2 files changed, 59 insertions, 6 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 07a63ce5811a..325fbbab7f89 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -94,6 +94,53 @@ enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_PIC;
 
 
 /*
+ * ISA irqs by default are the first 16 gsis but can be
+ * any gsi as specified by an interrupt source override.
+ */
+static u32 isa_irq_to_gsi[NR_IRQS_LEGACY] __read_mostly = {
+        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
+};
+
+static unsigned int gsi_to_irq(unsigned int gsi)
+{
+        unsigned int irq = gsi + NR_IRQS_LEGACY;
+        unsigned int i;
+
+        for (i = 0; i < NR_IRQS_LEGACY; i++) {
+                if (isa_irq_to_gsi[i] == gsi) {
+                        return i;
+                }
+        }
+
+        /* Provide an identity mapping of gsi == irq
+         * except on truly weird platforms that have
+         * non isa irqs in the first 16 gsis.
+         */
+        if (gsi >= NR_IRQS_LEGACY)
+                irq = gsi;
+        else
+                irq = gsi_end + 1 + gsi;
+
+        return irq;
+}
+
+static u32 irq_to_gsi(int irq)
+{
+        unsigned int gsi;
+
+        if (irq < NR_IRQS_LEGACY)
+                gsi = isa_irq_to_gsi[irq];
+        else if (irq <= gsi_end)
+                gsi = irq;
+        else if (irq <= (gsi_end + NR_IRQS_LEGACY))
+                gsi = irq - gsi_end;
+        else
+                gsi = 0xffffffff;
+
+        return gsi;
+}
+
+/*
  * Temporarily use the virtual area starting from FIX_IO_APIC_BASE_END,
  * to map the target physical address. The problem is that set_fixmap()
  * provides a single page, and it is possible that the page is not
@@ -449,7 +496,7 @@ void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger)
 
 int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
 {
-        *irq = gsi;
+        *irq = gsi_to_irq(gsi);
 
 #ifdef CONFIG_X86_IO_APIC
         if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
@@ -463,7 +510,7 @@ int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi)
 {
         if (isa_irq >= 16)
                 return -1;
-        *gsi = isa_irq;
+        *gsi = irq_to_gsi(isa_irq);
         return 0;
 }
 
@@ -491,7 +538,7 @@ int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
                 plat_gsi = mp_register_gsi(dev, gsi, trigger, polarity);
         }
 #endif
-        irq = plat_gsi;
+        irq = gsi_to_irq(plat_gsi);
 
         return irq;
 }
@@ -933,6 +980,8 @@ void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger, u32 gsi)
         mp_irq.dstirq = pin;    /* INTIN# */
 
         save_mp_irq(&mp_irq);
+
+        isa_irq_to_gsi[bus_irq] = gsi;
 }
 
 void __init mp_config_acpi_legacy_irqs(void)
@@ -1086,7 +1135,7 @@ int mp_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
         set_io_apic_irq_attr(&irq_attr, ioapic, ioapic_pin,
                              trigger == ACPI_EDGE_SENSITIVE ? 0 : 1,
                              polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
-        io_apic_set_pci_routing(dev, gsi, &irq_attr);
+        io_apic_set_pci_routing(dev, gsi_to_irq(gsi), &irq_attr);
 
         return gsi;
 }
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 9f3f6ca86dac..594827c3c615 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1037,7 +1037,11 @@ static int pin_2_irq(int idx, int apic, int pin)
                  */
                 if (ioapic_renumber_irq)
                         gsi = ioapic_renumber_irq(apic, gsi);
-                irq = gsi;
+
+                if (gsi >= NR_IRQS_LEGACY)
+                        irq = gsi;
+                else
+                        irq = gsi_end + 1 + gsi;
         }
 
 #ifdef CONFIG_X86_32
@@ -3852,7 +3856,7 @@ void __init probe_nr_irqs_gsi(void)
 {
         int nr;
 
-        nr = gsi_end + 1;
+        nr = gsi_end + 1 + NR_IRQS_LEGACY;
         if (nr > nr_irqs_gsi)
                 nr_irqs_gsi = nr;