Re: [PATCH v5 2/2] arm64: Work around Falkor erratum 1009

From	Christopher Covington <cov@codeaurora.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5 2/2] arm64: Work around Falkor erratum 1009
Date	2017-01-31 17:20 +0100
Message-ID	<t5JjY-2Qa-3@gated-at.bofh.it> (permalink)
References	<t5tfb-1B3-7@gated-at.bofh.it> <t5tfb-1B3-5@gated-at.bofh.it> <t5HUS-1S1-17@gated-at.bofh.it>
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On 01/31/2017 09:38 AM, Will Deacon wrote:
> On Mon, Jan 30, 2017 at 06:08:17PM -0500, Christopher Covington wrote:
>> diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
>> index deab52374119..fc434f421c7b 100644
>> --- a/arch/arm64/include/asm/tlbflush.h
>> +++ b/arch/arm64/include/asm/tlbflush.h
>> @@ -36,9 +36,21 @@
>>   * not. The macros handles invoking the asm with or without the
>>   * register argument as appropriate.
>>   */
>> -#define __TLBI_0(op, arg)		asm ("tlbi " #op)
>> -#define __TLBI_1(op, arg)		asm ("tlbi " #op ", %0" : : "r" (arg))
>> -#define __TLBI_N(op, arg, n, ...)	__TLBI_##n(op, arg)
>> +#define __TLBI_0(op, arg) asm volatile ("tlbi " #op "\n"		       \
>> +			    ALTERNATIVE("nop\n		nop",		       \
>> +					"dsb ish\n	tlbi " #op,	       \
>> +					ARM64_WORKAROUND_REPEAT_TLBI,	       \
>> +					CONFIG_QCOM_FALKOR_ERRATUM_1009)       \
>> +			    : : )
>> +
>> +#define __TLBI_1(op, arg) asm volatile ("tlbi " #op ", %0\n"		       \
>> +			    ALTERNATIVE("nop\n		nop",		       \
>> +					"dsb ish\n	tlbi " #op ", %0",     \
>> +					ARM64_WORKAROUND_REPEAT_TLBI,	       \
>> +					CONFIG_QCOM_FALKOR_ERRATUM_1009)       \
>> +			    : : "r" (arg))
>> +
> 
> Why are these now volatile? I asked the same question on the previous
> version but didn't get a response:
> 
> http://lists.infradead.org/pipermail/linux-arm-kernel/2017-January/483579.html

D'oh! Will fix in v6. Sorry about that.

Cov

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[PATCH v5 2/2] arm64: Work around Falkor erratum 1009 Christopher Covington <cov@codeaurora.org> - 2017-01-31 00:10 +0100
  Re: [PATCH v5 2/2] arm64: Work around Falkor erratum 1009 Mark Rutland <mark.rutland@arm.com> - 2017-01-31 13:50 +0100
    Re: [PATCH v5 2/2] arm64: Work around Falkor erratum 1009 Will Deacon <will.deacon@arm.com> - 2017-01-31 15:40 +0100
  Re: [PATCH v5 2/2] arm64: Work around Falkor erratum 1009 Will Deacon <will.deacon@arm.com> - 2017-01-31 15:50 +0100
    Re: [PATCH v5 2/2] arm64: Work around Falkor erratum 1009 Christopher Covington <cov@codeaurora.org> - 2017-01-31 17:20 +0100

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