Merge branch 'ptp-virtual-clocks-and-timestamping'

Yangbo Lu says:

====================
ptp: support virtual clocks and timestamping

Current PTP driver exposes one PTP device to user which binds network
interface/interfaces to provide timestamping. Actually we have a way
utilizing timecounter/cyclecounter to virtualize any number of PTP
clocks based on a same free running physical clock for using.
The purpose of having multiple PTP virtual clocks is for user space
to directly/easily use them for multiple domains synchronization.

user
space:     ^                                  ^
           | SO_TIMESTAMPING new flag:        | Packets with
           | SOF_TIMESTAMPING_BIND_PHC        | TX/RX HW timestamps
           v                                  v
         +--------------------------------------------+
sock:    |     sock (new member sk_bind_phc)          |
         +--------------------------------------------+
           ^                                  ^
           | ethtool_get_phc_vclocks          | Convert HW timestamps
           |                                  | to sk_bind_phc
           v                                  v
         +--------------+--------------+--------------+
vclock:  | ptp1         | ptp2         | ptpN         |
         +--------------+--------------+--------------+
pclock:  |             ptp0 free running              |
         +--------------------------------------------+

The block diagram may explain how it works. Besides the PTP virtual
clocks, the packet HW timestamp converting to the bound PHC is also
done in sock driver. For user space, PTP virtual clocks can be
created via sysfs, and extended SO_TIMESTAMPING API (new flag
SOF_TIMESTAMPING_BIND_PHC) can be used to bind one PTP virtual clock
for timestamping.

The test tool timestamping.c (together with linuxptp phc_ctl tool) can
be used to verify:

  # echo 4 > /sys/class/ptp/ptp0/n_vclocks
  [  129.399472] ptp ptp0: new virtual clock ptp2
  [  129.404234] ptp ptp0: new virtual clock ptp3
  [  129.409532] ptp ptp0: new virtual clock ptp4
  [  129.413942] ptp ptp0: new virtual clock ptp5
  [  129.418257] ptp ptp0: guarantee physical clock free running
  #
  # phc_ctl /dev/ptp2 set 10000
  # phc_ctl /dev/ptp3 set 20000
  #
  # timestamping eno0 2 SOF_TIMESTAMPING_TX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_BIND_PHC
  # timestamping eno0 2 SOF_TIMESTAMPING_RX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_BIND_PHC
  # timestamping eno0 3 SOF_TIMESTAMPING_TX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_BIND_PHC
  # timestamping eno0 3 SOF_TIMESTAMPING_RX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_BIND_PHC

Changes for v2:
	- Converted to num_vclocks for creating virtual clocks.
	- Guranteed physical clock free running when using virtual
	  clocks.
	- Fixed build warning.
	- Updated copyright.
Changes for v3:
	- Supported PTP virtual clock in default in PTP driver.
	- Protected concurrency of ptp->num_vclocks accessing.
	- Supported PHC vclocks query via ethtool.
	- Extended SO_TIMESTAMPING API for PHC binding.
	- Converted HW timestamps to PHC bound, instead of previous
	  binding domain value to PHC idea.
	- Other minor fixes.
Changes for v4:
	- Used do_aux_work callback for vclock refreshing instead.
	- Used unsigned int for vclocks number, and max_vclocks
	  for limitiation.
	- Fixed mutex locking.
	- Dynamically allocated memory for vclock index storage.
	- Removed ethtool ioctl command for vclocks getting.
	- Updated doc for ethtool phc vclocks get.
	- Converted to mptcp_setsockopt_sol_socket_timestamping().
	- Passed so_timestamping for sock_set_timestamping.
	- Fixed checkpatch/build.
	- Other minor fixed.
Changes for v5:
	- Fixed checkpatch/build/bug reported by test robot.
====================

Signed-off-by: David S. Miller <[email protected]>

2 files changed, 40 insertions, 1 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 29dbb603bc91..232daaec56e4 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -758,6 +758,16 @@ ethtool_params_from_link_mode(struct ethtool_link_ksettings *link_ksettings,
 			      enum ethtool_link_mode_bit_indices link_mode);
 
 /**
+ * ethtool_get_phc_vclocks - Derive phc vclocks information, and caller
+ *                           is responsible to free memory of vclock_index
+ * @dev: pointer to net_device structure
+ * @vclock_index: pointer to pointer of vclock index
+ *
+ * Return number of phc vclocks
+ */
+int ethtool_get_phc_vclocks(struct net_device *dev, int **vclock_index);
+
+/**
  * ethtool_sprintf - Write formatted string to ethtool string data
  * @data: Pointer to start of string to update
  * @fmt: Format of string to write
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index aba237c0b3a2..71fac9237725 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -11,7 +11,10 @@
 #include <linux/device.h>
 #include <linux/pps_kernel.h>
 #include <linux/ptp_clock.h>
+#include <linux/timecounter.h>
+#include <linux/skbuff.h>
 
+#define PTP_CLOCK_NAME_LEN	32
 /**
  * struct ptp_clock_request - request PTP clock event
  *
@@ -134,7 +137,7 @@ struct ptp_system_timestamp {
 
 struct ptp_clock_info {
 	struct module *owner;
-	char name[16];
+	char name[PTP_CLOCK_NAME_LEN];
 	s32 max_adj;
 	int n_alarm;
 	int n_ext_ts;
@@ -304,6 +307,27 @@ int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
  */
 void ptp_cancel_worker_sync(struct ptp_clock *ptp);
 
+/**
+ * ptp_get_vclocks_index() - get all vclocks index on pclock, and
+ *                           caller is responsible to free memory
+ *                           of vclock_index
+ *
+ * @pclock_index: phc index of ptp pclock.
+ * @vclock_index: pointer to pointer of vclock index.
+ *
+ * return number of vclocks.
+ */
+int ptp_get_vclocks_index(int pclock_index, int **vclock_index);
+
+/**
+ * ptp_convert_timestamp() - convert timestamp to a ptp vclock time
+ *
+ * @hwtstamps:    skb_shared_hwtstamps structure pointer
+ * @vclock_index: phc index of ptp vclock.
+ */
+void ptp_convert_timestamp(struct skb_shared_hwtstamps *hwtstamps,
+			   int vclock_index);
+
 #else
 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 						   struct device *parent)
@@ -323,6 +347,11 @@ static inline int ptp_schedule_worker(struct ptp_clock *ptp,
 { return -EOPNOTSUPP; }
 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
 { }
+static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
+{ return 0; }
+static inline void ptp_convert_timestamp(struct skb_shared_hwtstamps *hwtstamps,
+					 int vclock_index)
+{ }
 
 #endif