Re: [PATCH 3/3] Replace for_each_*_bit_from() with for_each_*_bit() where appropriate

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Yury Norov <yury.norov@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Lucas Stach <l.stach@pengutronix.de>,
	Russell King <linux+etnaviv@armlinux.org.uk>,
	Christian Gmeiner <christian.gmeiner@gmail.com>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Marc Zyngier <maz@kernel.org>,
	David Woodhouse <dwmw@amazon.co.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	Wei Yang <richard.weiyang@linux.alibaba.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Alexey Klimov <aklimov@redhat.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-hwmon@vger.kernel.org
Subject: Re: [PATCH 3/3] Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
Date: Sat, 19 Jun 2021 13:55:10 +0300	[thread overview]
Message-ID: <YM3NDrgF3znR+/4z@smile.fi.intel.com> (raw)
In-Reply-To: <YM3L1kciMw7zqhUp@smile.fi.intel.com>

On Sat, Jun 19, 2021 at 01:49:58PM +0300, Andy Shevchenko wrote:
> On Fri, Jun 18, 2021 at 12:57:35PM -0700, Yury Norov wrote:
> > A couple of kernel functions call for_each_*_bit_from() with start
> > bit equal to 0. Replace them with for_each_*_bit().
> > 
> > No functional changes, but might improve on readability.
> 
> ...
> 
> > --- a/drivers/hwmon/ltc2992.c
> > +++ b/drivers/hwmon/ltc2992.c
> > @@ -248,8 +248,7 @@ static int ltc2992_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
> >  
> >  	gpio_status = reg;
> >  
> > -	gpio_nr = 0;
> > -	for_each_set_bit_from(gpio_nr, mask, LTC2992_GPIO_NR) {
> > +	for_each_set_bit(gpio_nr, mask, LTC2992_GPIO_NR) {
> >  		if (test_bit(LTC2992_GPIO_BIT(gpio_nr), &gpio_status))
> >  			set_bit(gpio_nr, bits);
> >  	}
> 
> I would replace the entire loop by bitmap_replace() call.
> 
> Something like
> 	bitmap_replace(bits, bits, &gpio_status, mask, LTC2992_GPIO_NR);

Okay, it wouldn't work directly because it involves LTC2992_GPIO_BIT()
macro. So, it rather some kind of bitmap_remap().

-- 
With Best Regards,
Andy Shevchenko