drm: Remove users of drm_format_(horz|vert)_chroma_subsampling

drm_format_horz_chroma_subsampling and drm_format_vert_chroma_subsampling
are basically a lookup in the drm_format_info table plus an access to the
hsub and vsub fields of the appropriate entry.

Most drivers are using this function while having access to the entry
already, which means that we will perform an unnecessary lookup. Removing
the call to these functions is therefore more efficient.

Some drivers will not have access to that entry in the function, but in
this case the overhead is minimal (we just have to call drm_format_info()
to perform the lookup) and we can even avoid multiple, inefficient lookups
in some places that need multiple fields from the drm_format_info
structure.

This is amplified by the fact that most of the time the callers will have
to retrieve both the vsub and hsub fields, meaning that they would perform
twice the lookup.

Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/6b3cceb8161e2c1d40c2681de99202328b0a8abc.1558002671.git-series.maxime.ripard@bootlin.com

drivers/gpu/drm/rockchip/rockchip_drm_fb.c

@@ -79,18 +79,13 @@ rockchip_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
 	struct drm_framebuffer *fb;
 	struct drm_gem_object *objs[ROCKCHIP_MAX_FB_BUFFER];
 	struct drm_gem_object *obj;
-	unsigned int hsub;
-	unsigned int vsub;
 	int num_planes = min_t(int, info->num_planes, ROCKCHIP_MAX_FB_BUFFER);
 	int ret;
 	int i;
 
-	hsub = drm_format_horz_chroma_subsampling(mode_cmd->pixel_format);
-	vsub = drm_format_vert_chroma_subsampling(mode_cmd->pixel_format);
-
 	for (i = 0; i < num_planes; i++) {
-		unsigned int width = mode_cmd->width / (i ? hsub : 1);
-		unsigned int height = mode_cmd->height / (i ? vsub : 1);
+		unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
+		unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
 		unsigned int min_size;
 
 		obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[i]);

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

@@ -320,11 +320,9 @@ static void scl_vop_cal_scl_fac(struct vop *vop, const struct vop_win_data *win,
 	uint16_t yrgb_hor_scl_mode, yrgb_ver_scl_mode;
 	uint16_t cbcr_hor_scl_mode = SCALE_NONE;
 	uint16_t cbcr_ver_scl_mode = SCALE_NONE;
-	int hsub = drm_format_horz_chroma_subsampling(info->format);
-	int vsub = drm_format_vert_chroma_subsampling(info->format);
 	bool is_yuv = false;
-	uint16_t cbcr_src_w = src_w / hsub;
-	uint16_t cbcr_src_h = src_h / vsub;
+	uint16_t cbcr_src_w = src_w / info->hsub;
+	uint16_t cbcr_src_h = src_h / info->vsub;
 	uint16_t vsu_mode;
 	uint16_t lb_mode;
 	uint32_t val;
@@ -828,8 +826,8 @@ static void vop_plane_atomic_update(struct drm_plane *plane,
 		    (state->rotation & DRM_MODE_REFLECT_X) ? 1 : 0);
 
 	if (is_yuv) {
-		int hsub = drm_format_horz_chroma_subsampling(fb->format->format);
-		int vsub = drm_format_vert_chroma_subsampling(fb->format->format);
+		int hsub = fb->format->hsub;
+		int vsub = fb->format->vsub;
 		int bpp = fb->format->cpp[1];
 
 		uv_obj = fb->obj[1];