From: Huang, Ying Date: Wed, 30 Jan 2008 12:34:04 +0000 (+0100) Subject: x86: ioremap_nocache fix X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1c17f4d615f34a4ecfcf9132d643126b226f5e79;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git 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 Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/mm/ioremap_64.c b/arch/x86/mm/ioremap_64.c index 2815ab60009b..0a05f024dc22 100644 --- a/arch/x86/mm/ioremap_64.c +++ b/arch/x86/mm/ioremap_64.c @@ -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.