drm/i915: Split out load time HW initialization

According to the new init phases scheme we should have a definite step
in the init sequence where we setup things requiring accessing the
device, so move the corresponding code to separate function. The steps
in this init phase should avoid exposing the driver via some interface,
which is done in the last registration init phase. This changae also
has the benefit of making the error path cleaner both in the new
function and i915_driver_load()/unload().

No functional change.

Suggested by Chris.

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1458128348-15730-17-git-send-email-imre.deak@intel.com

drivers/gpu/drm/i915/i915_dma.c

@@ -1095,45 +1095,23 @@ static void i915_driver_cleanup_mmio(struct drm_i915_private *dev_priv)
 }
 
 /**
- * i915_driver_load - setup chip and create an initial config
- * @dev: DRM device
- * @flags: startup flags
+ * i915_driver_init_hw - setup state requiring device access
+ * @dev_priv: device private
  *
- * The driver load routine has to do several things:
- *   - drive output discovery via intel_modeset_init()
- *   - initialize the memory manager
- *   - allocate initial config memory
- *   - setup the DRM framebuffer with the allocated memory
+ * Setup state that requires accessing the device, but doesn't require
+ * exposing the driver via kernel internal or userspace interfaces.
  */
-int i915_driver_load(struct drm_device *dev, unsigned long flags)
+static int i915_driver_init_hw(struct drm_i915_private *dev_priv)
 {
-	struct drm_i915_private *dev_priv;
-	int ret = 0;
+	struct drm_device *dev = dev_priv->dev;
 	uint32_t aperture_size;
-
-	dev_priv = kzalloc(sizeof(*dev_priv), GFP_KERNEL);
-	if (dev_priv == NULL)
-		return -ENOMEM;
-
-	dev->dev_private = dev_priv;
-
-	ret = i915_driver_init_early(dev_priv, dev,
-				     (struct intel_device_info *)flags);
-
-	if (ret < 0)
-		goto out_free_priv;
-
-	intel_runtime_pm_get(dev_priv);
-
-	ret = i915_driver_init_mmio(dev_priv);
-	if (ret < 0)
-		goto out_runtime_pm_put;
+	int ret;
 
 	intel_device_info_runtime_init(dev);
 
 	ret = i915_gem_gtt_init(dev);
 	if (ret)
-		goto out_cleanup_mmio;
+		return ret;
 
 	/* WARNING: Apparently we must kick fbdev drivers before vgacon,
 	 * otherwise the vga fbdev driver falls over. */
@@ -1204,10 +1182,73 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 			DRM_DEBUG_DRIVER("can't enable MSI");
 	}
 
+	return 0;
+
+out_gtt:
+	i915_global_gtt_cleanup(dev);
+
+	return ret;
+}
+
+/**
+ * i915_driver_cleanup_hw - cleanup the setup done in i915_driver_init_hw()
+ * @dev_priv: device private
+ */
+static void i915_driver_cleanup_hw(struct drm_i915_private *dev_priv)
+{
+	struct drm_device *dev = dev_priv->dev;
+
+	if (dev->pdev->msi_enabled)
+		pci_disable_msi(dev->pdev);
+
+	pm_qos_remove_request(&dev_priv->pm_qos);
+	arch_phys_wc_del(dev_priv->gtt.mtrr);
+	io_mapping_free(dev_priv->gtt.mappable);
+	i915_global_gtt_cleanup(dev);
+}
+
+/**
+ * i915_driver_load - setup chip and create an initial config
+ * @dev: DRM device
+ * @flags: startup flags
+ *
+ * The driver load routine has to do several things:
+ *   - drive output discovery via intel_modeset_init()
+ *   - initialize the memory manager
+ *   - allocate initial config memory
+ *   - setup the DRM framebuffer with the allocated memory
+ */
+int i915_driver_load(struct drm_device *dev, unsigned long flags)
+{
+	struct drm_i915_private *dev_priv;
+	int ret = 0;
+
+	dev_priv = kzalloc(sizeof(*dev_priv), GFP_KERNEL);
+	if (dev_priv == NULL)
+		return -ENOMEM;
+
+	dev->dev_private = dev_priv;
+
+	ret = i915_driver_init_early(dev_priv, dev,
+				     (struct intel_device_info *)flags);
+
+	if (ret < 0)
+		goto out_free_priv;
+
+	intel_runtime_pm_get(dev_priv);
+
+	ret = i915_driver_init_mmio(dev_priv);
+	if (ret < 0)
+		goto out_runtime_pm_put;
+
+	ret = i915_driver_init_hw(dev_priv);
+	if (ret < 0)
+		goto out_cleanup_mmio;
+
 	if (INTEL_INFO(dev)->num_pipes) {
 		ret = drm_vblank_init(dev, INTEL_INFO(dev)->num_pipes);
 		if (ret)
-			goto out_disable_msi;
+			goto out_cleanup_hw;
 	}
 
 	ret = i915_load_modeset_init(dev);
@@ -1246,15 +1287,8 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 out_power_well:
 	intel_power_domains_fini(dev_priv);
 	drm_vblank_cleanup(dev);
-out_disable_msi:
-	if (dev->pdev->msi_enabled)
-		pci_disable_msi(dev->pdev);
-
-	pm_qos_remove_request(&dev_priv->pm_qos);
-	arch_phys_wc_del(dev_priv->gtt.mtrr);
-	io_mapping_free(dev_priv->gtt.mappable);
-out_gtt:
-	i915_global_gtt_cleanup(dev);
+out_cleanup_hw:
+	i915_driver_cleanup_hw(dev_priv);
 out_cleanup_mmio:
 	i915_driver_cleanup_mmio(dev_priv);
 out_runtime_pm_put:
@@ -1330,13 +1364,7 @@ int i915_driver_unload(struct drm_device *dev)
 
 	intel_power_domains_fini(dev_priv);
 
-	if (dev->pdev->msi_enabled)
-		pci_disable_msi(dev->pdev);
-	pm_qos_remove_request(&dev_priv->pm_qos);
-	arch_phys_wc_del(dev_priv->gtt.mtrr);
-	io_mapping_free(dev_priv->gtt.mappable);
-	i915_global_gtt_cleanup(dev);
-
+	i915_driver_cleanup_hw(dev_priv);
 	i915_driver_cleanup_mmio(dev_priv);
 
 	intel_display_power_put(dev_priv, POWER_DOMAIN_INIT);