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/errno.h>
37#include <linux/ktime.h>
38#include <linux/module.h>
39#include <linux/pps_kernel.h>
40#include <linux/ptp_clock_kernel.h>
41#include "net_driver.h"
42#include "efx.h"
43#include "mcdi.h"
44#include "mcdi_pcol.h"
45#include "io.h"
46#include "tx.h"
47#include "nic.h" /* indirectly includes ptp.h */
48#include "efx_channels.h"
49
50/* Maximum number of events expected to make up a PTP event */
51#define	MAX_EVENT_FRAGS			3
52
53/* Maximum delay, ms, to begin synchronisation */
54#define	MAX_SYNCHRONISE_WAIT_MS		2
55
56/* How long, at most, to spend synchronising */
57#define	SYNCHRONISE_PERIOD_NS		250000
58
59/* How often to update the shared memory time */
60#define	SYNCHRONISATION_GRANULARITY_NS	200
61
62/* Minimum permitted length of a (corrected) synchronisation time */
63#define	DEFAULT_MIN_SYNCHRONISATION_NS	120
64
65/* Maximum permitted length of a (corrected) synchronisation time */
66#define	MAX_SYNCHRONISATION_NS		1000
67
68/* How many (MC) receive events that can be queued */
69#define	MAX_RECEIVE_EVENTS		8
70
71/* Length of (modified) moving average. */
72#define	AVERAGE_LENGTH			16
73
74/* How long an unmatched event or packet can be held */
75#define PKT_EVENT_LIFETIME_MS		10
76
77/* How long unused unicast filters can be held */
78#define UCAST_FILTER_EXPIRY_JIFFIES	msecs_to_jiffies(30000)
79
80/* Offsets into PTP packet for identification.  These offsets are from the
81 * start of the IP header, not the MAC header.  Note that neither PTP V1 nor
82 * PTP V2 permit the use of IPV4 options.
83 */
84#define PTP_DPORT_OFFSET	22
85
86#define PTP_V1_VERSION_LENGTH	2
87#define PTP_V1_VERSION_OFFSET	28
88
89#define PTP_V1_SEQUENCE_LENGTH	2
90#define PTP_V1_SEQUENCE_OFFSET	58
91
92/* The minimum length of a PTP V1 packet for offsets, etc. to be valid:
93 * includes IP header.
94 */
95#define	PTP_V1_MIN_LENGTH	64
96
97#define PTP_V2_VERSION_LENGTH	1
98#define PTP_V2_VERSION_OFFSET	29
99
100#define PTP_V2_SEQUENCE_LENGTH	2
101#define PTP_V2_SEQUENCE_OFFSET	58
102
103/* The minimum length of a PTP V2 packet for offsets, etc. to be valid:
104 * includes IP header.
105 */
106#define	PTP_V2_MIN_LENGTH	63
107
108#define	PTP_MIN_LENGTH		63
109
110#define PTP_ADDR_IPV4		0xe0000181	/* 224.0.1.129 */
111
112/* ff0e::181 */
113static const struct in6_addr ptp_addr_ipv6 = { { {
114	0xff, 0x0e, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01, 0x81 } } };
115
116/* 01-1B-19-00-00-00 */
117static const u8 ptp_addr_ether[ETH_ALEN] __aligned(2) = {
118	0x01, 0x1b, 0x19, 0x00, 0x00, 0x00 };
119
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
131enum 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 * @expiry: Time after which the packet should be delivered irrespective of
162 *            event arrival.
163 * @state: The state of the packet - whether it is ready for processing or
164 *         whether that is of no interest.
165 */
166struct efx_ptp_match {
167	unsigned long expiry;
168	enum ptp_packet_state state;
169};
170
171/**
172 * struct efx_ptp_event_rx - A PTP receive event (from MC)
173 * @link: list of events
174 * @seq0: First part of (PTP) UUID
175 * @seq1: Second part of (PTP) UUID and sequence number
176 * @hwtimestamp: Event timestamp
177 * @expiry: Time which the packet arrived
178 */
179struct 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 */
198struct 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_rxfilter - Filter for PTP packets
209 * @list: Node of the list where the filter is added
210 * @ether_type: Network protocol of the filter (ETHER_P_IP / ETHER_P_IPV6)
211 * @loc_port: UDP port of the filter (PTP_EVENT_PORT / PTP_GENERAL_PORT)
212 * @loc_host: IPv4/v6 address of the filter
213 * @expiry: time when the filter expires, in jiffies
214 * @handle: Handle ID for the MCDI filters table
215 */
216struct efx_ptp_rxfilter {
217	struct list_head list;
218	__be16 ether_type;
219	__be16 loc_port;
220	__be32 loc_host[4];
221	unsigned long expiry;
222	int handle;
223};
224
225/**
226 * struct efx_ptp_data - Precision Time Protocol (PTP) state
227 * @efx: The NIC context
228 * @channel: The PTP channel (for Medford and Medford2)
229 * @rxq: Receive SKB queue (awaiting timestamps)
230 * @txq: Transmit SKB queue
231 * @workwq: Work queue for processing pending PTP operations
232 * @work: Work task
233 * @cleanup_work: Work task for periodic cleanup
234 * @reset_required: A serious error has occurred and the PTP task needs to be
235 *                  reset (disable, enable).
236 * @rxfilters_mcast: Receive filters for multicast PTP packets
237 * @rxfilters_ucast: Receive filters for unicast PTP packets
238 * @config: Current timestamp configuration
239 * @enabled: PTP operation enabled
240 * @mode: Mode in which PTP operating (PTP version)
241 * @ns_to_nic_time: Function to convert from scalar nanoseconds to NIC time
242 * @nic_to_kernel_time: Function to convert from NIC to kernel time
243 * @nic_time: contains time details
244 * @nic_time.minor_max: Wrap point for NIC minor times
245 * @nic_time.sync_event_diff_min: Minimum acceptable difference between time
246 * in packet prefix and last MCDI time sync event i.e. how much earlier than
247 * the last sync event time a packet timestamp can be.
248 * @nic_time.sync_event_diff_max: Maximum acceptable difference between time
249 * in packet prefix and last MCDI time sync event i.e. how much later than
250 * the last sync event time a packet timestamp can be.
251 * @nic_time.sync_event_minor_shift: Shift required to make minor time from
252 * field in MCDI time sync event.
253 * @min_synchronisation_ns: Minimum acceptable corrected sync window
254 * @capabilities: Capabilities flags from the NIC
255 * @ts_corrections: contains corrections details
256 * @ts_corrections.ptp_tx: Required driver correction of PTP packet transmit
257 *                         timestamps
258 * @ts_corrections.ptp_rx: Required driver correction of PTP packet receive
259 *                         timestamps
260 * @ts_corrections.pps_out: PPS output error (information only)
261 * @ts_corrections.pps_in: Required driver correction of PPS input timestamps
262 * @ts_corrections.general_tx: Required driver correction of general packet
263 *                             transmit timestamps
264 * @ts_corrections.general_rx: Required driver correction of general packet
265 *                             receive timestamps
266 * @evt_frags: Partly assembled PTP events
267 * @evt_frag_idx: Current fragment number
268 * @evt_code: Last event code
269 * @start: Address at which MC indicates ready for synchronisation
270 * @host_time_pps: Host time at last PPS
271 * @adjfreq_ppb_shift: Shift required to convert scaled parts-per-billion
272 * frequency adjustment into a fixed point fractional nanosecond format.
273 * @current_adjfreq: Current ppb adjustment.
274 * @phc_clock: Pointer to registered phc device (if primary function)
275 * @phc_clock_info: Registration structure for phc device
276 * @pps_work: pps work task for handling pps events
277 * @pps_workwq: pps work queue
278 * @nic_ts_enabled: Flag indicating if NIC generated TS events are handled
279 * @txbuf: Buffer for use when transmitting (PTP) packets to MC (avoids
280 *         allocations in main data path).
281 * @good_syncs: Number of successful synchronisations.
282 * @fast_syncs: Number of synchronisations requiring short delay
283 * @bad_syncs: Number of failed synchronisations.
284 * @sync_timeouts: Number of synchronisation timeouts
285 * @no_time_syncs: Number of synchronisations with no good times.
286 * @invalid_sync_windows: Number of sync windows with bad durations.
287 * @undersize_sync_windows: Number of corrected sync windows that are too small
288 * @oversize_sync_windows: Number of corrected sync windows that are too large
289 * @rx_no_timestamp: Number of packets received without a timestamp.
290 * @timeset: Last set of synchronisation statistics.
291 * @xmit_skb: Transmit SKB function.
292 */
293struct efx_ptp_data {
294	struct efx_nic *efx;
295	struct efx_channel *channel;
296	struct sk_buff_head rxq;
297	struct sk_buff_head txq;
298	struct workqueue_struct *workwq;
299	struct work_struct work;
300	struct delayed_work cleanup_work;
301	bool reset_required;
302	struct list_head rxfilters_mcast;
303	struct list_head rxfilters_ucast;
304	struct kernel_hwtstamp_config config;
305	bool enabled;
306	unsigned int mode;
307	void (*ns_to_nic_time)(s64 ns, u32 *nic_major, u32 *nic_minor);
308	ktime_t (*nic_to_kernel_time)(u32 nic_major, u32 nic_minor,
309				      s32 correction);
310	struct {
311		u32 minor_max;
312		u32 sync_event_diff_min;
313		u32 sync_event_diff_max;
314		unsigned int sync_event_minor_shift;
315	} nic_time;
316	unsigned int min_synchronisation_ns;
317	unsigned int capabilities;
318	struct {
319		s32 ptp_tx;
320		s32 ptp_rx;
321		s32 pps_out;
322		s32 pps_in;
323		s32 general_tx;
324		s32 general_rx;
325	} ts_corrections;
326	efx_qword_t evt_frags[MAX_EVENT_FRAGS];
327	int evt_frag_idx;
328	int evt_code;
329	struct efx_buffer start;
330	struct pps_event_time host_time_pps;
331	unsigned int adjfreq_ppb_shift;
332	s64 current_adjfreq;
333	struct ptp_clock *phc_clock;
334	struct ptp_clock_info phc_clock_info;
335	struct work_struct pps_work;
336	struct workqueue_struct *pps_workwq;
337	bool nic_ts_enabled;
338	efx_dword_t txbuf[MCDI_TX_BUF_LEN(MC_CMD_PTP_IN_TRANSMIT_LENMAX)];
339
340	unsigned int good_syncs;
341	unsigned int fast_syncs;
342	unsigned int bad_syncs;
343	unsigned int sync_timeouts;
344	unsigned int no_time_syncs;
345	unsigned int invalid_sync_windows;
346	unsigned int undersize_sync_windows;
347	unsigned int oversize_sync_windows;
348	unsigned int rx_no_timestamp;
349	struct efx_ptp_timeset
350	timeset[MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_MAXNUM];
351	void (*xmit_skb)(struct efx_nic *efx, struct sk_buff *skb);
352};
353
354static int efx_phc_adjfine(struct ptp_clock_info *ptp, long scaled_ppm);
355static int efx_phc_adjtime(struct ptp_clock_info *ptp, s64 delta);
356static int efx_phc_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts);
357static int efx_phc_settime(struct ptp_clock_info *ptp,
358			   const struct timespec64 *e_ts);
359static int efx_phc_enable(struct ptp_clock_info *ptp,
360			  struct ptp_clock_request *request, int on);
361static int efx_ptp_insert_unicast_filter(struct efx_nic *efx,
362					 struct sk_buff *skb);
363
364bool efx_ptp_use_mac_tx_timestamps(struct efx_nic *efx)
365{
366	return efx_has_cap(efx, TX_MAC_TIMESTAMPING);
367}
368
369/* PTP 'extra' channel is still a traffic channel, but we only create TX queues
370 * if PTP uses MAC TX timestamps, not if PTP uses the MC directly to transmit.
371 */
372static bool efx_ptp_want_txqs(struct efx_channel *channel)
373{
374	return efx_ptp_use_mac_tx_timestamps(channel->efx);
375}
376
377#define PTP_SW_STAT(ext_name, field_name)				\
378	{ #ext_name, 0, offsetof(struct efx_ptp_data, field_name) }
379#define PTP_MC_STAT(ext_name, mcdi_name)				\
380	{ #ext_name, 32, MC_CMD_PTP_OUT_STATUS_STATS_ ## mcdi_name ## _OFST }
381static const struct efx_hw_stat_desc efx_ptp_stat_desc[] = {
382	PTP_SW_STAT(ptp_good_syncs, good_syncs),
383	PTP_SW_STAT(ptp_fast_syncs, fast_syncs),
384	PTP_SW_STAT(ptp_bad_syncs, bad_syncs),
385	PTP_SW_STAT(ptp_sync_timeouts, sync_timeouts),
386	PTP_SW_STAT(ptp_no_time_syncs, no_time_syncs),
387	PTP_SW_STAT(ptp_invalid_sync_windows, invalid_sync_windows),
388	PTP_SW_STAT(ptp_undersize_sync_windows, undersize_sync_windows),
389	PTP_SW_STAT(ptp_oversize_sync_windows, oversize_sync_windows),
390	PTP_SW_STAT(ptp_rx_no_timestamp, rx_no_timestamp),
391	PTP_MC_STAT(ptp_tx_timestamp_packets, TX),
392	PTP_MC_STAT(ptp_rx_timestamp_packets, RX),
393	PTP_MC_STAT(ptp_timestamp_packets, TS),
394	PTP_MC_STAT(ptp_filter_matches, FM),
395	PTP_MC_STAT(ptp_non_filter_matches, NFM),
396};
397#define PTP_STAT_COUNT ARRAY_SIZE(efx_ptp_stat_desc)
398static const unsigned long efx_ptp_stat_mask[] = {
399	[0 ... BITS_TO_LONGS(PTP_STAT_COUNT) - 1] = ~0UL,
400};
401
402size_t efx_ptp_describe_stats(struct efx_nic *efx, u8 *strings)
403{
404	if (!efx->ptp_data)
405		return 0;
406
407	return efx_nic_describe_stats(efx_ptp_stat_desc, PTP_STAT_COUNT,
408				      efx_ptp_stat_mask, strings);
409}
410
411size_t efx_ptp_update_stats(struct efx_nic *efx, u64 *stats)
412{
413	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_STATUS_LEN);
414	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_STATUS_LEN);
415	size_t i;
416	int rc;
417
418	if (!efx->ptp_data)
419		return 0;
420
421	/* Copy software statistics */
422	for (i = 0; i < PTP_STAT_COUNT; i++) {
423		if (efx_ptp_stat_desc[i].dma_width)
424			continue;
425		stats[i] = *(unsigned int *)((char *)efx->ptp_data +
426					     efx_ptp_stat_desc[i].offset);
427	}
428
429	/* Fetch MC statistics.  We *must* fill in all statistics or
430	 * risk leaking kernel memory to userland, so if the MCDI
431	 * request fails we pretend we got zeroes.
432	 */
433	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_STATUS);
434	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
435	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
436			  outbuf, sizeof(outbuf), NULL);
437	if (rc)
438		memset(outbuf, 0, sizeof(outbuf));
439	efx_nic_update_stats(efx_ptp_stat_desc, PTP_STAT_COUNT,
440			     efx_ptp_stat_mask,
441			     stats, _MCDI_PTR(outbuf, 0), false);
442
443	return PTP_STAT_COUNT;
444}
445
446/* To convert from s27 format to ns we multiply then divide by a power of 2.
447 * For the conversion from ns to s27, the operation is also converted to a
448 * multiply and shift.
449 */
450#define S27_TO_NS_SHIFT	(27)
451#define NS_TO_S27_MULT	(((1ULL << 63) + NSEC_PER_SEC / 2) / NSEC_PER_SEC)
452#define NS_TO_S27_SHIFT	(63 - S27_TO_NS_SHIFT)
453#define S27_MINOR_MAX	(1 << S27_TO_NS_SHIFT)
454
455/* For Huntington platforms NIC time is in seconds and fractions of a second
456 * where the minor register only uses 27 bits in units of 2^-27s.
457 */
458static void efx_ptp_ns_to_s27(s64 ns, u32 *nic_major, u32 *nic_minor)
459{
460	struct timespec64 ts = ns_to_timespec64(ns);
461	u32 maj = (u32)ts.tv_sec;
462	u32 min = (u32)(((u64)ts.tv_nsec * NS_TO_S27_MULT +
463			 (1ULL << (NS_TO_S27_SHIFT - 1))) >> NS_TO_S27_SHIFT);
464
465	/* The conversion can result in the minor value exceeding the maximum.
466	 * In this case, round up to the next second.
467	 */
468	if (min >= S27_MINOR_MAX) {
469		min -= S27_MINOR_MAX;
470		maj++;
471	}
472
473	*nic_major = maj;
474	*nic_minor = min;
475}
476
477static inline ktime_t efx_ptp_s27_to_ktime(u32 nic_major, u32 nic_minor)
478{
479	u32 ns = (u32)(((u64)nic_minor * NSEC_PER_SEC +
480			(1ULL << (S27_TO_NS_SHIFT - 1))) >> S27_TO_NS_SHIFT);
481	return ktime_set(nic_major, ns);
482}
483
484static ktime_t efx_ptp_s27_to_ktime_correction(u32 nic_major, u32 nic_minor,
485					       s32 correction)
486{
487	/* Apply the correction and deal with carry */
488	nic_minor += correction;
489	if ((s32)nic_minor < 0) {
490		nic_minor += S27_MINOR_MAX;
491		nic_major--;
492	} else if (nic_minor >= S27_MINOR_MAX) {
493		nic_minor -= S27_MINOR_MAX;
494		nic_major++;
495	}
496
497	return efx_ptp_s27_to_ktime(nic_major, nic_minor);
498}
499
500/* For Medford2 platforms the time is in seconds and quarter nanoseconds. */
501static void efx_ptp_ns_to_s_qns(s64 ns, u32 *nic_major, u32 *nic_minor)
502{
503	struct timespec64 ts = ns_to_timespec64(ns);
504
505	*nic_major = (u32)ts.tv_sec;
506	*nic_minor = ts.tv_nsec * 4;
507}
508
509static ktime_t efx_ptp_s_qns_to_ktime_correction(u32 nic_major, u32 nic_minor,
510						 s32 correction)
511{
512	ktime_t kt;
513
514	nic_minor = DIV_ROUND_CLOSEST(nic_minor, 4);
515	correction = DIV_ROUND_CLOSEST(correction, 4);
516
517	kt = ktime_set(nic_major, nic_minor);
518
519	if (correction >= 0)
520		kt = ktime_add_ns(kt, (u64)correction);
521	else
522		kt = ktime_sub_ns(kt, (u64)-correction);
523	return kt;
524}
525
526struct efx_channel *efx_ptp_channel(struct efx_nic *efx)
527{
528	return efx->ptp_data ? efx->ptp_data->channel : NULL;
529}
530
531void efx_ptp_update_channel(struct efx_nic *efx, struct efx_channel *channel)
532{
533	if (efx->ptp_data)
534		efx->ptp_data->channel = channel;
535}
536
537static u32 last_sync_timestamp_major(struct efx_nic *efx)
538{
539	struct efx_channel *channel = efx_ptp_channel(efx);
540	u32 major = 0;
541
542	if (channel)
543		major = channel->sync_timestamp_major;
544	return major;
545}
546
547/* The 8000 series and later can provide the time from the MAC, which is only
548 * 48 bits long and provides meta-information in the top 2 bits.
549 */
550static ktime_t
551efx_ptp_mac_nic_to_ktime_correction(struct efx_nic *efx,
552				    struct efx_ptp_data *ptp,
553				    u32 nic_major, u32 nic_minor,
554				    s32 correction)
555{
556	u32 sync_timestamp;
557	ktime_t kt = { 0 };
558	s16 delta;
559
560	if (!(nic_major & 0x80000000)) {
561		WARN_ON_ONCE(nic_major >> 16);
562
563		/* Medford provides 48 bits of timestamp, so we must get the top
564		 * 16 bits from the timesync event state.
565		 *
566		 * We only have the lower 16 bits of the time now, but we do
567		 * have a full resolution timestamp at some point in past. As
568		 * long as the difference between the (real) now and the sync
569		 * is less than 2^15, then we can reconstruct the difference
570		 * between those two numbers using only the lower 16 bits of
571		 * each.
572		 *
573		 * Put another way
574		 *
575		 * a - b = ((a mod k) - b) mod k
576		 *
577		 * when -k/2 < (a-b) < k/2. In our case k is 2^16. We know
578		 * (a mod k) and b, so can calculate the delta, a - b.
579		 *
580		 */
581		sync_timestamp = last_sync_timestamp_major(efx);
582
583		/* Because delta is s16 this does an implicit mask down to
584		 * 16 bits which is what we need, assuming
585		 * MEDFORD_TX_SECS_EVENT_BITS is 16. delta is signed so that
586		 * we can deal with the (unlikely) case of sync timestamps
587		 * arriving from the future.
588		 */
589		delta = nic_major - sync_timestamp;
590
591		/* Recover the fully specified time now, by applying the offset
592		 * to the (fully specified) sync time.
593		 */
594		nic_major = sync_timestamp + delta;
595
596		kt = ptp->nic_to_kernel_time(nic_major, nic_minor,
597					     correction);
598	}
599	return kt;
600}
601
602ktime_t efx_ptp_nic_to_kernel_time(struct efx_tx_queue *tx_queue)
603{
604	struct efx_nic *efx = tx_queue->efx;
605	struct efx_ptp_data *ptp = efx->ptp_data;
606	ktime_t kt;
607
608	if (efx_ptp_use_mac_tx_timestamps(efx))
609		kt = efx_ptp_mac_nic_to_ktime_correction(efx, ptp,
610				tx_queue->completed_timestamp_major,
611				tx_queue->completed_timestamp_minor,
612				ptp->ts_corrections.general_tx);
613	else
614		kt = ptp->nic_to_kernel_time(
615				tx_queue->completed_timestamp_major,
616				tx_queue->completed_timestamp_minor,
617				ptp->ts_corrections.general_tx);
618	return kt;
619}
620
621/* Get PTP attributes and set up time conversions */
622static int efx_ptp_get_attributes(struct efx_nic *efx)
623{
624	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_GET_ATTRIBUTES_LEN);
625	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_GET_ATTRIBUTES_LEN);
626	struct efx_ptp_data *ptp = efx->ptp_data;
627	int rc;
628	u32 fmt;
629	size_t out_len;
630
631	/* Get the PTP attributes. If the NIC doesn't support the operation we
632	 * use the default format for compatibility with older NICs i.e.
633	 * seconds and nanoseconds.
634	 */
635	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_GET_ATTRIBUTES);
636	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
637	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
638				outbuf, sizeof(outbuf), &out_len);
639	if (rc == 0) {
640		fmt = MCDI_DWORD(outbuf, PTP_OUT_GET_ATTRIBUTES_TIME_FORMAT);
641	} else if (rc == -EINVAL) {
642		fmt = MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_NANOSECONDS;
643	} else if (rc == -EPERM) {
644		pci_info(efx->pci_dev, "no PTP support\n");
645		return rc;
646	} else {
647		efx_mcdi_display_error(efx, MC_CMD_PTP, sizeof(inbuf),
648				       outbuf, sizeof(outbuf), rc);
649		return rc;
650	}
651
652	switch (fmt) {
653	case MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_27FRACTION:
654		ptp->ns_to_nic_time = efx_ptp_ns_to_s27;
655		ptp->nic_to_kernel_time = efx_ptp_s27_to_ktime_correction;
656		ptp->nic_time.minor_max = 1 << 27;
657		ptp->nic_time.sync_event_minor_shift = 19;
658		break;
659	case MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_QTR_NANOSECONDS:
660		ptp->ns_to_nic_time = efx_ptp_ns_to_s_qns;
661		ptp->nic_to_kernel_time = efx_ptp_s_qns_to_ktime_correction;
662		ptp->nic_time.minor_max = 4000000000UL;
663		ptp->nic_time.sync_event_minor_shift = 24;
664		break;
665	default:
666		return -ERANGE;
667	}
668
669	/* Precalculate acceptable difference between the minor time in the
670	 * packet prefix and the last MCDI time sync event. We expect the
671	 * packet prefix timestamp to be after of sync event by up to one
672	 * sync event interval (0.25s) but we allow it to exceed this by a
673	 * fuzz factor of (0.1s)
674	 */
675	ptp->nic_time.sync_event_diff_min = ptp->nic_time.minor_max
676		- (ptp->nic_time.minor_max / 10);
677	ptp->nic_time.sync_event_diff_max = (ptp->nic_time.minor_max / 4)
678		+ (ptp->nic_time.minor_max / 10);
679
680	/* MC_CMD_PTP_OP_GET_ATTRIBUTES has been extended twice from an older
681	 * operation MC_CMD_PTP_OP_GET_TIME_FORMAT. The function now may return
682	 * a value to use for the minimum acceptable corrected synchronization
683	 * window and may return further capabilities.
684	 * If we have the extra information store it. For older firmware that
685	 * does not implement the extended command use the default value.
686	 */
687	if (rc == 0 &&
688	    out_len >= MC_CMD_PTP_OUT_GET_ATTRIBUTES_CAPABILITIES_OFST)
689		ptp->min_synchronisation_ns =
690			MCDI_DWORD(outbuf,
691				   PTP_OUT_GET_ATTRIBUTES_SYNC_WINDOW_MIN);
692	else
693		ptp->min_synchronisation_ns = DEFAULT_MIN_SYNCHRONISATION_NS;
694
695	if (rc == 0 &&
696	    out_len >= MC_CMD_PTP_OUT_GET_ATTRIBUTES_LEN)
697		ptp->capabilities = MCDI_DWORD(outbuf,
698					PTP_OUT_GET_ATTRIBUTES_CAPABILITIES);
699	else
700		ptp->capabilities = 0;
701
702	/* Set up the shift for conversion between frequency
703	 * adjustments in parts-per-billion and the fixed-point
704	 * fractional ns format that the adapter uses.
705	 */
706	if (ptp->capabilities & (1 << MC_CMD_PTP_OUT_GET_ATTRIBUTES_FP44_FREQ_ADJ_LBN))
707		ptp->adjfreq_ppb_shift = PPB_SHIFT_FP44;
708	else
709		ptp->adjfreq_ppb_shift = PPB_SHIFT_FP40;
710
711	return 0;
712}
713
714/* Get PTP timestamp corrections */
715static int efx_ptp_get_timestamp_corrections(struct efx_nic *efx)
716{
717	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_GET_TIMESTAMP_CORRECTIONS_LEN);
718	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_GET_TIMESTAMP_CORRECTIONS_V2_LEN);
719	int rc;
720	size_t out_len;
721
722	/* Get the timestamp corrections from the NIC. If this operation is
723	 * not supported (older NICs) then no correction is required.
724	 */
725	MCDI_SET_DWORD(inbuf, PTP_IN_OP,
726		       MC_CMD_PTP_OP_GET_TIMESTAMP_CORRECTIONS);
727	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
728
729	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
730				outbuf, sizeof(outbuf), &out_len);
731	if (rc == 0) {
732		efx->ptp_data->ts_corrections.ptp_tx = MCDI_DWORD(outbuf,
733			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_TRANSMIT);
734		efx->ptp_data->ts_corrections.ptp_rx = MCDI_DWORD(outbuf,
735			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_RECEIVE);
736		efx->ptp_data->ts_corrections.pps_out = MCDI_DWORD(outbuf,
737			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_PPS_OUT);
738		efx->ptp_data->ts_corrections.pps_in = MCDI_DWORD(outbuf,
739			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_PPS_IN);
740
741		if (out_len >= MC_CMD_PTP_OUT_GET_TIMESTAMP_CORRECTIONS_V2_LEN) {
742			efx->ptp_data->ts_corrections.general_tx = MCDI_DWORD(
743				outbuf,
744				PTP_OUT_GET_TIMESTAMP_CORRECTIONS_V2_GENERAL_TX);
745			efx->ptp_data->ts_corrections.general_rx = MCDI_DWORD(
746				outbuf,
747				PTP_OUT_GET_TIMESTAMP_CORRECTIONS_V2_GENERAL_RX);
748		} else {
749			efx->ptp_data->ts_corrections.general_tx =
750				efx->ptp_data->ts_corrections.ptp_tx;
751			efx->ptp_data->ts_corrections.general_rx =
752				efx->ptp_data->ts_corrections.ptp_rx;
753		}
754	} else if (rc == -EINVAL) {
755		efx->ptp_data->ts_corrections.ptp_tx = 0;
756		efx->ptp_data->ts_corrections.ptp_rx = 0;
757		efx->ptp_data->ts_corrections.pps_out = 0;
758		efx->ptp_data->ts_corrections.pps_in = 0;
759		efx->ptp_data->ts_corrections.general_tx = 0;
760		efx->ptp_data->ts_corrections.general_rx = 0;
761	} else {
762		efx_mcdi_display_error(efx, MC_CMD_PTP, sizeof(inbuf), outbuf,
763				       sizeof(outbuf), rc);
764		return rc;
765	}
766
767	return 0;
768}
769
770/* Enable MCDI PTP support. */
771static int efx_ptp_enable(struct efx_nic *efx)
772{
773	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_ENABLE_LEN);
774	MCDI_DECLARE_BUF_ERR(outbuf);
775	int rc;
776
777	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_ENABLE);
778	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
779	MCDI_SET_DWORD(inbuf, PTP_IN_ENABLE_QUEUE,
780		       efx->ptp_data->channel ?
781		       efx->ptp_data->channel->channel : 0);
782	MCDI_SET_DWORD(inbuf, PTP_IN_ENABLE_MODE, efx->ptp_data->mode);
783
784	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
785				outbuf, sizeof(outbuf), NULL);
786	rc = (rc == -EALREADY) ? 0 : rc;
787	if (rc)
788		efx_mcdi_display_error(efx, MC_CMD_PTP,
789				       MC_CMD_PTP_IN_ENABLE_LEN,
790				       outbuf, sizeof(outbuf), rc);
791	return rc;
792}
793
794/* Disable MCDI PTP support.
795 *
796 * Note that this function should never rely on the presence of ptp_data -
797 * may be called before that exists.
798 */
799static int efx_ptp_disable(struct efx_nic *efx)
800{
801	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_DISABLE_LEN);
802	MCDI_DECLARE_BUF_ERR(outbuf);
803	int rc;
804
805	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_DISABLE);
806	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
807	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
808				outbuf, sizeof(outbuf), NULL);
809	rc = (rc == -EALREADY) ? 0 : rc;
810	/* If we get ENOSYS, the NIC doesn't support PTP, and thus this function
811	 * should only have been called during probe.
812	 */
813	if (rc == -ENOSYS || rc == -EPERM)
814		pci_info(efx->pci_dev, "no PTP support\n");
815	else if (rc)
816		efx_mcdi_display_error(efx, MC_CMD_PTP,
817				       MC_CMD_PTP_IN_DISABLE_LEN,
818				       outbuf, sizeof(outbuf), rc);
819	return rc;
820}
821
822static void efx_ptp_deliver_rx_queue(struct sk_buff_head *q)
823{
824	struct sk_buff *skb;
825
826	while ((skb = skb_dequeue(q))) {
827		local_bh_disable();
828		netif_receive_skb(skb);
829		local_bh_enable();
830	}
831}
832
833static void efx_ptp_handle_no_channel(struct efx_nic *efx)
834{
835	netif_err(efx, drv, efx->net_dev,
836		  "ERROR: PTP requires MSI-X and 1 additional interrupt"
837		  "vector. PTP disabled\n");
838}
839
840/* Repeatedly send the host time to the MC which will capture the hardware
841 * time.
842 */
843static void efx_ptp_send_times(struct efx_nic *efx,
844			       struct pps_event_time *last_time)
845{
846	struct pps_event_time now;
847	struct timespec64 limit;
848	struct efx_ptp_data *ptp = efx->ptp_data;
849	int *mc_running = ptp->start.addr;
850
851	pps_get_ts(&now);
852	limit = now.ts_real;
853	timespec64_add_ns(&limit, SYNCHRONISE_PERIOD_NS);
854
855	/* Write host time for specified period or until MC is done */
856	while ((timespec64_compare(&now.ts_real, &limit) < 0) &&
857	       READ_ONCE(*mc_running)) {
858		struct timespec64 update_time;
859		unsigned int host_time;
860
861		/* Don't update continuously to avoid saturating the PCIe bus */
862		update_time = now.ts_real;
863		timespec64_add_ns(&update_time, SYNCHRONISATION_GRANULARITY_NS);
864		do {
865			pps_get_ts(&now);
866		} while ((timespec64_compare(&now.ts_real, &update_time) < 0) &&
867			 READ_ONCE(*mc_running));
868
869		/* Synchronise NIC with single word of time only */
870		host_time = (now.ts_real.tv_sec << MC_NANOSECOND_BITS |
871			     now.ts_real.tv_nsec);
872		/* Update host time in NIC memory */
873		efx->type->ptp_write_host_time(efx, host_time);
874	}
875	*last_time = now;
876}
877
878/* Read a timeset from the MC's results and partial process. */
879static void efx_ptp_read_timeset(MCDI_DECLARE_STRUCT_PTR(data),
880				 struct efx_ptp_timeset *timeset)
881{
882	unsigned start_ns, end_ns;
883
884	timeset->host_start = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_HOSTSTART);
885	timeset->major = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_MAJOR);
886	timeset->minor = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_MINOR);
887	timeset->host_end = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_HOSTEND),
888	timeset->wait = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_WAITNS);
889
890	/* Ignore seconds */
891	start_ns = timeset->host_start & MC_NANOSECOND_MASK;
892	end_ns = timeset->host_end & MC_NANOSECOND_MASK;
893	/* Allow for rollover */
894	if (end_ns < start_ns)
895		end_ns += NSEC_PER_SEC;
896	/* Determine duration of operation */
897	timeset->window = end_ns - start_ns;
898}
899
900/* Process times received from MC.
901 *
902 * Extract times from returned results, and establish the minimum value
903 * seen.  The minimum value represents the "best" possible time and events
904 * too much greater than this are rejected - the machine is, perhaps, too
905 * busy. A number of readings are taken so that, hopefully, at least one good
906 * synchronisation will be seen in the results.
907 */
908static int
909efx_ptp_process_times(struct efx_nic *efx, MCDI_DECLARE_STRUCT_PTR(synch_buf),
910		      size_t response_length,
911		      const struct pps_event_time *last_time)
912{
913	unsigned number_readings =
914		MCDI_VAR_ARRAY_LEN(response_length,
915				   PTP_OUT_SYNCHRONIZE_TIMESET);
916	unsigned i;
917	unsigned ngood = 0;
918	unsigned last_good = 0;
919	struct efx_ptp_data *ptp = efx->ptp_data;
920	u32 last_sec;
921	u32 start_sec;
922	struct timespec64 delta;
923	ktime_t mc_time;
924
925	if (number_readings == 0)
926		return -EAGAIN;
927
928	/* Read the set of results and find the last good host-MC
929	 * synchronization result. The MC times when it finishes reading the
930	 * host time so the corrected window time should be fairly constant
931	 * for a given platform. Increment stats for any results that appear
932	 * to be erroneous.
933	 */
934	for (i = 0; i < number_readings; i++) {
935		s32 window, corrected;
936		struct timespec64 wait;
937
938		efx_ptp_read_timeset(
939			MCDI_ARRAY_STRUCT_PTR(synch_buf,
940					      PTP_OUT_SYNCHRONIZE_TIMESET, i),
941			&ptp->timeset[i]);
942
943		wait = ktime_to_timespec64(
944			ptp->nic_to_kernel_time(0, ptp->timeset[i].wait, 0));
945		window = ptp->timeset[i].window;
946		corrected = window - wait.tv_nsec;
947
948		/* We expect the uncorrected synchronization window to be at
949		 * least as large as the interval between host start and end
950		 * times. If it is smaller than this then this is mostly likely
951		 * to be a consequence of the host's time being adjusted.
952		 * Check that the corrected sync window is in a reasonable
953		 * range. If it is out of range it is likely to be because an
954		 * interrupt or other delay occurred between reading the system
955		 * time and writing it to MC memory.
956		 */
957		if (window < SYNCHRONISATION_GRANULARITY_NS) {
958			++ptp->invalid_sync_windows;
959		} else if (corrected >= MAX_SYNCHRONISATION_NS) {
960			++ptp->oversize_sync_windows;
961		} else if (corrected < ptp->min_synchronisation_ns) {
962			++ptp->undersize_sync_windows;
963		} else {
964			ngood++;
965			last_good = i;
966		}
967	}
968
969	if (ngood == 0) {
970		netif_warn(efx, drv, efx->net_dev,
971			   "PTP no suitable synchronisations\n");
972		return -EAGAIN;
973	}
974
975	/* Calculate delay from last good sync (host time) to last_time.
976	 * It is possible that the seconds rolled over between taking
977	 * the start reading and the last value written by the host.  The
978	 * timescales are such that a gap of more than one second is never
979	 * expected.  delta is *not* normalised.
980	 */
981	start_sec = ptp->timeset[last_good].host_start >> MC_NANOSECOND_BITS;
982	last_sec = last_time->ts_real.tv_sec & MC_SECOND_MASK;
983	if (start_sec != last_sec &&
984	    ((start_sec + 1) & MC_SECOND_MASK) != last_sec) {
985		netif_warn(efx, hw, efx->net_dev,
986			   "PTP bad synchronisation seconds\n");
987		return -EAGAIN;
988	}
989	delta.tv_sec = (last_sec - start_sec) & 1;
990	delta.tv_nsec =
991		last_time->ts_real.tv_nsec -
992		(ptp->timeset[last_good].host_start & MC_NANOSECOND_MASK);
993
994	/* Convert the NIC time at last good sync into kernel time.
995	 * No correction is required - this time is the output of a
996	 * firmware process.
997	 */
998	mc_time = ptp->nic_to_kernel_time(ptp->timeset[last_good].major,
999					  ptp->timeset[last_good].minor, 0);
1000
1001	/* Calculate delay from NIC top of second to last_time */
1002	delta.tv_nsec += ktime_to_timespec64(mc_time).tv_nsec;
1003
1004	/* Set PPS timestamp to match NIC top of second */
1005	ptp->host_time_pps = *last_time;
1006	pps_sub_ts(&ptp->host_time_pps, delta);
1007
1008	return 0;
1009}
1010
1011/* Synchronize times between the host and the MC */
1012static int efx_ptp_synchronize(struct efx_nic *efx, unsigned int num_readings)
1013{
1014	struct efx_ptp_data *ptp = efx->ptp_data;
1015	MCDI_DECLARE_BUF(synch_buf, MC_CMD_PTP_OUT_SYNCHRONIZE_LENMAX);
1016	size_t response_length;
1017	int rc;
1018	unsigned long timeout;
1019	struct pps_event_time last_time = {};
1020	unsigned int loops = 0;
1021	int *start = ptp->start.addr;
1022
1023	MCDI_SET_DWORD(synch_buf, PTP_IN_OP, MC_CMD_PTP_OP_SYNCHRONIZE);
1024	MCDI_SET_DWORD(synch_buf, PTP_IN_PERIPH_ID, 0);
1025	MCDI_SET_DWORD(synch_buf, PTP_IN_SYNCHRONIZE_NUMTIMESETS,
1026		       num_readings);
1027	MCDI_SET_QWORD(synch_buf, PTP_IN_SYNCHRONIZE_START_ADDR,
1028		       ptp->start.dma_addr);
1029
1030	/* Clear flag that signals MC ready */
1031	WRITE_ONCE(*start, 0);
1032	rc = efx_mcdi_rpc_start(efx, MC_CMD_PTP, synch_buf,
1033				MC_CMD_PTP_IN_SYNCHRONIZE_LEN);
1034	EFX_WARN_ON_ONCE_PARANOID(rc);
1035
1036	/* Wait for start from MCDI (or timeout) */
1037	timeout = jiffies + msecs_to_jiffies(MAX_SYNCHRONISE_WAIT_MS);
1038	while (!READ_ONCE(*start) && (time_before(jiffies, timeout))) {
1039		udelay(20);	/* Usually start MCDI execution quickly */
1040		loops++;
1041	}
1042
1043	if (loops <= 1)
1044		++ptp->fast_syncs;
1045	if (!time_before(jiffies, timeout))
1046		++ptp->sync_timeouts;
1047
1048	if (READ_ONCE(*start))
1049		efx_ptp_send_times(efx, &last_time);
1050
1051	/* Collect results */
1052	rc = efx_mcdi_rpc_finish(efx, MC_CMD_PTP,
1053				 MC_CMD_PTP_IN_SYNCHRONIZE_LEN,
1054				 synch_buf, sizeof(synch_buf),
1055				 &response_length);
1056	if (rc == 0) {
1057		rc = efx_ptp_process_times(efx, synch_buf, response_length,
1058					   &last_time);
1059		if (rc == 0)
1060			++ptp->good_syncs;
1061		else
1062			++ptp->no_time_syncs;
1063	}
1064
1065	/* Increment the bad syncs counter if the synchronize fails, whatever
1066	 * the reason.
1067	 */
1068	if (rc != 0)
1069		++ptp->bad_syncs;
1070
1071	return rc;
1072}
1073
1074/* Transmit a PTP packet via the dedicated hardware timestamped queue. */
1075static void efx_ptp_xmit_skb_queue(struct efx_nic *efx, struct sk_buff *skb)
1076{
1077	struct efx_ptp_data *ptp_data = efx->ptp_data;
1078	u8 type = efx_tx_csum_type_skb(skb);
1079	struct efx_tx_queue *tx_queue;
1080
1081	tx_queue = efx_channel_get_tx_queue(ptp_data->channel, type);
1082	if (tx_queue && tx_queue->timestamping) {
1083		skb_get(skb);
1084
1085		/* This code invokes normal driver TX code which is always
1086		 * protected from softirqs when called from generic TX code,
1087		 * which in turn disables preemption. Look at __dev_queue_xmit
1088		 * which uses rcu_read_lock_bh disabling preemption for RCU
1089		 * plus disabling softirqs. We do not need RCU reader
1090		 * protection here.
1091		 *
1092		 * Although it is theoretically safe for current PTP TX/RX code
1093		 * running without disabling softirqs, there are three good
1094		 * reasond for doing so:
1095		 *
1096		 *      1) The code invoked is mainly implemented for non-PTP
1097		 *         packets and it is always executed with softirqs
1098		 *         disabled.
1099		 *      2) This being a single PTP packet, better to not
1100		 *         interrupt its processing by softirqs which can lead
1101		 *         to high latencies.
1102		 *      3) netdev_xmit_more checks preemption is disabled and
1103		 *         triggers a BUG_ON if not.
1104		 */
1105		local_bh_disable();
1106		efx_enqueue_skb(tx_queue, skb);
1107		local_bh_enable();
1108
1109		/* We need to add the filters after enqueuing the packet.
1110		 * Otherwise, there's high latency in sending back the
1111		 * timestamp, causing ptp4l timeouts
1112		 */
1113		efx_ptp_insert_unicast_filter(efx, skb);
1114		dev_consume_skb_any(skb);
1115	} else {
1116		WARN_ONCE(1, "PTP channel has no timestamped tx queue\n");
1117		dev_kfree_skb_any(skb);
1118	}
1119}
1120
1121/* Transmit a PTP packet, via the MCDI interface, to the wire. */
1122static void efx_ptp_xmit_skb_mc(struct efx_nic *efx, struct sk_buff *skb)
1123{
1124	MCDI_DECLARE_BUF(txtime, MC_CMD_PTP_OUT_TRANSMIT_LEN);
1125	struct efx_ptp_data *ptp_data = efx->ptp_data;
1126	struct skb_shared_hwtstamps timestamps;
1127	size_t len;
1128	int rc;
1129
1130	MCDI_SET_DWORD(ptp_data->txbuf, PTP_IN_OP, MC_CMD_PTP_OP_TRANSMIT);
1131	MCDI_SET_DWORD(ptp_data->txbuf, PTP_IN_PERIPH_ID, 0);
1132	MCDI_SET_DWORD(ptp_data->txbuf, PTP_IN_TRANSMIT_LENGTH, skb->len);
1133	if (skb_shinfo(skb)->nr_frags != 0) {
1134		rc = skb_linearize(skb);
1135		if (rc != 0)
1136			goto fail;
1137	}
1138
1139	if (skb->ip_summed == CHECKSUM_PARTIAL) {
1140		rc = skb_checksum_help(skb);
1141		if (rc != 0)
1142			goto fail;
1143	}
1144	skb_copy_from_linear_data(skb,
1145				  MCDI_PTR(ptp_data->txbuf,
1146					   PTP_IN_TRANSMIT_PACKET),
1147				  skb->len);
1148	rc = efx_mcdi_rpc(efx, MC_CMD_PTP,
1149			  ptp_data->txbuf, MC_CMD_PTP_IN_TRANSMIT_LEN(skb->len),
1150			  txtime, sizeof(txtime), &len);
1151	if (rc != 0)
1152		goto fail;
1153
1154	memset(&timestamps, 0, sizeof(timestamps));
1155	timestamps.hwtstamp = ptp_data->nic_to_kernel_time(
1156		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_MAJOR),
1157		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_MINOR),
1158		ptp_data->ts_corrections.ptp_tx);
1159
1160	skb_tstamp_tx(skb, &timestamps);
1161
1162	/* Add the filters after sending back the timestamp to avoid delaying it
1163	 * or ptp4l may timeout.
1164	 */
1165	efx_ptp_insert_unicast_filter(efx, skb);
1166
1167fail:
1168	dev_kfree_skb_any(skb);
1169
1170	return;
1171}
1172
1173/* Process any queued receive events and corresponding packets
1174 *
1175 * q is returned with all the packets that are ready for delivery.
1176 */
1177static void efx_ptp_process_events(struct efx_nic *efx, struct sk_buff_head *q)
1178{
1179	struct efx_ptp_data *ptp = efx->ptp_data;
1180	struct sk_buff *skb;
1181
1182	while ((skb = skb_dequeue(&ptp->rxq))) {
1183		struct efx_ptp_match *match;
1184
1185		match = (struct efx_ptp_match *)skb->cb;
1186		if (match->state == PTP_PACKET_STATE_MATCH_UNWANTED) {
1187			__skb_queue_tail(q, skb);
1188		} else if (time_after(jiffies, match->expiry)) {
1189			match->state = PTP_PACKET_STATE_TIMED_OUT;
1190			++ptp->rx_no_timestamp;
1191			__skb_queue_tail(q, skb);
1192		} else {
1193			/* Replace unprocessed entry and stop */
1194			skb_queue_head(&ptp->rxq, skb);
1195			break;
1196		}
1197	}
1198}
1199
1200/* Complete processing of a received packet */
1201static inline void efx_ptp_process_rx(struct efx_nic *efx, struct sk_buff *skb)
1202{
1203	local_bh_disable();
1204	netif_receive_skb(skb);
1205	local_bh_enable();
1206}
1207
1208static struct efx_ptp_rxfilter *
1209efx_ptp_find_filter(struct list_head *filter_list, struct efx_filter_spec *spec)
1210{
1211	struct efx_ptp_rxfilter *rxfilter;
1212
1213	list_for_each_entry(rxfilter, filter_list, list) {
1214		if (rxfilter->ether_type == spec->ether_type &&
1215		    rxfilter->loc_port == spec->loc_port &&
1216		    !memcmp(rxfilter->loc_host, spec->loc_host, sizeof(spec->loc_host)))
1217			return rxfilter;
1218	}
1219
1220	return NULL;
1221}
1222
1223static void efx_ptp_remove_one_filter(struct efx_nic *efx,
1224				      struct efx_ptp_rxfilter *rxfilter)
1225{
1226	efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
1227				  rxfilter->handle);
1228	list_del(&rxfilter->list);
1229	kfree(rxfilter);
1230}
1231
1232static void efx_ptp_remove_filters(struct efx_nic *efx,
1233				   struct list_head *filter_list)
1234{
1235	struct efx_ptp_rxfilter *rxfilter, *tmp;
1236
1237	list_for_each_entry_safe(rxfilter, tmp, filter_list, list)
1238		efx_ptp_remove_one_filter(efx, rxfilter);
1239}
1240
1241static void efx_ptp_init_filter(struct efx_nic *efx,
1242				struct efx_filter_spec *rxfilter)
1243{
1244	struct efx_channel *channel = efx->ptp_data->channel;
1245	struct efx_rx_queue *queue = efx_channel_get_rx_queue(channel);
1246
1247	efx_filter_init_rx(rxfilter, EFX_FILTER_PRI_REQUIRED, 0,
1248			   efx_rx_queue_index(queue));
1249}
1250
1251static int efx_ptp_insert_filter(struct efx_nic *efx,
1252				 struct list_head *filter_list,
1253				 struct efx_filter_spec *spec,
1254				 unsigned long expiry)
1255{
1256	struct efx_ptp_data *ptp = efx->ptp_data;
1257	struct efx_ptp_rxfilter *rxfilter;
1258	int rc;
1259
1260	rxfilter = efx_ptp_find_filter(filter_list, spec);
1261	if (rxfilter) {
1262		rxfilter->expiry = expiry;
1263		return 0;
1264	}
1265
1266	rxfilter = kzalloc(sizeof(*rxfilter), GFP_KERNEL);
1267	if (!rxfilter)
1268		return -ENOMEM;
1269
1270	rc = efx_filter_insert_filter(efx, spec, true);
1271	if (rc < 0)
1272		goto fail;
1273
1274	rxfilter->handle = rc;
1275	rxfilter->ether_type = spec->ether_type;
1276	rxfilter->loc_port = spec->loc_port;
1277	memcpy(rxfilter->loc_host, spec->loc_host, sizeof(spec->loc_host));
1278	rxfilter->expiry = expiry;
1279	list_add(&rxfilter->list, filter_list);
1280
1281	queue_delayed_work(ptp->workwq, &ptp->cleanup_work,
1282			   UCAST_FILTER_EXPIRY_JIFFIES + 1);
1283
1284	return 0;
1285
1286fail:
1287	kfree(rxfilter);
1288	return rc;
1289}
1290
1291static int efx_ptp_insert_ipv4_filter(struct efx_nic *efx,
1292				      struct list_head *filter_list,
1293				      __be32 addr, u16 port,
1294				      unsigned long expiry)
1295{
1296	struct efx_filter_spec spec;
1297
1298	efx_ptp_init_filter(efx, &spec);
1299	efx_filter_set_ipv4_local(&spec, IPPROTO_UDP, addr, htons(port));
1300	return efx_ptp_insert_filter(efx, filter_list, &spec, expiry);
1301}
1302
1303static int efx_ptp_insert_ipv6_filter(struct efx_nic *efx,
1304				      struct list_head *filter_list,
1305				      const struct in6_addr *addr, u16 port,
1306				      unsigned long expiry)
1307{
1308	struct efx_filter_spec spec;
1309
1310	efx_ptp_init_filter(efx, &spec);
1311	efx_filter_set_ipv6_local(&spec, IPPROTO_UDP, addr, htons(port));
1312	return efx_ptp_insert_filter(efx, filter_list, &spec, expiry);
1313}
1314
1315static int efx_ptp_insert_eth_multicast_filter(struct efx_nic *efx)
1316{
1317	struct efx_ptp_data *ptp = efx->ptp_data;
1318	struct efx_filter_spec spec;
1319
1320	efx_ptp_init_filter(efx, &spec);
1321	efx_filter_set_eth_local(&spec, EFX_FILTER_VID_UNSPEC, ptp_addr_ether);
1322	spec.match_flags |= EFX_FILTER_MATCH_ETHER_TYPE;
1323	spec.ether_type = htons(ETH_P_1588);
1324	return efx_ptp_insert_filter(efx, &ptp->rxfilters_mcast, &spec, 0);
1325}
1326
1327static int efx_ptp_insert_multicast_filters(struct efx_nic *efx)
1328{
1329	struct efx_ptp_data *ptp = efx->ptp_data;
1330	int rc;
1331
1332	if (!ptp->channel || !list_empty(&ptp->rxfilters_mcast))
1333		return 0;
1334
1335	/* Must filter on both event and general ports to ensure
1336	 * that there is no packet re-ordering.
1337	 */
1338	rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_mcast,
1339					htonl(PTP_ADDR_IPV4), PTP_EVENT_PORT,
1340					0);
1341	if (rc < 0)
1342		goto fail;
1343
1344	rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_mcast,
1345					htonl(PTP_ADDR_IPV4), PTP_GENERAL_PORT,
1346					0);
1347	if (rc < 0)
1348		goto fail;
1349
1350	/* if the NIC supports hw timestamps by the MAC, we can support
1351	 * PTP over IPv6 and Ethernet
1352	 */
1353	if (efx_ptp_use_mac_tx_timestamps(efx)) {
1354		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_mcast,
1355						&ptp_addr_ipv6, PTP_EVENT_PORT, 0);
1356		if (rc < 0)
1357			goto fail;
1358
1359		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_mcast,
1360						&ptp_addr_ipv6, PTP_GENERAL_PORT, 0);
1361		if (rc < 0)
1362			goto fail;
1363
1364		rc = efx_ptp_insert_eth_multicast_filter(efx);
1365
1366		/* Not all firmware variants support this filter */
1367		if (rc < 0 && rc != -EPROTONOSUPPORT)
1368			goto fail;
1369	}
1370
1371	return 0;
1372
1373fail:
1374	efx_ptp_remove_filters(efx, &ptp->rxfilters_mcast);
1375	return rc;
1376}
1377
1378static bool efx_ptp_valid_unicast_event_pkt(struct sk_buff *skb)
1379{
1380	if (skb->protocol == htons(ETH_P_IP)) {
1381		return ip_hdr(skb)->daddr != htonl(PTP_ADDR_IPV4) &&
1382			ip_hdr(skb)->protocol == IPPROTO_UDP &&
1383			udp_hdr(skb)->source == htons(PTP_EVENT_PORT);
1384	} else if (skb->protocol == htons(ETH_P_IPV6)) {
1385		return !ipv6_addr_equal(&ipv6_hdr(skb)->daddr, &ptp_addr_ipv6) &&
1386			ipv6_hdr(skb)->nexthdr == IPPROTO_UDP &&
1387			udp_hdr(skb)->source == htons(PTP_EVENT_PORT);
1388	}
1389	return false;
1390}
1391
1392static int efx_ptp_insert_unicast_filter(struct efx_nic *efx,
1393					 struct sk_buff *skb)
1394{
1395	struct efx_ptp_data *ptp = efx->ptp_data;
1396	unsigned long expiry;
1397	int rc;
1398
1399	if (!efx_ptp_valid_unicast_event_pkt(skb))
1400		return -EINVAL;
1401
1402	expiry = jiffies + UCAST_FILTER_EXPIRY_JIFFIES;
1403
1404	if (skb->protocol == htons(ETH_P_IP)) {
1405		__be32 addr = ip_hdr(skb)->saddr;
1406
1407		rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_ucast,
1408						addr, PTP_EVENT_PORT, expiry);
1409		if (rc < 0)
1410			goto out;
1411
1412		rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_ucast,
1413						addr, PTP_GENERAL_PORT, expiry);
1414	} else if (efx_ptp_use_mac_tx_timestamps(efx)) {
1415		/* IPv6 PTP only supported by devices with MAC hw timestamp */
1416		struct in6_addr *addr = &ipv6_hdr(skb)->saddr;
1417
1418		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_ucast,
1419						addr, PTP_EVENT_PORT, expiry);
1420		if (rc < 0)
1421			goto out;
1422
1423		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_ucast,
1424						addr, PTP_GENERAL_PORT, expiry);
1425	} else {
1426		return -EOPNOTSUPP;
1427	}
1428
1429out:
1430	return rc;
1431}
1432
1433static int efx_ptp_start(struct efx_nic *efx)
1434{
1435	struct efx_ptp_data *ptp = efx->ptp_data;
1436	int rc;
1437
1438	ptp->reset_required = false;
1439
1440	rc = efx_ptp_insert_multicast_filters(efx);
1441	if (rc)
1442		return rc;
1443
1444	rc = efx_ptp_enable(efx);
1445	if (rc != 0)
1446		goto fail;
1447
1448	ptp->evt_frag_idx = 0;
1449	ptp->current_adjfreq = 0;
1450
1451	return 0;
1452
1453fail:
1454	efx_ptp_remove_filters(efx, &ptp->rxfilters_mcast);
1455	return rc;
1456}
1457
1458static int efx_ptp_stop(struct efx_nic *efx)
1459{
1460	struct efx_ptp_data *ptp = efx->ptp_data;
1461	int rc;
1462
1463	if (ptp == NULL)
1464		return 0;
1465
1466	rc = efx_ptp_disable(efx);
1467
1468	efx_ptp_remove_filters(efx, &ptp->rxfilters_mcast);
1469	efx_ptp_remove_filters(efx, &ptp->rxfilters_ucast);
1470
1471	/* Make sure RX packets are really delivered */
1472	efx_ptp_deliver_rx_queue(&efx->ptp_data->rxq);
1473	skb_queue_purge(&efx->ptp_data->txq);
1474
1475	return rc;
1476}
1477
1478static int efx_ptp_restart(struct efx_nic *efx)
1479{
1480	if (efx->ptp_data && efx->ptp_data->enabled)
1481		return efx_ptp_start(efx);
1482	return 0;
1483}
1484
1485static void efx_ptp_pps_worker(struct work_struct *work)
1486{
1487	struct efx_ptp_data *ptp =
1488		container_of(work, struct efx_ptp_data, pps_work);
1489	struct efx_nic *efx = ptp->efx;
1490	struct ptp_clock_event ptp_evt;
1491
1492	if (efx_ptp_synchronize(efx, PTP_SYNC_ATTEMPTS))
1493		return;
1494
1495	ptp_evt.type = PTP_CLOCK_PPSUSR;
1496	ptp_evt.pps_times = ptp->host_time_pps;
1497	ptp_clock_event(ptp->phc_clock, &ptp_evt);
1498}
1499
1500static void efx_ptp_worker(struct work_struct *work)
1501{
1502	struct efx_ptp_data *ptp_data =
1503		container_of(work, struct efx_ptp_data, work);
1504	struct efx_nic *efx = ptp_data->efx;
1505	struct sk_buff *skb;
1506	struct sk_buff_head tempq;
1507
1508	if (ptp_data->reset_required) {
1509		efx_ptp_stop(efx);
1510		efx_ptp_start(efx);
1511		return;
1512	}
1513
1514	__skb_queue_head_init(&tempq);
1515	efx_ptp_process_events(efx, &tempq);
1516
1517	while ((skb = skb_dequeue(&ptp_data->txq)))
1518		ptp_data->xmit_skb(efx, skb);
1519
1520	while ((skb = __skb_dequeue(&tempq)))
1521		efx_ptp_process_rx(efx, skb);
1522}
1523
1524static void efx_ptp_cleanup_worker(struct work_struct *work)
1525{
1526	struct efx_ptp_data *ptp =
1527		container_of(work, struct efx_ptp_data, cleanup_work.work);
1528	struct efx_ptp_rxfilter *rxfilter, *tmp;
1529
1530	list_for_each_entry_safe(rxfilter, tmp, &ptp->rxfilters_ucast, list) {
1531		if (time_is_before_jiffies(rxfilter->expiry))
1532			efx_ptp_remove_one_filter(ptp->efx, rxfilter);
1533	}
1534
1535	if (!list_empty(&ptp->rxfilters_ucast)) {
1536		queue_delayed_work(ptp->workwq, &ptp->cleanup_work,
1537				   UCAST_FILTER_EXPIRY_JIFFIES + 1);
1538	}
1539}
1540
1541static const struct ptp_clock_info efx_phc_clock_info = {
1542	.owner		= THIS_MODULE,
1543	.name		= "sfc",
1544	.max_adj	= MAX_PPB,
1545	.n_alarm	= 0,
1546	.n_ext_ts	= 0,
1547	.n_per_out	= 0,
1548	.n_pins		= 0,
1549	.pps		= 1,
1550	.adjfine	= efx_phc_adjfine,
1551	.adjtime	= efx_phc_adjtime,
1552	.gettime64	= efx_phc_gettime,
1553	.settime64	= efx_phc_settime,
1554	.enable		= efx_phc_enable,
1555};
1556
1557/* Initialise PTP state. */
1558int efx_ptp_probe(struct efx_nic *efx, struct efx_channel *channel)
1559{
1560	struct efx_ptp_data *ptp;
1561	int rc = 0;
1562
1563	if (efx->ptp_data) {
1564		efx->ptp_data->channel = channel;
1565		return 0;
1566	}
1567
1568	ptp = kzalloc(sizeof(struct efx_ptp_data), GFP_KERNEL);
1569	efx->ptp_data = ptp;
1570	if (!efx->ptp_data)
1571		return -ENOMEM;
1572
1573	ptp->efx = efx;
1574	ptp->channel = channel;
1575
1576	rc = efx_nic_alloc_buffer(efx, &ptp->start, sizeof(int), GFP_KERNEL);
1577	if (rc != 0)
1578		goto fail1;
1579
1580	skb_queue_head_init(&ptp->rxq);
1581	skb_queue_head_init(&ptp->txq);
1582	ptp->workwq = create_singlethread_workqueue("sfc_ptp");
1583	if (!ptp->workwq) {
1584		rc = -ENOMEM;
1585		goto fail2;
1586	}
1587
1588	if (efx_ptp_use_mac_tx_timestamps(efx)) {
1589		ptp->xmit_skb = efx_ptp_xmit_skb_queue;
1590		/* Request sync events on this channel. */
1591		channel->sync_events_state = SYNC_EVENTS_QUIESCENT;
1592	} else {
1593		ptp->xmit_skb = efx_ptp_xmit_skb_mc;
1594	}
1595
1596	INIT_WORK(&ptp->work, efx_ptp_worker);
1597	INIT_DELAYED_WORK(&ptp->cleanup_work, efx_ptp_cleanup_worker);
1598	ptp->config.flags = 0;
1599	ptp->config.tx_type = HWTSTAMP_TX_OFF;
1600	ptp->config.rx_filter = HWTSTAMP_FILTER_NONE;
1601	INIT_LIST_HEAD(&ptp->rxfilters_mcast);
1602	INIT_LIST_HEAD(&ptp->rxfilters_ucast);
1603
1604	/* Get the NIC PTP attributes and set up time conversions */
1605	rc = efx_ptp_get_attributes(efx);
1606	if (rc < 0)
1607		goto fail3;
1608
1609	/* Get the timestamp corrections */
1610	rc = efx_ptp_get_timestamp_corrections(efx);
1611	if (rc < 0)
1612		goto fail3;
1613
1614	if (efx->mcdi->fn_flags &
1615	    (1 << MC_CMD_DRV_ATTACH_EXT_OUT_FLAG_PRIMARY)) {
1616		ptp->phc_clock_info = efx_phc_clock_info;
1617		ptp->phc_clock = ptp_clock_register(&ptp->phc_clock_info,
1618						    &efx->pci_dev->dev);
1619		if (IS_ERR(ptp->phc_clock)) {
1620			rc = PTR_ERR(ptp->phc_clock);
1621			goto fail3;
1622		} else if (ptp->phc_clock) {
1623			INIT_WORK(&ptp->pps_work, efx_ptp_pps_worker);
1624			ptp->pps_workwq = create_singlethread_workqueue("sfc_pps");
1625			if (!ptp->pps_workwq) {
1626				rc = -ENOMEM;
1627				goto fail4;
1628			}
1629		}
1630	}
1631	ptp->nic_ts_enabled = false;
1632
1633	return 0;
1634fail4:
1635	ptp_clock_unregister(efx->ptp_data->phc_clock);
1636
1637fail3:
1638	destroy_workqueue(efx->ptp_data->workwq);
1639
1640fail2:
1641	efx_nic_free_buffer(efx, &ptp->start);
1642
1643fail1:
1644	kfree(efx->ptp_data);
1645	efx->ptp_data = NULL;
1646
1647	return rc;
1648}
1649
1650/* Initialise PTP channel.
1651 *
1652 * Setting core_index to zero causes the queue to be initialised and doesn't
1653 * overlap with 'rxq0' because ptp.c doesn't use skb_record_rx_queue.
1654 */
1655static int efx_ptp_probe_channel(struct efx_channel *channel)
1656{
1657	struct efx_nic *efx = channel->efx;
1658	int rc;
1659
1660	channel->irq_moderation_us = 0;
1661	channel->rx_queue.core_index = 0;
1662
1663	rc = efx_ptp_probe(efx, channel);
1664	/* Failure to probe PTP is not fatal; this channel will just not be
1665	 * used for anything.
1666	 * In the case of EPERM, efx_ptp_probe will print its own message (in
1667	 * efx_ptp_get_attributes()), so we don't need to.
1668	 */
1669	if (rc && rc != -EPERM)
1670		netif_warn(efx, drv, efx->net_dev,
1671			   "Failed to probe PTP, rc=%d\n", rc);
1672	return 0;
1673}
1674
1675void efx_ptp_remove(struct efx_nic *efx)
1676{
1677	if (!efx->ptp_data)
1678		return;
1679
1680	(void)efx_ptp_disable(efx);
1681
1682	cancel_work_sync(&efx->ptp_data->work);
1683	cancel_delayed_work_sync(&efx->ptp_data->cleanup_work);
1684	if (efx->ptp_data->pps_workwq)
1685		cancel_work_sync(&efx->ptp_data->pps_work);
1686
1687	skb_queue_purge(&efx->ptp_data->rxq);
1688	skb_queue_purge(&efx->ptp_data->txq);
1689
1690	if (efx->ptp_data->phc_clock) {
1691		destroy_workqueue(efx->ptp_data->pps_workwq);
1692		ptp_clock_unregister(efx->ptp_data->phc_clock);
1693	}
1694
1695	destroy_workqueue(efx->ptp_data->workwq);
1696
1697	efx_nic_free_buffer(efx, &efx->ptp_data->start);
1698	kfree(efx->ptp_data);
1699	efx->ptp_data = NULL;
1700}
1701
1702static void efx_ptp_remove_channel(struct efx_channel *channel)
1703{
1704	efx_ptp_remove(channel->efx);
1705}
1706
1707static void efx_ptp_get_channel_name(struct efx_channel *channel,
1708				     char *buf, size_t len)
1709{
1710	snprintf(buf, len, "%s-ptp", channel->efx->name);
1711}
1712
1713/* Determine whether this packet should be processed by the PTP module
1714 * or transmitted conventionally.
1715 */
1716bool efx_ptp_is_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
1717{
1718	return efx->ptp_data &&
1719		efx->ptp_data->enabled &&
1720		skb->len >= PTP_MIN_LENGTH &&
1721		skb->len <= MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM &&
1722		likely(skb->protocol == htons(ETH_P_IP)) &&
1723		skb_transport_header_was_set(skb) &&
1724		skb_network_header_len(skb) >= sizeof(struct iphdr) &&
1725		ip_hdr(skb)->protocol == IPPROTO_UDP &&
1726		skb_headlen(skb) >=
1727		skb_transport_offset(skb) + sizeof(struct udphdr) &&
1728		udp_hdr(skb)->dest == htons(PTP_EVENT_PORT);
1729}
1730
1731/* Receive a PTP packet.  Packets are queued until the arrival of
1732 * the receive timestamp from the MC - this will probably occur after the
1733 * packet arrival because of the processing in the MC.
1734 */
1735static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
1736{
1737	struct efx_nic *efx = channel->efx;
1738	struct efx_ptp_data *ptp = efx->ptp_data;
1739	struct efx_ptp_match *match = (struct efx_ptp_match *)skb->cb;
1740	unsigned int version;
1741	u8 *data;
1742
1743	match->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS);
1744
1745	/* Correct version? */
1746	if (ptp->mode == MC_CMD_PTP_MODE_V1) {
1747		if (!pskb_may_pull(skb, PTP_V1_MIN_LENGTH)) {
1748			return false;
1749		}
1750		data = skb->data;
1751		version = ntohs(*(__be16 *)&data[PTP_V1_VERSION_OFFSET]);
1752		if (version != PTP_VERSION_V1) {
1753			return false;
1754		}
1755	} else {
1756		if (!pskb_may_pull(skb, PTP_V2_MIN_LENGTH)) {
1757			return false;
1758		}
1759		data = skb->data;
1760		version = data[PTP_V2_VERSION_OFFSET];
1761		if ((version & PTP_VERSION_V2_MASK) != PTP_VERSION_V2) {
1762			return false;
1763		}
1764	}
1765
1766	/* Does this packet require timestamping? */
1767	if (ntohs(*(__be16 *)&data[PTP_DPORT_OFFSET]) == PTP_EVENT_PORT) {
1768		match->state = PTP_PACKET_STATE_UNMATCHED;
1769
1770		/* We expect the sequence number to be in the same position in
1771		 * the packet for PTP V1 and V2
1772		 */
1773		BUILD_BUG_ON(PTP_V1_SEQUENCE_OFFSET != PTP_V2_SEQUENCE_OFFSET);
1774		BUILD_BUG_ON(PTP_V1_SEQUENCE_LENGTH != PTP_V2_SEQUENCE_LENGTH);
1775	} else {
1776		match->state = PTP_PACKET_STATE_MATCH_UNWANTED;
1777	}
1778
1779	skb_queue_tail(&ptp->rxq, skb);
1780	queue_work(ptp->workwq, &ptp->work);
1781
1782	return true;
1783}
1784
1785/* Transmit a PTP packet.  This has to be transmitted by the MC
1786 * itself, through an MCDI call.  MCDI calls aren't permitted
1787 * in the transmit path so defer the actual transmission to a suitable worker.
1788 */
1789int efx_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
1790{
1791	struct efx_ptp_data *ptp = efx->ptp_data;
1792
1793	skb_queue_tail(&ptp->txq, skb);
1794
1795	if ((udp_hdr(skb)->dest == htons(PTP_EVENT_PORT)) &&
1796	    (skb->len <= MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM))
1797		efx_xmit_hwtstamp_pending(skb);
1798	queue_work(ptp->workwq, &ptp->work);
1799
1800	return NETDEV_TX_OK;
1801}
1802
1803int efx_ptp_get_mode(struct efx_nic *efx)
1804{
1805	return efx->ptp_data->mode;
1806}
1807
1808int efx_ptp_change_mode(struct efx_nic *efx, bool enable_wanted,
1809			unsigned int new_mode)
1810{
1811	if ((enable_wanted != efx->ptp_data->enabled) ||
1812	    (enable_wanted && (efx->ptp_data->mode != new_mode))) {
1813		int rc = 0;
1814
1815		if (enable_wanted) {
1816			/* Change of mode requires disable */
1817			if (efx->ptp_data->enabled &&
1818			    (efx->ptp_data->mode != new_mode)) {
1819				efx->ptp_data->enabled = false;
1820				rc = efx_ptp_stop(efx);
1821				if (rc != 0)
1822					return rc;
1823			}
1824
1825			/* Set new operating mode and establish
1826			 * baseline synchronisation, which must
1827			 * succeed.
1828			 */
1829			efx->ptp_data->mode = new_mode;
1830			if (netif_running(efx->net_dev))
1831				rc = efx_ptp_start(efx);
1832			if (rc == 0) {
1833				rc = efx_ptp_synchronize(efx,
1834							 PTP_SYNC_ATTEMPTS * 2);
1835				if (rc != 0)
1836					efx_ptp_stop(efx);
1837			}
1838		} else {
1839			rc = efx_ptp_stop(efx);
1840		}
1841
1842		if (rc != 0)
1843			return rc;
1844
1845		efx->ptp_data->enabled = enable_wanted;
1846	}
1847
1848	return 0;
1849}
1850
1851static int efx_ptp_ts_init(struct efx_nic *efx, struct kernel_hwtstamp_config *init)
1852{
1853	int rc;
1854
1855	if ((init->tx_type != HWTSTAMP_TX_OFF) &&
1856	    (init->tx_type != HWTSTAMP_TX_ON))
1857		return -ERANGE;
1858
1859	rc = efx->type->ptp_set_ts_config(efx, init);
1860	if (rc)
1861		return rc;
1862
1863	efx->ptp_data->config = *init;
1864	return 0;
1865}
1866
1867void efx_ptp_get_ts_info(struct efx_nic *efx, struct ethtool_ts_info *ts_info)
1868{
1869	struct efx_ptp_data *ptp = efx->ptp_data;
1870	struct efx_nic *primary = efx->primary;
1871
1872	ASSERT_RTNL();
1873
1874	if (!ptp)
1875		return;
1876
1877	ts_info->so_timestamping |= (SOF_TIMESTAMPING_TX_HARDWARE |
1878				     SOF_TIMESTAMPING_RX_HARDWARE |
1879				     SOF_TIMESTAMPING_RAW_HARDWARE);
1880	/* Check licensed features.  If we don't have the license for TX
1881	 * timestamps, the NIC will not support them.
1882	 */
1883	if (efx_ptp_use_mac_tx_timestamps(efx)) {
1884		struct efx_ef10_nic_data *nic_data = efx->nic_data;
1885
1886		if (!(nic_data->licensed_features &
1887		      (1 << LICENSED_V3_FEATURES_TX_TIMESTAMPS_LBN)))
1888			ts_info->so_timestamping &=
1889				~SOF_TIMESTAMPING_TX_HARDWARE;
1890	}
1891	if (primary && primary->ptp_data && primary->ptp_data->phc_clock)
1892		ts_info->phc_index =
1893			ptp_clock_index(primary->ptp_data->phc_clock);
1894	ts_info->tx_types = 1 << HWTSTAMP_TX_OFF | 1 << HWTSTAMP_TX_ON;
1895	ts_info->rx_filters = ptp->efx->type->hwtstamp_filters;
1896}
1897
1898int efx_ptp_set_ts_config(struct efx_nic *efx,
1899			  struct kernel_hwtstamp_config *config,
1900			  struct netlink_ext_ack __always_unused *extack)
1901{
1902	/* Not a PTP enabled port */
1903	if (!efx->ptp_data)
1904		return -EOPNOTSUPP;
1905
1906	return efx_ptp_ts_init(efx, config);
1907}
1908
1909int efx_ptp_get_ts_config(struct efx_nic *efx,
1910			  struct kernel_hwtstamp_config *config)
1911{
1912	/* Not a PTP enabled port */
1913	if (!efx->ptp_data)
1914		return -EOPNOTSUPP;
1915	*config = efx->ptp_data->config;
1916	return 0;
1917}
1918
1919static void ptp_event_failure(struct efx_nic *efx, int expected_frag_len)
1920{
1921	struct efx_ptp_data *ptp = efx->ptp_data;
1922
1923	netif_err(efx, hw, efx->net_dev,
1924		"PTP unexpected event length: got %d expected %d\n",
1925		ptp->evt_frag_idx, expected_frag_len);
1926	ptp->reset_required = true;
1927	queue_work(ptp->workwq, &ptp->work);
1928}
1929
1930static void ptp_event_fault(struct efx_nic *efx, struct efx_ptp_data *ptp)
1931{
1932	int code = EFX_QWORD_FIELD(ptp->evt_frags[0], MCDI_EVENT_DATA);
1933	if (ptp->evt_frag_idx != 1) {
1934		ptp_event_failure(efx, 1);
1935		return;
1936	}
1937
1938	netif_err(efx, hw, efx->net_dev, "PTP error %d\n", code);
1939}
1940
1941static void ptp_event_pps(struct efx_nic *efx, struct efx_ptp_data *ptp)
1942{
1943	if (ptp->nic_ts_enabled)
1944		queue_work(ptp->pps_workwq, &ptp->pps_work);
1945}
1946
1947void efx_ptp_event(struct efx_nic *efx, efx_qword_t *ev)
1948{
1949	struct efx_ptp_data *ptp = efx->ptp_data;
1950	int code = EFX_QWORD_FIELD(*ev, MCDI_EVENT_CODE);
1951
1952	if (!ptp) {
1953		if (!efx->ptp_warned) {
1954			netif_warn(efx, drv, efx->net_dev,
1955				   "Received PTP event but PTP not set up\n");
1956			efx->ptp_warned = true;
1957		}
1958		return;
1959	}
1960
1961	if (!ptp->enabled)
1962		return;
1963
1964	if (ptp->evt_frag_idx == 0) {
1965		ptp->evt_code = code;
1966	} else if (ptp->evt_code != code) {
1967		netif_err(efx, hw, efx->net_dev,
1968			  "PTP out of sequence event %d\n", code);
1969		ptp->evt_frag_idx = 0;
1970	}
1971
1972	ptp->evt_frags[ptp->evt_frag_idx++] = *ev;
1973	if (!MCDI_EVENT_FIELD(*ev, CONT)) {
1974		/* Process resulting event */
1975		switch (code) {
1976		case MCDI_EVENT_CODE_PTP_FAULT:
1977			ptp_event_fault(efx, ptp);
1978			break;
1979		case MCDI_EVENT_CODE_PTP_PPS:
1980			ptp_event_pps(efx, ptp);
1981			break;
1982		default:
1983			netif_err(efx, hw, efx->net_dev,
1984				  "PTP unknown event %d\n", code);
1985			break;
1986		}
1987		ptp->evt_frag_idx = 0;
1988	} else if (MAX_EVENT_FRAGS == ptp->evt_frag_idx) {
1989		netif_err(efx, hw, efx->net_dev,
1990			  "PTP too many event fragments\n");
1991		ptp->evt_frag_idx = 0;
1992	}
1993}
1994
1995void efx_time_sync_event(struct efx_channel *channel, efx_qword_t *ev)
1996{
1997	struct efx_nic *efx = channel->efx;
1998	struct efx_ptp_data *ptp = efx->ptp_data;
1999
2000	/* When extracting the sync timestamp minor value, we should discard
2001	 * the least significant two bits. These are not required in order
2002	 * to reconstruct full-range timestamps and they are optionally used
2003	 * to report status depending on the options supplied when subscribing
2004	 * for sync events.
2005	 */
2006	channel->sync_timestamp_major = MCDI_EVENT_FIELD(*ev, PTP_TIME_MAJOR);
2007	channel->sync_timestamp_minor =
2008		(MCDI_EVENT_FIELD(*ev, PTP_TIME_MINOR_MS_8BITS) & 0xFC)
2009			<< ptp->nic_time.sync_event_minor_shift;
2010
2011	/* if sync events have been disabled then we want to silently ignore
2012	 * this event, so throw away result.
2013	 */
2014	(void) cmpxchg(&channel->sync_events_state, SYNC_EVENTS_REQUESTED,
2015		       SYNC_EVENTS_VALID);
2016}
2017
2018static inline u32 efx_rx_buf_timestamp_minor(struct efx_nic *efx, const u8 *eh)
2019{
2020#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
2021	return __le32_to_cpup((const __le32 *)(eh + efx->rx_packet_ts_offset));
2022#else
2023	const u8 *data = eh + efx->rx_packet_ts_offset;
2024	return (u32)data[0]       |
2025	       (u32)data[1] << 8  |
2026	       (u32)data[2] << 16 |
2027	       (u32)data[3] << 24;
2028#endif
2029}
2030
2031void __efx_rx_skb_attach_timestamp(struct efx_channel *channel,
2032				   struct sk_buff *skb)
2033{
2034	struct efx_nic *efx = channel->efx;
2035	struct efx_ptp_data *ptp = efx->ptp_data;
2036	u32 pkt_timestamp_major, pkt_timestamp_minor;
2037	u32 diff, carry;
2038	struct skb_shared_hwtstamps *timestamps;
2039
2040	if (channel->sync_events_state != SYNC_EVENTS_VALID)
2041		return;
2042
2043	pkt_timestamp_minor = efx_rx_buf_timestamp_minor(efx, skb_mac_header(skb));
2044
2045	/* get the difference between the packet and sync timestamps,
2046	 * modulo one second
2047	 */
2048	diff = pkt_timestamp_minor - channel->sync_timestamp_minor;
2049	if (pkt_timestamp_minor < channel->sync_timestamp_minor)
2050		diff += ptp->nic_time.minor_max;
2051
2052	/* do we roll over a second boundary and need to carry the one? */
2053	carry = (channel->sync_timestamp_minor >= ptp->nic_time.minor_max - diff) ?
2054		1 : 0;
2055
2056	if (diff <= ptp->nic_time.sync_event_diff_max) {
2057		/* packet is ahead of the sync event by a quarter of a second or
2058		 * less (allowing for fuzz)
2059		 */
2060		pkt_timestamp_major = channel->sync_timestamp_major + carry;
2061	} else if (diff >= ptp->nic_time.sync_event_diff_min) {
2062		/* packet is behind the sync event but within the fuzz factor.
2063		 * This means the RX packet and sync event crossed as they were
2064		 * placed on the event queue, which can sometimes happen.
2065		 */
2066		pkt_timestamp_major = channel->sync_timestamp_major - 1 + carry;
2067	} else {
2068		/* it's outside tolerance in both directions. this might be
2069		 * indicative of us missing sync events for some reason, so
2070		 * we'll call it an error rather than risk giving a bogus
2071		 * timestamp.
2072		 */
2073		netif_vdbg(efx, drv, efx->net_dev,
2074			  "packet timestamp %x too far from sync event %x:%x\n",
2075			  pkt_timestamp_minor, channel->sync_timestamp_major,
2076			  channel->sync_timestamp_minor);
2077		return;
2078	}
2079
2080	/* attach the timestamps to the skb */
2081	timestamps = skb_hwtstamps(skb);
2082	timestamps->hwtstamp =
2083		ptp->nic_to_kernel_time(pkt_timestamp_major,
2084					pkt_timestamp_minor,
2085					ptp->ts_corrections.general_rx);
2086}
2087
2088static int efx_phc_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
2089{
2090	struct efx_ptp_data *ptp_data = container_of(ptp,
2091						     struct efx_ptp_data,
2092						     phc_clock_info);
2093	s32 delta = scaled_ppm_to_ppb(scaled_ppm);
2094	struct efx_nic *efx = ptp_data->efx;
2095	MCDI_DECLARE_BUF(inadj, MC_CMD_PTP_IN_ADJUST_LEN);
2096	s64 adjustment_ns;
2097	int rc;
2098
2099	if (delta > MAX_PPB)
2100		delta = MAX_PPB;
2101	else if (delta < -MAX_PPB)
2102		delta = -MAX_PPB;
2103
2104	/* Convert ppb to fixed point ns taking care to round correctly. */
2105	adjustment_ns = ((s64)delta * PPB_SCALE_WORD +
2106			 (1 << (ptp_data->adjfreq_ppb_shift - 1))) >>
2107			ptp_data->adjfreq_ppb_shift;
2108
2109	MCDI_SET_DWORD(inadj, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);
2110	MCDI_SET_DWORD(inadj, PTP_IN_PERIPH_ID, 0);
2111	MCDI_SET_QWORD(inadj, PTP_IN_ADJUST_FREQ, adjustment_ns);
2112	MCDI_SET_DWORD(inadj, PTP_IN_ADJUST_SECONDS, 0);
2113	MCDI_SET_DWORD(inadj, PTP_IN_ADJUST_NANOSECONDS, 0);
2114	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inadj, sizeof(inadj),
2115			  NULL, 0, NULL);
2116	if (rc != 0)
2117		return rc;
2118
2119	ptp_data->current_adjfreq = adjustment_ns;
2120	return 0;
2121}
2122
2123static int efx_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
2124{
2125	u32 nic_major, nic_minor;
2126	struct efx_ptp_data *ptp_data = container_of(ptp,
2127						     struct efx_ptp_data,
2128						     phc_clock_info);
2129	struct efx_nic *efx = ptp_data->efx;
2130	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_ADJUST_LEN);
2131
2132	efx->ptp_data->ns_to_nic_time(delta, &nic_major, &nic_minor);
2133
2134	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);
2135	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
2136	MCDI_SET_QWORD(inbuf, PTP_IN_ADJUST_FREQ, ptp_data->current_adjfreq);
2137	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_MAJOR, nic_major);
2138	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_MINOR, nic_minor);
2139	return efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
2140			    NULL, 0, NULL);
2141}
2142
2143static int efx_phc_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
2144{
2145	struct efx_ptp_data *ptp_data = container_of(ptp,
2146						     struct efx_ptp_data,
2147						     phc_clock_info);
2148	struct efx_nic *efx = ptp_data->efx;
2149	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_READ_NIC_TIME_LEN);
2150	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_READ_NIC_TIME_LEN);
2151	int rc;
2152	ktime_t kt;
2153
2154	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_READ_NIC_TIME);
2155	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
2156
2157	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
2158			  outbuf, sizeof(outbuf), NULL);
2159	if (rc != 0)
2160		return rc;
2161
2162	kt = ptp_data->nic_to_kernel_time(
2163		MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_MAJOR),
2164		MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_MINOR), 0);
2165	*ts = ktime_to_timespec64(kt);
2166	return 0;
2167}
2168
2169static int efx_phc_settime(struct ptp_clock_info *ptp,
2170			   const struct timespec64 *e_ts)
2171{
2172	/* Get the current NIC time, efx_phc_gettime.
2173	 * Subtract from the desired time to get the offset
2174	 * call efx_phc_adjtime with the offset
2175	 */
2176	int rc;
2177	struct timespec64 time_now;
2178	struct timespec64 delta;
2179
2180	rc = efx_phc_gettime(ptp, &time_now);
2181	if (rc != 0)
2182		return rc;
2183
2184	delta = timespec64_sub(*e_ts, time_now);
2185
2186	rc = efx_phc_adjtime(ptp, timespec64_to_ns(&delta));
2187	if (rc != 0)
2188		return rc;
2189
2190	return 0;
2191}
2192
2193static int efx_phc_enable(struct ptp_clock_info *ptp,
2194			  struct ptp_clock_request *request,
2195			  int enable)
2196{
2197	struct efx_ptp_data *ptp_data = container_of(ptp,
2198						     struct efx_ptp_data,
2199						     phc_clock_info);
2200	if (request->type != PTP_CLK_REQ_PPS)
2201		return -EOPNOTSUPP;
2202
2203	ptp_data->nic_ts_enabled = !!enable;
2204	return 0;
2205}
2206
2207static const struct efx_channel_type efx_ptp_channel_type = {
2208	.handle_no_channel	= efx_ptp_handle_no_channel,
2209	.pre_probe		= efx_ptp_probe_channel,
2210	.post_remove		= efx_ptp_remove_channel,
2211	.get_name		= efx_ptp_get_channel_name,
2212	.copy                   = efx_copy_channel,
2213	.receive_skb		= efx_ptp_rx,
2214	.want_txqs		= efx_ptp_want_txqs,
2215	.keep_eventq		= false,
2216};
2217
2218void efx_ptp_defer_probe_with_channel(struct efx_nic *efx)
2219{
2220	/* Check whether PTP is implemented on this NIC.  The DISABLE
2221	 * operation will succeed if and only if it is implemented.
2222	 */
2223	if (efx_ptp_disable(efx) == 0)
2224		efx->extra_channel_type[EFX_EXTRA_CHANNEL_PTP] =
2225			&efx_ptp_channel_type;
2226}
2227
2228void efx_ptp_start_datapath(struct efx_nic *efx)
2229{
2230	if (efx_ptp_restart(efx))
2231		netif_err(efx, drv, efx->net_dev, "Failed to restart PTP.\n");
2232	/* re-enable timestamping if it was previously enabled */
2233	if (efx->type->ptp_set_ts_sync_events)
2234		efx->type->ptp_set_ts_sync_events(efx, true, true);
2235}
2236
2237void efx_ptp_stop_datapath(struct efx_nic *efx)
2238{
2239	/* temporarily disable timestamping */
2240	if (efx->type->ptp_set_ts_sync_events)
2241		efx->type->ptp_set_ts_sync_events(efx, false, true);
2242	efx_ptp_stop(efx);
2243}
2244