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

     2

     3

  Intel PRO/1000 Linux driver

     4

  Copyright(c) 1999 - 2012 Intel Corporation.

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

     7

  under the terms and conditions of the GNU General Public License,

     8

  version 2, as published by the Free Software Foundation.

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    10

  This program is distributed in the hope it will be useful, but WITHOUT

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  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    12

  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

    13

  more details.

    14

    15

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

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  this program; if not, write to the Free Software Foundation, Inc.,

    17

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

    18

    19

  The full GNU General Public License is included in this distribution in

    20

  the file called "COPYING".

    21

    22

  Contact Information:

    23

  Linux NICS <linux.nics@intel.com>

    24

  e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>

    25

  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497

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    27

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

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    29

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

    30

    31

#include <linux/module.h>

    32

#include <linux/types.h>

    33

#include <linux/init.h>

    34

#include <linux/pci.h>

    35

#include <linux/vmalloc.h>

    36

#include <linux/pagemap.h>

    37

#include <linux/delay.h>

    38

#include <linux/netdevice.h>

    39

#include <linux/interrupt.h>

    40

#include <linux/tcp.h>

    41

#include <linux/ipv6.h>

    42

#include <linux/slab.h>

    43

#include <net/checksum.h>

    44

#include <net/ip6_checksum.h>

    45

#include <linux/mii.h>

    46

#include <linux/ethtool.h>

    47

#include <linux/if_vlan.h>

    48

#include <linux/cpu.h>

    49

#include <linux/smp.h>

    50

#include <linux/pm_qos.h>

    51

#include <linux/pm_runtime.h>

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#include <linux/aer.h>

    53

#include <linux/prefetch.h>

    54

    55

#include "e1000.h"

    56

    57

#define DRV_EXTRAVERSION "-k"

    58

    59

#define DRV_VERSION "1.9.5" DRV_EXTRAVERSION

    60

char e1000e_driver_name[] = "e1000e";

    61

const char e1000e_driver_version[] = DRV_VERSION;

    62

    63

#define DEFAULT_MSG_ENABLE (NETIF_MSG_DRV|NETIF_MSG_PROBE|NETIF_MSG_LINK)

    64

static int debug = -1;

    65

module_param(debug, int, 0);

    66

MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");

    67

    68

static void e1000e_disable_aspm(struct pci_dev *pdev, u16 state);

    69

    70

static const struct e1000_info *e1000_info_tbl[] = {

    71

	[board_82571]		= &e1000_82571_info,

    72

	[board_82572]		= &e1000_82572_info,

    73

	[board_82573]		= &e1000_82573_info,

    74

	[board_82574]		= &e1000_82574_info,

    75

	[board_82583]		= &e1000_82583_info,

    76

	[board_80003es2lan]	= &e1000_es2_info,

    77

	[board_ich8lan]		= &e1000_ich8_info,

    78

	[board_ich9lan]		= &e1000_ich9_info,

    79

	[board_ich10lan]	= &e1000_ich10_info,

    80

	[board_pchlan]		= &e1000_pch_info,

    81

	[board_pch2lan]		= &e1000_pch2_info,

    82

};

    83

    84

struct e1000_reg_info {

    85

	u32 ofs;

    86

	char *name;

    87

};

    88

    89

#define E1000_RDFH	0x02410	/* Rx Data FIFO Head - RW */

    90

#define E1000_RDFT	0x02418	/* Rx Data FIFO Tail - RW */

    91

#define E1000_RDFHS	0x02420	/* Rx Data FIFO Head Saved - RW */

    92

#define E1000_RDFTS	0x02428	/* Rx Data FIFO Tail Saved - RW */

    93

#define E1000_RDFPC	0x02430	/* Rx Data FIFO Packet Count - RW */

    94

    95

#define E1000_TDFH	0x03410	/* Tx Data FIFO Head - RW */

    96

#define E1000_TDFT	0x03418	/* Tx Data FIFO Tail - RW */

    97

#define E1000_TDFHS	0x03420	/* Tx Data FIFO Head Saved - RW */

    98

#define E1000_TDFTS	0x03428	/* Tx Data FIFO Tail Saved - RW */

    99

#define E1000_TDFPC	0x03430	/* Tx Data FIFO Packet Count - RW */

   100

   101

static const struct e1000_reg_info e1000_reg_info_tbl[] = {

   102

   103

	/* General Registers */

   104

	{E1000_CTRL, "CTRL"},

   105

	{E1000_STATUS, "STATUS"},

   106

	{E1000_CTRL_EXT, "CTRL_EXT"},

   107

   108

	/* Interrupt Registers */

   109

	{E1000_ICR, "ICR"},

   110

   111

	/* Rx Registers */

   112

	{E1000_RCTL, "RCTL"},

   113

	{E1000_RDLEN, "RDLEN"},

   114

	{E1000_RDH, "RDH"},

   115

	{E1000_RDT, "RDT"},

   116

	{E1000_RDTR, "RDTR"},

   117

	{E1000_RXDCTL(0), "RXDCTL"},

   118

	{E1000_ERT, "ERT"},

   119

	{E1000_RDBAL, "RDBAL"},

   120

	{E1000_RDBAH, "RDBAH"},

   121

	{E1000_RDFH, "RDFH"},

   122

	{E1000_RDFT, "RDFT"},

   123

	{E1000_RDFHS, "RDFHS"},

   124

	{E1000_RDFTS, "RDFTS"},

   125

	{E1000_RDFPC, "RDFPC"},

   126

   127

	/* Tx Registers */

   128

	{E1000_TCTL, "TCTL"},

   129

	{E1000_TDBAL, "TDBAL"},

   130

	{E1000_TDBAH, "TDBAH"},

   131

	{E1000_TDLEN, "TDLEN"},

   132

	{E1000_TDH, "TDH"},

   133

	{E1000_TDT, "TDT"},

   134

	{E1000_TIDV, "TIDV"},

   135

	{E1000_TXDCTL(0), "TXDCTL"},

   136

	{E1000_TADV, "TADV"},

   137

	{E1000_TARC(0), "TARC"},

   138

	{E1000_TDFH, "TDFH"},

   139

	{E1000_TDFT, "TDFT"},

   140

	{E1000_TDFHS, "TDFHS"},

   141

	{E1000_TDFTS, "TDFTS"},

   142

	{E1000_TDFPC, "TDFPC"},

   143

   144

	/* List Terminator */

   145

	{0, NULL}

   146

};

   147

   148

/*

   149

 * e1000_regdump - register printout routine

   150

 */

   151

static void e1000_regdump(struct e1000_hw *hw, struct e1000_reg_info *reginfo)

   152

{

   153

	int n = 0;

   154

	char rname[16];

   155

	u32 regs[8];

   156

   157

	switch (reginfo->ofs) {

   158

	case E1000_RXDCTL(0):

   159

		for (n = 0; n < 2; n++)

   160

			regs[n] = __er32(hw, E1000_RXDCTL(n));

   161

		break;

   162

	case E1000_TXDCTL(0):

   163

		for (n = 0; n < 2; n++)

   164

			regs[n] = __er32(hw, E1000_TXDCTL(n));

   165

		break;

   166

	case E1000_TARC(0):

   167

		for (n = 0; n < 2; n++)

   168

			regs[n] = __er32(hw, E1000_TARC(n));

   169

		break;

   170

	default:

   171

		pr_info("%-15s %08x\n",

   172

			reginfo->name, __er32(hw, reginfo->ofs));

   173

		return;

   174

	}

   175

   176

	snprintf(rname, 16, "%s%s", reginfo->name, "[0-1]");

   177

	pr_info("%-15s %08x %08x\n", rname, regs[0], regs[1]);

   178

}

   179

   180

/*

   181

 * e1000e_dump - Print registers, Tx-ring and Rx-ring

   182

 */

   183

static void e1000e_dump(struct e1000_adapter *adapter)

   184

{

   185

	struct net_device *netdev = adapter->netdev;

   186

	struct e1000_hw *hw = &adapter->hw;

   187

	struct e1000_reg_info *reginfo;

   188

	struct e1000_ring *tx_ring = adapter->tx_ring;

   189

	struct e1000_tx_desc *tx_desc;

   190

	struct my_u0 {

   191

		__le64 a;

   192

		__le64 b;

   193

	} *u0;

   194

	struct e1000_buffer *buffer_info;

   195

	struct e1000_ring *rx_ring = adapter->rx_ring;

   196

	union e1000_rx_desc_packet_split *rx_desc_ps;

   197

	union e1000_rx_desc_extended *rx_desc;

   198

	struct my_u1 {

   199

		__le64 a;

   200

		__le64 b;

   201

		__le64 c;

   202

		__le64 d;

   203

	} *u1;

   204

	u32 staterr;

   205

	int i = 0;

   206

   207

	if (!netif_msg_hw(adapter))

   208

		return;

   209

   210

	/* Print netdevice Info */

   211

	if (netdev) {

   212

		dev_info(&adapter->pdev->dev, "Net device Info\n");

   213

		pr_info("Device Name     state            trans_start      last_rx\n");

   214

		pr_info("%-15s %016lX %016lX %016lX\n",

   215

			netdev->name, netdev->state, netdev->trans_start,

   216

			netdev->last_rx);

   217

	}

   218

   219

	/* Print Registers */

   220

	dev_info(&adapter->pdev->dev, "Register Dump\n");

   221

	pr_info(" Register Name   Value\n");

   222

	for (reginfo = (struct e1000_reg_info *)e1000_reg_info_tbl;

   223

	     reginfo->name; reginfo++) {

   224

		e1000_regdump(hw, reginfo);

   225

	}

   226

   227

	/* Print Tx Ring Summary */

   228

	if (!netdev || !netif_running(netdev))

   229

		return;

   230

   231

	dev_info(&adapter->pdev->dev, "Tx Ring Summary\n");

   232

	pr_info("Queue [NTU] [NTC] [bi(ntc)->dma  ] leng ntw timestamp\n");

   233

	buffer_info = &tx_ring->buffer_info[tx_ring->next_to_clean];

   234

	pr_info(" %5d %5X %5X %016llX %04X %3X %016llX\n",

   235

		0, tx_ring->next_to_use, tx_ring->next_to_clean,

   236

		(unsigned long long)buffer_info->dma,

   237

		buffer_info->length,

   238

		buffer_info->next_to_watch,

   239

		(unsigned long long)buffer_info->time_stamp);

   240

   241

	/* Print Tx Ring */

   242

	if (!netif_msg_tx_done(adapter))

   243

		goto rx_ring_summary;

   244

   245

	dev_info(&adapter->pdev->dev, "Tx Ring Dump\n");

   246

   247

	/* Transmit Descriptor Formats - DEXT[29] is 0 (Legacy) or 1 (Extended)

   248

	 *

   249

	 * Legacy Transmit Descriptor

   250

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

   251

	 * 0 |         Buffer Address [63:0] (Reserved on Write Back)       |

   252

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

   253

	 * 8 | Special  |    CSS     | Status |  CMD    |  CSO   |  Length  |

   254

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

   255

	 *   63       48 47        36 35    32 31     24 23    16 15        0

   256

	 *

   257

	 * Extended Context Descriptor (DTYP=0x0) for TSO or checksum offload

   258

	 *   63      48 47    40 39       32 31             16 15    8 7      0

   259

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

   260

	 * 0 |  TUCSE  | TUCS0  |   TUCSS   |     IPCSE       | IPCS0 | IPCSS |

   261

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

   262

	 * 8 |   MSS   | HDRLEN | RSV | STA | TUCMD | DTYP |      PAYLEN      |

   263

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

   264

	 *   63      48 47    40 39 36 35 32 31   24 23  20 19                0

   265

	 *

   266

	 * Extended Data Descriptor (DTYP=0x1)

   267

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

   268

	 * 0 |                     Buffer Address [63:0]                      |

   269

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

   270

	 * 8 | VLAN tag |  POPTS  | Rsvd | Status | Command | DTYP |  DTALEN  |

   271

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

   272

	 *   63       48 47     40 39  36 35    32 31     24 23  20 19        0

   273

	 */

   274

	pr_info("Tl[desc]     [address 63:0  ] [SpeCssSCmCsLen] [bi->dma       ] leng  ntw timestamp        bi->skb <-- Legacy format\n");

   275

	pr_info("Tc[desc]     [Ce CoCsIpceCoS] [MssHlRSCm0Plen] [bi->dma       ] leng  ntw timestamp        bi->skb <-- Ext Context format\n");

   276

	pr_info("Td[desc]     [address 63:0  ] [VlaPoRSCm1Dlen] [bi->dma       ] leng  ntw timestamp        bi->skb <-- Ext Data format\n");

   277

	for (i = 0; tx_ring->desc && (i < tx_ring->count); i++) {

   278

		const char *next_desc;

   279

		tx_desc = E1000_TX_DESC(*tx_ring, i);

   280

		buffer_info = &tx_ring->buffer_info[i];

   281

		u0 = (struct my_u0 *)tx_desc;

   282

		if (i == tx_ring->next_to_use && i == tx_ring->next_to_clean)

   283

			next_desc = " NTC/U";

   284

		else if (i == tx_ring->next_to_use)

   285

			next_desc = " NTU";

   286

		else if (i == tx_ring->next_to_clean)

   287

			next_desc = " NTC";

   288

		else

   289

			next_desc = "";

   290

		pr_info("T%c[0x%03X]    %016llX %016llX %016llX %04X  %3X %016llX %p%s\n",

   291

			(!(le64_to_cpu(u0->b) & (1 << 29)) ? 'l' :

   292

			 ((le64_to_cpu(u0->b) & (1 << 20)) ? 'd' : 'c')),

   293

			i,

   294

			(unsigned long long)le64_to_cpu(u0->a),

   295

			(unsigned long long)le64_to_cpu(u0->b),

   296

			(unsigned long long)buffer_info->dma,

   297

			buffer_info->length, buffer_info->next_to_watch,

   298

			(unsigned long long)buffer_info->time_stamp,

   299

			buffer_info->skb, next_desc);

   300

   301

		if (netif_msg_pktdata(adapter) && buffer_info->dma != 0)

   302

			print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS,

   303

				       16, 1, phys_to_virt(buffer_info->dma),

   304

				       buffer_info->length, true);

   305

	}

   306

   307

	/* Print Rx Ring Summary */

   308

rx_ring_summary:

   309

	dev_info(&adapter->pdev->dev, "Rx Ring Summary\n");

   310

	pr_info("Queue [NTU] [NTC]\n");

   311

	pr_info(" %5d %5X %5X\n",

   312

		0, rx_ring->next_to_use, rx_ring->next_to_clean);

   313

   314

	/* Print Rx Ring */

   315

	if (!netif_msg_rx_status(adapter))

   316

		return;

   317

   318

	dev_info(&adapter->pdev->dev, "Rx Ring Dump\n");

   319

	switch (adapter->rx_ps_pages) {

   320

	case 1:

   321

	case 2:

   322

	case 3:

   323

		/* [Extended] Packet Split Receive Descriptor Format

   324

		 *

   325

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

   326

		 *  0 |                Buffer Address 0 [63:0]              |

   327

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

   328

		 *  8 |                Buffer Address 1 [63:0]              |

   329

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

   330

		 * 16 |                Buffer Address 2 [63:0]              |

   331

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

   332

		 * 24 |                Buffer Address 3 [63:0]              |

   333

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

   334

		 */

   335

		pr_info("R  [desc]      [buffer 0 63:0 ] [buffer 1 63:0 ] [buffer 2 63:0 ] [buffer 3 63:0 ] [bi->dma       ] [bi->skb] <-- Ext Pkt Split format\n");

   336

		/* [Extended] Receive Descriptor (Write-Back) Format

   337

		 *

   338

		 *   63       48 47    32 31     13 12    8 7    4 3        0

   339

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

   340

		 * 0 | Packet   | IP     |  Rsvd   | MRQ   | Rsvd | MRQ RSS |

   341

		 *   | Checksum | Ident  |         | Queue |      |  Type   |

   342

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

   343

		 * 8 | VLAN Tag | Length | Extended Error | Extended Status |

   344

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

   345

		 *   63       48 47    32 31            20 19               0

   346

		 */

   347

		pr_info("RWB[desc]      [ck ipid mrqhsh] [vl   l0 ee  es] [ l3  l2  l1 hs] [reserved      ] ---------------- [bi->skb] <-- Ext Rx Write-Back format\n");

   348

		for (i = 0; i < rx_ring->count; i++) {

   349

			const char *next_desc;

   350

			buffer_info = &rx_ring->buffer_info[i];

   351

			rx_desc_ps = E1000_RX_DESC_PS(*rx_ring, i);

   352

			u1 = (struct my_u1 *)rx_desc_ps;

   353

			staterr =

   354

			    le32_to_cpu(rx_desc_ps->wb.middle.status_error);

   355

   356

			if (i == rx_ring->next_to_use)

   357

				next_desc = " NTU";

   358

			else if (i == rx_ring->next_to_clean)

   359

				next_desc = " NTC";

   360

			else

   361

				next_desc = "";

   362

   363

			if (staterr & E1000_RXD_STAT_DD) {

   364

				/* Descriptor Done */

   365

				pr_info("%s[0x%03X]     %016llX %016llX %016llX %016llX ---------------- %p%s\n",

   366

					"RWB", i,

   367

					(unsigned long long)le64_to_cpu(u1->a),

   368

					(unsigned long long)le64_to_cpu(u1->b),

   369

					(unsigned long long)le64_to_cpu(u1->c),

   370

					(unsigned long long)le64_to_cpu(u1->d),

   371

					buffer_info->skb, next_desc);

   372

			} else {

   373

				pr_info("%s[0x%03X]     %016llX %016llX %016llX %016llX %016llX %p%s\n",

   374

					"R  ", i,

   375

					(unsigned long long)le64_to_cpu(u1->a),

   376

					(unsigned long long)le64_to_cpu(u1->b),

   377

					(unsigned long long)le64_to_cpu(u1->c),

   378

					(unsigned long long)le64_to_cpu(u1->d),

   379

					(unsigned long long)buffer_info->dma,

   380

					buffer_info->skb, next_desc);

   381

   382

				if (netif_msg_pktdata(adapter))

   383

					print_hex_dump(KERN_INFO, "",

   384

						DUMP_PREFIX_ADDRESS, 16, 1,

   385

						phys_to_virt(buffer_info->dma),

   386

						adapter->rx_ps_bsize0, true);

   387

			}

   388

		}

   389

		break;

   390

	default:

   391

	case 0:

   392

		/* Extended Receive Descriptor (Read) Format

   393

		 *

   394

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

   395

		 * 0 |                Buffer Address [63:0]                |

   396

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

   397

		 * 8 |                      Reserved                       |

   398

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

   399

		 */

   400

		pr_info("R  [desc]      [buf addr 63:0 ] [reserved 63:0 ] [bi->dma       ] [bi->skb] <-- Ext (Read) format\n");

   401

		/* Extended Receive Descriptor (Write-Back) Format

   402

		 *

   403

		 *   63       48 47    32 31    24 23            4 3        0

   404

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

   405

		 *   |     RSS Hash      |        |               |         |

   406

		 * 0 +-------------------+  Rsvd  |   Reserved    | MRQ RSS |

   407

		 *   | Packet   | IP     |        |               |  Type   |

   408

		 *   | Checksum | Ident  |        |               |         |

   409

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

   410

		 * 8 | VLAN Tag | Length | Extended Error | Extended Status |

   411

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

   412

		 *   63       48 47    32 31            20 19               0

   413

		 */

   414

		pr_info("RWB[desc]      [cs ipid    mrq] [vt   ln xe  xs] [bi->skb] <-- Ext (Write-Back) format\n");

   415

   416

		for (i = 0; i < rx_ring->count; i++) {

   417

			const char *next_desc;

   418

   419

			buffer_info = &rx_ring->buffer_info[i];

   420

			rx_desc = E1000_RX_DESC_EXT(*rx_ring, i);

   421

			u1 = (struct my_u1 *)rx_desc;

   422

			staterr = le32_to_cpu(rx_desc->wb.upper.status_error);

   423

   424

			if (i == rx_ring->next_to_use)

   425

				next_desc = " NTU";

   426

			else if (i == rx_ring->next_to_clean)

   427

				next_desc = " NTC";

   428

			else

   429

				next_desc = "";

   430

   431

			if (staterr & E1000_RXD_STAT_DD) {

   432

				/* Descriptor Done */

   433

				pr_info("%s[0x%03X]     %016llX %016llX ---------------- %p%s\n",

   434

					"RWB", i,

   435

					(unsigned long long)le64_to_cpu(u1->a),

   436

					(unsigned long long)le64_to_cpu(u1->b),

   437

					buffer_info->skb, next_desc);

   438

			} else {

   439

				pr_info("%s[0x%03X]     %016llX %016llX %016llX %p%s\n",

   440

					"R  ", i,

   441

					(unsigned long long)le64_to_cpu(u1->a),

   442

					(unsigned long long)le64_to_cpu(u1->b),

   443

					(unsigned long long)buffer_info->dma,

   444

					buffer_info->skb, next_desc);

   445

   446

				if (netif_msg_pktdata(adapter))

   447

					print_hex_dump(KERN_INFO, "",

   448

						       DUMP_PREFIX_ADDRESS, 16,

   449

						       1,

   450

						       phys_to_virt

   451

						       (buffer_info->dma),

   452

						       adapter->rx_buffer_len,

   453

						       true);

   454

			}

   455

		}

   456

	}

   457

}

   458

   459

/**

   460

 * e1000_desc_unused - calculate if we have unused descriptors

   461

 **/

   462

static int e1000_desc_unused(struct e1000_ring *ring)

   463

{

   464

	if (ring->next_to_clean > ring->next_to_use)

   465

		return ring->next_to_clean - ring->next_to_use - 1;

   466

   467

	return ring->count + ring->next_to_clean - ring->next_to_use - 1;

   468

}

   469

   470

/**

   471

 * e1000_receive_skb - helper function to handle Rx indications

   472

 * @adapter: board private structure

   473

 * @status: descriptor status field as written by hardware

   474

 * @vlan: descriptor vlan field as written by hardware (no le/be conversion)

   475

 * @skb: pointer to sk_buff to be indicated to stack

   476

 **/

   477

static void e1000_receive_skb(struct e1000_adapter *adapter,

   478

			      struct net_device *netdev, struct sk_buff *skb,

   479

			      u8 status, __le16 vlan)

   480

{

   481

	u16 tag = le16_to_cpu(vlan);

   482

	skb->protocol = eth_type_trans(skb, netdev);

   483

   484

	if (status & E1000_RXD_STAT_VP)

   485

		__vlan_hwaccel_put_tag(skb, tag);

   486

   487

	napi_gro_receive(&adapter->napi, skb);

   488

}

   489

   490

/**

   491

 * e1000_rx_checksum - Receive Checksum Offload

   492

 * @adapter: board private structure

   493

 * @status_err: receive descriptor status and error fields

   494

 * @csum: receive descriptor csum field

   495

 * @sk_buff: socket buffer with received data

   496

 **/

   497

static void e1000_rx_checksum(struct e1000_adapter *adapter, u32 status_err,

   498

			      struct sk_buff *skb)

   499

{

   500

	u16 status = (u16)status_err;

   501

	u8 errors = (u8)(status_err >> 24);

   502

   503

	skb_checksum_none_assert(skb);

   504

   505

	/* Rx checksum disabled */

   506

	if (!(adapter->netdev->features & NETIF_F_RXCSUM))

   507

		return;

   508

   509

	/* Ignore Checksum bit is set */

   510

	if (status & E1000_RXD_STAT_IXSM)

   511

		return;

   512

   513

	/* TCP/UDP checksum error bit or IP checksum error bit is set */

   514

	if (errors & (E1000_RXD_ERR_TCPE | E1000_RXD_ERR_IPE)) {

   515

		/* let the stack verify checksum errors */

   516

		adapter->hw_csum_err++;

   517

		return;

   518

	}

   519

   520

	/* TCP/UDP Checksum has not been calculated */

   521

	if (!(status & (E1000_RXD_STAT_TCPCS | E1000_RXD_STAT_UDPCS)))

   522

		return;

   523

   524

	/* It must be a TCP or UDP packet with a valid checksum */

   525

	skb->ip_summed = CHECKSUM_UNNECESSARY;

   526

	adapter->hw_csum_good++;

   527

}

   528

   529

/**