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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/devicetree/bindings/cpu | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'Documentation/devicetree/bindings/cpu')
-rw-r--r-- | Documentation/devicetree/bindings/cpu/cpu-topology.txt | 553 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/cpu/idle-states.yaml | 855 |
2 files changed, 1408 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/cpu/cpu-topology.txt b/Documentation/devicetree/bindings/cpu/cpu-topology.txt new file mode 100644 index 000000000..9bd530a35 --- /dev/null +++ b/Documentation/devicetree/bindings/cpu/cpu-topology.txt @@ -0,0 +1,553 @@ +=========================================== +CPU topology binding description +=========================================== + +=========================================== +1 - Introduction +=========================================== + +In a SMP system, the hierarchy of CPUs is defined through three entities that +are used to describe the layout of physical CPUs in the system: + +- socket +- cluster +- core +- thread + +The bottom hierarchy level sits at core or thread level depending on whether +symmetric multi-threading (SMT) is supported or not. + +For instance in a system where CPUs support SMT, "cpu" nodes represent all +threads existing in the system and map to the hierarchy level "thread" above. +In systems where SMT is not supported "cpu" nodes represent all cores present +in the system and map to the hierarchy level "core" above. + +CPU topology bindings allow one to associate cpu nodes with hierarchical groups +corresponding to the system hierarchy; syntactically they are defined as device +tree nodes. + +Currently, only ARM/RISC-V intend to use this cpu topology binding but it may be +used for any other architecture as well. + +The cpu nodes, as per bindings defined in [4], represent the devices that +correspond to physical CPUs and are to be mapped to the hierarchy levels. + +A topology description containing phandles to cpu nodes that are not compliant +with bindings standardized in [4] is therefore considered invalid. + +=========================================== +2 - cpu-map node +=========================================== + +The ARM/RISC-V CPU topology is defined within the cpu-map node, which is a direct +child of the cpus node and provides a container where the actual topology +nodes are listed. + +- cpu-map node + + Usage: Optional - On SMP systems provide CPUs topology to the OS. + Uniprocessor systems do not require a topology + description and therefore should not define a + cpu-map node. + + Description: The cpu-map node is just a container node where its + subnodes describe the CPU topology. + + Node name must be "cpu-map". + + The cpu-map node's parent node must be the cpus node. + + The cpu-map node's child nodes can be: + + - one or more cluster nodes or + - one or more socket nodes in a multi-socket system + + Any other configuration is considered invalid. + +The cpu-map node can only contain 4 types of child nodes: + +- socket node +- cluster node +- core node +- thread node + +whose bindings are described in paragraph 3. + +The nodes describing the CPU topology (socket/cluster/core/thread) can +only be defined within the cpu-map node and every core/thread in the +system must be defined within the topology. Any other configuration is +invalid and therefore must be ignored. + +=========================================== +2.1 - cpu-map child nodes naming convention +=========================================== + +cpu-map child nodes must follow a naming convention where the node name +must be "socketN", "clusterN", "coreN", "threadN" depending on the node type +(ie socket/cluster/core/thread) (where N = {0, 1, ...} is the node number; nodes +which are siblings within a single common parent node must be given a unique and +sequential N value, starting from 0). +cpu-map child nodes which do not share a common parent node can have the same +name (ie same number N as other cpu-map child nodes at different device tree +levels) since name uniqueness will be guaranteed by the device tree hierarchy. + +=========================================== +3 - socket/cluster/core/thread node bindings +=========================================== + +Bindings for socket/cluster/cpu/thread nodes are defined as follows: + +- socket node + + Description: must be declared within a cpu-map node, one node + per physical socket in the system. A system can + contain single or multiple physical socket. + The association of sockets and NUMA nodes is beyond + the scope of this bindings, please refer [2] for + NUMA bindings. + + This node is optional for a single socket system. + + The socket node name must be "socketN" as described in 2.1 above. + A socket node can not be a leaf node. + + A socket node's child nodes must be one or more cluster nodes. + + Any other configuration is considered invalid. + +- cluster node + + Description: must be declared within a cpu-map node, one node + per cluster. A system can contain several layers of + clustering within a single physical socket and cluster + nodes can be contained in parent cluster nodes. + + The cluster node name must be "clusterN" as described in 2.1 above. + A cluster node can not be a leaf node. + + A cluster node's child nodes must be: + + - one or more cluster nodes; or + - one or more core nodes + + Any other configuration is considered invalid. + +- core node + + Description: must be declared in a cluster node, one node per core in + the cluster. If the system does not support SMT, core + nodes are leaf nodes, otherwise they become containers of + thread nodes. + + The core node name must be "coreN" as described in 2.1 above. + + A core node must be a leaf node if SMT is not supported. + + Properties for core nodes that are leaf nodes: + + - cpu + Usage: required + Value type: <phandle> + Definition: a phandle to the cpu node that corresponds to the + core node. + + If a core node is not a leaf node (CPUs supporting SMT) a core node's + child nodes can be: + + - one or more thread nodes + + Any other configuration is considered invalid. + +- thread node + + Description: must be declared in a core node, one node per thread + in the core if the system supports SMT. Thread nodes are + always leaf nodes in the device tree. + + The thread node name must be "threadN" as described in 2.1 above. + + A thread node must be a leaf node. + + A thread node must contain the following property: + + - cpu + Usage: required + Value type: <phandle> + Definition: a phandle to the cpu node that corresponds to + the thread node. + +=========================================== +4 - Example dts +=========================================== + +Example 1 (ARM 64-bit, 16-cpu system, two clusters of clusters in a single +physical socket): + +cpus { + #size-cells = <0>; + #address-cells = <2>; + + cpu-map { + socket0 { + cluster0 { + cluster0 { + core0 { + thread0 { + cpu = <&CPU0>; + }; + thread1 { + cpu = <&CPU1>; + }; + }; + + core1 { + thread0 { + cpu = <&CPU2>; + }; + thread1 { + cpu = <&CPU3>; + }; + }; + }; + + cluster1 { + core0 { + thread0 { + cpu = <&CPU4>; + }; + thread1 { + cpu = <&CPU5>; + }; + }; + + core1 { + thread0 { + cpu = <&CPU6>; + }; + thread1 { + cpu = <&CPU7>; + }; + }; + }; + }; + + cluster1 { + cluster0 { + core0 { + thread0 { + cpu = <&CPU8>; + }; + thread1 { + cpu = <&CPU9>; + }; + }; + core1 { + thread0 { + cpu = <&CPU10>; + }; + thread1 { + cpu = <&CPU11>; + }; + }; + }; + + cluster1 { + core0 { + thread0 { + cpu = <&CPU12>; + }; + thread1 { + cpu = <&CPU13>; + }; + }; + core1 { + thread0 { + cpu = <&CPU14>; + }; + thread1 { + cpu = <&CPU15>; + }; + }; + }; + }; + }; + }; + + CPU0: cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x0>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU1: cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x1>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU2: cpu@100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU3: cpu@101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU4: cpu@10000 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10000>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU5: cpu@10001 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10001>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU6: cpu@10100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU7: cpu@10101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU8: cpu@100000000 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x0>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU9: cpu@100000001 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x1>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU10: cpu@100000100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU11: cpu@100000101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU12: cpu@100010000 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x10000>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU13: cpu@100010001 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x10001>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU14: cpu@100010100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x10100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + CPU15: cpu@100010101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x10101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; +}; + +Example 2 (ARM 32-bit, dual-cluster, 8-cpu system, no SMT): + +cpus { + #size-cells = <0>; + #address-cells = <1>; + + cpu-map { + cluster0 { + core0 { + cpu = <&CPU0>; + }; + core1 { + cpu = <&CPU1>; + }; + core2 { + cpu = <&CPU2>; + }; + core3 { + cpu = <&CPU3>; + }; + }; + + cluster1 { + core0 { + cpu = <&CPU4>; + }; + core1 { + cpu = <&CPU5>; + }; + core2 { + cpu = <&CPU6>; + }; + core3 { + cpu = <&CPU7>; + }; + }; + }; + + CPU0: cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a15"; + reg = <0x0>; + }; + + CPU1: cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a15"; + reg = <0x1>; + }; + + CPU2: cpu@2 { + device_type = "cpu"; + compatible = "arm,cortex-a15"; + reg = <0x2>; + }; + + CPU3: cpu@3 { + device_type = "cpu"; + compatible = "arm,cortex-a15"; + reg = <0x3>; + }; + + CPU4: cpu@100 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x100>; + }; + + CPU5: cpu@101 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x101>; + }; + + CPU6: cpu@102 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x102>; + }; + + CPU7: cpu@103 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x103>; + }; +}; + +Example 3: HiFive Unleashed (RISC-V 64 bit, 4 core system) + +{ + #address-cells = <2>; + #size-cells = <2>; + compatible = "sifive,fu540g", "sifive,fu500"; + model = "sifive,hifive-unleashed-a00"; + + ... + cpus { + #address-cells = <1>; + #size-cells = <0>; + cpu-map { + socket0 { + cluster0 { + core0 { + cpu = <&CPU1>; + }; + core1 { + cpu = <&CPU2>; + }; + core2 { + cpu0 = <&CPU2>; + }; + core3 { + cpu0 = <&CPU3>; + }; + }; + }; + }; + + CPU1: cpu@1 { + device_type = "cpu"; + compatible = "sifive,rocket0", "riscv"; + reg = <0x1>; + } + + CPU2: cpu@2 { + device_type = "cpu"; + compatible = "sifive,rocket0", "riscv"; + reg = <0x2>; + } + CPU3: cpu@3 { + device_type = "cpu"; + compatible = "sifive,rocket0", "riscv"; + reg = <0x3>; + } + CPU4: cpu@4 { + device_type = "cpu"; + compatible = "sifive,rocket0", "riscv"; + reg = <0x4>; + } + } +}; +=============================================================================== +[1] ARM Linux kernel documentation + Documentation/devicetree/bindings/arm/cpus.yaml +[2] Devicetree NUMA binding description + Documentation/devicetree/bindings/numa.txt +[3] RISC-V Linux kernel documentation + Documentation/devicetree/bindings/riscv/cpus.yaml +[4] https://www.devicetree.org/specifications/ diff --git a/Documentation/devicetree/bindings/cpu/idle-states.yaml b/Documentation/devicetree/bindings/cpu/idle-states.yaml new file mode 100644 index 000000000..b8cc826c9 --- /dev/null +++ b/Documentation/devicetree/bindings/cpu/idle-states.yaml @@ -0,0 +1,855 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/cpu/idle-states.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Idle states + +maintainers: + - Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> + - Anup Patel <anup@brainfault.org> + +description: |+ + ========================================== + 1 - Introduction + ========================================== + + ARM and RISC-V systems contain HW capable of managing power consumption + dynamically, where cores can be put in different low-power states (ranging + from simple wfi to power gating) according to OS PM policies. The CPU states + representing the range of dynamic idle states that a processor can enter at + run-time, can be specified through device tree bindings representing the + parameters required to enter/exit specific idle states on a given processor. + + ========================================== + 2 - ARM idle states + ========================================== + + According to the Server Base System Architecture document (SBSA, [3]), the + power states an ARM CPU can be put into are identified by the following list: + + - Running + - Idle_standby + - Idle_retention + - Sleep + - Off + + The power states described in the SBSA document define the basic CPU states on + top of which ARM platforms implement power management schemes that allow an OS + PM implementation to put the processor in different idle states (which include + states listed above; "off" state is not an idle state since it does not have + wake-up capabilities, hence it is not considered in this document). + + Idle state parameters (e.g. entry latency) are platform specific and need to + be characterized with bindings that provide the required information to OS PM + code so that it can build the required tables and use them at runtime. + + The device tree binding definition for ARM idle states is the subject of this + document. + + ========================================== + 3 - RISC-V idle states + ========================================== + + On RISC-V systems, the HARTs (or CPUs) [6] can be put in platform specific + suspend (or idle) states (ranging from simple WFI, power gating, etc). The + RISC-V SBI v0.3 (or higher) [7] hart state management extension provides a + standard mechanism for OS to request HART state transitions. + + The platform specific suspend (or idle) states of a hart can be either + retentive or non-rententive in nature. A retentive suspend state will + preserve HART registers and CSR values for all privilege modes whereas + a non-retentive suspend state will not preserve HART registers and CSR + values. + + =========================================== + 4 - idle-states definitions + =========================================== + + Idle states are characterized for a specific system through a set of + timing and energy related properties, that underline the HW behaviour + triggered upon idle states entry and exit. + + The following diagram depicts the CPU execution phases and related timing + properties required to enter and exit an idle state: + + ..__[EXEC]__|__[PREP]__|__[ENTRY]__|__[IDLE]__|__[EXIT]__|__[EXEC]__.. + | | | | | + + |<------ entry ------->| + | latency | + |<- exit ->| + | latency | + |<-------- min-residency -------->| + |<------- wakeup-latency ------->| + + Diagram 1: CPU idle state execution phases + + EXEC: Normal CPU execution. + + PREP: Preparation phase before committing the hardware to idle mode + like cache flushing. This is abortable on pending wake-up + event conditions. The abort latency is assumed to be negligible + (i.e. less than the ENTRY + EXIT duration). If aborted, CPU + goes back to EXEC. This phase is optional. If not abortable, + this should be included in the ENTRY phase instead. + + ENTRY: The hardware is committed to idle mode. This period must run + to completion up to IDLE before anything else can happen. + + IDLE: This is the actual energy-saving idle period. This may last + between 0 and infinite time, until a wake-up event occurs. + + EXIT: Period during which the CPU is brought back to operational + mode (EXEC). + + entry-latency: Worst case latency required to enter the idle state. The + exit-latency may be guaranteed only after entry-latency has passed. + + min-residency: Minimum period, including preparation and entry, for a given + idle state to be worthwhile energywise. + + wakeup-latency: Maximum delay between the signaling of a wake-up event and the + CPU being able to execute normal code again. If not specified, this is assumed + to be entry-latency + exit-latency. + + These timing parameters can be used by an OS in different circumstances. + + An idle CPU requires the expected min-residency time to select the most + appropriate idle state based on the expected expiry time of the next IRQ + (i.e. wake-up) that causes the CPU to return to the EXEC phase. + + An operating system scheduler may need to compute the shortest wake-up delay + for CPUs in the system by detecting how long will it take to get a CPU out + of an idle state, e.g.: + + wakeup-delay = exit-latency + max(entry-latency - (now - entry-timestamp), 0) + + In other words, the scheduler can make its scheduling decision by selecting + (e.g. waking-up) the CPU with the shortest wake-up delay. + The wake-up delay must take into account the entry latency if that period + has not expired. The abortable nature of the PREP period can be ignored + if it cannot be relied upon (e.g. the PREP deadline may occur much sooner than + the worst case since it depends on the CPU operating conditions, i.e. caches + state). + + An OS has to reliably probe the wakeup-latency since some devices can enforce + latency constraint guarantees to work properly, so the OS has to detect the + worst case wake-up latency it can incur if a CPU is allowed to enter an + idle state, and possibly to prevent that to guarantee reliable device + functioning. + + The min-residency time parameter deserves further explanation since it is + expressed in time units but must factor in energy consumption coefficients. + + The energy consumption of a cpu when it enters a power state can be roughly + characterised by the following graph: + + | + | + | + e | + n | /--- + e | /------ + r | /------ + g | /----- + y | /------ + | ---- + | /| + | / | + | / | + | / | + | / | + | / | + |/ | + -----|-------+---------------------------------- + 0| 1 time(ms) + + Graph 1: Energy vs time example + + The graph is split in two parts delimited by time 1ms on the X-axis. + The graph curve with X-axis values = { x | 0 < x < 1ms } has a steep slope + and denotes the energy costs incurred while entering and leaving the idle + state. + The graph curve in the area delimited by X-axis values = {x | x > 1ms } has + shallower slope and essentially represents the energy consumption of the idle + state. + + min-residency is defined for a given idle state as the minimum expected + residency time for a state (inclusive of preparation and entry) after + which choosing that state become the most energy efficient option. A good + way to visualise this, is by taking the same graph above and comparing some + states energy consumptions plots. + + For sake of simplicity, let's consider a system with two idle states IDLE1, + and IDLE2: + + | + | + | + | /-- IDLE1 + e | /--- + n | /---- + e | /--- + r | /-----/--------- IDLE2 + g | /-------/--------- + y | ------------ /---| + | / /---- | + | / /--- | + | / /---- | + | / /--- | + | --- | + | / | + | / | + |/ | time + ---/----------------------------+------------------------ + |IDLE1-energy < IDLE2-energy | IDLE2-energy < IDLE1-energy + | + IDLE2-min-residency + + Graph 2: idle states min-residency example + + In graph 2 above, that takes into account idle states entry/exit energy + costs, it is clear that if the idle state residency time (i.e. time till next + wake-up IRQ) is less than IDLE2-min-residency, IDLE1 is the better idle state + choice energywise. + + This is mainly down to the fact that IDLE1 entry/exit energy costs are lower + than IDLE2. + + However, the lower power consumption (i.e. shallower energy curve slope) of + idle state IDLE2 implies that after a suitable time, IDLE2 becomes more energy + efficient. + + The time at which IDLE2 becomes more energy efficient than IDLE1 (and other + shallower states in a system with multiple idle states) is defined + IDLE2-min-residency and corresponds to the time when energy consumption of + IDLE1 and IDLE2 states breaks even. + + The definitions provided in this section underpin the idle states + properties specification that is the subject of the following sections. + + =========================================== + 5 - idle-states node + =========================================== + + The processor idle states are defined within the idle-states node, which is + a direct child of the cpus node [1] and provides a container where the + processor idle states, defined as device tree nodes, are listed. + + On ARM systems, it is a container of processor idle states nodes. If the + system does not provide CPU power management capabilities, or the processor + just supports idle_standby, an idle-states node is not required. + + =========================================== + 6 - References + =========================================== + + [1] ARM Linux Kernel documentation - CPUs bindings + Documentation/devicetree/bindings/arm/cpus.yaml + + [2] ARM Linux Kernel documentation - PSCI bindings + Documentation/devicetree/bindings/arm/psci.yaml + + [3] ARM Server Base System Architecture (SBSA) + http://infocenter.arm.com/help/index.jsp + + [4] ARM Architecture Reference Manuals + http://infocenter.arm.com/help/index.jsp + + [5] ARM Linux Kernel documentation - Booting AArch64 Linux + Documentation/arm64/booting.rst + + [6] RISC-V Linux Kernel documentation - CPUs bindings + Documentation/devicetree/bindings/riscv/cpus.yaml + + [7] RISC-V Supervisor Binary Interface (SBI) + http://github.com/riscv/riscv-sbi-doc/riscv-sbi.adoc + +properties: + $nodename: + const: idle-states + + entry-method: + description: | + Usage and definition depend on ARM architecture version. + + On ARM v8 64-bit this property is required. + On ARM 32-bit systems this property is optional + + This assumes that the "enable-method" property is set to "psci" in the cpu + node[5] that is responsible for setting up CPU idle management in the OS + implementation. + const: psci + +patternProperties: + "^(cpu|cluster)-": + type: object + description: | + Each state node represents an idle state description and must be defined + as follows. + + The idle state entered by executing the wfi instruction (idle_standby + SBSA,[3][4]) is considered standard on all ARM and RISC-V platforms and + therefore must not be listed. + + In addition to the properties listed above, a state node may require + additional properties specific to the entry-method defined in the + idle-states node. Please refer to the entry-method bindings + documentation for properties definitions. + + properties: + compatible: + enum: + - arm,idle-state + - riscv,idle-state + + arm,psci-suspend-param: + $ref: /schemas/types.yaml#/definitions/uint32 + description: | + power_state parameter to pass to the ARM PSCI suspend call. + + Device tree nodes that require usage of PSCI CPU_SUSPEND function + (i.e. idle states node with entry-method property is set to "psci") + must specify this property. + + riscv,sbi-suspend-param: + $ref: /schemas/types.yaml#/definitions/uint32 + description: | + suspend_type parameter to pass to the RISC-V SBI HSM suspend call. + + This property is required in idle state nodes of device tree meant + for RISC-V systems. For more details on the suspend_type parameter + refer the SBI specifiation v0.3 (or higher) [7]. + + local-timer-stop: + description: + If present the CPU local timer control logic is + lost on state entry, otherwise it is retained. + type: boolean + + entry-latency-us: + description: + Worst case latency in microseconds required to enter the idle state. + + exit-latency-us: + description: + Worst case latency in microseconds required to exit the idle state. + The exit-latency-us duration may be guaranteed only after + entry-latency-us has passed. + + min-residency-us: + description: + Minimum residency duration in microseconds, inclusive of preparation + and entry, for this idle state to be considered worthwhile energy wise + (refer to section 2 of this document for a complete description). + + wakeup-latency-us: + description: | + Maximum delay between the signaling of a wake-up event and the CPU + being able to execute normal code again. If omitted, this is assumed + to be equal to: + + entry-latency-us + exit-latency-us + + It is important to supply this value on systems where the duration of + PREP phase (see diagram 1, section 2) is non-neglibigle. In such + systems entry-latency-us + exit-latency-us will exceed + wakeup-latency-us by this duration. + + idle-state-name: + $ref: /schemas/types.yaml#/definitions/string + description: + A string used as a descriptive name for the idle state. + + additionalProperties: false + + required: + - compatible + - entry-latency-us + - exit-latency-us + - min-residency-us + +additionalProperties: false + +examples: + - | + + cpus { + #size-cells = <0>; + #address-cells = <2>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x0>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_0_0>, <&CPU_SLEEP_0_0>, + <&CLUSTER_RETENTION_0>, <&CLUSTER_SLEEP_0>; + }; + + cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x1>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_0_0>, <&CPU_SLEEP_0_0>, + <&CLUSTER_RETENTION_0>, <&CLUSTER_SLEEP_0>; + }; + + cpu@100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x100>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_0_0>, <&CPU_SLEEP_0_0>, + <&CLUSTER_RETENTION_0>, <&CLUSTER_SLEEP_0>; + }; + + cpu@101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x101>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_0_0>, <&CPU_SLEEP_0_0>, + <&CLUSTER_RETENTION_0>, <&CLUSTER_SLEEP_0>; + }; + + cpu@10000 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10000>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_0_0>, <&CPU_SLEEP_0_0>, + <&CLUSTER_RETENTION_0>, <&CLUSTER_SLEEP_0>; + }; + + cpu@10001 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10001>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_0_0>, <&CPU_SLEEP_0_0>, + <&CLUSTER_RETENTION_0>, <&CLUSTER_SLEEP_0>; + }; + + cpu@10100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10100>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_0_0>, <&CPU_SLEEP_0_0>, + <&CLUSTER_RETENTION_0>, <&CLUSTER_SLEEP_0>; + }; + + cpu@10101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10101>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_0_0>, <&CPU_SLEEP_0_0>, + <&CLUSTER_RETENTION_0>, <&CLUSTER_SLEEP_0>; + }; + + cpu@100000000 { + device_type = "cpu"; + compatible = "arm,cortex-a53"; + reg = <0x1 0x0>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_1_0>, <&CPU_SLEEP_1_0>, + <&CLUSTER_RETENTION_1>, <&CLUSTER_SLEEP_1>; + }; + + cpu@100000001 { + device_type = "cpu"; + compatible = "arm,cortex-a53"; + reg = <0x1 0x1>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_1_0>, <&CPU_SLEEP_1_0>, + <&CLUSTER_RETENTION_1>, <&CLUSTER_SLEEP_1>; + }; + + cpu@100000100 { + device_type = "cpu"; + compatible = "arm,cortex-a53"; + reg = <0x1 0x100>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_1_0>, <&CPU_SLEEP_1_0>, + <&CLUSTER_RETENTION_1>, <&CLUSTER_SLEEP_1>; + }; + + cpu@100000101 { + device_type = "cpu"; + compatible = "arm,cortex-a53"; + reg = <0x1 0x101>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_1_0>, <&CPU_SLEEP_1_0>, + <&CLUSTER_RETENTION_1>, <&CLUSTER_SLEEP_1>; + }; + + cpu@100010000 { + device_type = "cpu"; + compatible = "arm,cortex-a53"; + reg = <0x1 0x10000>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_1_0>, <&CPU_SLEEP_1_0>, + <&CLUSTER_RETENTION_1>, <&CLUSTER_SLEEP_1>; + }; + + cpu@100010001 { + device_type = "cpu"; + compatible = "arm,cortex-a53"; + reg = <0x1 0x10001>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_1_0>, <&CPU_SLEEP_1_0>, + <&CLUSTER_RETENTION_1>, <&CLUSTER_SLEEP_1>; + }; + + cpu@100010100 { + device_type = "cpu"; + compatible = "arm,cortex-a53"; + reg = <0x1 0x10100>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_1_0>, <&CPU_SLEEP_1_0>, + <&CLUSTER_RETENTION_1>, <&CLUSTER_SLEEP_1>; + }; + + cpu@100010101 { + device_type = "cpu"; + compatible = "arm,cortex-a53"; + reg = <0x1 0x10101>; + enable-method = "psci"; + cpu-idle-states = <&CPU_RETENTION_1_0>, <&CPU_SLEEP_1_0>, + <&CLUSTER_RETENTION_1>, <&CLUSTER_SLEEP_1>; + }; + + idle-states { + entry-method = "psci"; + + CPU_RETENTION_0_0: cpu-retention-0-0 { + compatible = "arm,idle-state"; + arm,psci-suspend-param = <0x0010000>; + entry-latency-us = <20>; + exit-latency-us = <40>; + min-residency-us = <80>; + }; + + CLUSTER_RETENTION_0: cluster-retention-0 { + compatible = "arm,idle-state"; + local-timer-stop; + arm,psci-suspend-param = <0x1010000>; + entry-latency-us = <50>; + exit-latency-us = <100>; + min-residency-us = <250>; + wakeup-latency-us = <130>; + }; + + CPU_SLEEP_0_0: cpu-sleep-0-0 { + compatible = "arm,idle-state"; + local-timer-stop; + arm,psci-suspend-param = <0x0010000>; + entry-latency-us = <250>; + exit-latency-us = <500>; + min-residency-us = <950>; + }; + + CLUSTER_SLEEP_0: cluster-sleep-0 { + compatible = "arm,idle-state"; + local-timer-stop; + arm,psci-suspend-param = <0x1010000>; + entry-latency-us = <600>; + exit-latency-us = <1100>; + min-residency-us = <2700>; + wakeup-latency-us = <1500>; + }; + + CPU_RETENTION_1_0: cpu-retention-1-0 { + compatible = "arm,idle-state"; + arm,psci-suspend-param = <0x0010000>; + entry-latency-us = <20>; + exit-latency-us = <40>; + min-residency-us = <90>; + }; + + CLUSTER_RETENTION_1: cluster-retention-1 { + compatible = "arm,idle-state"; + local-timer-stop; + arm,psci-suspend-param = <0x1010000>; + entry-latency-us = <50>; + exit-latency-us = <100>; + min-residency-us = <270>; + wakeup-latency-us = <100>; + }; + + CPU_SLEEP_1_0: cpu-sleep-1-0 { + compatible = "arm,idle-state"; + local-timer-stop; + arm,psci-suspend-param = <0x0010000>; + entry-latency-us = <70>; + exit-latency-us = <100>; + min-residency-us = <300>; + wakeup-latency-us = <150>; + }; + + CLUSTER_SLEEP_1: cluster-sleep-1 { + compatible = "arm,idle-state"; + local-timer-stop; + arm,psci-suspend-param = <0x1010000>; + entry-latency-us = <500>; + exit-latency-us = <1200>; + min-residency-us = <3500>; + wakeup-latency-us = <1300>; + }; + }; + }; + + - | + // Example 2 (ARM 32-bit, 8-cpu system, two clusters): + + cpus { + #size-cells = <0>; + #address-cells = <1>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a15"; + reg = <0x0>; + cpu-idle-states = <&cpu_sleep_0_0>, <&cluster_sleep_0>; + }; + + cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a15"; + reg = <0x1>; + cpu-idle-states = <&cpu_sleep_0_0>, <&cluster_sleep_0>; + }; + + cpu@2 { + device_type = "cpu"; + compatible = "arm,cortex-a15"; + reg = <0x2>; + cpu-idle-states = <&cpu_sleep_0_0>, <&cluster_sleep_0>; + }; + + cpu@3 { + device_type = "cpu"; + compatible = "arm,cortex-a15"; + reg = <0x3>; + cpu-idle-states = <&cpu_sleep_0_0>, <&cluster_sleep_0>; + }; + + cpu@100 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x100>; + cpu-idle-states = <&cpu_sleep_1_0>, <&cluster_sleep_1>; + }; + + cpu@101 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x101>; + cpu-idle-states = <&cpu_sleep_1_0>, <&cluster_sleep_1>; + }; + + cpu@102 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x102>; + cpu-idle-states = <&cpu_sleep_1_0>, <&cluster_sleep_1>; + }; + + cpu@103 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x103>; + cpu-idle-states = <&cpu_sleep_1_0>, <&cluster_sleep_1>; + }; + + idle-states { + cpu_sleep_0_0: cpu-sleep-0-0 { + compatible = "arm,idle-state"; + local-timer-stop; + entry-latency-us = <200>; + exit-latency-us = <100>; + min-residency-us = <400>; + wakeup-latency-us = <250>; + }; + + cluster_sleep_0: cluster-sleep-0 { + compatible = "arm,idle-state"; + local-timer-stop; + entry-latency-us = <500>; + exit-latency-us = <1500>; + min-residency-us = <2500>; + wakeup-latency-us = <1700>; + }; + + cpu_sleep_1_0: cpu-sleep-1-0 { + compatible = "arm,idle-state"; + local-timer-stop; + entry-latency-us = <300>; + exit-latency-us = <500>; + min-residency-us = <900>; + wakeup-latency-us = <600>; + }; + + cluster_sleep_1: cluster-sleep-1 { + compatible = "arm,idle-state"; + local-timer-stop; + entry-latency-us = <800>; + exit-latency-us = <2000>; + min-residency-us = <6500>; + wakeup-latency-us = <2300>; + }; + }; + }; + + - | + // Example 3 (RISC-V 64-bit, 4-cpu systems, two clusters): + + cpus { + #size-cells = <0>; + #address-cells = <1>; + + cpu@0 { + device_type = "cpu"; + compatible = "riscv"; + reg = <0x0>; + riscv,isa = "rv64imafdc"; + mmu-type = "riscv,sv48"; + cpu-idle-states = <&CPU_RET_0_0>, <&CPU_NONRET_0_0>, + <&CLUSTER_RET_0>, <&CLUSTER_NONRET_0>; + + cpu_intc0: interrupt-controller { + #interrupt-cells = <1>; + compatible = "riscv,cpu-intc"; + interrupt-controller; + }; + }; + + cpu@1 { + device_type = "cpu"; + compatible = "riscv"; + reg = <0x1>; + riscv,isa = "rv64imafdc"; + mmu-type = "riscv,sv48"; + cpu-idle-states = <&CPU_RET_0_0>, <&CPU_NONRET_0_0>, + <&CLUSTER_RET_0>, <&CLUSTER_NONRET_0>; + + cpu_intc1: interrupt-controller { + #interrupt-cells = <1>; + compatible = "riscv,cpu-intc"; + interrupt-controller; + }; + }; + + cpu@10 { + device_type = "cpu"; + compatible = "riscv"; + reg = <0x10>; + riscv,isa = "rv64imafdc"; + mmu-type = "riscv,sv48"; + cpu-idle-states = <&CPU_RET_1_0>, <&CPU_NONRET_1_0>, + <&CLUSTER_RET_1>, <&CLUSTER_NONRET_1>; + + cpu_intc10: interrupt-controller { + #interrupt-cells = <1>; + compatible = "riscv,cpu-intc"; + interrupt-controller; + }; + }; + + cpu@11 { + device_type = "cpu"; + compatible = "riscv"; + reg = <0x11>; + riscv,isa = "rv64imafdc"; + mmu-type = "riscv,sv48"; + cpu-idle-states = <&CPU_RET_1_0>, <&CPU_NONRET_1_0>, + <&CLUSTER_RET_1>, <&CLUSTER_NONRET_1>; + + cpu_intc11: interrupt-controller { + #interrupt-cells = <1>; + compatible = "riscv,cpu-intc"; + interrupt-controller; + }; + }; + + idle-states { + CPU_RET_0_0: cpu-retentive-0-0 { + compatible = "riscv,idle-state"; + riscv,sbi-suspend-param = <0x10000000>; + entry-latency-us = <20>; + exit-latency-us = <40>; + min-residency-us = <80>; + }; + + CPU_NONRET_0_0: cpu-nonretentive-0-0 { + compatible = "riscv,idle-state"; + riscv,sbi-suspend-param = <0x90000000>; + entry-latency-us = <250>; + exit-latency-us = <500>; + min-residency-us = <950>; + }; + + CLUSTER_RET_0: cluster-retentive-0 { + compatible = "riscv,idle-state"; + riscv,sbi-suspend-param = <0x11000000>; + local-timer-stop; + entry-latency-us = <50>; + exit-latency-us = <100>; + min-residency-us = <250>; + wakeup-latency-us = <130>; + }; + + CLUSTER_NONRET_0: cluster-nonretentive-0 { + compatible = "riscv,idle-state"; + riscv,sbi-suspend-param = <0x91000000>; + local-timer-stop; + entry-latency-us = <600>; + exit-latency-us = <1100>; + min-residency-us = <2700>; + wakeup-latency-us = <1500>; + }; + + CPU_RET_1_0: cpu-retentive-1-0 { + compatible = "riscv,idle-state"; + riscv,sbi-suspend-param = <0x10000010>; + entry-latency-us = <20>; + exit-latency-us = <40>; + min-residency-us = <80>; + }; + + CPU_NONRET_1_0: cpu-nonretentive-1-0 { + compatible = "riscv,idle-state"; + riscv,sbi-suspend-param = <0x90000010>; + entry-latency-us = <250>; + exit-latency-us = <500>; + min-residency-us = <950>; + }; + + CLUSTER_RET_1: cluster-retentive-1 { + compatible = "riscv,idle-state"; + riscv,sbi-suspend-param = <0x11000010>; + local-timer-stop; + entry-latency-us = <50>; + exit-latency-us = <100>; + min-residency-us = <250>; + wakeup-latency-us = <130>; + }; + + CLUSTER_NONRET_1: cluster-nonretentive-1 { + compatible = "riscv,idle-state"; + riscv,sbi-suspend-param = <0x91000010>; + local-timer-stop; + entry-latency-us = <600>; + exit-latency-us = <1100>; + min-residency-us = <2700>; + wakeup-latency-us = <1500>; + }; + }; + }; + +... |