xref: /linux/drivers/net/ethernet/intel/e1000e/mac.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 1999 - 2018 Intel Corporation. */
3 
4 #include <linux/bitfield.h>
5 
6 #include "e1000.h"
7 
8 /**
9  *  e1000e_get_bus_info_pcie - Get PCIe bus information
10  *  @hw: pointer to the HW structure
11  *
12  *  Determines and stores the system bus information for a particular
13  *  network interface.  The following bus information is determined and stored:
14  *  bus speed, bus width, type (PCIe), and PCIe function.
15  **/
16 s32 e1000e_get_bus_info_pcie(struct e1000_hw *hw)
17 {
18 	struct pci_dev *pdev = hw->adapter->pdev;
19 	struct e1000_mac_info *mac = &hw->mac;
20 	struct e1000_bus_info *bus = &hw->bus;
21 	u16 pcie_link_status;
22 
23 	if (!pci_pcie_cap(pdev)) {
24 		bus->width = e1000_bus_width_unknown;
25 	} else {
26 		pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &pcie_link_status);
27 		bus->width = (enum e1000_bus_width)FIELD_GET(PCI_EXP_LNKSTA_NLW,
28 							     pcie_link_status);
29 	}
30 
31 	mac->ops.set_lan_id(hw);
32 
33 	return 0;
34 }
35 
36 /**
37  *  e1000_set_lan_id_multi_port_pcie - Set LAN id for PCIe multiple port devices
38  *
39  *  @hw: pointer to the HW structure
40  *
41  *  Determines the LAN function id by reading memory-mapped registers
42  *  and swaps the port value if requested.
43  **/
44 void e1000_set_lan_id_multi_port_pcie(struct e1000_hw *hw)
45 {
46 	struct e1000_bus_info *bus = &hw->bus;
47 	u32 reg;
48 
49 	/* The status register reports the correct function number
50 	 * for the device regardless of function swap state.
51 	 */
52 	reg = er32(STATUS);
53 	bus->func = FIELD_GET(E1000_STATUS_FUNC_MASK, reg);
54 }
55 
56 /**
57  *  e1000_set_lan_id_single_port - Set LAN id for a single port device
58  *  @hw: pointer to the HW structure
59  *
60  *  Sets the LAN function id to zero for a single port device.
61  **/
62 void e1000_set_lan_id_single_port(struct e1000_hw *hw)
63 {
64 	struct e1000_bus_info *bus = &hw->bus;
65 
66 	bus->func = 0;
67 }
68 
69 /**
70  *  e1000_clear_vfta_generic - Clear VLAN filter table
71  *  @hw: pointer to the HW structure
72  *
73  *  Clears the register array which contains the VLAN filter table by
74  *  setting all the values to 0.
75  **/
76 void e1000_clear_vfta_generic(struct e1000_hw *hw)
77 {
78 	u32 offset;
79 
80 	for (offset = 0; offset < E1000_VLAN_FILTER_TBL_SIZE; offset++) {
81 		E1000_WRITE_REG_ARRAY(hw, E1000_VFTA, offset, 0);
82 		e1e_flush();
83 	}
84 }
85 
86 /**
87  *  e1000_write_vfta_generic - Write value to VLAN filter table
88  *  @hw: pointer to the HW structure
89  *  @offset: register offset in VLAN filter table
90  *  @value: register value written to VLAN filter table
91  *
92  *  Writes value at the given offset in the register array which stores
93  *  the VLAN filter table.
94  **/
95 void e1000_write_vfta_generic(struct e1000_hw *hw, u32 offset, u32 value)
96 {
97 	E1000_WRITE_REG_ARRAY(hw, E1000_VFTA, offset, value);
98 	e1e_flush();
99 }
100 
101 /**
102  *  e1000e_init_rx_addrs - Initialize receive address's
103  *  @hw: pointer to the HW structure
104  *  @rar_count: receive address registers
105  *
106  *  Setup the receive address registers by setting the base receive address
107  *  register to the devices MAC address and clearing all the other receive
108  *  address registers to 0.
109  **/
110 void e1000e_init_rx_addrs(struct e1000_hw *hw, u16 rar_count)
111 {
112 	u32 i;
113 	u8 mac_addr[ETH_ALEN] = { 0 };
114 
115 	/* Setup the receive address */
116 	e_dbg("Programming MAC Address into RAR[0]\n");
117 
118 	hw->mac.ops.rar_set(hw, hw->mac.addr, 0);
119 
120 	/* Zero out the other (rar_entry_count - 1) receive addresses */
121 	e_dbg("Clearing RAR[1-%u]\n", rar_count - 1);
122 	for (i = 1; i < rar_count; i++)
123 		hw->mac.ops.rar_set(hw, mac_addr, i);
124 }
125 
126 /**
127  *  e1000_check_alt_mac_addr_generic - Check for alternate MAC addr
128  *  @hw: pointer to the HW structure
129  *
130  *  Checks the nvm for an alternate MAC address.  An alternate MAC address
131  *  can be setup by pre-boot software and must be treated like a permanent
132  *  address and must override the actual permanent MAC address. If an
133  *  alternate MAC address is found it is programmed into RAR0, replacing
134  *  the permanent address that was installed into RAR0 by the Si on reset.
135  *  This function will return SUCCESS unless it encounters an error while
136  *  reading the EEPROM.
137  **/
138 s32 e1000_check_alt_mac_addr_generic(struct e1000_hw *hw)
139 {
140 	u32 i;
141 	s32 ret_val;
142 	u16 offset, nvm_alt_mac_addr_offset, nvm_data;
143 	u8 alt_mac_addr[ETH_ALEN];
144 
145 	ret_val = e1000_read_nvm(hw, NVM_COMPAT, 1, &nvm_data);
146 	if (ret_val)
147 		return ret_val;
148 
149 	/* not supported on 82573 */
150 	if (hw->mac.type == e1000_82573)
151 		return 0;
152 
153 	ret_val = e1000_read_nvm(hw, NVM_ALT_MAC_ADDR_PTR, 1,
154 				 &nvm_alt_mac_addr_offset);
155 	if (ret_val) {
156 		e_dbg("NVM Read Error\n");
157 		return ret_val;
158 	}
159 
160 	if ((nvm_alt_mac_addr_offset == 0xFFFF) ||
161 	    (nvm_alt_mac_addr_offset == 0x0000))
162 		/* There is no Alternate MAC Address */
163 		return 0;
164 
165 	if (hw->bus.func == E1000_FUNC_1)
166 		nvm_alt_mac_addr_offset += E1000_ALT_MAC_ADDRESS_OFFSET_LAN1;
167 	for (i = 0; i < ETH_ALEN; i += 2) {
168 		offset = nvm_alt_mac_addr_offset + (i >> 1);
169 		ret_val = e1000_read_nvm(hw, offset, 1, &nvm_data);
170 		if (ret_val) {
171 			e_dbg("NVM Read Error\n");
172 			return ret_val;
173 		}
174 
175 		alt_mac_addr[i] = (u8)(nvm_data & 0xFF);
176 		alt_mac_addr[i + 1] = (u8)(nvm_data >> 8);
177 	}
178 
179 	/* if multicast bit is set, the alternate address will not be used */
180 	if (is_multicast_ether_addr(alt_mac_addr)) {
181 		e_dbg("Ignoring Alternate Mac Address with MC bit set\n");
182 		return 0;
183 	}
184 
185 	/* We have a valid alternate MAC address, and we want to treat it the
186 	 * same as the normal permanent MAC address stored by the HW into the
187 	 * RAR. Do this by mapping this address into RAR0.
188 	 */
189 	hw->mac.ops.rar_set(hw, alt_mac_addr, 0);
190 
191 	return 0;
192 }
193 
194 u32 e1000e_rar_get_count_generic(struct e1000_hw *hw)
195 {
196 	return hw->mac.rar_entry_count;
197 }
198 
199 /**
200  *  e1000e_rar_set_generic - Set receive address register
201  *  @hw: pointer to the HW structure
202  *  @addr: pointer to the receive address
203  *  @index: receive address array register
204  *
205  *  Sets the receive address array register at index to the address passed
206  *  in by addr.
207  **/
208 int e1000e_rar_set_generic(struct e1000_hw *hw, u8 *addr, u32 index)
209 {
210 	u32 rar_low, rar_high;
211 
212 	/* HW expects these in little endian so we reverse the byte order
213 	 * from network order (big endian) to little endian
214 	 */
215 	rar_low = ((u32)addr[0] | ((u32)addr[1] << 8) |
216 		   ((u32)addr[2] << 16) | ((u32)addr[3] << 24));
217 
218 	rar_high = ((u32)addr[4] | ((u32)addr[5] << 8));
219 
220 	/* If MAC address zero, no need to set the AV bit */
221 	if (rar_low || rar_high)
222 		rar_high |= E1000_RAH_AV;
223 
224 	/* Some bridges will combine consecutive 32-bit writes into
225 	 * a single burst write, which will malfunction on some parts.
226 	 * The flushes avoid this.
227 	 */
228 	ew32(RAL(index), rar_low);
229 	e1e_flush();
230 	ew32(RAH(index), rar_high);
231 	e1e_flush();
232 
233 	return 0;
234 }
235 
236 /**
237  *  e1000_hash_mc_addr - Generate a multicast hash value
238  *  @hw: pointer to the HW structure
239  *  @mc_addr: pointer to a multicast address
240  *
241  *  Generates a multicast address hash value which is used to determine
242  *  the multicast filter table array address and new table value.
243  **/
244 static u32 e1000_hash_mc_addr(struct e1000_hw *hw, u8 *mc_addr)
245 {
246 	u32 hash_value, hash_mask;
247 	u8 bit_shift = 0;
248 
249 	/* Register count multiplied by bits per register */
250 	hash_mask = (hw->mac.mta_reg_count * 32) - 1;
251 
252 	/* For a mc_filter_type of 0, bit_shift is the number of left-shifts
253 	 * where 0xFF would still fall within the hash mask.
254 	 */
255 	while (hash_mask >> bit_shift != 0xFF)
256 		bit_shift++;
257 
258 	/* The portion of the address that is used for the hash table
259 	 * is determined by the mc_filter_type setting.
260 	 * The algorithm is such that there is a total of 8 bits of shifting.
261 	 * The bit_shift for a mc_filter_type of 0 represents the number of
262 	 * left-shifts where the MSB of mc_addr[5] would still fall within
263 	 * the hash_mask.  Case 0 does this exactly.  Since there are a total
264 	 * of 8 bits of shifting, then mc_addr[4] will shift right the
265 	 * remaining number of bits. Thus 8 - bit_shift.  The rest of the
266 	 * cases are a variation of this algorithm...essentially raising the
267 	 * number of bits to shift mc_addr[5] left, while still keeping the
268 	 * 8-bit shifting total.
269 	 *
270 	 * For example, given the following Destination MAC Address and an
271 	 * mta register count of 128 (thus a 4096-bit vector and 0xFFF mask),
272 	 * we can see that the bit_shift for case 0 is 4.  These are the hash
273 	 * values resulting from each mc_filter_type...
274 	 * [0] [1] [2] [3] [4] [5]
275 	 * 01  AA  00  12  34  56
276 	 * LSB           MSB
277 	 *
278 	 * case 0: hash_value = ((0x34 >> 4) | (0x56 << 4)) & 0xFFF = 0x563
279 	 * case 1: hash_value = ((0x34 >> 3) | (0x56 << 5)) & 0xFFF = 0xAC6
280 	 * case 2: hash_value = ((0x34 >> 2) | (0x56 << 6)) & 0xFFF = 0x163
281 	 * case 3: hash_value = ((0x34 >> 0) | (0x56 << 8)) & 0xFFF = 0x634
282 	 */
283 	switch (hw->mac.mc_filter_type) {
284 	default:
285 	case 0:
286 		break;
287 	case 1:
288 		bit_shift += 1;
289 		break;
290 	case 2:
291 		bit_shift += 2;
292 		break;
293 	case 3:
294 		bit_shift += 4;
295 		break;
296 	}
297 
298 	hash_value = hash_mask & (((mc_addr[4] >> (8 - bit_shift)) |
299 				   (((u16)mc_addr[5]) << bit_shift)));
300 
301 	return hash_value;
302 }
303 
304 /**
305  *  e1000e_update_mc_addr_list_generic - Update Multicast addresses
306  *  @hw: pointer to the HW structure
307  *  @mc_addr_list: array of multicast addresses to program
308  *  @mc_addr_count: number of multicast addresses to program
309  *
310  *  Updates entire Multicast Table Array.
311  *  The caller must have a packed mc_addr_list of multicast addresses.
312  **/
313 void e1000e_update_mc_addr_list_generic(struct e1000_hw *hw,
314 					u8 *mc_addr_list, u32 mc_addr_count)
315 {
316 	u32 hash_value, hash_bit, hash_reg;
317 	int i;
318 
319 	/* clear mta_shadow */
320 	memset(&hw->mac.mta_shadow, 0, sizeof(hw->mac.mta_shadow));
321 
322 	/* update mta_shadow from mc_addr_list */
323 	for (i = 0; (u32)i < mc_addr_count; i++) {
324 		hash_value = e1000_hash_mc_addr(hw, mc_addr_list);
325 
326 		hash_reg = (hash_value >> 5) & (hw->mac.mta_reg_count - 1);
327 		hash_bit = hash_value & 0x1F;
328 
329 		hw->mac.mta_shadow[hash_reg] |= BIT(hash_bit);
330 		mc_addr_list += (ETH_ALEN);
331 	}
332 
333 	/* replace the entire MTA table */
334 	for (i = hw->mac.mta_reg_count - 1; i >= 0; i--)
335 		E1000_WRITE_REG_ARRAY(hw, E1000_MTA, i, hw->mac.mta_shadow[i]);
336 	e1e_flush();
337 }
338 
339 /**
340  *  e1000e_clear_hw_cntrs_base - Clear base hardware counters
341  *  @hw: pointer to the HW structure
342  *
343  *  Clears the base hardware counters by reading the counter registers.
344  **/
345 void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw)
346 {
347 	er32(CRCERRS);
348 	er32(SYMERRS);
349 	er32(MPC);
350 	er32(SCC);
351 	er32(ECOL);
352 	er32(MCC);
353 	er32(LATECOL);
354 	er32(COLC);
355 	er32(DC);
356 	er32(SEC);
357 	er32(RLEC);
358 	er32(XONRXC);
359 	er32(XONTXC);
360 	er32(XOFFRXC);
361 	er32(XOFFTXC);
362 	er32(FCRUC);
363 	er32(GPRC);
364 	er32(BPRC);
365 	er32(MPRC);
366 	er32(GPTC);
367 	er32(GORCL);
368 	er32(GORCH);
369 	er32(GOTCL);
370 	er32(GOTCH);
371 	er32(RNBC);
372 	er32(RUC);
373 	er32(RFC);
374 	er32(ROC);
375 	er32(RJC);
376 	er32(TORL);
377 	er32(TORH);
378 	er32(TOTL);
379 	er32(TOTH);
380 	er32(TPR);
381 	er32(TPT);
382 	er32(MPTC);
383 	er32(BPTC);
384 }
385 
386 /**
387  *  e1000e_check_for_copper_link - Check for link (Copper)
388  *  @hw: pointer to the HW structure
389  *
390  *  Checks to see of the link status of the hardware has changed.  If a
391  *  change in link status has been detected, then we read the PHY registers
392  *  to get the current speed/duplex if link exists.
393  **/
394 s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
395 {
396 	struct e1000_mac_info *mac = &hw->mac;
397 	s32 ret_val;
398 	bool link;
399 
400 	/* We only want to go out to the PHY registers to see if Auto-Neg
401 	 * has completed and/or if our link status has changed.  The
402 	 * get_link_status flag is set upon receiving a Link Status
403 	 * Change or Rx Sequence Error interrupt.
404 	 */
405 	if (!mac->get_link_status)
406 		return 0;
407 	mac->get_link_status = false;
408 
409 	/* First we want to see if the MII Status Register reports
410 	 * link.  If so, then we want to get the current speed/duplex
411 	 * of the PHY.
412 	 */
413 	ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);
414 	if (ret_val || !link)
415 		goto out;
416 
417 	/* Check if there was DownShift, must be checked
418 	 * immediately after link-up
419 	 */
420 	e1000e_check_downshift(hw);
421 
422 	/* If we are forcing speed/duplex, then we simply return since
423 	 * we have already determined whether we have link or not.
424 	 */
425 	if (!mac->autoneg)
426 		return -E1000_ERR_CONFIG;
427 
428 	/* Auto-Neg is enabled.  Auto Speed Detection takes care
429 	 * of MAC speed/duplex configuration.  So we only need to
430 	 * configure Collision Distance in the MAC.
431 	 */
432 	mac->ops.config_collision_dist(hw);
433 
434 	/* Configure Flow Control now that Auto-Neg has completed.
435 	 * First, we need to restore the desired flow control
436 	 * settings because we may have had to re-autoneg with a
437 	 * different link partner.
438 	 */
439 	ret_val = e1000e_config_fc_after_link_up(hw);
440 	if (ret_val)
441 		e_dbg("Error configuring flow control\n");
442 
443 	return ret_val;
444 
445 out:
446 	mac->get_link_status = true;
447 	return ret_val;
448 }
449 
450 /**
451  *  e1000e_check_for_fiber_link - Check for link (Fiber)
452  *  @hw: pointer to the HW structure
453  *
454  *  Checks for link up on the hardware.  If link is not up and we have
455  *  a signal, then we need to force link up.
456  **/
457 s32 e1000e_check_for_fiber_link(struct e1000_hw *hw)
458 {
459 	struct e1000_mac_info *mac = &hw->mac;
460 	u32 rxcw;
461 	u32 ctrl;
462 	u32 status;
463 	s32 ret_val;
464 
465 	ctrl = er32(CTRL);
466 	status = er32(STATUS);
467 	rxcw = er32(RXCW);
468 
469 	/* If we don't have link (auto-negotiation failed or link partner
470 	 * cannot auto-negotiate), the cable is plugged in (we have signal),
471 	 * and our link partner is not trying to auto-negotiate with us (we
472 	 * are receiving idles or data), we need to force link up. We also
473 	 * need to give auto-negotiation time to complete, in case the cable
474 	 * was just plugged in. The autoneg_failed flag does this.
475 	 */
476 	/* (ctrl & E1000_CTRL_SWDPIN1) == 1 == have signal */
477 	if ((ctrl & E1000_CTRL_SWDPIN1) && !(status & E1000_STATUS_LU) &&
478 	    !(rxcw & E1000_RXCW_C)) {
479 		if (!mac->autoneg_failed) {
480 			mac->autoneg_failed = true;
481 			return 0;
482 		}
483 		e_dbg("NOT Rx'ing /C/, disable AutoNeg and force link.\n");
484 
485 		/* Disable auto-negotiation in the TXCW register */
486 		ew32(TXCW, (mac->txcw & ~E1000_TXCW_ANE));
487 
488 		/* Force link-up and also force full-duplex. */
489 		ctrl = er32(CTRL);
490 		ctrl |= (E1000_CTRL_SLU | E1000_CTRL_FD);
491 		ew32(CTRL, ctrl);
492 
493 		/* Configure Flow Control after forcing link up. */
494 		ret_val = e1000e_config_fc_after_link_up(hw);
495 		if (ret_val) {
496 			e_dbg("Error configuring flow control\n");
497 			return ret_val;
498 		}
499 	} else if ((ctrl & E1000_CTRL_SLU) && (rxcw & E1000_RXCW_C)) {
500 		/* If we are forcing link and we are receiving /C/ ordered
501 		 * sets, re-enable auto-negotiation in the TXCW register
502 		 * and disable forced link in the Device Control register
503 		 * in an attempt to auto-negotiate with our link partner.
504 		 */
505 		e_dbg("Rx'ing /C/, enable AutoNeg and stop forcing link.\n");
506 		ew32(TXCW, mac->txcw);
507 		ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));
508 
509 		mac->serdes_has_link = true;
510 	}
511 
512 	return 0;
513 }
514 
515 /**
516  *  e1000e_check_for_serdes_link - Check for link (Serdes)
517  *  @hw: pointer to the HW structure
518  *
519  *  Checks for link up on the hardware.  If link is not up and we have
520  *  a signal, then we need to force link up.
521  **/
522 s32 e1000e_check_for_serdes_link(struct e1000_hw *hw)
523 {
524 	struct e1000_mac_info *mac = &hw->mac;
525 	u32 rxcw;
526 	u32 ctrl;
527 	u32 status;
528 	s32 ret_val;
529 
530 	ctrl = er32(CTRL);
531 	status = er32(STATUS);
532 	rxcw = er32(RXCW);
533 
534 	/* If we don't have link (auto-negotiation failed or link partner
535 	 * cannot auto-negotiate), and our link partner is not trying to
536 	 * auto-negotiate with us (we are receiving idles or data),
537 	 * we need to force link up. We also need to give auto-negotiation
538 	 * time to complete.
539 	 */
540 	/* (ctrl & E1000_CTRL_SWDPIN1) == 1 == have signal */
541 	if (!(status & E1000_STATUS_LU) && !(rxcw & E1000_RXCW_C)) {
542 		if (!mac->autoneg_failed) {
543 			mac->autoneg_failed = true;
544 			return 0;
545 		}
546 		e_dbg("NOT Rx'ing /C/, disable AutoNeg and force link.\n");
547 
548 		/* Disable auto-negotiation in the TXCW register */
549 		ew32(TXCW, (mac->txcw & ~E1000_TXCW_ANE));
550 
551 		/* Force link-up and also force full-duplex. */
552 		ctrl = er32(CTRL);
553 		ctrl |= (E1000_CTRL_SLU | E1000_CTRL_FD);
554 		ew32(CTRL, ctrl);
555 
556 		/* Configure Flow Control after forcing link up. */
557 		ret_val = e1000e_config_fc_after_link_up(hw);
558 		if (ret_val) {
559 			e_dbg("Error configuring flow control\n");
560 			return ret_val;
561 		}
562 	} else if ((ctrl & E1000_CTRL_SLU) && (rxcw & E1000_RXCW_C)) {
563 		/* If we are forcing link and we are receiving /C/ ordered
564 		 * sets, re-enable auto-negotiation in the TXCW register
565 		 * and disable forced link in the Device Control register
566 		 * in an attempt to auto-negotiate with our link partner.
567 		 */
568 		e_dbg("Rx'ing /C/, enable AutoNeg and stop forcing link.\n");
569 		ew32(TXCW, mac->txcw);
570 		ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));
571 
572 		mac->serdes_has_link = true;
573 	} else if (!(E1000_TXCW_ANE & er32(TXCW))) {
574 		/* If we force link for non-auto-negotiation switch, check
575 		 * link status based on MAC synchronization for internal
576 		 * serdes media type.
577 		 */
578 		/* SYNCH bit and IV bit are sticky. */
579 		usleep_range(10, 20);
580 		rxcw = er32(RXCW);
581 		if (rxcw & E1000_RXCW_SYNCH) {
582 			if (!(rxcw & E1000_RXCW_IV)) {
583 				mac->serdes_has_link = true;
584 				e_dbg("SERDES: Link up - forced.\n");
585 			}
586 		} else {
587 			mac->serdes_has_link = false;
588 			e_dbg("SERDES: Link down - force failed.\n");
589 		}
590 	}
591 
592 	if (E1000_TXCW_ANE & er32(TXCW)) {
593 		status = er32(STATUS);
594 		if (status & E1000_STATUS_LU) {
595 			/* SYNCH bit and IV bit are sticky, so reread rxcw. */
596 			usleep_range(10, 20);
597 			rxcw = er32(RXCW);
598 			if (rxcw & E1000_RXCW_SYNCH) {
599 				if (!(rxcw & E1000_RXCW_IV)) {
600 					mac->serdes_has_link = true;
601 					e_dbg("SERDES: Link up - autoneg completed successfully.\n");
602 				} else {
603 					mac->serdes_has_link = false;
604 					e_dbg("SERDES: Link down - invalid codewords detected in autoneg.\n");
605 				}
606 			} else {
607 				mac->serdes_has_link = false;
608 				e_dbg("SERDES: Link down - no sync.\n");
609 			}
610 		} else {
611 			mac->serdes_has_link = false;
612 			e_dbg("SERDES: Link down - autoneg failed\n");
613 		}
614 	}
615 
616 	return 0;
617 }
618 
619 /**
620  *  e1000_set_default_fc_generic - Set flow control default values
621  *  @hw: pointer to the HW structure
622  *
623  *  Read the EEPROM for the default values for flow control and store the
624  *  values.
625  **/
626 static s32 e1000_set_default_fc_generic(struct e1000_hw *hw)
627 {
628 	s32 ret_val;
629 	u16 nvm_data;
630 
631 	/* Read and store word 0x0F of the EEPROM. This word contains bits
632 	 * that determine the hardware's default PAUSE (flow control) mode,
633 	 * a bit that determines whether the HW defaults to enabling or
634 	 * disabling auto-negotiation, and the direction of the
635 	 * SW defined pins. If there is no SW over-ride of the flow
636 	 * control setting, then the variable hw->fc will
637 	 * be initialized based on a value in the EEPROM.
638 	 */
639 	ret_val = e1000_read_nvm(hw, NVM_INIT_CONTROL2_REG, 1, &nvm_data);
640 
641 	if (ret_val) {
642 		e_dbg("NVM Read Error\n");
643 		return ret_val;
644 	}
645 
646 	if (!(nvm_data & NVM_WORD0F_PAUSE_MASK))
647 		hw->fc.requested_mode = e1000_fc_none;
648 	else if ((nvm_data & NVM_WORD0F_PAUSE_MASK) == NVM_WORD0F_ASM_DIR)
649 		hw->fc.requested_mode = e1000_fc_tx_pause;
650 	else
651 		hw->fc.requested_mode = e1000_fc_full;
652 
653 	return 0;
654 }
655 
656 /**
657  *  e1000e_setup_link_generic - Setup flow control and link settings
658  *  @hw: pointer to the HW structure
659  *
660  *  Determines which flow control settings to use, then configures flow
661  *  control.  Calls the appropriate media-specific link configuration
662  *  function.  Assuming the adapter has a valid link partner, a valid link
663  *  should be established.  Assumes the hardware has previously been reset
664  *  and the transmitter and receiver are not enabled.
665  **/
666 s32 e1000e_setup_link_generic(struct e1000_hw *hw)
667 {
668 	s32 ret_val;
669 
670 	/* In the case of the phy reset being blocked, we already have a link.
671 	 * We do not need to set it up again.
672 	 */
673 	if (hw->phy.ops.check_reset_block && hw->phy.ops.check_reset_block(hw))
674 		return 0;
675 
676 	/* If requested flow control is set to default, set flow control
677 	 * based on the EEPROM flow control settings.
678 	 */
679 	if (hw->fc.requested_mode == e1000_fc_default) {
680 		ret_val = e1000_set_default_fc_generic(hw);
681 		if (ret_val)
682 			return ret_val;
683 	}
684 
685 	/* Save off the requested flow control mode for use later.  Depending
686 	 * on the link partner's capabilities, we may or may not use this mode.
687 	 */
688 	hw->fc.current_mode = hw->fc.requested_mode;
689 
690 	e_dbg("After fix-ups FlowControl is now = %x\n", hw->fc.current_mode);
691 
692 	/* Call the necessary media_type subroutine to configure the link. */
693 	ret_val = hw->mac.ops.setup_physical_interface(hw);
694 	if (ret_val)
695 		return ret_val;
696 
697 	/* Initialize the flow control address, type, and PAUSE timer
698 	 * registers to their default values.  This is done even if flow
699 	 * control is disabled, because it does not hurt anything to
700 	 * initialize these registers.
701 	 */
702 	e_dbg("Initializing the Flow Control address, type and timer regs\n");
703 	ew32(FCT, FLOW_CONTROL_TYPE);
704 	ew32(FCAH, FLOW_CONTROL_ADDRESS_HIGH);
705 	ew32(FCAL, FLOW_CONTROL_ADDRESS_LOW);
706 
707 	ew32(FCTTV, hw->fc.pause_time);
708 
709 	return e1000e_set_fc_watermarks(hw);
710 }
711 
712 /**
713  *  e1000_commit_fc_settings_generic - Configure flow control
714  *  @hw: pointer to the HW structure
715  *
716  *  Write the flow control settings to the Transmit Config Word Register (TXCW)
717  *  base on the flow control settings in e1000_mac_info.
718  **/
719 static s32 e1000_commit_fc_settings_generic(struct e1000_hw *hw)
720 {
721 	struct e1000_mac_info *mac = &hw->mac;
722 	u32 txcw;
723 
724 	/* Check for a software override of the flow control settings, and
725 	 * setup the device accordingly.  If auto-negotiation is enabled, then
726 	 * software will have to set the "PAUSE" bits to the correct value in
727 	 * the Transmit Config Word Register (TXCW) and re-start auto-
728 	 * negotiation.  However, if auto-negotiation is disabled, then
729 	 * software will have to manually configure the two flow control enable
730 	 * bits in the CTRL register.
731 	 *
732 	 * The possible values of the "fc" parameter are:
733 	 *      0:  Flow control is completely disabled
734 	 *      1:  Rx flow control is enabled (we can receive pause frames,
735 	 *          but not send pause frames).
736 	 *      2:  Tx flow control is enabled (we can send pause frames but we
737 	 *          do not support receiving pause frames).
738 	 *      3:  Both Rx and Tx flow control (symmetric) are enabled.
739 	 */
740 	switch (hw->fc.current_mode) {
741 	case e1000_fc_none:
742 		/* Flow control completely disabled by a software over-ride. */
743 		txcw = (E1000_TXCW_ANE | E1000_TXCW_FD);
744 		break;
745 	case e1000_fc_rx_pause:
746 		/* Rx Flow control is enabled and Tx Flow control is disabled
747 		 * by a software over-ride. Since there really isn't a way to
748 		 * advertise that we are capable of Rx Pause ONLY, we will
749 		 * advertise that we support both symmetric and asymmetric Rx
750 		 * PAUSE.  Later, we will disable the adapter's ability to send
751 		 * PAUSE frames.
752 		 */
753 		txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_PAUSE_MASK);
754 		break;
755 	case e1000_fc_tx_pause:
756 		/* Tx Flow control is enabled, and Rx Flow control is disabled,
757 		 * by a software over-ride.
758 		 */
759 		txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_ASM_DIR);
760 		break;
761 	case e1000_fc_full:
762 		/* Flow control (both Rx and Tx) is enabled by a software
763 		 * over-ride.
764 		 */
765 		txcw = (E1000_TXCW_ANE | E1000_TXCW_FD | E1000_TXCW_PAUSE_MASK);
766 		break;
767 	default:
768 		e_dbg("Flow control param set incorrectly\n");
769 		return -E1000_ERR_CONFIG;
770 	}
771 
772 	ew32(TXCW, txcw);
773 	mac->txcw = txcw;
774 
775 	return 0;
776 }
777 
778 /**
779  *  e1000_poll_fiber_serdes_link_generic - Poll for link up
780  *  @hw: pointer to the HW structure
781  *
782  *  Polls for link up by reading the status register, if link fails to come
783  *  up with auto-negotiation, then the link is forced if a signal is detected.
784  **/
785 static s32 e1000_poll_fiber_serdes_link_generic(struct e1000_hw *hw)
786 {
787 	struct e1000_mac_info *mac = &hw->mac;
788 	u32 i, status;
789 	s32 ret_val;
790 
791 	/* If we have a signal (the cable is plugged in, or assumed true for
792 	 * serdes media) then poll for a "Link-Up" indication in the Device
793 	 * Status Register.  Time-out if a link isn't seen in 500 milliseconds
794 	 * seconds (Auto-negotiation should complete in less than 500
795 	 * milliseconds even if the other end is doing it in SW).
796 	 */
797 	for (i = 0; i < FIBER_LINK_UP_LIMIT; i++) {
798 		usleep_range(10000, 11000);
799 		status = er32(STATUS);
800 		if (status & E1000_STATUS_LU)
801 			break;
802 	}
803 	if (i == FIBER_LINK_UP_LIMIT) {
804 		e_dbg("Never got a valid link from auto-neg!!!\n");
805 		mac->autoneg_failed = true;
806 		/* AutoNeg failed to achieve a link, so we'll call
807 		 * mac->check_for_link. This routine will force the
808 		 * link up if we detect a signal. This will allow us to
809 		 * communicate with non-autonegotiating link partners.
810 		 */
811 		ret_val = mac->ops.check_for_link(hw);
812 		if (ret_val) {
813 			e_dbg("Error while checking for link\n");
814 			return ret_val;
815 		}
816 		mac->autoneg_failed = false;
817 	} else {
818 		mac->autoneg_failed = false;
819 		e_dbg("Valid Link Found\n");
820 	}
821 
822 	return 0;
823 }
824 
825 /**
826  *  e1000e_setup_fiber_serdes_link - Setup link for fiber/serdes
827  *  @hw: pointer to the HW structure
828  *
829  *  Configures collision distance and flow control for fiber and serdes
830  *  links.  Upon successful setup, poll for link.
831  **/
832 s32 e1000e_setup_fiber_serdes_link(struct e1000_hw *hw)
833 {
834 	u32 ctrl;
835 	s32 ret_val;
836 
837 	ctrl = er32(CTRL);
838 
839 	/* Take the link out of reset */
840 	ctrl &= ~E1000_CTRL_LRST;
841 
842 	hw->mac.ops.config_collision_dist(hw);
843 
844 	ret_val = e1000_commit_fc_settings_generic(hw);
845 	if (ret_val)
846 		return ret_val;
847 
848 	/* Since auto-negotiation is enabled, take the link out of reset (the
849 	 * link will be in reset, because we previously reset the chip). This
850 	 * will restart auto-negotiation.  If auto-negotiation is successful
851 	 * then the link-up status bit will be set and the flow control enable
852 	 * bits (RFCE and TFCE) will be set according to their negotiated value.
853 	 */
854 	e_dbg("Auto-negotiation enabled\n");
855 
856 	ew32(CTRL, ctrl);
857 	e1e_flush();
858 	usleep_range(1000, 2000);
859 
860 	/* For these adapters, the SW definable pin 1 is set when the optics
861 	 * detect a signal.  If we have a signal, then poll for a "Link-Up"
862 	 * indication.
863 	 */
864 	if (hw->phy.media_type == e1000_media_type_internal_serdes ||
865 	    (er32(CTRL) & E1000_CTRL_SWDPIN1)) {
866 		ret_val = e1000_poll_fiber_serdes_link_generic(hw);
867 	} else {
868 		e_dbg("No signal detected\n");
869 	}
870 
871 	return ret_val;
872 }
873 
874 /**
875  *  e1000e_config_collision_dist_generic - Configure collision distance
876  *  @hw: pointer to the HW structure
877  *
878  *  Configures the collision distance to the default value and is used
879  *  during link setup.
880  **/
881 void e1000e_config_collision_dist_generic(struct e1000_hw *hw)
882 {
883 	u32 tctl;
884 
885 	tctl = er32(TCTL);
886 
887 	tctl &= ~E1000_TCTL_COLD;
888 	tctl |= E1000_COLLISION_DISTANCE << E1000_COLD_SHIFT;
889 
890 	ew32(TCTL, tctl);
891 	e1e_flush();
892 }
893 
894 /**
895  *  e1000e_set_fc_watermarks - Set flow control high/low watermarks
896  *  @hw: pointer to the HW structure
897  *
898  *  Sets the flow control high/low threshold (watermark) registers.  If
899  *  flow control XON frame transmission is enabled, then set XON frame
900  *  transmission as well.
901  **/
902 s32 e1000e_set_fc_watermarks(struct e1000_hw *hw)
903 {
904 	u32 fcrtl = 0, fcrth = 0;
905 
906 	/* Set the flow control receive threshold registers.  Normally,
907 	 * these registers will be set to a default threshold that may be
908 	 * adjusted later by the driver's runtime code.  However, if the
909 	 * ability to transmit pause frames is not enabled, then these
910 	 * registers will be set to 0.
911 	 */
912 	if (hw->fc.current_mode & e1000_fc_tx_pause) {
913 		/* We need to set up the Receive Threshold high and low water
914 		 * marks as well as (optionally) enabling the transmission of
915 		 * XON frames.
916 		 */
917 		fcrtl = hw->fc.low_water;
918 		if (hw->fc.send_xon)
919 			fcrtl |= E1000_FCRTL_XONE;
920 
921 		fcrth = hw->fc.high_water;
922 	}
923 	ew32(FCRTL, fcrtl);
924 	ew32(FCRTH, fcrth);
925 
926 	return 0;
927 }
928 
929 /**
930  *  e1000e_force_mac_fc - Force the MAC's flow control settings
931  *  @hw: pointer to the HW structure
932  *
933  *  Force the MAC's flow control settings.  Sets the TFCE and RFCE bits in the
934  *  device control register to reflect the adapter settings.  TFCE and RFCE
935  *  need to be explicitly set by software when a copper PHY is used because
936  *  autonegotiation is managed by the PHY rather than the MAC.  Software must
937  *  also configure these bits when link is forced on a fiber connection.
938  **/
939 s32 e1000e_force_mac_fc(struct e1000_hw *hw)
940 {
941 	u32 ctrl;
942 
943 	ctrl = er32(CTRL);
944 
945 	/* Because we didn't get link via the internal auto-negotiation
946 	 * mechanism (we either forced link or we got link via PHY
947 	 * auto-neg), we have to manually enable/disable transmit an
948 	 * receive flow control.
949 	 *
950 	 * The "Case" statement below enables/disable flow control
951 	 * according to the "hw->fc.current_mode" parameter.
952 	 *
953 	 * The possible values of the "fc" parameter are:
954 	 *      0:  Flow control is completely disabled
955 	 *      1:  Rx flow control is enabled (we can receive pause
956 	 *          frames but not send pause frames).
957 	 *      2:  Tx flow control is enabled (we can send pause frames
958 	 *          but we do not receive pause frames).
959 	 *      3:  Both Rx and Tx flow control (symmetric) is enabled.
960 	 *  other:  No other values should be possible at this point.
961 	 */
962 	e_dbg("hw->fc.current_mode = %u\n", hw->fc.current_mode);
963 
964 	switch (hw->fc.current_mode) {
965 	case e1000_fc_none:
966 		ctrl &= (~(E1000_CTRL_TFCE | E1000_CTRL_RFCE));
967 		break;
968 	case e1000_fc_rx_pause:
969 		ctrl &= (~E1000_CTRL_TFCE);
970 		ctrl |= E1000_CTRL_RFCE;
971 		break;
972 	case e1000_fc_tx_pause:
973 		ctrl &= (~E1000_CTRL_RFCE);
974 		ctrl |= E1000_CTRL_TFCE;
975 		break;
976 	case e1000_fc_full:
977 		ctrl |= (E1000_CTRL_TFCE | E1000_CTRL_RFCE);
978 		break;
979 	default:
980 		e_dbg("Flow control param set incorrectly\n");
981 		return -E1000_ERR_CONFIG;
982 	}
983 
984 	ew32(CTRL, ctrl);
985 
986 	return 0;
987 }
988 
989 /**
990  *  e1000e_config_fc_after_link_up - Configures flow control after link
991  *  @hw: pointer to the HW structure
992  *
993  *  Checks the status of auto-negotiation after link up to ensure that the
994  *  speed and duplex were not forced.  If the link needed to be forced, then
995  *  flow control needs to be forced also.  If auto-negotiation is enabled
996  *  and did not fail, then we configure flow control based on our link
997  *  partner.
998  **/
999 s32 e1000e_config_fc_after_link_up(struct e1000_hw *hw)
1000 {
1001 	struct e1000_mac_info *mac = &hw->mac;
1002 	s32 ret_val = 0;
1003 	u32 pcs_status_reg, pcs_adv_reg, pcs_lp_ability_reg, pcs_ctrl_reg;
1004 	u16 mii_status_reg, mii_nway_adv_reg, mii_nway_lp_ability_reg;
1005 	u16 speed, duplex;
1006 
1007 	/* Check for the case where we have fiber media and auto-neg failed
1008 	 * so we had to force link.  In this case, we need to force the
1009 	 * configuration of the MAC to match the "fc" parameter.
1010 	 */
1011 	if (mac->autoneg_failed) {
1012 		if (hw->phy.media_type == e1000_media_type_fiber ||
1013 		    hw->phy.media_type == e1000_media_type_internal_serdes)
1014 			ret_val = e1000e_force_mac_fc(hw);
1015 	} else {
1016 		if (hw->phy.media_type == e1000_media_type_copper)
1017 			ret_val = e1000e_force_mac_fc(hw);
1018 	}
1019 
1020 	if (ret_val) {
1021 		e_dbg("Error forcing flow control settings\n");
1022 		return ret_val;
1023 	}
1024 
1025 	/* Check for the case where we have copper media and auto-neg is
1026 	 * enabled.  In this case, we need to check and see if Auto-Neg
1027 	 * has completed, and if so, how the PHY and link partner has
1028 	 * flow control configured.
1029 	 */
1030 	if ((hw->phy.media_type == e1000_media_type_copper) && mac->autoneg) {
1031 		/* Read the MII Status Register and check to see if AutoNeg
1032 		 * has completed.  We read this twice because this reg has
1033 		 * some "sticky" (latched) bits.
1034 		 */
1035 		ret_val = e1e_rphy(hw, MII_BMSR, &mii_status_reg);
1036 		if (ret_val)
1037 			return ret_val;
1038 		ret_val = e1e_rphy(hw, MII_BMSR, &mii_status_reg);
1039 		if (ret_val)
1040 			return ret_val;
1041 
1042 		if (!(mii_status_reg & BMSR_ANEGCOMPLETE)) {
1043 			e_dbg("Copper PHY and Auto Neg has not completed.\n");
1044 			return ret_val;
1045 		}
1046 
1047 		/* The AutoNeg process has completed, so we now need to
1048 		 * read both the Auto Negotiation Advertisement
1049 		 * Register (Address 4) and the Auto_Negotiation Base
1050 		 * Page Ability Register (Address 5) to determine how
1051 		 * flow control was negotiated.
1052 		 */
1053 		ret_val = e1e_rphy(hw, MII_ADVERTISE, &mii_nway_adv_reg);
1054 		if (ret_val)
1055 			return ret_val;
1056 		ret_val = e1e_rphy(hw, MII_LPA, &mii_nway_lp_ability_reg);
1057 		if (ret_val)
1058 			return ret_val;
1059 
1060 		/* Two bits in the Auto Negotiation Advertisement Register
1061 		 * (Address 4) and two bits in the Auto Negotiation Base
1062 		 * Page Ability Register (Address 5) determine flow control
1063 		 * for both the PHY and the link partner.  The following
1064 		 * table, taken out of the IEEE 802.3ab/D6.0 dated March 25,
1065 		 * 1999, describes these PAUSE resolution bits and how flow
1066 		 * control is determined based upon these settings.
1067 		 * NOTE:  DC = Don't Care
1068 		 *
1069 		 *   LOCAL DEVICE  |   LINK PARTNER
1070 		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution
1071 		 *-------|---------|-------|---------|--------------------
1072 		 *   0   |    0    |  DC   |   DC    | e1000_fc_none
1073 		 *   0   |    1    |   0   |   DC    | e1000_fc_none
1074 		 *   0   |    1    |   1   |    0    | e1000_fc_none
1075 		 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
1076 		 *   1   |    0    |   0   |   DC    | e1000_fc_none
1077 		 *   1   |   DC    |   1   |   DC    | e1000_fc_full
1078 		 *   1   |    1    |   0   |    0    | e1000_fc_none
1079 		 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
1080 		 *
1081 		 * Are both PAUSE bits set to 1?  If so, this implies
1082 		 * Symmetric Flow Control is enabled at both ends.  The
1083 		 * ASM_DIR bits are irrelevant per the spec.
1084 		 *
1085 		 * For Symmetric Flow Control:
1086 		 *
1087 		 *   LOCAL DEVICE  |   LINK PARTNER
1088 		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
1089 		 *-------|---------|-------|---------|--------------------
1090 		 *   1   |   DC    |   1   |   DC    | E1000_fc_full
1091 		 *
1092 		 */
1093 		if ((mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
1094 		    (mii_nway_lp_ability_reg & LPA_PAUSE_CAP)) {
1095 			/* Now we need to check if the user selected Rx ONLY
1096 			 * of pause frames.  In this case, we had to advertise
1097 			 * FULL flow control because we could not advertise Rx
1098 			 * ONLY. Hence, we must now check to see if we need to
1099 			 * turn OFF the TRANSMISSION of PAUSE frames.
1100 			 */
1101 			if (hw->fc.requested_mode == e1000_fc_full) {
1102 				hw->fc.current_mode = e1000_fc_full;
1103 				e_dbg("Flow Control = FULL.\n");
1104 			} else {
1105 				hw->fc.current_mode = e1000_fc_rx_pause;
1106 				e_dbg("Flow Control = Rx PAUSE frames only.\n");
1107 			}
1108 		}
1109 		/* For receiving PAUSE frames ONLY.
1110 		 *
1111 		 *   LOCAL DEVICE  |   LINK PARTNER
1112 		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
1113 		 *-------|---------|-------|---------|--------------------
1114 		 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
1115 		 */
1116 		else if (!(mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
1117 			 (mii_nway_adv_reg & ADVERTISE_PAUSE_ASYM) &&
1118 			 (mii_nway_lp_ability_reg & LPA_PAUSE_CAP) &&
1119 			 (mii_nway_lp_ability_reg & LPA_PAUSE_ASYM)) {
1120 			hw->fc.current_mode = e1000_fc_tx_pause;
1121 			e_dbg("Flow Control = Tx PAUSE frames only.\n");
1122 		}
1123 		/* For transmitting PAUSE frames ONLY.
1124 		 *
1125 		 *   LOCAL DEVICE  |   LINK PARTNER
1126 		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
1127 		 *-------|---------|-------|---------|--------------------
1128 		 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
1129 		 */
1130 		else if ((mii_nway_adv_reg & ADVERTISE_PAUSE_CAP) &&
1131 			 (mii_nway_adv_reg & ADVERTISE_PAUSE_ASYM) &&
1132 			 !(mii_nway_lp_ability_reg & LPA_PAUSE_CAP) &&
1133 			 (mii_nway_lp_ability_reg & LPA_PAUSE_ASYM)) {
1134 			hw->fc.current_mode = e1000_fc_rx_pause;
1135 			e_dbg("Flow Control = Rx PAUSE frames only.\n");
1136 		} else {
1137 			/* Per the IEEE spec, at this point flow control
1138 			 * should be disabled.
1139 			 */
1140 			hw->fc.current_mode = e1000_fc_none;
1141 			e_dbg("Flow Control = NONE.\n");
1142 		}
1143 
1144 		/* Now we need to do one last check...  If we auto-
1145 		 * negotiated to HALF DUPLEX, flow control should not be
1146 		 * enabled per IEEE 802.3 spec.
1147 		 */
1148 		ret_val = mac->ops.get_link_up_info(hw, &speed, &duplex);
1149 		if (ret_val) {
1150 			e_dbg("Error getting link speed and duplex\n");
1151 			return ret_val;
1152 		}
1153 
1154 		if (duplex == HALF_DUPLEX)
1155 			hw->fc.current_mode = e1000_fc_none;
1156 
1157 		/* Now we call a subroutine to actually force the MAC
1158 		 * controller to use the correct flow control settings.
1159 		 */
1160 		ret_val = e1000e_force_mac_fc(hw);
1161 		if (ret_val) {
1162 			e_dbg("Error forcing flow control settings\n");
1163 			return ret_val;
1164 		}
1165 	}
1166 
1167 	/* Check for the case where we have SerDes media and auto-neg is
1168 	 * enabled.  In this case, we need to check and see if Auto-Neg
1169 	 * has completed, and if so, how the PHY and link partner has
1170 	 * flow control configured.
1171 	 */
1172 	if ((hw->phy.media_type == e1000_media_type_internal_serdes) &&
1173 	    mac->autoneg) {
1174 		/* Read the PCS_LSTS and check to see if AutoNeg
1175 		 * has completed.
1176 		 */
1177 		pcs_status_reg = er32(PCS_LSTAT);
1178 
1179 		if (!(pcs_status_reg & E1000_PCS_LSTS_AN_COMPLETE)) {
1180 			e_dbg("PCS Auto Neg has not completed.\n");
1181 			return ret_val;
1182 		}
1183 
1184 		/* The AutoNeg process has completed, so we now need to
1185 		 * read both the Auto Negotiation Advertisement
1186 		 * Register (PCS_ANADV) and the Auto_Negotiation Base
1187 		 * Page Ability Register (PCS_LPAB) to determine how
1188 		 * flow control was negotiated.
1189 		 */
1190 		pcs_adv_reg = er32(PCS_ANADV);
1191 		pcs_lp_ability_reg = er32(PCS_LPAB);
1192 
1193 		/* Two bits in the Auto Negotiation Advertisement Register
1194 		 * (PCS_ANADV) and two bits in the Auto Negotiation Base
1195 		 * Page Ability Register (PCS_LPAB) determine flow control
1196 		 * for both the PHY and the link partner.  The following
1197 		 * table, taken out of the IEEE 802.3ab/D6.0 dated March 25,
1198 		 * 1999, describes these PAUSE resolution bits and how flow
1199 		 * control is determined based upon these settings.
1200 		 * NOTE:  DC = Don't Care
1201 		 *
1202 		 *   LOCAL DEVICE  |   LINK PARTNER
1203 		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution
1204 		 *-------|---------|-------|---------|--------------------
1205 		 *   0   |    0    |  DC   |   DC    | e1000_fc_none
1206 		 *   0   |    1    |   0   |   DC    | e1000_fc_none
1207 		 *   0   |    1    |   1   |    0    | e1000_fc_none
1208 		 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
1209 		 *   1   |    0    |   0   |   DC    | e1000_fc_none
1210 		 *   1   |   DC    |   1   |   DC    | e1000_fc_full
1211 		 *   1   |    1    |   0   |    0    | e1000_fc_none
1212 		 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
1213 		 *
1214 		 * Are both PAUSE bits set to 1?  If so, this implies
1215 		 * Symmetric Flow Control is enabled at both ends.  The
1216 		 * ASM_DIR bits are irrelevant per the spec.
1217 		 *
1218 		 * For Symmetric Flow Control:
1219 		 *
1220 		 *   LOCAL DEVICE  |   LINK PARTNER
1221 		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
1222 		 *-------|---------|-------|---------|--------------------
1223 		 *   1   |   DC    |   1   |   DC    | e1000_fc_full
1224 		 *
1225 		 */
1226 		if ((pcs_adv_reg & E1000_TXCW_PAUSE) &&
1227 		    (pcs_lp_ability_reg & E1000_TXCW_PAUSE)) {
1228 			/* Now we need to check if the user selected Rx ONLY
1229 			 * of pause frames.  In this case, we had to advertise
1230 			 * FULL flow control because we could not advertise Rx
1231 			 * ONLY. Hence, we must now check to see if we need to
1232 			 * turn OFF the TRANSMISSION of PAUSE frames.
1233 			 */
1234 			if (hw->fc.requested_mode == e1000_fc_full) {
1235 				hw->fc.current_mode = e1000_fc_full;
1236 				e_dbg("Flow Control = FULL.\n");
1237 			} else {
1238 				hw->fc.current_mode = e1000_fc_rx_pause;
1239 				e_dbg("Flow Control = Rx PAUSE frames only.\n");
1240 			}
1241 		}
1242 		/* For receiving PAUSE frames ONLY.
1243 		 *
1244 		 *   LOCAL DEVICE  |   LINK PARTNER
1245 		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
1246 		 *-------|---------|-------|---------|--------------------
1247 		 *   0   |    1    |   1   |    1    | e1000_fc_tx_pause
1248 		 */
1249 		else if (!(pcs_adv_reg & E1000_TXCW_PAUSE) &&
1250 			 (pcs_adv_reg & E1000_TXCW_ASM_DIR) &&
1251 			 (pcs_lp_ability_reg & E1000_TXCW_PAUSE) &&
1252 			 (pcs_lp_ability_reg & E1000_TXCW_ASM_DIR)) {
1253 			hw->fc.current_mode = e1000_fc_tx_pause;
1254 			e_dbg("Flow Control = Tx PAUSE frames only.\n");
1255 		}
1256 		/* For transmitting PAUSE frames ONLY.
1257 		 *
1258 		 *   LOCAL DEVICE  |   LINK PARTNER
1259 		 * PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
1260 		 *-------|---------|-------|---------|--------------------
1261 		 *   1   |    1    |   0   |    1    | e1000_fc_rx_pause
1262 		 */
1263 		else if ((pcs_adv_reg & E1000_TXCW_PAUSE) &&
1264 			 (pcs_adv_reg & E1000_TXCW_ASM_DIR) &&
1265 			 !(pcs_lp_ability_reg & E1000_TXCW_PAUSE) &&
1266 			 (pcs_lp_ability_reg & E1000_TXCW_ASM_DIR)) {
1267 			hw->fc.current_mode = e1000_fc_rx_pause;
1268 			e_dbg("Flow Control = Rx PAUSE frames only.\n");
1269 		} else {
1270 			/* Per the IEEE spec, at this point flow control
1271 			 * should be disabled.
1272 			 */
1273 			hw->fc.current_mode = e1000_fc_none;
1274 			e_dbg("Flow Control = NONE.\n");
1275 		}
1276 
1277 		/* Now we call a subroutine to actually force the MAC
1278 		 * controller to use the correct flow control settings.
1279 		 */
1280 		pcs_ctrl_reg = er32(PCS_LCTL);
1281 		pcs_ctrl_reg |= E1000_PCS_LCTL_FORCE_FCTRL;
1282 		ew32(PCS_LCTL, pcs_ctrl_reg);
1283 
1284 		ret_val = e1000e_force_mac_fc(hw);
1285 		if (ret_val) {
1286 			e_dbg("Error forcing flow control settings\n");
1287 			return ret_val;
1288 		}
1289 	}
1290 
1291 	return 0;
1292 }
1293 
1294 /**
1295  *  e1000e_get_speed_and_duplex_copper - Retrieve current speed/duplex
1296  *  @hw: pointer to the HW structure
1297  *  @speed: stores the current speed
1298  *  @duplex: stores the current duplex
1299  *
1300  *  Read the status register for the current speed/duplex and store the current
1301  *  speed and duplex for copper connections.
1302  **/
1303 s32 e1000e_get_speed_and_duplex_copper(struct e1000_hw *hw, u16 *speed,
1304 				       u16 *duplex)
1305 {
1306 	u32 status;
1307 
1308 	status = er32(STATUS);
1309 	if (status & E1000_STATUS_SPEED_1000)
1310 		*speed = SPEED_1000;
1311 	else if (status & E1000_STATUS_SPEED_100)
1312 		*speed = SPEED_100;
1313 	else
1314 		*speed = SPEED_10;
1315 
1316 	if (status & E1000_STATUS_FD)
1317 		*duplex = FULL_DUPLEX;
1318 	else
1319 		*duplex = HALF_DUPLEX;
1320 
1321 	e_dbg("%u Mbps, %s Duplex\n",
1322 	      *speed == SPEED_1000 ? 1000 : *speed == SPEED_100 ? 100 : 10,
1323 	      *duplex == FULL_DUPLEX ? "Full" : "Half");
1324 
1325 	return 0;
1326 }
1327 
1328 /**
1329  *  e1000e_get_speed_and_duplex_fiber_serdes - Retrieve current speed/duplex
1330  *  @hw: pointer to the HW structure
1331  *  @speed: stores the current speed
1332  *  @duplex: stores the current duplex
1333  *
1334  *  Sets the speed and duplex to gigabit full duplex (the only possible option)
1335  *  for fiber/serdes links.
1336  **/
1337 s32 e1000e_get_speed_and_duplex_fiber_serdes(struct e1000_hw __always_unused
1338 					     *hw, u16 *speed, u16 *duplex)
1339 {
1340 	*speed = SPEED_1000;
1341 	*duplex = FULL_DUPLEX;
1342 
1343 	return 0;
1344 }
1345 
1346 /**
1347  *  e1000e_get_hw_semaphore - Acquire hardware semaphore
1348  *  @hw: pointer to the HW structure
1349  *
1350  *  Acquire the HW semaphore to access the PHY or NVM
1351  **/
1352 s32 e1000e_get_hw_semaphore(struct e1000_hw *hw)
1353 {
1354 	u32 swsm;
1355 	s32 timeout = hw->nvm.word_size + 1;
1356 	s32 i = 0;
1357 
1358 	/* Get the SW semaphore */
1359 	while (i < timeout) {
1360 		swsm = er32(SWSM);
1361 		if (!(swsm & E1000_SWSM_SMBI))
1362 			break;
1363 
1364 		udelay(100);
1365 		i++;
1366 	}
1367 
1368 	if (i == timeout) {
1369 		e_dbg("Driver can't access device - SMBI bit is set.\n");
1370 		return -E1000_ERR_NVM;
1371 	}
1372 
1373 	/* Get the FW semaphore. */
1374 	for (i = 0; i < timeout; i++) {
1375 		swsm = er32(SWSM);
1376 		ew32(SWSM, swsm | E1000_SWSM_SWESMBI);
1377 
1378 		/* Semaphore acquired if bit latched */
1379 		if (er32(SWSM) & E1000_SWSM_SWESMBI)
1380 			break;
1381 
1382 		udelay(100);
1383 	}
1384 
1385 	if (i == timeout) {
1386 		/* Release semaphores */
1387 		e1000e_put_hw_semaphore(hw);
1388 		e_dbg("Driver can't access the NVM\n");
1389 		return -E1000_ERR_NVM;
1390 	}
1391 
1392 	return 0;
1393 }
1394 
1395 /**
1396  *  e1000e_put_hw_semaphore - Release hardware semaphore
1397  *  @hw: pointer to the HW structure
1398  *
1399  *  Release hardware semaphore used to access the PHY or NVM
1400  **/
1401 void e1000e_put_hw_semaphore(struct e1000_hw *hw)
1402 {
1403 	u32 swsm;
1404 
1405 	swsm = er32(SWSM);
1406 	swsm &= ~(E1000_SWSM_SMBI | E1000_SWSM_SWESMBI);
1407 	ew32(SWSM, swsm);
1408 }
1409 
1410 /**
1411  *  e1000e_get_auto_rd_done - Check for auto read completion
1412  *  @hw: pointer to the HW structure
1413  *
1414  *  Check EEPROM for Auto Read done bit.
1415  **/
1416 s32 e1000e_get_auto_rd_done(struct e1000_hw *hw)
1417 {
1418 	s32 i = 0;
1419 
1420 	while (i < AUTO_READ_DONE_TIMEOUT) {
1421 		if (er32(EECD) & E1000_EECD_AUTO_RD)
1422 			break;
1423 		usleep_range(1000, 2000);
1424 		i++;
1425 	}
1426 
1427 	if (i == AUTO_READ_DONE_TIMEOUT) {
1428 		e_dbg("Auto read by HW from NVM has not completed.\n");
1429 		return -E1000_ERR_RESET;
1430 	}
1431 
1432 	return 0;
1433 }
1434 
1435 /**
1436  *  e1000e_valid_led_default - Verify a valid default LED config
1437  *  @hw: pointer to the HW structure
1438  *  @data: pointer to the NVM (EEPROM)
1439  *
1440  *  Read the EEPROM for the current default LED configuration.  If the
1441  *  LED configuration is not valid, set to a valid LED configuration.
1442  **/
1443 s32 e1000e_valid_led_default(struct e1000_hw *hw, u16 *data)
1444 {
1445 	s32 ret_val;
1446 
1447 	ret_val = e1000_read_nvm(hw, NVM_ID_LED_SETTINGS, 1, data);
1448 	if (ret_val) {
1449 		e_dbg("NVM Read Error\n");
1450 		return ret_val;
1451 	}
1452 
1453 	if (*data == ID_LED_RESERVED_0000 || *data == ID_LED_RESERVED_FFFF)
1454 		*data = ID_LED_DEFAULT;
1455 
1456 	return 0;
1457 }
1458 
1459 /**
1460  *  e1000e_id_led_init_generic -
1461  *  @hw: pointer to the HW structure
1462  *
1463  **/
1464 s32 e1000e_id_led_init_generic(struct e1000_hw *hw)
1465 {
1466 	struct e1000_mac_info *mac = &hw->mac;
1467 	s32 ret_val;
1468 	const u32 ledctl_mask = 0x000000FF;
1469 	const u32 ledctl_on = E1000_LEDCTL_MODE_LED_ON;
1470 	const u32 ledctl_off = E1000_LEDCTL_MODE_LED_OFF;
1471 	u16 data, i, temp;
1472 	const u16 led_mask = 0x0F;
1473 
1474 	ret_val = hw->nvm.ops.valid_led_default(hw, &data);
1475 	if (ret_val)
1476 		return ret_val;
1477 
1478 	mac->ledctl_default = er32(LEDCTL);
1479 	mac->ledctl_mode1 = mac->ledctl_default;
1480 	mac->ledctl_mode2 = mac->ledctl_default;
1481 
1482 	for (i = 0; i < 4; i++) {
1483 		temp = (data >> (i << 2)) & led_mask;
1484 		switch (temp) {
1485 		case ID_LED_ON1_DEF2:
1486 		case ID_LED_ON1_ON2:
1487 		case ID_LED_ON1_OFF2:
1488 			mac->ledctl_mode1 &= ~(ledctl_mask << (i << 3));
1489 			mac->ledctl_mode1 |= ledctl_on << (i << 3);
1490 			break;
1491 		case ID_LED_OFF1_DEF2:
1492 		case ID_LED_OFF1_ON2:
1493 		case ID_LED_OFF1_OFF2:
1494 			mac->ledctl_mode1 &= ~(ledctl_mask << (i << 3));
1495 			mac->ledctl_mode1 |= ledctl_off << (i << 3);
1496 			break;
1497 		default:
1498 			/* Do nothing */
1499 			break;
1500 		}
1501 		switch (temp) {
1502 		case ID_LED_DEF1_ON2:
1503 		case ID_LED_ON1_ON2:
1504 		case ID_LED_OFF1_ON2:
1505 			mac->ledctl_mode2 &= ~(ledctl_mask << (i << 3));
1506 			mac->ledctl_mode2 |= ledctl_on << (i << 3);
1507 			break;
1508 		case ID_LED_DEF1_OFF2:
1509 		case ID_LED_ON1_OFF2:
1510 		case ID_LED_OFF1_OFF2:
1511 			mac->ledctl_mode2 &= ~(ledctl_mask << (i << 3));
1512 			mac->ledctl_mode2 |= ledctl_off << (i << 3);
1513 			break;
1514 		default:
1515 			/* Do nothing */
1516 			break;
1517 		}
1518 	}
1519 
1520 	return 0;
1521 }
1522 
1523 /**
1524  *  e1000e_setup_led_generic - Configures SW controllable LED
1525  *  @hw: pointer to the HW structure
1526  *
1527  *  This prepares the SW controllable LED for use and saves the current state
1528  *  of the LED so it can be later restored.
1529  **/
1530 s32 e1000e_setup_led_generic(struct e1000_hw *hw)
1531 {
1532 	u32 ledctl;
1533 
1534 	if (hw->mac.ops.setup_led != e1000e_setup_led_generic)
1535 		return -E1000_ERR_CONFIG;
1536 
1537 	if (hw->phy.media_type == e1000_media_type_fiber) {
1538 		ledctl = er32(LEDCTL);
1539 		hw->mac.ledctl_default = ledctl;
1540 		/* Turn off LED0 */
1541 		ledctl &= ~(E1000_LEDCTL_LED0_IVRT | E1000_LEDCTL_LED0_BLINK |
1542 			    E1000_LEDCTL_LED0_MODE_MASK);
1543 		ledctl |= (E1000_LEDCTL_MODE_LED_OFF <<
1544 			   E1000_LEDCTL_LED0_MODE_SHIFT);
1545 		ew32(LEDCTL, ledctl);
1546 	} else if (hw->phy.media_type == e1000_media_type_copper) {
1547 		ew32(LEDCTL, hw->mac.ledctl_mode1);
1548 	}
1549 
1550 	return 0;
1551 }
1552 
1553 /**
1554  *  e1000e_cleanup_led_generic - Set LED config to default operation
1555  *  @hw: pointer to the HW structure
1556  *
1557  *  Remove the current LED configuration and set the LED configuration
1558  *  to the default value, saved from the EEPROM.
1559  **/
1560 s32 e1000e_cleanup_led_generic(struct e1000_hw *hw)
1561 {
1562 	ew32(LEDCTL, hw->mac.ledctl_default);
1563 	return 0;
1564 }
1565 
1566 /**
1567  *  e1000e_blink_led_generic - Blink LED
1568  *  @hw: pointer to the HW structure
1569  *
1570  *  Blink the LEDs which are set to be on.
1571  **/
1572 s32 e1000e_blink_led_generic(struct e1000_hw *hw)
1573 {
1574 	u32 ledctl_blink = 0;
1575 	u32 i;
1576 
1577 	if (hw->phy.media_type == e1000_media_type_fiber) {
1578 		/* always blink LED0 for PCI-E fiber */
1579 		ledctl_blink = E1000_LEDCTL_LED0_BLINK |
1580 		    (E1000_LEDCTL_MODE_LED_ON << E1000_LEDCTL_LED0_MODE_SHIFT);
1581 	} else {
1582 		/* Set the blink bit for each LED that's "on" (0x0E)
1583 		 * (or "off" if inverted) in ledctl_mode2.  The blink
1584 		 * logic in hardware only works when mode is set to "on"
1585 		 * so it must be changed accordingly when the mode is
1586 		 * "off" and inverted.
1587 		 */
1588 		ledctl_blink = hw->mac.ledctl_mode2;
1589 		for (i = 0; i < 32; i += 8) {
1590 			u32 mode = (hw->mac.ledctl_mode2 >> i) &
1591 			    E1000_LEDCTL_LED0_MODE_MASK;
1592 			u32 led_default = hw->mac.ledctl_default >> i;
1593 
1594 			if ((!(led_default & E1000_LEDCTL_LED0_IVRT) &&
1595 			     (mode == E1000_LEDCTL_MODE_LED_ON)) ||
1596 			    ((led_default & E1000_LEDCTL_LED0_IVRT) &&
1597 			     (mode == E1000_LEDCTL_MODE_LED_OFF))) {
1598 				ledctl_blink &=
1599 				    ~(E1000_LEDCTL_LED0_MODE_MASK << i);
1600 				ledctl_blink |= (E1000_LEDCTL_LED0_BLINK |
1601 						 E1000_LEDCTL_MODE_LED_ON) << i;
1602 			}
1603 		}
1604 	}
1605 
1606 	ew32(LEDCTL, ledctl_blink);
1607 
1608 	return 0;
1609 }
1610 
1611 /**
1612  *  e1000e_led_on_generic - Turn LED on
1613  *  @hw: pointer to the HW structure
1614  *
1615  *  Turn LED on.
1616  **/
1617 s32 e1000e_led_on_generic(struct e1000_hw *hw)
1618 {
1619 	u32 ctrl;
1620 
1621 	switch (hw->phy.media_type) {
1622 	case e1000_media_type_fiber:
1623 		ctrl = er32(CTRL);
1624 		ctrl &= ~E1000_CTRL_SWDPIN0;
1625 		ctrl |= E1000_CTRL_SWDPIO0;
1626 		ew32(CTRL, ctrl);
1627 		break;
1628 	case e1000_media_type_copper:
1629 		ew32(LEDCTL, hw->mac.ledctl_mode2);
1630 		break;
1631 	default:
1632 		break;
1633 	}
1634 
1635 	return 0;
1636 }
1637 
1638 /**
1639  *  e1000e_led_off_generic - Turn LED off
1640  *  @hw: pointer to the HW structure
1641  *
1642  *  Turn LED off.
1643  **/
1644 s32 e1000e_led_off_generic(struct e1000_hw *hw)
1645 {
1646 	u32 ctrl;
1647 
1648 	switch (hw->phy.media_type) {
1649 	case e1000_media_type_fiber:
1650 		ctrl = er32(CTRL);
1651 		ctrl |= E1000_CTRL_SWDPIN0;
1652 		ctrl |= E1000_CTRL_SWDPIO0;
1653 		ew32(CTRL, ctrl);
1654 		break;
1655 	case e1000_media_type_copper:
1656 		ew32(LEDCTL, hw->mac.ledctl_mode1);
1657 		break;
1658 	default:
1659 		break;
1660 	}
1661 
1662 	return 0;
1663 }
1664 
1665 /**
1666  *  e1000e_set_pcie_no_snoop - Set PCI-express capabilities
1667  *  @hw: pointer to the HW structure
1668  *  @no_snoop: bitmap of snoop events
1669  *
1670  *  Set the PCI-express register to snoop for events enabled in 'no_snoop'.
1671  **/
1672 void e1000e_set_pcie_no_snoop(struct e1000_hw *hw, u32 no_snoop)
1673 {
1674 	u32 gcr;
1675 
1676 	if (no_snoop) {
1677 		gcr = er32(GCR);
1678 		gcr &= ~(PCIE_NO_SNOOP_ALL);
1679 		gcr |= no_snoop;
1680 		ew32(GCR, gcr);
1681 	}
1682 }
1683 
1684 /**
1685  *  e1000e_disable_pcie_master - Disables PCI-express master access
1686  *  @hw: pointer to the HW structure
1687  *
1688  *  Returns 0 if successful, else returns -10
1689  *  (-E1000_ERR_MASTER_REQUESTS_PENDING) if master disable bit has not caused
1690  *  the master requests to be disabled.
1691  *
1692  *  Disables PCI-Express master access and verifies there are no pending
1693  *  requests.
1694  **/
1695 s32 e1000e_disable_pcie_master(struct e1000_hw *hw)
1696 {
1697 	u32 ctrl;
1698 	s32 timeout = MASTER_DISABLE_TIMEOUT;
1699 
1700 	ctrl = er32(CTRL);
1701 	ctrl |= E1000_CTRL_GIO_MASTER_DISABLE;
1702 	ew32(CTRL, ctrl);
1703 
1704 	while (timeout) {
1705 		if (!(er32(STATUS) & E1000_STATUS_GIO_MASTER_ENABLE))
1706 			break;
1707 		usleep_range(100, 200);
1708 		timeout--;
1709 	}
1710 
1711 	if (!timeout) {
1712 		e_dbg("Master requests are pending.\n");
1713 		return -E1000_ERR_MASTER_REQUESTS_PENDING;
1714 	}
1715 
1716 	return 0;
1717 }
1718 
1719 /**
1720  *  e1000e_reset_adaptive - Reset Adaptive Interframe Spacing
1721  *  @hw: pointer to the HW structure
1722  *
1723  *  Reset the Adaptive Interframe Spacing throttle to default values.
1724  **/
1725 void e1000e_reset_adaptive(struct e1000_hw *hw)
1726 {
1727 	struct e1000_mac_info *mac = &hw->mac;
1728 
1729 	if (!mac->adaptive_ifs) {
1730 		e_dbg("Not in Adaptive IFS mode!\n");
1731 		return;
1732 	}
1733 
1734 	mac->current_ifs_val = 0;
1735 	mac->ifs_min_val = IFS_MIN;
1736 	mac->ifs_max_val = IFS_MAX;
1737 	mac->ifs_step_size = IFS_STEP;
1738 	mac->ifs_ratio = IFS_RATIO;
1739 
1740 	mac->in_ifs_mode = false;
1741 	ew32(AIT, 0);
1742 }
1743 
1744 /**
1745  *  e1000e_update_adaptive - Update Adaptive Interframe Spacing
1746  *  @hw: pointer to the HW structure
1747  *
1748  *  Update the Adaptive Interframe Spacing Throttle value based on the
1749  *  time between transmitted packets and time between collisions.
1750  **/
1751 void e1000e_update_adaptive(struct e1000_hw *hw)
1752 {
1753 	struct e1000_mac_info *mac = &hw->mac;
1754 
1755 	if (!mac->adaptive_ifs) {
1756 		e_dbg("Not in Adaptive IFS mode!\n");
1757 		return;
1758 	}
1759 
1760 	if ((mac->collision_delta * mac->ifs_ratio) > mac->tx_packet_delta) {
1761 		if (mac->tx_packet_delta > MIN_NUM_XMITS) {
1762 			mac->in_ifs_mode = true;
1763 			if (mac->current_ifs_val < mac->ifs_max_val) {
1764 				if (!mac->current_ifs_val)
1765 					mac->current_ifs_val = mac->ifs_min_val;
1766 				else
1767 					mac->current_ifs_val +=
1768 					    mac->ifs_step_size;
1769 				ew32(AIT, mac->current_ifs_val);
1770 			}
1771 		}
1772 	} else {
1773 		if (mac->in_ifs_mode &&
1774 		    (mac->tx_packet_delta <= MIN_NUM_XMITS)) {
1775 			mac->current_ifs_val = 0;
1776 			mac->in_ifs_mode = false;
1777 			ew32(AIT, 0);
1778 		}
1779 	}
1780 }
1781