x86: arch specific support for remapping HPET MSIs

x86 arch support for remapping HPET MSI's by associating the HPET timer block
with the interrupt-remapping HW unit and setting up appropriate irq_chip

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Jay Fenlason <fenlason@redhat.com>
LKML-Reference: <20090804190729.630510000@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index ba575f0..7f024ff 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -33,6 +33,7 @@
  * HPET address is set in acpi/boot.c, when an ACPI entry exists
  */
 unsigned long				hpet_address;
+u8					hpet_blockid; /* OS timer block num */
 #ifdef CONFIG_PCI_MSI
 static unsigned long			hpet_num_timers;
 #endif
@@ -467,7 +468,7 @@
 
 static int hpet_setup_msi_irq(unsigned int irq)
 {
-	if (arch_setup_hpet_msi(irq)) {
+	if (arch_setup_hpet_msi(irq, hpet_blockid)) {
 		destroy_irq(irq);
 		return -EINVAL;
 	}