diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-cxl')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 308 |
1 files changed, 272 insertions, 36 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 8494ef27e8d2..c80a1b5a03db 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -1,5 +1,5 @@ What: /sys/bus/cxl/flush -Date: Januarry, 2022 +Date: January, 2022 KernelVersion: v5.18 Contact: linux-cxl@vger.kernel.org Description: @@ -18,6 +18,24 @@ Description: specification. +What: /sys/bus/cxl/devices/memX/payload_max +Date: December, 2020 +KernelVersion: v5.12 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) Maximum size (in bytes) of the mailbox command payload + registers. Linux caps this at 1MB if the device reports a + larger size. + + +What: /sys/bus/cxl/devices/memX/label_storage_size +Date: May, 2021 +KernelVersion: v5.13 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) Size (in bytes) of the Label Storage Area (LSA). + + What: /sys/bus/cxl/devices/memX/ram/size Date: December, 2020 KernelVersion: v5.12 @@ -28,6 +46,23 @@ Description: Payload in the CXL-2.0 specification. +What: /sys/bus/cxl/devices/memX/ram/qos_class +Date: May, 2023 +KernelVersion: v6.8 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) For CXL host platforms that support "QoS Telemetry" + this attribute conveys a comma delimited list of platform + specific cookies that identifies a QoS performance class + for the volatile partition of the CXL mem device. These + class-ids can be compared against a similar "qos_class" + published for a root decoder. While it is not required + that the endpoints map their local memory-class to a + matching platform class, mismatches are not recommended + and there are platform specific performance related + side-effects that may result. First class-id is displayed. + + What: /sys/bus/cxl/devices/memX/pmem/size Date: December, 2020 KernelVersion: v5.12 @@ -38,6 +73,23 @@ Description: Payload in the CXL-2.0 specification. +What: /sys/bus/cxl/devices/memX/pmem/qos_class +Date: May, 2023 +KernelVersion: v6.8 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) For CXL host platforms that support "QoS Telemetry" + this attribute conveys a comma delimited list of platform + specific cookies that identifies a QoS performance class + for the persistent partition of the CXL mem device. These + class-ids can be compared against a similar "qos_class" + published for a root decoder. While it is not required + that the endpoints map their local memory-class to a + matching platform class, mismatches are not recommended + and there are platform specific performance related + side-effects that may result. First class-id is displayed. + + What: /sys/bus/cxl/devices/memX/serial Date: January, 2022 KernelVersion: v5.18 @@ -58,6 +110,65 @@ Description: affinity for this device. +What: /sys/bus/cxl/devices/memX/security/state +Date: June, 2023 +KernelVersion: v6.5 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) Reading this file will display the CXL security state for + that device. Such states can be: 'disabled', 'sanitize', when + a sanitization is currently underway; or those available only + for persistent memory: 'locked', 'unlocked' or 'frozen'. This + sysfs entry is select/poll capable from userspace to notify + upon completion of a sanitize operation. + + +What: /sys/bus/cxl/devices/memX/security/sanitize +Date: June, 2023 +KernelVersion: v6.5 +Contact: linux-cxl@vger.kernel.org +Description: + (WO) Write a boolean 'true' string value to this attribute to + sanitize the device to securely re-purpose or decommission it. + This is done by ensuring that all user data and meta-data, + whether it resides in persistent capacity, volatile capacity, + or the LSA, is made permanently unavailable by whatever means + is appropriate for the media type. This functionality requires + the device to be disabled, that is, not actively decoding any + HPA ranges. This permits avoiding explicit global CPU cache + management, relying instead for it to be done when a region + transitions between software programmed and hardware committed + states. If this file is not present, then there is no hardware + support for the operation. + + +What /sys/bus/cxl/devices/memX/security/erase +Date: June, 2023 +KernelVersion: v6.5 +Contact: linux-cxl@vger.kernel.org +Description: + (WO) Write a boolean 'true' string value to this attribute to + secure erase user data by changing the media encryption keys for + all user data areas of the device. This functionality requires + the device to be disabled, that is, not actively decoding any + HPA ranges. This permits avoiding explicit global CPU cache + management, relying instead for it to be done when a region + transitions between software programmed and hardware committed + states. If this file is not present, then there is no hardware + support for the operation. + + +What: /sys/bus/cxl/devices/memX/firmware/ +Date: April, 2023 +KernelVersion: v6.5 +Contact: linux-cxl@vger.kernel.org +Description: + (RW) Firmware uploader mechanism. The different files under + this directory can be used to upload and activate new + firmware for CXL devices. The interfaces under this are + documented in sysfs-class-firmware. + + What: /sys/bus/cxl/devices/*/devtype Date: June, 2021 KernelVersion: v5.14 @@ -90,6 +201,21 @@ Description: capability. +What: /sys/bus/cxl/devices/{port,endpoint}X/parent_dport +Date: January, 2023 +KernelVersion: v6.3 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) CXL port objects are instantiated for each upstream port in + a CXL/PCIe switch, and for each endpoint to map the + corresponding memory device into the CXL port hierarchy. When a + descendant CXL port (switch or endpoint) is enumerated it is + useful to know which 'dport' object in the parent CXL port + routes to this descendant. The 'parent_dport' symlink points to + the device representing the downstream port of a CXL switch that + routes to {port,endpoint}X. + + What: /sys/bus/cxl/devices/portX/dportY Date: June, 2021 KernelVersion: v5.14 @@ -104,6 +230,21 @@ Description: hardware decoder target list. +What: /sys/bus/cxl/devices/portX/decoders_committed +Date: October, 2023 +KernelVersion: v6.7 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) A memory device is considered active when any of its + decoders are in the "committed" state (See CXL 3.0 8.2.4.19.7 + CXL HDM Decoder n Control Register). Hotplug and destructive + operations like "sanitize" are blocked while device is actively + decoding a Host Physical Address range. Note that this number + may be elevated without any regionX objects active or even + enumerated, as this may be due to decoders established by + platform firmware or a previous kernel (kexec). + + What: /sys/bus/cxl/devices/decoderX.Y Date: June, 2021 KernelVersion: v5.14 @@ -183,7 +324,7 @@ Description: What: /sys/bus/cxl/devices/endpointX/CDAT Date: July, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RO) If this sysfs entry is not present no DOE mailbox was @@ -194,18 +335,17 @@ Description: What: /sys/bus/cxl/devices/decoderX.Y/mode Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it - translates from a host physical address range, to a device local - address range. Device-local address ranges are further split - into a 'ram' (volatile memory) range and 'pmem' (persistent - memory) range. The 'mode' attribute emits one of 'ram', 'pmem', - 'mixed', or 'none'. The 'mixed' indication is for error cases - when a decoder straddles the volatile/persistent partition - boundary, and 'none' indicates the decoder is not actively - decoding, or no DPA allocation policy has been set. + translates from a host physical address range, to a device + local address range. Device-local address ranges are further + split into a 'ram' (volatile memory) range and 'pmem' + (persistent memory) range. The 'mode' attribute emits one of + 'ram', 'pmem', or 'none'. The 'none' indicates the decoder is + not actively decoding, or no DPA allocation policy has been + set. 'mode' can be written, when the decoder is in the 'disabled' state, with either 'ram' or 'pmem' to set the boundaries for the @@ -214,7 +354,7 @@ Description: What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RO) When a CXL decoder is of devtype "cxl_decoder_endpoint", @@ -225,7 +365,7 @@ Description: What: /sys/bus/cxl/devices/decoderX.Y/dpa_size Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it @@ -245,7 +385,7 @@ Description: What: /sys/bus/cxl/devices/decoderX.Y/interleave_ways Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RO) The number of targets across which this decoder's host @@ -260,7 +400,7 @@ Description: What: /sys/bus/cxl/devices/decoderX.Y/interleave_granularity Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RO) The number of consecutive bytes of host physical address @@ -270,44 +410,60 @@ Description: interleave_granularity). -What: /sys/bus/cxl/devices/decoderX.Y/create_pmem_region -Date: May, 2022 -KernelVersion: v5.20 +What: /sys/bus/cxl/devices/decoderX.Y/create_{pmem,ram}_region +Date: May, 2022, January, 2023 +KernelVersion: v6.0 (pmem), v6.3 (ram) Contact: linux-cxl@vger.kernel.org Description: (RW) Write a string in the form 'regionZ' to start the process - of defining a new persistent memory region (interleave-set) - within the decode range bounded by root decoder 'decoderX.Y'. - The value written must match the current value returned from - reading this attribute. An atomic compare exchange operation is - done on write to assign the requested id to a region and - allocate the region-id for the next creation attempt. EBUSY is - returned if the region name written does not match the current - cached value. + of defining a new persistent, or volatile memory region + (interleave-set) within the decode range bounded by root decoder + 'decoderX.Y'. The value written must match the current value + returned from reading this attribute. An atomic compare exchange + operation is done on write to assign the requested id to a + region and allocate the region-id for the next creation attempt. + EBUSY is returned if the region name written does not match the + current cached value. What: /sys/bus/cxl/devices/decoderX.Y/delete_region Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (WO) Write a string in the form 'regionZ' to delete that region, provided it is currently idle / not bound to a driver. +What: /sys/bus/cxl/devices/decoderX.Y/qos_class +Date: May, 2023 +KernelVersion: v6.5 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) For CXL host platforms that support "QoS Telemetry" this + root-decoder-only attribute conveys a platform specific cookie + that identifies a QoS performance class for the CXL Window. + This class-id can be compared against a similar "qos_class" + published for each memory-type that an endpoint supports. While + it is not required that endpoints map their local memory-class + to a matching platform class, mismatches are not recommended and + there are platform specific side-effects that may result. + + What: /sys/bus/cxl/devices/regionZ/uuid Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RW) Write a unique identifier for the region. This field must be set for persistent regions and it must not conflict with the - UUID of another region. + UUID of another region. For volatile ram regions this + attribute is a read-only empty string. What: /sys/bus/cxl/devices/regionZ/interleave_granularity Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RW) Set the number of consecutive bytes each device in the @@ -318,7 +474,7 @@ Description: What: /sys/bus/cxl/devices/regionZ/interleave_ways Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RW) Configures the number of devices participating in the @@ -328,7 +484,7 @@ Description: What: /sys/bus/cxl/devices/regionZ/size Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RW) System physical address space to be consumed by the region. @@ -340,12 +496,32 @@ Description: changed, only freed by writing 0. The kernel makes no guarantees that data is maintained over an address space freeing event, and there is no guarantee that a free followed by an allocate - results in the same address being allocated. + results in the same address being allocated. If extended linear + cache is present, the size indicates extended linear cache size + plus the CXL region size. + +What: /sys/bus/cxl/devices/regionZ/extended_linear_cache_size +Date: October, 2025 +KernelVersion: v6.19 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) The size of extended linear cache, if there is an extended + linear cache. Otherwise the attribute will not be visible. + +What: /sys/bus/cxl/devices/regionZ/mode +Date: January, 2023 +KernelVersion: v6.3 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) The mode of a region is established at region creation time + and dictates the mode of the endpoint decoder that comprise the + region. For more details on the possible modes see + /sys/bus/cxl/devices/decoderX.Y/mode What: /sys/bus/cxl/devices/regionZ/resource Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RO) A region is a contiguous partition of a CXL root decoder @@ -357,7 +533,7 @@ Description: What: /sys/bus/cxl/devices/regionZ/target[0..N] Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RW) Write an endpoint decoder object name to 'targetX' where X @@ -376,7 +552,7 @@ Description: What: /sys/bus/cxl/devices/regionZ/commit Date: May, 2022 -KernelVersion: v5.20 +KernelVersion: v6.0 Contact: linux-cxl@vger.kernel.org Description: (RW) Write a boolean 'true' string value to this attribute to @@ -388,3 +564,63 @@ Description: 1), and checks that the hardware accepts the commit request. Reading this value indicates whether the region is committed or not. + + +What: /sys/bus/cxl/devices/memX/trigger_poison_list +Date: April, 2023 +KernelVersion: v6.4 +Contact: linux-cxl@vger.kernel.org +Description: + (WO) When a boolean 'true' is written to this attribute the + memdev driver retrieves the poison list from the device. The + list consists of addresses that are poisoned, or would result + in poison if accessed, and the source of the poison. This + attribute is only visible for devices supporting the + capability. The retrieved errors are logged as kernel + events when cxl_poison event tracing is enabled. + + +What: /sys/bus/cxl/devices/regionZ/accessY/read_bandwidth + /sys/bus/cxl/devices/regionZ/accessY/write_bandwidth +Date: Jan, 2024 +KernelVersion: v6.9 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) The aggregated read or write bandwidth of the region. The + number is the accumulated read or write bandwidth of all CXL memory + devices that contributes to the region in MB/s. It is + identical data that should appear in + /sys/devices/system/node/nodeX/accessY/initiators/read_bandwidth or + /sys/devices/system/node/nodeX/accessY/initiators/write_bandwidth. + See Documentation/ABI/stable/sysfs-devices-node. access0 provides + the number to the closest initiator and access1 provides the + number to the closest CPU. + + +What: /sys/bus/cxl/devices/regionZ/accessY/read_latency + /sys/bus/cxl/devices/regionZ/accessY/write_latency +Date: Jan, 2024 +KernelVersion: v6.9 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) The read or write latency of the region. The number is + the worst read or write latency of all CXL memory devices that + contributes to the region in nanoseconds. It is identical data + that should appear in + /sys/devices/system/node/nodeX/accessY/initiators/read_latency or + /sys/devices/system/node/nodeX/accessY/initiators/write_latency. + See Documentation/ABI/stable/sysfs-devices-node. access0 provides + the number to the closest initiator and access1 provides the + number to the closest CPU. + + +What: /sys/bus/cxl/devices/nvdimm-bridge0/ndbusX/nmemY/cxl/dirty_shutdown +Date: Feb, 2025 +KernelVersion: v6.15 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) The device dirty shutdown count value, which is the number + of times the device could have incurred in potential data loss. + The count is persistent across power loss and wraps back to 0 + upon overflow. If this file is not present, the device does not + have the necessary support for dirty tracking. |