linux-kernel - [PATCH 27/34] serial: sc12is7xx: optimize sc16is7xx_alloc

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Message-Id: <20231118155105.25678-28-yury.norov@gmail.com>
Date:   Sat, 18 Nov 2023 07:50:58 -0800
From:   Yury Norov <yury.norov@...il.com>
To:     linux-kernel@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>,
        Hugo Villeneuve <hvilleneuve@...onoff.com>,
        Lech Perczak <lech.perczak@...lingroup.com>,
        Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Hui Wang <hui.wang@...onical.com>,
        Isaac True <isaac.true@...onical.com>,
        Yury Norov <yury.norov@...il.com>, linux-serial@...r.kernel.org
Cc:     Jan Kara <jack@...e.cz>,
        Mirsad Todorovac <mirsad.todorovac@....unizg.hr>,
        Matthew Wilcox <willy@...radead.org>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Maxim Kuvyrkov <maxim.kuvyrkov@...aro.org>,
        Alexey Klimov <klimov.linux@...il.com>
Subject: [PATCH 27/34] serial: sc12is7xx: optimize sc16is7xx_alloc_line()

Instead of polling every bit in sc16is7xx_lines, switch it to using a
dedicated find_and_set_bit(), and make the function a simple one-liner.

Signed-off-by: Yury Norov <yury.norov@...il.com>
---
 drivers/tty/serial/sc16is7xx.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index db2bb1c0d36c..6a463988d5e0 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -427,15 +427,9 @@ static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
 
 static int sc16is7xx_alloc_line(void)
 {
-	int i;
-
 	BUILD_BUG_ON(SC16IS7XX_MAX_DEVS > BITS_PER_LONG);
 
-	for (i = 0; i < SC16IS7XX_MAX_DEVS; i++)
-		if (!test_and_set_bit(i, &sc16is7xx_lines))
-			break;
-
-	return i;
+	return find_and_set_bit(&sc16is7xx_lines, SC16IS7XX_MAX_DEVS);
 }
 
 static void sc16is7xx_power(struct uart_port *port, int on)
-- 
2.39.2