blob: 0703aa75b5e8eda4c8f469a74925e171804bdd92 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _ASM_GENERIC_PERCPU_H_
2#define _ASM_GENERIC_PERCPU_H_
David Howells5028eaa2009-04-21 23:00:29 +01003
Linus Torvalds1da177e2005-04-16 15:20:36 -07004#include <linux/compiler.h>
Rusty Russellae1ee112007-05-02 19:27:10 +02005#include <linux/threads.h>
David Howells5028eaa2009-04-21 23:00:29 +01006#include <linux/percpu-defs.h>
travis@sgi.comacdac872008-01-30 13:32:52 +01007
Linus Torvalds1da177e2005-04-16 15:20:36 -07008#ifdef CONFIG_SMP
9
travis@sgi.comacdac872008-01-30 13:32:52 +010010/*
11 * per_cpu_offset() is the offset that has to be added to a
12 * percpu variable to get to the instance for a certain processor.
13 *
14 * Most arches use the __per_cpu_offset array for those offsets but
15 * some arches have their own ways of determining the offset (x86_64, s390).
16 */
17#ifndef __per_cpu_offset
Linus Torvalds1da177e2005-04-16 15:20:36 -070018extern unsigned long __per_cpu_offset[NR_CPUS];
19
Ingo Molnara875a692006-07-03 00:24:26 -070020#define per_cpu_offset(x) (__per_cpu_offset[x])
travis@sgi.comacdac872008-01-30 13:32:52 +010021#endif
Ingo Molnara875a692006-07-03 00:24:26 -070022
travis@sgi.comacdac872008-01-30 13:32:52 +010023/*
24 * Determine the offset for the currently active processor.
25 * An arch may define __my_cpu_offset to provide a more effective
26 * means of obtaining the offset to the per cpu variables of the
27 * current processor.
28 */
29#ifndef __my_cpu_offset
30#define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
Hugh Dickins1e835272008-02-23 19:40:17 +000031#endif
32#ifdef CONFIG_DEBUG_PREEMPT
travis@sgi.comacdac872008-01-30 13:32:52 +010033#define my_cpu_offset per_cpu_offset(smp_processor_id())
34#else
35#define my_cpu_offset __my_cpu_offset
36#endif
37
38/*
39 * Add a offset to a pointer but keep the pointer as is.
40 *
41 * Only S390 provides its own means of moving the pointer.
42 */
43#ifndef SHIFT_PERCPU_PTR
Rusty Russelle0fdb0e2009-10-29 22:34:15 +090044/* Weird cast keeps both GCC and sparse happy. */
Tejun Heo545695f2009-10-29 22:34:15 +090045#define SHIFT_PERCPU_PTR(__p, __offset) ({ \
46 __verify_pcpu_ptr((__p)); \
47 RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)); \
48})
travis@sgi.comacdac872008-01-30 13:32:52 +010049#endif
50
51/*
Mike Travisdd5af902008-01-30 13:33:32 +010052 * A percpu variable may point to a discarded regions. The following are
travis@sgi.comacdac872008-01-30 13:32:52 +010053 * established ways to produce a usable pointer from the percpu variable
54 * offset.
55 */
56#define per_cpu(var, cpu) \
Rusty Russelldd17c8f2009-10-29 22:34:15 +090057 (*SHIFT_PERCPU_PTR(&(var), per_cpu_offset(cpu)))
travis@sgi.comacdac872008-01-30 13:32:52 +010058
Christoph Lameterb3ca1c12014-04-07 15:39:34 -070059#ifndef raw_cpu_ptr
60#define raw_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)
Brian Gerstdb7829c2010-09-09 18:17:26 +020061#endif
62#ifdef CONFIG_DEBUG_PREEMPT
63#define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset)
64#else
Christoph Lameterb3ca1c12014-04-07 15:39:34 -070065#define this_cpu_ptr(ptr) raw_cpu_ptr(ptr)
Brian Gerstdb7829c2010-09-09 18:17:26 +020066#endif
travis@sgi.comacdac872008-01-30 13:32:52 +010067
Brian Gerst677243d2010-09-09 18:17:26 +020068#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
Christoph Lameterb3ca1c12014-04-07 15:39:34 -070069#define __raw_get_cpu_var(var) (*raw_cpu_ptr(&(var)))
Brian Gerst677243d2010-09-09 18:17:26 +020070
Mike Travisdd5af902008-01-30 13:33:32 +010071#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
travis@sgi.comacdac872008-01-30 13:32:52 +010072extern void setup_per_cpu_areas(void);
73#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Linus Torvalds1da177e2005-04-16 15:20:36 -070075#else /* ! SMP */
76
Namhyung Kim18cb2aef2010-08-07 03:26:23 +090077#define VERIFY_PERCPU_PTR(__p) ({ \
78 __verify_pcpu_ptr((__p)); \
79 (typeof(*(__p)) __kernel __force *)(__p); \
80})
81
82#define per_cpu(var, cpu) (*((void)(cpu), VERIFY_PERCPU_PTR(&(var))))
83#define __get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var)))
84#define __raw_get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var)))
85#define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0)
Christoph Lameterb3ca1c12014-04-07 15:39:34 -070086#define raw_cpu_ptr(ptr) this_cpu_ptr(ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88#endif /* SMP */
89
David Howells9b8de742009-04-21 23:00:24 +010090#ifndef PER_CPU_BASE_SECTION
91#ifdef CONFIG_SMP
Denys Vlasenko3d9a8542010-02-20 01:03:43 +010092#define PER_CPU_BASE_SECTION ".data..percpu"
David Howells9b8de742009-04-21 23:00:24 +010093#else
94#define PER_CPU_BASE_SECTION ".data"
95#endif
96#endif
97
98#ifdef CONFIG_SMP
99
100#ifdef MODULE
101#define PER_CPU_SHARED_ALIGNED_SECTION ""
Jeremy Fitzhardinge53f82452009-09-03 14:31:44 -0700102#define PER_CPU_ALIGNED_SECTION ""
David Howells9b8de742009-04-21 23:00:24 +0100103#else
Denys Vlasenko3d9a8542010-02-20 01:03:43 +0100104#define PER_CPU_SHARED_ALIGNED_SECTION "..shared_aligned"
105#define PER_CPU_ALIGNED_SECTION "..shared_aligned"
David Howells9b8de742009-04-21 23:00:24 +0100106#endif
Denys Vlasenko3d9a8542010-02-20 01:03:43 +0100107#define PER_CPU_FIRST_SECTION "..first"
David Howells9b8de742009-04-21 23:00:24 +0100108
109#else
110
111#define PER_CPU_SHARED_ALIGNED_SECTION ""
Denys Vlasenko3d9a8542010-02-20 01:03:43 +0100112#define PER_CPU_ALIGNED_SECTION "..shared_aligned"
David Howells9b8de742009-04-21 23:00:24 +0100113#define PER_CPU_FIRST_SECTION ""
114
115#endif
116
travis@sgi.comacdac872008-01-30 13:32:52 +0100117#ifndef PER_CPU_ATTRIBUTES
118#define PER_CPU_ATTRIBUTES
119#endif
120
Tejun Heob01e8dc2009-06-30 11:41:18 -0700121#ifndef PER_CPU_DEF_ATTRIBUTES
122#define PER_CPU_DEF_ATTRIBUTES
123#endif
124
Christoph Lameterb3ca1c12014-04-07 15:39:34 -0700125/* Keep until we have removed all uses of __this_cpu_ptr */
126#define __this_cpu_ptr raw_cpu_ptr
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128#endif /* _ASM_GENERIC_PERCPU_H_ */