From patchwork Thu May 8 18:48:25 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Elder X-Patchwork-Id: 4138211 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 5DFF4BFF02 for ; Thu, 8 May 2014 18:51:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2369F20212 for ; Thu, 8 May 2014 18:51:05 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E2B4D2018B for ; Thu, 8 May 2014 18:51:03 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WiTNE-0005hm-9W; Thu, 08 May 2014 18:48:52 +0000 Received: from mail-ig0-f170.google.com ([209.85.213.170]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WiTNA-0005ZM-CD for linux-arm-kernel@lists.infradead.org; Thu, 08 May 2014 18:48:49 +0000 Received: by mail-ig0-f170.google.com with SMTP id r10so1200692igi.3 for ; Thu, 08 May 2014 11:48:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=SiuwnZdkw6gbOQEdzYFokdW2cDD4gzVzcoyDCj8ShZw=; b=Cmdrci3a22oEvD+nM7yn03LOGmqbKkz/Xf8r2r5+zWpTJQ2xh3oNrrldtM3CR+gKwI tHsgV5y0VucbRnDsAshAEoX59bIDiSO6oA5tLNiUmzcq2+vFFGrHvxj00IucF5F317da nHYSG0dF9sEeeSFw5bKym7NnlTAcpB4nHbhkib7jZhXBY/XktFn58alclNp4I8HNAR6H 7ACDn/CHtpQB+3EzAWCropp83l2vUwm/7z8ZczrBW+ipCu3/BH7dFRTvxJD4w6P0NX7F weK62RkAU3mUEfbJWwoDjpB5sUqfPWMKSy+xna+ksZTd8xLVC1BqYKn1f0qAS1W7kddZ IvDA== X-Gm-Message-State: ALoCoQmYmoZ/5OEKyORoIlBGbl/x/tkgl0LL9NfliGy0l69OPa1NOsQXUV4GSVXLqO76AaY/6bcJ X-Received: by 10.50.114.4 with SMTP id jc4mr11062874igb.33.1399574903919; Thu, 08 May 2014 11:48:23 -0700 (PDT) Received: from localhost.localdomain (c-71-195-31-37.hsd1.mn.comcast.net. [71.195.31.37]) by mx.google.com with ESMTPSA id ql7sm679926igc.19.2014.05.08.11.48.21 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 08 May 2014 11:48:22 -0700 (PDT) From: Alex Elder To: devicetree@vger.kernel.org Subject: [PATCH v2] devicetree: bindings: separate CPU enable method descriptions Date: Thu, 8 May 2014 13:48:25 -0500 Message-Id: <1399574905-6478-1-git-send-email-elder@linaro.org> X-Mailer: git-send-email 1.9.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140508_114848_498412_6466239E X-CRM114-Status: GOOD ( 16.38 ) X-Spam-Score: -0.7 (/) Cc: mark.rutland@arm.com, lorenzo.pieralisi@arm.com, jason@lakedaemon.net, pawel.moll@arm.com, ijc+devicetree@hellion.org.uk, linux-kernel@vger.kernel.org, rdunlap@infradead.org, sboyd@codeaurora.org, rvaswani@codeaurora.org, linux-doc@vger.kernel.org, robh+dt@kernel.org, galak@codeaurora.org, gregory.clement@free-electrons.com, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,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 The bindings for CPU enable methods are defined in ".../arm/cpus.txt". As additional 32-bit ARM CPUS are converted to use the "enable-method" CPU property to imply a particular set of SMP operations to use, the list of these methods is likely to become unwieldy. The current documentation already contains several property descriptions that are meaningful only for certain enable methods. This patch defines a new Documentation subdirectory whose purpose is to give each CPU enable method its own place to define how and when it's used, as well as what other properties (optional or required) are associated with the method. The existing enable method documentation is expanded and moved from ".../arm/cpus.txt" into new files accordingly. Signed-off-by: Alex Elder --- v2: Rename "arm,psci.txt" to be "psci.txt" and fix its content .../bindings/arm/cpu-enable-method/README | 20 +++++ .../bindings/arm/cpu-enable-method/psci.txt | 45 ++++++++++ .../arm/cpu-enable-method/qcom,gcc-msm8660 | 30 +++++++ .../arm/cpu-enable-method/qcom,kpss-acc-v1 | 56 +++++++++++++ .../arm/cpu-enable-method/qcom,kpss-acc-v2 | 56 +++++++++++++ .../bindings/arm/cpu-enable-method/spin-table.txt | 95 ++++++++++++++++++++++ Documentation/devicetree/bindings/arm/cpus.txt | 29 +------ 7 files changed, 305 insertions(+), 26 deletions(-) create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/README create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/psci.txt create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,gcc-msm8660 create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,kpss-acc-v1 create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,kpss-acc-v2 create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/spin-table.txt diff --git a/Documentation/devicetree/bindings/arm/cpu-enable-method/README b/Documentation/devicetree/bindings/arm/cpu-enable-method/README new file mode 100644 index 0000000..cc9431e --- /dev/null +++ b/Documentation/devicetree/bindings/arm/cpu-enable-method/README @@ -0,0 +1,20 @@ +========================== +CPU enable-method bindings +========================== + +The device tree describes the layout of CPUs in a machine in a single "cpus" +node, which in turn contains a number of "cpu" sub-nodes defining properties +for each cpu. + +For multiprocessing configurations, CPU cores can be individually enabled +and disabled. The enabling capability is used for SMP startup as well as +CPU hotplug. A CPU enable method--normally specified in the device tree +using an "enable-method" property--defines how cores are enabled. If all +CPUs in a machine use the same enable method and related property values, +these properties should be defined in the "cpus" node, which associates the +property values with all CPUs. Alternatively, every "cpu" node can define +its "enable-method" separately. + +Documents in this directory define how each of the CPU enable methods are to +be used, as well the names and possible values of related properties that +are required by or affect each enable method. diff --git a/Documentation/devicetree/bindings/arm/cpu-enable-method/psci.txt b/Documentation/devicetree/bindings/arm/cpu-enable-method/psci.txt new file mode 100644 index 0000000..68b26c2 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/cpu-enable-method/psci.txt @@ -0,0 +1,45 @@ +================================ +CPU enable-method "psci" binding +================================ + +This document describes the "psci" method for enabling secondary CPUs. A +"psci" enable method is supported only in individual "cpu" nodes (even if + all CPU cores use the "psci" enable method). + +Enable method name: "psci" +Compatible cpus: "arm,cortex-a57" (?) +Related properties: (none) + +Note: +This enable method is only available if a valid PSCI node[1] (compatible +with "arm,psci") is present in the device tree, and it defines a "cpu_on" +property. + +Example (contrived 2-core ARM Cortex-A57 64-bit system): + + psci { + compatible = "arm,psci"; + method = "smc"; + cpu_on = 0x1; + }; + cpus { + #size-cells = <0>; + #address-cells = <2>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x0>; + enable-method = "psci"; + }; + + cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x1>; + enable-method = "psci"; + }; + }; + +-- +[1] arm/psci.txt diff --git a/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,gcc-msm8660 b/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,gcc-msm8660 new file mode 100644 index 0000000..b19f51c --- /dev/null +++ b/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,gcc-msm8660 @@ -0,0 +1,30 @@ +====================================================== +Secondary CPU enable-method "qcom,gcc-msm8660" binding +====================================================== + +This document describes the "qcom,gcc-msm8660" method for enabling secondary +CPUs. A "qcom,gcc-msm8660" enable method should only be used in the "cpus" +node, to apply to all CPUs. + +Enable method name: "qcom,gcc-msm8660" +Compatible cpu: "qcom,scorpion" +Related properties: (none) + +Example: + + cpus { + #address-cells = <1>; + #size-cells = <0>; + compatible = "qcom,scorpion"; + enable-method = "qcom,gcc-msm8660"; + + cpu@0 { + device_type = "cpu"; + reg = <0>; + }; + + cpu@1 { + device_type = "cpu"; + reg = <1>; + }; + }; diff --git a/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,kpss-acc-v1 b/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,kpss-acc-v1 new file mode 100644 index 0000000..3f6ce56 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,kpss-acc-v1 @@ -0,0 +1,56 @@ +====================================================== +Secondary CPU enable-method "qcom,kpss-acc-v1" binding +====================================================== + +This document describes the "qcom,kpss-acc-v1" method for enabling CPUs. +This enable method can be used in either the "cpus" node or in individual +"cpu" nodes. Note that each "cpu" node must have both "qcom,saw" and +"qcom,acc" properties defined (even if the "enable-method" property was +defined only in the "cpus" node). + +Enable method name: "qcom,kpss-acc-v1" +Compatible machine: "qcom,msm8960" +Compatible cpu: "qcom,krait" +Related properties: + - qcom,saw + Usage: required (in each "cpu" node") + Value type: + Definition: + Specifies the SAW[1] node associated with this CPU. + + - qcom,acc + Usage: required (in each "cpu" node") + Value type: + Definition: + Specifies the ACC[2] node associated with this CPU. + +Example: + +/ { + compatible = "qcom,msm8960"; + + cpus { + #address-cells = <1>; + #size-cells = <0>; + compatible = "qcom,krait"; + enable-method = "qcom,kpss-acc-v1"; + + cpu@0 { + device_type = "cpu"; + reg = <0>; + qcom,acc = <&acc0>; + qcom,saw = <&saw0>; + }; + + cpu@1 { + device_type = "cpu"; + reg = <1>; + qcom,acc = <&acc1>; + qcom,saw = <&saw1>; + }; + }; +}; + +-- +[1] arm/msm/qcom,saw2.txt +[2] arm/msm/qcom,kpss-acc.txt diff --git a/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,kpss-acc-v2 b/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,kpss-acc-v2 new file mode 100644 index 0000000..4368d904 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/cpu-enable-method/qcom,kpss-acc-v2 @@ -0,0 +1,56 @@ +====================================================== +Secondary CPU enable-method "qcom,kpss-acc-v2" binding +====================================================== + +This document describes the "qcom,kpss-acc-v2" method for enabling CPUs. +This enable method can be used in either the "cpus" node or in individual +"cpu" nodes. Note that each "cpu" node must have both "qcom,saw" and +"qcom,acc" properties defined (even if the "enable-method" property was +defined only in the "cpus" node). + +Enable method name: "qcom,kpss-acc-v2" +Compatible machine: "qcom,msm8974" +Compatible cpu: "qcom,krait" +Related properties: + - qcom,saw + Usage: required (in each "cpu" node") + Value type: + Definition: + Specifies the SAW[1] node associated with this CPU. + + - qcom,acc + Usage: required (in each "cpu" node") + Value type: + Definition: + Specifies the ACC[2] node associated with this CPU. + +Example: + +/ { + compatible = "qcom,msm8974"; + + cpus { + #address-cells = <1>; + #size-cells = <0>; + compatible = "qcom,krait"; + enable-method = "qcom,kpss-acc-v2"; + + cpu@0 { + device_type = "cpu"; + reg = <0>; + qcom,acc = <&acc0>; + qcom,saw = <&saw0>; + }; + + cpu@1 { + device_type = "cpu"; + reg = <1>; + qcom,acc = <&acc1>; + qcom,saw = <&saw1>; + }; + }; +}; + +-- +[1] arm/msm/qcom,saw2.txt +[2] arm/msm/qcom,kpss-acc.txt diff --git a/Documentation/devicetree/bindings/arm/cpu-enable-method/spin-table.txt b/Documentation/devicetree/bindings/arm/cpu-enable-method/spin-table.txt new file mode 100644 index 0000000..aee3617 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/cpu-enable-method/spin-table.txt @@ -0,0 +1,95 @@ +================================================ +Secondary CPU enable-method "spin-table" binding +================================================ + +This document describes the "spin-table" method for enabling secondary CPUs. +A "spin-table" enable method can be used in either the "cpus" node or in +individual "cpu" nodes. + +Enable method name: "spin-table" +Compatible cpus: "arm,cortex-a57" (?) +Related properties: + - cpu-release-addr + Usage: required + Value type: + Definition: + A two cell value identifying a 64-bit memory location + used by the boot CPU to inform a secondary CPU it + should begin its kernel bootstrap. Memory at this + location must initially be zeroed. + +Examples (contrived 4-core ARM Cortex-A57 64-bit systems): + +The first example uses the same enable method for all cores. + + cpus { + #size-cells = <0>; + #address-cells = <2>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x0>; + }; + + cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x1>; + }; + + cpu@100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x100>; + }; + + cpu@101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x101>; + }; + }; + + +The second example uses specifies distinct enable method properties for each +CPU core. + + cpus { + #size-cells = <0>; + #address-cells = <2>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x0>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x1>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000008>; + }; + + cpu@100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000010>; + }; + + cpu@101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000018>; + }; + }; diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt index 333f4ae..2bb2a3e 100644 --- a/Documentation/devicetree/bindings/arm/cpus.txt +++ b/Documentation/devicetree/bindings/arm/cpus.txt @@ -185,30 +185,8 @@ nodes to be present and contain the properties described below. "qcom,gcc-msm8660" "qcom,kpss-acc-v1" "qcom,kpss-acc-v2" - - - cpu-release-addr - Usage: required for systems that have an "enable-method" - property value of "spin-table". - Value type: - Definition: - # On ARM v8 64-bit systems must be a two cell - property identifying a 64-bit zero-initialised - memory location. - - - qcom,saw - Usage: required for systems that have an "enable-method" - property value of "qcom,kpss-acc-v1" or - "qcom,kpss-acc-v2" - Value type: - Definition: Specifies the SAW[1] node associated with this CPU. - - - qcom,acc - Usage: required for systems that have an "enable-method" - property value of "qcom,kpss-acc-v1" or - "qcom,kpss-acc-v2" - Value type: - Definition: Specifies the ACC[2] node associated with this CPU. - + Details about use of these CPU enable methods is documented + elsewhere[1]. Example 1 (dual-cluster big.LITTLE system 32-bit): @@ -403,5 +381,4 @@ cpus { }; -- -[1] arm/msm/qcom,saw2.txt -[2] arm/msm/qcom,kpss-acc.txt +[1] arm/cpu-enable-method/