Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _ASM_GENERIC_PERCPU_H_ |
| 2 | #define _ASM_GENERIC_PERCPU_H_ |
| 3 | #include <linux/compiler.h> |
Rusty Russell | ae1ee11 | 2007-05-02 19:27:10 +0200 | [diff] [blame] | 4 | #include <linux/threads.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | |
travis@sgi.com | acdac87 | 2008-01-30 13:32:52 +0100 | [diff] [blame] | 6 | /* |
| 7 | * Determine the real variable name from the name visible in the |
| 8 | * kernel sources. |
| 9 | */ |
| 10 | #define per_cpu_var(var) per_cpu__##var |
| 11 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #ifdef CONFIG_SMP |
| 13 | |
travis@sgi.com | acdac87 | 2008-01-30 13:32:52 +0100 | [diff] [blame] | 14 | /* |
| 15 | * per_cpu_offset() is the offset that has to be added to a |
| 16 | * percpu variable to get to the instance for a certain processor. |
| 17 | * |
| 18 | * Most arches use the __per_cpu_offset array for those offsets but |
| 19 | * some arches have their own ways of determining the offset (x86_64, s390). |
| 20 | */ |
| 21 | #ifndef __per_cpu_offset |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | extern unsigned long __per_cpu_offset[NR_CPUS]; |
| 23 | |
Ingo Molnar | a875a69 | 2006-07-03 00:24:26 -0700 | [diff] [blame] | 24 | #define per_cpu_offset(x) (__per_cpu_offset[x]) |
travis@sgi.com | acdac87 | 2008-01-30 13:32:52 +0100 | [diff] [blame] | 25 | #endif |
Ingo Molnar | a875a69 | 2006-07-03 00:24:26 -0700 | [diff] [blame] | 26 | |
travis@sgi.com | acdac87 | 2008-01-30 13:32:52 +0100 | [diff] [blame] | 27 | /* |
| 28 | * Determine the offset for the currently active processor. |
| 29 | * An arch may define __my_cpu_offset to provide a more effective |
| 30 | * means of obtaining the offset to the per cpu variables of the |
| 31 | * current processor. |
| 32 | */ |
| 33 | #ifndef __my_cpu_offset |
| 34 | #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id()) |
| 35 | #define my_cpu_offset per_cpu_offset(smp_processor_id()) |
| 36 | #else |
| 37 | #define my_cpu_offset __my_cpu_offset |
| 38 | #endif |
| 39 | |
| 40 | /* |
| 41 | * Add a offset to a pointer but keep the pointer as is. |
| 42 | * |
| 43 | * Only S390 provides its own means of moving the pointer. |
| 44 | */ |
| 45 | #ifndef SHIFT_PERCPU_PTR |
| 46 | #define SHIFT_PERCPU_PTR(__p, __offset) RELOC_HIDE((__p), (__offset)) |
| 47 | #endif |
| 48 | |
| 49 | /* |
| 50 | * A percpu variable may point to a discarded reghions. The following are |
| 51 | * established ways to produce a usable pointer from the percpu variable |
| 52 | * offset. |
| 53 | */ |
| 54 | #define per_cpu(var, cpu) \ |
| 55 | (*SHIFT_PERCPU_PTR(&per_cpu_var(var), per_cpu_offset(cpu))) |
| 56 | #define __get_cpu_var(var) \ |
| 57 | (*SHIFT_PERCPU_PTR(&per_cpu_var(var), my_cpu_offset)) |
| 58 | #define __raw_get_cpu_var(var) \ |
| 59 | (*SHIFT_PERCPU_PTR(&per_cpu_var(var), __my_cpu_offset)) |
| 60 | |
| 61 | |
| 62 | #ifdef CONFIG_ARCH_SETS_UP_PER_CPU_AREA |
| 63 | extern void setup_per_cpu_areas(void); |
| 64 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | |
| 66 | /* A macro to avoid #include hell... */ |
| 67 | #define percpu_modcopy(pcpudst, src, size) \ |
| 68 | do { \ |
| 69 | unsigned int __i; \ |
KAMEZAWA Hiroyuki | 0a94502 | 2006-03-28 01:56:37 -0800 | [diff] [blame] | 70 | for_each_possible_cpu(__i) \ |
travis@sgi.com | acdac87 | 2008-01-30 13:32:52 +0100 | [diff] [blame] | 71 | memcpy((pcpudst)+per_cpu_offset(__i), \ |
Andrew Morton | 394e390 | 2006-03-23 03:01:05 -0800 | [diff] [blame] | 72 | (src), (size)); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | } while (0) |
| 74 | #else /* ! SMP */ |
| 75 | |
travis@sgi.com | acdac87 | 2008-01-30 13:32:52 +0100 | [diff] [blame] | 76 | #define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var))) |
| 77 | #define __get_cpu_var(var) per_cpu_var(var) |
| 78 | #define __raw_get_cpu_var(var) per_cpu_var(var) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | #endif /* SMP */ |
| 81 | |
travis@sgi.com | acdac87 | 2008-01-30 13:32:52 +0100 | [diff] [blame] | 82 | #ifndef PER_CPU_ATTRIBUTES |
| 83 | #define PER_CPU_ATTRIBUTES |
| 84 | #endif |
| 85 | |
| 86 | #define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \ |
| 87 | __typeof__(type) per_cpu_var(name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | #endif /* _ASM_GENERIC_PERCPU_H_ */ |