On Sun, 13 Apr 2025, Ira Weiny wrote:
To properly configure CXL regions user space will need to know the
details of the dynamic ram partition.
Expose the first dynamic ram partition through sysfs.
Signed-off-by: Ira Weiny <[email protected]>
---
Changes:
[iweiny: Complete rewrite of the old patch.]
---
Documentation/ABI/testing/sysfs-bus-cxl | 24 ++++++++++++++
drivers/cxl/core/memdev.c | 57 +++++++++++++++++++++++++++++++++
2 files changed, 81 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl
b/Documentation/ABI/testing/sysfs-bus-cxl
index 99bb3faf7a0e..2b59041bb410 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -89,6 +89,30 @@ Description:
and there are platform specific performance related
side-effects that may result. First class-id is displayed.
+What: /sys/bus/cxl/devices/memX/dynamic_ram_a/size
+Date: May, 2025
+KernelVersion: v6.16
+Contact: [email protected]
+Description:
+ (RO) The first Dynamic RAM partition capacity as bytes.
+
+
+What: /sys/bus/cxl/devices/memX/dynamic_ram_a/qos_class
+Date: May, 2025
+KernelVersion: v6.16
+Contact: [email protected]
+Description:
+ (RO) For CXL host platforms that support "QoS Telemmetry"
+ 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
^^ 'persistent' should be dropped
+ 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.
+
