+ 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'.