From: Mark Rutland <mark.rutland@arm.com>
To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: arm@kernel.org, devicetree@vger.kernel.org,
Kumar Gala <galak@codeaurora.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
Will Deacon <will.deacon@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] arm64: dts: uniphier: add /memreserve/ for spin-table release address
Date: Mon, 18 Apr 2016 10:04:16 +0100 [thread overview]
Message-ID: <20160418090415.GB21438@leverpostej> (raw)
In-Reply-To: <CAK7LNATtWyZtVWrW3nOYjN=aRvCO1w8Rvr6_JWm3QfMMPhrSAQ@mail.gmail.com>
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.
prev parent reply other threads:[~2016-04-18 9:04 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-15 17:58 [PATCH] arm64: dts: uniphier: add /memreserve/ for spin-table release address Masahiro Yamada
[not found] ` <1460743138-17768-1-git-send-email-yamada.masahiro-uWyLwvC0a2jby3iVrkZq2A@public.gmane.org>
2016-04-18 8:45 ` Mark Rutland
2016-04-18 8:55 ` Masahiro Yamada
2016-04-18 9:04 ` Mark Rutland [this message]
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