Re: [PATCH 12/16] drm/xe: Restructure reuse_vma()

Jani Nikula
2026-04-24T10:30:27Z

On Thu, 23 Apr 2026, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Restructure reuse_vma() into a form that doesn't need the plane
> state structs, and rename the result to xe_fb_pin_reuse_vma().
> This will become the new fb_pin parent interface.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

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

> ---
> drivers/gpu/drm/xe/display/xe_fb_pin.c | 48 ++++++++++++++------------
> 1 file changed, 25 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/display/xe_fb_pin.c b/drivers/gpu/drm/xe/display/xe_fb_pin.c
> index bdd6a4da0997..cd287efded28 100644
> --- a/drivers/gpu/drm/xe/display/xe_fb_pin.c
> +++ b/drivers/gpu/drm/xe/display/xe_fb_pin.c
> @@ -486,36 +486,31 @@ static void xe_fb_pin_dpt_unpin(struct intel_dpt *dpt,
> __xe_unpin_fb_vma(ggtt_vma);
> }
>
> -static bool reuse_vma(struct intel_plane_state *new_plane_state,
> - const struct intel_plane_state *old_plane_state)
> +static struct i915_vma *
> +xe_fb_pin_reuse_vma(struct i915_vma *old_ggtt_vma,
> + struct drm_gem_object *old_obj,
> + const struct i915_gtt_view *old_view,
> + struct drm_gem_object *new_obj,
> + const struct i915_gtt_view *new_view,
> + u32 *out_offset)
> {
> - struct intel_plane *plane = to_intel_plane(new_plane_state->uapi.plane);
> - struct i915_vma *vma;
> + if (old_ggtt_vma && old_obj == new_obj &&
> + !memcmp(&old_view, &new_view, sizeof(*new_view))) {
> + refcount_inc(&old_ggtt_vma->ref);
>
> - if (old_plane_state->hw.fb == new_plane_state->hw.fb &&
> - !memcmp(&old_plane_state->view.gtt,
> - &new_plane_state->view.gtt,
> - sizeof(new_plane_state->view.gtt))) {
> - vma = old_plane_state->ggtt_vma;
> - goto found;
> + *out_offset = xe_ggtt_node_addr(old_ggtt_vma->node);
> +
> + return old_ggtt_vma;
> }
>
> - return false;
> -
> -found:
> - refcount_inc(&vma->ref);
> - new_plane_state->ggtt_vma = vma;
> -
> - new_plane_state->surf = xe_ggtt_node_addr(new_plane_state->ggtt_vma->node) +
> - plane->surf_offset(new_plane_state);
> -
> - return true;
> + return NULL;
> }
>
> int intel_plane_pin_fb(struct intel_plane_state *new_plane_state,
> const struct intel_plane_state *old_plane_state)
> {
> - struct intel_framebuffer *fb = to_intel_framebuffer(new_plane_state->hw.fb);
> + 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 = {
> @@ -529,8 +524,14 @@ int intel_plane_pin_fb(struct intel_plane_state *new_plane_state,
> u32 offset;
> int ret;
>
> - if (reuse_vma(new_plane_state, old_plane_state))
> - return 0;
> + ggtt_vma = xe_fb_pin_reuse_vma(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 = xe_fb_pin_ggtt_pin(obj, &pin_params,
> @@ -544,6 +545,7 @@ int intel_plane_pin_fb(struct intel_plane_state *new_plane_state,
> 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;

--
Jani Nikula, Intel