What: /sys/firmware/sgi_uv/ Date: September 2020 Contact: Justin Ernst Description: The /sys/firmware/sgi_uv directory contains information about the UV platform. Under that directory are a number of read-only attributes:: archtype hub_type hubless partition_id coherence_id uv_type The archtype entry contains the UV architecture type that is used to select arch-dependent addresses and features. It can be set via the OEM_ID in the ACPI MADT table or by UVsystab entry both passed from UV BIOS. The hub_type entry is used to select the type of hub which is similar to uv_type but encoded in a binary format. Include the file uv_hub.h to get the definitions. The hubless entry basically is present and set only if there is no hub. In this case the hub_type entry is not present. The partition_id entry contains the partition id. UV systems can be partitioned into multiple physical machines, which each partition running a unique copy of the operating system. Each partition will have a unique partition id. The coherence_id entry contains the coherence id. A partitioned UV system can have one or more coherence domains. The coherence id indicates which coherence domain this partition is in. The uv_type entry contains the hub revision number. This value can be used to identify the UV system version:: "0.*" = Hubless UV ('*' is subtype) "3.0" = UV2 "5.0" = UV3 "7.0" = UV4 "7.1" = UV4a "9.0" = UV5 The /sys/firmware/sgi_uv directory also contains two directories:: hubs/ pcibuses/ The hubs directory contains a number of hub objects, each representing a UV Hub visible to the BIOS. Each hub object's name is appended by a unique ordinal value (ex. /sys/firmware/sgi_uv/hubs/hub_5) Each hub object directory contains a number of read-only attributes:: cnode location name nasid shared this_partition The cnode entry contains the cnode number of the corresponding hub. If a cnode value is not applicable, the value returned will be -1. The location entry contains the location string of the corresponding hub. This value is used to physically identify a hub within a system. The name entry contains the name of the corresponding hub. This name can be two variants:: "UVHub x.x" = A 'node' ASIC, connecting a CPU to the interconnect fabric. The 'x.x' value represents the ASIC revision. (ex. 'UVHub 5.0') "NLxRouter" = A 'router ASIC, only connecting other ASICs to the interconnect fabric. The 'x' value representing the fabric technology version. (ex. 'NL8Router') The nasid entry contains the nasid number of the corresponding hub. If a nasid value is not applicable, the value returned will be -1. The shared entry contains a boolean value describing whether the corresponding hub is shared between system partitions. The this_partition entry contains a boolean value describing whether the corresponding hub is local to the current partition. Each hub object directory also contains a number of port objects, each representing a fabric port on the corresponding hub. A port object's name is appended by a unique ordinal value (ex. /sys/firmware/sgi_uv/hubs/hub_5/port_3) Each port object directory contains a number of read-only attributes:: conn_hub conn_port The conn_hub entry contains a value representing the unique oridinal value of the hub on the other end of the fabric cable plugged into the port. If the port is disconnected, the value returned will be -1. The conn_port entry contains a value representing the unique oridinal value of the port on the other end of the fabric cable plugged into the port. If the port is disconnected, the value returned will be -1. Ex: A value of '3' is read from: /sys/firmware/sgi_uv/hubs/hub_5/port_3/conn_hub and a value of '6' is read from: /sys/firmware/sgi_uv/hubs/hub_5/port_3/conn_port representing that this port is connected to: /sys/firmware/sgi_uv/hubs/hub_3/port_6 The pcibuses directory contains a number of PCI bus objects. Each PCI bus object's name is appended by its PCI bus address. (ex. pcibus_0003:80) Each pcibus object has a number of possible read-only attributes:: type location slot ppb_addr iio_stack The type entry contains a value describing the type of IO at the corresponding PCI bus address. Known possible values across all UV versions are:: BASE IO PCIe IO PCIe SLOT NODE IO Riser PPB The location entry contains the location string of the UV Hub of the CPU physically connected to the corresponding PCI bus. The slot entry contains the physical slot number of the corresponding PCI bus. This value is used to physically locate PCI cards within a system. The ppb_addr entry contains the PCI address string of the bridged PCI bus. This entry is only present when the PCI bus object type is 'PPB'. The iio_stack entry contains a value describing the IIO stack number that the corresponding PCI bus object is connected to.