| 1 | /* |
| 2 | * Copyright 2004-2009 Analog Devices Inc. |
| 3 | * |
| 4 | * Licensed under the GPL-2 or later. |
| 5 | * |
| 6 | * Based on: include/asm-m68knommu/uaccess.h |
| 7 | */ |
| 8 | |
| 9 | #ifndef __BLACKFIN_UACCESS_H |
| 10 | #define __BLACKFIN_UACCESS_H |
| 11 | |
| 12 | /* |
| 13 | * User space memory access functions |
| 14 | */ |
| 15 | #include <linux/sched.h> |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/string.h> |
| 18 | |
| 19 | #include <asm/segment.h> |
| 20 | #include <asm/sections.h> |
| 21 | |
| 22 | #define get_ds() (KERNEL_DS) |
| 23 | #define get_fs() (current_thread_info()->addr_limit) |
| 24 | |
| 25 | static inline void set_fs(mm_segment_t fs) |
| 26 | { |
| 27 | current_thread_info()->addr_limit = fs; |
| 28 | } |
| 29 | |
| 30 | #define segment_eq(a, b) ((a) == (b)) |
| 31 | |
| 32 | #define VERIFY_READ 0 |
| 33 | #define VERIFY_WRITE 1 |
| 34 | |
| 35 | #define access_ok(type, addr, size) _access_ok((unsigned long)(addr), (size)) |
| 36 | |
| 37 | /* |
| 38 | * The fs value determines whether argument validity checking should be |
| 39 | * performed or not. If get_fs() == USER_DS, checking is performed, with |
| 40 | * get_fs() == KERNEL_DS, checking is bypassed. |
| 41 | */ |
| 42 | |
| 43 | #ifndef CONFIG_ACCESS_CHECK |
| 44 | static inline int _access_ok(unsigned long addr, unsigned long size) { return 1; } |
| 45 | #else |
| 46 | extern int _access_ok(unsigned long addr, unsigned long size); |
| 47 | #endif |
| 48 | |
| 49 | /* |
| 50 | * The exception table consists of pairs of addresses: the first is the |
| 51 | * address of an instruction that is allowed to fault, and the second is |
| 52 | * the address at which the program should continue. No registers are |
| 53 | * modified, so it is entirely up to the continuation code to figure out |
| 54 | * what to do. |
| 55 | * |
| 56 | * All the routines below use bits of fixup code that are out of line |
| 57 | * with the main instruction path. This means when everything is well, |
| 58 | * we don't even have to jump over them. Further, they do not intrude |
| 59 | * on our cache or tlb entries. |
| 60 | */ |
| 61 | |
| 62 | struct exception_table_entry { |
| 63 | unsigned long insn, fixup; |
| 64 | }; |
| 65 | |
| 66 | /* |
| 67 | * These are the main single-value transfer routines. They automatically |
| 68 | * use the right size if we just have the right pointer type. |
| 69 | */ |
| 70 | |
| 71 | #define put_user(x, p) \ |
| 72 | ({ \ |
| 73 | int _err = 0; \ |
| 74 | typeof(*(p)) _x = (x); \ |
| 75 | typeof(*(p)) __user *_p = (p); \ |
| 76 | if (!access_ok(VERIFY_WRITE, _p, sizeof(*(_p)))) {\ |
| 77 | _err = -EFAULT; \ |
| 78 | } \ |
| 79 | else { \ |
| 80 | switch (sizeof (*(_p))) { \ |
| 81 | case 1: \ |
| 82 | __put_user_asm(_x, _p, B); \ |
| 83 | break; \ |
| 84 | case 2: \ |
| 85 | __put_user_asm(_x, _p, W); \ |
| 86 | break; \ |
| 87 | case 4: \ |
| 88 | __put_user_asm(_x, _p, ); \ |
| 89 | break; \ |
| 90 | case 8: { \ |
| 91 | long _xl, _xh; \ |
| 92 | _xl = ((__force long *)&_x)[0]; \ |
| 93 | _xh = ((__force long *)&_x)[1]; \ |
| 94 | __put_user_asm(_xl, ((__force long __user *)_p)+0, );\ |
| 95 | __put_user_asm(_xh, ((__force long __user *)_p)+1, );\ |
| 96 | } break; \ |
| 97 | default: \ |
| 98 | _err = __put_user_bad(); \ |
| 99 | break; \ |
| 100 | } \ |
| 101 | } \ |
| 102 | _err; \ |
| 103 | }) |
| 104 | |
| 105 | #define __put_user(x, p) put_user(x, p) |
| 106 | static inline int bad_user_access_length(void) |
| 107 | { |
| 108 | panic("bad_user_access_length"); |
| 109 | return -1; |
| 110 | } |
| 111 | |
| 112 | #define __put_user_bad() (printk(KERN_INFO "put_user_bad %s:%d %s\n",\ |
| 113 | __FILE__, __LINE__, __func__),\ |
| 114 | bad_user_access_length(), (-EFAULT)) |
| 115 | |
| 116 | /* |
| 117 | * Tell gcc we read from memory instead of writing: this is because |
| 118 | * we do not write to any memory gcc knows about, so there are no |
| 119 | * aliasing issues. |
| 120 | */ |
| 121 | |
| 122 | #define __ptr(x) ((unsigned long __force *)(x)) |
| 123 | |
| 124 | #define __put_user_asm(x, p, bhw) \ |
| 125 | __asm__ (#bhw"[%1] = %0;\n\t" \ |
| 126 | : /* no outputs */ \ |
| 127 | :"d" (x), "a" (__ptr(p)) : "memory") |
| 128 | |
| 129 | #define get_user(x, ptr) \ |
| 130 | ({ \ |
| 131 | int _err = 0; \ |
| 132 | unsigned long _val = 0; \ |
| 133 | const typeof(*(ptr)) __user *_p = (ptr); \ |
| 134 | const size_t ptr_size = sizeof(*(_p)); \ |
| 135 | if (likely(access_ok(VERIFY_READ, _p, ptr_size))) { \ |
| 136 | BUILD_BUG_ON(ptr_size >= 8); \ |
| 137 | switch (ptr_size) { \ |
| 138 | case 1: \ |
| 139 | __get_user_asm(_val, _p, B, (Z)); \ |
| 140 | break; \ |
| 141 | case 2: \ |
| 142 | __get_user_asm(_val, _p, W, (Z)); \ |
| 143 | break; \ |
| 144 | case 4: \ |
| 145 | __get_user_asm(_val, _p, , ); \ |
| 146 | break; \ |
| 147 | } \ |
| 148 | } else \ |
| 149 | _err = -EFAULT; \ |
| 150 | x = (__force typeof(*(ptr)))_val; \ |
| 151 | _err; \ |
| 152 | }) |
| 153 | |
| 154 | #define __get_user(x, p) get_user(x, p) |
| 155 | |
| 156 | #define __get_user_bad() (bad_user_access_length(), (-EFAULT)) |
| 157 | |
| 158 | #define __get_user_asm(x, ptr, bhw, option) \ |
| 159 | ({ \ |
| 160 | __asm__ __volatile__ ( \ |
| 161 | "%0 =" #bhw "[%1]" #option ";" \ |
| 162 | : "=d" (x) \ |
| 163 | : "a" (__ptr(ptr))); \ |
| 164 | }) |
| 165 | |
| 166 | #define __copy_from_user(to, from, n) copy_from_user(to, from, n) |
| 167 | #define __copy_to_user(to, from, n) copy_to_user(to, from, n) |
| 168 | #define __copy_to_user_inatomic __copy_to_user |
| 169 | #define __copy_from_user_inatomic __copy_from_user |
| 170 | |
| 171 | static inline unsigned long __must_check |
| 172 | copy_from_user(void *to, const void __user *from, unsigned long n) |
| 173 | { |
| 174 | if (access_ok(VERIFY_READ, from, n)) |
| 175 | memcpy(to, (const void __force *)from, n); |
| 176 | else |
| 177 | return n; |
| 178 | return 0; |
| 179 | } |
| 180 | |
| 181 | static inline unsigned long __must_check |
| 182 | copy_to_user(void __user *to, const void *from, unsigned long n) |
| 183 | { |
| 184 | if (access_ok(VERIFY_WRITE, to, n)) |
| 185 | memcpy((void __force *)to, from, n); |
| 186 | else |
| 187 | return n; |
| 188 | SSYNC(); |
| 189 | return 0; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Copy a null terminated string from userspace. |
| 194 | */ |
| 195 | |
| 196 | static inline long __must_check |
| 197 | strncpy_from_user(char *dst, const char __user *src, long count) |
| 198 | { |
| 199 | char *tmp; |
| 200 | if (!access_ok(VERIFY_READ, src, 1)) |
| 201 | return -EFAULT; |
| 202 | strncpy(dst, (const char __force *)src, count); |
| 203 | for (tmp = dst; *tmp && count > 0; tmp++, count--) ; |
| 204 | return (tmp - dst); |
| 205 | } |
| 206 | |
| 207 | /* |
| 208 | * Get the size of a string in user space. |
| 209 | * src: The string to measure |
| 210 | * n: The maximum valid length |
| 211 | * |
| 212 | * Get the size of a NUL-terminated string in user space. |
| 213 | * |
| 214 | * Returns the size of the string INCLUDING the terminating NUL. |
| 215 | * On exception, returns 0. |
| 216 | * If the string is too long, returns a value greater than n. |
| 217 | */ |
| 218 | static inline long __must_check strnlen_user(const char __user *src, long n) |
| 219 | { |
| 220 | if (!access_ok(VERIFY_READ, src, 1)) |
| 221 | return 0; |
| 222 | return strnlen((const char __force *)src, n) + 1; |
| 223 | } |
| 224 | |
| 225 | static inline long __must_check strlen_user(const char __user *src) |
| 226 | { |
| 227 | if (!access_ok(VERIFY_READ, src, 1)) |
| 228 | return 0; |
| 229 | return strlen((const char __force *)src) + 1; |
| 230 | } |
| 231 | |
| 232 | /* |
| 233 | * Zero Userspace |
| 234 | */ |
| 235 | |
| 236 | static inline unsigned long __must_check |
| 237 | __clear_user(void __user *to, unsigned long n) |
| 238 | { |
| 239 | if (!access_ok(VERIFY_WRITE, to, n)) |
| 240 | return n; |
| 241 | memset((void __force *)to, 0, n); |
| 242 | return 0; |
| 243 | } |
| 244 | |
| 245 | #define clear_user(to, n) __clear_user(to, n) |
| 246 | |
| 247 | /* How to interpret these return values: |
| 248 | * CORE: can be accessed by core load or dma memcpy |
| 249 | * CORE_ONLY: can only be accessed by core load |
| 250 | * DMA: can only be accessed by dma memcpy |
| 251 | * IDMA: can only be accessed by interprocessor dma memcpy (BF561) |
| 252 | * ITEST: can be accessed by isram memcpy or dma memcpy |
| 253 | */ |
| 254 | enum { |
| 255 | BFIN_MEM_ACCESS_CORE = 0, |
| 256 | BFIN_MEM_ACCESS_CORE_ONLY, |
| 257 | BFIN_MEM_ACCESS_DMA, |
| 258 | BFIN_MEM_ACCESS_IDMA, |
| 259 | BFIN_MEM_ACCESS_ITEST, |
| 260 | }; |
| 261 | /** |
| 262 | * bfin_mem_access_type() - what kind of memory access is required |
| 263 | * @addr: the address to check |
| 264 | * @size: number of bytes needed |
| 265 | * @return: <0 is error, >=0 is BFIN_MEM_ACCESS_xxx enum (see above) |
| 266 | */ |
| 267 | int bfin_mem_access_type(unsigned long addr, unsigned long size); |
| 268 | |
| 269 | #endif /* _BLACKFIN_UACCESS_H */ |