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#if !defined(__XEN_ERR_H__) && !defined(__ASSEMBLY__)
#define __XEN_ERR_H__
#include <xen/compiler.h>
#include <xen/errno.h>
/*
* Kernel pointers have redundant information, so we can use a
* scheme where we can return either an error code or a dentry
* pointer with the same return value.
*
* This could be a per-architecture thing, to allow different
* error and pointer decisions.
*/
#define MAX_ERRNO 4095
#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
static inline void *__must_check ERR_PTR(long error)
{
return (void *)error;
}
static inline long __must_check PTR_ERR(const void *ptr)
{
return (long)ptr;
}
static inline long __must_check IS_ERR(const void *ptr)
{
return IS_ERR_VALUE((unsigned long)ptr);
}
static inline long __must_check IS_ERR_OR_NULL(const void *ptr)
{
return !ptr || IS_ERR_VALUE((unsigned long)ptr);
}
/**
* ERR_CAST - Explicitly cast an error-valued pointer to another pointer type
* @ptr: The pointer to cast.
*
* Explicitly cast an error-valued pointer to another pointer type in such a
* way as to make it clear that's what's going on.
*/
static inline void * __must_check ERR_CAST(const void *ptr)
{
/* cast away the const */
return (void *)ptr;
}
static inline int __must_check PTR_RET(const void *ptr)
{
return IS_ERR(ptr) ? PTR_ERR(ptr) : 0;
}
#endif /* __XEN_ERR_H__ */
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