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cfa460ad WJ |
1 | #ifndef _LINUX_ERR_H |
2 | #define _LINUX_ERR_H | |
3 | ||
cfa460ad | 4 | #include <linux/compiler.h> |
7b15e2bb | 5 | #include <linux/compat.h> |
cfa460ad | 6 | |
1221ce45 | 7 | #include <linux/errno.h> |
cfa460ad WJ |
8 | |
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 | ||
24 | static inline void *ERR_PTR(long error) | |
25 | { | |
8c59ca93 | 26 | return (void *)(CONFIG_ERR_PTR_OFFSET + error); |
cfa460ad WJ |
27 | } |
28 | ||
29 | static inline long PTR_ERR(const void *ptr) | |
30 | { | |
8c59ca93 | 31 | return ((long)ptr - CONFIG_ERR_PTR_OFFSET); |
cfa460ad WJ |
32 | } |
33 | ||
34 | static inline long IS_ERR(const void *ptr) | |
35 | { | |
8c59ca93 | 36 | return IS_ERR_VALUE((unsigned long)PTR_ERR(ptr)); |
cfa460ad WJ |
37 | } |
38 | ||
f790ca7c JT |
39 | static inline bool IS_ERR_OR_NULL(const void *ptr) |
40 | { | |
8c59ca93 | 41 | return !ptr || IS_ERR_VALUE((unsigned long)PTR_ERR(ptr)); |
f790ca7c JT |
42 | } |
43 | ||
cc96c9a7 HS |
44 | /** |
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 | */ | |
51 | static inline void * __must_check ERR_CAST(__force const void *ptr) | |
52 | { | |
53 | /* cast away the const */ | |
54 | return (void *) ptr; | |
55 | } | |
56 | ||
cfa460ad WJ |
57 | #endif |
58 | ||
59 | #endif /* _LINUX_ERR_H */ |