4764 Need a way to get tsc deltas
Reviewed by: Keith M Wesolowski <wesolows@foobazco.org>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Richard Lowe <richlowe@richlowe.net>

*** 234,243 ****
--- 234,256 ----
          } while ((old_hres_lock & ~1) != hres_lock);
  
          return (hrt);
  }
  
+ hrtime_t
+ tsc_gethrtime_tick_delta(void)
+ {
+         hrtime_t hrt;
+         ulong_t flags;
+ 
+         flags = clear_int_flag();
+         hrt = tsc_sync_tick_delta[CPU->cpu_id];
+         restore_int_flag(flags);
+ 
+         return (hrt);
+ }
+ 
  /*
   * This is similar to the above, but it cannot actually spin on hres_lock.
   * As a result, it caches all of the variables it needs; if the variables
   * don't change, it's done.
   */