1 /*******************************************************************************
2 
3   Intel 10 Gigabit PCI Express Linux driver
4   Copyright(c) 1999 - 2013 Intel Corporation.
5 
6   This program is free software; you can redistribute it and/or modify it
7   under the terms and conditions of the GNU General Public License,
8   version 2, as published by the Free Software Foundation.
9 
10   This program is distributed in the hope it will be useful, but WITHOUT
11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13   more details.
14 
15   You should have received a copy of the GNU General Public License along with
16   this program; if not, write to the Free Software Foundation, Inc.,
17   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 
19   The full GNU General Public License is included in this distribution in
20   the file called "COPYING".
21 
22   Contact Information:
23   Linux NICS <linux.nics@intel.com>
24   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
25   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
26 
27 *******************************************************************************/
28 #include "ixgbe.h"
29 #include <linux/ptp_classify.h>
30 
31 /*
32  * The 82599 and the X540 do not have true 64bit nanosecond scale
33  * counter registers. Instead, SYSTIME is defined by a fixed point
34  * system which allows the user to define the scale counter increment
35  * value at every level change of the oscillator driving the SYSTIME
36  * value. For both devices the TIMINCA:IV field defines this
37  * increment. On the X540 device, 31 bits are provided. However on the
38  * 82599 only provides 24 bits. The time unit is determined by the
39  * clock frequency of the oscillator in combination with the TIMINCA
40  * register. When these devices link at 10Gb the oscillator has a
41  * period of 6.4ns. In order to convert the scale counter into
42  * nanoseconds the cyclecounter and timecounter structures are
43  * used. The SYSTIME registers need to be converted to ns values by use
44  * of only a right shift (division by power of 2). The following math
45  * determines the largest incvalue that will fit into the available
46  * bits in the TIMINCA register.
47  *
48  * PeriodWidth: Number of bits to store the clock period
49  * MaxWidth: The maximum width value of the TIMINCA register
50  * Period: The clock period for the oscillator
51  * round(): discard the fractional portion of the calculation
52  *
53  * Period * [ 2 ^ ( MaxWidth - PeriodWidth ) ]
54  *
55  * For the X540, MaxWidth is 31 bits, and the base period is 6.4 ns
56  * For the 82599, MaxWidth is 24 bits, and the base period is 6.4 ns
57  *
58  * The period also changes based on the link speed:
59  * At 10Gb link or no link, the period remains the same.
60  * At 1Gb link, the period is multiplied by 10. (64ns)
61  * At 100Mb link, the period is multiplied by 100. (640ns)
62  *
63  * The calculated value allows us to right shift the SYSTIME register
64  * value in order to quickly convert it into a nanosecond clock,
65  * while allowing for the maximum possible adjustment value.
66  *
67  * These diagrams are only for the 10Gb link period
68  *
69  *           SYSTIMEH            SYSTIMEL
70  *       +--------------+  +--------------+
71  * X540  |      32      |  | 1 | 3 |  28  |
72  *       *--------------+  +--------------+
73  *        \________ 36 bits ______/  fract
74  *
75  *       +--------------+  +--------------+
76  * 82599 |      32      |  | 8 | 3 |  21  |
77  *       *--------------+  +--------------+
78  *        \________ 43 bits ______/  fract
79  *
80  * The 36 bit X540 SYSTIME overflows every
81  *   2^36 * 10^-9 / 60 = 1.14 minutes or 69 seconds
82  *
83  * The 43 bit 82599 SYSTIME overflows every
84  *   2^43 * 10^-9 / 3600 = 2.4 hours
85  */
86 #define IXGBE_INCVAL_10GB 0x66666666
87 #define IXGBE_INCVAL_1GB  0x40000000
88 #define IXGBE_INCVAL_100  0x50000000
89 
90 #define IXGBE_INCVAL_SHIFT_10GB  28
91 #define IXGBE_INCVAL_SHIFT_1GB   24
92 #define IXGBE_INCVAL_SHIFT_100   21
93 
94 #define IXGBE_INCVAL_SHIFT_82599 7
95 #define IXGBE_INCPER_SHIFT_82599 24
96 #define IXGBE_MAX_TIMEADJ_VALUE  0x7FFFFFFFFFFFFFFFULL
97 
98 #define IXGBE_OVERFLOW_PERIOD    (HZ * 30)
99 #define IXGBE_PTP_TX_TIMEOUT     (HZ * 15)
100 
101 /* half of a one second clock period, for use with PPS signal. We have to use
102  * this instead of something pre-defined like IXGBE_PTP_PPS_HALF_SECOND, in
103  * order to force at least 64bits of precision for shifting
104  */
105 #define IXGBE_PTP_PPS_HALF_SECOND 500000000ULL
106 
107 /**
108  * ixgbe_ptp_setup_sdp
109  * @hw: the hardware private structure
110  *
111  * this function enables or disables the clock out feature on SDP0 for
112  * the X540 device. It will create a 1second periodic output that can
113  * be used as the PPS (via an interrupt).
114  *
115  * It calculates when the systime will be on an exact second, and then
116  * aligns the start of the PPS signal to that value. The shift is
117  * necessary because it can change based on the link speed.
118  */
119 static void ixgbe_ptp_setup_sdp(struct ixgbe_adapter *adapter)
120 {
121 	struct ixgbe_hw *hw = &adapter->hw;
122 	int shift = adapter->cc.shift;
123 	u32 esdp, tsauxc, clktiml, clktimh, trgttiml, trgttimh, rem;
124 	u64 ns = 0, clock_edge = 0;
125 
126 	if ((adapter->flags2 & IXGBE_FLAG2_PTP_PPS_ENABLED) &&
127 	    (hw->mac.type == ixgbe_mac_X540)) {
128 
129 		/* disable the pin first */
130 		IXGBE_WRITE_REG(hw, IXGBE_TSAUXC, 0x0);
131 		IXGBE_WRITE_FLUSH(hw);
132 
133 		esdp = IXGBE_READ_REG(hw, IXGBE_ESDP);
134 
135 		/*
136 		 * enable the SDP0 pin as output, and connected to the
137 		 * native function for Timesync (ClockOut)
138 		 */
139 		esdp |= (IXGBE_ESDP_SDP0_DIR |
140 			 IXGBE_ESDP_SDP0_NATIVE);
141 
142 		/*
143 		 * enable the Clock Out feature on SDP0, and allow
144 		 * interrupts to occur when the pin changes
145 		 */
146 		tsauxc = (IXGBE_TSAUXC_EN_CLK |
147 			  IXGBE_TSAUXC_SYNCLK |
148 			  IXGBE_TSAUXC_SDP0_INT);
149 
150 		/* clock period (or pulse length) */
151 		clktiml = (u32)(IXGBE_PTP_PPS_HALF_SECOND << shift);
152 		clktimh = (u32)((IXGBE_PTP_PPS_HALF_SECOND << shift) >> 32);
153 
154 		/*
155 		 * Account for the cyclecounter wrap-around value by
156 		 * using the converted ns value of the current time to
157 		 * check for when the next aligned second would occur.
158 		 */
159 		clock_edge |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIML);
160 		clock_edge |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIMH) << 32;
161 		ns = timecounter_cyc2time(&adapter->tc, clock_edge);
162 
163 		div_u64_rem(ns, IXGBE_PTP_PPS_HALF_SECOND, &rem);
164 		clock_edge += ((IXGBE_PTP_PPS_HALF_SECOND - (u64)rem) << shift);
165 
166 		/* specify the initial clock start time */
167 		trgttiml = (u32)clock_edge;
168 		trgttimh = (u32)(clock_edge >> 32);
169 
170 		IXGBE_WRITE_REG(hw, IXGBE_CLKTIML, clktiml);
171 		IXGBE_WRITE_REG(hw, IXGBE_CLKTIMH, clktimh);
172 		IXGBE_WRITE_REG(hw, IXGBE_TRGTTIML0, trgttiml);
173 		IXGBE_WRITE_REG(hw, IXGBE_TRGTTIMH0, trgttimh);
174 
175 		IXGBE_WRITE_REG(hw, IXGBE_ESDP, esdp);
176 		IXGBE_WRITE_REG(hw, IXGBE_TSAUXC, tsauxc);
177 	} else {
178 		IXGBE_WRITE_REG(hw, IXGBE_TSAUXC, 0x0);
179 	}
180 
181 	IXGBE_WRITE_FLUSH(hw);
182 }
183 
184 /**
185  * ixgbe_ptp_read - read raw cycle counter (to be used by time counter)
186  * @cc: the cyclecounter structure
187  *
188  * this function reads the cyclecounter registers and is called by the
189  * cyclecounter structure used to construct a ns counter from the
190  * arbitrary fixed point registers
191  */
192 static cycle_t ixgbe_ptp_read(const struct cyclecounter *cc)
193 {
194 	struct ixgbe_adapter *adapter =
195 		container_of(cc, struct ixgbe_adapter, cc);
196 	struct ixgbe_hw *hw = &adapter->hw;
197 	u64 stamp = 0;
198 
199 	stamp |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIML);
200 	stamp |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIMH) << 32;
201 
202 	return stamp;
203 }
204 
205 /**
206  * ixgbe_ptp_adjfreq
207  * @ptp: the ptp clock structure
208  * @ppb: parts per billion adjustment from base
209  *
210  * adjust the frequency of the ptp cycle counter by the
211  * indicated ppb from the base frequency.
212  */
213 static int ixgbe_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
214 {
215 	struct ixgbe_adapter *adapter =
216 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
217 	struct ixgbe_hw *hw = &adapter->hw;
218 	u64 freq;
219 	u32 diff, incval;
220 	int neg_adj = 0;
221 
222 	if (ppb < 0) {
223 		neg_adj = 1;
224 		ppb = -ppb;
225 	}
226 
227 	smp_mb();
228 	incval = ACCESS_ONCE(adapter->base_incval);
229 
230 	freq = incval;
231 	freq *= ppb;
232 	diff = div_u64(freq, 1000000000ULL);
233 
234 	incval = neg_adj ? (incval - diff) : (incval + diff);
235 
236 	switch (hw->mac.type) {
237 	case ixgbe_mac_X540:
238 		IXGBE_WRITE_REG(hw, IXGBE_TIMINCA, incval);
239 		break;
240 	case ixgbe_mac_82599EB:
241 		IXGBE_WRITE_REG(hw, IXGBE_TIMINCA,
242 				(1 << IXGBE_INCPER_SHIFT_82599) |
243 				incval);
244 		break;
245 	default:
246 		break;
247 	}
248 
249 	return 0;
250 }
251 
252 /**
253  * ixgbe_ptp_adjtime
254  * @ptp: the ptp clock structure
255  * @delta: offset to adjust the cycle counter by
256  *
257  * adjust the timer by resetting the timecounter structure.
258  */
259 static int ixgbe_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
260 {
261 	struct ixgbe_adapter *adapter =
262 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
263 	unsigned long flags;
264 	u64 now;
265 
266 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
267 
268 	now = timecounter_read(&adapter->tc);
269 	now += delta;
270 
271 	/* reset the timecounter */
272 	timecounter_init(&adapter->tc,
273 			 &adapter->cc,
274 			 now);
275 
276 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
277 
278 	ixgbe_ptp_setup_sdp(adapter);
279 
280 	return 0;
281 }
282 
283 /**
284  * ixgbe_ptp_gettime
285  * @ptp: the ptp clock structure
286  * @ts: timespec structure to hold the current time value
287  *
288  * read the timecounter and return the correct value on ns,
289  * after converting it into a struct timespec.
290  */
291 static int ixgbe_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
292 {
293 	struct ixgbe_adapter *adapter =
294 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
295 	u64 ns;
296 	u32 remainder;
297 	unsigned long flags;
298 
299 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
300 	ns = timecounter_read(&adapter->tc);
301 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
302 
303 	ts->tv_sec = div_u64_rem(ns, 1000000000ULL, &remainder);
304 	ts->tv_nsec = remainder;
305 
306 	return 0;
307 }
308 
309 /**
310  * ixgbe_ptp_settime
311  * @ptp: the ptp clock structure
312  * @ts: the timespec containing the new time for the cycle counter
313  *
314  * reset the timecounter to use a new base value instead of the kernel
315  * wall timer value.
316  */
317 static int ixgbe_ptp_settime(struct ptp_clock_info *ptp,
318 			     const struct timespec *ts)
319 {
320 	struct ixgbe_adapter *adapter =
321 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
322 	u64 ns;
323 	unsigned long flags;
324 
325 	ns = ts->tv_sec * 1000000000ULL;
326 	ns += ts->tv_nsec;
327 
328 	/* reset the timecounter */
329 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
330 	timecounter_init(&adapter->tc, &adapter->cc, ns);
331 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
332 
333 	ixgbe_ptp_setup_sdp(adapter);
334 	return 0;
335 }
336 
337 /**
338  * ixgbe_ptp_feature_enable
339  * @ptp: the ptp clock structure
340  * @rq: the requested feature to change
341  * @on: whether to enable or disable the feature
342  *
343  * enable (or disable) ancillary features of the phc subsystem.
344  * our driver only supports the PPS feature on the X540
345  */
346 static int ixgbe_ptp_feature_enable(struct ptp_clock_info *ptp,
347 				    struct ptp_clock_request *rq, int on)
348 {
349 	struct ixgbe_adapter *adapter =
350 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
351 
352 	/**
353 	 * When PPS is enabled, unmask the interrupt for the ClockOut
354 	 * feature, so that the interrupt handler can send the PPS
355 	 * event when the clock SDP triggers. Clear mask when PPS is
356 	 * disabled
357 	 */
358 	if (rq->type == PTP_CLK_REQ_PPS) {
359 		switch (adapter->hw.mac.type) {
360 		case ixgbe_mac_X540:
361 			if (on)
362 				adapter->flags2 |= IXGBE_FLAG2_PTP_PPS_ENABLED;
363 			else
364 				adapter->flags2 &= ~IXGBE_FLAG2_PTP_PPS_ENABLED;
365 
366 			ixgbe_ptp_setup_sdp(adapter);
367 			return 0;
368 		default:
369 			break;
370 		}
371 	}
372 
373 	return -ENOTSUPP;
374 }
375 
376 /**
377  * ixgbe_ptp_check_pps_event
378  * @adapter: the private adapter structure
379  * @eicr: the interrupt cause register value
380  *
381  * This function is called by the interrupt routine when checking for
382  * interrupts. It will check and handle a pps event.
383  */
384 void ixgbe_ptp_check_pps_event(struct ixgbe_adapter *adapter, u32 eicr)
385 {
386 	struct ixgbe_hw *hw = &adapter->hw;
387 	struct ptp_clock_event event;
388 
389 	event.type = PTP_CLOCK_PPS;
390 
391 	/* this check is necessary in case the interrupt was enabled via some
392 	 * alternative means (ex. debug_fs). Better to check here than
393 	 * everywhere that calls this function.
394 	 */
395 	if (!adapter->ptp_clock)
396 		return;
397 
398 	switch (hw->mac.type) {
399 	case ixgbe_mac_X540:
400 		ptp_clock_event(adapter->ptp_clock, &event);
401 		break;
402 	default:
403 		break;
404 	}
405 }
406 
407 /**
408  * ixgbe_ptp_overflow_check - watchdog task to detect SYSTIME overflow
409  * @adapter: private adapter struct
410  *
411  * this watchdog task periodically reads the timecounter
412  * in order to prevent missing when the system time registers wrap
413  * around. This needs to be run approximately twice a minute.
414  */
415 void ixgbe_ptp_overflow_check(struct ixgbe_adapter *adapter)
416 {
417 	bool timeout = time_is_before_jiffies(adapter->last_overflow_check +
418 					     IXGBE_OVERFLOW_PERIOD);
419 	struct timespec ts;
420 
421 	if (timeout) {
422 		ixgbe_ptp_gettime(&adapter->ptp_caps, &ts);
423 		adapter->last_overflow_check = jiffies;
424 	}
425 }
426 
427 /**
428  * ixgbe_ptp_rx_hang - detect error case when Rx timestamp registers latched
429  * @adapter: private network adapter structure
430  *
431  * this watchdog task is scheduled to detect error case where hardware has
432  * dropped an Rx packet that was timestamped when the ring is full. The
433  * particular error is rare but leaves the device in a state unable to timestamp
434  * any future packets.
435  */
436 void ixgbe_ptp_rx_hang(struct ixgbe_adapter *adapter)
437 {
438 	struct ixgbe_hw *hw = &adapter->hw;
439 	u32 tsyncrxctl = IXGBE_READ_REG(hw, IXGBE_TSYNCRXCTL);
440 	unsigned long rx_event;
441 
442 	/* if we don't have a valid timestamp in the registers, just update the
443 	 * timeout counter and exit
444 	 */
445 	if (!(tsyncrxctl & IXGBE_TSYNCRXCTL_VALID)) {
446 		adapter->last_rx_ptp_check = jiffies;
447 		return;
448 	}
449 
450 	/* determine the most recent watchdog or rx_timestamp event */
451 	rx_event = adapter->last_rx_ptp_check;
452 	if (time_after(adapter->last_rx_timestamp, rx_event))
453 		rx_event = adapter->last_rx_timestamp;
454 
455 	/* only need to read the high RXSTMP register to clear the lock */
456 	if (time_is_before_jiffies(rx_event + 5*HZ)) {
457 		IXGBE_READ_REG(hw, IXGBE_RXSTMPH);
458 		adapter->last_rx_ptp_check = jiffies;
459 
460 		e_warn(drv, "clearing RX Timestamp hang\n");
461 	}
462 }
463 
464 /**
465  * ixgbe_ptp_tx_hwtstamp - utility function which checks for TX time stamp
466  * @adapter: the private adapter struct
467  *
468  * if the timestamp is valid, we convert it into the timecounter ns
469  * value, then store that result into the shhwtstamps structure which
470  * is passed up the network stack
471  */
472 static void ixgbe_ptp_tx_hwtstamp(struct ixgbe_adapter *adapter)
473 {
474 	struct ixgbe_hw *hw = &adapter->hw;
475 	struct skb_shared_hwtstamps shhwtstamps;
476 	u64 regval = 0, ns;
477 	unsigned long flags;
478 
479 	regval |= (u64)IXGBE_READ_REG(hw, IXGBE_TXSTMPL);
480 	regval |= (u64)IXGBE_READ_REG(hw, IXGBE_TXSTMPH) << 32;
481 
482 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
483 	ns = timecounter_cyc2time(&adapter->tc, regval);
484 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
485 
486 	memset(&shhwtstamps, 0, sizeof(shhwtstamps));
487 	shhwtstamps.hwtstamp = ns_to_ktime(ns);
488 	skb_tstamp_tx(adapter->ptp_tx_skb, &shhwtstamps);
489 
490 	dev_kfree_skb_any(adapter->ptp_tx_skb);
491 	adapter->ptp_tx_skb = NULL;
492 	clear_bit_unlock(__IXGBE_PTP_TX_IN_PROGRESS, &adapter->state);
493 }
494 
495 /**
496  * ixgbe_ptp_tx_hwtstamp_work
497  * @work: pointer to the work struct
498  *
499  * This work item polls TSYNCTXCTL valid bit to determine when a Tx hardware
500  * timestamp has been taken for the current skb. It is necesary, because the
501  * descriptor's "done" bit does not correlate with the timestamp event.
502  */
503 static void ixgbe_ptp_tx_hwtstamp_work(struct work_struct *work)
504 {
505 	struct ixgbe_adapter *adapter = container_of(work, struct ixgbe_adapter,
506 						     ptp_tx_work);
507 	struct ixgbe_hw *hw = &adapter->hw;
508 	bool timeout = time_is_before_jiffies(adapter->ptp_tx_start +
509 					      IXGBE_PTP_TX_TIMEOUT);
510 	u32 tsynctxctl;
511 
512 	if (timeout) {
513 		dev_kfree_skb_any(adapter->ptp_tx_skb);
514 		adapter->ptp_tx_skb = NULL;
515 		clear_bit_unlock(__IXGBE_PTP_TX_IN_PROGRESS, &adapter->state);
516 		e_warn(drv, "clearing Tx Timestamp hang\n");
517 		return;
518 	}
519 
520 	tsynctxctl = IXGBE_READ_REG(hw, IXGBE_TSYNCTXCTL);
521 	if (tsynctxctl & IXGBE_TSYNCTXCTL_VALID)
522 		ixgbe_ptp_tx_hwtstamp(adapter);
523 	else
524 		/* reschedule to keep checking if it's not available yet */
525 		schedule_work(&adapter->ptp_tx_work);
526 }
527 
528 /**
529  * ixgbe_ptp_rx_hwtstamp - utility function which checks for RX time stamp
530  * @adapter: pointer to adapter struct
531  * @skb: particular skb to send timestamp with
532  *
533  * if the timestamp is valid, we convert it into the timecounter ns
534  * value, then store that result into the shhwtstamps structure which
535  * is passed up the network stack
536  */
537 void ixgbe_ptp_rx_hwtstamp(struct ixgbe_adapter *adapter, struct sk_buff *skb)
538 {
539 	struct ixgbe_hw *hw = &adapter->hw;
540 	struct skb_shared_hwtstamps *shhwtstamps;
541 	u64 regval = 0, ns;
542 	u32 tsyncrxctl;
543 	unsigned long flags;
544 
545 	tsyncrxctl = IXGBE_READ_REG(hw, IXGBE_TSYNCRXCTL);
546 	if (!(tsyncrxctl & IXGBE_TSYNCRXCTL_VALID))
547 		return;
548 
549 	regval |= (u64)IXGBE_READ_REG(hw, IXGBE_RXSTMPL);
550 	regval |= (u64)IXGBE_READ_REG(hw, IXGBE_RXSTMPH) << 32;
551 
552 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
553 	ns = timecounter_cyc2time(&adapter->tc, regval);
554 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
555 
556 	shhwtstamps = skb_hwtstamps(skb);
557 	shhwtstamps->hwtstamp = ns_to_ktime(ns);
558 
559 	/* Update the last_rx_timestamp timer in order to enable watchdog check
560 	 * for error case of latched timestamp on a dropped packet.
561 	 */
562 	adapter->last_rx_timestamp = jiffies;
563 }
564 
565 int ixgbe_ptp_get_ts_config(struct ixgbe_adapter *adapter, struct ifreq *ifr)
566 {
567 	struct hwtstamp_config *config = &adapter->tstamp_config;
568 
569 	return copy_to_user(ifr->ifr_data, config,
570 			    sizeof(*config)) ? -EFAULT : 0;
571 }
572 
573 /**
574  * ixgbe_ptp_set_timestamp_mode - setup the hardware for the requested mode
575  * @adapter: the private ixgbe adapter structure
576  * @config: the hwtstamp configuration requested
577  *
578  * Outgoing time stamping can be enabled and disabled. Play nice and
579  * disable it when requested, although it shouldn't cause any overhead
580  * when no packet needs it. At most one packet in the queue may be
581  * marked for time stamping, otherwise it would be impossible to tell
582  * for sure to which packet the hardware time stamp belongs.
583  *
584  * Incoming time stamping has to be configured via the hardware
585  * filters. Not all combinations are supported, in particular event
586  * type has to be specified. Matching the kind of event packet is
587  * not supported, with the exception of "all V2 events regardless of
588  * level 2 or 4".
589  *
590  * Since hardware always timestamps Path delay packets when timestamping V2
591  * packets, regardless of the type specified in the register, only use V2
592  * Event mode. This more accurately tells the user what the hardware is going
593  * to do anyways.
594  *
595  * Note: this may modify the hwtstamp configuration towards a more general
596  * mode, if required to support the specifically requested mode.
597  */
598 static int ixgbe_ptp_set_timestamp_mode(struct ixgbe_adapter *adapter,
599 				 struct hwtstamp_config *config)
600 {
601 	struct ixgbe_hw *hw = &adapter->hw;
602 	u32 tsync_tx_ctl = IXGBE_TSYNCTXCTL_ENABLED;
603 	u32 tsync_rx_ctl = IXGBE_TSYNCRXCTL_ENABLED;
604 	u32 tsync_rx_mtrl = PTP_EV_PORT << 16;
605 	bool is_l2 = false;
606 	u32 regval;
607 
608 	/* reserved for future extensions */
609 	if (config->flags)
610 		return -EINVAL;
611 
612 	switch (config->tx_type) {
613 	case HWTSTAMP_TX_OFF:
614 		tsync_tx_ctl = 0;
615 	case HWTSTAMP_TX_ON:
616 		break;
617 	default:
618 		return -ERANGE;
619 	}
620 
621 	switch (config->rx_filter) {
622 	case HWTSTAMP_FILTER_NONE:
623 		tsync_rx_ctl = 0;
624 		tsync_rx_mtrl = 0;
625 		break;
626 	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
627 		tsync_rx_ctl |= IXGBE_TSYNCRXCTL_TYPE_L4_V1;
628 		tsync_rx_mtrl |= IXGBE_RXMTRL_V1_SYNC_MSG;
629 		break;
630 	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
631 		tsync_rx_ctl |= IXGBE_TSYNCRXCTL_TYPE_L4_V1;
632 		tsync_rx_mtrl |= IXGBE_RXMTRL_V1_DELAY_REQ_MSG;
633 		break;
634 	case HWTSTAMP_FILTER_PTP_V2_EVENT:
635 	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
636 	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
637 	case HWTSTAMP_FILTER_PTP_V2_SYNC:
638 	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
639 	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
640 	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
641 	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
642 	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
643 		tsync_rx_ctl |= IXGBE_TSYNCRXCTL_TYPE_EVENT_V2;
644 		is_l2 = true;
645 		config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
646 		break;
647 	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
648 	case HWTSTAMP_FILTER_ALL:
649 	default:
650 		/*
651 		 * register RXMTRL must be set in order to do V1 packets,
652 		 * therefore it is not possible to time stamp both V1 Sync and
653 		 * Delay_Req messages and hardware does not support
654 		 * timestamping all packets => return error
655 		 */
656 		config->rx_filter = HWTSTAMP_FILTER_NONE;
657 		return -ERANGE;
658 	}
659 
660 	if (hw->mac.type == ixgbe_mac_82598EB) {
661 		if (tsync_rx_ctl | tsync_tx_ctl)
662 			return -ERANGE;
663 		return 0;
664 	}
665 
666 	/* define ethertype filter for timestamping L2 packets */
667 	if (is_l2)
668 		IXGBE_WRITE_REG(hw, IXGBE_ETQF(IXGBE_ETQF_FILTER_1588),
669 				(IXGBE_ETQF_FILTER_EN | /* enable filter */
670 				 IXGBE_ETQF_1588 | /* enable timestamping */
671 				 ETH_P_1588));     /* 1588 eth protocol type */
672 	else
673 		IXGBE_WRITE_REG(hw, IXGBE_ETQF(IXGBE_ETQF_FILTER_1588), 0);
674 
675 	/* enable/disable TX */
676 	regval = IXGBE_READ_REG(hw, IXGBE_TSYNCTXCTL);
677 	regval &= ~IXGBE_TSYNCTXCTL_ENABLED;
678 	regval |= tsync_tx_ctl;
679 	IXGBE_WRITE_REG(hw, IXGBE_TSYNCTXCTL, regval);
680 
681 	/* enable/disable RX */
682 	regval = IXGBE_READ_REG(hw, IXGBE_TSYNCRXCTL);
683 	regval &= ~(IXGBE_TSYNCRXCTL_ENABLED | IXGBE_TSYNCRXCTL_TYPE_MASK);
684 	regval |= tsync_rx_ctl;
685 	IXGBE_WRITE_REG(hw, IXGBE_TSYNCRXCTL, regval);
686 
687 	/* define which PTP packets are time stamped */
688 	IXGBE_WRITE_REG(hw, IXGBE_RXMTRL, tsync_rx_mtrl);
689 
690 	IXGBE_WRITE_FLUSH(hw);
691 
692 	/* clear TX/RX time stamp registers, just to be sure */
693 	regval = IXGBE_READ_REG(hw, IXGBE_TXSTMPH);
694 	regval = IXGBE_READ_REG(hw, IXGBE_RXSTMPH);
695 
696 	return 0;
697 }
698 
699 /**
700  * ixgbe_ptp_set_ts_config - user entry point for timestamp mode
701  * @adapter: pointer to adapter struct
702  * @ifreq: ioctl data
703  *
704  * Set hardware to requested mode. If unsupported, return an error with no
705  * changes. Otherwise, store the mode for future reference.
706  */
707 int ixgbe_ptp_set_ts_config(struct ixgbe_adapter *adapter, struct ifreq *ifr)
708 {
709 	struct hwtstamp_config config;
710 	int err;
711 
712 	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
713 		return -EFAULT;
714 
715 	err = ixgbe_ptp_set_timestamp_mode(adapter, &config);
716 	if (err)
717 		return err;
718 
719 	/* save these settings for future reference */
720 	memcpy(&adapter->tstamp_config, &config,
721 	       sizeof(adapter->tstamp_config));
722 
723 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
724 		-EFAULT : 0;
725 }
726 
727 /**
728  * ixgbe_ptp_start_cyclecounter - create the cycle counter from hw
729  * @adapter: pointer to the adapter structure
730  *
731  * This function should be called to set the proper values for the TIMINCA
732  * register and tell the cyclecounter structure what the tick rate of SYSTIME
733  * is. It does not directly modify SYSTIME registers or the timecounter
734  * structure. It should be called whenever a new TIMINCA value is necessary,
735  * such as during initialization or when the link speed changes.
736  */
737 void ixgbe_ptp_start_cyclecounter(struct ixgbe_adapter *adapter)
738 {
739 	struct ixgbe_hw *hw = &adapter->hw;
740 	u32 incval = 0;
741 	u32 shift = 0;
742 	unsigned long flags;
743 
744 	/**
745 	 * Scale the NIC cycle counter by a large factor so that
746 	 * relatively small corrections to the frequency can be added
747 	 * or subtracted. The drawbacks of a large factor include
748 	 * (a) the clock register overflows more quickly, (b) the cycle
749 	 * counter structure must be able to convert the systime value
750 	 * to nanoseconds using only a multiplier and a right-shift,
751 	 * and (c) the value must fit within the timinca register space
752 	 * => math based on internal DMA clock rate and available bits
753 	 *
754 	 * Note that when there is no link, internal DMA clock is same as when
755 	 * link speed is 10Gb. Set the registers correctly even when link is
756 	 * down to preserve the clock setting
757 	 */
758 	switch (adapter->link_speed) {
759 	case IXGBE_LINK_SPEED_100_FULL:
760 		incval = IXGBE_INCVAL_100;
761 		shift = IXGBE_INCVAL_SHIFT_100;
762 		break;
763 	case IXGBE_LINK_SPEED_1GB_FULL:
764 		incval = IXGBE_INCVAL_1GB;
765 		shift = IXGBE_INCVAL_SHIFT_1GB;
766 		break;
767 	case IXGBE_LINK_SPEED_10GB_FULL:
768 	default:
769 		incval = IXGBE_INCVAL_10GB;
770 		shift = IXGBE_INCVAL_SHIFT_10GB;
771 		break;
772 	}
773 
774 	/**
775 	 * Modify the calculated values to fit within the correct
776 	 * number of bits specified by the hardware. The 82599 doesn't
777 	 * have the same space as the X540, so bitshift the calculated
778 	 * values to fit.
779 	 */
780 	switch (hw->mac.type) {
781 	case ixgbe_mac_X540:
782 		IXGBE_WRITE_REG(hw, IXGBE_TIMINCA, incval);
783 		break;
784 	case ixgbe_mac_82599EB:
785 		incval >>= IXGBE_INCVAL_SHIFT_82599;
786 		shift -= IXGBE_INCVAL_SHIFT_82599;
787 		IXGBE_WRITE_REG(hw, IXGBE_TIMINCA,
788 				(1 << IXGBE_INCPER_SHIFT_82599) |
789 				incval);
790 		break;
791 	default:
792 		/* other devices aren't supported */
793 		return;
794 	}
795 
796 	/* update the base incval used to calculate frequency adjustment */
797 	ACCESS_ONCE(adapter->base_incval) = incval;
798 	smp_mb();
799 
800 	/* need lock to prevent incorrect read while modifying cyclecounter */
801 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
802 
803 	memset(&adapter->cc, 0, sizeof(adapter->cc));
804 	adapter->cc.read = ixgbe_ptp_read;
805 	adapter->cc.mask = CLOCKSOURCE_MASK(64);
806 	adapter->cc.shift = shift;
807 	adapter->cc.mult = 1;
808 
809 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
810 }
811 
812 /**
813  * ixgbe_ptp_reset
814  * @adapter: the ixgbe private board structure
815  *
816  * When the MAC resets, all the hardware bits for timesync are reset. This
817  * function is used to re-enable the device for PTP based on current settings.
818  * We do lose the current clock time, so just reset the cyclecounter to the
819  * system real clock time.
820  *
821  * This function will maintain hwtstamp_config settings, and resets the SDP
822  * output if it was enabled.
823  */
824 void ixgbe_ptp_reset(struct ixgbe_adapter *adapter)
825 {
826 	struct ixgbe_hw *hw = &adapter->hw;
827 	unsigned long flags;
828 
829 	/* set SYSTIME registers to 0 just in case */
830 	IXGBE_WRITE_REG(hw, IXGBE_SYSTIML, 0x00000000);
831 	IXGBE_WRITE_REG(hw, IXGBE_SYSTIMH, 0x00000000);
832 	IXGBE_WRITE_FLUSH(hw);
833 
834 	/* reset the hardware timestamping mode */
835 	ixgbe_ptp_set_timestamp_mode(adapter, &adapter->tstamp_config);
836 
837 	ixgbe_ptp_start_cyclecounter(adapter);
838 
839 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
840 
841 	/* reset the ns time counter */
842 	timecounter_init(&adapter->tc, &adapter->cc,
843 			 ktime_to_ns(ktime_get_real()));
844 
845 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
846 
847 	/*
848 	 * Now that the shift has been calculated and the systime
849 	 * registers reset, (re-)enable the Clock out feature
850 	 */
851 	ixgbe_ptp_setup_sdp(adapter);
852 }
853 
854 /**
855  * ixgbe_ptp_create_clock
856  * @adapter: the ixgbe private adapter structure
857  *
858  * This function performs setup of the user entry point function table and
859  * initializes the PTP clock device, which is used to access the clock-like
860  * features of the PTP core. It will be called by ixgbe_ptp_init, only if
861  * there isn't already a clock device (such as after a suspend/resume cycle,
862  * where the clock device wasn't destroyed).
863  */
864 static int ixgbe_ptp_create_clock(struct ixgbe_adapter *adapter)
865 {
866 	struct net_device *netdev = adapter->netdev;
867 	long err;
868 
869 	/* do nothing if we already have a clock device */
870 	if (!IS_ERR_OR_NULL(adapter->ptp_clock))
871 		return 0;
872 
873 	switch (adapter->hw.mac.type) {
874 	case ixgbe_mac_X540:
875 		snprintf(adapter->ptp_caps.name,
876 			 sizeof(adapter->ptp_caps.name),
877 			 "%s", netdev->name);
878 		adapter->ptp_caps.owner = THIS_MODULE;
879 		adapter->ptp_caps.max_adj = 250000000;
880 		adapter->ptp_caps.n_alarm = 0;
881 		adapter->ptp_caps.n_ext_ts = 0;
882 		adapter->ptp_caps.n_per_out = 0;
883 		adapter->ptp_caps.pps = 1;
884 		adapter->ptp_caps.adjfreq = ixgbe_ptp_adjfreq;
885 		adapter->ptp_caps.adjtime = ixgbe_ptp_adjtime;
886 		adapter->ptp_caps.gettime = ixgbe_ptp_gettime;
887 		adapter->ptp_caps.settime = ixgbe_ptp_settime;
888 		adapter->ptp_caps.enable = ixgbe_ptp_feature_enable;
889 		break;
890 	case ixgbe_mac_82599EB:
891 		snprintf(adapter->ptp_caps.name,
892 			 sizeof(adapter->ptp_caps.name),
893 			 "%s", netdev->name);
894 		adapter->ptp_caps.owner = THIS_MODULE;
895 		adapter->ptp_caps.max_adj = 250000000;
896 		adapter->ptp_caps.n_alarm = 0;
897 		adapter->ptp_caps.n_ext_ts = 0;
898 		adapter->ptp_caps.n_per_out = 0;
899 		adapter->ptp_caps.pps = 0;
900 		adapter->ptp_caps.adjfreq = ixgbe_ptp_adjfreq;
901 		adapter->ptp_caps.adjtime = ixgbe_ptp_adjtime;
902 		adapter->ptp_caps.gettime = ixgbe_ptp_gettime;
903 		adapter->ptp_caps.settime = ixgbe_ptp_settime;
904 		adapter->ptp_caps.enable = ixgbe_ptp_feature_enable;
905 		break;
906 	default:
907 		adapter->ptp_clock = NULL;
908 		return -EOPNOTSUPP;
909 	}
910 
911 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps,
912 						&adapter->pdev->dev);
913 	if (IS_ERR(adapter->ptp_clock)) {
914 		err = PTR_ERR(adapter->ptp_clock);
915 		adapter->ptp_clock = NULL;
916 		e_dev_err("ptp_clock_register failed\n");
917 		return err;
918 	} else
919 		e_dev_info("registered PHC device on %s\n", netdev->name);
920 
921 	/* set default timestamp mode to disabled here. We do this in
922 	 * create_clock instead of init, because we don't want to override the
923 	 * previous settings during a resume cycle.
924 	 */
925 	adapter->tstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
926 	adapter->tstamp_config.tx_type = HWTSTAMP_TX_OFF;
927 
928 	return 0;
929 }
930 
931 /**
932  * ixgbe_ptp_init
933  * @adapter: the ixgbe private adapter structure
934  *
935  * This function performs the required steps for enabling PTP
936  * support. If PTP support has already been loaded it simply calls the
937  * cyclecounter init routine and exits.
938  */
939 void ixgbe_ptp_init(struct ixgbe_adapter *adapter)
940 {
941 	/* initialize the spin lock first since we can't control when a user
942 	 * will call the entry functions once we have initialized the clock
943 	 * device
944 	 */
945 	spin_lock_init(&adapter->tmreg_lock);
946 
947 	/* obtain a PTP device, or re-use an existing device */
948 	if (ixgbe_ptp_create_clock(adapter))
949 		return;
950 
951 	/* we have a clock so we can initialize work now */
952 	INIT_WORK(&adapter->ptp_tx_work, ixgbe_ptp_tx_hwtstamp_work);
953 
954 	/* reset the PTP related hardware bits */
955 	ixgbe_ptp_reset(adapter);
956 
957 	/* enter the IXGBE_PTP_RUNNING state */
958 	set_bit(__IXGBE_PTP_RUNNING, &adapter->state);
959 
960 	return;
961 }
962 
963 /**
964  * ixgbe_ptp_suspend - stop PTP work items
965  * @ adapter: pointer to adapter struct
966  *
967  * this function suspends PTP activity, and prevents more PTP work from being
968  * generated, but does not destroy the PTP clock device.
969  */
970 void ixgbe_ptp_suspend(struct ixgbe_adapter *adapter)
971 {
972 	/* Leave the IXGBE_PTP_RUNNING state. */
973 	if (!test_and_clear_bit(__IXGBE_PTP_RUNNING, &adapter->state))
974 		return;
975 
976 	/* since this might be called in suspend, we don't clear the state,
977 	 * but simply reset the auxiliary PPS signal control register
978 	 */
979 	IXGBE_WRITE_REG(&adapter->hw, IXGBE_TSAUXC, 0x0);
980 
981 	/* ensure that we cancel any pending PTP Tx work item in progress */
982 	cancel_work_sync(&adapter->ptp_tx_work);
983 	if (adapter->ptp_tx_skb) {
984 		dev_kfree_skb_any(adapter->ptp_tx_skb);
985 		adapter->ptp_tx_skb = NULL;
986 		clear_bit_unlock(__IXGBE_PTP_TX_IN_PROGRESS, &adapter->state);
987 	}
988 }
989 
990 /**
991  * ixgbe_ptp_stop - close the PTP device
992  * @adapter: pointer to adapter struct
993  *
994  * completely destroy the PTP device, should only be called when the device is
995  * being fully closed.
996  */
997 void ixgbe_ptp_stop(struct ixgbe_adapter *adapter)
998 {
999 	/* first, suspend PTP activity */
1000 	ixgbe_ptp_suspend(adapter);
1001 
1002 	/* disable the PTP clock device */
1003 	if (adapter->ptp_clock) {
1004 		ptp_clock_unregister(adapter->ptp_clock);
1005 		adapter->ptp_clock = NULL;
1006 		e_dev_info("removed PHC on %s\n",
1007 			   adapter->netdev->name);
1008 	}
1009 }
1010