From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 0/4] Hacks to allow booting ARM SMP kernel on UP ARMv7 Date: Thu, 19 Aug 2010 10:38:11 +0300 Message-ID: <20100819073810.GR12184@atomide.com> References: <20100817104414.19061.38999.stgit@baageli.muru.com> <20100817135205.GC20325@n2100.arm.linux.org.uk> <20100817141210.GJ12184@atomide.com> <20100817154035.GD20325@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="2hMgfIw2X+zgXrFs" Return-path: Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:57116 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751447Ab0HSHiU (ORCPT ); Thu, 19 Aug 2010 03:38:20 -0400 Content-Disposition: inline In-Reply-To: <20100817154035.GD20325@n2100.arm.linux.org.uk> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Russell King - ARM Linux Cc: linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, bryan.wu@canonical.com --2hMgfIw2X+zgXrFs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline * Russell King - ARM Linux [100817 18:33]: > On Tue, Aug 17, 2010 at 05:12:11PM +0300, Tony Lindgren wrote: > > Great, will give it a try hopefully tomorrow. Sounds like that's the way > > to deal with fixing up things when booting up older UP ARMv6 without the > > 32v6 support :) > > What I've also been debating about is adding another word to the > smpalt structure, that being a set of flags which denote the situation > where the alternative should be used. > > That means we can use it to do individual word replacements for SMP vs > UP, ARMv6 vs ARMv6k etc. Sounds good to me. Maybe it should then be called cpualt instead of smpalt? Tried booting your patch and needed the following fix for Cortex-A8 UP. Now it boots to the following error: Machine configuration botched (nr -1073741824), unable to continue. Does some struct size need to be changed or something? Regards, Tony --2hMgfIw2X+zgXrFs Content-Type: text/x-diff; charset=us-ascii Content-Disposition: inline; filename="smp-on-up-fix.patch" From: Tony Lindgren Date: Thu, 19 Aug 2010 10:22:23 +0300 Subject: [PATCH] Fix smp_on_up detection This is needed to detect UP properly on older ARMv7 like Cortex-A8. Signed-off-by: Tony Lindgren --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -346,8 +346,10 @@ __fixup_smp: bne smp_on_up @ no, assume UP mrc p15, 0, r0, c0, c0, 5 @ read MIDR movs r0, r0, lsr #30 - teqne r0, #3 @ check top two bits 00 or 11 - moveq pc, lr + teq r0, #0 @ check two top bits 00 + beq smp_on_up @ yes, assume UP + teq r0, #3 @ check top two bits 11 + movne pc, lr @ no, running on SMP hw smp_on_up: adr r0, 1f --2hMgfIw2X+zgXrFs-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Thu, 19 Aug 2010 10:38:11 +0300 Subject: [PATCH 0/4] Hacks to allow booting ARM SMP kernel on UP ARMv7 In-Reply-To: <20100817154035.GD20325@n2100.arm.linux.org.uk> References: <20100817104414.19061.38999.stgit@baageli.muru.com> <20100817135205.GC20325@n2100.arm.linux.org.uk> <20100817141210.GJ12184@atomide.com> <20100817154035.GD20325@n2100.arm.linux.org.uk> Message-ID: <20100819073810.GR12184@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Russell King - ARM Linux [100817 18:33]: > On Tue, Aug 17, 2010 at 05:12:11PM +0300, Tony Lindgren wrote: > > Great, will give it a try hopefully tomorrow. Sounds like that's the way > > to deal with fixing up things when booting up older UP ARMv6 without the > > 32v6 support :) > > What I've also been debating about is adding another word to the > smpalt structure, that being a set of flags which denote the situation > where the alternative should be used. > > That means we can use it to do individual word replacements for SMP vs > UP, ARMv6 vs ARMv6k etc. Sounds good to me. Maybe it should then be called cpualt instead of smpalt? Tried booting your patch and needed the following fix for Cortex-A8 UP. Now it boots to the following error: Machine configuration botched (nr -1073741824), unable to continue. Does some struct size need to be changed or something? Regards, Tony -------------- next part -------------- A non-text attachment was scrubbed... Name: smp-on-up-fix.patch Type: text/x-diff Size: 667 bytes Desc: not available URL: