Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "The time/timekeeping/timer folks deliver with this update:

   - Fix a reintroduced signed/unsigned issue and cleanup the whole
     signed/unsigned mess in the timekeeping core so this wont happen
     accidentaly again.

   - Add a new trace clock based on boot time

   - Prevent injection of random sleep times when PM tracing abuses the
     RTC for storage

   - Make posix timers configurable for real tiny systems

   - Add tracepoints for the alarm timer subsystem so timer based
     suspend wakeups can be instrumented

   - The usual pile of fixes and updates to core and drivers"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  timekeeping: Use mul_u64_u32_shr() instead of open coding it
  timekeeping: Get rid of pointless typecasts
  timekeeping: Make the conversion call chain consistently unsigned
  timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion
  alarmtimer: Add tracepoints for alarm timers
  trace: Update documentation for mono, mono_raw and boot clock
  trace: Add an option for boot clock as trace clock
  timekeeping: Add a fast and NMI safe boot clock
  timekeeping/clocksource_cyc2ns: Document intended range limitation
  timekeeping: Ignore the bogus sleep time if pm_trace is enabled
  selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous"
  clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap
  clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()
  arm64: dts: rockchip: Arch counter doesn't tick in system suspend
  clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend
  posix-timers: Make them configurable
  posix_cpu_timers: Move the add_device_randomness() call to a proper place
  timer: Move sys_alarm from timer.c to itimer.c
  ptp_clock: Allow for it to be optional
  Kconfig: Regenerate *.c_shipped files after previous changes
  ...

1 files changed, 51 insertions, 39 deletions

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 37dec7e3db43..da233cdf89b0 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -258,10 +258,9 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
 	tk->cycle_interval = interval;
 
 	/* Go back from cycles -> shifted ns */
-	tk->xtime_interval = (u64) interval * clock->mult;
+	tk->xtime_interval = interval * clock->mult;
 	tk->xtime_remainder = ntpinterval - tk->xtime_interval;
-	tk->raw_interval =
-		((u64) interval * clock->mult) >> clock->shift;
+	tk->raw_interval = (interval * clock->mult) >> clock->shift;
 
 	 /* if changing clocks, convert xtime_nsec shift units */
 	if (old_clock) {
@@ -299,10 +298,10 @@ u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
 static inline u32 arch_gettimeoffset(void) { return 0; }
 #endif
 
-static inline s64 timekeeping_delta_to_ns(struct tk_read_base *tkr,
+static inline u64 timekeeping_delta_to_ns(struct tk_read_base *tkr,
 					  cycle_t delta)
 {
-	s64 nsec;
+	u64 nsec;
 
 	nsec = delta * tkr->mult + tkr->xtime_nsec;
 	nsec >>= tkr->shift;
@@ -311,7 +310,7 @@ static inline s64 timekeeping_delta_to_ns(struct tk_read_base *tkr,
 	return nsec + arch_gettimeoffset();
 }
 
-static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
+static inline u64 timekeeping_get_ns(struct tk_read_base *tkr)
 {
 	cycle_t delta;
 
@@ -319,8 +318,8 @@ static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
 	return timekeeping_delta_to_ns(tkr, delta);
 }
 
-static inline s64 timekeeping_cycles_to_ns(struct tk_read_base *tkr,
-					    cycle_t cycles)
+static inline u64 timekeeping_cycles_to_ns(struct tk_read_base *tkr,
+					   cycle_t cycles)
 {
 	cycle_t delta;
 
@@ -425,6 +424,35 @@ u64 ktime_get_raw_fast_ns(void)
 }
 EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
 
+/**
+ * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock.
+ *
+ * To keep it NMI safe since we're accessing from tracing, we're not using a
+ * separate timekeeper with updates to monotonic clock and boot offset
+ * protected with seqlocks. This has the following minor side effects:
+ *
+ * (1) Its possible that a timestamp be taken after the boot offset is updated
+ * but before the timekeeper is updated. If this happens, the new boot offset
+ * is added to the old timekeeping making the clock appear to update slightly
+ * earlier:
+ *    CPU 0                                        CPU 1
+ *    timekeeping_inject_sleeptime64()
+ *    __timekeeping_inject_sleeptime(tk, delta);
+ *                                                 timestamp();
+ *    timekeeping_update(tk, TK_CLEAR_NTP...);
+ *
+ * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
+ * partially updated.  Since the tk->offs_boot update is a rare event, this
+ * should be a rare occurrence which postprocessing should be able to handle.
+ */
+u64 notrace ktime_get_boot_fast_ns(void)
+{
+	struct timekeeper *tk = &tk_core.timekeeper;
+
+	return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot));
+}
+EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns);
+
 /* Suspend-time cycles value for halted fast timekeeper. */
 static cycle_t cycles_at_suspend;
 
@@ -623,7 +651,7 @@ static void timekeeping_forward_now(struct timekeeper *tk)
 {
 	struct clocksource *clock = tk->tkr_mono.clock;
 	cycle_t cycle_now, delta;
-	s64 nsec;
+	u64 nsec;
 
 	cycle_now = tk->tkr_mono.read(clock);
 	delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
@@ -652,7 +680,7 @@ int __getnstimeofday64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned long seq;
-	s64 nsecs = 0;
+	u64 nsecs;
 
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
@@ -692,7 +720,7 @@ ktime_t ktime_get(void)
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned int seq;
 	ktime_t base;
-	s64 nsecs;
+	u64 nsecs;
 
 	WARN_ON(timekeeping_suspended);
 
@@ -735,7 +763,7 @@ ktime_t ktime_get_with_offset(enum tk_offsets offs)
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned int seq;
 	ktime_t base, *offset = offsets[offs];
-	s64 nsecs;
+	u64 nsecs;
 
 	WARN_ON(timekeeping_suspended);
 
@@ -779,7 +807,7 @@ ktime_t ktime_get_raw(void)
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned int seq;
 	ktime_t base;
-	s64 nsecs;
+	u64 nsecs;
 
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
@@ -804,8 +832,8 @@ void ktime_get_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	struct timespec64 tomono;
-	s64 nsec;
 	unsigned int seq;
+	u64 nsec;
 
 	WARN_ON(timekeeping_suspended);
 
@@ -893,8 +921,8 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
 	unsigned long seq;
 	ktime_t base_raw;
 	ktime_t base_real;
-	s64 nsec_raw;
-	s64 nsec_real;
+	u64 nsec_raw;
+	u64 nsec_real;
 	cycle_t now;
 
 	WARN_ON_ONCE(timekeeping_suspended);
@@ -1052,7 +1080,7 @@ int get_device_system_crosststamp(int (*get_time_fn)
 	cycle_t cycles, now, interval_start;
 	unsigned int clock_was_set_seq = 0;
 	ktime_t base_real, base_raw;
-	s64 nsec_real, nsec_raw;
+	u64 nsec_real, nsec_raw;
 	u8 cs_was_changed_seq;
 	unsigned long seq;
 	bool do_interp;
@@ -1365,7 +1393,7 @@ void getrawmonotonic64(struct timespec64 *ts)
 	struct timekeeper *tk = &tk_core.timekeeper;
 	struct timespec64 ts64;
 	unsigned long seq;
-	s64 nsecs;
+	u64 nsecs;
 
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
@@ -1616,7 +1644,7 @@ void timekeeping_resume(void)
 	struct clocksource *clock = tk->tkr_mono.clock;
 	unsigned long flags;
 	struct timespec64 ts_new, ts_delta;
-	cycle_t cycle_now, cycle_delta;
+	cycle_t cycle_now;
 
 	sleeptime_injected = false;
 	read_persistent_clock64(&ts_new);
@@ -1642,27 +1670,11 @@ void timekeeping_resume(void)
 	cycle_now = tk->tkr_mono.read(clock);
 	if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
 		cycle_now > tk->tkr_mono.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->tkr_mono.cycle_last,
-						tk->tkr_mono.mask);
-
-		/*
-		 * "cycle_delta * mutl" may cause 64 bits overflow, if the
-		 * suspended time is too long. In that case we need do the
-		 * 64 bits math carefully
-		 */
-		do_div(max, mult);
-		if (cycle_delta > max) {
-			num = div64_u64(cycle_delta, max);
-			nsec = (((u64) max * mult) >> shift) * num;
-			cycle_delta -= num * max;
-		}
-		nsec += ((u64) cycle_delta * mult) >> shift;
+		u64 nsec, cyc_delta;
 
+		cyc_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last,
+					      tk->tkr_mono.mask);
+		nsec = mul_u64_u32_shr(cyc_delta, clock->mult, clock->shift);
 		ts_delta = ns_to_timespec64(nsec);
 		sleeptime_injected = true;
 	} else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) {