Re: [PATCH net-next 1/5] devlink: Add port-level resource infrastructure

[Or Har-Toov <ohartoov@nvidia.com>]

On 04/02/2026 11:51, Jiri Pirko wrote:
> External email: Use caution opening links or attachments
>
>
> Tue, Feb 03, 2026 at 08:10:29AM +0100, tariqt@nvidia.com wrote:
>> From: Or Har-Toov <ohartoov@nvidia.com>
>>
>> The current devlink resource infrastructure only supports device-level
>> resources. Some hardware resources are associated with specific ports
>> rather than the entire device, and today we have no way to show resource
>> per-port.
>>
>> Add support for registering and querying resources at the port level,
>> 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>
>> Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
>> ---
>> Documentation/netlink/specs/devlink.yaml |  23 ++
>> include/net/devlink.h                    |   8 +
>> include/uapi/linux/devlink.h             |   2 +
>> net/devlink/netlink.c                    |   2 +-
>> net/devlink/netlink_gen.c                |  32 ++-
>> net/devlink/netlink_gen.h                |   6 +-
>> net/devlink/port.c                       |   3 +
>> net/devlink/resource.c                   | 282 ++++++++++++++++++-----
>> 8 files changed, 301 insertions(+), 57 deletions(-)
> Way too big for a single patch. Could you split it in logical chunks
> please?
>
>
>> diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
>> index 837112da6738..0290db1b8393 100644
>> --- a/Documentation/netlink/specs/devlink.yaml
>> +++ b/Documentation/netlink/specs/devlink.yaml
>> @@ -2336,3 +2336,26 @@ operations:
>>              - bus-name
>>              - dev-name
>>              - port-index
>> +
>> +    -
>> +      name: port-resource-get
> Why this is not aligned with DEVLINK_CMD_RESOURCE_* ?
> $ git grep CMD_RESOURCE_ include/uapi/linux/devlink.h
> include/uapi/linux/devlink.h:   DEVLINK_CMD_RESOURCE_SET,
> include/uapi/linux/devlink.h:   DEVLINK_CMD_RESOURCE_DUMP,
>
> I'm aware that DEVLINK_CMD_RESOURCE_DUMP only implements "do" now, but I
> think both should be named the same, no?
>
Thanks for the feedback, fixed everything in V2 except for this comment.
Port level operations use get and not dump so I think it make sense to 
align with port and not device level resource
>> +      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
> [...]
>
>
>> -int devl_resource_register(struct devlink *devlink,
>> -                         const char *resource_name,
>> -                         u64 resource_size,
>> -                         u64 resource_id,
>> -                         u64 parent_resource_id,
>> -                         const struct devlink_resource_size_params *size_params)
>> +static int
>> +devl_resource_reg_by_list(struct devlink *devlink,
>
> can't this be "register"?
>
> Also, why "by_list"? Sounds odd. Could you perhaps have it as
> __devl_resource_register(). That's the usual pattern for similar
> functions here, isn't it?
>
> Also, could you do this "list" abstraction in a separate patch?
>
>
>
>> +                        struct list_head *res_list_head,
>> +                        const char *resource_name, u64 resource_size,
>> +                        u64 resource_id, u64 parent_res_id,
>> +                        const struct devlink_resource_size_params *params)
>> {
>>        struct devlink_resource *resource;
>>        struct list_head *resource_list;
>> @@ -341,9 +344,10 @@ int devl_resource_register(struct devlink *devlink,
>>
>>        lockdep_assert_held(&devlink->lock);
>>
>> -      top_hierarchy = parent_resource_id == DEVLINK_RESOURCE_ID_PARENT_TOP;
>> +      top_hierarchy = parent_res_id == DEVLINK_RESOURCE_ID_PARENT_TOP;
>>
>> -      resource = devlink_resource_find(devlink, NULL, resource_id);
>> +      resource = devlink_resource_find_by_list(res_list_head, NULL,
>> +                                               resource_id);
>>        if (resource)
>>                return -EEXIST;
>>
>> @@ -352,15 +356,15 @@ int devl_resource_register(struct devlink *devlink,
>>                return -ENOMEM;
>>
>>        if (top_hierarchy) {
>> -              resource_list = &devlink->resource_list;
>> +              resource_list = res_list_head;
>>        } else {
>> -              struct devlink_resource *parent_resource;
>> +              struct devlink_resource *parent_res;
>>
>> -              parent_resource = devlink_resource_find(devlink, NULL,
>> -                                                      parent_resource_id);
>> -              if (parent_resource) {
>> -                      resource_list = &parent_resource->resource_list;
>> -                      resource->parent = parent_resource;
>> +              parent_res = devlink_resource_find_by_list(res_list_head, NULL,
>> +                                                         parent_res_id);
>> +              if (parent_res) {
>> +                      resource_list = &parent_res->resource_list;
>> +                      resource->parent = parent_res;
>>                } else {
>>                        kfree(resource);
>>                        return -EINVAL;
>> @@ -372,46 +376,78 @@ int devl_resource_register(struct devlink *devlink,
>>        resource->size_new = resource_size;
>>        resource->id = resource_id;
>>        resource->size_valid = true;
>> -      memcpy(&resource->size_params, size_params,
>> -             sizeof(resource->size_params));
>> +      memcpy(&resource->size_params, params, sizeof(resource->size_params));
>>        INIT_LIST_HEAD(&resource->resource_list);
>>        list_add_tail(&resource->list, resource_list);
>>
>>        return 0;
>> }
>> +
>> +/**
>> + * devl_resource_register - devlink resource register
>> + *
>> + * @devlink: devlink
>> + * @resource_name: resource's name
>> + * @resource_size: resource's size
>> + * @resource_id: resource's id
>> + * @parent_resource_id: resource's parent id
>> + * @params: size parameters
>> + *
>> + * Generic resources should reuse the same names across drivers.
>> + * Please see the generic resources list at:
>> + * Documentation/networking/devlink/devlink-resource.rst
>> + *
>> + * Return: 0 on success, negative error code otherwise.
>> + */
>> +int devl_resource_register(struct devlink *devlink, const char *resource_name,
>> +                         u64 resource_size, u64 resource_id,
>> +                         u64 parent_resource_id,
>> +                         const struct devlink_resource_size_params *params)
>> +{
>> +      return devl_resource_reg_by_list(devlink, &devlink->resource_list,
>> +                                            resource_name, resource_size,
>> +                                            resource_id, parent_resource_id,
>> +                                            params);
>> +}
> [...]