Export the QoS Throttling Group ID from the CXL Fixed Memory Window
Structure (CFMWS) under the root decoder sysfs attributes.
CXL rev3.0 9.17.1.3 CXL Fixed Memory Window Structure (CFMWS)
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-cxl | 7 +++++++
drivers/cxl/acpi.c | 3 +++
drivers/cxl/core/port.c | 14 ++++++++++++++
drivers/cxl/cxl.h | 3 +++
4 files changed, 27 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
index 8494ef27e8d2..0932c2f6fbf4 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -294,6 +294,13 @@ Description:
(WO) Write a string in the form 'regionZ' to delete that region,
provided it is currently idle / not bound to a driver.
+What: /sys/bus/cxl/devices/decoderX.Y/qtg_id
+Date: Jan, 2023
+KernelVersion: v6.3
+Contact: linux-cxl@xxxxxxxxxxxxxxx
+Description:
+ (RO) Shows the QoS Throttling Group ID. The QTG ID for a root
+ decoder comes from the CFMWS structure of the CEDT.
What: /sys/bus/cxl/devices/regionZ/uuid
Date: May, 2022
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index 13cde44c6086..7a71bb5041c7 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -289,6 +289,9 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
}
}
}
+
+ cxld->qtg_id = cfmws->qtg_id;
+
rc = cxl_decoder_add(cxld, target_map);
err_xormap:
if (rc)
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index b631a0520456..fe78daf7e7c8 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -284,6 +284,16 @@ static ssize_t interleave_ways_show(struct device *dev,
static DEVICE_ATTR_RO(interleave_ways);
+static ssize_t qtg_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct cxl_decoder *cxld = to_cxl_decoder(dev);
+
+ return sysfs_emit(buf, "%d\n", cxld->qtg_id);
+}
+
+static DEVICE_ATTR_RO(qtg_id);
+
static struct attribute *cxl_decoder_base_attrs[] = {
&dev_attr_start.attr,
&dev_attr_size.attr,
@@ -303,6 +313,7 @@ static struct attribute *cxl_decoder_root_attrs[] = {
&dev_attr_cap_type2.attr,
&dev_attr_cap_type3.attr,
&dev_attr_target_list.attr,
+ &dev_attr_qtg_id.attr,
SET_CXL_REGION_ATTR(create_pmem_region)
SET_CXL_REGION_ATTR(delete_region)
NULL,
@@ -1606,6 +1617,7 @@ struct cxl_root_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
}
atomic_set(&cxlrd->region_id, rc);
+ cxld->qtg_id = CXL_QTG_ID_INVALID;
return cxlrd;
}
EXPORT_SYMBOL_NS_GPL(cxl_root_decoder_alloc, CXL);
@@ -1643,6 +1655,7 @@ struct cxl_switch_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
cxld = &cxlsd->cxld;
cxld->dev.type = &cxl_decoder_switch_type;
+ cxld->qtg_id = CXL_QTG_ID_INVALID;
return cxlsd;
}
EXPORT_SYMBOL_NS_GPL(cxl_switch_decoder_alloc, CXL);
@@ -1675,6 +1688,7 @@ struct cxl_endpoint_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port)
}
cxld->dev.type = &cxl_decoder_endpoint_type;
+ cxld->qtg_id = CXL_QTG_ID_INVALID;
return cxled;
}
EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_alloc, CXL);
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 1b1cf459ac77..f558bbfc0332 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -279,6 +279,7 @@ enum cxl_decoder_type {
*/
#define CXL_DECODER_MAX_INTERLEAVE 16
+#define CXL_QTG_ID_INVALID -1
/**
* struct cxl_decoder - Common CXL HDM Decoder Attributes
@@ -290,6 +291,7 @@ enum cxl_decoder_type {
* @target_type: accelerator vs expander (type2 vs type3) selector
* @region: currently assigned region for this decoder
* @flags: memory type capabilities and locking
+ * @qtg_id: QoS Throttling Group ID
* @commit: device/decoder-type specific callback to commit settings to hw
* @reset: device/decoder-type specific callback to reset hw settings
*/
@@ -302,6 +304,7 @@ struct cxl_decoder {
enum cxl_decoder_type target_type;
struct cxl_region *region;
unsigned long flags;
+ int qtg_id;
int (*commit)(struct cxl_decoder *cxld);
int (*reset)(struct cxl_decoder *cxld);
};
