cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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mac.c (51960B)


      1// SPDX-License-Identifier: GPL-2.0
      2/* Copyright(c) 1999 - 2018 Intel Corporation. */
      3
      4#include "e1000.h"
      5
      6/**
      7 *  e1000e_get_bus_info_pcie - Get PCIe bus information
      8 *  @hw: pointer to the HW structure
      9 *
     10 *  Determines and stores the system bus information for a particular
     11 *  network interface.  The following bus information is determined and stored:
     12 *  bus speed, bus width, type (PCIe), and PCIe function.
     13 **/
     14s32 e1000e_get_bus_info_pcie(struct e1000_hw *hw)
     15{
     16	struct e1000_mac_info *mac = &hw->mac;
     17	struct e1000_bus_info *bus = &hw->bus;
     18	struct e1000_adapter *adapter = hw->adapter;
     19	u16 pcie_link_status, cap_offset;
     20
     21	cap_offset = adapter->pdev->pcie_cap;
     22	if (!cap_offset) {
     23		bus->width = e1000_bus_width_unknown;
     24	} else {
     25		pci_read_config_word(adapter->pdev,
     26				     cap_offset + PCIE_LINK_STATUS,
     27				     &pcie_link_status);
     28		bus->width = (enum e1000_bus_width)((pcie_link_status &
     29						     PCIE_LINK_WIDTH_MASK) >>
     30						    PCIE_LINK_WIDTH_SHIFT);
     31	}
     32
     33	mac->ops.set_lan_id(hw);
     34
     35	return 0;
     36}
     37
     38/**
     39 *  e1000_set_lan_id_multi_port_pcie - Set LAN id for PCIe multiple port devices
     40 *
     41 *  @hw: pointer to the HW structure
     42 *
     43 *  Determines the LAN function id by reading memory-mapped registers
     44 *  and swaps the port value if requested.
     45 **/
     46void e1000_set_lan_id_multi_port_pcie(struct e1000_hw *hw)
     47{
     48	struct e1000_bus_info *bus = &hw->bus;
     49	u32 reg;
     50
     51	/* The status register reports the correct function number
     52	 * for the device regardless of function swap state.
     53	 */
     54	reg = er32(STATUS);
     55	bus->func = (reg & E1000_STATUS_FUNC_MASK) >> E1000_STATUS_FUNC_SHIFT;
     56}
     57
     58/**
     59 *  e1000_set_lan_id_single_port - Set LAN id for a single port device
     60 *  @hw: pointer to the HW structure
     61 *
     62 *  Sets the LAN function id to zero for a single port device.
     63 **/
     64void e1000_set_lan_id_single_port(struct e1000_hw *hw)
     65{
     66	struct e1000_bus_info *bus = &hw->bus;
     67
     68	bus->func = 0;
     69}
     70
     71/**
     72 *  e1000_clear_vfta_generic - Clear VLAN filter table
     73 *  @hw: pointer to the HW structure
     74 *
     75 *  Clears the register array which contains the VLAN filter table by
     76 *  setting all the values to 0.
     77 **/
     78void e1000_clear_vfta_generic(struct e1000_hw *hw)
     79{
     80	u32 offset;
     81
     82	for (offset = 0; offset < E1000_VLAN_FILTER_TBL_SIZE; offset++) {
     83		E1000_WRITE_REG_ARRAY(hw, E1000_VFTA, offset, 0);
     84		e1e_flush();
     85	}
     86}
     87
     88/**
     89 *  e1000_write_vfta_generic - Write value to VLAN filter table
     90 *  @hw: pointer to the HW structure
     91 *  @offset: register offset in VLAN filter table
     92 *  @value: register value written to VLAN filter table
     93 *
     94 *  Writes value at the given offset in the register array which stores
     95 *  the VLAN filter table.
     96 **/
     97void e1000_write_vfta_generic(struct e1000_hw *hw, u32 offset, u32 value)
     98{
     99	E1000_WRITE_REG_ARRAY(hw, E1000_VFTA, offset, value);
    100	e1e_flush();
    101}
    102
    103/**
    104 *  e1000e_init_rx_addrs - Initialize receive address's
    105 *  @hw: pointer to the HW structure
    106 *  @rar_count: receive address registers
    107 *
    108 *  Setup the receive address registers by setting the base receive address
    109 *  register to the devices MAC address and clearing all the other receive
    110 *  address registers to 0.
    111 **/
    112void e1000e_init_rx_addrs(struct e1000_hw *hw, u16 rar_count)
    113{
    114	u32 i;
    115	u8 mac_addr[ETH_ALEN] = { 0 };
    116
    117	/* Setup the receive address */
    118	e_dbg("Programming MAC Address into RAR[0]\n");
    119
    120	hw->mac.ops.rar_set(hw, hw->mac.addr, 0);
    121
    122	/* Zero out the other (rar_entry_count - 1) receive addresses */
    123	e_dbg("Clearing RAR[1-%u]\n", rar_count - 1);
    124	for (i = 1; i < rar_count; i++)
    125		hw->mac.ops.rar_set(hw, mac_addr, i);
    126}
    127
    128/**
    129 *  e1000_check_alt_mac_addr_generic - Check for alternate MAC addr
    130 *  @hw: pointer to the HW structure
    131 *
    132 *  Checks the nvm for an alternate MAC address.  An alternate MAC address
    133 *  can be setup by pre-boot software and must be treated like a permanent
    134 *  address and must override the actual permanent MAC address. If an
    135 *  alternate MAC address is found it is programmed into RAR0, replacing
    136 *  the permanent address that was installed into RAR0 by the Si on reset.
    137 *  This function will return SUCCESS unless it encounters an error while
    138 *  reading the EEPROM.
    139 **/
    140s32 e1000_check_alt_mac_addr_generic(struct e1000_hw *hw)
    141{
    142	u32 i;
    143	s32 ret_val;
    144	u16 offset, nvm_alt_mac_addr_offset, nvm_data;
    145	u8 alt_mac_addr[ETH_ALEN];
    146
    147	ret_val = e1000_read_nvm(hw, NVM_COMPAT, 1, &nvm_data);
    148	if (ret_val)
    149		return ret_val;
    150
    151	/* not supported on 82573 */
    152	if (hw->mac.type == e1000_82573)
    153		return 0;
    154
    155	ret_val = e1000_read_nvm(hw, NVM_ALT_MAC_ADDR_PTR, 1,
    156				 &nvm_alt_mac_addr_offset);
    157	if (ret_val) {
    158		e_dbg("NVM Read Error\n");
    159		return ret_val;
    160	}
    161
    162	if ((nvm_alt_mac_addr_offset == 0xFFFF) ||
    163	    (nvm_alt_mac_addr_offset == 0x0000))
    164		/* There is no Alternate MAC Address */
    165		return 0;
    166
    167	if (hw->bus.func == E1000_FUNC_1)
    168		nvm_alt_mac_addr_offset += E1000_ALT_MAC_ADDRESS_OFFSET_LAN1;
    169	for (i = 0; i < ETH_ALEN; i += 2) {
    170		offset = nvm_alt_mac_addr_offset + (i >> 1);
    171		ret_val = e1000_read_nvm(hw, offset, 1, &nvm_data);
    172		if (ret_val) {
    173			e_dbg("NVM Read Error\n");
    174			return ret_val;
    175		}
    176
    177		alt_mac_addr[i] = (u8)(nvm_data & 0xFF);
    178		alt_mac_addr[i + 1] = (u8)(nvm_data >> 8);
    179	}
    180
    181	/* if multicast bit is set, the alternate address will not be used */
    182	if (is_multicast_ether_addr(alt_mac_addr)) {
    183		e_dbg("Ignoring Alternate Mac Address with MC bit set\n");
    184		return 0;
    185	}
    186
    187	/* We have a valid alternate MAC address, and we want to treat it the
    188	 * same as the normal permanent MAC address stored by the HW into the
    189	 * RAR. Do this by mapping this address into RAR0.
    190	 */
    191	hw->mac.ops.rar_set(hw, alt_mac_addr, 0);
    192
    193	return 0;
    194}
    195
    196u32 e1000e_rar_get_count_generic(struct e1000_hw *hw)
    197{
    198	return hw->mac.rar_entry_count;
    199}
    200
    201/**
    202 *  e1000e_rar_set_generic - Set receive address register
    203 *  @hw: pointer to the HW structure
    204 *  @addr: pointer to the receive address
    205 *  @index: receive address array register
    206 *
    207 *  Sets the receive address array register at index to the address passed
    208 *  in by addr.
    209 **/
    210int e1000e_rar_set_generic(struct e1000_hw *hw, u8 *addr, u32 index)
    211{
    212	u32 rar_low, rar_high;
    213
    214	/* HW expects these in little endian so we reverse the byte order
    215	 * from network order (big endian) to little endian
    216	 */
    217	rar_low = ((u32)addr[0] | ((u32)addr[1] << 8) |
    218		   ((u32)addr[2] << 16) | ((u32)addr[3] << 24));
    219
    220	rar_high = ((u32)addr[4] | ((u32)addr[5] << 8));
    221
    222	/* If MAC address zero, no need to set the AV bit */
    223	if (rar_low || rar_high)
    224		rar_high |= E1000_RAH_AV;
    225
    226	/* Some bridges will combine consecutive 32-bit writes into
    227	 * a single burst write, which will malfunction on some parts.
    228	 * The flushes avoid this.
    229	 */
    230	ew32(RAL(index), rar_low);
    231	e1e_flush();
    232	ew32(RAH(index), rar_high);
    233	e1e_flush();
    234
    235	return 0;
    236}
    237
    238/**
    239 *  e1000_hash_mc_addr - Generate a multicast hash value
    240 *  @hw: pointer to the HW structure
    241 *  @mc_addr: pointer to a multicast address
    242 *
    243 *  Generates a multicast address hash value which is used to determine
    244 *  the multicast filter table array address and new table value.
    245 **/
    246static u32 e1000_hash_mc_addr(struct e1000_hw *hw, u8 *mc_addr)
    247{
    248	u32 hash_value, hash_mask;
    249	u8 bit_shift = 0;
    250
    251	/* Register count multiplied by bits per register */
    252	hash_mask = (hw->mac.mta_reg_count * 32) - 1;
    253
    254	/* For a mc_filter_type of 0, bit_shift is the number of left-shifts
    255	 * where 0xFF would still fall within the hash mask.
    256	 */
    257	while (hash_mask >> bit_shift != 0xFF)
    258		bit_shift++;
    259
    260	/* The portion of the address that is used for the hash table
    261	 * is determined by the mc_filter_type setting.
    262	 * The algorithm is such that there is a total of 8 bits of shifting.
    263	 * The bit_shift for a mc_filter_type of 0 represents the number of
    264	 * left-shifts where the MSB of mc_addr[5] would still fall within
    265	 * the hash_mask.  Case 0 does this exactly.  Since there are a total
    266	 * of 8 bits of shifting, then mc_addr[4] will shift right the
    267	 * remaining number of bits. Thus 8 - bit_shift.  The rest of the
    268	 * cases are a variation of this algorithm...essentially raising the
    269	 * number of bits to shift mc_addr[5] left, while still keeping the
    270	 * 8-bit shifting total.
    271	 *
    272	 * For example, given the following Destination MAC Address and an
    273	 * mta register count of 128 (thus a 4096-bit vector and 0xFFF mask),
    274	 * we can see that the bit_shift for case 0 is 4.  These are the hash
    275	 * values resulting from each mc_filter_type...
    276	 * [0] [1] [2] [3] [4] [5]
    277	 * 01  AA  00  12  34  56
    278	 * LSB           MSB
    279	 *
    280	 * case 0: hash_value = ((0x34 >> 4) | (0x56 << 4)) & 0xFFF = 0x563
    281	 * case 1: hash_value = ((0x34 >> 3) | (0x56 << 5)) & 0xFFF = 0xAC6
    282	 * case 2: hash_value = ((0x34 >> 2) | (0x56 << 6)) & 0xFFF = 0x163
    283	 * case 3: hash_value = ((0x34 >> 0) | (0x56 << 8)) & 0xFFF = 0x634
    284	 */
    285	switch (hw->mac.mc_filter_type) {
    286	default:
    287	case 0:
    288		break;
    289	case 1:
    290		bit_shift += 1;
    291		break;
    292	case 2:
    293		bit_shift += 2;
    294		break;
    295	case 3:
    296		bit_shift += 4;
    297		break;
    298	}
    299
    300	hash_value = hash_mask & (((mc_addr[4] >> (8 - bit_shift)) |
    301				   (((u16)mc_addr[5]) << bit_shift)));
    302
    303	return hash_value;
    304}
    305
    306/**
    307 *  e1000e_update_mc_addr_list_generic - Update Multicast addresses
    308 *  @hw: pointer to the HW structure
    309 *  @mc_addr_list: array of multicast addresses to program
    310 *  @mc_addr_count: number of multicast addresses to program
    311 *
    312 *  Updates entire Multicast Table Array.
    313 *  The caller must have a packed mc_addr_list of multicast addresses.
    314 **/
    315void e1000e_update_mc_addr_list_generic(struct e1000_hw *hw,
    316					u8 *mc_addr_list, u32 mc_addr_count)
    317{
    318	u32 hash_value, hash_bit, hash_reg;
    319	int i;
    320
    321	/* clear mta_shadow */
    322	memset(&hw->mac.mta_shadow, 0, sizeof(hw->mac.mta_shadow));
    323
    324	/* update mta_shadow from mc_addr_list */
    325	for (i = 0; (u32)i < mc_addr_count; i++) {
    326		hash_value = e1000_hash_mc_addr(hw, mc_addr_list);
    327
    328		hash_reg = (hash_value >> 5) & (hw->mac.mta_reg_count - 1);
    329		hash_bit = hash_value & 0x1F;
    330
    331		hw->mac.mta_shadow[hash_reg] |= BIT(hash_bit);
    332		mc_addr_list += (ETH_ALEN);
    333	}
    334
    335	/* replace the entire MTA table */
    336	for (i = hw->mac.mta_reg_count - 1; i >= 0; i--)
    337		E1000_WRITE_REG_ARRAY(hw, E1000_MTA, i, hw->mac.mta_shadow[i]);
    338	e1e_flush();
    339}
    340
    341/**
    342 *  e1000e_clear_hw_cntrs_base - Clear base hardware counters
    343 *  @hw: pointer to the HW structure
    344 *
    345 *  Clears the base hardware counters by reading the counter registers.
    346 **/
    347void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw)
    348{
    349	er32(CRCERRS);
    350	er32(SYMERRS);
    351	er32(MPC);
    352	er32(SCC);
    353	er32(ECOL);
    354	er32(MCC);
    355	er32(LATECOL);
    356	er32(COLC);
    357	er32(DC);
    358	er32(SEC);
    359	er32(RLEC);
    360	er32(XONRXC);
    361	er32(XONTXC);
    362	er32(XOFFRXC);
    363	er32(XOFFTXC);
    364	er32(FCRUC);
    365	er32(GPRC);
    366	er32(BPRC);
    367	er32(MPRC);
    368	er32(GPTC);
    369	er32(GORCL);
    370	er32(GORCH);
    371	er32(GOTCL);
    372	er32(GOTCH);
    373	er32(RNBC);
    374	er32(RUC);
    375	er32(RFC);
    376	er32(ROC);
    377	er32(RJC);
    378	er32(TORL);
    379	er32(TORH);
    380	er32(TOTL);
    381	er32(TOTH);
    382	er32(TPR);
    383	er32(TPT);
    384	er32(MPTC);
    385	er32(BPTC);
    386}
    387
    388/**
    389 *  e1000e_check_for_copper_link - Check for link (Copper)
    390 *  @hw: pointer to the HW structure
    391 *
    392 *  Checks to see of the link status of the hardware has changed.  If a
    393 *  change in link status has been detected, then we read the PHY registers
    394 *  to get the current speed/duplex if link exists.
    395 **/
    396s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
    397{
    398	struct e1000_mac_info *mac = &hw->mac;
    399	s32 ret_val;
    400	bool link;
    401
    402	/* We only want to go out to the PHY registers to see if Auto-Neg
    403	 * has completed and/or if our link status has changed.  The
    404	 * get_link_status flag is set upon receiving a Link Status
    405	 * Change or Rx Sequence Error interrupt.
    406	 */
    407	if (!mac->get_link_status)
    408		return 0;
    409	mac->get_link_status = false;
    410
    411	/* First we want to see if the MII Status Register reports
    412	 * link.  If so, then we want to get the current speed/duplex
    413	 * of the PHY.
    414	 */
    415	ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);
    416	if (ret_val || !link)
    417		goto out;
    418
    419	/* Check if there was DownShift, must be checked
    420	 * immediately after link-up
    421	 */
    422	e1000e_check_downshift(hw);
    423
    424	/* If we are forcing speed/duplex, then we simply return since
    425	 * we have already determined whether we have link or not.
    426	 */
    427	if (!mac->autoneg)
    428		return -E1000_ERR_CONFIG;
    429
    430	/* Auto-Neg is enabled.  Auto Speed Detection takes care
    431	 * of MAC speed/duplex configuration.  So we only need to
    432	 * configure Collision Distance in the MAC.
    433	 */
    434	mac->ops.config_collision_dist(hw);
    435
    436	/* Configure Flow Control now that Auto-Neg has completed.
    437	 * First, we need to restore the desired flow control
    438	 * settings because we may have had to re-autoneg with a
    439	 * different link partner.
    440	 */
    441	ret_val = e1000e_config_fc_after_link_up(hw);
    442	if (ret_val)
    443		e_dbg("Error configuring flow control\n");
    444
    445	return ret_val;
    446
    447out:
    448	mac->get_link_status = true;
    449	return ret_val;
    450}
    451
    452/**
    453 *  e1000e_check_for_fiber_link - Check for link (Fiber)
    454 *  @hw: pointer to the HW structure
    455 *
    456 *  Checks for link up on the hardware.  If link is not up and we have
    457 *  a signal, then we need to force link up.
    458 **/
    459s32 e1000e_check_for_fiber_link(struct e1000_hw *hw)
    460{
    461	struct e1000_mac_info *mac = &hw->mac;
    462	u32 rxcw;
    463	u32 ctrl;
    464	u32 status;
    465	s32 ret_val;
    466
    467	ctrl = er32(CTRL);
    468	status = er32(STATUS);
    469	rxcw = er32(RXCW);
    470
    471	/* If we don't have link (auto-negotiation failed or link partner
    472	 * cannot auto-negotiate), the cable is plugged in (we have signal),
    473	 * and our link partner is not trying to auto-negotiate with us (we
    474	 * are receiving idles or data), we need to force link up. We also
    475	 * need to give auto-negotiation time to complete, in case the cable
    476	 * was just plugged in. The autoneg_failed flag does this.
    477	 */
    478	/* (ctrl & E1000_CTRL_SWDPIN1) == 1 == have signal */
    479	if ((ctrl & E1000_CTRL_SWDPIN1) && !(status & E1000_STATUS_LU) &&
    480	    !(rxcw & E1000_RXCW_C)) {
    481		if (!mac->autoneg_failed) {
    482			mac->autoneg_failed = true;
    483			return 0;
    484		}
    485		e_dbg("NOT Rx'ing /C/, disable AutoNeg and force link.\n");
    486
    487		/* Disable auto-negotiation in the TXCW register */
    488		ew32(TXCW, (mac->txcw & ~E1000_TXCW_ANE));
    489
    490		/* Force link-up and also force full-duplex. */
    491		ctrl = er32(CTRL);
    492		ctrl |= (E1000_CTRL_SLU | E1000_CTRL_FD);
    493		ew32(CTRL, ctrl);
    494
    495		/* Configure Flow Control after forcing link up. */
    496		ret_val = e1000e_config_fc_after_link_up(hw);
    497		if (ret_val) {
    498			e_dbg("Error configuring flow control\n");
    499			return ret_val;
    500		}
    501	} else if ((ctrl & E1000_CTRL_SLU) && (rxcw & E1000_RXCW_C)) {
    502		/* If we are forcing link and we are receiving /C/ ordered
    503		 * sets, re-enable auto-negotiation in the TXCW register
    504		 * and disable forced link in the Device Control register
    505		 * in an attempt to auto-negotiate with our link partner.
    506		 */
    507		e_dbg("Rx'ing /C/, enable AutoNeg and stop forcing link.\n");
    508		ew32(TXCW, mac->txcw);
    509		ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));
    510
    511		mac->serdes_has_link = true;
    512	}
    513
    514	return 0;
    515}
    516
    517/**
    518 *  e1000e_check_for_serdes_link - Check for link (Serdes)
    519 *  @hw: pointer to the HW structure
    520 *
    521 *  Checks for link up on the hardware.  If link is not up and we have
    522 *  a signal, then we need to force link up.
    523 **/
    524s32 e1000e_check_for_serdes_link(struct e1000_hw *hw)
    525{
    526	struct e1000_mac_info *mac = &hw->mac;
    527	u32 rxcw;
    528	u32 ctrl;
    529	u32 status;
    530	s32 ret_val;
    531
    532	ctrl = er32(CTRL);
    533	status = er32(STATUS);
    534	rxcw = er32(RXCW);
    535
    536	/* If we don't have link (auto-negotiation failed or link partner
    537	 * cannot auto-negotiate), and our link partner is not trying to
    538	 * auto-negotiate with us (we are receiving idles or data),
    539	 * we need to force link up. We also need to give auto-negotiation
    540	 * time to complete.
    541	 */
    542	/* (ctrl & E1000_CTRL_SWDPIN1) == 1 == have signal */
    543	if (!(status & E1000_STATUS_LU) && !(rxcw & E1000_RXCW_C)) {
    544		if (!mac->autoneg_failed) {
    545			mac->autoneg_failed = true;
    546			return 0;
    547		}
    548		e_dbg("NOT Rx'ing /C/, disable AutoNeg and force link.\n");
    549
    550		/* Disable auto-negotiation in the TXCW register */
    551		ew32(TXCW, (mac->txcw & ~E1000_TXCW_ANE));
    552
    553		/* Force link-up and also force full-duplex. */
    554		ctrl = er32(CTRL);
    555		ctrl |= (E1000_CTRL_SLU | E1000_CTRL_FD);
    556		ew32(CTRL, ctrl);
    557
    558		/* Configure Flow Control after forcing link up. */
    559		ret_val = e1000e_config_fc_after_link_up(hw);
    560		if (ret_val) {
    561			e_dbg("Error configuring flow control\n");
    562			return ret_val;
    563		}
    564	} else if ((ctrl & E1000_CTRL_SLU) && (rxcw & E1000_RXCW_C)) {
    565		/* If we are forcing link and we are receiving /C/ ordered
    566		 * sets, re-enable auto-negotiation in the TXCW register
    567		 * and disable forced link in the Device Control register
    568		 * in an attempt to auto-negotiate with our link partner.
    569		 */
    570		e_dbg("Rx'ing /C/, enable AutoNeg and stop forcing link.\n");
    571		ew32(TXCW, mac->txcw);
    572		ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));
    573
    574		mac->serdes_has_link = true;
    575	} else if (!(E1000_TXCW_ANE & er32(TXCW))) {
    576		/* If we force link for non-auto-negotiation switch, check
    577		 * link status based on MAC synchronization for internal
    578		 * serdes media type.
    579		 */
    580		/* SYNCH bit and IV bit are sticky. */
    581		usleep_range(10, 20);
    582		rxcw = er32(RXCW);
    583		if (rxcw & E1000_RXCW_SYNCH) {
    584			if (!(rxcw & E1000_RXCW_IV)) {
    585				mac->serdes_has_link = true;
    586				e_dbg("SERDES: Link up - forced.\n");
    587			}
    588		} else {
    589			mac->serdes_has_link = false;
    590			e_dbg("SERDES: Link down - force failed.\n");
    591		}
    592	}
    593
    594	if (E1000_TXCW_ANE & er32(TXCW)) {
    595		status = er32(STATUS);
    596		if (status & E1000_STATUS_LU) {
    597			/* SYNCH bit and IV bit are sticky, so reread rxcw. */
    598			usleep_range(10, 20);
    599			rxcw = er32(RXCW);
    600			if (rxcw & E1000_RXCW_SYNCH) {
    601				if (!(rxcw & E1000_RXCW_IV)) {
    602					mac->serdes_has_link = true;
    603					e_dbg("SERDES: Link up - autoneg completed successfully.\n");
    604				} else {
    605					mac->serdes_has_link = false;
    606					e_dbg("SERDES: Link down - invalid codewords detected in autoneg.\n");
    607				}
    608			} else {
    609				mac->serdes_has_link = false;
    610				e_dbg("SERDES: Link down - no sync.\n");
    611			}
    612		} else {
    613			mac->serdes_has_link = false;
    614			e_dbg("SERDES: Link down - autoneg failed\n");
    615		}
    616	}
    617
    618	return 0;
    619}
    620
    621/**
    622 *  e1000_set_default_fc_generic - Set flow control default values
    623 *  @hw: pointer to the HW structure
    624 *
    625 *  Read the EEPROM for the default values for flow control and store the
    626 *  values.
    627 **/
    628static s32 e1000_set_default_fc_generic(struct e1000_hw *hw)
    629{
    630	s32 ret_val;
    631	u16 nvm_data;
    632
    633	/* Read and store word 0x0F of the EEPROM. This word contains bits
    634	 * that determine the hardware's default PAUSE (flow control) mode,
    635	 * a bit that determines whether the HW defaults to enabling or
    636	 * disabling auto-negotiation, and the direction of the
    637	 * SW defined pins. If there is no SW over-ride of the flow
    638	 * control setting, then the variable hw->fc will
    639	 * be initialized based on a value in the EEPROM.
    640	 */
    641	ret_val = e1000_read_nvm(hw, NVM_INIT_CONTROL2_REG, 1, &nvm_data);
    642
    643	if (ret_val) {
    644		e_dbg("NVM Read Error\n");
    645		return ret_val;
    646	}
    647
    648	if (!(nvm_data & NVM_WORD0F_PAUSE_MASK))
    649		hw->fc.requested_mode = e1000_fc_none;
    650	else if ((nvm_data & NVM_WORD0F_PAUSE_MASK) == NVM_WORD0F_ASM_DIR)
    651		hw->fc.requested_mode = e1000_fc_tx_pause;
    652	else
    653		hw->fc.requested_mode = e1000_fc_full;
    654
    655	return 0;
    656}
    657
    658/**
    659 *  e1000e_setup_link_generic - Setup flow control and link settings
    660 *  @hw: pointer to the HW structure
    661 *
    662 *  Determines which flow control settings to use, then configures flow
    663 *  control.  Calls the appropriate media-specific link configuration
    664 *  function.  Assuming the adapter has a valid link partner, a valid link
    665 *  should be established.  Assumes the hardware has previously been reset
    666 *  and the transmitter and receiver are not enabled.
    667 **/
    668s32 e1000e_setup_link_generic(struct e1000_hw *hw)
    669{
    670	s32 ret_val;
    671
    672	/* In the case of the phy reset being blocked, we already have a link.
    673	 * We do not need to set it up again.
    674	 */
    675	if (hw->phy.ops.check_reset_block && hw->phy.ops.check_reset_block(hw))
    676		return 0;
    677
    678	/* If requested flow control is set to default, set flow control
    679	 * based on the EEPROM flow control settings.
    680	 */
    681	if (hw->fc.requested_mode == e1000_fc_default) {
    682		ret_val = e1000_set_default_fc_generic(hw);
    683		if (ret_val)
    684			return ret_val;
    685	}
    686
    687	/* Save off the requested flow control mode for use later.  Depending
    688	 * on the link partner's capabilities, we may or may not use this mode.
    689	 */
    690	hw->fc.current_mode = hw->fc.requested_mode;
    691
    692	e_dbg("After fix-ups FlowControl is now = %x\n", hw->fc.current_mode);
    693
    694	/* Call the necessary media_type subroutine to configure the link. */
    695	ret_val = hw->mac.ops.setup_physical_interface(hw);
    696	if (ret_val)
    697		return ret_val;
    698
    699	/* Initialize the flow control address, type, and PAUSE timer
    700	 * registers to their default values.  This is done even if flow
    701	 * control is disabled, because it does not hurt anything to
    702	 * initialize these registers.
    703	 */
    704	e_dbg("Initializing the Flow Control address, type and timer regs\n");
    705	ew32(FCT, FLOW_CONTROL_TYPE);
    706	ew32(FCAH, FLOW_CONTROL_ADDRESS_HIGH);
    707	ew32(FCAL, FLOW_CONTROL_ADDRESS_LOW);
    708
    709	ew32(FCTTV, hw->fc.pause_time);
    710
    711	return e1000e_set_fc_watermarks(hw);
    712}
    713
    714/**
    715 *  e1000_commit_fc_settings_generic - Configure flow control
    716 *  @hw: pointer to the HW structure
    717 *
    718 *  Write the flow control settings to the Transmit Config Word Register (TXCW)
    719 *  base on the flow control settings in e1000_mac_info.
    720 **/
    721static s32 e1000_commit_fc_settings_generic(struct e1000_hw *hw)
    722{
    723	struct e1000_mac_info *mac = &hw->mac;
    724	u32 txcw;
    725
    726	/* Check for a software override of the flow control settings, and
    727	 * setup the device accordingly.  If auto-negotiation is enabled, then
    728	 * software will have to set the "PAUSE" bits to the correct value in
    729	 * the Transmit Config Word Register (TXCW) and re-start auto-
    730	 * negotiation.  However, if auto-negotiation is disabled, then
    731	 * software will have to manually configure the two flow control enable
    732	 * bits in the CTRL register.
    733	 *
    734	 * The possible values of the "fc" parameter are:
    735	 *      0:  Flow control is completely disabled
    736	 *      1:  Rx flow control is enabled (we can receive pause frames,
    737	 *          but not send pause frames).
    738	 *      2:  Tx flow control is enabled (we can send pause frames but we
    739	 *          do not support receiving pause frames).
    740	 *      3:  Both Rx and Tx flow control (symmetric) are enabled.
    741	 */
    742	switch (hw->fc.current_mode) {
    743	case e1000_fc_none:
    744		/* Flow control completely disabled by a software over-ride. */
    745		txcw = (E1000_TXCW_ANE | E1000_TXCW_FD);
    746		break;
    747	case e1000_fc_rx_pause:
    748		/* Rx Flow control is enabled and Tx Flow control is disabled
    749		 * by a software over-ride. Since there really isn't a way to
    750		 * advertise that we are capable of Rx Pause ONLY, we will
    751		 * advertise that we support both symmetric and asymmetric Rx
    752		 * PAUSE.  Later, we will disable the adapter's ability to send
    753		 * PAUSE frames.
    754		 */
    755		txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_PAUSE_MASK);
    756		break;
    757	case e1000_fc_tx_pause:
    758		/* Tx Flow control is enabled, and Rx Flow control is disabled,
    759		 * by a software over-ride.
    760		 */
    761		txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_ASM_DIR);
    762		break;
    763	case e1000_fc_full:
    764		/* Flow control (both Rx and Tx) is enabled by a software
    765		 * over-ride.
    766		 */
    767		txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_PAUSE_MASK);
    768		break;
    769	default:
    770		e_dbg("Flow control param set incorrectly\n");
    771		return -E1000_ERR_CONFIG;
    772	}
    773
    774	ew32(TXCW, txcw);
    775	mac->txcw = txcw;
    776
    777	return 0;
    778}
    779
    780/**
    781 *  e1000_poll_fiber_serdes_link_generic - Poll for link up
    782 *  @hw: pointer to the HW structure
    783 *
    784 *  Polls for link up by reading the status register, if link fails to come
    785 *  up with auto-negotiation, then the link is forced if a signal is detected.
    786 **/
    787static s32 e1000_poll_fiber_serdes_link_generic(struct e1000_hw *hw)
    788{
    789	struct e1000_mac_info *mac = &hw->mac;
    790	u32 i, status;
    791	s32 ret_val;
    792
    793	/* If we have a signal (the cable is plugged in, or assumed true for
    794	 * serdes media) then poll for a "Link-Up" indication in the Device
    795	 * Status Register.  Time-out if a link isn't seen in 500 milliseconds
    796	 * seconds (Auto-negotiation should complete in less than 500
    797	 * milliseconds even if the other end is doing it in SW).
    798	 */
    799	for (i = 0; i < FIBER_LINK_UP_LIMIT; i++) {
    800		usleep_range(10000, 11000);
    801		status = er32(STATUS);
    802		if (status & E1000_STATUS_LU)
    803			break;
    804	}
    805	if (i == FIBER_LINK_UP_LIMIT) {
    806		e_dbg("Never got a valid link from auto-neg!!!\n");
    807		mac->autoneg_failed = true;
    808		/* AutoNeg failed to achieve a link, so we'll call
    809		 * mac->check_for_link. This routine will force the
    810		 * link up if we detect a signal. This will allow us to
    811		 * communicate with non-autonegotiating link partners.
    812		 */
    813		ret_val = mac->ops.check_for_link(hw);
    814		if (ret_val) {
    815			e_dbg("Error while checking for link\n");
    816			return ret_val;
    817		}
    818		mac->autoneg_failed = false;
    819	} else {
    820		mac->autoneg_failed = false;
    821		e_dbg("Valid Link Found\n");
    822	}
    823
    824	return 0;
    825}
    826
    827/**
    828 *  e1000e_setup_fiber_serdes_link - Setup link for fiber/serdes
    829 *  @hw: pointer to the HW structure
    830 *
    831 *  Configures collision distance and flow control for fiber and serdes
    832 *  links.  Upon successful setup, poll for link.
    833 **/
    834s32 e1000e_setup_fiber_serdes_link(struct e1000_hw *hw)
    835{
    836	u32 ctrl;
    837	s32 ret_val;
    838
    839	ctrl = er32(CTRL);
    840
    841	/* Take the link out of reset */
    842	ctrl &= ~E1000_CTRL_LRST;
    843
    844	hw->mac.ops.config_collision_dist(hw);
    845
    846	ret_val = e1000_commit_fc_settings_generic(hw);
    847	if (ret_val)
    848		return ret_val;
    849
    850	/* Since auto-negotiation is enabled, take the link out of reset (the
    851	 * link will be in reset, because we previously reset the chip). This
    852	 * will restart auto-negotiation.  If auto-negotiation is successful
    853	 * then the link-up status bit will be set and the flow control enable
    854	 * bits (RFCE and TFCE) will be set according to their negotiated value.
    855	 */
    856	e_dbg("Auto-negotiation enabled\n");
    857
    858	ew32(CTRL, ctrl);
    859	e1e_flush();
    860	usleep_range(1000, 2000);
    861
    862	/* For these adapters, the SW definable pin 1 is set when the optics
    863	 * detect a signal.  If we have a signal, then poll for a "Link-Up"
    864	 * indication.
    865	 */
    866	if (hw->phy.media_type == e1000_media_type_internal_serdes ||
    867	    (er32(CTRL) & E1000_CTRL_SWDPIN1)) {
    868		ret_val = e1000_poll_fiber_serdes_link_generic(hw);
    869	} else {
    870		e_dbg("No signal detected\n");
    871	}
    872
    873	return ret_val;
    874}
    875
    876/**
    877 *  e1000e_config_collision_dist_generic - Configure collision distance
    878 *  @hw: pointer to the HW structure
    879 *
    880 *  Configures the collision distance to the default value and is used
    881 *  during link setup.
    882 **/
    883void e1000e_config_collision_dist_generic(struct e1000_hw *hw)
    884{
    885	u32 tctl;
    886
    887	tctl = er32(TCTL);
    888
    889	tctl &= ~E1000_TCTL_COLD;
    890	tctl |= E1000_COLLISION_DISTANCE << E1000_COLD_SHIFT;
    891
    892	ew32(TCTL, tctl);
    893	e1e_flush();
    894}
    895
    896/**
    897 *  e1000e_set_fc_watermarks - Set flow control high/low watermarks
    898 *  @hw: pointer to the HW structure
    899 *
    900 *  Sets the flow control high/low threshold (watermark) registers.  If
    901 *  flow control XON frame transmission is enabled, then set XON frame
    902 *  transmission as well.
    903 **/
    904s32 e1000e_set_fc_watermarks(struct e1000_hw *hw)
    905{
    906	u32 fcrtl = 0, fcrth = 0;
    907
    908	/* Set the flow control receive threshold registers.  Normally,
    909	 * these registers will be set to a default threshold that may be
    910	 * adjusted later by the driver's runtime code.  However, if the
    911	 * ability to transmit pause frames is not enabled, then these
    912	 * registers will be set to 0.
    913	 */
    914	if (hw->fc.current_mode & e1000_fc_tx_pause) {
    915		/* We need to set up the Receive Threshold high and low water
    916		 * marks as well as (optionally) enabling the transmission of
    917		 * XON frames.
    918		 */
    919		fcrtl = hw->fc.low_water;
    920		if (hw->fc.send_xon)
    921			fcrtl |= E1000_FCRTL_XONE;
    922
    923		fcrth = hw->fc.high_water;
    924	}
    925	ew32(FCRTL, fcrtl);
    926	ew32(FCRTH, fcrth);
    927
    928	return 0;
    929}
    930
    931/**
    932 *  e1000e_force_mac_fc - Force the MAC's flow control settings
    933 *  @hw: pointer to the HW structure
    934 *
    935 *  Force the MAC's flow control settings.  Sets the TFCE and RFCE bits in the
    936 *  device control register to reflect the adapter settings.  TFCE and RFCE
    937 *  need to be explicitly set by software when a copper PHY is used because
    938 *  autonegotiation is managed by the PHY rather than the MAC.  Software must
    939 *  also configure these bits when link is forced on a fiber connection.
    940 **/
    941s32 e1000e_force_mac_fc(struct e1000_hw *hw)
    942{
    943	u32 ctrl;
    944
    945	ctrl = er32(CTRL);
    946
    947	/* Because we didn't get link via the internal auto-negotiation
    948	 * mechanism (we either forced link or we got link via PHY
    949	 * auto-neg), we have to manually enable/disable transmit an
    950	 * receive flow control.
    951	 *
    952	 * The "Case" statement below enables/disable flow control
    953	 * according to the "hw->fc.current_mode" parameter.
    954	 *
    955	 * The possible values of the "fc" parameter are:
    956	 *      0:  Flow control is completely disabled
    957	 *      1:  Rx flow control is enabled (we can receive pause
    958	 *          frames but not send pause frames).
    959	 *      2:  Tx flow control is enabled (we can send pause frames
    960	 *          frames but we do not receive pause frames).
    961	 *      3:  Both Rx and Tx flow control (symmetric) is enabled.
    962	 *  other:  No other values should be possible at this point.
    963	 */
    964	e_dbg("hw->fc.current_mode = %u\n", hw->fc.current_mode);
    965
    966	switch (hw->fc.current_mode) {
    967	case e1000_fc_none:
    968		ctrl &= (~(E1000_CTRL_TFCE | E1000_CTRL_RFCE));
    969		break;
    970	case e1000_fc_rx_pause:
    971		ctrl &= (~E1000_CTRL_TFCE);
    972		ctrl |= E1000_CTRL_RFCE;
    973		break;
    974	case e1000_fc_tx_pause:
    975		ctrl &= (~E1000_CTRL_RFCE);
    976		ctrl |= E1000_CTRL_TFCE;
    977		break;
    978	case e1000_fc_full:
    979		ctrl |= (E1000_CTRL_TFCE | E1000_CTRL_RFCE);
    980		break;
    981	default:
    982		e_dbg("Flow control param set incorrectly\n");
    983		return -E1000_ERR_CONFIG;
    984	}
    985
    986	ew32(CTRL, ctrl);
    987
    988	return 0;
    989}
    990
    991/**
    992 *  e1000e_config_fc_after_link_up - Configures flow control after link
    993 *  @hw: pointer to the HW structure
    994 *
    995 *  Checks the status of auto-negotiation after link up to ensure that the
    996 *  speed and duplex were not forced.  If the link needed to be forced, then
    997 *  flow control needs to be forced also.  If auto-negotiation is enabled
    998 *  and did not fail, then we configure flow control based on our link
    999 *  partner.
   1000 **/
   1001s32 e1000e_config_fc_after_link_up(struct e1000_hw *hw)
   1002{
   1003	struct e1000_mac_info *mac = &hw->mac;
   1004	s32 ret_val = 0;
   1005	u32 pcs_status_reg, pcs_adv_reg, pcs_lp_ability_reg, pcs_ctrl_reg;
   1006	u16 mii_status_reg, mii_nway_adv_reg, mii_nway_lp_ability_reg;
   1007	u16 speed, duplex;
   1008
   1009	/* Check for the case where we have fiber media and auto-neg failed
   1010	 * so we had to force link.  In this case, we need to force the
   1011	 * configuration of the MAC to match the "fc" parameter.
   1012	 */
   1013	if (mac->autoneg_failed) {
   1014		if (hw->phy.media_type == e1000_media_type_fiber ||
   1015		    hw->phy.media_type == e1000_media_type_internal_serdes)
   1016			ret_val = e1000e_force_mac_fc(hw);
   1017	} else {
   1018		if (hw->phy.media_type == e1000_media_type_copper)
   1019			ret_val = e1000e_force_mac_fc(hw);
   1020	}
   1021
   1022	if (ret_val) {
   1023		e_dbg("Error forcing flow control settings\n");
   1024		return ret_val;
   1025	}
   1026
   1027	/* Check for the case where we have copper media and auto-neg is
   1028	 * enabled.  In this case, we need to check and see if Auto-Neg
   1029	 * has completed, and if so, how the PHY and link partner has
   1030	 * flow control configured.
   1031	 */
   1032	if ((hw->phy.media_type == e1000_media_type_copper) && mac->autoneg) {
   1033		/* Read the MII Status Register and check to see if AutoNeg
   1034		 * has completed.  We read this twice because this reg has
   1035		 * some "sticky" (latched) bits.
   1036		 */
   1037		ret_val = e1e_rphy(hw, MII_BMSR, &mii_status_reg);
   1038		if (ret_val)
   1039			return ret_val;
   1040		ret_val = e1e_rphy(hw, MII_BMSR, &mii_status_reg);
   1041		if (ret_val)
   1042			return ret_val;
   1043
   1044		if (!(mii_status_reg & BMSR_ANEGCOMPLETE)) {
   1045			e_dbg("Copper PHY and Auto Neg has not completed.\n");
   1046			return ret_val;
   1047		}
   1048
   1049		/* The AutoNeg process has completed, so we now need to
   1050		 * read both the Auto Negotiation Advertisement
   1051		 * Register (Address 4) and the Auto_Negotiation Base
   1052		 * Page Ability Register (Address 5) to determine how
   1053		 * flow control was negotiated.
   1054		 */
   1055		ret_val = e1e_rphy(hw, MII_ADVERTISE, &mii_nway_adv_reg);
   1056		if (ret_val)
   1057			return ret_val;
   1058		ret_val = e1e_rphy(hw, MII_LPA, &mii_nway_lp_ability_reg);
   1059		if (ret_val)
   1060			return ret_val;
   1061
   1062		/* Two bits in the Auto Negotiation Advertisement Register
   1063		 * (Address 4) and two bits in the Auto Negotiation Base
   1064		 * Page Ability Register (Address 5) determine flow control
   1065		 * for both the PHY and the link partner.  The following
   1066		 * table, taken out of the IEEE 802.3ab/D6.0 dated March 25,
   1067		 * 1999, describes these PAUSE resolution bits and how flow
   1068		 * control is determined based upon these settings.
   1069		 * NOTE:  DC = Don't Care
   1070		 *
   1071		 *   LOCAL DEVICE  |   LINK PARTNER
   1072		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution
   1073		 *-------|---------|-------|---------|--------------------
   1074		 *   0   |    0    |  DC   |   DC    | e1000_fc_none
   1075		 *   0   |    1    |   0   |   DC    | e1000_fc_none
   1076		 *   0   |    1    |   1   |    0    | e1000_fc_none
   1077		 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
   1078		 *   1   |    0    |   0   |   DC    | e1000_fc_none
   1079		 *   1   |   DC    |   1   |   DC    | e1000_fc_full
   1080		 *   1   |    1    |   0   |    0    | e1000_fc_none
   1081		 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
   1082		 *
   1083		 * Are both PAUSE bits set to 1?  If so, this implies
   1084		 * Symmetric Flow Control is enabled at both ends.  The
   1085		 * ASM_DIR bits are irrelevant per the spec.
   1086		 *
   1087		 * For Symmetric Flow Control:
   1088		 *
   1089		 *   LOCAL DEVICE  |   LINK PARTNER
   1090		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
   1091		 *-------|---------|-------|---------|--------------------
   1092		 *   1   |   DC    |   1   |   DC    | E1000_fc_full
   1093		 *
   1094		 */
   1095		if ((mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
   1096		    (mii_nway_lp_ability_reg & LPA_PAUSE_CAP)) {
   1097			/* Now we need to check if the user selected Rx ONLY
   1098			 * of pause frames.  In this case, we had to advertise
   1099			 * FULL flow control because we could not advertise Rx
   1100			 * ONLY. Hence, we must now check to see if we need to
   1101			 * turn OFF the TRANSMISSION of PAUSE frames.
   1102			 */
   1103			if (hw->fc.requested_mode == e1000_fc_full) {
   1104				hw->fc.current_mode = e1000_fc_full;
   1105				e_dbg("Flow Control = FULL.\n");
   1106			} else {
   1107				hw->fc.current_mode = e1000_fc_rx_pause;
   1108				e_dbg("Flow Control = Rx PAUSE frames only.\n");
   1109			}
   1110		}
   1111		/* For receiving PAUSE frames ONLY.
   1112		 *
   1113		 *   LOCAL DEVICE  |   LINK PARTNER
   1114		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
   1115		 *-------|---------|-------|---------|--------------------
   1116		 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
   1117		 */
   1118		else if (!(mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
   1119			 (mii_nway_adv_reg & ADVERTISE_PAUSE_ASYM) &&
   1120			 (mii_nway_lp_ability_reg & LPA_PAUSE_CAP) &&
   1121			 (mii_nway_lp_ability_reg & LPA_PAUSE_ASYM)) {
   1122			hw->fc.current_mode = e1000_fc_tx_pause;
   1123			e_dbg("Flow Control = Tx PAUSE frames only.\n");
   1124		}
   1125		/* For transmitting PAUSE frames ONLY.
   1126		 *
   1127		 *   LOCAL DEVICE  |   LINK PARTNER
   1128		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
   1129		 *-------|---------|-------|---------|--------------------
   1130		 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
   1131		 */
   1132		else if ((mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
   1133			 (mii_nway_adv_reg & ADVERTISE_PAUSE_ASYM) &&
   1134			 !(mii_nway_lp_ability_reg & LPA_PAUSE_CAP) &&
   1135			 (mii_nway_lp_ability_reg & LPA_PAUSE_ASYM)) {
   1136			hw->fc.current_mode = e1000_fc_rx_pause;
   1137			e_dbg("Flow Control = Rx PAUSE frames only.\n");
   1138		} else {
   1139			/* Per the IEEE spec, at this point flow control
   1140			 * should be disabled.
   1141			 */
   1142			hw->fc.current_mode = e1000_fc_none;
   1143			e_dbg("Flow Control = NONE.\n");
   1144		}
   1145
   1146		/* Now we need to do one last check...  If we auto-
   1147		 * negotiated to HALF DUPLEX, flow control should not be
   1148		 * enabled per IEEE 802.3 spec.
   1149		 */
   1150		ret_val = mac->ops.get_link_up_info(hw, &speed, &duplex);
   1151		if (ret_val) {
   1152			e_dbg("Error getting link speed and duplex\n");
   1153			return ret_val;
   1154		}
   1155
   1156		if (duplex == HALF_DUPLEX)
   1157			hw->fc.current_mode = e1000_fc_none;
   1158
   1159		/* Now we call a subroutine to actually force the MAC
   1160		 * controller to use the correct flow control settings.
   1161		 */
   1162		ret_val = e1000e_force_mac_fc(hw);
   1163		if (ret_val) {
   1164			e_dbg("Error forcing flow control settings\n");
   1165			return ret_val;
   1166		}
   1167	}
   1168
   1169	/* Check for the case where we have SerDes media and auto-neg is
   1170	 * enabled.  In this case, we need to check and see if Auto-Neg
   1171	 * has completed, and if so, how the PHY and link partner has
   1172	 * flow control configured.
   1173	 */
   1174	if ((hw->phy.media_type == e1000_media_type_internal_serdes) &&
   1175	    mac->autoneg) {
   1176		/* Read the PCS_LSTS and check to see if AutoNeg
   1177		 * has completed.
   1178		 */
   1179		pcs_status_reg = er32(PCS_LSTAT);
   1180
   1181		if (!(pcs_status_reg & E1000_PCS_LSTS_AN_COMPLETE)) {
   1182			e_dbg("PCS Auto Neg has not completed.\n");
   1183			return ret_val;
   1184		}
   1185
   1186		/* The AutoNeg process has completed, so we now need to
   1187		 * read both the Auto Negotiation Advertisement
   1188		 * Register (PCS_ANADV) and the Auto_Negotiation Base
   1189		 * Page Ability Register (PCS_LPAB) to determine how
   1190		 * flow control was negotiated.
   1191		 */
   1192		pcs_adv_reg = er32(PCS_ANADV);
   1193		pcs_lp_ability_reg = er32(PCS_LPAB);
   1194
   1195		/* Two bits in the Auto Negotiation Advertisement Register
   1196		 * (PCS_ANADV) and two bits in the Auto Negotiation Base
   1197		 * Page Ability Register (PCS_LPAB) determine flow control
   1198		 * for both the PHY and the link partner.  The following
   1199		 * table, taken out of the IEEE 802.3ab/D6.0 dated March 25,
   1200		 * 1999, describes these PAUSE resolution bits and how flow
   1201		 * control is determined based upon these settings.
   1202		 * NOTE:  DC = Don't Care
   1203		 *
   1204		 *   LOCAL DEVICE  |   LINK PARTNER
   1205		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution
   1206		 *-------|---------|-------|---------|--------------------
   1207		 *   0   |    0    |  DC   |   DC    | e1000_fc_none
   1208		 *   0   |    1    |   0   |   DC    | e1000_fc_none
   1209		 *   0   |    1    |   1   |    0    | e1000_fc_none
   1210		 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
   1211		 *   1   |    0    |   0   |   DC    | e1000_fc_none
   1212		 *   1   |   DC    |   1   |   DC    | e1000_fc_full
   1213		 *   1   |    1    |   0   |    0    | e1000_fc_none
   1214		 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
   1215		 *
   1216		 * Are both PAUSE bits set to 1?  If so, this implies
   1217		 * Symmetric Flow Control is enabled at both ends.  The
   1218		 * ASM_DIR bits are irrelevant per the spec.
   1219		 *
   1220		 * For Symmetric Flow Control:
   1221		 *
   1222		 *   LOCAL DEVICE  |   LINK PARTNER
   1223		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
   1224		 *-------|---------|-------|---------|--------------------
   1225		 *   1   |   DC    |   1   |   DC    | e1000_fc_full
   1226		 *
   1227		 */
   1228		if ((pcs_adv_reg & E1000_TXCW_PAUSE) &&
   1229		    (pcs_lp_ability_reg & E1000_TXCW_PAUSE)) {
   1230			/* Now we need to check if the user selected Rx ONLY
   1231			 * of pause frames.  In this case, we had to advertise
   1232			 * FULL flow control because we could not advertise Rx
   1233			 * ONLY. Hence, we must now check to see if we need to
   1234			 * turn OFF the TRANSMISSION of PAUSE frames.
   1235			 */
   1236			if (hw->fc.requested_mode == e1000_fc_full) {
   1237				hw->fc.current_mode = e1000_fc_full;
   1238				e_dbg("Flow Control = FULL.\n");
   1239			} else {
   1240				hw->fc.current_mode = e1000_fc_rx_pause;
   1241				e_dbg("Flow Control = Rx PAUSE frames only.\n");
   1242			}
   1243		}
   1244		/* For receiving PAUSE frames ONLY.
   1245		 *
   1246		 *   LOCAL DEVICE  |   LINK PARTNER
   1247		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
   1248		 *-------|---------|-------|---------|--------------------
   1249		 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
   1250		 */
   1251		else if (!(pcs_adv_reg & E1000_TXCW_PAUSE) &&
   1252			 (pcs_adv_reg & E1000_TXCW_ASM_DIR) &&
   1253			 (pcs_lp_ability_reg & E1000_TXCW_PAUSE) &&
   1254			 (pcs_lp_ability_reg & E1000_TXCW_ASM_DIR)) {
   1255			hw->fc.current_mode = e1000_fc_tx_pause;
   1256			e_dbg("Flow Control = Tx PAUSE frames only.\n");
   1257		}
   1258		/* For transmitting PAUSE frames ONLY.
   1259		 *
   1260		 *   LOCAL DEVICE  |   LINK PARTNER
   1261		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
   1262		 *-------|---------|-------|---------|--------------------
   1263		 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
   1264		 */
   1265		else if ((pcs_adv_reg & E1000_TXCW_PAUSE) &&
   1266			 (pcs_adv_reg & E1000_TXCW_ASM_DIR) &&
   1267			 !(pcs_lp_ability_reg & E1000_TXCW_PAUSE) &&
   1268			 (pcs_lp_ability_reg & E1000_TXCW_ASM_DIR)) {
   1269			hw->fc.current_mode = e1000_fc_rx_pause;
   1270			e_dbg("Flow Control = Rx PAUSE frames only.\n");
   1271		} else {
   1272			/* Per the IEEE spec, at this point flow control
   1273			 * should be disabled.
   1274			 */
   1275			hw->fc.current_mode = e1000_fc_none;
   1276			e_dbg("Flow Control = NONE.\n");
   1277		}
   1278
   1279		/* Now we call a subroutine to actually force the MAC
   1280		 * controller to use the correct flow control settings.
   1281		 */
   1282		pcs_ctrl_reg = er32(PCS_LCTL);
   1283		pcs_ctrl_reg |= E1000_PCS_LCTL_FORCE_FCTRL;
   1284		ew32(PCS_LCTL, pcs_ctrl_reg);
   1285
   1286		ret_val = e1000e_force_mac_fc(hw);
   1287		if (ret_val) {
   1288			e_dbg("Error forcing flow control settings\n");
   1289			return ret_val;
   1290		}
   1291	}
   1292
   1293	return 0;
   1294}
   1295
   1296/**
   1297 *  e1000e_get_speed_and_duplex_copper - Retrieve current speed/duplex
   1298 *  @hw: pointer to the HW structure
   1299 *  @speed: stores the current speed
   1300 *  @duplex: stores the current duplex
   1301 *
   1302 *  Read the status register for the current speed/duplex and store the current
   1303 *  speed and duplex for copper connections.
   1304 **/
   1305s32 e1000e_get_speed_and_duplex_copper(struct e1000_hw *hw, u16 *speed,
   1306				       u16 *duplex)
   1307{
   1308	u32 status;
   1309
   1310	status = er32(STATUS);
   1311	if (status & E1000_STATUS_SPEED_1000)
   1312		*speed = SPEED_1000;
   1313	else if (status & E1000_STATUS_SPEED_100)
   1314		*speed = SPEED_100;
   1315	else
   1316		*speed = SPEED_10;
   1317
   1318	if (status & E1000_STATUS_FD)
   1319		*duplex = FULL_DUPLEX;
   1320	else
   1321		*duplex = HALF_DUPLEX;
   1322
   1323	e_dbg("%u Mbps, %s Duplex\n",
   1324	      *speed == SPEED_1000 ? 1000 : *speed == SPEED_100 ? 100 : 10,
   1325	      *duplex == FULL_DUPLEX ? "Full" : "Half");
   1326
   1327	return 0;
   1328}
   1329
   1330/**
   1331 *  e1000e_get_speed_and_duplex_fiber_serdes - Retrieve current speed/duplex
   1332 *  @hw: pointer to the HW structure
   1333 *  @speed: stores the current speed
   1334 *  @duplex: stores the current duplex
   1335 *
   1336 *  Sets the speed and duplex to gigabit full duplex (the only possible option)
   1337 *  for fiber/serdes links.
   1338 **/
   1339s32 e1000e_get_speed_and_duplex_fiber_serdes(struct e1000_hw __always_unused
   1340					     *hw, u16 *speed, u16 *duplex)
   1341{
   1342	*speed = SPEED_1000;
   1343	*duplex = FULL_DUPLEX;
   1344
   1345	return 0;
   1346}
   1347
   1348/**
   1349 *  e1000e_get_hw_semaphore - Acquire hardware semaphore
   1350 *  @hw: pointer to the HW structure
   1351 *
   1352 *  Acquire the HW semaphore to access the PHY or NVM
   1353 **/
   1354s32 e1000e_get_hw_semaphore(struct e1000_hw *hw)
   1355{
   1356	u32 swsm;
   1357	s32 timeout = hw->nvm.word_size + 1;
   1358	s32 i = 0;
   1359
   1360	/* Get the SW semaphore */
   1361	while (i < timeout) {
   1362		swsm = er32(SWSM);
   1363		if (!(swsm & E1000_SWSM_SMBI))
   1364			break;
   1365
   1366		udelay(100);
   1367		i++;
   1368	}
   1369
   1370	if (i == timeout) {
   1371		e_dbg("Driver can't access device - SMBI bit is set.\n");
   1372		return -E1000_ERR_NVM;
   1373	}
   1374
   1375	/* Get the FW semaphore. */
   1376	for (i = 0; i < timeout; i++) {
   1377		swsm = er32(SWSM);
   1378		ew32(SWSM, swsm | E1000_SWSM_SWESMBI);
   1379
   1380		/* Semaphore acquired if bit latched */
   1381		if (er32(SWSM) & E1000_SWSM_SWESMBI)
   1382			break;
   1383
   1384		udelay(100);
   1385	}
   1386
   1387	if (i == timeout) {
   1388		/* Release semaphores */
   1389		e1000e_put_hw_semaphore(hw);
   1390		e_dbg("Driver can't access the NVM\n");
   1391		return -E1000_ERR_NVM;
   1392	}
   1393
   1394	return 0;
   1395}
   1396
   1397/**
   1398 *  e1000e_put_hw_semaphore - Release hardware semaphore
   1399 *  @hw: pointer to the HW structure
   1400 *
   1401 *  Release hardware semaphore used to access the PHY or NVM
   1402 **/
   1403void e1000e_put_hw_semaphore(struct e1000_hw *hw)
   1404{
   1405	u32 swsm;
   1406
   1407	swsm = er32(SWSM);
   1408	swsm &= ~(E1000_SWSM_SMBI | E1000_SWSM_SWESMBI);
   1409	ew32(SWSM, swsm);
   1410}
   1411
   1412/**
   1413 *  e1000e_get_auto_rd_done - Check for auto read completion
   1414 *  @hw: pointer to the HW structure
   1415 *
   1416 *  Check EEPROM for Auto Read done bit.
   1417 **/
   1418s32 e1000e_get_auto_rd_done(struct e1000_hw *hw)
   1419{
   1420	s32 i = 0;
   1421
   1422	while (i < AUTO_READ_DONE_TIMEOUT) {
   1423		if (er32(EECD) & E1000_EECD_AUTO_RD)
   1424			break;
   1425		usleep_range(1000, 2000);
   1426		i++;
   1427	}
   1428
   1429	if (i == AUTO_READ_DONE_TIMEOUT) {
   1430		e_dbg("Auto read by HW from NVM has not completed.\n");
   1431		return -E1000_ERR_RESET;
   1432	}
   1433
   1434	return 0;
   1435}
   1436
   1437/**
   1438 *  e1000e_valid_led_default - Verify a valid default LED config
   1439 *  @hw: pointer to the HW structure
   1440 *  @data: pointer to the NVM (EEPROM)
   1441 *
   1442 *  Read the EEPROM for the current default LED configuration.  If the
   1443 *  LED configuration is not valid, set to a valid LED configuration.
   1444 **/
   1445s32 e1000e_valid_led_default(struct e1000_hw *hw, u16 *data)
   1446{
   1447	s32 ret_val;
   1448
   1449	ret_val = e1000_read_nvm(hw, NVM_ID_LED_SETTINGS, 1, data);
   1450	if (ret_val) {
   1451		e_dbg("NVM Read Error\n");
   1452		return ret_val;
   1453	}
   1454
   1455	if (*data == ID_LED_RESERVED_0000 || *data == ID_LED_RESERVED_FFFF)
   1456		*data = ID_LED_DEFAULT;
   1457
   1458	return 0;
   1459}
   1460
   1461/**
   1462 *  e1000e_id_led_init_generic -
   1463 *  @hw: pointer to the HW structure
   1464 *
   1465 **/
   1466s32 e1000e_id_led_init_generic(struct e1000_hw *hw)
   1467{
   1468	struct e1000_mac_info *mac = &hw->mac;
   1469	s32 ret_val;
   1470	const u32 ledctl_mask = 0x000000FF;
   1471	const u32 ledctl_on = E1000_LEDCTL_MODE_LED_ON;
   1472	const u32 ledctl_off = E1000_LEDCTL_MODE_LED_OFF;
   1473	u16 data, i, temp;
   1474	const u16 led_mask = 0x0F;
   1475
   1476	ret_val = hw->nvm.ops.valid_led_default(hw, &data);
   1477	if (ret_val)
   1478		return ret_val;
   1479
   1480	mac->ledctl_default = er32(LEDCTL);
   1481	mac->ledctl_mode1 = mac->ledctl_default;
   1482	mac->ledctl_mode2 = mac->ledctl_default;
   1483
   1484	for (i = 0; i < 4; i++) {
   1485		temp = (data >> (i << 2)) & led_mask;
   1486		switch (temp) {
   1487		case ID_LED_ON1_DEF2:
   1488		case ID_LED_ON1_ON2:
   1489		case ID_LED_ON1_OFF2:
   1490			mac->ledctl_mode1 &= ~(ledctl_mask << (i << 3));
   1491			mac->ledctl_mode1 |= ledctl_on << (i << 3);
   1492			break;
   1493		case ID_LED_OFF1_DEF2:
   1494		case ID_LED_OFF1_ON2:
   1495		case ID_LED_OFF1_OFF2:
   1496			mac->ledctl_mode1 &= ~(ledctl_mask << (i << 3));
   1497			mac->ledctl_mode1 |= ledctl_off << (i << 3);
   1498			break;
   1499		default:
   1500			/* Do nothing */
   1501			break;
   1502		}
   1503		switch (temp) {
   1504		case ID_LED_DEF1_ON2:
   1505		case ID_LED_ON1_ON2:
   1506		case ID_LED_OFF1_ON2:
   1507			mac->ledctl_mode2 &= ~(ledctl_mask << (i << 3));
   1508			mac->ledctl_mode2 |= ledctl_on << (i << 3);
   1509			break;
   1510		case ID_LED_DEF1_OFF2:
   1511		case ID_LED_ON1_OFF2:
   1512		case ID_LED_OFF1_OFF2:
   1513			mac->ledctl_mode2 &= ~(ledctl_mask << (i << 3));
   1514			mac->ledctl_mode2 |= ledctl_off << (i << 3);
   1515			break;
   1516		default:
   1517			/* Do nothing */
   1518			break;
   1519		}
   1520	}
   1521
   1522	return 0;
   1523}
   1524
   1525/**
   1526 *  e1000e_setup_led_generic - Configures SW controllable LED
   1527 *  @hw: pointer to the HW structure
   1528 *
   1529 *  This prepares the SW controllable LED for use and saves the current state
   1530 *  of the LED so it can be later restored.
   1531 **/
   1532s32 e1000e_setup_led_generic(struct e1000_hw *hw)
   1533{
   1534	u32 ledctl;
   1535
   1536	if (hw->mac.ops.setup_led != e1000e_setup_led_generic)
   1537		return -E1000_ERR_CONFIG;
   1538
   1539	if (hw->phy.media_type == e1000_media_type_fiber) {
   1540		ledctl = er32(LEDCTL);
   1541		hw->mac.ledctl_default = ledctl;
   1542		/* Turn off LED0 */
   1543		ledctl &= ~(E1000_LEDCTL_LED0_IVRT | E1000_LEDCTL_LED0_BLINK |
   1544			    E1000_LEDCTL_LED0_MODE_MASK);
   1545		ledctl |= (E1000_LEDCTL_MODE_LED_OFF <<
   1546			   E1000_LEDCTL_LED0_MODE_SHIFT);
   1547		ew32(LEDCTL, ledctl);
   1548	} else if (hw->phy.media_type == e1000_media_type_copper) {
   1549		ew32(LEDCTL, hw->mac.ledctl_mode1);
   1550	}
   1551
   1552	return 0;
   1553}
   1554
   1555/**
   1556 *  e1000e_cleanup_led_generic - Set LED config to default operation
   1557 *  @hw: pointer to the HW structure
   1558 *
   1559 *  Remove the current LED configuration and set the LED configuration
   1560 *  to the default value, saved from the EEPROM.
   1561 **/
   1562s32 e1000e_cleanup_led_generic(struct e1000_hw *hw)
   1563{
   1564	ew32(LEDCTL, hw->mac.ledctl_default);
   1565	return 0;
   1566}
   1567
   1568/**
   1569 *  e1000e_blink_led_generic - Blink LED
   1570 *  @hw: pointer to the HW structure
   1571 *
   1572 *  Blink the LEDs which are set to be on.
   1573 **/
   1574s32 e1000e_blink_led_generic(struct e1000_hw *hw)
   1575{
   1576	u32 ledctl_blink = 0;
   1577	u32 i;
   1578
   1579	if (hw->phy.media_type == e1000_media_type_fiber) {
   1580		/* always blink LED0 for PCI-E fiber */
   1581		ledctl_blink = E1000_LEDCTL_LED0_BLINK |
   1582		    (E1000_LEDCTL_MODE_LED_ON << E1000_LEDCTL_LED0_MODE_SHIFT);
   1583	} else {
   1584		/* Set the blink bit for each LED that's "on" (0x0E)
   1585		 * (or "off" if inverted) in ledctl_mode2.  The blink
   1586		 * logic in hardware only works when mode is set to "on"
   1587		 * so it must be changed accordingly when the mode is
   1588		 * "off" and inverted.
   1589		 */
   1590		ledctl_blink = hw->mac.ledctl_mode2;
   1591		for (i = 0; i < 32; i += 8) {
   1592			u32 mode = (hw->mac.ledctl_mode2 >> i) &
   1593			    E1000_LEDCTL_LED0_MODE_MASK;
   1594			u32 led_default = hw->mac.ledctl_default >> i;
   1595
   1596			if ((!(led_default & E1000_LEDCTL_LED0_IVRT) &&
   1597			     (mode == E1000_LEDCTL_MODE_LED_ON)) ||
   1598			    ((led_default & E1000_LEDCTL_LED0_IVRT) &&
   1599			     (mode == E1000_LEDCTL_MODE_LED_OFF))) {
   1600				ledctl_blink &=
   1601				    ~(E1000_LEDCTL_LED0_MODE_MASK << i);
   1602				ledctl_blink |= (E1000_LEDCTL_LED0_BLINK |
   1603						 E1000_LEDCTL_MODE_LED_ON) << i;
   1604			}
   1605		}
   1606	}
   1607
   1608	ew32(LEDCTL, ledctl_blink);
   1609
   1610	return 0;
   1611}
   1612
   1613/**
   1614 *  e1000e_led_on_generic - Turn LED on
   1615 *  @hw: pointer to the HW structure
   1616 *
   1617 *  Turn LED on.
   1618 **/
   1619s32 e1000e_led_on_generic(struct e1000_hw *hw)
   1620{
   1621	u32 ctrl;
   1622
   1623	switch (hw->phy.media_type) {
   1624	case e1000_media_type_fiber:
   1625		ctrl = er32(CTRL);
   1626		ctrl &= ~E1000_CTRL_SWDPIN0;
   1627		ctrl |= E1000_CTRL_SWDPIO0;
   1628		ew32(CTRL, ctrl);
   1629		break;
   1630	case e1000_media_type_copper:
   1631		ew32(LEDCTL, hw->mac.ledctl_mode2);
   1632		break;
   1633	default:
   1634		break;
   1635	}
   1636
   1637	return 0;
   1638}
   1639
   1640/**
   1641 *  e1000e_led_off_generic - Turn LED off
   1642 *  @hw: pointer to the HW structure
   1643 *
   1644 *  Turn LED off.
   1645 **/
   1646s32 e1000e_led_off_generic(struct e1000_hw *hw)
   1647{
   1648	u32 ctrl;
   1649
   1650	switch (hw->phy.media_type) {
   1651	case e1000_media_type_fiber:
   1652		ctrl = er32(CTRL);
   1653		ctrl |= E1000_CTRL_SWDPIN0;
   1654		ctrl |= E1000_CTRL_SWDPIO0;
   1655		ew32(CTRL, ctrl);
   1656		break;
   1657	case e1000_media_type_copper:
   1658		ew32(LEDCTL, hw->mac.ledctl_mode1);
   1659		break;
   1660	default:
   1661		break;
   1662	}
   1663
   1664	return 0;
   1665}
   1666
   1667/**
   1668 *  e1000e_set_pcie_no_snoop - Set PCI-express capabilities
   1669 *  @hw: pointer to the HW structure
   1670 *  @no_snoop: bitmap of snoop events
   1671 *
   1672 *  Set the PCI-express register to snoop for events enabled in 'no_snoop'.
   1673 **/
   1674void e1000e_set_pcie_no_snoop(struct e1000_hw *hw, u32 no_snoop)
   1675{
   1676	u32 gcr;
   1677
   1678	if (no_snoop) {
   1679		gcr = er32(GCR);
   1680		gcr &= ~(PCIE_NO_SNOOP_ALL);
   1681		gcr |= no_snoop;
   1682		ew32(GCR, gcr);
   1683	}
   1684}
   1685
   1686/**
   1687 *  e1000e_disable_pcie_master - Disables PCI-express master access
   1688 *  @hw: pointer to the HW structure
   1689 *
   1690 *  Returns 0 if successful, else returns -10
   1691 *  (-E1000_ERR_MASTER_REQUESTS_PENDING) if master disable bit has not caused
   1692 *  the master requests to be disabled.
   1693 *
   1694 *  Disables PCI-Express master access and verifies there are no pending
   1695 *  requests.
   1696 **/
   1697s32 e1000e_disable_pcie_master(struct e1000_hw *hw)
   1698{
   1699	u32 ctrl;
   1700	s32 timeout = MASTER_DISABLE_TIMEOUT;
   1701
   1702	ctrl = er32(CTRL);
   1703	ctrl |= E1000_CTRL_GIO_MASTER_DISABLE;
   1704	ew32(CTRL, ctrl);
   1705
   1706	while (timeout) {
   1707		if (!(er32(STATUS) & E1000_STATUS_GIO_MASTER_ENABLE))
   1708			break;
   1709		usleep_range(100, 200);
   1710		timeout--;
   1711	}
   1712
   1713	if (!timeout) {
   1714		e_dbg("Master requests are pending.\n");
   1715		return -E1000_ERR_MASTER_REQUESTS_PENDING;
   1716	}
   1717
   1718	return 0;
   1719}
   1720
   1721/**
   1722 *  e1000e_reset_adaptive - Reset Adaptive Interframe Spacing
   1723 *  @hw: pointer to the HW structure
   1724 *
   1725 *  Reset the Adaptive Interframe Spacing throttle to default values.
   1726 **/
   1727void e1000e_reset_adaptive(struct e1000_hw *hw)
   1728{
   1729	struct e1000_mac_info *mac = &hw->mac;
   1730
   1731	if (!mac->adaptive_ifs) {
   1732		e_dbg("Not in Adaptive IFS mode!\n");
   1733		return;
   1734	}
   1735
   1736	mac->current_ifs_val = 0;
   1737	mac->ifs_min_val = IFS_MIN;
   1738	mac->ifs_max_val = IFS_MAX;
   1739	mac->ifs_step_size = IFS_STEP;
   1740	mac->ifs_ratio = IFS_RATIO;
   1741
   1742	mac->in_ifs_mode = false;
   1743	ew32(AIT, 0);
   1744}
   1745
   1746/**
   1747 *  e1000e_update_adaptive - Update Adaptive Interframe Spacing
   1748 *  @hw: pointer to the HW structure
   1749 *
   1750 *  Update the Adaptive Interframe Spacing Throttle value based on the
   1751 *  time between transmitted packets and time between collisions.
   1752 **/
   1753void e1000e_update_adaptive(struct e1000_hw *hw)
   1754{
   1755	struct e1000_mac_info *mac = &hw->mac;
   1756
   1757	if (!mac->adaptive_ifs) {
   1758		e_dbg("Not in Adaptive IFS mode!\n");
   1759		return;
   1760	}
   1761
   1762	if ((mac->collision_delta * mac->ifs_ratio) > mac->tx_packet_delta) {
   1763		if (mac->tx_packet_delta > MIN_NUM_XMITS) {
   1764			mac->in_ifs_mode = true;
   1765			if (mac->current_ifs_val < mac->ifs_max_val) {
   1766				if (!mac->current_ifs_val)
   1767					mac->current_ifs_val = mac->ifs_min_val;
   1768				else
   1769					mac->current_ifs_val +=
   1770					    mac->ifs_step_size;
   1771				ew32(AIT, mac->current_ifs_val);
   1772			}
   1773		}
   1774	} else {
   1775		if (mac->in_ifs_mode &&
   1776		    (mac->tx_packet_delta <= MIN_NUM_XMITS)) {
   1777			mac->current_ifs_val = 0;
   1778			mac->in_ifs_mode = false;
   1779			ew32(AIT, 0);
   1780		}
   1781	}
   1782}