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From: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
To: gregkh@linuxfoundation.org
Cc: Kees Cook <keescook@chromium.org>,
	linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Subject: [PATCH 11/11] tty: vt: cache row count in con_scroll()
Date: Thu, 12 Jan 2023 09:01:36 +0100	[thread overview]
Message-ID: <20230112080136.4929-11-jirislaby@kernel.org> (raw)
In-Reply-To: <20230112080136.4929-1-jirislaby@kernel.org>

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


  parent reply	other threads:[~2023-01-12  8:03 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-12  8:01 [PATCH 01/11] tty: vt: remove vc_uniscr_debug_check() Jiri Slaby (SUSE)
2023-01-12  8:01 ` [PATCH 02/11] tty: vt: drop get_vc_uniscr() Jiri Slaby (SUSE)
2023-01-12  8:41   ` Ilpo Järvinen
2023-01-12  8:01 ` [PATCH 03/11] tty: vt: remove reference to undefined NO_VC_UNI_SCREEN Jiri Slaby (SUSE)
2023-01-12  8:44   ` Ilpo Järvinen
2023-01-12  8:01 ` [PATCH 04/11] tty: vt: use sizeof(*variable) where possible Jiri Slaby (SUSE)
2023-01-12  8:58   ` Ilpo Järvinen
2023-01-12  8:01 ` [PATCH 05/11] tty: vt: remove char32_t typedef Jiri Slaby (SUSE)
2023-01-12  8:52   ` Ilpo Järvinen
2023-01-12  9:34   ` Ilpo Järvinen
2023-01-12  8:01 ` [PATCH 06/11] tty: vt: remove struct uni_screen Jiri Slaby (SUSE)
2023-01-12  9:42   ` Ilpo Järvinen
2023-01-12  8:01 ` [PATCH 07/11] tty: vt: replace BUG_ON() by WARN_ON_ONCE() Jiri Slaby (SUSE)
2023-01-12  9:42   ` Ilpo Järvinen
2023-01-12  8:01 ` [PATCH 08/11] tty: vt: simplify some unicode conditions Jiri Slaby (SUSE)
2023-01-12  9:52   ` Ilpo Järvinen
2023-01-12  8:01 ` [PATCH 09/11] tty: vt: separate array juggling to juggle_array() Jiri Slaby (SUSE)
2023-01-12 10:15   ` Ilpo Järvinen
2023-01-12  8:01 ` [PATCH 10/11] tty: vt: saner names for more scroll variables Jiri Slaby (SUSE)
2023-01-12  9:59   ` Ilpo Järvinen
2023-01-12  8:01 ` Jiri Slaby (SUSE) [this message]
2023-01-12 10:00   ` [PATCH 11/11] tty: vt: cache row count in con_scroll() Ilpo Järvinen
2023-01-12  8:43 ` [PATCH 01/11] tty: vt: remove vc_uniscr_debug_check() Ilpo Järvinen

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