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| author | Dan Williams <dan.j.williams@intel.com> | 2022-05-23 12:15:35 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2022-07-21 17:19:23 -0700 |
| commit | 2c8669033f16f5d791e10a5bdd42e39c7380da57 (patch) | |
| tree | 56607c894bdaf54da1f0d7a197263f8879e33a8e /Documentation | |
| parent | 9c57cde0dcbd0f76f649d152b83a2b9316277b22 (diff) | |
| download | linux-2c8669033f16f5d791e10a5bdd42e39c7380da57.tar.gz | |
cxl/hdm: Add 'mode' attribute to decoder objects
Recall that the Device Physical Address (DPA) space of a CXL Memory Expander is potentially partitioned into a volatile and persistent portion. A decoder maps a Host Physical Address (HPA) range to a DPA range and that translation depends on the value of all previous (lower instance number) decoders before the current one. In preparation for allowing dynamic provisioning of regions, decoders need an ABI to indicate which DPA partition a decoder targets. This ABI needs to be prepared for the possibility that some other agent committed and locked a decoder that spans the partition boundary. Add 'decoderX.Y/mode' to endpoint decoders that indicates which partition 'ram' / 'pmem' the decoder targets, or 'mixed' if the decoder currently spans the partition boundary. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165603881967.551046.6007594190951596439.stgit@dwillia2-xfh Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 5ada6d9543d3..0b672248d126 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -190,3 +190,19 @@ Description: found to support CDAT data. If it is present and the length of the data is 0 reading the CDAT data failed. Otherwise the CDAT data is reported. + + +What: /sys/bus/cxl/devices/decoderX.Y/mode +Date: May, 2022 +KernelVersion: v5.20 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) 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. |