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