[PATCH net-next v4 2/6] ptp: Request cycles for TX timestamp
From: Gerhard Engleder <hidden>
Date: 2022-05-06 20:02:10
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
The free running cycle counter of physical clocks called cycles shall be used for hardware timestamps to enable synchronisation. Introduce new flag SKBTX_HW_TSTAMP_USE_CYCLES, which signals driver to provide a TX timestamp based on cycles if cycles are supported. Signed-off-by: Gerhard Engleder <redacted> Acked-by: Richard Cochran <richardcochran@gmail.com> --- include/linux/skbuff.h | 7 ++++++- net/socket.c | 11 ++++++++++- 2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 5c2599e3fe7d..4d49503bdc4d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -615,6 +615,9 @@ enum { /* device driver is going to provide hardware time stamp */ SKBTX_IN_PROGRESS = 1 << 2, + /* generate hardware time stamp based on cycles if supported */ + SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, + /* generate wifi status information (where possible) */ SKBTX_WIFI_STATUS = 1 << 4,
@@ -624,7 +627,9 @@ enum { #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ SKBTX_SCHED_TSTAMP) -#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) +#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \ + SKBTX_HW_TSTAMP_USE_CYCLES | \ + SKBTX_ANY_SW_TSTAMP) /* Definitions for flags in struct skb_shared_info */ enum {
diff --git a/net/socket.c b/net/socket.c
index f0c39c874665..5c1c5e6100e1 100644
--- a/net/socket.c
+++ b/net/socket.c@@ -683,9 +683,18 @@ void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags) { u8 flags = *tx_flags; - if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE) + if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE) { flags |= SKBTX_HW_TSTAMP; + /* PTP hardware clocks can provide a free running cycle counter + * as a time base for virtual clocks. Tell driver to use the + * free running cycle counter for timestamp if socket is bound + * to virtual clock. + */ + if (tsflags & SOF_TIMESTAMPING_BIND_PHC) + flags |= SKBTX_HW_TSTAMP_USE_CYCLES; + } + if (tsflags & SOF_TIMESTAMPING_TX_SOFTWARE) flags |= SKBTX_SW_TSTAMP;
--
2.20.1