From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Simek Subject: Re: Microblaze noMMU/MMU merge Date: Tue, 21 Apr 2009 11:46:06 +0200 Message-ID: <49ED95DE.5070804@petalogix.com> References: <49ED79AB.10004@petalogix.com> <20090421082523.GA19864@uranus.ravnborg.org> Reply-To: michal.simek@petalogix.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from fg-out-1718.google.com ([72.14.220.159]:47859 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753326AbZDUJqJ (ORCPT ); Tue, 21 Apr 2009 05:46:09 -0400 In-Reply-To: <20090421082523.GA19864@uranus.ravnborg.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Sam Ravnborg Cc: Ingo Molnar , lkml , Andrew Morton , Arnd Bergmann , Linux Kernel list Sam Ravnborg wrote: > On Tue, Apr 21, 2009 at 09:45:47AM +0200, Michal Simek wrote: > >> Hi All, >> >> I would like to say your opinion about putting together Microblaze MMU >> arch to noMMU version. >> >> In C code will be #ifdef CONFIG_MMU ... #endif or #ifndef. >> >> Here is proposal for headers. The similar style is used in m68k but I >> would like to have the same code >> for both archs in main file. >> >> #ifndef _ASM_MICROBLAZE_PAGE_H >> #define _ASM_MICROBLAZE_PAGE_H >> >> code for noMMU and MMU which is the same for both. >> >> #ifdef __uClinux__ >> #include "page_no.h" -> noMMU specific >> #else >> #include "page_mm.h"-> MMU specific >> #endif >> #endif /* _ASM_MICROBLAZE_PAGE_H */ >> > > Use dedicated header files for nommu / mmu only when it is really necessary. > > In headers that are _NOT_ exported you can use CONFIG_MMU to test > if you are building for MMU or not - which is more readable. > > The reason why you cannot use CONFIG_MMU in exported headers > are that CONFIG_MMU is not valid in the userspace headers (not set/unset). > > In the optimal case you have no conditionals in the exported haders > and then just use CONFIG_MMU all over. > ok. I'll create first proposal and you can look if is ok or not. Thanks. Michal > Sam > > -- Michal Simek, Ing. (M.Eng) PetaLogix - Linux Solutions for a Reconfigurable World w: www.petalogix.com p: +61-7-30090663,+42-0-721842854 f: +61-7-30090663