ionic: add hw timestamp support files

This adds the file of code for supporting Tx and Rx hardware
timestamps and the raw clock interface, but does not yet link
it in for compiling or use.

Signed-off-by: Allen Hubbe <allenbh@pensando.io>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 589 insertions, 0 deletions

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_phc.c b/drivers/net/ethernet/pensando/ionic/ionic_phc.c
new file mode 100644
index 000000000000..86ae5011ac9b
--- /dev/null
+++ b/drivers/net/ethernet/pensando/ionic/ionic_phc.c
@@ -0,0 +1,589 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2017 - 2021 Pensando Systems, Inc */
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+
+#include "ionic.h"
+#include "ionic_bus.h"
+#include "ionic_lif.h"
+#include "ionic_ethtool.h"
+
+static int ionic_hwstamp_tx_mode(int config_tx_type)
+{
+	switch (config_tx_type) {
+	case HWTSTAMP_TX_OFF:
+		return IONIC_TXSTAMP_OFF;
+	case HWTSTAMP_TX_ON:
+		return IONIC_TXSTAMP_ON;
+	case HWTSTAMP_TX_ONESTEP_SYNC:
+		return IONIC_TXSTAMP_ONESTEP_SYNC;
+#ifdef HAVE_HWSTAMP_TX_ONESTEP_P2P
+	case HWTSTAMP_TX_ONESTEP_P2P:
+		return IONIC_TXSTAMP_ONESTEP_P2P;
+#endif
+	default:
+		return -ERANGE;
+	}
+}
+
+static u64 ionic_hwstamp_rx_filt(int config_rx_filter)
+{
+	switch (config_rx_filter) {
+	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
+		return IONIC_PKT_CLS_PTP1_ALL;
+	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+		return IONIC_PKT_CLS_PTP1_SYNC;
+	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+		return IONIC_PKT_CLS_PTP1_SYNC | IONIC_PKT_CLS_PTP1_DREQ;
+
+	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
+		return IONIC_PKT_CLS_PTP2_L4_ALL;
+	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+		return IONIC_PKT_CLS_PTP2_L4_SYNC;
+	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
+		return IONIC_PKT_CLS_PTP2_L4_SYNC | IONIC_PKT_CLS_PTP2_L4_DREQ;
+
+	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+		return IONIC_PKT_CLS_PTP2_L2_ALL;
+	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
+		return IONIC_PKT_CLS_PTP2_L2_SYNC;
+	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
+		return IONIC_PKT_CLS_PTP2_L2_SYNC | IONIC_PKT_CLS_PTP2_L2_DREQ;
+
+	case HWTSTAMP_FILTER_PTP_V2_EVENT:
+		return IONIC_PKT_CLS_PTP2_ALL;
+	case HWTSTAMP_FILTER_PTP_V2_SYNC:
+		return IONIC_PKT_CLS_PTP2_SYNC;
+	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+		return IONIC_PKT_CLS_PTP2_SYNC | IONIC_PKT_CLS_PTP2_DREQ;
+
+	case HWTSTAMP_FILTER_NTP_ALL:
+		return IONIC_PKT_CLS_NTP_ALL;
+
+	default:
+		return 0;
+	}
+}
+
+int ionic_lif_hwstamp_set(struct ionic_lif *lif, struct ifreq *ifr)
+{
+	struct ionic *ionic = lif->ionic;
+	struct hwtstamp_config config;
+	int tx_mode = 0;
+	u64 rx_filt = 0;
+	int err, err2;
+	bool rx_all;
+	__le64 mask;
+
+	if (!lif->phc || !lif->phc->ptp)
+		return -EOPNOTSUPP;
+
+	if (ifr) {
+		if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
+			return -EFAULT;
+	} else {
+		/* if called with ifr == NULL, behave as if called with the
+		 * current ts_config from the initial cleared state.
+		 */
+		memcpy(&config, &lif->phc->ts_config, sizeof(config));
+		memset(&lif->phc->ts_config, 0, sizeof(config));
+	}
+
+	tx_mode = ionic_hwstamp_tx_mode(config.tx_type);
+	if (tx_mode < 0)
+		return tx_mode;
+
+	mask = cpu_to_le64(BIT_ULL(tx_mode));
+	if ((ionic->ident.lif.eth.hwstamp_tx_modes & mask) != mask)
+		return -ERANGE;
+
+	rx_filt = ionic_hwstamp_rx_filt(config.rx_filter);
+	rx_all = config.rx_filter != HWTSTAMP_FILTER_NONE && !rx_filt;
+
+	mask = cpu_to_le64(rx_filt);
+	if ((ionic->ident.lif.eth.hwstamp_rx_filters & mask) != mask) {
+		rx_filt = 0;
+		rx_all = true;
+		config.rx_filter = HWTSTAMP_FILTER_ALL;
+	}
+
+	dev_dbg(ionic->dev, "config_rx_filter %d rx_filt %#llx rx_all %d\n",
+		config.rx_filter, rx_filt, rx_all);
+
+	mutex_lock(&lif->phc->config_lock);
+
+	if (tx_mode) {
+		err = ionic_lif_create_hwstamp_txq(lif);
+		if (err)
+			goto err_queues;
+	}
+
+	if (rx_filt) {
+		err = ionic_lif_create_hwstamp_rxq(lif);
+		if (err)
+			goto err_queues;
+	}
+
+	if (tx_mode != lif->phc->ts_config_tx_mode) {
+		err = ionic_lif_set_hwstamp_txmode(lif, tx_mode);
+		if (err)
+			goto err_txmode;
+	}
+
+	if (rx_filt != lif->phc->ts_config_rx_filt) {
+		err = ionic_lif_set_hwstamp_rxfilt(lif, rx_filt);
+		if (err)
+			goto err_rxfilt;
+	}
+
+	if (rx_all != (lif->phc->ts_config.rx_filter == HWTSTAMP_FILTER_ALL)) {
+		err = ionic_lif_config_hwstamp_rxq_all(lif, rx_all);
+		if (err)
+			goto err_rxall;
+	}
+
+	if (ifr) {
+		err = copy_to_user(ifr->ifr_data, &config, sizeof(config));
+		if (err) {
+			err = -EFAULT;
+			goto err_final;
+		}
+	}
+
+	memcpy(&lif->phc->ts_config, &config, sizeof(config));
+	lif->phc->ts_config_rx_filt = rx_filt;
+	lif->phc->ts_config_tx_mode = tx_mode;
+
+	mutex_unlock(&lif->phc->config_lock);
+
+	return 0;
+
+err_final:
+	if (rx_all != (lif->phc->ts_config.rx_filter == HWTSTAMP_FILTER_ALL)) {
+		rx_all = lif->phc->ts_config.rx_filter == HWTSTAMP_FILTER_ALL;
+		err2 = ionic_lif_config_hwstamp_rxq_all(lif, rx_all);
+		if (err2)
+			dev_err(ionic->dev,
+				"Failed to revert all-rxq timestamp config: %d\n", err2);
+	}
+err_rxall:
+	if (rx_filt != lif->phc->ts_config_rx_filt) {
+		rx_filt = lif->phc->ts_config_rx_filt;
+		err2 = ionic_lif_set_hwstamp_rxfilt(lif, rx_filt);
+		if (err2)
+			dev_err(ionic->dev,
+				"Failed to revert rx timestamp filter: %d\n", err2);
+	}
+err_rxfilt:
+	if (tx_mode != lif->phc->ts_config_tx_mode) {
+		tx_mode = lif->phc->ts_config_tx_mode;
+		err2 = ionic_lif_set_hwstamp_txmode(lif, tx_mode);
+		if (err2)
+			dev_err(ionic->dev,
+				"Failed to revert tx timestamp mode: %d\n", err2);
+	}
+err_txmode:
+	/* special queues remain allocated, just unused */
+err_queues:
+	mutex_unlock(&lif->phc->config_lock);
+	return err;
+}
+
+int ionic_lif_hwstamp_get(struct ionic_lif *lif, struct ifreq *ifr)
+{
+	struct hwtstamp_config config;
+
+	if (!lif->phc || !lif->phc->ptp)
+		return -EOPNOTSUPP;
+
+	mutex_lock(&lif->phc->config_lock);
+	memcpy(&config, &lif->phc->ts_config, sizeof(config));
+	mutex_unlock(&lif->phc->config_lock);
+
+	return copy_to_user(ifr->ifr_data, &config, sizeof(config));
+}
+
+static u64 ionic_hwstamp_read(struct ionic *ionic,
+			      struct ptp_system_timestamp *sts)
+{
+	u32 tick_high_before, tick_high, tick_low;
+
+	/* read and discard low part to defeat hw staging of high part */
+	(void)ioread32(&ionic->idev.hwstamp_regs->tick_low);
+
+	tick_high_before = ioread32(&ionic->idev.hwstamp_regs->tick_high);
+
+	ptp_read_system_prets(sts);
+	tick_low = ioread32(&ionic->idev.hwstamp_regs->tick_low);
+	ptp_read_system_postts(sts);
+
+	tick_high = ioread32(&ionic->idev.hwstamp_regs->tick_high);
+
+	/* If tick_high changed, re-read tick_low once more.  Assume tick_high
+	 * cannot change again so soon as in the span of re-reading tick_low.
+	 */
+	if (tick_high != tick_high_before) {
+		ptp_read_system_prets(sts);
+		tick_low = ioread32(&ionic->idev.hwstamp_regs->tick_low);
+		ptp_read_system_postts(sts);
+	}
+
+	return (u64)tick_low | ((u64)tick_high << 32);
+}
+
+static u64 ionic_cc_read(const struct cyclecounter *cc)
+{
+	struct ionic_phc *phc = container_of(cc, struct ionic_phc, cc);
+	struct ionic *ionic = phc->lif->ionic;
+
+	return ionic_hwstamp_read(ionic, NULL);
+}
+
+static int ionic_setphc_cmd(struct ionic_phc *phc, struct ionic_admin_ctx *ctx)
+{
+	ctx->work = COMPLETION_INITIALIZER_ONSTACK(ctx->work);
+
+	ctx->cmd.lif_setphc.opcode = IONIC_CMD_LIF_SETPHC;
+	ctx->cmd.lif_setphc.lif_index = cpu_to_le16(phc->lif->index);
+
+	ctx->cmd.lif_setphc.tick = cpu_to_le64(phc->tc.cycle_last);
+	ctx->cmd.lif_setphc.nsec = cpu_to_le64(phc->tc.nsec);
+	ctx->cmd.lif_setphc.frac = cpu_to_le64(phc->tc.frac);
+	ctx->cmd.lif_setphc.mult = cpu_to_le32(phc->cc.mult);
+	ctx->cmd.lif_setphc.shift = cpu_to_le32(phc->cc.shift);
+
+	return ionic_adminq_post(phc->lif, ctx);
+}
+
+static int ionic_phc_adjfine(struct ptp_clock_info *info, long scaled_ppm)
+{
+	struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
+	struct ionic_admin_ctx ctx = {};
+	unsigned long irqflags;
+	s64 adj;
+	int err;
+
+	/* Reject phc adjustments during device upgrade */
+	if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
+		return -EBUSY;
+
+	/* Adjustment value scaled by 2^16 million */
+	adj = (s64)scaled_ppm * phc->init_cc_mult;
+
+	/* Adjustment value to scale */
+	adj /= (s64)SCALED_PPM;
+
+	/* Final adjusted multiplier */
+	adj += phc->init_cc_mult;
+
+	spin_lock_irqsave(&phc->lock, irqflags);
+
+	/* update the point-in-time basis to now, before adjusting the rate */
+	timecounter_read(&phc->tc);
+	phc->cc.mult = adj;
+
+	/* Setphc commands are posted in-order, sequenced by phc->lock.  We
+	 * need to drop the lock before waiting for the command to complete.
+	 */
+	err = ionic_setphc_cmd(phc, &ctx);
+
+	spin_unlock_irqrestore(&phc->lock, irqflags);
+
+	return ionic_adminq_wait(phc->lif, &ctx, err);
+}
+
+static int ionic_phc_adjtime(struct ptp_clock_info *info, s64 delta)
+{
+	struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
+	struct ionic_admin_ctx ctx = {};
+	unsigned long irqflags;
+	int err;
+
+	/* Reject phc adjustments during device upgrade */
+	if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
+		return -EBUSY;
+
+	spin_lock_irqsave(&phc->lock, irqflags);
+
+	timecounter_adjtime(&phc->tc, delta);
+
+	/* Setphc commands are posted in-order, sequenced by phc->lock.  We
+	 * need to drop the lock before waiting for the command to complete.
+	 */
+	err = ionic_setphc_cmd(phc, &ctx);
+
+	spin_unlock_irqrestore(&phc->lock, irqflags);
+
+	return ionic_adminq_wait(phc->lif, &ctx, err);
+}
+
+static int ionic_phc_settime64(struct ptp_clock_info *info,
+			       const struct timespec64 *ts)
+{
+	struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
+	struct ionic_admin_ctx ctx = {};
+	unsigned long irqflags;
+	int err;
+	u64 ns;
+
+	/* Reject phc adjustments during device upgrade */
+	if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
+		return -EBUSY;
+
+	ns = timespec64_to_ns(ts);
+
+	spin_lock_irqsave(&phc->lock, irqflags);
+
+	timecounter_init(&phc->tc, &phc->cc, ns);
+
+	/* Setphc commands are posted in-order, sequenced by phc->lock.  We
+	 * need to drop the lock before waiting for the command to complete.
+	 */
+	err = ionic_setphc_cmd(phc, &ctx);
+
+	spin_unlock_irqrestore(&phc->lock, irqflags);
+
+	return ionic_adminq_wait(phc->lif, &ctx, err);
+}
+
+static int ionic_phc_gettimex64(struct ptp_clock_info *info,
+				struct timespec64 *ts,
+				struct ptp_system_timestamp *sts)
+{
+	struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
+	struct ionic *ionic = phc->lif->ionic;
+	unsigned long irqflags;
+	u64 tick, ns;
+
+	/* Do not attempt to read device time during upgrade */
+	if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
+		return -EBUSY;
+
+	spin_lock_irqsave(&phc->lock, irqflags);
+
+	tick = ionic_hwstamp_read(ionic, sts);
+
+	ns = timecounter_cyc2time(&phc->tc, tick);
+
+	spin_unlock_irqrestore(&phc->lock, irqflags);
+
+	*ts = ns_to_timespec64(ns);
+
+	return 0;
+}
+
+static long ionic_phc_aux_work(struct ptp_clock_info *info)
+{
+	struct ionic_phc *phc = container_of(info, struct ionic_phc, ptp_info);
+	struct ionic_admin_ctx ctx = {};
+	unsigned long irqflags;
+	int err;
+
+	/* Do not update phc during device upgrade, but keep polling to resume
+	 * after upgrade.  Since we don't update the point in time basis, there
+	 * is no expectation that we are maintaining the phc time during the
+	 * upgrade.  After upgrade, it will need to be readjusted back to the
+	 * correct time by the ptp daemon.
+	 */
+	if (test_bit(IONIC_LIF_F_FW_RESET, phc->lif->state))
+		return phc->aux_work_delay;
+
+	spin_lock_irqsave(&phc->lock, irqflags);
+
+	/* update point-in-time basis to now */
+	timecounter_read(&phc->tc);
+
+	/* Setphc commands are posted in-order, sequenced by phc->lock.  We
+	 * need to drop the lock before waiting for the command to complete.
+	 */
+	err = ionic_setphc_cmd(phc, &ctx);
+
+	spin_unlock_irqrestore(&phc->lock, irqflags);
+
+	ionic_adminq_wait(phc->lif, &ctx, err);
+
+	return phc->aux_work_delay;
+}
+
+ktime_t ionic_lif_phc_ktime(struct ionic_lif *lif, u64 tick)
+{
+	unsigned long irqflags;
+	u64 ns;
+
+	if (!lif->phc)
+		return 0;
+
+	spin_lock_irqsave(&lif->phc->lock, irqflags);
+	ns = timecounter_cyc2time(&lif->phc->tc, tick);
+	spin_unlock_irqrestore(&lif->phc->lock, irqflags);
+
+	return ns_to_ktime(ns);
+}
+
+static const struct ptp_clock_info ionic_ptp_info = {
+	.owner		= THIS_MODULE,
+	.name		= "ionic_ptp",
+	.adjfine	= ionic_phc_adjfine,
+	.adjtime	= ionic_phc_adjtime,
+	.gettimex64	= ionic_phc_gettimex64,
+	.settime64	= ionic_phc_settime64,
+	.do_aux_work	= ionic_phc_aux_work,
+};
+
+void ionic_lif_register_phc(struct ionic_lif *lif)
+{
+	if (!lif->phc || !(lif->hw_features & IONIC_ETH_HW_TIMESTAMP))
+		return;
+
+	lif->phc->ptp = ptp_clock_register(&lif->phc->ptp_info, lif->ionic->dev);
+
+	if (IS_ERR(lif->phc->ptp)) {
+		dev_warn(lif->ionic->dev, "Cannot register phc device: %ld\n",
+			 PTR_ERR(lif->phc->ptp));
+
+		lif->phc->ptp = NULL;
+	}
+
+	if (lif->phc->ptp)
+		ptp_schedule_worker(lif->phc->ptp, lif->phc->aux_work_delay);
+}
+
+void ionic_lif_unregister_phc(struct ionic_lif *lif)
+{
+	if (!lif->phc || !lif->phc->ptp)
+		return;
+
+	ptp_clock_unregister(lif->phc->ptp);
+
+	lif->phc->ptp = NULL;
+}
+
+void ionic_lif_alloc_phc(struct ionic_lif *lif)
+{
+	struct ionic *ionic = lif->ionic;
+	struct ionic_phc *phc;
+	u64 delay, diff, mult;
+	u64 frac = 0;
+	u64 features;
+	u32 shift;
+
+	if (!ionic->idev.hwstamp_regs)
+		return;
+
+	features = le64_to_cpu(ionic->ident.lif.eth.config.features);
+	if (!(features & IONIC_ETH_HW_TIMESTAMP))
+		return;
+
+	phc = devm_kzalloc(ionic->dev, sizeof(*phc), GFP_KERNEL);
+	if (!phc)
+		return;
+
+	phc->lif = lif;
+
+	phc->cc.read = ionic_cc_read;
+	phc->cc.mask = le64_to_cpu(ionic->ident.dev.hwstamp_mask);
+	phc->cc.mult = le32_to_cpu(ionic->ident.dev.hwstamp_mult);
+	phc->cc.shift = le32_to_cpu(ionic->ident.dev.hwstamp_shift);
+
+	if (!phc->cc.mult) {
+		dev_err(lif->ionic->dev,
+			"Invalid device PHC mask multiplier %u, disabling HW timestamp support\n",
+			phc->cc.mult);
+		devm_kfree(lif->ionic->dev, phc);
+		lif->phc = NULL;
+		return;
+	}
+
+	dev_dbg(lif->ionic->dev, "Device PHC mask %#llx mult %u shift %u\n",
+		phc->cc.mask, phc->cc.mult, phc->cc.shift);
+
+	spin_lock_init(&phc->lock);
+	mutex_init(&phc->config_lock);
+
+	/* max ticks is limited by the multiplier, or by the update period. */
+	if (phc->cc.shift + 2 + ilog2(IONIC_PHC_UPDATE_NS) >= 64) {
+		/* max ticks that do not overflow when multiplied by max
+		 * adjusted multiplier (twice the initial multiplier)
+		 */
+		diff = U64_MAX / phc->cc.mult / 2;
+	} else {
+		/* approx ticks at four times the update period */
+		diff = (u64)IONIC_PHC_UPDATE_NS << (phc->cc.shift + 2);
+		diff = DIV_ROUND_UP(diff, phc->cc.mult);
+	}
+
+	/* transform to bitmask */
+	diff |= diff >> 1;
+	diff |= diff >> 2;
+	diff |= diff >> 4;
+	diff |= diff >> 8;
+	diff |= diff >> 16;
+	diff |= diff >> 32;
+
+	/* constrain to the hardware bitmask, and use this as the bitmask */
+	diff &= phc->cc.mask;
+	phc->cc.mask = diff;
+
+	/* the wrap period is now defined by diff (or phc->cc.mask)
+	 *
+	 * we will update the time basis at about 1/4 the wrap period, so
+	 * should not see a difference of more than +/- diff/4.
+	 *
+	 * this is sufficient not see a difference of more than +/- diff/2, as
+	 * required by timecounter_cyc2time, to detect an old time stamp.
+	 *
+	 * adjust the initial multiplier, being careful to avoid overflow:
+	 *  - do not overflow 63 bits: init_cc_mult * SCALED_PPM
+	 *  - do not overflow 64 bits: max_mult * (diff / 2)
+	 *
+	 * we want to increase the initial multiplier as much as possible, to
+	 * allow for more precise adjustment in ionic_phc_adjfine.
+	 *
+	 * only adjust the multiplier if we can double it or more.
+	 */
+	mult = U64_MAX / 2 / max(diff / 2, SCALED_PPM);
+	shift = mult / phc->cc.mult;
+	if (shift >= 2) {
+		/* initial multiplier will be 2^n of hardware cc.mult */
+		shift = fls(shift);
+		/* increase cc.mult and cc.shift by the same 2^n and n. */
+		phc->cc.mult <<= shift;
+		phc->cc.shift += shift;
+	}
+
+	dev_dbg(lif->ionic->dev, "Initial PHC mask %#llx mult %u shift %u\n",
+		phc->cc.mask, phc->cc.mult, phc->cc.shift);
+
+	/* frequency adjustments are relative to the initial multiplier */
+	phc->init_cc_mult = phc->cc.mult;
+
+	timecounter_init(&phc->tc, &phc->cc, ktime_get_real_ns());
+
+	/* Update cycle_last at 1/4 the wrap period, or IONIC_PHC_UPDATE_NS */
+	delay = min_t(u64, IONIC_PHC_UPDATE_NS,
+		      cyclecounter_cyc2ns(&phc->cc, diff / 4, 0, &frac));
+	dev_dbg(lif->ionic->dev, "Work delay %llu ms\n", delay / NSEC_PER_MSEC);
+
+	phc->aux_work_delay = nsecs_to_jiffies(delay);
+
+	phc->ptp_info = ionic_ptp_info;
+
+	/* We have allowed to adjust the multiplier up to +/- 1 part per 1.
+	 * Here expressed as NORMAL_PPB (1 billion parts per billion).
+	 */
+	phc->ptp_info.max_adj = NORMAL_PPB;
+
+	lif->phc = phc;
+}
+
+void ionic_lif_free_phc(struct ionic_lif *lif)
+{
+	if (!lif->phc)
+		return;
+
+	mutex_destroy(&lif->phc->config_lock);
+
+	devm_kfree(lif->ionic->dev, lif->phc);
+	lif->phc = NULL;
+}