[NDCTL PATCH v2 1/2] cxl: Save the number of decoders committed to a port

[Dave Jiang <dave.jiang@intel.com>]

Save the number of decoders committed to a port exposed by the kernel to the
libcxl cxl_port context. The attribute is helpful for determing if a region is
active.  Add libcxl API to retrieve the number of decoders committed.
Add the decoders_committed attribute to the port for cxl list command.

Link: https://lore.kernel.org/linux-cxl/169645700414.623072.3893376765415910289.stgit@djiang5-mobl3/T/#t
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
v2:
- Rebase against latest pending branch
---
 Documentation/cxl/lib/libcxl.txt |    1 +
 cxl/json.c                       |    4 ++++
 cxl/lib/libcxl.c                 |    9 +++++++++
 cxl/lib/libcxl.sym               |    1 +
 cxl/lib/private.h                |    1 +
 cxl/libcxl.h                     |    1 +
 6 files changed, 17 insertions(+)

diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt
index bcb89288afaf..93c32b54f19e 100644
--- a/Documentation/cxl/lib/libcxl.txt
+++ b/Documentation/cxl/lib/libcxl.txt
@@ -295,6 +295,7 @@ bool cxl_port_is_endpoint(struct cxl_port *port);
 int cxl_port_get_depth(struct cxl_port *port);
 bool cxl_port_hosts_memdev(struct cxl_port *port, struct cxl_memdev *memdev);
 int cxl_port_get_nr_dports(struct cxl_port *port);
+struct cxl_port *cxl_port_decoders_committed(struct cxl_port *port);
 ----
 The port type is communicated via cxl_port_is_<type>(). An 'enabled' port
 is one that has succeeded in discovering the CXL component registers in
diff --git a/cxl/json.c b/cxl/json.c
index 6fb17582a1cb..477e35a5157a 100644
--- a/cxl/json.c
+++ b/cxl/json.c
@@ -1331,6 +1331,10 @@ static struct json_object *__util_cxl_port_to_json(struct cxl_port *port,
 			json_object_object_add(jport, "state", jobj);
 	}
 
+	jobj = json_object_new_int(cxl_port_decoders_committed(port));
+	if (jobj)
+		json_object_object_add(jport, "decoders_committed", jobj);
+
 	json_object_set_userdata(jport, port, NULL);
 	return jport;
 }
diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index bdec2959508b..c1a127f66a1d 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -1880,6 +1880,10 @@ static int cxl_port_init(struct cxl_port *port, struct cxl_port *parent_port,
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		port->module = util_modalias_to_module(ctx, buf);
 
+	sprintf(path, "%s/decoders_committed", cxlport_base);
+	if (sysfs_read_attr(ctx, path, buf) == 0)
+		port->decoders_committed = strtoul(buf, NULL, 0);
+
 	free(path);
 	return 0;
 err:
@@ -3121,6 +3125,11 @@ cxl_port_get_dport_by_memdev(struct cxl_port *port, struct cxl_memdev *memdev)
 	return NULL;
 }
 
+CXL_EXPORT int cxl_port_decoders_committed(struct cxl_port *port)
+{
+	return port->decoders_committed;
+}
+
 static void *add_cxl_bus(void *parent, int id, const char *cxlbus_base)
 {
 	const char *devname = devpath_to_devname(cxlbus_base);
diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
index 42f523fda16d..16eca09b3d8b 100644
--- a/cxl/lib/libcxl.sym
+++ b/cxl/lib/libcxl.sym
@@ -277,4 +277,5 @@ global:
 	cxl_cmd_new_set_alert_config;
 	cxl_memdev_trigger_poison_list;
 	cxl_region_trigger_poison_list;
+	cxl_port_decoders_committed;
 } LIBCXL_6;
diff --git a/cxl/lib/private.h b/cxl/lib/private.h
index b26a8629e047..30c898940dec 100644
--- a/cxl/lib/private.h
+++ b/cxl/lib/private.h
@@ -87,6 +87,7 @@ struct cxl_port {
 	int dports_init;
 	int nr_dports;
 	int depth;
+	int decoders_committed;
 	struct cxl_ctx *ctx;
 	struct cxl_bus *bus;
 	enum cxl_port_type type;
diff --git a/cxl/libcxl.h b/cxl/libcxl.h
index 1154f4ce34d1..f7db400f574a 100644
--- a/cxl/libcxl.h
+++ b/cxl/libcxl.h
@@ -145,6 +145,7 @@ bool cxl_port_hosts_memdev(struct cxl_port *port, struct cxl_memdev *memdev);
 int cxl_port_get_nr_dports(struct cxl_port *port);
 int cxl_port_disable_invalidate(struct cxl_port *port);
 int cxl_port_enable(struct cxl_port *port);
+int cxl_port_decoders_committed(struct cxl_port *port);
 struct cxl_port *cxl_port_get_next_all(struct cxl_port *port,
 				       const struct cxl_port *top);