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Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index f680da85fd44..0b6a2e6e8fbb 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -57,3 +57,73 @@ Description: 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 + 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 + cxl_port container of this decoder, and 'Y' represents the + instance id of a given decoder resource. + +What: /sys/bus/cxl/devices/decoderX.Y/{start,size} +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. + +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. + +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. + +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 + 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 + memory, volatile memory, accelerator memory, and / or expander + memory may be mapped behind this decoder's memory window. + +What: /sys/bus/cxl/devices/decoderX.Y/target_type +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 + memory regions are activated in this decode hierarchy. |