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  1/*
  2 * Copyright (c) 2012 Mellanox Technologies. All rights reserved.
  3 *
  4 * This software is available to you under a choice of one of two
  5 * licenses.  You may choose to be licensed under the terms of the GNU
  6 * General Public License (GPL) Version 2, available from the file
  7 * COPYING in the main directory of this source tree, or the
  8 * OpenIB.org BSD license below:
  9 *
 10 *     Redistribution and use in source and binary forms, with or
 11 *     without modification, are permitted provided that the following
 12 *     conditions are met:
 13 *
 14 *      - Redistributions of source code must retain the above
 15 *        copyright notice, this list of conditions and the following
 16 *        disclaimer.
 17 *
 18 *      - Redistributions in binary form must reproduce the above
 19 *        copyright notice, this list of conditions and the following
 20 *        disclaimer in the documentation and/or other materials
 21 *        provided with the distribution.
 22 *
 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 30 * SOFTWARE.
 31 *
 32 */
 33
 34#include <linux/mlx4/device.h>
 
 35
 36#include "mlx4_en.h"
 37
 38int mlx4_en_timestamp_config(struct net_device *dev, int tx_type, int rx_filter)
 39{
 40	struct mlx4_en_priv *priv = netdev_priv(dev);
 41	struct mlx4_en_dev *mdev = priv->mdev;
 42	int port_up = 0;
 43	int err = 0;
 44
 45	if (priv->hwtstamp_config.tx_type == tx_type &&
 46	    priv->hwtstamp_config.rx_filter == rx_filter)
 47		return 0;
 48
 49	mutex_lock(&mdev->state_lock);
 50	if (priv->port_up) {
 51		port_up = 1;
 52		mlx4_en_stop_port(dev, 1);
 53	}
 54
 55	mlx4_en_free_resources(priv);
 56
 57	en_warn(priv, "Changing Time Stamp configuration\n");
 58
 59	priv->hwtstamp_config.tx_type = tx_type;
 60	priv->hwtstamp_config.rx_filter = rx_filter;
 61
 62	if (rx_filter != HWTSTAMP_FILTER_NONE)
 63		dev->features &= ~NETIF_F_HW_VLAN_CTAG_RX;
 64	else
 65		dev->features |= NETIF_F_HW_VLAN_CTAG_RX;
 66
 67	err = mlx4_en_alloc_resources(priv);
 68	if (err) {
 69		en_err(priv, "Failed reallocating port resources\n");
 70		goto out;
 71	}
 72	if (port_up) {
 73		err = mlx4_en_start_port(dev);
 74		if (err)
 75			en_err(priv, "Failed starting port\n");
 76	}
 77
 78out:
 79	mutex_unlock(&mdev->state_lock);
 80	netdev_features_change(dev);
 81	return err;
 82}
 83
 84/* mlx4_en_read_clock - read raw cycle counter (to be used by time counter)
 85 */
 86static cycle_t mlx4_en_read_clock(const struct cyclecounter *tc)
 87{
 88	struct mlx4_en_dev *mdev =
 89		container_of(tc, struct mlx4_en_dev, cycles);
 90	struct mlx4_dev *dev = mdev->dev;
 91
 92	return mlx4_read_clock(dev) & tc->mask;
 93}
 94
 95u64 mlx4_en_get_cqe_ts(struct mlx4_cqe *cqe)
 96{
 97	u64 hi, lo;
 98	struct mlx4_ts_cqe *ts_cqe = (struct mlx4_ts_cqe *)cqe;
 99
100	lo = (u64)be16_to_cpu(ts_cqe->timestamp_lo);
101	hi = ((u64)be32_to_cpu(ts_cqe->timestamp_hi) + !lo) << 16;
102
103	return hi | lo;
104}
105
106void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
107			    struct skb_shared_hwtstamps *hwts,
108			    u64 timestamp)
109{
110	unsigned long flags;
111	u64 nsec;
112
113	read_lock_irqsave(&mdev->clock_lock, flags);
114	nsec = timecounter_cyc2time(&mdev->clock, timestamp);
115	read_unlock_irqrestore(&mdev->clock_lock, flags);
116
117	memset(hwts, 0, sizeof(struct skb_shared_hwtstamps));
118	hwts->hwtstamp = ns_to_ktime(nsec);
119}
120
121/**
122 * mlx4_en_remove_timestamp - disable PTP device
123 * @mdev: board private structure
124 *
125 * Stop the PTP support.
126 **/
127void mlx4_en_remove_timestamp(struct mlx4_en_dev *mdev)
128{
129	if (mdev->ptp_clock) {
130		ptp_clock_unregister(mdev->ptp_clock);
131		mdev->ptp_clock = NULL;
132		mlx4_info(mdev, "removed PHC\n");
133	}
134}
135
136void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev)
137{
138	bool timeout = time_is_before_jiffies(mdev->last_overflow_check +
139					      mdev->overflow_period);
140	unsigned long flags;
141
142	if (timeout) {
143		write_lock_irqsave(&mdev->clock_lock, flags);
144		timecounter_read(&mdev->clock);
145		write_unlock_irqrestore(&mdev->clock_lock, flags);
146		mdev->last_overflow_check = jiffies;
147	}
148}
149
150/**
151 * mlx4_en_phc_adjfreq - adjust the frequency of the hardware clock
152 * @ptp: ptp clock structure
153 * @delta: Desired frequency change in parts per billion
154 *
155 * Adjust the frequency of the PHC cycle counter by the indicated delta from
156 * the base frequency.
157 **/
158static int mlx4_en_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
159{
160	u64 adj;
161	u32 diff, mult;
162	int neg_adj = 0;
163	unsigned long flags;
164	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
165						ptp_clock_info);
166
167	if (delta < 0) {
168		neg_adj = 1;
169		delta = -delta;
170	}
171	mult = mdev->nominal_c_mult;
172	adj = mult;
173	adj *= delta;
174	diff = div_u64(adj, 1000000000ULL);
175
176	write_lock_irqsave(&mdev->clock_lock, flags);
177	timecounter_read(&mdev->clock);
178	mdev->cycles.mult = neg_adj ? mult - diff : mult + diff;
179	write_unlock_irqrestore(&mdev->clock_lock, flags);
180
181	return 0;
182}
183
184/**
185 * mlx4_en_phc_adjtime - Shift the time of the hardware clock
186 * @ptp: ptp clock structure
187 * @delta: Desired change in nanoseconds
188 *
189 * Adjust the timer by resetting the timecounter structure.
190 **/
191static int mlx4_en_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
192{
193	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
194						ptp_clock_info);
195	unsigned long flags;
196	s64 now;
197
198	write_lock_irqsave(&mdev->clock_lock, flags);
199	now = timecounter_read(&mdev->clock);
200	now += delta;
201	timecounter_init(&mdev->clock, &mdev->cycles, now);
202	write_unlock_irqrestore(&mdev->clock_lock, flags);
203
204	return 0;
205}
206
207/**
208 * mlx4_en_phc_gettime - Reads the current time from the hardware clock
209 * @ptp: ptp clock structure
210 * @ts: timespec structure to hold the current time value
211 *
212 * Read the timecounter and return the correct value in ns after converting
213 * it into a struct timespec.
214 **/
215static int mlx4_en_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
 
216{
217	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
218						ptp_clock_info);
219	unsigned long flags;
220	u32 remainder;
221	u64 ns;
222
223	write_lock_irqsave(&mdev->clock_lock, flags);
224	ns = timecounter_read(&mdev->clock);
225	write_unlock_irqrestore(&mdev->clock_lock, flags);
226
227	ts->tv_sec = div_u64_rem(ns, NSEC_PER_SEC, &remainder);
228	ts->tv_nsec = remainder;
229
230	return 0;
231}
232
233/**
234 * mlx4_en_phc_settime - Set the current time on the hardware clock
235 * @ptp: ptp clock structure
236 * @ts: timespec containing the new time for the cycle counter
237 *
238 * Reset the timecounter to use a new base value instead of the kernel
239 * wall timer value.
240 **/
241static int mlx4_en_phc_settime(struct ptp_clock_info *ptp,
242			       const struct timespec *ts)
243{
244	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
245						ptp_clock_info);
246	u64 ns = timespec_to_ns(ts);
247	unsigned long flags;
248
249	/* reset the timecounter */
250	write_lock_irqsave(&mdev->clock_lock, flags);
251	timecounter_init(&mdev->clock, &mdev->cycles, ns);
252	write_unlock_irqrestore(&mdev->clock_lock, flags);
253
254	return 0;
255}
256
257/**
258 * mlx4_en_phc_enable - enable or disable an ancillary feature
259 * @ptp: ptp clock structure
260 * @request: Desired resource to enable or disable
261 * @on: Caller passes one to enable or zero to disable
262 *
263 * Enable (or disable) ancillary features of the PHC subsystem.
264 * Currently, no ancillary features are supported.
265 **/
266static int mlx4_en_phc_enable(struct ptp_clock_info __always_unused *ptp,
267			      struct ptp_clock_request __always_unused *request,
268			      int __always_unused on)
269{
270	return -EOPNOTSUPP;
271}
272
273static const struct ptp_clock_info mlx4_en_ptp_clock_info = {
274	.owner		= THIS_MODULE,
275	.max_adj	= 100000000,
276	.n_alarm	= 0,
277	.n_ext_ts	= 0,
278	.n_per_out	= 0,
279	.n_pins		= 0,
280	.pps		= 0,
281	.adjfreq	= mlx4_en_phc_adjfreq,
282	.adjtime	= mlx4_en_phc_adjtime,
283	.gettime	= mlx4_en_phc_gettime,
284	.settime	= mlx4_en_phc_settime,
285	.enable		= mlx4_en_phc_enable,
286};
287
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
288void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
289{
290	struct mlx4_dev *dev = mdev->dev;
291	unsigned long flags;
292	u64 ns;
 
 
 
 
 
 
 
293
294	rwlock_init(&mdev->clock_lock);
295
296	memset(&mdev->cycles, 0, sizeof(mdev->cycles));
297	mdev->cycles.read = mlx4_en_read_clock;
298	mdev->cycles.mask = CLOCKSOURCE_MASK(48);
299	/* Using shift to make calculation more accurate. Since current HW
300	 * clock frequency is 427 MHz, and cycles are given using a 48 bits
301	 * register, the biggest shift when calculating using u64, is 14
302	 * (max_cycles * multiplier < 2^64)
303	 */
304	mdev->cycles.shift = 14;
305	mdev->cycles.mult =
306		clocksource_khz2mult(1000 * dev->caps.hca_core_clock, mdev->cycles.shift);
307	mdev->nominal_c_mult = mdev->cycles.mult;
308
309	write_lock_irqsave(&mdev->clock_lock, flags);
310	timecounter_init(&mdev->clock, &mdev->cycles,
311			 ktime_to_ns(ktime_get_real()));
312	write_unlock_irqrestore(&mdev->clock_lock, flags);
313
314	/* Calculate period in seconds to call the overflow watchdog - to make
315	 * sure counter is checked at least once every wrap around.
316	 */
317	ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask);
318	do_div(ns, NSEC_PER_SEC / 2 / HZ);
319	mdev->overflow_period = ns;
320
321	/* Configure the PHC */
322	mdev->ptp_clock_info = mlx4_en_ptp_clock_info;
323	snprintf(mdev->ptp_clock_info.name, 16, "mlx4 ptp");
324
325	mdev->ptp_clock = ptp_clock_register(&mdev->ptp_clock_info,
326					     &mdev->pdev->dev);
327	if (IS_ERR(mdev->ptp_clock)) {
328		mdev->ptp_clock = NULL;
329		mlx4_err(mdev, "ptp_clock_register failed\n");
330	} else {
331		mlx4_info(mdev, "registered PHC clock\n");
332	}
333
334}
  1/*
  2 * Copyright (c) 2012 Mellanox Technologies. All rights reserved.
  3 *
  4 * This software is available to you under a choice of one of two
  5 * licenses.  You may choose to be licensed under the terms of the GNU
  6 * General Public License (GPL) Version 2, available from the file
  7 * COPYING in the main directory of this source tree, or the
  8 * OpenIB.org BSD license below:
  9 *
 10 *     Redistribution and use in source and binary forms, with or
 11 *     without modification, are permitted provided that the following
 12 *     conditions are met:
 13 *
 14 *      - Redistributions of source code must retain the above
 15 *        copyright notice, this list of conditions and the following
 16 *        disclaimer.
 17 *
 18 *      - Redistributions in binary form must reproduce the above
 19 *        copyright notice, this list of conditions and the following
 20 *        disclaimer in the documentation and/or other materials
 21 *        provided with the distribution.
 22 *
 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 30 * SOFTWARE.
 31 *
 32 */
 33
 34#include <linux/mlx4/device.h>
 35#include <linux/clocksource.h>
 36
 37#include "mlx4_en.h"
 38
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 39/* mlx4_en_read_clock - read raw cycle counter (to be used by time counter)
 40 */
 41static cycle_t mlx4_en_read_clock(const struct cyclecounter *tc)
 42{
 43	struct mlx4_en_dev *mdev =
 44		container_of(tc, struct mlx4_en_dev, cycles);
 45	struct mlx4_dev *dev = mdev->dev;
 46
 47	return mlx4_read_clock(dev) & tc->mask;
 48}
 49
 50u64 mlx4_en_get_cqe_ts(struct mlx4_cqe *cqe)
 51{
 52	u64 hi, lo;
 53	struct mlx4_ts_cqe *ts_cqe = (struct mlx4_ts_cqe *)cqe;
 54
 55	lo = (u64)be16_to_cpu(ts_cqe->timestamp_lo);
 56	hi = ((u64)be32_to_cpu(ts_cqe->timestamp_hi) + !lo) << 16;
 57
 58	return hi | lo;
 59}
 60
 61void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
 62			    struct skb_shared_hwtstamps *hwts,
 63			    u64 timestamp)
 64{
 65	unsigned long flags;
 66	u64 nsec;
 67
 68	read_lock_irqsave(&mdev->clock_lock, flags);
 69	nsec = timecounter_cyc2time(&mdev->clock, timestamp);
 70	read_unlock_irqrestore(&mdev->clock_lock, flags);
 71
 72	memset(hwts, 0, sizeof(struct skb_shared_hwtstamps));
 73	hwts->hwtstamp = ns_to_ktime(nsec);
 74}
 75
 76/**
 77 * mlx4_en_remove_timestamp - disable PTP device
 78 * @mdev: board private structure
 79 *
 80 * Stop the PTP support.
 81 **/
 82void mlx4_en_remove_timestamp(struct mlx4_en_dev *mdev)
 83{
 84	if (mdev->ptp_clock) {
 85		ptp_clock_unregister(mdev->ptp_clock);
 86		mdev->ptp_clock = NULL;
 87		mlx4_info(mdev, "removed PHC\n");
 88	}
 89}
 90
 91void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev)
 92{
 93	bool timeout = time_is_before_jiffies(mdev->last_overflow_check +
 94					      mdev->overflow_period);
 95	unsigned long flags;
 96
 97	if (timeout) {
 98		write_lock_irqsave(&mdev->clock_lock, flags);
 99		timecounter_read(&mdev->clock);
100		write_unlock_irqrestore(&mdev->clock_lock, flags);
101		mdev->last_overflow_check = jiffies;
102	}
103}
104
105/**
106 * mlx4_en_phc_adjfreq - adjust the frequency of the hardware clock
107 * @ptp: ptp clock structure
108 * @delta: Desired frequency change in parts per billion
109 *
110 * Adjust the frequency of the PHC cycle counter by the indicated delta from
111 * the base frequency.
112 **/
113static int mlx4_en_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
114{
115	u64 adj;
116	u32 diff, mult;
117	int neg_adj = 0;
118	unsigned long flags;
119	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
120						ptp_clock_info);
121
122	if (delta < 0) {
123		neg_adj = 1;
124		delta = -delta;
125	}
126	mult = mdev->nominal_c_mult;
127	adj = mult;
128	adj *= delta;
129	diff = div_u64(adj, 1000000000ULL);
130
131	write_lock_irqsave(&mdev->clock_lock, flags);
132	timecounter_read(&mdev->clock);
133	mdev->cycles.mult = neg_adj ? mult - diff : mult + diff;
134	write_unlock_irqrestore(&mdev->clock_lock, flags);
135
136	return 0;
137}
138
139/**
140 * mlx4_en_phc_adjtime - Shift the time of the hardware clock
141 * @ptp: ptp clock structure
142 * @delta: Desired change in nanoseconds
143 *
144 * Adjust the timer by resetting the timecounter structure.
145 **/
146static int mlx4_en_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
147{
148	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
149						ptp_clock_info);
150	unsigned long flags;
 
151
152	write_lock_irqsave(&mdev->clock_lock, flags);
153	timecounter_adjtime(&mdev->clock, delta);
 
 
154	write_unlock_irqrestore(&mdev->clock_lock, flags);
155
156	return 0;
157}
158
159/**
160 * mlx4_en_phc_gettime - Reads the current time from the hardware clock
161 * @ptp: ptp clock structure
162 * @ts: timespec structure to hold the current time value
163 *
164 * Read the timecounter and return the correct value in ns after converting
165 * it into a struct timespec.
166 **/
167static int mlx4_en_phc_gettime(struct ptp_clock_info *ptp,
168			       struct timespec64 *ts)
169{
170	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
171						ptp_clock_info);
172	unsigned long flags;
 
173	u64 ns;
174
175	write_lock_irqsave(&mdev->clock_lock, flags);
176	ns = timecounter_read(&mdev->clock);
177	write_unlock_irqrestore(&mdev->clock_lock, flags);
178
179	*ts = ns_to_timespec64(ns);
 
180
181	return 0;
182}
183
184/**
185 * mlx4_en_phc_settime - Set the current time on the hardware clock
186 * @ptp: ptp clock structure
187 * @ts: timespec containing the new time for the cycle counter
188 *
189 * Reset the timecounter to use a new base value instead of the kernel
190 * wall timer value.
191 **/
192static int mlx4_en_phc_settime(struct ptp_clock_info *ptp,
193			       const struct timespec64 *ts)
194{
195	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
196						ptp_clock_info);
197	u64 ns = timespec64_to_ns(ts);
198	unsigned long flags;
199
200	/* reset the timecounter */
201	write_lock_irqsave(&mdev->clock_lock, flags);
202	timecounter_init(&mdev->clock, &mdev->cycles, ns);
203	write_unlock_irqrestore(&mdev->clock_lock, flags);
204
205	return 0;
206}
207
208/**
209 * mlx4_en_phc_enable - enable or disable an ancillary feature
210 * @ptp: ptp clock structure
211 * @request: Desired resource to enable or disable
212 * @on: Caller passes one to enable or zero to disable
213 *
214 * Enable (or disable) ancillary features of the PHC subsystem.
215 * Currently, no ancillary features are supported.
216 **/
217static int mlx4_en_phc_enable(struct ptp_clock_info __always_unused *ptp,
218			      struct ptp_clock_request __always_unused *request,
219			      int __always_unused on)
220{
221	return -EOPNOTSUPP;
222}
223
224static const struct ptp_clock_info mlx4_en_ptp_clock_info = {
225	.owner		= THIS_MODULE,
226	.max_adj	= 100000000,
227	.n_alarm	= 0,
228	.n_ext_ts	= 0,
229	.n_per_out	= 0,
230	.n_pins		= 0,
231	.pps		= 0,
232	.adjfreq	= mlx4_en_phc_adjfreq,
233	.adjtime	= mlx4_en_phc_adjtime,
234	.gettime64	= mlx4_en_phc_gettime,
235	.settime64	= mlx4_en_phc_settime,
236	.enable		= mlx4_en_phc_enable,
237};
238
239#define MLX4_EN_WRAP_AROUND_SEC	10ULL
240
241/* This function calculates the max shift that enables the user range
242 * of MLX4_EN_WRAP_AROUND_SEC values in the cycles register.
243 */
244static u32 freq_to_shift(u16 freq)
245{
246	u32 freq_khz = freq * 1000;
247	u64 max_val_cycles = freq_khz * 1000 * MLX4_EN_WRAP_AROUND_SEC;
248	u64 max_val_cycles_rounded = is_power_of_2(max_val_cycles + 1) ?
249		max_val_cycles : roundup_pow_of_two(max_val_cycles) - 1;
250	/* calculate max possible multiplier in order to fit in 64bit */
251	u64 max_mul = div_u64(0xffffffffffffffffULL, max_val_cycles_rounded);
252
253	/* This comes from the reverse of clocksource_khz2mult */
254	return ilog2(div_u64(max_mul * freq_khz, 1000000));
255}
256
257void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
258{
259	struct mlx4_dev *dev = mdev->dev;
260	unsigned long flags;
261	u64 ns, zero = 0;
262
263	/* mlx4_en_init_timestamp is called for each netdev.
264	 * mdev->ptp_clock is common for all ports, skip initialization if
265	 * was done for other port.
266	 */
267	if (mdev->ptp_clock)
268		return;
269
270	rwlock_init(&mdev->clock_lock);
271
272	memset(&mdev->cycles, 0, sizeof(mdev->cycles));
273	mdev->cycles.read = mlx4_en_read_clock;
274	mdev->cycles.mask = CLOCKSOURCE_MASK(48);
275	mdev->cycles.shift = freq_to_shift(dev->caps.hca_core_clock);
 
 
 
 
 
276	mdev->cycles.mult =
277		clocksource_khz2mult(1000 * dev->caps.hca_core_clock, mdev->cycles.shift);
278	mdev->nominal_c_mult = mdev->cycles.mult;
279
280	write_lock_irqsave(&mdev->clock_lock, flags);
281	timecounter_init(&mdev->clock, &mdev->cycles,
282			 ktime_to_ns(ktime_get_real()));
283	write_unlock_irqrestore(&mdev->clock_lock, flags);
284
285	/* Calculate period in seconds to call the overflow watchdog - to make
286	 * sure counter is checked at least once every wrap around.
287	 */
288	ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask, zero, &zero);
289	do_div(ns, NSEC_PER_SEC / 2 / HZ);
290	mdev->overflow_period = ns;
291
292	/* Configure the PHC */
293	mdev->ptp_clock_info = mlx4_en_ptp_clock_info;
294	snprintf(mdev->ptp_clock_info.name, 16, "mlx4 ptp");
295
296	mdev->ptp_clock = ptp_clock_register(&mdev->ptp_clock_info,
297					     &mdev->pdev->dev);
298	if (IS_ERR(mdev->ptp_clock)) {
299		mdev->ptp_clock = NULL;
300		mlx4_err(mdev, "ptp_clock_register failed\n");
301	} else {
302		mlx4_info(mdev, "registered PHC clock\n");
303	}
304
305}