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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Christophe Leroy <christophe.leroy@csgroup.eu>,
        Pali =?utf-8?Q?Roh?= =?utf-8?Q?=C3=A1r?= <pali@kernel.org>
Cc:     Nicholas Piggin <npiggin@gmail.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH v1 5/5] powerpc/64e: Fix build failure with GCC 12
 (unrecognized opcode: `wrteei')
In-Reply-To: <101320ce-8f0c-d4d8-9d73-7f231d651f4e@csgroup.eu>
References: <8abab4888da69ff78b73a56f64d9678a7bf684e9.1657549153.git.christophe.leroy@csgroup.eu>
 <77255a5a957967723b84d0356d9e5fb21569f4e8.1657549153.git.christophe.leroy@csgroup.eu>
 <20221211173232.7hvgnadyr7wrdm2f@pali>
 <101320ce-8f0c-d4d8-9d73-7f231d651f4e@csgroup.eu>
Date:   Mon, 12 Dec 2022 21:27:59 +1100
Message-ID: <87edt4kjbk.fsf@mpe.ellerman.id.au>
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Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> Le 11/12/2022 =C3=A0 18:32, Pali Roh=C3=A1r a =C3=A9crit=C2=A0:
>> On Monday 11 July 2022 16:19:33 Christophe Leroy wrote:
>>> With GCC 12, corenet64_smp_defconfig leads to the following build error=
s:
>>>
>>>    CC      arch/powerpc/kernel/irq.o
>>> {standard input}: Assembler messages:
>>> {standard input}:3616: Error: unrecognized opcode: `wrteei'
>>> {standard input}:5689: Error: unrecognized opcode: `wrteei'
>>>    CC      arch/powerpc/kernel/pmc.o
>>> {standard input}: Assembler messages:
>>> {standard input}:42: Error: unrecognized opcode: `mfpmr'
>>> {standard input}:53: Error: unrecognized opcode: `mtpmr'
>>>    CC      arch/powerpc/kernel/io.o
>>> {standard input}: Assembler messages:
>>> {standard input}:376: Error: unrecognized opcode: `mbar'
>>> ...
>>>    CC      arch/powerpc/mm/nohash/book3e_hugetlbpage.o
>>> {standard input}: Assembler messages:
>>> {standard input}:291: Error: unrecognized opcode: `tlbsx'
>>> {standard input}:482: Error: unrecognized opcode: `tlbwe'
>>> {standard input}:608: Error: unrecognized opcode: `lbarx'
>>> {standard input}:608: Error: unrecognized opcode: `stbcx.'
>>>
>>> -mpcu=3Dpowerpc64 cannot be used anymore for book3e, it must be a booke=
 CPU.
>>>
>>> But then we get:
>>>
>>>    CC      arch/powerpc/lib/xor_vmx.o
>>> cc1: error: AltiVec not supported in this target
>>>
>>> Altivec is not supported with -mcpu=3De5500 so don't allow selection
>>> of altivec when e5500 is selected.
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>>> ---
>>>   arch/powerpc/Makefile                  | 8 +-------
>>>   arch/powerpc/platforms/Kconfig.cputype | 8 ++++----
>>>   2 files changed, 5 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
>>> index d54e1fe03551..02742facf895 100644
>>> --- a/arch/powerpc/Makefile
>>> +++ b/arch/powerpc/Makefile
>>> @@ -168,13 +168,7 @@ endif
>>>   CFLAGS-$(CONFIG_TARGET_CPU_BOOL) +=3D $(call cc-option,-mcpu=3D$(CONF=
IG_TARGET_CPU))
>>>   AFLAGS-$(CONFIG_TARGET_CPU_BOOL) +=3D $(call cc-option,-mcpu=3D$(CONF=
IG_TARGET_CPU))
>>>=20=20=20
>>> -# Altivec option not allowed with e500mc64 in GCC.
>>> -ifdef CONFIG_ALTIVEC
>>> -E5500_CPU :=3D -mcpu=3Dpowerpc64
>>> -else
>>> -E5500_CPU :=3D $(call cc-option,-mcpu=3De500mc64,-mcpu=3Dpowerpc64)
>>> -endif
>>> -CFLAGS-$(CONFIG_E5500_CPU) +=3D $(E5500_CPU)
>>> +CFLAGS-$(CONFIG_E5500_CPU) +=3D $(call cc-option,-mcpu=3De500mc64,-mcp=
u=3Dpowerpc64)
>>>   CFLAGS-$(CONFIG_E6500_CPU) +=3D $(call cc-option,-mcpu=3De6500,$(E550=
0_CPU))
>>=20
>> Hello! I think that there is an issue. After removal of E5500_CPU
>> variable few line above, it cannot be used in CFLAGS-$(CONFIG_E6500_CPU)
>> assignment, because it is empty.
>>=20
>
> Ah yes, you are right.
>
> It should be fixed by=20
> https://github.com/linuxppc/linux/commit/f2636eaac7dee1d7d096cc115ff4f511=
1b0c508c
>
> Michael, I see the patch is in next-test. Can you add:
>
> Fixes: d6b551b8f90c ("powerpc/64e: Fix build failure with GCC 12=20
> (unrecognized opcode: `wrteei')")

Yep, will do.

cheers