Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030351AbWJCRbA (ORCPT ); Tue, 3 Oct 2006 13:31:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030349AbWJCRam (ORCPT ); Tue, 3 Oct 2006 13:30:42 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:45211 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1030351AbWJCRaf (ORCPT ); Tue, 3 Oct 2006 13:30:35 -0400 Date: Tue, 3 Oct 2006 13:10:55 -0400 From: Vivek Goyal To: linux kernel mailing list Cc: Reloc Kernel List , ebiederm@xmission.com, akpm@osdl.org, ak@suse.de, horms@verge.net.au, lace@jankratochvil.net, hpa@zytor.com, magnus.damm@gmail.com, lwang@redhat.com, dzickus@redhat.com, maneesh@in.ibm.com Subject: [PATCH 4/12] i386: define __pa_symbol() Message-ID: <20061003171055.GD3164@in.ibm.com> Reply-To: vgoyal@in.ibm.com References: <20061003170032.GA30036@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061003170032.GA30036@in.ibm.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1860 Lines: 45 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 Signed-off-by: Vivek Goyal --- include/asm-i386/page.h | 6 ++++++ 1 file changed, 6 insertions(+) diff -puN include/asm-i386/page.h~i386-define-__pa_symbol include/asm-i386/page.h --- linux-2.6.18-git17/include/asm-i386/page.h~i386-define-__pa_symbol 2006-10-02 13:17:58.000000000 -0400 +++ linux-2.6.18-git17-root/include/asm-i386/page.h 2006-10-02 14:36:32.000000000 -0400 @@ -124,6 +124,12 @@ extern int page_is_ram(unsigned long pag #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) \ + ({unsigned long v; \ + asm("" : "=r" (v) : "0" (x)); \ + __pa(v); }) #define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET)) #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) #ifdef CONFIG_FLATMEM _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/