drm/i915: call intel_enable_gtt

When drm/i915 is in control of the gtt, we need to call
the enable function at all the relevant places ourselves.
Reviewed-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/char/agp/intel-gtt.c

@@ -777,7 +777,7 @@ static void i830_write_entry(dma_addr_t addr, unsigned int entry,
 	writel(addr | pte_flags, intel_private.gtt + entry);
 }
 
-static bool intel_enable_gtt(void)
+bool intel_enable_gtt(void)
 {
 	u8 __iomem *reg;
 
@@ -823,6 +823,7 @@ static bool intel_enable_gtt(void)
 
 	return true;
 }
+EXPORT_SYMBOL(intel_enable_gtt);
 
 static int i830_setup(void)
 {

drivers/gpu/drm/i915/i915_gem.c

@@ -3689,6 +3689,9 @@ i915_gem_init_hw(struct drm_device *dev)
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	int ret;
 
+	if (!intel_enable_gtt())
+		return -EIO;
+
 	i915_gem_l3_remap(dev);
 
 	i915_gem_init_swizzling(dev);

include/drm/intel-gtt.h

@@ -27,6 +27,8 @@ int intel_gmch_probe(struct pci_dev *bridge_pdev, struct pci_dev *gpu_pdev,
 		     struct agp_bridge_data *bridge);
 void intel_gmch_remove(void);
 
+bool intel_enable_gtt(void);
+
 void intel_gtt_chipset_flush(void);
 void intel_gtt_unmap_memory(struct scatterlist *sg_list, int num_sg);
 void intel_gtt_clear_range(unsigned int first_entry, unsigned int num_entries);