linux-kernel - Re: [PATCH v15 1/2] math.h: provide rounddown

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Message-ID: <aFpkmjlc-14xxkn4@smile.fi.intel.com>
Date: Tue, 24 Jun 2025 11:40:58 +0300
From: Andy Shevchenko <andriy.shevchenko@...el.com>
To: Christian Marangi <ansuelsmth@...il.com>
Cc: Andy Shevchenko <andy.shevchenko@...il.com>,
	Uwe Kleine-König <ukleinek@...nel.org>,
	Lukas Wunner <lukas@...ner.de>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
	Herbert Xu <herbert@...dor.apana.org.au>,
	Andy Shevchenko <andy@...nel.org>,
	Jonathan Cameron <Jonathan.Cameron@...wei.com>,
	linux-kernel@...r.kernel.org, linux-pwm@...r.kernel.org
Subject: Re: [PATCH v15 1/2] math.h: provide rounddown_ull variant for
 rounddown MACRO

On Tue, Jun 24, 2025 at 09:45:08AM +0200, Christian Marangi wrote:
> On Tue, Jun 24, 2025 at 09:08:32AM +0300, Andy Shevchenko wrote:
> > On Tue, Jun 24, 2025 at 12:11 AM Christian Marangi <ansuelsmth@...il.com> wrote:

...

> > rounddown(),
> 
> For this and the other... Is it correct to use () for MACRO?
> I assume () should be used only for functions.

When it takes argument, yes. When it doesn't then you don't put it.

...

> > rounddown_ull()

Btw, I don't like name for this, it's better to be in math64 with the u64 or similar suffixes like it's used for div/mul variants.

Also add a roundup to make the API symmetrical (yes, it's okay that it has no
users, it's a macro and doesn't consume memory at run-time).

...

> > > - Add this patch
> > 
> > Why are math64 APIs not usable here?
> 
> There isn't a rounddown API for math64.

Then implementing it there (in math64.h) looks to me natural thingy that will
implicitly suggest this.

-- 
With Best Regards,
Andy Shevchenko