drm/i915: Limit the display memory alignment to 32 bit instead of 64

The coming commit "drm/i915: Introduce guard pages to i915_vma"
from Chris, was originally changing display_alignment to u32
from u64. The reason is that the display GGTT is and will be
limited o 4GB.

Put it in a separate patch and use "max(...)" instead of
"max_t(64, ...)" when asigning the value. We can safely use max
as we know beforehand that the comparison is between two u32
variables.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221130235805.221010-2-andi.shyti@linux.intel.com

drivers/gpu/drm/i915/display/intel_fb_pin.c

@@ -91,7 +91,7 @@ intel_pin_fb_obj_dpt(struct drm_framebuffer *fb,
 		goto err;
 	}
 
-	vma->display_alignment = max_t(u64, vma->display_alignment, alignment);
+	vma->display_alignment = max(vma->display_alignment, alignment);
 
 	i915_gem_object_flush_if_display(obj);
 

drivers/gpu/drm/i915/gem/i915_gem_domain.c

@@ -444,7 +444,7 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
 	if (IS_ERR(vma))
 		return vma;
 
-	vma->display_alignment = max_t(u64, vma->display_alignment, alignment);
+	vma->display_alignment = max(vma->display_alignment, alignment);
 	i915_vma_mark_scanout(vma);
 
 	i915_gem_object_flush_if_display_locked(obj);

drivers/gpu/drm/i915/i915_vma_types.h

@@ -197,7 +197,6 @@ struct i915_vma {
 	struct i915_fence_reg *fence;
 
 	u64 size;
-	u64 display_alignment;
 	struct i915_page_sizes page_sizes;
 
 	/* mmap-offset associated with fencing for this vma */
@@ -205,6 +204,7 @@ struct i915_vma {
 
 	u32 fence_size;
 	u32 fence_alignment;
+	u32 display_alignment;
 
 	/**
 	 * Count of the number of times this vma has been opened by different