arch/tile/include/asm/uaccess.h

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #ifndef _ASM_TILE_UACCESS_H
  16 #define _ASM_TILE_UACCESS_H
  17
  18 /*
  19  * User space memory access functions
  20  */
  21 #include <linux/mm.h>
  22 #include <asm-generic/uaccess-unaligned.h>
  23 #include <asm/processor.h>
  24 #include <asm/page.h>
  25
  26 /*
  27  * The fs value determines whether argument validity checking should be
  28  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  29  * get_fs() == KERNEL_DS, checking is bypassed.
  30  *
  31  * For historical reasons, these macros are grossly misnamed.
  32  */
  33 #define MAKE_MM_SEG(a)  ((mm_segment_t) { (a) })
  34
  35 #define KERNEL_DS       MAKE_MM_SEG(-1UL)
  36 #define USER_DS         MAKE_MM_SEG(PAGE_OFFSET)
  37
  38 #define get_ds()        (KERNEL_DS)
  39 #define get_fs()        (current_thread_info()->addr_limit)
  40 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  41
  42 #define segment_eq(a, b) ((a).seg == (b).seg)
  43
  44 #ifndef __tilegx__
  45 /*
  46  * We could allow mapping all 16 MB at 0xfc000000, but we set up a
  47  * special hack in arch_setup_additional_pages() to auto-create a mapping
  48  * for the first 16 KB, and it would seem strange to have different
  49  * user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
  50  */
  51 static inline int is_arch_mappable_range(unsigned long addr,
  52                                          unsigned long size)
  53 {
  54         return (addr >= MEM_USER_INTRPT &&
  55                 addr < (MEM_USER_INTRPT + INTRPT_SIZE) &&
  56                 size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr);
  57 }
  58 #define is_arch_mappable_range is_arch_mappable_range
  59 #else
  60 #define is_arch_mappable_range(addr, size) 0
  61 #endif
  62
  63 /*
  64  * Note that using this definition ignores is_arch_mappable_range(),
  65  * so on tilepro code that uses user_addr_max() is constrained not
  66  * to reference the tilepro user-interrupt region.
  67  */
  68 #define user_addr_max() (current_thread_info()->addr_limit.seg)
  69
  70 /*
  71  * Test whether a block of memory is a valid user space address.
  72  * Returns 0 if the range is valid, nonzero otherwise.
  73  */
  74 int __range_ok(unsigned long addr, unsigned long size);
  75
  76 /**
  77  * access_ok: - Checks if a user space pointer is valid
  78  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
  79  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
  80  *        to write to a block, it is always safe to read from it.
  81  * @addr: User space pointer to start of block to check
  82  * @size: Size of block to check
  83  *
  84  * Context: User context only. This function may sleep if pagefaults are
  85  *          enabled.
  86  *
  87  * Checks if a pointer to a block of memory in user space is valid.
  88  *
  89  * Returns true (nonzero) if the memory block may be valid, false (zero)
  90  * if it is definitely invalid.
  91  *
  92  * Note that, depending on architecture, this function probably just
  93  * checks that the pointer is in the user space range - after calling
  94  * this function, memory access functions may still return -EFAULT.
  95  */
  96 #define access_ok(type, addr, size) ({ \
  97         __chk_user_ptr(addr); \
  98         likely(__range_ok((unsigned long)(addr), (size)) == 0); \
  99 })
 100
 101 #include <asm/extable.h>
 102
 103 /*
 104  * This is a type: either unsigned long, if the argument fits into
 105  * that type, or otherwise unsigned long long.
 106  */
 107 #define __inttype(x) \
 108         __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
 109
 110 /*
 111  * Support macros for __get_user().
 112  * Note that __get_user() and __put_user() assume proper alignment.
 113  */
 114
 115 #ifdef __LP64__
 116 #define _ASM_PTR        ".quad"
 117 #define _ASM_ALIGN      ".align 8"
 118 #else
 119 #define _ASM_PTR        ".long"
 120 #define _ASM_ALIGN      ".align 4"
 121 #endif
 122
 123 #define __get_user_asm(OP, x, ptr, ret)                                 \
 124         asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n"              \
 125                      ".pushsection .fixup,\"ax\"\n"                     \
 126                      "0: { movei %1, 0; movei %0, %3 }\n"               \
 127                      "j 9f\n"                                           \
 128                      ".section __ex_table,\"a\"\n"                      \
 129                      _ASM_ALIGN "\n"                                    \
 130                      _ASM_PTR " 1b, 0b\n"                               \
 131                      ".popsection\n"                                    \
 132                      "9:"                                               \
 133                      : "=r" (ret), "=r" (x)                             \
 134                      : "r" (ptr), "i" (-EFAULT))
 135
 136 #ifdef __tilegx__
 137 #define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret)
 138 #define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret)
 139 #define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret)
 140 #define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret)
 141 #else
 142 #define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret)
 143 #define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret)
 144 #define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret)
 145 #ifdef __LITTLE_ENDIAN
 146 #define __lo32(a, b) a
 147 #define __hi32(a, b) b
 148 #else
 149 #define __lo32(a, b) b
 150 #define __hi32(a, b) a
 151 #endif
 152 #define __get_user_8(x, ptr, ret)                                       \
 153         ({                                                              \
 154                 unsigned int __a, __b;                                  \
 155                 asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n"       \
 156                              "2: { lw %2, %2; movei %0, 0 }\n"          \
 157                              ".pushsection .fixup,\"ax\"\n"             \
 158                              "0: { movei %1, 0; movei %2, 0 }\n"        \
 159                              "{ movei %0, %4; j 9f }\n"                 \
 160                              ".section __ex_table,\"a\"\n"              \
 161                              ".align 4\n"                               \
 162                              ".word 1b, 0b\n"                           \
 163                              ".word 2b, 0b\n"                           \
 164                              ".popsection\n"                            \
 165                              "9:"                                       \
 166                              : "=r" (ret), "=r" (__a), "=&r" (__b)      \
 167                              : "r" (ptr), "i" (-EFAULT));               \
 168                 (x) = (__force __typeof(x))(__inttype(x))               \
 169                         (((u64)__hi32(__a, __b) << 32) |                \
 170                          __lo32(__a, __b));                             \
 171         })
 172 #endif
 173
 174 extern int __get_user_bad(void)
 175   __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8")));
 176
 177 /**
 178  * __get_user: - Get a simple variable from user space, with less checking.
 179  * @x:   Variable to store result.
 180  * @ptr: Source address, in user space.
 181  *
 182  * Context: User context only. This function may sleep if pagefaults are
 183  *          enabled.
 184  *
 185  * This macro copies a single simple variable from user space to kernel
 186  * space.  It supports simple types like char and int, but not larger
 187  * data types like structures or arrays.
 188  *
 189  * @ptr must have pointer-to-simple-variable type, and the result of
 190  * dereferencing @ptr must be assignable to @x without a cast.
 191  *
 192  * Returns zero on success, or -EFAULT on error.
 193  * On error, the variable @x is set to zero.
 194  *
 195  * Caller must check the pointer with access_ok() before calling this
 196  * function.
 197  */
 198 #define __get_user(x, ptr)                                              \
 199         ({                                                              \
 200                 int __ret;                                              \
 201                 typeof(x) _x;                                           \
 202                 __chk_user_ptr(ptr);                                    \
 203                 switch (sizeof(*(ptr))) {                               \
 204                 case 1: __get_user_1(_x, ptr, __ret); break;            \
 205                 case 2: __get_user_2(_x, ptr, __ret); break;            \
 206                 case 4: __get_user_4(_x, ptr, __ret); break;            \
 207                 case 8: __get_user_8(_x, ptr, __ret); break;            \
 208                 default: __ret = __get_user_bad(); break;               \
 209                 }                                                       \
 210                 (x) = (typeof(*(ptr))) _x;                              \
 211                 __ret;                                                  \
 212         })
 213
 214 /* Support macros for __put_user(). */
 215
 216 #define __put_user_asm(OP, x, ptr, ret)                 \
 217         asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n"              \
 218                      ".pushsection .fixup,\"ax\"\n"                     \
 219                      "0: { movei %0, %3; j 9f }\n"                      \
 220                      ".section __ex_table,\"a\"\n"                      \
 221                      _ASM_ALIGN "\n"                                    \
 222                      _ASM_PTR " 1b, 0b\n"                               \
 223                      ".popsection\n"                                    \
 224                      "9:"                                               \
 225                      : "=r" (ret)                                       \
 226                      : "r" (ptr), "r" (x), "i" (-EFAULT))
 227
 228 #ifdef __tilegx__
 229 #define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret)
 230 #define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret)
 231 #define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret)
 232 #define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret)
 233 #else
 234 #define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret)
 235 #define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret)
 236 #define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret)
 237 #define __put_user_8(x, ptr, ret)                                       \
 238         ({                                                              \
 239                 u64 __x = (__force __inttype(x))(x);                    \
 240                 int __lo = (int) __x, __hi = (int) (__x >> 32);         \
 241                 asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n"       \
 242                              "2: { sw %0, %3; movei %0, 0 }\n"          \
 243                              ".pushsection .fixup,\"ax\"\n"             \
 244                              "0: { movei %0, %4; j 9f }\n"              \
 245                              ".section __ex_table,\"a\"\n"              \
 246                              ".align 4\n"                               \
 247                              ".word 1b, 0b\n"                           \
 248                              ".word 2b, 0b\n"                           \
 249                              ".popsection\n"                            \
 250                              "9:"                                       \
 251                              : "=&r" (ret)                              \
 252                              : "r" (ptr), "r" (__lo32(__lo, __hi)),     \
 253                              "r" (__hi32(__lo, __hi)), "i" (-EFAULT));  \
 254         })
 255 #endif
 256
 257 extern int __put_user_bad(void)
 258   __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8")));
 259
 260 /**
 261  * __put_user: - Write a simple value into user space, with less checking.
 262  * @x:   Value to copy to user space.
 263  * @ptr: Destination address, in user space.
 264  *
 265  * Context: User context only. This function may sleep if pagefaults are
 266  *          enabled.
 267  *
 268  * This macro copies a single simple value from kernel space to user
 269  * space.  It supports simple types like char and int, but not larger
 270  * data types like structures or arrays.
 271  *
 272  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 273  * to the result of dereferencing @ptr.
 274  *
 275  * Caller must check the pointer with access_ok() before calling this
 276  * function.
 277  *
 278  * Returns zero on success, or -EFAULT on error.
 279  */
 280 #define __put_user(x, ptr)                                              \
 281 ({                                                                      \
 282         int __ret;                                                      \
 283         typeof(*(ptr)) _x = (x);                                        \
 284         __chk_user_ptr(ptr);                                            \
 285         switch (sizeof(*(ptr))) {                                       \
 286         case 1: __put_user_1(_x, ptr, __ret); break;                    \
 287         case 2: __put_user_2(_x, ptr, __ret); break;                    \
 288         case 4: __put_user_4(_x, ptr, __ret); break;                    \
 289         case 8: __put_user_8(_x, ptr, __ret); break;                    \
 290         default: __ret = __put_user_bad(); break;                       \
 291         }                                                               \
 292         __ret;                                                          \
 293 })
 294
 295 /*
 296  * The versions of get_user and put_user without initial underscores
 297  * check the address of their arguments to make sure they are not
 298  * in kernel space.
 299  */
 300 #define put_user(x, ptr)                                                \
 301 ({                                                                      \
 302         __typeof__(*(ptr)) __user *__Pu_addr = (ptr);                   \
 303         access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ?    \
 304                 __put_user((x), (__Pu_addr)) :                          \
 305                 -EFAULT;                                                \
 306 })
 307
 308 #define get_user(x, ptr)                                                \
 309 ({                                                                      \
 310         __typeof__(*(ptr)) const __user *__Gu_addr = (ptr);             \
 311         access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ?     \
 312                 __get_user((x), (__Gu_addr)) :                          \
 313                 ((x) = 0, -EFAULT);                                     \
 314 })
 315
 316 extern unsigned long __must_check
 317 raw_copy_to_user(void __user *to, const void *from, unsigned long n);
 318 extern unsigned long __must_check
 319 raw_copy_from_user(void *to, const void __user *from, unsigned long n);
 320 #define INLINE_COPY_FROM_USER
 321 #define INLINE_COPY_TO_USER
 322
 323 #ifdef __tilegx__
 324 extern unsigned long raw_copy_in_user(
 325         void __user *to, const void __user *from, unsigned long n);
 326 #endif
 327
 328
 329 extern long strnlen_user(const char __user *str, long n);
 330 extern long strncpy_from_user(char *dst, const char __user *src, long);
 331
 332 /**
 333  * clear_user: - Zero a block of memory in user space.
 334  * @mem:   Destination address, in user space.
 335  * @len:   Number of bytes to zero.
 336  *
 337  * Zero a block of memory in user space.
 338  *
 339  * Returns number of bytes that could not be cleared.
 340  * On success, this will be zero.
 341  */
 342 extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
 343 static inline unsigned long __must_check __clear_user(
 344         void __user *mem, unsigned long len)
 345 {
 346         might_fault();
 347         return clear_user_asm(mem, len);
 348 }
 349 static inline unsigned long __must_check clear_user(
 350         void __user *mem, unsigned long len)
 351 {
 352         if (access_ok(VERIFY_WRITE, mem, len))
 353                 return __clear_user(mem, len);
 354         return len;
 355 }
 356
 357 /**
 358  * flush_user: - Flush a block of memory in user space from cache.
 359  * @mem:   Destination address, in user space.
 360  * @len:   Number of bytes to flush.
 361  *
 362  * Returns number of bytes that could not be flushed.
 363  * On success, this will be zero.
 364  */
 365 extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
 366 static inline unsigned long __must_check __flush_user(
 367         void __user *mem, unsigned long len)
 368 {
 369         int retval;
 370
 371         might_fault();
 372         retval = flush_user_asm(mem, len);
 373         mb_incoherent();
 374         return retval;
 375 }
 376
 377 static inline unsigned long __must_check flush_user(
 378         void __user *mem, unsigned long len)
 379 {
 380         if (access_ok(VERIFY_WRITE, mem, len))
 381                 return __flush_user(mem, len);
 382         return len;
 383 }
 384
 385 /**
 386  * finv_user: - Flush-inval a block of memory in user space from cache.
 387  * @mem:   Destination address, in user space.
 388  * @len:   Number of bytes to invalidate.
 389  *
 390  * Returns number of bytes that could not be flush-invalidated.
 391  * On success, this will be zero.
 392  */
 393 extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
 394 static inline unsigned long __must_check __finv_user(
 395         void __user *mem, unsigned long len)
 396 {
 397         int retval;
 398
 399         might_fault();
 400         retval = finv_user_asm(mem, len);
 401         mb_incoherent();
 402         return retval;
 403 }
 404 static inline unsigned long __must_check finv_user(
 405         void __user *mem, unsigned long len)
 406 {
 407         if (access_ok(VERIFY_WRITE, mem, len))
 408                 return __finv_user(mem, len);
 409         return len;
 410 }
 411
 412 #endif /* _ASM_TILE_UACCESS_H */