igb_ptp.c

/*
 * PTP Hardware Clock (PHC) driver for the Intel 82576 and 82580
 *
 * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include <linux/module.h>
#include <linux/device.h>
#include <linux/pci.h>

#include "igb.h"

#define INCVALUE_MASK		0x7fffffff
#define ISGN			0x80000000

/*
 * The 82580 timesync updates the system timer every 8ns by 8ns,
 * and this update value cannot be reprogrammed.
 *
 * Neither the 82576 nor the 82580 offer registers wide enough to hold
 * nanoseconds time values for very long. For the 82580, SYSTIM always
 * counts nanoseconds, but the upper 24 bits are not availible. The
 * frequency is adjusted by changing the 32 bit fractional nanoseconds
 * register, TIMINCA.
 *
 * For the 82576, the SYSTIM register time unit is affect by the
 * choice of the 24 bit TININCA:IV (incvalue) field. Five bits of this
 * field are needed to provide the nominal 16 nanosecond period,
 * leaving 19 bits for fractional nanoseconds.
 *
 * We scale the NIC clock cycle by a large factor so that relatively
 * small clock corrections can be added or subtracted at each clock
 * tick. The drawbacks of a large factor are a) that the clock
 * register overflows more quickly (not such a big deal) and b) that
 * the increment per tick has to fit into 24 bits.  As a result we
 * need to use a shift of 19 so we can fit a value of 16 into the
 * TIMINCA register.
 *
 *
 *             SYSTIMH            SYSTIML
 *        +--------------+   +---+---+------+
 *  82576 |      32      |   | 8 | 5 |  19  |
 *        +--------------+   +---+---+------+
 *         \________ 45 bits _______/  fract
 *
 *        +----------+---+   +--------------+
 *  82580 |    24    | 8 |   |      32      |
 *        +----------+---+   +--------------+
 *          reserved  \______ 40 bits _____/
 *
 *
 * The 45 bit 82576 SYSTIM overflows every
 *   2^45 * 10^-9 / 3600 = 9.77 hours.
 *
 * The 40 bit 82580 SYSTIM overflows every
 *   2^40 * 10^-9 /  60  = 18.3 minutes.
 */

#define IGB_SYSTIM_OVERFLOW_PERIOD	(HZ * 60 * 9)
#define INCPERIOD_82576			(1 << E1000_TIMINCA_16NS_SHIFT)
#define INCVALUE_82576_MASK		((1 << E1000_TIMINCA_16NS_SHIFT) - 1)
#define INCVALUE_82576			(16 << IGB_82576_TSYNC_SHIFT)
#define IGB_NBITS_82580			40

/*
 * SYSTIM read access for the 82576
 */

static cycle_t igb_ptp_read_82576(const struct cyclecounter *cc)
{
	struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);
	struct e1000_hw *hw = &igb->hw;
	u64 val;
	u32 lo, hi;

	lo = rd32(E1000_SYSTIML);
	hi = rd32(E1000_SYSTIMH);

	val = ((u64) hi) << 32;
	val |= lo;

	return val;
}

/*
 * SYSTIM read access for the 82580
 */

static cycle_t igb_ptp_read_82580(const struct cyclecounter *cc)
{
	struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);
	struct e1000_hw *hw = &igb->hw;
	u64 val;
	u32 lo, hi, jk;

	/*
	 * The timestamp latches on lowest register read. For the 82580
	 * the lowest register is SYSTIMR instead of SYSTIML.  However we only
	 * need to provide nanosecond resolution, so we just ignore it.
	 */
	jk = rd32(E1000_SYSTIMR);
	lo = rd32(E1000_SYSTIML);
	hi = rd32(E1000_SYSTIMH);

	val = ((u64) hi) << 32;
	val |= lo;

	return val;
}

/**
 * igb_ptp_systim_to_hwtstamp - convert system time value to hw timestamp
 * @adapter: board private structure
 * @hwtstamps: timestamp structure to update
 * @systim: unsigned 64bit system time value.
 *
 * We need to convert the system time value stored in the RX/TXSTMP registers
 * into a hwtstamp which can be used by the upper level timestamping functions.
 *
 * The 'tmreg_lock' spinlock is used to protect the consistency of the
 * system time value. This is needed because reading the 64 bit time
 * value involves reading two (or three) 32 bit registers. The first
 * read latches the value. Ditto for writing.
 *
 * In addition, here have extended the system time with an overflow
 * counter in software.
 **/
static void igb_ptp_systim_to_hwtstamp(struct igb_adapter *adapter,
				       struct skb_shared_hwtstamps *hwtstamps,
				       u64 systim)
{
	unsigned long flags;
	u64 ns;

	switch (adapter->hw.mac.type) {
	case e1000_i210:
	case e1000_i211:
	case e1000_i350:
	case e1000_82580:
	case e1000_82576:
		break;
	default:
		return;
	}

	spin_lock_irqsave(&adapter->tmreg_lock, flags);

	ns = timecounter_cyc2time(&adapter->tc, systim);

	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);

	memset(hwtstamps, 0, sizeof(*hwtstamps));
	hwtstamps->hwtstamp = ns_to_ktime(ns);
}

/*
 * PTP clock operations
 */

static int igb_ptp_adjfreq_82576(struct ptp_clock_info *ptp, s32 ppb)
{
	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
					       ptp_caps);
	struct e1000_hw *hw = &igb->hw;
	int neg_adj = 0;
	u64 rate;
	u32 incvalue;

	if (ppb < 0) {
		neg_adj = 1;
		ppb = -ppb;
	}
	rate = ppb;
	rate <<= 14;
	rate = div_u64(rate, 1953125);

	incvalue = 16 << IGB_82576_TSYNC_SHIFT;

	if (neg_adj)
		incvalue -= rate;
	else
		incvalue += rate;

	wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue & INCVALUE_82576_MASK));

	return 0;
}

static int igb_ptp_adjfreq_82580(struct ptp_clock_info *ptp, s32 ppb)
{
	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
					       ptp_caps);
	struct e1000_hw *hw = &igb->hw;
	int neg_adj = 0;
	u64 rate;
	u32 inca;

	if (ppb < 0) {
		neg_adj = 1;
		ppb = -ppb;
	}
	rate = ppb;
	rate <<= 26;
	rate = div_u64(rate, 1953125);

	inca = rate & INCVALUE_MASK;
	if (neg_adj)
		inca |= ISGN;

	wr32(E1000_TIMINCA, inca);

	return 0;
}

static int igb_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
					       ptp_caps);
	unsigned long flags;
	s64 now;

	spin_lock_irqsave(&igb->tmreg_lock, flags);

	now = timecounter_read(&igb->tc);
	now += delta;
	timecounter_init(&igb->tc, &igb->cc, now);

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

	return 0;
}

static int igb_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
{
	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
					       ptp_caps);
	unsigned long flags;
	u64 ns;
	u32 remainder;

	spin_lock_irqsave(&igb->tmreg_lock, flags);

	ns = timecounter_read(&igb->tc);

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

	ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
	ts->tv_nsec = remainder;

	return 0;
}

static int igb_ptp_settime(struct ptp_clock_info *ptp,
			   const struct timespec *ts)
{
	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
					       ptp_caps);
	unsigned long flags;
	u64 ns;

	ns = ts->tv_sec * 1000000000ULL;
	ns += ts->tv_nsec;

	spin_lock_irqsave(&igb->tmreg_lock, flags);

	timecounter_init(&igb->tc, &igb->cc, ns);

	spin_unlock_irqrestore(&igb->tmreg_lock, flags);

	return 0;
}

static int igb_ptp_enable(struct ptp_clock_info *ptp,
			  struct ptp_clock_request *rq, int on)
{
	return -EOPNOTSUPP;
}

static void igb_ptp_overflow_check(struct work_struct *work)
{
	struct igb_adapter *igb =
		container_of(work, struct igb_adapter, ptp_overflow_work.work);
	struct timespec ts;

	igb_ptp_gettime(&igb->ptp_caps, &ts);

	pr_debug("igb overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);

	schedule_delayed_work(&igb->ptp_overflow_work,
			      IGB_SYSTIM_OVERFLOW_PERIOD);
}

/**
 * igb_ptp_tx_hwtstamp - utility function which checks for TX time stamp
 * @q_vector: pointer to q_vector containing needed info
 * @buffer: pointer to igb_tx_buffer structure
 *
 * If we were asked to do hardware stamping and such a time stamp is
 * available, then it must have been for this skb here because we only
 * allow only one such packet into the queue.
 */
void igb_ptp_tx_hwtstamp(struct igb_q_vector *q_vector,
			 struct igb_tx_buffer *buffer_info)
{
	struct igb_adapter *adapter = q_vector->adapter;
	struct e1000_hw *hw = &adapter->hw;
	struct skb_shared_hwtstamps shhwtstamps;
	u64 regval;

	/* if skb does not support hw timestamp or TX stamp not valid exit */
	if (likely(!(buffer_info->tx_flags & IGB_TX_FLAGS_TSTAMP)) ||
	    !(rd32(E1000_TSYNCTXCTL) & E1000_TSYNCTXCTL_VALID))
		return;

	regval = rd32(E1000_TXSTMPL);
	regval |= (u64)rd32(E1000_TXSTMPH) << 32;

	igb_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval);
	skb_tstamp_tx(buffer_info->skb, &shhwtstamps);
}

void igb_ptp_rx_hwtstamp(struct igb_q_vector *q_vector,
			 union e1000_adv_rx_desc *rx_desc,
			 struct sk_buff *skb)
{
	struct igb_adapter *adapter = q_vector->adapter;
	struct e1000_hw *hw = &adapter->hw;
	u64 regval;

	if (!igb_test_staterr(rx_desc, E1000_RXDADV_STAT_TSIP |
				       E1000_RXDADV_STAT_TS))
		return;

	/*
	 * If this bit is set, then the RX registers contain the time stamp. No
	 * other packet will be time stamped until we read these registers, so
	 * read the registers to make them available again. Because only one
	 * packet can be time stamped at a time, we know that the register
	 * values must belong to this one here and therefore we don't need to
	 * compare any of the additional attributes stored for it.
	 *
	 * If nothing went wrong, then it should have a shared tx_flags that we
	 * can turn into a skb_shared_hwtstamps.
	 */
	if (igb_test_staterr(rx_desc, E1000_RXDADV_STAT_TSIP)) {
		u32 *stamp = (u32 *)skb->data;
		regval = le32_to_cpu(*(stamp + 2));
		regval |= (u64)le32_to_cpu(*(stamp + 3)) << 32;
		skb_pull(skb, IGB_TS_HDR_LEN);
	} else {
		if (!(rd32(E1000_TSYNCRXCTL) & E1000_TSYNCRXCTL_VALID))
			return;

		regval = rd32(E1000_RXSTMPL);
		regval |= (u64)rd32(E1000_RXSTMPH) << 32;
	}

	igb_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
}

/**
 * igb_ptp_hwtstamp_ioctl - control hardware time stamping
 * @netdev:
 * @ifreq:
 * @cmd:
 *
 * Outgoing time stamping can be enabled and disabled. Play nice and
 * disable it when requested, although it shouldn't case any overhead
 * when no packet needs it. At most one packet in the queue may be
 * marked for time stamping, otherwise it would be impossible to tell
 * for sure to which packet the hardware time stamp belongs.
 *
 * Incoming time stamping has to be configured via the hardware
 * filters. Not all combinations are supported, in particular event
 * type has to be specified. Matching the kind of event packet is
 * not supported, with the exception of "all V2 events regardless of
 * level 2 or 4".
 *
 **/
int igb_ptp_hwtstamp_ioctl(struct net_device *netdev,
			   struct ifreq *ifr, int cmd)
{
	struct igb_adapter *adapter = netdev_priv(netdev);
	struct e1000_hw *hw = &adapter->hw;
	struct hwtstamp_config config;
	u32 tsync_tx_ctl = E1000_TSYNCTXCTL_ENABLED;
	u32 tsync_rx_ctl = E1000_TSYNCRXCTL_ENABLED;
	u32 tsync_rx_cfg = 0;
	bool is_l4 = false;
	bool is_l2 = false;
	u32 regval;

	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
		return -EFAULT;

	/* reserved for future extensions */
	if (config.flags)
		return -EINVAL;

	switch (config.tx_type) {
	case HWTSTAMP_TX_OFF:
		tsync_tx_ctl = 0;
	case HWTSTAMP_TX_ON:
		break;
	default:
		return -ERANGE;
	}

	switch (config.rx_filter) {
	case HWTSTAMP_FILTER_NONE:
		tsync_rx_ctl = 0;
		break;
	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
	case HWTSTAMP_FILTER_ALL:
		/*
		 * register TSYNCRXCFG must be set, therefore it is not
		 * possible to time stamp both Sync and Delay_Req messages
		 * => fall back to time stamping all packets
		 */
		tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_ALL;
		config.rx_filter = HWTSTAMP_FILTER_ALL;
		break;
	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
		tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_L4_V1;
		tsync_rx_cfg = E1000_TSYNCRXCFG_PTP_V1_SYNC_MESSAGE;
		is_l4 = true;
		break;
	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
		tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_L4_V1;
		tsync_rx_cfg = E1000_TSYNCRXCFG_PTP_V1_DELAY_REQ_MESSAGE;
		is_l4 = true;
		break;
	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
		tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_L2_L4_V2;
		tsync_rx_cfg = E1000_TSYNCRXCFG_PTP_V2_SYNC_MESSAGE;
		is_l2 = true;
		is_l4 = true;
		config.rx_filter = HWTSTAMP_FILTER_SOME;
		break;
	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
		tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_L2_L4_V2;
		tsync_rx_cfg = E1000_TSYNCRXCFG_PTP_V2_DELAY_REQ_MESSAGE;
		is_l2 = true;
		is_l4 = true;
		config.rx_filter = HWTSTAMP_FILTER_SOME;
		break;
	case HWTSTAMP_FILTER_PTP_V2_EVENT:
	case HWTSTAMP_FILTER_PTP_V2_SYNC:
	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
		tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_EVENT_V2;
		config.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
		is_l2 = true;
		is_l4 = true;
		break;
	default:
		return -ERANGE;
	}

	if (hw->mac.type == e1000_82575) {
		if (tsync_rx_ctl | tsync_tx_ctl)
			return -EINVAL;
		return 0;
	}

	/*
	 * Per-packet timestamping only works if all packets are
	 * timestamped, so enable timestamping in all packets as
	 * long as one rx filter was configured.
	 */
	if ((hw->mac.type >= e1000_82580) && tsync_rx_ctl) {
		tsync_rx_ctl = E1000_TSYNCRXCTL_ENABLED;
		tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_ALL;
	}

	/* enable/disable TX */
	regval = rd32(E1000_TSYNCTXCTL);
	regval &= ~E1000_TSYNCTXCTL_ENABLED;
	regval |= tsync_tx_ctl;
	wr32(E1000_TSYNCTXCTL, regval);

	/* enable/disable RX */
	regval = rd32(E1000_TSYNCRXCTL);
	regval &= ~(E1000_TSYNCRXCTL_ENABLED | E1000_TSYNCRXCTL_TYPE_MASK);
	regval |= tsync_rx_ctl;
	wr32(E1000_TSYNCRXCTL, regval);

	/* define which PTP packets are time stamped */
	wr32(E1000_TSYNCRXCFG, tsync_rx_cfg);

	/* define ethertype filter for timestamped packets */
	if (is_l2)
		wr32(E1000_ETQF(3),
		     (E1000_ETQF_FILTER_ENABLE | /* enable filter */
		      E1000_ETQF_1588 | /* enable timestamping */
		      ETH_P_1588));     /* 1588 eth protocol type */
	else
		wr32(E1000_ETQF(3), 0);

#define PTP_PORT 319
	/* L4 Queue Filter[3]: filter by destination port and protocol */
	if (is_l4) {
		u32 ftqf = (IPPROTO_UDP /* UDP */
			| E1000_FTQF_VF_BP /* VF not compared */
			| E1000_FTQF_1588_TIME_STAMP /* Enable Timestamping */
			| E1000_FTQF_MASK); /* mask all inputs */
		ftqf &= ~E1000_FTQF_MASK_PROTO_BP; /* enable protocol check */

		wr32(E1000_IMIR(3), htons(PTP_PORT));
		wr32(E1000_IMIREXT(3),
		     (E1000_IMIREXT_SIZE_BP | E1000_IMIREXT_CTRL_BP));
		if (hw->mac.type == e1000_82576) {
			/* enable source port check */
			wr32(E1000_SPQF(3), htons(PTP_PORT));
			ftqf &= ~E1000_FTQF_MASK_SOURCE_PORT_BP;
		}
		wr32(E1000_FTQF(3), ftqf);
	} else {
		wr32(E1000_FTQF(3), E1000_FTQF_MASK);
	}
	wrfl();

	/* clear TX/RX time stamp registers, just to be sure */
	regval = rd32(E1000_TXSTMPH);
	regval = rd32(E1000_RXSTMPH);

	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
		-EFAULT : 0;
}

void igb_ptp_init(struct igb_adapter *adapter)
{
	struct e1000_hw *hw = &adapter->hw;

	switch (hw->mac.type) {
	case e1000_i210:
	case e1000_i211:
	case e1000_i350:
	case e1000_82580:
		adapter->ptp_caps.owner = THIS_MODULE;
		strcpy(adapter->ptp_caps.name, "igb-82580");
		adapter->ptp_caps.max_adj = 62499999;
		adapter->ptp_caps.n_ext_ts = 0;
		adapter->ptp_caps.pps = 0;
		adapter->ptp_caps.adjfreq = igb_ptp_adjfreq_82580;
		adapter->ptp_caps.adjtime = igb_ptp_adjtime;
		adapter->ptp_caps.gettime = igb_ptp_gettime;
		adapter->ptp_caps.settime = igb_ptp_settime;
		adapter->ptp_caps.enable = igb_ptp_enable;
		adapter->cc.read = igb_ptp_read_82580;
		adapter->cc.mask = CLOCKSOURCE_MASK(IGB_NBITS_82580);
		adapter->cc.mult = 1;
		adapter->cc.shift = 0;
		/* Enable the timer functions by clearing bit 31. */
		wr32(E1000_TSAUXC, 0x0);
		break;

	case e1000_82576:
		adapter->ptp_caps.owner = THIS_MODULE;
		strcpy(adapter->ptp_caps.name, "igb-82576");
		adapter->ptp_caps.max_adj = 1000000000;
		adapter->ptp_caps.n_ext_ts = 0;
		adapter->ptp_caps.pps = 0;
		adapter->ptp_caps.adjfreq = igb_ptp_adjfreq_82576;
		adapter->ptp_caps.adjtime = igb_ptp_adjtime;
		adapter->ptp_caps.gettime = igb_ptp_gettime;
		adapter->ptp_caps.settime = igb_ptp_settime;
		adapter->ptp_caps.enable = igb_ptp_enable;
		adapter->cc.read = igb_ptp_read_82576;
		adapter->cc.mask = CLOCKSOURCE_MASK(64);
		adapter->cc.mult = 1;
		adapter->cc.shift = IGB_82576_TSYNC_SHIFT;
		/* Dial the nominal frequency. */
		wr32(E1000_TIMINCA, INCPERIOD_82576 | INCVALUE_82576);
		break;

	default:
		adapter->ptp_clock = NULL;
		return;
	}

	wrfl();

	timecounter_init(&adapter->tc, &adapter->cc,
			 ktime_to_ns(ktime_get_real()));

	INIT_DELAYED_WORK(&adapter->ptp_overflow_work, igb_ptp_overflow_check);

	spin_lock_init(&adapter->tmreg_lock);

	schedule_delayed_work(&adapter->ptp_overflow_work,
			      IGB_SYSTIM_OVERFLOW_PERIOD);

	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps);
	if (IS_ERR(adapter->ptp_clock)) {
		adapter->ptp_clock = NULL;
		dev_err(&adapter->pdev->dev, "ptp_clock_register failed\n");
	} else
		dev_info(&adapter->pdev->dev, "added PHC on %s\n",
			 adapter->netdev->name);
}

/**
 * igb_ptp_stop - Disable PTP device and stop the overflow check.
 * @adapter: Board private structure.
 *
 * This function stops the PTP support and cancels the delayed work.
 **/
void igb_ptp_stop(struct igb_adapter *adapter)
{
	switch (adapter->hw.mac.type) {
	case e1000_i211:
	case e1000_i210:
	case e1000_i350:
	case e1000_82580:
	case e1000_82576:
		cancel_delayed_work_sync(&adapter->ptp_overflow_work);
		break;
	default:
		return;
	}

	if (adapter->ptp_clock) {
		ptp_clock_unregister(adapter->ptp_clock);
		dev_info(&adapter->pdev->dev, "removed PHC on %s\n",
			 adapter->netdev->name);
	}
}