From patchwork Fri Apr 6 05:21:15 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver O'Halloran X-Patchwork-Id: 895603 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="MPWmKmnp"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40HSjv48N8z9s25 for ; Fri, 6 Apr 2018 15:21:55 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751278AbeDFFVy (ORCPT ); Fri, 6 Apr 2018 01:21:54 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:33487 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750749AbeDFFVx (ORCPT ); Fri, 6 Apr 2018 01:21:53 -0400 Received: by mail-pf0-f194.google.com with SMTP id f15so10157634pfn.0 for ; Thu, 05 Apr 2018 22:21:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=nue+V4PghiS5B/eXo4Rizu2Y5ALzKq9yDVYMT+Kpfdk=; b=MPWmKmnpSH8ot5eJjEghQh4cpFjHHl3KwdwfZ5MP8VAM+Yxx281poc+6pxWWYUsCN/ XOkZZhMnCd+yo9SVpRiXZmmcuIKx0b4tBS6CsgBTOGHiK6O3CrU2RNgE39LRhVEcOADt ME5B20CpWsaJ87Ciz03dYEyELeyzhyk7zg78lm1bcA/Rdvfs9/7t1AqzpSXE//Y5de6T qdrNmGTqeaEvaj57FfXayqUBZaRxut5yBu4ftte59soBARN/Z9ETF3JcN93PV7YS7pF4 x4faYAbn5fTx4ekgtVtZL5BeLA0avWQH6o6dyA/9tK6ReIEfnqb+ezx9Kn2vcAQV0rFK 3oVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=nue+V4PghiS5B/eXo4Rizu2Y5ALzKq9yDVYMT+Kpfdk=; b=ERQKC+lTXeyhGQ1NJr7w34UAkG+hEEbRlNx2C72K8QSB7+iRAKZQyjlgN1tzYxOjTl 3wiwYzbGQ/Y0KcQ7bHb3abpqSjfC6z3twwRTe/yZI3RjAnW2mMFFONXrmB5WCaI2jELW +GrFKy2n7dUrp90d1gGFubaJBNunZLb1PaU92d6SHnVUbfI9bsUd4tOyjUD21vFgUSvU Ud0E+Vp4SfLZnZ0eQ6fC7qrfhTNUH7kkSbpd0yRbzTe8p7Yesu8ZQhUWPP14BDmAS02z jSkccziUg+6Tb3B7LVcarzHIZtM59S+w3PhFslPJffMPHkSZAqXUCru3QwRBHOqS5uvP 0dxg== X-Gm-Message-State: AElRT7GBYg9r2IZH/NnCjhA4eRAjgc3AsTaDtbRIhQQLDA1MEAEPJtNn jGq9bmy/0mamj88OsHhhguJlfg== X-Google-Smtp-Source: AIpwx48sRuErPk1fMqu1RZ3iXDcHwKzg9cz9pS3On6rT8FYZsf94m16rvFDd9Y9UG1cQWiBsBZN1ZA== X-Received: by 10.101.64.7 with SMTP id f7mr16923858pgp.216.1522992112863; Thu, 05 Apr 2018 22:21:52 -0700 (PDT) Received: from flat-canetoad.ozlabs.ibm.com ([122.99.82.10]) by smtp.gmail.com with ESMTPSA id s63sm19748498pfe.6.2018.04.05.22.21.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Apr 2018 22:21:52 -0700 (PDT) From: Oliver O'Halloran To: linuxppc-dev@lists.ozlabs.org Cc: linux-nvdimm@lists.01.org, Oliver O'Halloran , devicetree@vger.kernel.org Subject: [PATCH v3 3/4] doc/devicetree: Persistent memory region bindings Date: Fri, 6 Apr 2018 15:21:15 +1000 Message-Id: <20180406052116.31483-3-oohall@gmail.com> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20180406052116.31483-1-oohall@gmail.com> References: <20180406052116.31483-1-oohall@gmail.com> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Add device-tree binding documentation for the nvdimm region driver. Cc: devicetree@vger.kernel.org Signed-off-by: Oliver O'Halloran Acked-by: Michael Ellerman --- v2: Changed name from nvdimm-region to pmem-region. Cleaned up the example binding and fixed the overlapping regions. Added support for multiple regions in a single reg. v3: Removed platform bus boilerplate from the example. Changed description of the volatile and reg properties to make them more clear. --- .../devicetree/bindings/pmem/pmem-region.txt | 65 ++++++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 66 insertions(+) create mode 100644 Documentation/devicetree/bindings/pmem/pmem-region.txt diff --git a/Documentation/devicetree/bindings/pmem/pmem-region.txt b/Documentation/devicetree/bindings/pmem/pmem-region.txt new file mode 100644 index 000000000000..5cfa4f016a00 --- /dev/null +++ b/Documentation/devicetree/bindings/pmem/pmem-region.txt @@ -0,0 +1,65 @@ +Device-tree bindings for persistent memory regions +----------------------------------------------------- + +Persistent memory refers to a class of memory devices that are: + + a) Usable as main system memory (i.e. cacheable), and + b) Retain their contents across power failure. + +Given b) it is best to think of persistent memory as a kind of memory mapped +storage device. To ensure data integrity the operating system needs to manage +persistent regions separately to the normal memory pool. To aid with that this +binding provides a standardised interface for discovering where persistent +memory regions exist inside the physical address space. + +Bindings for the region nodes: +----------------------------- + +Required properties: + - compatible = "pmem-region" + + - reg = ; + The reg property should specificy an address range that is + translatable to a system physical address range. This address + range should be mappable as normal system memory would be + (i.e cacheable). + + If the reg property contains multiple address ranges + each address range will be treated as though it was specified + in a separate device node. Having multiple address ranges in a + node implies no special relationship between the two ranges. + +Optional properties: + - Any relevant NUMA assocativity properties for the target platform. + + - volatile; This property indicates that this region is actually + backed by non-persistent memory. This lets the OS know that it + may skip the cache flushes required to ensure data is made + persistent after a write. + + If this property is absent then the OS must assume that the region + is backed by non-volatile memory. + +Examples: +-------------------- + + /* + * This node specifies one 4KB region spanning from + * 0x5000 to 0x5fff that is backed by non-volatile memory. + */ + pmem@5000 { + compatible = "pmem-region"; + reg = <0x00005000 0x00001000>; + }; + + /* + * This node specifies two 4KB regions that are backed by + * volatile (normal) memory. + */ + pmem@6000 { + compatible = "pmem-region"; + reg = < 0x00006000 0x00001000 + 0x00008000 0x00001000 >; + volatile; + }; + diff --git a/MAINTAINERS b/MAINTAINERS index df240740ca78..cbd289d58644 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8020,6 +8020,7 @@ L: linux-nvdimm@lists.01.org Q: https://patchwork.kernel.org/project/linux-nvdimm/list/ S: Supported F: drivers/nvdimm/of_pmem.c +F: Documentation/devicetree/bindings/pmem/pmem-region.txt LIBNVDIMM: NON-VOLATILE MEMORY DEVICE SUBSYSTEM M: Dan Williams