drm/gem: convert to new unified vma manager

Use the new vma manager instead of the old hashtable. Also convert all
drivers to use the new convenience helpers. This drops all the
(map_list.hash.key << PAGE_SHIFT) non-sense.

Locking and access-management is exactly the same as before with an
additional lock inside of the vma-manager, which strictly wouldn't be
needed for gem.

v2:
 - rebase on drm-next
 - init nodes via drm_vma_node_reset() in drm_gem.c
v3:
 - fix tegra
v4:
 - remove duplicate if (drm_vma_node_has_offset()) checks
 - inline now trivial drm_vma_node_offset_addr() calls
v5:
 - skip node-reset on gem-init due to kzalloc()
 - do not allow mapping gem-objects with offsets (backwards compat)
 - remove unneccessary casts

Cc: Inki Dae <inki.dae@samsung.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@gmail.com>

include/drm/drmP.h

@@ -71,6 +71,7 @@
 #include <asm/pgalloc.h>
 #include <drm/drm.h>
 #include <drm/drm_sarea.h>
+#include <drm/drm_vma_manager.h>
 
 #include <linux/idr.h>
 
@@ -587,7 +588,6 @@ struct drm_map_list {
 	struct drm_local_map *map;	/**< mapping */
 	uint64_t user_token;
 	struct drm_master *master;
-	struct drm_mm_node *file_offset_node;	/**< fake offset */
 };
 
 /**
@@ -622,8 +622,7 @@ struct drm_ati_pcigart_info {
  * GEM specific mm private for tracking GEM objects
  */
 struct drm_gem_mm {
-	struct drm_mm offset_manager;	/**< Offset mgmt for buffer objects */
-	struct drm_open_hash offset_hash; /**< User token hash table for maps */
+	struct drm_vma_offset_manager vma_manager;
 };
 
 /**
@@ -644,7 +643,7 @@ struct drm_gem_object {
 	struct file *filp;
 
 	/* Mapping info for this object */
-	struct drm_map_list map_list;
+	struct drm_vma_offset_node vma_node;
 
 	/**
 	 * Size of the object, in bytes.  Immutable over the object's