Commit | Line | Data |
---|---|---|
14318efb RH |
1 | /* |
2 | * Copyright 2012 Calxeda, Inc. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms and conditions of the GNU General Public License, | |
6 | * version 2, as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program. If not, see <http://www.gnu.org/licenses/>. | |
15 | */ | |
16 | #ifndef _ASM_ARM_PERCPU_H_ | |
17 | #define _ASM_ARM_PERCPU_H_ | |
18 | ||
19 | /* | |
20 | * Same as asm-generic/percpu.h, except that we store the per cpu offset | |
21 | * in the TPIDRPRW. TPIDRPRW only exists on V6K and V7 | |
22 | */ | |
23 | #if defined(CONFIG_SMP) && !defined(CONFIG_CPU_V6) | |
24 | static inline void set_my_cpu_offset(unsigned long off) | |
25 | { | |
26 | /* Set TPIDRPRW */ | |
27 | asm volatile("mcr p15, 0, %0, c13, c0, 4" : : "r" (off) : "memory"); | |
28 | } | |
29 | ||
30 | static inline unsigned long __my_cpu_offset(void) | |
31 | { | |
32 | unsigned long off; | |
509eb76e WD |
33 | |
34 | /* | |
35 | * Read TPIDRPRW. | |
36 | * We want to allow caching the value, so avoid using volatile and | |
37 | * instead use a fake stack read to hazard against barrier(). | |
38 | */ | |
ccbd2da5 MC |
39 | asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) |
40 | : "Q" (*(const unsigned long *)current_stack_pointer)); | |
509eb76e | 41 | |
14318efb RH |
42 | return off; |
43 | } | |
44 | #define __my_cpu_offset __my_cpu_offset() | |
45 | #else | |
46 | #define set_my_cpu_offset(x) do {} while(0) | |
47 | ||
48 | #endif /* CONFIG_SMP */ | |
49 | ||
50 | #include <asm-generic/percpu.h> | |
51 | ||
52 | #endif /* _ASM_ARM_PERCPU_H_ */ |