devlink: Implement devlink param multi attribute nested data values

Devlink param value attribute is not defined since devlink is handling the value validating and parsing internally, this allows us to implement multi attribute values without breaking any policies. Devlink param multi-attribute values are considered to be dynamically sized arrays of u64 values, by introducing a new devlink param type DEVLINK_PARAM_TYPE_U64_ARRAY, driver and user space can set a variable count of u64 values into the DEVLINK_ATTR_PARAM_VALUE_DATA attribute. Implement get/set parsing and add to the internal value structure passed to drivers. This is useful for devices that need to configure a list of values for a specific configuration. example: $ devlink dev param show pci/... name multi-value-param name multi-value-param type driver-specific values: cmode permanent value: 0,1,2,3,4,5,6,7 $ devlink dev param set pci/... name multi-value-param \ value 4,5,6,7,0,1,2,3 cmode permanent

SMSaeed Mahameed committed 5 months ago