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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 3CBBEC04EB8 for ; Tue, 4 Dec 2018 17:09:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 059442082B for ; Tue, 4 Dec 2018 17:09:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 059442082B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727180AbeLDRJN (ORCPT ); Tue, 4 Dec 2018 12:09:13 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:37330 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726487AbeLDRJN (ORCPT ); Tue, 4 Dec 2018 12:09:13 -0500 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 2D348A78; Tue, 4 Dec 2018 09:09:13 -0800 (PST) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.113]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 605CF3F614; Tue, 4 Dec 2018 09:09:11 -0800 (PST) Date: Tue, 4 Dec 2018 17:09:08 +0000 From: Catalin Marinas To: Julien Thierry Cc: linux-arm-kernel@lists.infradead.org, daniel.thompson@linaro.org, marc.zyngier@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, christoffer.dall@arm.com, james.morse@arm.com, joel@joelfernandes.org, Dave Martin Subject: Re: [PATCH v6 07/24] arm64: Make PMR part of task context Message-ID: <20181204170908.GB19210@arrakis.emea.arm.com> References: <1542023835-21446-1-git-send-email-julien.thierry@arm.com> <1542023835-21446-8-git-send-email-julien.thierry@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1542023835-21446-8-git-send-email-julien.thierry@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 12, 2018 at 11:56:58AM +0000, Julien Thierry wrote: > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 039144e..eb8120e 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -249,6 +249,12 @@ alternative_else_nop_endif > msr sp_el0, tsk > .endif > > + /* Save pmr */ > +alternative_if ARM64_HAS_IRQ_PRIO_MASKING > + mrs_s x20, SYS_ICC_PMR_EL1 > + str x20, [sp, #S_PMR_SAVE] > +alternative_else_nop_endif > + > /* > * Registers that may be useful after this macro is invoked: > * > @@ -269,6 +275,13 @@ alternative_else_nop_endif > /* No need to restore UAO, it will be restored from SPSR_EL1 */ > .endif > > + /* Restore pmr */ > +alternative_if ARM64_HAS_IRQ_PRIO_MASKING > + ldr x20, [sp, #S_PMR_SAVE] > + msr_s SYS_ICC_PMR_EL1, x20 > + dsb sy > +alternative_else_nop_endif What's this DSB for? If it's needed, please add a comment. I would have expected an ISB (or none at all as we are going to return from an exception). -- Catalin