[RFC PATCH 2/2] macb: Enable 1588 support in SAMA5D2 platform.

From: Andrei Pistirica
Date: Fri Sep 02 2016 - 08:54:42 EST


Hardware time stamp on the PTP Ethernet packets are received using the
SO_TIMESTAMPING API. Timers are obtained from the PTP event/peer
gem registers.

Signed-off-by: Andrei Pistirica <andrei.pistirica@xxxxxxxxxxxxx>
---
Integration with SAMA5D2 only. This feature wasn't tested on any
other platform that might use cadence/gem.

Patch is not completely ported to the very latest version of net-next,
and it will be after review.

drivers/net/ethernet/cadence/macb.c | 25 +++-
drivers/net/ethernet/cadence/macb.h | 13 ++
drivers/net/ethernet/cadence/macb_ptp.c | 217 ++++++++++++++++++++++++++++++++
3 files changed, 254 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 8d54e7b..18f0715 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -697,6 +697,11 @@ static void macb_tx_interrupt(struct macb_queue *queue)

/* First, update TX stats if needed */
if (skb) {
+/* guard the hot-path */
+#ifdef CONFIG_MACB_USE_HWSTAMP
+ if (bp->hwts_tx_en)
+ macb_ptp_do_txstamp(bp, skb);
+#endif
netdev_vdbg(bp->dev, "skb %u (data %p) TX complete\n",
macb_tx_ring_wrap(tail), skb->data);
bp->stats.tx_packets++;
@@ -853,6 +858,11 @@ static int gem_rx(struct macb *bp, int budget)
GEM_BFEXT(RX_CSUM, ctrl) & GEM_RX_CSUM_CHECKED_MASK)
skb->ip_summed = CHECKSUM_UNNECESSARY;

+/* guard the hot-path */
+#ifdef CONFIG_MACB_USE_HWSTAMP
+ if (bp->hwts_rx_en)
+ macb_ptp_do_rxstamp(bp, skb);
+#endif
bp->stats.rx_packets++;
bp->stats.rx_bytes += skb->len;

@@ -1723,6 +1733,11 @@ static void macb_init_hw(struct macb *bp)

/* Enable TX and RX */
macb_writel(bp, NCR, MACB_BIT(RE) | MACB_BIT(TE) | MACB_BIT(MPE));
+
+#ifdef CONFIG_MACB_USE_HWSTAMP
+ bp->hwts_tx_en = 0;
+ bp->hwts_rx_en = 0;
+#endif
}

/*
@@ -1885,6 +1900,8 @@ static int macb_open(struct net_device *dev)

netif_tx_start_all_queues(dev);

+ macb_ptp_init(dev);
+
return 0;
}

@@ -2143,7 +2160,7 @@ static const struct ethtool_ops gem_ethtool_ops = {
.get_regs_len = macb_get_regs_len,
.get_regs = macb_get_regs,
.get_link = ethtool_op_get_link,
- .get_ts_info = ethtool_op_get_ts_info,
+ .get_ts_info = macb_get_ts_info,
.get_ethtool_stats = gem_get_ethtool_stats,
.get_strings = gem_get_ethtool_strings,
.get_sset_count = gem_get_sset_count,
@@ -2157,6 +2174,12 @@ static int macb_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
if (!netif_running(dev))
return -EINVAL;

+ if (cmd == SIOCSHWTSTAMP)
+ return macb_hwtst_set(dev, rq, cmd);
+
+ if (cmd == SIOCGHWTSTAMP)
+ return macb_hwtst_get(dev, rq);
+
if (!phydev)
return -ENODEV;

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 8c3779d..555316a 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -920,8 +920,21 @@ struct macb {

#ifdef CONFIG_MACB_USE_HWSTAMP
void macb_ptp_init(struct net_device *ndev);
+void macb_ptp_do_rxstamp(struct macb *bp, struct sk_buff *skb);
+void macb_ptp_do_txstamp(struct macb *bp, struct sk_buff *skb);
+int macb_ptp_get_ts_info(struct net_device *dev, struct ethtool_ts_info *info);
+#define macb_get_ts_info macb_ptp_get_ts_info
+int macb_hwtst_set(struct net_device *netdev, struct ifreq *ifr, int cmd);
+int macb_hwtst_get(struct net_device *netdev, struct ifreq *ifr);
#else
void macb_ptp_init(struct net_device *ndev) { }
+void macb_ptp_do_rxstamp(struct macb *bp, struct sk_buff *skb) { }
+void macb_ptp_do_txstamp(struct macb *bp, struct sk_buff *skb) { }
+#define macb_get_ts_info ethtool_op_get_ts_info
+int macb_hwtst_set(struct net_device *netdev, struct ifreq *ifr, int cmd)
+ { return -1; }
+int macb_hwtst_get(struct net_device *netdev, struct ifreq *ifr)
+ { return -1; }
#endif

static inline bool macb_is_gem(struct macb *bp)
diff --git a/drivers/net/ethernet/cadence/macb_ptp.c b/drivers/net/ethernet/cadence/macb_ptp.c
index 6d6a6ec..e3f784a 100644
--- a/drivers/net/ethernet/cadence/macb_ptp.c
+++ b/drivers/net/ethernet/cadence/macb_ptp.c
@@ -5,6 +5,7 @@
* Copyright (C) 2016 Microchip Technology
*
* Authors: Harini Katakam <harinik@xxxxxxxxxx>
+ * Andrei Pistirica <andrei.pistirica@xxxxxxxxxxxxx>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
@@ -222,3 +223,219 @@ void macb_ptp_init(struct net_device *ndev)

dev_info(&bp->pdev->dev, "%s ptp clock registered.\n", GMAC_TIMER_NAME);
}
+
+/* While the GEM can timestamp PTP packets, it does not mark the RX descriptor
+ * to identify them. This is entirely the wrong place to be parsing UDP
+ * headers, but some minimal effort must be made.
+ *
+ * Note: Inspired from drivers/net/ethernet/ti/cpts.c
+ */
+static inline int macb_get_ptp_peer(struct sk_buff *skb, int ptp_class)
+{
+ unsigned int offset = 0;
+ u8 *msgtype, *data = skb->data;
+
+ if (ptp_class == PTP_CLASS_NONE)
+ return -1;
+
+ if (ptp_class & PTP_CLASS_VLAN)
+ offset += VLAN_HLEN;
+
+ switch (ptp_class & PTP_CLASS_PMASK) {
+ case PTP_CLASS_IPV4:
+ offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
+ break;
+ case PTP_CLASS_IPV6:
+ offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
+ break;
+ case PTP_CLASS_L2:
+ offset += ETH_HLEN;
+ break;
+
+ /* something went wrong! */
+ default:
+ return -1;
+ }
+
+ if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID)
+ return -1;
+
+ if (unlikely(ptp_class & PTP_CLASS_V1))
+ msgtype = data + offset + OFF_PTP_CONTROL;
+ else
+ msgtype = data + offset;
+
+ return (*msgtype) & 0x2;
+}
+
+static inline void macb_ptp_tx_hwtstamp(struct macb *bp, struct sk_buff *skb,
+ int peer_ev)
+{
+ struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
+ struct timespec64 ts;
+ u64 ns;
+
+ /* PTP Peer Event Frame packets */
+ if (peer_ev) {
+ ts.tv_sec = gem_readl(bp, PEFTSL);
+ ts.tv_nsec = gem_readl(bp, PEFTN);
+
+ /* PTP Event Frame packets */
+ } else {
+ ts.tv_sec = gem_readl(bp, EFTSL);
+ ts.tv_nsec = gem_readl(bp, EFTN);
+ }
+ ns = timespec64_to_ns(&ts);
+
+ memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
+ shhwtstamps->hwtstamp = ns_to_ktime(ns);
+ skb_tstamp_tx(skb, skb_hwtstamps(skb));
+}
+
+inline void macb_ptp_do_txstamp(struct macb *bp, struct sk_buff *skb)
+{
+ if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {
+ int class = ptp_classify_raw(skb);
+ int peer;
+
+ peer = macb_get_ptp_peer(skb, class);
+ if (peer < 0)
+ return;
+
+ /* Timestamp this packet */
+ macb_ptp_tx_hwtstamp(bp, skb, peer);
+ }
+}
+
+static inline void macb_ptp_rx_hwtstamp(struct macb *bp, struct sk_buff *skb,
+ int peer_ev)
+{
+ struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
+ struct timespec64 ts;
+ u64 ns;
+
+ if (peer_ev) {
+ /* PTP Peer Event Frame packets */
+ ts.tv_sec = gem_readl(bp, PEFRSL);
+ ts.tv_nsec = gem_readl(bp, PEFRN);
+ } else {
+ /* PTP Event Frame packets */
+ ts.tv_sec = gem_readl(bp, EFRSL);
+ ts.tv_nsec = gem_readl(bp, EFRN);
+ }
+ ns = timespec64_to_ns(&ts);
+
+ memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
+ shhwtstamps->hwtstamp = ns_to_ktime(ns);
+}
+
+inline void macb_ptp_do_rxstamp(struct macb *bp, struct sk_buff *skb)
+{
+ int class;
+ int peer;
+
+ /* ffs !!! */
+ __skb_push(skb, ETH_HLEN);
+ class = ptp_classify_raw(skb);
+ __skb_pull(skb, ETH_HLEN);
+
+ peer = macb_get_ptp_peer(skb, class);
+ if (peer < 0)
+ return;
+
+ macb_ptp_rx_hwtstamp(bp, skb, peer);
+}
+
+int macb_ptp_get_ts_info(struct net_device *dev, struct ethtool_ts_info *info)
+{
+ struct macb *bp = netdev_priv(dev);
+
+ ethtool_op_get_ts_info(dev, info);
+ info->so_timestamping =
+ SOF_TIMESTAMPING_TX_SOFTWARE |
+ SOF_TIMESTAMPING_RX_SOFTWARE |
+ SOF_TIMESTAMPING_SOFTWARE |
+ SOF_TIMESTAMPING_TX_HARDWARE |
+ SOF_TIMESTAMPING_RX_HARDWARE |
+ SOF_TIMESTAMPING_RAW_HARDWARE;
+ info->phc_index = -1;
+
+ if (bp->ptp_clock)
+ info->phc_index = ptp_clock_index(bp->ptp_clock);
+
+ return 0;
+}
+
+int macb_hwtst_set(struct net_device *netdev, struct ifreq *ifr, int cmd)
+{
+ struct hwtstamp_config config;
+ struct macb *priv = netdev_priv(netdev);
+ u32 regval;
+
+ netdev_vdbg(netdev, "macb_hwtstamp_ioctl\n");
+
+ 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:
+ priv->hwts_tx_en = 0;
+ break;
+ case HWTSTAMP_TX_ON:
+ priv->hwts_tx_en = 1;
+ break;
+ default:
+ return -ERANGE;
+ }
+
+ switch (config.rx_filter) {
+ case HWTSTAMP_FILTER_NONE:
+ if (priv->hwts_rx_en)
+ priv->hwts_rx_en = 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:
+ case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+ case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+ case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
+ case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+ case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
+ case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
+ case HWTSTAMP_FILTER_PTP_V2_EVENT:
+ case HWTSTAMP_FILTER_PTP_V2_SYNC:
+ case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+ config.rx_filter = HWTSTAMP_FILTER_ALL;
+ regval = macb_readl(priv, NCR);
+ macb_writel(priv, NCR, (regval | MACB_BIT(SRTSM)));
+
+ if (!priv->hwts_rx_en)
+ priv->hwts_rx_en = 1;
+ break;
+ default:
+ return -ERANGE;
+ }
+
+ return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
+ -EFAULT : 0;
+}
+
+int macb_hwtst_get(struct net_device *netdev, struct ifreq *ifr)
+{
+ struct hwtstamp_config config;
+ struct macb *priv = netdev_priv(netdev);
+
+ config.flags = 0;
+ config.tx_type = priv->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
+ config.rx_filter = (priv->hwts_rx_en ?
+ HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);
+
+ return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
+ -EFAULT : 0;
+}
+
--
1.9.1