#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 <linux/cpumask.h>
+
#include <asm/percpu.h>
/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
#define PERCPU_ENOUGH_ROOM 32768
#endif
-/* Must be an lvalue. */
-#define get_cpu_var(var) (*({ preempt_disable(); &__get_cpu_var(var); }))
+/*
+ * 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[NR_CPUS];
- void *blkp;
};
+#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
/*
- * Use this to get to a cpu's version of the per-cpu object allocated using
- * alloc_percpu. If you want to get "this cpu's version", maybe you want
- * to use get_cpu_ptr...
+ * 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) \
-({ \
- struct percpu_data *__p = (struct percpu_data *)~(unsigned long)(ptr); \
- (__typeof__(ptr))__p->ptrs[(cpu)]; \
+#define percpu_ptr(ptr, cpu) \
+({ \
+ struct percpu_data *__p = __percpu_disguise(ptr); \
+ (__typeof__(ptr))__p->ptrs[(cpu)]; \
})
-extern void *__alloc_percpu(size_t size, size_t align);
-extern void free_percpu(const void *);
+extern void *percpu_populate(void *__pdata, size_t size, gfp_t gfp, int cpu);
+extern void percpu_depopulate(void *__pdata, int cpu);
+extern int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
+ cpumask_t *mask);
+extern void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask);
+extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask);
+extern void percpu_free(void *__pdata);
#else /* CONFIG_SMP */
-#define per_cpu_ptr(ptr, cpu) (ptr)
+#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
+
+static inline void percpu_depopulate(void *__pdata, int cpu)
+{
+}
-static inline void *__alloc_percpu(size_t size, size_t align)
+static inline void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask)
{
- void *ret = kmalloc(size, GFP_KERNEL);
- if (ret)
- memset(ret, 0, size);
- return ret;
}
-static inline void free_percpu(const void *ptr)
-{
- kfree(ptr);
+
+static inline void *percpu_populate(void *__pdata, size_t size, gfp_t gfp,
+ int cpu)
+{
+ return percpu_ptr(__pdata, cpu);
+}
+
+static inline int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
+ cpumask_t *mask)
+{
+ return 0;
+}
+
+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 */
-/* Simple wrapper for the common case: zeros memory. */
-#define alloc_percpu(type) \
- ((type *)(__alloc_percpu(sizeof(type), __alignof__(type))))
+#define percpu_populate_mask(__pdata, size, gfp, mask) \
+ __percpu_populate_mask((__pdata), (size), (gfp), &(mask))
+#define percpu_depopulate_mask(__pdata, mask) \
+ __percpu_depopulate_mask((__pdata), &(mask))
+#define percpu_alloc_mask(size, gfp, mask) \
+ __percpu_alloc_mask((size), (gfp), &(mask))
-/*
- * Use these with alloc_percpu. If
- * 1. You want to operate on memory allocated by alloc_percpu (dereference
- * and read/modify/write) AND
- * 2. You want "this cpu's version" of the object AND
- * 3. You want to do this safely since:
- * a. On multiprocessors, you don't want to switch between cpus after
- * you've read the current processor id due to preemption -- this would
- * take away the implicit advantage to not have any kind of traditional
- * serialization for per-cpu data
- * b. On uniprocessors, you don't want another kernel thread messing
- * up with the same per-cpu data due to preemption
- *
- * So, Use get_cpu_ptr to disable preemption and get pointer to the
- * local cpu version of the per-cpu object. Use put_cpu_ptr to enable
- * preemption. Operations on per-cpu data between get_ and put_ is
- * then considered to be safe. And ofcourse, "Thou shalt not sleep between
- * get_cpu_ptr and put_cpu_ptr"
- */
-#define get_cpu_ptr(ptr) per_cpu_ptr(ptr, get_cpu())
-#define put_cpu_ptr(ptr) put_cpu()
+#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 */
git://git.onelab.eu / linux-2.6.git / blobdiff