drm/i915/fbdev: Extract intel_fbdev_fb_prefer_stolen()

Consolidate the "should we allocate fbdev fb in stolen?"
check into a helper function. Makes it easier to change the
heuristics without having to change so many places.

v2: rebase related changes and consolidate all the prefer
    stolen conditions into a single function (Vinod)

v3: avoid including intel_display_core.h (Jani)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patch.msgid.link/20260220170908.201422-4-vinod.govindapillai@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_fbdev_fb.c b/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
index e5251ed15948dc6bb2d1b2f1d356fd25307f3347..90993d09a73f89bfea9258ed0ce4bf9d177194a4 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
+++ b/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
@@ -17,6 +17,22 @@ u32 intel_fbdev_fb_pitch_align(u32 stride)
        return ALIGN(stride, 64);
 }
 
+bool intel_fbdev_fb_prefer_stolen(struct drm_device *drm, unsigned int size)
+{
+       struct drm_i915_private *i915 = to_i915(drm);
+
+       /* Skip stolen on MTL as Wa_22018444074 mitigation. */
+       if (IS_METEORLAKE(i915))
+               return false;
+
+       /*
+        * If the FB is too big, just don't use it since fbdev is not very
+        * important and we should probably use that space with FBC or other
+        * features.
+        */
+       return i915->dsm.usable_size >= size * 2;
+}
+
 struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size)
 {
        struct drm_i915_private *i915 = to_i915(drm);
@@ -28,14 +44,7 @@ struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size
                                                  I915_BO_ALLOC_CONTIGUOUS |
                                                  I915_BO_ALLOC_USER);
        } else {
-               /*
-                * If the FB is too big, just don't use it since fbdev is not very
-                * important and we should probably use that space with FBC or other
-                * features.
-                *
-                * Also skip stolen on MTL as Wa_22018444074 mitigation.
-                */
-               if (!IS_METEORLAKE(i915) && size * 2 < i915->dsm.usable_size)
+               if (intel_fbdev_fb_prefer_stolen(drm, size))
                        obj = i915_gem_object_create_stolen(i915, size);
                if (IS_ERR(obj))
                        obj = i915_gem_object_create_shmem(i915, size);

diff --git a/drivers/gpu/drm/i915/display/intel_fbdev_fb.h b/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
index fd0b3775dc1f2012f2bda607e3e161396a9f243f..34ed2b9c2b4fcf7b8f29a1e5d9bcf109ff9b2d9d 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
+++ b/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
@@ -19,5 +19,6 @@ struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size
 void intel_fbdev_fb_bo_destroy(struct drm_gem_object *obj);
 int intel_fbdev_fb_fill_info(struct drm_device *drm, struct fb_info *info,
                             struct drm_gem_object *obj, struct i915_vma *vma);
+bool intel_fbdev_fb_prefer_stolen(struct drm_device *drm, unsigned int size);
 
 #endif

diff --git a/drivers/gpu/drm/i915/i915_initial_plane.c b/drivers/gpu/drm/i915/i915_initial_plane.c
index 7fb52d81f7b6d648f7ba80f55924485d13a15e98..5594548f51d827d7a08ec109568165baa1af5ec1 100644 (file)
--- a/drivers/gpu/drm/i915/i915_initial_plane.c
+++ b/drivers/gpu/drm/i915/i915_initial_plane.c
@@ -9,6 +9,7 @@
 #include "display/intel_crtc.h"
 #include "display/intel_display_types.h"
 #include "display/intel_fb.h"
+#include "display/intel_fbdev_fb.h"
 #include "gem/i915_gem_lmem.h"
 #include "gem/i915_gem_region.h"
 
@@ -116,7 +117,7 @@ initial_plane_vma(struct drm_i915_private *i915,
         */
        if (IS_ENABLED(CONFIG_FRAMEBUFFER_CONSOLE) &&
            mem == i915->mm.stolen_region &&
-           size * 2 > i915->dsm.usable_size) {
+           !intel_fbdev_fb_prefer_stolen(&i915->drm, size)) {
                drm_dbg_kms(&i915->drm, "Initial FB size exceeds half of stolen, discarding\n");
                return NULL;
        }