From patchwork Tue Aug 27 21:38:13 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Dooks X-Patchwork-Id: 2850394 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 275269F271 for ; Tue, 27 Aug 2013 21:41:05 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 605D520412 for ; Tue, 27 Aug 2013 21:41:04 +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 5D60F20413 for ; Tue, 27 Aug 2013 21:41:03 +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 1VEQzj-0003RE-A2; Tue, 27 Aug 2013 21:40:11 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEQzP-0006YS-Ki; Tue, 27 Aug 2013 21:39:51 +0000 Received: from 82-68-191-81.dsl.posilan.com ([82.68.191.81] helo=rainbowdash.ducie.codethink.co.uk) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEQyW-0006QX-IQ for linux-arm-kernel@lists.infradead.org; Tue, 27 Aug 2013 21:39:04 +0000 Received: from ben by rainbowdash.ducie.codethink.co.uk with local (Exim 4.80) (envelope-from ) id 1VEQy7-0005wo-BA; Tue, 27 Aug 2013 22:38:31 +0100 From: Ben Dooks To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 03/19] ARM: fixup_pv_table bug when CPU_ENDIAN_BE8 Date: Tue, 27 Aug 2013 22:38:13 +0100 Message-Id: <1377639509-22778-4-git-send-email-ben.dooks@codethink.co.uk> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1377639509-22778-1-git-send-email-ben.dooks@codethink.co.uk> References: <1377639509-22778-1-git-send-email-ben.dooks@codethink.co.uk> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130827_173857_270295_29A856B1 X-CRM114-Status: GOOD ( 12.22 ) X-Spam-Score: -0.3 (/) Cc: Ben Dooks 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-6.7 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 The fixup_pv_table assumes that the instructions are in the same endian configuration as the data, but when the CPU is running in BE8 the instructions stay in little-endian format. Make sure if CONFIG_CPU_ENDIAN_BE8 is set that we do all the alterations to the instructions taking in to account the LDR/STR will be swapping the data endian-ness. Since the code is only modifying a byte, we avoid dual-swapping the data, and just change the bits we clear and ORR in (in the case where the code is not thumb2). For thumb2, we add the necessary rev16 instructions to ensure that the instructions are processed in the correct format, as it was easier than re-writing the code to contain a mask and shift. Signed-off-by: Ben Dooks Reviewed-by: Dave Martin --- arch/arm/kernel/head.S | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 2c7cc1e..9e5906c 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -582,8 +582,10 @@ __fixup_a_pv_table: b 2f 1: add r7, r3 ldrh ip, [r7, #2] +ARM_BE8(rev16 ip, ip) and ip, 0x8f00 orr ip, r6 @ mask in offset bits 31-24 +ARM_BE8(rev16 ip, ip) strh ip, [r7, #2] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot @@ -592,8 +594,14 @@ __fixup_a_pv_table: #else b 2f 1: ldr ip, [r7, r3] +#ifdef CONFIG_CPU_ENDIAN_BE8 + @ in BE8, we load data in BE, but instructions still in LE + bic ip, ip, #0xff000000 + orr ip, ip, r6, lsl#24 +#else bic ip, ip, #0x000000ff orr ip, ip, r6 @ mask in offset bits 31-24 +#endif str ip, [r7, r3] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot