mask lapic interrupts (and 8259 interrupts for good measure)
when ndnr'ing (permemantly parking the processor.

Reference: /n/atom/patch/applied2013/ndnrirq
Date: Sun Dec 29 14:39:52 CET 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/archk10.c	Sun Dec 29 14:39:07 2013
+++ /sys/src/nix/k10/archk10.c	Sun Dec 29 14:39:08 2013
@@ -5,6 +5,7 @@
 #include "fns.h"
 #include "adr.h"
 #include "io.h"
+#include "apic.h"
 
 void (*monmwait)(void*, uintptr) = nopmonmwait;
 
@@ -160,28 +161,6 @@
 	return m->npgsz;
 }
 
-int
-fmtR(Fmt* f)
-{
-	u64int r;
-
-	r = va_arg(f->args, u64int);
-
-	return fmtprint(f, "%#16.16llux", r);
-}
-
-/* virtual address fmt */
-static int
-fmtW(Fmt *f)
-{
-	uintptr va;
-
-	va = va_arg(f->args, uintptr);
-	return fmtprint(f, "%#llux=0x[%llux][%llux][%llux][%llux][%llux]", va,
-		PTLX(va, 3), PTLX(va, 2), PTLX(va, 1), PTLX(va, 0),
-		va & ((1<<PGSHIFT)-1));
-}
-
 void
 archfmtinstall(void)
 {
@@ -223,4 +202,16 @@
 archpciinit(void)
 {
 	pcireservemem();
+}
+
+/* no deposit, no return */
+void
+ndnr(void)
+{
+	splhi();
+	lapicpri(0xff);
+	outb(0x21, 0xff);		/* 8259 pic 0: mask irqs */
+	outb(0xa1, 0xff);		/* 8259 pic 1: mask irqs */
+	for(;;)
+		hardhalt();
 }
--- /sys/src/nix/k10/l32p.s	Sun Dec 29 14:39:09 2013
+++ /sys/src/nix/k10/l32p.s	Sun Dec 29 14:39:09 2013
@@ -222,9 +222,3 @@
 	POPFQ
 
 	CALL	main(SB)
-
-TEXT ndnr(SB), 1, $-4				/* no deposit, no return */
-_dnr:
-	STI
-	HLT
-	JMP	_dnr				/* do not resuscitate */