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x86: ioremap_nocache fix 

This patch fixes a bug of ioremap_nocache. ioremap_nocache() will call
__ioremap() with flags != 0 to do the real work, which will call
change_page_attr_addr() if phys_addr + size - 1 < (end_pfn_map << PAGE_SHIFT).
But some pages between 0 ~ end_pfn_map << PAGE_SHIFT are not mapped by
identity map, this will make change_page_attr_addr failed.

This patch is based on latest x86 git and has been tested on x86_64 platform.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Huang, Ying 2008-01-30 13:34:04 +01:00 committed by Ingo Molnar
parent d2e626f45c
commit 1c17f4d615
1 changed files with 7 additions and 0 deletions
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7
arch/x86/mm/ioremap_64.c
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@ -41,7 +41,14 @@ ioremap_change_attr(unsigned long phys_addr, unsigned long size,
if (phys_addr + size - 1 < (end_pfn_map << PAGE_SHIFT)) {
unsigned long npages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
unsigned long vaddr = (unsigned long) __va(phys_addr);
int level;
/*
* If there is no identity map for this address,
* change_page_attr_addr is unnecessary
*/
if (!lookup_address(vaddr, &level))
return err;
/*
* Must use a address here and not struct page because the phys addr
* can be a in hole between nodes and not have an memmap entry.