From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F0EAC432C1 for ; Wed, 25 Sep 2019 02:59:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF642214AF for ; Wed, 25 Sep 2019 02:59:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2411425AbfIYC7m (ORCPT ); Tue, 24 Sep 2019 22:59:42 -0400 Received: from foss.arm.com ([217.140.110.172]:40410 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727934AbfIYC7l (ORCPT ); Tue, 24 Sep 2019 22:59:41 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 60B3F1570; Tue, 24 Sep 2019 19:59:40 -0700 (PDT) Received: from localhost.localdomain (entos-thunderx2-02.shanghai.arm.com [10.169.40.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 19A4B3F694; Tue, 24 Sep 2019 19:59:34 -0700 (PDT) From: Jia He To: Catalin Marinas , Will Deacon , Mark Rutland , James Morse , Marc Zyngier , Matthew Wilcox , "Kirill A. Shutemov" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Suzuki Poulose Cc: Punit Agrawal , Anshuman Khandual , Alex Van Brunt , Robin Murphy , Thomas Gleixner , Andrew Morton , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Ralph Campbell , hejianet@gmail.com, Kaly Xin , nd@arm.com, Jia He Subject: [PATCH v9 1/3] arm64: cpufeature: introduce helper cpu_has_hw_af() Date: Wed, 25 Sep 2019 10:59:20 +0800 Message-Id: <20190925025922.176362-2-justin.he@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190925025922.176362-1-justin.he@arm.com> References: <20190925025922.176362-1-justin.he@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We unconditionally set the HW_AFDBM capability and only enable it on CPUs which really have the feature. But sometimes we need to know whether this cpu has the capability of HW AF. So decouple AF from DBM by new helper cpu_has_hw_af(). Signed-off-by: Jia He Suggested-by: Suzuki Poulose Reported-by: kbuild test robot Reviewed-by: Catalin Marinas --- arch/arm64/include/asm/cpufeature.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index c96ffa4722d3..c2e3abd39faa 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -667,6 +667,16 @@ static inline u32 id_aa64mmfr0_parange_to_phys_shift(int parange) default: return CONFIG_ARM64_PA_BITS; } } + +/* Check whether hardware update of the Access flag is supported */ +static inline bool cpu_has_hw_af(void) +{ + if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM)) + return read_cpuid(ID_AA64MMFR1_EL1) & 0xf; + + return false; +} + #endif /* __ASSEMBLY__ */ #endif -- 2.17.1