Normally context switches happen in mi_switch() but there are 3 cases

where a switch happens outside. Cleanup these code paths and make the
machine independent.

- when a process forks (fork, tfork, kthread), the new proc needs to
  somehow be scheduled for the first time. This is done by proc_trampoline.
  Since proc_trampoline is machine dependent assembler code change
  the MP specific proc_trampoline_mp() to proc_trampoline_mi() and make
  sure it is now always called.
- cpu_hatch: when booting APs the code needs to jump to the first proc
  running on that CPU. This should be the idle thread for that CPU.
- sched_exit: when a proc exits it needs to switch away from itself and
  then instruct the reaper to clean up the rest. This is done by switching
  to the idle loop.

Since the last two cases require a context switch to the idle proc factor
out the common code to sched_toidle() and use it in those places.

Tested by many on all archs.
OK miod@ mpi@ cheloha@

2 files changed, 4 insertions, 14 deletions

diff --git a/sys/arch/hppa/dev/cpu.c b/sys/arch/hppa/dev/cpu.c
index 777bbd44587..35801a4b8c2 100644
--- a/sys/arch/hppa/dev/cpu.c
+++ b/sys/arch/hppa/dev/cpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.c,v 1.46 2023/08/29 16:19:34 claudio Exp $	*/
+/*	$OpenBSD: cpu.c,v 1.47 2023/10/24 13:20:09 claudio Exp $	*/
 
 /*
  * Copyright (c) 1998-2003 Michael Shalayeff
@@ -243,7 +243,6 @@ void
 cpu_hatch(void)
 {
 	struct cpu_info *ci = curcpu();
-	int s;
 
 	/* Initialise IPIs. */
 	hppa_ipi_init(ci);
@@ -263,12 +262,7 @@ cpu_hatch(void)
 	while (!start_secondary_cpu)
 		;
 
-	s = splhigh();
-	nanouptime(&ci->ci_schedstate.spc_runtime);
-	splx(s);
-
-	SCHED_LOCK(s);
-	cpu_switchto(NULL, sched_chooseproc());
+	sched_toidle();
 }
 
 void
diff --git a/sys/arch/hppa/hppa/locore.S b/sys/arch/hppa/hppa/locore.S
index a9963b380ee..068440760e1 100644
--- a/sys/arch/hppa/hppa/locore.S
+++ b/sys/arch/hppa/hppa/locore.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.S,v 1.204 2022/10/25 15:15:38 guenther Exp $	*/
+/*	$OpenBSD: locore.S,v 1.205 2023/10/24 13:20:10 claudio Exp $	*/
 
 /*
  * Copyright (c) 1998-2004 Michael Shalayeff
@@ -2697,16 +2697,12 @@ EXIT(cpu_idle_leave)
 
 ENTRY(proc_trampoline,0)
 	copy	r0, r3
-#ifdef MULTIPROCESSOR
 	copy	t4, r5
 	copy	arg0, r4
-	bl	proc_trampoline_mp, rp
+	bl	proc_trampoline_mi, rp
 	nop
 	copy	r4, arg0
 	copy	r5, t4
-#endif
-	mfctl	cr29, t1
-	stw	r0, CI_CPL(t1)
 	.call
 	blr	r0, rp
 	bv,n	r0(t4)