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ethercat/master/ethernet.c

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/******************************************************************************
*
* $Id$
*
* Copyright (C) 2006 Florian Pose, Ingenieurgemeinschaft IgH
*
* This file is part of the IgH EtherCAT Master.
*
* The IgH EtherCAT Master 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.
*
* The IgH EtherCAT Master is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the IgH EtherCAT Master; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* The right to use EtherCAT Technology is granted and comes free of
* charge under condition of compatibility of product made by
* Licensee. People intending to distribute/sell products based on the
* code, have to sign an agreement to guarantee that products using
* software based on IgH EtherCAT master stay compatible with the actual
* EtherCAT specification (which are released themselves as an open
* standard) as the (only) precondition to have the right to use EtherCAT
* Technology, IP and trade marks.
*
*****************************************************************************/
/**
\file
Ethernet-over-EtherCAT (EoE).
*/
/*****************************************************************************/
#include <linux/etherdevice.h>
#include "../include/ecrt.h"
#include "globals.h"
#include "master.h"
#include "slave.h"
#include "mailbox.h"
#include "ethernet.h"
#define EOE_DEBUG_LEVEL 0
/*****************************************************************************/
void ec_eoe_flush(ec_eoe_t *);
// state functions
void ec_eoe_state_rx_start(ec_eoe_t *);
void ec_eoe_state_rx_check(ec_eoe_t *);
void ec_eoe_state_rx_fetch(ec_eoe_t *);
void ec_eoe_state_tx_start(ec_eoe_t *);
void ec_eoe_state_tx_sent(ec_eoe_t *);
// net_device functions
int ec_eoedev_open(struct net_device *);
int ec_eoedev_stop(struct net_device *);
int ec_eoedev_tx(struct sk_buff *, struct net_device *);
struct net_device_stats *ec_eoedev_stats(struct net_device *);
/*****************************************************************************/
/**
EoE constructor.
Initializes the EoE handler, creates a net_device and registeres it.
*/
int ec_eoe_init(ec_eoe_t *eoe /**< EoE handler */)
{
ec_eoe_t **priv;
int result, i;
eoe->slave = NULL;
eoe->state = ec_eoe_state_rx_start;
eoe->opened = 0;
eoe->rx_skb = NULL;
eoe->rx_expected_fragment = 0;
INIT_LIST_HEAD(&eoe->tx_queue);
eoe->tx_frame = NULL;
eoe->tx_queue_active = 0;
eoe->tx_queued_frames = 0;
eoe->tx_queue_lock = SPIN_LOCK_UNLOCKED;
eoe->tx_frame_number = 0xFF;
memset(&eoe->stats, 0, sizeof(struct net_device_stats));
if (!(eoe->dev =
alloc_netdev(sizeof(ec_eoe_t *), "eoe%d", ether_setup))) {
EC_ERR("Unable to allocate net_device for EoE handler!\n");
goto out_return;
}
// initialize net_device
eoe->dev->open = ec_eoedev_open;
eoe->dev->stop = ec_eoedev_stop;
eoe->dev->hard_start_xmit = ec_eoedev_tx;
eoe->dev->get_stats = ec_eoedev_stats;
for (i = 0; i < ETH_ALEN; i++)
eoe->dev->dev_addr[i] = i | (i << 4);
// initialize private data
priv = netdev_priv(eoe->dev);
*priv = eoe;
// Usually setting the MTU appropriately makes the upper layers
// do the frame fragmenting. In some cases this doesn't work
// so the MTU is left on the Ethernet standard value and fragmenting
// is done "manually".
#if 0
eoe->dev->mtu = slave->sii_rx_mailbox_size - ETH_HLEN - 10;
#endif
// connect the net_device to the kernel
if ((result = register_netdev(eoe->dev))) {
EC_ERR("Unable to register net_device: error %i\n", result);
goto out_free;
}
// make the last address octet unique
eoe->dev->dev_addr[ETH_ALEN - 1] = (uint8_t) eoe->dev->ifindex;
return 0;
out_free:
free_netdev(eoe->dev);
eoe->dev = NULL;
out_return:
return -1;
}
/*****************************************************************************/
/**
EoE destructor.
Unregisteres the net_device and frees allocated memory.
*/
void ec_eoe_clear(ec_eoe_t *eoe /**< EoE handler */)
{
if (eoe->dev) {
unregister_netdev(eoe->dev);
free_netdev(eoe->dev);
}
// empty transmit queue
ec_eoe_flush(eoe);
if (eoe->tx_frame) {
dev_kfree_skb(eoe->tx_frame->skb);
kfree(eoe->tx_frame);
}
if (eoe->rx_skb) dev_kfree_skb(eoe->rx_skb);
}
/*****************************************************************************/
/**
Empties the transmit queue.
*/
void ec_eoe_flush(ec_eoe_t *eoe /**< EoE handler */)
{
ec_eoe_frame_t *frame, *next;
spin_lock_bh(&eoe->tx_queue_lock);
list_for_each_entry_safe(frame, next, &eoe->tx_queue, queue) {
list_del(&frame->queue);
dev_kfree_skb(frame->skb);
kfree(frame);
}
eoe->tx_queued_frames = 0;
spin_unlock_bh(&eoe->tx_queue_lock);
}
/*****************************************************************************/
/**
Sends a frame or the next fragment.
*/
int ec_eoe_send(ec_eoe_t *eoe /**< EoE handler */)
{
size_t remaining_size, current_size, complete_offset;
unsigned int last_fragment;
uint8_t *data;
#if EOE_DEBUG_LEVEL > 1
unsigned int i;
#endif
remaining_size = eoe->tx_frame->skb->len - eoe->tx_offset;
if (remaining_size <= eoe->slave->sii_tx_mailbox_size - 10) {
current_size = remaining_size;
last_fragment = 1;
}
else {
current_size = ((eoe->slave->sii_tx_mailbox_size - 10) / 32) * 32;
last_fragment = 0;
}
if (eoe->tx_fragment_number) {
complete_offset = eoe->tx_offset / 32;
}
else {
complete_offset = remaining_size / 32 + 1;
}
#if EOE_DEBUG_LEVEL > 0
EC_DBG("EoE TX sending %sfragment %i with %i octets (%i)."
" %i frames queued.\n", last_fragment ? "last " : "",
eoe->tx_fragment_number, current_size, complete_offset,
eoe->tx_queued_frames);
#endif
#if EOE_DEBUG_LEVEL > 1
EC_DBG("");
for (i = 0; i < current_size; i++) {
printk("%02X ", frame->skb->data[eoe->tx_offset + i]);
if ((i + 1) % 16 == 0) {
printk("\n");
EC_DBG("");
}
}
printk("\n");
#endif
if (!(data = ec_slave_mbox_prepare_send(eoe->slave, 0x02,
current_size + 4)))
return -1;
EC_WRITE_U8 (data, 0x00); // eoe fragment req.
EC_WRITE_U8 (data + 1, last_fragment);
EC_WRITE_U16(data + 2, ((eoe->tx_fragment_number & 0x3F) |
(complete_offset & 0x3F) << 6 |
(eoe->tx_frame_number & 0x0F) << 12));
memcpy(data + 4, eoe->tx_frame->skb->data + eoe->tx_offset, current_size);
ec_master_queue_command(eoe->slave->master, &eoe->slave->mbox_command);
eoe->tx_offset += current_size;
eoe->tx_fragment_number++;
return 0;
}
/*****************************************************************************/
/**
Runs the EoE state machine.
*/
void ec_eoe_run(ec_eoe_t *eoe /**< EoE handler */)
{
if (!eoe->opened) return;
// call state function
eoe->state(eoe);
}
/*****************************************************************************/
/**
Returns the state of the device.
\return 1 if the device is "up", 0 if it is "down"
*/
unsigned int ec_eoe_active(const ec_eoe_t *eoe /**< EoE handler */)
{
return eoe->slave && eoe->opened;
}
/*****************************************************************************/
/**
Prints EoE handler information.
*/
void ec_eoe_print(const ec_eoe_t *eoe /**< EoE handler */)
{
EC_INFO(" EoE handler %s\n", eoe->dev->name);
EC_INFO(" State: %s\n", eoe->opened ? "opened" : "closed");
if (eoe->slave)
EC_INFO(" Coupled to slave %i.\n", eoe->slave->ring_position);
else
EC_INFO(" Not coupled.\n");
}
/******************************************************************************
* STATE PROCESSING FUNCTIONS
*****************************************************************************/
/**
State: RX_START.
Starts a new receiving sequence by queueing a command that checks the
slave's mailbox for a new EoE command.
*/
void ec_eoe_state_rx_start(ec_eoe_t *eoe /**< EoE handler */)
{
if (!eoe->slave->online || !eoe->slave->master->device->link_state)
return;
ec_slave_mbox_prepare_check(eoe->slave);
ec_master_queue_command(eoe->slave->master, &eoe->slave->mbox_command);
eoe->state = ec_eoe_state_rx_check;
}
/*****************************************************************************/
/**
State: RX_CHECK.
Processes the checking command sent in RX_START and issues a receive
command, if new data is available.
*/
void ec_eoe_state_rx_check(ec_eoe_t *eoe /**< EoE handler */)
{
if (eoe->slave->mbox_command.state != EC_CMD_RECEIVED) {
eoe->stats.rx_errors++;
eoe->state = ec_eoe_state_tx_start;
return;
}
if (!ec_slave_mbox_check(eoe->slave)) {
eoe->state = ec_eoe_state_tx_start;
return;
}
ec_slave_mbox_prepare_fetch(eoe->slave);
ec_master_queue_command(eoe->slave->master, &eoe->slave->mbox_command);
eoe->state = ec_eoe_state_rx_fetch;
}
/*****************************************************************************/
/**
State: RX_FETCH.
Checks if the requested data of RX_CHECK was received and processes the
EoE command.
*/
void ec_eoe_state_rx_fetch(ec_eoe_t *eoe /**< EoE handler */)
{
size_t rec_size, data_size;
uint8_t *data, frame_type, last_fragment, time_appended;
uint8_t frame_number, fragment_offset, fragment_number;
off_t offset;
if (eoe->slave->mbox_command.state != EC_CMD_RECEIVED) {
eoe->stats.rx_errors++;
eoe->state = ec_eoe_state_tx_start;
return;
}
if (!(data = ec_slave_mbox_fetch(eoe->slave, 0x02, &rec_size))) {
eoe->stats.rx_errors++;
eoe->state = ec_eoe_state_tx_start;
return;
}
frame_type = EC_READ_U16(data) & 0x000F;
if (frame_type == 0x00) { // EoE Fragment Request
last_fragment = (EC_READ_U16(data) >> 8) & 0x0001;
time_appended = (EC_READ_U16(data) >> 9) & 0x0001;
fragment_number = EC_READ_U16(data + 2) & 0x003F;
fragment_offset = (EC_READ_U16(data + 2) >> 6) & 0x003F;
frame_number = (EC_READ_U16(data + 2) >> 12) & 0x000F;
#if EOE_DEBUG_LEVEL > 0
EC_DBG("EoE RX fragment %i, offset %i, frame %i%s%s,"
" %i octets\n", fragment_number, fragment_offset,
frame_number,
last_fragment ? ", last fragment" : "",
time_appended ? ", + timestamp" : "",
time_appended ? rec_size - 8 : rec_size - 4);
#endif
#if EOE_DEBUG_LEVEL > 1
EC_DBG("");
for (i = 0; i < rec_size - 4; i++) {
printk("%02X ", data[i + 4]);
if ((i + 1) % 16 == 0) {
printk("\n");
EC_DBG("");
}
}
printk("\n");
#endif
data_size = time_appended ? rec_size - 8 : rec_size - 4;
if (!fragment_number) {
if (eoe->rx_skb) {
EC_WARN("EoE RX freeing old socket buffer...\n");
dev_kfree_skb(eoe->rx_skb);
}
// new socket buffer
if (!(eoe->rx_skb = dev_alloc_skb(fragment_offset * 32))) {
if (printk_ratelimit())
EC_WARN("EoE RX low on mem. frame dropped.\n");
eoe->stats.rx_dropped++;
eoe->state = ec_eoe_state_tx_start;
return;
}
eoe->rx_skb_offset = 0;
eoe->rx_skb_size = fragment_offset * 32;
eoe->rx_expected_fragment = 0;
}
else {
if (!eoe->rx_skb) {
eoe->stats.rx_dropped++;
eoe->state = ec_eoe_state_tx_start;
return;
}
offset = fragment_offset * 32;
if (offset != eoe->rx_skb_offset ||
offset + data_size > eoe->rx_skb_size ||
fragment_number != eoe->rx_expected_fragment) {
eoe->stats.rx_errors++;
eoe->state = ec_eoe_state_tx_start;
dev_kfree_skb(eoe->rx_skb);
eoe->rx_skb = NULL;
return;
}
}
// copy fragment into socket buffer
memcpy(skb_put(eoe->rx_skb, data_size), data + 4, data_size);
eoe->rx_skb_offset += data_size;
if (last_fragment) {
// update statistics
eoe->stats.rx_packets++;
eoe->stats.rx_bytes += eoe->rx_skb->len;
#if EOE_DEBUG_LEVEL > 0
EC_DBG("EoE RX frame completed with %u octets.\n",
eoe->rx_skb->len);
#endif
// pass socket buffer to network stack
eoe->rx_skb->dev = eoe->dev;
eoe->rx_skb->protocol = eth_type_trans(eoe->rx_skb, eoe->dev);
eoe->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
if (netif_rx(eoe->rx_skb)) {
EC_WARN("EoE RX netif_rx failed.\n");
}
eoe->rx_skb = NULL;
eoe->state = ec_eoe_state_tx_start;
}
else {
eoe->rx_expected_fragment++;
#if EOE_DEBUG_LEVEL > 0
EC_DBG("EoE RX expecting fragment %i\n",
eoe->rx_expected_fragment);
#endif
eoe->state = ec_eoe_state_rx_start;
}
}
else {
#if EOE_DEBUG_LEVEL > 0
EC_DBG("other frame received.\n");
#endif
eoe->stats.rx_dropped++;
eoe->state = ec_eoe_state_tx_start;
}
}
/*****************************************************************************/
/**
State: TX START.
Starts a new transmit sequence. If no data is available, a new receive
sequence is started instead.
*/
void ec_eoe_state_tx_start(ec_eoe_t *eoe /**< EoE handler */)
{
#if EOE_DEBUG_LEVEL > 0
unsigned int wakeup;
#endif
if (!eoe->slave->online || !eoe->slave->master->device->link_state)
return;
spin_lock_bh(&eoe->tx_queue_lock);
if (!eoe->tx_queued_frames || list_empty(&eoe->tx_queue)) {
spin_unlock_bh(&eoe->tx_queue_lock);
// no data available.
// start a new receive immediately.
ec_eoe_state_rx_start(eoe);
return;
}
// take the first frame out of the queue
eoe->tx_frame = list_entry(eoe->tx_queue.next, ec_eoe_frame_t, queue);
list_del(&eoe->tx_frame->queue);
if (!eoe->tx_queue_active &&
eoe->tx_queued_frames == EC_EOE_TX_QUEUE_SIZE / 2) {
netif_wake_queue(eoe->dev);
eoe->tx_queue_active = 1;
#if EOE_DEBUG_LEVEL > 0
wakeup = 1;
#endif
}
eoe->tx_queued_frames--;
spin_unlock_bh(&eoe->tx_queue_lock);
eoe->tx_frame_number++;
eoe->tx_frame_number %= 16;
eoe->tx_fragment_number = 0;
eoe->tx_offset = 0;
if (ec_eoe_send(eoe)) {
dev_kfree_skb(eoe->tx_frame->skb);
kfree(eoe->tx_frame);
eoe->tx_frame = NULL;
eoe->stats.tx_errors++;
eoe->state = ec_eoe_state_rx_start;
return;
}
#if EOE_DEBUG_LEVEL > 0
if (wakeup) EC_DBG("waking up TX queue...\n");
#endif
eoe->state = ec_eoe_state_tx_sent;
}
/*****************************************************************************/
/**
State: TX SENT.
Checks is the previous transmit command succeded and sends the next
fragment, if necessary.
*/
void ec_eoe_state_tx_sent(ec_eoe_t *eoe /**< EoE handler */)
{
if (eoe->slave->mbox_command.state != EC_CMD_RECEIVED) {
eoe->stats.tx_errors++;
eoe->state = ec_eoe_state_rx_start;
return;
}
if (eoe->slave->mbox_command.working_counter != 1) {
eoe->stats.tx_errors++;
eoe->state = ec_eoe_state_rx_start;
return;
}
// frame completely sent
if (eoe->tx_offset >= eoe->tx_frame->skb->len) {
eoe->stats.tx_packets++;
eoe->stats.tx_bytes += eoe->tx_frame->skb->len;
dev_kfree_skb(eoe->tx_frame->skb);
kfree(eoe->tx_frame);
eoe->tx_frame = NULL;
eoe->state = ec_eoe_state_rx_start;
}
else { // send next fragment
if (ec_eoe_send(eoe)) {
dev_kfree_skb(eoe->tx_frame->skb);
kfree(eoe->tx_frame);
eoe->tx_frame = NULL;
eoe->stats.tx_errors++;
eoe->state = ec_eoe_state_rx_start;
}
}
}
/******************************************************************************
* NET_DEVICE functions
*****************************************************************************/
/**
Opens the virtual network device.
*/
int ec_eoedev_open(struct net_device *dev /**< EoE net_device */)
{
ec_eoe_t *eoe = *((ec_eoe_t **) netdev_priv(dev));
ec_eoe_flush(eoe);
eoe->opened = 1;
netif_start_queue(dev);
eoe->tx_queue_active = 1;
EC_INFO("%s opened.\n", dev->name);
if (!eoe->slave)
EC_WARN("device %s is not coupled to any EoE slave!\n", dev->name);
else {
eoe->slave->requested_state = EC_SLAVE_STATE_OP;
eoe->slave->state_error = 0;
}
return 0;
}
/*****************************************************************************/
/**
Stops the virtual network device.
*/
int ec_eoedev_stop(struct net_device *dev /**< EoE net_device */)
{
ec_eoe_t *eoe = *((ec_eoe_t **) netdev_priv(dev));
netif_stop_queue(dev);
eoe->tx_queue_active = 0;
eoe->opened = 0;
ec_eoe_flush(eoe);
EC_INFO("%s stopped.\n", dev->name);
if (!eoe->slave)
EC_WARN("device %s is not coupled to any EoE slave!\n", dev->name);
else {
eoe->slave->requested_state = EC_SLAVE_STATE_INIT;
eoe->slave->state_error = 0;
}
return 0;
}
/*****************************************************************************/
/**
Transmits data via the virtual network device.
*/
int ec_eoedev_tx(struct sk_buff *skb, /**< transmit socket buffer */
struct net_device *dev /**< EoE net_device */
)
{
ec_eoe_t *eoe = *((ec_eoe_t **) netdev_priv(dev));
ec_eoe_frame_t *frame;
#if 0
if (skb->len > eoe->slave->sii_tx_mailbox_size - 10) {
EC_WARN("EoE TX frame (%i octets) exceeds MTU. dropping.\n", skb->len);
dev_kfree_skb(skb);
eoe->stats.tx_dropped++;
return 0;
}
#endif
if (!(frame =
(ec_eoe_frame_t *) kmalloc(sizeof(ec_eoe_frame_t), GFP_ATOMIC))) {
if (printk_ratelimit())
EC_WARN("EoE TX: low on mem. frame dropped.\n");
return 1;
}
frame->skb = skb;
spin_lock_bh(&eoe->tx_queue_lock);
list_add_tail(&frame->queue, &eoe->tx_queue);
eoe->tx_queued_frames++;
if (eoe->tx_queued_frames == EC_EOE_TX_QUEUE_SIZE) {
netif_stop_queue(dev);
eoe->tx_queue_active = 0;
}
spin_unlock_bh(&eoe->tx_queue_lock);
#if EOE_DEBUG_LEVEL > 0
EC_DBG("EoE TX queued frame with %i octets (%i frames queued).\n",
skb->len, eoe->tx_queued_frames);
if (!eoe->tx_queue_active)
EC_WARN("EoE TX queue is now full.\n");
#endif
return 0;
}
/*****************************************************************************/
/**
Gets statistics about the virtual network device.
*/
struct net_device_stats *ec_eoedev_stats(struct net_device *dev
/**< EoE net_device */)
{
ec_eoe_t *eoe = *((ec_eoe_t **) netdev_priv(dev));
return &eoe->stats;
}
/*****************************************************************************/
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