ARM atomic_full_barrier implementation question

[Lael Jones]

Recently I was searching for a barrier type instruction for use on ARM
when working on a project and came across the implementation used in
the glibc ports directory in atomic.h for the ARM:

#ifdef __thumb2__
#define atomic_full_barrier() \
     __asm__ __volatile__                             \
         ("movw\tip, #0x0fa0\n\t"                         \
          "movt\tip, #0xffff\n\t"                         \
          "blx\tip"                               \
          : : : "ip", "lr", "cc", "memory");
#else
#define atomic_full_barrier() \
     __asm__ __volatile__                             \
         ("mov\tip, #0xffff0fff\n\t"                      \
          "mov\tlr, pc\n\t"                           \
          "add\tpc, ip, #(0xffff0fa0 - 0xffff0fff)"               \
          : : : "ip", "lr", "cc", "memory");
#endif

This looks to me like it is making a function call to a fixed address.
 Can someone explain exactly how this implements a barrier?  Does the
Linux kernel install some code at that specific address?

Thanks

Lael Jones