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