From patchwork Tue Feb 2 18:26:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 8193481 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 1A3FEBEEE5 for ; Tue, 2 Feb 2016 18:27:28 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2E750202D1 for ; Tue, 2 Feb 2016 18:27:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FB91202E9 for ; Tue, 2 Feb 2016 18:27:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751980AbcBBS1W (ORCPT ); Tue, 2 Feb 2016 13:27:22 -0500 Received: from foss.arm.com ([217.140.101.70]:57777 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756784AbcBBS1C (ORCPT ); Tue, 2 Feb 2016 13:27:02 -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 7B28E3F8; Tue, 2 Feb 2016 10:26:18 -0800 (PST) Received: from e104818-lin.cambridge.arm.com (e104818-lin.cambridge.arm.com [10.1.203.148]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C19C13F246; Tue, 2 Feb 2016 10:27:00 -0800 (PST) Date: Tue, 2 Feb 2016 18:26:58 +0000 From: Catalin Marinas To: Lorenzo Pieralisi Cc: linux-arm-kernel@lists.infradead.org, Mark Rutland , Mark Salter , Will Deacon , linux-acpi@vger.kernel.org, Hanjun Guo , Sudeep Holla , Al Stone , Loc Ho Subject: Re: [PATCH v3] ARM64: kernel: implement ACPI parking protocol Message-ID: <20160202182657.GC15706@e104818-lin.cambridge.arm.com> References: <1453806638-23167-1-git-send-email-lorenzo.pieralisi@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1453806638-23167-1-git-send-email-lorenzo.pieralisi@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Tue, Jan 26, 2016 at 11:10:38AM +0000, Lorenzo Pieralisi wrote: > The SBBR and ACPI specifications allow ACPI based systems that do not > implement PSCI (eg systems with no EL3) to boot through the ACPI parking > protocol specification[1]. > > This patch implements the ACPI parking protocol CPU operations, and adds > code that eases parsing the parking protocol data structures to the > ARM64 SMP initializion carried out at the same time as cpus enumeration. > > To wake-up the CPUs from the parked state, this patch implements a > wakeup IPI for ARM64 (ie arch_send_wakeup_ipi_mask()) that mirrors the > ARM one, so that a specific IPI is sent for wake-up purpose in order > to distinguish it from other IPI sources. > > Given the current ACPI MADT parsing API, the patch implements a glue > layer that helps passing MADT GICC data structure from SMP initialization > code to the parking protocol implementation somewhat overriding the CPU > operations interfaces. This to avoid creating a completely trasparent > DT/ACPI CPU operations layer that would require creating opaque > structure handling for CPUs data (DT represents CPU through DT nodes, ACPI > through static MADT table entries), which seems overkill given that ACPI > on ARM64 mandates only two booting protocols (PSCI and parking protocol), > so there is no need for further protocol additions. > > Based on the original work by Mark Salter > > [1] https://acpica.org/sites/acpica/files/MP%20Startup%20for%20ARM%20platforms.docx > > Signed-off-by: Lorenzo Pieralisi > Cc: Will Deacon > Cc: Hanjun Guo > Cc: Loc Ho > Cc: Sudeep Holla > Cc: Catalin Marinas > Cc: Mark Rutland > Cc: Mark Salter > Cc: Al Stone Applied, with a minor addition just to warn people from not using it in other configurations (#ifdef still needed otherwise the acpi_parking_protocol_valid symbol is not available; but I prefer uglier code than people starting to use this IPI in their firmware): Thanks. --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -767,6 +767,12 @@ void handle_IPI(int ipinr, struct pt_regs *regs) break; #endif + +#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL case IPI_WAKEUP: + WARN_ONCE(!acpi_parking_protocol_valid(cpu), + "CPU%u: Wake-up IPI outside the ACPI parking protocol\n", + cpu); break; +#endif default: