PAGE_MASK no longer defined on all arches.

diff --git a/bogl.c b/bogl.c
index 5b3a9f0..06a20f5 100644
--- a/bogl.c
+++ b/bogl.c
@@ -40,9 +40,11 @@
 #include <termios.h>
 #include <unistd.h>
 
+#if 0 /* stopped being safe.. */
 /* Yes, I know, we shouldn't be including headers from the kernel.  But
    XFree86 also uses this one (to get PAGE_MASK) so it's probably safe.  */
 #include <asm/page.h>
+#endif
 
 #include "bogl.h"
 #include "boglP.h"
@@ -112,6 +114,7 @@ bogl_init (void)
   unsigned long bogl_frame_offset, bogl_frame_len;
   struct fb_var_screeninfo fb_var;
   struct vt_stat vts;
+  int PAGE_MASK = ~(sysconf(_SC_PAGESIZE) - 1);
 
   assert (status < 2);
   visible = 1;
