root/net/core/netdev_config.c
// SPDX-License-Identifier: GPL-2.0-only

#include <linux/netdevice.h>
#include <net/netdev_queues.h>
#include <net/netdev_rx_queue.h>

#include "dev.h"

static int netdev_nop_validate_qcfg(struct net_device *dev,
                                    struct netdev_queue_config *qcfg,
                                    struct netlink_ext_ack *extack)
{
        return 0;
}

static int __netdev_queue_config(struct net_device *dev, int rxq_idx,
                                 struct netdev_queue_config *qcfg,
                                 struct netlink_ext_ack *extack,
                                 bool validate)
{
        int (*validate_cb)(struct net_device *dev,
                           struct netdev_queue_config *qcfg,
                           struct netlink_ext_ack *extack);
        struct pp_memory_provider_params *mpp;
        int err;

        validate_cb = netdev_nop_validate_qcfg;
        if (validate && dev->queue_mgmt_ops->ndo_validate_qcfg)
                validate_cb = dev->queue_mgmt_ops->ndo_validate_qcfg;

        memset(qcfg, 0, sizeof(*qcfg));

        /* Get defaults from the driver, in case user config not set */
        if (dev->queue_mgmt_ops->ndo_default_qcfg)
                dev->queue_mgmt_ops->ndo_default_qcfg(dev, qcfg);
        err = validate_cb(dev, qcfg, extack);
        if (err)
                return err;

        /* Apply MP overrides */
        mpp = &__netif_get_rx_queue(dev, rxq_idx)->mp_params;
        if (mpp->rx_page_size)
                qcfg->rx_page_size = mpp->rx_page_size;
        err = validate_cb(dev, qcfg, extack);
        if (err)
                return err;

        return 0;
}

/**
 * netdev_queue_config() - get configuration for a given queue
 * @dev:      net_device instance
 * @rxq_idx:  index of the queue of interest
 * @qcfg: queue configuration struct (output)
 *
 * Render the configuration for a given queue. This helper should be used
 * by drivers which support queue configuration to retrieve config for
 * a particular queue.
 *
 * @qcfg is an output parameter and is always fully initialized by this
 * function. Some values may not be set by the user, drivers may either
 * deal with the "unset" values in @qcfg, or provide the callback
 * to populate defaults in queue_management_ops.
 */
void netdev_queue_config(struct net_device *dev, int rxq_idx,
                         struct netdev_queue_config *qcfg)
{
        __netdev_queue_config(dev, rxq_idx, qcfg, NULL, false);
}
EXPORT_SYMBOL(netdev_queue_config);

int netdev_queue_config_validate(struct net_device *dev, int rxq_idx,
                                 struct netdev_queue_config *qcfg,
                                 struct netlink_ext_ack *extack)
{
        return __netdev_queue_config(dev, rxq_idx, qcfg, extack, true);
}