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/******************************************************************************

     2

 *

     3

 *  $Id$

     4

 *

     5

 *  Copyright (C) 2006  Florian Pose, Ingenieurgemeinschaft IgH

     6

 *

     7

 *  This file is part of the IgH EtherCAT Master.

     8

 *

     9

 *  The IgH EtherCAT Master is free software; you can redistribute it

    10

 *  and/or modify it under the terms of the GNU General Public License

    11

 *  as published by the Free Software Foundation; either version 2 of the

    12

 *  License, or (at your option) any later version.

    13

 *

    14

 *  The IgH EtherCAT Master is distributed in the hope that it will be

    15

 *  useful, but WITHOUT ANY WARRANTY; without even the implied warranty of

    16

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    17

 *  GNU General Public License for more details.

    18

 *

    19

 *  You should have received a copy of the GNU General Public License

    20

 *  along with the IgH EtherCAT Master; if not, write to the Free Software

    21

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    22

 *

    23

 *  The right to use EtherCAT Technology is granted and comes free of

    24

 *  charge under condition of compatibility of product made by

    25

 *  Licensee. People intending to distribute/sell products based on the

    26

 *  code, have to sign an agreement to guarantee that products using

    27

 *  software based on IgH EtherCAT master stay compatible with the actual

    28

 *  EtherCAT specification (which are released themselves as an open

    29

 *  standard) as the (only) precondition to have the right to use EtherCAT

    30

 *  Technology, IP and trade marks.

    31

 *

    32

 *****************************************************************************/

    33

    34

/**

    35

   \file

    36

   Ethernet-over-EtherCAT (EoE).

    37

*/

    38

    39

/*****************************************************************************/

    40

    41

#include <linux/netdevice.h>

    42

#include <linux/etherdevice.h>

    43

    44

#include "../include/ecrt.h"

    45

#include "globals.h"

    46

#include "master.h"

    47

#include "slave.h"

    48

#include "mailbox.h"

    49

#include "ethernet.h"

    50

    51

/**

    52

   Defines the debug level of EoE processing

    53

    54

   0 = No debug messages.

    55

   1 = Output actions.

    56

   2 = Output actions and frame data.

    57

*/

    58

    59

#define EOE_DEBUG_LEVEL 0

    60

    61

/*****************************************************************************/

    62

    63

void ec_eoe_flush(ec_eoe_t *);

    64

    65

// state functions

    66

void ec_eoe_state_rx_start(ec_eoe_t *);

    67

void ec_eoe_state_rx_check(ec_eoe_t *);

    68

void ec_eoe_state_rx_fetch(ec_eoe_t *);

    69

void ec_eoe_state_tx_start(ec_eoe_t *);

    70

void ec_eoe_state_tx_sent(ec_eoe_t *);

    71

    72

// net_device functions

    73

int ec_eoedev_open(struct net_device *);

    74

int ec_eoedev_stop(struct net_device *);

    75

int ec_eoedev_tx(struct sk_buff *, struct net_device *);

    76

struct net_device_stats *ec_eoedev_stats(struct net_device *);

    77

    78

/*****************************************************************************/

    79

    80

/**

    81

   EoE constructor.

    82

   Initializes the EoE handler, creates a net_device and registeres it.

    83

*/

    84

    85

int ec_eoe_init(ec_eoe_t *eoe /**< EoE handler */)

    86

{

    87

    ec_eoe_t **priv;

    88

    int result, i;

    89

    90

    eoe->slave = NULL;

    91

    ec_datagram_init(&eoe->datagram);

    92

    eoe->state = ec_eoe_state_rx_start;

    93

    eoe->opened = 0;

    94

    eoe->rx_skb = NULL;

    95

    eoe->rx_expected_fragment = 0;

    96

    INIT_LIST_HEAD(&eoe->tx_queue);

    97

    eoe->tx_frame = NULL;

    98

    eoe->tx_queue_active = 0;

    99

    eoe->tx_queued_frames = 0;

   100

    eoe->tx_queue_lock = SPIN_LOCK_UNLOCKED;

   101

    eoe->tx_frame_number = 0xFF;

   102

    memset(&eoe->stats, 0, sizeof(struct net_device_stats));

   103

   104

    eoe->rx_counter = 0;

   105

    eoe->tx_counter = 0;

   106

    eoe->rx_rate = 0;

   107

    eoe->tx_rate = 0;

   108

    eoe->t_last = 0;

   109

   110

    if (!(eoe->dev =

   111

          alloc_netdev(sizeof(ec_eoe_t *), "eoe%d", ether_setup))) {

   112

        EC_ERR("Unable to allocate net_device for EoE handler!\n");

   113

        goto out_return;

   114

    }

   115

   116

    // initialize net_device

   117

    eoe->dev->open = ec_eoedev_open;

   118

    eoe->dev->stop = ec_eoedev_stop;

   119

    eoe->dev->hard_start_xmit = ec_eoedev_tx;

   120

    eoe->dev->get_stats = ec_eoedev_stats;

   121

   122

    for (i = 0; i < ETH_ALEN; i++)

   123

        eoe->dev->dev_addr[i] = i | (i << 4);

   124

   125

    // initialize private data

   126

    priv = netdev_priv(eoe->dev);

   127

    *priv = eoe;

   128

   129

    // Usually setting the MTU appropriately makes the upper layers

   130

    // do the frame fragmenting. In some cases this doesn't work

   131

    // so the MTU is left on the Ethernet standard value and fragmenting

   132

    // is done "manually".

   133

#if 0

   134

    eoe->dev->mtu = slave->sii_rx_mailbox_size - ETH_HLEN - 10;

   135

#endif

   136

   137

    // connect the net_device to the kernel

   138

    if ((result = register_netdev(eoe->dev))) {

   139

        EC_ERR("Unable to register net_device: error %i\n", result);

   140

        goto out_free;

   141

    }

   142

   143

    // make the last address octet unique

   144

    eoe->dev->dev_addr[ETH_ALEN - 1] = (uint8_t) eoe->dev->ifindex;

   145

   146

    return 0;

   147

   148

 out_free:

   149

    free_netdev(eoe->dev);

   150

    eoe->dev = NULL;

   151

 out_return:

   152

    return -1;

   153

}

   154

   155

/*****************************************************************************/

   156

   157

/**

   158

   EoE destructor.

   159

   Unregisteres the net_device and frees allocated memory.

   160

*/

   161

   162

void ec_eoe_clear(ec_eoe_t *eoe /**< EoE handler */)

   163

{

   164

    unregister_netdev(eoe->dev);

   165

    free_netdev(eoe->dev);

   166

   167

    // empty transmit queue

   168

    ec_eoe_flush(eoe);

   169

   170

    if (eoe->tx_frame) {

   171

        dev_kfree_skb(eoe->tx_frame->skb);

   172

        kfree(eoe->tx_frame);

   173

    }

   174

   175

    if (eoe->rx_skb) dev_kfree_skb(eoe->rx_skb);

   176

   177

    ec_datagram_clear(&eoe->datagram);

   178

}

   179

   180

/*****************************************************************************/

   181

   182

/**

   183

   Empties the transmit queue.

   184

*/

   185

   186

void ec_eoe_flush(ec_eoe_t *eoe /**< EoE handler */)

   187

{

   188

    ec_eoe_frame_t *frame, *next;

   189

   190

    spin_lock_bh(&eoe->tx_queue_lock);

   191

   192

    list_for_each_entry_safe(frame, next, &eoe->tx_queue, queue) {

   193

        list_del(&frame->queue);

   194

        dev_kfree_skb(frame->skb);

   195

        kfree(frame);

   196

    }

   197

    eoe->tx_queued_frames = 0;

   198

   199

    spin_unlock_bh(&eoe->tx_queue_lock);

   200

}

   201

   202

/*****************************************************************************/

   203

   204

/**

   205

   Sends a frame or the next fragment.

   206

*/

   207

   208

int ec_eoe_send(ec_eoe_t *eoe /**< EoE handler */)

   209

{

   210

    size_t remaining_size, current_size, complete_offset;

   211

    unsigned int last_fragment;

   212

    uint8_t *data;

   213

#if EOE_DEBUG_LEVEL > 1

   214

    unsigned int i;

   215

#endif

   216

   217

    remaining_size = eoe->tx_frame->skb->len - eoe->tx_offset;

   218

   219

    if (remaining_size <= eoe->slave->sii_tx_mailbox_size - 10) {

   220

        current_size = remaining_size;

   221

        last_fragment = 1;

   222

    }

   223

    else {

   224

        current_size = ((eoe->slave->sii_tx_mailbox_size - 10) / 32) * 32;

   225

        last_fragment = 0;

   226

    }

   227

   228

    if (eoe->tx_fragment_number) {

   229

        complete_offset = eoe->tx_offset / 32;

   230

    }

   231

    else {

   232

        // complete size in 32 bit blocks, rounded up.

   233

        complete_offset = remaining_size / 32 + 1;

   234

    }

   235

   236

#if EOE_DEBUG_LEVEL > 0

   237

    EC_DBG("EoE TX sending %sfragment %i with %i octets (%i)."

   238

           " %i frames queued.\n", last_fragment ? "last " : "",

   239

           eoe->tx_fragment_number, current_size, complete_offset,

   240

           eoe->tx_queued_frames);

   241

#endif

   242

   243

#if EOE_DEBUG_LEVEL > 1

   244

    EC_DBG("");

   245

    for (i = 0; i < current_size; i++) {

   247

        if ((i + 1) % 16 == 0) {

   248

            printk("\n");

   249

            EC_DBG("");

   250

        }

   251

    }

   252

    printk("\n");

   253

#endif

   254

   255

    if (!(data = ec_slave_mbox_prepare_send(eoe->slave, &eoe->datagram,

   256

                                            0x02, current_size + 4)))

   257

        return -1;

   258

   259

    EC_WRITE_U8 (data,     0x00); // eoe fragment req.

   260

    EC_WRITE_U8 (data + 1, last_fragment);

   261

    EC_WRITE_U16(data + 2, ((eoe->tx_fragment_number & 0x3F) |

   262

                            (complete_offset & 0x3F) << 6 |

   263

                            (eoe->tx_frame_number & 0x0F) << 12));

   264

   265

    memcpy(data + 4, eoe->tx_frame->skb->data + eoe->tx_offset, current_size);

   266

    ec_master_queue_datagram(eoe->slave->master, &eoe->datagram);

   267

   268

    eoe->tx_offset += current_size;

   269

    eoe->tx_fragment_number++;

   270

    return 0;

   271

}

   272

   273

/*****************************************************************************/

   274

   275

/**

   276

   Runs the EoE state machine.

   277

*/

   278

   279

void ec_eoe_run(ec_eoe_t *eoe /**< EoE handler */)

   280

{

   281

    cycles_t t_now;

   282

   283

    if (!eoe->opened) return;

   284

   285

    // call state function

   286

    eoe->state(eoe);

   287

   288

    // update statistics

   289

    t_now = get_cycles();

   290

    if ((u32) (t_now - eoe->t_last) > cpu_khz * 1000) {

   291

        eoe->rx_rate = eoe->rx_counter * 8;

   292

        eoe->tx_rate = eoe->tx_counter * 8;

   293

        eoe->rx_counter = 0;

   294

        eoe->tx_counter = 0;

   295

        eoe->t_last = t_now;

   296

    }

   297

}

   298

   299

/*****************************************************************************/

   300

   301

/**

   302

   Returns the state of the device.

   303

   \return 1 if the device is "up", 0 if it is "down"

   304

*/

   305

   306

int ec_eoe_active(const ec_eoe_t *eoe /**< EoE handler */)

   307

{

   308

    return eoe->slave && eoe->opened;

   309

}

   310

   311

/******************************************************************************

   312

 *  STATE PROCESSING FUNCTIONS

   313

 *****************************************************************************/

   314

   315

/**

   316

   State: RX_START.

   317

   Starts a new receiving sequence by queueing a datagram that checks the

   318

   slave's mailbox for a new EoE datagram.

   319

*/

   320

   321

void ec_eoe_state_rx_start(ec_eoe_t *eoe /**< EoE handler */)

   322

{

   323

    if (!eoe->slave->online || !eoe->slave->master->device->link_state)

   324

        return;

   325

   326

    ec_slave_mbox_prepare_check(eoe->slave, &eoe->datagram);

   327

    ec_master_queue_datagram(eoe->slave->master, &eoe->datagram);

   328

    eoe->state = ec_eoe_state_rx_check;

   329

}

   330

   331

/*****************************************************************************/

   332

   333

/**

   334

   State: RX_CHECK.

   335

   Processes the checking datagram sent in RX_START and issues a receive

   336

   datagram, if new data is available.

   337

*/

   338

   339

void ec_eoe_state_rx_check(ec_eoe_t *eoe /**< EoE handler */)

   340

{

   341

    if (eoe->datagram.state != EC_DATAGRAM_RECEIVED) {

   342

        eoe->stats.rx_errors++;

   343

        eoe->state = ec_eoe_state_tx_start;

   344

        return;

   345

    }

   346

   347

    if (!ec_slave_mbox_check(&eoe->datagram)) {

   348

        eoe->state = ec_eoe_state_tx_start;

   349

        return;

   350

    }

   351

   352

    ec_slave_mbox_prepare_fetch(eoe->slave, &eoe->datagram);

   353

    ec_master_queue_datagram(eoe->slave->master, &eoe->datagram);

   354

    eoe->state = ec_eoe_state_rx_fetch;

   355

}

   356

   357

/*****************************************************************************/

   358

   359

/**

   360

   State: RX_FETCH.

   361

   Checks if the requested data of RX_CHECK was received and processes the

   362

   EoE datagram.

   363

*/

   364

   365

void ec_eoe_state_rx_fetch(ec_eoe_t *eoe /**< EoE handler */)

   366

{

   367

    size_t rec_size, data_size;

   368

    uint8_t *data, frame_type, last_fragment, time_appended;

   369

    uint8_t frame_number, fragment_offset, fragment_number;

   370

    off_t offset;

   374

   375

    if (eoe->datagram.state != EC_DATAGRAM_RECEIVED) {

   376

        eoe->stats.rx_errors++;

   377

        eoe->state = ec_eoe_state_tx_start;

   378

        return;

   379

    }

   380

   381

    if (!(data = ec_slave_mbox_fetch(eoe->slave, &eoe->datagram,

   382

                                     0x02, &rec_size))) {

   383

        eoe->stats.rx_errors++;

   384

        eoe->state = ec_eoe_state_tx_start;

   385

        return;

   386

    }

   387

   388

    frame_type = EC_READ_U16(data) & 0x000F;

   389

   390

    if (frame_type != 0x00) {

   391

#if EOE_DEBUG_LEVEL > 0

   392

        EC_DBG("other frame received.\n");

   393

#endif

   394

        eoe->stats.rx_dropped++;

   395

        eoe->state = ec_eoe_state_tx_start;

   396

        return;

   397

    }

   398

   399

    // EoE Fragment Request received

   400

   401

    last_fragment = (EC_READ_U16(data) >> 8) & 0x0001;

   402

    time_appended = (EC_READ_U16(data) >> 9) & 0x0001;

   403

    fragment_number = EC_READ_U16(data + 2) & 0x003F;

   404

    fragment_offset = (EC_READ_U16(data + 2) >> 6) & 0x003F;

   405

    frame_number = (EC_READ_U16(data + 2) >> 12) & 0x000F;

   406

   407

#if EOE_DEBUG_LEVEL > 0

   408

    EC_DBG("EoE RX fragment %i, offset %i, frame %i%s%s,"

   409

           " %i octets\n", fragment_number, fragment_offset,

   410

           frame_number,

   411

           last_fragment ? ", last fragment" : "",

   412

           time_appended ? ", + timestamp" : "",

   413

           time_appended ? rec_size - 8 : rec_size - 4);

   414

#endif

   415

   416

#if EOE_DEBUG_LEVEL > 1

   417

    EC_DBG("");

   418

    for (i = 0; i < rec_size - 4; i++) {

   419

        printk("%02X ", data[i + 4]);

   420

        if ((i + 1) % 16 == 0) {

   421

            printk("\n");

   422

            EC_DBG("");

   423

        }

   424

    }

   425

    printk("\n");

   426

#endif

   427

   428

    data_size = time_appended ? rec_size - 8 : rec_size - 4;

   429

   430

    if (!fragment_number) {

   431

        if (eoe->rx_skb) {

   432

            EC_WARN("EoE RX freeing old socket buffer...\n");

   433

            dev_kfree_skb(eoe->rx_skb);

   434

        }

   435

   436

        // new socket buffer

   437

        if (!(eoe->rx_skb = dev_alloc_skb(fragment_offset * 32))) {

   438

            if (printk_ratelimit())

   439

                EC_WARN("EoE RX low on mem. frame dropped.\n");

   440

            eoe->stats.rx_dropped++;

   441

            eoe->state = ec_eoe_state_tx_start;

   442

            return;

   443

        }

   444

   445

        eoe->rx_skb_offset = 0;

   446

        eoe->rx_skb_size = fragment_offset * 32;

   447

        eoe->rx_expected_fragment = 0;

   448

    }

   449

    else {

   450

        if (!eoe->rx_skb) {

   451

            eoe->stats.rx_dropped++;

   452

            eoe->state = ec_eoe_state_tx_start;

   453

            return;

   454

        }

   455

   456

        offset = fragment_offset * 32;

   457

        if (offset != eoe->rx_skb_offset ||

   458

            offset + data_size > eoe->rx_skb_size ||

   459

            fragment_number != eoe->rx_expected_fragment) {

   460

            dev_kfree_skb(eoe->rx_skb);

   461

            eoe->rx_skb = NULL;

   462

            eoe->stats.rx_errors++;

   463

            eoe->state = ec_eoe_state_tx_start;

   464

            return;

   465

        }

   466

    }

   467

   468

    // copy fragment into socket buffer

   469

    memcpy(skb_put(eoe->rx_skb, data_size), data + 4, data_size);

   470

    eoe->rx_skb_offset += data_size;

   471

   472

    if (last_fragment) {

   473

        // update statistics

   474

        eoe->stats.rx_packets++;

   475

        eoe->stats.rx_bytes += eoe->rx_skb->len;

   476

        eoe->rx_counter += eoe->rx_skb->len;

   477

   478

#if EOE_DEBUG_LEVEL > 0

   479

        EC_DBG("EoE RX frame completed with %u octets.\n",

   480

               eoe->rx_skb->len);

   481

#endif

   482

   483

        // pass socket buffer to network stack

   484

        eoe->rx_skb->dev = eoe->dev;

   485

        eoe->rx_skb->protocol = eth_type_trans(eoe->rx_skb, eoe->dev);

   486

        eoe->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;

   487

        if (netif_rx(eoe->rx_skb)) {

   488

            EC_WARN("EoE RX netif_rx failed.\n");

   489

        }

   490

        eoe->rx_skb = NULL;