x86/platform/uv: Update ABI documentation of /sys/firmware/sgi_uv/

Update the ABI documentation to describe the sysfs interface provided by
the new uv_sysfs platform driver.

 [ bp: Merge in kernel-doc warning fixes, see second Link: below. ]

Signed-off-by: Justin Ernst <justin.ernst@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lkml.kernel.org/r/20201125175444.279074-5-justin.ernst@hpe.com
Link: https://lkml.kernel.org/r/20201130214304.369348-1-justin.ernst@hpe.com
This commit is contained in:
Justin Ernst 2020-11-25 11:54:43 -06:00 committed by Borislav Petkov
parent 4fc2cf1f2d
commit c159376490
1 changed files with 130 additions and 14 deletions

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@ -1,27 +1,143 @@
What: /sys/firmware/sgi_uv/
Date: August 2008
Contact: Russ Anderson <rja@sgi.com>
Date: September 2020
Contact: Justin Ernst <justin.ernst@hpe.com>
Description:
The /sys/firmware/sgi_uv directory contains information
about the SGI UV platform.
about the UV platform.
Under that directory are a number of files::
Under that directory are a number of read-only attributes::
partition_id
coherence_id
uv_type
The partition_id entry contains the partition id.
SGI UV systems can be partitioned into multiple physical
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. To display the partition id, use the command::
cat /sys/firmware/sgi_uv/partition_id
of the operating system. Each partition will have a unique
partition id.
The coherence_id entry contains the coherence id.
A partitioned SGI UV system can have one or more coherence
domain. The coherence id indicates which coherence domain
this partition is in. To display the coherence id, use the
command::
A partitioned UV system can have one or more coherence
domains. The coherence id indicates which coherence domain
this partition is in.
cat /sys/firmware/sgi_uv/coherence_id
The uv_type entry contains the hub revision number.
This value can be used to identify the UV system version::
"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.