Commit 9f45accf authored Dec 07, 2006 by Eric W. Biederman Committed by Andi Kleen Dec 07, 2006

[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>

parent 6ed01884

include/asm-i386/page.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -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