x86, acpi/irq: Fix acpi_sci_ioapic_setup so it has both bus_irq and gsi

Currently acpi_sci_ioapic_setup calls mp_override_legacy_irq with
bus_irq == gsi, which is wrong if we are comming from an override
Instead pass the bus_irq into acpi_sci_ioapic_setup.

This fix was inspired by a similar fix from:
Yinghai Lu <yinghai@kernel.org>

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
LKML-Reference: <1269936436-7039-4-git-send-email-ebiederm@xmission.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/acpi/boot.c

@@ -313,7 +313,7 @@ acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
 /*
  * Parse Interrupt Source Override for the ACPI SCI
  */
-static void __init acpi_sci_ioapic_setup(u32 gsi, u16 polarity, u16 trigger)
+static void __init acpi_sci_ioapic_setup(u8 bus_irq, u16 polarity, u16 trigger, u32 gsi)
 {
 	if (trigger == 0)	/* compatible SCI trigger is level */
 		trigger = 3;
@@ -333,7 +333,7 @@ static void __init acpi_sci_ioapic_setup(u32 gsi, u16 polarity, u16 trigger)
 	 * If GSI is < 16, this will update its flags,
 	 * else it will create a new mp_irqs[] entry.
 	 */
-	mp_override_legacy_irq(gsi, polarity, trigger, gsi);
+	mp_override_legacy_irq(bus_irq, polarity, trigger, gsi);
 
 	/*
 	 * stash over-ride to indicate we've been here
@@ -357,9 +357,10 @@ acpi_parse_int_src_ovr(struct acpi_subtable_header * header,
 	acpi_table_print_madt_entry(header);
 
 	if (intsrc->source_irq == acpi_gbl_FADT.sci_interrupt) {
-		acpi_sci_ioapic_setup(intsrc->global_irq,
+		acpi_sci_ioapic_setup(intsrc->source_irq,
 				      intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
-				      (intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
+				      (intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2,
+				      intsrc->global_irq);
 		return 0;
 	}
 
@@ -1162,7 +1163,8 @@ static int __init acpi_parse_madt_ioapic_entries(void)
 	 * pretend we got one so we can set the SCI flags.
 	 */
 	if (!acpi_sci_override_gsi)
-		acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0);
+		acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0,
+				      acpi_gbl_FADT.sci_interrupt);
 
 	/* Fill in identity legacy mappings where no override */
 	mp_config_acpi_legacy_irqs();