drm/i915: Mark up object tiling-and-stride getters as const

For that little bit of defense against a tired programmer.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180725155447.11909-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem.c

@@ -1911,7 +1911,7 @@ i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
 	return 0;
 }
 
-static unsigned int tile_row_pages(struct drm_i915_gem_object *obj)
+static unsigned int tile_row_pages(const struct drm_i915_gem_object *obj)
 {
 	return i915_gem_object_get_tile_row_size(obj) >> PAGE_SHIFT;
 }
@@ -1970,7 +1970,7 @@ int i915_gem_mmap_gtt_version(void)
 }
 
 static inline struct i915_ggtt_view
-compute_partial_view(struct drm_i915_gem_object *obj,
+compute_partial_view(const struct drm_i915_gem_object *obj,
 		     pgoff_t page_offset,
 		     unsigned int chunk)
 {

drivers/gpu/drm/i915/i915_gem_object.h

@@ -421,19 +421,19 @@ i915_gem_object_is_framebuffer(const struct drm_i915_gem_object *obj)
 }
 
 static inline unsigned int
-i915_gem_object_get_tiling(struct drm_i915_gem_object *obj)
+i915_gem_object_get_tiling(const struct drm_i915_gem_object *obj)
 {
 	return obj->tiling_and_stride & TILING_MASK;
 }
 
 static inline bool
-i915_gem_object_is_tiled(struct drm_i915_gem_object *obj)
+i915_gem_object_is_tiled(const struct drm_i915_gem_object *obj)
 {
 	return i915_gem_object_get_tiling(obj) != I915_TILING_NONE;
 }
 
 static inline unsigned int
-i915_gem_object_get_stride(struct drm_i915_gem_object *obj)
+i915_gem_object_get_stride(const struct drm_i915_gem_object *obj)
 {
 	return obj->tiling_and_stride & STRIDE_MASK;
 }
@@ -446,13 +446,13 @@ i915_gem_tile_height(unsigned int tiling)
 }
 
 static inline unsigned int
-i915_gem_object_get_tile_height(struct drm_i915_gem_object *obj)
+i915_gem_object_get_tile_height(const struct drm_i915_gem_object *obj)
 {
 	return i915_gem_tile_height(i915_gem_object_get_tiling(obj));
 }
 
 static inline unsigned int
-i915_gem_object_get_tile_row_size(struct drm_i915_gem_object *obj)
+i915_gem_object_get_tile_row_size(const struct drm_i915_gem_object *obj)
 {
 	return (i915_gem_object_get_stride(obj) *
 		i915_gem_object_get_tile_height(obj));