x86/pci: update pirq_enable_irq() to setup io apic routing

So we can set io apic routing only when enabling the device irq.

This is advantageous for IRQ descriptor allocation affinity: if we set up
the IO-APIC entry later, we have a chance to allocate the IRQ descriptor
later and know which device it is on and can set affinity accordingly.

[ Impact: standardize/enhance irq-enabling sequence for mptable irqs ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A01C46E.8000501@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/apic/io_apic.c

@@ -1480,9 +1480,13 @@ static void setup_IO_APIC_irq(int apic_id, int pin, unsigned int irq, struct irq
 	ioapic_write_entry(apic_id, pin, entry);
 }
 
+static struct {
+	DECLARE_BITMAP(pin_programmed, MP_MAX_IOAPIC_PIN + 1);
+} mp_ioapic_routing[MAX_IO_APICS];
+
 static void __init setup_IO_APIC_irqs(void)
 {
-	int apic_id, pin, idx, irq;
+	int apic_id = 0, pin, idx, irq;
 	int notcon = 0;
 	struct irq_desc *desc;
 	struct irq_cfg *cfg;
@@ -1490,9 +1494,15 @@ static void __init setup_IO_APIC_irqs(void)
 
 	apic_printk(APIC_VERBOSE, KERN_DEBUG "init IO_APIC IRQs\n");
 
-	for (apic_id = 0; apic_id < nr_ioapics; apic_id++) {
-		for (pin = 0; pin < nr_ioapic_registers[apic_id]; pin++) {
+#ifdef CONFIG_ACPI
+	if (!acpi_disabled && acpi_ioapic) {
+		apic_id = mp_find_ioapic(0);
+		if (apic_id < 0)
+			apic_id = 0;
+	}
+#endif
 
+	for (pin = 0; pin < nr_ioapic_registers[apic_id]; pin++) {
 		idx = find_irq_entry(apic_id, pin, mp_INT);
 		if (idx == -1) {
 			if (!notcon) {
@@ -1528,11 +1538,10 @@ static void __init setup_IO_APIC_irqs(void)
 		}
 		cfg = desc->chip_data;
 		add_pin_to_irq_node(cfg, node, apic_id, pin);
-
+		set_bit(pin, mp_ioapic_routing[apic_id].pin_programmed);
 		setup_IO_APIC_irq(apic_id, pin, irq, desc,
 				irq_trigger(idx), irq_polarity(idx));
 	}
-	}
 
 	if (notcon)
 		apic_printk(APIC_VERBOSE,
@@ -3876,10 +3885,6 @@ static int __io_apic_set_pci_routing(struct device *dev, int ioapic, int pin, in
 	return 0;
 }
 
-static struct {
-	DECLARE_BITMAP(pin_programmed, MP_MAX_IOAPIC_PIN + 1);
-} mp_ioapic_routing[MAX_IO_APICS];
-
 int io_apic_set_pci_routing(struct device *dev, int ioapic, int pin, int irq,
 				 int triggering, int polarity)
 {
@@ -4023,34 +4028,28 @@ int acpi_get_override_irq(int bus_irq, int *trigger, int *polarity)
 #ifdef CONFIG_SMP
 void __init setup_ioapic_dest(void)
 {
-	int pin, ioapic, irq, irq_entry;
+	int pin, ioapic = 0, irq, irq_entry;
 	struct irq_desc *desc;
-	struct irq_cfg *cfg;
 	const struct cpumask *mask;
 
 	if (skip_ioapic_setup == 1)
 		return;
 
-	for (ioapic = 0; ioapic < nr_ioapics; ioapic++) {
+#ifdef CONFIG_ACPI
+	if (!acpi_disabled && acpi_ioapic) {
+		ioapic = mp_find_ioapic(0);
+		if (ioapic < 0)
+			ioapic = 0;
+	}
+#endif
+
 	for (pin = 0; pin < nr_ioapic_registers[ioapic]; pin++) {
 		irq_entry = find_irq_entry(ioapic, pin, mp_INT);
 		if (irq_entry == -1)
 			continue;
 		irq = pin_2_irq(irq_entry, ioapic, pin);
 
-			/* setup_IO_APIC_irqs could fail to get vector for some device
-			 * when you have too many devices, because at that time only boot
-			 * cpu is online.
-			 */
 		desc = irq_to_desc(irq);
-			cfg = desc->chip_data;
-			if (!cfg->vector) {
-				setup_IO_APIC_irq(ioapic, pin, irq, desc,
-						  irq_trigger(irq_entry),
-						  irq_polarity(irq_entry));
-				continue;
-
-			}
 
 		/*
 		 * Honour affinities which have been set in early boot
@@ -4067,7 +4066,6 @@ void __init setup_ioapic_dest(void)
 			set_ioapic_affinity_irq_desc(desc, mask);
 	}
 
-	}
 }
 #endif
 

arch/x86/pci/irq.c

@@ -889,6 +889,9 @@ static int pcibios_lookup_irq(struct pci_dev *dev, int assign)
 		return 0;
 	}
 
+	if (io_apic_assign_pci_irqs)
+		return 0;
+
 	/* Find IRQ routing entry */
 
 	if (!pirq_table)
@@ -1039,63 +1042,15 @@ static void __init pcibios_fixup_irqs(void)
 		pirq_penalty[dev->irq]++;
 	}
 
+	if (io_apic_assign_pci_irqs)
+		return;
+
 	dev = NULL;
 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
 		pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 		if (!pin)
 			continue;
 
-#ifdef CONFIG_X86_IO_APIC
-		/*
-		 * Recalculate IRQ numbers if we use the I/O APIC.
-		 */
-		if (io_apic_assign_pci_irqs) {
-			int irq;
-			int ioapic = -1, ioapic_pin = -1;
-			int triggering, polarity;
-
-			/*
-			 * interrupt pins are numbered starting from 1
-			 */
-			irq = IO_APIC_get_PCI_irq_vector(dev->bus->number,
-						PCI_SLOT(dev->devfn), pin - 1,
-						&ioapic, &ioapic_pin,
-						&triggering, &polarity);
-			/*
-			 * Busses behind bridges are typically not listed in the
-			 * MP-table.  In this case we have to look up the IRQ
-			 * based on the parent bus, parent slot, and pin number.
-			 * The SMP code detects such bridged busses itself so we
-			 * should get into this branch reliably.
-			 */
-			if (irq < 0 && dev->bus->parent) {
-				/* go back to the bridge */
-				struct pci_dev *bridge = dev->bus->self;
-				int bus;
-
-				pin = pci_swizzle_interrupt_pin(dev, pin);
-				bus = bridge->bus->number;
-				irq = IO_APIC_get_PCI_irq_vector(bus,
-						PCI_SLOT(bridge->devfn),
-						pin - 1,
-						&ioapic, &ioapic_pin,
-						&triggering, &polarity);
-				if (irq >= 0)
-					dev_warn(&dev->dev,
-						"using bridge %s INT %c to "
-							"get IRQ %d\n",
-						 pci_name(bridge),
-						 'A' + pin - 1, irq);
-			}
-			if (irq >= 0) {
-				dev_info(&dev->dev,
-					"PCI->APIC IRQ transform: INT %c "
-						"-> IRQ %d\n",
-					'A' + pin - 1, irq);
-				dev->irq = irq;
-			}
-		}
-#endif
 		/*
 		 * Still no IRQ? Try to lookup one...
 		 */
@@ -1190,6 +1145,19 @@ int __init pcibios_irq_init(void)
 	pcibios_enable_irq = pirq_enable_irq;
 
 	pcibios_fixup_irqs();
+
+	if (io_apic_assign_pci_irqs && pci_routeirq) {
+		struct pci_dev *dev = NULL;
+		/*
+		 * PCI IRQ routing is set up by pci_enable_device(), but we
+		 * also do it here in case there are still broken drivers that
+		 * don't use pci_enable_device().
+		 */
+		printk(KERN_INFO "PCI: Routing PCI interrupts for all devices because \"pci=routeirq\" specified\n");
+		for_each_pci_dev(dev)
+			pirq_enable_irq(dev);
+	}
+
 	return 0;
 }
 
@@ -1220,13 +1188,17 @@ void pcibios_penalize_isa_irq(int irq, int active)
 static int pirq_enable_irq(struct pci_dev *dev)
 {
 	u8 pin;
-	struct pci_dev *temp_dev;
 
 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
-	if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
+	if (pin && !pcibios_lookup_irq(dev, 1)) {
 		char *msg = "";
 
+		if (!io_apic_assign_pci_irqs && dev->irq)
+			return 0;
+
 		if (io_apic_assign_pci_irqs) {
+#ifdef CONFIG_X86_IO_APIC
+			struct pci_dev *temp_dev;
 			int irq;
 			int ioapic = -1, ioapic_pin = -1;
 			int triggering, polarity;
@@ -1261,12 +1233,16 @@ static int pirq_enable_irq(struct pci_dev *dev)
 			}
 			dev = temp_dev;
 			if (irq >= 0) {
+				io_apic_set_pci_routing(&dev->dev, ioapic,
+							ioapic_pin, irq,
+							triggering, polarity);
+				dev->irq = irq;
 				dev_info(&dev->dev, "PCI->APIC IRQ transform: "
 					 "INT %c -> IRQ %d\n", 'A' + pin - 1, irq);
-				dev->irq = irq;
 				return 0;
 			} else
 				msg = "; probably buggy MP table";
+#endif
 		} else if (pci_probe & PCI_BIOS_IRQ_SCAN)
 			msg = "";
 		else