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 #define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE) 46 47 /* 48 * Zero Userspace 49 */ 50 51 static inline unsigned long __must_check __clear_user(void __user *to, 52 unsigned long n) 53 { 54 __asm__ __volatile__ ( 55 "1: stb zero, 0(%1)\n" 56 " addi %0, %0, -1\n" 57 " addi %1, %1, 1\n" 58 " bne %0, zero, 1b\n" 59 "2:\n" 60 __EX_TABLE_SECTION 61 ".word 1b, 2b\n" 62 ".previous\n" 63 : "=r" (n), "=r" (to) 64 : "0" (n), "1" (to) 65 ); 66 67 return n; 68 } 69 70 static inline unsigned long __must_check clear_user(void __user *to, 71 unsigned long n) 72 { 73 if (!access_ok(VERIFY_WRITE, to, n)) 74 return n; 75 return __clear_user(to, n); 76 } 77 78 extern unsigned long 79 raw_copy_from_user(void *to, const void __user *from, unsigned long n); 80 extern unsigned long 81 raw_copy_to_user(void __user *to, const void *from, unsigned long n); 82 #define INLINE_COPY_FROM_USER 83 #define INLINE_COPY_TO_USER 84 85 extern long strncpy_from_user(char *__to, const char __user *__from, 86 long __len); 87 extern __must_check long strlen_user(const char __user *str); 88 extern __must_check long strnlen_user(const char __user *s, long n); 89 90 /* Optimized macros */ 91 #define __get_user_asm(val, insn, addr, err) \ 92 { \ 93 __asm__ __volatile__( \ 94 " movi %0, %3\n" \ 95 "1: " insn " %1, 0(%2)\n" \ 96 " movi %0, 0\n" \ 97 "2:\n" \ 98 " .section __ex_table,\"a\"\n" \ 99 " .word 1b, 2b\n" \ 100 " .previous" \ 101 : "=&r" (err), "=r" (val) \ 102 : "r" (addr), "i" (-EFAULT)); \ 103 } 104 105 #define __get_user_unknown(val, size, ptr, err) do { \ 106 err = 0; \ 107 if (__copy_from_user(&(val), ptr, size)) { \ 108 err = -EFAULT; \ 109 } \ 110 } while (0) 111 112 #define __get_user_common(val, size, ptr, err) \ 113 do { \ 114 switch (size) { \ 115 case 1: \ 116 __get_user_asm(val, "ldbu", ptr, err); \ 117 break; \ 118 case 2: \ 119 __get_user_asm(val, "ldhu", ptr, err); \ 120 break; \ 121 case 4: \ 122 __get_user_asm(val, "ldw", ptr, err); \ 123 break; \ 124 default: \ 125 __get_user_unknown(val, size, ptr, err); \ 126 break; \ 127 } \ 128 } while (0) 129 130 #define __get_user(x, ptr) \ 131 ({ \ 132 long __gu_err = -EFAULT; \ 133 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ 134 unsigned long __gu_val = 0; \ 135 __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\ 136 (x) = (__force __typeof__(x))__gu_val; \ 137 __gu_err; \ 138 }) 139 140 #define get_user(x, ptr) \ 141 ({ \ 142 long __gu_err = -EFAULT; \ 143 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ 144 unsigned long __gu_val = 0; \ 145 if (access_ok(VERIFY_READ, __gu_ptr, sizeof(*__gu_ptr))) \ 146 __get_user_common(__gu_val, sizeof(*__gu_ptr), \ 147 __gu_ptr, __gu_err); \ 148 (x) = (__force __typeof__(x))__gu_val; \ 149 __gu_err; \ 150 }) 151 152 #define __put_user_asm(val, insn, ptr, err) \ 153 { \ 154 __asm__ __volatile__( \ 155 " movi %0, %3\n" \ 156 "1: " insn " %1, 0(%2)\n" \ 157 " movi %0, 0\n" \ 158 "2:\n" \ 159 " .section __ex_table,\"a\"\n" \ 160 " .word 1b, 2b\n" \ 161 " .previous\n" \ 162 : "=&r" (err) \ 163 : "r" (val), "r" (ptr), "i" (-EFAULT)); \ 164 } 165 166 #define put_user(x, ptr) \ 167 ({ \ 168 long __pu_err = -EFAULT; \ 169 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \ 170 __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \ 171 if (access_ok(VERIFY_WRITE, __pu_ptr, sizeof(*__pu_ptr))) { \ 172 switch (sizeof(*__pu_ptr)) { \ 173 case 1: \ 174 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \ 175 break; \ 176 case 2: \ 177 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \ 178 break; \ 179 case 4: \ 180 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \ 181 break; \ 182 default: \ 183 /* XXX: This looks wrong... */ \ 184 __pu_err = 0; \ 185 if (copy_to_user(__pu_ptr, &(__pu_val), \ 186 sizeof(*__pu_ptr))) \ 187 __pu_err = -EFAULT; \ 188 break; \ 189 } \ 190 } \ 191 __pu_err; \ 192 }) 193 194 #define __put_user(x, ptr) put_user(x, ptr) 195 196 #endif /* _ASM_NIOS2_UACCESS_H */ 197