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cxl/Documentation: List attribute permissions

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Clarify the access permission of CXL sysfs attributes in the
documentation to help development of userspace tooling.

Reported-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165603881198.551046.12893348287451903699.stgit@dwillia2-xfh
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2022-06-21 17:23:16 -07:00
parent 14e473e1a7
commit 86677a4e71
1 changed files with 41 additions and 40 deletions
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81
Documentation/ABI/testing/sysfs-bus-cxl
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@ -57,28 +57,28 @@ Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL device objects export the devtype attribute which mirrors
the same value communicated in the DEVTYPE environment variable
for uevents for devices on the "cxl" bus.
(RO) CXL device objects export the devtype attribute which
mirrors the same value communicated in the DEVTYPE environment
variable for uevents for devices on the "cxl" bus.
What: /sys/bus/cxl/devices/*/modalias
Date: December, 2021
KernelVersion: v5.18
Contact: linux-cxl@vger.kernel.org
Description:
CXL device objects export the modalias attribute which mirrors
the same value communicated in the MODALIAS environment variable
for uevents for devices on the "cxl" bus.
(RO) CXL device objects export the modalias attribute which
mirrors the same value communicated in the MODALIAS environment
variable for uevents for devices on the "cxl" bus.
What: /sys/bus/cxl/devices/portX/uport
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL port objects are enumerated from either a platform firmware
device (ACPI0017 and ACPI0016) or PCIe switch upstream port with
CXL component registers. The 'uport' symlink connects the CXL
portX object to the device that published the CXL port
(RO) CXL port objects are enumerated from either a platform
firmware device (ACPI0017 and ACPI0016) or PCIe switch upstream
port with CXL component registers. The 'uport' symlink connects
the CXL portX object to the device that published the CXL port
capability.
What: /sys/bus/cxl/devices/portX/dportY
@ -86,20 +86,20 @@ Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL port objects are enumerated from either a platform firmware
device (ACPI0017 and ACPI0016) or PCIe switch upstream port with
CXL component registers. The 'dportY' symlink identifies one or
more downstream ports that the upstream port may target in its
decode of CXL memory resources. The 'Y' integer reflects the
hardware port unique-id used in the hardware decoder target
list.
(RO) CXL port objects are enumerated from either a platform
firmware device (ACPI0017 and ACPI0016) or PCIe switch upstream
port with CXL component registers. The 'dportY' symlink
identifies one or more downstream ports that the upstream port
may target in its decode of CXL memory resources. The 'Y'
integer reflects the hardware port unique-id used in the
hardware decoder target list.
What: /sys/bus/cxl/devices/decoderX.Y
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL decoder objects are enumerated from either a platform
(RO) CXL decoder objects are enumerated from either a platform
firmware description, or a CXL HDM decoder register set in a
PCIe device (see CXL 2.0 section 8.2.5.12 CXL HDM Decoder
Capability Structure). The 'X' in decoderX.Y represents the
@ -111,42 +111,43 @@ Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
The 'start' and 'size' attributes together convey the physical
address base and number of bytes mapped in the decoder's decode
window. For decoders of devtype "cxl_decoder_root" the address
range is fixed. For decoders of devtype "cxl_decoder_switch" the
address is bounded by the decode range of the cxl_port ancestor
of the decoder's cxl_port, and dynamically updates based on the
active memory regions in that address space.
(RO) The 'start' and 'size' attributes together convey the
physical address base and number of bytes mapped in the
decoder's decode window. For decoders of devtype
"cxl_decoder_root" the address range is fixed. For decoders of
devtype "cxl_decoder_switch" the address is bounded by the
decode range of the cxl_port ancestor of the decoder's cxl_port,
and dynamically updates based on the active memory regions in
that address space.
What: /sys/bus/cxl/devices/decoderX.Y/locked
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
CXL HDM decoders have the capability to lock the configuration
until the next device reset. For decoders of devtype
"cxl_decoder_root" there is no standard facility to unlock them.
For decoders of devtype "cxl_decoder_switch" a secondary bus
reset, of the PCIe bridge that provides the bus for this
decoders uport, unlocks / resets the decoder.
(RO) CXL HDM decoders have the capability to lock the
configuration until the next device reset. For decoders of
devtype "cxl_decoder_root" there is no standard facility to
unlock them. For decoders of devtype "cxl_decoder_switch" a
secondary bus reset, of the PCIe bridge that provides the bus
for this decoders uport, unlocks / resets the decoder.
What: /sys/bus/cxl/devices/decoderX.Y/target_list
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
Display a comma separated list of the current decoder target
configuration. The list is ordered by the current configured
interleave order of the decoder's dport instances. Each entry in
the list is a dport id.
(RO) Display a comma separated list of the current decoder
target configuration. The list is ordered by the current
configured interleave order of the decoder's dport instances.
Each entry in the list is a dport id.
What: /sys/bus/cxl/devices/decoderX.Y/cap_{pmem,ram,type2,type3}
Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
When a CXL decoder is of devtype "cxl_decoder_root", it
(RO) When a CXL decoder is of devtype "cxl_decoder_root", it
represents a fixed memory window identified by platform
firmware. A fixed window may only support a subset of memory
types. The 'cap_*' attributes indicate whether persistent
@ -158,8 +159,8 @@ Date: June, 2021
KernelVersion: v5.14
Contact: linux-cxl@vger.kernel.org
Description:
When a CXL decoder is of devtype "cxl_decoder_switch", it can
optionally decode either accelerator memory (type-2) or expander
memory (type-3). The 'target_type' attribute indicates the
current setting which may dynamically change based on what
(RO) When a CXL decoder is of devtype "cxl_decoder_switch", it
can optionally decode either accelerator memory (type-2) or
expander memory (type-3). The 'target_type' attribute indicates
the current setting which may dynamically change based on what
memory regions are activated in this decode hierarchy.