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authorEric W. Biederman <ebiederm@xmission.com>2006-12-07 02:14:03 +0100
committerAndi Kleen <andi@basil.nowhere.org>2006-12-07 02:14:03 +0100
commit9f45accf17efc050ba26bf77cc4f166c950b284e (patch)
tree1ea566184cfa02f4a1dd5e2643ad2d999f398f0f /include/asm-i386/page.h
parent6ed018845f1172cdc94f8a20ad807df901c6b7eb (diff)
downloadop-kernel-dev-9f45accf17efc050ba26bf77cc4f166c950b284e.zip
op-kernel-dev-9f45accf17efc050ba26bf77cc4f166c950b284e.tar.gz
[PATCH] i386: define __pa_symbol()
On x86_64 we have to be careful with calculating the physical address of kernel symbols. Both because of compiler odditities and because the symbols live in a different range of the virtual address space. Having a defintition of __pa_symbol that works on both x86_64 and i386 simplifies writing code that works for both x86_64 and i386 that has these kinds of dependencies. So this patch adds the trivial i386 __pa_symbol definition. Added assembly magic similar to RELOC_HIDE as suggested by Andi Kleen. Just picked it up from x86_64. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'include/asm-i386/page.h')
-rw-r--r--include/asm-i386/page.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/asm-i386/page.h b/include/asm-i386/page.h
index f5bf544..5a70501 100644
--- a/include/asm-i386/page.h
+++ b/include/asm-i386/page.h
@@ -124,6 +124,9 @@ extern int page_is_ram(unsigned long pagenr);
#define VMALLOC_RESERVE ((unsigned long)__VMALLOC_RESERVE)
#define MAXMEM (-__PAGE_OFFSET-__VMALLOC_RESERVE)
#define __pa(x) ((unsigned long)(x)-PAGE_OFFSET)
+/* __pa_symbol should be used for C visible symbols.
+ This seems to be the official gcc blessed way to do such arithmetic. */
+#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x),0))
#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
#ifdef CONFIG_FLATMEM
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