From patchwork Sat Jul 27 12:22:21 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 2834621 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 38AC29F243 for ; Sat, 27 Jul 2013 12:23:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6B76A20136 for ; Sat, 27 Jul 2013 12:23:13 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E9C0620134 for ; Sat, 27 Jul 2013 12:23:11 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1V33Wd-0006nF-9c; Sat, 27 Jul 2013 12:23:07 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1V33Wb-0004Wo-4Y; Sat, 27 Jul 2013 12:23:05 +0000 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1V33WX-0004WR-Jc for linux-arm-kernel@lists.infradead.org; Sat, 27 Jul 2013 12:23:02 +0000 Received: from mudshark.cambridge.arm.com (mudshark.cambridge.arm.com [10.1.203.36]) by cam-admin0.cambridge.arm.com (8.12.6/8.12.6) with ESMTP id r6RCMPki009839; Sat, 27 Jul 2013 13:22:25 +0100 (BST) Date: Sat, 27 Jul 2013 13:22:21 +0100 From: Will Deacon To: Paul Walmsley Subject: Re: OMAP2430 SDP boot broken after Linus' rmk merge Message-ID: <20130727122221.GB6618@mudshark.cambridge.arm.com> References: <20130722184325.GA21614@n2100.arm.linux.org.uk> <51EE2AA7.5060503@ti.com> <51EE474D.5070804@ti.com> <20130724135617.GI11072@mudshark.cambridge.arm.com> <51EFE1DD.8070801@ti.com> <20130724142059.GJ11072@mudshark.cambridge.arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130727_082301_862698_6223C79D X-CRM114-Status: GOOD ( 17.39 ) X-Spam-Score: -8.4 (--------) Cc: Russell King - ARM Linux , "linux-omap@vger.kernel.org" , Rajendra Nayak , Santosh Shilimkar , "linux-arm-kernel@lists.infradead.org" X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Sat, Jul 27, 2013 at 05:10:56AM +0100, Paul Walmsley wrote: > > Tonight I put on a Jon Hopkins album, in recollection of my UK ARM Linux > colleagues perhaps, and started testing, and eventually wound up with this > one: > > commit 621a0147d5c921f4cc33636ccd0602ad5d7cbfbc > Author: Will Deacon Oh, great... > Date: Wed Jun 12 12:25:56 2013 +0100 > > ARM: 7757/1: mm: don't flush icache in switch_mm with hardware broadcasting > > When scheduling an mm on a CPU where it hasn't previously been used, we > flush the icache on that CPU so that any code loaded previously on > a different core can be safely executed. > > For cores with hardware broadcasting of cache maintenance operations, > this is clearly unnecessary, since the inner-shareable invalidation in > __sync_icache_dcache will affect all CPUs. > > This patch conditionalises the icache flush in switch_mm based on > cache_ops_need_broadcast(). > > Acked-by: Catalin Marinas > Reported-by: Albin Tonnerre > Signed-off-by: Will Deacon > Signed-off-by: Russell King > > ... > > v3.11-rc2 boots with it reverted. What also works is v3.11-rc2 with the > below patch applied. That's very odd -- I *suspect* your bootloader is up to no good (iirc, we've had issues with the bootloader on this machine in the past, since it enters the kernel in ABT mode or something). > Would be pleased to boot-test anything you'd care to send my way, as long > as you can tolerate response latency jitter. Can you try this quick hack please? It clobbers the I-cache as soon as we enter the kernel, so it should tell us whether my theory is correct. Cheers, Will --->8 diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 9cf6063..d74c64c 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -83,6 +83,9 @@ ENTRY(stext) THUMB( .thumb ) @ switch to Thumb now. THUMB(1: ) + mov r9, #0 + mcr p15, 0, r9, c7, c5, 0 + #ifdef CONFIG_ARM_VIRT_EXT bl __hyp_stub_install #endif