kernel: cleanup exit()/shutdown()/reboot() code

introduce cpushutdown() function that does the common
operation of initiating shutdown, returning once all
cpu's got the message and are about to shutdown. this
avoids duplicated code which isnt really machine specific.

automatic reboot on panic only when *debug= is not set
and the machine is a cpu server or has no display,
otherwise just hang.

3 files changed, 5 insertions, 52 deletions

diff --git a/sys/src/9/pc/dat.h b/sys/src/9/pc/dat.h
index 8bcc5053a..19b7dfae2 100644
--- a/sys/src/9/pc/dat.h
+++ b/sys/src/9/pc/dat.h
@@ -272,7 +272,6 @@ struct
 	Lock;
 	int	machs;			/* bitmap of active CPUs */
 	int	exiting;		/* shutdown */
-	int	ispanic;		/* shutdown in response to a panic */
 	int	thunderbirdsarego;	/* lets the added processors continue to schedinit */
 }active;
 
diff --git a/sys/src/9/pc/main.c b/sys/src/9/pc/main.c
index 6672717c2..6d8341997 100644
--- a/sys/src/9/pc/main.c
+++ b/sys/src/9/pc/main.c
@@ -163,7 +163,6 @@ main(void)
 		pcimatch(0, 0, 0);
 	}else
 		links();
-	conf.monitor = 1;
 	chandevreset();
 	pageinit();
 	swapinit();
@@ -890,50 +889,6 @@ procsave(Proc *p)
 	mmuflushtlb(PADDR(m->pdb));
 }
 
-static void
-shutdown(int ispanic)
-{
-	int ms, once;
-
-	lock(&active);
-	if(ispanic)
-		active.ispanic = ispanic;
-	else if(m->machno == 0 && (active.machs & (1<<m->machno)) == 0)
-		active.ispanic = 0;
-	once = active.machs & (1<<m->machno);
-	/*
-	 * setting exiting will make hzclock() on each processor call exit(0),
-	 * which calls shutdown(0) and arch->reset(), which on mp systems calls
-	 * mpshutdown(), from which there is no return: the processor is idled
-	 * or initiates a reboot.  clearing our bit in machs avoids calling
-	 * exit(0) from hzclock() on this processor.
-	 */
-	active.machs &= ~(1<<m->machno);
-	active.exiting = 1;
-	unlock(&active);
-
-	if(once)
-		iprint("cpu%d: exiting\n", m->machno);
-
-	/* wait for any other processors to shutdown */
-	spllo();
-	for(ms = 5*1000; ms > 0; ms -= TK2MS(2)){
-		delay(TK2MS(2));
-		if(active.machs == 0 && consactive() == 0)
-			break;
-	}
-
-	if(active.ispanic){
-		if(!cpuserver)
-			for(;;)
-				halt();
-		if(getconf("*debug"))
-			delay(5*60*1000);
-		else
-			delay(10000);
-	}
-}
-
 void
 reboot(void *entry, void *code, ulong size)
 {
@@ -952,10 +907,7 @@ reboot(void *entry, void *code, ulong size)
 		procwired(up, 0);
 		sched();
 	}
-	shutdown(0);
-
-	iprint("shutting down...\n");
-	delay(200);
+	cpushutdown();
 
 	splhi();
 
@@ -985,8 +937,8 @@ reboot(void *entry, void *code, ulong size)
 
 
 void
-exit(int ispanic)
+exit(int)
 {
-	shutdown(ispanic);
+	cpushutdown();
 	arch->reset();
 }
diff --git a/sys/src/9/pc/screen.c b/sys/src/9/pc/screen.c
index 4ff7a9485..c74d2da71 100644
--- a/sys/src/9/pc/screen.c
+++ b/sys/src/9/pc/screen.c
@@ -664,6 +664,8 @@ bootscreeninit(void)
 	scr->cur = &swcursor;
 	scr->cur->enable(scr);
 	cursoron();
+
+	conf.monitor = 1;
 }
 
 /*