[PATCH 04/11] drm/i915: Introduce pin_params.needs_cpu_lmem_access

Ville Syrjala
2026-04-16T17:45:12Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Add a new flag pin_params.neeeds_cpu_lmem_access so that the
low level pinning code doesn't need to peek into the display
driver's framebuffer structure.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/display/intel_fb_pin.h | 1 +
drivers/gpu/drm/i915/i915_fb_pin.c | 4 +++-
drivers/gpu/drm/xe/display/xe_fb_pin.c | 3 ++-
3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_fb_pin.h b/drivers/gpu/drm/i915/display/intel_fb_pin.h
index e6271437459d..bcf5a1f46092 100644
--- a/drivers/gpu/drm/i915/display/intel_fb_pin.h
+++ b/drivers/gpu/drm/i915/display/intel_fb_pin.h
@@ -19,6 +19,7 @@ struct intel_fb_pin_params {
unsigned int alignment;
unsigned int phys_alignment;
unsigned int vtd_guard;
+ bool needs_cpu_lmem_access;
};

struct i915_vma *
diff --git a/drivers/gpu/drm/i915/i915_fb_pin.c b/drivers/gpu/drm/i915/i915_fb_pin.c
index 780be25ad43b..96ffc4b0d809 100644
--- a/drivers/gpu/drm/i915/i915_fb_pin.c
+++ b/drivers/gpu/drm/i915/i915_fb_pin.c
@@ -61,7 +61,7 @@ intel_fb_pin_to_dpt(const struct drm_framebuffer *fb,
* ensure it is always in the mappable part of lmem, if this is
* a small-bar device.
*/
- if (intel_fb_needs_cpu_access(fb))
+ if (pin_params->needs_cpu_lmem_access)
flags &= ~I915_BO_ALLOC_GPU_ONLY;
ret = __i915_gem_object_migrate(obj, &ww, INTEL_REGION_LMEM_0,
flags);
@@ -275,6 +275,7 @@ int intel_plane_pin_fb(struct intel_plane_state *plane_state,
.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),
};
int fence_id = -1;

@@ -289,6 +290,7 @@ int intel_plane_pin_fb(struct intel_plane_state *plane_state,
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),
};

vma = i915_dpt_pin_to_ggtt(fb->dpt, pin_params.alignment / 512);
diff --git a/drivers/gpu/drm/xe/display/xe_fb_pin.c b/drivers/gpu/drm/xe/display/xe_fb_pin.c
index 205492639dba..a4eb06cfa769 100644
--- a/drivers/gpu/drm/xe/display/xe_fb_pin.c
+++ b/drivers/gpu/drm/xe/display/xe_fb_pin.c
@@ -335,7 +335,7 @@ static struct i915_vma *__xe_pin_fb_vma(const struct intel_framebuffer *fb,

refcount_set(&vma->ref, 1);
if (IS_DGFX(to_xe_device(bo->ttm.base.dev)) &&
- intel_fb_needs_cpu_access(&fb->base) &&
+ pin_params->needs_cpu_lmem_access &&
!(bo->flags & XE_BO_FLAG_NEEDS_CPU_ACCESS)) {
struct xe_vram_region *vram = xe_device_get_root_tile(xe)->mem.vram;

@@ -474,6 +474,7 @@ int intel_plane_pin_fb(struct intel_plane_state *new_plane_state,
struct intel_fb_pin_params pin_params = {
.view = &new_plane_state->view.gtt,
.alignment = plane->min_alignment(plane, fb, 0),
+ .needs_cpu_lmem_access = intel_fb_needs_cpu_access(fb),
};

if (reuse_vma(new_plane_state, old_plane_state))
--
2.52.0