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From: Ingo Molnar <mingo@elte.hu>
To: Andi Kleen <andi@firstfloor.org>
Cc: torvalds@osdl.org, tglx@linutronix.de,
	linux-kernel@vger.kernel.org, ying.huang@intel.com
Subject: Re: [PATCH] Fix left over EFI cache mapping problems
Date: Thu, 14 Feb 2008 17:12:18 +0100	[thread overview]
Message-ID: <20080214161218.GA28152@elte.hu> (raw)
In-Reply-To: <20080214131317.GA27769@basil.nowhere.org>


* Andi Kleen <andi@firstfloor.org> wrote:

> --- linux.orig/arch/x86/kernel/efi.c
> +++ linux/arch/x86/kernel/efi.c
> @@ -413,17 +413,31 @@ void __init efi_enter_virtual_mode(void)
>  
>  	efi.systab = NULL;
>  	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
> +		int cached;
> +		unsigned numpages;
> +
>  		md = p;
>  		if (!(md->attribute & EFI_MEMORY_RUNTIME))
>  			continue;
>  
> +		/*
> +		 * RED-PEN The spec (and ia64) has a lot more memory
> +		 *         attribute flags should we handle those too?
> +		 */
> + 		cached = !!(md->attribute & EFI_MEMORY_WB);
>  		size = md->num_pages << EFI_PAGE_SHIFT;
>  		end = md->phys_addr + size;
> +		numpages = ALIGN(size, PAGE_SIZE) >> PAGE_SHIFT;
>  
> -		if ((end >> PAGE_SHIFT) <= max_pfn_mapped)
> +		/* RED-PEN does not handle overlapping */
> +		if ((end >> PAGE_SHIFT) <= max_pfn_mapped) {
>  			va = __va(md->phys_addr);
> -		else
> -			va = efi_ioremap(md->phys_addr, size);
> +			/* RED-PEN someone else could UCed it. */
> +			if (!cached)
> +				set_memory_uc((unsigned long)va, numpages);
> +		} else {
> +			va = efi_ioremap(md->phys_addr, size, cached);
> +		}
>  
>  		md->virt_addr = (u64) (unsigned long) va;

this is indeed a bug (we change the attributes for a larger area than 
needed), but your fix is unclean. Find below a cleaner solution.

Ying, if you agree with this fix could you please test and ACK it before 
we push it to Linus? (this fix is also in the latest x86.git#mm)

Thanks,

	Ingo

----------------->
Subject: x86: EFI set_memory_x()/set_memory_uc() fixes
From: Ingo Molnar <mingo@elte.hu>
Date: Thu Feb 14 14:21:32 CET 2008

The EFI-runtime mapping code changed a larger memory area than it
should have, due to a pages/bytes parameter mixup.

noticed by Andi Kleen.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/efi.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-x86.q/arch/x86/kernel/efi.c
===================================================================
--- linux-x86.q.orig/arch/x86/kernel/efi.c
+++ linux-x86.q/arch/x86/kernel/efi.c
@@ -391,7 +391,7 @@ static void __init runtime_code_page_mke
 		if (md->type != EFI_RUNTIME_SERVICES_CODE)
 			continue;
 
-		set_memory_x(md->virt_addr, md->num_pages << EFI_PAGE_SHIFT);
+		set_memory_x(md->virt_addr, md->num_pages);
 	}
 }
 
@@ -434,7 +434,7 @@ void __init efi_enter_virtual_mode(void)
 		}
 
 		if (!(md->attribute & EFI_MEMORY_WB))
-			set_memory_uc(md->virt_addr, size);
+			set_memory_uc(md->virt_addr, md->num_pages);
 
 		systab = (u64) (unsigned long) efi_phys.systab;
 		if (md->phys_addr <= systab && systab < end) {

  reply	other threads:[~2008-02-14 16:12 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-14 13:13 Andi Kleen
2008-02-14 16:12 ` Ingo Molnar [this message]
2008-02-14 17:16   ` Andi Kleen
2008-02-14 18:38     ` Ingo Molnar
2008-02-14 21:42       ` Andi Kleen
2008-02-14 22:08         ` Arjan van de Ven
2008-02-14 23:01           ` Andi Kleen
2008-02-15  2:52       ` Huang, Ying
2008-02-15  8:55         ` Andi Kleen
2008-02-15  9:16           ` Huang, Ying
2008-02-15  4:48   ` Huang, Ying
2008-02-15  5:44     ` Linus Torvalds
2008-02-15  6:24       ` Huang, Ying
2008-02-15  7:30       ` Ingo Molnar
2008-02-15  7:08     ` Ingo Molnar
2008-02-15  7:32       ` Huang, Ying
2008-02-18  1:53       ` Huang, Ying
2008-02-18 11:26         ` Andi Kleen
2008-02-18 14:05           ` Ingo Molnar
2008-02-15  8:48     ` Andi Kleen
2008-02-15  9:21       ` Huang, Ying
2008-02-15  9:43         ` Andi Kleen

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