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

From: bdegraaf
Date: Mon Sep 19 2016 - 14:41:18 EST

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?


Code inspection only.