x86_read_per_cpu() and its writeish sister are not present in x86_64. So in
this patch, we replace them with __get_cpu_var(), which is present in both
Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>