timecounter: Merge FreeBSD change r303382

Hide the boottime and bootimebin globals, provide the getboottime(9) and getboottimebin(9) KPI. Change consumers of boottime to use the KPI. The variables were renamed to avoid shadowing issues with local variables of the same name.

Issue is that boottime* should be adjusted from tc_windup(), which
requires them to be members of the timehands structure.  As a
preparation, this commit only introduces the interface.

Some uses of boottime were found doubtful, e.g. NLM uses boottime to
identify the system boot instance.  Arguably the identity should not
change on the leap second adjustment, but the commit is about the
timekeeping code and the consumers were kept bug-to-bug compatible.

Tested by:	pho (as part of the bigger patch)
Reviewed by:	jhb (same)
Discussed with:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
X-Differential revision:	https://reviews.freebsd.org/D7302

Update #3175.

3 files changed, 62 insertions, 31 deletions

diff --git a/cpukit/libcsupport/include/machine/_kernel_time.h b/cpukit/libcsupport/include/machine/_kernel_time.h
index 4eeebbadea..51fa719442 100644
--- a/cpukit/libcsupport/include/machine/_kernel_time.h
+++ b/cpukit/libcsupport/include/machine/_kernel_time.h
@@ -73,7 +73,6 @@ void	resettodr(void);
 
 #define	time_second _Timecounter_Time_second
 #define	time_uptime _Timecounter_Time_uptime
-#define	boottimebin _Timecounter_Boottimebin
 extern struct timeval boottime;
 extern struct bintime tc_tick_bt;
 extern sbintime_t tc_tick_sbt;
@@ -141,6 +140,9 @@ getsbinuptime(void)
 #define	getnanotime(_tsp) _Timecounter_Getnanotime(_tsp)
 #define	getmicrotime(_tvp) _Timecounter_Getmicrotime(_tvp)
 
+#define	getboottime(_tvp) _Timecounter_Getboottime(_tvp)
+#define	getboottimebin(_bt) _Timecounter_Getboottimebin(_bt)
+
 /* Other functions */
 int	itimerdecr(struct itimerval *itp, int usec);
 int	itimerfix(struct timeval *tv);
diff --git a/cpukit/score/include/rtems/score/timecounter.h b/cpukit/score/include/rtems/score/timecounter.h
index f7912a5fd8..1c318e2a78 100644
--- a/cpukit/score/include/rtems/score/timecounter.h
+++ b/cpukit/score/include/rtems/score/timecounter.h
@@ -154,6 +154,20 @@ void _Timecounter_Getnanouptime( struct timespec *ts );
 void _Timecounter_Getmicrouptime( struct timeval *tv );
 
 /**
+ * @brief Returns the boot time in the timeval format.
+ *
+ * @param[out] tv Returns the boot time.
+ */
+void _Timecounter_Getboottime( struct timeval *tv );
+
+/**
+ * @brief Returns the boot time in the bintime format.
+ *
+ * @param[out] tv Returns the boot time.
+ */
+void _Timecounter_Getboottimebin( struct bintime *bt );
+
+/**
  * @brief Installs the timecounter.
  *
  * The timecounter structure must contain valid values in the fields
@@ -216,13 +230,6 @@ extern volatile time_t _Timecounter_Time_second;
 extern volatile time_t _Timecounter_Time_uptime;
 
 /**
- * @brief The binary boot time.
- *
- * The boot time changes via _Timecounter_Set_clock().
- */
-extern struct bintime _Timecounter_Boottimebin;
-
-/**
  * @brief The current timecounter.
  */
 extern struct timecounter *_Timecounter;
diff --git a/cpukit/score/src/kern_tc.c b/cpukit/score/src/kern_tc.c
index 6955e84799..c157584190 100644
--- a/cpukit/score/src/kern_tc.c
+++ b/cpukit/score/src/kern_tc.c
@@ -28,11 +28,12 @@
 #define	getbintime(_bt) _Timecounter_Getbintime(_bt)
 #define	getnanotime(_tsp) _Timecounter_Getnanotime(_tsp)
 #define	getmicrotime(_tvp) _Timecounter_Getmicrotime(_tvp)
+#define	getboottime(_tvp) _Timecounter_Getboottime(_tvp)
+#define	getboottimebin(_bt) _Timecounter_Getboottimebin(_bt)
 #define	tc_init _Timecounter_Install
 #define	timecounter _Timecounter
 #define	time_second _Timecounter_Time_second
 #define	time_uptime _Timecounter_Time_uptime
-#define	boottimebin _Timecounter_Boottimebin
 #include <rtems/score/timecounterimpl.h>
 #include <rtems/score/atomic.h>
 #include <rtems/score/smp.h>
@@ -210,14 +211,14 @@ volatile time_t time_second = TOD_SECONDS_1970_THROUGH_1988;
 volatile time_t time_uptime = 1;
 
 #ifndef __rtems__
-struct bintime boottimebin;
+static struct bintime boottimebin_x;
 #else /* __rtems__ */
-struct bintime boottimebin = {
+static struct bintime boottimebin_x = {
   .sec = TOD_SECONDS_1970_THROUGH_1988 - 1
 };
 #endif /* __rtems__ */
 #ifndef __rtems__
-struct timeval boottime;
+static struct timeval boottime_x;
 static int sysctl_kern_boottime(SYSCTL_HANDLER_ARGS);
 SYSCTL_PROC(_kern, KERN_BOOTTIME, boottime, CTLTYPE_STRUCT|CTLFLAG_RD,
     NULL, 0, sysctl_kern_boottime, "S,timeval", "System boottime");
@@ -259,6 +260,10 @@ void dtrace_getnanotime(struct timespec *tsp);
 static int
 sysctl_kern_boottime(SYSCTL_HANDLER_ARGS)
 {
+	struct timeval boottime;
+
+	getboottime(&boottime);
+
 #ifndef __mips__
 #ifdef SCTL_MASK32
 	int tv[2];
@@ -266,11 +271,11 @@ sysctl_kern_boottime(SYSCTL_HANDLER_ARGS)
 	if (req->flags & SCTL_MASK32) {
 		tv[0] = boottime.tv_sec;
 		tv[1] = boottime.tv_usec;
-		return SYSCTL_OUT(req, tv, sizeof(tv));
-	} else
+		return (SYSCTL_OUT(req, tv, sizeof(tv)));
+	}
 #endif
 #endif
-		return SYSCTL_OUT(req, &boottime, sizeof(boottime));
+	return (SYSCTL_OUT(req, &boottime, sizeof(boottime)));
 }
 
 static int
@@ -353,7 +358,7 @@ fbclock_bintime(struct bintime *bt)
 {
 
 	fbclock_binuptime(bt);
-	bintime_add(bt, &boottimebin);
+	bintime_add(bt, &boottimebin_x);
 }
 
 void
@@ -428,7 +433,7 @@ fbclock_getbintime(struct bintime *bt)
 		*bt = th->th_offset;
 		atomic_thread_fence_acq();
 	} while (gen == 0 || gen != th->th_generation);
-	bintime_add(bt, &boottimebin);
+	bintime_add(bt, &boottimebin_x);
 }
 
 void
@@ -516,7 +521,7 @@ bintime(struct bintime *bt)
 {
 
 	binuptime(bt);
-	bintime_add(bt, &boottimebin);
+	bintime_add(bt, &boottimebin_x);
 }
 
 void
@@ -591,7 +596,7 @@ getbintime(struct bintime *bt)
 		*bt = th->th_offset;
 		atomic_thread_fence_acq();
 	} while (gen == 0 || gen != th->th_generation);
-	bintime_add(bt, &boottimebin);
+	bintime_add(bt, &boottimebin_x);
 }
 
 void
@@ -623,6 +628,20 @@ getmicrotime(struct timeval *tvp)
 }
 #endif /* FFCLOCK */
 
+void
+getboottime(struct timeval *boottime)
+{
+
+	*boottime = boottime_x;
+}
+
+void
+getboottimebin(struct bintime *boottimebin)
+{
+
+	*boottimebin = boottimebin_x;
+}
+
 #ifdef FFCLOCK
 /*
  * Support for feed-forward synchronization algorithms. This is heavily inspired
@@ -1246,6 +1265,7 @@ int
 sysclock_snap2bintime(struct sysclock_snap *cs, struct bintime *bt,
     int whichclock, uint32_t flags)
 {
+	struct bintime boottimebin;
 #ifdef FFCLOCK
 	struct bintime bt2;
 	uint64_t period;
@@ -1259,8 +1279,10 @@ sysclock_snap2bintime(struct sysclock_snap *cs, struct bintime *bt,
 		if (cs->delta > 0)
 			bintime_addx(bt, cs->fb_info.th_scale * cs->delta);
 
-		if ((flags & FBCLOCK_UPTIME) == 0)
+		if ((flags & FBCLOCK_UPTIME) == 0) {
+			getboottimebin(&boottimebin);
 			bintime_add(bt, &boottimebin);
+		}
 		break;
 #ifdef FFCLOCK
 	case SYSCLOCK_FFWD:
@@ -1406,10 +1428,10 @@ _Timecounter_Set_clock(const struct bintime *_bt,
 #endif /* __rtems__ */
 	binuptime(&bt2);
 	bintime_sub(&bt, &bt2);
-	bintime_add(&bt2, &boottimebin);
-	boottimebin = bt;
+	bintime_add(&bt2, &boottimebin_x);
+	boottimebin_x = bt;
 #ifndef __rtems__
-	bintime2timeval(&bt, &boottime);
+	bintime2timeval(&bt, &boottime_x);
 
 	/* XXX fiddle all the little crinkly bits around the fiords... */
 	tc_windup();
@@ -1523,7 +1545,7 @@ _Timecounter_Windup(ISR_lock_Context *lock_context)
 	 * case we missed a leap second.
 	 */
 	bt = th->th_offset;
-	bintime_add(&bt, &boottimebin);
+	bintime_add(&bt, &boottimebin_x);
 	i = bt.sec - tho->th_microtime.tv_sec;
 	if (i > LARGE_STEP)
 		i = 2;
@@ -1531,7 +1553,7 @@ _Timecounter_Windup(ISR_lock_Context *lock_context)
 		t = bt.sec;
 		ntp_update_second(&th->th_adjustment, &bt.sec);
 		if (bt.sec != t)
-			boottimebin.sec += bt.sec - t;
+			boottimebin_x.sec += bt.sec - t;
 	}
 	/* Update the UTC timestamps used by the get*() functions. */
 	/* XXX shouldn't do this here.  Should force non-`get' versions. */
@@ -1968,7 +1990,7 @@ pps_event(struct pps_state *pps, int event)
 	tcount &= pps->capth->th_counter->tc_counter_mask;
 	bt = pps->capth->th_offset;
 	bintime_addx(&bt, pps->capth->th_scale * tcount);
-	bintime_add(&bt, &boottimebin);
+	bintime_add(&bt, &boottimebin_x);
 	bintime2timespec(&bt, &ts);
 
 	/* If the timecounter was wound up underneath us, bail out. */
@@ -2080,8 +2102,8 @@ _Timecounter_Tick_simple(uint32_t delta, uint32_t offset,
 	bintime_addx(&th->th_offset, th->th_scale * delta);
 
 	bt = th->th_offset;
-	bintime_add(&bt, &boottimebin);
-
+	th->th_bintime = bt;
+	bintime_add(&th->th_bintime, &th->th_boottime);
 	/* Update the UTC timestamps used by the get*() functions. */
 	/* XXX shouldn't do this here.  Should force non-`get' versions. */
 	bintime2timeval(&bt, &th->th_microtime);
@@ -2356,7 +2378,7 @@ tc_fill_vdso_timehands(struct vdso_timehands *vdso_th)
 	vdso_th->th_offset_count = th->th_offset_count;
 	vdso_th->th_counter_mask = th->th_counter->tc_counter_mask;
 	vdso_th->th_offset = th->th_offset;
-	vdso_th->th_boottime = boottimebin;
+	vdso_th->th_boottime = boottimebin_x;
 	enabled = cpu_fill_vdso_timehands(vdso_th, th->th_counter);
 	if (!vdso_th_enable)
 		enabled = 0;
@@ -2378,8 +2400,8 @@ tc_fill_vdso_timehands32(struct vdso_timehands32 *vdso_th32)
 	vdso_th32->th_counter_mask = th->th_counter->tc_counter_mask;
 	vdso_th32->th_offset.sec = th->th_offset.sec;
 	*(uint64_t *)&vdso_th32->th_offset.frac[0] = th->th_offset.frac;
-	vdso_th32->th_boottime.sec = boottimebin.sec;
-	*(uint64_t *)&vdso_th32->th_boottime.frac[0] = boottimebin.frac;
+	vdso_th32->th_boottime.sec = boottimebin_x.sec;
+	*(uint64_t *)&vdso_th32->th_boottime.frac[0] = boottimebin_x.frac;
 	enabled = cpu_fill_vdso_timehands32(vdso_th32, th->th_counter);
 	if (!vdso_th_enable)
 		enabled = 0;