1#ifndef _LINUX_ERR_H 2#define _LINUX_ERR_H 3 4#include <linux/compiler.h> 5#include <linux/types.h> 6 7#include <asm/errno.h> 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 normal 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((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO) 22 23static inline void * __must_check ERR_PTR(long error) 24{ 25 return (void *) error; 26} 27 28static inline long __must_check PTR_ERR(__force const void *ptr) 29{ 30 return (long) ptr; 31} 32 33static inline bool __must_check IS_ERR(__force const void *ptr) 34{ 35 return IS_ERR_VALUE((unsigned long)ptr); 36} 37 38static inline bool __must_check IS_ERR_OR_NULL(__force const void *ptr) 39{ 40 return unlikely(!ptr) || IS_ERR_VALUE((unsigned long)ptr); 41} 42 43/** 44 * ERR_CAST - Explicitly cast an error-valued pointer to another pointer type 45 * @ptr: The pointer to cast. 46 * 47 * Explicitly cast an error-valued pointer to another pointer type in such a 48 * way as to make it clear that's what's going on. 49 */ 50static inline void * __must_check ERR_CAST(__force const void *ptr) 51{ 52 /* cast away the const */ 53 return (void *) ptr; 54} 55 56static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr) 57{ 58 if (IS_ERR(ptr)) 59 return PTR_ERR(ptr); 60 else 61 return 0; 62} 63 64/* Deprecated */ 65#define PTR_RET(p) PTR_ERR_OR_ZERO(p) 66 67#endif 68 69#endif /* _LINUX_ERR_H */ 70