From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org, Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [PATCH v2] powerpc/64: system call implement the bulk of the logic in C
Date: Thu, 05 Sep 2019 14:29:13 +1000 [thread overview]
Message-ID: <1567657627.xi0syilmvi.astroid@bobo.none> (raw)
In-Reply-To: <875zm7pefl.fsf@mpe.ellerman.id.au>
Michael Ellerman's on September 5, 2019 2:14 pm:
> Nicholas Piggin <npiggin@gmail.com> writes:
>> System call entry and particularly exit code is beyond the limit of what
>> is reasonable to implement in asm.
>>
>> This conversion moves all conditional branches out of the asm code,
>> except for the case that all GPRs should be restored at exit.
>>
>> Null syscall test is about 5% faster after this patch, because the exit
>> work is handled under local_irq_disable, and the hard mask and pending
>> interrupt replay is handled after that, which avoids games with MSR.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>> Since v1:
>> - Fix big endian build (mpe)
>> - Fix order of exit tracing to after the result registers have been set.
>> - Move ->softe store before MSR[EE] is set, fix the now obsolete comment.
>> - More #ifdef tidyups and writing the accounting helpers nicer (Christophe)
>> - Minor things like move the TM debug store into C
>
> This doesn't build in a few configs.
>
> It needed:
>
> +#else
> +static inline void kuap_check_amr(void) { }
>
> In kup-radix.h to fix the KUAP=n build.
Thanks.
>
> It still fails to build on ppc64e with:
>
> arch/powerpc/kernel/syscall_64.c:161:2: error: implicit declaration of function '__mtmsrd' [-Werror=implicit-function-declaration]
Ah, no __mtmsrd or RI on BookE, so that will need a new function in
hw_irq.h. I think I also need to do the irq tracing with RI=1 now I
think about it.
I'll resend a fixed patch.
Thanks,
Nick
prev parent reply other threads:[~2019-09-05 4:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-02 22:58 [PATCH v2] powerpc/64: system call implement the bulk of the logic in C Nicholas Piggin
2019-09-05 4:14 ` Michael Ellerman
2019-09-05 4:29 ` Nicholas Piggin [this message]
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