Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936485AbcLMRRG (ORCPT ); Tue, 13 Dec 2016 12:17:06 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:57290 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936327AbcLMRQr (ORCPT ); Tue, 13 Dec 2016 12:16:47 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Benjamin Herrenschmidt , "Aneesh Kumar K.V" , Michael Ellerman Subject: [PATCH 4.8 02/33] powerpc/mm: Fix lazy icache flush on pre-POWER5 Date: Tue, 13 Dec 2016 09:16:03 -0800 Message-Id: <20161213171534.268668279@linuxfoundation.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161213171534.171564506@linuxfoundation.org> References: <20161213171534.171564506@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2558 Lines: 73 4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Herrenschmidt commit dd7b2f035ec41a409f7a7cec7aabc0ec0eacf476 upstream. On 64-bit CPUs with no-execute support and non-snooping icache, such as 970 or POWER4, we have a software mechanism to ensure coherency of the cache (using exec faults when needed). This was broken due to a logic error when the code was rewritten from assembly to C, previously the assembly code did: BEGIN_FTR_SECTION mr r4,r30 mr r5,r7 bl hash_page_do_lazy_icache END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE) Which tests that: (cpu_features & (NOEXECUTE | COHERENT_ICACHE)) == NOEXECUTE Which says that the current cpu does have NOEXECUTE, but does not have COHERENT_ICACHE. Fixes: 91f1da99792a ("powerpc/mm: Convert 4k hash insert to C") Fixes: 89ff725051d1 ("powerpc/mm: Convert __hash_page_64K to C") Fixes: a43c0eb8364c ("powerpc/mm: Convert 4k insert from asm to C") Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Aneesh Kumar K.V [mpe: Change log verbosification] Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/mm/hash64_4k.c | 2 +- arch/powerpc/mm/hash64_64k.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) --- a/arch/powerpc/mm/hash64_4k.c +++ b/arch/powerpc/mm/hash64_4k.c @@ -55,7 +55,7 @@ int __hash_page_4K(unsigned long ea, uns */ rflags = htab_convert_pte_flags(new_pte); - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && + if (cpu_has_feature(CPU_FTR_NOEXECUTE) && !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap); --- a/arch/powerpc/mm/hash64_64k.c +++ b/arch/powerpc/mm/hash64_64k.c @@ -87,7 +87,7 @@ int __hash_page_4K(unsigned long ea, uns subpg_pte = new_pte & ~subpg_prot; rflags = htab_convert_pte_flags(subpg_pte); - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && + if (cpu_has_feature(CPU_FTR_NOEXECUTE) && !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) { /* @@ -258,7 +258,7 @@ int __hash_page_64K(unsigned long ea, un rflags = htab_convert_pte_flags(new_pte); - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && + if (cpu_has_feature(CPU_FTR_NOEXECUTE) && !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);