[PATCH 11/11] tty: vt: cache row count in con_scroll()

Jiri Slaby (SUSE)
2023-01-12T08:03:10Z

It's used on few places, so make the code easier to follow by caching
the subtraction result.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
---
drivers/tty/vt/vt.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 165c81211bdc..671304b31f9f 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -561,10 +561,11 @@ static void con_scroll(struct vc_data *vc, unsigned int top,
unsigned int bottom, enum con_scroll dir,
unsigned int nr)
{
+ unsigned int rows = bottom - top;
u16 *clear, *dst, *src;

if (top + nr >= bottom)
- nr = bottom - top - 1;
+ nr = rows - 1;
if (bottom > vc->vc_rows || top >= bottom || nr < 1)
return;

@@ -577,10 +578,10 @@ static void con_scroll(struct vc_data *vc, unsigned int top,
dst = (u16 *)(vc->vc_origin + vc->vc_size_row * (top + nr));

if (dir == SM_UP) {
- clear = src + (bottom - top - nr) * vc->vc_cols;
+ clear = src + (rows - nr) * vc->vc_cols;
swap(src, dst);
}
- scr_memmovew(dst, src, (bottom - top - nr) * vc->vc_size_row);
+ scr_memmovew(dst, src, (rows - nr) * vc->vc_size_row);
scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
}

--
2.39.0