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>

1 files changed, 30 insertions, 54 deletions

diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index a2f6bde9c4eb..2f3e192615c0 100644
--- a/arch/x86/pci/irq.c
+++ b/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