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Re: [PATCH] arm64: dts: uniphier: add /memreserve/ for spin-table release address

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On Mon, Apr 18, 2016 at 05:55:14PM +0900, Masahiro Yamada wrote:
> 2016-04-18 17:45 GMT+09:00 Mark Rutland <mark.rutland@arm.com>:
> > I take it that the code for the spin-table is not in RAM, and does not
> > need to be protected similarly?
> 
> I use U-Boot to boot Linux for this board.
> 
> The code for the spin-table is on SDRAM, and not protected.
> 
> I already recognize this problem.
> 
> The difficulty for U-Boot is that
> U-Boot relocates itself to the top of the DRAM.
> So, it is difficult to predict
> where the code will be placed.
> 
> I will discuss this issue in the U-Boot ML.

Ok, please do.

> So, My current solution is pre-fetch the code for the spin-table onto
> I-cache.

As you are probably aware, this is incredibly unsafe, and very likely to
go wrong. Nothing guarantees that (stale) entries remain in the I-cache.

I would very much advise fixing this ASAP.

Thanks,
Mark.

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[PATCH] arm64: dts: uniphier: add /memreserve/ for spin-table release address Masahiro Yamada <yamada.masahiro@socionext.com> - 2016-04-15 20:10 +0200
  Re: [PATCH] arm64: dts: uniphier: add /memreserve/ for spin-table  release address Mark Rutland <mark.rutland@arm.com> - 2016-04-18 10:50 +0200
    Re: [PATCH] arm64: dts: uniphier: add /memreserve/ for spin-table  release address Masahiro Yamada <yamada.masahiro@socionext.com> - 2016-04-18 11:00 +0200
      Re: [PATCH] arm64: dts: uniphier: add /memreserve/ for spin-table  release address Mark Rutland <mark.rutland@arm.com> - 2016-04-18 11:10 +0200

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