make apic functions completely private to apic.h rather than splitting
them between fns.h and apic.h.  also fix a nil dereference bug in mpacpi.c

Reference: /n/atom/patch/applied2013/nixapicpriv
Date: Mon Aug 26 17:58:00 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/mpacpi.c	Mon Aug 26 17:57:10 2013
+++ /sys/src/nix/k10/mpacpi.c	Mon Aug 26 17:57:10 2013
@@ -40,8 +40,11 @@
 			if((apic = ioapiclookup(st->ioapic.id)) != nil){
 				apic->ibase = st->ioapic.ibase;	/* gnarly */
 				already = "(mp)";
-			}else
-				ioapicinit(st->ioapic.id, st->ioapic.ibase, st->ioapic.addr);
+			}else{
+				apic = ioapicinit(st->ioapic.id, st->ioapic.ibase, st->ioapic.addr);
+				if(apic == nil)
+					continue;
+			}
 			print("ioapic: %d ", st->ioapic.id);
 			print("addr %p base %d %s\n", apic->paddr, apic->ibase, already);
 			break;
--- /sys/src/nix/k10/main.c	Mon Aug 26 17:57:10 2013
+++ /sys/src/nix/k10/main.c	Mon Aug 26 17:57:10 2013
@@ -6,6 +6,7 @@
 
 #include "init.h"
 #include "io.h"
+#include "apic.h"
 
 Conf	conf;
 uintptr	kseg0 = KZERO;
--- /sys/src/nix/k10/ioapic.c	Mon Aug 26 17:57:10 2013
+++ /sys/src/nix/k10/ioapic.c	Mon Aug 26 17:57:10 2013
@@ -200,7 +200,7 @@
 	return nil;
 }
 
-void
+Apic*
 ioapicinit(int id, int ibase, uintmem pa)
 {
 	Apic *apic, *p;
@@ -210,20 +210,22 @@
 	 * Mark the IOAPIC useable if it has a good ID
 	 * and the registers can be mapped.
 	 */
-	if(id >= Napic || (apic = xioapic+id)->useable)
-		return;
+	if(id >= Napic)
+		return nil;
+	if((apic = xioapic+id)->useable)
+		return apic;
 
 	if((p = dupaddr(pa)) != nil){
 		print("ioapic%d: same pa as apic%ld\n", id, p-xioapic);
 		if(ibase != -1)
-			return;		/* mp irqs reference mp apic#s */
+			return nil;		/* mp irqs reference mp apic#s */
 		apic->addr = p->addr;
 	}
 	else{
 		adrmapck(pa, 1024, Aapic, Mfree);	/* not in adr? */
 		if((apic->addr = vmap(pa, 1024)) == nil){
 			print("ioapic%d: can't vmap %#P\n", id, pa);
-			return;
+			return nil;
 		}
 	}
 	apic->useable = 1;
@@ -246,6 +248,8 @@
 	apic->addr[Ioregsel] = Ioapicid;
 	apic->addr[Iowin] = id<<24;
 	unlock(apic);
+
+	return apic;
 }
 
 void
--- /sys/src/nix/k10/fns.h	Mon Aug 26 17:57:10 2013
+++ /sys/src/nix/k10/fns.h	Mon Aug 26 17:57:10 2013
@@ -169,20 +169,6 @@
 #define BIOSSEG(a)	KADDR(((uint)(a))<<4)
 
 /*
- * (l|io)apic.c
- */
-int	lapiceoi(int);
-void	lapicipi(int);
-void	lapicinit(int, uintmem, int);
-int	lapicisr(int);
-int	lapiconline(void);
-void	lapicpri(int);
-void	lapicsipi(int, uintmem);
-
-void	ioapicinit(int, int, uintmem);
-void	ioapiconline(void);
-
-/*
  * archk10.c
  */
 void k10mwait(void*);
--- /sys/src/nix/k10/apic.h	Mon Aug 26 17:57:10 2013
+++ /sys/src/nix/k10/apic.h	Mon Aug 26 17:57:10 2013
@@ -80,10 +80,19 @@
 void	apictimerenab(void);
 int	gsitoapicid(int, uint*);
 void	ioapicdump(void);
+Apic*	ioapicinit(int, int, uintmem);
 void	ioapicintrinit(int, int, int, int, int, u32int);
 Apic*	ioapiclookup(uint);
+void	ioapiconline(void);
 void	lapicdump(void);
+int	lapiceoi(int);
+void	lapicinit(int, uintmem, int);
+void	lapicipi(int);
+int	lapicisr(int);
 Apic*	lapiclookup(uint);
+int	lapiconline(void);
+void	lapicpri(int);
+void	lapicsipi(int, uintmem);
 
 int	pcimsienable(Pcidev*, uvlong);
 int	pcimsimask(Pcidev*, int);