1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_ERR_H |
3 | #define _LINUX_ERR_H |
4 | |
5 | #include <linux/compiler.h> |
6 | #include <linux/types.h> |
7 | |
8 | #include <asm/errno.h> |
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 normal |
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((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO) |
23 | |
24 | static inline void * __must_check ERR_PTR(long error) |
25 | { |
26 | return (void *) error; |
27 | } |
28 | |
29 | static inline long __must_check PTR_ERR(__force const void *ptr) |
30 | { |
31 | return (long) ptr; |
32 | } |
33 | |
34 | static inline bool __must_check IS_ERR(__force const void *ptr) |
35 | { |
36 | return IS_ERR_VALUE((unsigned long)ptr); |
37 | } |
38 | |
39 | static inline bool __must_check IS_ERR_OR_NULL(__force const void *ptr) |
40 | { |
41 | return unlikely(!ptr) || IS_ERR_VALUE((unsigned long)ptr); |
42 | } |
43 | |
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 | |
57 | static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr) |
58 | { |
59 | if (IS_ERR(ptr)) |
60 | return PTR_ERR(ptr); |
61 | else |
62 | return 0; |
63 | } |
64 | |
65 | #endif |
66 | |
67 | #endif /* _LINUX_ERR_H */ |
68 | |