Index: dev/rnd.c
===================================================================
RCS file: /cvs/src/sys/dev/rnd.c,v
retrieving revision 1.215
diff -u -p -r1.215 rnd.c
--- dev/rnd.c	25 May 2020 17:52:57 -0000	1.215
+++ dev/rnd.c	25 May 2020 22:20:44 -0000
@@ -155,6 +155,18 @@ int	filt_randomwrite(struct knote *, lon
 static void _rs_seed(u_char *, size_t);
 static void _rs_clearseed(const void *p, size_t s);
 
+#ifndef cpu_rnd_cycles
+static inline unsigned int
+cpu_rnd_cycles(void)
+{
+	struct timespec	ts;
+
+	nanotime(&ts);
+
+	return (ts.tv_nsec ^ (ts.tv_sec << 20));
+}
+#endif
+
 const struct filterops randomread_filtops = {
 	.f_flags	= FILTEROP_ISFD,
 	.f_attach	= NULL,
@@ -206,16 +218,14 @@ void
 enqueue_randomness(u_int val)
 {
 	struct rand_event *rep;
-	struct timespec	ts;
+	unsigned int cycles;
 	u_int qlen;
 
-	timespecclear(&ts);
-	if (timeout_initialized(&rnd_timeout))
-		nanotime(&ts);
+	cycles = cpu_rnd_cycles();
 
 	mtx_enter(&rnd_enqlck);
 	rep = rnd_put();
-	rep->re_time += ts.tv_nsec ^ (ts.tv_sec << 20);
+	rep->re_time += cycles;
 	rep->re_val += val;
 	qlen = rnd_qlen();
 	mtx_leave(&rnd_enqlck);
Index: arch/amd64/include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/amd64/include/cpu.h,v
retrieving revision 1.135
diff -u -p -r1.135 cpu.h
--- arch/amd64/include/cpu.h	28 Apr 2020 12:58:28 -0000	1.135
+++ arch/amd64/include/cpu.h	25 May 2020 22:20:44 -0000
@@ -314,6 +314,18 @@ void cpu_unidle(struct cpu_info *);
 
 #define curpcb		curcpu()->ci_curpcb
 
+static inline unsigned int
+__cpu_rnd_cycles(void)
+{
+	unsigned int hi, lo;
+
+	__asm volatile("rdtsc" : "=d" (hi), "=a" (lo));
+
+        return (hi ^ lo);
+}
+
+#define cpu_rnd_cycles()	__cpu_rnd_cycles()
+
 /*
  * Arguments to hardclock, softclock and statclock
  * encapsulate the previous machine state in an opaque
Index: arch/alpha/include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/alpha/include/cpu.h,v
retrieving revision 1.61
diff -u -p -r1.61 cpu.h
--- arch/alpha/include/cpu.h	24 Mar 2019 06:19:26 -0000	1.61
+++ arch/alpha/include/cpu.h	25 May 2020 22:20:44 -0000
@@ -282,6 +282,15 @@ do {									\
 #define	fpcurproc	curcpu()->ci_fpcurproc
 #define	curpcb		curcpu()->ci_curpcb
 
+static inline unsinged int
+__cpu_rnd_cycles(void)
+{
+	unsigned long pcc = alpha_rpcc();
+	return ((pcc >> 32) ^ pcc);
+}
+
+#define cpu_rnd_cycles()		__cpu_rnd_cycles()
+
 /*
  * definitions of cpu-dependent requirements
  * referenced in generic code
Index: arch/hppa/include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/hppa/include/cpu.h,v
retrieving revision 1.91
diff -u -p -r1.91 cpu.h
--- arch/hppa/include/cpu.h	5 Dec 2018 10:28:21 -0000	1.91
+++ arch/hppa/include/cpu.h	25 May 2020 22:20:44 -0000
@@ -154,6 +154,17 @@ enum hppa_cpu_type {
 extern enum hppa_cpu_type cpu_type;
 extern const char *cpu_typename;
 extern int cpu_hvers;
+
+static inline unsigned int
+__cpu_rnd_cycles(void)
+{
+	unsigned int cycles;
+
+	asm volatile ("mfctl %%cr16, %0" : "=r"(cycles));
+
+	return (cycles);
+}
+#define cpu_rnd_cycles()	__cpu_rnd_cycles()
 #endif
 #endif
 
Index: arch/powerpc/include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/powerpc/include/cpu.h,v
retrieving revision 1.66
diff -u -p -r1.66 cpu.h
--- arch/powerpc/include/cpu.h	17 Mar 2020 10:14:45 -0000	1.66
+++ arch/powerpc/include/cpu.h	25 May 2020 22:20:44 -0000
@@ -161,6 +161,19 @@ extern int ppc_nobat;
 
 void	cpu_bootstrap(void);
 
+static inline unsigned int
+__cpu_rnd_cycles(void)
+{
+	unsigned int lo, hi;
+
+	__asm volatile("mftbu %0" : "=r"(hi));
+	__asm volatile("mftb %0" : "=r"(lo));
+
+	return (hi ^ lo);
+}
+
+#define cpu_rnd_cycles()	__cpu_rnd_cycles()
+
 /*
  * This is used during profiling to integrate system time.
  */
Index: arch/powerpc64/include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/powerpc64/include/cpu.h,v
retrieving revision 1.5
diff -u -p -r1.5 cpu.h
--- arch/powerpc64/include/cpu.h	22 May 2020 16:27:49 -0000	1.5
+++ arch/powerpc64/include/cpu.h	25 May 2020 22:20:44 -0000
@@ -28,7 +28,7 @@ struct cpu_info {
 
 extern struct cpu_info cpu_info_primary;
 
-register struct cpu_info *__curcpu asm("r13");
+register struct cpu_info * const __curcpu asm("r13");
 #define curcpu()	__curcpu
 
 #define MAXCPUS			1
Index: arch/sparc64/include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/sparc64/include/cpu.h,v
retrieving revision 1.93
diff -u -p -r1.93 cpu.h
--- arch/sparc64/include/cpu.h	5 Dec 2018 10:28:21 -0000	1.93
+++ arch/sparc64/include/cpu.h	25 May 2020 22:20:44 -0000
@@ -172,7 +172,7 @@ extern struct cpu_info *cpus;
 
 #ifdef MULTIPROCESSOR
 
-register struct cpu_info *__curcpu asm ("g7");
+register struct cpu_info * const __curcpu asm ("g7");
 
 #define curcpu()	(__curcpu->ci_self)
 #define cpu_number()	(__curcpu->ci_cpuid)
@@ -210,6 +210,15 @@ void	cpu_unidle(struct cpu_info *);
 
 #define curpcb		__curcpu->ci_cpcb
 #define fpproc		__curcpu->ci_fpproc
+
+static inline unsigned int
+__cpu_rnd_cycles(void)
+{
+	uint64_t cycles = tick();
+	return ((cycles >> 32) ^ cycles);
+}
+
+#define cpu_rnd_cycles		__cpu_rnd_cycles()
 
 /*
  * On processors with multiple threads we force a thread switch.