[deliverable/linux.git] / include / linux / percpu.h

#ifndef __LINUX_PERCPU_H
#define __LINUX_PERCPU_H

#include <linux/preempt.h>
#include <linux/slab.h> /* For kmalloc() */
#include <linux/smp.h>
#include <linux/cpumask.h>

#include <asm/percpu.h>

#ifdef CONFIG_SMP
#define DEFINE_PER_CPU(type, name)					\
	__attribute__((__section__(".data.percpu")))			\
	PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name

#ifdef MODULE
#define SHARED_ALIGNED_SECTION ".data.percpu"
#else
#define SHARED_ALIGNED_SECTION ".data.percpu.shared_aligned"
#endif

#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)			\
	__attribute__((__section__(SHARED_ALIGNED_SECTION)))		\
	PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name		\
	____cacheline_aligned_in_smp

#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name)			\
	__attribute__((__section__(".data.percpu.page_aligned")))	\
	PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
#else
#define DEFINE_PER_CPU(type, name)					\
	PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name

#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)		      \
	DEFINE_PER_CPU(type, name)

#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name)		      \
	DEFINE_PER_CPU(type, name)
#endif

#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)

/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
#ifndef PERCPU_ENOUGH_ROOM
#ifdef CONFIG_MODULES
#define PERCPU_MODULE_RESERVE	8192
#else
#define PERCPU_MODULE_RESERVE	0
#endif

#define PERCPU_ENOUGH_ROOM						\
	(__per_cpu_end - __per_cpu_start + PERCPU_MODULE_RESERVE)
#endif	/* PERCPU_ENOUGH_ROOM */

/*
 * Must be an lvalue. Since @var must be a simple identifier,
 * we force a syntax error here if it isn't.
 */
#define get_cpu_var(var) (*({				\
	extern int simple_identifier_##var(void);	\
	preempt_disable();				\
	&__get_cpu_var(var); }))
#define put_cpu_var(var) preempt_enable()

#ifdef CONFIG_SMP

struct percpu_data {
	void *ptrs[1];
};

#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
/* 
 * Use this to get to a cpu's version of the per-cpu object dynamically
 * allocated. Non-atomic access to the current CPU's version should
 * probably be combined with get_cpu()/put_cpu().
 */ 
#define percpu_ptr(ptr, cpu)                              \
({                                                        \
        struct percpu_data *__p = __percpu_disguise(ptr); \
        (__typeof__(ptr))__p->ptrs[(cpu)];	          \
})

extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask);
extern void percpu_free(void *__pdata);

#else /* CONFIG_SMP */

#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })

static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
{
	return kzalloc(size, gfp);
}

static inline void percpu_free(void *__pdata)
{
	kfree(__pdata);
}

#endif /* CONFIG_SMP */

#define percpu_alloc_mask(size, gfp, mask) \
	__percpu_alloc_mask((size), (gfp), &(mask))

#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)

/* (legacy) interface for use without CPU hotplug handling */

#define __alloc_percpu(size)	percpu_alloc_mask((size), GFP_KERNEL, \
						  cpu_possible_map)
#define alloc_percpu(type)	(type *)__alloc_percpu(sizeof(type))
#define free_percpu(ptr)	percpu_free((ptr))
#define per_cpu_ptr(ptr, cpu)	percpu_ptr((ptr), (cpu))

#endif /* __LINUX_PERCPU_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef __LINUX_PERCPU_H
1da177e4 LT	2	#define __LINUX_PERCPU_H
7ff6f082	3
0a3021f4	4	#include <linux/preempt.h>
1da177e4 LT	5	#include <linux/slab.h> /* For kmalloc() */
1da177e4 LT	6	#include <linux/smp.h>
7ff6f082 MP	7	#include <linux/cpumask.h>
7ff6f082 MP	8
1da177e4 LT	9	#include <asm/percpu.h>
1da177e4 LT	10
5280e004	11	#ifdef CONFIG_SMP
	12	#define DEFINE_PER_CPU(type, name) \
	13	__attribute__((__section__(".data.percpu"))) \
	14	PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
	15
44c81433 ED	16	#ifdef MODULE
	17	#define SHARED_ALIGNED_SECTION ".data.percpu"
	18	#else
	19	#define SHARED_ALIGNED_SECTION ".data.percpu.shared_aligned"
	20	#endif
	21
5280e004	22	#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \
44c81433	23	__attribute__((__section__(SHARED_ALIGNED_SECTION))) \
5280e004	24	PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name \
5280e004	25	____cacheline_aligned_in_smp
63cc8c75 ED	26
	27	#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \
	28	__attribute__((__section__(".data.percpu.page_aligned"))) \
	29	PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
5280e004	30	#else
	31	#define DEFINE_PER_CPU(type, name) \
	32	PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
	33
	34	#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \
	35	DEFINE_PER_CPU(type, name)
63cc8c75 ED	36
	37	#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \
	38	DEFINE_PER_CPU(type, name)
5280e004	39	#endif
	40
	41	#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
	42	#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
	43
1da177e4 LT	44	/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
1da177e4 LT	45	#ifndef PERCPU_ENOUGH_ROOM
b00742d3 JF	46	#ifdef CONFIG_MODULES
	47	#define PERCPU_MODULE_RESERVE 8192
	48	#else
	49	#define PERCPU_MODULE_RESERVE 0
1da177e4 LT	50	#endif
1da177e4 LT	51
b00742d3 JF	52	#define PERCPU_ENOUGH_ROOM \
	53	(__per_cpu_end - __per_cpu_start + PERCPU_MODULE_RESERVE)
	54	#endif /* PERCPU_ENOUGH_ROOM */
	55
632bbfee JB	56	/*
	57	* Must be an lvalue. Since @var must be a simple identifier,
	58	* we force a syntax error here if it isn't.
	59	*/
	60	#define get_cpu_var(var) (*({ \
a666ecfb	61	extern int simple_identifier_##var(void); \
632bbfee JB	62	preempt_disable(); \
632bbfee JB	63	&__get_cpu_var(var); }))
1da177e4 LT	64	#define put_cpu_var(var) preempt_enable()
	65
	66	#ifdef CONFIG_SMP
	67
	68	struct percpu_data {
b3242151	69	void *ptrs[1];
1da177e4 LT	70	};
1da177e4 LT	71
7ff6f082	72	#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
1da177e4	73	/*
7ff6f082 MP	74	* Use this to get to a cpu's version of the per-cpu object dynamically
7ff6f082 MP	75	* allocated. Non-atomic access to the current CPU's version should
1da177e4 LT	76	* probably be combined with get_cpu()/put_cpu().
1da177e4 LT	77	*/
7ff6f082 MP	78	#define percpu_ptr(ptr, cpu) \
	79	({ \
	80	struct percpu_data *__p = __percpu_disguise(ptr); \
	81	(__typeof__(ptr))__p->ptrs[(cpu)]; \
1da177e4 LT	82	})
1da177e4 LT	83
7ff6f082 MP	84	extern void __percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t mask);
7ff6f082 MP	85	extern void percpu_free(void *__pdata);
1da177e4 LT	86
	87	#else /* CONFIG_SMP */
	88
7ff6f082 MP	89	#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
7ff6f082 MP	90
0891a8d7	91	static __always_inline void __percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t mask)
7ff6f082 MP	92	{
	93	return kzalloc(size, gfp);
	94	}
	95
	96	static inline void percpu_free(void *__pdata)
	97	{
	98	kfree(__pdata);
1da177e4 LT	99	}
	100
	101	#endif /* CONFIG_SMP */
	102
7ff6f082 MP	103	#define percpu_alloc_mask(size, gfp, mask) \
	104	__percpu_alloc_mask((size), (gfp), &(mask))
	105
	106	#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)
	107
	108	/* (legacy) interface for use without CPU hotplug handling */
	109
	110	#define __alloc_percpu(size) percpu_alloc_mask((size), GFP_KERNEL, \
	111	cpu_possible_map)
	112	#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type))
	113	#define free_percpu(ptr) percpu_free((ptr))
	114	#define per_cpu_ptr(ptr, cpu) percpu_ptr((ptr), (cpu))
1da177e4 LT	115
1da177e4 LT	116	#endif /* __LINUX_PERCPU_H */