[linux-block.git] / include / asm-generic / percpu.h

#ifndef _ASM_GENERIC_PERCPU_H_
#define _ASM_GENERIC_PERCPU_H_

#include <linux/compiler.h>
#include <linux/threads.h>
#include <linux/percpu-defs.h>

#ifdef CONFIG_SMP

/*
 * per_cpu_offset() is the offset that has to be added to a
 * percpu variable to get to the instance for a certain processor.
 *
 * Most arches use the __per_cpu_offset array for those offsets but
 * some arches have their own ways of determining the offset (x86_64, s390).
 */
#ifndef __per_cpu_offset
extern unsigned long __per_cpu_offset[NR_CPUS];

#define per_cpu_offset(x) (__per_cpu_offset[x])
#endif

/*
 * Determine the offset for the currently active processor.
 * An arch may define __my_cpu_offset to provide a more effective
 * means of obtaining the offset to the per cpu variables of the
 * current processor.
 */
#ifndef __my_cpu_offset
#define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
#endif
#ifdef CONFIG_DEBUG_PREEMPT
#define my_cpu_offset per_cpu_offset(smp_processor_id())
#else
#define my_cpu_offset __my_cpu_offset
#endif

/*
 * Add a offset to a pointer but keep the pointer as is.
 *
 * Only S390 provides its own means of moving the pointer.
 */
#ifndef SHIFT_PERCPU_PTR
#define SHIFT_PERCPU_PTR(__p, __offset)	RELOC_HIDE((__p), (__offset))
#endif

/*
 * A percpu variable may point to a discarded regions. The following are
 * established ways to produce a usable pointer from the percpu variable
 * offset.
 */
#define per_cpu(var, cpu) \
	(*SHIFT_PERCPU_PTR(&per_cpu_var(var), per_cpu_offset(cpu)))
#define __get_cpu_var(var) \
	(*SHIFT_PERCPU_PTR(&per_cpu_var(var), my_cpu_offset))
#define __raw_get_cpu_var(var) \
	(*SHIFT_PERCPU_PTR(&per_cpu_var(var), __my_cpu_offset))

#define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset)
#define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)


#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
extern void setup_per_cpu_areas(void);
#endif

#else /* ! SMP */

#define per_cpu(var, cpu)			(*((void)(cpu), &per_cpu_var(var)))
#define __get_cpu_var(var)			per_cpu_var(var)
#define __raw_get_cpu_var(var)			per_cpu_var(var)
#define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0)
#define __this_cpu_ptr(ptr) this_cpu_ptr(ptr)

#endif	/* SMP */

#ifndef PER_CPU_BASE_SECTION
#ifdef CONFIG_SMP
#define PER_CPU_BASE_SECTION ".data.percpu"
#else
#define PER_CPU_BASE_SECTION ".data"
#endif
#endif

#ifdef CONFIG_SMP

#ifdef MODULE
#define PER_CPU_SHARED_ALIGNED_SECTION ""
#define PER_CPU_ALIGNED_SECTION ""
#else
#define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned"
#define PER_CPU_ALIGNED_SECTION ".shared_aligned"
#endif
#define PER_CPU_FIRST_SECTION ".first"

#else

#define PER_CPU_SHARED_ALIGNED_SECTION ""
#define PER_CPU_ALIGNED_SECTION ".shared_aligned"
#define PER_CPU_FIRST_SECTION ""

#endif

#ifndef PER_CPU_ATTRIBUTES
#define PER_CPU_ATTRIBUTES
#endif

#ifndef PER_CPU_DEF_ATTRIBUTES
#define PER_CPU_DEF_ATTRIBUTES
#endif

#endif /* _ASM_GENERIC_PERCPU_H_ */
Commit	Line	Data
1da177e4 LT	1	#ifndef _ASM_GENERIC_PERCPU_H_
1da177e4 LT	2	#define _ASM_GENERIC_PERCPU_H_
5028eaa9	3
1da177e4	4	#include <linux/compiler.h>
ae1ee11b	5	#include <linux/threads.h>
5028eaa9	6	#include <linux/percpu-defs.h>
acdac872	7
1da177e4 LT	8	#ifdef CONFIG_SMP
1da177e4 LT	9
acdac872	10	/*
	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
1da177e4 LT	18	extern unsigned long __per_cpu_offset[NR_CPUS];
1da177e4 LT	19
a875a69f	20	#define per_cpu_offset(x) (__per_cpu_offset[x])
acdac872	21	#endif
	22
	23	/*
	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())
1e835278 HD	31	#endif
1e835278 HD	32	#ifdef CONFIG_DEBUG_PREEMPT
acdac872	33	#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
	44	#define SHIFT_PERCPU_PTR(__p, __offset) RELOC_HIDE((__p), (__offset))
	45	#endif
a875a69f	46
acdac872	47	/*
dd5af90a	48	* A percpu variable may point to a discarded regions. The following are
acdac872	49	* established ways to produce a usable pointer from the percpu variable
	50	* offset.
	51	*/
	52	#define per_cpu(var, cpu) \
	53	(*SHIFT_PERCPU_PTR(&per_cpu_var(var), per_cpu_offset(cpu)))
	54	#define __get_cpu_var(var) \
	55	(*SHIFT_PERCPU_PTR(&per_cpu_var(var), my_cpu_offset))
	56	#define __raw_get_cpu_var(var) \
	57	(*SHIFT_PERCPU_PTR(&per_cpu_var(var), __my_cpu_offset))
	58
7340a0b1 CL	59	#define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset)
	60	#define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)
	61
acdac872	62
dd5af90a	63	#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
acdac872	64	extern void setup_per_cpu_areas(void);
acdac872	65	#endif
1da177e4	66
1da177e4 LT	67	#else /* ! SMP */
1da177e4 LT	68
acdac872	69	#define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var)))
	70	#define __get_cpu_var(var) per_cpu_var(var)
	71	#define __raw_get_cpu_var(var) per_cpu_var(var)
7340a0b1 CL	72	#define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0)
7340a0b1 CL	73	#define __this_cpu_ptr(ptr) this_cpu_ptr(ptr)
1da177e4 LT	74
	75	#endif /* SMP */
	76
9b8de747 DH	77	#ifndef PER_CPU_BASE_SECTION
	78	#ifdef CONFIG_SMP
	79	#define PER_CPU_BASE_SECTION ".data.percpu"
	80	#else
	81	#define PER_CPU_BASE_SECTION ".data"
	82	#endif
	83	#endif
	84
	85	#ifdef CONFIG_SMP
	86
	87	#ifdef MODULE
	88	#define PER_CPU_SHARED_ALIGNED_SECTION ""
53f82452	89	#define PER_CPU_ALIGNED_SECTION ""
9b8de747 DH	90	#else
9b8de747 DH	91	#define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned"
53f82452	92	#define PER_CPU_ALIGNED_SECTION ".shared_aligned"
9b8de747 DH	93	#endif
	94	#define PER_CPU_FIRST_SECTION ".first"
	95
	96	#else
	97
	98	#define PER_CPU_SHARED_ALIGNED_SECTION ""
53f82452	99	#define PER_CPU_ALIGNED_SECTION ".shared_aligned"
9b8de747 DH	100	#define PER_CPU_FIRST_SECTION ""
	101
	102	#endif
	103
acdac872	104	#ifndef PER_CPU_ATTRIBUTES
	105	#define PER_CPU_ATTRIBUTES
	106	#endif
	107
b01e8dc3 TH	108	#ifndef PER_CPU_DEF_ATTRIBUTES
	109	#define PER_CPU_DEF_ATTRIBUTES
	110	#endif
	111
1da177e4	112	#endif /* _ASM_GENERIC_PERCPU_H_ */