[RFC 3/9] drm/agp: fix AGP cleanup paths

[David Herrmann <dh.herrmann@gmail.com>]

Introduce two new helpers, drm_agp_clear() and drm_agp_destroy() which
clear all AGP mappings and destroy the AGP head. This allows to reduce the
AGP code in core DRM and move it all to drm_agpsupport.c.

Also use these new helpers to clean up AGP allocations in the
drm_dev_register() error path.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
---
 drivers/gpu/drm/drm_agpsupport.c | 51 ++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_drv.c        | 21 +----------------
 drivers/gpu/drm/drm_pci.c        | 12 ++++++++++
 drivers/gpu/drm/drm_stub.c       | 12 ++++------
 include/drm/drmP.h               |  3 +++
 5 files changed, 71 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/drm_agpsupport.c b/drivers/gpu/drm/drm_agpsupport.c
index 3d8fed1..e301d65 100644
--- a/drivers/gpu/drm/drm_agpsupport.c
+++ b/drivers/gpu/drm/drm_agpsupport.c
@@ -424,6 +424,57 @@ struct drm_agp_head *drm_agp_init(struct drm_device *dev)
 }
 
 /**
+ * drm_agp_clear - Clear AGP resource list
+ * @dev: DRM device
+ *
+ * Iterate over all AGP resources and remove them. But keep the AGP head
+ * intact so it can still be used. It is safe to call this if AGP is disabled or
+ * was already removed.
+ *
+ * If DRIVER_MODESET is active, nothing is done to protect the modesetting
+ * resources from getting destroyed. Drivers are responsible of cleaning them up
+ * during device shutdown.
+ */
+void drm_agp_clear(struct drm_device *dev)
+{
+	struct drm_agp_mem *entry, *tempe;
+
+	if (!drm_core_has_AGP(dev) || !dev->agp)
+		return;
+	if (drm_core_check_feature(dev, DRIVER_MODESET))
+		return;
+
+	list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
+		if (entry->bound)
+			drm_unbind_agp(entry->memory);
+		drm_free_agp(entry->memory, entry->pages);
+		kfree(entry);
+	}
+	INIT_LIST_HEAD(&dev->agp->memory);
+
+	if (dev->agp->acquired)
+		drm_agp_release(dev);
+
+	dev->agp->acquired = 0;
+	dev->agp->enabled = 0;
+}
+
+/**
+ * drm_agp_destroy - Destroy AGP head
+ * @dev: DRM device
+ *
+ * Destroy resources that were previously allocated via drm_agp_initp. Caller
+ * must ensure to clean up all AGP resources before calling this. See
+ * drm_agp_clear().
+ *
+ * Call this to destroy AGP heads allocated via drm_agp_init().
+ */
+void drm_agp_destroy(struct drm_agp_head *agp)
+{
+	kfree(agp);
+}
+
+/**
  * Binds a collection of pages into AGP memory at the given offset, returning
  * the AGP memory structure containing them.
  *
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 36103d1..dddd799 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -195,27 +195,8 @@ int drm_lastclose(struct drm_device * dev)
 
 	mutex_lock(&dev->struct_mutex);
 
-	/* Clear AGP information */
-	if (drm_core_has_AGP(dev) && dev->agp &&
-			!drm_core_check_feature(dev, DRIVER_MODESET)) {
-		struct drm_agp_mem *entry, *tempe;
-
-		/* Remove AGP resources, but leave dev->agp
-		   intact until drv_cleanup is called. */
-		list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
-			if (entry->bound)
-				drm_unbind_agp(entry->memory);
-			drm_free_agp(entry->memory, entry->pages);
-			kfree(entry);
-		}
-		INIT_LIST_HEAD(&dev->agp->memory);
-
-		if (dev->agp->acquired)
-			drm_agp_release(dev);
+	drm_agp_clear(dev);
 
-		dev->agp->acquired = 0;
-		dev->agp->enabled = 0;
-	}
 	if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
 	    !drm_core_check_feature(dev, DRIVER_MODESET)) {
 		drm_sg_cleanup(dev->sg);
diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c
index ab861ca..0daee24 100644
--- a/drivers/gpu/drm/drm_pci.c
+++ b/drivers/gpu/drm/drm_pci.c
@@ -283,6 +283,17 @@ static int drm_pci_agp_init(struct drm_device *dev)
 	return 0;
 }
 
+static void drm_pci_agp_destroy(struct drm_device *dev)
+{
+	if (drm_core_has_AGP(dev) && dev->agp) {
+		if (drm_core_has_MTRR(dev))
+			arch_phys_wc_del(dev->agp->agp_mtrr);
+		drm_agp_clear(dev);
+		drm_agp_destroy(dev->agp);
+		dev->agp = NULL;
+	}
+}
+
 static struct drm_bus drm_pci_bus = {
 	.bus_type = DRIVER_BUS_PCI,
 	.get_irq = drm_pci_get_irq,
@@ -291,6 +302,7 @@ static struct drm_bus drm_pci_bus = {
 	.set_unique = drm_pci_set_unique,
 	.irq_by_busid = drm_pci_irq_by_busid,
 	.agp_init = drm_pci_agp_init,
+	.agp_destroy = drm_pci_agp_destroy,
 };
 
 /**
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index bc1d860..f016ed8 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -387,16 +387,11 @@ void drm_put_dev(struct drm_device *dev)
 
 	drm_lastclose(dev);
 
-	if (drm_core_has_MTRR(dev) && drm_core_has_AGP(dev) && dev->agp)
-		arch_phys_wc_del(dev->agp->agp_mtrr);
-
 	if (dev->driver->unload)
 		dev->driver->unload(dev);
 
-	if (drm_core_has_AGP(dev) && dev->agp) {
-		kfree(dev->agp);
-		dev->agp = NULL;
-	}
+	if (dev->driver->bus->agp_destroy)
+		dev->driver->bus->agp_destroy(dev);
 
 	drm_vblank_cleanup(dev);
 
@@ -575,7 +570,8 @@ err_control_node:
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		drm_put_minor(&dev->control);
 err_agp:
-	/* FIXME: cleanup AGP leftovers */
+	if (dev->driver->bus->agp_destroy)
+		dev->driver->bus->agp_destroy(dev);
 out_unlock:
 	mutex_unlock(&drm_global_mutex);
 	return ret;
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index ea5e130..30f83ee 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -737,6 +737,7 @@ struct drm_bus {
 	int (*irq_by_busid)(struct drm_device *dev, struct drm_irq_busid *p);
 	/* hooks that are for PCI */
 	int (*agp_init)(struct drm_device *dev);
+	void (*agp_destroy)(struct drm_device *dev);
 
 };
 
@@ -1454,6 +1455,8 @@ extern int drm_modeset_ctl(struct drm_device *dev, void *data,
 
 				/* AGP/GART support (drm_agpsupport.h) */
 extern struct drm_agp_head *drm_agp_init(struct drm_device *dev);
+extern void drm_agp_destroy(struct drm_agp_head *agp);
+extern void drm_agp_clear(struct drm_device *dev);
 extern int drm_agp_acquire(struct drm_device *dev);
 extern int drm_agp_acquire_ioctl(struct drm_device *dev, void *data,
 				 struct drm_file *file_priv);
-- 
1.8.3.3