1/*
2 * @TAG(OTHER_GPL)
3 */
4#pragma once
5
6#include <errno.h>
7
8
9/*
10 * Kernel pointers have redundant information, so we can use a
11 * scheme where we can return either an error code or a dentry
12 * pointer with the same return value.
13 *
14 * This should be a per-architecture thing, to allow different
15 * error and pointer decisions.
16 */
17#define MAX_ERRNO   4095
18
19#ifndef __ASSEMBLY__
20
21#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
22
23static inline void *ERR_PTR(long error)
24{
25    return (void *) error;
26}
27
28static inline long PTR_ERR(const void *ptr)
29{
30    return (long) ptr;
31}
32
33static inline long IS_ERR(const void *ptr)
34{
35    return IS_ERR_VALUE((unsigned long)ptr);
36}
37
38/**
39 * ERR_CAST - Explicitly cast an error-valued pointer to another pointer type
40 * @ptr: The pointer to cast.
41 *
42 * Explicitly cast an error-valued pointer to another pointer type in such a
43 * way as to make it clear that's what's going on.
44 */
45static inline void *__must_check ERR_CAST(__force const void *ptr)
46{
47    /* cast away the const */
48    return (void *) ptr;
49}
50
51#endif
52