(const struct intel_plane_state *plane_state)
> -{
> -	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
> -	const struct drm_framebuffer *fb = plane_state->hw.fb;
> -
> -	if (!intel_plane_needs_physical(plane))
> -		return 0;
> -
> -	return plane->min_alignment(plane, fb, 0);
> -}
> -
> -static unsigned int
> -intel_plane_fb_vtd_guard(const struct intel_plane_state *plane_state)
> -{
> -	return intel_fb_view_vtd_guard(plane_state->hw.fb,
> -				       &plane_state->view,
> -				       plane_state->hw.rotation);
> -}
> -
>  static int i915_fb_pin_ggtt_pin(struct drm_gem_object *obj,
>  				const struct intel_fb_pin_params *pin_params,
>  				struct i915_vma **out_ggtt_vma,
> @@ -336,81 +297,6 @@ static void i915_fb_pin_dpt_unpin(struct intel_dpt *dpt,
>  		i915_dpt_unpin_from_ggtt(dpt);
>  }
>  
> -int intel_plane_pin_fb(struct intel_plane_state *plane_state,
> -		       const struct intel_plane_state *old_plane_state)
> -{
> -	struct intel_display *display = to_intel_display(plane_state);
> -	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
> -	const struct intel_framebuffer *fb =
> -		to_intel_framebuffer(plane_state->hw.fb);
> -	struct i915_vma *ggtt_vma = NULL;
> -	struct i915_vma *dpt_vma = NULL;
> -	int fence_id = -1;
> -	u32 offset;
> -	int ret;
> -
> -	if (!intel_fb_uses_dpt(&fb->base)) {
> -		struct intel_fb_pin_params pin_params = {
> -			.view = &plane_state->view.gtt,
> -			.alignment = intel_plane_fb_min_alignment(plane_state),
> -			.phys_alignment = intel_plane_fb_min_phys_alignment(plane_state),
> -			.vtd_guard = intel_plane_fb_vtd_guard(plane_state),
> -			.needs_cpu_lmem_access = intel_fb_needs_cpu_access(&fb->base),
> -			.needs_low_address = intel_plane_needs_low_address(display),
> -			.needs_physical = intel_plane_needs_physical(plane),
> -			.needs_fence = intel_plane_needs_fence(display),
> -		};
> -
> -		ret = intel_parent_fb_pin_ggtt_pin(display, intel_fb_bo(&fb->base),
> -						   &pin_params, &ggtt_vma, &offset,
> -						   intel_plane_uses_fence(plane_state) ? &fence_id : NULL);
> -		if (ret)
> -			return ret;
> -	} else {
> -		struct intel_fb_pin_params pin_params = {
> -			.view = &plane_state->view.gtt,
> -			.alignment = intel_plane_fb_min_alignment(plane_state),
> -			.needs_cpu_lmem_access = intel_fb_needs_cpu_access(&fb->base),
> -		};
> -
> -		ret = intel_parent_fb_pin_dpt_pin(display, intel_fb_bo(&fb->base),
> -						  fb->dpt, &pin_params,
> -						  &dpt_vma, &ggtt_vma, &offset);
> -		if (ret)
> -			return ret;
> -	}
> -
> -	plane_state->dpt_vma = dpt_vma;
> -	plane_state->ggtt_vma = ggtt_vma;
> -	plane_state->fence_id = fence_id;
> -	plane_state->surf = offset + plane->surf_offset(plane_state);
> -
> -	return 0;
> -}
> -
> -void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state)
> -{
> -	struct intel_display *display = to_intel_display(old_plane_state);
> -	const struct intel_framebuffer *fb =
> -		to_intel_framebuffer(old_plane_state->hw.fb);
> -
> -	if (!intel_fb_uses_dpt(&fb->base)) {
> -		intel_parent_fb_pin_ggtt_unpin(display,
> -					       old_plane_state->ggtt_vma,
> -					       old_plane_state->fence_id);
> -
> -		old_plane_state->ggtt_vma = NULL;
> -		old_plane_state->fence_id = -1;
> -	} else {
> -		intel_parent_fb_pin_dpt_unpin(display, fb->dpt,
> -					      old_plane_state->dpt_vma,
> -					      old_plane_state->ggtt_vma);
> -
> -		old_plane_state->dpt_vma = NULL;
> -		old_plane_state->ggtt_vma = NULL;
> -	}
> -}
> -
>  static void i915_fb_pin_get_map(struct i915_vma *vma, struct iosys_map *map)
>  {
>  	iosys_map_set_vaddr_iomem(map, i915_vma_get_iomap(vma));
> diff --git a/drivers/gpu/drm/xe/display/xe_fb_pin.c b/drivers/gpu/drm/xe/display/xe_fb_pin.c
> index c92c30ceba36..19f4d45f5acb 100644
> --- a/drivers/gpu/drm/xe/display/xe_fb_pin.c
> +++ b/drivers/gpu/drm/xe/display/xe_fb_pin.c
> @@ -6,11 +6,12 @@
>  #include <drm/intel/display_parent_interface.h>
>  #include <drm/ttm/ttm_bo.h>
>  
> -#include "intel_display_core.h"
> -#include "intel_display_types.h"
> +/* FIXME move the types to parent interface? */
> +#include "i915_gtt_view_types.h"
> +
> +/* FIXME move intel_remapped_info_size() & co. to parent interface? */
>  #include "intel_fb.h"
> -#include "intel_fb_pin.h"
> -#include "intel_parent.h"
> +
>  #include "xe_bo.h"
>  #include "xe_device.h"
>  #include "xe_display_vma.h"
> @@ -491,79 +492,6 @@ xe_fb_pin_reuse_vma(struct i915_vma *old_ggtt_vma,
>  	return NULL;
>  }
>  
> -int intel_plane_pin_fb(struct intel_plane_state *new_plane_state,
> -		       const struct intel_plane_state *old_plane_state)
> -{
> -	struct intel_display *display = to_intel_display(new_plane_state);
> -	const struct intel_framebuffer *fb = to_intel_framebuffer(new_plane_state->hw.fb);
> -	const struct intel_framebuffer *old_fb = to_intel_framebuffer(old_plane_state->hw.fb);
> -	struct drm_gem_object *obj = intel_fb_bo(&fb->base);
> -	struct intel_plane *plane = to_intel_plane(new_plane_state->uapi.plane);
> -	struct intel_fb_pin_params pin_params = {
> -		.view = &new_plane_state->view.gtt,
> -		.alignment = plane->min_alignment(plane, &fb->base, 0),

However xe had something different here.

Basically fb->min_alignment is initialized to intel_fb_min_alignment(),
which does call plane->min_alignment() for all planes, and works it out
from there.

Could or should we have switched xe to use fb->min_alignment here as an
intermediate step? It kind of sticks out as a change in this patch.


> -		.needs_cpu_lmem_access = intel_fb_needs_cpu_access(&fb->base),
> -	};
> -	struct i915_vma *ggtt_vma = NULL;
> -	struct i915_vma *dpt_vma = NULL;
> -	int fence_id = -1;
> -	u32 offset;
> -	int ret;
> -
> -	ggtt_vma = intel_parent_fb_pin_reuse_vma(display,
> -						 old_plane_state->ggtt_vma,
> -						 intel_fb_bo(&old_fb->base),
> -						 &old_plane_state->view.gtt,
> -						 intel_fb_bo(&fb->base),
> -						 &new_plane_state->view.gtt,
> -						 &offset);
> -	if (ggtt_vma)
> -		goto got_vma;
> -
> -	if (!intel_fb_uses_dpt(&fb->base)) {
> -		ret = intel_parent_fb_pin_ggtt_pin(display, obj, &pin_params,
> -						   &ggtt_vma, &offset, NULL);
> -		if (ret)
> -			return ret;
> -	} else {
> -		ret = intel_parent_fb_pin_dpt_pin(display, obj, fb->dpt,
> -						  &pin_params, &dpt_vma,
> -						  &ggtt_vma, &offset);
> -		if (ret)
> -			return ret;
> -	}
> -
> -got_vma:
> -	new_plane_state->dpt_vma = dpt_vma;
> -	new_plane_state->ggtt_vma = ggtt_vma;
> -	new_plane_state->fence_id = fence_id;
> -	new_plane_state->surf = offset + plane->surf_offset(new_plane_state);
> -
> -	return 0;
> -}
> -
> -void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state)
> -{
> -	struct intel_display *display = to_intel_display(old_plane_state);
> -	const struct intel_framebuffer *fb = to_intel_framebuffer(old_plane_state->hw.fb);
> -
> -	if (!intel_fb_uses_dpt(&fb->base)) {
> -		intel_parent_fb_pin_ggtt_unpin(display,
> -					       old_plane_state->ggtt_vma,
> -					       old_plane_state->fence_id);
> -
> -		old_plane_state->ggtt_vma = NULL;
> -		old_plane_state->fence_id = -1;
> -	} else {
> -		intel_parent_fb_pin_dpt_unpin(display, fb->dpt,
> -					      old_plane_state->dpt_vma,
> -					      old_plane_state->ggtt_vma);
> -
> -		old_plane_state->dpt_vma = NULL;
> -		old_plane_state->ggtt_vma = NULL;
> -	}
> -}
> -
>  static void xe_fb_pin_get_map(struct i915_vma *vma, struct iosys_map *map)
>  {
>  	*map = vma->bo->vmap;

-- 
Jani Nikula, Intel