diff mbox series

[net-next,v4,2/6] ptp: Request cycles for TX timestamp

Message ID 20220506200142.3329-3-gerhard@engleder-embedded.com (mailing list archive)
State Accepted
Commit 51eb7492af276b5b4d27cfa4474d40bdac7b9cf8
Delegated to: Netdev Maintainers
Headers show
Series ptp: Support hardware clocks with additional free running cycle counter | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5740 this patch: 5740
netdev/cc_maintainers warning 3 maintainers not CCed: edumazet@google.com imagedong@tencent.com pabeni@redhat.com
netdev/build_clang success Errors and warnings before: 1137 this patch: 1137
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5884 this patch: 5884
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 38 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Gerhard Engleder May 6, 2022, 8:01 p.m. UTC 
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 <gerhard@engleder-embedded.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
---
 include/linux/skbuff.h |  7 ++++++-
 net/socket.c           | 11 ++++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)
diff mbox series

Patch

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;