devlink: Include port resources in resource dump dumpit

Allow querying devlink resources per-port via the resource-dump dumpit
handler. Both device-level and all ports resources are included in the
reply.

For example:

$ devlink resource show
pci/0000:03:00.0:
  name local_max_SFs size 508 unit entry
  name external_max_SFs size 508 unit entry
pci/0000:03:00.0/196608:
  name max_SFs size 20 unit entry
pci/0000:03:00.1:
  name local_max_SFs size 508 unit entry
  name external_max_SFs size 508 unit entry
pci/0000:03:00.1/262144:
  name max_SFs size 20 unit entry

Signed-off-by: Or Har-Toov <ohartoov@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260407194107.148063-7-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 58 insertions, 8 deletions

diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 7dfb7cdd2d23..e4e48ee2da5a 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -164,6 +164,11 @@ struct devlink_nl_dump_state {
 		struct {
 			u64 dump_ts;
 		};
+		/* DEVLINK_CMD_RESOURCE_DUMP */
+		struct {
+			u32 index;
+			bool index_valid;
+		} port_ctx;
 	};
 };
 
diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c
index 32ddbe244cb7..ae4afc739678 100644
--- a/net/devlink/netlink.c
+++ b/net/devlink/netlink.c
@@ -370,6 +370,8 @@ static int devlink_nl_inst_iter_dumpit(struct sk_buff *msg,
 
 		/* restart sub-object walk for the next instance */
 		state->idx = 0;
+		state->port_ctx.index = 0;
+		state->port_ctx.index_valid = false;
 	}
 
 	if (err != -EMSGSIZE)
diff --git a/net/devlink/resource.c b/net/devlink/resource.c
index 02fb36e25c52..7984eda63eb6 100644
--- a/net/devlink/resource.c
+++ b/net/devlink/resource.c
@@ -328,16 +328,20 @@ int devlink_nl_resource_dump_doit(struct sk_buff *skb, struct genl_info *info)
 }
 
 static int
-devlink_nl_resource_dump_one(struct sk_buff *skb, struct devlink *devlink,
-			     struct netlink_callback *cb, int flags)
+devlink_resource_dump_fill_one(struct sk_buff *skb, struct devlink *devlink,
+			       struct devlink_port *devlink_port,
+			       struct netlink_callback *cb, int flags, int *idx)
 {
-	struct devlink_nl_dump_state *state = devlink_dump_state(cb);
+	struct list_head *resource_list;
 	struct nlattr *resources_attr;
-	int start_idx = state->idx;
+	int start_idx = *idx;
 	void *hdr;
 	int err;
 
-	if (list_empty(&devlink->resource_list))
+	resource_list = devlink_port ?
+		&devlink_port->resource_list : &devlink->resource_list;
+
+	if (list_empty(resource_list))
 		return 0;
 
 	err = -EMSGSIZE;
@@ -348,15 +352,17 @@ devlink_nl_resource_dump_one(struct sk_buff *skb, struct devlink *devlink,
 
 	if (devlink_nl_put_handle(skb, devlink))
 		goto nla_put_failure;
+	if (devlink_port &&
+	    nla_put_u32(skb, DEVLINK_ATTR_PORT_INDEX, devlink_port->index))
+		goto nla_put_failure;
 
 	resources_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_RESOURCE_LIST);
 	if (!resources_attr)
 		goto nla_put_failure;
 
-	err = devlink_resource_list_fill(skb, devlink,
-					 &devlink->resource_list, &state->idx);
+	err = devlink_resource_list_fill(skb, devlink, resource_list, idx);
 	if (err) {
-		if (state->idx == start_idx)
+		if (*idx == start_idx)
 			goto resource_list_cancel;
 		nla_nest_end(skb, resources_attr);
 		genlmsg_end(skb, hdr);
@@ -373,6 +379,43 @@ nla_put_failure:
 	return err;
 }
 
+static int
+devlink_nl_resource_dump_one(struct sk_buff *skb, struct devlink *devlink,
+			     struct netlink_callback *cb, int flags)
+{
+	struct devlink_nl_dump_state *state = devlink_dump_state(cb);
+	struct devlink_port *devlink_port;
+	unsigned long port_idx;
+	int err;
+
+	if (!state->port_ctx.index_valid) {
+		err = devlink_resource_dump_fill_one(skb, devlink, NULL,
+						     cb, flags, &state->idx);
+		if (err)
+			return err;
+		state->idx = 0;
+	}
+
+	/* Check in case port was removed between dump callbacks. */
+	if (state->port_ctx.index_valid &&
+	    !xa_load(&devlink->ports, state->port_ctx.index))
+		state->idx = 0;
+	state->port_ctx.index_valid = true;
+	xa_for_each_start(&devlink->ports, port_idx, devlink_port,
+			  state->port_ctx.index) {
+		err = devlink_resource_dump_fill_one(skb, devlink, devlink_port,
+						     cb, flags, &state->idx);
+		if (err) {
+			state->port_ctx.index = port_idx;
+			return err;
+		}
+		state->idx = 0;
+	}
+	state->port_ctx.index_valid = false;
+	state->port_ctx.index = 0;
+	return 0;
+}
+
 int devlink_nl_resource_dump_dumpit(struct sk_buff *skb,
 				    struct netlink_callback *cb)
 {