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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 2E5E0C3A5A4 for ; Sun, 1 Sep 2019 11:22:44 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 043E222CE9 for ; Sun, 1 Sep 2019 11:22:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 043E222CE9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56562 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i4NwR-0005Ot-7O for qemu-devel@archiver.kernel.org; Sun, 01 Sep 2019 07:22:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46945) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i4Nu6-0003mh-MA for qemu-devel@nongnu.org; Sun, 01 Sep 2019 07:20:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i4Nu5-0003Oe-Gy for qemu-devel@nongnu.org; Sun, 01 Sep 2019 07:20:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53192) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i4Nu1-0003J7-UY; Sun, 01 Sep 2019 07:20:14 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 23E71307D88D; Sun, 1 Sep 2019 11:20:13 +0000 (UTC) Received: from [10.36.116.105] (ovpn-116-105.ams2.redhat.com [10.36.116.105]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0488C600C8; Sun, 1 Sep 2019 11:20:09 +0000 (UTC) To: Shameer Kolothum , qemu-devel@nongnu.org, qemu-arm@nongnu.org, imammedo@redhat.com References: <20190813210539.31164-1-shameerali.kolothum.thodi@huawei.com> <20190813210539.31164-11-shameerali.kolothum.thodi@huawei.com> From: Auger Eric Message-ID: Date: Sun, 1 Sep 2019 13:20:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190813210539.31164-11-shameerali.kolothum.thodi@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Sun, 01 Sep 2019 11:20:13 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH-for-4.2 v9 10/12] docs/specs: Add ACPI GED documentation X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, sameo@linux.intel.com, ard.biesheuvel@linaro.org, linuxarm@huawei.com, xuwei5@hisilicon.com, shannon.zhaosl@gmail.com, sebastien.boeuf@intel.com, lersek@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Shameer, On 8/13/19 11:05 PM, Shameer Kolothum wrote: > Documents basic concepts of ACPI Generic Event device(GED) > and interface between QEMU and the ACPI BIOS. > > Signed-off-by: Shameer Kolothum Reviewed-by: Eric Auger Thanks Eric > --- > docs/specs/acpi_hw_reduced_hotplug.txt | 60 ++++++++++++++++++++++++++ > 1 file changed, 60 insertions(+) > create mode 100644 docs/specs/acpi_hw_reduced_hotplug.txt > > diff --git a/docs/specs/acpi_hw_reduced_hotplug.txt b/docs/specs/acpi_hw_reduced_hotplug.txt > new file mode 100644 > index 0000000000..46839be5ff > --- /dev/null > +++ b/docs/specs/acpi_hw_reduced_hotplug.txt > @@ -0,0 +1,60 @@ > +QEMU<->ACPI BIOS Generic Event Device interface > + > +The ACPI Generic Event Device (GED) is a HW reduced platform > +specific device introduced in ACPI v6.1 that handles all platform > +events, including the hotplug ones. GED is modelled as a device > +in the namespace with a _HID defined to be ACPI0013. This document > +describes the interface between QEMU and the ACPI BIOS. > + > +GED allows HW reduced platforms to handle interrupts in ACPI ASL > +statements. It follows a very similar approach like the _EVT method > +from GPIO events. All interrupts are listed in _CRS and the handler > +is written in _EVT method. However, Qemu implementation uses a single > +interrupt for the GED device, relying on IO memory region to communicate > +the type of device affected by the interrupt. This way, we can support > +up to 32 events with a unique interrupt. > + > +Here is an example. > + > +Device (\_SB.GED) > +{ > + Name (_HID, "ACPI0013") > + Name (_UID, Zero) > + Name (_CRS, ResourceTemplate () > + { > + Interrupt (ResourceConsumer, Edge, ActiveHigh, Exclusive, ,, ) > + { > + 0x00000029, > + } > + }) > + OperationRegion (EREG, SystemMemory, 0x09080000, 0x04) > + Field (EREG, DWordAcc, NoLock, WriteAsZeros) > + { > + ESEL, 32 > + } > + Method (_EVT, 1, Serialized) > + { > + Local0 = ESEL // ESEL = IO memory region which specifies the > + // device type. > + If (((Local0 & One) == One)) > + { > + MethodEvent1() > + } > + If ((Local0 & 0x2) == 0x2) > + { > + MethodEvent2() > + } > + ... > + } > +} > + > +GED IO interface (4 byte access): > +read access: > + [0x0-0x3] Event selector bit field(32 bit) set by Qemu. > + bits: > + 1: Memory hotplug event > + 2: System power down event > + 3-31: Reserved > + > +write_access: > + Nothing is expected to be written into GED IO memory >