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| author |   Ira Weiny <ira.weiny@intel.com> | 2022-07-19 13:52:49 -0700 |
|---|---|---|
| committer |   Dan Williams <dan.j.williams@intel.com> | 2022-07-19 15:38:05 -0700 |
| commit | c97006046c791f82cb5ba3219ef4a511ec5f3932 (patch) | |
| tree | ce58b9bb8620483ddf69d173a95a911361db7003 /drivers/cxl/cxlpci.h | |
| parent | driver-core: Introduce BIN_ATTR_ADMIN_{RO,RW} (diff) | |
| download | linux-dev-c97006046c791f82cb5ba3219ef4a511ec5f3932.tar.xz linux-dev-c97006046c791f82cb5ba3219ef4a511ec5f3932.zip | |
cxl/port: Read CDAT table
The per-device CDAT data provides performance data that is relevant for
mapping which CXL devices can participate in which CXL ranges by QTG
(QoS Throttling Group) (per ECN: CXL 2.0 CEDT CFMWS & QTG_DSM) [1]. The
QTG association specified in the ECN is advisory. Until the
cxl_acpi driver grows support for invoking the QTG _DSM method the CDAT
data is only of interest to userspace that may need it for debug
purposes.
Search the DOE mailboxes available, query CDAT data, cache the data and
make it available via a sysfs binary attribute per endpoint at:
/sys/bus/cxl/devices/endpointX/CDAT
...similar to other ACPI-structured table data in
/sys/firmware/ACPI/tables. The CDAT is relative to 'struct cxl_port'
objects since switches in addition to endpoints can host a CDAT
instance. Switch CDAT support is not implemented.
This does not support table updates at runtime. It will always provide
whatever was there when first cached. It is also the case that table
updates are not expected outside of explicit DPA address map affecting
commands like Set Partition with the immediate flag set. Given that the
driver does not support Set Partition with the immediate flag set there
is no current need for update support.
Link: https://www.computeexpresslink.org/spec-landing [1]
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
[djbw: drop in-kernel parsing infra for now, and other minor fixups]
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20220719205249.566684-7-ira.weiny@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/cxlpci.h')
| -rw-r--r-- | drivers/cxl/cxlpci.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h index fce1c11729c2..eec597dbe763 100644 --- a/drivers/cxl/cxlpci.h +++ b/drivers/cxl/cxlpci.h @@ -74,4 +74,5 @@ static inline resource_size_t cxl_regmap_to_base(struct pci_dev *pdev, int devm_cxl_port_enumerate_dports(struct cxl_port *port); struct cxl_dev_state; int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm); +void read_cdat_data(struct cxl_port *port); #endif /* __CXL_PCI_H__ */ |