statclock: move profil(2), GPROF code to profclock(), gmonclock()

This patch isolates profil(2) and GPROF from statclock().  Currently,
statclock() implements both profil(2) and GPROF through a complex
mechanism involving both platform code (setstatclockrate) and the
scheduler (pscnt, psdiv, and psratio).  We have a machine-independent
interface to the clock interrupt hardware now, so we no longer need to
do it this way.

- Move profil(2)-specific code from statclock() to a new clock
  interrupt callback, profclock(), in subr_prof.c.  Each
  schedstate_percpu has its own profclock handle.  The profclock is
  enabled/disabled for a given CPU when it is needed by the running
  thread during mi_switch() and sched_exit().

- Move GPROF-specific code from statclock() to a new clock interrupt
  callback, gmonclock(), in subr_prof.c.  Where available, each cpu_info
  has its own gmonclock handle .  The gmonclock is enabled/disabled for
  a given CPU via sysctl(2) in prof_state_toggle().

- Both profclock() and gmonclock() have a fixed period, profclock_period,
  that is initialized during initclocks().

- Export clockintr_advance(), clockintr_cancel(), clockintr_establish(),
  and clockintr_stagger() via <sys/clockintr.h>.  They have external
  callers now.

- Delete pscnt, psdiv, psratio.  From schedstate_percpu, also delete
  spc_pscnt and spc_psdiv.  The statclock frequency is not dynamic
  anymore so these variables are now useless.

- Delete code/state related to the dynamic statclock frequency from
  kern_clockintr.c.  The statclock frequency can still be pseudo-random,
  so move the contents of clockintr_statvar_init() into clockintr_init().

With input from miod@, deraadt@, and claudio@.  Early revisions
cleaned up by claudio.  Early revisions tested by claudio@.  Tested by
cheloha@ on amd64, arm64, macppc, octeon, and sparc64 (sun4v).
Compile- and boot- tested on i386 by mlarkin@.  riscv64 compilation
bugs found by mlarkin@.  Tested on riscv64 by jca@.  Tested on
powerpc64 by gkoehler@.

3 files changed, 4 insertions, 5 deletions

diff --git a/sys/arch/arm/cortex/agtimer.c b/sys/arch/arm/cortex/agtimer.c
index 9ccf56fc3bf..13b0af6f8e1 100644
--- a/sys/arch/arm/cortex/agtimer.c
+++ b/sys/arch/arm/cortex/agtimer.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: agtimer.c,v 1.17 2023/02/04 19:19:36 cheloha Exp $ */
+/* $OpenBSD: agtimer.c,v 1.18 2023/07/25 18:16:19 cheloha Exp $ */
 /*
  * Copyright (c) 2011 Dale Rahn <drahn@openbsd.org>
  * Copyright (c) 2013 Patrick Wildt <patrick@blueri.se>
@@ -288,7 +288,6 @@ agtimer_delay(u_int usecs)
 void
 agtimer_setstatclockrate(int newhz)
 {
-	clockintr_setstatclockrate(newhz);
 }
 
 void
diff --git a/sys/arch/arm/cortex/amptimer.c b/sys/arch/arm/cortex/amptimer.c
index 455d75e2aeb..6fcf495791c 100644
--- a/sys/arch/arm/cortex/amptimer.c
+++ b/sys/arch/arm/cortex/amptimer.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: amptimer.c,v 1.16 2023/02/04 19:19:36 cheloha Exp $ */
+/* $OpenBSD: amptimer.c,v 1.17 2023/07/25 18:16:19 cheloha Exp $ */
 /*
  * Copyright (c) 2011 Dale Rahn <drahn@openbsd.org>
  *
@@ -343,7 +343,6 @@ amptimer_delay(u_int usecs)
 void
 amptimer_setstatclockrate(int newhz)
 {
-	clockintr_setstatclockrate(newhz);
 }
 
 void
diff --git a/sys/arch/arm/include/cpu.h b/sys/arch/arm/include/cpu.h
index 7f6b95ccf92..986e1798cb9 100644
--- a/sys/arch/arm/include/cpu.h
+++ b/sys/arch/arm/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.62 2023/01/17 02:27:14 cheloha Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.63 2023/07/25 18:16:19 cheloha Exp $	*/
 /*	$NetBSD: cpu.h,v 1.34 2003/06/23 11:01:08 martin Exp $	*/
 
 /*
@@ -198,6 +198,7 @@ struct cpu_info {
 
 #ifdef GPROF
 	struct gmonparam *ci_gmon;
+	struct clockintr *ci_gmonclock;
 #endif
 	struct clockintr_queue	ci_queue;
 	char			ci_panicbuf[512];