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From:   Alexander Lobakin <alexandr.lobakin@intel.com>
To:     Mark Rutland <mark.rutland@arm.com>
Cc:     Alexander Lobakin <alexandr.lobakin@intel.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Yury Norov <yury.norov@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Richard Henderson <rth@twiddle.net>,
        Matt Turner <mattst88@gmail.com>,
        Brian Cain <bcain@quicinc.com>,
        "Geert Uytterhoeven" <geert@linux-m68k.org>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        Rich Felker <dalias@libc.org>,
        "David S. Miller" <davem@davemloft.net>,
        Kees Cook <keescook@chromium.org>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
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Subject: Re: [PATCH 5/6] bitops: wrap non-atomic bitops with a transparent macro
Date:   Tue,  7 Jun 2022 13:07:05 +0200
Message-Id: <20220607110705.72887-1-alexandr.lobakin@intel.com>
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From: Alexander Lobakin <alexandr.lobakin@intel.com>
Date: Tue, 7 Jun 2022 12:57:18 +0200

> From: Mark Rutland <mark.rutland@arm.com>
> Date: Mon, 6 Jun 2022 17:27:16 +0100
> 
> > On Mon, Jun 06, 2022 at 01:49:06PM +0200, Alexander Lobakin wrote:
> > > In preparation for altering the non-atomic bitops with a macro, wrap
> > > them in a transparent definition. This requires prepending one more
> > > '_' to their names in order to be able to do that seamlessly.
> > > sparc32 already has the triple-underscored functions, so I had to
> > > rename them ('___' -> 'sp32_').
> > 
> > Could we use an 'arch_' prefix here, like we do for the atomics, or is that
> > already overloaded?
> 
> Yeah it is, for example, x86 has 'arch_' functions defined in its
> architecture headers[0] and at the same time uses generic
> instrumented '__' helpers[1], so on x86 both underscored and 'arch_'
> are defined and they are not the same.

Oh well, forgot to attach the links. Can be found at the bottom of
this mail.

> Same with those sparc32 triple-underscored, sparc32 at the same time
> uses generic non-instrumented, so it has underscored, 'arch_' and
> triple-underscored.
> 
> In general, bitops are overloaded with tons of prefixes already :)
> I'm not really glad that I introduced one more level, but not that
> we have many options here.
> 
> > 
> > Thanks,
> > Mark.
> > 
> > > 
> > > Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
> > > ---
> 
> [...]
> 
> > > -- 
> > > 2.36.1
> 
> Thanks,
> Olek

[0] https://elixir.bootlin.com/linux/v5.19-rc1/source/arch/x86/include/asm/bitops.h#L136
[1] https://elixir.bootlin.com/linux/v5.19-rc1/source/include/asm-generic/bitops/instrumented-non-atomic.h#L93

Thanks,
Olek