From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ruth.realtime.net (mercury.realtime.net [205.238.132.86]) by ozlabs.org (Postfix) with ESMTP id 839BEDDF0F for ; Tue, 19 Jun 2007 00:08:45 +1000 (EST) Mime-Version: 1.0 (Apple Message framework v624) In-Reply-To: <46730D5B.300@am.sony.com> Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <891b0e086ebe9ebf85355f893f5dafa9@bga.com> From: Milton Miller Subject: Re: [patch 23/33] powerpc: Localize mmu_off Date: Mon, 18 Jun 2007 09:08:56 -0500 To: Geoff Levand Cc: ppcdev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sat Jun 16 08:06:19 EST 2007, Geoff Levand wrote: > This just removes the dependency __mmu_off has on the symbol > __after_prom_start. I found the current code inconvenient when I > wanted to put some debugging code between the call to __mmu_off > and the branch to __after_prom_start. You are entering this code with the mmu on? My first thought was that is unexpected, but aparently Apple machines do that, so its supported for the master -- not the slaves. > Signed-off-by: Geoff Levand > --- > arch/powerpc/kernel/head_64.S | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > --- a/arch/powerpc/kernel/head_64.S > +++ b/arch/powerpc/kernel/head_64.S > @@ -1695,9 +1695,11 @@ _GLOBAL(__start_initialization_multiplat > 2: > > /* Switch off MMU if not already */ > - LOAD_REG_IMMEDIATE(r4, .__after_prom_start - KERNELBASE) > + LOAD_REG_IMMEDIATE(r4, __mmu_off_return - KERNELBASE) > add r4,r4,r30 > bl .__mmu_off > +__mmu_off_return: > + > b .__after_prom_start > > _STATIC(__boot_from_prom) > > -- That seems like a long label. I could stand a 1: there (ie a local numeric label). Hmm... how about always going directly there: - bl .__mmu_off - b .__after_prom_start + mtlr r4 + b .__mmu_off So that there is no space to add code that is skipped if the mmu was on? milton