[patch V2 0/3] ptp: Provide support for auxiliary clocks for PTP_SYS_OFFSET_EXTENDED

[patch V2 0/3] ptp: Provide support for auxiliary clocks for PTP_SYS_OFFSET_EXTENDED

[Thomas Gleixner]

This is a follow up to the V1 series, which can be found here:

     https://lore.kernel.org/all/20250626124327.667087805@linutronix.de

to address the merge logistics problem, which I created myself.

Changes vs. V1:

    - Make patch 1, which provides the timestamping function temporarily
      define CLOCK_AUX* if undefined so that it can be merged independently,

    - Add a missing check for CONFIG_POSIX_AUX_CLOCK in the PTP IOCTL

    - Picked up tags

Merge logistics if agreed on:

    1) Patch #1 is applied to the tip tree on top of plain v6.16-rc1 and
       tagged

    2) That tag is merged into tip:timers/ptp and the temporary CLOCK_AUX
       define is removed in a subsequent commit

    3) Network folks merge the tag and apply patches #2 + #3

So the only fallout from this are the extra merges in both trees and the
cleanup commit in the tip tree. But that way there are no dependencies and
no duplicate commits with different SHAs.

Thoughts?

Due to the above constraints there is no branch offered to pull from right
now. Sorry for the inconveniance. Should have thought about that earlier.

Thanks,

	tglx
---
 drivers/ptp/ptp_chardev.c        |   24 +++++++++++++++++++-----
 include/linux/ptp_clock_kernel.h |   34 ++++------------------------------
 include/linux/timekeeping.h      |   10 ++++++++++
 kernel/time/timekeeping.c        |   33 +++++++++++++++++++++++++++++++++
 4 files changed, 66 insertions(+), 35 deletions(-)

[patch V2 1/3] timekeeping: Provide ktime_get_clock_ts64()

[Thomas Gleixner]

PTP implements an inline switch case for taking timestamps from various
POSIX clock IDs, which already consumes quite some text space. Expanding it
for auxiliary clocks really becomes too big for inlining.

Provide a out of line version. 

The function invalidates the timestamp in case the clock is invalid. The
invalidation allows to implement a validation check without the need to
propagate a return value through deep existing call chains.

Due to merge logistics this temporarily defines CLOCK_AUX[_LAST] if
undefined, so that the plain branch, which does not contain any of the core
timekeeper changes, can be pulled into the networking tree as prerequisite
for the PTP side changes. These temporary defines are removed after that
branch is merged into the tip::timers/ptp branch. That way the result in
-next or upstream in the next merge window has zero dependencies.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Acked-by: John Stultz <jstultz@google.com>
---
V2: Provide a workaround for networking folks to handle merge logistics.
---
 include/linux/timekeeping.h |   10 ++++++++++
 kernel/time/timekeeping.c   |   33 +++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -44,6 +44,7 @@ extern void ktime_get_ts64(struct timesp
 extern void ktime_get_real_ts64(struct timespec64 *tv);
 extern void ktime_get_coarse_ts64(struct timespec64 *ts);
 extern void ktime_get_coarse_real_ts64(struct timespec64 *ts);
+extern void ktime_get_clock_ts64(clockid_t id, struct timespec64 *ts);
 
 /* Multigrain timestamp interfaces */
 extern void ktime_get_coarse_real_ts64_mg(struct timespec64 *ts);
@@ -345,4 +346,13 @@ void read_persistent_wall_and_boot_offse
 extern int update_persistent_clock64(struct timespec64 now);
 #endif
 
+/* Temporary workaround to avoid merge dependencies and cross tree messes */
+#ifndef CLOCK_AUX
+#define CLOCK_AUX			MAX_CLOCKS
+#define MAX_AUX_CLOCKS			8
+#define CLOCK_AUX_LAST			(CLOCK_AUX + MAX_AUX_CLOCKS - 1)
+
+static inline bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt) { return false; }
+#endif
+
 #endif
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1573,6 +1573,39 @@ void ktime_get_raw_ts64(struct timespec6
 }
 EXPORT_SYMBOL(ktime_get_raw_ts64);
 
+/**
+ * ktime_get_clock_ts64 - Returns time of a clock in a timespec
+ * @id:		POSIX clock ID of the clock to read
+ * @ts:		Pointer to the timespec64 to be set
+ *
+ * The timestamp is invalidated (@ts->sec is set to -1) if the
+ * clock @id is not available.
+ */
+void ktime_get_clock_ts64(clockid_t id, struct timespec64 *ts)
+{
+	/* Invalidate time stamp */
+	ts->tv_sec = -1;
+	ts->tv_nsec = 0;
+
+	switch (id) {
+	case CLOCK_REALTIME:
+		ktime_get_real_ts64(ts);
+		return;
+	case CLOCK_MONOTONIC:
+		ktime_get_ts64(ts);
+		return;
+	case CLOCK_MONOTONIC_RAW:
+		ktime_get_raw_ts64(ts);
+		return;
+	case CLOCK_AUX ... CLOCK_AUX_LAST:
+		if (IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS))
+			ktime_get_aux_ts64(id, ts);
+		return;
+	default:
+		WARN_ON_ONCE(1);
+	}
+}
+EXPORT_SYMBOL_GPL(ktime_get_clock_ts64);
 
 /**
  * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres

[patch V2 2/3] ptp: Use ktime_get_clock_ts64() for timestamping

[Thomas Gleixner]

The inlined ptp_read_system_[pre|post]ts() switch cases expand to a copious
amount of text in drivers, e.g. ~500 bytes in e1000e. Adding auxiliary
clock support to the inlines would increase it further.

Replace the inline switch case with a call to ktime_get_clock_ts64(), which
reduces the code size in drivers and allows to access auxiliary clocks once
they are enabled in the IOCTL parameter filter.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Acked-by: John Stultz <jstultz@google.com>

---
 include/linux/ptp_clock_kernel.h |   34 ++++------------------------------
 1 file changed, 4 insertions(+), 30 deletions(-)

--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -477,40 +477,14 @@ static inline ktime_t ptp_convert_timest
 
 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
 {
-	if (sts) {
-		switch (sts->clockid) {
-		case CLOCK_REALTIME:
-			ktime_get_real_ts64(&sts->pre_ts);
-			break;
-		case CLOCK_MONOTONIC:
-			ktime_get_ts64(&sts->pre_ts);
-			break;
-		case CLOCK_MONOTONIC_RAW:
-			ktime_get_raw_ts64(&sts->pre_ts);
-			break;
-		default:
-			break;
-		}
-	}
+	if (sts)
+		ktime_get_clock_ts64(sts->clockid, &sts->pre_ts);
 }
 
 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
 {
-	if (sts) {
-		switch (sts->clockid) {
-		case CLOCK_REALTIME:
-			ktime_get_real_ts64(&sts->post_ts);
-			break;
-		case CLOCK_MONOTONIC:
-			ktime_get_ts64(&sts->post_ts);
-			break;
-		case CLOCK_MONOTONIC_RAW:
-			ktime_get_raw_ts64(&sts->post_ts);
-			break;
-		default:
-			break;
-		}
-	}
+	if (sts)
+		ktime_get_clock_ts64(sts->clockid, &sts->post_ts);
 }
 
 #endif

[patch V2 3/3] ptp: Enable auxiliary clocks for PTP_SYS_OFFSET_EXTENDED

[Thomas Gleixner]

Allow ioctl(PTP_SYS_OFFSET_EXTENDED*) to select CLOCK_AUX clock ids for
generating the pre and post hardware readout timestamps.

Aside of adding these clocks to the clock ID validation, this also requires
to check the timestamp to be valid, i.e. the seconds value being greater
than or equal zero. This is necessary because AUX clocks can be
asynchronously enabled or disabled, so there is no way to validate the
availability upfront.

The same could have been achieved by handing the return value of
ktime_get_aux_ts64() all the way down to the IOCTL call site, but that'd
require to modify all existing ptp::gettimex64() callbacks and their inner
call chains. The timestamp check achieves the same with less churn and less
complicated code all over the place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
---
V2: Catch CONFIG_POSIX_AUX_CLOCKS=n right at the clockid check
---
 drivers/ptp/ptp_chardev.c |   24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -325,13 +325,22 @@ static long ptp_sys_offset_extended(stru
 	if (IS_ERR(extoff))
 		return PTR_ERR(extoff);
 
-	if (extoff->n_samples > PTP_MAX_SAMPLES ||
-	    extoff->rsv[0] || extoff->rsv[1] ||
-	    (extoff->clockid != CLOCK_REALTIME &&
-	     extoff->clockid != CLOCK_MONOTONIC &&
-	     extoff->clockid != CLOCK_MONOTONIC_RAW))
+	if (extoff->n_samples > PTP_MAX_SAMPLES || extoff->rsv[0] || extoff->rsv[1])
 		return -EINVAL;
 
+	switch (extoff->clockid) {
+	case CLOCK_REALTIME:
+	case CLOCK_MONOTONIC:
+	case CLOCK_MONOTONIC_RAW:
+		break;
+	case CLOCK_AUX ... CLOCK_AUX_LAST:
+		if (IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS))
+			break;
+		fallthrough;
+	default:
+		return -EINVAL;
+	}
+
 	sts.clockid = extoff->clockid;
 	for (unsigned int i = 0; i < extoff->n_samples; i++) {
 		struct timespec64 ts;
@@ -340,6 +349,11 @@ static long ptp_sys_offset_extended(stru
 		err = ptp->info->gettimex64(ptp->info, &ts, &sts);
 		if (err)
 			return err;
+
+		/* Filter out disabled or unavailable clocks */
+		if (sts.pre_ts.tv_sec < 0 || sts.post_ts.tv_sec < 0)
+			return -EINVAL;
+
 		extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
 		extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
 		extoff->ts[i][1].sec = ts.tv_sec;

Re: [patch V2 0/3] ptp: Provide support for auxiliary clocks for PTP_SYS_OFFSET_EXTENDED

[Paolo Abeni]

On 7/1/25 3:26 PM, Thomas Gleixner wrote:
> This is a follow up to the V1 series, which can be found here:
> 
>      https://lore.kernel.org/all/20250626124327.667087805@linutronix.de
> 
> to address the merge logistics problem, which I created myself.
> 
> Changes vs. V1:
> 
>     - Make patch 1, which provides the timestamping function temporarily
>       define CLOCK_AUX* if undefined so that it can be merged independently,
> 
>     - Add a missing check for CONFIG_POSIX_AUX_CLOCK in the PTP IOCTL
> 
>     - Picked up tags
> 
> Merge logistics if agreed on:
> 
>     1) Patch #1 is applied to the tip tree on top of plain v6.16-rc1 and
>        tagged
> 
>     2) That tag is merged into tip:timers/ptp and the temporary CLOCK_AUX
>        define is removed in a subsequent commit
> 
>     3) Network folks merge the tag and apply patches #2 + #3
> 
> So the only fallout from this are the extra merges in both trees and the
> cleanup commit in the tip tree. But that way there are no dependencies and
> no duplicate commits with different SHAs.
> 
> Thoughts?

I'm sorry for the latency here; the plan works for me! I'll wait for the
tag reference.

Could you please drop a notice here when such tag will be available?

Thanks,

Paolo

Re: [patch V2 0/3] ptp: Provide support for auxiliary clocks for PTP_SYS_OFFSET_EXTENDED

[Thomas Gleixner]

Paolo!

On Thu, Jul 03 2025 at 12:27, Paolo Abeni wrote:
> On 7/1/25 3:26 PM, Thomas Gleixner wrote:
>> Merge logistics if agreed on:
>> 
>>     1) Patch #1 is applied to the tip tree on top of plain v6.16-rc1 and
>>        tagged
>> 
>>     2) That tag is merged into tip:timers/ptp and the temporary CLOCK_AUX
>>        define is removed in a subsequent commit
>> 
>>     3) Network folks merge the tag and apply patches #2 + #3
>> 
>> So the only fallout from this are the extra merges in both trees and the
>> cleanup commit in the tip tree. But that way there are no dependencies and
>> no duplicate commits with different SHAs.
>> 
>> Thoughts?
>
> I'm sorry for the latency here; the plan works for me! I'll wait for the
> tag reference.

No problem. Rome wasn't built in a day either :)

> Could you please drop a notice here when such tag will be available?

Here you go:

  git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git ktime-get-clock-ts64-for-ptp

I merged it locally into net-next, applied the PTP patches on top and
verified that the combination with the tip timers/ptp branch, which has
the tag integrated and the workaround removed, creates the expected
working result.

Thanks,

        tglx

Re: [patch V2 0/3] ptp: Provide support for auxiliary clocks for PTP_SYS_OFFSET_EXTENDED

[Paolo Abeni]

On 7/3/25 2:48 PM, Thomas Gleixner wrote:
> On Thu, Jul 03 2025 at 12:27, Paolo Abeni wrote:
>> On 7/1/25 3:26 PM, Thomas Gleixner wrote:
>>> Merge logistics if agreed on:
>>>
>>>     1) Patch #1 is applied to the tip tree on top of plain v6.16-rc1 and
>>>        tagged
>>>
>>>     2) That tag is merged into tip:timers/ptp and the temporary CLOCK_AUX
>>>        define is removed in a subsequent commit
>>>
>>>     3) Network folks merge the tag and apply patches #2 + #3
>>>
>>> So the only fallout from this are the extra merges in both trees and the
>>> cleanup commit in the tip tree. But that way there are no dependencies and
>>> no duplicate commits with different SHAs.
>>>
>>> Thoughts?
>>
>> I'm sorry for the latency here; the plan works for me! I'll wait for the
>> tag reference.
> 
> No problem. Rome wasn't built in a day either :)
> 
>> Could you please drop a notice here when such tag will be available?
> 
> Here you go:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git ktime-get-clock-ts64-for-ptp
> 
> I merged it locally into net-next, applied the PTP patches on top and
> verified that the combination with the tip timers/ptp branch, which has
> the tag integrated and the workaround removed, creates the expected
> working result.

I had to wrestle a bit with the script I use - since the whole thing was
a little different from my usual workflow - but it's in now, hoping I
did not mess badly with something.

/P

Re: [patch V2 0/3] ptp: Provide support for auxiliary clocks for PTP_SYS_OFFSET_EXTENDED

[Thomas Gleixner]

On Thu, Jul 03 2025 at 15:48, Paolo Abeni wrote:
> On 7/3/25 2:48 PM, Thomas Gleixner wrote:
>> Here you go:
>> 
>>   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git ktime-get-clock-ts64-for-ptp
>> 
>> I merged it locally into net-next, applied the PTP patches on top and
>> verified that the combination with the tip timers/ptp branch, which has
>> the tag integrated and the workaround removed, creates the expected
>> working result.
>
> I had to wrestle a bit with the script I use - since the whole thing was
> a little different from my usual workflow - but it's in now, hoping I
> did not mess badly with something.

Looks perfect!

Thank you for the extra mile!

      tglx

Re: [patch V2 0/3] ptp: Provide support for auxiliary clocks for PTP_SYS_OFFSET_EXTENDED

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Tue,  1 Jul 2025 15:26:56 +0200 (CEST) you wrote:
> This is a follow up to the V1 series, which can be found here:
> 
>      https://lore.kernel.org/all/20250626124327.667087805@linutronix.de
> 
> to address the merge logistics problem, which I created myself.
> 
> Changes vs. V1:
> 
> [...]

Here is the summary with links:
  - [V2,1/3] timekeeping: Provide ktime_get_clock_ts64()
    https://git.kernel.org/netdev/net-next/c/5b605dbee07d
  - [V2,2/3] ptp: Use ktime_get_clock_ts64() for timestamping
    https://git.kernel.org/netdev/net-next/c/4c09a4cebd03
  - [V2,3/3] ptp: Enable auxiliary clocks for PTP_SYS_OFFSET_EXTENDED
    https://git.kernel.org/netdev/net-next/c/17c395bba1a3

You are awesome, thank you!
-- 
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