[PATCH net-next V3 01/10] devlink: Add dump support for device-level resources

[Tariq Toukan <tariqt@nvidia.com>]

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

Add dumpit handler for resource-dump command to iterate over all devlink
devices and show their resources. This aligns the device-level resource
command with the port-level resource command that will be added in next
patches.

  $ devlink resource show
  pci/0000:08:00.0:
    name local_max_SFs size 508 unit entry
    name external_max_SFs size 508 unit entry
  pci/0000:08:00.1:
    name local_max_SFs size 508 unit entry
    name external_max_SFs size 508 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 |  6 +-
 net/devlink/netlink_gen.c                | 19 ++++-
 net/devlink/netlink_gen.h                |  4 +-
 net/devlink/resource.c                   | 99 ++++++++++++++++++++----
 4 files changed, 109 insertions(+), 19 deletions(-)

diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index 837112da6738..ee679ac14261 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -1733,12 +1733,16 @@ operations:
           attributes:
             - bus-name
             - dev-name
-        reply:
+        reply: &resource-dump-reply
           value: 36
           attributes:
             - bus-name
             - dev-name
             - resource-list
+      dump:
+        request:
+          attributes: *dev-id-attrs
+        reply: *resource-dump-reply
 
     -
       name: reload
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index f4c61c2b4f22..d6667a3f87a0 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -272,7 +272,13 @@ static const struct nla_policy devlink_resource_set_nl_policy[DEVLINK_ATTR_RESOU
 };
 
 /* DEVLINK_CMD_RESOURCE_DUMP - do */
-static const struct nla_policy devlink_resource_dump_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
+static const struct nla_policy devlink_resource_dump_do_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
+	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
+};
+
+/* DEVLINK_CMD_RESOURCE_DUMP - dump */
+static const struct nla_policy devlink_resource_dump_dump_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
 	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
 	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
 };
@@ -605,7 +611,7 @@ static const struct nla_policy devlink_notify_filter_set_nl_policy[DEVLINK_ATTR_
 };
 
 /* Ops table for devlink */
-const struct genl_split_ops devlink_nl_ops[74] = {
+const struct genl_split_ops devlink_nl_ops[75] = {
 	{
 		.cmd		= DEVLINK_CMD_GET,
 		.validate	= GENL_DONT_VALIDATE_STRICT,
@@ -883,10 +889,17 @@ const struct genl_split_ops devlink_nl_ops[74] = {
 		.pre_doit	= devlink_nl_pre_doit,
 		.doit		= devlink_nl_resource_dump_doit,
 		.post_doit	= devlink_nl_post_doit,
-		.policy		= devlink_resource_dump_nl_policy,
+		.policy		= devlink_resource_dump_do_nl_policy,
 		.maxattr	= DEVLINK_ATTR_DEV_NAME,
 		.flags		= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= DEVLINK_CMD_RESOURCE_DUMP,
+		.dumpit		= devlink_nl_resource_dump_dumpit,
+		.policy		= devlink_resource_dump_dump_nl_policy,
+		.maxattr	= DEVLINK_ATTR_DEV_NAME,
+		.flags		= GENL_CMD_CAP_DUMP,
+	},
 	{
 		.cmd		= DEVLINK_CMD_RELOAD,
 		.validate	= GENL_DONT_VALIDATE_STRICT,
diff --git a/net/devlink/netlink_gen.h b/net/devlink/netlink_gen.h
index 2817d53a0eba..d79f6a0888f6 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[74];
+extern const struct genl_split_ops devlink_nl_ops[75];
 
 int devlink_nl_pre_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
 			struct genl_info *info);
@@ -80,6 +80,8 @@ int devlink_nl_dpipe_table_counters_set_doit(struct sk_buff *skb,
 					     struct genl_info *info);
 int devlink_nl_resource_set_doit(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_resource_dump_doit(struct sk_buff *skb, struct genl_info *info);
+int devlink_nl_resource_dump_dumpit(struct sk_buff *skb,
+				    struct netlink_callback *cb);
 int devlink_nl_reload_doit(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_param_get_doit(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_param_get_dumpit(struct sk_buff *skb,
diff --git a/net/devlink/resource.c b/net/devlink/resource.c
index 2d6324f3d91f..5131875482ec 100644
--- a/net/devlink/resource.c
+++ b/net/devlink/resource.c
@@ -213,21 +213,43 @@ static int devlink_resource_put(struct devlink *devlink, struct sk_buff *skb,
 	return -EMSGSIZE;
 }
 
+static int devlink_resource_list_fill(struct sk_buff *skb,
+				      struct devlink *devlink,
+				      int *idx)
+{
+	struct devlink_resource *resource;
+	int i = 0;
+	int err;
+
+	list_for_each_entry(resource, &devlink->resource_list, list) {
+		if (i < *idx) {
+			i++;
+			continue;
+		}
+		err = devlink_resource_put(devlink, skb, resource);
+		if (err) {
+			*idx = i;
+			return err;
+		}
+		i++;
+	}
+	*idx = 0;
+	return 0;
+}
+
 static int devlink_resource_fill(struct genl_info *info,
 				 enum devlink_command cmd, int flags)
 {
 	struct devlink *devlink = info->user_ptr[0];
-	struct devlink_resource *resource;
 	struct nlattr *resources_attr;
 	struct sk_buff *skb = NULL;
 	struct nlmsghdr *nlh;
 	bool incomplete;
+	int start_idx;
 	void *hdr;
-	int i;
+	int i = 0;
 	int err;
 
-	resource = list_first_entry(&devlink->resource_list,
-				    struct devlink_resource, list);
 start_again:
 	err = devlink_nl_msg_reply_and_new(&skb, info);
 	if (err)
@@ -249,16 +271,12 @@ static int devlink_resource_fill(struct genl_info *info,
 		goto nla_put_failure;
 
 	incomplete = false;
-	i = 0;
-	list_for_each_entry_from(resource, &devlink->resource_list, list) {
-		err = devlink_resource_put(devlink, skb, resource);
-		if (err) {
-			if (!i)
-				goto err_resource_put;
-			incomplete = true;
-			break;
-		}
-		i++;
+	start_idx = i;
+	err = devlink_resource_list_fill(skb, devlink, &i);
+	if (err) {
+		if (i == start_idx)
+			goto err_resource_put;
+		incomplete = true;
 	}
 	nla_nest_end(skb, resources_attr);
 	genlmsg_end(skb, hdr);
@@ -292,6 +310,59 @@ int devlink_nl_resource_dump_doit(struct sk_buff *skb, struct genl_info *info)
 	return devlink_resource_fill(info, DEVLINK_CMD_RESOURCE_DUMP, 0);
 }
 
+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 nlattr *resources_attr;
+	int start_idx = state->idx;
+	void *hdr;
+	int err;
+
+	if (list_empty(&devlink->resource_list))
+		return 0;
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &devlink_nl_family, flags, DEVLINK_CMD_RESOURCE_DUMP);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	err = devlink_nl_put_handle(skb, devlink);
+	if (err)
+		goto nla_put_failure;
+
+	resources_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_RESOURCE_LIST);
+	if (!resources_attr) {
+		err = -EMSGSIZE;
+		goto nla_put_failure;
+	}
+
+	err = devlink_resource_list_fill(skb, devlink, &state->idx);
+	if (err) {
+		if (state->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);
+	return 0;
+
+nla_put_failure_unwind:
+	nla_nest_cancel(skb, resources_attr);
+nla_put_failure:
+	genlmsg_cancel(skb, hdr);
+	return err;
+}
+
+int devlink_nl_resource_dump_dumpit(struct sk_buff *skb,
+				    struct netlink_callback *cb)
+{
+	return devlink_nl_dumpit(skb, cb, devlink_nl_resource_dump_one);
+}
+
 int devlink_resources_validate(struct devlink *devlink,
 			       struct devlink_resource *resource,
 			       struct genl_info *info)
-- 
2.44.0