1

/* PTP Hardware Clock (PHC) driver for the Intel 82576 and 82580

     2

 *

     3

 * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>

     4

 *

     5

 * This program is free software; you can redistribute it and/or modify

     6

 * it under the terms of the GNU General Public License as published by

     7

 * the Free Software Foundation; either version 2 of the License, or

     8

 * (at your option) any later version.

     9

 *

    10

 * This program is distributed in the hope that it will be useful,

    11

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

    12

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 * GNU General Public License for more details.

    14

 *

    15

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

    16

 * this program; if not, see <http://www.gnu.org/licenses/>.

    17

 */

    18

#include <linux/module.h>

    19

#include <linux/device.h>

    20

#include <linux/pci.h>

    21

#include <linux/ptp_classify.h>

    22

    23

#include "igb.h"

    24

    25

#define INCVALUE_MASK		0x7fffffff

    26

#define ISGN			0x80000000

    27

    28

/* The 82580 timesync updates the system timer every 8ns by 8ns,

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 * and this update value cannot be reprogrammed.

    30

 *

    31

 * Neither the 82576 nor the 82580 offer registers wide enough to hold

    32

 * nanoseconds time values for very long. For the 82580, SYSTIM always

    33

 * counts nanoseconds, but the upper 24 bits are not availible. The

    34

 * frequency is adjusted by changing the 32 bit fractional nanoseconds

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 * register, TIMINCA.

    36

 *

    37

 * For the 82576, the SYSTIM register time unit is affect by the

    38

 * choice of the 24 bit TININCA:IV (incvalue) field. Five bits of this

    39

 * field are needed to provide the nominal 16 nanosecond period,

    40

 * leaving 19 bits for fractional nanoseconds.

    41

 *

    42

 * We scale the NIC clock cycle by a large factor so that relatively

    43

 * small clock corrections can be added or subtracted at each clock

    44

 * tick. The drawbacks of a large factor are a) that the clock

    45

 * register overflows more quickly (not such a big deal) and b) that

    46

 * the increment per tick has to fit into 24 bits.  As a result we

    47

 * need to use a shift of 19 so we can fit a value of 16 into the

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 * TIMINCA register.

    49

 *

    50

 *

    51

 *             SYSTIMH            SYSTIML

    52

 *        +--------------+   +---+---+------+

    53

 *  82576 |      32      |   | 8 | 5 |  19  |

    54

 *        +--------------+   +---+---+------+

    55

 *         \________ 45 bits _______/  fract

    56

 *

    57

 *        +----------+---+   +--------------+

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 *  82580 |    24    | 8 |   |      32      |

    59

 *        +----------+---+   +--------------+

    60

 *          reserved  \______ 40 bits _____/

    61

 *

    62

 *

    63

 * The 45 bit 82576 SYSTIM overflows every

    64

 *   2^45 * 10^-9 / 3600 = 9.77 hours.

    65

 *

    66

 * The 40 bit 82580 SYSTIM overflows every

    67

 *   2^40 * 10^-9 /  60  = 18.3 minutes.

    68

 */

    69

    70

#define IGB_SYSTIM_OVERFLOW_PERIOD	(HZ * 60 * 9)

    71

#define IGB_PTP_TX_TIMEOUT		(HZ * 15)

    72

#define INCPERIOD_82576			(1 << E1000_TIMINCA_16NS_SHIFT)

    73

#define INCVALUE_82576_MASK		((1 << E1000_TIMINCA_16NS_SHIFT) - 1)

    74

#define INCVALUE_82576			(16 << IGB_82576_TSYNC_SHIFT)

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#define IGB_NBITS_82580			40

    76

    77

static void igb_ptp_tx_hwtstamp(struct igb_adapter *adapter);

    78

    79

/* SYSTIM read access for the 82576 */

    80

static cycle_t igb_ptp_read_82576(const struct cyclecounter *cc)

    81

{

    82

	struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);

    83

	struct e1000_hw *hw = &igb->hw;

    84

	u64 val;

    85

	u32 lo, hi;

    86

    87

	lo = rd32(E1000_SYSTIML);

    88

	hi = rd32(E1000_SYSTIMH);

    89

    90

	val = ((u64) hi) << 32;

    91

	val |= lo;

    92

    93

	return val;

    94

}

    95

    96

/* SYSTIM read access for the 82580 */

    97

static cycle_t igb_ptp_read_82580(const struct cyclecounter *cc)

    98

{

    99

	struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);

   100

	struct e1000_hw *hw = &igb->hw;

   101

	u32 lo, hi;

   102

	u64 val;

   103

   104

	/* The timestamp latches on lowest register read. For the 82580

   105

	 * the lowest register is SYSTIMR instead of SYSTIML.  However we only

   106

	 * need to provide nanosecond resolution, so we just ignore it.

   107

	 */

   108

	rd32(E1000_SYSTIMR);

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	lo = rd32(E1000_SYSTIML);

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	hi = rd32(E1000_SYSTIMH);

   111

   112

	val = ((u64) hi) << 32;

   113

	val |= lo;

   114

   115

	return val;

   116

}

   117

   118

/* SYSTIM read access for I210/I211 */

   119

static void igb_ptp_read_i210(struct igb_adapter *adapter, struct timespec *ts)

   120

{

   121

	struct e1000_hw *hw = &adapter->hw;

   122

	u32 sec, nsec;

   123

   124

	/* The timestamp latches on lowest register read. For I210/I211, the

   125

	 * lowest register is SYSTIMR. Since we only need to provide nanosecond

   126

	 * resolution, we can ignore it.

   127

	 */

   128

	rd32(E1000_SYSTIMR);

   129

	nsec = rd32(E1000_SYSTIML);

   130

	sec = rd32(E1000_SYSTIMH);

   131

   132

	ts->tv_sec = sec;

   133

	ts->tv_nsec = nsec;

   134

}

   135

   136

static void igb_ptp_write_i210(struct igb_adapter *adapter,

   137

			       const struct timespec *ts)

   138

{

   139

	struct e1000_hw *hw = &adapter->hw;

   140

   141

	/* Writing the SYSTIMR register is not necessary as it only provides

   142

	 * sub-nanosecond resolution.

   143

	 */

   144

	wr32(E1000_SYSTIML, ts->tv_nsec);

   145

	wr32(E1000_SYSTIMH, ts->tv_sec);

   146

}

   147

   148

/**

   149

 * igb_ptp_systim_to_hwtstamp - convert system time value to hw timestamp

   150

 * @adapter: board private structure

   151

 * @hwtstamps: timestamp structure to update

   152

 * @systim: unsigned 64bit system time value.

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 *

   154

 * We need to convert the system time value stored in the RX/TXSTMP registers

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 * into a hwtstamp which can be used by the upper level timestamping functions.

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 *

   157

 * The 'tmreg_lock' spinlock is used to protect the consistency of the

   158

 * system time value. This is needed because reading the 64 bit time

   159

 * value involves reading two (or three) 32 bit registers. The first

   160

 * read latches the value. Ditto for writing.

   161

 *

   162

 * In addition, here have extended the system time with an overflow

   163

 * counter in software.

   164

 **/

   165

static void igb_ptp_systim_to_hwtstamp(struct igb_adapter *adapter,

   166

				       struct skb_shared_hwtstamps *hwtstamps,

   167

				       u64 systim)

   168

{

   169

	unsigned long flags;

   170

	u64 ns;

   171

   172

	switch (adapter->hw.mac.type) {

   173

	case e1000_82576:

   174

	case e1000_82580:

   175

	case e1000_i354:

   176

	case e1000_i350:

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		spin_lock_irqsave(&adapter->tmreg_lock, flags);

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   179

		ns = timecounter_cyc2time(&adapter->tc, systim);

   180

   181

		spin_unlock_irqrestore(&adapter->tmreg_lock, flags);

   182

   183

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

   184

		hwtstamps->hwtstamp = ns_to_ktime(ns);

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		break;

   186

	case e1000_i210:

   187

	case e1000_i211:

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

   189

		/* Upper 32 bits contain s, lower 32 bits contain ns. */

   190

		hwtstamps->hwtstamp = ktime_set(systim >> 32,

   191

						systim & 0xFFFFFFFF);

   192

		break;

   193

	default:

   194

		break;

   195

	}

   196

}

   197

   198

/* PTP clock operations */

   199

static int igb_ptp_adjfreq_82576(struct ptp_clock_info *ptp, s32 ppb)

   200

{

   201

	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,

   202

					       ptp_caps);

   203

	struct e1000_hw *hw = &igb->hw;

   204

	int neg_adj = 0;

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	u64 rate;

   206

	u32 incvalue;

   207

   208

	if (ppb < 0) {

   209

		neg_adj = 1;

   210

		ppb = -ppb;

   211

	}

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	rate = ppb;

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	rate <<= 14;

   214

	rate = div_u64(rate, 1953125);

   215

   216

	incvalue = 16 << IGB_82576_TSYNC_SHIFT;

   217

   218

	if (neg_adj)

   219

		incvalue -= rate;

   220

	else

   221

		incvalue += rate;

   222

   223

	wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue & INCVALUE_82576_MASK));

   224

   225

	return 0;

   226

}

   227

   228

static int igb_ptp_adjfreq_82580(struct ptp_clock_info *ptp, s32 ppb)

   229

{

   230

	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,

   231

					       ptp_caps);

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	struct e1000_hw *hw = &igb->hw;

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	int neg_adj = 0;

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	u64 rate;

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	u32 inca;

   236

   237

	if (ppb < 0) {

   238

		neg_adj = 1;

   239

		ppb = -ppb;

   240

	}

   241

	rate = ppb;

   242

	rate <<= 26;

   243

	rate = div_u64(rate, 1953125);

   244

   245

	inca = rate & INCVALUE_MASK;

   246

	if (neg_adj)

   247

		inca |= ISGN;

   248

   249

	wr32(E1000_TIMINCA, inca);

   250

   251

	return 0;

   252

}

   253

   254

static int igb_ptp_adjtime_82576(struct ptp_clock_info *ptp, s64 delta)

   255

{

   256

	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,

   257

					       ptp_caps);

   258

	unsigned long flags;

   259

	s64 now;

   260

   261

	spin_lock_irqsave(&igb->tmreg_lock, flags);

   262

   263

	now = timecounter_read(&igb->tc);

   264

	now += delta;

   265

	timecounter_init(&igb->tc, &igb->cc, now);

   266

   267

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

   268

   269

	return 0;

   270

}

   271

   272

static int igb_ptp_adjtime_i210(struct ptp_clock_info *ptp, s64 delta)

   273

{

   274

	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,

   275

					       ptp_caps);

   276

	unsigned long flags;

   277

	struct timespec now, then = ns_to_timespec(delta);

   278

   279

	spin_lock_irqsave(&igb->tmreg_lock, flags);

   280

   281

	igb_ptp_read_i210(igb, &now);

   282

	now = timespec_add(now, then);

   283

	igb_ptp_write_i210(igb, (const struct timespec *)&now);

   284

   285

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

   286

   287

	return 0;

   288

}

   289

   290

static int igb_ptp_gettime_82576(struct ptp_clock_info *ptp,

   291

				 struct timespec *ts)

   292

{

   293

	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,

   294

					       ptp_caps);

   295

	unsigned long flags;

   296

	u64 ns;

   297

	u32 remainder;

   298

   299

	spin_lock_irqsave(&igb->tmreg_lock, flags);

   300

   301

	ns = timecounter_read(&igb->tc);

   302

   303

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

   304

   305

	ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);

   306

	ts->tv_nsec = remainder;

   307

   308

	return 0;

   309

}

   310

   311

static int igb_ptp_gettime_i210(struct ptp_clock_info *ptp,

   312

				struct timespec *ts)

   313

{

   314

	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,

   315

					       ptp_caps);

   316

	unsigned long flags;

   317

   318

	spin_lock_irqsave(&igb->tmreg_lock, flags);

   319

   320

	igb_ptp_read_i210(igb, ts);

   321

   322

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

   323

   324

	return 0;

   325

}

   326

   327

static int igb_ptp_settime_82576(struct ptp_clock_info *ptp,

   328

				 const struct timespec *ts)

   329

{

   330

	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,

   331

					       ptp_caps);

   332

	unsigned long flags;

   333

	u64 ns;

   334

   335

	ns = ts->tv_sec * 1000000000ULL;

   336

	ns += ts->tv_nsec;

   337

   338

	spin_lock_irqsave(&igb->tmreg_lock, flags);

   339

   340

	timecounter_init(&igb->tc, &igb->cc, ns);

   341

   342

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

   343

   344

	return 0;

   345

}

   346

   347

static int igb_ptp_settime_i210(struct ptp_clock_info *ptp,

   348

				const struct timespec *ts)

   349

{

   350

	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,

   351

					       ptp_caps);

   352

	unsigned long flags;

   353

   354

	spin_lock_irqsave(&igb->tmreg_lock, flags);

   355

   356

	igb_ptp_write_i210(igb, ts);

   357

   358

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

   359

   360

	return 0;

   361

}

   362

   363

static int igb_ptp_feature_enable(struct ptp_clock_info *ptp,

   364

				  struct ptp_clock_request *rq, int on)

   365

{

   366

	return -EOPNOTSUPP;

   367

}

   368

   369

/**

   370

 * igb_ptp_tx_work

   371

 * @work: pointer to work struct

   372

 *

   373

 * This work function polls the TSYNCTXCTL valid bit to determine when a

   374

 * timestamp has been taken for the current stored skb.

   375

 **/

   376

static void igb_ptp_tx_work(struct work_struct *work)

   377

{

   378

	struct igb_adapter *adapter = container_of(work, struct igb_adapter,

   379

						   ptp_tx_work);

   380

	struct e1000_hw *hw = &adapter->hw;

   381

	u32 tsynctxctl;

   382

   383

	if (!adapter->ptp_tx_skb)

   384

		return;

   385

   386

	if (time_is_before_jiffies(adapter->ptp_tx_start +

   387

				   IGB_PTP_TX_TIMEOUT)) {

   388

		dev_kfree_skb_any(adapter->ptp_tx_skb);

   389

		adapter->ptp_tx_skb = NULL;

   390

		clear_bit_unlock(__IGB_PTP_TX_IN_PROGRESS, &adapter->state);

   391

		adapter->tx_hwtstamp_timeouts++;

   392

		dev_warn(&adapter->pdev->dev, "clearing Tx timestamp hang\n");

   393

		return;

   394

	}

   395

   396

	tsynctxctl = rd32(E1000_TSYNCTXCTL);

   397

	if (tsynctxctl & E1000_TSYNCTXCTL_VALID)

   398

		igb_ptp_tx_hwtstamp(adapter);

   399

	else

   400

		/* reschedule to check later */

   401

		schedule_work(&adapter->ptp_tx_work);

   402

}

   403

   404

static void igb_ptp_overflow_check(struct work_struct *work)

   405

{

   406

	struct igb_adapter *igb =

   407

		container_of(work, struct igb_adapter, ptp_overflow_work.work);

   408

	struct timespec ts;

   409

   410

	igb->ptp_caps.gettime(&igb->ptp_caps, &ts);

   411

   412

	pr_debug("igb overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);

   413

   414

	schedule_delayed_work(&igb->ptp_overflow_work,

   415

			      IGB_SYSTIM_OVERFLOW_PERIOD);

   416

}

   417

   418

/**

   419

 * igb_ptp_rx_hang - detect error case when Rx timestamp registers latched

   420

 * @adapter: private network adapter structure

   421

 *

   422

 * This watchdog task is scheduled to detect error case where hardware has

   423

 * dropped an Rx packet that was timestamped when the ring is full. The

   424

 * particular error is rare but leaves the device in a state unable to timestamp

   425

 * any future packets.

   426

 **/

   427

void igb_ptp_rx_hang(struct igb_adapter *adapter)

   428

{

   429

	struct e1000_hw *hw = &adapter->hw;

   430

	u32 tsyncrxctl = rd32(E1000_TSYNCRXCTL);

   431

	unsigned long rx_event;

   432

   433

	if (hw->mac.type != e1000_82576)

   434

		return;

   435

   436

	/* If we don't have a valid timestamp in the registers, just update the

   437

	 * timeout counter and exit

   438

	 */

   439

	if (!(tsyncrxctl & E1000_TSYNCRXCTL_VALID)) {

   440

		adapter->last_rx_ptp_check = jiffies;

   441

		return;

   442

	}

   443

   444

	/* Determine the most recent watchdog or rx_timestamp event */

   445

	rx_event = adapter->last_rx_ptp_check;

   446

	if (time_after(adapter->last_rx_timestamp, rx_event))

   447

		rx_event = adapter->last_rx_timestamp;

   448

   449

	/* Only need to read the high RXSTMP register to clear the lock */

   450

	if (time_is_before_jiffies(rx_event + 5 * HZ)) {

   451

		rd32(E1000_RXSTMPH);

   452

		adapter->last_rx_ptp_check = jiffies;

   453

		adapter->rx_hwtstamp_cleared++;

   454

		dev_warn(&adapter->pdev->dev, "clearing Rx timestamp hang\n");

   455

	}

   456

}

   457

   458

/**

   459

 * igb_ptp_tx_hwtstamp - utility function which checks for TX time stamp

   460

 * @adapter: Board private structure.

   461

 *

   462

 * If we were asked to do hardware stamping and such a time stamp is

   463

 * available, then it must have been for this skb here because we only

   464

 * allow only one such packet into the queue.

   465

 **/

   466

static void igb_ptp_tx_hwtstamp(struct igb_adapter *adapter)

   467

{

   468

	struct e1000_hw *hw = &adapter->hw;

   469

	struct skb_shared_hwtstamps shhwtstamps;

   470

	u64 regval;

   471

   472

	regval = rd32(E1000_TXSTMPL);

   473

	regval |= (u64)rd32(E1000_TXSTMPH) << 32;

   474

   475

	igb_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval);

   476

	skb_tstamp_tx(adapter->ptp_tx_skb, &shhwtstamps);

   477

	dev_kfree_skb_any(adapter->ptp_tx_skb);

   478

	adapter->ptp_tx_skb = NULL;

   479

	clear_bit_unlock(__IGB_PTP_TX_IN_PROGRESS, &adapter->state);

   480

}

   481

   482

/**

   483

 * igb_ptp_rx_pktstamp - retrieve Rx per packet timestamp

   484

 * @q_vector: Pointer to interrupt specific structure

   485

 * @va: Pointer to address containing Rx buffer

   486

 * @skb: Buffer containing timestamp and packet

   487

 *

   488

 * This function is meant to retrieve a timestamp from the first buffer of an

   489

 * incoming frame.  The value is stored in little endian format starting on

   490

 * byte 8.

   491

 **/

   492

void igb_ptp_rx_pktstamp(struct igb_q_vector *q_vector,

   493

			 unsigned char *va,

   494

			 struct sk_buff *skb)

   495

{

   496

	__le64 *regval = (__le64 *)va;

   497

   498

	/* The timestamp is recorded in little endian format.

   499

	 * DWORD: 0        1        2        3

   500

	 * Field: Reserved Reserved SYSTIML  SYSTIMH

   501

	 */

   502

	igb_ptp_systim_to_hwtstamp(q_vector->adapter, skb_hwtstamps(skb),

   503

				   le64_to_cpu(regval[1]));

   504

}

   505

   506

/**

   507

 * igb_ptp_rx_rgtstamp - retrieve Rx timestamp stored in register

   508

 * @q_vector: Pointer to interrupt specific structure

   509

 * @skb: Buffer containing timestamp and packet

   510

 *

   511

 * This function is meant to retrieve a timestamp from the internal registers

   512

 * of the adapter and store it in the skb.

   513

 **/

   514

void igb_ptp_rx_rgtstamp(struct igb_q_vector *q_vector,

   515

			 struct sk_buff *skb)

   516

{

   517

	struct igb_adapter *adapter = q_vector->adapter;

   518

	struct e1000_hw *hw = &adapter->hw;

   519

	u64 regval;

   520

   521

	/* If this bit is set, then the RX registers contain the time stamp. No

   522

	 * other packet will be time stamped until we read these registers, so

   523

	 * read the registers to make them available again. Because only one

   524

	 * packet can be time stamped at a time, we know that the register

   525

	 * values must belong to this one here and therefore we don't need to

   526

	 * compare any of the additional attributes stored for it.

   527

	 *

   528

	 * If nothing went wrong, then it should have a shared tx_flags that we

   529

	 * can turn into a skb_shared_hwtstamps.

   530