devlink: Add support for resource abstraction

Add support for hardware resource abstraction over devlink. Each resource
is identified via id, furthermore it contains information regarding its
size and its related sub resources. Each resource can also provide its
current occupancy.

In some cases the sizes of some resources can be changed, yet for those
changes to take place a hot driver reload may be needed. The reload
capability will be introduced in the next patch.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 488 insertions, 0 deletions

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 4d2c6fc94837..ceb1895d119b 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -26,6 +26,7 @@ struct devlink {
 	struct list_head port_list;
 	struct list_head sb_list;
 	struct list_head dpipe_table_list;
+	struct list_head resource_list;
 	struct devlink_dpipe_headers *dpipe_headers;
 	const struct devlink_ops *ops;
 	struct device *dev;
@@ -224,6 +225,61 @@ struct devlink_dpipe_headers {
 	unsigned int headers_count;
 };
 
+/**
+ * struct devlink_resource_ops - resource ops
+ * @occ_get: get the occupied size
+ * @size_validate: validate the size of the resource before update, reload
+ *                 is needed for changes to take place
+ */
+struct devlink_resource_ops {
+	u64 (*occ_get)(struct devlink *devlink);
+	int (*size_validate)(struct devlink *devlink, u64 size,
+			     struct netlink_ext_ack *extack);
+};
+
+/**
+ * struct devlink_resource_size_params - resource's size parameters
+ * @size_min: minimum size which can be set
+ * @size_max: maximum size which can be set
+ * @size_granularity: size granularity
+ * @size_unit: resource's basic unit
+ */
+struct devlink_resource_size_params {
+	u64 size_min;
+	u64 size_max;
+	u64 size_granularity;
+	enum devlink_resource_unit unit;
+};
+
+/**
+ * struct devlink_resource - devlink resource
+ * @name: name of the resource
+ * @id: id, per devlink instance
+ * @size: size of the resource
+ * @size_new: updated size of the resource, reload is needed
+ * @size_valid: valid in case the total size of the resource is valid
+ *              including its children
+ * @parent: parent resource
+ * @size_params: size parameters
+ * @list: parent list
+ * @resource_list: list of child resources
+ * @resource_ops: resource ops
+ */
+struct devlink_resource {
+	const char *name;
+	u64 id;
+	u64 size;
+	u64 size_new;
+	bool size_valid;
+	struct devlink_resource *parent;
+	struct devlink_resource_size_params *size_params;
+	struct list_head list;
+	struct list_head resource_list;
+	const struct devlink_resource_ops *resource_ops;
+};
+
+#define DEVLINK_RESOURCE_ID_PARENT_TOP 0
+
 struct devlink_ops {
 	int (*port_type_set)(struct devlink_port *devlink_port,
 			     enum devlink_port_type port_type);
@@ -333,6 +389,20 @@ extern struct devlink_dpipe_header devlink_dpipe_header_ethernet;
 extern struct devlink_dpipe_header devlink_dpipe_header_ipv4;
 extern struct devlink_dpipe_header devlink_dpipe_header_ipv6;
 
+int devlink_resource_register(struct devlink *devlink,
+			      const char *resource_name,
+			      bool top_hierarchy,
+			      u64 resource_size,
+			      u64 resource_id,
+			      u64 parent_resource_id,
+			      struct devlink_resource_size_params *size_params,
+			      const struct devlink_resource_ops *resource_ops);
+void devlink_resources_unregister(struct devlink *devlink,
+				  struct devlink_resource *resource);
+int devlink_resource_size_get(struct devlink *devlink,
+			      u64 resource_id,
+			      u64 *p_resource_size);
+
 #else
 
 static inline struct devlink *devlink_alloc(const struct devlink_ops *ops,
@@ -469,6 +539,32 @@ devlink_dpipe_match_put(struct sk_buff *skb,
 	return 0;
 }
 
+static inline int
+devlink_resource_register(struct devlink *devlink,
+			  const char *resource_name,
+			  bool top_hierarchy,
+			  u64 resource_size,
+			  u64 resource_id,
+			  u64 parent_resource_id,
+			  struct devlink_resource_size_params *size_params,
+			  const struct devlink_resource_ops *resource_ops)
+{
+	return 0;
+}
+
+static inline void
+devlink_resources_unregister(struct devlink *devlink,
+			     struct devlink_resource *resource)
+{
+}
+
+static inline int
+devlink_resource_size_get(struct devlink *devlink, u64 resource_id,
+			  u64 *p_resource_size)
+{
+	return -EOPNOTSUPP;
+}
+
 #endif
 
 #endif /* _NET_DEVLINK_H_ */
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 6665df69e26a..f89950443e17 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -70,6 +70,8 @@ enum devlink_command {
 	DEVLINK_CMD_DPIPE_ENTRIES_GET,
 	DEVLINK_CMD_DPIPE_HEADERS_GET,
 	DEVLINK_CMD_DPIPE_TABLE_COUNTERS_SET,
+	DEVLINK_CMD_RESOURCE_SET,
+	DEVLINK_CMD_RESOURCE_DUMP,
 
 	/* add new commands above here */
 	__DEVLINK_CMD_MAX,
@@ -202,6 +204,18 @@ enum devlink_attr {
 	DEVLINK_ATTR_PAD,
 
 	DEVLINK_ATTR_ESWITCH_ENCAP_MODE,	/* u8 */
+	DEVLINK_ATTR_RESOURCE_LIST,		/* nested */
+	DEVLINK_ATTR_RESOURCE,			/* nested */
+	DEVLINK_ATTR_RESOURCE_NAME,		/* string */
+	DEVLINK_ATTR_RESOURCE_ID,		/* u64 */
+	DEVLINK_ATTR_RESOURCE_SIZE,		/* u64 */
+	DEVLINK_ATTR_RESOURCE_SIZE_NEW,		/* u64 */
+	DEVLINK_ATTR_RESOURCE_SIZE_VALID,	/* u8 */
+	DEVLINK_ATTR_RESOURCE_SIZE_MIN,		/* u64 */
+	DEVLINK_ATTR_RESOURCE_SIZE_MAX,		/* u64 */
+	DEVLINK_ATTR_RESOURCE_SIZE_GRAN,        /* u64 */
+	DEVLINK_ATTR_RESOURCE_UNIT,		/* u8 */
+	DEVLINK_ATTR_RESOURCE_OCC,		/* u64 */
 
 	/* add new attributes above here, update the policy in devlink.c */
 
@@ -245,4 +259,8 @@ enum devlink_dpipe_header_id {
 	DEVLINK_DPIPE_HEADER_IPV6,
 };
 
+enum devlink_resource_unit {
+	DEVLINK_RESOURCE_UNIT_ENTRY,
+};
+
 #endif /* _UAPI_LINUX_DEVLINK_H_ */
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 2f71734c4ff6..89b3704fa450 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2288,6 +2288,233 @@ static int devlink_nl_cmd_dpipe_table_counters_set(struct sk_buff *skb,
 						counters_enable);
 }
 
+struct devlink_resource *
+devlink_resource_find(struct devlink *devlink,
+		      struct devlink_resource *resource, u64 resource_id)
+{
+	struct list_head *resource_list;
+
+	if (resource)
+		resource_list = &resource->resource_list;
+	else
+		resource_list = &devlink->resource_list;
+
+	list_for_each_entry(resource, resource_list, list) {
+		struct devlink_resource *child_resource;
+
+		if (resource->id == resource_id)
+			return resource;
+
+		child_resource = devlink_resource_find(devlink, resource,
+						       resource_id);
+		if (child_resource)
+			return child_resource;
+	}
+	return NULL;
+}
+
+void devlink_resource_validate_children(struct devlink_resource *resource)
+{
+	struct devlink_resource *child_resource;
+	bool size_valid = true;
+	u64 parts_size = 0;
+
+	if (list_empty(&resource->resource_list))
+		goto out;
+
+	list_for_each_entry(child_resource, &resource->resource_list, list)
+		parts_size += child_resource->size_new;
+
+	if (parts_size > resource->size)
+		size_valid = false;
+out:
+	resource->size_valid = size_valid;
+}
+
+static int devlink_nl_cmd_resource_set(struct sk_buff *skb,
+				       struct genl_info *info)
+{
+	struct devlink *devlink = info->user_ptr[0];
+	struct devlink_resource *resource;
+	u64 resource_id;
+	u64 size;
+	int err;
+
+	if (!info->attrs[DEVLINK_ATTR_RESOURCE_ID] ||
+	    !info->attrs[DEVLINK_ATTR_RESOURCE_SIZE])
+		return -EINVAL;
+	resource_id = nla_get_u64(info->attrs[DEVLINK_ATTR_RESOURCE_ID]);
+
+	resource = devlink_resource_find(devlink, NULL, resource_id);
+	if (!resource)
+		return -EINVAL;
+
+	if (!resource->resource_ops->size_validate)
+		return -EINVAL;
+
+	size = nla_get_u64(info->attrs[DEVLINK_ATTR_RESOURCE_SIZE]);
+	err = resource->resource_ops->size_validate(devlink, size,
+						    info->extack);
+	if (err)
+		return err;
+
+	resource->size_new = size;
+	devlink_resource_validate_children(resource);
+	if (resource->parent)
+		devlink_resource_validate_children(resource->parent);
+	return 0;
+}
+
+static void
+devlink_resource_size_params_put(struct devlink_resource *resource,
+				 struct sk_buff *skb)
+{
+	struct devlink_resource_size_params *size_params;
+
+	size_params = resource->size_params;
+	nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_SIZE_GRAN,
+			  size_params->size_granularity, DEVLINK_ATTR_PAD);
+	nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_SIZE_MAX,
+			  size_params->size_max, DEVLINK_ATTR_PAD);
+	nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_SIZE_MIN,
+			  size_params->size_min, DEVLINK_ATTR_PAD);
+	nla_put_u8(skb, DEVLINK_ATTR_RESOURCE_UNIT, size_params->unit);
+}
+
+static int devlink_resource_put(struct devlink *devlink, struct sk_buff *skb,
+				struct devlink_resource *resource)
+{
+	struct devlink_resource *child_resource;
+	struct nlattr *child_resource_attr;
+	struct nlattr *resource_attr;
+
+	resource_attr = nla_nest_start(skb, DEVLINK_ATTR_RESOURCE);
+	if (!resource_attr)
+		return -EMSGSIZE;
+
+	if (nla_put_string(skb, DEVLINK_ATTR_RESOURCE_NAME, resource->name) ||
+	    nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_SIZE, resource->size,
+			      DEVLINK_ATTR_PAD) ||
+	    nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_ID, resource->id,
+			      DEVLINK_ATTR_PAD))
+		goto nla_put_failure;
+	if (resource->size != resource->size_new)
+		nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_SIZE_NEW,
+				  resource->size_new, DEVLINK_ATTR_PAD);
+	if (resource->resource_ops && resource->resource_ops->occ_get)
+		nla_put_u64_64bit(skb, DEVLINK_ATTR_RESOURCE_OCC,
+				  resource->resource_ops->occ_get(devlink),
+				  DEVLINK_ATTR_PAD);
+	devlink_resource_size_params_put(resource, skb);
+	if (list_empty(&resource->resource_list))
+		goto out;
+
+	if (nla_put_u8(skb, DEVLINK_ATTR_RESOURCE_SIZE_VALID,
+		       resource->size_valid))
+		goto nla_put_failure;
+
+	child_resource_attr = nla_nest_start(skb, DEVLINK_ATTR_RESOURCE_LIST);
+	if (!child_resource_attr)
+		goto nla_put_failure;
+
+	list_for_each_entry(child_resource, &resource->resource_list, list) {
+		if (devlink_resource_put(devlink, skb, child_resource))
+			goto resource_put_failure;
+	}
+
+	nla_nest_end(skb, child_resource_attr);
+out:
+	nla_nest_end(skb, resource_attr);
+	return 0;
+
+resource_put_failure:
+	nla_nest_cancel(skb, child_resource_attr);
+nla_put_failure:
+	nla_nest_cancel(skb, resource_attr);
+	return -EMSGSIZE;
+}
+
+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;
+	void *hdr;
+	int i;
+	int err;
+
+	resource = list_first_entry(&devlink->resource_list,
+				    struct devlink_resource, list);
+start_again:
+	err = devlink_dpipe_send_and_alloc_skb(&skb, info);
+	if (err)
+		return err;
+
+	hdr = genlmsg_put(skb, info->snd_portid, info->snd_seq,
+			  &devlink_nl_family, NLM_F_MULTI, cmd);
+	if (!hdr) {
+		nlmsg_free(skb);
+		return -EMSGSIZE;
+	}
+
+	if (devlink_nl_put_handle(skb, devlink))
+		goto nla_put_failure;
+
+	resources_attr = nla_nest_start(skb, DEVLINK_ATTR_RESOURCE_LIST);
+	if (!resources_attr)
+		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++;
+	}
+	nla_nest_end(skb, resources_attr);
+	genlmsg_end(skb, hdr);
+	if (incomplete)
+		goto start_again;
+send_done:
+	nlh = nlmsg_put(skb, info->snd_portid, info->snd_seq,
+			NLMSG_DONE, 0, flags | NLM_F_MULTI);
+	if (!nlh) {
+		err = devlink_dpipe_send_and_alloc_skb(&skb, info);
+		if (err)
+			goto err_skb_send_alloc;
+		goto send_done;
+	}
+	return genlmsg_reply(skb, info);
+
+nla_put_failure:
+	err = -EMSGSIZE;
+err_resource_put:
+err_skb_send_alloc:
+	genlmsg_cancel(skb, hdr);
+	nlmsg_free(skb);
+	return err;
+}
+
+static int devlink_nl_cmd_resource_dump(struct sk_buff *skb,
+					struct genl_info *info)
+{
+	struct devlink *devlink = info->user_ptr[0];
+
+	if (list_empty(&devlink->resource_list))
+		return -EOPNOTSUPP;
+
+	return devlink_resource_fill(info, DEVLINK_CMD_RESOURCE_DUMP, 0);
+}
+
 static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING },
 	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING },
@@ -2306,6 +2533,8 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_ESWITCH_ENCAP_MODE] = { .type = NLA_U8 },
 	[DEVLINK_ATTR_DPIPE_TABLE_NAME] = { .type = NLA_NUL_STRING },
 	[DEVLINK_ATTR_DPIPE_TABLE_COUNTERS_ENABLED] = { .type = NLA_U8 },
+	[DEVLINK_ATTR_RESOURCE_ID] = { .type = NLA_U64},
+	[DEVLINK_ATTR_RESOURCE_SIZE] = { .type = NLA_U64},
 };
 
 static const struct genl_ops devlink_nl_ops[] = {
@@ -2466,6 +2695,20 @@ static const struct genl_ops devlink_nl_ops[] = {
 		.flags = GENL_ADMIN_PERM,
 		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
 	},
+	{
+		.cmd = DEVLINK_CMD_RESOURCE_SET,
+		.doit = devlink_nl_cmd_resource_set,
+		.policy = devlink_nl_policy,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
+	},
+	{
+		.cmd = DEVLINK_CMD_RESOURCE_DUMP,
+		.doit = devlink_nl_cmd_resource_dump,
+		.policy = devlink_nl_policy,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
+	},
 };
 
 static struct genl_family devlink_nl_family __ro_after_init = {
@@ -2503,6 +2746,7 @@ struct devlink *devlink_alloc(const struct devlink_ops *ops, size_t priv_size)
 	INIT_LIST_HEAD(&devlink->port_list);
 	INIT_LIST_HEAD(&devlink->sb_list);
 	INIT_LIST_HEAD_RCU(&devlink->dpipe_table_list);
+	INIT_LIST_HEAD(&devlink->resource_list);
 	mutex_init(&devlink->lock);
 	return devlink;
 }
@@ -2833,6 +3077,136 @@ unlock:
 }
 EXPORT_SYMBOL_GPL(devlink_dpipe_table_unregister);
 
+/**
+ *	devlink_resource_register - devlink resource register
+ *
+ *	@devlink: devlink
+ *	@resource_name: resource's name
+ *	@top_hierarchy: top hierarchy
+ *	@reload_required: reload is required for new configuration to
+ *			  apply
+ *	@resource_size: resource's size
+ *	@resource_id: resource's id
+ *	@parent_reosurce_id: resource's parent id
+ *	@size params: size parameters
+ *	@resource_ops: resource ops
+ */
+int devlink_resource_register(struct devlink *devlink,
+			      const char *resource_name,
+			      bool top_hierarchy,
+			      u64 resource_size,
+			      u64 resource_id,
+			      u64 parent_resource_id,
+			      struct devlink_resource_size_params *size_params,
+			      const struct devlink_resource_ops *resource_ops)
+{
+	struct devlink_resource *resource;
+	struct list_head *resource_list;
+	int err = 0;
+
+	mutex_lock(&devlink->lock);
+	resource = devlink_resource_find(devlink, NULL, resource_id);
+	if (resource) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	resource = kzalloc(sizeof(*resource), GFP_KERNEL);
+	if (!resource) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	if (top_hierarchy) {
+		resource_list = &devlink->resource_list;
+	} else {
+		struct devlink_resource *parent_resource;
+
+		parent_resource = devlink_resource_find(devlink, NULL,
+							parent_resource_id);
+		if (parent_resource) {
+			resource_list = &parent_resource->resource_list;
+			resource->parent = parent_resource;
+		} else {
+			err = -EINVAL;
+			goto out;
+		}
+	}
+
+	resource->name = resource_name;
+	resource->size = resource_size;
+	resource->size_new = resource_size;
+	resource->id = resource_id;
+	resource->resource_ops = resource_ops;
+	resource->size_valid = true;
+	resource->size_params = size_params;
+	INIT_LIST_HEAD(&resource->resource_list);
+	list_add_tail(&resource->list, resource_list);
+out:
+	mutex_unlock(&devlink->lock);
+	return err;
+}
+EXPORT_SYMBOL_GPL(devlink_resource_register);
+
+/**
+ *	devlink_resources_unregister - free all resources
+ *
+ *	@devlink: devlink
+ *	@resource: resource
+ */
+void devlink_resources_unregister(struct devlink *devlink,
+				  struct devlink_resource *resource)
+{
+	struct devlink_resource *tmp, *child_resource;
+	struct list_head *resource_list;
+
+	if (resource)
+		resource_list = &resource->resource_list;
+	else
+		resource_list = &devlink->resource_list;
+
+	if (!resource)
+		mutex_lock(&devlink->lock);
+
+	list_for_each_entry_safe(child_resource, tmp, resource_list, list) {
+		devlink_resources_unregister(devlink, child_resource);
+		list_del(&child_resource->list);
+		kfree(child_resource);
+	}
+
+	if (!resource)
+		mutex_unlock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devlink_resources_unregister);
+
+/**
+ *	devlink_resource_size_get - get and update size
+ *
+ *	@devlink: devlink
+ *	@resource_id: the requested resource id
+ *	@p_resource_size: ptr to update
+ */
+int devlink_resource_size_get(struct devlink *devlink,
+			      u64 resource_id,
+			      u64 *p_resource_size)
+{
+	struct devlink_resource *resource;
+	int err = 0;
+
+	mutex_lock(&devlink->lock);
+	resource = devlink_resource_find(devlink, NULL, resource_id);
+	if (!resource) {
+		err = -EINVAL;
+		goto out;
+	}
+	*p_resource_size = resource->size_new;
+	resource->size = resource->size_new;
+out:
+	mutex_unlock(&devlink->lock);
+	return err;
+}
+EXPORT_SYMBOL_GPL(devlink_resource_size_get);
+
 static int __init devlink_module_init(void)
 {
 	return genl_register_family(&devlink_nl_family);