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Date:   Tue, 28 May 2019 19:03:41 +0200
Message-ID: <20190528190341.Horde.nTXOule-IO2ReXFiNIqNbg8@messagerie.si.c-s.fr>
From:   Christophe Leroy <christophe.leroy@c-s.fr>
To:     Michael Ellerman <mpe@ellerman.id.au>
Cc:     Nicholas Piggin <npiggin@gmail.com>, linux-kernel@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, Paul Mackerras <paulus@ozlabs.org>
Subject: Re: [PATCH v3 14/16] powerpc/32: implement fast entry for syscalls
 on BOOKE
References: <cover.1556627571.git.christophe.leroy@c-s.fr>
 <3e254178a157e7eaeef48f983880f71f97d1f296.1556627571.git.christophe.leroy@c-s.fr>
 <20190523061427.GA19655@blackberry>
 <98bf5745-88ae-7f17-fcb9-7d06ba5b9e49@c-s.fr>
 <58f0e70f-ed9d-965e-e8d2-cc5d13a4c9eb@c-s.fr>
 <87r28jp2b0.fsf@concordia.ellerman.id.au>
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Michael Ellerman <mpe@ellerman.id.au> a écrit :

> Christophe Leroy <christophe.leroy@c-s.fr> writes:
>> Le 23/05/2019 à 09:00, Christophe Leroy a écrit :
>>
>> [...]
>>
>>>> arch/powerpc/kernel/head_fsl_booke.o: In function `SystemCall':
>>>> arch/powerpc/kernel/head_fsl_booke.S:416: undefined reference to
>>>> `kvmppc_handler_BOOKE_INTERRUPT_SYSCALL_SPRN_SRR1'
>>>> Makefile:1052: recipe for target 'vmlinux' failed
>>>>
>>>>> +.macro SYSCALL_ENTRY trapno intno
>>>>> +    mfspr    r10, SPRN_SPRG_THREAD
>>>>> +#ifdef CONFIG_KVM_BOOKE_HV
>>>>> +BEGIN_FTR_SECTION
>>>>> +    mtspr    SPRN_SPRG_WSCRATCH0, r10
>>>>> +    stw    r11, THREAD_NORMSAVE(0)(r10)
>>>>> +    stw    r13, THREAD_NORMSAVE(2)(r10)
>>>>> +    mfcr    r13            /* save CR in r13 for now       */
>>>>> +    mfspr    r11, SPRN_SRR1
>>>>> +    mtocrf    0x80, r11    /* check MSR[GS] without clobbering reg */
>>>>> +    bf    3, 1975f
>>>>> +    b    kvmppc_handler_BOOKE_INTERRUPT_\intno\()_SPRN_SRR1
>>>>
>>>> It seems to me that the "_SPRN_SRR1" on the end of this line
>>>> isn't meant to be there...  However, it still fails to link with that
>>>> removed.
>>
>> It looks like I missed the macro expansion.
>>
>> The called function should be kvmppc_handler_8_0x01B
>>
>> Seems like kisskb doesn't build any config like this.
>
> I thought we did, ie:
>
> http://kisskb.ellerman.id.au/kisskb/buildresult/13817941/

That's a ppc64 config it seems. The problem was on booke32.

Christophe

>
> But clearly something is missing to trigger the bug.
>
> cheers