Documentation/ABI/testing/sysfs-firmware-sgi_uv

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-firmware-sgi_uv

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-firmware-sgi_uv
Extension
[no extension]
Size
5149 bytes
Lines
160
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

What:		/sys/firmware/sgi_uv/
Date:		September 2020
Contact:	Justin Ernst <justin.ernst@hpe.com>
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.

Annotation

Implementation Notes