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, 74 insertions, 76 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 3a68daee0d9..5d5f4120c74 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