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SubjectRe: [PATCH] Fix left over EFI cache mapping problems

* 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) {

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