PTP device system crosstime stamps support only CLOCK_REALTIME, which is meaningless for AUX clocks. The PTP core hands in the clock ID already, so prepare the core code to honor it.
- Add a new sys_systime field to struct system_device_crosststamp which aliases the sys_realtime field. Once all users are converted sys_realtime can be removed. - Prepare get_device_system_crosststamp() and the related code for it by switching to sys_systime and providing the initial changes to utilize different time keepers. No functional change intended. Signed-off-by: Thomas Gleixner <[email protected]> --- include/linux/timekeeping.h | 7 ++++- kernel/time/timekeeping.c | 60 +++++++++++++++++++++++++------------------- 2 files changed, 41 insertions(+), 26 deletions(-) --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -319,13 +319,18 @@ struct system_counterval_t { * @device: Device time * @sys_counter: Clocksource counter value simultaneous with device time * @sys_realtime: Realtime simultaneous with device time + * @sys_systime: System time for @clock_id * @sys_monoraw: Monotonic raw simultaneous with device time */ struct system_device_crosststamp { clockid_t clock_id; ktime_t device; struct system_counterval_t sys_counter; - ktime_t sys_realtime; + union { + /* realtime goes away once all users are converted */ + ktime_t sys_realtime; + ktime_t sys_systime; + }; ktime_t sys_monoraw; }; --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1313,7 +1313,7 @@ static int adjust_historical_crosststamp struct system_device_crosststamp *ts) { struct timekeeper *tk = &tk_core.timekeeper; - u64 corr_raw, corr_real; + u64 corr_raw, corr_sys; bool interp_forward; int ret; @@ -1330,8 +1330,7 @@ static int adjust_historical_crosststamp * Scale the monotonic raw time delta by: * partial_history_cycles / total_history_cycles */ - corr_raw = (u64)ktime_to_ns( - ktime_sub(ts->sys_monoraw, history->raw)); + corr_raw = (u64)ktime_to_ns(ktime_sub(ts->sys_monoraw, history->raw)); ret = scale64_check_overflow(partial_history_cycles, total_history_cycles, &corr_raw); if (ret) @@ -1339,30 +1338,29 @@ static int adjust_historical_crosststamp /* * If there is a discontinuity in the history, scale monotonic raw - * correction by: - * mult(real)/mult(raw) yielding the realtime correction - * Otherwise, calculate the realtime correction similar to monotonic - * raw calculation + * correction by: + * mult(sys)/mult(raw) yielding the system time correction + * + * Otherwise, calculate the system time correction similar to monotonic + * raw calculation */ if (discontinuity) { - corr_real = mul_u64_u32_div - (corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult); + corr_sys = mul_u64_u32_div(corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult); } else { - corr_real = (u64)ktime_to_ns( - ktime_sub(ts->sys_realtime, history->sys)); - ret = scale64_check_overflow(partial_history_cycles, - total_history_cycles, &corr_real); + corr_sys = (u64)ktime_to_ns(ktime_sub(ts->sys_systime, history->sys)); + ret = scale64_check_overflow(partial_history_cycles, total_history_cycles, + &corr_sys); if (ret) return ret; } - /* Fixup monotonic raw and real time time values */ + /* Fixup monotonic raw and system time time values */ if (interp_forward) { ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw); - ts->sys_realtime = ktime_add_ns(history->sys, corr_real); + ts->sys_systime = ktime_add_ns(history->sys, corr_sys); } else { ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw); - ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real); + ts->sys_systime = ktime_sub_ns(ts->sys_systime, corr_sys); } return 0; @@ -1506,16 +1504,29 @@ int get_device_system_crosststamp(int (* struct system_device_crosststamp *xtstamp) { u64 syscnt_cycles, cycles, now, interval_start; - struct timekeeper *tk = &tk_core.timekeeper; unsigned int seq, clock_was_set_seq = 0; - ktime_t base_real, base_raw; - u64 nsec_real, nsec_raw; + ktime_t base_sys, base_raw, *offs; + u64 nsec_sys, nsec_raw; u8 cs_was_changed_seq; bool do_interp; + struct timekeeper *tk; + struct tk_data *tkd; int ret; + switch (xtstamp->clock_id) { + case CLOCK_REALTIME: + tkd = &tk_core; + offs = &tk_core.timekeeper.offs_real; + break; + default: + WARN_ON_ONCE(1); + return false; + } + + tk = &tkd->timekeeper; + do { - seq = read_seqcount_begin(&tk_core.seq); + seq = read_seqcount_begin(&tkd->seq); /* * Try to synchronously capture device time and a system * counter value calling back into the device driver @@ -1550,15 +1561,14 @@ int get_device_system_crosststamp(int (* do_interp = false; } - base_real = ktime_add(tk->tkr_mono.base, - tk_core.timekeeper.offs_real); + base_sys = ktime_add(tk->tkr_mono.base, *offs); base_raw = tk->tkr_raw.base; - nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, cycles); + nsec_sys = timekeeping_cycles_to_ns(&tk->tkr_mono, cycles); nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, cycles); - } while (read_seqcount_retry(&tk_core.seq, seq)); + } while (read_seqcount_retry(&tkd->seq, seq)); - xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real); + xtstamp->sys_systime = ktime_add_ns(base_sys, nsec_sys); xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw); /*
