1 files changed, 33 insertions, 19 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 3c8f9e75d038..809e1cf86d6b 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -96,6 +96,11 @@ struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
 /* # of MP IRQ source entries */
 int mp_irq_entries;
 
+/* Number of legacy interrupts */
+static int nr_legacy_irqs __read_mostly = NR_IRQS_LEGACY;
+/* GSI interrupts */
+static int nr_irqs_gsi = NR_IRQS_LEGACY;
+
 #if defined (CONFIG_MCA) || defined (CONFIG_EISA)
 int mp_bus_id_to_type[MAX_MP_BUSSES];
 #endif
@@ -173,6 +178,12 @@ static struct irq_cfg irq_cfgx[NR_IRQS] = {
         [15] = { .vector = IRQ15_VECTOR, },
 };
 
+void __init io_apic_disable_legacy(void)
+{
+        nr_legacy_irqs = 0;
+        nr_irqs_gsi = 0;
+}
+
 int __init arch_early_irq_init(void)
 {
         struct irq_cfg *cfg;
@@ -190,7 +201,7 @@ int __init arch_early_irq_init(void)
                 desc->chip_data = &cfg[i];
                 zalloc_cpumask_var_node(&cfg[i].domain, GFP_NOWAIT, node);
                 zalloc_cpumask_var_node(&cfg[i].old_domain, GFP_NOWAIT, node);
-                if (i < NR_IRQS_LEGACY)
+                if (i < nr_legacy_irqs)
                         cpumask_setall(cfg[i].domain);
         }
 
@@ -867,7 +878,7 @@ static int __init find_isa_irq_apic(int irq, int type)
  */
 static int EISA_ELCR(unsigned int irq)
 {
-        if (irq < NR_IRQS_LEGACY) {
+        if (irq < nr_legacy_irqs) {
                 unsigned int port = 0x4d0 + (irq >> 3);
                 return (inb(port) >> (irq & 7)) & 1;
         }
@@ -1464,7 +1475,7 @@ static void setup_IO_APIC_irq(int apic_id, int pin, unsigned int irq, struct irq
         }
 
         ioapic_register_intr(irq, desc, trigger);
-        if (irq < NR_IRQS_LEGACY)
+        if (irq < nr_legacy_irqs)
                 disable_8259A_irq(irq);
 
         ioapic_write_entry(apic_id, pin, entry);
@@ -1831,7 +1842,7 @@ __apicdebuginit(void) print_PIC(void)
         unsigned int v;
         unsigned long flags;
 
-        if (apic_verbosity == APIC_QUIET)
+        if (apic_verbosity == APIC_QUIET || !nr_legacy_irqs)
                 return;
 
         printk(KERN_DEBUG "\nprinting PIC contents\n");
@@ -1894,6 +1905,10 @@ void __init enable_IO_APIC(void)
                 spin_unlock_irqrestore(&ioapic_lock, flags);
                 nr_ioapic_registers[apic] = reg_01.bits.entries+1;
         }
+
+        if (!nr_legacy_irqs)
+                return;
+
         for(apic = 0; apic < nr_ioapics; apic++) {
                 int pin;
                 /* See if any of the pins is in ExtINT mode */
@@ -1948,6 +1963,9 @@ void disable_IO_APIC(void)
          */
         clear_IO_APIC();
 
+        if (!nr_legacy_irqs)
+                return;
+
         /*
          * If the i8259 is routed through an IOAPIC
          * Put that IOAPIC in virtual wire mode
@@ -1994,7 +2012,7 @@ void disable_IO_APIC(void)
  * by Matt Domsch <Matt_Domsch@dell.com>  Tue Dec 21 12:25:05 CST 1999
  */
 
-static void __init setup_ioapic_ids_from_mpc(void)
+void __init setup_ioapic_ids_from_mpc(void)
 {
         union IO_APIC_reg_00 reg_00;
         physid_mask_t phys_id_present_map;
@@ -2003,9 +2021,8 @@ static void __init setup_ioapic_ids_from_mpc(void)
         unsigned char old_id;
         unsigned long flags;
 
-        if (x86_quirks->setup_ioapic_ids && x86_quirks->setup_ioapic_ids())
+        if (acpi_ioapic)
                 return;
-
         /*
          * Don't check I/O APIC IDs for xAPIC systems.  They have
          * no meaning without the serial APIC bus.
@@ -2179,7 +2196,7 @@ static unsigned int startup_ioapic_irq(unsigned int irq)
         struct irq_cfg *cfg;
 
         spin_lock_irqsave(&ioapic_lock, flags);
-        if (irq < NR_IRQS_LEGACY) {
+        if (irq < nr_legacy_irqs) {
                 disable_8259A_irq(irq);
                 if (i8259A_irq_pending(irq))
                         was_pending = 1;
@@ -2657,7 +2674,7 @@ static inline void init_IO_APIC_traps(void)
                          * so default to an old-fashioned 8259
                          * interrupt if we can..
                          */
-                        if (irq < NR_IRQS_LEGACY)
+                        if (irq < nr_legacy_irqs)
                                 make_8259A_irq(irq);
                         else
                                 /* Strange. Oh, well.. */
@@ -2993,7 +3010,7 @@ out:
  * the I/O APIC in all cases now.  No actual device should request
  * it anyway.  --macro
  */
-#define PIC_IRQS        (1 << PIC_CASCADE_IR)
+#define PIC_IRQS        (1UL << PIC_CASCADE_IR)
 
 void __init setup_IO_APIC(void)
 {
@@ -3001,21 +3018,19 @@ void __init setup_IO_APIC(void)
         /*
          * calling enable_IO_APIC() is moved to setup_local_APIC for BP
          */
-
-        io_apic_irqs = ~PIC_IRQS;
+        io_apic_irqs = nr_legacy_irqs ? ~PIC_IRQS : ~0UL;
 
         apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
         /*
          * Set up IO-APIC IRQ routing.
          */
-#ifdef CONFIG_X86_32
-        if (!acpi_ioapic)
-                setup_ioapic_ids_from_mpc();
-#endif
+        x86_init.mpparse.setup_ioapic_ids();
+
         sync_Arb_IDs();
         setup_IO_APIC_irqs();
         init_IO_APIC_traps();
-        check_timer();
+        if (nr_legacy_irqs)
+                check_timer();
 }
 
 /*
@@ -3116,7 +3131,6 @@ static int __init ioapic_init_sysfs(void)
 
 device_initcall(ioapic_init_sysfs);
 
-static int nr_irqs_gsi = NR_IRQS_LEGACY;
 /*
  * Dynamic irq allocate and deallocation
  */
@@ -3856,7 +3870,7 @@ static int __io_apic_set_pci_routing(struct device *dev, int irq,
         /*
          * IRQs < 16 are already in the irq_2_pin[] map
          */
-        if (irq >= NR_IRQS_LEGACY) {
+        if (irq >= nr_legacy_irqs) {
                 cfg = desc->chip_data;
                 if (add_pin_to_irq_node_nopanic(cfg, node, ioapic, pin)) {
                         printk(KERN_INFO "can not add pin %d for irq %d\n",