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 A5266C04EB8 for ; Tue, 4 Dec 2018 17:36:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4AD652081C for ; Tue, 4 Dec 2018 17:36:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4AD652081C 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 S1727314AbeLDRgQ (ORCPT ); Tue, 4 Dec 2018 12:36:16 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:37840 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726056AbeLDRgP (ORCPT ); Tue, 4 Dec 2018 12:36:15 -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 36368A78; Tue, 4 Dec 2018 09:36:15 -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 459533F59C; Tue, 4 Dec 2018 09:36:13 -0800 (PST) Date: Tue, 4 Dec 2018 17:36:10 +0000 From: Catalin Marinas To: Julien Thierry Cc: linux-arm-kernel@lists.infradead.org, daniel.thompson@linaro.org, marc.zyngier@arm.com, Ard Biesheuvel , will.deacon@arm.com, linux-kernel@vger.kernel.org, christoffer.dall@arm.com, james.morse@arm.com, Oleg Nesterov , joel@joelfernandes.org Subject: Re: [PATCH v6 10/24] arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking Message-ID: <20181204173610.GC19210@arrakis.emea.arm.com> References: <1542023835-21446-1-git-send-email-julien.thierry@arm.com> <1542023835-21446-11-git-send-email-julien.thierry@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1542023835-21446-11-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 11:57:01AM +0000, Julien Thierry wrote: > diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h > index 24692ed..e0a32e4 100644 > --- a/arch/arm64/include/asm/irqflags.h > +++ b/arch/arm64/include/asm/irqflags.h > @@ -18,7 +18,27 @@ > > #ifdef __KERNEL__ > > +#include > +#include > #include > +#include > + > + > +/* > + * When ICC_PMR_EL1 is used for interrupt masking, only the bit indicating > + * whether the normal interrupts are masked is kept along with the daif > + * flags. > + */ > +#define ARCH_FLAG_PMR_EN 0x1 > + > +#define MAKE_ARCH_FLAGS(daif, pmr) \ > + ((daif) | (((pmr) >> GIC_PRIO_STATUS_SHIFT) & ARCH_FLAG_PMR_EN)) > + > +#define ARCH_FLAGS_GET_PMR(flags) \ > + ((((flags) & ARCH_FLAG_PMR_EN) << GIC_PRIO_STATUS_SHIFT) \ > + | GIC_PRIO_IRQOFF) > + > +#define ARCH_FLAGS_GET_DAIF(flags) ((flags) & ~ARCH_FLAG_PMR_EN) I wonder whether we could just use the PSR_I_BIT here to decide whether to set the GIC_PRIO_IRQ{ON,OFF}. We could clear the PSR_I_BIT in _restore_daif() with an alternative. > +/* > + * CPU interrupt mask handling. > + */ > static inline void arch_local_irq_enable(void) > { > - asm volatile( > - "msr daifclr, #2 // arch_local_irq_enable" > - : > + unsigned long unmasked = GIC_PRIO_IRQON; > + > + asm volatile(ALTERNATIVE( > + "msr daifclr, #2 // arch_local_irq_enable\n" > + "nop", > + "msr_s " __stringify(SYS_ICC_PMR_EL1) ",%0\n" > + "dsb sy", > + ARM64_HAS_IRQ_PRIO_MASKING) DSB needed here as well? I guess I'd have to read the GIC spec before asking again ;). -- Catalin