drm/i915: split irq handling into per-chipset functions

Set the IRQ handling functions in driver load so they'll just be used
directly, rather than branching over most of the code in the chipset
functions.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index b1ddcdc..a3ee159 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1266,6 +1266,18 @@
 
 	intel_modeset_gem_init(dev);
 
+	if (HAS_PCH_SPLIT(dev)) {
+		dev->driver->irq_handler = ironlake_irq_handler;
+		dev->driver->irq_preinstall = ironlake_irq_preinstall;
+		dev->driver->irq_postinstall = ironlake_irq_postinstall;
+		dev->driver->irq_uninstall = ironlake_irq_uninstall;
+	} else {
+		dev->driver->irq_preinstall = i915_driver_irq_preinstall;
+		dev->driver->irq_postinstall = i915_driver_irq_postinstall;
+		dev->driver->irq_uninstall = i915_driver_irq_uninstall;
+		dev->driver->irq_handler = i915_driver_irq_handler;
+	}
+
 	ret = drm_irq_install(dev);
 	if (ret)
 		goto cleanup_gem;