diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -959,28 +959,6 @@
 	sd->sd_gran  = ssd->ssd_gran;
 }
 
-#if !defined(DEV_ATPIC) && defined(DEV_ISA)
-#include <isa/isavar.h>
-#include <isa/isareg.h>
-/*
- * Return a bitmap of the current interrupt requests.  This is 8259-specific
- * and is only suitable for use at probe time.
- * This is only here to pacify sio.  It is NOT FATAL if this doesn't work.
- * It shouldn't be here.  There should probably be an APIC centric
- * implementation in the apic driver code, if at all.
- */
-intrmask_t
-isa_irq_pending(void)
-{
-	u_char irr1;
-	u_char irr2;
-
-	irr1 = inb(IO_ICU1);
-	irr2 = inb(IO_ICU2);
-	return ((irr2 << 8) | irr1);
-}
-#endif
-
 u_int basemem;
 
 static int
diff --git a/sys/isa/isavar.h b/sys/isa/isavar.h
--- a/sys/isa/isavar.h
+++ b/sys/isa/isavar.h
@@ -168,7 +168,6 @@
 /* Device class for ISA bridges. */
 extern devclass_t isab_devclass;
 
-extern intrmask_t isa_irq_pending(void);
 extern void	isa_probe_children(device_t dev);
 
 void	isa_dmacascade(int chan);
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -664,7 +664,6 @@
 	{ "ap boot", &lock_class_mtx_spin },
 #endif
 	{ "rm.mutex_mtx", &lock_class_mtx_spin },
-	{ "sio", &lock_class_mtx_spin },
 #ifdef __i386__
 	{ "cy", &lock_class_mtx_spin },
 #endif
diff --git a/sys/x86/isa/atpic.c b/sys/x86/isa/atpic.c
--- a/sys/x86/isa/atpic.c
+++ b/sys/x86/isa/atpic.c
@@ -591,21 +591,6 @@
 	return (0);
 }
 
-/*
- * Return a bitmap of the current interrupt requests.  This is 8259-specific
- * and is only suitable for use at probe time.
- */
-intrmask_t
-isa_irq_pending(void)
-{
-	u_char irr1;
-	u_char irr2;
-
-	irr1 = inb(IO_ICU1);
-	irr2 = inb(IO_ICU2);
-	return ((irr2 << 8) | irr1);
-}
-
 static device_method_t atpic_methods[] = {
 	/* Device interface */
 	DEVMETHOD(device_probe,		atpic_probe),