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William Juulcfa460a2007-10-31 13:53:06 +01001#ifndef _LINUX_ERR_H
2#define _LINUX_ERR_H
3
William Juulcfa460a2007-10-31 13:53:06 +01004#include <linux/compiler.h>
Mike Frysinger7b15e2b2012-04-09 13:39:55 +00005#include <linux/compat.h>
William Juulcfa460a2007-10-31 13:53:06 +01006
Masahiro Yamada1221ce42016-09-21 11:28:55 +09007#include <linux/errno.h>
William Juulcfa460a2007-10-31 13:53:06 +01008
9
10/*
11 * Kernel pointers have redundant information, so we can use a
12 * scheme where we can return either an error code or a dentry
13 * pointer with the same return value.
14 *
15 * This should be a per-architecture thing, to allow different
16 * error and pointer decisions.
17 */
18#define MAX_ERRNO 4095
19
20#ifndef __ASSEMBLY__
21
22#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
23
24static inline void *ERR_PTR(long error)
25{
26 return (void *) error;
27}
28
29static inline long PTR_ERR(const void *ptr)
30{
31 return (long) ptr;
32}
33
34static inline long IS_ERR(const void *ptr)
35{
36 return IS_ERR_VALUE((unsigned long)ptr);
37}
38
Jagan Tekif790ca72016-10-30 23:16:10 +053039static inline bool IS_ERR_OR_NULL(const void *ptr)
40{
41 return !ptr || IS_ERR_VALUE((unsigned long)ptr);
42}
43
Heiko Schochercc96c9a2014-06-24 10:10:02 +020044/**
45 * ERR_CAST - Explicitly cast an error-valued pointer to another pointer type
46 * @ptr: The pointer to cast.
47 *
48 * Explicitly cast an error-valued pointer to another pointer type in such a
49 * way as to make it clear that's what's going on.
50 */
51static inline void * __must_check ERR_CAST(__force const void *ptr)
52{
53 /* cast away the const */
54 return (void *) ptr;
55}
56
William Juulcfa460a2007-10-31 13:53:06 +010057#endif
58
59#endif /* _LINUX_ERR_H */