x86/UV: Fix conditional in gru_exit()

Fix supported system conditional in gru_exit(), in preparation for UV3.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Link: http://lkml.kernel.org/r/20140331152320.GA31495@sgi.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

drivers/misc/sgi-gru/grufile.c

@@ -6,7 +6,7 @@
  * This file supports the user system call for file open, close, mmap, etc.
  * This also incudes the driver initialization code.
  *
- *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ *  Copyright (c) 2008-2014 Silicon Graphics, Inc.  All Rights Reserved.
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -58,6 +58,11 @@ static int max_user_cbrs, max_user_dsr_bytes;
 
 static struct miscdevice gru_miscdev;
 
+static int gru_supported(void)
+{
+	return is_uv_system() &&
+		(uv_hub_info->hub_revision < UV3_HUB_REVISION_BASE);
+}
 
 /*
  * gru_vma_close
@@ -518,7 +523,7 @@ static int __init gru_init(void)
 {
 	int ret;
 
-	if (!is_uv_system() || (is_uvx_hub() && !is_uv2_hub()))
+	if (!gru_supported())
 		return 0;
 
 #if defined CONFIG_IA64
@@ -573,7 +578,7 @@ static int __init gru_init(void)
 
 static void __exit gru_exit(void)
 {
-	if (!is_uv_system())
+	if (!gru_supported())
 		return;
 
 	gru_teardown_tlb_irqs();