1/* Intel Ethernet Switch Host Interface Driver
2 * Copyright(c) 2013 - 2015 Intel Corporation.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11 * more details.
12 *
13 * The full GNU General Public License is included in this distribution in
14 * the file called "COPYING".
15 *
16 * Contact Information:
17 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
18 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
19 */
20
21#include <linux/ptp_classify.h>
22#include <linux/ptp_clock_kernel.h>
23
24#include "fm10k.h"
25
26#define FM10K_TS_TX_TIMEOUT		(HZ * 15)
27
28void fm10k_systime_to_hwtstamp(struct fm10k_intfc *interface,
29			       struct skb_shared_hwtstamps *hwtstamp,
30			       u64 systime)
31{
32	unsigned long flags;
33
34	read_lock_irqsave(&interface->systime_lock, flags);
35	systime += interface->ptp_adjust;
36	read_unlock_irqrestore(&interface->systime_lock, flags);
37
38	hwtstamp->hwtstamp = ns_to_ktime(systime);
39}
40
41static struct sk_buff *fm10k_ts_tx_skb(struct fm10k_intfc *interface,
42				       __le16 dglort)
43{
44	struct sk_buff_head *list = &interface->ts_tx_skb_queue;
45	struct sk_buff *skb;
46
47	skb_queue_walk(list, skb) {
48		if (FM10K_CB(skb)->fi.w.dglort == dglort)
49			return skb;
50	}
51
52	return NULL;
53}
54
55void fm10k_ts_tx_enqueue(struct fm10k_intfc *interface, struct sk_buff *skb)
56{
57	struct sk_buff_head *list = &interface->ts_tx_skb_queue;
58	struct sk_buff *clone;
59	unsigned long flags;
60
61	/* create clone for us to return on the Tx path */
62	clone = skb_clone_sk(skb);
63	if (!clone)
64		return;
65
66	FM10K_CB(clone)->ts_tx_timeout = jiffies + FM10K_TS_TX_TIMEOUT;
67	spin_lock_irqsave(&list->lock, flags);
68
69	/* attempt to locate any buffers with the same dglort,
70	 * if none are present then insert skb in tail of list
71	 */
72	skb = fm10k_ts_tx_skb(interface, FM10K_CB(clone)->fi.w.dglort);
73	if (!skb) {
74		skb_shinfo(clone)->tx_flags |= SKBTX_IN_PROGRESS;
75		__skb_queue_tail(list, clone);
76	}
77
78	spin_unlock_irqrestore(&list->lock, flags);
79
80	/* if list is already has one then we just free the clone */
81	if (skb)
82		dev_kfree_skb(clone);
83}
84
85void fm10k_ts_tx_hwtstamp(struct fm10k_intfc *interface, __le16 dglort,
86			  u64 systime)
87{
88	struct skb_shared_hwtstamps shhwtstamps;
89	struct sk_buff_head *list = &interface->ts_tx_skb_queue;
90	struct sk_buff *skb;
91	unsigned long flags;
92
93	spin_lock_irqsave(&list->lock, flags);
94
95	/* attempt to locate and pull the sk_buff out of the list */
96	skb = fm10k_ts_tx_skb(interface, dglort);
97	if (skb)
98		__skb_unlink(skb, list);
99
100	spin_unlock_irqrestore(&list->lock, flags);
101
102	/* if not found do nothing */
103	if (!skb)
104		return;
105
106	/* timestamp the sk_buff and free out copy */
107	fm10k_systime_to_hwtstamp(interface, &shhwtstamps, systime);
108	skb_tstamp_tx(skb, &shhwtstamps);
109	dev_kfree_skb_any(skb);
110}
111
112void fm10k_ts_tx_subtask(struct fm10k_intfc *interface)
113{
114	struct sk_buff_head *list = &interface->ts_tx_skb_queue;
115	struct sk_buff *skb, *tmp;
116	unsigned long flags;
117
118	/* If we're down or resetting, just bail */
119	if (test_bit(__FM10K_DOWN, &interface->state) ||
120	    test_bit(__FM10K_RESETTING, &interface->state))
121		return;
122
123	spin_lock_irqsave(&list->lock, flags);
124
125	/* walk though the list and flush any expired timestamp packets */
126	skb_queue_walk_safe(list, skb, tmp) {
127		if (!time_is_after_jiffies(FM10K_CB(skb)->ts_tx_timeout))
128			continue;
129		__skb_unlink(skb, list);
130		kfree_skb(skb);
131		interface->tx_hwtstamp_timeouts++;
132	}
133
134	spin_unlock_irqrestore(&list->lock, flags);
135}
136
137static u64 fm10k_systime_read(struct fm10k_intfc *interface)
138{
139	struct fm10k_hw *hw = &interface->hw;
140
141	return hw->mac.ops.read_systime(hw);
142}
143
144void fm10k_ts_reset(struct fm10k_intfc *interface)
145{
146	s64 ns = ktime_to_ns(ktime_get_real());
147	unsigned long flags;
148
149	/* reinitialize the clock */
150	write_lock_irqsave(&interface->systime_lock, flags);
151	interface->ptp_adjust = fm10k_systime_read(interface) - ns;
152	write_unlock_irqrestore(&interface->systime_lock, flags);
153}
154
155void fm10k_ts_init(struct fm10k_intfc *interface)
156{
157	/* Initialize lock protecting systime access */
158	rwlock_init(&interface->systime_lock);
159
160	/* Initialize skb queue for pending timestamp requests */
161	skb_queue_head_init(&interface->ts_tx_skb_queue);
162
163	/* reset the clock to current kernel time */
164	fm10k_ts_reset(interface);
165}
166
167/**
168 * fm10k_get_ts_config - get current hardware timestamping configuration
169 * @netdev: network interface device structure
170 * @ifreq: ioctl data
171 *
172 * This function returns the current timestamping settings. Rather than
173 * attempt to deconstruct registers to fill in the values, simply keep a copy
174 * of the old settings around, and return a copy when requested.
175 */
176int fm10k_get_ts_config(struct net_device *netdev, struct ifreq *ifr)
177{
178	struct fm10k_intfc *interface = netdev_priv(netdev);
179	struct hwtstamp_config *config = &interface->ts_config;
180
181	return copy_to_user(ifr->ifr_data, config, sizeof(*config)) ?
182		-EFAULT : 0;
183}
184
185/**
186 * fm10k_set_ts_config - control hardware time stamping
187 * @netdev: network interface device structure
188 * @ifreq: ioctl data
189 *
190 * Outgoing time stamping can be enabled and disabled. Play nice and
191 * disable it when requested, although it shouldn't cause any overhead
192 * when no packet needs it. At most one packet in the queue may be
193 * marked for time stamping, otherwise it would be impossible to tell
194 * for sure to which packet the hardware time stamp belongs.
195 *
196 * Incoming time stamping has to be configured via the hardware
197 * filters. Not all combinations are supported, in particular event
198 * type has to be specified. Matching the kind of event packet is
199 * not supported, with the exception of "all V2 events regardless of
200 * level 2 or 4".
201 *
202 * Since hardware always timestamps Path delay packets when timestamping V2
203 * packets, regardless of the type specified in the register, only use V2
204 * Event mode. This more accurately tells the user what the hardware is going
205 * to do anyways.
206 */
207int fm10k_set_ts_config(struct net_device *netdev, struct ifreq *ifr)
208{
209	struct fm10k_intfc *interface = netdev_priv(netdev);
210	struct hwtstamp_config ts_config;
211
212	if (copy_from_user(&ts_config, ifr->ifr_data, sizeof(ts_config)))
213		return -EFAULT;
214
215	/* reserved for future extensions */
216	if (ts_config.flags)
217		return -EINVAL;
218
219	switch (ts_config.tx_type) {
220	case HWTSTAMP_TX_OFF:
221		break;
222	case HWTSTAMP_TX_ON:
223		/* we likely need some check here to see if this is supported */
224		break;
225	default:
226		return -ERANGE;
227	}
228
229	switch (ts_config.rx_filter) {
230	case HWTSTAMP_FILTER_NONE:
231		interface->flags &= ~FM10K_FLAG_RX_TS_ENABLED;
232		break;
233	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
234	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
235	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
236	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
237	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
238	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
239	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
240	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
241	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
242	case HWTSTAMP_FILTER_PTP_V2_EVENT:
243	case HWTSTAMP_FILTER_PTP_V2_SYNC:
244	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
245	case HWTSTAMP_FILTER_ALL:
246		interface->flags |= FM10K_FLAG_RX_TS_ENABLED;
247		ts_config.rx_filter = HWTSTAMP_FILTER_ALL;
248		break;
249	default:
250		return -ERANGE;
251	}
252
253	/* save these settings for future reference */
254	interface->ts_config = ts_config;
255
256	return copy_to_user(ifr->ifr_data, &ts_config, sizeof(ts_config)) ?
257		-EFAULT : 0;
258}
259
260static int fm10k_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
261{
262	struct fm10k_intfc *interface;
263	struct fm10k_hw *hw;
264	int err;
265
266	interface = container_of(ptp, struct fm10k_intfc, ptp_caps);
267	hw = &interface->hw;
268
269	err = hw->mac.ops.adjust_systime(hw, ppb);
270
271	/* the only error we should see is if the value is out of range */
272	return (err == FM10K_ERR_PARAM) ? -ERANGE : err;
273}
274
275static int fm10k_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
276{
277	struct fm10k_intfc *interface;
278	unsigned long flags;
279
280	interface = container_of(ptp, struct fm10k_intfc, ptp_caps);
281
282	write_lock_irqsave(&interface->systime_lock, flags);
283	interface->ptp_adjust += delta;
284	write_unlock_irqrestore(&interface->systime_lock, flags);
285
286	return 0;
287}
288
289static int fm10k_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
290{
291	struct fm10k_intfc *interface;
292	unsigned long flags;
293	u64 now;
294
295	interface = container_of(ptp, struct fm10k_intfc, ptp_caps);
296
297	read_lock_irqsave(&interface->systime_lock, flags);
298	now = fm10k_systime_read(interface) + interface->ptp_adjust;
299	read_unlock_irqrestore(&interface->systime_lock, flags);
300
301	*ts = ns_to_timespec64(now);
302
303	return 0;
304}
305
306static int fm10k_ptp_settime(struct ptp_clock_info *ptp,
307			     const struct timespec64 *ts)
308{
309	struct fm10k_intfc *interface;
310	unsigned long flags;
311	u64 ns = timespec64_to_ns(ts);
312
313	interface = container_of(ptp, struct fm10k_intfc, ptp_caps);
314
315	write_lock_irqsave(&interface->systime_lock, flags);
316	interface->ptp_adjust = fm10k_systime_read(interface) - ns;
317	write_unlock_irqrestore(&interface->systime_lock, flags);
318
319	return 0;
320}
321
322static int fm10k_ptp_enable(struct ptp_clock_info *ptp,
323			    struct ptp_clock_request *rq,
324			    int __always_unused on)
325{
326	struct ptp_clock_time *t = &rq->perout.period;
327	struct fm10k_intfc *interface;
328	struct fm10k_hw *hw;
329	u64 period;
330	u32 step;
331
332	/* we can only support periodic output */
333	if (rq->type != PTP_CLK_REQ_PEROUT)
334		return -EINVAL;
335
336	/* verify the requested channel is there */
337	if (rq->perout.index >= ptp->n_per_out)
338		return -EINVAL;
339
340	/* we cannot enforce start time as there is no
341	 * mechanism for that in the hardware, we can only control
342	 * the period.
343	 */
344
345	/* we cannot support periods greater than 4 seconds due to reg limit */
346	if (t->sec > 4 || t->sec < 0)
347		return -ERANGE;
348
349	interface = container_of(ptp, struct fm10k_intfc, ptp_caps);
350	hw = &interface->hw;
351
352	/* we simply cannot support the operation if we don't have BAR4 */
353	if (!hw->sw_addr)
354		return -ENOTSUPP;
355
356	/* convert to unsigned 64b ns, verify we can put it in a 32b register */
357	period = t->sec * 1000000000LL + t->nsec;
358
359	/* determine the minimum size for period */
360	step = 2 * (fm10k_read_reg(hw, FM10K_SYSTIME_CFG) &
361		    FM10K_SYSTIME_CFG_STEP_MASK);
362
363	/* verify the value is in range supported by hardware */
364	if ((period && (period < step)) || (period > U32_MAX))
365		return -ERANGE;
366
367	/* notify hardware of request to being sending pulses */
368	fm10k_write_sw_reg(hw, FM10K_SW_SYSTIME_PULSE(rq->perout.index),
369			   (u32)period);
370
371	return 0;
372}
373
374static struct ptp_pin_desc fm10k_ptp_pd[2] = {
375	{
376		.name = "IEEE1588_PULSE0",
377		.index = 0,
378		.func = PTP_PF_PEROUT,
379		.chan = 0
380	},
381	{
382		.name = "IEEE1588_PULSE1",
383		.index = 1,
384		.func = PTP_PF_PEROUT,
385		.chan = 1
386	}
387};
388
389static int fm10k_ptp_verify(struct ptp_clock_info *ptp, unsigned int pin,
390			    enum ptp_pin_function func, unsigned int chan)
391{
392	/* verify the requested pin is there */
393	if (pin >= ptp->n_pins || !ptp->pin_config)
394		return -EINVAL;
395
396	/* enforce locked channels, no changing them */
397	if (chan != ptp->pin_config[pin].chan)
398		return -EINVAL;
399
400	/* we want to keep the functions locked as well */
401	if (func != ptp->pin_config[pin].func)
402		return -EINVAL;
403
404	return 0;
405}
406
407void fm10k_ptp_register(struct fm10k_intfc *interface)
408{
409	struct ptp_clock_info *ptp_caps = &interface->ptp_caps;
410	struct device *dev = &interface->pdev->dev;
411	struct ptp_clock *ptp_clock;
412
413	snprintf(ptp_caps->name, sizeof(ptp_caps->name),
414		 "%s", interface->netdev->name);
415	ptp_caps->owner		= THIS_MODULE;
416	/* This math is simply the inverse of the math in
417	 * fm10k_adjust_systime_pf applied to an adjustment value
418	 * of 2^30 - 1 which is the maximum value of the register:
419	 * 	max_ppb == ((2^30 - 1) * 5^9) / 2^31
420	 */
421	ptp_caps->max_adj	= 976562;
422	ptp_caps->adjfreq	= fm10k_ptp_adjfreq;
423	ptp_caps->adjtime	= fm10k_ptp_adjtime;
424	ptp_caps->gettime64	= fm10k_ptp_gettime;
425	ptp_caps->settime64	= fm10k_ptp_settime;
426
427	/* provide pins if BAR4 is accessible */
428	if (interface->sw_addr) {
429		/* enable periodic outputs */
430		ptp_caps->n_per_out = 2;
431		ptp_caps->enable	= fm10k_ptp_enable;
432
433		/* enable clock pins */
434		ptp_caps->verify	= fm10k_ptp_verify;
435		ptp_caps->n_pins = 2;
436		ptp_caps->pin_config = fm10k_ptp_pd;
437	}
438
439	ptp_clock = ptp_clock_register(ptp_caps, dev);
440	if (IS_ERR(ptp_clock)) {
441		ptp_clock = NULL;
442		dev_err(dev, "ptp_clock_register failed\n");
443	} else {
444		dev_info(dev, "registered PHC device %s\n", ptp_caps->name);
445	}
446
447	interface->ptp_clock = ptp_clock;
448}
449
450void fm10k_ptp_unregister(struct fm10k_intfc *interface)
451{
452	struct ptp_clock *ptp_clock = interface->ptp_clock;
453	struct device *dev = &interface->pdev->dev;
454
455	if (!ptp_clock)
456		return;
457
458	interface->ptp_clock = NULL;
459
460	ptp_clock_unregister(ptp_clock);
461	dev_info(dev, "removed PHC %s\n", interface->ptp_caps.name);
462}
463