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 #ifdef 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 */ 50