Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753603AbbEGKEA (ORCPT ); Thu, 7 May 2015 06:04:00 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:48157 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752990AbbEGJuC (ORCPT ); Thu, 7 May 2015 05:50:02 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mark Rutland , Catalin Marinas , Will Deacon , Luis Henriques Subject: [PATCH 3.16.y-ckt 154/180] arm64: head.S: ensure visibility of page tables Date: Thu, 7 May 2015 10:46:03 +0100 Message-Id: <1430991989-23170-155-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1430991989-23170-1-git-send-email-luis.henriques@canonical.com> References: <1430991989-23170-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2053 Lines: 51 3.16.7-ckt11 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland commit 91d57155dc5ab4b311624b7ee570339b6af19ad5 upstream. After writing the page tables, we use __inval_cache_range to invalidate any stale cache entries. Strongly Ordered memory accesses are not ordered w.r.t. cache maintenance instructions, and hence explicit memory barriers are required to provide this ordering. However, __inval_cache_range was written to be used on Normal Cacheable memory once the MMU and caches are on, and does not have any barriers prior to the DC instructions. This patch adds a DMB between the page tables being written and the corresponding cachelines being invalidated, ensuring that the invalidation makes the new data visible to subsequent cacheable accesses. A barrier is not required before the prior invalidate as we do not access the page table memory area prior to this, and earlier barriers in preserve_boot_args and set_cpu_boot_mode_flag ensures ordering w.r.t. any stores performed prior to entering Linux. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Fixes: c218bca74eeafa2f ("arm64: Relax the kernel cache requirements for boot") Signed-off-by: Will Deacon Signed-off-by: Luis Henriques --- arch/arm64/kernel/head.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index a2c1195abb7f..1cd11e73058f 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -599,6 +599,7 @@ __create_page_tables: */ mov x0, x25 add x1, x26, #SWAPPER_DIR_SIZE + dmb sy bl __inval_cache_range mov lr, x27 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/