drm/vmwgfx: Add support for CursorMob and CursorBypass 4

* Add support for CursorMob
* Add support for CursorBypass 4
* Refactor vmw_du_cursor_plane_atomic_update to be kms-helper-atomic
  -- move BO mappings to vmw_du_cursor_plane_prepare_fb
  -- move BO unmappings to vmw_du_cursor_plane_cleanup_fb

Cursor mobs are a new svga feature which enables support for large
cursors, e.g. large accessibility cursor on platforms with vmwgfx. It
also cleans up the cursor code and makes it more uniform with the rest
of modern guest backed objects support.

Signed-off-by: Martin Krastev <[email protected]>
Reviewed-by: Zack Rusin <[email protected]>
Reviewed-by: Maaz Mombasawala <[email protected]>
Signed-off-by: Zack Rusin <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: Martin Krastev

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0 OR MIT
 /**************************************************************************
  *
- * Copyright 2009-2016 VMware, Inc., Palo Alto, CA., USA
+ * Copyright 2009-2022 VMware, Inc., Palo Alto, CA., USA
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the

drivers/gpu/drm/vmwgfx/vmwgfx_drv.h

@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
 /**************************************************************************
  *
- * Copyright 2009-2021 VMware, Inc., Palo Alto, CA., USA
+ * Copyright 2009-2022 VMware, Inc., Palo Alto, CA., USA
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
@@ -101,6 +101,7 @@ struct vmw_fpriv {
  * struct vmw_buffer_object - TTM buffer object with vmwgfx additions
  * @base: The TTM buffer object
  * @res_tree: RB tree of resources using this buffer object as a backing MOB
+ * @base_mapped_count: ttm BO mapping count; used by KMS atomic helpers.
  * @cpu_writers: Number of synccpu write grabs. Protected by reservation when
  * increased. May be decreased without reservation.
  * @dx_query_ctx: DX context if this buffer object is used as a DX query MOB
@@ -111,6 +112,9 @@ struct vmw_fpriv {
 struct vmw_buffer_object {
 	struct ttm_buffer_object base;
 	struct rb_root res_tree;
+	/* For KMS atomic helpers: ttm bo mapping count */
+	atomic_t base_mapped_count;
+
 	atomic_t cpu_writers;
 	/* Not ref-counted.  Protected by binding_mutex */
 	struct vmw_resource *dx_query_ctx;