From patchwork Sat Jan 27 00:43:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Dai X-Patchwork-Id: 767004 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 31F123D75 for ; Sat, 27 Jan 2024 00:43:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706316215; cv=none; b=Rl0iIQnM8mgY/Oj1SRilBmLvAipMqOKl3OJCcJiV9GTrnHFx0NeP3Pvc6MtGOXW5RAq1K5MQMFjHuCW6fEWm9UMOzviAeHqFzVnKvxcicP1SWe0jN7GcMD5G+US+aL6B5VqzroBQCuI8359yQin1wHQuDNnkRYAWYtUzEx9o1FY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706316215; c=relaxed/simple; bh=FLh37MtrGgxAZbOEtksVIMPeDxGh9lhShCJV0PP9zsA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=e7aIf/Y4IsjolX3GY6R2pPof3MhKIt0AaviBtbaqg7zjsho8kUJqIEXGhkRt3VQ2ZtbYeZ7iWSZC9yLebuufCq8dbNQ3CBl1E1KgsA+5nRpUCIsRCMbVU7bMqprR4TiPztuy70w7j3cBPw0rZUcvljd5lBKYXQ4+LpeRssEhpFo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--davidai.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=g8rS4Tr6; arc=none smtp.client-ip=209.85.219.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--davidai.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="g8rS4Tr6" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-dbe9e13775aso1369250276.1 for ; Fri, 26 Jan 2024 16:43:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1706316213; x=1706921013; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=vWcySjj6Okvs9yBn0W41qrIqSKP3wnCoOn0mL6uTY9k=; b=g8rS4Tr6cxN0qQ6y2ez5wRpJwQe8CttNRVm8XTSa/Umc4aDOOTPUN7qfMQv6kGqeyF VcEK/H8W8zYzVMNsfCMOIwWgVA0mZrXu+hMIMYEuB2Ern+20nIfXgGBDtUCLCJJWkWMm 0RcnpUK/KTHP42JFjErPSzBILCte7CdafjxK+vZopc3e8HrWT/H/6bK6lTJ4QkXDffXh WD20W+vXe6KP0V8VhqiNlvEQgWxAsyZU/gesJvNKOXhOrtNJpzioM9vI1izRyZUlJgwM jX6hoANKrCMuaVTuCVy6xtWX70XBDOMdl5dKfi66YDcPTRU5NoPy2OwTXoQcxSEvzPkx J+eQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706316213; x=1706921013; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=vWcySjj6Okvs9yBn0W41qrIqSKP3wnCoOn0mL6uTY9k=; b=Z2ynmVO5MxkIkoEcicx/Bl7vIoEQ08G8esoCb1tSo1GeSSDDB/Hnv73xEEh9QqZvO3 K3igX4yyIDPoq9dsPMjb99G81fBmtiyxMTJp4r3/uuphaWdAOw4q/MX+ISGCceAxJLUy wlNJChHNtMQ6DkMrT4a1i5pjVDLtLNFW4xdTH8oPIdR8a/dRouNKJ+BAvhrWpMzbHu8V h7tjB61ihbwxOK3B8yy7oGqQnTi6spvFufP4l9YKX686PEJSaAadURnqlD7WhQNFPA8d KVGDKSdeiWLLbainVfjww3+kupnQdxUZUo0zzU2o1v7mgkhgAMGLrQAMFk6vqiHdCXLL 0bzA== X-Gm-Message-State: AOJu0Yx+5sZJ3j4pdH5kwSUHrhe98k4CZfoCrF0Z/jxKi/gVvVLCOAEL nLtdOUvtidZzcAadNCJMRDk84zJ4olWcCvyxZi/bH3L79jZ1vCTqCH1WPNBIa8VFL2/rTc5ep5P Q4b1ZrQ== X-Google-Smtp-Source: AGHT+IHE75xRExeRW8631Xw+f5EC+Wzp3aOn5SVy5OmK0nm2p16TAsb9X9xJgRY4CGuHCaB1HiVAMZrps4aD X-Received: from davidai2.mtv.corp.google.com ([2620:15c:211:201:d621:88fa:6f6:1b46]) (user=davidai job=sendgmr) by 2002:a05:6902:2489:b0:dc2:2d2c:962a with SMTP id ds9-20020a056902248900b00dc22d2c962amr348609ybb.8.1706316213251; Fri, 26 Jan 2024 16:43:33 -0800 (PST) Date: Fri, 26 Jan 2024 16:43:15 -0800 In-Reply-To: <20240127004321.1902477-1-davidai@google.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240127004321.1902477-1-davidai@google.com> X-Mailer: git-send-email 2.43.0.429.g432eaa2c6b-goog Message-ID: <20240127004321.1902477-2-davidai@google.com> Subject: [PATCH v5 1/2] dt-bindings: cpufreq: add virtual cpufreq device From: David Dai To: "Rafael J. Wysocki" , Viresh Kumar , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Sudeep Holla , David Dai , Saravana Kannan Cc: Quentin Perret , Masami Hiramatsu , Will Deacon , Peter Zijlstra , Vincent Guittot , Marc Zyngier , Oliver Upton , Dietmar Eggemann , Pavan Kondeti , Gupta Pankaj , Mel Gorman , kernel-team@android.com, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Adding bindings to represent a virtual cpufreq device. Virtual machines may expose MMIO regions for a virtual cpufreq device for guests to read frequency information or to request frequency selection. The virtual cpufreq device has an individual controller for each frequency domain. Performance points for a given domain can be normalized across all domains for ease of allowing for virtual machines to migrate between hosts. Co-developed-by: Saravana Kannan Signed-off-by: Saravana Kannan Signed-off-by: David Dai --- .../cpufreq/qemu,cpufreq-virtual.yaml | 110 ++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 Documentation/devicetree/bindings/cpufreq/qemu,cpufreq-virtual.yaml diff --git a/Documentation/devicetree/bindings/cpufreq/qemu,cpufreq-virtual.yaml b/Documentation/devicetree/bindings/cpufreq/qemu,cpufreq-virtual.yaml new file mode 100644 index 000000000000..cd617baf75e7 --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/qemu,cpufreq-virtual.yaml @@ -0,0 +1,110 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/cpufreq/qemu,cpufreq-virtual.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Virtual CPUFreq + +maintainers: + - David Dai + - Saravana Kannan + +description: + Virtual CPUFreq is a virtualized driver in guest kernels that sends frequency + selection of its vCPUs as a hint to the host through MMIO regions. Each vCPU + is associated with a frequency domain which can be shared with other vCPUs. + Each frequency domain has its own set of registers for frequency controls. + +properties: + compatible: + const: qemu,virtual-cpufreq + + reg: + maxItems: 1 + description: + Address and size of region containing frequency controls for each of the + frequency domains. Regions for each frequency domain is placed + contiguously and contain registers for controlling DVFS(Dynamic Frequency + and Voltage) characteristics. The size of the region is proportional to + total number of frequency domains. This device also needs the CPUs to + list their OPPs using operating-points-v2 tables. The OPP tables for the + CPUs should use normalized "frequency" values where the OPP with the + highest performance among all the vCPUs is listed as 1024 KHz. The rest + of the frequencies of all the vCPUs should be normalized based on their + performance relative to that 1024 KHz OPP. This makes it much easier to + migrate the VM across systems which might have different physical CPU + OPPs. + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + // This example shows a two CPU configuration with a frequency domain + // for each CPU showing normalized performance points. + cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu@0 { + compatible = "arm,armv8"; + device_type = "cpu"; + reg = <0x0>; + operating-points-v2 = <&opp_table0>; + }; + + cpu@1 { + compatible = "arm,armv8"; + device_type = "cpu"; + reg = <0x0>; + operating-points-v2 = <&opp_table1>; + }; + }; + + opp_table0: opp-table-0 { + compatible = "operating-points-v2"; + + opp64000 { opp-hz = /bits/ 64 <64000>; }; + opp128000 { opp-hz = /bits/ 64 <128000>; }; + opp192000 { opp-hz = /bits/ 64 <192000>; }; + opp256000 { opp-hz = /bits/ 64 <256000>; }; + opp320000 { opp-hz = /bits/ 64 <320000>; }; + opp384000 { opp-hz = /bits/ 64 <384000>; }; + opp425000 { opp-hz = /bits/ 64 <425000>; }; + }; + + opp_table1: opp-table-1 { + compatible = "operating-points-v2"; + + opp64000 { opp-hz = /bits/ 64 <64000>; }; + opp128000 { opp-hz = /bits/ 64 <128000>; }; + opp192000 { opp-hz = /bits/ 64 <192000>; }; + opp256000 { opp-hz = /bits/ 64 <256000>; }; + opp320000 { opp-hz = /bits/ 64 <320000>; }; + opp384000 { opp-hz = /bits/ 64 <384000>; }; + opp448000 { opp-hz = /bits/ 64 <448000>; }; + opp512000 { opp-hz = /bits/ 64 <512000>; }; + opp576000 { opp-hz = /bits/ 64 <576000>; }; + opp640000 { opp-hz = /bits/ 64 <640000>; }; + opp704000 { opp-hz = /bits/ 64 <704000>; }; + opp768000 { opp-hz = /bits/ 64 <768000>; }; + opp832000 { opp-hz = /bits/ 64 <832000>; }; + opp896000 { opp-hz = /bits/ 64 <896000>; }; + opp960000 { opp-hz = /bits/ 64 <960000>; }; + opp1024000 { opp-hz = /bits/ 64 <1024000>; }; + + }; + + soc { + #address-cells = <1>; + #size-cells = <1>; + + cpufreq@1040000 { + compatible = "qemu,virtual-cpufreq"; + reg = <0x1040000 0x10>; + }; + };