#ifndef _ASM_GENERIC_PERCPU_H_
#define _ASM_GENERIC_PERCPU_H_
#include <linux/compiler.h>
#include <linux/threads.h>
/*
* Determine the real variable name from the name visible in the
* kernel sources.
*/
#define per_cpu_var(var) per_cpu__##var
#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))
#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)
#endif /* SMP */
#ifndef PER_CPU_ATTRIBUTES
#define PER_CPU_ATTRIBUTES
#endif
#define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \
__typeof__(type) per_cpu_var(name)
/*
* Optional methods for optimized non-lvalue per-cpu variable access.
*
* @var can be a percpu variable or a field of it and its size should
* equal char, int or long. percpu_read() evaluates to a lvalue and
* all others to void.
*
* These operations are guaranteed to be atomic w.r.t. preemption.
* The generic versions use plain get/put_cpu_var(). Archs are
* encouraged to implement single-instruction alternatives which don't
* require preemption protection.
*/
#ifndef percpu_read
# define percpu_read(var) \
({ \
typeof(per_cpu_var(var)) __tmp_var__; \
__tmp_var__ = get_cpu_var(var); \
put_cpu_var(var); \
__tmp_var__; \
})
#endif
#define __percpu_generic_to_op(var, val, op) \
do { \
get_cpu_var(var) op val; \
put_cpu_var(var); \
} while (0)
#ifndef percpu_write
# define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
#endif
#ifndef percpu_add
# define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
#endif
#ifndef percpu_sub
# define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
#endif
#ifndef percpu_and
# define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
#endif
#ifndef percpu_or
# define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
#endif
#ifndef percpu_xor
# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
#endif
#endif /* _ASM_GENERIC_PERCPU_H_ */
