linux-kernel - [PATCH 11/44] tty: 8250, use ms_to

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue,  2 Mar 2021 07:21:41 +0100
From:   Jiri Slaby <jslaby@...e.cz>
To:     gregkh@...uxfoundation.org
Cc:     linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jiri Slaby <jslaby@...e.cz>
Subject: [PATCH 11/44] tty: 8250, use ms_to_ktime

This really eliminates multiplications from the assembly. I would have
thought they are optimized by inlining ktime_set, but not on x86_64 with
gcc 10.

Signed-off-by: Jiri Slaby <jslaby@...e.cz>
---
 drivers/tty/serial/8250/8250_port.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index b0af13074cd3..167c1e3e53bc 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1487,11 +1487,7 @@ static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t)
 
 static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
 {
-	long sec = msec / 1000;
-	long nsec = (msec % 1000) * 1000000;
-	ktime_t t = ktime_set(sec, nsec);
-
-	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
+	hrtimer_start(hrt, ms_to_ktime(msec), HRTIMER_MODE_REL);
 }
 
 static void __stop_tx_rs485(struct uart_8250_port *p)
-- 
2.30.1