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Date:   Tue, 10 Jan 2023 15:52:20 +0200
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Andrzej Hajda <andrzej.hajda@intel.com>
Cc:     Mark Rutland <mark.rutland@arm.com>, linux-ia64@vger.kernel.org,
        linux-sh@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
        dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org,
        sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-s390@vger.kernel.org, linux-hexagon@vger.kernel.org,
        linux-snps-arc@lists.infradead.org,
        Boqun Feng <boqun.feng@gmail.com>,
        linux-xtensa@linux-xtensa.org, Arnd Bergmann <arnd@arndb.de>,
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        openrisc@lists.librecores.org, loongarch@lists.linux.dev,
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        Andrew Morton <akpm@linux-foundation.org>,
        linuxppc-dev@lists.ozlabs.org
Subject: Re: [Intel-gfx] [RFC DO NOT MERGE] treewide: use __xchg in most
 obvious places
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On Tue, Jan 10, 2023 at 01:46:37PM +0100, Andrzej Hajda wrote:
> On 10.01.2023 12:07, Andy Shevchenko wrote:
> > On Tue, Jan 10, 2023 at 11:53:06AM +0100, Andrzej Hajda wrote:

...

> > > +	return __xchg(&p_chain->p_prod_elem,
> > > +		      (void *)(((u8 *)p_chain->p_prod_elem) + p_chain->elem_size));
> > 
> > Wondering if you still need a (void *) casting after the change. Ditto for the
> > rest of similar cases.
> 
> IMHO it is not needed also before the change and IIRC gcc has an extension
> which allows to drop (u8 *) cast as well [1].

I guess you can drop at least the former one.

> [1]: https://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html

...

> > Btw, is it done by coccinelle? If no, why not providing the script?
> 
> Yes I have used cocci. My cocci skills are far from perfect, so I did not
> want to share my dirty code, but this is nothing secret:

Thank you! It's not about secrecy, it's about automation / error proofness.

-- 
With Best Regards,
Andy Shevchenko