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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 5F802C43219 for ; Tue, 30 Apr 2019 14:24:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33EBE20835 for ; Tue, 30 Apr 2019 14:24:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727599AbfD3OYA (ORCPT ); Tue, 30 Apr 2019 10:24:00 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:48224 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726303AbfD3OYA (ORCPT ); Tue, 30 Apr 2019 10:24:00 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8AC2280D; Tue, 30 Apr 2019 07:23:59 -0700 (PDT) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AB2183F719; Tue, 30 Apr 2019 07:23:57 -0700 (PDT) Date: Tue, 30 Apr 2019 15:23:55 +0100 From: Will Deacon To: Marc Zyngier , linux@armlinux.org.uk Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas , Mark Rutland , Daniel Lezcano , Wim Van Sebroeck , Guenter Roeck , Valentin Schneider Subject: Re: [PATCH 1/7] ARM: vdso: Remove dependency with the arch_timer driver internals Message-ID: <20190430142355.GF17870@fuggles.cambridge.arm.com> References: <20190408154907.223536-1-marc.zyngier@arm.com> <20190408154907.223536-2-marc.zyngier@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190408154907.223536-2-marc.zyngier@arm.com> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marc, On Mon, Apr 08, 2019 at 04:49:01PM +0100, Marc Zyngier wrote: > THe VDSO code uses the kernel helper that was originally designed > to abstract the access between 32 and 64bit systems. It worked so > far because this function is declared as 'inline'. > > As we're about to revamp that part of the code, the VDSO would > break. Let's fix it by doing what should have been done from > the start, a proper system register access. > > Signed-off-by: Marc Zyngier > --- > arch/arm/include/asm/cp15.h | 2 ++ > arch/arm/vdso/vgettimeofday.c | 5 +++-- > 2 files changed, 5 insertions(+), 2 deletions(-) This looks ok to me and I'd like to take the series via arm64, but I could do with an Ack from Russell on these 32-bit ARM parts first. Will > diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h > index 07e27f212dc7..d2453e2d3f1f 100644 > --- a/arch/arm/include/asm/cp15.h > +++ b/arch/arm/include/asm/cp15.h > @@ -68,6 +68,8 @@ > #define BPIALL __ACCESS_CP15(c7, 0, c5, 6) > #define ICIALLU __ACCESS_CP15(c7, 0, c5, 0) > > +#define CNTVCT __ACCESS_CP15_64(1, c14) > + > extern unsigned long cr_alignment; /* defined in entry-armv.S */ > > static inline unsigned long get_cr(void) > diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c > index a9dd619c6c29..7bdbf5d5c47d 100644 > --- a/arch/arm/vdso/vgettimeofday.c > +++ b/arch/arm/vdso/vgettimeofday.c > @@ -18,9 +18,9 @@ > #include > #include > #include > -#include > #include > #include > +#include > #include > #include > #include > @@ -123,7 +123,8 @@ static notrace u64 get_ns(struct vdso_data *vdata) > u64 cycle_now; > u64 nsec; > > - cycle_now = arch_counter_get_cntvct(); > + isb(); > + cycle_now = read_sysreg(CNTVCT); > > cycle_delta = (cycle_now - vdata->cs_cycle_last) & vdata->cs_mask; > > -- > 2.20.1 >