| Message ID | 20220501111836.10910-5-gerhard@engleder-embedded.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | ptp: Support hardware clocks with additional free running cycle counter | expand |
On Sun, May 01, 2022 at 01:18:34PM +0200, Gerhard Engleder wrote: > If a physical clock supports a free running cycle counter, then > timestamps shall be based on this time too. For TX it is known in > advance before the transmission if a timestamp based on the free running > cycle counter is needed. For RX it is impossible to know which timestamp > is needed before the packet is received and assigned to a socket. > > Support late timestamp determination by a network device. Therefore, an > address/cookie is stored within the new netdev_data field of struct > skb_shared_hwtstamps. This address/cookie is provided to a new network > device function called ndo_get_tstamp(), which returns a timestamp based > on the normal/adjustable time or based on the free running cycle > counter. If function is not supported, then timestamp handling is not > changed. > > Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com> > --- > include/linux/netdevice.h | 21 ++++++++++++++++++++ > include/linux/skbuff.h | 16 ++++++++++++--- > net/socket.c | 42 +++++++++++++++++++++++++++++---------- > 3 files changed, 66 insertions(+), 13 deletions(-) > > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index 4aba92a4042a..47dca9adfb17 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -1356,6 +1356,12 @@ struct netdev_net_notifier { > * The caller must be under RCU read context. > * int (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx, struct net_device_path *path); > * Get the forwarding path to reach the real device from the HW destination address > + * ktime_t (*ndo_get_tstamp)(struct net_device *dev, > + * const struct skb_shared_hwtstamps *hwtstamps, > + * bool cycles); > + * Get hardware timestamp based on normal/adjustable time or free running > + * cycle counter. This function is required if physical clock supports a > + * free running cycle counter. > */ > struct net_device_ops { > int (*ndo_init)(struct net_device *dev); > @@ -1578,6 +1584,9 @@ struct net_device_ops { > struct net_device * (*ndo_get_peer_dev)(struct net_device *dev); > int (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx, > struct net_device_path *path); > + ktime_t (*ndo_get_tstamp)(struct net_device *dev, > + const struct skb_shared_hwtstamps *hwtstamps, > + bool cycles); > }; > > /** > @@ -4738,6 +4747,18 @@ static inline void netdev_rx_csum_fault(struct net_device *dev, > void net_enable_timestamp(void); > void net_disable_timestamp(void); > > +static inline ktime_t netdev_get_tstamp(struct net_device *dev, > + const struct skb_shared_hwtstamps *hwtstamps, > + bool cycles) > +{ > + const struct net_device_ops *ops = dev->netdev_ops; > + > + if (ops->ndo_get_tstamp) > + return ops->ndo_get_tstamp(dev, hwtstamps, cycles); > + > + return hwtstamps->hwtstamp; > +} > + > static inline netdev_tx_t __netdev_start_xmit(const struct net_device_ops *ops, > struct sk_buff *skb, struct net_device *dev, > bool more) > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index fa03e02b761d..732b995fe54e 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -588,8 +588,10 @@ static inline bool skb_frag_must_loop(struct page *p) > > /** > * struct skb_shared_hwtstamps - hardware time stamps > - * @hwtstamp: hardware time stamp transformed into duration > - * since arbitrary point in time > + * @hwtstamp: hardware time stamp transformed into duration > + * since arbitrary point in time > + * @netdev_data: address/cookie of network device driver used as > + * reference to actual hardware time stamp > * > * Software time stamps generated by ktime_get_real() are stored in > * skb->tstamp. > @@ -601,7 +603,10 @@ static inline bool skb_frag_must_loop(struct page *p) > * &skb_shared_info. Use skb_hwtstamps() to get a pointer. > */ > struct skb_shared_hwtstamps { > - ktime_t hwtstamp; > + union { > + ktime_t hwtstamp; > + void *netdev_data; > + }; > }; > > /* Definitions for tx_flags in struct skb_shared_info */ > @@ -620,6 +625,11 @@ enum { > */ > SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, > > + /* determine hardware time stamp based on time or cycles, flag is used > + * only for RX path > + */ > + SKBTX_HW_TSTAMP_NETDEV = 1 << 3, > + > /* generate wifi status information (where possible) */ > SKBTX_WIFI_STATUS = 1 << 4, I follow what is being done here, although it seems a bit messy: - abusing tx_flags for recive - keeping a pointer into skb->data for later use. > diff --git a/net/socket.c b/net/socket.c > index 0f680c7d968a..ee81e25e9b98 100644 > --- a/net/socket.c > +++ b/net/socket.c > @@ -805,7 +805,8 @@ static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp) > return skb->tstamp && !false_tstamp && skb_is_err_queue(skb); > } > > -static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) > +static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb, > + int if_index) > { > struct scm_ts_pktinfo ts_pktinfo; > struct net_device *orig_dev; > @@ -815,11 +816,15 @@ static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) > > memset(&ts_pktinfo, 0, sizeof(ts_pktinfo)); > > - rcu_read_lock(); > - orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); > - if (orig_dev) > - ts_pktinfo.if_index = orig_dev->ifindex; > - rcu_read_unlock(); > + if (if_index == -1) { > + rcu_read_lock(); > + orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); > + if (orig_dev) > + ts_pktinfo.if_index = orig_dev->ifindex; > + rcu_read_unlock(); > + } else { > + ts_pktinfo.if_index = if_index; > + } if_index of 0 is invalid - see dev_new_index(). So this optimization would be better written as: if (!if_index) { rcu_read_lock(); orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); if (orig_dev) if_index = orig_dev->ifindex; rcu_read_unlock(); } ts_pktinfo.if_index = if_index; > ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb); > put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO, > @@ -839,6 +844,8 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, > int empty = 1, false_tstamp = 0; > struct skb_shared_hwtstamps *shhwtstamps = > skb_hwtstamps(skb); > + struct net_device *orig_dev; > + int if_index = -1; This should be set to 0 in the SOF_TIMESTAMPING_RAW_HARDWARE block. (see below) > ktime_t hwtstamp; > > /* Race occurred between timestamp enabling and packet > @@ -887,18 +894,33 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, > if (shhwtstamps && > (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) && > !skb_is_swtx_tstamp(skb, false_tstamp)) { > + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV) { > + rcu_read_lock(); > + orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); > + if (orig_dev) { > + if_index = orig_dev->ifindex; > + hwtstamp = netdev_get_tstamp(orig_dev, > + shhwtstamps, > + sk->sk_tsflags & > + SOF_TIMESTAMPING_BIND_PHC); > + } else { > + hwtstamp = shhwtstamps->hwtstamp; > + } > + rcu_read_unlock(); > + } else { > + hwtstamp = shhwtstamps->hwtstamp; > + } > + I'd suggest moving all this into a helper function, so it reads something like this: if_index = 0; if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV) hwtstamp = recover_hw_tstamp(skb, sk, &if_index); else hwtstamp = shhwtstamps->hwtstamp; > if (sk->sk_tsflags & SOF_TIMESTAMPING_BIND_PHC) > - hwtstamp = ptp_convert_timestamp(&shhwtstamps->hwtstamp, > + hwtstamp = ptp_convert_timestamp(&hwtstamp, > sk->sk_bind_phc); > - else > - hwtstamp = shhwtstamps->hwtstamp; > > if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) { > empty = 0; > > if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) && > !skb_is_err_queue(skb)) > - put_ts_pktinfo(msg, skb); > + put_ts_pktinfo(msg, skb, if_index); > } > } > if (!empty) { > -- > 2.20.1 >
> > If a physical clock supports a free running cycle counter, then > > timestamps shall be based on this time too. For TX it is known in > > advance before the transmission if a timestamp based on the free running > > cycle counter is needed. For RX it is impossible to know which timestamp > > is needed before the packet is received and assigned to a socket. > > > > Support late timestamp determination by a network device. Therefore, an > > address/cookie is stored within the new netdev_data field of struct > > skb_shared_hwtstamps. This address/cookie is provided to a new network > > device function called ndo_get_tstamp(), which returns a timestamp based > > on the normal/adjustable time or based on the free running cycle > > counter. If function is not supported, then timestamp handling is not > > changed. > > > > Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com> > > --- > > include/linux/netdevice.h | 21 ++++++++++++++++++++ > > include/linux/skbuff.h | 16 ++++++++++++--- > > net/socket.c | 42 +++++++++++++++++++++++++++++---------- > > 3 files changed, 66 insertions(+), 13 deletions(-) > > > > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > > index 4aba92a4042a..47dca9adfb17 100644 > > --- a/include/linux/netdevice.h > > +++ b/include/linux/netdevice.h > > @@ -1356,6 +1356,12 @@ struct netdev_net_notifier { > > * The caller must be under RCU read context. > > * int (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx, struct net_device_path *path); > > * Get the forwarding path to reach the real device from the HW destination address > > + * ktime_t (*ndo_get_tstamp)(struct net_device *dev, > > + * const struct skb_shared_hwtstamps *hwtstamps, > > + * bool cycles); > > + * Get hardware timestamp based on normal/adjustable time or free running > > + * cycle counter. This function is required if physical clock supports a > > + * free running cycle counter. > > */ > > struct net_device_ops { > > int (*ndo_init)(struct net_device *dev); > > @@ -1578,6 +1584,9 @@ struct net_device_ops { > > struct net_device * (*ndo_get_peer_dev)(struct net_device *dev); > > int (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx, > > struct net_device_path *path); > > + ktime_t (*ndo_get_tstamp)(struct net_device *dev, > > + const struct skb_shared_hwtstamps *hwtstamps, > > + bool cycles); > > }; > > > > /** > > @@ -4738,6 +4747,18 @@ static inline void netdev_rx_csum_fault(struct net_device *dev, > > void net_enable_timestamp(void); > > void net_disable_timestamp(void); > > > > +static inline ktime_t netdev_get_tstamp(struct net_device *dev, > > + const struct skb_shared_hwtstamps *hwtstamps, > > + bool cycles) > > +{ > > + const struct net_device_ops *ops = dev->netdev_ops; > > + > > + if (ops->ndo_get_tstamp) > > + return ops->ndo_get_tstamp(dev, hwtstamps, cycles); > > + > > + return hwtstamps->hwtstamp; > > +} > > + > > static inline netdev_tx_t __netdev_start_xmit(const struct net_device_ops *ops, > > struct sk_buff *skb, struct net_device *dev, > > bool more) > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > > index fa03e02b761d..732b995fe54e 100644 > > --- a/include/linux/skbuff.h > > +++ b/include/linux/skbuff.h > > @@ -588,8 +588,10 @@ static inline bool skb_frag_must_loop(struct page *p) > > > > /** > > * struct skb_shared_hwtstamps - hardware time stamps > > - * @hwtstamp: hardware time stamp transformed into duration > > - * since arbitrary point in time > > + * @hwtstamp: hardware time stamp transformed into duration > > + * since arbitrary point in time > > + * @netdev_data: address/cookie of network device driver used as > > + * reference to actual hardware time stamp > > * > > * Software time stamps generated by ktime_get_real() are stored in > > * skb->tstamp. > > @@ -601,7 +603,10 @@ static inline bool skb_frag_must_loop(struct page *p) > > * &skb_shared_info. Use skb_hwtstamps() to get a pointer. > > */ > > struct skb_shared_hwtstamps { > > - ktime_t hwtstamp; > > + union { > > + ktime_t hwtstamp; > > + void *netdev_data; > > + }; > > }; > > > > /* Definitions for tx_flags in struct skb_shared_info */ > > @@ -620,6 +625,11 @@ enum { > > */ > > SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, > > > > + /* determine hardware time stamp based on time or cycles, flag is used > > + * only for RX path > > + */ > > + SKBTX_HW_TSTAMP_NETDEV = 1 << 3, > > + > > /* generate wifi status information (where possible) */ > > SKBTX_WIFI_STATUS = 1 << 4, > > I follow what is being done here, although it seems a bit messy: > - abusing tx_flags for recive > - keeping a pointer into skb->data for later use. Abuse of tx_flags is because of saving bits for future flags. The same bit is used for TX and RX, instead of a separate bit for RX. > > > > diff --git a/net/socket.c b/net/socket.c > > index 0f680c7d968a..ee81e25e9b98 100644 > > --- a/net/socket.c > > +++ b/net/socket.c > > @@ -805,7 +805,8 @@ static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp) > > return skb->tstamp && !false_tstamp && skb_is_err_queue(skb); > > } > > > > -static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) > > +static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb, > > + int if_index) > > { > > struct scm_ts_pktinfo ts_pktinfo; > > struct net_device *orig_dev; > > @@ -815,11 +816,15 @@ static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) > > > > memset(&ts_pktinfo, 0, sizeof(ts_pktinfo)); > > > > - rcu_read_lock(); > > - orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); > > - if (orig_dev) > > - ts_pktinfo.if_index = orig_dev->ifindex; > > - rcu_read_unlock(); > > + if (if_index == -1) { > > + rcu_read_lock(); > > + orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); > > + if (orig_dev) > > + ts_pktinfo.if_index = orig_dev->ifindex; > > + rcu_read_unlock(); > > + } else { > > + ts_pktinfo.if_index = if_index; > > + } > > if_index of 0 is invalid - see dev_new_index(). > So this optimization would be better written as: > > if (!if_index) { > rcu_read_lock(); > orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); > if (orig_dev) > if_index = orig_dev->ifindex; > rcu_read_unlock(); > } > ts_pktinfo.if_index = if_index; I will fix that. > > ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb); > > put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO, > > @@ -839,6 +844,8 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, > > int empty = 1, false_tstamp = 0; > > struct skb_shared_hwtstamps *shhwtstamps = > > skb_hwtstamps(skb); > > + struct net_device *orig_dev; > > + int if_index = -1; > > This should be set to 0 in the SOF_TIMESTAMPING_RAW_HARDWARE block. > (see below) I will fix that. > > ktime_t hwtstamp; > > > > /* Race occurred between timestamp enabling and packet > > @@ -887,18 +894,33 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, > > if (shhwtstamps && > > (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) && > > !skb_is_swtx_tstamp(skb, false_tstamp)) { > > + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV) { > > + rcu_read_lock(); > > + orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); > > + if (orig_dev) { > > + if_index = orig_dev->ifindex; > > + hwtstamp = netdev_get_tstamp(orig_dev, > > + shhwtstamps, > > + sk->sk_tsflags & > > + SOF_TIMESTAMPING_BIND_PHC); > > + } else { > > + hwtstamp = shhwtstamps->hwtstamp; > > + } > > + rcu_read_unlock(); > > + } else { > > + hwtstamp = shhwtstamps->hwtstamp; > > + } > > + > > I'd suggest moving all this into a helper function, so it reads > something like this: > > if_index = 0; > > if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV) > hwtstamp = recover_hw_tstamp(skb, sk, &if_index); > else > hwtstamp = shhwtstamps->hwtstamp; I will add a helper function. > > if (sk->sk_tsflags & SOF_TIMESTAMPING_BIND_PHC) > > - hwtstamp = ptp_convert_timestamp(&shhwtstamps->hwtstamp, > > + hwtstamp = ptp_convert_timestamp(&hwtstamp, > > sk->sk_bind_phc); > > - else > > - hwtstamp = shhwtstamps->hwtstamp; > > > > if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) { > > empty = 0; > > > > if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) && > > !skb_is_err_queue(skb)) > > - put_ts_pktinfo(msg, skb); > > + put_ts_pktinfo(msg, skb, if_index); > > } > > } > > if (!empty) { > > -- > > 2.20.1 > > > > -- > Jonathan Thank you for the review! Gerhard
On Sun, May 01, 2022 at 01:18:34PM +0200, Gerhard Engleder wrote: > @@ -620,6 +625,11 @@ enum { > */ > SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, > > + /* determine hardware time stamp based on time or cycles, flag is used > + * only for RX path > + */ > + SKBTX_HW_TSTAMP_NETDEV = 1 << 3, Rather than re-using bit 3, why not just use bit 5? Then you can: - remove the magic clearing in patch #2 - protect against future changes that would skip the magic clearing > /* generate wifi status information (where possible) */ > SKBTX_WIFI_STATUS = 1 << 4, > Thanks, Richard
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 4aba92a4042a..47dca9adfb17 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1356,6 +1356,12 @@ struct netdev_net_notifier { * The caller must be under RCU read context. * int (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx, struct net_device_path *path); * Get the forwarding path to reach the real device from the HW destination address + * ktime_t (*ndo_get_tstamp)(struct net_device *dev, + * const struct skb_shared_hwtstamps *hwtstamps, + * bool cycles); + * Get hardware timestamp based on normal/adjustable time or free running + * cycle counter. This function is required if physical clock supports a + * free running cycle counter. */ struct net_device_ops { int (*ndo_init)(struct net_device *dev); @@ -1578,6 +1584,9 @@ struct net_device_ops { struct net_device * (*ndo_get_peer_dev)(struct net_device *dev); int (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx, struct net_device_path *path); + ktime_t (*ndo_get_tstamp)(struct net_device *dev, + const struct skb_shared_hwtstamps *hwtstamps, + bool cycles); }; /** @@ -4738,6 +4747,18 @@ static inline void netdev_rx_csum_fault(struct net_device *dev, void net_enable_timestamp(void); void net_disable_timestamp(void); +static inline ktime_t netdev_get_tstamp(struct net_device *dev, + const struct skb_shared_hwtstamps *hwtstamps, + bool cycles) +{ + const struct net_device_ops *ops = dev->netdev_ops; + + if (ops->ndo_get_tstamp) + return ops->ndo_get_tstamp(dev, hwtstamps, cycles); + + return hwtstamps->hwtstamp; +} + static inline netdev_tx_t __netdev_start_xmit(const struct net_device_ops *ops, struct sk_buff *skb, struct net_device *dev, bool more) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index fa03e02b761d..732b995fe54e 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -588,8 +588,10 @@ static inline bool skb_frag_must_loop(struct page *p) /** * struct skb_shared_hwtstamps - hardware time stamps - * @hwtstamp: hardware time stamp transformed into duration - * since arbitrary point in time + * @hwtstamp: hardware time stamp transformed into duration + * since arbitrary point in time + * @netdev_data: address/cookie of network device driver used as + * reference to actual hardware time stamp * * Software time stamps generated by ktime_get_real() are stored in * skb->tstamp. @@ -601,7 +603,10 @@ static inline bool skb_frag_must_loop(struct page *p) * &skb_shared_info. Use skb_hwtstamps() to get a pointer. */ struct skb_shared_hwtstamps { - ktime_t hwtstamp; + union { + ktime_t hwtstamp; + void *netdev_data; + }; }; /* Definitions for tx_flags in struct skb_shared_info */ @@ -620,6 +625,11 @@ enum { */ SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, + /* determine hardware time stamp based on time or cycles, flag is used + * only for RX path + */ + SKBTX_HW_TSTAMP_NETDEV = 1 << 3, + /* generate wifi status information (where possible) */ SKBTX_WIFI_STATUS = 1 << 4, diff --git a/net/socket.c b/net/socket.c index 0f680c7d968a..ee81e25e9b98 100644 --- a/net/socket.c +++ b/net/socket.c @@ -805,7 +805,8 @@ static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp) return skb->tstamp && !false_tstamp && skb_is_err_queue(skb); } -static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) +static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb, + int if_index) { struct scm_ts_pktinfo ts_pktinfo; struct net_device *orig_dev; @@ -815,11 +816,15 @@ static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) memset(&ts_pktinfo, 0, sizeof(ts_pktinfo)); - rcu_read_lock(); - orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); - if (orig_dev) - ts_pktinfo.if_index = orig_dev->ifindex; - rcu_read_unlock(); + if (if_index == -1) { + rcu_read_lock(); + orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); + if (orig_dev) + ts_pktinfo.if_index = orig_dev->ifindex; + rcu_read_unlock(); + } else { + ts_pktinfo.if_index = if_index; + } ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb); put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO, @@ -839,6 +844,8 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, int empty = 1, false_tstamp = 0; struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); + struct net_device *orig_dev; + int if_index = -1; ktime_t hwtstamp; /* Race occurred between timestamp enabling and packet @@ -887,18 +894,33 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, if (shhwtstamps && (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) && !skb_is_swtx_tstamp(skb, false_tstamp)) { + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV) { + rcu_read_lock(); + orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); + if (orig_dev) { + if_index = orig_dev->ifindex; + hwtstamp = netdev_get_tstamp(orig_dev, + shhwtstamps, + sk->sk_tsflags & + SOF_TIMESTAMPING_BIND_PHC); + } else { + hwtstamp = shhwtstamps->hwtstamp; + } + rcu_read_unlock(); + } else { + hwtstamp = shhwtstamps->hwtstamp; + } + if (sk->sk_tsflags & SOF_TIMESTAMPING_BIND_PHC) - hwtstamp = ptp_convert_timestamp(&shhwtstamps->hwtstamp, + hwtstamp = ptp_convert_timestamp(&hwtstamp, sk->sk_bind_phc); - else - hwtstamp = shhwtstamps->hwtstamp; if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) { empty = 0; if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) && !skb_is_err_queue(skb)) - put_ts_pktinfo(msg, skb); + put_ts_pktinfo(msg, skb, if_index); } } if (!empty) {
If a physical clock supports a free running cycle counter, then timestamps shall be based on this time too. For TX it is known in advance before the transmission if a timestamp based on the free running cycle counter is needed. For RX it is impossible to know which timestamp is needed before the packet is received and assigned to a socket. Support late timestamp determination by a network device. Therefore, an address/cookie is stored within the new netdev_data field of struct skb_shared_hwtstamps. This address/cookie is provided to a new network device function called ndo_get_tstamp(), which returns a timestamp based on the normal/adjustable time or based on the free running cycle counter. If function is not supported, then timestamp handling is not changed. Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com> --- include/linux/netdevice.h | 21 ++++++++++++++++++++ include/linux/skbuff.h | 16 ++++++++++++--- net/socket.c | 42 +++++++++++++++++++++++++++++---------- 3 files changed, 66 insertions(+), 13 deletions(-)