+union entry_union {
+ struct { u32 w1, w2; };
+ struct IO_APIC_route_entry entry;
+};
+
+static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
+{
+ union entry_union eu;
+ unsigned long flags;
+ spin_lock_irqsave(&ioapic_lock, flags);
+ eu.w1 = io_apic_read(apic, 0x10 + 2 * pin);
+ eu.w2 = io_apic_read(apic, 0x11 + 2 * pin);
+ spin_unlock_irqrestore(&ioapic_lock, flags);
+ return eu.entry;
+}
+
+/*
+ * When we write a new IO APIC routing entry, we need to write the high
+ * word first! If the mask bit in the low word is clear, we will enable
+ * the interrupt, and we need to make sure the entry is fully populated
+ * before that happens.
+ */
+static void
+__ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
+{
+ union entry_union eu;
+ eu.entry = e;
+ io_apic_write(apic, 0x11 + 2*pin, eu.w2);
+ io_apic_write(apic, 0x10 + 2*pin, eu.w1);
+}
+
+static void ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&ioapic_lock, flags);
+ __ioapic_write_entry(apic, pin, e);
+ spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+/*
+ * When we mask an IO APIC routing entry, we need to write the low
+ * word first, in order to set the mask bit before we change the
+ * high bits!
+ */
+static void ioapic_mask_entry(int apic, int pin)
+{
+ unsigned long flags;
+ union entry_union eu = { .entry.mask = 1 };
+
+ spin_lock_irqsave(&ioapic_lock, flags);
+ io_apic_write(apic, 0x10 + 2*pin, eu.w1);
+ io_apic_write(apic, 0x11 + 2*pin, eu.w2);
+ spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+#ifdef CONFIG_SMP
+static void __target_IO_APIC_irq(unsigned int irq, unsigned int dest, u8 vector)
+{
+ int apic, pin;
+ struct irq_pin_list *entry = irq_2_pin + irq;
+
+ BUG_ON(irq >= NR_IRQS);
+ for (;;) {
+ unsigned int reg;
+ apic = entry->apic;
+ pin = entry->pin;
+ if (pin == -1)
+ break;
+ io_apic_write(apic, 0x11 + pin*2, dest);
+ reg = io_apic_read(apic, 0x10 + pin*2);
+ reg &= ~0x000000ff;
+ reg |= vector;
+ io_apic_modify(apic, reg);
+ if (!entry->next)
+ break;
+ entry = irq_2_pin + entry->next;
+ }
+}
+
+static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t mask)
+{
+ unsigned long flags;
+ unsigned int dest;
+ cpumask_t tmp;
+ int vector;
+
+ cpus_and(tmp, mask, cpu_online_map);
+ if (cpus_empty(tmp))
+ tmp = TARGET_CPUS;
+
+ cpus_and(mask, tmp, CPU_MASK_ALL);
+
+ vector = assign_irq_vector(irq, mask, &tmp);
+ if (vector < 0)
+ return;
+
+ dest = cpu_mask_to_apicid(tmp);
+
+ /*
+ * Only the high 8 bits are valid.
+ */
+ dest = SET_APIC_LOGICAL_ID(dest);
+
+ spin_lock_irqsave(&ioapic_lock, flags);
+ __target_IO_APIC_irq(irq, dest, vector);
+ set_native_irq_info(irq, mask);
+ spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+#endif
+
+/*
+ * The common case is 1:1 IRQ<->pin mappings. Sometimes there are
+ * 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 int first_free_entry = NR_IRQS;
+ struct irq_pin_list *entry = irq_2_pin + irq;
+
+ BUG_ON(irq >= NR_IRQS);
+ while (entry->next)
+ entry = irq_2_pin + entry->next;
+
+ if (entry->pin != -1) {
+ entry->next = first_free_entry;
+ entry = irq_2_pin + entry->next;
+ if (++first_free_entry >= PIN_MAP_SIZE)
+ panic("io_apic.c: ran out of irq_2_pin entries!");
+ }
+ entry->apic = apic;
+ entry->pin = pin;
+}
+
+