[RFC PATCH 2/2] macb: Enable 1588 support in SAMA5D2 platform.
Richard Cochran
richardcochran at gmail.com
Tue Sep 6 09:37:18 PDT 2016
On Fri, Sep 02, 2016 at 02:53:37PM +0200, Andrei Pistirica wrote:
> 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 at microchip.com>
> ---
> Integration with SAMA5D2 only. This feature wasn't tested on any
> other platform that might use cadence/gem.
What does that mean? I didn't see any references to SAMA5D2 anywhere
in your patch.
The driver needs to positively identify the HW that supports this
feature.
> 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
Pull the test into the helper function, and then you can drop the
ifdef and the funny comment.
> 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
Same here.
> 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
We don't initialize to zero unless we have to.
> }
>
> /*
> @@ -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);
switch/case?
> +
> 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; }
Use a proper return code please.
> #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 at xilinx.com>
> + * Andrei Pistirica <andrei.pistirica at microchip.com>
We don't add additional authors any more, because git tells us that info.
> *
> * 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.
If you must parse, then it isn't the wrong place.
> + *
> + * Note: Inspired from drivers/net/ethernet/ti/cpts.c
> + */
> +static inline int macb_get_ptp_peer(struct sk_buff *skb, int ptp_class)
Leave off inline, let the compiler decide.
> +{
> + 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)
no 'inline' please
> +{
> + 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)
s/inline/static/
> +{
> + 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);
> + }
So you say the HW provides no matching information? Then it is really
poor. I surely don't want to let this out into the wild. I'll get
questions on the linuxptp list, like "PTP on mainline Linux is
mysteriously broken!"
> + 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 !!! */
What is this comment for?
> + __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);
> +}
Thanks,
Richard
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