GRU Driver V3: fixes to resolve code review comments

Fixes problems identified in a code review:
	- add comment with high level dscription of the GRU
	- prepend "gru_" to all global names
	- delete unused function
	- couple of trivial bug fixes

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/sgi-gru/grufile.c b/drivers/misc/sgi-gru/grufile.c
index 09c9c65..23c91f5 100644
--- a/drivers/misc/sgi-gru/grufile.c
+++ b/drivers/misc/sgi-gru/grufile.c
@@ -112,6 +112,10 @@
 	if ((vma->vm_flags & (VM_SHARED | VM_WRITE)) != (VM_SHARED | VM_WRITE))
 		return -EPERM;
 
+	if (vma->vm_start & (GRU_GSEG_PAGESIZE - 1) ||
+			vma->vm_end & (GRU_GSEG_PAGESIZE - 1))
+		return -EINVAL;
+
 	vma->vm_flags |=
 	    (VM_IO | VM_DONTCOPY | VM_LOCKED | VM_DONTEXPAND | VM_PFNMAP |
 			VM_RESERVED);
@@ -471,8 +475,8 @@
 module_init(gru_init);
 module_exit(gru_exit);
 
-module_param(options, ulong, 0644);
-MODULE_PARM_DESC(options, "Various debug options");
+module_param(gru_options, ulong, 0644);
+MODULE_PARM_DESC(gru_options, "Various debug options");
 
 MODULE_AUTHOR("Silicon Graphics, Inc.");
 MODULE_LICENSE("GPL");