From patchwork Fri May 25 09:49:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10426917 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A9EBB601D5 for ; Fri, 25 May 2018 10:06:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9F9332961A for ; Fri, 25 May 2018 10:06:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 92F7C29642; Fri, 25 May 2018 10:06:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E039B2961A for ; Fri, 25 May 2018 10:06:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=KzvpCRgyiOyH99Bco/E1zF9qaRJSFesK147GBoX+cxk=; b=FpBmZDf5EI5brOAuDcCy/IJqO2 /ViCwe3hM4h/DjJt4V2ntT0ma9TDLF1rpPZRk595/0JCIFIyZniRevTfaifgYBHwxpq/2zTvXYdy1 aVyGiCe2ISixhqCYU89wRyTfJIoa0wmB2J2NezXW89V6m/W3k6hD2IIiOd8P1riy5lgs2Wd/B4tts zaS8/F/6RJZVUAnxmaU8fAGPZsAR0qH2jWf1Owaw8wvc7x3SwNX1t8RQ8jEG5rr8NewopxWiDrKvs MjlGoLx2gdvVJfayAZltmAriNlyQ+srTpFY5Awfg8ttJ7bhI47iyYz7CNIgPIEGTHrVBgIhU//T9N RbJgnMtQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fM9cM-00043x-02; Fri, 25 May 2018 10:06:38 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fM9Mz-0007tc-JP for linux-arm-kernel@lists.infradead.org; Fri, 25 May 2018 09:50:49 +0000 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 0F06B1993; Fri, 25 May 2018 02:50:25 -0700 (PDT) Received: from e112298-lin.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 050E53F25D; Fri, 25 May 2018 02:50:22 -0700 (PDT) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 12/26] arm64: Unmask PMR before going idle Date: Fri, 25 May 2018 10:49:18 +0100 Message-Id: <1527241772-48007-13-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1527241772-48007-1-git-send-email-julien.thierry@arm.com> References: <1527241772-48007-1-git-send-email-julien.thierry@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180525_025045_785441_B01E8133 X-CRM114-Status: GOOD ( 11.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, daniel.thompson@linaro.org, Julien Thierry , marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, christoffer.dall@arm.com, james.morse@arm.com, joel@joelfernandes.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP CPU does not received signals for interrupts with a priority masked by ICC_PMR_EL1. This means the CPU might not come back from a WFI instruction. Make sure ICC_PMR_EL1 does not mask interrupts when doing a WFI. Signed-off-by: Julien Thierry Suggested-by: Daniel Thompson Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/mm/proc.S | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 5f9a73a..e7cafbf 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -20,6 +20,7 @@ #include #include +#include #include #include #include @@ -53,10 +54,27 @@ * cpu_do_idle() * * Idle the processor (wait for interrupt). + * + * If the CPU supports priority masking we must do additional work to + * ensure that interrupts are not masked at the PMR (because the core will + * not wake up if we block the wake up signal in the interrupt controller). */ ENTRY(cpu_do_idle) +alternative_if_not ARM64_HAS_IRQ_PRIO_MASKING + dsb sy // WFI may enter a low-power mode + wfi + ret +alternative_else + mrs x0, daif // save I bit + msr daifset, #2 // set I bit + mrs_s x1, SYS_ICC_PMR_EL1 // save PMR +alternative_endif + mov x2, #ICC_PMR_EL1_UNMASKED + msr_s SYS_ICC_PMR_EL1, x2 // unmask at PMR dsb sy // WFI may enter a low-power mode wfi + msr_s SYS_ICC_PMR_EL1, x1 // restore PMR + msr daif, x0 // restore I bit ret ENDPROC(cpu_do_idle)