diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-cxl')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 171 |
1 files changed, 159 insertions, 12 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 6350dd82b9a9..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 @@ -82,7 +134,12 @@ Description: 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 not be actively decoding any HPA ranges. + 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 @@ -92,7 +149,13 @@ 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. + 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/ @@ -167,6 +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 @@ -261,14 +339,13 @@ 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 @@ -358,6 +435,21 @@ Description: 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: v6.0 @@ -404,8 +496,17 @@ 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 @@ -477,3 +578,49 @@ Description: 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. |