[ndctl,v2,07/18] cxl/list: Add parent_dport attribute to port listings

Commit Message

Dan Williams Dec. 8, 2022, 9:28 p.m. UTC

---
 cxl/json.c         |    8 ++++++++
 cxl/lib/libcxl.c   |   38 ++++++++++++++++++++++++++++++++++++++
 cxl/lib/libcxl.sym |    1 +
 cxl/lib/private.h  |    2 ++
 cxl/libcxl.h       |    1 +
 5 files changed, 50 insertions(+)

Comments

Dan Williams Dec. 17, 2022, 1:36 a.m. UTC | #1

Dan Williams wrote:
> 
> ---
>  cxl/json.c         |    8 ++++++++
>  cxl/lib/libcxl.c   |   38 ++++++++++++++++++++++++++++++++++++++
>  cxl/lib/libcxl.sym |    1 +
>  cxl/lib/private.h  |    2 ++
>  cxl/libcxl.h       |    1 +
>  5 files changed, 50 insertions(+)

I should not have sent this out. It was sitting in my development tree
for other work, but should have been held back until the kernel support
landed.

Drop this for now as the kernel support will not arrive until v6.3:

http://lore.kernel.org/r/[e-mail]

Verma, Vishal L Jan. 4, 2023, 8:15 p.m. UTC | #2

On Fri, 2022-12-16 at 17:36 -0800, Dan Williams wrote:
> Dan Williams wrote:
> > 
> > ---
> >  cxl/json.c         |    8 ++++++++
> >  cxl/lib/libcxl.c   |   38 ++++++++++++++++++++++++++++++++++++++
> >  cxl/lib/libcxl.sym |    1 +
> >  cxl/lib/private.h  |    2 ++
> >  cxl/libcxl.h       |    1 +
> >  5 files changed, 50 insertions(+)
> 
> I should not have sent this out. It was sitting in my development
> tree
> for other work, but should have been held back until the kernel
> support
> landed.
> 
> Drop this for now as the kernel support will not arrive until v6.3:
> 
> http://lore.kernel.org/r/[e-mail]

Ah it has made it out to pending already.. shall I just revert it?

Patch

diff --git a/cxl/json.c b/cxl/json.c
index 5cff532acb13..2f3639ede2f8 100644
--- a/cxl/json.c
+++ b/cxl/json.c
@@ -783,6 +783,14 @@  static struct json_object *__util_cxl_port_to_json(struct cxl_port *port,
 	if (jobj)
 		json_object_object_add(jport, "host", jobj);
 
+	if (cxl_port_get_parent_dport(port)) {
+		struct cxl_dport *dport = cxl_port_get_parent_dport(port);
+
+		jobj = json_object_new_string(cxl_dport_get_devname(dport));
+		if (jobj)
+			json_object_object_add(jport, "parent_dport", jobj);
+	}
+
 	jobj = json_object_new_int(cxl_port_get_depth(port));
 	if (jobj)
 		json_object_object_add(jport, "depth", jobj);
diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index a69e31bc8a6e..9475d0e51f8c 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -162,6 +162,7 @@  static void __free_port(struct cxl_port *port, struct list_head *head)
 	free(port->dev_buf);
 	free(port->dev_path);
 	free(port->uport);
+	free(port->parent_dport_path);
 }
 
 static void free_port(struct cxl_port *port, struct list_head *head)
@@ -1488,6 +1489,20 @@  static int cxl_port_init(struct cxl_port *port, struct cxl_port *parent_port,
 	if (!port->uport)
 		goto err;
 
+	/*
+	 * CXL root devices have no parents and level 1 ports are both
+	 * CXL root targets and hosts of the next level, so:
+	 *     parent_dport == uport
+	 * ...at depth == 1
+	 */
+	if (port->depth > 1) {
+		rc = snprintf(port->dev_buf, port->buf_len, "%s/parent_dport",
+			      cxlport_base);
+		if (rc >= port->buf_len)
+			goto err;
+		port->parent_dport_path = realpath(port->dev_buf, NULL);
+	}
+
 	sprintf(path, "%s/modalias", cxlport_base);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		port->module = util_modalias_to_module(ctx, buf);
@@ -2465,6 +2480,29 @@  CXL_EXPORT const char *cxl_port_get_host(struct cxl_port *port)
 	return devpath_to_devname(port->uport);
 }
 
+CXL_EXPORT struct cxl_dport *cxl_port_get_parent_dport(struct cxl_port *port)
+{
+	struct cxl_port *parent;
+	struct cxl_dport *dport;
+	const char *name;
+
+	if (port->parent_dport)
+		return port->parent_dport;
+
+	if (!port->parent_dport_path)
+		return NULL;
+
+	parent = cxl_port_get_parent(port);
+	name = devpath_to_devname(port->parent_dport_path);
+	cxl_dport_foreach(parent, dport)
+		if (strcmp(cxl_dport_get_devname(dport), name) == 0) {
+			port->parent_dport = dport;
+			return dport;
+		}
+
+	return NULL;
+}
+
 CXL_EXPORT bool cxl_port_hosts_memdev(struct cxl_port *port,
 				      struct cxl_memdev *memdev)
 {
diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
index 490ed1fda5d3..cc5c1d543484 100644
--- a/cxl/lib/libcxl.sym
+++ b/cxl/lib/libcxl.sym
@@ -222,4 +222,5 @@  LIBCXL_4 {
 global:
 	cxl_target_get_firmware_node;
 	cxl_dport_get_firmware_node;
+	cxl_port_get_parent_dport;
 } LIBCXL_3;
diff --git a/cxl/lib/private.h b/cxl/lib/private.h
index e378339ec353..da2fce33cb07 100644
--- a/cxl/lib/private.h
+++ b/cxl/lib/private.h
@@ -62,6 +62,8 @@  struct cxl_port {
 	size_t buf_len;
 	char *dev_path;
 	char *uport;
+	char *parent_dport_path;
+	struct cxl_dport *parent_dport;
 	int ports_init;
 	int endpoints_init;
 	int decoders_init;
diff --git a/cxl/libcxl.h b/cxl/libcxl.h
index 1e0076908901..8d75330886f8 100644
--- a/cxl/libcxl.h
+++ b/cxl/libcxl.h
@@ -96,6 +96,7 @@  bool cxl_port_is_endpoint(struct cxl_port *port);
 struct cxl_endpoint *cxl_port_to_endpoint(struct cxl_port *port);
 struct cxl_bus *cxl_port_get_bus(struct cxl_port *port);
 const char *cxl_port_get_host(struct cxl_port *port);
+struct cxl_dport *cxl_port_get_parent_dport(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);
 int cxl_port_disable_invalidate(struct cxl_port *port);