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From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Matt Fleming <matt@console-pimps.org>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	"H. Peter Anvin" <hpa@zytor.com>, Zhang Rui <rui.zhang@intel.com>,
	Huang Ying <huang.ying.caritas@gmail.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] x86, efi: Calling __pa() with an ioremap'd address is invalid
Date: Mon, 7 Nov 2011 20:23:24 +0000	[thread overview]
Message-ID: <20111107202324.GA27515@srcf.ucam.org> (raw)
In-Reply-To: <1320680088-2584-1-git-send-email-matt@console-pimps.org>

On Mon, Nov 07, 2011 at 03:34:48PM +0000, Matt Fleming wrote:

> After the feedback from v1 I tried to unify the efi_ioremap()
> implementations but ran into the issue detailed in the RH bug report
> in the changelog. Unless we teach the x86 setup code that
> EFI_RUNTIME_SERVICES_DATA regions should be part of the direct kernel
> mapping table (even though they're marked as E820_RESERVED) I think
> this patch makes the most sense.

Honestly it seems like there may well be an argument for that. We're 
talking about executable code that the kernel will be calling - it seems 
theoretically neater for it to be added to the direct mapping. We're 
just heavily constrained by our collapsing of the EFI memory map onto 
the rather less fine-grained E820 one and the lack of any obvious way to 
extend that in an OS-specific manner. I guess we could expect the 
bootloader to conform to the standard and then re-walk the EFI memory 
map ourselves to fix things up, but eww...

-- 
Matthew Garrett | mjg59@srcf.ucam.org

       reply	other threads:[~2011-11-07 20:23 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1320680088-2584-1-git-send-email-matt@console-pimps.org>
2011-11-07 20:23 ` Matthew Garrett [this message]
2011-11-07 20:36   ` [PATCH v3] x86, efi: Calling __pa() with an ioremap'd address is invalid H. Peter Anvin
2011-11-07 20:37     ` Matthew Garrett
2011-11-07 20:45       ` H. Peter Anvin
2011-11-07 20:48         ` Matthew Garrett
2011-11-07 20:57           ` H. Peter Anvin
2011-11-07 20:58             ` Matthew Garrett
2011-11-07 21:01               ` H. Peter Anvin
2011-11-07 21:07                 ` Matthew Garrett
2011-11-07 21:20                   ` H. Peter Anvin
2011-11-07 21:23                     ` Matthew Garrett
2011-11-07 21:34                       ` H. Peter Anvin
2011-11-07 21:36                         ` Matthew Garrett
2011-11-07 22:43                       ` Alan Cox
2011-11-11  1:02   ` huang ying
2011-11-11 13:12     ` Matt Fleming
2011-11-11 13:49       ` Matt Fleming
2011-11-07 15:46 Matt Fleming

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