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 <linux/string.h>
  26
  27 #define VERIFY_READ     0
  28 #define VERIFY_WRITE    1
  29
  30 /*
  31  * On Microblaze the fs value is actually the top of the corresponding
  32  * address space.
  33  *
  34  * The fs value determines whether argument validity checking should be
  35  * performed or not. If get_fs() == USER_DS, checking is performed, with
  36  * get_fs() == KERNEL_DS, checking is bypassed.
  37  *
  38  * For historical reasons, these macros are grossly misnamed.
  39  *
  40  * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
  41  */
  42 # define MAKE_MM_SEG(s)       ((mm_segment_t) { (s) })
  43
  44 #  ifndef CONFIG_MMU
  45 #  define KERNEL_DS     MAKE_MM_SEG(0)
  46 #  define USER_DS       KERNEL_DS
  47 #  else
  48 #  define KERNEL_DS     MAKE_MM_SEG(0xFFFFFFFF)
  49 #  define USER_DS       MAKE_MM_SEG(TASK_SIZE - 1)
  50 #  endif
  51
  52 # define get_ds()       (KERNEL_DS)
  53 # define get_fs()       (current_thread_info()->addr_limit)
  54 # define set_fs(val)    (current_thread_info()->addr_limit = (val))
  55
  56 # define segment_eq(a, b)       ((a).seg == (b).seg)
  57
  58 /*
  59  * The exception table consists of pairs of addresses: the first is the
  60  * address of an instruction that is allowed to fault, and the second is
  61  * the address at which the program should continue. No registers are
  62  * modified, so it is entirely up to the continuation code to figure out
  63  * what to do.
  64  *
  65  * All the routines below use bits of fixup code that are out of line
  66  * with the main instruction path. This means when everything is well,
  67  * we don't even have to jump over them. Further, they do not intrude
  68  * on our cache or tlb entries.
  69  */
  70 struct exception_table_entry {
  71         unsigned long insn, fixup;
  72 };
  73
  74 #define __clear_user(addr, n)   (memset((void *)(addr), 0, (n)), 0)
  75
  76 #ifndef CONFIG_MMU
  77
  78 extern int ___range_ok(unsigned long addr, unsigned long size);
  79
  80 #define __range_ok(addr, size) \
  81                 ___range_ok((unsigned long)(addr), (unsigned long)(size))
  82
  83 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
  84 #define __access_ok(add, size) (__range_ok((addr), (size)) == 0)
  85
  86 /* Undefined function to trigger linker error */
  87 extern int bad_user_access_length(void);
  88
  89 /* FIXME this is function for optimalization -> memcpy */
  90 #define __get_user(var, ptr)                            \
  91 ({                                                      \
  92         int __gu_err = 0;                               \
  93         switch (sizeof(*(ptr))) {                       \
  94         case 1:                                         \
  95         case 2:                                         \
  96         case 4:                                         \
  97                 (var) = *(ptr);                         \
  98                 break;                                  \
  99         case 8:                                         \
 100                 memcpy((void *) &(var), (ptr), 8);      \
 101                 break;                                  \
 102         default:                                        \
 103                 (var) = 0;                              \
 104                 __gu_err = __get_user_bad();            \
 105                 break;                                  \
 106         }                                               \
 107         __gu_err;                                       \
 108 })
 109
 110 #define __get_user_bad()        (bad_user_access_length(), (-EFAULT))
 111
 112 /* FIXME is not there defined __pu_val */
 113 #define __put_user(var, ptr)                                    \
 114 ({                                                              \
 115         int __pu_err = 0;                                       \
 116         switch (sizeof(*(ptr))) {                               \
 117         case 1:                                                 \
 118         case 2:                                                 \
 119         case 4:                                                 \
 120                 *(ptr) = (var);                                 \
 121                 break;                                          \
 122         case 8: {                                               \
 123                 typeof(*(ptr)) __pu_val = (var);                \
 124                 memcpy(ptr, &__pu_val, sizeof(__pu_val));       \
 125                 }                                               \
 126                 break;                                          \
 127         default:                                                \
 128                 __pu_err = __put_user_bad();                    \
 129                 break;                                          \
 130         }                                                       \
 131         __pu_err;                                               \
 132 })
 133
 134 #define __put_user_bad()        (bad_user_access_length(), (-EFAULT))
 135
 136 #define put_user(x, ptr)        __put_user((x), (ptr))
 137 #define get_user(x, ptr)        __get_user((x), (ptr))
 138
 139 #define copy_to_user(to, from, n)       (memcpy((to), (from), (n)), 0)
 140 #define copy_from_user(to, from, n)     (memcpy((to), (from), (n)), 0)
 141
 142 #define __copy_to_user(to, from, n)     (copy_to_user((to), (from), (n)))
 143 #define __copy_from_user(to, from, n)   (copy_from_user((to), (from), (n)))
 144 #define __copy_to_user_inatomic(to, from, n) \
 145                         (__copy_to_user((to), (from), (n)))
 146 #define __copy_from_user_inatomic(to, from, n) \
 147                         (__copy_from_user((to), (from), (n)))
 148
 149 static inline unsigned long clear_user(void *addr, unsigned long size)
 150 {
 151         if (access_ok(VERIFY_WRITE, addr, size))
 152                 size = __clear_user(addr, size);
 153         return size;
 154 }
 155
 156 /* Returns 0 if exception not found and fixup otherwise.  */
 157 extern unsigned long search_exception_table(unsigned long);
 158
 159 extern long strncpy_from_user(char *dst, const char *src, long count);
 160 extern long strnlen_user(const char *src, long count);
 161
 162 #else /* CONFIG_MMU */
 163
 164 /*
 165  * Address is valid if:
 166  *  - "addr", "addr + size" and "size" are all below the limit
 167  */
 168 #define access_ok(type, addr, size) \
 169         (get_fs().seg > (((unsigned long)(addr)) | \
 170                 (size) | ((unsigned long)(addr) + (size))))
 171
 172 /* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n",
 173  type?"WRITE":"READ",addr,size,get_fs().seg)) */
 174
 175 /*
 176  * All the __XXX versions macros/functions below do not perform
 177  * access checking. It is assumed that the necessary checks have been
 178  * already performed before the finction (macro) is called.
 179  */
 180
 181 #define get_user(x, ptr)                                                \
 182 ({                                                                      \
 183         access_ok(VERIFY_READ, (ptr), sizeof(*(ptr)))                   \
 184                 ? __get_user((x), (ptr)) : -EFAULT;                     \
 185 })
 186
 187 #define put_user(x, ptr)                                                \
 188 ({                                                                      \
 189         access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr)))                  \
 190                 ? __put_user((x), (ptr)) : -EFAULT;                     \
 191 })
 192
 193 #define __get_user(x, ptr)                                              \
 194 ({                                                                      \
 195         unsigned long __gu_val;                                         \
 196         /*unsigned long __gu_ptr = (unsigned long)(ptr);*/              \
 197         long __gu_err;                                                  \
 198         switch (sizeof(*(ptr))) {                                       \
 199         case 1:                                                         \
 200                 __get_user_asm("lbu", (ptr), __gu_val, __gu_err);       \
 201                 break;                                                  \
 202         case 2:                                                         \
 203                 __get_user_asm("lhu", (ptr), __gu_val, __gu_err);       \
 204                 break;                                                  \
 205         case 4:                                                         \
 206                 __get_user_asm("lw", (ptr), __gu_val, __gu_err);        \
 207                 break;                                                  \
 208         default:                                                        \
 209                 __gu_val = 0; __gu_err = -EINVAL;                       \
 210         }                                                               \
 211         x = (__typeof__(*(ptr))) __gu_val;                              \
 212         __gu_err;                                                       \
 213 })
 214
 215 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)              \
 216 ({                                                                      \
 217         __asm__ __volatile__ (                                          \
 218                         "1:"    insn    " %1, %2, r0;                   \
 219                                 addk    %0, r0, r0;                     \
 220                         2:                                              \
 221                         .section .fixup,\"ax\";                         \
 222                         3:      brid    2b;                             \
 223                                 addik   %0, r0, %3;                     \
 224                         .previous;                                      \
 225                         .section __ex_table,\"a\";                      \
 226                         .word   1b,3b;                                  \
 227                         .previous;"                                     \
 228                 : "=r"(__gu_err), "=r"(__gu_val)                        \
 229                 : "r"(__gu_ptr), "i"(-EFAULT)                           \
 230         );                                                              \
 231 })
 232
 233 #define __put_user(x, ptr)                                              \
 234 ({                                                                      \
 235         __typeof__(*(ptr)) volatile __gu_val = (x);                     \
 236         long __gu_err = 0;                                              \
 237         switch (sizeof(__gu_val)) {                                     \
 238         case 1:                                                         \
 239                 __put_user_asm("sb", (ptr), __gu_val, __gu_err);        \
 240                 break;                                                  \
 241         case 2:                                                         \
 242                 __put_user_asm("sh", (ptr), __gu_val, __gu_err);        \
 243                 break;                                                  \
 244         case 4:                                                         \
 245                 __put_user_asm("sw", (ptr), __gu_val, __gu_err);        \
 246                 break;                                                  \
 247         case 8:                                                         \
 248                 __put_user_asm_8((ptr), __gu_val, __gu_err);            \
 249                 break;                                                  \
 250         default:                                                        \
 251                 __gu_err = -EINVAL;                                     \
 252         }                                                               \
 253         __gu_err;                                                       \
 254 })
 255
 256 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err)  \
 257 ({                                                      \
 258 __asm__ __volatile__ (" lwi     %0, %1, 0;              \
 259                 1:      swi     %0, %2, 0;              \
 260                         lwi     %0, %1, 4;              \
 261                 2:      swi     %0, %2, 4;              \
 262                         addk    %0,r0,r0;               \
 263                 3:                                      \
 264                 .section .fixup,\"ax\";                 \
 265                 4:      brid    3b;                     \
 266                         addik   %0, r0, %3;             \
 267                 .previous;                              \
 268                 .section __ex_table,\"a\";              \
 269                 .word   1b,4b,2b,4b;                    \
 270                 .previous;"                             \
 271         : "=&r"(__gu_err)                               \
 272         : "r"(&__gu_val),                               \
 273         "r"(__gu_ptr), "i"(-EFAULT)                     \
 274         );                                              \
 275 })
 276
 277 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
 278 ({                                                              \
 279         __asm__ __volatile__ (                                  \
 280                         "1:"    insn    " %1, %2, r0;           \
 281                                 addk    %0, r0, r0;             \
 282                         2:                                      \
 283                         .section .fixup,\"ax\";                 \
 284                         3:      brid    2b;                     \
 285                                 addik   %0, r0, %3;             \
 286                         .previous;                              \
 287                         .section __ex_table,\"a\";              \
 288                         .word   1b,3b;                          \
 289                         .previous;"                             \
 290                 : "=r"(__gu_err)                                \
 291                 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT)    \
 292         );                                                      \
 293 })
 294
 295 /*
 296  * Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail.
 297  */
 298 static inline int clear_user(char *to, int size)
 299 {
 300         if (size && access_ok(VERIFY_WRITE, to, size)) {
 301                 __asm__ __volatile__ ("                         \
 302                                 1:                              \
 303                                         sb      r0, %2, r0;     \
 304                                         addik   %0, %0, -1;     \
 305                                         bneid   %0, 1b;         \
 306                                         addik   %2, %2, 1;      \
 307                                 2:                              \
 308                                 .section __ex_table,\"a\";      \
 309                                 .word   1b,2b;                  \
 310                                 .section .text;"                \
 311                         : "=r"(size)                            \
 312                         : "0"(size), "r"(to)
 313                 );
 314         }
 315         return size;
 316 }
 317
 318 #define __copy_from_user(to, from, n)   copy_from_user((to), (from), (n))
 319 #define __copy_from_user_inatomic(to, from, n) \
 320                 copy_from_user((to), (from), (n))
 321
 322 #define copy_to_user(to, from, n)                                       \
 323         (access_ok(VERIFY_WRITE, (to), (n)) ?                           \
 324                 __copy_tofrom_user((void __user *)(to),                 \
 325                         (__force const void __user *)(from), (n))       \
 326                 : -EFAULT)
 327
 328 #define __copy_to_user(to, from, n)     copy_to_user((to), (from), (n))
 329 #define __copy_to_user_inatomic(to, from, n)    copy_to_user((to), (from), (n))
 330
 331 #define copy_from_user(to, from, n)                                     \
 332         (access_ok(VERIFY_READ, (from), (n)) ?                          \
 333                 __copy_tofrom_user((__force void __user *)(to),         \
 334                         (void __user *)(from), (n))                     \
 335                 : -EFAULT)
 336
 337 extern int __strncpy_user(char *to, const char __user *from, int len);
 338 extern int __strnlen_user(const char __user *sstr, int len);
 339
 340 #define strncpy_from_user(to, from, len)        \
 341                 (access_ok(VERIFY_READ, from, 1) ?      \
 342                         __strncpy_user(to, from, len) : -EFAULT)
 343 #define strnlen_user(str, len)  \
 344                 (access_ok(VERIFY_READ, str, 1) ? __strnlen_user(str, len) : 0)
 345
 346 #endif /* CONFIG_MMU */
 347
 348 extern unsigned long __copy_tofrom_user(void __user *to,
 349                 const void __user *from, unsigned long size);
 350
 351 #endif  /* __ASSEMBLY__ */
 352 #endif /* __KERNEL__ */
 353
 354 #endif /* _ASM_MICROBLAZE_UACCESS_H */