dsa.h

Go to the documentation of this file.

/*
 * include/net/dsa.h - Driver for Distributed Switch Architecture switch chips
 * Copyright (c) 2008-2009 Marvell Semiconductor
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#ifndef __LINUX_NET_DSA_H
#define __LINUX_NET_DSA_H

#include <linux/if_ether.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/workqueue.h>

#define DSA_MAX_SWITCHES    4
#define DSA_MAX_PORTS       12

struct dsa_chip_data {
    /*
     * How to access the switch configuration registers.
     */
    struct device   *mii_bus;
    int     sw_addr;

    /*
     * The names of the switch's ports.  Use "cpu" to
     * designate the switch port that the cpu is connected to,
     * "dsa" to indicate that this port is a DSA link to
     * another switch, NULL to indicate the port is unused,
     * or any other string to indicate this is a physical port.
     */
    char        *port_names[DSA_MAX_PORTS];

    /*
     * An array (with nr_chips elements) of which element [a]
     * indicates which port on this switch should be used to
     * send packets to that are destined for switch a.  Can be
     * NULL if there is only one switch chip.
     */
    s8      *rtable;
};

struct dsa_platform_data {
    /*
     * Reference to a Linux network interface that connects
     * to the root switch chip of the tree.
     */
    struct device   *netdev;

    /*
     * Info structs describing each of the switch chips
     * connected via this network interface.
     */
    int     nr_chips;
    struct dsa_chip_data    *chip;
};

struct dsa_switch_tree {
    /*
     * Configuration data for the platform device that owns
     * this dsa switch tree instance.
     */
    struct dsa_platform_data    *pd;

    /*
     * Reference to network device to use, and which tagging
     * protocol to use.
     */
    struct net_device   *master_netdev;
    __be16          tag_protocol;

    /*
     * The switch and port to which the CPU is attached.
     */
    s8          cpu_switch;
    s8          cpu_port;

    /*
     * Link state polling.
     */
    int         link_poll_needed;
    struct work_struct  link_poll_work;
    struct timer_list   link_poll_timer;

    /*
     * Data for the individual switch chips.
     */
    struct dsa_switch   *ds[DSA_MAX_SWITCHES];
};

struct dsa_switch {
    /*
     * Parent switch tree, and switch index.
     */
    struct dsa_switch_tree  *dst;
    int         index;

    /*
     * Configuration data for this switch.
     */
    struct dsa_chip_data    *pd;

    /*
     * The used switch driver.
     */
    struct dsa_switch_driver    *drv;

    /*
     * Reference to mii bus to use.
     */
    struct mii_bus      *master_mii_bus;

    /*
     * Slave mii_bus and devices for the individual ports.
     */
    u32         dsa_port_mask;
    u32         phys_port_mask;
    struct mii_bus      *slave_mii_bus;
    struct net_device   *ports[DSA_MAX_PORTS];
};

static inline bool dsa_is_cpu_port(struct dsa_switch *ds, int p)
{
    return !!(ds->index == ds->dst->cpu_switch && p == ds->dst->cpu_port);
}

static inline u8 dsa_upstream_port(struct dsa_switch *ds)
{
    struct dsa_switch_tree *dst = ds->dst;

    /*
     * If this is the root switch (i.e. the switch that connects
     * to the CPU), return the cpu port number on this switch.
     * Else return the (DSA) port number that connects to the
     * switch that is one hop closer to the cpu.
     */
    if (dst->cpu_switch == ds->index)
        return dst->cpu_port;
    else
        return ds->pd->rtable[dst->cpu_switch];
}

struct dsa_switch_driver {
    struct list_head    list;

    __be16          tag_protocol;
    int         priv_size;

    /*
     * Probing and setup.
     */
    char    *(*probe)(struct mii_bus *bus, int sw_addr);
    int (*setup)(struct dsa_switch *ds);
    int (*set_addr)(struct dsa_switch *ds, u8 *addr);

    /*
     * Access to the switch's PHY registers.
     */
    int (*phy_read)(struct dsa_switch *ds, int port, int regnum);
    int (*phy_write)(struct dsa_switch *ds, int port,
                 int regnum, u16 val);

    /*
     * Link state polling and IRQ handling.
     */
    void    (*poll_link)(struct dsa_switch *ds);

    /*
     * ethtool hardware statistics.
     */
    void    (*get_strings)(struct dsa_switch *ds, int port, uint8_t *data);
    void    (*get_ethtool_stats)(struct dsa_switch *ds,
                     int port, uint64_t *data);
    int (*get_sset_count)(struct dsa_switch *ds);
};

void register_switch_driver(struct dsa_switch_driver *type);
void unregister_switch_driver(struct dsa_switch_driver *type);

/*
 * The original DSA tag format and some other tag formats have no
 * ethertype, which means that we need to add a little hack to the
 * networking receive path to make sure that received frames get
 * the right ->protocol assigned to them when one of those tag
 * formats is in use.
 */
static inline bool dsa_uses_dsa_tags(struct dsa_switch_tree *dst)
{
    return !!(dst->tag_protocol == htons(ETH_P_DSA));
}

static inline bool dsa_uses_trailer_tags(struct dsa_switch_tree *dst)
{
    return !!(dst->tag_protocol == htons(ETH_P_TRAILER));
}

#endif