[PATCH 6/7] tty/vt: consolemap: improve UNI_*() macros definitions

From: Jiri Slaby
Date: Tue Jun 14 2022 - 03:57:44 EST


Use FIELD_GET() and GENMASK() helpers instead of direct shifts and ANDs.
This makes the code even more obvious. I didn't know about the helpers
at the time of writing the macros.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/tty/vt/consolemap.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index 16d0d8f04f0e..9e94ec0e0f83 100644
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -23,6 +23,8 @@
* stack overflow.
*/

+#include <linux/bitfield.h>
+#include <linux/bits.h>
#include <linux/module.h>
#include <linux/kd.h>
#include <linux/errno.h>
@@ -190,10 +192,17 @@ static enum translation_map inv_translate[MAX_NR_CONSOLES];
#define UNI_DIR_ROWS 32U
#define UNI_ROW_GLYPHS 64U

-#define UNI_DIR(uni) ( (uni) >> 11)
-#define UNI_ROW(uni) (((uni) & GENMASK(10, 6)) >> 6)
-#define UNI_GLYPH(uni) ( (uni) & GENMASK( 5, 0))
-#define UNI(dir, row, glyph) (((dir) << 11) | ((row) << 6) | (glyph))
+#define UNI_DIR_BITS GENMASK(15, 11)
+#define UNI_ROW_BITS GENMASK(10, 6)
+#define UNI_GLYPH_BITS GENMASK( 5, 0)
+
+#define UNI_DIR(uni) FIELD_GET(UNI_DIR_BITS, (uni))
+#define UNI_ROW(uni) FIELD_GET(UNI_ROW_BITS, (uni))
+#define UNI_GLYPH(uni) FIELD_GET(UNI_GLYPH_BITS, (uni))
+
+#define UNI(dir, row, glyph) (FIELD_PREP(UNI_DIR_BITS, (dir)) | \
+ FIELD_PREP(UNI_ROW_BITS, (row)) | \
+ FIELD_PREP(UNI_GLYPH_BITS, (glyph)))

/**
* struct uni_pagedict -- unicode directory
--
2.36.1