diff options
Diffstat (limited to 'kernel/time/timekeeping.c')
| -rw-r--r-- | kernel/time/timekeeping.c | 771 |
1 files changed, 620 insertions, 151 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 929846b8b45a..059fa8b79be6 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -6,6 +6,7 @@ #include <linux/timekeeper_internal.h> #include <linux/module.h> #include <linux/interrupt.h> +#include <linux/kobject.h> #include <linux/percpu.h> #include <linux/init.h> #include <linux/mm.h> @@ -25,6 +26,8 @@ #include <linux/audit.h> #include <linux/random.h> +#include <vdso/auxclock.h> + #include "tick-internal.h" #include "ntp_internal.h" #include "timekeeping_internal.h" @@ -53,7 +56,32 @@ struct tk_data { raw_spinlock_t lock; } ____cacheline_aligned; -static struct tk_data tk_core; +static struct tk_data timekeeper_data[TIMEKEEPERS_MAX]; + +/* The core timekeeper */ +#define tk_core (timekeeper_data[TIMEKEEPER_CORE]) + +#ifdef CONFIG_POSIX_AUX_CLOCKS +static inline bool tk_get_aux_ts64(unsigned int tkid, struct timespec64 *ts) +{ + return ktime_get_aux_ts64(CLOCK_AUX + tkid - TIMEKEEPER_AUX_FIRST, ts); +} + +static inline bool tk_is_aux(const struct timekeeper *tk) +{ + return tk->id >= TIMEKEEPER_AUX_FIRST && tk->id <= TIMEKEEPER_AUX_LAST; +} +#else +static inline bool tk_get_aux_ts64(unsigned int tkid, struct timespec64 *ts) +{ + return false; +} + +static inline bool tk_is_aux(const struct timekeeper *tk) +{ + return false; +} +#endif /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; @@ -113,6 +141,16 @@ static struct tk_fast tk_fast_raw ____cacheline_aligned = { .base[1] = FAST_TK_INIT, }; +#ifdef CONFIG_POSIX_AUX_CLOCKS +static __init void tk_aux_setup(void); +static void tk_aux_update_clocksource(void); +static void tk_aux_advance(void); +#else +static inline void tk_aux_setup(void) { } +static inline void tk_aux_update_clocksource(void) { } +static inline void tk_aux_advance(void) { } +#endif + unsigned long timekeeper_lock_irqsave(void) { unsigned long flags; @@ -164,10 +202,34 @@ static inline struct timespec64 tk_xtime(const struct timekeeper *tk) return ts; } +static inline struct timespec64 tk_xtime_coarse(const struct timekeeper *tk) +{ + struct timespec64 ts; + + ts.tv_sec = tk->xtime_sec; + ts.tv_nsec = tk->coarse_nsec; + return ts; +} + +/* + * Update the nanoseconds part for the coarse time keepers. They can't rely + * on xtime_nsec because xtime_nsec could be adjusted by a small negative + * amount when the multiplication factor of the clock is adjusted, which + * could cause the coarse clocks to go slightly backwards. See + * timekeeping_apply_adjustment(). Thus we keep a separate copy for the coarse + * clockids which only is updated when the clock has been set or we have + * accumulated time. + */ +static inline void tk_update_coarse_nsecs(struct timekeeper *tk) +{ + tk->coarse_nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; +} + static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts) { tk->xtime_sec = ts->tv_sec; tk->tkr_mono.xtime_nsec = (u64)ts->tv_nsec << tk->tkr_mono.shift; + tk_update_coarse_nsecs(tk); } static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts) @@ -175,6 +237,7 @@ static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts) tk->xtime_sec += ts->tv_sec; tk->tkr_mono.xtime_nsec += (u64)ts->tv_nsec << tk->tkr_mono.shift; tk_normalize_xtime(tk); + tk_update_coarse_nsecs(tk); } static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm) @@ -576,7 +639,7 @@ EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); */ static inline void tk_update_leap_state(struct timekeeper *tk) { - tk->next_leap_ktime = ntp_get_next_leap(); + tk->next_leap_ktime = ntp_get_next_leap(tk->id); if (tk->next_leap_ktime != KTIME_MAX) /* Convert to monotonic time */ tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real); @@ -638,7 +701,7 @@ static void timekeeping_restore_shadow(struct tk_data *tkd) static void timekeeping_update_from_shadow(struct tk_data *tkd, unsigned int action) { - struct timekeeper *tk = &tk_core.shadow_timekeeper; + struct timekeeper *tk = &tkd->shadow_timekeeper; lockdep_assert_held(&tkd->lock); @@ -653,18 +716,22 @@ static void timekeeping_update_from_shadow(struct tk_data *tkd, unsigned int act if (action & TK_CLEAR_NTP) { tk->ntp_error = 0; - ntp_clear(); + ntp_clear(tk->id); } tk_update_leap_state(tk); tk_update_ktime_data(tk); + tk->tkr_mono.base_real = tk->tkr_mono.base + tk->offs_real; - update_vsyscall(tk); - update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); + if (tk->id == TIMEKEEPER_CORE) { + update_vsyscall(tk); + update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); - tk->tkr_mono.base_real = tk->tkr_mono.base + tk->offs_real; - update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); - update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); + update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); + update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); + } else if (tk_is_aux(tk)) { + vdso_time_update_aux(tk); + } if (action & TK_CLOCK_WAS_SET) tk->clock_was_set_seq++; @@ -682,19 +749,20 @@ static void timekeeping_update_from_shadow(struct tk_data *tkd, unsigned int act } /** - * timekeeping_forward - update clock to given cycle now value + * timekeeping_forward_now - update clock to the current time * @tk: Pointer to the timekeeper to update - * @cycle_now: Current clocksource read value * * Forward the current clock to update its state since the last call to * update_wall_time(). This is useful before significant clock changes, * as it avoids having to deal with this time offset explicitly. */ -static void timekeeping_forward(struct timekeeper *tk, u64 cycle_now) +static void timekeeping_forward_now(struct timekeeper *tk) { - u64 delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask, - tk->tkr_mono.clock->max_raw_delta); + u64 cycle_now, delta; + cycle_now = tk_clock_read(&tk->tkr_mono); + delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask, + tk->tkr_mono.clock->max_raw_delta); tk->tkr_mono.cycle_last = cycle_now; tk->tkr_raw.cycle_last = cycle_now; @@ -707,21 +775,7 @@ static void timekeeping_forward(struct timekeeper *tk, u64 cycle_now) tk_normalize_xtime(tk); delta -= incr; } -} - -/** - * timekeeping_forward_now - update clock to the current time - * @tk: Pointer to the timekeeper to update - * - * Forward the current clock to update its state since the last call to - * update_wall_time(). This is useful before significant clock changes, - * as it avoids having to deal with this time offset explicitly. - */ -static void timekeeping_forward_now(struct timekeeper *tk) -{ - u64 cycle_now = tk_clock_read(&tk->tkr_mono); - - timekeeping_forward(tk, cycle_now); + tk_update_coarse_nsecs(tk); } /** @@ -818,8 +872,8 @@ EXPORT_SYMBOL_GPL(ktime_get_with_offset); ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs) { struct timekeeper *tk = &tk_core.timekeeper; - unsigned int seq; ktime_t base, *offset = offsets[offs]; + unsigned int seq; u64 nsecs; WARN_ON(timekeeping_suspended); @@ -827,7 +881,7 @@ ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs) do { seq = read_seqcount_begin(&tk_core.seq); base = ktime_add(tk->tkr_mono.base, *offset); - nsecs = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; + nsecs = tk->coarse_nsec; } while (read_seqcount_retry(&tk_core.seq, seq)); @@ -963,9 +1017,14 @@ time64_t ktime_get_real_seconds(void) EXPORT_SYMBOL_GPL(ktime_get_real_seconds); /** - * __ktime_get_real_seconds - The same as ktime_get_real_seconds - * but without the sequence counter protect. This internal function - * is called just when timekeeping lock is already held. + * __ktime_get_real_seconds - Unprotected access to CLOCK_REALTIME seconds + * + * The same as ktime_get_real_seconds() but without the sequence counter + * protection. This function is used in restricted contexts like the x86 MCE + * handler and in KGDB. It's unprotected on 32-bit vs. concurrent half + * completed modification and only to be used for such critical contexts. + * + * Returns: Racy snapshot of the CLOCK_REALTIME seconds value */ noinstr time64_t __ktime_get_real_seconds(void) { @@ -1244,7 +1303,7 @@ int get_device_system_crosststamp(int (*get_time_fn) struct system_time_snapshot *history_begin, struct system_device_crosststamp *xtstamp) { - struct system_counterval_t system_counterval; + struct system_counterval_t system_counterval = {}; struct timekeeper *tk = &tk_core.timekeeper; u64 cycles, now, interval_start; unsigned int clock_was_set_seq = 0; @@ -1400,41 +1459,73 @@ int do_settimeofday64(const struct timespec64 *ts) } EXPORT_SYMBOL(do_settimeofday64); +static inline bool timekeeper_is_core_tk(struct timekeeper *tk) +{ + return !IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS) || tk->id == TIMEKEEPER_CORE; +} + /** - * timekeeping_inject_offset - Adds or subtracts from the current time. + * __timekeeping_inject_offset - Adds or subtracts from the current time. + * @tkd: Pointer to the timekeeper to modify * @ts: Pointer to the timespec variable containing the offset * * Adds or subtracts an offset value from the current time. */ -static int timekeeping_inject_offset(const struct timespec64 *ts) +static int __timekeeping_inject_offset(struct tk_data *tkd, const struct timespec64 *ts) { + struct timekeeper *tks = &tkd->shadow_timekeeper; + struct timespec64 tmp; + if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; - scoped_guard (raw_spinlock_irqsave, &tk_core.lock) { - struct timekeeper *tks = &tk_core.shadow_timekeeper; - struct timespec64 tmp; - - timekeeping_forward_now(tks); + timekeeping_forward_now(tks); + if (timekeeper_is_core_tk(tks)) { /* Make sure the proposed value is valid */ tmp = timespec64_add(tk_xtime(tks), *ts); if (timespec64_compare(&tks->wall_to_monotonic, ts) > 0 || !timespec64_valid_settod(&tmp)) { - timekeeping_restore_shadow(&tk_core); + timekeeping_restore_shadow(tkd); return -EINVAL; } tk_xtime_add(tks, ts); tk_set_wall_to_mono(tks, timespec64_sub(tks->wall_to_monotonic, *ts)); - timekeeping_update_from_shadow(&tk_core, TK_UPDATE_ALL); + } else { + struct tk_read_base *tkr_mono = &tks->tkr_mono; + ktime_t now, offs; + + /* Get the current time */ + now = ktime_add_ns(tkr_mono->base, timekeeping_get_ns(tkr_mono)); + /* Add the relative offset change */ + offs = ktime_add(tks->offs_aux, timespec64_to_ktime(*ts)); + + /* Prevent that the resulting time becomes negative */ + if (ktime_add(now, offs) < 0) { + timekeeping_restore_shadow(tkd); + return -EINVAL; + } + tks->offs_aux = offs; } - /* Signal hrtimers about time change */ - clock_was_set(CLOCK_SET_WALL); + timekeeping_update_from_shadow(tkd, TK_UPDATE_ALL); return 0; } +static int timekeeping_inject_offset(const struct timespec64 *ts) +{ + int ret; + + scoped_guard (raw_spinlock_irqsave, &tk_core.lock) + ret = __timekeeping_inject_offset(&tk_core, ts); + + /* Signal hrtimers about time change */ + if (!ret) + clock_was_set(CLOCK_SET_WALL); + return ret; +} + /* * Indicates if there is an offset between the system clock and the hardware * clock/persistent clock/rtc. @@ -1510,6 +1601,8 @@ static int change_clocksource(void *data) timekeeping_update_from_shadow(&tk_core, TK_UPDATE_ALL); } + tk_aux_update_clocksource(); + if (old) { if (old->disable) old->disable(old); @@ -1561,6 +1654,39 @@ void ktime_get_raw_ts64(struct timespec64 *ts) } 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 @@ -1637,10 +1763,12 @@ read_persistent_wall_and_boot_offset(struct timespec64 *wall_time, *boot_offset = ns_to_timespec64(local_clock()); } -static __init void tkd_basic_setup(struct tk_data *tkd) +static __init void tkd_basic_setup(struct tk_data *tkd, enum timekeeper_ids tk_id, bool valid) { raw_spin_lock_init(&tkd->lock); seqcount_raw_spinlock_init(&tkd->seq, &tkd->lock); + tkd->timekeeper.id = tkd->shadow_timekeeper.id = tk_id; + tkd->timekeeper.clock_valid = tkd->shadow_timekeeper.clock_valid = valid; } /* @@ -1670,7 +1798,8 @@ void __init timekeeping_init(void) struct timekeeper *tks = &tk_core.shadow_timekeeper; struct clocksource *clock; - tkd_basic_setup(&tk_core); + tkd_basic_setup(&tk_core, TIMEKEEPER_CORE, true); + tk_aux_setup(); read_persistent_wall_and_boot_offset(&wall_time, &boot_offset); if (timespec64_valid_settod(&wall_time) && @@ -2022,7 +2151,7 @@ static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk, */ static void timekeeping_adjust(struct timekeeper *tk, s64 offset) { - u64 ntp_tl = ntp_tick_length(); + u64 ntp_tl = ntp_tick_length(tk->id); u32 mult; /* @@ -2103,7 +2232,7 @@ static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) } /* Figure out if its a leap sec and apply if needed */ - leap = second_overflow(tk->xtime_sec); + leap = second_overflow(tk->id, tk->xtime_sec); if (unlikely(leap)) { struct timespec64 ts; @@ -2165,32 +2294,29 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset, return offset; } -static u64 timekeeping_accumulate(struct timekeeper *tk, u64 offset, - enum timekeeping_adv_mode mode, - unsigned int *clock_set) +/* + * timekeeping_advance - Updates the timekeeper to the current time and + * current NTP tick length + */ +static bool __timekeeping_advance(struct tk_data *tkd, enum timekeeping_adv_mode mode) { + struct timekeeper *tk = &tkd->shadow_timekeeper; + struct timekeeper *real_tk = &tkd->timekeeper; + unsigned int clock_set = 0; int shift = 0, maxshift; + u64 offset, orig_offset; - /* - * TK_ADV_FREQ indicates that adjtimex(2) directly set the - * frequency or the tick length. - * - * Accumulate the offset, so that the new multiplier starts from - * now. This is required as otherwise for offsets, which are - * smaller than tk::cycle_interval, timekeeping_adjust() could set - * xtime_nsec backwards, which subsequently causes time going - * backwards in the coarse time getters. But even for the case - * where offset is greater than tk::cycle_interval the periodic - * accumulation does not have much value. - * - * Also reset tk::ntp_error as it does not make sense to keep the - * old accumulated error around in this case. - */ - if (mode == TK_ADV_FREQ) { - timekeeping_forward(tk, tk->tkr_mono.cycle_last + offset); - tk->ntp_error = 0; - return 0; - } + /* Make sure we're fully resumed: */ + if (unlikely(timekeeping_suspended)) + return false; + + offset = clocksource_delta(tk_clock_read(&tk->tkr_mono), + tk->tkr_mono.cycle_last, tk->tkr_mono.mask, + tk->tkr_mono.clock->max_raw_delta); + orig_offset = offset; + /* Check if there's really nothing to do */ + if (offset < real_tk->cycle_interval && mode == TK_ADV_TICK) + return false; /* * With NO_HZ we may have to accumulate many cycle_intervals @@ -2203,42 +2329,13 @@ static u64 timekeeping_accumulate(struct timekeeper *tk, u64 offset, shift = ilog2(offset) - ilog2(tk->cycle_interval); shift = max(0, shift); /* Bound shift to one less than what overflows tick_length */ - maxshift = (64 - (ilog2(ntp_tick_length()) + 1)) - 1; + maxshift = (64 - (ilog2(ntp_tick_length(tk->id)) + 1)) - 1; shift = min(shift, maxshift); while (offset >= tk->cycle_interval) { - offset = logarithmic_accumulation(tk, offset, shift, clock_set); - if (offset < tk->cycle_interval << shift) + offset = logarithmic_accumulation(tk, offset, shift, &clock_set); + if (offset < tk->cycle_interval<<shift) shift--; } - return offset; -} - -/* - * timekeeping_advance - Updates the timekeeper to the current time and - * current NTP tick length - */ -static bool timekeeping_advance(enum timekeeping_adv_mode mode) -{ - struct timekeeper *tk = &tk_core.shadow_timekeeper; - struct timekeeper *real_tk = &tk_core.timekeeper; - unsigned int clock_set = 0; - u64 offset; - - guard(raw_spinlock_irqsave)(&tk_core.lock); - - /* Make sure we're fully resumed: */ - if (unlikely(timekeeping_suspended)) - return false; - - offset = clocksource_delta(tk_clock_read(&tk->tkr_mono), - tk->tkr_mono.cycle_last, tk->tkr_mono.mask, - tk->tkr_mono.clock->max_raw_delta); - - /* Check if there's really nothing to do */ - if (offset < real_tk->cycle_interval && mode == TK_ADV_TICK) - return false; - - offset = timekeeping_accumulate(tk, offset, mode, &clock_set); /* Adjust the multiplier to correct NTP error */ timekeeping_adjust(tk, offset); @@ -2249,19 +2346,35 @@ static bool timekeeping_advance(enum timekeeping_adv_mode mode) */ clock_set |= accumulate_nsecs_to_secs(tk); - timekeeping_update_from_shadow(&tk_core, clock_set); + /* + * To avoid inconsistencies caused adjtimex TK_ADV_FREQ calls + * making small negative adjustments to the base xtime_nsec + * value, only update the coarse clocks if we accumulated time + */ + if (orig_offset != offset) + tk_update_coarse_nsecs(tk); + + timekeeping_update_from_shadow(tkd, clock_set); return !!clock_set; } +static bool timekeeping_advance(enum timekeeping_adv_mode mode) +{ + guard(raw_spinlock_irqsave)(&tk_core.lock); + return __timekeeping_advance(&tk_core, mode); +} + /** * update_wall_time - Uses the current clocksource to increment the wall time * + * It also updates the enabled auxiliary clock timekeepers */ void update_wall_time(void) { if (timekeeping_advance(TK_ADV_TICK)) clock_was_set_delayed(); + tk_aux_advance(); } /** @@ -2292,7 +2405,7 @@ void ktime_get_coarse_real_ts64(struct timespec64 *ts) do { seq = read_seqcount_begin(&tk_core.seq); - *ts = tk_xtime(tk); + *ts = tk_xtime_coarse(tk); } while (read_seqcount_retry(&tk_core.seq, seq)); } EXPORT_SYMBOL(ktime_get_coarse_real_ts64); @@ -2315,7 +2428,7 @@ void ktime_get_coarse_real_ts64_mg(struct timespec64 *ts) do { seq = read_seqcount_begin(&tk_core.seq); - *ts = tk_xtime(tk); + *ts = tk_xtime_coarse(tk); offset = tk_core.timekeeper.offs_real; } while (read_seqcount_retry(&tk_core.seq, seq)); @@ -2394,12 +2507,12 @@ void ktime_get_coarse_ts64(struct timespec64 *ts) do { seq = read_seqcount_begin(&tk_core.seq); - now = tk_xtime(tk); + now = tk_xtime_coarse(tk); mono = tk->wall_to_monotonic; } while (read_seqcount_retry(&tk_core.seq, seq)); set_normalized_timespec64(ts, now.tv_sec + mono.tv_sec, - now.tv_nsec + mono.tv_nsec); + now.tv_nsec + mono.tv_nsec); } EXPORT_SYMBOL(ktime_get_coarse_ts64); @@ -2459,7 +2572,7 @@ ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, /* * timekeeping_validate_timex - Ensures the timex is ok for use in do_adjtimex */ -static int timekeeping_validate_timex(const struct __kernel_timex *txc) +static int timekeeping_validate_timex(const struct __kernel_timex *txc, bool aux_clock) { if (txc->modes & ADJ_ADJTIME) { /* singleshot must not be used with any other mode bits */ @@ -2518,6 +2631,20 @@ static int timekeeping_validate_timex(const struct __kernel_timex *txc) return -EINVAL; } + if (aux_clock) { + /* Auxiliary clocks are similar to TAI and do not have leap seconds */ + if (txc->status & (STA_INS | STA_DEL)) + return -EINVAL; + + /* No TAI offset setting */ + if (txc->modes & ADJ_TAI) + return -EINVAL; + + /* No PPS support either */ + if (txc->status & (STA_PPSFREQ | STA_PPSTIME)) + return -EINVAL; + } + return 0; } @@ -2536,74 +2663,103 @@ unsigned long random_get_entropy_fallback(void) } EXPORT_SYMBOL_GPL(random_get_entropy_fallback); -/** - * do_adjtimex() - Accessor function to NTP __do_adjtimex function - * @txc: Pointer to kernel_timex structure containing NTP parameters - */ -int do_adjtimex(struct __kernel_timex *txc) +struct adjtimex_result { + struct audit_ntp_data ad; + struct timespec64 delta; + bool clock_set; +}; + +static int __do_adjtimex(struct tk_data *tkd, struct __kernel_timex *txc, + struct adjtimex_result *result) { - struct audit_ntp_data ad; - bool offset_set = false; - bool clock_set = false; + struct timekeeper *tks = &tkd->shadow_timekeeper; + bool aux_clock = !timekeeper_is_core_tk(tks); struct timespec64 ts; + s32 orig_tai, tai; int ret; /* Validate the data before disabling interrupts */ - ret = timekeeping_validate_timex(txc); + ret = timekeeping_validate_timex(txc, aux_clock); if (ret) return ret; add_device_randomness(txc, sizeof(*txc)); - if (txc->modes & ADJ_SETOFFSET) { - struct timespec64 delta; + if (!aux_clock) + ktime_get_real_ts64(&ts); + else + tk_get_aux_ts64(tkd->timekeeper.id, &ts); + + add_device_randomness(&ts, sizeof(ts)); - delta.tv_sec = txc->time.tv_sec; - delta.tv_nsec = txc->time.tv_usec; + guard(raw_spinlock_irqsave)(&tkd->lock); + + if (!tks->clock_valid) + return -ENODEV; + + if (txc->modes & ADJ_SETOFFSET) { + result->delta.tv_sec = txc->time.tv_sec; + result->delta.tv_nsec = txc->time.tv_usec; if (!(txc->modes & ADJ_NANO)) - delta.tv_nsec *= 1000; - ret = timekeeping_inject_offset(&delta); + result->delta.tv_nsec *= 1000; + ret = __timekeeping_inject_offset(tkd, &result->delta); if (ret) return ret; - - offset_set = delta.tv_sec != 0; - audit_tk_injoffset(delta); + result->clock_set = true; } - audit_ntp_init(&ad); + orig_tai = tai = tks->tai_offset; + ret = ntp_adjtimex(tks->id, txc, &ts, &tai, &result->ad); - ktime_get_real_ts64(&ts); - add_device_randomness(&ts, sizeof(ts)); + if (tai != orig_tai) { + __timekeeping_set_tai_offset(tks, tai); + timekeeping_update_from_shadow(tkd, TK_CLOCK_WAS_SET); + result->clock_set = true; + } else { + tk_update_leap_state_all(&tk_core); + } - scoped_guard (raw_spinlock_irqsave, &tk_core.lock) { - struct timekeeper *tks = &tk_core.shadow_timekeeper; - s32 orig_tai, tai; + /* Update the multiplier immediately if frequency was set directly */ + if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK)) + result->clock_set |= __timekeeping_advance(tkd, TK_ADV_FREQ); - orig_tai = tai = tks->tai_offset; - ret = __do_adjtimex(txc, &ts, &tai, &ad); + return ret; +} - if (tai != orig_tai) { - __timekeeping_set_tai_offset(tks, tai); - timekeeping_update_from_shadow(&tk_core, TK_CLOCK_WAS_SET); - clock_set = true; - } else { - tk_update_leap_state_all(&tk_core); - } - } +/** + * do_adjtimex() - Accessor function to NTP __do_adjtimex function + * @txc: Pointer to kernel_timex structure containing NTP parameters + */ +int do_adjtimex(struct __kernel_timex *txc) +{ + struct adjtimex_result result = { }; + int ret; + + ret = __do_adjtimex(&tk_core, txc, &result); + if (ret < 0) + return ret; - audit_ntp_log(&ad); + if (txc->modes & ADJ_SETOFFSET) + audit_tk_injoffset(result.delta); - /* Update the multiplier immediately if frequency was set directly */ - if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK)) - clock_set |= timekeeping_advance(TK_ADV_FREQ); + audit_ntp_log(&result.ad); - if (clock_set) + if (result.clock_set) clock_was_set(CLOCK_SET_WALL); - ntp_notify_cmos_timer(offset_set); + ntp_notify_cmos_timer(result.delta.tv_sec != 0); return ret; } +/* + * Invoked from NTP with the time keeper lock held, so lockless access is + * fine. + */ +long ktime_get_ntp_seconds(unsigned int id) +{ + return timekeeper_data[id].timekeeper.xtime_sec; +} + #ifdef CONFIG_NTP_PPS /** * hardpps() - Accessor function to NTP __hardpps function @@ -2617,3 +2773,316 @@ void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) } EXPORT_SYMBOL(hardpps); #endif /* CONFIG_NTP_PPS */ + +#ifdef CONFIG_POSIX_AUX_CLOCKS +#include "posix-timers.h" + +/* + * Bitmap for the activated auxiliary timekeepers to allow lockless quick + * checks in the hot paths without touching extra cache lines. If set, then + * the state of the corresponding timekeeper has to be re-checked under + * timekeeper::lock. + */ +static unsigned long aux_timekeepers; + +static inline unsigned int clockid_to_tkid(unsigned int id) +{ + return TIMEKEEPER_AUX_FIRST + id - CLOCK_AUX; +} + +static inline struct tk_data *aux_get_tk_data(clockid_t id) +{ + if (!clockid_aux_valid(id)) + return NULL; + return &timekeeper_data[clockid_to_tkid(id)]; +} + +/* Invoked from timekeeping after a clocksource change */ +static void tk_aux_update_clocksource(void) +{ + unsigned long active = READ_ONCE(aux_timekeepers); + unsigned int id; + + for_each_set_bit(id, &active, BITS_PER_LONG) { + struct tk_data *tkd = &timekeeper_data[id + TIMEKEEPER_AUX_FIRST]; + struct timekeeper *tks = &tkd->shadow_timekeeper; + + guard(raw_spinlock_irqsave)(&tkd->lock); + if (!tks->clock_valid) + continue; + + timekeeping_forward_now(tks); + tk_setup_internals(tks, tk_core.timekeeper.tkr_mono.clock); + timekeeping_update_from_shadow(tkd, TK_UPDATE_ALL); + } +} + +static void tk_aux_advance(void) +{ + unsigned long active = READ_ONCE(aux_timekeepers); + unsigned int id; + + /* Lockless quick check to avoid extra cache lines */ + for_each_set_bit(id, &active, BITS_PER_LONG) { + struct tk_data *aux_tkd = &timekeeper_data[id + TIMEKEEPER_AUX_FIRST]; + + guard(raw_spinlock)(&aux_tkd->lock); + if (aux_tkd->shadow_timekeeper.clock_valid) + __timekeeping_advance(aux_tkd, TK_ADV_TICK); + } +} + +/** + * ktime_get_aux - Get time for a AUX clock + * @id: ID of the clock to read (CLOCK_AUX...) + * @kt: Pointer to ktime_t to store the time stamp + * + * Returns: True if the timestamp is valid, false otherwise + */ +bool ktime_get_aux(clockid_t id, ktime_t *kt) +{ + struct tk_data *aux_tkd = aux_get_tk_data(id); + struct timekeeper *aux_tk; + unsigned int seq; + ktime_t base; + u64 nsecs; + + WARN_ON(timekeeping_suspended); + + if (!aux_tkd) + return false; + + aux_tk = &aux_tkd->timekeeper; + do { + seq = read_seqcount_begin(&aux_tkd->seq); + if (!aux_tk->clock_valid) + return false; + + base = ktime_add(aux_tk->tkr_mono.base, aux_tk->offs_aux); + nsecs = timekeeping_get_ns(&aux_tk->tkr_mono); + } while (read_seqcount_retry(&aux_tkd->seq, seq)); + + *kt = ktime_add_ns(base, nsecs); + return true; +} +EXPORT_SYMBOL_GPL(ktime_get_aux); + +/** + * ktime_get_aux_ts64 - Get time for a AUX clock + * @id: ID of the clock to read (CLOCK_AUX...) + * @ts: Pointer to timespec64 to store the time stamp + * + * Returns: True if the timestamp is valid, false otherwise + */ +bool ktime_get_aux_ts64(clockid_t id, struct timespec64 *ts) +{ + ktime_t now; + + if (!ktime_get_aux(id, &now)) + return false; + *ts = ktime_to_timespec64(now); + return true; +} +EXPORT_SYMBOL_GPL(ktime_get_aux_ts64); + +static int aux_get_res(clockid_t id, struct timespec64 *tp) +{ + if (!clockid_aux_valid(id)) + return -ENODEV; + + tp->tv_sec = aux_clock_resolution_ns() / NSEC_PER_SEC; + tp->tv_nsec = aux_clock_resolution_ns() % NSEC_PER_SEC; + return 0; +} + +static int aux_get_timespec(clockid_t id, struct timespec64 *tp) +{ + return ktime_get_aux_ts64(id, tp) ? 0 : -ENODEV; +} + +static int aux_clock_set(const clockid_t id, const struct timespec64 *tnew) +{ + struct tk_data *aux_tkd = aux_get_tk_data(id); + struct timekeeper *aux_tks; + ktime_t tnow, nsecs; + + if (!timespec64_valid_settod(tnew)) + return -EINVAL; + if (!aux_tkd) + return -ENODEV; + + aux_tks = &aux_tkd->shadow_timekeeper; + + guard(raw_spinlock_irq)(&aux_tkd->lock); + if (!aux_tks->clock_valid) + return -ENODEV; + + /* Forward the timekeeper base time */ + timekeeping_forward_now(aux_tks); + /* + * Get the updated base time. tkr_mono.base has not been + * updated yet, so do that first. That makes the update + * in timekeeping_update_from_shadow() redundant, but + * that's harmless. After that @tnow can be calculated + * by using tkr_mono::cycle_last, which has been set + * by timekeeping_forward_now(). + */ + tk_update_ktime_data(aux_tks); + nsecs = timekeeping_cycles_to_ns(&aux_tks->tkr_mono, aux_tks->tkr_mono.cycle_last); + tnow = ktime_add(aux_tks->tkr_mono.base, nsecs); + + /* + * Calculate the new AUX offset as delta to @tnow ("monotonic"). + * That avoids all the tk::xtime back and forth conversions as + * xtime ("realtime") is not applicable for auxiliary clocks and + * kept in sync with "monotonic". + */ + aux_tks->offs_aux = ktime_sub(timespec64_to_ktime(*tnew), tnow); + + timekeeping_update_from_shadow(aux_tkd, TK_UPDATE_ALL); + return 0; +} + +static int aux_clock_adj(const clockid_t id, struct __kernel_timex *txc) +{ + struct tk_data *aux_tkd = aux_get_tk_data(id); + struct adjtimex_result result = { }; + + if (!aux_tkd) + return -ENODEV; + + /* + * @result is ignored for now as there are neither hrtimers nor a + * RTC related to auxiliary clocks for now. + */ + return __do_adjtimex(aux_tkd, txc, &result); +} + +const struct k_clock clock_aux = { + .clock_getres = aux_get_res, + .clock_get_timespec = aux_get_timespec, + .clock_set = aux_clock_set, + .clock_adj = aux_clock_adj, +}; + +static void aux_clock_enable(clockid_t id) +{ + struct tk_read_base *tkr_raw = &tk_core.timekeeper.tkr_raw; + struct tk_data *aux_tkd = aux_get_tk_data(id); + struct timekeeper *aux_tks = &aux_tkd->shadow_timekeeper; + + /* Prevent the core timekeeper from changing. */ + guard(raw_spinlock_irq)(&tk_core.lock); + + /* + * Setup the auxiliary clock assuming that the raw core timekeeper + * clock frequency conversion is close enough. Userspace has to + * adjust for the deviation via clock_adjtime(2). + */ + guard(raw_spinlock_nested)(&aux_tkd->lock); + + /* Remove leftovers of a previous registration */ + memset(aux_tks, 0, sizeof(*aux_tks)); + /* Restore the timekeeper id */ + aux_tks->id = aux_tkd->timekeeper.id; + /* Setup the timekeeper based on the current system clocksource */ + tk_setup_internals(aux_tks, tkr_raw->clock); + + /* Mark it valid and set it live */ + aux_tks->clock_valid = true; + timekeeping_update_from_shadow(aux_tkd, TK_UPDATE_ALL); +} + +static void aux_clock_disable(clockid_t id) +{ + struct tk_data *aux_tkd = aux_get_tk_data(id); + + guard(raw_spinlock_irq)(&aux_tkd->lock); + aux_tkd->shadow_timekeeper.clock_valid = false; + timekeeping_update_from_shadow(aux_tkd, TK_UPDATE_ALL); +} + +static DEFINE_MUTEX(aux_clock_mutex); + +static ssize_t aux_clock_enable_store(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t count) +{ + /* Lazy atoi() as name is "0..7" */ + int id = kobj->name[0] & 0x7; + bool enable; + + if (!capable(CAP_SYS_TIME)) + return -EPERM; + + if (kstrtobool(buf, &enable) < 0) + return -EINVAL; + + guard(mutex)(&aux_clock_mutex); + if (enable == test_bit(id, &aux_timekeepers)) + return count; + + if (enable) { + aux_clock_enable(CLOCK_AUX + id); + set_bit(id, &aux_timekeepers); + } else { + aux_clock_disable(CLOCK_AUX + id); + clear_bit(id, &aux_timekeepers); + } + return count; +} + +static ssize_t aux_clock_enable_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) +{ + unsigned long active = READ_ONCE(aux_timekeepers); + /* Lazy atoi() as name is "0..7" */ + int id = kobj->name[0] & 0x7; + + return sysfs_emit(buf, "%d\n", test_bit(id, &active)); +} + +static struct kobj_attribute aux_clock_enable_attr = __ATTR_RW(aux_clock_enable); + +static struct attribute *aux_clock_enable_attrs[] = { + &aux_clock_enable_attr.attr, + NULL +}; + +static const struct attribute_group aux_clock_enable_attr_group = { + .attrs = aux_clock_enable_attrs, +}; + +static int __init tk_aux_sysfs_init(void) +{ + struct kobject *auxo, *tko = kobject_create_and_add("time", kernel_kobj); + + if (!tko) + return -ENOMEM; + + auxo = kobject_create_and_add("aux_clocks", tko); + if (!auxo) { + kobject_put(tko); + return -ENOMEM; + } + + for (int i = 0; i <= MAX_AUX_CLOCKS; i++) { + char id[2] = { [0] = '0' + i, }; + struct kobject *clk = kobject_create_and_add(id, auxo); + + if (!clk) + return -ENOMEM; + + int ret = sysfs_create_group(clk, &aux_clock_enable_attr_group); + + if (ret) + return ret; + } + return 0; +} +late_initcall(tk_aux_sysfs_init); + +static __init void tk_aux_setup(void) +{ + for (int i = TIMEKEEPER_AUX_FIRST; i <= TIMEKEEPER_AUX_LAST; i++) + tkd_basic_setup(&timekeeper_data[i], i, false); +} +#endif /* CONFIG_POSIX_AUX_CLOCKS */ |