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 #endif
  18
  19 #ifndef __ASSEMBLY__
  20
  21 /*
  22  * Sparc64 is segmented, though more like the M68K than the I386.
  23  * We use the secondary ASI to address user memory, which references a
  24  * completely different VM map, thus there is zero chance of the user
  25  * doing something queer and tricking us into poking kernel memory.
  26  *
  27  * What is left here is basically what is needed for the other parts of
  28  * the kernel that expect to be able to manipulate, erum, "segments".
  29  * Or perhaps more properly, permissions.
  30  *
  31  * "For historical reasons, these macros are grossly misnamed." -Linus
  32  */
  33
  34 #define KERNEL_DS   ((mm_segment_t) { ASI_P })
  35 #define USER_DS     ((mm_segment_t) { ASI_AIUS })       /* har har har */
  36
  37 #define VERIFY_READ     0
  38 #define VERIFY_WRITE    1
  39
  40 #define get_fs() ((mm_segment_t) { get_thread_current_ds() })
  41 #define get_ds() (KERNEL_DS)
  42
  43 #define segment_eq(a,b)  ((a).seg == (b).seg)
  44
  45 #define set_fs(val)                                                             \
  46 do {                                                                            \
  47         set_thread_current_ds((val).seg);                                       \
  48         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
  49 } while(0)
  50
  51 #define __user_ok(addr,size) 1
  52 #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
  53 #define __access_ok(addr,size) 1
  54 #define access_ok(type,addr,size) 1
  55
  56 static inline int verify_area(int type, const void __user * addr, unsigned long size)
  57 {
  58         return 0;
  59 }
  60
  61 /*
  62  * The exception table consists of pairs of addresses: the first is the
  63  * address of an instruction that is allowed to fault, and the second is
  64  * the address at which the program should continue.  No registers are
  65  * modified, so it is entirely up to the continuation code to figure out
  66  * what to do.
  67  *
  68  * All the routines below use bits of fixup code that are out of line
  69  * with the main instruction path.  This means when everything is well,
  70  * we don't even have to jump over them.  Further, they do not intrude
  71  * on our cache or tlb entries.
  72  *
  73  * There is a special way how to put a range of potentially faulting
  74  * insns (like twenty ldd/std's with now intervening other instructions)
  75  * You specify address of first in insn and 0 in fixup and in the next
  76  * exception_table_entry you specify last potentially faulting insn + 1
  77  * and in fixup the routine which should handle the fault.
  78  * That fixup code will get
  79  * (faulting_insn_address - first_insn_in_the_range_address)/4
  80  * in %g2 (ie. index of the faulting instruction in the range).
  81  */
  82
  83 struct exception_table_entry
  84 {
  85         unsigned insn, fixup;
  86 };
  87
  88 /* Special exable search, which handles ranges.  Returns fixup */
  89 unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
  90
  91 extern void __ret_efault(void);
  92
  93 /* Uh, these should become the main single-value transfer routines..
  94  * They automatically use the right size if we just have the right
  95  * pointer type..
  96  *
  97  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  98  * and yet we don't want to do any pointers, because that is too much
  99  * of a performance impact. Thus we have a few rather ugly macros here,
 100  * and hide all the ugliness from the user.
 101  */
 102 #define put_user(x,ptr) ({ \
 103 unsigned long __pu_addr = (unsigned long)(ptr); \
 104 __put_user_nocheck((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
 105
 106 #define get_user(x,ptr) ({ \
 107 unsigned long __gu_addr = (unsigned long)(ptr); \
 108 __get_user_nocheck((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
 109
 110 #define __put_user(x,ptr) put_user(x,ptr)
 111 #define __get_user(x,ptr) get_user(x,ptr)
 112
 113 struct __large_struct { unsigned long buf[100]; };
 114 #define __m(x) ((struct __large_struct *)(x))
 115
 116 #define __put_user_nocheck(data,addr,size) ({ \
 117 register int __pu_ret; \
 118 switch (size) { \
 119 case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
 120 case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
 121 case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
 122 case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
 123 default: __pu_ret = __put_user_bad(); break; \
 124 } __pu_ret; })
 125
 126 #define __put_user_nocheck_ret(data,addr,size,retval) ({ \
 127 register int __foo __asm__ ("l1"); \
 128 switch (size) { \
 129 case 1: __put_user_asm_ret(data,b,addr,retval,__foo); break; \
 130 case 2: __put_user_asm_ret(data,h,addr,retval,__foo); break; \
 131 case 4: __put_user_asm_ret(data,w,addr,retval,__foo); break; \
 132 case 8: __put_user_asm_ret(data,x,addr,retval,__foo); break; \
 133 default: if (__put_user_bad()) return retval; break; \
 134 } })
 135
 136 #define __put_user_asm(x,size,addr,ret)                                 \
 137 __asm__ __volatile__(                                                   \
 138         "/* Put user asm, inline. */\n"                                 \
 139 "1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                                \
 140         "clr    %0\n"                                                   \
 141 "2:\n\n\t"                                                              \
 142         ".section .fixup,#alloc,#execinstr\n\t"                         \
 143         ".align 4\n"                                                    \
 144 "3:\n\t"                                                                \
 145         "b      2b\n\t"                                                 \
 146         " mov   %3, %0\n\n\t"                                           \
 147         ".previous\n\t"                                                 \
 148         ".section __ex_table,#alloc\n\t"                                \
 149         ".align 4\n\t"                                                  \
 150         ".word  1b, 3b\n\t"                                             \
 151         ".previous\n\n\t"                                               \
 152        : "=r" (ret) : "r" (x), "r" (__m(addr)),                         \
 153          "i" (-EFAULT))
 154
 155 #define __put_user_asm_ret(x,size,addr,ret,foo)                         \
 156 if (__builtin_constant_p(ret) && ret == -EFAULT)                        \
 157 __asm__ __volatile__(                                                   \
 158         "/* Put user asm ret, inline. */\n"                             \
 159 "1:\t"  "st"#size "a %1, [%2] %%asi\n\n\t"                              \
 160         ".section __ex_table,#alloc\n\t"                                \
 161         ".align 4\n\t"                                                  \
 162         ".word  1b, __ret_efault\n\n\t"                                 \
 163         ".previous\n\n\t"                                               \
 164        : "=r" (foo) : "r" (x), "r" (__m(addr)));                        \
 165 else                                                                    \
 166 __asm__ __volatile(                                                     \
 167         "/* Put user asm ret, inline. */\n"                             \
 168 "1:\t"  "st"#size "a %1, [%2] %%asi\n\n\t"                              \
 169         ".section .fixup,#alloc,#execinstr\n\t"                         \
 170         ".align 4\n"                                                    \
 171 "3:\n\t"                                                                \
 172         "ret\n\t"                                                       \
 173         " restore %%g0, %3, %%o0\n\n\t"                                 \
 174         ".previous\n\t"                                                 \
 175         ".section __ex_table,#alloc\n\t"                                \
 176         ".align 4\n\t"                                                  \
 177         ".word  1b, 3b\n\n\t"                                           \
 178         ".previous\n\n\t"                                               \
 179        : "=r" (foo) : "r" (x), "r" (__m(addr)),                         \
 180          "i" (ret))
 181
 182 extern int __put_user_bad(void);
 183
 184 #define __get_user_nocheck(data,addr,size,type) ({ \
 185 register int __gu_ret; \
 186 register unsigned long __gu_val; \
 187 switch (size) { \
 188 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 189 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 190 case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
 191 case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
 192 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 193 } data = (type) __gu_val; __gu_ret; })
 194
 195 #define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
 196 register unsigned long __gu_val __asm__ ("l1"); \
 197 switch (size) { \
 198 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 199 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 200 case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
 201 case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
 202 default: if (__get_user_bad()) return retval; \
 203 } data = (type) __gu_val; })
 204
 205 #define __get_user_asm(x,size,addr,ret)                                 \
 206 __asm__ __volatile__(                                                   \
 207         "/* Get user asm, inline. */\n"                                 \
 208 "1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                                \
 209         "clr    %0\n"                                                   \
 210 "2:\n\n\t"                                                              \
 211         ".section .fixup,#alloc,#execinstr\n\t"                         \
 212         ".align 4\n"                                                    \
 213 "3:\n\t"                                                                \
 214         "clr    %1\n\t"                                                 \
 215         "b      2b\n\t"                                                 \
 216         " mov   %3, %0\n\n\t"                                           \
 217         ".previous\n\t"                                                 \
 218         ".section __ex_table,#alloc\n\t"                                \
 219         ".align 4\n\t"                                                  \
 220         ".word  1b, 3b\n\n\t"                                           \
 221         ".previous\n\t"                                                 \
 222        : "=r" (ret), "=r" (x) : "r" (__m(addr)),                        \
 223          "i" (-EFAULT))
 224
 225 #define __get_user_asm_ret(x,size,addr,retval)                          \
 226 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 227 __asm__ __volatile__(                                                   \
 228         "/* Get user asm ret, inline. */\n"                             \
 229 "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 230         ".section __ex_table,#alloc\n\t"                                \
 231         ".align 4\n\t"                                                  \
 232         ".word  1b,__ret_efault\n\n\t"                                  \
 233         ".previous\n\t"                                                 \
 234        : "=r" (x) : "r" (__m(addr)));                                   \
 235 else                                                                    \
 236 __asm__ __volatile__(                                                   \
 237         "/* Get user asm ret, inline. */\n"                             \
 238 "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
 239         ".section .fixup,#alloc,#execinstr\n\t"                         \
 240         ".align 4\n"                                                    \
 241 "3:\n\t"                                                                \
 242         "ret\n\t"                                                       \
 243         " restore %%g0, %2, %%o0\n\n\t"                                 \
 244         ".previous\n\t"                                                 \
 245         ".section __ex_table,#alloc\n\t"                                \
 246         ".align 4\n\t"                                                  \
 247         ".word  1b, 3b\n\n\t"                                           \
 248         ".previous\n\t"                                                 \
 249        : "=r" (x) : "r" (__m(addr)), "i" (retval))
 250
 251 extern int __get_user_bad(void);
 252
 253 extern unsigned long __copy_from_user(void *to, const void __user *from,
 254                                       unsigned long size);
 255
 256 extern unsigned long __copy_to_user(void __user *to, const void *from,
 257                                     unsigned long size);
 258
 259 extern unsigned long __copy_in_user(void __user *to, const void __user *from,
 260                                     unsigned long size);
 261
 262 #define copy_from_user __copy_from_user
 263 #define copy_to_user __copy_to_user
 264 #define copy_in_user __copy_in_user
 265
 266 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 267 {
 268         extern unsigned long __bzero_noasi(void *addr, unsigned long size);
 269
 270         return __bzero_noasi((void *) addr, size);
 271 }
 272
 273 #define clear_user __clear_user
 274
 275 extern long __strncpy_from_user(char *dest, const char __user *src, long count);
 276
 277 #define strncpy_from_user __strncpy_from_user
 278
 279 extern long __strlen_user(const char __user *);
 280 extern long __strnlen_user(const char __user *, long len);
 281
 282 #define strlen_user __strlen_user
 283 #define strnlen_user __strnlen_user
 284
 285 #endif  /* __ASSEMBLY__ */
 286
 287 #endif /* _ASM_UACCESS_H */