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