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>

2 files changed, 104 insertions, 130 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 3a68daee0d99..5d5f4120c743 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/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;
@@ -1490,48 +1494,53 @@ 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++) {
-
-                        idx = find_irq_entry(apic_id, pin, mp_INT);
-                        if (idx == -1) {
-                                if (!notcon) {
-                                        notcon = 1;
-                                        apic_printk(APIC_VERBOSE,
-                                                KERN_DEBUG " %d-%d",
-                                                mp_ioapics[apic_id].apicid, pin);
-                                } else
-                                        apic_printk(APIC_VERBOSE, " %d-%d",
-                                                mp_ioapics[apic_id].apicid, pin);
-                                continue;
-                        }
-                        if (notcon) {
-                                apic_printk(APIC_VERBOSE,
-                                        " (apicid-pin) not connected\n");
-                                notcon = 0;
-                        }
+#ifdef CONFIG_ACPI
+        if (!acpi_disabled && acpi_ioapic) {
+                apic_id = mp_find_ioapic(0);
+                if (apic_id < 0)
+                        apic_id = 0;
+        }
+#endif
 
-                        irq = pin_2_irq(idx, apic_id, pin);
+        for (pin = 0; pin < nr_ioapic_registers[apic_id]; pin++) {
+                idx = find_irq_entry(apic_id, pin, mp_INT);
+                if (idx == -1) {
+                        if (!notcon) {
+                                notcon = 1;
+                                apic_printk(APIC_VERBOSE,
+                                        KERN_DEBUG " %d-%d",
+                                        mp_ioapics[apic_id].apicid, pin);
+                        } else
+                                apic_printk(APIC_VERBOSE, " %d-%d",
+                                        mp_ioapics[apic_id].apicid, pin);
+                        continue;
+                }
+                if (notcon) {
+                        apic_printk(APIC_VERBOSE,
+                                " (apicid-pin) not connected\n");
+                        notcon = 0;
+                }
 
-                        /*
-                         * Skip the timer IRQ if there's a quirk handler
-                         * installed and if it returns 1:
-                         */
-                        if (apic->multi_timer_check &&
-                                        apic->multi_timer_check(apic_id, irq))
-                                continue;
+                irq = pin_2_irq(idx, apic_id, pin);
 
-                        desc = irq_to_desc_alloc_node(irq, node);
-                        if (!desc) {
-                                printk(KERN_INFO "can not get irq_desc for %d\n", irq);
-                                continue;
-                        }
-                        cfg = desc->chip_data;
-                        add_pin_to_irq_node(cfg, node, apic_id, pin);
+                /*
+                 * Skip the timer IRQ if there's a quirk handler
+                 * installed and if it returns 1:
+                 */
+                if (apic->multi_timer_check &&
+                                apic->multi_timer_check(apic_id, irq))
+                        continue;
 
-                        setup_IO_APIC_irq(apic_id, pin, irq, desc,
-                                        irq_trigger(idx), irq_polarity(idx));
+                desc = irq_to_desc_alloc_node(irq, node);
+                if (!desc) {
+                        printk(KERN_INFO "can not get irq_desc for %d\n", irq);
+                        continue;
                 }
+                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)
@@ -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)
 {
@@ -4023,51 +4028,44 @@ 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++) {
-                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;
+#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);
 
-                        /*
-                         * Honour affinities which have been set in early boot
-                         */
-                        if (desc->status &
-                            (IRQ_NO_BALANCING | IRQ_AFFINITY_SET))
-                                mask = desc->affinity;
-                        else
-                                mask = apic->target_cpus();
+                desc = irq_to_desc(irq);
 
-                        if (intr_remapping_enabled)
-                                set_ir_ioapic_affinity_irq_desc(desc, mask);
-                        else
-                                set_ioapic_affinity_irq_desc(desc, mask);
-                }
+                /*
+                 * Honour affinities which have been set in early boot
+                 */
+                if (desc->status &
+                    (IRQ_NO_BALANCING | IRQ_AFFINITY_SET))
+                        mask = desc->affinity;
+                else
+                        mask = apic->target_cpus();
 
+                if (intr_remapping_enabled)
+                        set_ir_ioapic_affinity_irq_desc(desc, mask);
+                else
+                        set_ioapic_affinity_irq_desc(desc, mask);
         }
+
 }
 #endif
 
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