ppc32: Fix boot on PowerMac

Index: linux-work/arch/ppc/platforms/chrp_setup.c
===================================================================
@@ -374,6 +374,9 @@
 static int __init
 chrp_request_cascade(void)
 {
+	if (_machine != _MACH_chrp)
+		return 0;
+
 	/* We have a cascade on OpenPIC IRQ 0, Linux IRQ 16 */
 	openpic_hookup_cascade(NUM_8259_INTERRUPTS, "82c59 cascade",
 			       i8259_irq);

Index: linux-work/arch/ppc/syslib/i8259.c
===================================================================
@@ -13,6 +13,7 @@
 static spinlock_t i8259_lock = SPIN_LOCK_UNLOCKED;
 
 int i8259_pic_irq_offset;
+static int i8259_present;
 
 /*
  * Acknowledge the IRQ using either the PCI host bridge's interrupt

@@ -154,6 +155,9 @@
 static int __init
 i8259_hook_cascade(void)
 {
+	if (!i8259_present)
+		return 0;
+
 	/* reserve our resources */
 	request_irq( i8259_pic_irq_offset + 2, no_action, SA_INTERRUPT,
 				"82c59 secondary cascade", NULL );

@@ -201,4 +205,6 @@
 
 	if (intack_addr != 0)
 		pci_intack = ioremap(intack_addr, 1);
+
+	i8259_present = 1;
 }

Index: linux-work/arch/ppc/platforms/prep_setup.c
===================================================================
@@ -961,6 +961,9 @@
 static int __init
 prep_request_cascade(void)
 {
+	if (_machine != _MACH_prep)
+		return 0;
+
 	if (OpenPIC_Addr != NULL)
 		/* We have a cascade on OpenPIC IRQ 0, Linux IRQ 16 */
 		openpic_hookup_cascade(NUM_8259_INTERRUPTS, "82c59 cascade",