1 /* 2 * User space memory access functions for Nios II 3 * 4 * Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch> 5 * Copyright (C) 2009, Wind River Systems Inc 6 * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com 7 * 8 * This file is subject to the terms and conditions of the GNU General Public 9 * License. See the file "COPYING" in the main directory of this archive 10 * for more details. 11 */ 12 13 #ifndef _ASM_NIOS2_UACCESS_H 14 #define _ASM_NIOS2_UACCESS_H 15 16 #include <linux/string.h> 17 18 #include <asm/page.h> 19 20 #include <asm/extable.h> 21 22 /* 23 * Segment stuff 24 */ 25 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 26 #define USER_DS MAKE_MM_SEG(0x80000000UL) 27 #define KERNEL_DS MAKE_MM_SEG(0) 28 29 #define get_ds() (KERNEL_DS) 30 31 #define get_fs() (current_thread_info()->addr_limit) 32 #define set_fs(seg) (current_thread_info()->addr_limit = (seg)) 33 34 #define segment_eq(a, b) ((a).seg == (b).seg) 35 36 #define __access_ok(addr, len) \ 37 (((signed long)(((long)get_fs().seg) & \ 38 ((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0) 39 40 #define access_ok(type, addr, len) \ 41 likely(__access_ok((unsigned long)(addr), (unsigned long)(len))) 42 43 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" 44 45 /* 46 * Zero Userspace 47 */ 48 49 static inline unsigned long __must_check __clear_user(void __user *to, 50 unsigned long n) 51 { 52 __asm__ __volatile__ ( 53 "1: stb zero, 0(%1)\n" 54 " addi %0, %0, -1\n" 55 " addi %1, %1, 1\n" 56 " bne %0, zero, 1b\n" 57 "2:\n" 58 __EX_TABLE_SECTION 59 ".word 1b, 2b\n" 60 ".previous\n" 61 : "=r" (n), "=r" (to) 62 : "0" (n), "1" (to) 63 ); 64 65 return n; 66 } 67 68 static inline unsigned long __must_check clear_user(void __user *to, 69 unsigned long n) 70 { 71 if (!access_ok(VERIFY_WRITE, to, n)) 72 return n; 73 return __clear_user(to, n); 74 } 75 76 extern unsigned long 77 raw_copy_from_user(void *to, const void __user *from, unsigned long n); 78 extern unsigned long 79 raw_copy_to_user(void __user *to, const void *from, unsigned long n); 80 #define INLINE_COPY_FROM_USER 81 #define INLINE_COPY_TO_USER 82 83 extern long strncpy_from_user(char *__to, const char __user *__from, 84 long __len); 85 extern long strnlen_user(const char __user *s, long n); 86 87 /* Optimized macros */ 88 #define __get_user_asm(val, insn, addr, err) \ 89 { \ 90 __asm__ __volatile__( \ 91 " movi %0, %3\n" \ 92 "1: " insn " %1, 0(%2)\n" \ 93 " movi %0, 0\n" \ 94 "2:\n" \ 95 " .section __ex_table,\"a\"\n" \ 96 " .word 1b, 2b\n" \ 97 " .previous" \ 98 : "=&r" (err), "=r" (val) \ 99 : "r" (addr), "i" (-EFAULT)); \ 100 } 101 102 #define __get_user_unknown(val, size, ptr, err) do { \ 103 err = 0; \ 104 if (__copy_from_user(&(val), ptr, size)) { \ 105 err = -EFAULT; \ 106 } \ 107 } while (0) 108 109 #define __get_user_common(val, size, ptr, err) \ 110 do { \ 111 switch (size) { \ 112 case 1: \ 113 __get_user_asm(val, "ldbu", ptr, err); \ 114 break; \ 115 case 2: \ 116 __get_user_asm(val, "ldhu", ptr, err); \ 117 break; \ 118 case 4: \ 119 __get_user_asm(val, "ldw", ptr, err); \ 120 break; \ 121 default: \ 122 __get_user_unknown(val, size, ptr, err); \ 123 break; \ 124 } \ 125 } while (0) 126 127 #define __get_user(x, ptr) \ 128 ({ \ 129 long __gu_err = -EFAULT; \ 130 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ 131 unsigned long __gu_val = 0; \ 132 __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\ 133 (x) = (__force __typeof__(x))__gu_val; \ 134 __gu_err; \ 135 }) 136 137 #define get_user(x, ptr) \ 138 ({ \ 139 long __gu_err = -EFAULT; \ 140 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ 141 unsigned long __gu_val = 0; \ 142 if (access_ok(VERIFY_READ, __gu_ptr, sizeof(*__gu_ptr))) \ 143 __get_user_common(__gu_val, sizeof(*__gu_ptr), \ 144 __gu_ptr, __gu_err); \ 145 (x) = (__force __typeof__(x))__gu_val; \ 146 __gu_err; \ 147 }) 148 149 #define __put_user_asm(val, insn, ptr, err) \ 150 { \ 151 __asm__ __volatile__( \ 152 " movi %0, %3\n" \ 153 "1: " insn " %1, 0(%2)\n" \ 154 " movi %0, 0\n" \ 155 "2:\n" \ 156 " .section __ex_table,\"a\"\n" \ 157 " .word 1b, 2b\n" \ 158 " .previous\n" \ 159 : "=&r" (err) \ 160 : "r" (val), "r" (ptr), "i" (-EFAULT)); \ 161 } 162 163 #define put_user(x, ptr) \ 164 ({ \ 165 long __pu_err = -EFAULT; \ 166 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \ 167 __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \ 168 if (access_ok(VERIFY_WRITE, __pu_ptr, sizeof(*__pu_ptr))) { \ 169 switch (sizeof(*__pu_ptr)) { \ 170 case 1: \ 171 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \ 172 break; \ 173 case 2: \ 174 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \ 175 break; \ 176 case 4: \ 177 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \ 178 break; \ 179 default: \ 180 /* XXX: This looks wrong... */ \ 181 __pu_err = 0; \ 182 if (copy_to_user(__pu_ptr, &(__pu_val), \ 183 sizeof(*__pu_ptr))) \ 184 __pu_err = -EFAULT; \ 185 break; \ 186 } \ 187 } \ 188 __pu_err; \ 189 }) 190 191 #define __put_user(x, ptr) put_user(x, ptr) 192 193 #endif /* _ASM_NIOS2_UACCESS_H */ 194