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 30 #define get_fs() (current_thread_info()->addr_limit) 31 #define set_fs(seg) (current_thread_info()->addr_limit = (seg)) 32 33 #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) 34 35 #define __access_ok(addr, len) \ 36 (((signed long)(((long)get_fs().seg) & \ 37 ((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0) 38 39 #define access_ok(addr, len) \ 40 likely(__access_ok((unsigned long)(addr), (unsigned long)(len))) 41 42 # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" 43 44 #define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE) 45 46 /* 47 * Zero Userspace 48 */ 49 50 static inline unsigned long __must_check __clear_user(void __user *to, 51 unsigned long n) 52 { 53 __asm__ __volatile__ ( 54 "1: stb zero, 0(%1)\n" 55 " addi %0, %0, -1\n" 56 " addi %1, %1, 1\n" 57 " bne %0, zero, 1b\n" 58 "2:\n" 59 __EX_TABLE_SECTION 60 ".word 1b, 2b\n" 61 ".previous\n" 62 : "=r" (n), "=r" (to) 63 : "0" (n), "1" (to) 64 ); 65 66 return n; 67 } 68 69 static inline unsigned long __must_check clear_user(void __user *to, 70 unsigned long n) 71 { 72 if (!access_ok(to, n)) 73 return n; 74 return __clear_user(to, n); 75 } 76 77 extern unsigned long 78 raw_copy_from_user(void *to, const void __user *from, unsigned long n); 79 extern unsigned long 80 raw_copy_to_user(void __user *to, const void *from, unsigned long n); 81 #define INLINE_COPY_FROM_USER 82 #define INLINE_COPY_TO_USER 83 84 extern long strncpy_from_user(char *__to, const char __user *__from, 85 long __len); 86 extern __must_check long strlen_user(const char __user *str); 87 extern __must_check long strnlen_user(const char __user *s, long n); 88 89 /* Optimized macros */ 90 #define __get_user_asm(val, insn, addr, err) \ 91 { \ 92 __asm__ __volatile__( \ 93 " movi %0, %3\n" \ 94 "1: " insn " %1, 0(%2)\n" \ 95 " movi %0, 0\n" \ 96 "2:\n" \ 97 " .section __ex_table,\"a\"\n" \ 98 " .word 1b, 2b\n" \ 99 " .previous" \ 100 : "=&r" (err), "=r" (val) \ 101 : "r" (addr), "i" (-EFAULT)); \ 102 } 103 104 #define __get_user_unknown(val, size, ptr, err) do { \ 105 err = 0; \ 106 if (__copy_from_user(&(val), ptr, size)) { \ 107 err = -EFAULT; \ 108 } \ 109 } while (0) 110 111 #define __get_user_common(val, size, ptr, err) \ 112 do { \ 113 switch (size) { \ 114 case 1: \ 115 __get_user_asm(val, "ldbu", ptr, err); \ 116 break; \ 117 case 2: \ 118 __get_user_asm(val, "ldhu", ptr, err); \ 119 break; \ 120 case 4: \ 121 __get_user_asm(val, "ldw", ptr, err); \ 122 break; \ 123 default: \ 124 __get_user_unknown(val, size, ptr, err); \ 125 break; \ 126 } \ 127 } while (0) 128 129 #define __get_user(x, ptr) \ 130 ({ \ 131 long __gu_err = -EFAULT; \ 132 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ 133 unsigned long __gu_val = 0; \ 134 __get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\ 135 (x) = (__force __typeof__(x))__gu_val; \ 136 __gu_err; \ 137 }) 138 139 #define get_user(x, ptr) \ 140 ({ \ 141 long __gu_err = -EFAULT; \ 142 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ 143 unsigned long __gu_val = 0; \ 144 if (access_ok( __gu_ptr, sizeof(*__gu_ptr))) \ 145 __get_user_common(__gu_val, sizeof(*__gu_ptr), \ 146 __gu_ptr, __gu_err); \ 147 (x) = (__force __typeof__(x))__gu_val; \ 148 __gu_err; \ 149 }) 150 151 #define __put_user_asm(val, insn, ptr, err) \ 152 { \ 153 __asm__ __volatile__( \ 154 " movi %0, %3\n" \ 155 "1: " insn " %1, 0(%2)\n" \ 156 " movi %0, 0\n" \ 157 "2:\n" \ 158 " .section __ex_table,\"a\"\n" \ 159 " .word 1b, 2b\n" \ 160 " .previous\n" \ 161 : "=&r" (err) \ 162 : "r" (val), "r" (ptr), "i" (-EFAULT)); \ 163 } 164 165 #define put_user(x, ptr) \ 166 ({ \ 167 long __pu_err = -EFAULT; \ 168 __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \ 169 __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \ 170 if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) { \ 171 switch (sizeof(*__pu_ptr)) { \ 172 case 1: \ 173 __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \ 174 break; \ 175 case 2: \ 176 __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \ 177 break; \ 178 case 4: \ 179 __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \ 180 break; \ 181 default: \ 182 /* XXX: This looks wrong... */ \ 183 __pu_err = 0; \ 184 if (copy_to_user(__pu_ptr, &(__pu_val), \ 185 sizeof(*__pu_ptr))) \ 186 __pu_err = -EFAULT; \ 187 break; \ 188 } \ 189 } \ 190 __pu_err; \ 191 }) 192 193 #define __put_user(x, ptr) put_user(x, ptr) 194 195 #endif /* _ASM_NIOS2_UACCESS_H */ 196