patch-2.4.19 linux-2.4.19/arch/i386/kernel/io_apic.c

• Lines: 87
• Date: Fri Aug 2 17:39:42 2002
• Orig file: linux-2.4.18/arch/i386/kernel/io_apic.c
• Orig date: Tue Nov 13 17:28:41 2001

diff -urN linux-2.4.18/arch/i386/kernel/io_apic.c linux-2.4.19/arch/i386/kernel/io_apic.c
@@ -67,7 +67,7 @@
  * shared ISA-space IRQs, so we have to support them. We are super
  * fast in the common case, and fast for shared ISA-space IRQs.
  */
-static void add_pin_to_irq(unsigned int irq, int apic, int pin)
+static void __init add_pin_to_irq(unsigned int irq, int apic, int pin)
 {
 	static int first_free_entry = NR_IRQS;
 	struct irq_pin_list *entry = irq_2_pin + irq;
@@ -85,6 +85,26 @@
 	entry->pin = pin;
 }
 
+/*
+ * Reroute an IRQ to a different pin.
+ */
+static void __init replace_pin_at_irq(unsigned int irq,
+				      int oldapic, int oldpin,
+				      int newapic, int newpin)
+{
+	struct irq_pin_list *entry = irq_2_pin + irq;
+
+	while (1) {
+		if (entry->apic == oldapic && entry->pin == oldpin) {
+			entry->apic = newapic;
+			entry->pin = newpin;
+		}
+		if (!entry->next)
+			break;
+		entry = irq_2_pin + entry->next;
+	}
+}
+
 #define __DO_ACTION(R, ACTION, FINAL)					\
 									\
 {									\
@@ -173,13 +193,21 @@
 int pirqs_enabled;
 int skip_ioapic_setup;
 
-static int __init ioapic_setup(char *str)
+static int __init noioapic_setup(char *str)
 {
 	skip_ioapic_setup = 1;
 	return 1;
 }
 
-__setup("noapic", ioapic_setup);
+__setup("noapic", noioapic_setup);
+
+static int __init ioapic_setup(char *str)
+{
+	skip_ioapic_setup = 0;
+	return 1;
+}
+
+__setup("apic", ioapic_setup);
 
 static int __init ioapic_pirq_setup(char *str)
 {
@@ -622,7 +650,14 @@
 		}
 
 		irq = pin_2_irq(idx, apic, pin);
-		add_pin_to_irq(irq, apic, pin);
+		/*
+		 * skip adding the timer int on secondary nodes, which causes
+		 * a small but painful rift in the time-space continuum
+		 */
+		if (clustered_apic_mode && (apic != 0) && (irq == 0))
+			continue;
+		else
+			add_pin_to_irq(irq, apic, pin);
 
 		if (!apic && !IO_APIC_IRQ(irq))
 			continue;
@@ -1533,6 +1568,10 @@
 		setup_ExtINT_IRQ0_pin(pin2, vector);
 		if (timer_irq_works()) {
 			printk("works.\n");
+			if (pin1 != -1)
+				replace_pin_at_irq(0, 0, pin1, 0, pin2);
+			else
+				add_pin_to_irq(0, 0, pin2);
 			if (nmi_watchdog == NMI_IO_APIC) {
 				setup_nmi();
 				check_nmi_watchdog();