linux/drivers/net/ethernet/intel/igc/igc_mac.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright (c)  2018 Intel Corporation */
   3
   4#include <linux/pci.h>
   5#include <linux/delay.h>
   6
   7#include "igc_mac.h"
   8#include "igc_hw.h"
   9
  10/**
  11 * igc_disable_pcie_master - Disables PCI-express master access
  12 * @hw: pointer to the HW structure
  13 *
  14 * Returns 0 (0) if successful, else returns -10
  15 * (-IGC_ERR_MASTER_REQUESTS_PENDING) if master disable bit has not caused
  16 * the master requests to be disabled.
  17 *
  18 * Disables PCI-Express master access and verifies there are no pending
  19 * requests.
  20 */
  21s32 igc_disable_pcie_master(struct igc_hw *hw)
  22{
  23        s32 timeout = MASTER_DISABLE_TIMEOUT;
  24        s32 ret_val = 0;
  25        u32 ctrl;
  26
  27        ctrl = rd32(IGC_CTRL);
  28        ctrl |= IGC_CTRL_GIO_MASTER_DISABLE;
  29        wr32(IGC_CTRL, ctrl);
  30
  31        while (timeout) {
  32                if (!(rd32(IGC_STATUS) &
  33                    IGC_STATUS_GIO_MASTER_ENABLE))
  34                        break;
  35                usleep_range(2000, 3000);
  36                timeout--;
  37        }
  38
  39        if (!timeout) {
  40                hw_dbg("Master requests are pending.\n");
  41                ret_val = -IGC_ERR_MASTER_REQUESTS_PENDING;
  42                goto out;
  43        }
  44
  45out:
  46        return ret_val;
  47}
  48
  49/**
  50 * igc_init_rx_addrs - Initialize receive addresses
  51 * @hw: pointer to the HW structure
  52 * @rar_count: receive address registers
  53 *
  54 * Setup the receive address registers by setting the base receive address
  55 * register to the devices MAC address and clearing all the other receive
  56 * address registers to 0.
  57 */
  58void igc_init_rx_addrs(struct igc_hw *hw, u16 rar_count)
  59{
  60        u8 mac_addr[ETH_ALEN] = {0};
  61        u32 i;
  62
  63        /* Setup the receive address */
  64        hw_dbg("Programming MAC Address into RAR[0]\n");
  65
  66        hw->mac.ops.rar_set(hw, hw->mac.addr, 0);
  67
  68        /* Zero out the other (rar_entry_count - 1) receive addresses */
  69        hw_dbg("Clearing RAR[1-%u]\n", rar_count - 1);
  70        for (i = 1; i < rar_count; i++)
  71                hw->mac.ops.rar_set(hw, mac_addr, i);
  72}
  73
  74/**
  75 * igc_set_fc_watermarks - Set flow control high/low watermarks
  76 * @hw: pointer to the HW structure
  77 *
  78 * Sets the flow control high/low threshold (watermark) registers.  If
  79 * flow control XON frame transmission is enabled, then set XON frame
  80 * transmission as well.
  81 */
  82static s32 igc_set_fc_watermarks(struct igc_hw *hw)
  83{
  84        u32 fcrtl = 0, fcrth = 0;
  85
  86        /* Set the flow control receive threshold registers.  Normally,
  87         * these registers will be set to a default threshold that may be
  88         * adjusted later by the driver's runtime code.  However, if the
  89         * ability to transmit pause frames is not enabled, then these
  90         * registers will be set to 0.
  91         */
  92        if (hw->fc.current_mode & igc_fc_tx_pause) {
  93                /* We need to set up the Receive Threshold high and low water
  94                 * marks as well as (optionally) enabling the transmission of
  95                 * XON frames.
  96                 */
  97                fcrtl = hw->fc.low_water;
  98                if (hw->fc.send_xon)
  99                        fcrtl |= IGC_FCRTL_XONE;
 100
 101                fcrth = hw->fc.high_water;
 102        }
 103        wr32(IGC_FCRTL, fcrtl);
 104        wr32(IGC_FCRTH, fcrth);
 105
 106        return 0;
 107}
 108
 109/**
 110 * igc_setup_link - Setup flow control and link settings
 111 * @hw: pointer to the HW structure
 112 *
 113 * Determines which flow control settings to use, then configures flow
 114 * control.  Calls the appropriate media-specific link configuration
 115 * function.  Assuming the adapter has a valid link partner, a valid link
 116 * should be established.  Assumes the hardware has previously been reset
 117 * and the transmitter and receiver are not enabled.
 118 */
 119s32 igc_setup_link(struct igc_hw *hw)
 120{
 121        s32 ret_val = 0;
 122
 123        /* In the case of the phy reset being blocked, we already have a link.
 124         * We do not need to set it up again.
 125         */
 126        if (igc_check_reset_block(hw))
 127                goto out;
 128
 129        /* If requested flow control is set to default, set flow control
 130         * to the both 'rx' and 'tx' pause frames.
 131         */
 132        if (hw->fc.requested_mode == igc_fc_default)
 133                hw->fc.requested_mode = igc_fc_full;
 134
 135        /* We want to save off the original Flow Control configuration just
 136         * in case we get disconnected and then reconnected into a different
 137         * hub or switch with different Flow Control capabilities.
 138         */
 139        hw->fc.current_mode = hw->fc.requested_mode;
 140
 141        hw_dbg("After fix-ups FlowControl is now = %x\n", hw->fc.current_mode);
 142
 143        /* Call the necessary media_type subroutine to configure the link. */
 144        ret_val = hw->mac.ops.setup_physical_interface(hw);
 145        if (ret_val)
 146                goto out;
 147
 148        /* Initialize the flow control address, type, and PAUSE timer
 149         * registers to their default values.  This is done even if flow
 150         * control is disabled, because it does not hurt anything to
 151         * initialize these registers.
 152         */
 153        hw_dbg("Initializing the Flow Control address, type and timer regs\n");
 154        wr32(IGC_FCT, FLOW_CONTROL_TYPE);
 155        wr32(IGC_FCAH, FLOW_CONTROL_ADDRESS_HIGH);
 156        wr32(IGC_FCAL, FLOW_CONTROL_ADDRESS_LOW);
 157
 158        wr32(IGC_FCTTV, hw->fc.pause_time);
 159
 160        ret_val = igc_set_fc_watermarks(hw);
 161
 162out:
 163        return ret_val;
 164}
 165
 166/**
 167 * igc_force_mac_fc - Force the MAC's flow control settings
 168 * @hw: pointer to the HW structure
 169 *
 170 * Force the MAC's flow control settings.  Sets the TFCE and RFCE bits in the
 171 * device control register to reflect the adapter settings.  TFCE and RFCE
 172 * need to be explicitly set by software when a copper PHY is used because
 173 * autonegotiation is managed by the PHY rather than the MAC.  Software must
 174 * also configure these bits when link is forced on a fiber connection.
 175 */
 176s32 igc_force_mac_fc(struct igc_hw *hw)
 177{
 178        s32 ret_val = 0;
 179        u32 ctrl;
 180
 181        ctrl = rd32(IGC_CTRL);
 182
 183        /* Because we didn't get link via the internal auto-negotiation
 184         * mechanism (we either forced link or we got link via PHY
 185         * auto-neg), we have to manually enable/disable transmit an
 186         * receive flow control.
 187         *
 188         * The "Case" statement below enables/disable flow control
 189         * according to the "hw->fc.current_mode" parameter.
 190         *
 191         * The possible values of the "fc" parameter are:
 192         *      0:  Flow control is completely disabled
 193         *      1:  Rx flow control is enabled (we can receive pause
 194         *          frames but not send pause frames).
 195         *      2:  Tx flow control is enabled (we can send pause frames
 196         *          frames but we do not receive pause frames).
 197         *      3:  Both Rx and TX flow control (symmetric) is enabled.
 198         *  other:  No other values should be possible at this point.
 199         */
 200        hw_dbg("hw->fc.current_mode = %u\n", hw->fc.current_mode);
 201
 202        switch (hw->fc.current_mode) {
 203        case igc_fc_none:
 204                ctrl &= (~(IGC_CTRL_TFCE | IGC_CTRL_RFCE));
 205                break;
 206        case igc_fc_rx_pause:
 207                ctrl &= (~IGC_CTRL_TFCE);
 208                ctrl |= IGC_CTRL_RFCE;
 209                break;
 210        case igc_fc_tx_pause:
 211                ctrl &= (~IGC_CTRL_RFCE);
 212                ctrl |= IGC_CTRL_TFCE;
 213                break;
 214        case igc_fc_full:
 215                ctrl |= (IGC_CTRL_TFCE | IGC_CTRL_RFCE);
 216                break;
 217        default:
 218                hw_dbg("Flow control param set incorrectly\n");
 219                ret_val = -IGC_ERR_CONFIG;
 220                goto out;
 221        }
 222
 223        wr32(IGC_CTRL, ctrl);
 224
 225out:
 226        return ret_val;
 227}
 228
 229/**
 230 * igc_clear_hw_cntrs_base - Clear base hardware counters
 231 * @hw: pointer to the HW structure
 232 *
 233 * Clears the base hardware counters by reading the counter registers.
 234 */
 235void igc_clear_hw_cntrs_base(struct igc_hw *hw)
 236{
 237        rd32(IGC_CRCERRS);
 238        rd32(IGC_SYMERRS);
 239        rd32(IGC_MPC);
 240        rd32(IGC_SCC);
 241        rd32(IGC_ECOL);
 242        rd32(IGC_MCC);
 243        rd32(IGC_LATECOL);
 244        rd32(IGC_COLC);
 245        rd32(IGC_DC);
 246        rd32(IGC_SEC);
 247        rd32(IGC_RLEC);
 248        rd32(IGC_XONRXC);
 249        rd32(IGC_XONTXC);
 250        rd32(IGC_XOFFRXC);
 251        rd32(IGC_XOFFTXC);
 252        rd32(IGC_FCRUC);
 253        rd32(IGC_GPRC);
 254        rd32(IGC_BPRC);
 255        rd32(IGC_MPRC);
 256        rd32(IGC_GPTC);
 257        rd32(IGC_GORCL);
 258        rd32(IGC_GORCH);
 259        rd32(IGC_GOTCL);
 260        rd32(IGC_GOTCH);
 261        rd32(IGC_RNBC);
 262        rd32(IGC_RUC);
 263        rd32(IGC_RFC);
 264        rd32(IGC_ROC);
 265        rd32(IGC_RJC);
 266        rd32(IGC_TORL);
 267        rd32(IGC_TORH);
 268        rd32(IGC_TOTL);
 269        rd32(IGC_TOTH);
 270        rd32(IGC_TPR);
 271        rd32(IGC_TPT);
 272        rd32(IGC_MPTC);
 273        rd32(IGC_BPTC);
 274
 275        rd32(IGC_PRC64);
 276        rd32(IGC_PRC127);
 277        rd32(IGC_PRC255);
 278        rd32(IGC_PRC511);
 279        rd32(IGC_PRC1023);
 280        rd32(IGC_PRC1522);
 281        rd32(IGC_PTC64);
 282        rd32(IGC_PTC127);
 283        rd32(IGC_PTC255);
 284        rd32(IGC_PTC511);
 285        rd32(IGC_PTC1023);
 286        rd32(IGC_PTC1522);
 287
 288        rd32(IGC_ALGNERRC);
 289        rd32(IGC_RXERRC);
 290        rd32(IGC_TNCRS);
 291        rd32(IGC_CEXTERR);
 292        rd32(IGC_TSCTC);
 293        rd32(IGC_TSCTFC);
 294
 295        rd32(IGC_MGTPRC);
 296        rd32(IGC_MGTPDC);
 297        rd32(IGC_MGTPTC);
 298
 299        rd32(IGC_IAC);
 300        rd32(IGC_ICRXOC);
 301
 302        rd32(IGC_ICRXPTC);
 303        rd32(IGC_ICRXATC);
 304        rd32(IGC_ICTXPTC);
 305        rd32(IGC_ICTXATC);
 306        rd32(IGC_ICTXQEC);
 307        rd32(IGC_ICTXQMTC);
 308        rd32(IGC_ICRXDMTC);
 309
 310        rd32(IGC_CBTMPC);
 311        rd32(IGC_HTDPMC);
 312        rd32(IGC_CBRMPC);
 313        rd32(IGC_RPTHC);
 314        rd32(IGC_HGPTC);
 315        rd32(IGC_HTCBDPC);
 316        rd32(IGC_HGORCL);
 317        rd32(IGC_HGORCH);
 318        rd32(IGC_HGOTCL);
 319        rd32(IGC_HGOTCH);
 320        rd32(IGC_LENERRS);
 321}
 322
 323/**
 324 * igc_rar_set - Set receive address register
 325 * @hw: pointer to the HW structure
 326 * @addr: pointer to the receive address
 327 * @index: receive address array register
 328 *
 329 * Sets the receive address array register at index to the address passed
 330 * in by addr.
 331 */
 332void igc_rar_set(struct igc_hw *hw, u8 *addr, u32 index)
 333{
 334        u32 rar_low, rar_high;
 335
 336        /* HW expects these in little endian so we reverse the byte order
 337         * from network order (big endian) to little endian
 338         */
 339        rar_low = ((u32)addr[0] |
 340                   ((u32)addr[1] << 8) |
 341                   ((u32)addr[2] << 16) | ((u32)addr[3] << 24));
 342
 343        rar_high = ((u32)addr[4] | ((u32)addr[5] << 8));
 344
 345        /* If MAC address zero, no need to set the AV bit */
 346        if (rar_low || rar_high)
 347                rar_high |= IGC_RAH_AV;
 348
 349        /* Some bridges will combine consecutive 32-bit writes into
 350         * a single burst write, which will malfunction on some parts.
 351         * The flushes avoid this.
 352         */
 353        wr32(IGC_RAL(index), rar_low);
 354        wrfl();
 355        wr32(IGC_RAH(index), rar_high);
 356        wrfl();
 357}
 358
 359/**
 360 * igc_check_for_copper_link - Check for link (Copper)
 361 * @hw: pointer to the HW structure
 362 *
 363 * Checks to see of the link status of the hardware has changed.  If a
 364 * change in link status has been detected, then we read the PHY registers
 365 * to get the current speed/duplex if link exists.
 366 */
 367s32 igc_check_for_copper_link(struct igc_hw *hw)
 368{
 369        struct igc_mac_info *mac = &hw->mac;
 370        s32 ret_val;
 371        bool link;
 372
 373        /* We only want to go out to the PHY registers to see if Auto-Neg
 374         * has completed and/or if our link status has changed.  The
 375         * get_link_status flag is set upon receiving a Link Status
 376         * Change or Rx Sequence Error interrupt.
 377         */
 378        if (!mac->get_link_status) {
 379                ret_val = 0;
 380                goto out;
 381        }
 382
 383        /* First we want to see if the MII Status Register reports
 384         * link.  If so, then we want to get the current speed/duplex
 385         * of the PHY.
 386         */
 387        ret_val = igc_phy_has_link(hw, 1, 0, &link);
 388        if (ret_val)
 389                goto out;
 390
 391        if (!link)
 392                goto out; /* No link detected */
 393
 394        mac->get_link_status = false;
 395
 396        /* Check if there was DownShift, must be checked
 397         * immediately after link-up
 398         */
 399        igc_check_downshift(hw);
 400
 401        /* If we are forcing speed/duplex, then we simply return since
 402         * we have already determined whether we have link or not.
 403         */
 404        if (!mac->autoneg) {
 405                ret_val = -IGC_ERR_CONFIG;
 406                goto out;
 407        }
 408
 409        /* Auto-Neg is enabled.  Auto Speed Detection takes care
 410         * of MAC speed/duplex configuration.  So we only need to
 411         * configure Collision Distance in the MAC.
 412         */
 413        igc_config_collision_dist(hw);
 414
 415        /* Configure Flow Control now that Auto-Neg has completed.
 416         * First, we need to restore the desired flow control
 417         * settings because we may have had to re-autoneg with a
 418         * different link partner.
 419         */
 420        ret_val = igc_config_fc_after_link_up(hw);
 421        if (ret_val)
 422                hw_dbg("Error configuring flow control\n");
 423
 424out:
 425        return ret_val;
 426}
 427
 428/**
 429 * igc_config_collision_dist - Configure collision distance
 430 * @hw: pointer to the HW structure
 431 *
 432 * Configures the collision distance to the default value and is used
 433 * during link setup. Currently no func pointer exists and all
 434 * implementations are handled in the generic version of this function.
 435 */
 436void igc_config_collision_dist(struct igc_hw *hw)
 437{
 438        u32 tctl;
 439
 440        tctl = rd32(IGC_TCTL);
 441
 442        tctl &= ~IGC_TCTL_COLD;
 443        tctl |= IGC_COLLISION_DISTANCE << IGC_COLD_SHIFT;
 444
 445        wr32(IGC_TCTL, tctl);
 446        wrfl();
 447}
 448
 449/**
 450 * igc_config_fc_after_link_up - Configures flow control after link
 451 * @hw: pointer to the HW structure
 452 *
 453 * Checks the status of auto-negotiation after link up to ensure that the
 454 * speed and duplex were not forced.  If the link needed to be forced, then
 455 * flow control needs to be forced also.  If auto-negotiation is enabled
 456 * and did not fail, then we configure flow control based on our link
 457 * partner.
 458 */
 459s32 igc_config_fc_after_link_up(struct igc_hw *hw)
 460{
 461        u16 mii_status_reg, mii_nway_adv_reg, mii_nway_lp_ability_reg;
 462        struct igc_mac_info *mac = &hw->mac;
 463        u16 speed, duplex;
 464        s32 ret_val = 0;
 465
 466        /* Check for the case where we have fiber media and auto-neg failed
 467         * so we had to force link.  In this case, we need to force the
 468         * configuration of the MAC to match the "fc" parameter.
 469         */
 470        if (mac->autoneg_failed) {
 471                if (hw->phy.media_type == igc_media_type_copper)
 472                        ret_val = igc_force_mac_fc(hw);
 473        }
 474
 475        if (ret_val) {
 476                hw_dbg("Error forcing flow control settings\n");
 477                goto out;
 478        }
 479
 480        /* Check for the case where we have copper media and auto-neg is
 481         * enabled.  In this case, we need to check and see if Auto-Neg
 482         * has completed, and if so, how the PHY and link partner has
 483         * flow control configured.
 484         */
 485        if (hw->phy.media_type == igc_media_type_copper && mac->autoneg) {
 486                /* Read the MII Status Register and check to see if AutoNeg
 487                 * has completed.  We read this twice because this reg has
 488                 * some "sticky" (latched) bits.
 489                 */
 490                ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS,
 491                                               &mii_status_reg);
 492                if (ret_val)
 493                        goto out;
 494                ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS,
 495                                               &mii_status_reg);
 496                if (ret_val)
 497                        goto out;
 498
 499                if (!(mii_status_reg & MII_SR_AUTONEG_COMPLETE)) {
 500                        hw_dbg("Copper PHY and Auto Neg has not completed.\n");
 501                        goto out;
 502                }
 503
 504                /* The AutoNeg process has completed, so we now need to
 505                 * read both the Auto Negotiation Advertisement
 506                 * Register (Address 4) and the Auto_Negotiation Base
 507                 * Page Ability Register (Address 5) to determine how
 508                 * flow control was negotiated.
 509                 */
 510                ret_val = hw->phy.ops.read_reg(hw, PHY_AUTONEG_ADV,
 511                                               &mii_nway_adv_reg);
 512                if (ret_val)
 513                        goto out;
 514                ret_val = hw->phy.ops.read_reg(hw, PHY_LP_ABILITY,
 515                                               &mii_nway_lp_ability_reg);
 516                if (ret_val)
 517                        goto out;
 518                /* Two bits in the Auto Negotiation Advertisement Register
 519                 * (Address 4) and two bits in the Auto Negotiation Base
 520                 * Page Ability Register (Address 5) determine flow control
 521                 * for both the PHY and the link partner.  The following
 522                 * table, taken out of the IEEE 802.3ab/D6.0 dated March 25,
 523                 * 1999, describes these PAUSE resolution bits and how flow
 524                 * control is determined based upon these settings.
 525                 * NOTE:  DC = Don't Care
 526                 *
 527                 *   LOCAL DEVICE  |   LINK PARTNER
 528                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution
 529                 *-------|---------|-------|---------|--------------------
 530                 *   0   |    0    |  DC   |   DC    | igc_fc_none
 531                 *   0   |    1    |   0   |   DC    | igc_fc_none
 532                 *   0   |    1    |   1   |    0    | igc_fc_none
 533                 *   0   |    1    |   1   |    1    | igc_fc_tx_pause
 534                 *   1   |    0    |   0   |   DC    | igc_fc_none
 535                 *   1   |   DC    |   1   |   DC    | igc_fc_full
 536                 *   1   |    1    |   0   |    0    | igc_fc_none
 537                 *   1   |    1    |   0   |    1    | igc_fc_rx_pause
 538                 *
 539                 * Are both PAUSE bits set to 1?  If so, this implies
 540                 * Symmetric Flow Control is enabled at both ends.  The
 541                 * ASM_DIR bits are irrelevant per the spec.
 542                 *
 543                 * For Symmetric Flow Control:
 544                 *
 545                 *   LOCAL DEVICE  |   LINK PARTNER
 546                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
 547                 *-------|---------|-------|---------|--------------------
 548                 *   1   |   DC    |   1   |   DC    | IGC_fc_full
 549                 *
 550                 */
 551                if ((mii_nway_adv_reg & NWAY_AR_PAUSE) &&
 552                    (mii_nway_lp_ability_reg & NWAY_LPAR_PAUSE)) {
 553                        /* Now we need to check if the user selected RX ONLY
 554                         * of pause frames.  In this case, we had to advertise
 555                         * FULL flow control because we could not advertise RX
 556                         * ONLY. Hence, we must now check to see if we need to
 557                         * turn OFF  the TRANSMISSION of PAUSE frames.
 558                         */
 559                        if (hw->fc.requested_mode == igc_fc_full) {
 560                                hw->fc.current_mode = igc_fc_full;
 561                                hw_dbg("Flow Control = FULL.\n");
 562                        } else {
 563                                hw->fc.current_mode = igc_fc_rx_pause;
 564                                hw_dbg("Flow Control = RX PAUSE frames only.\n");
 565                        }
 566                }
 567
 568                /* For receiving PAUSE frames ONLY.
 569                 *
 570                 *   LOCAL DEVICE  |   LINK PARTNER
 571                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
 572                 *-------|---------|-------|---------|--------------------
 573                 *   0   |    1    |   1   |    1    | igc_fc_tx_pause
 574                 */
 575                else if (!(mii_nway_adv_reg & NWAY_AR_PAUSE) &&
 576                         (mii_nway_adv_reg & NWAY_AR_ASM_DIR) &&
 577                         (mii_nway_lp_ability_reg & NWAY_LPAR_PAUSE) &&
 578                         (mii_nway_lp_ability_reg & NWAY_LPAR_ASM_DIR)) {
 579                        hw->fc.current_mode = igc_fc_tx_pause;
 580                        hw_dbg("Flow Control = TX PAUSE frames only.\n");
 581                }
 582                /* For transmitting PAUSE frames ONLY.
 583                 *
 584                 *   LOCAL DEVICE  |   LINK PARTNER
 585                 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
 586                 *-------|---------|-------|---------|--------------------
 587                 *   1   |    1    |   0   |    1    | igc_fc_rx_pause
 588                 */
 589                else if ((mii_nway_adv_reg & NWAY_AR_PAUSE) &&
 590                         (mii_nway_adv_reg & NWAY_AR_ASM_DIR) &&
 591                         !(mii_nway_lp_ability_reg & NWAY_LPAR_PAUSE) &&
 592                         (mii_nway_lp_ability_reg & NWAY_LPAR_ASM_DIR)) {
 593                        hw->fc.current_mode = igc_fc_rx_pause;
 594                        hw_dbg("Flow Control = RX PAUSE frames only.\n");
 595                }
 596                /* Per the IEEE spec, at this point flow control should be
 597                 * disabled.  However, we want to consider that we could
 598                 * be connected to a legacy switch that doesn't advertise
 599                 * desired flow control, but can be forced on the link
 600                 * partner.  So if we advertised no flow control, that is
 601                 * what we will resolve to.  If we advertised some kind of
 602                 * receive capability (Rx Pause Only or Full Flow Control)
 603                 * and the link partner advertised none, we will configure
 604                 * ourselves to enable Rx Flow Control only.  We can do
 605                 * this safely for two reasons:  If the link partner really
 606                 * didn't want flow control enabled, and we enable Rx, no
 607                 * harm done since we won't be receiving any PAUSE frames
 608                 * anyway.  If the intent on the link partner was to have
 609                 * flow control enabled, then by us enabling RX only, we
 610                 * can at least receive pause frames and process them.
 611                 * This is a good idea because in most cases, since we are
 612                 * predominantly a server NIC, more times than not we will
 613                 * be asked to delay transmission of packets than asking
 614                 * our link partner to pause transmission of frames.
 615                 */
 616                else if ((hw->fc.requested_mode == igc_fc_none) ||
 617                         (hw->fc.requested_mode == igc_fc_tx_pause) ||
 618                         (hw->fc.strict_ieee)) {
 619                        hw->fc.current_mode = igc_fc_none;
 620                        hw_dbg("Flow Control = NONE.\n");
 621                } else {
 622                        hw->fc.current_mode = igc_fc_rx_pause;
 623                        hw_dbg("Flow Control = RX PAUSE frames only.\n");
 624                }
 625
 626                /* Now we need to do one last check...  If we auto-
 627                 * negotiated to HALF DUPLEX, flow control should not be
 628                 * enabled per IEEE 802.3 spec.
 629                 */
 630                ret_val = hw->mac.ops.get_speed_and_duplex(hw, &speed, &duplex);
 631                if (ret_val) {
 632                        hw_dbg("Error getting link speed and duplex\n");
 633                        goto out;
 634                }
 635
 636                if (duplex == HALF_DUPLEX)
 637                        hw->fc.current_mode = igc_fc_none;
 638
 639                /* Now we call a subroutine to actually force the MAC
 640                 * controller to use the correct flow control settings.
 641                 */
 642                ret_val = igc_force_mac_fc(hw);
 643                if (ret_val) {
 644                        hw_dbg("Error forcing flow control settings\n");
 645                        goto out;
 646                }
 647        }
 648
 649out:
 650        return 0;
 651}
 652
 653/**
 654 * igc_get_auto_rd_done - Check for auto read completion
 655 * @hw: pointer to the HW structure
 656 *
 657 * Check EEPROM for Auto Read done bit.
 658 */
 659s32 igc_get_auto_rd_done(struct igc_hw *hw)
 660{
 661        s32 ret_val = 0;
 662        s32 i = 0;
 663
 664        while (i < AUTO_READ_DONE_TIMEOUT) {
 665                if (rd32(IGC_EECD) & IGC_EECD_AUTO_RD)
 666                        break;
 667                usleep_range(1000, 2000);
 668                i++;
 669        }
 670
 671        if (i == AUTO_READ_DONE_TIMEOUT) {
 672                hw_dbg("Auto read by HW from NVM has not completed.\n");
 673                ret_val = -IGC_ERR_RESET;
 674                goto out;
 675        }
 676
 677out:
 678        return ret_val;
 679}
 680
 681/**
 682 * igc_get_speed_and_duplex_copper - Retrieve current speed/duplex
 683 * @hw: pointer to the HW structure
 684 * @speed: stores the current speed
 685 * @duplex: stores the current duplex
 686 *
 687 * Read the status register for the current speed/duplex and store the current
 688 * speed and duplex for copper connections.
 689 */
 690s32 igc_get_speed_and_duplex_copper(struct igc_hw *hw, u16 *speed,
 691                                    u16 *duplex)
 692{
 693        u32 status;
 694
 695        status = rd32(IGC_STATUS);
 696        if (status & IGC_STATUS_SPEED_1000) {
 697                /* For I225, STATUS will indicate 1G speed in both 1 Gbps
 698                 * and 2.5 Gbps link modes. An additional bit is used
 699                 * to differentiate between 1 Gbps and 2.5 Gbps.
 700                 */
 701                if (hw->mac.type == igc_i225 &&
 702                    (status & IGC_STATUS_SPEED_2500)) {
 703                        *speed = SPEED_2500;
 704                        hw_dbg("2500 Mbs, ");
 705                } else {
 706                        *speed = SPEED_1000;
 707                        hw_dbg("1000 Mbs, ");
 708                }
 709        } else if (status & IGC_STATUS_SPEED_100) {
 710                *speed = SPEED_100;
 711                hw_dbg("100 Mbs, ");
 712        } else {
 713                *speed = SPEED_10;
 714                hw_dbg("10 Mbs, ");
 715        }
 716
 717        if (status & IGC_STATUS_FD) {
 718                *duplex = FULL_DUPLEX;
 719                hw_dbg("Full Duplex\n");
 720        } else {
 721                *duplex = HALF_DUPLEX;
 722                hw_dbg("Half Duplex\n");
 723        }
 724
 725        return 0;
 726}
 727
 728/**
 729 * igc_put_hw_semaphore - Release hardware semaphore
 730 * @hw: pointer to the HW structure
 731 *
 732 * Release hardware semaphore used to access the PHY or NVM
 733 */
 734void igc_put_hw_semaphore(struct igc_hw *hw)
 735{
 736        u32 swsm;
 737
 738        swsm = rd32(IGC_SWSM);
 739
 740        swsm &= ~(IGC_SWSM_SMBI | IGC_SWSM_SWESMBI);
 741
 742        wr32(IGC_SWSM, swsm);
 743}
 744
 745/**
 746 * igc_enable_mng_pass_thru - Enable processing of ARP's
 747 * @hw: pointer to the HW structure
 748 *
 749 * Verifies the hardware needs to leave interface enabled so that frames can
 750 * be directed to and from the management interface.
 751 */
 752bool igc_enable_mng_pass_thru(struct igc_hw *hw)
 753{
 754        bool ret_val = false;
 755        u32 fwsm, factps;
 756        u32 manc;
 757
 758        if (!hw->mac.asf_firmware_present)
 759                goto out;
 760
 761        manc = rd32(IGC_MANC);
 762
 763        if (!(manc & IGC_MANC_RCV_TCO_EN))
 764                goto out;
 765
 766        if (hw->mac.arc_subsystem_valid) {
 767                fwsm = rd32(IGC_FWSM);
 768                factps = rd32(IGC_FACTPS);
 769
 770                if (!(factps & IGC_FACTPS_MNGCG) &&
 771                    ((fwsm & IGC_FWSM_MODE_MASK) ==
 772                    (igc_mng_mode_pt << IGC_FWSM_MODE_SHIFT))) {
 773                        ret_val = true;
 774                        goto out;
 775                }
 776        } else {
 777                if ((manc & IGC_MANC_SMBUS_EN) &&
 778                    !(manc & IGC_MANC_ASF_EN)) {
 779                        ret_val = true;
 780                        goto out;
 781                }
 782        }
 783
 784out:
 785        return ret_val;
 786}
 787
 788/**
 789 *  igc_hash_mc_addr - Generate a multicast hash value
 790 *  @hw: pointer to the HW structure
 791 *  @mc_addr: pointer to a multicast address
 792 *
 793 *  Generates a multicast address hash value which is used to determine
 794 *  the multicast filter table array address and new table value.  See
 795 *  igc_mta_set()
 796 **/
 797static u32 igc_hash_mc_addr(struct igc_hw *hw, u8 *mc_addr)
 798{
 799        u32 hash_value, hash_mask;
 800        u8 bit_shift = 0;
 801
 802        /* Register count multiplied by bits per register */
 803        hash_mask = (hw->mac.mta_reg_count * 32) - 1;
 804
 805        /* For a mc_filter_type of 0, bit_shift is the number of left-shifts
 806         * where 0xFF would still fall within the hash mask.
 807         */
 808        while (hash_mask >> bit_shift != 0xFF)
 809                bit_shift++;
 810
 811        /* The portion of the address that is used for the hash table
 812         * is determined by the mc_filter_type setting.
 813         * The algorithm is such that there is a total of 8 bits of shifting.
 814         * The bit_shift for a mc_filter_type of 0 represents the number of
 815         * left-shifts where the MSB of mc_addr[5] would still fall within
 816         * the hash_mask.  Case 0 does this exactly.  Since there are a total
 817         * of 8 bits of shifting, then mc_addr[4] will shift right the
 818         * remaining number of bits. Thus 8 - bit_shift.  The rest of the
 819         * cases are a variation of this algorithm...essentially raising the
 820         * number of bits to shift mc_addr[5] left, while still keeping the
 821         * 8-bit shifting total.
 822         *
 823         * For example, given the following Destination MAC Address and an
 824         * MTA register count of 128 (thus a 4096-bit vector and 0xFFF mask),
 825         * we can see that the bit_shift for case 0 is 4.  These are the hash
 826         * values resulting from each mc_filter_type...
 827         * [0] [1] [2] [3] [4] [5]
 828         * 01  AA  00  12  34  56
 829         * LSB                 MSB
 830         *
 831         * case 0: hash_value = ((0x34 >> 4) | (0x56 << 4)) & 0xFFF = 0x563
 832         * case 1: hash_value = ((0x34 >> 3) | (0x56 << 5)) & 0xFFF = 0xAC6
 833         * case 2: hash_value = ((0x34 >> 2) | (0x56 << 6)) & 0xFFF = 0x163
 834         * case 3: hash_value = ((0x34 >> 0) | (0x56 << 8)) & 0xFFF = 0x634
 835         */
 836        switch (hw->mac.mc_filter_type) {
 837        default:
 838        case 0:
 839                break;
 840        case 1:
 841                bit_shift += 1;
 842                break;
 843        case 2:
 844                bit_shift += 2;
 845                break;
 846        case 3:
 847                bit_shift += 4;
 848                break;
 849        }
 850
 851        hash_value = hash_mask & (((mc_addr[4] >> (8 - bit_shift)) |
 852                                  (((u16)mc_addr[5]) << bit_shift)));
 853
 854        return hash_value;
 855}
 856
 857/**
 858 *  igc_update_mc_addr_list - Update Multicast addresses
 859 *  @hw: pointer to the HW structure
 860 *  @mc_addr_list: array of multicast addresses to program
 861 *  @mc_addr_count: number of multicast addresses to program
 862 *
 863 *  Updates entire Multicast Table Array.
 864 *  The caller must have a packed mc_addr_list of multicast addresses.
 865 **/
 866void igc_update_mc_addr_list(struct igc_hw *hw,
 867                             u8 *mc_addr_list, u32 mc_addr_count)
 868{
 869        u32 hash_value, hash_bit, hash_reg;
 870        int i;
 871
 872        /* clear mta_shadow */
 873        memset(&hw->mac.mta_shadow, 0, sizeof(hw->mac.mta_shadow));
 874
 875        /* update mta_shadow from mc_addr_list */
 876        for (i = 0; (u32)i < mc_addr_count; i++) {
 877                hash_value = igc_hash_mc_addr(hw, mc_addr_list);
 878
 879                hash_reg = (hash_value >> 5) & (hw->mac.mta_reg_count - 1);
 880                hash_bit = hash_value & 0x1F;
 881
 882                hw->mac.mta_shadow[hash_reg] |= BIT(hash_bit);
 883                mc_addr_list += ETH_ALEN;
 884        }
 885
 886        /* replace the entire MTA table */
 887        for (i = hw->mac.mta_reg_count - 1; i >= 0; i--)
 888                array_wr32(IGC_MTA, i, hw->mac.mta_shadow[i]);
 889        wrfl();
 890}
 891