git.oblomov.eu Git - linux-2.6/blob - arch/s390/lib/uaccess_std.c

   1 /*
   2  *  arch/s390/lib/uaccess_std.c
   3  *
   4  *  Standard user space access functions based on mvcp/mvcs and doing
   5  *  interesting things in the secondary space mode.
   6  *
   7  *    Copyright (C) IBM Corp. 2006
   8  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   9  *               Gerald Schaefer (gerald.schaefer@de.ibm.com)
  10  */
  11
  12 #include <linux/errno.h>
  13 #include <linux/mm.h>
  14 #include <linux/uaccess.h>
  15 #include <asm/futex.h>
  16
  17 #ifndef __s390x__
  18 #define AHI     "ahi"
  19 #define ALR     "alr"
  20 #define CLR     "clr"
  21 #define LHI     "lhi"
  22 #define SLR     "slr"
  23 #else
  24 #define AHI     "aghi"
  25 #define ALR     "algr"
  26 #define CLR     "clgr"
  27 #define LHI     "lghi"
  28 #define SLR     "slgr"
  29 #endif
  30
  31 extern size_t copy_from_user_pt(size_t n, const void __user *from, void *to);
  32 extern size_t copy_to_user_pt(size_t n, void __user *to, const void *from);
  33
  34 size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
  35 {
  36         unsigned long tmp1, tmp2;
  37
  38         tmp1 = -256UL;
  39         asm volatile(
  40                 "0: mvcp  0(%0,%2),0(%1),%3\n"
  41                 "   jz    8f\n"
  42                 "1:"ALR"  %0,%3\n"
  43                 "   la    %1,256(%1)\n"
  44                 "   la    %2,256(%2)\n"
  45                 "2: mvcp  0(%0,%2),0(%1),%3\n"
  46                 "   jnz   1b\n"
  47                 "   j     8f\n"
  48                 "3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
  49                 "  "LHI"  %3,-4096\n"
  50                 "   nr    %4,%3\n"      /* %4 = (ptr + 255) & -4096 */
  51                 "  "SLR"  %4,%1\n"
  52                 "  "CLR"  %0,%4\n"      /* copy crosses next page boundary? */
  53                 "   jnh   5f\n"
  54                 "4: mvcp  0(%4,%2),0(%1),%3\n"
  55                 "  "SLR"  %0,%4\n"
  56                 "  "ALR"  %2,%4\n"
  57                 "5:"LHI"  %4,-1\n"
  58                 "  "ALR"  %4,%0\n"      /* copy remaining size, subtract 1 */
  59                 "   bras  %3,7f\n"      /* memset loop */
  60                 "   xc    0(1,%2),0(%2)\n"
  61                 "6: xc    0(256,%2),0(%2)\n"
  62                 "   la    %2,256(%2)\n"
  63                 "7:"AHI"  %4,-256\n"
  64                 "   jnm   6b\n"
  65                 "   ex    %4,0(%3)\n"
  66                 "   j     9f\n"
  67                 "8:"SLR"  %0,%0\n"
  68                 "9: \n"
  69                 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
  70                 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
  71                 : : "cc", "memory");
  72         return size;
  73 }
  74
  75 size_t copy_from_user_std_check(size_t size, const void __user *ptr, void *x)
  76 {
  77         if (size <= 1024)
  78                 return copy_from_user_std(size, ptr, x);
  79         return copy_from_user_pt(size, ptr, x);
  80 }
  81
  82 size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
  83 {
  84         unsigned long tmp1, tmp2;
  85
  86         tmp1 = -256UL;
  87         asm volatile(
  88                 "0: mvcs  0(%0,%1),0(%2),%3\n"
  89                 "   jz    5f\n"
  90                 "1:"ALR"  %0,%3\n"
  91                 "   la    %1,256(%1)\n"
  92                 "   la    %2,256(%2)\n"
  93                 "2: mvcs  0(%0,%1),0(%2),%3\n"
  94                 "   jnz   1b\n"
  95                 "   j     5f\n"
  96                 "3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
  97                 "  "LHI"  %3,-4096\n"
  98                 "   nr    %4,%3\n"      /* %4 = (ptr + 255) & -4096 */
  99                 "  "SLR"  %4,%1\n"
 100                 "  "CLR"  %0,%4\n"      /* copy crosses next page boundary? */
 101                 "   jnh   6f\n"
 102                 "4: mvcs  0(%4,%1),0(%2),%3\n"
 103                 "  "SLR"  %0,%4\n"
 104                 "   j     6f\n"
 105                 "5:"SLR"  %0,%0\n"
 106                 "6: \n"
 107                 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
 108                 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
 109                 : : "cc", "memory");
 110         return size;
 111 }
 112
 113 size_t copy_to_user_std_check(size_t size, void __user *ptr, const void *x)
 114 {
 115         if (size <= 1024)
 116                 return copy_to_user_std(size, ptr, x);
 117         return copy_to_user_pt(size, ptr, x);
 118 }
 119
 120 size_t copy_in_user_std(size_t size, void __user *to, const void __user *from)
 121 {
 122         unsigned long tmp1;
 123
 124         asm volatile(
 125                 "  "AHI"  %0,-1\n"
 126                 "   jo    5f\n"
 127                 "   sacf  256\n"
 128                 "   bras  %3,3f\n"
 129                 "0:"AHI"  %0,257\n"
 130                 "1: mvc   0(1,%1),0(%2)\n"
 131                 "   la    %1,1(%1)\n"
 132                 "   la    %2,1(%2)\n"
 133                 "  "AHI"  %0,-1\n"
 134                 "   jnz   1b\n"
 135                 "   j     5f\n"
 136                 "2: mvc   0(256,%1),0(%2)\n"
 137                 "   la    %1,256(%1)\n"
 138                 "   la    %2,256(%2)\n"
 139                 "3:"AHI"  %0,-256\n"
 140                 "   jnm   2b\n"
 141                 "4: ex    %0,1b-0b(%3)\n"
 142                 "   sacf  0\n"
 143                 "5: "SLR"  %0,%0\n"
 144                 "6:\n"
 145                 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
 146                 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
 147                 : : "cc", "memory");
 148         return size;
 149 }
 150
 151 size_t clear_user_std(size_t size, void __user *to)
 152 {
 153         unsigned long tmp1, tmp2;
 154
 155         asm volatile(
 156                 "  "AHI"  %0,-1\n"
 157                 "   jo    5f\n"
 158                 "   sacf  256\n"
 159                 "   bras  %3,3f\n"
 160                 "   xc    0(1,%1),0(%1)\n"
 161                 "0:"AHI"  %0,257\n"
 162                 "   la    %2,255(%1)\n" /* %2 = ptr + 255 */
 163                 "   srl   %2,12\n"
 164                 "   sll   %2,12\n"      /* %2 = (ptr + 255) & -4096 */
 165                 "  "SLR"  %2,%1\n"
 166                 "  "CLR"  %0,%2\n"      /* clear crosses next page boundary? */
 167                 "   jnh   5f\n"
 168                 "  "AHI"  %2,-1\n"
 169                 "1: ex    %2,0(%3)\n"
 170                 "  "AHI"  %2,1\n"
 171                 "  "SLR"  %0,%2\n"
 172                 "   j     5f\n"
 173                 "2: xc    0(256,%1),0(%1)\n"
 174                 "   la    %1,256(%1)\n"
 175                 "3:"AHI"  %0,-256\n"
 176                 "   jnm   2b\n"
 177                 "4: ex    %0,0(%3)\n"
 178                 "   sacf  0\n"
 179                 "5: "SLR"  %0,%0\n"
 180                 "6:\n"
 181                 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
 182                 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
 183                 : : "cc", "memory");
 184         return size;
 185 }
 186
 187 size_t strnlen_user_std(size_t size, const char __user *src)
 188 {
 189         register unsigned long reg0 asm("0") = 0UL;
 190         unsigned long tmp1, tmp2;
 191
 192         asm volatile(
 193                 "   la    %2,0(%1)\n"
 194                 "   la    %3,0(%0,%1)\n"
 195                 "  "SLR"  %0,%0\n"
 196                 "   sacf  256\n"
 197                 "0: srst  %3,%2\n"
 198                 "   jo    0b\n"
 199                 "   la    %0,1(%3)\n"   /* strnlen_user results includes \0 */
 200                 "  "SLR"  %0,%1\n"
 201                 "1: sacf  0\n"
 202                 EX_TABLE(0b,1b)
 203                 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
 204                 : "d" (reg0) : "cc", "memory");
 205         return size;
 206 }
 207
 208 size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst)
 209 {
 210         register unsigned long reg0 asm("0") = 0UL;
 211         unsigned long tmp1, tmp2;
 212
 213         asm volatile(
 214                 "   la    %3,0(%1)\n"
 215                 "   la    %4,0(%0,%1)\n"
 216                 "   sacf  256\n"
 217                 "0: srst  %4,%3\n"
 218                 "   jo    0b\n"
 219                 "   sacf  0\n"
 220                 "   la    %0,0(%4)\n"
 221                 "   jh    1f\n"         /* found \0 in string ? */
 222                 "  "AHI"  %4,1\n"       /* include \0 in copy */
 223                 "1:"SLR"  %0,%1\n"      /* %0 = return length (without \0) */
 224                 "  "SLR"  %4,%1\n"      /* %4 = copy length (including \0) */
 225                 "2: mvcp  0(%4,%2),0(%1),%5\n"
 226                 "   jz    9f\n"
 227                 "3:"AHI"  %4,-256\n"
 228                 "   la    %1,256(%1)\n"
 229                 "   la    %2,256(%2)\n"
 230                 "4: mvcp  0(%4,%2),0(%1),%5\n"
 231                 "   jnz   3b\n"
 232                 "   j     9f\n"
 233                 "7: sacf  0\n"
 234                 "8:"LHI"  %0,%6\n"
 235                 "9:\n"
 236                 EX_TABLE(0b,7b) EX_TABLE(2b,8b) EX_TABLE(4b,8b)
 237                 : "+a" (size), "+a" (src), "+d" (dst), "=a" (tmp1), "=a" (tmp2)
 238                 : "d" (reg0), "K" (-EFAULT) : "cc", "memory");
 239         return size;
 240 }
 241
 242 #define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)      \
 243         asm volatile(                                                   \
 244                 "   sacf  256\n"                                        \
 245                 "0: l     %1,0(%6)\n"                                   \
 246                 "1:"insn                                                \
 247                 "2: cs    %1,%2,0(%6)\n"                                \
 248                 "3: jl    1b\n"                                         \
 249                 "   lhi   %0,0\n"                                       \
 250                 "4: sacf  0\n"                                          \
 251                 EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b)         \
 252                 : "=d" (ret), "=&d" (oldval), "=&d" (newval),           \
 253                   "=m" (*uaddr)                                         \
 254                 : "0" (-EFAULT), "d" (oparg), "a" (uaddr),              \
 255                   "m" (*uaddr) : "cc");
 256
 257 int futex_atomic_op(int op, int __user *uaddr, int oparg, int *old)
 258 {
 259         int oldval = 0, newval, ret;
 260
 261         pagefault_disable();
 262
 263         switch (op) {
 264         case FUTEX_OP_SET:
 265                 __futex_atomic_op("lr %2,%5\n",
 266                                   ret, oldval, newval, uaddr, oparg);
 267                 break;
 268         case FUTEX_OP_ADD:
 269                 __futex_atomic_op("lr %2,%1\nar %2,%5\n",
 270                                   ret, oldval, newval, uaddr, oparg);
 271                 break;
 272         case FUTEX_OP_OR:
 273                 __futex_atomic_op("lr %2,%1\nor %2,%5\n",
 274                                   ret, oldval, newval, uaddr, oparg);
 275                 break;
 276         case FUTEX_OP_ANDN:
 277                 __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
 278                                   ret, oldval, newval, uaddr, oparg);
 279                 break;
 280         case FUTEX_OP_XOR:
 281                 __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
 282                                   ret, oldval, newval, uaddr, oparg);
 283                 break;
 284         default:
 285                 ret = -ENOSYS;
 286         }
 287         pagefault_enable();
 288         *old = oldval;
 289         return ret;
 290 }
 291
 292 int futex_atomic_cmpxchg(int __user *uaddr, int oldval, int newval)
 293 {
 294         int ret;
 295
 296         asm volatile(
 297                 "   sacf 256\n"
 298                 "   cs   %1,%4,0(%5)\n"
 299                 "0: lr   %0,%1\n"
 300                 "1: sacf 0\n"
 301                 EX_TABLE(0b,1b)
 302                 : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
 303                 : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
 304                 : "cc", "memory" );
 305         return ret;
 306 }
 307
 308 struct uaccess_ops uaccess_std = {
 309         .copy_from_user = copy_from_user_std_check,
 310         .copy_from_user_small = copy_from_user_std,
 311         .copy_to_user = copy_to_user_std_check,
 312         .copy_to_user_small = copy_to_user_std,
 313         .copy_in_user = copy_in_user_std,
 314         .clear_user = clear_user_std,
 315         .strnlen_user = strnlen_user_std,
 316         .strncpy_from_user = strncpy_from_user_std,
 317         .futex_atomic_op = futex_atomic_op,
 318         .futex_atomic_cmpxchg = futex_atomic_cmpxchg,
 319 };