#include <linux/jiffies.h>
#include <linux/time.h>
-/*
- * Structure holding internal timekeeping values.
- *
- * Note: wall_to_monotonic is what we need to add to xtime (or xtime
- * corrected for sub jiffie times) to get to monotonic time.
- * Monotonic is pegged at zero at system boot time, so
- * wall_to_monotonic will be negative, however, we will ALWAYS keep
- * the tv_nsec part positive so we can use the usual normalization.
+/**
+ * struct tk_read_base - base structure for timekeeping readout
+ * @clock: Current clocksource used for timekeeping.
+ * @read: Read function of @clock
+ * @mask: Bitmask for two's complement subtraction of non 64bit clocks
+ * @cycle_last: @clock cycle value at last update
+ * @mult: NTP adjusted multiplier for scaled math conversion
+ * @shift: Shift value for scaled math conversion
+ * @xtime_nsec: Shifted (fractional) nano seconds offset for readout
+ * @base_mono: ktime_t (nanoseconds) base time for readout
*
- * wall_to_monotonic is moved after resume from suspend for the
- * monotonic time not to jump. To calculate the real boot time offset
- * we need to do offs_real - offs_boot.
+ * This struct has size 56 byte on 64 bit. Together with a seqcount it
+ * occupies a single 64byte cache line.
*
- * - wall_to_monotonic is no longer the boot time, getboottime must be
- * used instead.
+ * The struct is separate from struct timekeeper as it is also used
+ * for a fast NMI safe accessor to clock monotonic.
*/
-struct timekeeper {
- /* Current clocksource used for timekeeping. */
+struct tk_read_base {
struct clocksource *clock;
- /* Read function of @clock */
cycle_t (*read)(struct clocksource *cs);
- /* Bitmask for two's complement subtraction of non 64bit counters */
cycle_t mask;
- /* Last cycle value */
cycle_t cycle_last;
- /* NTP adjusted clock multiplier */
u32 mult;
- /* The shift value of the current clocksource. */
u32 shift;
- /* Clock shifted nano seconds */
u64 xtime_nsec;
-
- /* Monotonic base time */
ktime_t base_mono;
+};
- /* Current CLOCK_REALTIME time in seconds */
+/**
+ * struct timekeeper - Structure holding internal timekeeping values.
+ * @tkr: The readout base structure
+ * @xtime_sec: Current CLOCK_REALTIME time in seconds
+ * @wall_to_monotonic: CLOCK_REALTIME to CLOCK_MONOTONIC offset
+ * @offs_real: Offset clock monotonic -> clock realtime
+ * @offs_boot: Offset clock monotonic -> clock boottime
+ * @offs_tai: Offset clock monotonic -> clock tai
+ * @tai_offset: The current UTC to TAI offset in seconds
+ * @base_raw: Monotonic raw base time in ktime_t format
+ * @raw_time: Monotonic raw base time in timespec64 format
+ * @cycle_interval: Number of clock cycles in one NTP interval
+ * @xtime_interval: Number of clock shifted nano seconds in one NTP
+ * interval.
+ * @xtime_remainder: Shifted nano seconds left over when rounding
+ * @cycle_interval
+ * @raw_interval: Raw nano seconds accumulated per NTP interval.
+ * @ntp_error: Difference between accumulated time and NTP time in ntp
+ * shifted nano seconds.
+ * @ntp_error_shift: Shift conversion between clock shifted nano seconds and
+ * ntp shifted nano seconds.
+ *
+ * Note: For timespec(64) based interfaces wall_to_monotonic is what
+ * we need to add to xtime (or xtime corrected for sub jiffie times)
+ * to get to monotonic time. Monotonic is pegged at zero at system
+ * boot time, so wall_to_monotonic will be negative, however, we will
+ * ALWAYS keep the tv_nsec part positive so we can use the usual
+ * normalization.
+ *
+ * wall_to_monotonic is moved after resume from suspend for the
+ * monotonic time not to jump. We need to add total_sleep_time to
+ * wall_to_monotonic to get the real boot based time offset.
+ *
+ * wall_to_monotonic is no longer the boot time, getboottime must be
+ * used instead.
+ */
+struct timekeeper {
+ struct tk_read_base tkr;
u64 xtime_sec;
- /* CLOCK_REALTIME to CLOCK_MONOTONIC offset */
struct timespec64 wall_to_monotonic;
-
- /* Offset clock monotonic -> clock realtime */
ktime_t offs_real;
- /* Offset clock monotonic -> clock boottime */
ktime_t offs_boot;
- /* Offset clock monotonic -> clock tai */
ktime_t offs_tai;
-
- /* The current UTC to TAI offset in seconds */
s32 tai_offset;
-
- /* Monotonic raw base time */
ktime_t base_raw;
-
- /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
struct timespec64 raw_time;
- /* Number of clock cycles in one NTP interval. */
+ /* The following members are for timekeeping internal use */
cycle_t cycle_interval;
- /* Number of clock shifted nano seconds in one NTP interval. */
u64 xtime_interval;
- /* shifted nano seconds left over when rounding cycle_interval */
s64 xtime_remainder;
- /* Raw nano seconds accumulated per NTP interval. */
u32 raw_interval;
-
- /*
- * Difference between accumulated time and NTP time in ntp
- * shifted nano seconds.
- */
s64 ntp_error;
- /*
- * Shift conversion between clock shifted nano seconds and
- * ntp shifted nano seconds.
- */
u32 ntp_error_shift;
};
static inline void tk_normalize_xtime(struct timekeeper *tk)
{
- while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
- tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift;
+ while (tk->tkr.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr.shift)) {
+ tk->tkr.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr.shift;
tk->xtime_sec++;
}
}
struct timespec64 ts;
ts.tv_sec = tk->xtime_sec;
- ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
+ ts.tv_nsec = (long)(tk->tkr.xtime_nsec >> tk->tkr.shift);
return ts;
}
static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts)
{
tk->xtime_sec = ts->tv_sec;
- tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift;
+ tk->tkr.xtime_nsec = (u64)ts->tv_nsec << tk->tkr.shift;
}
static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts)
{
tk->xtime_sec += ts->tv_sec;
- tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
+ tk->tkr.xtime_nsec += (u64)ts->tv_nsec << tk->tkr.shift;
tk_normalize_xtime(tk);
}
u64 tmp, ntpinterval;
struct clocksource *old_clock;
- old_clock = tk->clock;
- tk->clock = clock;
- tk->read = clock->read;
- tk->mask = clock->mask;
- tk->cycle_last = tk->read(clock);
+ old_clock = tk->tkr.clock;
+ tk->tkr.clock = clock;
+ tk->tkr.read = clock->read;
+ tk->tkr.mask = clock->mask;
+ tk->tkr.cycle_last = tk->tkr.read(clock);
/* Do the ns -> cycle conversion first, using original mult */
tmp = NTP_INTERVAL_LENGTH;
if (old_clock) {
int shift_change = clock->shift - old_clock->shift;
if (shift_change < 0)
- tk->xtime_nsec >>= -shift_change;
+ tk->tkr.xtime_nsec >>= -shift_change;
else
- tk->xtime_nsec <<= shift_change;
+ tk->tkr.xtime_nsec <<= shift_change;
}
- tk->shift = clock->shift;
+ tk->tkr.shift = clock->shift;
tk->ntp_error = 0;
tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
* active clocksource. These value will be adjusted via NTP
* to counteract clock drifting.
*/
- tk->mult = clock->mult;
+ tk->tkr.mult = clock->mult;
}
/* Timekeeper helper functions. */
s64 nsec;
/* read clocksource: */
- cycle_now = tk->read(tk->clock);
+ cycle_now = tk->tkr.read(tk->tkr.clock);
/* calculate the delta since the last update_wall_time: */
- delta = clocksource_delta(cycle_now, tk->cycle_last, tk->mask);
+ delta = clocksource_delta(cycle_now, tk->tkr.cycle_last, tk->tkr.mask);
- nsec = delta * tk->mult + tk->xtime_nsec;
- nsec >>= tk->shift;
+ nsec = delta * tk->tkr.mult + tk->tkr.xtime_nsec;
+ nsec >>= tk->tkr.shift;
/* If arch requires, add in get_arch_timeoffset() */
return nsec + arch_gettimeoffset();
static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
{
- struct clocksource *clock = tk->clock;
+ struct clocksource *clock = tk->tkr.clock;
cycle_t cycle_now, delta;
s64 nsec;
/* read clocksource: */
- cycle_now = tk->read(clock);
+ cycle_now = tk->tkr.read(clock);
/* calculate the delta since the last update_wall_time: */
- delta = clocksource_delta(cycle_now, tk->cycle_last, tk->mask);
+ delta = clocksource_delta(cycle_now, tk->tkr.cycle_last, tk->tkr.mask);
/* convert delta to nanoseconds. */
nsec = clocksource_cyc2ns(delta, clock->mult, clock->shift);
struct timespec xt;
xt = tk_xtime(tk);
- update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult,
- tk->cycle_last);
+ update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->tkr.clock, tk->tkr.mult,
+ tk->tkr.cycle_last);
}
static inline void old_vsyscall_fixup(struct timekeeper *tk)
* (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
* users are removed, this can be killed.
*/
- remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
- tk->xtime_nsec -= remainder;
- tk->xtime_nsec += 1ULL << tk->shift;
+ remainder = tk->tkr.xtime_nsec & ((1ULL << tk->tkr.shift) - 1);
+ tk->tkr.xtime_nsec -= remainder;
+ tk->tkr.xtime_nsec += 1ULL << tk->tkr.shift;
tk->ntp_error += remainder << tk->ntp_error_shift;
- tk->ntp_error -= (1ULL << tk->shift) << tk->ntp_error_shift;
+ tk->ntp_error -= (1ULL << tk->tkr.shift) << tk->ntp_error_shift;
}
#else
#define old_vsyscall_fixup(tk)
nsec = (s64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec);
nsec *= NSEC_PER_SEC;
nsec += tk->wall_to_monotonic.tv_nsec;
- tk->base_mono = ns_to_ktime(nsec);
+ tk->tkr.base_mono = ns_to_ktime(nsec);
/* Update the monotonic raw base */
tk->base_raw = timespec64_to_ktime(tk->raw_time);
*/
static void timekeeping_forward_now(struct timekeeper *tk)
{
- struct clocksource *clock = tk->clock;
+ struct clocksource *clock = tk->tkr.clock;
cycle_t cycle_now, delta;
s64 nsec;
- cycle_now = tk->read(clock);
- delta = clocksource_delta(cycle_now, tk->cycle_last, tk->mask);
- tk->cycle_last = cycle_now;
+ cycle_now = tk->tkr.read(clock);
+ delta = clocksource_delta(cycle_now, tk->tkr.cycle_last, tk->tkr.mask);
+ tk->tkr.cycle_last = cycle_now;
- tk->xtime_nsec += delta * tk->mult;
+ tk->tkr.xtime_nsec += delta * tk->tkr.mult;
/* If arch requires, add in get_arch_timeoffset() */
- tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
+ tk->tkr.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr.shift;
tk_normalize_xtime(tk);
do {
seq = read_seqcount_begin(&tk_core.seq);
- base = tk->base_mono;
+ base = tk->tkr.base_mono;
nsecs = timekeeping_get_ns(tk);
} while (read_seqcount_retry(&tk_core.seq, seq));
do {
seq = read_seqcount_begin(&tk_core.seq);
- base = ktime_add(tk->base_mono, *offset);
+ base = ktime_add(tk->tkr.base_mono, *offset);
nsecs = timekeeping_get_ns(tk);
} while (read_seqcount_retry(&tk_core.seq, seq));
*/
if (try_module_get(new->owner)) {
if (!new->enable || new->enable(new) == 0) {
- old = tk->clock;
+ old = tk->tkr.clock;
tk_setup_internals(tk, new);
if (old->disable)
old->disable(old);
{
struct timekeeper *tk = &tk_core.timekeeper;
- if (tk->clock == clock)
+ if (tk->tkr.clock == clock)
return 0;
stop_machine(change_clocksource, clock, NULL);
tick_clock_notify();
- return tk->clock == clock ? 0 : -1;
+ return tk->tkr.clock == clock ? 0 : -1;
}
/**
do {
seq = read_seqcount_begin(&tk_core.seq);
- ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+ ret = tk->tkr.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
} while (read_seqcount_retry(&tk_core.seq, seq));
do {
seq = read_seqcount_begin(&tk_core.seq);
- ret = tk->clock->max_idle_ns;
+ ret = tk->tkr.clock->max_idle_ns;
} while (read_seqcount_retry(&tk_core.seq, seq));
static void timekeeping_resume(void)
{
struct timekeeper *tk = &tk_core.timekeeper;
- struct clocksource *clock = tk->clock;
+ struct clocksource *clock = tk->tkr.clock;
unsigned long flags;
struct timespec64 ts_new, ts_delta;
struct timespec tmp;
* The less preferred source will only be tried if there is no better
* usable source. The rtc part is handled separately in rtc core code.
*/
- cycle_now = tk->read(clock);
+ cycle_now = tk->tkr.read(clock);
if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
- cycle_now > tk->cycle_last) {
+ cycle_now > tk->tkr.cycle_last) {
u64 num, max = ULLONG_MAX;
u32 mult = clock->mult;
u32 shift = clock->shift;
s64 nsec = 0;
- cycle_delta = clocksource_delta(cycle_now, tk->cycle_last,
- tk->mask);
+ cycle_delta = clocksource_delta(cycle_now, tk->tkr.cycle_last,
+ tk->tkr.mask);
/*
* "cycle_delta * mutl" may cause 64 bits overflow, if the
__timekeeping_inject_sleeptime(tk, &ts_delta);
/* Re-base the last cycle value */
- tk->cycle_last = cycle_now;
+ tk->tkr.cycle_last = cycle_now;
tk->ntp_error = 0;
timekeeping_suspended = 0;
timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
}
}
- if (unlikely(tk->clock->maxadj &&
- (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) {
+ if (unlikely(tk->tkr.clock->maxadj &&
+ (tk->tkr.mult + adj > tk->tkr.clock->mult + tk->tkr.clock->maxadj))) {
printk_deferred_once(KERN_WARNING
"Adjusting %s more than 11%% (%ld vs %ld)\n",
- tk->clock->name, (long)tk->mult + adj,
- (long)tk->clock->mult + tk->clock->maxadj);
+ tk->tkr.clock->name, (long)tk->tkr.mult + adj,
+ (long)tk->tkr.clock->mult + tk->tkr.clock->maxadj);
}
/*
* So the following can be confusing.
*
* XXX - TODO: Doc ntp_error calculation.
*/
- tk->mult += adj;
+ tk->tkr.mult += adj;
tk->xtime_interval += interval;
- tk->xtime_nsec -= offset;
+ tk->tkr.xtime_nsec -= offset;
tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
out_adjust:
* We'll correct this error next time through this function, when
* xtime_nsec is not as small.
*/
- if (unlikely((s64)tk->xtime_nsec < 0)) {
- s64 neg = -(s64)tk->xtime_nsec;
- tk->xtime_nsec = 0;
+ if (unlikely((s64)tk->tkr.xtime_nsec < 0)) {
+ s64 neg = -(s64)tk->tkr.xtime_nsec;
+ tk->tkr.xtime_nsec = 0;
tk->ntp_error += neg << tk->ntp_error_shift;
}
*/
static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
{
- u64 nsecps = (u64)NSEC_PER_SEC << tk->shift;
+ u64 nsecps = (u64)NSEC_PER_SEC << tk->tkr.shift;
unsigned int clock_set = 0;
- while (tk->xtime_nsec >= nsecps) {
+ while (tk->tkr.xtime_nsec >= nsecps) {
int leap;
- tk->xtime_nsec -= nsecps;
+ tk->tkr.xtime_nsec -= nsecps;
tk->xtime_sec++;
/* Figure out if its a leap sec and apply if needed */
/* Accumulate one shifted interval */
offset -= interval;
- tk->cycle_last += interval;
+ tk->tkr.cycle_last += interval;
- tk->xtime_nsec += tk->xtime_interval << shift;
+ tk->tkr.xtime_nsec += tk->xtime_interval << shift;
*clock_set |= accumulate_nsecs_to_secs(tk);
/* Accumulate raw time */
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
offset = real_tk->cycle_interval;
#else
- offset = clocksource_delta(tk->read(tk->clock), tk->cycle_last,
- tk->mask);
+ offset = clocksource_delta(tk->tkr.read(tk->tkr.clock),
+ tk->tkr.cycle_last, tk->tkr.mask);
#endif
/* Check if there's really nothing to do */
do {
seq = read_seqcount_begin(&tk_core.seq);
- base = tk->base_mono;
- nsecs = tk->xtime_nsec >> tk->shift;
+ base = tk->tkr.base_mono;
+ nsecs = tk->tkr.xtime_nsec >> tk->tkr.shift;
*offs_real = tk->offs_real;
*offs_boot = tk->offs_boot;
do {
seq = read_seqcount_begin(&tk_core.seq);
- base = tk->base_mono;
+ base = tk->tkr.base_mono;
nsecs = timekeeping_get_ns(tk);
*offs_real = tk->offs_real;
projects / users / dwmw2 / linux.git / commitdiff