From patchwork Tue Aug 28 15:51:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10578769 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4C2BB14BD for ; Tue, 28 Aug 2018 16:00:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 391252A638 for ; Tue, 28 Aug 2018 16:00:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 368A42A678; Tue, 28 Aug 2018 16:00:43 +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,RCVD_IN_DNSWL_NONE 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 8CF9A2A638 for ; Tue, 28 Aug 2018 16:00:42 +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=cG9xlcgeBwniMeGQDrKi8GMNNJpoJIzdnl2Hz8C6qbM=; b=K+KdsTMX/nx5fvIkcj8BzFXekQ Y8HjMhVbs6uzHDUyAN/HZ4oWuUmY2Z0yWR+KITiHFFo23Bp9myk2nJYSkkHVpjbicJS6EFMG7gbBw 7OhhDqJgedBESfGwLGB6z43XNCf4Fy165+Rjxr5zerbiUwdt2ZNfypJC6/kesVLJ5eCLR3oZ7BhqZ HThGBNtowc4rM/tQtuL3rFOhcNkOS64xuuBMcwPgChVIlL0rnBCKsStn8InWxmMDb5KLkVs7HnTAi KvyUpeCPJrDfF5hSLdMMoDAFe4HQniV+XEEQqKSO9C5UM7nByIylwvyeZx/oR93mEaJ3WX5JOZPXe JEOLm8mw==; 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 1fugPt-0002Cx-8t; Tue, 28 Aug 2018 16:00:29 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fugHw-00058P-Ln for linux-arm-kernel@lists.infradead.org; Tue, 28 Aug 2018 15:52:18 +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 9DC1BED1; Tue, 28 Aug 2018 08:52:16 -0700 (PDT) Received: from e112298-lin.Emea.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 AF97B3F557; Tue, 28 Aug 2018 08:52:14 -0700 (PDT) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 12/27] arm64: Unmask PMR before going idle Date: Tue, 28 Aug 2018 16:51:22 +0100 Message-Id: <1535471497-38854-13-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1535471497-38854-1-git-send-email-julien.thierry@arm.com> References: <1535471497-38854-1-git-send-email-julien.thierry@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180828_085216_785642_5CB1900E X-CRM114-Status: GOOD ( 12.89 ) 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. Tested-by: Daniel Thompson 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(+) -- 1.9.1 diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 03646e6..cc1caf7 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)