1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 1999 - 2018 Intel Corporation. */
3 
4 #include "ixgbe.h"
5 #include <linux/ptp_classify.h>
6 #include <linux/clocksource.h>
7 
8 /*
9  * The 82599 and the X540 do not have true 64bit nanosecond scale
10  * counter registers. Instead, SYSTIME is defined by a fixed point
11  * system which allows the user to define the scale counter increment
12  * value at every level change of the oscillator driving the SYSTIME
13  * value. For both devices the TIMINCA:IV field defines this
14  * increment. On the X540 device, 31 bits are provided. However on the
15  * 82599 only provides 24 bits. The time unit is determined by the
16  * clock frequency of the oscillator in combination with the TIMINCA
17  * register. When these devices link at 10Gb the oscillator has a
18  * period of 6.4ns. In order to convert the scale counter into
19  * nanoseconds the cyclecounter and timecounter structures are
20  * used. The SYSTIME registers need to be converted to ns values by use
21  * of only a right shift (division by power of 2). The following math
22  * determines the largest incvalue that will fit into the available
23  * bits in the TIMINCA register.
24  *
25  * PeriodWidth: Number of bits to store the clock period
26  * MaxWidth: The maximum width value of the TIMINCA register
27  * Period: The clock period for the oscillator
28  * round(): discard the fractional portion of the calculation
29  *
30  * Period * [ 2 ^ ( MaxWidth - PeriodWidth ) ]
31  *
32  * For the X540, MaxWidth is 31 bits, and the base period is 6.4 ns
33  * For the 82599, MaxWidth is 24 bits, and the base period is 6.4 ns
34  *
35  * The period also changes based on the link speed:
36  * At 10Gb link or no link, the period remains the same.
37  * At 1Gb link, the period is multiplied by 10. (64ns)
38  * At 100Mb link, the period is multiplied by 100. (640ns)
39  *
40  * The calculated value allows us to right shift the SYSTIME register
41  * value in order to quickly convert it into a nanosecond clock,
42  * while allowing for the maximum possible adjustment value.
43  *
44  * These diagrams are only for the 10Gb link period
45  *
46  *           SYSTIMEH            SYSTIMEL
47  *       +--------------+  +--------------+
48  * X540  |      32      |  | 1 | 3 |  28  |
49  *       *--------------+  +--------------+
50  *        \________ 36 bits ______/  fract
51  *
52  *       +--------------+  +--------------+
53  * 82599 |      32      |  | 8 | 3 |  21  |
54  *       *--------------+  +--------------+
55  *        \________ 43 bits ______/  fract
56  *
57  * The 36 bit X540 SYSTIME overflows every
58  *   2^36 * 10^-9 / 60 = 1.14 minutes or 69 seconds
59  *
60  * The 43 bit 82599 SYSTIME overflows every
61  *   2^43 * 10^-9 / 3600 = 2.4 hours
62  */
63 #define IXGBE_INCVAL_10GB 0x66666666
64 #define IXGBE_INCVAL_1GB  0x40000000
65 #define IXGBE_INCVAL_100  0x50000000
66 
67 #define IXGBE_INCVAL_SHIFT_10GB  28
68 #define IXGBE_INCVAL_SHIFT_1GB   24
69 #define IXGBE_INCVAL_SHIFT_100   21
70 
71 #define IXGBE_INCVAL_SHIFT_82599 7
72 #define IXGBE_INCPER_SHIFT_82599 24
73 
74 #define IXGBE_OVERFLOW_PERIOD    (HZ * 30)
75 #define IXGBE_PTP_TX_TIMEOUT     (HZ * 15)
76 
77 /* half of a one second clock period, for use with PPS signal. We have to use
78  * this instead of something pre-defined like IXGBE_PTP_PPS_HALF_SECOND, in
79  * order to force at least 64bits of precision for shifting
80  */
81 #define IXGBE_PTP_PPS_HALF_SECOND 500000000ULL
82 
83 /* In contrast, the X550 controller has two registers, SYSTIMEH and SYSTIMEL
84  * which contain measurements of seconds and nanoseconds respectively. This
85  * matches the standard linux representation of time in the kernel. In addition,
86  * the X550 also has a SYSTIMER register which represents residue, or
87  * subnanosecond overflow adjustments. To control clock adjustment, the TIMINCA
88  * register is used, but it is unlike the X540 and 82599 devices. TIMINCA
89  * represents units of 2^-32 nanoseconds, and uses 31 bits for this, with the
90  * high bit representing whether the adjustent is positive or negative. Every
91  * clock cycle, the X550 will add 12.5 ns + TIMINCA which can result in a range
92  * of 12 to 13 nanoseconds adjustment. Unlike the 82599 and X540 devices, the
93  * X550's clock for purposes of SYSTIME generation is constant and not dependent
94  * on the link speed.
95  *
96  *           SYSTIMEH           SYSTIMEL        SYSTIMER
97  *       +--------------+  +--------------+  +-------------+
98  * X550  |      32      |  |      32      |  |     32      |
99  *       *--------------+  +--------------+  +-------------+
100  *       \____seconds___/   \_nanoseconds_/  \__2^-32 ns__/
101  *
102  * This results in a full 96 bits to represent the clock, with 32 bits for
103  * seconds, 32 bits for nanoseconds (largest value is 0d999999999 or just under
104  * 1 second) and an additional 32 bits to measure sub nanosecond adjustments for
105  * underflow of adjustments.
106  *
107  * The 32 bits of seconds for the X550 overflows every
108  *   2^32 / ( 365.25 * 24 * 60 * 60 ) = ~136 years.
109  *
110  * In order to adjust the clock frequency for the X550, the TIMINCA register is
111  * provided. This register represents a + or minus nearly 0.5 ns adjustment to
112  * the base frequency. It is measured in 2^-32 ns units, with the high bit being
113  * the sign bit. This register enables software to calculate frequency
114  * adjustments and apply them directly to the clock rate.
115  *
116  * The math for converting ppb into TIMINCA values is fairly straightforward.
117  *   TIMINCA value = ( Base_Frequency * ppb ) / 1000000000ULL
118  *
119  * This assumes that ppb is never high enough to create a value bigger than
120  * TIMINCA's 31 bits can store. This is ensured by the stack. Calculating this
121  * value is also simple.
122  *   Max ppb = ( Max Adjustment / Base Frequency ) / 1000000000ULL
123  *
124  * For the X550, the Max adjustment is +/- 0.5 ns, and the base frequency is
125  * 12.5 nanoseconds. This means that the Max ppb is 39999999
126  *   Note: We subtract one in order to ensure no overflow, because the TIMINCA
127  *         register can only hold slightly under 0.5 nanoseconds.
128  *
129  * Because TIMINCA is measured in 2^-32 ns units, we have to convert 12.5 ns
130  * into 2^-32 units, which is
131  *
132  *  12.5 * 2^32 = C80000000
133  *
134  * Some revisions of hardware have a faster base frequency than the registers
135  * were defined for. To fix this, we use a timecounter structure with the
136  * proper mult and shift to convert the cycles into nanoseconds of time.
137  */
138 #define IXGBE_X550_BASE_PERIOD 0xC80000000ULL
139 #define INCVALUE_MASK	0x7FFFFFFF
140 #define ISGN		0x80000000
141 #define MAX_TIMADJ	0x7FFFFFFF
142 
143 /**
144  * ixgbe_ptp_setup_sdp_x540
145  * @adapter: private adapter structure
146  *
147  * this function enables or disables the clock out feature on SDP0 for
148  * the X540 device. It will create a 1second periodic output that can
149  * be used as the PPS (via an interrupt).
150  *
151  * It calculates when the systime will be on an exact second, and then
152  * aligns the start of the PPS signal to that value. The shift is
153  * necessary because it can change based on the link speed.
154  */
155 static void ixgbe_ptp_setup_sdp_x540(struct ixgbe_adapter *adapter)
156 {
157 	struct ixgbe_hw *hw = &adapter->hw;
158 	int shift = adapter->hw_cc.shift;
159 	u32 esdp, tsauxc, clktiml, clktimh, trgttiml, trgttimh, rem;
160 	u64 ns = 0, clock_edge = 0;
161 
162 	/* disable the pin first */
163 	IXGBE_WRITE_REG(hw, IXGBE_TSAUXC, 0x0);
164 	IXGBE_WRITE_FLUSH(hw);
165 
166 	if (!(adapter->flags2 & IXGBE_FLAG2_PTP_PPS_ENABLED))
167 		return;
168 
169 	esdp = IXGBE_READ_REG(hw, IXGBE_ESDP);
170 
171 	/* enable the SDP0 pin as output, and connected to the
172 	 * native function for Timesync (ClockOut)
173 	 */
174 	esdp |= IXGBE_ESDP_SDP0_DIR |
175 		IXGBE_ESDP_SDP0_NATIVE;
176 
177 	/* enable the Clock Out feature on SDP0, and allow
178 	 * interrupts to occur when the pin changes
179 	 */
180 	tsauxc = IXGBE_TSAUXC_EN_CLK |
181 		 IXGBE_TSAUXC_SYNCLK |
182 		 IXGBE_TSAUXC_SDP0_INT;
183 
184 	/* clock period (or pulse length) */
185 	clktiml = (u32)(IXGBE_PTP_PPS_HALF_SECOND << shift);
186 	clktimh = (u32)((IXGBE_PTP_PPS_HALF_SECOND << shift) >> 32);
187 
188 	/* Account for the cyclecounter wrap-around value by
189 	 * using the converted ns value of the current time to
190 	 * check for when the next aligned second would occur.
191 	 */
192 	clock_edge |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIML);
193 	clock_edge |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIMH) << 32;
194 	ns = timecounter_cyc2time(&adapter->hw_tc, clock_edge);
195 
196 	div_u64_rem(ns, IXGBE_PTP_PPS_HALF_SECOND, &rem);
197 	clock_edge += ((IXGBE_PTP_PPS_HALF_SECOND - (u64)rem) << shift);
198 
199 	/* specify the initial clock start time */
200 	trgttiml = (u32)clock_edge;
201 	trgttimh = (u32)(clock_edge >> 32);
202 
203 	IXGBE_WRITE_REG(hw, IXGBE_CLKTIML, clktiml);
204 	IXGBE_WRITE_REG(hw, IXGBE_CLKTIMH, clktimh);
205 	IXGBE_WRITE_REG(hw, IXGBE_TRGTTIML0, trgttiml);
206 	IXGBE_WRITE_REG(hw, IXGBE_TRGTTIMH0, trgttimh);
207 
208 	IXGBE_WRITE_REG(hw, IXGBE_ESDP, esdp);
209 	IXGBE_WRITE_REG(hw, IXGBE_TSAUXC, tsauxc);
210 
211 	IXGBE_WRITE_FLUSH(hw);
212 }
213 
214 /**
215  * ixgbe_ptp_read_X550 - read cycle counter value
216  * @hw_cc: cyclecounter structure
217  *
218  * This function reads SYSTIME registers. It is called by the cyclecounter
219  * structure to convert from internal representation into nanoseconds. We need
220  * this for X550 since some skews do not have expected clock frequency and
221  * result of SYSTIME is 32bits of "billions of cycles" and 32 bits of
222  * "cycles", rather than seconds and nanoseconds.
223  */
224 static u64 ixgbe_ptp_read_X550(const struct cyclecounter *hw_cc)
225 {
226 	struct ixgbe_adapter *adapter =
227 			container_of(hw_cc, struct ixgbe_adapter, hw_cc);
228 	struct ixgbe_hw *hw = &adapter->hw;
229 	struct timespec64 ts;
230 
231 	/* storage is 32 bits of 'billions of cycles' and 32 bits of 'cycles'.
232 	 * Some revisions of hardware run at a higher frequency and so the
233 	 * cycles are not guaranteed to be nanoseconds. The timespec64 created
234 	 * here is used for its math/conversions but does not necessarily
235 	 * represent nominal time.
236 	 *
237 	 * It should be noted that this cyclecounter will overflow at a
238 	 * non-bitmask field since we have to convert our billions of cycles
239 	 * into an actual cycles count. This results in some possible weird
240 	 * situations at high cycle counter stamps. However given that 32 bits
241 	 * of "seconds" is ~138 years this isn't a problem. Even at the
242 	 * increased frequency of some revisions, this is still ~103 years.
243 	 * Since the SYSTIME values start at 0 and we never write them, it is
244 	 * highly unlikely for the cyclecounter to overflow in practice.
245 	 */
246 	IXGBE_READ_REG(hw, IXGBE_SYSTIMR);
247 	ts.tv_nsec = IXGBE_READ_REG(hw, IXGBE_SYSTIML);
248 	ts.tv_sec = IXGBE_READ_REG(hw, IXGBE_SYSTIMH);
249 
250 	return (u64)timespec64_to_ns(&ts);
251 }
252 
253 /**
254  * ixgbe_ptp_read_82599 - read raw cycle counter (to be used by time counter)
255  * @cc: the cyclecounter structure
256  *
257  * this function reads the cyclecounter registers and is called by the
258  * cyclecounter structure used to construct a ns counter from the
259  * arbitrary fixed point registers
260  */
261 static u64 ixgbe_ptp_read_82599(const struct cyclecounter *cc)
262 {
263 	struct ixgbe_adapter *adapter =
264 		container_of(cc, struct ixgbe_adapter, hw_cc);
265 	struct ixgbe_hw *hw = &adapter->hw;
266 	u64 stamp = 0;
267 
268 	stamp |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIML);
269 	stamp |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIMH) << 32;
270 
271 	return stamp;
272 }
273 
274 /**
275  * ixgbe_ptp_convert_to_hwtstamp - convert register value to hw timestamp
276  * @adapter: private adapter structure
277  * @hwtstamp: stack timestamp structure
278  * @timestamp: unsigned 64bit system time value
279  *
280  * We need to convert the adapter's RX/TXSTMP registers into a hwtstamp value
281  * which can be used by the stack's ptp functions.
282  *
283  * The lock is used to protect consistency of the cyclecounter and the SYSTIME
284  * registers. However, it does not need to protect against the Rx or Tx
285  * timestamp registers, as there can't be a new timestamp until the old one is
286  * unlatched by reading.
287  *
288  * In addition to the timestamp in hardware, some controllers need a software
289  * overflow cyclecounter, and this function takes this into account as well.
290  **/
291 static void ixgbe_ptp_convert_to_hwtstamp(struct ixgbe_adapter *adapter,
292 					  struct skb_shared_hwtstamps *hwtstamp,
293 					  u64 timestamp)
294 {
295 	unsigned long flags;
296 	struct timespec64 systime;
297 	u64 ns;
298 
299 	memset(hwtstamp, 0, sizeof(*hwtstamp));
300 
301 	switch (adapter->hw.mac.type) {
302 	/* X550 and later hardware supposedly represent time using a seconds
303 	 * and nanoseconds counter, instead of raw 64bits nanoseconds. We need
304 	 * to convert the timestamp into cycles before it can be fed to the
305 	 * cyclecounter. We need an actual cyclecounter because some revisions
306 	 * of hardware run at a higher frequency and thus the counter does
307 	 * not represent seconds/nanoseconds. Instead it can be thought of as
308 	 * cycles and billions of cycles.
309 	 */
310 	case ixgbe_mac_X550:
311 	case ixgbe_mac_X550EM_x:
312 	case ixgbe_mac_x550em_a:
313 		/* Upper 32 bits represent billions of cycles, lower 32 bits
314 		 * represent cycles. However, we use timespec64_to_ns for the
315 		 * correct math even though the units haven't been corrected
316 		 * yet.
317 		 */
318 		systime.tv_sec = timestamp >> 32;
319 		systime.tv_nsec = timestamp & 0xFFFFFFFF;
320 
321 		timestamp = timespec64_to_ns(&systime);
322 		break;
323 	default:
324 		break;
325 	}
326 
327 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
328 	ns = timecounter_cyc2time(&adapter->hw_tc, timestamp);
329 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
330 
331 	hwtstamp->hwtstamp = ns_to_ktime(ns);
332 }
333 
334 /**
335  * ixgbe_ptp_adjfreq_82599
336  * @ptp: the ptp clock structure
337  * @ppb: parts per billion adjustment from base
338  *
339  * adjust the frequency of the ptp cycle counter by the
340  * indicated ppb from the base frequency.
341  */
342 static int ixgbe_ptp_adjfreq_82599(struct ptp_clock_info *ptp, s32 ppb)
343 {
344 	struct ixgbe_adapter *adapter =
345 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
346 	struct ixgbe_hw *hw = &adapter->hw;
347 	u64 freq, incval;
348 	u32 diff;
349 	int neg_adj = 0;
350 
351 	if (ppb < 0) {
352 		neg_adj = 1;
353 		ppb = -ppb;
354 	}
355 
356 	smp_mb();
357 	incval = READ_ONCE(adapter->base_incval);
358 
359 	freq = incval;
360 	freq *= ppb;
361 	diff = div_u64(freq, 1000000000ULL);
362 
363 	incval = neg_adj ? (incval - diff) : (incval + diff);
364 
365 	switch (hw->mac.type) {
366 	case ixgbe_mac_X540:
367 		if (incval > 0xFFFFFFFFULL)
368 			e_dev_warn("PTP ppb adjusted SYSTIME rate overflowed!\n");
369 		IXGBE_WRITE_REG(hw, IXGBE_TIMINCA, (u32)incval);
370 		break;
371 	case ixgbe_mac_82599EB:
372 		if (incval > 0x00FFFFFFULL)
373 			e_dev_warn("PTP ppb adjusted SYSTIME rate overflowed!\n");
374 		IXGBE_WRITE_REG(hw, IXGBE_TIMINCA,
375 				BIT(IXGBE_INCPER_SHIFT_82599) |
376 				((u32)incval & 0x00FFFFFFUL));
377 		break;
378 	default:
379 		break;
380 	}
381 
382 	return 0;
383 }
384 
385 /**
386  * ixgbe_ptp_adjfreq_X550
387  * @ptp: the ptp clock structure
388  * @ppb: parts per billion adjustment from base
389  *
390  * adjust the frequency of the SYSTIME registers by the indicated ppb from base
391  * frequency
392  */
393 static int ixgbe_ptp_adjfreq_X550(struct ptp_clock_info *ptp, s32 ppb)
394 {
395 	struct ixgbe_adapter *adapter =
396 			container_of(ptp, struct ixgbe_adapter, ptp_caps);
397 	struct ixgbe_hw *hw = &adapter->hw;
398 	int neg_adj = 0;
399 	u64 rate = IXGBE_X550_BASE_PERIOD;
400 	u32 inca;
401 
402 	if (ppb < 0) {
403 		neg_adj = 1;
404 		ppb = -ppb;
405 	}
406 	rate *= ppb;
407 	rate = div_u64(rate, 1000000000ULL);
408 
409 	/* warn if rate is too large */
410 	if (rate >= INCVALUE_MASK)
411 		e_dev_warn("PTP ppb adjusted SYSTIME rate overflowed!\n");
412 
413 	inca = rate & INCVALUE_MASK;
414 	if (neg_adj)
415 		inca |= ISGN;
416 
417 	IXGBE_WRITE_REG(hw, IXGBE_TIMINCA, inca);
418 
419 	return 0;
420 }
421 
422 /**
423  * ixgbe_ptp_adjtime
424  * @ptp: the ptp clock structure
425  * @delta: offset to adjust the cycle counter by
426  *
427  * adjust the timer by resetting the timecounter structure.
428  */
429 static int ixgbe_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
430 {
431 	struct ixgbe_adapter *adapter =
432 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
433 	unsigned long flags;
434 
435 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
436 	timecounter_adjtime(&adapter->hw_tc, delta);
437 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
438 
439 	if (adapter->ptp_setup_sdp)
440 		adapter->ptp_setup_sdp(adapter);
441 
442 	return 0;
443 }
444 
445 /**
446  * ixgbe_ptp_gettime
447  * @ptp: the ptp clock structure
448  * @ts: timespec structure to hold the current time value
449  *
450  * read the timecounter and return the correct value on ns,
451  * after converting it into a struct timespec.
452  */
453 static int ixgbe_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
454 {
455 	struct ixgbe_adapter *adapter =
456 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
457 	unsigned long flags;
458 	u64 ns;
459 
460 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
461 	ns = timecounter_read(&adapter->hw_tc);
462 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
463 
464 	*ts = ns_to_timespec64(ns);
465 
466 	return 0;
467 }
468 
469 /**
470  * ixgbe_ptp_settime
471  * @ptp: the ptp clock structure
472  * @ts: the timespec containing the new time for the cycle counter
473  *
474  * reset the timecounter to use a new base value instead of the kernel
475  * wall timer value.
476  */
477 static int ixgbe_ptp_settime(struct ptp_clock_info *ptp,
478 			     const struct timespec64 *ts)
479 {
480 	struct ixgbe_adapter *adapter =
481 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
482 	unsigned long flags;
483 	u64 ns = timespec64_to_ns(ts);
484 
485 	/* reset the timecounter */
486 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
487 	timecounter_init(&adapter->hw_tc, &adapter->hw_cc, ns);
488 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
489 
490 	if (adapter->ptp_setup_sdp)
491 		adapter->ptp_setup_sdp(adapter);
492 	return 0;
493 }
494 
495 /**
496  * ixgbe_ptp_feature_enable
497  * @ptp: the ptp clock structure
498  * @rq: the requested feature to change
499  * @on: whether to enable or disable the feature
500  *
501  * enable (or disable) ancillary features of the phc subsystem.
502  * our driver only supports the PPS feature on the X540
503  */
504 static int ixgbe_ptp_feature_enable(struct ptp_clock_info *ptp,
505 				    struct ptp_clock_request *rq, int on)
506 {
507 	struct ixgbe_adapter *adapter =
508 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
509 
510 	/**
511 	 * When PPS is enabled, unmask the interrupt for the ClockOut
512 	 * feature, so that the interrupt handler can send the PPS
513 	 * event when the clock SDP triggers. Clear mask when PPS is
514 	 * disabled
515 	 */
516 	if (rq->type != PTP_CLK_REQ_PPS || !adapter->ptp_setup_sdp)
517 		return -ENOTSUPP;
518 
519 	if (on)
520 		adapter->flags2 |= IXGBE_FLAG2_PTP_PPS_ENABLED;
521 	else
522 		adapter->flags2 &= ~IXGBE_FLAG2_PTP_PPS_ENABLED;
523 
524 	adapter->ptp_setup_sdp(adapter);
525 	return 0;
526 }
527 
528 /**
529  * ixgbe_ptp_check_pps_event
530  * @adapter: the private adapter structure
531  *
532  * This function is called by the interrupt routine when checking for
533  * interrupts. It will check and handle a pps event.
534  */
535 void ixgbe_ptp_check_pps_event(struct ixgbe_adapter *adapter)
536 {
537 	struct ixgbe_hw *hw = &adapter->hw;
538 	struct ptp_clock_event event;
539 
540 	event.type = PTP_CLOCK_PPS;
541 
542 	/* this check is necessary in case the interrupt was enabled via some
543 	 * alternative means (ex. debug_fs). Better to check here than
544 	 * everywhere that calls this function.
545 	 */
546 	if (!adapter->ptp_clock)
547 		return;
548 
549 	switch (hw->mac.type) {
550 	case ixgbe_mac_X540:
551 		ptp_clock_event(adapter->ptp_clock, &event);
552 		break;
553 	default:
554 		break;
555 	}
556 }
557 
558 /**
559  * ixgbe_ptp_overflow_check - watchdog task to detect SYSTIME overflow
560  * @adapter: private adapter struct
561  *
562  * this watchdog task periodically reads the timecounter
563  * in order to prevent missing when the system time registers wrap
564  * around. This needs to be run approximately twice a minute.
565  */
566 void ixgbe_ptp_overflow_check(struct ixgbe_adapter *adapter)
567 {
568 	bool timeout = time_is_before_jiffies(adapter->last_overflow_check +
569 					     IXGBE_OVERFLOW_PERIOD);
570 	struct timespec64 ts;
571 
572 	if (timeout) {
573 		ixgbe_ptp_gettime(&adapter->ptp_caps, &ts);
574 		adapter->last_overflow_check = jiffies;
575 	}
576 }
577 
578 /**
579  * ixgbe_ptp_rx_hang - detect error case when Rx timestamp registers latched
580  * @adapter: private network adapter structure
581  *
582  * this watchdog task is scheduled to detect error case where hardware has
583  * dropped an Rx packet that was timestamped when the ring is full. The
584  * particular error is rare but leaves the device in a state unable to timestamp
585  * any future packets.
586  */
587 void ixgbe_ptp_rx_hang(struct ixgbe_adapter *adapter)
588 {
589 	struct ixgbe_hw *hw = &adapter->hw;
590 	u32 tsyncrxctl = IXGBE_READ_REG(hw, IXGBE_TSYNCRXCTL);
591 	struct ixgbe_ring *rx_ring;
592 	unsigned long rx_event;
593 	int n;
594 
595 	/* if we don't have a valid timestamp in the registers, just update the
596 	 * timeout counter and exit
597 	 */
598 	if (!(tsyncrxctl & IXGBE_TSYNCRXCTL_VALID)) {
599 		adapter->last_rx_ptp_check = jiffies;
600 		return;
601 	}
602 
603 	/* determine the most recent watchdog or rx_timestamp event */
604 	rx_event = adapter->last_rx_ptp_check;
605 	for (n = 0; n < adapter->num_rx_queues; n++) {
606 		rx_ring = adapter->rx_ring[n];
607 		if (time_after(rx_ring->last_rx_timestamp, rx_event))
608 			rx_event = rx_ring->last_rx_timestamp;
609 	}
610 
611 	/* only need to read the high RXSTMP register to clear the lock */
612 	if (time_is_before_jiffies(rx_event + 5 * HZ)) {
613 		IXGBE_READ_REG(hw, IXGBE_RXSTMPH);
614 		adapter->last_rx_ptp_check = jiffies;
615 
616 		adapter->rx_hwtstamp_cleared++;
617 		e_warn(drv, "clearing RX Timestamp hang\n");
618 	}
619 }
620 
621 /**
622  * ixgbe_ptp_clear_tx_timestamp - utility function to clear Tx timestamp state
623  * @adapter: the private adapter structure
624  *
625  * This function should be called whenever the state related to a Tx timestamp
626  * needs to be cleared. This helps ensure that all related bits are reset for
627  * the next Tx timestamp event.
628  */
629 static void ixgbe_ptp_clear_tx_timestamp(struct ixgbe_adapter *adapter)
630 {
631 	struct ixgbe_hw *hw = &adapter->hw;
632 
633 	IXGBE_READ_REG(hw, IXGBE_TXSTMPH);
634 	if (adapter->ptp_tx_skb) {
635 		dev_kfree_skb_any(adapter->ptp_tx_skb);
636 		adapter->ptp_tx_skb = NULL;
637 	}
638 	clear_bit_unlock(__IXGBE_PTP_TX_IN_PROGRESS, &adapter->state);
639 }
640 
641 /**
642  * ixgbe_ptp_tx_hang - detect error case where Tx timestamp never finishes
643  * @adapter: private network adapter structure
644  */
645 void ixgbe_ptp_tx_hang(struct ixgbe_adapter *adapter)
646 {
647 	bool timeout = time_is_before_jiffies(adapter->ptp_tx_start +
648 					      IXGBE_PTP_TX_TIMEOUT);
649 
650 	if (!adapter->ptp_tx_skb)
651 		return;
652 
653 	if (!test_bit(__IXGBE_PTP_TX_IN_PROGRESS, &adapter->state))
654 		return;
655 
656 	/* If we haven't received a timestamp within the timeout, it is
657 	 * reasonable to assume that it will never occur, so we can unlock the
658 	 * timestamp bit when this occurs.
659 	 */
660 	if (timeout) {
661 		cancel_work_sync(&adapter->ptp_tx_work);
662 		ixgbe_ptp_clear_tx_timestamp(adapter);
663 		adapter->tx_hwtstamp_timeouts++;
664 		e_warn(drv, "clearing Tx timestamp hang\n");
665 	}
666 }
667 
668 /**
669  * ixgbe_ptp_tx_hwtstamp - utility function which checks for TX time stamp
670  * @adapter: the private adapter struct
671  *
672  * if the timestamp is valid, we convert it into the timecounter ns
673  * value, then store that result into the shhwtstamps structure which
674  * is passed up the network stack
675  */
676 static void ixgbe_ptp_tx_hwtstamp(struct ixgbe_adapter *adapter)
677 {
678 	struct sk_buff *skb = adapter->ptp_tx_skb;
679 	struct ixgbe_hw *hw = &adapter->hw;
680 	struct skb_shared_hwtstamps shhwtstamps;
681 	u64 regval = 0;
682 
683 	regval |= (u64)IXGBE_READ_REG(hw, IXGBE_TXSTMPL);
684 	regval |= (u64)IXGBE_READ_REG(hw, IXGBE_TXSTMPH) << 32;
685 	ixgbe_ptp_convert_to_hwtstamp(adapter, &shhwtstamps, regval);
686 
687 	/* Handle cleanup of the ptp_tx_skb ourselves, and unlock the state
688 	 * bit prior to notifying the stack via skb_tstamp_tx(). This prevents
689 	 * well behaved applications from attempting to timestamp again prior
690 	 * to the lock bit being clear.
691 	 */
692 	adapter->ptp_tx_skb = NULL;
693 	clear_bit_unlock(__IXGBE_PTP_TX_IN_PROGRESS, &adapter->state);
694 
695 	/* Notify the stack and then free the skb after we've unlocked */
696 	skb_tstamp_tx(skb, &shhwtstamps);
697 	dev_kfree_skb_any(skb);
698 }
699 
700 /**
701  * ixgbe_ptp_tx_hwtstamp_work
702  * @work: pointer to the work struct
703  *
704  * This work item polls TSYNCTXCTL valid bit to determine when a Tx hardware
705  * timestamp has been taken for the current skb. It is necessary, because the
706  * descriptor's "done" bit does not correlate with the timestamp event.
707  */
708 static void ixgbe_ptp_tx_hwtstamp_work(struct work_struct *work)
709 {
710 	struct ixgbe_adapter *adapter = container_of(work, struct ixgbe_adapter,
711 						     ptp_tx_work);
712 	struct ixgbe_hw *hw = &adapter->hw;
713 	bool timeout = time_is_before_jiffies(adapter->ptp_tx_start +
714 					      IXGBE_PTP_TX_TIMEOUT);
715 	u32 tsynctxctl;
716 
717 	/* we have to have a valid skb to poll for a timestamp */
718 	if (!adapter->ptp_tx_skb) {
719 		ixgbe_ptp_clear_tx_timestamp(adapter);
720 		return;
721 	}
722 
723 	/* stop polling once we have a valid timestamp */
724 	tsynctxctl = IXGBE_READ_REG(hw, IXGBE_TSYNCTXCTL);
725 	if (tsynctxctl & IXGBE_TSYNCTXCTL_VALID) {
726 		ixgbe_ptp_tx_hwtstamp(adapter);
727 		return;
728 	}
729 
730 	if (timeout) {
731 		ixgbe_ptp_clear_tx_timestamp(adapter);
732 		adapter->tx_hwtstamp_timeouts++;
733 		e_warn(drv, "clearing Tx Timestamp hang\n");
734 	} else {
735 		/* reschedule to keep checking if it's not available yet */
736 		schedule_work(&adapter->ptp_tx_work);
737 	}
738 }
739 
740 /**
741  * ixgbe_ptp_rx_pktstamp - utility function to get RX time stamp from buffer
742  * @q_vector: structure containing interrupt and ring information
743  * @skb: the packet
744  *
745  * This function will be called by the Rx routine of the timestamp for this
746  * packet is stored in the buffer. The value is stored in little endian format
747  * starting at the end of the packet data.
748  */
749 void ixgbe_ptp_rx_pktstamp(struct ixgbe_q_vector *q_vector,
750 			   struct sk_buff *skb)
751 {
752 	__le64 regval;
753 
754 	/* copy the bits out of the skb, and then trim the skb length */
755 	skb_copy_bits(skb, skb->len - IXGBE_TS_HDR_LEN, &regval,
756 		      IXGBE_TS_HDR_LEN);
757 	__pskb_trim(skb, skb->len - IXGBE_TS_HDR_LEN);
758 
759 	/* The timestamp is recorded in little endian format, and is stored at
760 	 * the end of the packet.
761 	 *
762 	 * DWORD: N              N + 1      N + 2
763 	 * Field: End of Packet  SYSTIMH    SYSTIML
764 	 */
765 	ixgbe_ptp_convert_to_hwtstamp(q_vector->adapter, skb_hwtstamps(skb),
766 				      le64_to_cpu(regval));
767 }
768 
769 /**
770  * ixgbe_ptp_rx_rgtstamp - utility function which checks for RX time stamp
771  * @q_vector: structure containing interrupt and ring information
772  * @skb: particular skb to send timestamp with
773  *
774  * if the timestamp is valid, we convert it into the timecounter ns
775  * value, then store that result into the shhwtstamps structure which
776  * is passed up the network stack
777  */
778 void ixgbe_ptp_rx_rgtstamp(struct ixgbe_q_vector *q_vector,
779 			   struct sk_buff *skb)
780 {
781 	struct ixgbe_adapter *adapter;
782 	struct ixgbe_hw *hw;
783 	u64 regval = 0;
784 	u32 tsyncrxctl;
785 
786 	/* we cannot process timestamps on a ring without a q_vector */
787 	if (!q_vector || !q_vector->adapter)
788 		return;
789 
790 	adapter = q_vector->adapter;
791 	hw = &adapter->hw;
792 
793 	/* Read the tsyncrxctl register afterwards in order to prevent taking an
794 	 * I/O hit on every packet.
795 	 */
796 
797 	tsyncrxctl = IXGBE_READ_REG(hw, IXGBE_TSYNCRXCTL);
798 	if (!(tsyncrxctl & IXGBE_TSYNCRXCTL_VALID))
799 		return;
800 
801 	regval |= (u64)IXGBE_READ_REG(hw, IXGBE_RXSTMPL);
802 	regval |= (u64)IXGBE_READ_REG(hw, IXGBE_RXSTMPH) << 32;
803 
804 	ixgbe_ptp_convert_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
805 }
806 
807 int ixgbe_ptp_get_ts_config(struct ixgbe_adapter *adapter, struct ifreq *ifr)
808 {
809 	struct hwtstamp_config *config = &adapter->tstamp_config;
810 
811 	return copy_to_user(ifr->ifr_data, config,
812 			    sizeof(*config)) ? -EFAULT : 0;
813 }
814 
815 /**
816  * ixgbe_ptp_set_timestamp_mode - setup the hardware for the requested mode
817  * @adapter: the private ixgbe adapter structure
818  * @config: the hwtstamp configuration requested
819  *
820  * Outgoing time stamping can be enabled and disabled. Play nice and
821  * disable it when requested, although it shouldn't cause any overhead
822  * when no packet needs it. At most one packet in the queue may be
823  * marked for time stamping, otherwise it would be impossible to tell
824  * for sure to which packet the hardware time stamp belongs.
825  *
826  * Incoming time stamping has to be configured via the hardware
827  * filters. Not all combinations are supported, in particular event
828  * type has to be specified. Matching the kind of event packet is
829  * not supported, with the exception of "all V2 events regardless of
830  * level 2 or 4".
831  *
832  * Since hardware always timestamps Path delay packets when timestamping V2
833  * packets, regardless of the type specified in the register, only use V2
834  * Event mode. This more accurately tells the user what the hardware is going
835  * to do anyways.
836  *
837  * Note: this may modify the hwtstamp configuration towards a more general
838  * mode, if required to support the specifically requested mode.
839  */
840 static int ixgbe_ptp_set_timestamp_mode(struct ixgbe_adapter *adapter,
841 				 struct hwtstamp_config *config)
842 {
843 	struct ixgbe_hw *hw = &adapter->hw;
844 	u32 tsync_tx_ctl = IXGBE_TSYNCTXCTL_ENABLED;
845 	u32 tsync_rx_ctl = IXGBE_TSYNCRXCTL_ENABLED;
846 	u32 tsync_rx_mtrl = PTP_EV_PORT << 16;
847 	bool is_l2 = false;
848 	u32 regval;
849 
850 	/* reserved for future extensions */
851 	if (config->flags)
852 		return -EINVAL;
853 
854 	switch (config->tx_type) {
855 	case HWTSTAMP_TX_OFF:
856 		tsync_tx_ctl = 0;
857 	case HWTSTAMP_TX_ON:
858 		break;
859 	default:
860 		return -ERANGE;
861 	}
862 
863 	switch (config->rx_filter) {
864 	case HWTSTAMP_FILTER_NONE:
865 		tsync_rx_ctl = 0;
866 		tsync_rx_mtrl = 0;
867 		adapter->flags &= ~(IXGBE_FLAG_RX_HWTSTAMP_ENABLED |
868 				    IXGBE_FLAG_RX_HWTSTAMP_IN_REGISTER);
869 		break;
870 	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
871 		tsync_rx_ctl |= IXGBE_TSYNCRXCTL_TYPE_L4_V1;
872 		tsync_rx_mtrl |= IXGBE_RXMTRL_V1_SYNC_MSG;
873 		adapter->flags |= (IXGBE_FLAG_RX_HWTSTAMP_ENABLED |
874 				   IXGBE_FLAG_RX_HWTSTAMP_IN_REGISTER);
875 		break;
876 	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
877 		tsync_rx_ctl |= IXGBE_TSYNCRXCTL_TYPE_L4_V1;
878 		tsync_rx_mtrl |= IXGBE_RXMTRL_V1_DELAY_REQ_MSG;
879 		adapter->flags |= (IXGBE_FLAG_RX_HWTSTAMP_ENABLED |
880 				   IXGBE_FLAG_RX_HWTSTAMP_IN_REGISTER);
881 		break;
882 	case HWTSTAMP_FILTER_PTP_V2_EVENT:
883 	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
884 	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
885 	case HWTSTAMP_FILTER_PTP_V2_SYNC:
886 	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
887 	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
888 	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
889 	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
890 	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
891 		tsync_rx_ctl |= IXGBE_TSYNCRXCTL_TYPE_EVENT_V2;
892 		is_l2 = true;
893 		config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
894 		adapter->flags |= (IXGBE_FLAG_RX_HWTSTAMP_ENABLED |
895 				   IXGBE_FLAG_RX_HWTSTAMP_IN_REGISTER);
896 		break;
897 	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
898 	case HWTSTAMP_FILTER_NTP_ALL:
899 	case HWTSTAMP_FILTER_ALL:
900 		/* The X550 controller is capable of timestamping all packets,
901 		 * which allows it to accept any filter.
902 		 */
903 		if (hw->mac.type >= ixgbe_mac_X550) {
904 			tsync_rx_ctl |= IXGBE_TSYNCRXCTL_TYPE_ALL;
905 			config->rx_filter = HWTSTAMP_FILTER_ALL;
906 			adapter->flags |= IXGBE_FLAG_RX_HWTSTAMP_ENABLED;
907 			break;
908 		}
909 		/* fall through */
910 	default:
911 		/*
912 		 * register RXMTRL must be set in order to do V1 packets,
913 		 * therefore it is not possible to time stamp both V1 Sync and
914 		 * Delay_Req messages and hardware does not support
915 		 * timestamping all packets => return error
916 		 */
917 		adapter->flags &= ~(IXGBE_FLAG_RX_HWTSTAMP_ENABLED |
918 				    IXGBE_FLAG_RX_HWTSTAMP_IN_REGISTER);
919 		config->rx_filter = HWTSTAMP_FILTER_NONE;
920 		return -ERANGE;
921 	}
922 
923 	if (hw->mac.type == ixgbe_mac_82598EB) {
924 		adapter->flags &= ~(IXGBE_FLAG_RX_HWTSTAMP_ENABLED |
925 				    IXGBE_FLAG_RX_HWTSTAMP_IN_REGISTER);
926 		if (tsync_rx_ctl | tsync_tx_ctl)
927 			return -ERANGE;
928 		return 0;
929 	}
930 
931 	/* Per-packet timestamping only works if the filter is set to all
932 	 * packets. Since this is desired, always timestamp all packets as long
933 	 * as any Rx filter was configured.
934 	 */
935 	switch (hw->mac.type) {
936 	case ixgbe_mac_X550:
937 	case ixgbe_mac_X550EM_x:
938 	case ixgbe_mac_x550em_a:
939 		/* enable timestamping all packets only if at least some
940 		 * packets were requested. Otherwise, play nice and disable
941 		 * timestamping
942 		 */
943 		if (config->rx_filter == HWTSTAMP_FILTER_NONE)
944 			break;
945 
946 		tsync_rx_ctl = IXGBE_TSYNCRXCTL_ENABLED |
947 			       IXGBE_TSYNCRXCTL_TYPE_ALL |
948 			       IXGBE_TSYNCRXCTL_TSIP_UT_EN;
949 		config->rx_filter = HWTSTAMP_FILTER_ALL;
950 		adapter->flags |= IXGBE_FLAG_RX_HWTSTAMP_ENABLED;
951 		adapter->flags &= ~IXGBE_FLAG_RX_HWTSTAMP_IN_REGISTER;
952 		is_l2 = true;
953 		break;
954 	default:
955 		break;
956 	}
957 
958 	/* define ethertype filter for timestamping L2 packets */
959 	if (is_l2)
960 		IXGBE_WRITE_REG(hw, IXGBE_ETQF(IXGBE_ETQF_FILTER_1588),
961 				(IXGBE_ETQF_FILTER_EN | /* enable filter */
962 				 IXGBE_ETQF_1588 | /* enable timestamping */
963 				 ETH_P_1588));     /* 1588 eth protocol type */
964 	else
965 		IXGBE_WRITE_REG(hw, IXGBE_ETQF(IXGBE_ETQF_FILTER_1588), 0);
966 
967 	/* enable/disable TX */
968 	regval = IXGBE_READ_REG(hw, IXGBE_TSYNCTXCTL);
969 	regval &= ~IXGBE_TSYNCTXCTL_ENABLED;
970 	regval |= tsync_tx_ctl;
971 	IXGBE_WRITE_REG(hw, IXGBE_TSYNCTXCTL, regval);
972 
973 	/* enable/disable RX */
974 	regval = IXGBE_READ_REG(hw, IXGBE_TSYNCRXCTL);
975 	regval &= ~(IXGBE_TSYNCRXCTL_ENABLED | IXGBE_TSYNCRXCTL_TYPE_MASK);
976 	regval |= tsync_rx_ctl;
977 	IXGBE_WRITE_REG(hw, IXGBE_TSYNCRXCTL, regval);
978 
979 	/* define which PTP packets are time stamped */
980 	IXGBE_WRITE_REG(hw, IXGBE_RXMTRL, tsync_rx_mtrl);
981 
982 	IXGBE_WRITE_FLUSH(hw);
983 
984 	/* clear TX/RX time stamp registers, just to be sure */
985 	ixgbe_ptp_clear_tx_timestamp(adapter);
986 	IXGBE_READ_REG(hw, IXGBE_RXSTMPH);
987 
988 	return 0;
989 }
990 
991 /**
992  * ixgbe_ptp_set_ts_config - user entry point for timestamp mode
993  * @adapter: pointer to adapter struct
994  * @ifr: ioctl data
995  *
996  * Set hardware to requested mode. If unsupported, return an error with no
997  * changes. Otherwise, store the mode for future reference.
998  */
999 int ixgbe_ptp_set_ts_config(struct ixgbe_adapter *adapter, struct ifreq *ifr)
1000 {
1001 	struct hwtstamp_config config;
1002 	int err;
1003 
1004 	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
1005 		return -EFAULT;
1006 
1007 	err = ixgbe_ptp_set_timestamp_mode(adapter, &config);
1008 	if (err)
1009 		return err;
1010 
1011 	/* save these settings for future reference */
1012 	memcpy(&adapter->tstamp_config, &config,
1013 	       sizeof(adapter->tstamp_config));
1014 
1015 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
1016 		-EFAULT : 0;
1017 }
1018 
1019 static void ixgbe_ptp_link_speed_adjust(struct ixgbe_adapter *adapter,
1020 					u32 *shift, u32 *incval)
1021 {
1022 	/**
1023 	 * Scale the NIC cycle counter by a large factor so that
1024 	 * relatively small corrections to the frequency can be added
1025 	 * or subtracted. The drawbacks of a large factor include
1026 	 * (a) the clock register overflows more quickly, (b) the cycle
1027 	 * counter structure must be able to convert the systime value
1028 	 * to nanoseconds using only a multiplier and a right-shift,
1029 	 * and (c) the value must fit within the timinca register space
1030 	 * => math based on internal DMA clock rate and available bits
1031 	 *
1032 	 * Note that when there is no link, internal DMA clock is same as when
1033 	 * link speed is 10Gb. Set the registers correctly even when link is
1034 	 * down to preserve the clock setting
1035 	 */
1036 	switch (adapter->link_speed) {
1037 	case IXGBE_LINK_SPEED_100_FULL:
1038 		*shift = IXGBE_INCVAL_SHIFT_100;
1039 		*incval = IXGBE_INCVAL_100;
1040 		break;
1041 	case IXGBE_LINK_SPEED_1GB_FULL:
1042 		*shift = IXGBE_INCVAL_SHIFT_1GB;
1043 		*incval = IXGBE_INCVAL_1GB;
1044 		break;
1045 	case IXGBE_LINK_SPEED_10GB_FULL:
1046 	default:
1047 		*shift = IXGBE_INCVAL_SHIFT_10GB;
1048 		*incval = IXGBE_INCVAL_10GB;
1049 		break;
1050 	}
1051 }
1052 
1053 /**
1054  * ixgbe_ptp_start_cyclecounter - create the cycle counter from hw
1055  * @adapter: pointer to the adapter structure
1056  *
1057  * This function should be called to set the proper values for the TIMINCA
1058  * register and tell the cyclecounter structure what the tick rate of SYSTIME
1059  * is. It does not directly modify SYSTIME registers or the timecounter
1060  * structure. It should be called whenever a new TIMINCA value is necessary,
1061  * such as during initialization or when the link speed changes.
1062  */
1063 void ixgbe_ptp_start_cyclecounter(struct ixgbe_adapter *adapter)
1064 {
1065 	struct ixgbe_hw *hw = &adapter->hw;
1066 	struct cyclecounter cc;
1067 	unsigned long flags;
1068 	u32 incval = 0;
1069 	u32 tsauxc = 0;
1070 	u32 fuse0 = 0;
1071 
1072 	/* For some of the boards below this mask is technically incorrect.
1073 	 * The timestamp mask overflows at approximately 61bits. However the
1074 	 * particular hardware does not overflow on an even bitmask value.
1075 	 * Instead, it overflows due to conversion of upper 32bits billions of
1076 	 * cycles. Timecounters are not really intended for this purpose so
1077 	 * they do not properly function if the overflow point isn't 2^N-1.
1078 	 * However, the actual SYSTIME values in question take ~138 years to
1079 	 * overflow. In practice this means they won't actually overflow. A
1080 	 * proper fix to this problem would require modification of the
1081 	 * timecounter delta calculations.
1082 	 */
1083 	cc.mask = CLOCKSOURCE_MASK(64);
1084 	cc.mult = 1;
1085 	cc.shift = 0;
1086 
1087 	switch (hw->mac.type) {
1088 	case ixgbe_mac_X550EM_x:
1089 		/* SYSTIME assumes X550EM_x board frequency is 300Mhz, and is
1090 		 * designed to represent seconds and nanoseconds when this is
1091 		 * the case. However, some revisions of hardware have a 400Mhz
1092 		 * clock and we have to compensate for this frequency
1093 		 * variation using corrected mult and shift values.
1094 		 */
1095 		fuse0 = IXGBE_READ_REG(hw, IXGBE_FUSES0_GROUP(0));
1096 		if (!(fuse0 & IXGBE_FUSES0_300MHZ)) {
1097 			cc.mult = 3;
1098 			cc.shift = 2;
1099 		}
1100 		/* fallthrough */
1101 	case ixgbe_mac_x550em_a:
1102 	case ixgbe_mac_X550:
1103 		cc.read = ixgbe_ptp_read_X550;
1104 
1105 		/* enable SYSTIME counter */
1106 		IXGBE_WRITE_REG(hw, IXGBE_SYSTIMR, 0);
1107 		IXGBE_WRITE_REG(hw, IXGBE_SYSTIML, 0);
1108 		IXGBE_WRITE_REG(hw, IXGBE_SYSTIMH, 0);
1109 		tsauxc = IXGBE_READ_REG(hw, IXGBE_TSAUXC);
1110 		IXGBE_WRITE_REG(hw, IXGBE_TSAUXC,
1111 				tsauxc & ~IXGBE_TSAUXC_DISABLE_SYSTIME);
1112 		IXGBE_WRITE_REG(hw, IXGBE_TSIM, IXGBE_TSIM_TXTS);
1113 		IXGBE_WRITE_REG(hw, IXGBE_EIMS, IXGBE_EIMS_TIMESYNC);
1114 
1115 		IXGBE_WRITE_FLUSH(hw);
1116 		break;
1117 	case ixgbe_mac_X540:
1118 		cc.read = ixgbe_ptp_read_82599;
1119 
1120 		ixgbe_ptp_link_speed_adjust(adapter, &cc.shift, &incval);
1121 		IXGBE_WRITE_REG(hw, IXGBE_TIMINCA, incval);
1122 		break;
1123 	case ixgbe_mac_82599EB:
1124 		cc.read = ixgbe_ptp_read_82599;
1125 
1126 		ixgbe_ptp_link_speed_adjust(adapter, &cc.shift, &incval);
1127 		incval >>= IXGBE_INCVAL_SHIFT_82599;
1128 		cc.shift -= IXGBE_INCVAL_SHIFT_82599;
1129 		IXGBE_WRITE_REG(hw, IXGBE_TIMINCA,
1130 				BIT(IXGBE_INCPER_SHIFT_82599) | incval);
1131 		break;
1132 	default:
1133 		/* other devices aren't supported */
1134 		return;
1135 	}
1136 
1137 	/* update the base incval used to calculate frequency adjustment */
1138 	WRITE_ONCE(adapter->base_incval, incval);
1139 	smp_mb();
1140 
1141 	/* need lock to prevent incorrect read while modifying cyclecounter */
1142 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
1143 	memcpy(&adapter->hw_cc, &cc, sizeof(adapter->hw_cc));
1144 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
1145 }
1146 
1147 /**
1148  * ixgbe_ptp_reset
1149  * @adapter: the ixgbe private board structure
1150  *
1151  * When the MAC resets, all the hardware bits for timesync are reset. This
1152  * function is used to re-enable the device for PTP based on current settings.
1153  * We do lose the current clock time, so just reset the cyclecounter to the
1154  * system real clock time.
1155  *
1156  * This function will maintain hwtstamp_config settings, and resets the SDP
1157  * output if it was enabled.
1158  */
1159 void ixgbe_ptp_reset(struct ixgbe_adapter *adapter)
1160 {
1161 	struct ixgbe_hw *hw = &adapter->hw;
1162 	unsigned long flags;
1163 
1164 	/* reset the hardware timestamping mode */
1165 	ixgbe_ptp_set_timestamp_mode(adapter, &adapter->tstamp_config);
1166 
1167 	/* 82598 does not support PTP */
1168 	if (hw->mac.type == ixgbe_mac_82598EB)
1169 		return;
1170 
1171 	ixgbe_ptp_start_cyclecounter(adapter);
1172 
1173 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
1174 	timecounter_init(&adapter->hw_tc, &adapter->hw_cc,
1175 			 ktime_to_ns(ktime_get_real()));
1176 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
1177 
1178 	adapter->last_overflow_check = jiffies;
1179 
1180 	/* Now that the shift has been calculated and the systime
1181 	 * registers reset, (re-)enable the Clock out feature
1182 	 */
1183 	if (adapter->ptp_setup_sdp)
1184 		adapter->ptp_setup_sdp(adapter);
1185 }
1186 
1187 /**
1188  * ixgbe_ptp_create_clock
1189  * @adapter: the ixgbe private adapter structure
1190  *
1191  * This function performs setup of the user entry point function table and
1192  * initializes the PTP clock device, which is used to access the clock-like
1193  * features of the PTP core. It will be called by ixgbe_ptp_init, and may
1194  * reuse a previously initialized clock (such as during a suspend/resume
1195  * cycle).
1196  */
1197 static long ixgbe_ptp_create_clock(struct ixgbe_adapter *adapter)
1198 {
1199 	struct net_device *netdev = adapter->netdev;
1200 	long err;
1201 
1202 	/* do nothing if we already have a clock device */
1203 	if (!IS_ERR_OR_NULL(adapter->ptp_clock))
1204 		return 0;
1205 
1206 	switch (adapter->hw.mac.type) {
1207 	case ixgbe_mac_X540:
1208 		snprintf(adapter->ptp_caps.name,
1209 			 sizeof(adapter->ptp_caps.name),
1210 			 "%s", netdev->name);
1211 		adapter->ptp_caps.owner = THIS_MODULE;
1212 		adapter->ptp_caps.max_adj = 250000000;
1213 		adapter->ptp_caps.n_alarm = 0;
1214 		adapter->ptp_caps.n_ext_ts = 0;
1215 		adapter->ptp_caps.n_per_out = 0;
1216 		adapter->ptp_caps.pps = 1;
1217 		adapter->ptp_caps.adjfreq = ixgbe_ptp_adjfreq_82599;
1218 		adapter->ptp_caps.adjtime = ixgbe_ptp_adjtime;
1219 		adapter->ptp_caps.gettime64 = ixgbe_ptp_gettime;
1220 		adapter->ptp_caps.settime64 = ixgbe_ptp_settime;
1221 		adapter->ptp_caps.enable = ixgbe_ptp_feature_enable;
1222 		adapter->ptp_setup_sdp = ixgbe_ptp_setup_sdp_x540;
1223 		break;
1224 	case ixgbe_mac_82599EB:
1225 		snprintf(adapter->ptp_caps.name,
1226 			 sizeof(adapter->ptp_caps.name),
1227 			 "%s", netdev->name);
1228 		adapter->ptp_caps.owner = THIS_MODULE;
1229 		adapter->ptp_caps.max_adj = 250000000;
1230 		adapter->ptp_caps.n_alarm = 0;
1231 		adapter->ptp_caps.n_ext_ts = 0;
1232 		adapter->ptp_caps.n_per_out = 0;
1233 		adapter->ptp_caps.pps = 0;
1234 		adapter->ptp_caps.adjfreq = ixgbe_ptp_adjfreq_82599;
1235 		adapter->ptp_caps.adjtime = ixgbe_ptp_adjtime;
1236 		adapter->ptp_caps.gettime64 = ixgbe_ptp_gettime;
1237 		adapter->ptp_caps.settime64 = ixgbe_ptp_settime;
1238 		adapter->ptp_caps.enable = ixgbe_ptp_feature_enable;
1239 		break;
1240 	case ixgbe_mac_X550:
1241 	case ixgbe_mac_X550EM_x:
1242 	case ixgbe_mac_x550em_a:
1243 		snprintf(adapter->ptp_caps.name, 16, "%s", netdev->name);
1244 		adapter->ptp_caps.owner = THIS_MODULE;
1245 		adapter->ptp_caps.max_adj = 30000000;
1246 		adapter->ptp_caps.n_alarm = 0;
1247 		adapter->ptp_caps.n_ext_ts = 0;
1248 		adapter->ptp_caps.n_per_out = 0;
1249 		adapter->ptp_caps.pps = 0;
1250 		adapter->ptp_caps.adjfreq = ixgbe_ptp_adjfreq_X550;
1251 		adapter->ptp_caps.adjtime = ixgbe_ptp_adjtime;
1252 		adapter->ptp_caps.gettime64 = ixgbe_ptp_gettime;
1253 		adapter->ptp_caps.settime64 = ixgbe_ptp_settime;
1254 		adapter->ptp_caps.enable = ixgbe_ptp_feature_enable;
1255 		adapter->ptp_setup_sdp = NULL;
1256 		break;
1257 	default:
1258 		adapter->ptp_clock = NULL;
1259 		adapter->ptp_setup_sdp = NULL;
1260 		return -EOPNOTSUPP;
1261 	}
1262 
1263 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps,
1264 						&adapter->pdev->dev);
1265 	if (IS_ERR(adapter->ptp_clock)) {
1266 		err = PTR_ERR(adapter->ptp_clock);
1267 		adapter->ptp_clock = NULL;
1268 		e_dev_err("ptp_clock_register failed\n");
1269 		return err;
1270 	} else if (adapter->ptp_clock)
1271 		e_dev_info("registered PHC device on %s\n", netdev->name);
1272 
1273 	/* set default timestamp mode to disabled here. We do this in
1274 	 * create_clock instead of init, because we don't want to override the
1275 	 * previous settings during a resume cycle.
1276 	 */
1277 	adapter->tstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
1278 	adapter->tstamp_config.tx_type = HWTSTAMP_TX_OFF;
1279 
1280 	return 0;
1281 }
1282 
1283 /**
1284  * ixgbe_ptp_init
1285  * @adapter: the ixgbe private adapter structure
1286  *
1287  * This function performs the required steps for enabling PTP
1288  * support. If PTP support has already been loaded it simply calls the
1289  * cyclecounter init routine and exits.
1290  */
1291 void ixgbe_ptp_init(struct ixgbe_adapter *adapter)
1292 {
1293 	/* initialize the spin lock first since we can't control when a user
1294 	 * will call the entry functions once we have initialized the clock
1295 	 * device
1296 	 */
1297 	spin_lock_init(&adapter->tmreg_lock);
1298 
1299 	/* obtain a PTP device, or re-use an existing device */
1300 	if (ixgbe_ptp_create_clock(adapter))
1301 		return;
1302 
1303 	/* we have a clock so we can initialize work now */
1304 	INIT_WORK(&adapter->ptp_tx_work, ixgbe_ptp_tx_hwtstamp_work);
1305 
1306 	/* reset the PTP related hardware bits */
1307 	ixgbe_ptp_reset(adapter);
1308 
1309 	/* enter the IXGBE_PTP_RUNNING state */
1310 	set_bit(__IXGBE_PTP_RUNNING, &adapter->state);
1311 
1312 	return;
1313 }
1314 
1315 /**
1316  * ixgbe_ptp_suspend - stop PTP work items
1317  * @adapter: pointer to adapter struct
1318  *
1319  * this function suspends PTP activity, and prevents more PTP work from being
1320  * generated, but does not destroy the PTP clock device.
1321  */
1322 void ixgbe_ptp_suspend(struct ixgbe_adapter *adapter)
1323 {
1324 	/* Leave the IXGBE_PTP_RUNNING state. */
1325 	if (!test_and_clear_bit(__IXGBE_PTP_RUNNING, &adapter->state))
1326 		return;
1327 
1328 	adapter->flags2 &= ~IXGBE_FLAG2_PTP_PPS_ENABLED;
1329 	if (adapter->ptp_setup_sdp)
1330 		adapter->ptp_setup_sdp(adapter);
1331 
1332 	/* ensure that we cancel any pending PTP Tx work item in progress */
1333 	cancel_work_sync(&adapter->ptp_tx_work);
1334 	ixgbe_ptp_clear_tx_timestamp(adapter);
1335 }
1336 
1337 /**
1338  * ixgbe_ptp_stop - close the PTP device
1339  * @adapter: pointer to adapter struct
1340  *
1341  * completely destroy the PTP device, should only be called when the device is
1342  * being fully closed.
1343  */
1344 void ixgbe_ptp_stop(struct ixgbe_adapter *adapter)
1345 {
1346 	/* first, suspend PTP activity */
1347 	ixgbe_ptp_suspend(adapter);
1348 
1349 	/* disable the PTP clock device */
1350 	if (adapter->ptp_clock) {
1351 		ptp_clock_unregister(adapter->ptp_clock);
1352 		adapter->ptp_clock = NULL;
1353 		e_dev_info("removed PHC on %s\n",
1354 			   adapter->netdev->name);
1355 	}
1356 }
1357