drivers/net/ethernet/mellanox/mlx4/en_clock.c - linux - Git at Google

 /*
  * Copyright (c) 2012 Mellanox Technologies. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
  * General Public License (GPL) Version 2, available from the file
  * COPYING in the main directory of this source tree, or the
  * OpenIB.org BSD license below:
  *
  *     Redistribution and use in source and binary forms, with or
  *     without modification, are permitted provided that the following
  *     conditions are met:
  *
  *      - Redistributions of source code must retain the above
  *        copyright notice, this list of conditions and the following
  *        disclaimer.
  *
  *      - Redistributions in binary form must reproduce the above
  *        copyright notice, this list of conditions and the following
  *        disclaimer in the documentation and/or other materials
  *        provided with the distribution.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
  */

 #include <linux/mlx4/device.h>
 #include <linux/clocksource.h>

 #include "mlx4_en.h"

 /* mlx4_en_read_clock - read raw cycle counter (to be used by time counter)
  */
 static u64 mlx4_en_read_clock(const struct cyclecounter *tc)
 {
 	struct mlx4_en_dev *mdev =
 		container_of(tc, struct mlx4_en_dev, cycles);
 	struct mlx4_dev *dev = mdev->dev;

 	return mlx4_read_clock(dev) & tc->mask;
 }

 u64 mlx4_en_get_cqe_ts(struct mlx4_cqe *cqe)
 {
 	u64 hi, lo;
 	struct mlx4_ts_cqe *ts_cqe = (struct mlx4_ts_cqe *)cqe;

 	lo = (u64)be16_to_cpu(ts_cqe->timestamp_lo);
 	hi = ((u64)be32_to_cpu(ts_cqe->timestamp_hi) + !lo) << 16;

 	return hi | lo;
 }

 u64 mlx4_en_get_hwtstamp(struct mlx4_en_dev *mdev, u64 timestamp)
 {
 	unsigned int seq;
 	u64 nsec;

 	do {
 		seq = read_seqbegin(&mdev->clock_lock);
 		nsec = timecounter_cyc2time(&mdev->clock, timestamp);
 	} while (read_seqretry(&mdev->clock_lock, seq));

 	return ns_to_ktime(nsec);
 }

 void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
 			    struct skb_shared_hwtstamps *hwts,
 			    u64 timestamp)
 {
 	memset(hwts, 0, sizeof(struct skb_shared_hwtstamps));
 	hwts->hwtstamp = mlx4_en_get_hwtstamp(mdev, timestamp);
 }

 /**
  * mlx4_en_remove_timestamp - disable PTP device
  * @mdev: board private structure
  *
  * Stop the PTP support.
  **/
 void mlx4_en_remove_timestamp(struct mlx4_en_dev *mdev)
 {
 	if (mdev->ptp_clock) {
 		ptp_clock_unregister(mdev->ptp_clock);
 		mdev->ptp_clock = NULL;
 		mlx4_info(mdev, "removed PHC\n");
 	}
 }

 #define MLX4_EN_WRAP_AROUND_SEC	10UL
 /* By scheduling the overflow check every 5 seconds, we have a reasonably
  * good chance we won't miss a wrap around.
  * TODO: Use a timer instead of a work queue to increase the guarantee.
  */
 #define MLX4_EN_OVERFLOW_PERIOD (MLX4_EN_WRAP_AROUND_SEC * HZ / 2)

 void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev)
 {
 	bool timeout = time_is_before_jiffies(mdev->last_overflow_check +
 					      MLX4_EN_OVERFLOW_PERIOD);
 	unsigned long flags;

 	if (timeout) {
 		write_seqlock_irqsave(&mdev->clock_lock, flags);
 		timecounter_read(&mdev->clock);
 		write_sequnlock_irqrestore(&mdev->clock_lock, flags);
 		mdev->last_overflow_check = jiffies;
 	}
 }

 /**
  * mlx4_en_phc_adjfine - adjust the frequency of the hardware clock
  * @ptp: ptp clock structure
  * @scaled_ppm: Desired frequency change in scaled parts per million
  *
  * Adjust the frequency of the PHC cycle counter by the indicated scaled_ppm
  * from the base frequency.
  *
  * Scaled parts per million is ppm with a 16-bit binary fractional field.
  **/
 static int mlx4_en_phc_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 {
 	u32 mult;
 	unsigned long flags;
 	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
 						ptp_clock_info);

 	mult = (u32)adjust_by_scaled_ppm(mdev->nominal_c_mult, scaled_ppm);

 	write_seqlock_irqsave(&mdev->clock_lock, flags);
 	timecounter_read(&mdev->clock);
 	mdev->cycles.mult = mult;
 	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

 	return 0;
 }

 /**
  * mlx4_en_phc_adjtime - Shift the time of the hardware clock
  * @ptp: ptp clock structure
  * @delta: Desired change in nanoseconds
  *
  * Adjust the timer by resetting the timecounter structure.
  **/
 static int mlx4_en_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
 {
 	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
 						ptp_clock_info);
 	unsigned long flags;

 	write_seqlock_irqsave(&mdev->clock_lock, flags);
 	timecounter_adjtime(&mdev->clock, delta);
 	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

 	return 0;
 }

 /**
  * mlx4_en_phc_gettime - Reads the current time from the hardware clock
  * @ptp: ptp clock structure
  * @ts: timespec structure to hold the current time value
  *
  * Read the timecounter and return the correct value in ns after converting
  * it into a struct timespec.
  **/
 static int mlx4_en_phc_gettime(struct ptp_clock_info *ptp,
 			       struct timespec64 *ts)
 {
 	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
 						ptp_clock_info);
 	unsigned long flags;
 	u64 ns;

 	write_seqlock_irqsave(&mdev->clock_lock, flags);
 	ns = timecounter_read(&mdev->clock);
 	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

 	*ts = ns_to_timespec64(ns);

 	return 0;
 }

 /**
  * mlx4_en_phc_settime - Set the current time on the hardware clock
  * @ptp: ptp clock structure
  * @ts: timespec containing the new time for the cycle counter
  *
  * Reset the timecounter to use a new base value instead of the kernel
  * wall timer value.
  **/
 static int mlx4_en_phc_settime(struct ptp_clock_info *ptp,
 			       const struct timespec64 *ts)
 {
 	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
 						ptp_clock_info);
 	u64 ns = timespec64_to_ns(ts);
 	unsigned long flags;

 	/* reset the timecounter */
 	write_seqlock_irqsave(&mdev->clock_lock, flags);
 	timecounter_init(&mdev->clock, &mdev->cycles, ns);
 	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

 	return 0;
 }

 /**
  * mlx4_en_phc_enable - enable or disable an ancillary feature
  * @ptp: ptp clock structure
  * @request: Desired resource to enable or disable
  * @on: Caller passes one to enable or zero to disable
  *
  * Enable (or disable) ancillary features of the PHC subsystem.
  * Currently, no ancillary features are supported.
  **/
 static int mlx4_en_phc_enable(struct ptp_clock_info __always_unused *ptp,
 			      struct ptp_clock_request __always_unused *request,
 			      int __always_unused on)
 {
 	return -EOPNOTSUPP;
 }

 static const struct ptp_clock_info mlx4_en_ptp_clock_info = {
 	.owner		= THIS_MODULE,
 	.max_adj	= 100000000,
 	.n_alarm	= 0,
 	.n_ext_ts	= 0,
 	.n_per_out	= 0,
 	.n_pins		= 0,
 	.pps		= 0,
 	.adjfine	= mlx4_en_phc_adjfine,
 	.adjtime	= mlx4_en_phc_adjtime,
 	.gettime64	= mlx4_en_phc_gettime,
 	.settime64	= mlx4_en_phc_settime,
 	.enable		= mlx4_en_phc_enable,
 };


 /* This function calculates the max shift that enables the user range
  * of MLX4_EN_WRAP_AROUND_SEC values in the cycles register.
  */
 static u32 freq_to_shift(u16 freq)
 {
 	u32 freq_khz = freq * 1000;
 	u64 max_val_cycles = freq_khz * 1000 * MLX4_EN_WRAP_AROUND_SEC;
 	u64 max_val_cycles_rounded = 1ULL << fls64(max_val_cycles - 1);
 	/* calculate max possible multiplier in order to fit in 64bit */
 	u64 max_mul = div64_u64(ULLONG_MAX, max_val_cycles_rounded);

 	/* This comes from the reverse of clocksource_khz2mult */
 	return ilog2(div_u64(max_mul * freq_khz, 1000000));
 }

 void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
 {
 	struct mlx4_dev *dev = mdev->dev;
 	unsigned long flags;

 	/* mlx4_en_init_timestamp is called for each netdev.
 	 * mdev->ptp_clock is common for all ports, skip initialization if
 	 * was done for other port.
 	 */
 	if (mdev->ptp_clock)
 		return;

 	seqlock_init(&mdev->clock_lock);

 	memset(&mdev->cycles, 0, sizeof(mdev->cycles));
 	mdev->cycles.read = mlx4_en_read_clock;
 	mdev->cycles.mask = CLOCKSOURCE_MASK(48);
 	mdev->cycles.shift = freq_to_shift(dev->caps.hca_core_clock);
 	mdev->cycles.mult =
 		clocksource_khz2mult(1000 * dev->caps.hca_core_clock, mdev->cycles.shift);
 	mdev->nominal_c_mult = mdev->cycles.mult;

 	write_seqlock_irqsave(&mdev->clock_lock, flags);
 	timecounter_init(&mdev->clock, &mdev->cycles,
 			 ktime_to_ns(ktime_get_real()));
 	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

 	/* Configure the PHC */
 	mdev->ptp_clock_info = mlx4_en_ptp_clock_info;
 	snprintf(mdev->ptp_clock_info.name, 16, "mlx4 ptp");

 	mdev->ptp_clock = ptp_clock_register(&mdev->ptp_clock_info,
 					     &mdev->pdev->dev);
 	if (IS_ERR(mdev->ptp_clock)) {
 		mdev->ptp_clock = NULL;
 		mlx4_err(mdev, "ptp_clock_register failed\n");
 	} else if (mdev->ptp_clock) {
 		mlx4_info(mdev, "registered PHC clock\n");
 	}

 }
	/*
	* Copyright (c) 2012 Mellanox Technologies. All rights reserved.
	*
	* This software is available to you under a choice of one of two
	* licenses. You may choose to be licensed under the terms of the GNU
	* General Public License (GPL) Version 2, available from the file
	* COPYING in the main directory of this source tree, or the
	* OpenIB.org BSD license below:
	*
	* Redistribution and use in source and binary forms, with or
	* without modification, are permitted provided that the following
	* conditions are met:
	*
	* - Redistributions of source code must retain the above
	* copyright notice, this list of conditions and the following
	* disclaimer.
	*
	* - Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials
	* provided with the distribution.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	* SOFTWARE.
	*
	*/

	#include <linux/mlx4/device.h>
	#include <linux/clocksource.h>

	#include "mlx4_en.h"

	/* mlx4_en_read_clock - read raw cycle counter (to be used by time counter)
	*/
	static u64 mlx4_en_read_clock(const struct cyclecounter *tc)
	{
	struct mlx4_en_dev *mdev =
	container_of(tc, struct mlx4_en_dev, cycles);
	struct mlx4_dev *dev = mdev->dev;

	return mlx4_read_clock(dev) & tc->mask;
	}

	u64 mlx4_en_get_cqe_ts(struct mlx4_cqe *cqe)
	{
	u64 hi, lo;
	struct mlx4_ts_cqe ts_cqe = (struct mlx4_ts_cqe )cqe;

	lo = (u64)be16_to_cpu(ts_cqe->timestamp_lo);
	hi = ((u64)be32_to_cpu(ts_cqe->timestamp_hi) + !lo) << 16;

	return hi \| lo;
	}

	u64 mlx4_en_get_hwtstamp(struct mlx4_en_dev *mdev, u64 timestamp)
	{
	unsigned int seq;
	u64 nsec;

	do {
	seq = read_seqbegin(&mdev->clock_lock);
	nsec = timecounter_cyc2time(&mdev->clock, timestamp);
	} while (read_seqretry(&mdev->clock_lock, seq));

	return ns_to_ktime(nsec);
	}

	void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
	struct skb_shared_hwtstamps *hwts,
	u64 timestamp)
	{
	memset(hwts, 0, sizeof(struct skb_shared_hwtstamps));
	hwts->hwtstamp = mlx4_en_get_hwtstamp(mdev, timestamp);
	}

	/**
	* mlx4_en_remove_timestamp - disable PTP device
	* @mdev: board private structure
	*
	* Stop the PTP support.
	**/
	void mlx4_en_remove_timestamp(struct mlx4_en_dev *mdev)
	{
	if (mdev->ptp_clock) {
	ptp_clock_unregister(mdev->ptp_clock);
	mdev->ptp_clock = NULL;
	mlx4_info(mdev, "removed PHC\n");
	}
	}

	#define MLX4_EN_WRAP_AROUND_SEC 10UL
	/* By scheduling the overflow check every 5 seconds, we have a reasonably
	* good chance we won't miss a wrap around.
	* TODO: Use a timer instead of a work queue to increase the guarantee.
	*/
	#define MLX4_EN_OVERFLOW_PERIOD (MLX4_EN_WRAP_AROUND_SEC * HZ / 2)

	void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev)
	{
	bool timeout = time_is_before_jiffies(mdev->last_overflow_check +
	MLX4_EN_OVERFLOW_PERIOD);
	unsigned long flags;

	if (timeout) {
	write_seqlock_irqsave(&mdev->clock_lock, flags);
	timecounter_read(&mdev->clock);
	write_sequnlock_irqrestore(&mdev->clock_lock, flags);
	mdev->last_overflow_check = jiffies;
	}
	}

	/**
	* mlx4_en_phc_adjfine - adjust the frequency of the hardware clock
	* @ptp: ptp clock structure
	* @scaled_ppm: Desired frequency change in scaled parts per million
	*
	* Adjust the frequency of the PHC cycle counter by the indicated scaled_ppm
	* from the base frequency.
	*
	* Scaled parts per million is ppm with a 16-bit binary fractional field.
	**/
	static int mlx4_en_phc_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
	{
	u32 mult;
	unsigned long flags;
	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
	ptp_clock_info);

	mult = (u32)adjust_by_scaled_ppm(mdev->nominal_c_mult, scaled_ppm);

	write_seqlock_irqsave(&mdev->clock_lock, flags);
	timecounter_read(&mdev->clock);
	mdev->cycles.mult = mult;
	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

	return 0;
	}

	/**
	* mlx4_en_phc_adjtime - Shift the time of the hardware clock
	* @ptp: ptp clock structure
	* @delta: Desired change in nanoseconds
	*
	* Adjust the timer by resetting the timecounter structure.
	**/
	static int mlx4_en_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
	{
	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
	ptp_clock_info);
	unsigned long flags;

	write_seqlock_irqsave(&mdev->clock_lock, flags);
	timecounter_adjtime(&mdev->clock, delta);
	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

	return 0;
	}

	/**
	* mlx4_en_phc_gettime - Reads the current time from the hardware clock
	* @ptp: ptp clock structure
	* @ts: timespec structure to hold the current time value
	*
	* Read the timecounter and return the correct value in ns after converting
	* it into a struct timespec.
	**/
	static int mlx4_en_phc_gettime(struct ptp_clock_info *ptp,
	struct timespec64 *ts)
	{
	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
	ptp_clock_info);
	unsigned long flags;
	u64 ns;

	write_seqlock_irqsave(&mdev->clock_lock, flags);
	ns = timecounter_read(&mdev->clock);
	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

	*ts = ns_to_timespec64(ns);

	return 0;
	}

	/**
	* mlx4_en_phc_settime - Set the current time on the hardware clock
	* @ptp: ptp clock structure
	* @ts: timespec containing the new time for the cycle counter
	*
	* Reset the timecounter to use a new base value instead of the kernel
	* wall timer value.
	**/
	static int mlx4_en_phc_settime(struct ptp_clock_info *ptp,
	const struct timespec64 *ts)
	{
	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
	ptp_clock_info);
	u64 ns = timespec64_to_ns(ts);
	unsigned long flags;

	/* reset the timecounter */
	write_seqlock_irqsave(&mdev->clock_lock, flags);
	timecounter_init(&mdev->clock, &mdev->cycles, ns);
	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

	return 0;
	}

	/**
	* mlx4_en_phc_enable - enable or disable an ancillary feature
	* @ptp: ptp clock structure
	* @request: Desired resource to enable or disable
	* @on: Caller passes one to enable or zero to disable
	*
	* Enable (or disable) ancillary features of the PHC subsystem.
	* Currently, no ancillary features are supported.
	**/
	static int mlx4_en_phc_enable(struct ptp_clock_info __always_unused *ptp,
	struct ptp_clock_request __always_unused *request,
	int __always_unused on)
	{
	return -EOPNOTSUPP;
	}

	static const struct ptp_clock_info mlx4_en_ptp_clock_info = {
	.owner = THIS_MODULE,
	.max_adj = 100000000,
	.n_alarm = 0,
	.n_ext_ts = 0,
	.n_per_out = 0,
	.n_pins = 0,
	.pps = 0,
	.adjfine = mlx4_en_phc_adjfine,
	.adjtime = mlx4_en_phc_adjtime,
	.gettime64 = mlx4_en_phc_gettime,
	.settime64 = mlx4_en_phc_settime,
	.enable = mlx4_en_phc_enable,
	};


	/* This function calculates the max shift that enables the user range
	* of MLX4_EN_WRAP_AROUND_SEC values in the cycles register.
	*/
	static u32 freq_to_shift(u16 freq)
	{
	u32 freq_khz = freq * 1000;
	u64 max_val_cycles = freq_khz * 1000 * MLX4_EN_WRAP_AROUND_SEC;
	u64 max_val_cycles_rounded = 1ULL << fls64(max_val_cycles - 1);
	/* calculate max possible multiplier in order to fit in 64bit */
	u64 max_mul = div64_u64(ULLONG_MAX, max_val_cycles_rounded);

	/* This comes from the reverse of clocksource_khz2mult */
	return ilog2(div_u64(max_mul * freq_khz, 1000000));
	}

	void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
	{
	struct mlx4_dev *dev = mdev->dev;
	unsigned long flags;

	/* mlx4_en_init_timestamp is called for each netdev.
	* mdev->ptp_clock is common for all ports, skip initialization if
	* was done for other port.
	*/
	if (mdev->ptp_clock)
	return;

	seqlock_init(&mdev->clock_lock);

	memset(&mdev->cycles, 0, sizeof(mdev->cycles));
	mdev->cycles.read = mlx4_en_read_clock;
	mdev->cycles.mask = CLOCKSOURCE_MASK(48);
	mdev->cycles.shift = freq_to_shift(dev->caps.hca_core_clock);
	mdev->cycles.mult =
	clocksource_khz2mult(1000 * dev->caps.hca_core_clock, mdev->cycles.shift);
	mdev->nominal_c_mult = mdev->cycles.mult;

	write_seqlock_irqsave(&mdev->clock_lock, flags);
	timecounter_init(&mdev->clock, &mdev->cycles,
	ktime_to_ns(ktime_get_real()));
	write_sequnlock_irqrestore(&mdev->clock_lock, flags);

	/* Configure the PHC */
	mdev->ptp_clock_info = mlx4_en_ptp_clock_info;
	snprintf(mdev->ptp_clock_info.name, 16, "mlx4 ptp");

	mdev->ptp_clock = ptp_clock_register(&mdev->ptp_clock_info,
	&mdev->pdev->dev);
	if (IS_ERR(mdev->ptp_clock)) {
	mdev->ptp_clock = NULL;
	mlx4_err(mdev, "ptp_clock_register failed\n");
	} else if (mdev->ptp_clock) {
	mlx4_info(mdev, "registered PHC clock\n");
	}

	}