b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef __M68KNOMMU_UACCESS_H |
| 3 | #define __M68KNOMMU_UACCESS_H |
| 4 | |
| 5 | /* |
| 6 | * User space memory access functions |
| 7 | */ |
| 8 | #include <linux/mm.h> |
| 9 | #include <linux/string.h> |
| 10 | |
| 11 | #include <asm/segment.h> |
| 12 | |
| 13 | #define access_ok(addr,size) _access_ok((unsigned long)(addr),(size)) |
| 14 | |
| 15 | /* |
| 16 | * It is not enough to just have access_ok check for a real RAM address. |
| 17 | * This would disallow the case of code/ro-data running XIP in flash/rom. |
| 18 | * Ideally we would check the possible flash ranges too, but that is |
| 19 | * currently not so easy. |
| 20 | */ |
| 21 | static inline int _access_ok(unsigned long addr, unsigned long size) |
| 22 | { |
| 23 | return 1; |
| 24 | } |
| 25 | |
| 26 | /* |
| 27 | * These are the main single-value transfer routines. They automatically |
| 28 | * use the right size if we just have the right pointer type. |
| 29 | */ |
| 30 | |
| 31 | #define put_user(x, ptr) \ |
| 32 | ({ \ |
| 33 | int __pu_err = 0; \ |
| 34 | typeof(*(ptr)) __pu_val = (x); \ |
| 35 | switch (sizeof (*(ptr))) { \ |
| 36 | case 1: \ |
| 37 | __put_user_asm(__pu_err, __pu_val, ptr, b); \ |
| 38 | break; \ |
| 39 | case 2: \ |
| 40 | __put_user_asm(__pu_err, __pu_val, ptr, w); \ |
| 41 | break; \ |
| 42 | case 4: \ |
| 43 | __put_user_asm(__pu_err, __pu_val, ptr, l); \ |
| 44 | break; \ |
| 45 | case 8: \ |
| 46 | memcpy(ptr, &__pu_val, sizeof (*(ptr))); \ |
| 47 | break; \ |
| 48 | default: \ |
| 49 | __pu_err = __put_user_bad(); \ |
| 50 | break; \ |
| 51 | } \ |
| 52 | __pu_err; \ |
| 53 | }) |
| 54 | #define __put_user(x, ptr) put_user(x, ptr) |
| 55 | |
| 56 | extern int __put_user_bad(void); |
| 57 | |
| 58 | /* |
| 59 | * Tell gcc we read from memory instead of writing: this is because |
| 60 | * we do not write to any memory gcc knows about, so there are no |
| 61 | * aliasing issues. |
| 62 | */ |
| 63 | |
| 64 | #define __ptr(x) ((unsigned long *)(x)) |
| 65 | |
| 66 | #define __put_user_asm(err,x,ptr,bwl) \ |
| 67 | __asm__ ("move" #bwl " %0,%1" \ |
| 68 | : /* no outputs */ \ |
| 69 | :"d" (x),"m" (*__ptr(ptr)) : "memory") |
| 70 | |
| 71 | #define get_user(x, ptr) \ |
| 72 | ({ \ |
| 73 | int __gu_err = 0; \ |
| 74 | typeof(x) __gu_val = 0; \ |
| 75 | switch (sizeof(*(ptr))) { \ |
| 76 | case 1: \ |
| 77 | __get_user_asm(__gu_err, __gu_val, ptr, b, "=d"); \ |
| 78 | break; \ |
| 79 | case 2: \ |
| 80 | __get_user_asm(__gu_err, __gu_val, ptr, w, "=r"); \ |
| 81 | break; \ |
| 82 | case 4: \ |
| 83 | __get_user_asm(__gu_err, __gu_val, ptr, l, "=r"); \ |
| 84 | break; \ |
| 85 | case 8: \ |
| 86 | memcpy((void *) &__gu_val, ptr, sizeof (*(ptr))); \ |
| 87 | break; \ |
| 88 | default: \ |
| 89 | __gu_val = 0; \ |
| 90 | __gu_err = __get_user_bad(); \ |
| 91 | break; \ |
| 92 | } \ |
| 93 | (x) = (typeof(*(ptr))) __gu_val; \ |
| 94 | __gu_err; \ |
| 95 | }) |
| 96 | #define __get_user(x, ptr) get_user(x, ptr) |
| 97 | |
| 98 | extern int __get_user_bad(void); |
| 99 | |
| 100 | #define __get_user_asm(err,x,ptr,bwl,reg) \ |
| 101 | __asm__ ("move" #bwl " %1,%0" \ |
| 102 | : "=d" (x) \ |
| 103 | : "m" (*__ptr(ptr))) |
| 104 | |
| 105 | static inline unsigned long |
| 106 | raw_copy_from_user(void *to, const void __user *from, unsigned long n) |
| 107 | { |
| 108 | memcpy(to, (__force const void *)from, n); |
| 109 | return 0; |
| 110 | } |
| 111 | |
| 112 | static inline unsigned long |
| 113 | raw_copy_to_user(void __user *to, const void *from, unsigned long n) |
| 114 | { |
| 115 | memcpy((__force void *)to, from, n); |
| 116 | return 0; |
| 117 | } |
| 118 | #define INLINE_COPY_FROM_USER |
| 119 | #define INLINE_COPY_TO_USER |
| 120 | |
| 121 | /* |
| 122 | * Copy a null terminated string from userspace. |
| 123 | */ |
| 124 | |
| 125 | static inline long |
| 126 | strncpy_from_user(char *dst, const char *src, long count) |
| 127 | { |
| 128 | char *tmp; |
| 129 | strncpy(dst, src, count); |
| 130 | for (tmp = dst; *tmp && count > 0; tmp++, count--) |
| 131 | ; |
| 132 | return(tmp - dst); /* DAVIDM should we count a NUL ? check getname */ |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | * Return the size of a string (including the ending 0) |
| 137 | * |
| 138 | * Return 0 on exception, a value greater than N if too long |
| 139 | */ |
| 140 | static inline long strnlen_user(const char *src, long n) |
| 141 | { |
| 142 | return(strlen(src) + 1); /* DAVIDM make safer */ |
| 143 | } |
| 144 | |
| 145 | /* |
| 146 | * Zero Userspace |
| 147 | */ |
| 148 | |
| 149 | static inline unsigned long |
| 150 | __clear_user(void *to, unsigned long n) |
| 151 | { |
| 152 | memset(to, 0, n); |
| 153 | return 0; |
| 154 | } |
| 155 | |
| 156 | #define clear_user(to,n) __clear_user(to,n) |
| 157 | |
| 158 | #endif /* _M68KNOMMU_UACCESS_H */ |