arch/microblaze/include/asm/uaccess.h

   1 /*
   2  * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2008-2009 PetaLogix
   4  * Copyright (C) 2006 Atmark Techno, Inc.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License. See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 #ifndef _ASM_MICROBLAZE_UACCESS_H
  12 #define _ASM_MICROBLAZE_UACCESS_H
  13
  14 #ifdef __KERNEL__
  15 #ifndef __ASSEMBLY__
  16
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/sched.h> /* RLIMIT_FSIZE */
  20 #include <linux/mm.h>
  21
  22 #include <asm/mmu.h>
  23 #include <asm/page.h>
  24 #include <asm/pgtable.h>
  25 #include <asm/segment.h>
  26 #include <linux/string.h>
  27
  28 #define VERIFY_READ     0
  29 #define VERIFY_WRITE    1
  30
  31 #define __clear_user(addr, n)   (memset((void *)(addr), 0, (n)), 0)
  32
  33 #ifndef CONFIG_MMU
  34
  35 extern int ___range_ok(unsigned long addr, unsigned long size);
  36
  37 #define __range_ok(addr, size) \
  38                 ___range_ok((unsigned long)(addr), (unsigned long)(size))
  39
  40 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
  41 #define __access_ok(add, size) (__range_ok((addr), (size)) == 0)
  42
  43 /* Undefined function to trigger linker error */
  44 extern int bad_user_access_length(void);
  45
  46 /* FIXME this is function for optimalization -> memcpy */
  47 #define __get_user(var, ptr)                            \
  48 ({                                                      \
  49         int __gu_err = 0;                               \
  50         switch (sizeof(*(ptr))) {                       \
  51         case 1:                                         \
  52         case 2:                                         \
  53         case 4:                                         \
  54                 (var) = *(ptr);                         \
  55                 break;                                  \
  56         case 8:                                         \
  57                 memcpy((void *) &(var), (ptr), 8);      \
  58                 break;                                  \
  59         default:                                        \
  60                 (var) = 0;                              \
  61                 __gu_err = __get_user_bad();            \
  62                 break;                                  \
  63         }                                               \
  64         __gu_err;                                       \
  65 })
  66
  67 #define __get_user_bad()        (bad_user_access_length(), (-EFAULT))
  68
  69 /* FIXME is not there defined __pu_val */
  70 #define __put_user(var, ptr)                                    \
  71 ({                                                              \
  72         int __pu_err = 0;                                       \
  73         switch (sizeof(*(ptr))) {                               \
  74         case 1:                                                 \
  75         case 2:                                                 \
  76         case 4:                                                 \
  77                 *(ptr) = (var);                                 \
  78                 break;                                          \
  79         case 8: {                                               \
  80                 typeof(*(ptr)) __pu_val = (var);                \
  81                 memcpy(ptr, &__pu_val, sizeof(__pu_val));       \
  82                 }                                               \
  83                 break;                                          \
  84         default:                                                \
  85                 __pu_err = __put_user_bad();                    \
  86                 break;                                          \
  87         }                                                       \
  88         __pu_err;                                               \
  89 })
  90
  91 #define __put_user_bad()        (bad_user_access_length(), (-EFAULT))
  92
  93 #define put_user(x, ptr)        __put_user((x), (ptr))
  94 #define get_user(x, ptr)        __get_user((x), (ptr))
  95
  96 #define copy_to_user(to, from, n)       (memcpy((to), (from), (n)), 0)
  97 #define copy_from_user(to, from, n)     (memcpy((to), (from), (n)), 0)
  98
  99 #define __copy_to_user(to, from, n)     (copy_to_user((to), (from), (n)))
 100 #define __copy_from_user(to, from, n)   (copy_from_user((to), (from), (n)))
 101 #define __copy_to_user_inatomic(to, from, n) \
 102                         (__copy_to_user((to), (from), (n)))
 103 #define __copy_from_user_inatomic(to, from, n) \
 104                         (__copy_from_user((to), (from), (n)))
 105
 106 static inline unsigned long clear_user(void *addr, unsigned long size)
 107 {
 108         if (access_ok(VERIFY_WRITE, addr, size))
 109                 size = __clear_user(addr, size);
 110         return size;
 111 }
 112
 113 /* Returns 0 if exception not found and fixup otherwise.  */
 114 extern unsigned long search_exception_table(unsigned long);
 115
 116 extern long strncpy_from_user(char *dst, const char *src, long count);
 117 extern long strnlen_user(const char *src, long count);
 118
 119 #else /* CONFIG_MMU */
 120
 121 /*
 122  * Address is valid if:
 123  *  - "addr", "addr + size" and "size" are all below the limit
 124  */
 125 #define access_ok(type, addr, size) \
 126         (get_fs().seg > (((unsigned long)(addr)) | \
 127                 (size) | ((unsigned long)(addr) + (size))))
 128
 129 /* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n",
 130  type?"WRITE":"READ",addr,size,get_fs().seg)) */
 131
 132 /*
 133  * All the __XXX versions macros/functions below do not perform
 134  * access checking. It is assumed that the necessary checks have been
 135  * already performed before the finction (macro) is called.
 136  */
 137
 138 #define get_user(x, ptr)                                                \
 139 ({                                                                      \
 140         access_ok(VERIFY_READ, (ptr), sizeof(*(ptr)))                   \
 141                 ? __get_user((x), (ptr)) : -EFAULT;                     \
 142 })
 143
 144 #define put_user(x, ptr)                                                \
 145 ({                                                                      \
 146         access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr)))                  \
 147                 ? __put_user((x), (ptr)) : -EFAULT;                     \
 148 })
 149
 150 #define __get_user(x, ptr)                                              \
 151 ({                                                                      \
 152         unsigned long __gu_val;                                         \
 153         /*unsigned long __gu_ptr = (unsigned long)(ptr);*/              \
 154         long __gu_err;                                                  \
 155         switch (sizeof(*(ptr))) {                                       \
 156         case 1:                                                         \
 157                 __get_user_asm("lbu", (ptr), __gu_val, __gu_err);       \
 158                 break;                                                  \
 159         case 2:                                                         \
 160                 __get_user_asm("lhu", (ptr), __gu_val, __gu_err);       \
 161                 break;                                                  \
 162         case 4:                                                         \
 163                 __get_user_asm("lw", (ptr), __gu_val, __gu_err);        \
 164                 break;                                                  \
 165         default:                                                        \
 166                 __gu_val = 0; __gu_err = -EINVAL;                       \
 167         }                                                               \
 168         x = (__typeof__(*(ptr))) __gu_val;                              \
 169         __gu_err;                                                       \
 170 })
 171
 172 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)              \
 173 ({                                                                      \
 174         __asm__ __volatile__ (                                          \
 175                         "1:"    insn    " %1, %2, r0;                   \
 176                                 addk    %0, r0, r0;                     \
 177                         2:                                              \
 178                         .section .fixup,\"ax\";                         \
 179                         3:      brid    2b;                             \
 180                                 addik   %0, r0, %3;                     \
 181                         .previous;                                      \
 182                         .section __ex_table,\"a\";                      \
 183                         .word   1b,3b;                                  \
 184                         .previous;"                                     \
 185                 : "=r"(__gu_err), "=r"(__gu_val)                        \
 186                 : "r"(__gu_ptr), "i"(-EFAULT)                           \
 187         );                                                              \
 188 })
 189
 190 #define __put_user(x, ptr)                                              \
 191 ({                                                                      \
 192         __typeof__(*(ptr)) __gu_val = x;                                \
 193         long __gu_err = 0;                                              \
 194         switch (sizeof(__gu_val)) {                                     \
 195         case 1:                                                         \
 196                 __put_user_asm("sb", (ptr), __gu_val, __gu_err);        \
 197                 break;                                                  \
 198         case 2:                                                         \
 199                 __put_user_asm("sh", (ptr), __gu_val, __gu_err);        \
 200                 break;                                                  \
 201         case 4:                                                         \
 202                 __put_user_asm("sw", (ptr), __gu_val, __gu_err);        \
 203                 break;                                                  \
 204         case 8:                                                         \
 205                 __put_user_asm_8((ptr), __gu_val, __gu_err);            \
 206                 break;                                                  \
 207         default:                                                        \
 208                 __gu_err = -EINVAL;                                     \
 209         }                                                               \
 210         __gu_err;                                                       \
 211 })
 212
 213 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err)  \
 214 ({                                                      \
 215 __asm__ __volatile__ (" lwi     %0, %1, 0;              \
 216                 1:      swi     %0, %2, 0;              \
 217                         lwi     %0, %1, 4;              \
 218                 2:      swi     %0, %2, 4;              \
 219                         addk    %0,r0,r0;               \
 220                 3:                                      \
 221                 .section .fixup,\"ax\";                 \
 222                 4:      brid    3b;                     \
 223                         addik   %0, r0, %3;             \
 224                 .previous;                              \
 225                 .section __ex_table,\"a\";              \
 226                 .word   1b,4b,2b,4b;                    \
 227                 .previous;"                             \
 228         : "=&r"(__gu_err)                               \
 229         : "r"(&__gu_val),                               \
 230         "r"(__gu_ptr), "i"(-EFAULT)                     \
 231         );                                              \
 232 })
 233
 234 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
 235 ({                                                              \
 236         __asm__ __volatile__ (                                  \
 237                         "1:"    insn    " %1, %2, r0;           \
 238                                 addk    %0, r0, r0;             \
 239                         2:                                      \
 240                         .section .fixup,\"ax\";                 \
 241                         3:      brid    2b;                     \
 242                                 addik   %0, r0, %3;             \
 243                         .previous;                              \
 244                         .section __ex_table,\"a\";              \
 245                         .word   1b,3b;                          \
 246                         .previous;"                             \
 247                 : "=r"(__gu_err)                                \
 248                 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT)    \
 249         );                                                      \
 250 })
 251
 252 /*
 253  * Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail.
 254  */
 255 static inline int clear_user(char *to, int size)
 256 {
 257         if (size && access_ok(VERIFY_WRITE, to, size)) {
 258                 __asm__ __volatile__ ("                         \
 259                                 1:                              \
 260                                         sb      r0, %2, r0;     \
 261                                         addik   %0, %0, -1;     \
 262                                         bneid   %0, 1b;         \
 263                                         addik   %2, %2, 1;      \
 264                                 2:                              \
 265                                 .section __ex_table,\"a\";      \
 266                                 .word   1b,2b;                  \
 267                                 .section .text;"                \
 268                         : "=r"(size)                            \
 269                         : "0"(size), "r"(to)
 270                 );
 271         }
 272         return size;
 273 }
 274
 275 extern unsigned long __copy_tofrom_user(void __user *to,
 276                 const void __user *from, unsigned long size);
 277
 278 #define copy_to_user(to, from, n)                                       \
 279         (access_ok(VERIFY_WRITE, (to), (n)) ?                           \
 280                 __copy_tofrom_user((void __user *)(to),                 \
 281                         (__force const void __user *)(from), (n))       \
 282                 : -EFAULT)
 283
 284 #define __copy_to_user(to, from, n)     copy_to_user((to), (from), (n))
 285 #define __copy_to_user_inatomic(to, from, n)    copy_to_user((to), (from), (n))
 286
 287 #define copy_from_user(to, from, n)                                     \
 288         (access_ok(VERIFY_READ, (from), (n)) ?                          \
 289                 __copy_tofrom_user((__force void __user *)(to),         \
 290                         (void __user *)(from), (n))                     \
 291                 : -EFAULT)
 292
 293 #define __copy_from_user(to, from, n)   copy_from_user((to), (from), (n))
 294 #define __copy_from_user_inatomic(to, from, n) \
 295                 copy_from_user((to), (from), (n))
 296
 297 extern int __strncpy_user(char *to, const char __user *from, int len);
 298 extern int __strnlen_user(const char __user *sstr, int len);
 299
 300 #define strncpy_from_user(to, from, len)        \
 301                 (access_ok(VERIFY_READ, from, 1) ?      \
 302                         __strncpy_user(to, from, len) : -EFAULT)
 303 #define strnlen_user(str, len)  \
 304                 (access_ok(VERIFY_READ, str, 1) ? __strnlen_user(str, len) : 0)
 305
 306 #endif /* CONFIG_MMU */
 307
 308 /*
 309  * The exception table consists of pairs of addresses: the first is the
 310  * address of an instruction that is allowed to fault, and the second is
 311  * the address at which the program should continue. No registers are
 312  * modified, so it is entirely up to the continuation code to figure out
 313  * what to do.
 314  *
 315  * All the routines below use bits of fixup code that are out of line
 316  * with the main instruction path. This means when everything is well,
 317  * we don't even have to jump over them. Further, they do not intrude
 318  * on our cache or tlb entries.
 319  */
 320 struct exception_table_entry {
 321         unsigned long insn, fixup;
 322 };
 323
 324 #endif  /* __ASSEMBLY__ */
 325 #endif /* __KERNEL__ */
 326
 327 #endif /* _ASM_MICROBLAZE_UACCESS_H */