From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- include/linux/percpu.h | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 include/linux/percpu.h (limited to 'include/linux/percpu.h') diff --git a/include/linux/percpu.h b/include/linux/percpu.h new file mode 100644 index 000000000000..5451eb1e781d --- /dev/null +++ b/include/linux/percpu.h @@ -0,0 +1,61 @@ +#ifndef __LINUX_PERCPU_H +#define __LINUX_PERCPU_H +#include /* For preempt_disable() */ +#include /* For kmalloc() */ +#include +#include /* For memset() */ +#include + +/* 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]; + void *blkp; +}; + +/* + * 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, size_t align); +extern void free_percpu(const void *); + +#else /* CONFIG_SMP */ + +#define per_cpu_ptr(ptr, cpu) (ptr) + +static inline void *__alloc_percpu(size_t size, size_t align) +{ + 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), __alignof__(type)))) + +#endif /* __LINUX_PERCPU_H */ -- cgit v1.2.3