xref: /openbmc/linux/drivers/net/ethernet/sfc/ptp.c (revision 29c37341)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /****************************************************************************
3  * Driver for Solarflare network controllers and boards
4  * Copyright 2011-2013 Solarflare Communications Inc.
5  */
6 
7 /* Theory of operation:
8  *
9  * PTP support is assisted by firmware running on the MC, which provides
10  * the hardware timestamping capabilities.  Both transmitted and received
11  * PTP event packets are queued onto internal queues for subsequent processing;
12  * this is because the MC operations are relatively long and would block
13  * block NAPI/interrupt operation.
14  *
15  * Receive event processing:
16  *	The event contains the packet's UUID and sequence number, together
17  *	with the hardware timestamp.  The PTP receive packet queue is searched
18  *	for this UUID/sequence number and, if found, put on a pending queue.
19  *	Packets not matching are delivered without timestamps (MCDI events will
20  *	always arrive after the actual packet).
21  *	It is important for the operation of the PTP protocol that the ordering
22  *	of packets between the event and general port is maintained.
23  *
24  * Work queue processing:
25  *	If work waiting, synchronise host/hardware time
26  *
27  *	Transmit: send packet through MC, which returns the transmission time
28  *	that is converted to an appropriate timestamp.
29  *
30  *	Receive: the packet's reception time is converted to an appropriate
31  *	timestamp.
32  */
33 #include <linux/ip.h>
34 #include <linux/udp.h>
35 #include <linux/time.h>
36 #include <linux/ktime.h>
37 #include <linux/module.h>
38 #include <linux/pps_kernel.h>
39 #include <linux/ptp_clock_kernel.h>
40 #include "net_driver.h"
41 #include "efx.h"
42 #include "mcdi.h"
43 #include "mcdi_pcol.h"
44 #include "io.h"
45 #include "farch_regs.h"
46 #include "nic.h" /* indirectly includes ptp.h */
47 
48 /* Maximum number of events expected to make up a PTP event */
49 #define	MAX_EVENT_FRAGS			3
50 
51 /* Maximum delay, ms, to begin synchronisation */
52 #define	MAX_SYNCHRONISE_WAIT_MS		2
53 
54 /* How long, at most, to spend synchronising */
55 #define	SYNCHRONISE_PERIOD_NS		250000
56 
57 /* How often to update the shared memory time */
58 #define	SYNCHRONISATION_GRANULARITY_NS	200
59 
60 /* Minimum permitted length of a (corrected) synchronisation time */
61 #define	DEFAULT_MIN_SYNCHRONISATION_NS	120
62 
63 /* Maximum permitted length of a (corrected) synchronisation time */
64 #define	MAX_SYNCHRONISATION_NS		1000
65 
66 /* How many (MC) receive events that can be queued */
67 #define	MAX_RECEIVE_EVENTS		8
68 
69 /* Length of (modified) moving average. */
70 #define	AVERAGE_LENGTH			16
71 
72 /* How long an unmatched event or packet can be held */
73 #define PKT_EVENT_LIFETIME_MS		10
74 
75 /* Offsets into PTP packet for identification.  These offsets are from the
76  * start of the IP header, not the MAC header.  Note that neither PTP V1 nor
77  * PTP V2 permit the use of IPV4 options.
78  */
79 #define PTP_DPORT_OFFSET	22
80 
81 #define PTP_V1_VERSION_LENGTH	2
82 #define PTP_V1_VERSION_OFFSET	28
83 
84 #define PTP_V1_UUID_LENGTH	6
85 #define PTP_V1_UUID_OFFSET	50
86 
87 #define PTP_V1_SEQUENCE_LENGTH	2
88 #define PTP_V1_SEQUENCE_OFFSET	58
89 
90 /* The minimum length of a PTP V1 packet for offsets, etc. to be valid:
91  * includes IP header.
92  */
93 #define	PTP_V1_MIN_LENGTH	64
94 
95 #define PTP_V2_VERSION_LENGTH	1
96 #define PTP_V2_VERSION_OFFSET	29
97 
98 #define PTP_V2_UUID_LENGTH	8
99 #define PTP_V2_UUID_OFFSET	48
100 
101 /* Although PTP V2 UUIDs are comprised a ClockIdentity (8) and PortNumber (2),
102  * the MC only captures the last six bytes of the clock identity. These values
103  * reflect those, not the ones used in the standard.  The standard permits
104  * mapping of V1 UUIDs to V2 UUIDs with these same values.
105  */
106 #define PTP_V2_MC_UUID_LENGTH	6
107 #define PTP_V2_MC_UUID_OFFSET	50
108 
109 #define PTP_V2_SEQUENCE_LENGTH	2
110 #define PTP_V2_SEQUENCE_OFFSET	58
111 
112 /* The minimum length of a PTP V2 packet for offsets, etc. to be valid:
113  * includes IP header.
114  */
115 #define	PTP_V2_MIN_LENGTH	63
116 
117 #define	PTP_MIN_LENGTH		63
118 
119 #define PTP_ADDRESS		0xe0000181	/* 224.0.1.129 */
120 #define PTP_EVENT_PORT		319
121 #define PTP_GENERAL_PORT	320
122 
123 /* Annoyingly the format of the version numbers are different between
124  * versions 1 and 2 so it isn't possible to simply look for 1 or 2.
125  */
126 #define	PTP_VERSION_V1		1
127 
128 #define	PTP_VERSION_V2		2
129 #define	PTP_VERSION_V2_MASK	0x0f
130 
131 enum ptp_packet_state {
132 	PTP_PACKET_STATE_UNMATCHED = 0,
133 	PTP_PACKET_STATE_MATCHED,
134 	PTP_PACKET_STATE_TIMED_OUT,
135 	PTP_PACKET_STATE_MATCH_UNWANTED
136 };
137 
138 /* NIC synchronised with single word of time only comprising
139  * partial seconds and full nanoseconds: 10^9 ~ 2^30 so 2 bits for seconds.
140  */
141 #define	MC_NANOSECOND_BITS	30
142 #define	MC_NANOSECOND_MASK	((1 << MC_NANOSECOND_BITS) - 1)
143 #define	MC_SECOND_MASK		((1 << (32 - MC_NANOSECOND_BITS)) - 1)
144 
145 /* Maximum parts-per-billion adjustment that is acceptable */
146 #define MAX_PPB			1000000
147 
148 /* Precalculate scale word to avoid long long division at runtime */
149 /* This is equivalent to 2^66 / 10^9. */
150 #define PPB_SCALE_WORD  ((1LL << (57)) / 1953125LL)
151 
152 /* How much to shift down after scaling to convert to FP40 */
153 #define PPB_SHIFT_FP40		26
154 /* ... and FP44. */
155 #define PPB_SHIFT_FP44		22
156 
157 #define PTP_SYNC_ATTEMPTS	4
158 
159 /**
160  * struct efx_ptp_match - Matching structure, stored in sk_buff's cb area.
161  * @words: UUID and (partial) sequence number
162  * @expiry: Time after which the packet should be delivered irrespective of
163  *            event arrival.
164  * @state: The state of the packet - whether it is ready for processing or
165  *         whether that is of no interest.
166  */
167 struct efx_ptp_match {
168 	u32 words[DIV_ROUND_UP(PTP_V1_UUID_LENGTH, 4)];
169 	unsigned long expiry;
170 	enum ptp_packet_state state;
171 };
172 
173 /**
174  * struct efx_ptp_event_rx - A PTP receive event (from MC)
175  * @seq0: First part of (PTP) UUID
176  * @seq1: Second part of (PTP) UUID and sequence number
177  * @hwtimestamp: Event timestamp
178  */
179 struct efx_ptp_event_rx {
180 	struct list_head link;
181 	u32 seq0;
182 	u32 seq1;
183 	ktime_t hwtimestamp;
184 	unsigned long expiry;
185 };
186 
187 /**
188  * struct efx_ptp_timeset - Synchronisation between host and MC
189  * @host_start: Host time immediately before hardware timestamp taken
190  * @major: Hardware timestamp, major
191  * @minor: Hardware timestamp, minor
192  * @host_end: Host time immediately after hardware timestamp taken
193  * @wait: Number of NIC clock ticks between hardware timestamp being read and
194  *          host end time being seen
195  * @window: Difference of host_end and host_start
196  * @valid: Whether this timeset is valid
197  */
198 struct efx_ptp_timeset {
199 	u32 host_start;
200 	u32 major;
201 	u32 minor;
202 	u32 host_end;
203 	u32 wait;
204 	u32 window;	/* Derived: end - start, allowing for wrap */
205 };
206 
207 /**
208  * struct efx_ptp_data - Precision Time Protocol (PTP) state
209  * @efx: The NIC context
210  * @channel: The PTP channel (Siena only)
211  * @rx_ts_inline: Flag for whether RX timestamps are inline (else they are
212  *	separate events)
213  * @rxq: Receive SKB queue (awaiting timestamps)
214  * @txq: Transmit SKB queue
215  * @evt_list: List of MC receive events awaiting packets
216  * @evt_free_list: List of free events
217  * @evt_lock: Lock for manipulating evt_list and evt_free_list
218  * @rx_evts: Instantiated events (on evt_list and evt_free_list)
219  * @workwq: Work queue for processing pending PTP operations
220  * @work: Work task
221  * @reset_required: A serious error has occurred and the PTP task needs to be
222  *                  reset (disable, enable).
223  * @rxfilter_event: Receive filter when operating
224  * @rxfilter_general: Receive filter when operating
225  * @config: Current timestamp configuration
226  * @enabled: PTP operation enabled
227  * @mode: Mode in which PTP operating (PTP version)
228  * @ns_to_nic_time: Function to convert from scalar nanoseconds to NIC time
229  * @nic_to_kernel_time: Function to convert from NIC to kernel time
230  * @nic_time.minor_max: Wrap point for NIC minor times
231  * @nic_time.sync_event_diff_min: Minimum acceptable difference between time
232  * in packet prefix and last MCDI time sync event i.e. how much earlier than
233  * the last sync event time a packet timestamp can be.
234  * @nic_time.sync_event_diff_max: Maximum acceptable difference between time
235  * in packet prefix and last MCDI time sync event i.e. how much later than
236  * the last sync event time a packet timestamp can be.
237  * @nic_time.sync_event_minor_shift: Shift required to make minor time from
238  * field in MCDI time sync event.
239  * @min_synchronisation_ns: Minimum acceptable corrected sync window
240  * @capabilities: Capabilities flags from the NIC
241  * @ts_corrections.ptp_tx: Required driver correction of PTP packet transmit
242  *                         timestamps
243  * @ts_corrections.ptp_rx: Required driver correction of PTP packet receive
244  *                         timestamps
245  * @ts_corrections.pps_out: PPS output error (information only)
246  * @ts_corrections.pps_in: Required driver correction of PPS input timestamps
247  * @ts_corrections.general_tx: Required driver correction of general packet
248  *                             transmit timestamps
249  * @ts_corrections.general_rx: Required driver correction of general packet
250  *                             receive timestamps
251  * @evt_frags: Partly assembled PTP events
252  * @evt_frag_idx: Current fragment number
253  * @evt_code: Last event code
254  * @start: Address at which MC indicates ready for synchronisation
255  * @host_time_pps: Host time at last PPS
256  * @adjfreq_ppb_shift: Shift required to convert scaled parts-per-billion
257  * frequency adjustment into a fixed point fractional nanosecond format.
258  * @current_adjfreq: Current ppb adjustment.
259  * @phc_clock: Pointer to registered phc device (if primary function)
260  * @phc_clock_info: Registration structure for phc device
261  * @pps_work: pps work task for handling pps events
262  * @pps_workwq: pps work queue
263  * @nic_ts_enabled: Flag indicating if NIC generated TS events are handled
264  * @txbuf: Buffer for use when transmitting (PTP) packets to MC (avoids
265  *         allocations in main data path).
266  * @good_syncs: Number of successful synchronisations.
267  * @fast_syncs: Number of synchronisations requiring short delay
268  * @bad_syncs: Number of failed synchronisations.
269  * @sync_timeouts: Number of synchronisation timeouts
270  * @no_time_syncs: Number of synchronisations with no good times.
271  * @invalid_sync_windows: Number of sync windows with bad durations.
272  * @undersize_sync_windows: Number of corrected sync windows that are too small
273  * @oversize_sync_windows: Number of corrected sync windows that are too large
274  * @rx_no_timestamp: Number of packets received without a timestamp.
275  * @timeset: Last set of synchronisation statistics.
276  * @xmit_skb: Transmit SKB function.
277  */
278 struct efx_ptp_data {
279 	struct efx_nic *efx;
280 	struct efx_channel *channel;
281 	bool rx_ts_inline;
282 	struct sk_buff_head rxq;
283 	struct sk_buff_head txq;
284 	struct list_head evt_list;
285 	struct list_head evt_free_list;
286 	spinlock_t evt_lock;
287 	struct efx_ptp_event_rx rx_evts[MAX_RECEIVE_EVENTS];
288 	struct workqueue_struct *workwq;
289 	struct work_struct work;
290 	bool reset_required;
291 	u32 rxfilter_event;
292 	u32 rxfilter_general;
293 	bool rxfilter_installed;
294 	struct hwtstamp_config config;
295 	bool enabled;
296 	unsigned int mode;
297 	void (*ns_to_nic_time)(s64 ns, u32 *nic_major, u32 *nic_minor);
298 	ktime_t (*nic_to_kernel_time)(u32 nic_major, u32 nic_minor,
299 				      s32 correction);
300 	struct {
301 		u32 minor_max;
302 		u32 sync_event_diff_min;
303 		u32 sync_event_diff_max;
304 		unsigned int sync_event_minor_shift;
305 	} nic_time;
306 	unsigned int min_synchronisation_ns;
307 	unsigned int capabilities;
308 	struct {
309 		s32 ptp_tx;
310 		s32 ptp_rx;
311 		s32 pps_out;
312 		s32 pps_in;
313 		s32 general_tx;
314 		s32 general_rx;
315 	} ts_corrections;
316 	efx_qword_t evt_frags[MAX_EVENT_FRAGS];
317 	int evt_frag_idx;
318 	int evt_code;
319 	struct efx_buffer start;
320 	struct pps_event_time host_time_pps;
321 	unsigned int adjfreq_ppb_shift;
322 	s64 current_adjfreq;
323 	struct ptp_clock *phc_clock;
324 	struct ptp_clock_info phc_clock_info;
325 	struct work_struct pps_work;
326 	struct workqueue_struct *pps_workwq;
327 	bool nic_ts_enabled;
328 	_MCDI_DECLARE_BUF(txbuf, MC_CMD_PTP_IN_TRANSMIT_LENMAX);
329 
330 	unsigned int good_syncs;
331 	unsigned int fast_syncs;
332 	unsigned int bad_syncs;
333 	unsigned int sync_timeouts;
334 	unsigned int no_time_syncs;
335 	unsigned int invalid_sync_windows;
336 	unsigned int undersize_sync_windows;
337 	unsigned int oversize_sync_windows;
338 	unsigned int rx_no_timestamp;
339 	struct efx_ptp_timeset
340 	timeset[MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_MAXNUM];
341 	void (*xmit_skb)(struct efx_nic *efx, struct sk_buff *skb);
342 };
343 
344 static int efx_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta);
345 static int efx_phc_adjtime(struct ptp_clock_info *ptp, s64 delta);
346 static int efx_phc_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts);
347 static int efx_phc_settime(struct ptp_clock_info *ptp,
348 			   const struct timespec64 *e_ts);
349 static int efx_phc_enable(struct ptp_clock_info *ptp,
350 			  struct ptp_clock_request *request, int on);
351 
352 bool efx_ptp_use_mac_tx_timestamps(struct efx_nic *efx)
353 {
354 	return efx_has_cap(efx, TX_MAC_TIMESTAMPING);
355 }
356 
357 /* PTP 'extra' channel is still a traffic channel, but we only create TX queues
358  * if PTP uses MAC TX timestamps, not if PTP uses the MC directly to transmit.
359  */
360 static bool efx_ptp_want_txqs(struct efx_channel *channel)
361 {
362 	return efx_ptp_use_mac_tx_timestamps(channel->efx);
363 }
364 
365 #define PTP_SW_STAT(ext_name, field_name)				\
366 	{ #ext_name, 0, offsetof(struct efx_ptp_data, field_name) }
367 #define PTP_MC_STAT(ext_name, mcdi_name)				\
368 	{ #ext_name, 32, MC_CMD_PTP_OUT_STATUS_STATS_ ## mcdi_name ## _OFST }
369 static const struct efx_hw_stat_desc efx_ptp_stat_desc[] = {
370 	PTP_SW_STAT(ptp_good_syncs, good_syncs),
371 	PTP_SW_STAT(ptp_fast_syncs, fast_syncs),
372 	PTP_SW_STAT(ptp_bad_syncs, bad_syncs),
373 	PTP_SW_STAT(ptp_sync_timeouts, sync_timeouts),
374 	PTP_SW_STAT(ptp_no_time_syncs, no_time_syncs),
375 	PTP_SW_STAT(ptp_invalid_sync_windows, invalid_sync_windows),
376 	PTP_SW_STAT(ptp_undersize_sync_windows, undersize_sync_windows),
377 	PTP_SW_STAT(ptp_oversize_sync_windows, oversize_sync_windows),
378 	PTP_SW_STAT(ptp_rx_no_timestamp, rx_no_timestamp),
379 	PTP_MC_STAT(ptp_tx_timestamp_packets, TX),
380 	PTP_MC_STAT(ptp_rx_timestamp_packets, RX),
381 	PTP_MC_STAT(ptp_timestamp_packets, TS),
382 	PTP_MC_STAT(ptp_filter_matches, FM),
383 	PTP_MC_STAT(ptp_non_filter_matches, NFM),
384 };
385 #define PTP_STAT_COUNT ARRAY_SIZE(efx_ptp_stat_desc)
386 static const unsigned long efx_ptp_stat_mask[] = {
387 	[0 ... BITS_TO_LONGS(PTP_STAT_COUNT) - 1] = ~0UL,
388 };
389 
390 size_t efx_ptp_describe_stats(struct efx_nic *efx, u8 *strings)
391 {
392 	if (!efx->ptp_data)
393 		return 0;
394 
395 	return efx_nic_describe_stats(efx_ptp_stat_desc, PTP_STAT_COUNT,
396 				      efx_ptp_stat_mask, strings);
397 }
398 
399 size_t efx_ptp_update_stats(struct efx_nic *efx, u64 *stats)
400 {
401 	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_STATUS_LEN);
402 	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_STATUS_LEN);
403 	size_t i;
404 	int rc;
405 
406 	if (!efx->ptp_data)
407 		return 0;
408 
409 	/* Copy software statistics */
410 	for (i = 0; i < PTP_STAT_COUNT; i++) {
411 		if (efx_ptp_stat_desc[i].dma_width)
412 			continue;
413 		stats[i] = *(unsigned int *)((char *)efx->ptp_data +
414 					     efx_ptp_stat_desc[i].offset);
415 	}
416 
417 	/* Fetch MC statistics.  We *must* fill in all statistics or
418 	 * risk leaking kernel memory to userland, so if the MCDI
419 	 * request fails we pretend we got zeroes.
420 	 */
421 	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_STATUS);
422 	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
423 	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
424 			  outbuf, sizeof(outbuf), NULL);
425 	if (rc)
426 		memset(outbuf, 0, sizeof(outbuf));
427 	efx_nic_update_stats(efx_ptp_stat_desc, PTP_STAT_COUNT,
428 			     efx_ptp_stat_mask,
429 			     stats, _MCDI_PTR(outbuf, 0), false);
430 
431 	return PTP_STAT_COUNT;
432 }
433 
434 /* For Siena platforms NIC time is s and ns */
435 static void efx_ptp_ns_to_s_ns(s64 ns, u32 *nic_major, u32 *nic_minor)
436 {
437 	struct timespec64 ts = ns_to_timespec64(ns);
438 	*nic_major = (u32)ts.tv_sec;
439 	*nic_minor = ts.tv_nsec;
440 }
441 
442 static ktime_t efx_ptp_s_ns_to_ktime_correction(u32 nic_major, u32 nic_minor,
443 						s32 correction)
444 {
445 	ktime_t kt = ktime_set(nic_major, nic_minor);
446 	if (correction >= 0)
447 		kt = ktime_add_ns(kt, (u64)correction);
448 	else
449 		kt = ktime_sub_ns(kt, (u64)-correction);
450 	return kt;
451 }
452 
453 /* To convert from s27 format to ns we multiply then divide by a power of 2.
454  * For the conversion from ns to s27, the operation is also converted to a
455  * multiply and shift.
456  */
457 #define S27_TO_NS_SHIFT	(27)
458 #define NS_TO_S27_MULT	(((1ULL << 63) + NSEC_PER_SEC / 2) / NSEC_PER_SEC)
459 #define NS_TO_S27_SHIFT	(63 - S27_TO_NS_SHIFT)
460 #define S27_MINOR_MAX	(1 << S27_TO_NS_SHIFT)
461 
462 /* For Huntington platforms NIC time is in seconds and fractions of a second
463  * where the minor register only uses 27 bits in units of 2^-27s.
464  */
465 static void efx_ptp_ns_to_s27(s64 ns, u32 *nic_major, u32 *nic_minor)
466 {
467 	struct timespec64 ts = ns_to_timespec64(ns);
468 	u32 maj = (u32)ts.tv_sec;
469 	u32 min = (u32)(((u64)ts.tv_nsec * NS_TO_S27_MULT +
470 			 (1ULL << (NS_TO_S27_SHIFT - 1))) >> NS_TO_S27_SHIFT);
471 
472 	/* The conversion can result in the minor value exceeding the maximum.
473 	 * In this case, round up to the next second.
474 	 */
475 	if (min >= S27_MINOR_MAX) {
476 		min -= S27_MINOR_MAX;
477 		maj++;
478 	}
479 
480 	*nic_major = maj;
481 	*nic_minor = min;
482 }
483 
484 static inline ktime_t efx_ptp_s27_to_ktime(u32 nic_major, u32 nic_minor)
485 {
486 	u32 ns = (u32)(((u64)nic_minor * NSEC_PER_SEC +
487 			(1ULL << (S27_TO_NS_SHIFT - 1))) >> S27_TO_NS_SHIFT);
488 	return ktime_set(nic_major, ns);
489 }
490 
491 static ktime_t efx_ptp_s27_to_ktime_correction(u32 nic_major, u32 nic_minor,
492 					       s32 correction)
493 {
494 	/* Apply the correction and deal with carry */
495 	nic_minor += correction;
496 	if ((s32)nic_minor < 0) {
497 		nic_minor += S27_MINOR_MAX;
498 		nic_major--;
499 	} else if (nic_minor >= S27_MINOR_MAX) {
500 		nic_minor -= S27_MINOR_MAX;
501 		nic_major++;
502 	}
503 
504 	return efx_ptp_s27_to_ktime(nic_major, nic_minor);
505 }
506 
507 /* For Medford2 platforms the time is in seconds and quarter nanoseconds. */
508 static void efx_ptp_ns_to_s_qns(s64 ns, u32 *nic_major, u32 *nic_minor)
509 {
510 	struct timespec64 ts = ns_to_timespec64(ns);
511 
512 	*nic_major = (u32)ts.tv_sec;
513 	*nic_minor = ts.tv_nsec * 4;
514 }
515 
516 static ktime_t efx_ptp_s_qns_to_ktime_correction(u32 nic_major, u32 nic_minor,
517 						 s32 correction)
518 {
519 	ktime_t kt;
520 
521 	nic_minor = DIV_ROUND_CLOSEST(nic_minor, 4);
522 	correction = DIV_ROUND_CLOSEST(correction, 4);
523 
524 	kt = ktime_set(nic_major, nic_minor);
525 
526 	if (correction >= 0)
527 		kt = ktime_add_ns(kt, (u64)correction);
528 	else
529 		kt = ktime_sub_ns(kt, (u64)-correction);
530 	return kt;
531 }
532 
533 struct efx_channel *efx_ptp_channel(struct efx_nic *efx)
534 {
535 	return efx->ptp_data ? efx->ptp_data->channel : NULL;
536 }
537 
538 static u32 last_sync_timestamp_major(struct efx_nic *efx)
539 {
540 	struct efx_channel *channel = efx_ptp_channel(efx);
541 	u32 major = 0;
542 
543 	if (channel)
544 		major = channel->sync_timestamp_major;
545 	return major;
546 }
547 
548 /* The 8000 series and later can provide the time from the MAC, which is only
549  * 48 bits long and provides meta-information in the top 2 bits.
550  */
551 static ktime_t
552 efx_ptp_mac_nic_to_ktime_correction(struct efx_nic *efx,
553 				    struct efx_ptp_data *ptp,
554 				    u32 nic_major, u32 nic_minor,
555 				    s32 correction)
556 {
557 	u32 sync_timestamp;
558 	ktime_t kt = { 0 };
559 	s16 delta;
560 
561 	if (!(nic_major & 0x80000000)) {
562 		WARN_ON_ONCE(nic_major >> 16);
563 
564 		/* Medford provides 48 bits of timestamp, so we must get the top
565 		 * 16 bits from the timesync event state.
566 		 *
567 		 * We only have the lower 16 bits of the time now, but we do
568 		 * have a full resolution timestamp at some point in past. As
569 		 * long as the difference between the (real) now and the sync
570 		 * is less than 2^15, then we can reconstruct the difference
571 		 * between those two numbers using only the lower 16 bits of
572 		 * each.
573 		 *
574 		 * Put another way
575 		 *
576 		 * a - b = ((a mod k) - b) mod k
577 		 *
578 		 * when -k/2 < (a-b) < k/2. In our case k is 2^16. We know
579 		 * (a mod k) and b, so can calculate the delta, a - b.
580 		 *
581 		 */
582 		sync_timestamp = last_sync_timestamp_major(efx);
583 
584 		/* Because delta is s16 this does an implicit mask down to
585 		 * 16 bits which is what we need, assuming
586 		 * MEDFORD_TX_SECS_EVENT_BITS is 16. delta is signed so that
587 		 * we can deal with the (unlikely) case of sync timestamps
588 		 * arriving from the future.
589 		 */
590 		delta = nic_major - sync_timestamp;
591 
592 		/* Recover the fully specified time now, by applying the offset
593 		 * to the (fully specified) sync time.
594 		 */
595 		nic_major = sync_timestamp + delta;
596 
597 		kt = ptp->nic_to_kernel_time(nic_major, nic_minor,
598 					     correction);
599 	}
600 	return kt;
601 }
602 
603 ktime_t efx_ptp_nic_to_kernel_time(struct efx_tx_queue *tx_queue)
604 {
605 	struct efx_nic *efx = tx_queue->efx;
606 	struct efx_ptp_data *ptp = efx->ptp_data;
607 	ktime_t kt;
608 
609 	if (efx_ptp_use_mac_tx_timestamps(efx))
610 		kt = efx_ptp_mac_nic_to_ktime_correction(efx, ptp,
611 				tx_queue->completed_timestamp_major,
612 				tx_queue->completed_timestamp_minor,
613 				ptp->ts_corrections.general_tx);
614 	else
615 		kt = ptp->nic_to_kernel_time(
616 				tx_queue->completed_timestamp_major,
617 				tx_queue->completed_timestamp_minor,
618 				ptp->ts_corrections.general_tx);
619 	return kt;
620 }
621 
622 /* Get PTP attributes and set up time conversions */
623 static int efx_ptp_get_attributes(struct efx_nic *efx)
624 {
625 	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_GET_ATTRIBUTES_LEN);
626 	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_GET_ATTRIBUTES_LEN);
627 	struct efx_ptp_data *ptp = efx->ptp_data;
628 	int rc;
629 	u32 fmt;
630 	size_t out_len;
631 
632 	/* Get the PTP attributes. If the NIC doesn't support the operation we
633 	 * use the default format for compatibility with older NICs i.e.
634 	 * seconds and nanoseconds.
635 	 */
636 	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_GET_ATTRIBUTES);
637 	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
638 	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
639 				outbuf, sizeof(outbuf), &out_len);
640 	if (rc == 0) {
641 		fmt = MCDI_DWORD(outbuf, PTP_OUT_GET_ATTRIBUTES_TIME_FORMAT);
642 	} else if (rc == -EINVAL) {
643 		fmt = MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_NANOSECONDS;
644 	} else if (rc == -EPERM) {
645 		netif_info(efx, probe, efx->net_dev, "no PTP support\n");
646 		return rc;
647 	} else {
648 		efx_mcdi_display_error(efx, MC_CMD_PTP, sizeof(inbuf),
649 				       outbuf, sizeof(outbuf), rc);
650 		return rc;
651 	}
652 
653 	switch (fmt) {
654 	case MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_27FRACTION:
655 		ptp->ns_to_nic_time = efx_ptp_ns_to_s27;
656 		ptp->nic_to_kernel_time = efx_ptp_s27_to_ktime_correction;
657 		ptp->nic_time.minor_max = 1 << 27;
658 		ptp->nic_time.sync_event_minor_shift = 19;
659 		break;
660 	case MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_NANOSECONDS:
661 		ptp->ns_to_nic_time = efx_ptp_ns_to_s_ns;
662 		ptp->nic_to_kernel_time = efx_ptp_s_ns_to_ktime_correction;
663 		ptp->nic_time.minor_max = 1000000000;
664 		ptp->nic_time.sync_event_minor_shift = 22;
665 		break;
666 	case MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_QTR_NANOSECONDS:
667 		ptp->ns_to_nic_time = efx_ptp_ns_to_s_qns;
668 		ptp->nic_to_kernel_time = efx_ptp_s_qns_to_ktime_correction;
669 		ptp->nic_time.minor_max = 4000000000UL;
670 		ptp->nic_time.sync_event_minor_shift = 24;
671 		break;
672 	default:
673 		return -ERANGE;
674 	}
675 
676 	/* Precalculate acceptable difference between the minor time in the
677 	 * packet prefix and the last MCDI time sync event. We expect the
678 	 * packet prefix timestamp to be after of sync event by up to one
679 	 * sync event interval (0.25s) but we allow it to exceed this by a
680 	 * fuzz factor of (0.1s)
681 	 */
682 	ptp->nic_time.sync_event_diff_min = ptp->nic_time.minor_max
683 		- (ptp->nic_time.minor_max / 10);
684 	ptp->nic_time.sync_event_diff_max = (ptp->nic_time.minor_max / 4)
685 		+ (ptp->nic_time.minor_max / 10);
686 
687 	/* MC_CMD_PTP_OP_GET_ATTRIBUTES has been extended twice from an older
688 	 * operation MC_CMD_PTP_OP_GET_TIME_FORMAT. The function now may return
689 	 * a value to use for the minimum acceptable corrected synchronization
690 	 * window and may return further capabilities.
691 	 * If we have the extra information store it. For older firmware that
692 	 * does not implement the extended command use the default value.
693 	 */
694 	if (rc == 0 &&
695 	    out_len >= MC_CMD_PTP_OUT_GET_ATTRIBUTES_CAPABILITIES_OFST)
696 		ptp->min_synchronisation_ns =
697 			MCDI_DWORD(outbuf,
698 				   PTP_OUT_GET_ATTRIBUTES_SYNC_WINDOW_MIN);
699 	else
700 		ptp->min_synchronisation_ns = DEFAULT_MIN_SYNCHRONISATION_NS;
701 
702 	if (rc == 0 &&
703 	    out_len >= MC_CMD_PTP_OUT_GET_ATTRIBUTES_LEN)
704 		ptp->capabilities = MCDI_DWORD(outbuf,
705 					PTP_OUT_GET_ATTRIBUTES_CAPABILITIES);
706 	else
707 		ptp->capabilities = 0;
708 
709 	/* Set up the shift for conversion between frequency
710 	 * adjustments in parts-per-billion and the fixed-point
711 	 * fractional ns format that the adapter uses.
712 	 */
713 	if (ptp->capabilities & (1 << MC_CMD_PTP_OUT_GET_ATTRIBUTES_FP44_FREQ_ADJ_LBN))
714 		ptp->adjfreq_ppb_shift = PPB_SHIFT_FP44;
715 	else
716 		ptp->adjfreq_ppb_shift = PPB_SHIFT_FP40;
717 
718 	return 0;
719 }
720 
721 /* Get PTP timestamp corrections */
722 static int efx_ptp_get_timestamp_corrections(struct efx_nic *efx)
723 {
724 	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_GET_TIMESTAMP_CORRECTIONS_LEN);
725 	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_GET_TIMESTAMP_CORRECTIONS_V2_LEN);
726 	int rc;
727 	size_t out_len;
728 
729 	/* Get the timestamp corrections from the NIC. If this operation is
730 	 * not supported (older NICs) then no correction is required.
731 	 */
732 	MCDI_SET_DWORD(inbuf, PTP_IN_OP,
733 		       MC_CMD_PTP_OP_GET_TIMESTAMP_CORRECTIONS);
734 	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
735 
736 	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
737 				outbuf, sizeof(outbuf), &out_len);
738 	if (rc == 0) {
739 		efx->ptp_data->ts_corrections.ptp_tx = MCDI_DWORD(outbuf,
740 			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_TRANSMIT);
741 		efx->ptp_data->ts_corrections.ptp_rx = MCDI_DWORD(outbuf,
742 			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_RECEIVE);
743 		efx->ptp_data->ts_corrections.pps_out = MCDI_DWORD(outbuf,
744 			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_PPS_OUT);
745 		efx->ptp_data->ts_corrections.pps_in = MCDI_DWORD(outbuf,
746 			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_PPS_IN);
747 
748 		if (out_len >= MC_CMD_PTP_OUT_GET_TIMESTAMP_CORRECTIONS_V2_LEN) {
749 			efx->ptp_data->ts_corrections.general_tx = MCDI_DWORD(
750 				outbuf,
751 				PTP_OUT_GET_TIMESTAMP_CORRECTIONS_V2_GENERAL_TX);
752 			efx->ptp_data->ts_corrections.general_rx = MCDI_DWORD(
753 				outbuf,
754 				PTP_OUT_GET_TIMESTAMP_CORRECTIONS_V2_GENERAL_RX);
755 		} else {
756 			efx->ptp_data->ts_corrections.general_tx =
757 				efx->ptp_data->ts_corrections.ptp_tx;
758 			efx->ptp_data->ts_corrections.general_rx =
759 				efx->ptp_data->ts_corrections.ptp_rx;
760 		}
761 	} else if (rc == -EINVAL) {
762 		efx->ptp_data->ts_corrections.ptp_tx = 0;
763 		efx->ptp_data->ts_corrections.ptp_rx = 0;
764 		efx->ptp_data->ts_corrections.pps_out = 0;
765 		efx->ptp_data->ts_corrections.pps_in = 0;
766 		efx->ptp_data->ts_corrections.general_tx = 0;
767 		efx->ptp_data->ts_corrections.general_rx = 0;
768 	} else {
769 		efx_mcdi_display_error(efx, MC_CMD_PTP, sizeof(inbuf), outbuf,
770 				       sizeof(outbuf), rc);
771 		return rc;
772 	}
773 
774 	return 0;
775 }
776 
777 /* Enable MCDI PTP support. */
778 static int efx_ptp_enable(struct efx_nic *efx)
779 {
780 	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_ENABLE_LEN);
781 	MCDI_DECLARE_BUF_ERR(outbuf);
782 	int rc;
783 
784 	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_ENABLE);
785 	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
786 	MCDI_SET_DWORD(inbuf, PTP_IN_ENABLE_QUEUE,
787 		       efx->ptp_data->channel ?
788 		       efx->ptp_data->channel->channel : 0);
789 	MCDI_SET_DWORD(inbuf, PTP_IN_ENABLE_MODE, efx->ptp_data->mode);
790 
791 	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
792 				outbuf, sizeof(outbuf), NULL);
793 	rc = (rc == -EALREADY) ? 0 : rc;
794 	if (rc)
795 		efx_mcdi_display_error(efx, MC_CMD_PTP,
796 				       MC_CMD_PTP_IN_ENABLE_LEN,
797 				       outbuf, sizeof(outbuf), rc);
798 	return rc;
799 }
800 
801 /* Disable MCDI PTP support.
802  *
803  * Note that this function should never rely on the presence of ptp_data -
804  * may be called before that exists.
805  */
806 static int efx_ptp_disable(struct efx_nic *efx)
807 {
808 	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_DISABLE_LEN);
809 	MCDI_DECLARE_BUF_ERR(outbuf);
810 	int rc;
811 
812 	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_DISABLE);
813 	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
814 	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
815 				outbuf, sizeof(outbuf), NULL);
816 	rc = (rc == -EALREADY) ? 0 : rc;
817 	/* If we get ENOSYS, the NIC doesn't support PTP, and thus this function
818 	 * should only have been called during probe.
819 	 */
820 	if (rc == -ENOSYS || rc == -EPERM)
821 		netif_info(efx, probe, efx->net_dev, "no PTP support\n");
822 	else if (rc)
823 		efx_mcdi_display_error(efx, MC_CMD_PTP,
824 				       MC_CMD_PTP_IN_DISABLE_LEN,
825 				       outbuf, sizeof(outbuf), rc);
826 	return rc;
827 }
828 
829 static void efx_ptp_deliver_rx_queue(struct sk_buff_head *q)
830 {
831 	struct sk_buff *skb;
832 
833 	while ((skb = skb_dequeue(q))) {
834 		local_bh_disable();
835 		netif_receive_skb(skb);
836 		local_bh_enable();
837 	}
838 }
839 
840 static void efx_ptp_handle_no_channel(struct efx_nic *efx)
841 {
842 	netif_err(efx, drv, efx->net_dev,
843 		  "ERROR: PTP requires MSI-X and 1 additional interrupt"
844 		  "vector. PTP disabled\n");
845 }
846 
847 /* Repeatedly send the host time to the MC which will capture the hardware
848  * time.
849  */
850 static void efx_ptp_send_times(struct efx_nic *efx,
851 			       struct pps_event_time *last_time)
852 {
853 	struct pps_event_time now;
854 	struct timespec64 limit;
855 	struct efx_ptp_data *ptp = efx->ptp_data;
856 	int *mc_running = ptp->start.addr;
857 
858 	pps_get_ts(&now);
859 	limit = now.ts_real;
860 	timespec64_add_ns(&limit, SYNCHRONISE_PERIOD_NS);
861 
862 	/* Write host time for specified period or until MC is done */
863 	while ((timespec64_compare(&now.ts_real, &limit) < 0) &&
864 	       READ_ONCE(*mc_running)) {
865 		struct timespec64 update_time;
866 		unsigned int host_time;
867 
868 		/* Don't update continuously to avoid saturating the PCIe bus */
869 		update_time = now.ts_real;
870 		timespec64_add_ns(&update_time, SYNCHRONISATION_GRANULARITY_NS);
871 		do {
872 			pps_get_ts(&now);
873 		} while ((timespec64_compare(&now.ts_real, &update_time) < 0) &&
874 			 READ_ONCE(*mc_running));
875 
876 		/* Synchronise NIC with single word of time only */
877 		host_time = (now.ts_real.tv_sec << MC_NANOSECOND_BITS |
878 			     now.ts_real.tv_nsec);
879 		/* Update host time in NIC memory */
880 		efx->type->ptp_write_host_time(efx, host_time);
881 	}
882 	*last_time = now;
883 }
884 
885 /* Read a timeset from the MC's results and partial process. */
886 static void efx_ptp_read_timeset(MCDI_DECLARE_STRUCT_PTR(data),
887 				 struct efx_ptp_timeset *timeset)
888 {
889 	unsigned start_ns, end_ns;
890 
891 	timeset->host_start = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_HOSTSTART);
892 	timeset->major = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_MAJOR);
893 	timeset->minor = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_MINOR);
894 	timeset->host_end = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_HOSTEND),
895 	timeset->wait = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_WAITNS);
896 
897 	/* Ignore seconds */
898 	start_ns = timeset->host_start & MC_NANOSECOND_MASK;
899 	end_ns = timeset->host_end & MC_NANOSECOND_MASK;
900 	/* Allow for rollover */
901 	if (end_ns < start_ns)
902 		end_ns += NSEC_PER_SEC;
903 	/* Determine duration of operation */
904 	timeset->window = end_ns - start_ns;
905 }
906 
907 /* Process times received from MC.
908  *
909  * Extract times from returned results, and establish the minimum value
910  * seen.  The minimum value represents the "best" possible time and events
911  * too much greater than this are rejected - the machine is, perhaps, too
912  * busy. A number of readings are taken so that, hopefully, at least one good
913  * synchronisation will be seen in the results.
914  */
915 static int
916 efx_ptp_process_times(struct efx_nic *efx, MCDI_DECLARE_STRUCT_PTR(synch_buf),
917 		      size_t response_length,
918 		      const struct pps_event_time *last_time)
919 {
920 	unsigned number_readings =
921 		MCDI_VAR_ARRAY_LEN(response_length,
922 				   PTP_OUT_SYNCHRONIZE_TIMESET);
923 	unsigned i;
924 	unsigned ngood = 0;
925 	unsigned last_good = 0;
926 	struct efx_ptp_data *ptp = efx->ptp_data;
927 	u32 last_sec;
928 	u32 start_sec;
929 	struct timespec64 delta;
930 	ktime_t mc_time;
931 
932 	if (number_readings == 0)
933 		return -EAGAIN;
934 
935 	/* Read the set of results and find the last good host-MC
936 	 * synchronization result. The MC times when it finishes reading the
937 	 * host time so the corrected window time should be fairly constant
938 	 * for a given platform. Increment stats for any results that appear
939 	 * to be erroneous.
940 	 */
941 	for (i = 0; i < number_readings; i++) {
942 		s32 window, corrected;
943 		struct timespec64 wait;
944 
945 		efx_ptp_read_timeset(
946 			MCDI_ARRAY_STRUCT_PTR(synch_buf,
947 					      PTP_OUT_SYNCHRONIZE_TIMESET, i),
948 			&ptp->timeset[i]);
949 
950 		wait = ktime_to_timespec64(
951 			ptp->nic_to_kernel_time(0, ptp->timeset[i].wait, 0));
952 		window = ptp->timeset[i].window;
953 		corrected = window - wait.tv_nsec;
954 
955 		/* We expect the uncorrected synchronization window to be at
956 		 * least as large as the interval between host start and end
957 		 * times. If it is smaller than this then this is mostly likely
958 		 * to be a consequence of the host's time being adjusted.
959 		 * Check that the corrected sync window is in a reasonable
960 		 * range. If it is out of range it is likely to be because an
961 		 * interrupt or other delay occurred between reading the system
962 		 * time and writing it to MC memory.
963 		 */
964 		if (window < SYNCHRONISATION_GRANULARITY_NS) {
965 			++ptp->invalid_sync_windows;
966 		} else if (corrected >= MAX_SYNCHRONISATION_NS) {
967 			++ptp->oversize_sync_windows;
968 		} else if (corrected < ptp->min_synchronisation_ns) {
969 			++ptp->undersize_sync_windows;
970 		} else {
971 			ngood++;
972 			last_good = i;
973 		}
974 	}
975 
976 	if (ngood == 0) {
977 		netif_warn(efx, drv, efx->net_dev,
978 			   "PTP no suitable synchronisations\n");
979 		return -EAGAIN;
980 	}
981 
982 	/* Calculate delay from last good sync (host time) to last_time.
983 	 * It is possible that the seconds rolled over between taking
984 	 * the start reading and the last value written by the host.  The
985 	 * timescales are such that a gap of more than one second is never
986 	 * expected.  delta is *not* normalised.
987 	 */
988 	start_sec = ptp->timeset[last_good].host_start >> MC_NANOSECOND_BITS;
989 	last_sec = last_time->ts_real.tv_sec & MC_SECOND_MASK;
990 	if (start_sec != last_sec &&
991 	    ((start_sec + 1) & MC_SECOND_MASK) != last_sec) {
992 		netif_warn(efx, hw, efx->net_dev,
993 			   "PTP bad synchronisation seconds\n");
994 		return -EAGAIN;
995 	}
996 	delta.tv_sec = (last_sec - start_sec) & 1;
997 	delta.tv_nsec =
998 		last_time->ts_real.tv_nsec -
999 		(ptp->timeset[last_good].host_start & MC_NANOSECOND_MASK);
1000 
1001 	/* Convert the NIC time at last good sync into kernel time.
1002 	 * No correction is required - this time is the output of a
1003 	 * firmware process.
1004 	 */
1005 	mc_time = ptp->nic_to_kernel_time(ptp->timeset[last_good].major,
1006 					  ptp->timeset[last_good].minor, 0);
1007 
1008 	/* Calculate delay from NIC top of second to last_time */
1009 	delta.tv_nsec += ktime_to_timespec64(mc_time).tv_nsec;
1010 
1011 	/* Set PPS timestamp to match NIC top of second */
1012 	ptp->host_time_pps = *last_time;
1013 	pps_sub_ts(&ptp->host_time_pps, delta);
1014 
1015 	return 0;
1016 }
1017 
1018 /* Synchronize times between the host and the MC */
1019 static int efx_ptp_synchronize(struct efx_nic *efx, unsigned int num_readings)
1020 {
1021 	struct efx_ptp_data *ptp = efx->ptp_data;
1022 	MCDI_DECLARE_BUF(synch_buf, MC_CMD_PTP_OUT_SYNCHRONIZE_LENMAX);
1023 	size_t response_length;
1024 	int rc;
1025 	unsigned long timeout;
1026 	struct pps_event_time last_time = {};
1027 	unsigned int loops = 0;
1028 	int *start = ptp->start.addr;
1029 
1030 	MCDI_SET_DWORD(synch_buf, PTP_IN_OP, MC_CMD_PTP_OP_SYNCHRONIZE);
1031 	MCDI_SET_DWORD(synch_buf, PTP_IN_PERIPH_ID, 0);
1032 	MCDI_SET_DWORD(synch_buf, PTP_IN_SYNCHRONIZE_NUMTIMESETS,
1033 		       num_readings);
1034 	MCDI_SET_QWORD(synch_buf, PTP_IN_SYNCHRONIZE_START_ADDR,
1035 		       ptp->start.dma_addr);
1036 
1037 	/* Clear flag that signals MC ready */
1038 	WRITE_ONCE(*start, 0);
1039 	rc = efx_mcdi_rpc_start(efx, MC_CMD_PTP, synch_buf,
1040 				MC_CMD_PTP_IN_SYNCHRONIZE_LEN);
1041 	EFX_WARN_ON_ONCE_PARANOID(rc);
1042 
1043 	/* Wait for start from MCDI (or timeout) */
1044 	timeout = jiffies + msecs_to_jiffies(MAX_SYNCHRONISE_WAIT_MS);
1045 	while (!READ_ONCE(*start) && (time_before(jiffies, timeout))) {
1046 		udelay(20);	/* Usually start MCDI execution quickly */
1047 		loops++;
1048 	}
1049 
1050 	if (loops <= 1)
1051 		++ptp->fast_syncs;
1052 	if (!time_before(jiffies, timeout))
1053 		++ptp->sync_timeouts;
1054 
1055 	if (READ_ONCE(*start))
1056 		efx_ptp_send_times(efx, &last_time);
1057 
1058 	/* Collect results */
1059 	rc = efx_mcdi_rpc_finish(efx, MC_CMD_PTP,
1060 				 MC_CMD_PTP_IN_SYNCHRONIZE_LEN,
1061 				 synch_buf, sizeof(synch_buf),
1062 				 &response_length);
1063 	if (rc == 0) {
1064 		rc = efx_ptp_process_times(efx, synch_buf, response_length,
1065 					   &last_time);
1066 		if (rc == 0)
1067 			++ptp->good_syncs;
1068 		else
1069 			++ptp->no_time_syncs;
1070 	}
1071 
1072 	/* Increment the bad syncs counter if the synchronize fails, whatever
1073 	 * the reason.
1074 	 */
1075 	if (rc != 0)
1076 		++ptp->bad_syncs;
1077 
1078 	return rc;
1079 }
1080 
1081 /* Transmit a PTP packet via the dedicated hardware timestamped queue. */
1082 static void efx_ptp_xmit_skb_queue(struct efx_nic *efx, struct sk_buff *skb)
1083 {
1084 	struct efx_ptp_data *ptp_data = efx->ptp_data;
1085 	struct efx_tx_queue *tx_queue;
1086 	u8 type = skb->ip_summed == CHECKSUM_PARTIAL ? EFX_TXQ_TYPE_OFFLOAD : 0;
1087 
1088 	tx_queue = &ptp_data->channel->tx_queue[type];
1089 	if (tx_queue && tx_queue->timestamping) {
1090 		efx_enqueue_skb(tx_queue, skb);
1091 	} else {
1092 		WARN_ONCE(1, "PTP channel has no timestamped tx queue\n");
1093 		dev_kfree_skb_any(skb);
1094 	}
1095 }
1096 
1097 /* Transmit a PTP packet, via the MCDI interface, to the wire. */
1098 static void efx_ptp_xmit_skb_mc(struct efx_nic *efx, struct sk_buff *skb)
1099 {
1100 	struct efx_ptp_data *ptp_data = efx->ptp_data;
1101 	struct skb_shared_hwtstamps timestamps;
1102 	int rc = -EIO;
1103 	MCDI_DECLARE_BUF(txtime, MC_CMD_PTP_OUT_TRANSMIT_LEN);
1104 	size_t len;
1105 
1106 	MCDI_SET_DWORD(ptp_data->txbuf, PTP_IN_OP, MC_CMD_PTP_OP_TRANSMIT);
1107 	MCDI_SET_DWORD(ptp_data->txbuf, PTP_IN_PERIPH_ID, 0);
1108 	MCDI_SET_DWORD(ptp_data->txbuf, PTP_IN_TRANSMIT_LENGTH, skb->len);
1109 	if (skb_shinfo(skb)->nr_frags != 0) {
1110 		rc = skb_linearize(skb);
1111 		if (rc != 0)
1112 			goto fail;
1113 	}
1114 
1115 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
1116 		rc = skb_checksum_help(skb);
1117 		if (rc != 0)
1118 			goto fail;
1119 	}
1120 	skb_copy_from_linear_data(skb,
1121 				  MCDI_PTR(ptp_data->txbuf,
1122 					   PTP_IN_TRANSMIT_PACKET),
1123 				  skb->len);
1124 	rc = efx_mcdi_rpc(efx, MC_CMD_PTP,
1125 			  ptp_data->txbuf, MC_CMD_PTP_IN_TRANSMIT_LEN(skb->len),
1126 			  txtime, sizeof(txtime), &len);
1127 	if (rc != 0)
1128 		goto fail;
1129 
1130 	memset(&timestamps, 0, sizeof(timestamps));
1131 	timestamps.hwtstamp = ptp_data->nic_to_kernel_time(
1132 		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_MAJOR),
1133 		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_MINOR),
1134 		ptp_data->ts_corrections.ptp_tx);
1135 
1136 	skb_tstamp_tx(skb, &timestamps);
1137 
1138 	rc = 0;
1139 
1140 fail:
1141 	dev_kfree_skb_any(skb);
1142 
1143 	return;
1144 }
1145 
1146 static void efx_ptp_drop_time_expired_events(struct efx_nic *efx)
1147 {
1148 	struct efx_ptp_data *ptp = efx->ptp_data;
1149 	struct list_head *cursor;
1150 	struct list_head *next;
1151 
1152 	if (ptp->rx_ts_inline)
1153 		return;
1154 
1155 	/* Drop time-expired events */
1156 	spin_lock_bh(&ptp->evt_lock);
1157 	list_for_each_safe(cursor, next, &ptp->evt_list) {
1158 		struct efx_ptp_event_rx *evt;
1159 
1160 		evt = list_entry(cursor, struct efx_ptp_event_rx,
1161 				 link);
1162 		if (time_after(jiffies, evt->expiry)) {
1163 			list_move(&evt->link, &ptp->evt_free_list);
1164 			netif_warn(efx, hw, efx->net_dev,
1165 				   "PTP rx event dropped\n");
1166 		}
1167 	}
1168 	spin_unlock_bh(&ptp->evt_lock);
1169 }
1170 
1171 static enum ptp_packet_state efx_ptp_match_rx(struct efx_nic *efx,
1172 					      struct sk_buff *skb)
1173 {
1174 	struct efx_ptp_data *ptp = efx->ptp_data;
1175 	bool evts_waiting;
1176 	struct list_head *cursor;
1177 	struct list_head *next;
1178 	struct efx_ptp_match *match;
1179 	enum ptp_packet_state rc = PTP_PACKET_STATE_UNMATCHED;
1180 
1181 	WARN_ON_ONCE(ptp->rx_ts_inline);
1182 
1183 	spin_lock_bh(&ptp->evt_lock);
1184 	evts_waiting = !list_empty(&ptp->evt_list);
1185 	spin_unlock_bh(&ptp->evt_lock);
1186 
1187 	if (!evts_waiting)
1188 		return PTP_PACKET_STATE_UNMATCHED;
1189 
1190 	match = (struct efx_ptp_match *)skb->cb;
1191 	/* Look for a matching timestamp in the event queue */
1192 	spin_lock_bh(&ptp->evt_lock);
1193 	list_for_each_safe(cursor, next, &ptp->evt_list) {
1194 		struct efx_ptp_event_rx *evt;
1195 
1196 		evt = list_entry(cursor, struct efx_ptp_event_rx, link);
1197 		if ((evt->seq0 == match->words[0]) &&
1198 		    (evt->seq1 == match->words[1])) {
1199 			struct skb_shared_hwtstamps *timestamps;
1200 
1201 			/* Match - add in hardware timestamp */
1202 			timestamps = skb_hwtstamps(skb);
1203 			timestamps->hwtstamp = evt->hwtimestamp;
1204 
1205 			match->state = PTP_PACKET_STATE_MATCHED;
1206 			rc = PTP_PACKET_STATE_MATCHED;
1207 			list_move(&evt->link, &ptp->evt_free_list);
1208 			break;
1209 		}
1210 	}
1211 	spin_unlock_bh(&ptp->evt_lock);
1212 
1213 	return rc;
1214 }
1215 
1216 /* Process any queued receive events and corresponding packets
1217  *
1218  * q is returned with all the packets that are ready for delivery.
1219  */
1220 static void efx_ptp_process_events(struct efx_nic *efx, struct sk_buff_head *q)
1221 {
1222 	struct efx_ptp_data *ptp = efx->ptp_data;
1223 	struct sk_buff *skb;
1224 
1225 	while ((skb = skb_dequeue(&ptp->rxq))) {
1226 		struct efx_ptp_match *match;
1227 
1228 		match = (struct efx_ptp_match *)skb->cb;
1229 		if (match->state == PTP_PACKET_STATE_MATCH_UNWANTED) {
1230 			__skb_queue_tail(q, skb);
1231 		} else if (efx_ptp_match_rx(efx, skb) ==
1232 			   PTP_PACKET_STATE_MATCHED) {
1233 			__skb_queue_tail(q, skb);
1234 		} else if (time_after(jiffies, match->expiry)) {
1235 			match->state = PTP_PACKET_STATE_TIMED_OUT;
1236 			++ptp->rx_no_timestamp;
1237 			__skb_queue_tail(q, skb);
1238 		} else {
1239 			/* Replace unprocessed entry and stop */
1240 			skb_queue_head(&ptp->rxq, skb);
1241 			break;
1242 		}
1243 	}
1244 }
1245 
1246 /* Complete processing of a received packet */
1247 static inline void efx_ptp_process_rx(struct efx_nic *efx, struct sk_buff *skb)
1248 {
1249 	local_bh_disable();
1250 	netif_receive_skb(skb);
1251 	local_bh_enable();
1252 }
1253 
1254 static void efx_ptp_remove_multicast_filters(struct efx_nic *efx)
1255 {
1256 	struct efx_ptp_data *ptp = efx->ptp_data;
1257 
1258 	if (ptp->rxfilter_installed) {
1259 		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
1260 					  ptp->rxfilter_general);
1261 		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
1262 					  ptp->rxfilter_event);
1263 		ptp->rxfilter_installed = false;
1264 	}
1265 }
1266 
1267 static int efx_ptp_insert_multicast_filters(struct efx_nic *efx)
1268 {
1269 	struct efx_ptp_data *ptp = efx->ptp_data;
1270 	struct efx_filter_spec rxfilter;
1271 	int rc;
1272 
1273 	if (!ptp->channel || ptp->rxfilter_installed)
1274 		return 0;
1275 
1276 	/* Must filter on both event and general ports to ensure
1277 	 * that there is no packet re-ordering.
1278 	 */
1279 	efx_filter_init_rx(&rxfilter, EFX_FILTER_PRI_REQUIRED, 0,
1280 			   efx_rx_queue_index(
1281 				   efx_channel_get_rx_queue(ptp->channel)));
1282 	rc = efx_filter_set_ipv4_local(&rxfilter, IPPROTO_UDP,
1283 				       htonl(PTP_ADDRESS),
1284 				       htons(PTP_EVENT_PORT));
1285 	if (rc != 0)
1286 		return rc;
1287 
1288 	rc = efx_filter_insert_filter(efx, &rxfilter, true);
1289 	if (rc < 0)
1290 		return rc;
1291 	ptp->rxfilter_event = rc;
1292 
1293 	efx_filter_init_rx(&rxfilter, EFX_FILTER_PRI_REQUIRED, 0,
1294 			   efx_rx_queue_index(
1295 				   efx_channel_get_rx_queue(ptp->channel)));
1296 	rc = efx_filter_set_ipv4_local(&rxfilter, IPPROTO_UDP,
1297 				       htonl(PTP_ADDRESS),
1298 				       htons(PTP_GENERAL_PORT));
1299 	if (rc != 0)
1300 		goto fail;
1301 
1302 	rc = efx_filter_insert_filter(efx, &rxfilter, true);
1303 	if (rc < 0)
1304 		goto fail;
1305 	ptp->rxfilter_general = rc;
1306 
1307 	ptp->rxfilter_installed = true;
1308 	return 0;
1309 
1310 fail:
1311 	efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
1312 				  ptp->rxfilter_event);
1313 	return rc;
1314 }
1315 
1316 static int efx_ptp_start(struct efx_nic *efx)
1317 {
1318 	struct efx_ptp_data *ptp = efx->ptp_data;
1319 	int rc;
1320 
1321 	ptp->reset_required = false;
1322 
1323 	rc = efx_ptp_insert_multicast_filters(efx);
1324 	if (rc)
1325 		return rc;
1326 
1327 	rc = efx_ptp_enable(efx);
1328 	if (rc != 0)
1329 		goto fail;
1330 
1331 	ptp->evt_frag_idx = 0;
1332 	ptp->current_adjfreq = 0;
1333 
1334 	return 0;
1335 
1336 fail:
1337 	efx_ptp_remove_multicast_filters(efx);
1338 	return rc;
1339 }
1340 
1341 static int efx_ptp_stop(struct efx_nic *efx)
1342 {
1343 	struct efx_ptp_data *ptp = efx->ptp_data;
1344 	struct list_head *cursor;
1345 	struct list_head *next;
1346 	int rc;
1347 
1348 	if (ptp == NULL)
1349 		return 0;
1350 
1351 	rc = efx_ptp_disable(efx);
1352 
1353 	efx_ptp_remove_multicast_filters(efx);
1354 
1355 	/* Make sure RX packets are really delivered */
1356 	efx_ptp_deliver_rx_queue(&efx->ptp_data->rxq);
1357 	skb_queue_purge(&efx->ptp_data->txq);
1358 
1359 	/* Drop any pending receive events */
1360 	spin_lock_bh(&efx->ptp_data->evt_lock);
1361 	list_for_each_safe(cursor, next, &efx->ptp_data->evt_list) {
1362 		list_move(cursor, &efx->ptp_data->evt_free_list);
1363 	}
1364 	spin_unlock_bh(&efx->ptp_data->evt_lock);
1365 
1366 	return rc;
1367 }
1368 
1369 static int efx_ptp_restart(struct efx_nic *efx)
1370 {
1371 	if (efx->ptp_data && efx->ptp_data->enabled)
1372 		return efx_ptp_start(efx);
1373 	return 0;
1374 }
1375 
1376 static void efx_ptp_pps_worker(struct work_struct *work)
1377 {
1378 	struct efx_ptp_data *ptp =
1379 		container_of(work, struct efx_ptp_data, pps_work);
1380 	struct efx_nic *efx = ptp->efx;
1381 	struct ptp_clock_event ptp_evt;
1382 
1383 	if (efx_ptp_synchronize(efx, PTP_SYNC_ATTEMPTS))
1384 		return;
1385 
1386 	ptp_evt.type = PTP_CLOCK_PPSUSR;
1387 	ptp_evt.pps_times = ptp->host_time_pps;
1388 	ptp_clock_event(ptp->phc_clock, &ptp_evt);
1389 }
1390 
1391 static void efx_ptp_worker(struct work_struct *work)
1392 {
1393 	struct efx_ptp_data *ptp_data =
1394 		container_of(work, struct efx_ptp_data, work);
1395 	struct efx_nic *efx = ptp_data->efx;
1396 	struct sk_buff *skb;
1397 	struct sk_buff_head tempq;
1398 
1399 	if (ptp_data->reset_required) {
1400 		efx_ptp_stop(efx);
1401 		efx_ptp_start(efx);
1402 		return;
1403 	}
1404 
1405 	efx_ptp_drop_time_expired_events(efx);
1406 
1407 	__skb_queue_head_init(&tempq);
1408 	efx_ptp_process_events(efx, &tempq);
1409 
1410 	while ((skb = skb_dequeue(&ptp_data->txq)))
1411 		ptp_data->xmit_skb(efx, skb);
1412 
1413 	while ((skb = __skb_dequeue(&tempq)))
1414 		efx_ptp_process_rx(efx, skb);
1415 }
1416 
1417 static const struct ptp_clock_info efx_phc_clock_info = {
1418 	.owner		= THIS_MODULE,
1419 	.name		= "sfc",
1420 	.max_adj	= MAX_PPB,
1421 	.n_alarm	= 0,
1422 	.n_ext_ts	= 0,
1423 	.n_per_out	= 0,
1424 	.n_pins		= 0,
1425 	.pps		= 1,
1426 	.adjfreq	= efx_phc_adjfreq,
1427 	.adjtime	= efx_phc_adjtime,
1428 	.gettime64	= efx_phc_gettime,
1429 	.settime64	= efx_phc_settime,
1430 	.enable		= efx_phc_enable,
1431 };
1432 
1433 /* Initialise PTP state. */
1434 int efx_ptp_probe(struct efx_nic *efx, struct efx_channel *channel)
1435 {
1436 	struct efx_ptp_data *ptp;
1437 	int rc = 0;
1438 	unsigned int pos;
1439 
1440 	ptp = kzalloc(sizeof(struct efx_ptp_data), GFP_KERNEL);
1441 	efx->ptp_data = ptp;
1442 	if (!efx->ptp_data)
1443 		return -ENOMEM;
1444 
1445 	ptp->efx = efx;
1446 	ptp->channel = channel;
1447 	ptp->rx_ts_inline = efx_nic_rev(efx) >= EFX_REV_HUNT_A0;
1448 
1449 	rc = efx_nic_alloc_buffer(efx, &ptp->start, sizeof(int), GFP_KERNEL);
1450 	if (rc != 0)
1451 		goto fail1;
1452 
1453 	skb_queue_head_init(&ptp->rxq);
1454 	skb_queue_head_init(&ptp->txq);
1455 	ptp->workwq = create_singlethread_workqueue("sfc_ptp");
1456 	if (!ptp->workwq) {
1457 		rc = -ENOMEM;
1458 		goto fail2;
1459 	}
1460 
1461 	if (efx_ptp_use_mac_tx_timestamps(efx)) {
1462 		ptp->xmit_skb = efx_ptp_xmit_skb_queue;
1463 		/* Request sync events on this channel. */
1464 		channel->sync_events_state = SYNC_EVENTS_QUIESCENT;
1465 	} else {
1466 		ptp->xmit_skb = efx_ptp_xmit_skb_mc;
1467 	}
1468 
1469 	INIT_WORK(&ptp->work, efx_ptp_worker);
1470 	ptp->config.flags = 0;
1471 	ptp->config.tx_type = HWTSTAMP_TX_OFF;
1472 	ptp->config.rx_filter = HWTSTAMP_FILTER_NONE;
1473 	INIT_LIST_HEAD(&ptp->evt_list);
1474 	INIT_LIST_HEAD(&ptp->evt_free_list);
1475 	spin_lock_init(&ptp->evt_lock);
1476 	for (pos = 0; pos < MAX_RECEIVE_EVENTS; pos++)
1477 		list_add(&ptp->rx_evts[pos].link, &ptp->evt_free_list);
1478 
1479 	/* Get the NIC PTP attributes and set up time conversions */
1480 	rc = efx_ptp_get_attributes(efx);
1481 	if (rc < 0)
1482 		goto fail3;
1483 
1484 	/* Get the timestamp corrections */
1485 	rc = efx_ptp_get_timestamp_corrections(efx);
1486 	if (rc < 0)
1487 		goto fail3;
1488 
1489 	if (efx->mcdi->fn_flags &
1490 	    (1 << MC_CMD_DRV_ATTACH_EXT_OUT_FLAG_PRIMARY)) {
1491 		ptp->phc_clock_info = efx_phc_clock_info;
1492 		ptp->phc_clock = ptp_clock_register(&ptp->phc_clock_info,
1493 						    &efx->pci_dev->dev);
1494 		if (IS_ERR(ptp->phc_clock)) {
1495 			rc = PTR_ERR(ptp->phc_clock);
1496 			goto fail3;
1497 		} else if (ptp->phc_clock) {
1498 			INIT_WORK(&ptp->pps_work, efx_ptp_pps_worker);
1499 			ptp->pps_workwq = create_singlethread_workqueue("sfc_pps");
1500 			if (!ptp->pps_workwq) {
1501 				rc = -ENOMEM;
1502 				goto fail4;
1503 			}
1504 		}
1505 	}
1506 	ptp->nic_ts_enabled = false;
1507 
1508 	return 0;
1509 fail4:
1510 	ptp_clock_unregister(efx->ptp_data->phc_clock);
1511 
1512 fail3:
1513 	destroy_workqueue(efx->ptp_data->workwq);
1514 
1515 fail2:
1516 	efx_nic_free_buffer(efx, &ptp->start);
1517 
1518 fail1:
1519 	kfree(efx->ptp_data);
1520 	efx->ptp_data = NULL;
1521 
1522 	return rc;
1523 }
1524 
1525 /* Initialise PTP channel.
1526  *
1527  * Setting core_index to zero causes the queue to be initialised and doesn't
1528  * overlap with 'rxq0' because ptp.c doesn't use skb_record_rx_queue.
1529  */
1530 static int efx_ptp_probe_channel(struct efx_channel *channel)
1531 {
1532 	struct efx_nic *efx = channel->efx;
1533 	int rc;
1534 
1535 	channel->irq_moderation_us = 0;
1536 	channel->rx_queue.core_index = 0;
1537 
1538 	rc = efx_ptp_probe(efx, channel);
1539 	/* Failure to probe PTP is not fatal; this channel will just not be
1540 	 * used for anything.
1541 	 * In the case of EPERM, efx_ptp_probe will print its own message (in
1542 	 * efx_ptp_get_attributes()), so we don't need to.
1543 	 */
1544 	if (rc && rc != -EPERM)
1545 		netif_warn(efx, drv, efx->net_dev,
1546 			   "Failed to probe PTP, rc=%d\n", rc);
1547 	return 0;
1548 }
1549 
1550 void efx_ptp_remove(struct efx_nic *efx)
1551 {
1552 	if (!efx->ptp_data)
1553 		return;
1554 
1555 	(void)efx_ptp_disable(efx);
1556 
1557 	cancel_work_sync(&efx->ptp_data->work);
1558 	if (efx->ptp_data->pps_workwq)
1559 		cancel_work_sync(&efx->ptp_data->pps_work);
1560 
1561 	skb_queue_purge(&efx->ptp_data->rxq);
1562 	skb_queue_purge(&efx->ptp_data->txq);
1563 
1564 	if (efx->ptp_data->phc_clock) {
1565 		destroy_workqueue(efx->ptp_data->pps_workwq);
1566 		ptp_clock_unregister(efx->ptp_data->phc_clock);
1567 	}
1568 
1569 	destroy_workqueue(efx->ptp_data->workwq);
1570 
1571 	efx_nic_free_buffer(efx, &efx->ptp_data->start);
1572 	kfree(efx->ptp_data);
1573 	efx->ptp_data = NULL;
1574 }
1575 
1576 static void efx_ptp_remove_channel(struct efx_channel *channel)
1577 {
1578 	efx_ptp_remove(channel->efx);
1579 }
1580 
1581 static void efx_ptp_get_channel_name(struct efx_channel *channel,
1582 				     char *buf, size_t len)
1583 {
1584 	snprintf(buf, len, "%s-ptp", channel->efx->name);
1585 }
1586 
1587 /* Determine whether this packet should be processed by the PTP module
1588  * or transmitted conventionally.
1589  */
1590 bool efx_ptp_is_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
1591 {
1592 	return efx->ptp_data &&
1593 		efx->ptp_data->enabled &&
1594 		skb->len >= PTP_MIN_LENGTH &&
1595 		skb->len <= MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM &&
1596 		likely(skb->protocol == htons(ETH_P_IP)) &&
1597 		skb_transport_header_was_set(skb) &&
1598 		skb_network_header_len(skb) >= sizeof(struct iphdr) &&
1599 		ip_hdr(skb)->protocol == IPPROTO_UDP &&
1600 		skb_headlen(skb) >=
1601 		skb_transport_offset(skb) + sizeof(struct udphdr) &&
1602 		udp_hdr(skb)->dest == htons(PTP_EVENT_PORT);
1603 }
1604 
1605 /* Receive a PTP packet.  Packets are queued until the arrival of
1606  * the receive timestamp from the MC - this will probably occur after the
1607  * packet arrival because of the processing in the MC.
1608  */
1609 static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
1610 {
1611 	struct efx_nic *efx = channel->efx;
1612 	struct efx_ptp_data *ptp = efx->ptp_data;
1613 	struct efx_ptp_match *match = (struct efx_ptp_match *)skb->cb;
1614 	u8 *match_data_012, *match_data_345;
1615 	unsigned int version;
1616 	u8 *data;
1617 
1618 	match->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS);
1619 
1620 	/* Correct version? */
1621 	if (ptp->mode == MC_CMD_PTP_MODE_V1) {
1622 		if (!pskb_may_pull(skb, PTP_V1_MIN_LENGTH)) {
1623 			return false;
1624 		}
1625 		data = skb->data;
1626 		version = ntohs(*(__be16 *)&data[PTP_V1_VERSION_OFFSET]);
1627 		if (version != PTP_VERSION_V1) {
1628 			return false;
1629 		}
1630 
1631 		/* PTP V1 uses all six bytes of the UUID to match the packet
1632 		 * to the timestamp
1633 		 */
1634 		match_data_012 = data + PTP_V1_UUID_OFFSET;
1635 		match_data_345 = data + PTP_V1_UUID_OFFSET + 3;
1636 	} else {
1637 		if (!pskb_may_pull(skb, PTP_V2_MIN_LENGTH)) {
1638 			return false;
1639 		}
1640 		data = skb->data;
1641 		version = data[PTP_V2_VERSION_OFFSET];
1642 		if ((version & PTP_VERSION_V2_MASK) != PTP_VERSION_V2) {
1643 			return false;
1644 		}
1645 
1646 		/* The original V2 implementation uses bytes 2-7 of
1647 		 * the UUID to match the packet to the timestamp. This
1648 		 * discards two of the bytes of the MAC address used
1649 		 * to create the UUID (SF bug 33070).  The PTP V2
1650 		 * enhanced mode fixes this issue and uses bytes 0-2
1651 		 * and byte 5-7 of the UUID.
1652 		 */
1653 		match_data_345 = data + PTP_V2_UUID_OFFSET + 5;
1654 		if (ptp->mode == MC_CMD_PTP_MODE_V2) {
1655 			match_data_012 = data + PTP_V2_UUID_OFFSET + 2;
1656 		} else {
1657 			match_data_012 = data + PTP_V2_UUID_OFFSET + 0;
1658 			BUG_ON(ptp->mode != MC_CMD_PTP_MODE_V2_ENHANCED);
1659 		}
1660 	}
1661 
1662 	/* Does this packet require timestamping? */
1663 	if (ntohs(*(__be16 *)&data[PTP_DPORT_OFFSET]) == PTP_EVENT_PORT) {
1664 		match->state = PTP_PACKET_STATE_UNMATCHED;
1665 
1666 		/* We expect the sequence number to be in the same position in
1667 		 * the packet for PTP V1 and V2
1668 		 */
1669 		BUILD_BUG_ON(PTP_V1_SEQUENCE_OFFSET != PTP_V2_SEQUENCE_OFFSET);
1670 		BUILD_BUG_ON(PTP_V1_SEQUENCE_LENGTH != PTP_V2_SEQUENCE_LENGTH);
1671 
1672 		/* Extract UUID/Sequence information */
1673 		match->words[0] = (match_data_012[0]         |
1674 				   (match_data_012[1] << 8)  |
1675 				   (match_data_012[2] << 16) |
1676 				   (match_data_345[0] << 24));
1677 		match->words[1] = (match_data_345[1]         |
1678 				   (match_data_345[2] << 8)  |
1679 				   (data[PTP_V1_SEQUENCE_OFFSET +
1680 					 PTP_V1_SEQUENCE_LENGTH - 1] <<
1681 				    16));
1682 	} else {
1683 		match->state = PTP_PACKET_STATE_MATCH_UNWANTED;
1684 	}
1685 
1686 	skb_queue_tail(&ptp->rxq, skb);
1687 	queue_work(ptp->workwq, &ptp->work);
1688 
1689 	return true;
1690 }
1691 
1692 /* Transmit a PTP packet.  This has to be transmitted by the MC
1693  * itself, through an MCDI call.  MCDI calls aren't permitted
1694  * in the transmit path so defer the actual transmission to a suitable worker.
1695  */
1696 int efx_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
1697 {
1698 	struct efx_ptp_data *ptp = efx->ptp_data;
1699 
1700 	skb_queue_tail(&ptp->txq, skb);
1701 
1702 	if ((udp_hdr(skb)->dest == htons(PTP_EVENT_PORT)) &&
1703 	    (skb->len <= MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM))
1704 		efx_xmit_hwtstamp_pending(skb);
1705 	queue_work(ptp->workwq, &ptp->work);
1706 
1707 	return NETDEV_TX_OK;
1708 }
1709 
1710 int efx_ptp_get_mode(struct efx_nic *efx)
1711 {
1712 	return efx->ptp_data->mode;
1713 }
1714 
1715 int efx_ptp_change_mode(struct efx_nic *efx, bool enable_wanted,
1716 			unsigned int new_mode)
1717 {
1718 	if ((enable_wanted != efx->ptp_data->enabled) ||
1719 	    (enable_wanted && (efx->ptp_data->mode != new_mode))) {
1720 		int rc = 0;
1721 
1722 		if (enable_wanted) {
1723 			/* Change of mode requires disable */
1724 			if (efx->ptp_data->enabled &&
1725 			    (efx->ptp_data->mode != new_mode)) {
1726 				efx->ptp_data->enabled = false;
1727 				rc = efx_ptp_stop(efx);
1728 				if (rc != 0)
1729 					return rc;
1730 			}
1731 
1732 			/* Set new operating mode and establish
1733 			 * baseline synchronisation, which must
1734 			 * succeed.
1735 			 */
1736 			efx->ptp_data->mode = new_mode;
1737 			if (netif_running(efx->net_dev))
1738 				rc = efx_ptp_start(efx);
1739 			if (rc == 0) {
1740 				rc = efx_ptp_synchronize(efx,
1741 							 PTP_SYNC_ATTEMPTS * 2);
1742 				if (rc != 0)
1743 					efx_ptp_stop(efx);
1744 			}
1745 		} else {
1746 			rc = efx_ptp_stop(efx);
1747 		}
1748 
1749 		if (rc != 0)
1750 			return rc;
1751 
1752 		efx->ptp_data->enabled = enable_wanted;
1753 	}
1754 
1755 	return 0;
1756 }
1757 
1758 static int efx_ptp_ts_init(struct efx_nic *efx, struct hwtstamp_config *init)
1759 {
1760 	int rc;
1761 
1762 	if (init->flags)
1763 		return -EINVAL;
1764 
1765 	if ((init->tx_type != HWTSTAMP_TX_OFF) &&
1766 	    (init->tx_type != HWTSTAMP_TX_ON))
1767 		return -ERANGE;
1768 
1769 	rc = efx->type->ptp_set_ts_config(efx, init);
1770 	if (rc)
1771 		return rc;
1772 
1773 	efx->ptp_data->config = *init;
1774 	return 0;
1775 }
1776 
1777 void efx_ptp_get_ts_info(struct efx_nic *efx, struct ethtool_ts_info *ts_info)
1778 {
1779 	struct efx_ptp_data *ptp = efx->ptp_data;
1780 	struct efx_nic *primary = efx->primary;
1781 
1782 	ASSERT_RTNL();
1783 
1784 	if (!ptp)
1785 		return;
1786 
1787 	ts_info->so_timestamping |= (SOF_TIMESTAMPING_TX_HARDWARE |
1788 				     SOF_TIMESTAMPING_RX_HARDWARE |
1789 				     SOF_TIMESTAMPING_RAW_HARDWARE);
1790 	/* Check licensed features.  If we don't have the license for TX
1791 	 * timestamps, the NIC will not support them.
1792 	 */
1793 	if (efx_ptp_use_mac_tx_timestamps(efx)) {
1794 		struct efx_ef10_nic_data *nic_data = efx->nic_data;
1795 
1796 		if (!(nic_data->licensed_features &
1797 		      (1 << LICENSED_V3_FEATURES_TX_TIMESTAMPS_LBN)))
1798 			ts_info->so_timestamping &=
1799 				~SOF_TIMESTAMPING_TX_HARDWARE;
1800 	}
1801 	if (primary && primary->ptp_data && primary->ptp_data->phc_clock)
1802 		ts_info->phc_index =
1803 			ptp_clock_index(primary->ptp_data->phc_clock);
1804 	ts_info->tx_types = 1 << HWTSTAMP_TX_OFF | 1 << HWTSTAMP_TX_ON;
1805 	ts_info->rx_filters = ptp->efx->type->hwtstamp_filters;
1806 }
1807 
1808 int efx_ptp_set_ts_config(struct efx_nic *efx, struct ifreq *ifr)
1809 {
1810 	struct hwtstamp_config config;
1811 	int rc;
1812 
1813 	/* Not a PTP enabled port */
1814 	if (!efx->ptp_data)
1815 		return -EOPNOTSUPP;
1816 
1817 	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
1818 		return -EFAULT;
1819 
1820 	rc = efx_ptp_ts_init(efx, &config);
1821 	if (rc != 0)
1822 		return rc;
1823 
1824 	return copy_to_user(ifr->ifr_data, &config, sizeof(config))
1825 		? -EFAULT : 0;
1826 }
1827 
1828 int efx_ptp_get_ts_config(struct efx_nic *efx, struct ifreq *ifr)
1829 {
1830 	if (!efx->ptp_data)
1831 		return -EOPNOTSUPP;
1832 
1833 	return copy_to_user(ifr->ifr_data, &efx->ptp_data->config,
1834 			    sizeof(efx->ptp_data->config)) ? -EFAULT : 0;
1835 }
1836 
1837 static void ptp_event_failure(struct efx_nic *efx, int expected_frag_len)
1838 {
1839 	struct efx_ptp_data *ptp = efx->ptp_data;
1840 
1841 	netif_err(efx, hw, efx->net_dev,
1842 		"PTP unexpected event length: got %d expected %d\n",
1843 		ptp->evt_frag_idx, expected_frag_len);
1844 	ptp->reset_required = true;
1845 	queue_work(ptp->workwq, &ptp->work);
1846 }
1847 
1848 /* Process a completed receive event.  Put it on the event queue and
1849  * start worker thread.  This is required because event and their
1850  * correspoding packets may come in either order.
1851  */
1852 static void ptp_event_rx(struct efx_nic *efx, struct efx_ptp_data *ptp)
1853 {
1854 	struct efx_ptp_event_rx *evt = NULL;
1855 
1856 	if (WARN_ON_ONCE(ptp->rx_ts_inline))
1857 		return;
1858 
1859 	if (ptp->evt_frag_idx != 3) {
1860 		ptp_event_failure(efx, 3);
1861 		return;
1862 	}
1863 
1864 	spin_lock_bh(&ptp->evt_lock);
1865 	if (!list_empty(&ptp->evt_free_list)) {
1866 		evt = list_first_entry(&ptp->evt_free_list,
1867 				       struct efx_ptp_event_rx, link);
1868 		list_del(&evt->link);
1869 
1870 		evt->seq0 = EFX_QWORD_FIELD(ptp->evt_frags[2], MCDI_EVENT_DATA);
1871 		evt->seq1 = (EFX_QWORD_FIELD(ptp->evt_frags[2],
1872 					     MCDI_EVENT_SRC)        |
1873 			     (EFX_QWORD_FIELD(ptp->evt_frags[1],
1874 					      MCDI_EVENT_SRC) << 8) |
1875 			     (EFX_QWORD_FIELD(ptp->evt_frags[0],
1876 					      MCDI_EVENT_SRC) << 16));
1877 		evt->hwtimestamp = efx->ptp_data->nic_to_kernel_time(
1878 			EFX_QWORD_FIELD(ptp->evt_frags[0], MCDI_EVENT_DATA),
1879 			EFX_QWORD_FIELD(ptp->evt_frags[1], MCDI_EVENT_DATA),
1880 			ptp->ts_corrections.ptp_rx);
1881 		evt->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS);
1882 		list_add_tail(&evt->link, &ptp->evt_list);
1883 
1884 		queue_work(ptp->workwq, &ptp->work);
1885 	} else if (net_ratelimit()) {
1886 		/* Log a rate-limited warning message. */
1887 		netif_err(efx, rx_err, efx->net_dev, "PTP event queue overflow\n");
1888 	}
1889 	spin_unlock_bh(&ptp->evt_lock);
1890 }
1891 
1892 static void ptp_event_fault(struct efx_nic *efx, struct efx_ptp_data *ptp)
1893 {
1894 	int code = EFX_QWORD_FIELD(ptp->evt_frags[0], MCDI_EVENT_DATA);
1895 	if (ptp->evt_frag_idx != 1) {
1896 		ptp_event_failure(efx, 1);
1897 		return;
1898 	}
1899 
1900 	netif_err(efx, hw, efx->net_dev, "PTP error %d\n", code);
1901 }
1902 
1903 static void ptp_event_pps(struct efx_nic *efx, struct efx_ptp_data *ptp)
1904 {
1905 	if (ptp->nic_ts_enabled)
1906 		queue_work(ptp->pps_workwq, &ptp->pps_work);
1907 }
1908 
1909 void efx_ptp_event(struct efx_nic *efx, efx_qword_t *ev)
1910 {
1911 	struct efx_ptp_data *ptp = efx->ptp_data;
1912 	int code = EFX_QWORD_FIELD(*ev, MCDI_EVENT_CODE);
1913 
1914 	if (!ptp) {
1915 		if (!efx->ptp_warned) {
1916 			netif_warn(efx, drv, efx->net_dev,
1917 				   "Received PTP event but PTP not set up\n");
1918 			efx->ptp_warned = true;
1919 		}
1920 		return;
1921 	}
1922 
1923 	if (!ptp->enabled)
1924 		return;
1925 
1926 	if (ptp->evt_frag_idx == 0) {
1927 		ptp->evt_code = code;
1928 	} else if (ptp->evt_code != code) {
1929 		netif_err(efx, hw, efx->net_dev,
1930 			  "PTP out of sequence event %d\n", code);
1931 		ptp->evt_frag_idx = 0;
1932 	}
1933 
1934 	ptp->evt_frags[ptp->evt_frag_idx++] = *ev;
1935 	if (!MCDI_EVENT_FIELD(*ev, CONT)) {
1936 		/* Process resulting event */
1937 		switch (code) {
1938 		case MCDI_EVENT_CODE_PTP_RX:
1939 			ptp_event_rx(efx, ptp);
1940 			break;
1941 		case MCDI_EVENT_CODE_PTP_FAULT:
1942 			ptp_event_fault(efx, ptp);
1943 			break;
1944 		case MCDI_EVENT_CODE_PTP_PPS:
1945 			ptp_event_pps(efx, ptp);
1946 			break;
1947 		default:
1948 			netif_err(efx, hw, efx->net_dev,
1949 				  "PTP unknown event %d\n", code);
1950 			break;
1951 		}
1952 		ptp->evt_frag_idx = 0;
1953 	} else if (MAX_EVENT_FRAGS == ptp->evt_frag_idx) {
1954 		netif_err(efx, hw, efx->net_dev,
1955 			  "PTP too many event fragments\n");
1956 		ptp->evt_frag_idx = 0;
1957 	}
1958 }
1959 
1960 void efx_time_sync_event(struct efx_channel *channel, efx_qword_t *ev)
1961 {
1962 	struct efx_nic *efx = channel->efx;
1963 	struct efx_ptp_data *ptp = efx->ptp_data;
1964 
1965 	/* When extracting the sync timestamp minor value, we should discard
1966 	 * the least significant two bits. These are not required in order
1967 	 * to reconstruct full-range timestamps and they are optionally used
1968 	 * to report status depending on the options supplied when subscribing
1969 	 * for sync events.
1970 	 */
1971 	channel->sync_timestamp_major = MCDI_EVENT_FIELD(*ev, PTP_TIME_MAJOR);
1972 	channel->sync_timestamp_minor =
1973 		(MCDI_EVENT_FIELD(*ev, PTP_TIME_MINOR_MS_8BITS) & 0xFC)
1974 			<< ptp->nic_time.sync_event_minor_shift;
1975 
1976 	/* if sync events have been disabled then we want to silently ignore
1977 	 * this event, so throw away result.
1978 	 */
1979 	(void) cmpxchg(&channel->sync_events_state, SYNC_EVENTS_REQUESTED,
1980 		       SYNC_EVENTS_VALID);
1981 }
1982 
1983 static inline u32 efx_rx_buf_timestamp_minor(struct efx_nic *efx, const u8 *eh)
1984 {
1985 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1986 	return __le32_to_cpup((const __le32 *)(eh + efx->rx_packet_ts_offset));
1987 #else
1988 	const u8 *data = eh + efx->rx_packet_ts_offset;
1989 	return (u32)data[0]       |
1990 	       (u32)data[1] << 8  |
1991 	       (u32)data[2] << 16 |
1992 	       (u32)data[3] << 24;
1993 #endif
1994 }
1995 
1996 void __efx_rx_skb_attach_timestamp(struct efx_channel *channel,
1997 				   struct sk_buff *skb)
1998 {
1999 	struct efx_nic *efx = channel->efx;
2000 	struct efx_ptp_data *ptp = efx->ptp_data;
2001 	u32 pkt_timestamp_major, pkt_timestamp_minor;
2002 	u32 diff, carry;
2003 	struct skb_shared_hwtstamps *timestamps;
2004 
2005 	if (channel->sync_events_state != SYNC_EVENTS_VALID)
2006 		return;
2007 
2008 	pkt_timestamp_minor = efx_rx_buf_timestamp_minor(efx, skb_mac_header(skb));
2009 
2010 	/* get the difference between the packet and sync timestamps,
2011 	 * modulo one second
2012 	 */
2013 	diff = pkt_timestamp_minor - channel->sync_timestamp_minor;
2014 	if (pkt_timestamp_minor < channel->sync_timestamp_minor)
2015 		diff += ptp->nic_time.minor_max;
2016 
2017 	/* do we roll over a second boundary and need to carry the one? */
2018 	carry = (channel->sync_timestamp_minor >= ptp->nic_time.minor_max - diff) ?
2019 		1 : 0;
2020 
2021 	if (diff <= ptp->nic_time.sync_event_diff_max) {
2022 		/* packet is ahead of the sync event by a quarter of a second or
2023 		 * less (allowing for fuzz)
2024 		 */
2025 		pkt_timestamp_major = channel->sync_timestamp_major + carry;
2026 	} else if (diff >= ptp->nic_time.sync_event_diff_min) {
2027 		/* packet is behind the sync event but within the fuzz factor.
2028 		 * This means the RX packet and sync event crossed as they were
2029 		 * placed on the event queue, which can sometimes happen.
2030 		 */
2031 		pkt_timestamp_major = channel->sync_timestamp_major - 1 + carry;
2032 	} else {
2033 		/* it's outside tolerance in both directions. this might be
2034 		 * indicative of us missing sync events for some reason, so
2035 		 * we'll call it an error rather than risk giving a bogus
2036 		 * timestamp.
2037 		 */
2038 		netif_vdbg(efx, drv, efx->net_dev,
2039 			  "packet timestamp %x too far from sync event %x:%x\n",
2040 			  pkt_timestamp_minor, channel->sync_timestamp_major,
2041 			  channel->sync_timestamp_minor);
2042 		return;
2043 	}
2044 
2045 	/* attach the timestamps to the skb */
2046 	timestamps = skb_hwtstamps(skb);
2047 	timestamps->hwtstamp =
2048 		ptp->nic_to_kernel_time(pkt_timestamp_major,
2049 					pkt_timestamp_minor,
2050 					ptp->ts_corrections.general_rx);
2051 }
2052 
2053 static int efx_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
2054 {
2055 	struct efx_ptp_data *ptp_data = container_of(ptp,
2056 						     struct efx_ptp_data,
2057 						     phc_clock_info);
2058 	struct efx_nic *efx = ptp_data->efx;
2059 	MCDI_DECLARE_BUF(inadj, MC_CMD_PTP_IN_ADJUST_LEN);
2060 	s64 adjustment_ns;
2061 	int rc;
2062 
2063 	if (delta > MAX_PPB)
2064 		delta = MAX_PPB;
2065 	else if (delta < -MAX_PPB)
2066 		delta = -MAX_PPB;
2067 
2068 	/* Convert ppb to fixed point ns taking care to round correctly. */
2069 	adjustment_ns = ((s64)delta * PPB_SCALE_WORD +
2070 			 (1 << (ptp_data->adjfreq_ppb_shift - 1))) >>
2071 			ptp_data->adjfreq_ppb_shift;
2072 
2073 	MCDI_SET_DWORD(inadj, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);
2074 	MCDI_SET_DWORD(inadj, PTP_IN_PERIPH_ID, 0);
2075 	MCDI_SET_QWORD(inadj, PTP_IN_ADJUST_FREQ, adjustment_ns);
2076 	MCDI_SET_DWORD(inadj, PTP_IN_ADJUST_SECONDS, 0);
2077 	MCDI_SET_DWORD(inadj, PTP_IN_ADJUST_NANOSECONDS, 0);
2078 	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inadj, sizeof(inadj),
2079 			  NULL, 0, NULL);
2080 	if (rc != 0)
2081 		return rc;
2082 
2083 	ptp_data->current_adjfreq = adjustment_ns;
2084 	return 0;
2085 }
2086 
2087 static int efx_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
2088 {
2089 	u32 nic_major, nic_minor;
2090 	struct efx_ptp_data *ptp_data = container_of(ptp,
2091 						     struct efx_ptp_data,
2092 						     phc_clock_info);
2093 	struct efx_nic *efx = ptp_data->efx;
2094 	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_ADJUST_LEN);
2095 
2096 	efx->ptp_data->ns_to_nic_time(delta, &nic_major, &nic_minor);
2097 
2098 	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);
2099 	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
2100 	MCDI_SET_QWORD(inbuf, PTP_IN_ADJUST_FREQ, ptp_data->current_adjfreq);
2101 	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_MAJOR, nic_major);
2102 	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_MINOR, nic_minor);
2103 	return efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
2104 			    NULL, 0, NULL);
2105 }
2106 
2107 static int efx_phc_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
2108 {
2109 	struct efx_ptp_data *ptp_data = container_of(ptp,
2110 						     struct efx_ptp_data,
2111 						     phc_clock_info);
2112 	struct efx_nic *efx = ptp_data->efx;
2113 	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_READ_NIC_TIME_LEN);
2114 	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_READ_NIC_TIME_LEN);
2115 	int rc;
2116 	ktime_t kt;
2117 
2118 	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_READ_NIC_TIME);
2119 	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
2120 
2121 	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
2122 			  outbuf, sizeof(outbuf), NULL);
2123 	if (rc != 0)
2124 		return rc;
2125 
2126 	kt = ptp_data->nic_to_kernel_time(
2127 		MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_MAJOR),
2128 		MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_MINOR), 0);
2129 	*ts = ktime_to_timespec64(kt);
2130 	return 0;
2131 }
2132 
2133 static int efx_phc_settime(struct ptp_clock_info *ptp,
2134 			   const struct timespec64 *e_ts)
2135 {
2136 	/* Get the current NIC time, efx_phc_gettime.
2137 	 * Subtract from the desired time to get the offset
2138 	 * call efx_phc_adjtime with the offset
2139 	 */
2140 	int rc;
2141 	struct timespec64 time_now;
2142 	struct timespec64 delta;
2143 
2144 	rc = efx_phc_gettime(ptp, &time_now);
2145 	if (rc != 0)
2146 		return rc;
2147 
2148 	delta = timespec64_sub(*e_ts, time_now);
2149 
2150 	rc = efx_phc_adjtime(ptp, timespec64_to_ns(&delta));
2151 	if (rc != 0)
2152 		return rc;
2153 
2154 	return 0;
2155 }
2156 
2157 static int efx_phc_enable(struct ptp_clock_info *ptp,
2158 			  struct ptp_clock_request *request,
2159 			  int enable)
2160 {
2161 	struct efx_ptp_data *ptp_data = container_of(ptp,
2162 						     struct efx_ptp_data,
2163 						     phc_clock_info);
2164 	if (request->type != PTP_CLK_REQ_PPS)
2165 		return -EOPNOTSUPP;
2166 
2167 	ptp_data->nic_ts_enabled = !!enable;
2168 	return 0;
2169 }
2170 
2171 static const struct efx_channel_type efx_ptp_channel_type = {
2172 	.handle_no_channel	= efx_ptp_handle_no_channel,
2173 	.pre_probe		= efx_ptp_probe_channel,
2174 	.post_remove		= efx_ptp_remove_channel,
2175 	.get_name		= efx_ptp_get_channel_name,
2176 	/* no copy operation; there is no need to reallocate this channel */
2177 	.receive_skb		= efx_ptp_rx,
2178 	.want_txqs		= efx_ptp_want_txqs,
2179 	.keep_eventq		= false,
2180 };
2181 
2182 void efx_ptp_defer_probe_with_channel(struct efx_nic *efx)
2183 {
2184 	/* Check whether PTP is implemented on this NIC.  The DISABLE
2185 	 * operation will succeed if and only if it is implemented.
2186 	 */
2187 	if (efx_ptp_disable(efx) == 0)
2188 		efx->extra_channel_type[EFX_EXTRA_CHANNEL_PTP] =
2189 			&efx_ptp_channel_type;
2190 }
2191 
2192 void efx_ptp_start_datapath(struct efx_nic *efx)
2193 {
2194 	if (efx_ptp_restart(efx))
2195 		netif_err(efx, drv, efx->net_dev, "Failed to restart PTP.\n");
2196 	/* re-enable timestamping if it was previously enabled */
2197 	if (efx->type->ptp_set_ts_sync_events)
2198 		efx->type->ptp_set_ts_sync_events(efx, true, true);
2199 }
2200 
2201 void efx_ptp_stop_datapath(struct efx_nic *efx)
2202 {
2203 	/* temporarily disable timestamping */
2204 	if (efx->type->ptp_set_ts_sync_events)
2205 		efx->type->ptp_set_ts_sync_events(efx, false, true);
2206 	efx_ptp_stop(efx);
2207 }
2208