include/asm-sparc64/uaccess.h

   1 /* $Id: uaccess.h,v 1.35 2002/02/09 19:49:31 davem Exp $ */
   2 #ifndef _ASM_UACCESS_H
   3 #define _ASM_UACCESS_H
   4
   5 /*
   6  * User space memory access functions
   7  */
   8
   9 #ifdef __KERNEL__
  10 #include <linux/compiler.h>
  11 #include <linux/sched.h>
  12 #include <linux/string.h>
  13 #include <asm/a.out.h>
  14 #include <asm/asi.h>
  15 #include <asm/system.h>
  16 #include <asm/spitfire.h>
  17 #include <asm-generic/uaccess.h>
  18 #endif
  19
  20 #ifndef __ASSEMBLY__
  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) { get_thread_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         set_thread_current_ds((val).seg);                                       \
  49         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  50 } while(0)
  51
  52 #define __user_ok(addr,size) 1
  53 #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
  54 #define __access_ok(addr,size) 1
  55 #define access_ok(type,addr,size) 1
  56
  57 static inline int verify_area(int type, const void __user * addr, unsigned long size)
  58 {
  59         return 0;
  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  * There is a special way how to put a range of potentially faulting
  75  * insns (like twenty ldd/std's with now intervening other instructions)
  76  * You specify address of first in insn and 0 in fixup and in the next
  77  * exception_table_entry you specify last potentially faulting insn + 1
  78  * and in fixup the routine which should handle the fault.
  79  * That fixup code will get
  80  * (faulting_insn_address - first_insn_in_the_range_address)/4
  81  * in %g2 (ie. index of the faulting instruction in the range).
  82  */
  83
  84 struct exception_table_entry
  85 {
  86         unsigned insn, fixup;
  87 };
  88
  89 /* Special exable search, which handles ranges.  Returns fixup */
  90 unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
  91
  92 extern void __ret_efault(void);
  93
  94 /* Uh, these should become the main single-value transfer routines..
  95  * They automatically use the right size if we just have the right
  96  * pointer type..
  97  *
  98  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  99  * and yet we don't want to do any pointers, because that is too much
 100  * of a performance impact. Thus we have a few rather ugly macros here,
 101  * and hide all the ugliness from the user.
 102  */
 103 #define put_user(x,ptr) ({ \
 104 unsigned long __pu_addr = (unsigned long)(ptr); \
 105 __chk_user_ptr(ptr); \
 106 __put_user_nocheck((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
 107
 108 #define get_user(x,ptr) ({ \
 109 unsigned long __gu_addr = (unsigned long)(ptr); \
 110 __chk_user_ptr(ptr); \
 111 __get_user_nocheck((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
 112
 113 #define __put_user(x,ptr) put_user(x,ptr)
 114 #define __get_user(x,ptr) get_user(x,ptr)
 115
 116 struct __large_struct { unsigned long buf[100]; };
 117 #define __m(x) ((struct __large_struct *)(x))
 118
 119 #define __put_user_nocheck(data,addr,size) ({ \
 120 register int __pu_ret; \
 121 switch (size) { \
 122 case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
 123 case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
 124 case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
 125 case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
 126 default: __pu_ret = __put_user_bad(); break; \
 127 } __pu_ret; })
 128
 129 #define __put_user_nocheck_ret(data,addr,size,retval) ({ \
 130 register int __foo __asm__ ("l1"); \
 131 switch (size) { \
 132 case 1: __put_user_asm_ret(data,b,addr,retval,__foo); break; \
 133 case 2: __put_user_asm_ret(data,h,addr,retval,__foo); break; \
 134 case 4: __put_user_asm_ret(data,w,addr,retval,__foo); break; \
 135 case 8: __put_user_asm_ret(data,x,addr,retval,__foo); break; \
 136 default: if (__put_user_bad()) return retval; break; \
 137 } })
 138
 139 #define __put_user_asm(x,size,addr,ret)                                 \
 140 __asm__ __volatile__(                                                   \
 141         "/* Put user asm, inline. */\n"                                 \
 142 "1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                                \
 143         "clr    %0\n"                                                   \
 144 "2:\n\n\t"                                                              \
 145         ".section .fixup,#alloc,#execinstr\n\t"                         \
 146         ".align 4\n"                                                    \
 147 "3:\n\t"                                                                \
 148         "b      2b\n\t"                                                 \
 149         " mov   %3, %0\n\n\t"                                           \
 150         ".previous\n\t"                                                 \
 151         ".section __ex_table,#alloc\n\t"                                \
 152         ".align 4\n\t"                                                  \
 153         ".word  1b, 3b\n\t"                                             \
 154         ".previous\n\n\t"                                               \
 155        : "=r" (ret) : "r" (x), "r" (__m(addr)),                         \
 156          "i" (-EFAULT))
 157
 158 #define __put_user_asm_ret(x,size,addr,ret,foo)                         \
 159 if (__builtin_constant_p(ret) && ret == -EFAULT)                        \
 160 __asm__ __volatile__(                                                   \
 161         "/* Put user asm ret, inline. */\n"                             \
 162 "1:\t"  "st"#size "a %1, [%2] %%asi\n\n\t"                              \
 163         ".section __ex_table,#alloc\n\t"                                \
 164         ".align 4\n\t"                                                  \
 165         ".word  1b, __ret_efault\n\n\t"                                 \
 166         ".previous\n\n\t"                                               \
 167        : "=r" (foo) : "r" (x), "r" (__m(addr)));                        \
 168 else                                                                    \
 169 __asm__ __volatile__(                                                   \
 170         "/* Put user asm ret, inline. */\n"                             \
 171 "1:\t"  "st"#size "a %1, [%2] %%asi\n\n\t"                              \
 172         ".section .fixup,#alloc,#execinstr\n\t"                         \
 173         ".align 4\n"                                                    \
 174 "3:\n\t"                                                                \
 175         "ret\n\t"                                                       \
 176         " restore %%g0, %3, %%o0\n\n\t"                                 \
 177         ".previous\n\t"                                                 \
 178         ".section __ex_table,#alloc\n\t"                                \
 179         ".align 4\n\t"                                                  \
 180         ".word  1b, 3b\n\n\t"                                           \
 181         ".previous\n\n\t"                                               \
 182        : "=r" (foo) : "r" (x), "r" (__m(addr)),                         \
 183          "i" (ret))
 184
 185 extern int __put_user_bad(void);
 186
 187 #define __get_user_nocheck(data,addr,size,type) ({ \
 188 register int __gu_ret; \
 189 register unsigned long __gu_val; \
 190 switch (size) { \
 191 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 192 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 193 case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
 194 case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
 195 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 196 } data = (type) __gu_val; __gu_ret; })
 197
 198 #define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
 199 register unsigned long __gu_val __asm__ ("l1"); \
 200 switch (size) { \
 201 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 202 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 203 case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
 204 case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
 205 default: if (__get_user_bad()) return retval; \
 206 } data = (type) __gu_val; })
 207
 208 #define __get_user_asm(x,size,addr,ret)                                 \
 209 __asm__ __volatile__(                                                   \
 210         "/* Get user asm, inline. */\n"                                 \
 211 "1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                                \
 212         "clr    %0\n"                                                   \
 213 "2:\n\n\t"                                                              \
 214         ".section .fixup,#alloc,#execinstr\n\t"                         \
 215         ".align 4\n"                                                    \
 216 "3:\n\t"                                                                \
 217         "clr    %1\n\t"                                                 \
 218         "b      2b\n\t"                                                 \
 219         " mov   %3, %0\n\n\t"                                           \
 220         ".previous\n\t"                                                 \
 221         ".section __ex_table,#alloc\n\t"                                \
 222         ".align 4\n\t"                                                  \
 223         ".word  1b, 3b\n\n\t"                                           \
 224         ".previous\n\t"                                                 \
 225        : "=r" (ret), "=r" (x) : "r" (__m(addr)),                        \
 226          "i" (-EFAULT))
 227
 228 #define __get_user_asm_ret(x,size,addr,retval)                          \
 229 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 230 __asm__ __volatile__(                                                   \
 231         "/* Get user asm ret, inline. */\n"                             \
 232 "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 233         ".section __ex_table,#alloc\n\t"                                \
 234         ".align 4\n\t"                                                  \
 235         ".word  1b,__ret_efault\n\n\t"                                  \
 236         ".previous\n\t"                                                 \
 237        : "=r" (x) : "r" (__m(addr)));                                   \
 238 else                                                                    \
 239 __asm__ __volatile__(                                                   \
 240         "/* Get user asm ret, inline. */\n"                             \
 241 "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 242         ".section .fixup,#alloc,#execinstr\n\t"                         \
 243         ".align 4\n"                                                    \
 244 "3:\n\t"                                                                \
 245         "ret\n\t"                                                       \
 246         " restore %%g0, %2, %%o0\n\n\t"                                 \
 247         ".previous\n\t"                                                 \
 248         ".section __ex_table,#alloc\n\t"                                \
 249         ".align 4\n\t"                                                  \
 250         ".word  1b, 3b\n\n\t"                                           \
 251         ".previous\n\t"                                                 \
 252        : "=r" (x) : "r" (__m(addr)), "i" (retval))
 253
 254 extern int __get_user_bad(void);
 255
 256 extern unsigned long ___copy_from_user(void *to, const void __user *from,
 257                                        unsigned long size);
 258 extern unsigned long copy_from_user_fixup(void *to, const void __user *from,
 259                                           unsigned long size);
 260 static inline unsigned long copy_from_user(void *to, const void __user *from,
 261                                            unsigned long size)
 262 {
 263         unsigned long ret = ___copy_from_user(to, from, size);
 264
 265         if (ret)
 266                 ret = copy_from_user_fixup(to, from, size);
 267         return ret;
 268 }
 269 #define __copy_from_user copy_from_user
 270
 271 extern unsigned long ___copy_to_user(void __user *to, const void *from,
 272                                      unsigned long size);
 273 extern unsigned long copy_to_user_fixup(void __user *to, const void *from,
 274                                         unsigned long size);
 275 static inline unsigned long copy_to_user(void __user *to, const void *from,
 276                                          unsigned long size)
 277 {
 278         unsigned long ret = ___copy_to_user(to, from, size);
 279
 280         if (ret)
 281                 ret = copy_to_user_fixup(to, from, size);
 282         return ret;
 283 }
 284 #define __copy_to_user copy_to_user
 285
 286 extern unsigned long ___copy_in_user(void __user *to, const void __user *from,
 287                                      unsigned long size);
 288 extern unsigned long copy_in_user_fixup(void __user *to, void __user *from,
 289                                         unsigned long size);
 290 static inline unsigned long copy_in_user(void __user *to, void __user *from,
 291                                          unsigned long size)
 292 {
 293         unsigned long ret = ___copy_in_user(to, from, size);
 294
 295         if (ret)
 296                 ret = copy_in_user_fixup(to, from, size);
 297         return ret;
 298 }
 299 #define __copy_in_user copy_in_user
 300
 301 extern unsigned long __bzero_noasi(void __user *, unsigned long);
 302
 303 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 304 {
 305
 306         return __bzero_noasi(addr, size);
 307 }
 308
 309 #define clear_user __clear_user
 310
 311 extern long __strncpy_from_user(char *dest, const char __user *src, long count);
 312
 313 #define strncpy_from_user __strncpy_from_user
 314
 315 extern long __strlen_user(const char __user *);
 316 extern long __strnlen_user(const char __user *, long len);
 317
 318 #define strlen_user __strlen_user
 319 #define strnlen_user __strnlen_user
 320 #define __copy_to_user_inatomic __copy_to_user
 321 #define __copy_from_user_inatomic __copy_from_user
 322
 323 #endif  /* __ASSEMBLY__ */
 324
 325 #endif /* _ASM_UACCESS_H */