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Date:   Wed, 23 Feb 2022 09:21:57 -0600
From:   Segher Boessenkool <segher@kernel.crashing.org>
To:     Anders Roxell <anders.roxell@linaro.org>
Cc:     mpe@ellerman.id.au, Arnd Bergmann <arnd@arndb.de>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
Subject: Re: [PATCH 2/3] powerpc: fix build errors
Message-ID: <20220223152157.GE614@gate.crashing.org>
References: <20220223135820.2252470-1-anders.roxell@linaro.org> <20220223135820.2252470-2-anders.roxell@linaro.org>
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Hi!

On Wed, Feb 23, 2022 at 02:58:19PM +0100, Anders Roxell wrote:
> Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
> 2.37.90.20220207) the following build error shows up:
> 
>  {standard input}: Assembler messages:
>  {standard input}:1190: Error: unrecognized opcode: `stbcix'
>  {standard input}:1433: Error: unrecognized opcode: `lwzcix'
>  {standard input}:1453: Error: unrecognized opcode: `stbcix'
>  {standard input}:1460: Error: unrecognized opcode: `stwcix'
>  {standard input}:1596: Error: unrecognized opcode: `stbcix'
>  ...
> 
> Rework to add assembler directives [1] around the instruction. Going
> through the them one by one shows that the changes should be safe.  Like
> __get_user_atomic_128_aligned() is only called in p9_hmi_special_emu(),
> which according to the name is specific to power9.  And __raw_rm_read*()
> are only called in things that are powernv or book3s_hv specific.

Thanks for doing this.

> +	__asm__ __volatile__(".machine \"push\"\n"
> +			     ".machine \"power6\"\n"
> +			     "stbcix %0,0,%1\n"
> +			     ".machine \"pop\"\n"

Just leave out the quotes completely?  Assembler is not C, barewords are
normal and expected and better style.

Other than that this looks perfect to me :-)

Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>


Segher