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984638e443
Adding bindings to represent a virtual cpufreq device. Virtual machines may expose MMIO regions for a virtual cpufreq device for guests to read performance information or to request performance selection. The virtual cpufreq device has an individual controller for each performance 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 <saravanak@google.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Signed-off-by: David Dai <davidai@google.com> Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
49 lines
1.3 KiB
YAML
49 lines
1.3 KiB
YAML
# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
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%YAML 1.2
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---
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$id: http://devicetree.org/schemas/cpufreq/qemu,virtual-cpufreq.yaml#
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$schema: http://devicetree.org/meta-schemas/core.yaml#
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title: Virtual CPUFreq
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maintainers:
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- David Dai <davidai@google.com>
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- Saravana Kannan <saravanak@google.com>
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description:
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Virtual CPUFreq is a virtualized driver in guest kernels that sends performance
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selection of its vCPUs as a hint to the host through MMIO regions. Each vCPU
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is associated with a performance domain which can be shared with other vCPUs.
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Each performance domain has its own set of registers for performance controls.
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properties:
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compatible:
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const: qemu,virtual-cpufreq
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reg:
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maxItems: 1
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description:
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Address and size of region containing performance controls for each of the
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performance domains. Regions for each performance domain is placed
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contiguously and contain registers for controlling DVFS(Dynamic Frequency
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and Voltage) characteristics. The size of the region is proportional to
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total number of performance domains.
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required:
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- compatible
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- reg
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additionalProperties: false
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examples:
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- |
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soc {
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#address-cells = <1>;
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#size-cells = <1>;
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cpufreq@1040000 {
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compatible = "qemu,virtual-cpufreq";
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reg = <0x1040000 0x2000>;
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};
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};
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