[PATCH net-next V3 06/10] devlink: Add port resource netlink command

[Tariq Toukan <tariqt@nvidia.com>]

From: Or Har-Toov <ohartoov@nvidia.com>

Add support for userspace to query resources registered on devlink
ports, allowing drivers to expose per-port resource limits and usage.

Example output:

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

  $ devlink port resource show pci/0000:03:00.0/196608
  pci/0000:03:00.0/196608:
    name max_SFs size 20 unit entry

Signed-off-by: Or Har-Toov <ohartoov@nvidia.com>
Reviewed-by: Shay Drori <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 Documentation/netlink/specs/devlink.yaml | 23 ++++++
 include/uapi/linux/devlink.h             |  3 +
 net/devlink/devl_internal.h              |  4 ++
 net/devlink/netlink.c                    |  2 +-
 net/devlink/netlink_gen.c                | 32 ++++++++-
 net/devlink/netlink_gen.h                |  6 +-
 net/devlink/resource.c                   | 90 +++++++++++++++++++++++-
 7 files changed, 155 insertions(+), 5 deletions(-)

diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index ee679ac14261..9b813f5fc51c 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -2340,3 +2340,26 @@ operations:
             - bus-name
             - dev-name
             - port-index
+
+    -
+      name: port-resource-get
+      doc: Get port resources.
+      attribute-set: devlink
+      dont-validate: [strict]
+      do:
+        pre: devlink-nl-pre-doit-port
+        post: devlink-nl-post-doit
+        request:
+          value: 85
+          attributes: *port-id-attrs
+        reply: &port-resource-get-reply
+          value: 85
+          attributes:
+            - bus-name
+            - dev-name
+            - port-index
+            - resource-list
+      dump:
+        request:
+          attributes: *dev-id-attrs
+        reply: *port-resource-get-reply
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index e7d6b6d13470..1cabd1f6cba0 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -141,6 +141,9 @@ enum devlink_command {
 
 	DEVLINK_CMD_NOTIFY_FILTER_SET,
 
+	DEVLINK_CMD_PORT_RESOURCE_GET,	/* can dump */
+	DEVLINK_CMD_PORT_RESOURCE_SET,
+
 	/* add new commands above here */
 	__DEVLINK_CMD_MAX,
 	DEVLINK_CMD_MAX = __DEVLINK_CMD_MAX - 1
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 1377864383bc..ddf855bc893f 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -148,6 +148,10 @@ struct devlink_nl_dump_state {
 		struct {
 			u64 dump_ts;
 		};
+		/* DEVLINK_CMD_PORT_RESOURCE_GET - dump */
+		struct {
+			unsigned long port_index;
+		};
 	};
 };
 
diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c
index 593605c1b1ef..c78c31779622 100644
--- a/net/devlink/netlink.c
+++ b/net/devlink/netlink.c
@@ -367,7 +367,7 @@ struct genl_family devlink_nl_family __ro_after_init = {
 	.module		= THIS_MODULE,
 	.split_ops	= devlink_nl_ops,
 	.n_split_ops	= ARRAY_SIZE(devlink_nl_ops),
-	.resv_start_op	= DEVLINK_CMD_SELFTESTS_RUN + 1,
+	.resv_start_op	= DEVLINK_CMD_PORT_RESOURCE_GET + 1,
 	.mcgrps		= devlink_nl_mcgrps,
 	.n_mcgrps	= ARRAY_SIZE(devlink_nl_mcgrps),
 	.sock_priv_size		= sizeof(struct devlink_nl_sock_priv),
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index d6667a3f87a0..a235748d0688 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -610,8 +610,21 @@ static const struct nla_policy devlink_notify_filter_set_nl_policy[DEVLINK_ATTR_
 	[DEVLINK_ATTR_PORT_INDEX] = { .type = NLA_U32, },
 };
 
+/* DEVLINK_CMD_PORT_RESOURCE_GET - do */
+static const struct nla_policy devlink_port_resource_get_do_nl_policy[DEVLINK_ATTR_PORT_INDEX + 1] = {
+	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_PORT_INDEX] = { .type = NLA_U32, },
+};
+
+/* DEVLINK_CMD_PORT_RESOURCE_GET - dump */
+static const struct nla_policy devlink_port_resource_get_dump_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
+	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
+};
+
 /* Ops table for devlink */
-const struct genl_split_ops devlink_nl_ops[75] = {
+const struct genl_split_ops devlink_nl_ops[77] = {
 	{
 		.cmd		= DEVLINK_CMD_GET,
 		.validate	= GENL_DONT_VALIDATE_STRICT,
@@ -1297,4 +1310,21 @@ const struct genl_split_ops devlink_nl_ops[75] = {
 		.maxattr	= DEVLINK_ATTR_PORT_INDEX,
 		.flags		= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= DEVLINK_CMD_PORT_RESOURCE_GET,
+		.validate	= GENL_DONT_VALIDATE_STRICT,
+		.pre_doit	= devlink_nl_pre_doit_port,
+		.doit		= devlink_nl_port_resource_get_doit,
+		.post_doit	= devlink_nl_post_doit,
+		.policy		= devlink_port_resource_get_do_nl_policy,
+		.maxattr	= DEVLINK_ATTR_PORT_INDEX,
+		.flags		= GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd		= DEVLINK_CMD_PORT_RESOURCE_GET,
+		.dumpit		= devlink_nl_port_resource_get_dumpit,
+		.policy		= devlink_port_resource_get_dump_nl_policy,
+		.maxattr	= DEVLINK_ATTR_DEV_NAME,
+		.flags		= GENL_CMD_CAP_DUMP,
+	},
 };
diff --git a/net/devlink/netlink_gen.h b/net/devlink/netlink_gen.h
index d79f6a0888f6..cab9d30e913a 100644
--- a/net/devlink/netlink_gen.h
+++ b/net/devlink/netlink_gen.h
@@ -18,7 +18,7 @@ extern const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_RATE_TC_
 extern const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1];
 
 /* Ops table for devlink */
-extern const struct genl_split_ops devlink_nl_ops[75];
+extern const struct genl_split_ops devlink_nl_ops[77];
 
 int devlink_nl_pre_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
 			struct genl_info *info);
@@ -148,5 +148,9 @@ int devlink_nl_selftests_get_dumpit(struct sk_buff *skb,
 int devlink_nl_selftests_run_doit(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_notify_filter_set_doit(struct sk_buff *skb,
 				      struct genl_info *info);
+int devlink_nl_port_resource_get_doit(struct sk_buff *skb,
+				      struct genl_info *info);
+int devlink_nl_port_resource_get_dumpit(struct sk_buff *skb,
+					struct netlink_callback *cb);
 
 #endif /* _LINUX_DEVLINK_GEN_H */
diff --git a/net/devlink/resource.c b/net/devlink/resource.c
index 71f00e580f59..0a1d1610ff67 100644
--- a/net/devlink/resource.c
+++ b/net/devlink/resource.c
@@ -252,6 +252,7 @@ static int __devlink_resource_fill(struct genl_info *info,
 				   struct list_head *resource_list_head,
 				   enum devlink_command cmd, int flags)
 {
+	struct devlink_port *devlink_port = info->user_ptr[1];
 	struct devlink *devlink = info->user_ptr[0];
 	struct nlattr *resources_attr;
 	struct sk_buff *skb = NULL;
@@ -279,9 +280,13 @@ static int __devlink_resource_fill(struct genl_info *info,
 
 	if (devlink_nl_put_handle(skb, devlink))
 		goto nla_put_failure;
+	if (devlink_port) {
+		if (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);
+	resources_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_RESOURCE_LIST);
 	if (!resources_attr)
 		goto nla_put_failure;
 
@@ -656,3 +661,84 @@ void devl_port_resources_unregister(struct devlink_port *devlink_port)
 				    &devlink_port->resource_list);
 }
 EXPORT_SYMBOL_GPL(devl_port_resources_unregister);
+
+int devlink_nl_port_resource_get_doit(struct sk_buff *skb,
+				      struct genl_info *info)
+{
+	struct devlink_port *devlink_port = info->user_ptr[1];
+
+	return __devlink_resource_fill(info, &devlink_port->resource_list,
+				       DEVLINK_CMD_PORT_RESOURCE_GET, 0);
+}
+
+static int
+devlink_nl_port_resource_get_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;
+	struct list_head *resource_list;
+	struct nlattr *resources_attr;
+	int resource_idx, start_idx;
+	unsigned long port_idx;
+	void *hdr;
+	int err;
+
+	xa_for_each_start(&devlink->ports, port_idx, devlink_port,
+			  state->port_index) {
+		if (list_empty(&devlink_port->resource_list))
+			continue;
+
+		resource_idx = (port_idx == state->port_index) ? state->idx : 0;
+		start_idx = resource_idx;
+		err = -EMSGSIZE;
+
+		hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+				  cb->nlh->nlmsg_seq, &devlink_nl_family, flags,
+				  DEVLINK_CMD_PORT_RESOURCE_GET);
+		if (!hdr)
+			return err;
+
+		if (devlink_nl_put_handle(skb, devlink) ||
+		    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;
+
+		resource_list = &devlink_port->resource_list;
+		err = devlink_resource_list_fill(skb, devlink, resource_list,
+						 &resource_idx);
+		if (err) {
+			state->port_index = port_idx;
+			state->idx = resource_idx;
+			if (resource_idx == start_idx)
+				goto nla_put_failure_unwind;
+			nla_nest_end(skb, resources_attr);
+			genlmsg_end(skb, hdr);
+			return err;
+		}
+		nla_nest_end(skb, resources_attr);
+		genlmsg_end(skb, hdr);
+	}
+	state->port_index = 0;
+	state->idx = 0;
+	return 0;
+
+nla_put_failure_unwind:
+	nla_nest_cancel(skb, resources_attr);
+nla_put_failure:
+	genlmsg_cancel(skb, hdr);
+	return err;
+}
+
+int devlink_nl_port_resource_get_dumpit(struct sk_buff *skb,
+					struct netlink_callback *cb)
+{
+	return devlink_nl_dumpit(skb, cb,
+				 devlink_nl_port_resource_get_dump_one);
+}
-- 
2.44.0