kernel/arch/sparc/include/asm/uaccess_64.h

   1 #ifndef _ASM_UACCESS_H
   2 #define _ASM_UACCESS_H
   3
   4 /*
   5  * User space memory access functions
   6  */
   7
   8 #ifdef __KERNEL__
   9 #include <linux/errno.h>
  10 #include <linux/compiler.h>
  11 #include <linux/string.h>
  12 #include <linux/thread_info.h>
  13 #include <asm/asi.h>
  14 #include <asm/spitfire.h>
  15 #include <asm-generic/uaccess-unaligned.h>
  16 #endif
  17
  18 #ifndef __ASSEMBLY__
  19
  20 #include <asm/processor.h>
  21
  22 /*
  23  * Sparc64 is segmented, though more like the M68K than the I386.
  24  * We use the secondary ASI to address user memory, which references a
  25  * completely different VM map, thus there is zero chance of the user
  26  * doing something queer and tricking us into poking kernel memory.
  27  *
  28  * What is left here is basically what is needed for the other parts of
  29  * the kernel that expect to be able to manipulate, erum, "segments".
  30  * Or perhaps more properly, permissions.
  31  *
  32  * "For historical reasons, these macros are grossly misnamed." -Linus
  33  */
  34
  35 #define KERNEL_DS   ((mm_segment_t) { ASI_P })
  36 #define USER_DS     ((mm_segment_t) { ASI_AIUS })       /* har har har */
  37
  38 #define VERIFY_READ     0
  39 #define VERIFY_WRITE    1
  40
  41 #define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
  42 #define get_ds() (KERNEL_DS)
  43
  44 #define segment_eq(a, b)  ((a).seg == (b).seg)
  45
  46 #define set_fs(val)                                                             \
  47 do {                                                                            \
  48         current_thread_info()->current_ds = (val).seg;                          \
  49         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  50 } while(0)
  51
  52 static inline int __access_ok(const void __user * addr, unsigned long size)
  53 {
  54         return 1;
  55 }
  56
  57 static inline int access_ok(int type, const void __user * addr, unsigned long size)
  58 {
  59         return 1;
  60 }
  61
  62 /*
  63  * The exception table consists of pairs of addresses: the first is the
  64  * address of an instruction that is allowed to fault, and the second is
  65  * the address at which the program should continue.  No registers are
  66  * modified, so it is entirely up to the continuation code to figure out
  67  * what to do.
  68  *
  69  * All the routines below use bits of fixup code that are out of line
  70  * with the main instruction path.  This means when everything is well,
  71  * we don't even have to jump over them.  Further, they do not intrude
  72  * on our cache or tlb entries.
  73  */
  74
  75 struct exception_table_entry {
  76         unsigned int insn, fixup;
  77 };
  78
  79 void __ret_efault(void);
  80 void __retl_efault(void);
  81
  82 /* Uh, these should become the main single-value transfer routines..
  83  * They automatically use the right size if we just have the right
  84  * pointer type..
  85  *
  86  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  87  * and yet we don't want to do any pointers, because that is too much
  88  * of a performance impact. Thus we have a few rather ugly macros here,
  89  * and hide all the ugliness from the user.
  90  */
  91 #define put_user(x, ptr) ({ \
  92         unsigned long __pu_addr = (unsigned long)(ptr); \
  93         __chk_user_ptr(ptr); \
  94         __put_user_nocheck((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr)));\
  95 })
  96
  97 #define get_user(x, ptr) ({ \
  98         unsigned long __gu_addr = (unsigned long)(ptr); \
  99         __chk_user_ptr(ptr); \
 100         __get_user_nocheck((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr)));\
 101 })
 102
 103 #define __put_user(x, ptr) put_user(x, ptr)
 104 #define __get_user(x, ptr) get_user(x, ptr)
 105
 106 struct __large_struct { unsigned long buf[100]; };
 107 #define __m(x) ((struct __large_struct *)(x))
 108
 109 #define __put_user_nocheck(data, addr, size) ({                 \
 110         register int __pu_ret;                                  \
 111         switch (size) {                                         \
 112         case 1: __put_user_asm(data, b, addr, __pu_ret); break; \
 113         case 2: __put_user_asm(data, h, addr, __pu_ret); break; \
 114         case 4: __put_user_asm(data, w, addr, __pu_ret); break; \
 115         case 8: __put_user_asm(data, x, addr, __pu_ret); break; \
 116         default: __pu_ret = __put_user_bad(); break;            \
 117         }                                                       \
 118         __pu_ret;                                               \
 119 })
 120
 121 #define __put_user_asm(x, size, addr, ret)                              \
 122 __asm__ __volatile__(                                                   \
 123                 "/* Put user asm, inline. */\n"                         \
 124         "1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                        \
 125                 "clr    %0\n"                                           \
 126         "2:\n\n\t"                                                      \
 127                 ".section .fixup,#alloc,#execinstr\n\t"                 \
 128                 ".align 4\n"                                            \
 129         "3:\n\t"                                                        \
 130                 "sethi  %%hi(2b), %0\n\t"                               \
 131                 "jmpl   %0 + %%lo(2b), %%g0\n\t"                        \
 132                 " mov   %3, %0\n\n\t"                                   \
 133                 ".previous\n\t"                                         \
 134                 ".section __ex_table,\"a\"\n\t"                         \
 135                 ".align 4\n\t"                                          \
 136                 ".word  1b, 3b\n\t"                                     \
 137                 ".previous\n\n\t"                                       \
 138                : "=r" (ret) : "r" (x), "r" (__m(addr)),                 \
 139                  "i" (-EFAULT))
 140
 141 int __put_user_bad(void);
 142
 143 #define __get_user_nocheck(data, addr, size, type) ({                        \
 144         register int __gu_ret;                                               \
 145         register unsigned long __gu_val;                                     \
 146         switch (size) {                                                      \
 147                 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
 148                 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
 149                 case 4: __get_user_asm(__gu_val, uw, addr, __gu_ret); break; \
 150                 case 8: __get_user_asm(__gu_val, x, addr, __gu_ret); break;  \
 151                 default:                                                     \
 152                         __gu_val = 0;                                        \
 153                         __gu_ret = __get_user_bad();                         \
 154                         break;                                               \
 155         }                                                                    \
 156         data = (__force type) __gu_val;                                      \
 157          __gu_ret;                                                           \
 158 })
 159
 160 #define __get_user_nocheck_ret(data, addr, size, type, retval) ({       \
 161         register unsigned long __gu_val __asm__ ("l1");                 \
 162         switch (size) {                                                 \
 163         case 1: __get_user_asm_ret(__gu_val, ub, addr, retval); break;  \
 164         case 2: __get_user_asm_ret(__gu_val, uh, addr, retval); break;  \
 165         case 4: __get_user_asm_ret(__gu_val, uw, addr, retval); break;  \
 166         case 8: __get_user_asm_ret(__gu_val, x, addr, retval); break;   \
 167         default:                                                        \
 168                 if (__get_user_bad())                                   \
 169                         return retval;                                  \
 170         }                                                               \
 171         data = (__force type) __gu_val;                                 \
 172 })
 173
 174 #define __get_user_asm(x, size, addr, ret)                              \
 175 __asm__ __volatile__(                                                   \
 176                 "/* Get user asm, inline. */\n"                         \
 177         "1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                        \
 178                 "clr    %0\n"                                           \
 179         "2:\n\n\t"                                                      \
 180                 ".section .fixup,#alloc,#execinstr\n\t"                 \
 181                 ".align 4\n"                                            \
 182         "3:\n\t"                                                        \
 183                 "sethi  %%hi(2b), %0\n\t"                               \
 184                 "clr    %1\n\t"                                         \
 185                 "jmpl   %0 + %%lo(2b), %%g0\n\t"                        \
 186                 " mov   %3, %0\n\n\t"                                   \
 187                 ".previous\n\t"                                         \
 188                 ".section __ex_table,\"a\"\n\t"                         \
 189                 ".align 4\n\t"                                          \
 190                 ".word  1b, 3b\n\n\t"                                   \
 191                 ".previous\n\t"                                         \
 192                : "=r" (ret), "=r" (x) : "r" (__m(addr)),                \
 193                  "i" (-EFAULT))
 194
 195 #define __get_user_asm_ret(x, size, addr, retval)                       \
 196 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 197         __asm__ __volatile__(                                           \
 198                 "/* Get user asm ret, inline. */\n"                     \
 199         "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                      \
 200                 ".section __ex_table,\"a\"\n\t"                         \
 201                 ".align 4\n\t"                                          \
 202                 ".word  1b,__ret_efault\n\n\t"                          \
 203                 ".previous\n\t"                                         \
 204                : "=r" (x) : "r" (__m(addr)));                           \
 205 else                                                                    \
 206         __asm__ __volatile__(                                           \
 207                 "/* Get user asm ret, inline. */\n"                     \
 208         "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                      \
 209                 ".section .fixup,#alloc,#execinstr\n\t"                 \
 210                 ".align 4\n"                                            \
 211         "3:\n\t"                                                        \
 212                 "ret\n\t"                                               \
 213                 " restore %%g0, %2, %%o0\n\n\t"                         \
 214                 ".previous\n\t"                                         \
 215                 ".section __ex_table,\"a\"\n\t"                         \
 216                 ".align 4\n\t"                                          \
 217                 ".word  1b, 3b\n\n\t"                                   \
 218                 ".previous\n\t"                                         \
 219                : "=r" (x) : "r" (__m(addr)), "i" (retval))
 220
 221 int __get_user_bad(void);
 222
 223 unsigned long __must_check ___copy_from_user(void *to,
 224                                              const void __user *from,
 225                                              unsigned long size);
 226 unsigned long copy_from_user_fixup(void *to, const void __user *from,
 227                                    unsigned long size);
 228 static inline unsigned long __must_check
 229 copy_from_user(void *to, const void __user *from, unsigned long size)
 230 {
 231         unsigned long ret = ___copy_from_user(to, from, size);
 232
 233         if (unlikely(ret))
 234                 ret = copy_from_user_fixup(to, from, size);
 235
 236         return ret;
 237 }
 238 #define __copy_from_user copy_from_user
 239
 240 unsigned long __must_check ___copy_to_user(void __user *to,
 241                                            const void *from,
 242                                            unsigned long size);
 243 unsigned long copy_to_user_fixup(void __user *to, const void *from,
 244                                  unsigned long size);
 245 static inline unsigned long __must_check
 246 copy_to_user(void __user *to, const void *from, unsigned long size)
 247 {
 248         unsigned long ret = ___copy_to_user(to, from, size);
 249
 250         if (unlikely(ret))
 251                 ret = copy_to_user_fixup(to, from, size);
 252         return ret;
 253 }
 254 #define __copy_to_user copy_to_user
 255
 256 unsigned long __must_check ___copy_in_user(void __user *to,
 257                                            const void __user *from,
 258                                            unsigned long size);
 259 unsigned long copy_in_user_fixup(void __user *to, void __user *from,
 260                                  unsigned long size);
 261 static inline unsigned long __must_check
 262 copy_in_user(void __user *to, void __user *from, unsigned long size)
 263 {
 264         unsigned long ret = ___copy_in_user(to, from, size);
 265
 266         if (unlikely(ret))
 267                 ret = copy_in_user_fixup(to, from, size);
 268         return ret;
 269 }
 270 #define __copy_in_user copy_in_user
 271
 272 unsigned long __must_check __clear_user(void __user *, unsigned long);
 273
 274 #define clear_user __clear_user
 275
 276 __must_check long strlen_user(const char __user *str);
 277 __must_check long strnlen_user(const char __user *str, long n);
 278
 279 #define __copy_to_user_inatomic __copy_to_user
 280 #define __copy_from_user_inatomic __copy_from_user
 281
 282 struct pt_regs;
 283 unsigned long compute_effective_address(struct pt_regs *,
 284                                         unsigned int insn,
 285                                         unsigned int rd);
 286
 287 #endif  /* __ASSEMBLY__ */
 288
 289 #endif /* _ASM_UACCESS_H */