From: Will Deacon <will.deacon@arm.com>
To: Chris Clayton <chris2553@googlemail.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] iommu: prompt for IOMMU_IO_PGTABLE_LPAE on ARM archs only
Date: Mon, 16 Feb 2015 16:32:48 +0000 [thread overview]
Message-ID: <20150216163247.GM10634@arm.com> (raw)
In-Reply-To: <54E0803F.5080707@googlemail.com>
Hi Chris,
On Sun, Feb 15, 2015 at 11:17:19AM +0000, Chris Clayton wrote:
> When running "make oldconfig" for an x86_64 kernel, I was prompted for a
> setting for IOMMU_IO_PGTABLE_LPAE. From the prompt and the help text it
> appears that this config item is relevant to ARMv7/v8 only. This patch
> prevents the prompt on non-ARM architectures. Compile tested building a
> cross-compiled x86_64 kernel in an x86 user space. The resultant kernel
> boots fine and I am running it now.
>
> Fixes: e1d3c0fd701df831169b116cd5c5d6203ac07f70
> Cc: will.deacon@arm.com
> Signed-off-by: Chris Clayton <chris2553@googlemail.com>
>
> --- linux/drivers/iommu/Kconfig.orig 2015-02-15 09:44:01.235927248 +0000
> +++ linux/drivers/iommu/Kconfig 2015-02-15 09:44:41.131926434 +0000
> @@ -22,6 +22,7 @@ config IOMMU_IO_PGTABLE
>
> config IOMMU_IO_PGTABLE_LPAE
> bool "ARMv7/v8 Long Descriptor Format"
> + depends on ARM || ARM64
> select IOMMU_IO_PGTABLE
> help
> Enable support for the ARM long descriptor pagetable format.
What's the problem with this? The page-table code is intentionally
decoupled from the CPU architecture and having this boot-tested on x86
found some real bugs that I'm currently fixing. Sure, you probably don't
need this on your box, but it's not default y and you don't have to
select it.
Will
next prev parent reply other threads:[~2015-02-16 16:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-15 11:17 [PATCH] iommu: prompt for IOMMU_IO_PGTABLE_LPAE on ARM archs only Chris Clayton
2015-02-16 16:32 ` Will Deacon [this message]
2015-02-16 19:25 ` Chris Clayton
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