introduce "cpu_rnd_messybits" for use instead of nanotime in dev/rnd.c.

rnd.c uses nanotime to get access to some bits that change quickly
between events that it can mix into the entropy pool. it doesn't
use nanotime to get a monotonically increasing set or ordered and
accurate timestamps, it just wants something with bits that change.

there's been discussions for years about letting rnd use a clock
that's super fast to read, but not necessarily accurate, but it
wasn't until recently that i figured out it wasn't interested in
time at all, so things like keeping a fast clock coherent between
cpu cores or correct according to ntp is unecessary. this means we
can just let rnd read the cycle counters on cpus and things will
be fine.  cpus with cycle counters that vary in their speed and
arent kept consistent between cores may even be desirable in this
context.

so this is the first step in converting rnd.c to reading cycle
counter. it copies the nanotime backend to each arch, and they can
replace it with something MD as a second step later on.

djm@ suggested rnd_messybytes, but we landed on cpu_rnd_messybits.
thanks to visa for his eyes.
ok deraadt@ visa@
deraadt@ says he will help handle any MD fallout that occurs.

27 files changed, 175 insertions, 29 deletions

diff --git a/sys/arch/alpha/alpha/machdep.c b/sys/arch/alpha/alpha/machdep.c
index e7e3bcfcd36..09dc7e9cba5 100644
--- a/sys/arch/alpha/alpha/machdep.c
+++ b/sys/arch/alpha/alpha/machdep.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: machdep.c,v 1.190 2020/05/25 15:00:22 deraadt Exp $ */
+/* $OpenBSD: machdep.c,v 1.191 2020/05/31 06:23:56 dlg Exp $ */
 /* $NetBSD: machdep.c,v 1.210 2000/06/01 17:12:38 thorpej Exp $ */
 
 /*-
@@ -1854,3 +1854,12 @@ alpha_XXX_dmamap(v)						/* XXX */
 	return (vtophys(v) | alpha_XXX_dmamap_or);		/* XXX */
 }								/* XXX */
 /* XXX XXX END XXX XXX */
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/alpha/include/cpu.h b/sys/arch/alpha/include/cpu.h
index 4a67099a8d5..5c06ad3aa15 100644
--- a/sys/arch/alpha/include/cpu.h
+++ b/sys/arch/alpha/include/cpu.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: cpu.h,v 1.61 2019/03/24 06:19:26 visa Exp $ */
+/* $OpenBSD: cpu.h,v 1.62 2020/05/31 06:23:56 dlg Exp $ */
 /* $NetBSD: cpu.h,v 1.45 2000/08/21 02:03:12 thorpej Exp $ */
 
 /*-
@@ -288,6 +288,8 @@ do {									\
  */
 #define	cpu_number()		alpha_pal_whami()
 
+unsigned int cpu_rnd_messybits(void);
+
 /*
  * Arguments to hardclock and gatherstats encapsulate the previous
  * machine state in an opaque clockframe.  On the Alpha, we use
diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c
index de97b6c74f4..fe16af19570 100644
--- a/sys/arch/amd64/amd64/machdep.c
+++ b/sys/arch/amd64/amd64/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.265 2020/05/28 15:06:36 yasuoka Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.266 2020/05/31 06:23:56 dlg Exp $	*/
 /*	$NetBSD: machdep.c,v 1.3 2003/05/07 22:58:18 fvdl Exp $	*/
 
 /*-
@@ -2055,3 +2055,12 @@ check_context(const struct reg *regs, struct trapframe *tf)
 
 	return 0;
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/amd64/include/cpu.h b/sys/arch/amd64/include/cpu.h
index 0c96b8abde8..95f715d5e0f 100644
--- a/sys/arch/amd64/include/cpu.h
+++ b/sys/arch/amd64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.135 2020/04/28 12:58:28 kettenis Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.136 2020/05/31 06:23:56 dlg Exp $	*/
 /*	$NetBSD: cpu.h,v 1.1 2003/04/26 18:39:39 fvdl Exp $	*/
 
 /*-
@@ -304,6 +304,8 @@ void cpu_unidle(struct cpu_info *);
 #include <machine/cpufunc.h>
 #include <machine/psl.h>
 
+unsigned int cpu_rnd_messybits(void);
+
 #endif /* _KERNEL */
 
 #ifdef MULTIPROCESSOR
diff --git a/sys/arch/arm/include/cpu.h b/sys/arch/arm/include/cpu.h
index c4d47ec0e18..118381e7fc7 100644
--- a/sys/arch/arm/include/cpu.h
+++ b/sys/arch/arm/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.58 2020/05/17 15:36:50 kettenis Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.59 2020/05/31 06:23:57 dlg Exp $	*/
 /*	$NetBSD: cpu.h,v 1.34 2003/06/23 11:01:08 martin Exp $	*/
 
 /*
@@ -249,6 +249,8 @@ void cpu_boot_secondary_processors(void);
 
 #define curpcb		curcpu()->ci_curpcb
 
+unsigned int cpu_rnd_messybits(void);
+
 /*
  * Scheduling glue
  */
diff --git a/sys/arch/arm64/arm64/machdep.c b/sys/arch/arm64/arm64/machdep.c
index 93e0f973b62..4e292479233 100644
--- a/sys/arch/arm64/arm64/machdep.c
+++ b/sys/arch/arm64/arm64/machdep.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: machdep.c,v 1.51 2020/05/23 19:54:12 kettenis Exp $ */
+/* $OpenBSD: machdep.c,v 1.52 2020/05/31 06:23:57 dlg Exp $ */
 /*
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
  *
@@ -1247,3 +1247,12 @@ dumpregs(struct trapframe *frame)
 	printf("pc: 0x%016lx\n", frame->tf_elr);
 	printf("spsr: 0x%016lx\n", frame->tf_spsr);
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/arm64/include/cpu.h b/sys/arch/arm64/include/cpu.h
index 6f1da4c0720..099567d225c 100644
--- a/sys/arch/arm64/include/cpu.h
+++ b/sys/arch/arm64/include/cpu.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: cpu.h,v 1.16 2020/05/17 13:36:33 kettenis Exp $ */
+/* $OpenBSD: cpu.h,v 1.17 2020/05/31 06:23:57 dlg Exp $ */
 /*
  * Copyright (c) 2016 Dale Rahn <drahn@dalerahn.com>
  *
@@ -183,6 +183,8 @@ void cpu_boot_secondary_processors(void);
 
 #define curpcb		curcpu()->ci_curpcb
 
+unsigned int		cpu_rnd_messybits(void);
+
 /*
  * Scheduling glue
  */
diff --git a/sys/arch/armv7/armv7/armv7_machdep.c b/sys/arch/armv7/armv7/armv7_machdep.c
index 81b6e72019f..1a5418cbf58 100644
--- a/sys/arch/armv7/armv7/armv7_machdep.c
+++ b/sys/arch/armv7/armv7/armv7_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: armv7_machdep.c,v 1.60 2020/05/23 20:32:47 kettenis Exp $ */
+/*	$OpenBSD: armv7_machdep.c,v 1.61 2020/05/31 06:23:57 dlg Exp $ */
 /*	$NetBSD: lubbock_machdep.c,v 1.2 2003/07/15 00:25:06 lukem Exp $ */
 
 /*
@@ -1013,3 +1013,12 @@ board_startup(void)
 #endif
 	}
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/hppa/hppa/machdep.c b/sys/arch/hppa/hppa/machdep.c
index 8c7d053ee51..f7bb998d53e 100644
--- a/sys/arch/hppa/hppa/machdep.c
+++ b/sys/arch/hppa/hppa/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.258 2020/05/16 14:44:44 kettenis Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.259 2020/05/31 06:23:57 dlg Exp $	*/
 
 /*
  * Copyright (c) 1999-2003 Michael Shalayeff
@@ -1496,3 +1496,12 @@ blink_led_timeout(void *vsc)
 	t = (((averunnable.ldavg[0] + FSCALE) * hz) >> (FSHIFT + 1));
 	timeout_add(&sc->bls_to, t);
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/hppa/include/cpu.h b/sys/arch/hppa/include/cpu.h
index 934be69ea1b..902b10e8d6b 100644
--- a/sys/arch/hppa/include/cpu.h
+++ b/sys/arch/hppa/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.91 2018/12/05 10:28:21 jsg Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.92 2020/05/31 06:23:57 dlg Exp $	*/
 
 /*
  * Copyright (c) 2000-2004 Michael Shalayeff
@@ -237,6 +237,7 @@ int	copy_on_fault(void);
 void	switch_trampoline(void);
 int	cpu_dumpsize(void);
 int	cpu_dump(void);
+unsigned int cpu_rnd_messybits(void);
 
 #ifdef MULTIPROCESSOR
 void	cpu_boot_secondary_processors(void);
diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index fe97bd1c047..0d392c75802 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.635 2020/05/29 04:42:23 deraadt Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.636 2020/05/31 06:23:57 dlg Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -4038,3 +4038,12 @@ intr_barrier(void *ih)
 {
 	sched_barrier(NULL);
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/i386/include/cpu.h b/sys/arch/i386/include/cpu.h
index 63e5e840e96..ec4f2e432e7 100644
--- a/sys/arch/i386/include/cpu.h
+++ b/sys/arch/i386/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.169 2020/04/29 08:53:45 kettenis Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.170 2020/05/31 06:23:57 dlg Exp $	*/
 /*	$NetBSD: cpu.h,v 1.35 1996/05/05 19:29:26 christos Exp $	*/
 
 /*-
@@ -267,6 +267,8 @@ void cpu_unidle(struct cpu_info *);
 
 #define want_resched (curcpu()->ci_want_resched)
 
+unsigned int cpu_rnd_messybits(void);
+
 /*
  * Preempt the current process if in interrupt from user mode,
  * or after the current trap/syscall if in system mode.
diff --git a/sys/arch/landisk/landisk/machdep.c b/sys/arch/landisk/landisk/machdep.c
index 48de8c85ee4..d5ea8df1740 100644
--- a/sys/arch/landisk/landisk/machdep.c
+++ b/sys/arch/landisk/landisk/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.47 2019/04/01 07:00:52 tedu Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.48 2020/05/31 06:23:57 dlg Exp $	*/
 /*	$NetBSD: machdep.c,v 1.1 2006/09/01 21:26:18 uwe Exp $	*/
 
 /*-
@@ -509,3 +509,12 @@ blink_led(void *whatever)
 	timeout_add(&blink_tmo,
 	    ((averunnable.ldavg[0] + FSCALE) * hz) >> FSHIFT);
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/loongson/loongson/machdep.c b/sys/arch/loongson/loongson/machdep.c
index 53a1c403ea6..aaceb54bea8 100644
--- a/sys/arch/loongson/loongson/machdep.c
+++ b/sys/arch/loongson/loongson/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.87 2019/04/01 07:02:04 tedu Exp $ */
+/*	$OpenBSD: machdep.c,v 1.88 2020/05/31 06:23:57 dlg Exp $ */
 
 /*
  * Copyright (c) 2009, 2010, 2014 Miodrag Vallat.
@@ -1354,3 +1354,12 @@ hw_ipi_intr_clear(u_long cpuid)
 }
 
 #endif /* MULTIPROCESSOR */
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/luna88k/luna88k/machdep.c b/sys/arch/luna88k/luna88k/machdep.c
index c0f11bfcc9b..9501ad85210 100644
--- a/sys/arch/luna88k/luna88k/machdep.c
+++ b/sys/arch/luna88k/luna88k/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.133 2020/05/29 04:42:24 deraadt Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.134 2020/05/31 06:23:57 dlg Exp $	*/
 /*
  * Copyright (c) 1998, 1999, 2000, 2001 Steve Murphree, Jr.
  * Copyright (c) 1996 Nivas Madhur
@@ -1355,3 +1355,12 @@ m88k_broadcast_ipi(int ipi)
 	}
 }
 #endif
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/m88k/include/cpu.h b/sys/arch/m88k/include/cpu.h
index f6ee4eb5541..48e6d36e1d4 100644
--- a/sys/arch/m88k/include/cpu.h
+++ b/sys/arch/m88k/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.67 2019/08/28 13:48:40 aoyama Exp $ */
+/*	$OpenBSD: cpu.h,v 1.68 2020/05/31 06:23:57 dlg Exp $ */
 /*
  * Copyright (c) 1996 Nivas Madhur
  * Copyright (c) 1992, 1993
@@ -229,6 +229,8 @@ struct cpu_info *set_cpu_number(cpuid_t);
 
 #define	curpcb			curcpu()->ci_curpcb
 
+unsigned int cpu_rnd_messybits(void);
+
 #endif /* _LOCORE */
 
 /*
diff --git a/sys/arch/macppc/macppc/machdep.c b/sys/arch/macppc/macppc/machdep.c
index ee394d305e8..178fe0995da 100644
--- a/sys/arch/macppc/macppc/machdep.c
+++ b/sys/arch/macppc/macppc/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.190 2020/05/25 15:10:18 deraadt Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.191 2020/05/31 06:23:57 dlg Exp $	*/
 /*	$NetBSD: machdep.c,v 1.4 1996/10/16 19:33:11 ws Exp $	*/
 
 /*
@@ -913,3 +913,12 @@ cpu_switchto(struct proc *oldproc, struct proc *newproc)
 
 	cpu_switchto_asm(oldproc, newproc);
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/mips64/include/cpu.h b/sys/arch/mips64/include/cpu.h
index 40e1f59a39f..6614cf9c321 100644
--- a/sys/arch/mips64/include/cpu.h
+++ b/sys/arch/mips64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.128 2019/09/02 02:35:08 deraadt Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.129 2020/05/31 06:23:58 dlg Exp $	*/
 
 /*-
  * Copyright (c) 1992, 1993
@@ -277,6 +277,8 @@ void	smp_rendezvous_cpus(unsigned long, void (*)(void *), void *arg);
 extern void (*md_startclock)(struct cpu_info *);
 void	cp0_calibrate(struct cpu_info *);
 
+unsigned int cpu_rnd_messybits(void);
+
 #include <machine/frame.h>
 
 /*
diff --git a/sys/arch/octeon/octeon/machdep.c b/sys/arch/octeon/octeon/machdep.c
index 7b4875ca680..1387af284ca 100644
--- a/sys/arch/octeon/octeon/machdep.c
+++ b/sys/arch/octeon/octeon/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.122 2020/05/29 04:42:24 deraadt Exp $ */
+/*	$OpenBSD: machdep.c,v 1.123 2020/05/31 06:23:58 dlg Exp $ */
 
 /*
  * Copyright (c) 2009, 2010 Miodrag Vallat.
@@ -1247,3 +1247,12 @@ hw_cpu_hatch(struct cpu_info *ci)
 	cpu_switchto(NULL, sched_chooseproc());
 }
 #endif /* MULTIPROCESSOR */
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/powerpc/include/cpu.h b/sys/arch/powerpc/include/cpu.h
index 65d3625d692..cc3dcd16aa6 100644
--- a/sys/arch/powerpc/include/cpu.h
+++ b/sys/arch/powerpc/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.66 2020/03/17 10:14:45 kettenis Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.67 2020/05/31 06:23:58 dlg Exp $	*/
 /*	$NetBSD: cpu.h,v 1.1 1996/09/30 16:34:21 ws Exp $	*/
 
 /*
@@ -161,6 +161,8 @@ extern int ppc_nobat;
 
 void	cpu_bootstrap(void);
 
+unsigned int cpu_rnd_messybits(void);
+
 /*
  * This is used during profiling to integrate system time.
  */
diff --git a/sys/arch/powerpc64/include/cpu.h b/sys/arch/powerpc64/include/cpu.h
index 30efd9f46ad..86713353383 100644
--- a/sys/arch/powerpc64/include/cpu.h
+++ b/sys/arch/powerpc64/include/cpu.h
@@ -51,6 +51,8 @@ register struct cpu_info *__curcpu asm("r13");
 #define CPU_BUSY_CYCLE()	do {} while (0)
 #define signotify(p)		setsoftast()
 
+unsigned int cpu_rnd_messybits(void);
+
 void need_resched(struct cpu_info *);
 #define clear_resched(ci)	((ci)->ci_want_resched = 0)
 
diff --git a/sys/arch/powerpc64/powerpc64/machdep.c b/sys/arch/powerpc64/powerpc64/machdep.c
index d7677469bbc..bae64a1f297 100644
--- a/sys/arch/powerpc64/powerpc64/machdep.c
+++ b/sys/arch/powerpc64/powerpc64/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.10 2020/05/27 22:22:04 gkoehler Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.11 2020/05/31 06:23:58 dlg Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -460,3 +460,12 @@ boot(int howto)
 		continue;
 	/* NOTREACHED */
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/sgi/sgi/machdep.c b/sys/arch/sgi/sgi/machdep.c
index 2cd4e1ead57..d251c15fc01 100644
--- a/sys/arch/sgi/sgi/machdep.c
+++ b/sys/arch/sgi/sgi/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.161 2019/12/20 13:34:41 visa Exp $ */
+/*	$OpenBSD: machdep.c,v 1.162 2020/05/31 06:23:58 dlg Exp $ */
 
 /*
  * Copyright (c) 2003-2004 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -1017,3 +1017,12 @@ intr_barrier(void *cookie)
 {
 	sched_barrier(NULL);
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/arch/sh/include/cpu.h b/sys/arch/sh/include/cpu.h
index c548e265e74..04384bbe847 100644
--- a/sys/arch/sh/include/cpu.h
+++ b/sys/arch/sh/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.28 2019/03/24 06:09:09 visa Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.29 2020/05/31 06:23:58 dlg Exp $	*/
 /*	$NetBSD: cpu.h,v 1.41 2006/01/21 04:24:12 uwe Exp $	*/
 
 /*-
@@ -271,6 +271,7 @@ u_int cpu_dump(int (*)(dev_t, daddr_t, caddr_t, size_t), daddr_t *);
 u_int cpu_dumpsize(void);
 void dumpconf(void);
 void dumpsys(void);
+unsigned int cpu_rnd_messybits(void);
 
 static inline u_long
 intr_disable(void)
diff --git a/sys/arch/sparc64/include/cpu.h b/sys/arch/sparc64/include/cpu.h
index c61fb5d3c9e..d3873dc821d 100644
--- a/sys/arch/sparc64/include/cpu.h
+++ b/sys/arch/sparc64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.93 2018/12/05 10:28:21 jsg Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.94 2020/05/31 06:23:58 dlg Exp $	*/
 /*	$NetBSD: cpu.h,v 1.28 2001/06/14 22:56:58 thorpej Exp $ */
 
 /*
@@ -211,6 +211,8 @@ void	cpu_unidle(struct cpu_info *);
 #define curpcb		__curcpu->ci_cpcb
 #define fpproc		__curcpu->ci_fpproc
 
+unsigned int cpu_rnd_messybits(void);
+
 /*
  * On processors with multiple threads we force a thread switch.
  *
diff --git a/sys/arch/sparc64/sparc64/machdep.c b/sys/arch/sparc64/sparc64/machdep.c
index ae4fdc94274..05aa4342943 100644
--- a/sys/arch/sparc64/sparc64/machdep.c
+++ b/sys/arch/sparc64/sparc64/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.195 2020/05/29 04:42:24 deraadt Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.196 2020/05/31 06:23:58 dlg Exp $	*/
 /*	$NetBSD: machdep.c,v 1.108 2001/07/24 19:30:14 eeh Exp $ */
 
 /*-
@@ -2114,3 +2114,12 @@ blink_led_timeout(void *vsc)
 	t = (((averunnable.ldavg[0] + FSCALE) * hz) >> (FSHIFT + 1));
 	timeout_add(&sc->bls_to, t);
 }
+
+unsigned int
+cpu_rnd_messybits(void)
+{
+	struct timespec ts;
+
+	nanotime(&ts);
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
diff --git a/sys/dev/rnd.c b/sys/dev/rnd.c
index 8802965514a..ae68999910c 100644
--- a/sys/dev/rnd.c
+++ b/sys/dev/rnd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rnd.c,v 1.219 2020/05/29 04:42:24 deraadt Exp $	*/
+/*	$OpenBSD: rnd.c,v 1.220 2020/05/31 06:23:56 dlg Exp $	*/
 
 /*
  * Copyright (c) 2011 Theo de Raadt.
@@ -177,13 +177,11 @@ void
 enqueue_randomness(u_int val)
 {
 	struct rand_event *rep;
-	struct timespec	ts;
 	int e;
 
-	nanotime(&ts);
 	e = (atomic_inc_int_nv(&rnd_event_prod) - 1) & (QEVLEN-1);
 	rep = &rnd_event_space[e];
-	rep->re_time += ts.tv_nsec ^ (ts.tv_sec << 20);
+	rep->re_time += cpu_rnd_messybits();
 	rep->re_val += val;
 
 	if (rnd_cold) {