[PATCH] genirq: x86_64 irq: Kill irq compression

With more irqs in the system we don't need this.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/mpparse.c b/arch/x86_64/kernel/mpparse.c
index b8d53df..b147ab1 100644
--- a/arch/x86_64/kernel/mpparse.c
+++ b/arch/x86_64/kernel/mpparse.c
@@ -790,20 +790,11 @@
 	}
 }
 
-#define MAX_GSI_NUM	4096
-
 int mp_register_gsi(u32 gsi, int triggering, int polarity)
 {
 	int ioapic = -1;
 	int ioapic_pin = 0;
 	int idx, bit = 0;
-	static int pci_irq = 16;
-	/*
-	 * Mapping between Global System Interrupts, which
-	 * represent all possible interrupts, to the IRQs
-	 * assigned to actual devices.
-	 */
-	static int gsi_to_irq[MAX_GSI_NUM];
 
 	if (acpi_irq_model != ACPI_IRQ_MODEL_IOAPIC)
 		return gsi;
@@ -836,42 +827,11 @@
 	if ((1<<bit) & mp_ioapic_routing[ioapic].pin_programmed[idx]) {
 		Dprintk(KERN_DEBUG "Pin %d-%d already programmed\n",
 			mp_ioapic_routing[ioapic].apic_id, ioapic_pin);
-		return gsi_to_irq[gsi];
+		return gsi;
 	}
 
 	mp_ioapic_routing[ioapic].pin_programmed[idx] |= (1<<bit);
 
-	if (triggering == ACPI_LEVEL_SENSITIVE) {
-		/*
-		 * For PCI devices assign IRQs in order, avoiding gaps
-		 * due to unused I/O APIC pins.
-		 */
-		int irq = gsi;
-		if (gsi < MAX_GSI_NUM) {
-			/*
-			 * Retain the VIA chipset work-around (gsi > 15), but
-			 * avoid a problem where the 8254 timer (IRQ0) is setup
-			 * via an override (so it's not on pin 0 of the ioapic),
-			 * and at the same time, the pin 0 interrupt is a PCI
-			 * type.  The gsi > 15 test could cause these two pins
-			 * to be shared as IRQ0, and they are not shareable.
-			 * So test for this condition, and if necessary, avoid
-			 * the pin collision.
-			 */
-			if (gsi > 15 || (gsi == 0 && !timer_uses_ioapic_pin_0))
-				gsi = pci_irq++;
-			/*
-			 * Don't assign IRQ used by ACPI SCI
-			 */
-			if (gsi == acpi_fadt.sci_int)
-				gsi = pci_irq++;
-			gsi_to_irq[irq] = gsi;
-		} else {
-			printk(KERN_ERR "GSI %u is too high\n", gsi);
-			return gsi;
-		}
-	}
-
 	io_apic_set_pci_routing(ioapic, ioapic_pin, gsi,
 		triggering == ACPI_EDGE_SENSITIVE ? 0 : 1,
 		polarity == ACPI_ACTIVE_HIGH ? 0 : 1);