diff mbox series

[v7,11/11] cxl/mem: Add debugfs output for QTG related data

Message ID 168695176491.3031571.5598696106816884313.stgit@djiang5-mobl3
State New, archived
Headers show
Series cxl: Add support for QTG ID retrieval for CXL subsystem | expand

Commit Message

Dave Jiang June 16, 2023, 9:42 p.m. UTC 
Add debugfs output to /sys/kernel/debug/cxl/memX/qtgmap
The debugfs attribute will dump out all the DSMAS ranges and the associated
QTG ID exported by the CXL device CDAT.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

---
v4:
- Use cxlds->qos_list instead of the stray cxlmd->qos_list
---
 Documentation/ABI/testing/debugfs-cxl |   13 +++++++++++++
 MAINTAINERS                           |    1 +
 drivers/cxl/mem.c                     |   26 ++++++++++++++++++++++++++
 3 files changed, 40 insertions(+)
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/debugfs-cxl b/Documentation/ABI/testing/debugfs-cxl
index fe61d372e3fa..e2b5b583c031 100644
--- a/Documentation/ABI/testing/debugfs-cxl
+++ b/Documentation/ABI/testing/debugfs-cxl
@@ -33,3 +33,16 @@  Description:
 		device cannot clear poison from the address, -ENXIO is returned.
 		The clear_poison attribute is only visible for devices
 		supporting the capability.
+
+
+What:		/sys/kernel/debug/cxl/memX/qtg_map
+Date:		Mar, 2023
+KernelVersion:	v6.5
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(RO) Entries of all Device Physical Address (DPA) ranges
+		provided by the device Coherent Device Attributes Table (CDAT)
+		Device Scoped Memory Affinity Structure (DSMAS) entries with
+		the matching QoS Throttling Group (QTG) id calculated from the
+		latency and bandwidth of the CXL path from the memory device
+		to the CPU.
diff --git a/MAINTAINERS b/MAINTAINERS
index 2145438e00dc..34dafe98e9bd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5192,6 +5192,7 @@  M:	Ben Widawsky <bwidawsk@kernel.org>
 M:	Dan Williams <dan.j.williams@intel.com>
 L:	linux-cxl@vger.kernel.org
 S:	Maintained
+F:	Documentation/ABI/testing/debugfs-cxl
 F:	drivers/cxl/
 F:	include/uapi/linux/cxl_mem.h
 
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 519edd0eb196..99bb68ae21ac 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -45,6 +45,31 @@  static int cxl_mem_dpa_show(struct seq_file *file, void *data)
 	return 0;
 }
 
+static int cxl_mem_qtg_show(struct seq_file *file, void *data)
+{
+	struct device *dev = file->private;
+	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct perf_prop_entry *perf;
+
+	list_for_each_entry(perf, &cxlds->perf_list, list) {
+		struct qos_class *qos_class = &perf->qos_class;
+		int i;
+
+		seq_printf(file, "%08llx-%08llx : QoS Class: ",
+			   perf->dpa_range.start, perf->dpa_range.end);
+		for (i = 0; i < qos_class->nr; i++) {
+			seq_printf(file, "%d", qos_class->entries[i]);
+			if (i + 1 == qos_class->nr)
+				seq_puts(file, "\n");
+			else
+				seq_puts(file, ", ");
+		}
+	}
+
+	return 0;
+}
+
 static int devm_cxl_add_endpoint(struct device *host, struct cxl_memdev *cxlmd,
 				 struct cxl_dport *parent_dport)
 {
@@ -140,6 +165,7 @@  static int cxl_mem_probe(struct device *dev)
 
 	dentry = cxl_debugfs_create_dir(dev_name(dev));
 	debugfs_create_devm_seqfile(dev, "dpamem", dentry, cxl_mem_dpa_show);
+	debugfs_create_devm_seqfile(dev, "qtgmap", dentry, cxl_mem_qtg_show);
 
 	if (test_bit(CXL_POISON_ENABLED_INJECT, cxlds->poison.enabled_cmds))
 		debugfs_create_file("inject_poison", 0200, dentry, cxlmd,