// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2018 Intel Corporation */ #include <linux/pci.h> #include <linux/delay.h> #include "igc_mac.h" #include "igc_hw.h" /** * igc_disable_pcie_master - Disables PCI-express master access * @hw: pointer to the HW structure * * Returns 0 (0) if successful, else returns -10 * (-IGC_ERR_MASTER_REQUESTS_PENDING) if master disable bit has not caused * the master requests to be disabled. * * Disables PCI-Express master access and verifies there are no pending * requests. */ s32 igc_disable_pcie_master(struct igc_hw *hw) { s32 timeout = MASTER_DISABLE_TIMEOUT; s32 ret_val = 0; u32 ctrl; ctrl = rd32(IGC_CTRL); ctrl |= IGC_CTRL_GIO_MASTER_DISABLE; wr32(IGC_CTRL, ctrl); while (timeout) { if (!(rd32(IGC_STATUS) & IGC_STATUS_GIO_MASTER_ENABLE)) break; usleep_range(2000, 3000); timeout--; } if (!timeout) { hw_dbg("Master requests are pending.\n"); ret_val = -IGC_ERR_MASTER_REQUESTS_PENDING; goto out; } out: return ret_val; } /** * igc_init_rx_addrs - Initialize receive addresses * @hw: pointer to the HW structure * @rar_count: receive address registers * * Setup the receive address registers by setting the base receive address * register to the devices MAC address and clearing all the other receive * address registers to 0. */ void igc_init_rx_addrs(struct igc_hw *hw, u16 rar_count) { u8 mac_addr[ETH_ALEN] = {0}; u32 i; /* Setup the receive address */ hw_dbg("Programming MAC Address into RAR[0]\n"); hw->mac.ops.rar_set(hw, hw->mac.addr, 0); /* Zero out the other (rar_entry_count - 1) receive addresses */ hw_dbg("Clearing RAR[1-%u]\n", rar_count - 1); for (i = 1; i < rar_count; i++) hw->mac.ops.rar_set(hw, mac_addr, i); } /** * igc_set_fc_watermarks - Set flow control high/low watermarks * @hw: pointer to the HW structure * * Sets the flow control high/low threshold (watermark) registers. If * flow control XON frame transmission is enabled, then set XON frame * transmission as well. */ static s32 igc_set_fc_watermarks(struct igc_hw *hw) { u32 fcrtl = 0, fcrth = 0; /* Set the flow control receive threshold registers. Normally, * these registers will be set to a default threshold that may be * adjusted later by the driver's runtime code. However, if the * ability to transmit pause frames is not enabled, then these * registers will be set to 0. */ if (hw->fc.current_mode & igc_fc_tx_pause) { /* We need to set up the Receive Threshold high and low water * marks as well as (optionally) enabling the transmission of * XON frames. */ fcrtl = hw->fc.low_water; if (hw->fc.send_xon) fcrtl |= IGC_FCRTL_XONE; fcrth = hw->fc.high_water; } wr32(IGC_FCRTL, fcrtl); wr32(IGC_FCRTH, fcrth); return 0; } /** * igc_setup_link - Setup flow control and link settings * @hw: pointer to the HW structure * * Determines which flow control settings to use, then configures flow * control. Calls the appropriate media-specific link configuration * function. Assuming the adapter has a valid link partner, a valid link * should be established. Assumes the hardware has previously been reset * and the transmitter and receiver are not enabled. */ s32 igc_setup_link(struct igc_hw *hw) { s32 ret_val = 0; /* In the case of the phy reset being blocked, we already have a link. * We do not need to set it up again. */ if (igc_check_reset_block(hw)) goto out; /* If requested flow control is set to default, set flow control * to the both 'rx' and 'tx' pause frames. */ if (hw->fc.requested_mode == igc_fc_default) hw->fc.requested_mode = igc_fc_full; /* We want to save off the original Flow Control configuration just * in case we get disconnected and then reconnected into a different * hub or switch with different Flow Control capabilities. */ hw->fc.current_mode = hw->fc.requested_mode; hw_dbg("After fix-ups FlowControl is now = %x\n", hw->fc.current_mode); /* Call the necessary media_type subroutine to configure the link. */ ret_val = hw->mac.ops.setup_physical_interface(hw); if (ret_val) goto out; /* Initialize the flow control address, type, and PAUSE timer * registers to their default values. This is done even if flow * control is disabled, because it does not hurt anything to * initialize these registers. */ hw_dbg("Initializing the Flow Control address, type and timer regs\n"); wr32(IGC_FCT, FLOW_CONTROL_TYPE); wr32(IGC_FCAH, FLOW_CONTROL_ADDRESS_HIGH); wr32(IGC_FCAL, FLOW_CONTROL_ADDRESS_LOW); wr32(IGC_FCTTV, hw->fc.pause_time); ret_val = igc_set_fc_watermarks(hw); out: return ret_val; } /** * igc_force_mac_fc - Force the MAC's flow control settings * @hw: pointer to the HW structure * * Force the MAC's flow control settings. Sets the TFCE and RFCE bits in the * device control register to reflect the adapter settings. TFCE and RFCE * need to be explicitly set by software when a copper PHY is used because * autonegotiation is managed by the PHY rather than the MAC. Software must * also configure these bits when link is forced on a fiber connection. */ s32 igc_force_mac_fc(struct igc_hw *hw) { s32 ret_val = 0; u32 ctrl; ctrl = rd32(IGC_CTRL); /* Because we didn't get link via the internal auto-negotiation * mechanism (we either forced link or we got link via PHY * auto-neg), we have to manually enable/disable transmit an * receive flow control. * * The "Case" statement below enables/disable flow control * according to the "hw->fc.current_mode" parameter. * * The possible values of the "fc" parameter are: * 0: Flow control is completely disabled * 1: Rx flow control is enabled (we can receive pause * frames but not send pause frames). * 2: Tx flow control is enabled (we can send pause frames * but we do not receive pause frames). * 3: Both Rx and TX flow control (symmetric) is enabled. * other: No other values should be possible at this point. */ hw_dbg("hw->fc.current_mode = %u\n", hw->fc.current_mode); switch (hw->fc.current_mode) { case igc_fc_none: ctrl &= (~(IGC_CTRL_TFCE | IGC_CTRL_RFCE)); break; case igc_fc_rx_pause: ctrl &= (~IGC_CTRL_TFCE); ctrl |= IGC_CTRL_RFCE; break; case igc_fc_tx_pause: ctrl &= (~IGC_CTRL_RFCE); ctrl |= IGC_CTRL_TFCE; break; case igc_fc_full: ctrl |= (IGC_CTRL_TFCE | IGC_CTRL_RFCE); break; default: hw_dbg("Flow control param set incorrectly\n"); ret_val = -IGC_ERR_CONFIG; goto out; } wr32(IGC_CTRL, ctrl); out: return ret_val; } /** * igc_clear_hw_cntrs_base - Clear base hardware counters * @hw: pointer to the HW structure * * Clears the base hardware counters by reading the counter registers. */ void igc_clear_hw_cntrs_base(struct igc_hw *hw) { rd32(IGC_CRCERRS); rd32(IGC_MPC); rd32(IGC_SCC); rd32(IGC_ECOL); rd32(IGC_MCC); rd32(IGC_LATECOL); rd32(IGC_COLC); rd32(IGC_RERC); rd32(IGC_DC); rd32(IGC_RLEC); rd32(IGC_XONRXC); rd32(IGC_XONTXC); rd32(IGC_XOFFRXC); rd32(IGC_XOFFTXC); rd32(IGC_FCRUC); rd32(IGC_GPRC); rd32(IGC_BPRC); rd32(IGC_MPRC); rd32(IGC_GPTC); rd32(IGC_GORCL); rd32(IGC_GORCH); rd32(IGC_GOTCL); rd32(IGC_GOTCH); rd32(IGC_RNBC); rd32(IGC_RUC); rd32(IGC_RFC); rd32(IGC_ROC); rd32(IGC_RJC); rd32(IGC_TORL); rd32(IGC_TORH); rd32(IGC_TOTL); rd32(IGC_TOTH); rd32(IGC_TPR); rd32(IGC_TPT); rd32(IGC_MPTC); rd32(IGC_BPTC); rd32(IGC_PRC64); rd32(IGC_PRC127); rd32(IGC_PRC255); rd32(IGC_PRC511); rd32(IGC_PRC1023); rd32(IGC_PRC1522); rd32(IGC_PTC64); rd32(IGC_PTC127); rd32(IGC_PTC255); rd32(IGC_PTC511); rd32(IGC_PTC1023); rd32(IGC_PTC1522); rd32(IGC_ALGNERRC); rd32(IGC_RXERRC); rd32(IGC_TNCRS); rd32(IGC_HTDPMC); rd32(IGC_TSCTC); rd32(IGC_MGTPRC); rd32(IGC_MGTPDC); rd32(IGC_MGTPTC); rd32(IGC_IAC); rd32(IGC_RPTHC); rd32(IGC_TLPIC); rd32(IGC_RLPIC); rd32(IGC_HGPTC); rd32(IGC_RXDMTC); rd32(IGC_HGORCL); rd32(IGC_HGORCH); rd32(IGC_HGOTCL); rd32(IGC_HGOTCH); rd32(IGC_LENERRS); } /** * igc_rar_set - Set receive address register * @hw: pointer to the HW structure * @addr: pointer to the receive address * @index: receive address array register * * Sets the receive address array register at index to the address passed * in by addr. */ void igc_rar_set(struct igc_hw *hw, u8 *addr, u32 index) { u32 rar_low, rar_high; /* HW expects these in little endian so we reverse the byte order * from network order (big endian) to little endian */ rar_low = ((u32)addr[0] | ((u32)addr[1] << 8) | ((u32)addr[2] << 16) | ((u32)addr[3] << 24)); rar_high = ((u32)addr[4] | ((u32)addr[5] << 8)); /* If MAC address zero, no need to set the AV bit */ if (rar_low || rar_high) rar_high |= IGC_RAH_AV; /* Some bridges will combine consecutive 32-bit writes into * a single burst write, which will malfunction on some parts. * The flushes avoid this. */ wr32(IGC_RAL(index), rar_low); wrfl(); wr32(IGC_RAH(index), rar_high); wrfl(); } /** * igc_check_for_copper_link - Check for link (Copper) * @hw: pointer to the HW structure * * Checks to see of the link status of the hardware has changed. If a * change in link status has been detected, then we read the PHY registers * to get the current speed/duplex if link exists. */ s32 igc_check_for_copper_link(struct igc_hw *hw) { struct igc_mac_info *mac = &hw->mac; bool link = false; s32 ret_val; /* We only want to go out to the PHY registers to see if Auto-Neg * has completed and/or if our link status has changed. The * get_link_status flag is set upon receiving a Link Status * Change or Rx Sequence Error interrupt. */ if (!mac->get_link_status) { ret_val = 0; goto out; } /* First we want to see if the MII Status Register reports * link. If so, then we want to get the current speed/duplex * of the PHY. */ ret_val = igc_phy_has_link(hw, 1, 0, &link); if (ret_val) goto out; if (!link) goto out; /* No link detected */ mac->get_link_status = false; /* Check if there was DownShift, must be checked * immediately after link-up */ igc_check_downshift(hw); /* If we are forcing speed/duplex, then we simply return since * we have already determined whether we have link or not. */ if (!mac->autoneg) { ret_val = -IGC_ERR_CONFIG; goto out; } /* Auto-Neg is enabled. Auto Speed Detection takes care * of MAC speed/duplex configuration. So we only need to * configure Collision Distance in the MAC. */ igc_config_collision_dist(hw); /* Configure Flow Control now that Auto-Neg has completed. * First, we need to restore the desired flow control * settings because we may have had to re-autoneg with a * different link partner. */ ret_val = igc_config_fc_after_link_up(hw); if (ret_val) hw_dbg("Error configuring flow control\n"); out: /* Now that we are aware of our link settings, we can set the LTR * thresholds. */ ret_val = igc_set_ltr_i225(hw, link); return ret_val; } /** * igc_config_collision_dist - Configure collision distance * @hw: pointer to the HW structure * * Configures the collision distance to the default value and is used * during link setup. Currently no func pointer exists and all * implementations are handled in the generic version of this function. */ void igc_config_collision_dist(struct igc_hw *hw) { u32 tctl; tctl = rd32(IGC_TCTL); tctl &= ~IGC_TCTL_COLD; tctl |= IGC_COLLISION_DISTANCE << IGC_COLD_SHIFT; wr32(IGC_TCTL, tctl); wrfl(); } /** * igc_config_fc_after_link_up - Configures flow control after link * @hw: pointer to the HW structure * * Checks the status of auto-negotiation after link up to ensure that the * speed and duplex were not forced. If the link needed to be forced, then * flow control needs to be forced also. If auto-negotiation is enabled * and did not fail, then we configure flow control based on our link * partner. */ s32 igc_config_fc_after_link_up(struct igc_hw *hw) { u16 mii_status_reg, mii_nway_adv_reg, mii_nway_lp_ability_reg; struct igc_mac_info *mac = &hw->mac; u16 speed, duplex; s32 ret_val = 0; /* Check for the case where we have fiber media and auto-neg failed * so we had to force link. In this case, we need to force the * configuration of the MAC to match the "fc" parameter. */ if (mac->autoneg_failed) ret_val = igc_force_mac_fc(hw); if (ret_val) { hw_dbg("Error forcing flow control settings\n"); goto out; } /* Check for the case where we have copper media and auto-neg is * enabled. In this case, we need to check and see if Auto-Neg * has completed, and if so, how the PHY and link partner has * flow control configured. */ if (mac->autoneg) { /* Read the MII Status Register and check to see if AutoNeg * has completed. We read this twice because this reg has * some "sticky" (latched) bits. */ ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS, &mii_status_reg); if (ret_val) goto out; ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS, &mii_status_reg); if (ret_val) goto out; if (!(mii_status_reg & MII_SR_AUTONEG_COMPLETE)) { hw_dbg("Copper PHY and Auto Neg has not completed.\n"); goto out; } /* The AutoNeg process has completed, so we now need to * read both the Auto Negotiation Advertisement * Register (Address 4) and the Auto_Negotiation Base * Page Ability Register (Address 5) to determine how * flow control was negotiated. */ ret_val = hw->phy.ops.read_reg(hw, PHY_AUTONEG_ADV, &mii_nway_adv_reg); if (ret_val) goto out; ret_val = hw->phy.ops.read_reg(hw, PHY_LP_ABILITY, &mii_nway_lp_ability_reg); if (ret_val) goto out; /* Two bits in the Auto Negotiation Advertisement Register * (Address 4) and two bits in the Auto Negotiation Base * Page Ability Register (Address 5) determine flow control * for both the PHY and the link partner. The following * table, taken out of the IEEE 802.3ab/D6.0 dated March 25, * 1999, describes these PAUSE resolution bits and how flow * control is determined based upon these settings. * NOTE: DC = Don't Care * * LOCAL DEVICE | LINK PARTNER * PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution *-------|---------|-------|---------|-------------------- * 0 | 0 | DC | DC | igc_fc_none * 0 | 1 | 0 | DC | igc_fc_none * 0 | 1 | 1 | 0 | igc_fc_none * 0 | 1 | 1 | 1 | igc_fc_tx_pause * 1 | 0 | 0 | DC | igc_fc_none * 1 | DC | 1 | DC | igc_fc_full * 1 | 1 | 0 | 0 | igc_fc_none * 1 | 1 | 0 | 1 | igc_fc_rx_pause * * Are both PAUSE bits set to 1? If so, this implies * Symmetric Flow Control is enabled at both ends. The * ASM_DIR bits are irrelevant per the spec. * * For Symmetric Flow Control: * * LOCAL DEVICE | LINK PARTNER * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result *-------|---------|-------|---------|-------------------- * 1 | DC | 1 | DC | IGC_fc_full * */ if ((mii_nway_adv_reg & NWAY_AR_PAUSE) && (mii_nway_lp_ability_reg & NWAY_LPAR_PAUSE)) { /* Now we need to check if the user selected RX ONLY * of pause frames. In this case, we had to advertise * FULL flow control because we could not advertise RX * ONLY. Hence, we must now check to see if we need to * turn OFF the TRANSMISSION of PAUSE frames. */ if (hw->fc.requested_mode == igc_fc_full) { hw->fc.current_mode = igc_fc_full; hw_dbg("Flow Control = FULL.\n"); } else { hw->fc.current_mode = igc_fc_rx_pause; hw_dbg("Flow Control = RX PAUSE frames only.\n"); } } /* For receiving PAUSE frames ONLY. * * LOCAL DEVICE | LINK PARTNER * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result *-------|---------|-------|---------|-------------------- * 0 | 1 | 1 | 1 | igc_fc_tx_pause */ else if (!(mii_nway_adv_reg & NWAY_AR_PAUSE) && (mii_nway_adv_reg & NWAY_AR_ASM_DIR) && (mii_nway_lp_ability_reg & NWAY_LPAR_PAUSE) && (mii_nway_lp_ability_reg & NWAY_LPAR_ASM_DIR)) { hw->fc.current_mode = igc_fc_tx_pause; hw_dbg("Flow Control = TX PAUSE frames only.\n"); } /* For transmitting PAUSE frames ONLY. * * LOCAL DEVICE | LINK PARTNER * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result *-------|---------|-------|---------|-------------------- * 1 | 1 | 0 | 1 | igc_fc_rx_pause */ else if ((mii_nway_adv_reg & NWAY_AR_PAUSE) && (mii_nway_adv_reg & NWAY_AR_ASM_DIR) && !(mii_nway_lp_ability_reg & NWAY_LPAR_PAUSE) && (mii_nway_lp_ability_reg & NWAY_LPAR_ASM_DIR)) { hw->fc.current_mode = igc_fc_rx_pause; hw_dbg("Flow Control = RX PAUSE frames only.\n"); } /* Per the IEEE spec, at this point flow control should be * disabled. However, we want to consider that we could * be connected to a legacy switch that doesn't advertise * desired flow control, but can be forced on the link * partner. So if we advertised no flow control, that is * what we will resolve to. If we advertised some kind of * receive capability (Rx Pause Only or Full Flow Control) * and the link partner advertised none, we will configure * ourselves to enable Rx Flow Control only. We can do * this safely for two reasons: If the link partner really * didn't want flow control enabled, and we enable Rx, no * harm done since we won't be receiving any PAUSE frames * anyway. If the intent on the link partner was to have * flow control enabled, then by us enabling RX only, we * can at least receive pause frames and process them. * This is a good idea because in most cases, since we are * predominantly a server NIC, more times than not we will * be asked to delay transmission of packets than asking * our link partner to pause transmission of frames. */ else if ((hw->fc.requested_mode == igc_fc_none) || (hw->fc.requested_mode == igc_fc_tx_pause) || (hw->fc.strict_ieee)) { hw->fc.current_mode = igc_fc_none; hw_dbg("Flow Control = NONE.\n"); } else { hw->fc.current_mode = igc_fc_rx_pause; hw_dbg("Flow Control = RX PAUSE frames only.\n"); } /* Now we need to do one last check... If we auto- * negotiated to HALF DUPLEX, flow control should not be * enabled per IEEE 802.3 spec. */ ret_val = hw->mac.ops.get_speed_and_duplex(hw, &speed, &duplex); if (ret_val) { hw_dbg("Error getting link speed and duplex\n"); goto out; } if (duplex == HALF_DUPLEX) hw->fc.current_mode = igc_fc_none; /* Now we call a subroutine to actually force the MAC * controller to use the correct flow control settings. */ ret_val = igc_force_mac_fc(hw); if (ret_val) { hw_dbg("Error forcing flow control settings\n"); goto out; } } out: return ret_val; } /** * igc_get_auto_rd_done - Check for auto read completion * @hw: pointer to the HW structure * * Check EEPROM for Auto Read done bit. */ s32 igc_get_auto_rd_done(struct igc_hw *hw) { s32 ret_val = 0; s32 i = 0; while (i < AUTO_READ_DONE_TIMEOUT) { if (rd32(IGC_EECD) & IGC_EECD_AUTO_RD) break; usleep_range(1000, 2000); i++; } if (i == AUTO_READ_DONE_TIMEOUT) { hw_dbg("Auto read by HW from NVM has not completed.\n"); ret_val = -IGC_ERR_RESET; goto out; } out: return ret_val; } /** * igc_get_speed_and_duplex_copper - Retrieve current speed/duplex * @hw: pointer to the HW structure * @speed: stores the current speed * @duplex: stores the current duplex * * Read the status register for the current speed/duplex and store the current * speed and duplex for copper connections. */ s32 igc_get_speed_and_duplex_copper(struct igc_hw *hw, u16 *speed, u16 *duplex) { u32 status; status = rd32(IGC_STATUS); if (status & IGC_STATUS_SPEED_1000) { /* For I225, STATUS will indicate 1G speed in both 1 Gbps * and 2.5 Gbps link modes. An additional bit is used * to differentiate between 1 Gbps and 2.5 Gbps. */ if (hw->mac.type == igc_i225 && (status & IGC_STATUS_SPEED_2500)) { *speed = SPEED_2500; hw_dbg("2500 Mbs, "); } else { *speed = SPEED_1000; hw_dbg("1000 Mbs, "); } } else if (status & IGC_STATUS_SPEED_100) { *speed = SPEED_100; hw_dbg("100 Mbs, "); } else { *speed = SPEED_10; hw_dbg("10 Mbs, "); } if (status & IGC_STATUS_FD) { *duplex = FULL_DUPLEX; hw_dbg("Full Duplex\n"); } else { *duplex = HALF_DUPLEX; hw_dbg("Half Duplex\n"); } return 0; } /** * igc_put_hw_semaphore - Release hardware semaphore * @hw: pointer to the HW structure * * Release hardware semaphore used to access the PHY or NVM */ void igc_put_hw_semaphore(struct igc_hw *hw) { u32 swsm; swsm = rd32(IGC_SWSM); swsm &= ~(IGC_SWSM_SMBI | IGC_SWSM_SWESMBI); wr32(IGC_SWSM, swsm); } /** * igc_enable_mng_pass_thru - Enable processing of ARP's * @hw: pointer to the HW structure * * Verifies the hardware needs to leave interface enabled so that frames can * be directed to and from the management interface. */ bool igc_enable_mng_pass_thru(struct igc_hw *hw) { bool ret_val = false; u32 fwsm, factps; u32 manc; if (!hw->mac.asf_firmware_present) goto out; manc = rd32(IGC_MANC); if (!(manc & IGC_MANC_RCV_TCO_EN)) goto out; if (hw->mac.arc_subsystem_valid) { fwsm = rd32(IGC_FWSM); factps = rd32(IGC_FACTPS); if (!(factps & IGC_FACTPS_MNGCG) && ((fwsm & IGC_FWSM_MODE_MASK) == (igc_mng_mode_pt << IGC_FWSM_MODE_SHIFT))) { ret_val = true; goto out; } } else { if ((manc & IGC_MANC_SMBUS_EN) && !(manc & IGC_MANC_ASF_EN)) { ret_val = true; goto out; } } out: return ret_val; } /** * igc_hash_mc_addr - Generate a multicast hash value * @hw: pointer to the HW structure * @mc_addr: pointer to a multicast address * * Generates a multicast address hash value which is used to determine * the multicast filter table array address and new table value. See * igc_mta_set() **/ static u32 igc_hash_mc_addr(struct igc_hw *hw, u8 *mc_addr) { u32 hash_value, hash_mask; u8 bit_shift = 0; /* Register count multiplied by bits per register */ hash_mask = (hw->mac.mta_reg_count * 32) - 1; /* For a mc_filter_type of 0, bit_shift is the number of left-shifts * where 0xFF would still fall within the hash mask. */ while (hash_mask >> bit_shift != 0xFF) bit_shift++; /* The portion of the address that is used for the hash table * is determined by the mc_filter_type setting. * The algorithm is such that there is a total of 8 bits of shifting. * The bit_shift for a mc_filter_type of 0 represents the number of * left-shifts where the MSB of mc_addr[5] would still fall within * the hash_mask. Case 0 does this exactly. Since there are a total * of 8 bits of shifting, then mc_addr[4] will shift right the * remaining number of bits. Thus 8 - bit_shift. The rest of the * cases are a variation of this algorithm...essentially raising the * number of bits to shift mc_addr[5] left, while still keeping the * 8-bit shifting total. * * For example, given the following Destination MAC Address and an * MTA register count of 128 (thus a 4096-bit vector and 0xFFF mask), * we can see that the bit_shift for case 0 is 4. These are the hash * values resulting from each mc_filter_type... * [0] [1] [2] [3] [4] [5] * 01 AA 00 12 34 56 * LSB MSB * * case 0: hash_value = ((0x34 >> 4) | (0x56 << 4)) & 0xFFF = 0x563 * case 1: hash_value = ((0x34 >> 3) | (0x56 << 5)) & 0xFFF = 0xAC6 * case 2: hash_value = ((0x34 >> 2) | (0x56 << 6)) & 0xFFF = 0x163 * case 3: hash_value = ((0x34 >> 0) | (0x56 << 8)) & 0xFFF = 0x634 */ switch (hw->mac.mc_filter_type) { default: case 0: break; case 1: bit_shift += 1; break; case 2: bit_shift += 2; break; case 3: bit_shift += 4; break; } hash_value = hash_mask & (((mc_addr[4] >> (8 - bit_shift)) | (((u16)mc_addr[5]) << bit_shift))); return hash_value; } /** * igc_update_mc_addr_list - Update Multicast addresses * @hw: pointer to the HW structure * @mc_addr_list: array of multicast addresses to program * @mc_addr_count: number of multicast addresses to program * * Updates entire Multicast Table Array. * The caller must have a packed mc_addr_list of multicast addresses. **/ void igc_update_mc_addr_list(struct igc_hw *hw, u8 *mc_addr_list, u32 mc_addr_count) { u32 hash_value, hash_bit, hash_reg; int i; /* clear mta_shadow */ memset(&hw->mac.mta_shadow, 0, sizeof(hw->mac.mta_shadow)); /* update mta_shadow from mc_addr_list */ for (i = 0; (u32)i < mc_addr_count; i++) { hash_value = igc_hash_mc_addr(hw, mc_addr_list); hash_reg = (hash_value >> 5) & (hw->mac.mta_reg_count - 1); hash_bit = hash_value & 0x1F; hw->mac.mta_shadow[hash_reg] |= BIT(hash_bit); mc_addr_list += ETH_ALEN; } /* replace the entire MTA table */ for (i = hw->mac.mta_reg_count - 1; i >= 0; i--) array_wr32(IGC_MTA, i, hw->mac.mta_shadow[i]); wrfl(); }