arch/arm64/include/asm/percpu.h

   1 /*
   2  * Copyright (C) 2013 ARM Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #ifndef __ASM_PERCPU_H
  17 #define __ASM_PERCPU_H
  18
  19 #if 0 //def CONFIG_SMP
  20
  21 static inline void set_my_cpu_offset(unsigned long off)
  22 {
  23         asm volatile("msr tpidr_el1, %0" :: "r" (off) : "memory");
  24 }
  25
  26 static inline unsigned long __my_cpu_offset(void)
  27 {
  28         unsigned long off;
  29         register unsigned long *sp asm ("sp");
  30
  31         /*
  32          * We want to allow caching the value, so avoid using volatile and
  33          * instead use a fake stack read to hazard against barrier().
  34          */
  35         asm("mrs %0, tpidr_el1" : "=r" (off) : "Q" (*sp));
  36
  37         return off;
  38 }
  39 #define __my_cpu_offset __my_cpu_offset()
  40
  41 #else   /* !CONFIG_SMP */
  42
  43 #define set_my_cpu_offset(x)    do { } while (0)
  44
  45 #endif /* CONFIG_SMP */
  46
  47 #include <asm-generic/percpu.h>
  48
  49 #endif /* __ASM_PERCPU_H */