drm/i915: Move MCHBAR setup earlier during init

Move the MCHBAR setup right after the MMIO setup, since the two things
are logically related and the MCHBAR setup code doesn't depend on any
other device specific resource. We'll also need MCHBAR to be ready
earlier in an upcoming patch, so this is also a preparation for that.

Factor out the init/clean-up code to separate functions to make things
clearer in the i915_driver_load()/unload() functions.
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: David Weinehall <david.weinehall@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453209992-25995-7-git-send-email-imre.deak@intel.com

drivers/gpu/drm/i915/i915_dma.c

@@ -904,6 +904,46 @@ static void i915_workqueues_cleanup(struct drm_i915_private *dev_priv)
 	destroy_workqueue(dev_priv->wq);
 }
 
+static int i915_mmio_setup(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	int mmio_bar;
+	int mmio_size;
+
+	mmio_bar = IS_GEN2(dev) ? 1 : 0;
+	/*
+	 * Before gen4, the registers and the GTT are behind different BARs.
+	 * However, from gen4 onwards, the registers and the GTT are shared
+	 * in the same BAR, so we want to restrict this ioremap from
+	 * clobbering the GTT which we want ioremap_wc instead. Fortunately,
+	 * the register BAR remains the same size for all the earlier
+	 * generations up to Ironlake.
+	 */
+	if (INTEL_INFO(dev)->gen < 5)
+		mmio_size = 512 * 1024;
+	else
+		mmio_size = 2 * 1024 * 1024;
+	dev_priv->regs = pci_iomap(dev->pdev, mmio_bar, mmio_size);
+	if (dev_priv->regs == NULL) {
+		DRM_ERROR("failed to map registers\n");
+
+		return -EIO;
+	}
+
+	/* Try to make sure MCHBAR is enabled before poking at it */
+	intel_setup_mchbar(dev);
+
+	return 0;
+}
+
+static void i915_mmio_cleanup(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = to_i915(dev);
+
+	intel_teardown_mchbar(dev);
+	pci_iounmap(dev->pdev, dev_priv->regs);
+}
+
 /**
  * i915_driver_load - setup chip and create an initial config
  * @dev: DRM device
@@ -919,7 +959,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 {
 	struct drm_i915_private *dev_priv;
 	struct intel_device_info *info, *device_info;
-	int ret = 0, mmio_bar, mmio_size;
+	int ret = 0;
 	uint32_t aperture_size;
 
 	info = (struct intel_device_info *) flags;
@@ -971,25 +1011,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 		goto out_runtime_pm_put;
 	}
 
-	mmio_bar = IS_GEN2(dev) ? 1 : 0;
-	/* Before gen4, the registers and the GTT are behind different BARs.
-	 * However, from gen4 onwards, the registers and the GTT are shared
-	 * in the same BAR, so we want to restrict this ioremap from
-	 * clobbering the GTT which we want ioremap_wc instead. Fortunately,
-	 * the register BAR remains the same size for all the earlier
-	 * generations up to Ironlake.
-	 */
-	if (info->gen < 5)
-		mmio_size = 512*1024;
-	else
-		mmio_size = 2*1024*1024;
-
-	dev_priv->regs = pci_iomap(dev->pdev, mmio_bar, mmio_size);
-	if (!dev_priv->regs) {
-		DRM_ERROR("failed to map registers\n");
-		ret = -EIO;
+	ret = i915_mmio_setup(dev);
+	if (ret < 0)
 		goto put_bridge;
-	}
 
 	/* This must be called before any calls to HAS_PCH_* */
 	intel_detect_pch(dev);
@@ -1047,8 +1071,6 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	intel_irq_init(dev_priv);
 	intel_uncore_sanitize(dev);
 
-	/* Try to make sure MCHBAR is enabled before poking at it */
-	intel_setup_mchbar(dev);
 	intel_opregion_setup(dev);
 
 	i915_gem_load_init(dev);
@@ -1129,7 +1151,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	i915_global_gtt_cleanup(dev);
 out_uncore_fini:
 	intel_uncore_fini(dev);
-	pci_iounmap(dev->pdev, dev_priv->regs);
+	i915_mmio_cleanup(dev);
 put_bridge:
 	pci_dev_put(dev_priv->bridge_dev);
 	i915_gem_load_cleanup(dev);
@@ -1213,15 +1235,12 @@ int i915_driver_unload(struct drm_device *dev)
 	intel_fbc_cleanup_cfb(dev_priv);
 	i915_gem_cleanup_stolen(dev);
 
-	intel_teardown_mchbar(dev);
-
 	pm_qos_remove_request(&dev_priv->pm_qos);
 
 	i915_global_gtt_cleanup(dev);
 
 	intel_uncore_fini(dev);
-	if (dev_priv->regs != NULL)
-		pci_iounmap(dev->pdev, dev_priv->regs);
+	i915_mmio_cleanup(dev);
 
 	i915_gem_load_cleanup(dev);
 	pci_dev_put(dev_priv->bridge_dev);