drm/i915: Avoid pointer arithmetic in calculating plane surface offset

[cascardo/linux.git] / drivers / gpu / drm / i915 / intel_display.c

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2e05c7e..5a938ff 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2915,13 +2915,13 @@ u32 intel_fb_stride_alignment(struct drm_device *dev, uint64_t fb_modifier,
        }
 }
 
-unsigned long intel_plane_obj_offset(struct intel_plane *intel_plane,
-                                    struct drm_i915_gem_object *obj,
-                                    unsigned int plane)
+u32 intel_plane_obj_offset(struct intel_plane *intel_plane,
+                          struct drm_i915_gem_object *obj,
+                          unsigned int plane)
 {
        const struct i915_ggtt_view *view = &i915_ggtt_view_normal;
        struct i915_vma *vma;
-       unsigned char *offset;
+       u64 offset;
 
        if (intel_rotation_90_or_270(intel_plane->base.state->rotation))
                view = &i915_ggtt_view_rotated;
@@ -2931,14 +2931,16 @@ unsigned long intel_plane_obj_offset(struct intel_plane *intel_plane,
                view->type))
                return -1;
 
-       offset = (unsigned char *)vma->node.start;
+       offset = vma->node.start;
 
        if (plane == 1) {
                offset += vma->ggtt_view.rotation_info.uv_start_page *
                          PAGE_SIZE;
        }
 
-       return (unsigned long)offset;
+       WARN_ON(upper_32_bits(offset));
+
+       return lower_32_bits(offset);
 }
 
 static void skl_detach_scaler(struct intel_crtc *intel_crtc, int id)
@@ -3064,7 +3066,7 @@ static void skylake_update_primary_plane(struct drm_crtc *crtc,
        u32 tile_height, plane_offset, plane_size;
        unsigned int rotation;
        int x_offset, y_offset;
-       unsigned long surf_addr;
+       u32 surf_addr;
        struct intel_crtc_state *crtc_state = intel_crtc->config;
        struct intel_plane_state *plane_state;
        int src_x = 0, src_y = 0, src_w = 0, src_h = 0;