#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 <linux/pfn.h>
#include <asm/percpu.h>
/* enough to cover all DEFINE_PER_CPUs in modules */
#ifdef CONFIG_MODULES
#define PERCPU_MODULE_RESERVE (8 << 10)
#else
#define PERCPU_MODULE_RESERVE 0
#endif
#ifndef PERCPU_ENOUGH_ROOM
#define PERCPU_ENOUGH_ROOM \
(ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
PERCPU_MODULE_RESERVE)
#endif
/*
* 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
#ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
/* minimum unit size, also is the maximum supported allocation size */
#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10)
/*
* PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
* back on the first chunk for dynamic percpu allocation if arch is
* manually allocating and mapping it for faster access (as a part of
* large page mapping for example).
*
* The following values give between one and two pages of free space
* after typical minimal boot (2-way SMP, single disk and NIC) with
* both defconfig and a distro config on x86_64 and 32. More
* intelligent way to determine this would be nice.
*/
#if BITS_PER_LONG > 32
#define PERCPU_DYNAMIC_RESERVE (20 << 10)
#else
#define PERCPU_DYNAMIC_RESERVE (12 << 10)
#endif
extern void *pcpu_base_addr;
typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno);
typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr);
extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
size_t static_size, size_t reserved_size,
ssize_t dyn_size, ssize_t unit_size,
void *base_addr,
pcpu_populate_pte_fn_t populate_pte_fn);
extern ssize_t __init pcpu_embed_first_chunk(
size_t static_size, size_t reserved_size,
ssize_t dyn_size, ssize_t unit_size);
/*
* 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 per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
extern void *__alloc_reserved_percpu(size_t size, size_t align);
#else /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
struct percpu_data {
void *ptrs[1];
};
#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
#define per_cpu_ptr(ptr, cpu) \
({ \
struct percpu_data *__p = __percpu_disguise(ptr); \
(__typeof__(ptr))__p->ptrs[(cpu)]; \
})
#endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
extern void *__alloc_percpu(size_t size, size_t align);
extern void free_percpu(void *__pdata);
#else /* CONFIG_SMP */
#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
static inline void *__alloc_percpu(size_t size, size_t align)
{
/*
* Can't easily make larger alignment work with kmalloc. WARN
* on it. Larger alignment should only be used for module
* percpu sections on SMP for which this path isn't used.
*/
WARN_ON_ONCE(align > SMP_CACHE_BYTES);
return kzalloc(size, GFP_KERNEL);
}
static inline void free_percpu(void *p)
{
kfree(p);
}
#endif /* CONFIG_SMP */
#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
__alignof__(type))
/*
* 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 /* __LINUX_PERCPU_H */
