#ifndef __LINUX_PERCPU_H #define __LINUX_PERCPU_H #include <linux/spinlock.h> /* For preempt_disable() */ #include <linux/slab.h> /* For kmalloc() */ #include <linux/smp.h> #include <linux/string.h> /* For memset() */ #include <asm/percpu.h> /* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */ #ifndef PERCPU_ENOUGH_ROOM #define PERCPU_ENOUGH_ROOM 32768 #endif /* Must be an lvalue. */ #define get_cpu_var(var) (*({ preempt_disable(); &__get_cpu_var(var); })) #define put_cpu_var(var) preempt_enable() #ifdef CONFIG_SMP struct percpu_data { void *ptrs[NR_CPUS]; }; /* * Use this to get to a cpu's version of the per-cpu object allocated using * alloc_percpu. Non-atomic access to the current CPU's version should * probably be combined with get_cpu()/put_cpu(). */ #define per_cpu_ptr(ptr, cpu) \ ({ \ struct percpu_data *__p = (struct percpu_data *)~(unsigned long)(ptr); \ (__typeof__(ptr))__p->ptrs[(cpu)]; \ }) extern void *__alloc_percpu(size_t size); extern void free_percpu(const void *); #else /* CONFIG_SMP */ #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); }) static inline void *__alloc_percpu(size_t size) { void *ret = kmalloc(size, GFP_KERNEL); if (ret) memset(ret, 0, size); return ret; } static inline void free_percpu(const void *ptr) { kfree(ptr); } #endif /* CONFIG_SMP */ /* Simple wrapper for the common case: zeros memory. */ #define alloc_percpu(type) ((type *)(__alloc_percpu(sizeof(type)))) #endif /* __LINUX_PERCPU_H */