linux/drivers/net/ethernet/mellanox/mlx4/en_clock.c

/*
 * 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 "mlx4_en.h"

int mlx4_en_timestamp_config(struct net_device *dev, int tx_type, int rx_filter)
{
	struct mlx4_en_priv *priv = netdev_priv(dev);
	struct mlx4_en_dev *mdev = priv->mdev;
	int port_up = 0;
	int err = 0;

	mutex_lock(&mdev->state_lock);
	if (priv->port_up) {
		port_up = 1;
		mlx4_en_stop_port(dev, 1);
	}

	mlx4_en_free_resources(priv);

	en_warn(priv, "Changing Time Stamp configuration\n");

	priv->hwtstamp_config.tx_type = tx_type;
	priv->hwtstamp_config.rx_filter = rx_filter;

	if (rx_filter != HWTSTAMP_FILTER_NONE)
		dev->features &= ~NETIF_F_HW_VLAN_CTAG_RX;
	else
		dev->features |= NETIF_F_HW_VLAN_CTAG_RX;

	err = mlx4_en_alloc_resources(priv);
	if (err) {
		en_err(priv, "Failed reallocating port resources\n");
		goto out;
	}
	if (port_up) {
		err = mlx4_en_start_port(dev);
		if (err)
			en_err(priv, "Failed starting port\n");
	}

out:
	mutex_unlock(&mdev->state_lock);
	netdev_features_change(dev);
	return err;
}

/* mlx4_en_read_clock - read raw cycle counter (to be used by time counter)
 */
static cycle_t 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;
}

void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev,
			    struct skb_shared_hwtstamps *hwts,
			    u64 timestamp)
{
	u64 nsec;

	nsec = timecounter_cyc2time(&mdev->clock, timestamp);

	memset(hwts, 0, sizeof(struct skb_shared_hwtstamps));
	hwts->hwtstamp = ns_to_ktime(nsec);
}

void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
{
	struct mlx4_dev *dev = mdev->dev;
	u64 ns;

	memset(&mdev->cycles, 0, sizeof(mdev->cycles));
	mdev->cycles.read = mlx4_en_read_clock;
	mdev->cycles.mask = CLOCKSOURCE_MASK(48);
	/* Using shift to make calculation more accurate. Since current HW
	 * clock frequency is 427 MHz, and cycles are given using a 48 bits
	 * register, the biggest shift when calculating using u64, is 14
	 * (max_cycles * multiplier < 2^64)
	 */
	mdev->cycles.shift = 14;
	mdev->cycles.mult =
		clocksource_khz2mult(1000 * dev->caps.hca_core_clock, mdev->cycles.shift);

	timecounter_init(&mdev->clock, &mdev->cycles,
			 ktime_to_ns(ktime_get_real()));

	/* Calculate period in seconds to call the overflow watchdog - to make
	 * sure counter is checked at least once every wrap around.
	 */
	ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask);
	do_div(ns, NSEC_PER_SEC / 2 / HZ);
	mdev->overflow_period = ns;
}

void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev)
{
	bool timeout = time_is_before_jiffies(mdev->last_overflow_check +
					      mdev->overflow_period);

	if (timeout) {
		timecounter_read(&mdev->clock);
		mdev->last_overflow_check = jiffies;
	}
}