From: Ilias Apalodimas <ilias.apalodimas@linaro.org>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: catalin.marinas@arm.com, labbott@redhat.com,
linux-arm-kernel@lists.infradead.org, ard.biesheuvel@linaro.org
Subject: Re: Memory size and section boundary on armv7
Date: Fri, 12 Apr 2019 14:26:11 +0300 [thread overview]
Message-ID: <20190412112611.GA8295@apalos> (raw)
In-Reply-To: <20190412111614.xbwnffum25ny7ddy@shell.armlinux.org.uk>
> > Can we at least we can print a warning saying "What you are trying to do is not
> > good enough, please re-check the mappings" or something like that,
> > to help people avoid that in the future.
> > The BUG_ON is supposed to do that, but for some reason i can't see it on my
> > console, any ideas why?
>
> That may be a possibility, we would have to ignore the request to setup
> the mapping, which means we could end silently locking up shortly
> there-after.
>
> It may also be possible to slightly rearrange the code to map the
> vectors page before we setup any of the memory mappings (so that
> exceptions can work), but that may need careful handling.
>
Ok, i'll try to have a look at that, since i can easily reproduce the splat
> > Yes. U-Boot wise we could fix that, by placing the dtb on a non section
> > aligned boundary
>
> That's actually misleading.
>
> The problem happens when you have a small no-map section within a 2MB
> region, and it doesn't cross the even-odd 1MB boundary.
>
> To illustrate what I'm saying, if you arranged for it to be (eg) one
> page higher (iow, 0xc7f01000) then you'll hit the same problem.
Yes correct, i actually tried that as well in one of my tests and still had the
same effect
> >
> > The easiest way out of it is to place the fdt on !SECTION_SIZE right?
Yes noted,
Thanks
/Ilias
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next prev parent reply other threads:[~2019-04-12 11:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-11 15:13 Memory size and section boundary on armv7 Ilias Apalodimas
2019-04-11 15:41 ` Russell King - ARM Linux admin
2019-04-11 15:50 ` Ilias Apalodimas
2019-04-11 16:22 ` Russell King - ARM Linux admin
2019-04-12 5:23 ` Ilias Apalodimas
2019-04-12 8:40 ` Russell King - ARM Linux admin
2019-04-12 10:10 ` Ilias Apalodimas
2019-04-12 11:16 ` Russell King - ARM Linux admin
2019-04-12 11:26 ` Ilias Apalodimas [this message]
2019-04-12 11:43 ` Ilias Apalodimas
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