Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp

From	bdegraaf@codeaurora.org
Newsgroups	linux.kernel
Subject	Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp
Date	2016-09-19 20:50 +0200
Message-ID	<sjbND-Bs-5@gated-at.bofh.it> (permalink)
References	<sjaHU-8o6-37@gated-at.bofh.it> <sjbuh-uN-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 2016-09-19 14:28, Laura Abbott wrote:
> On 09/19/2016 10:36 AM, Brent DeGraaf wrote:
>> According to section 6.3.8 of the ARM Programmer's Guide, non-temporal
>> loads and stores do not verify that address dependency is met between 
>> a
>> load of an address to a register and a subsequent non-temporal load or
>> store using that address on the executing PE. Therefore, context 
>> switch
>> code and subroutine calls that use non-temporally accessed addresses 
>> as
>> parameters that might depend on a load of an address into an argument
>> register must ensure that ordering requirements are met by introducing
>> a barrier prior to the successive non-temporal access.  Add 
>> appropriate
>> barriers whereever this specific situation comes into play.
>> 
> 
> Was this found by code inspection or is there a (public) exciting test
> case to observe this behavior?
> 
> Thanks,
> Laura
> 

Code inspection only.

Brent

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[RFC] arm64: Ensure proper addressing for ldnp/stnp Brent DeGraaf <bdegraaf@codeaurora.org> - 2016-09-19 19:40 +0200
  Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp Robin Murphy <robin.murphy@arm.com> - 2016-09-19 20:10 +0200
    Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp bdegraaf@codeaurora.org - 2016-09-19 20:30 +0200
      Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp Robin Murphy <robin.murphy@arm.com> - 2016-09-20 13:20 +0200
        Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp bdegraaf@codeaurora.org - 2016-09-20 15:10 +0200
  Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp Laura Abbott <labbott@redhat.com> - 2016-09-19 20:30 +0200
    Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp bdegraaf@codeaurora.org - 2016-09-19 20:50 +0200

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