sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h

   1 /* Copyright (C) 2000-2019 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library.  If not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _LINUX_MIPS_SYSDEP_H
  19 #define _LINUX_MIPS_SYSDEP_H 1
  20
  21 /* There is some commonality.  */
  22 #include <sysdeps/unix/sysv/linux/mips/sysdep.h>
  23 #include <sysdeps/unix/sysv/linux/sysdep.h>
  24 #include <sysdeps/unix/mips/mips64/n64/sysdep.h>
  25
  26 #include <tls.h>
  27
  28 /* In order to get __set_errno() definition in INLINE_SYSCALL.  */
  29 #ifndef __ASSEMBLER__
  30 #include <errno.h>
  31 #endif
  32
  33 /* For Linux we can use the system call table in the header file
  34         /usr/include/asm/unistd.h
  35    of the kernel.  But these symbols do not follow the SYS_* syntax
  36    so we have to redefine the `SYS_ify' macro here.  */
  37 #undef SYS_ify
  38 #define SYS_ify(syscall_name)   __NR_##syscall_name
  39
  40 #ifdef __ASSEMBLER__
  41
  42 /* We don't want the label for the error handler to be visible in the symbol
  43    table when we define it here.  */
  44 # define SYSCALL_ERROR_LABEL 99b
  45
  46 #else   /* ! __ASSEMBLER__ */
  47
  48 /* Define a macro which expands into the inline wrapper code for a system
  49    call.  */
  50 #undef INLINE_SYSCALL
  51 #define INLINE_SYSCALL(name, nr, args...)                               \
  52   ({ INTERNAL_SYSCALL_DECL (_sc_err);                                   \
  53      long result_var = INTERNAL_SYSCALL (name, _sc_err, nr, args);      \
  54      if ( INTERNAL_SYSCALL_ERROR_P (result_var, _sc_err) )              \
  55        {                                                                \
  56          __set_errno (INTERNAL_SYSCALL_ERRNO (result_var, _sc_err));    \
  57          result_var = -1L;                                              \
  58        }                                                                \
  59      result_var; })
  60
  61 #undef INTERNAL_SYSCALL_DECL
  62 #define INTERNAL_SYSCALL_DECL(err) long err __attribute__ ((unused))
  63
  64 #undef INTERNAL_SYSCALL_ERROR_P
  65 #define INTERNAL_SYSCALL_ERROR_P(val, err)   ((void) (val), (long) (err))
  66
  67 #undef INTERNAL_SYSCALL_ERRNO
  68 #define INTERNAL_SYSCALL_ERRNO(val, err)     ((void) (err), val)
  69
  70 /* Note that the original Linux syscall restart convention required the
  71    instruction immediately preceding SYSCALL to initialize $v0 with the
  72    syscall number.  Then if a restart triggered, $v0 would have been
  73    clobbered by the syscall interrupted, and needed to be reinititalized.
  74    The kernel would decrement the PC by 4 before switching back to the
  75    user mode so that $v0 had been reloaded before SYSCALL was executed
  76    again.  This implied the place $v0 was loaded from must have been
  77    preserved across a syscall, e.g. an immediate, static register, stack
  78    slot, etc.
  79
  80    The convention was relaxed in Linux with a change applied to the kernel
  81    GIT repository as commit 96187fb0bc30cd7919759d371d810e928048249d, that
  82    first appeared in the 2.6.36 release.  Since then the kernel has had
  83    code that reloads $v0 upon syscall restart and resumes right at the
  84    SYSCALL instruction, so no special arrangement is needed anymore.
  85
  86    For backwards compatibility with existing kernel binaries we support
  87    the old convention by choosing the instruction preceding SYSCALL
  88    carefully.  This also means we have to force a 32-bit encoding of the
  89    microMIPS MOVE instruction if one is used.  */
  90
  91 #ifdef __mips_micromips
  92 # define MOVE32 "move32"
  93 #else
  94 # define MOVE32 "move"
  95 #endif
  96
  97 #undef INTERNAL_SYSCALL
  98 #define INTERNAL_SYSCALL(name, err, nr, args...)                        \
  99         internal_syscall##nr ("li\t%0, %2\t\t\t# " #name "\n\t",        \
 100                               "IK" (SYS_ify (name)),                    \
 101                               0, err, args)
 102
 103 #undef INTERNAL_SYSCALL_NCS
 104 #define INTERNAL_SYSCALL_NCS(number, err, nr, args...)                  \
 105         internal_syscall##nr (MOVE32 "\t%0, %2\n\t",                    \
 106                               "r" (__s0),                               \
 107                               number, err, args)
 108
 109 #define internal_syscall0(v0_init, input, number, err, dummy...)        \
 110 ({                                                                      \
 111         long _sys_result;                                               \
 112                                                                         \
 113         {                                                               \
 114         register long __s0 asm ("$16") __attribute__ ((unused))         \
 115           = (number);                                                   \
 116         register long __v0 asm ("$2");                                  \
 117         register long __a3 asm ("$7");                                  \
 118         __asm__ volatile (                                              \
 119         ".set\tnoreorder\n\t"                                           \
 120         v0_init                                                         \
 121         "syscall\n\t"                                                   \
 122         ".set reorder"                                                  \
 123         : "=r" (__v0), "=r" (__a3)                                      \
 124         : input                                                         \
 125         : __SYSCALL_CLOBBERS);                                          \
 126         err = __a3;                                                     \
 127         _sys_result = __v0;                                             \
 128         }                                                               \
 129         _sys_result;                                                    \
 130 })
 131
 132 #define internal_syscall1(v0_init, input, number, err, arg1)            \
 133 ({                                                                      \
 134         long _sys_result;                                               \
 135                                                                         \
 136         {                                                               \
 137         register long __s0 asm ("$16") __attribute__ ((unused))         \
 138           = (number);                                                   \
 139         register long __v0 asm ("$2");                                  \
 140         register long __a0 asm ("$4") = (long) (arg1);                  \
 141         register long __a3 asm ("$7");                                  \
 142         __asm__ volatile (                                              \
 143         ".set\tnoreorder\n\t"                                           \
 144         v0_init                                                         \
 145         "syscall\n\t"                                                   \
 146         ".set reorder"                                                  \
 147         : "=r" (__v0), "=r" (__a3)                                      \
 148         : input, "r" (__a0)                                             \
 149         : __SYSCALL_CLOBBERS);                                          \
 150         err = __a3;                                                     \
 151         _sys_result = __v0;                                             \
 152         }                                                               \
 153         _sys_result;                                                    \
 154 })
 155
 156 #define internal_syscall2(v0_init, input, number, err, arg1, arg2)      \
 157 ({                                                                      \
 158         long _sys_result;                                               \
 159                                                                         \
 160         {                                                               \
 161         register long __s0 asm ("$16") __attribute__ ((unused))         \
 162           = (number);                                                   \
 163         register long __v0 asm ("$2");                                  \
 164         register long __a0 asm ("$4") = (long) (arg1);                  \
 165         register long __a1 asm ("$5") = (long) (arg2);                  \
 166         register long __a3 asm ("$7");                                  \
 167         __asm__ volatile (                                              \
 168         ".set\tnoreorder\n\t"                                           \
 169         v0_init                                                         \
 170         "syscall\n\t"                                                   \
 171         ".set\treorder"                                                 \
 172         : "=r" (__v0), "=r" (__a3)                                      \
 173         : input, "r" (__a0), "r" (__a1)                                 \
 174         : __SYSCALL_CLOBBERS);                                          \
 175         err = __a3;                                                     \
 176         _sys_result = __v0;                                             \
 177         }                                                               \
 178         _sys_result;                                                    \
 179 })
 180
 181 #define internal_syscall3(v0_init, input, number, err,                  \
 182                           arg1, arg2, arg3)                             \
 183 ({                                                                      \
 184         long _sys_result;                                               \
 185                                                                         \
 186         {                                                               \
 187         register long __s0 asm ("$16") __attribute__ ((unused))         \
 188           = (number);                                                   \
 189         register long __v0 asm ("$2");                                  \
 190         register long __a0 asm ("$4") = (long) (arg1);                  \
 191         register long __a1 asm ("$5") = (long) (arg2);                  \
 192         register long __a2 asm ("$6") = (long) (arg3);                  \
 193         register long __a3 asm ("$7");                                  \
 194         __asm__ volatile (                                              \
 195         ".set\tnoreorder\n\t"                                           \
 196         v0_init                                                         \
 197         "syscall\n\t"                                                   \
 198         ".set\treorder"                                                 \
 199         : "=r" (__v0), "=r" (__a3)                                      \
 200         : input, "r" (__a0), "r" (__a1), "r" (__a2)                     \
 201         : __SYSCALL_CLOBBERS);                                          \
 202         err = __a3;                                                     \
 203         _sys_result = __v0;                                             \
 204         }                                                               \
 205         _sys_result;                                                    \
 206 })
 207
 208 #define internal_syscall4(v0_init, input, number, err,                  \
 209                           arg1, arg2, arg3, arg4)                       \
 210 ({                                                                      \
 211         long _sys_result;                                               \
 212                                                                         \
 213         {                                                               \
 214         register long __s0 asm ("$16") __attribute__ ((unused))         \
 215           = (number);                                                   \
 216         register long __v0 asm ("$2");                                  \
 217         register long __a0 asm ("$4") = (long) (arg1);                  \
 218         register long __a1 asm ("$5") = (long) (arg2);                  \
 219         register long __a2 asm ("$6") = (long) (arg3);                  \
 220         register long __a3 asm ("$7") = (long) (arg4);                  \
 221         __asm__ volatile (                                              \
 222         ".set\tnoreorder\n\t"                                           \
 223         v0_init                                                         \
 224         "syscall\n\t"                                                   \
 225         ".set\treorder"                                                 \
 226         : "=r" (__v0), "+r" (__a3)                                      \
 227         : input, "r" (__a0), "r" (__a1), "r" (__a2)                     \
 228         : __SYSCALL_CLOBBERS);                                          \
 229         err = __a3;                                                     \
 230         _sys_result = __v0;                                             \
 231         }                                                               \
 232         _sys_result;                                                    \
 233 })
 234
 235 #define internal_syscall5(v0_init, input, number, err,                  \
 236                           arg1, arg2, arg3, arg4, arg5)                 \
 237 ({                                                                      \
 238         long _sys_result;                                               \
 239                                                                         \
 240         {                                                               \
 241         register long __s0 asm ("$16") __attribute__ ((unused))         \
 242           = (number);                                                   \
 243         register long __v0 asm ("$2");                                  \
 244         register long __a0 asm ("$4") = (long) (arg1);                  \
 245         register long __a1 asm ("$5") = (long) (arg2);                  \
 246         register long __a2 asm ("$6") = (long) (arg3);                  \
 247         register long __a3 asm ("$7") = (long) (arg4);                  \
 248         register long __a4 asm ("$8") = (long) (arg5);                  \
 249         __asm__ volatile (                                              \
 250         ".set\tnoreorder\n\t"                                           \
 251         v0_init                                                         \
 252         "syscall\n\t"                                                   \
 253         ".set\treorder"                                                 \
 254         : "=r" (__v0), "+r" (__a3)                                      \
 255         : input, "r" (__a0), "r" (__a1), "r" (__a2), "r" (__a4)         \
 256         : __SYSCALL_CLOBBERS);                                          \
 257         err = __a3;                                                     \
 258         _sys_result = __v0;                                             \
 259         }                                                               \
 260         _sys_result;                                                    \
 261 })
 262
 263 #define internal_syscall6(v0_init, input, number, err,                  \
 264                           arg1, arg2, arg3, arg4, arg5, arg6)           \
 265 ({                                                                      \
 266         long _sys_result;                                               \
 267                                                                         \
 268         {                                                               \
 269         register long __s0 asm ("$16") __attribute__ ((unused))         \
 270           = (number);                                                   \
 271         register long __v0 asm ("$2");                                  \
 272         register long __a0 asm ("$4") = (long) (arg1);                  \
 273         register long __a1 asm ("$5") = (long) (arg2);                  \
 274         register long __a2 asm ("$6") = (long) (arg3);                  \
 275         register long __a3 asm ("$7") = (long) (arg4);                  \
 276         register long __a4 asm ("$8") = (long) (arg5);                  \
 277         register long __a5 asm ("$9") = (long) (arg6);                  \
 278         __asm__ volatile (                                              \
 279         ".set\tnoreorder\n\t"                                           \
 280         v0_init                                                         \
 281         "syscall\n\t"                                                   \
 282         ".set\treorder"                                                 \
 283         : "=r" (__v0), "+r" (__a3)                                      \
 284         : input, "r" (__a0), "r" (__a1), "r" (__a2), "r" (__a4),        \
 285           "r" (__a5)                                                    \
 286         : __SYSCALL_CLOBBERS);                                          \
 287         err = __a3;                                                     \
 288         _sys_result = __v0;                                             \
 289         }                                                               \
 290         _sys_result;                                                    \
 291 })
 292
 293 #define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \
 294         "$14", "$15", "$24", "$25", "hi", "lo", "memory"
 295
 296 /* Standard MIPS syscalls have an error flag, and return a positive errno
 297    when the error flag is set. Emulate this behaviour for vsyscalls so that
 298    the INTERNAL_SYSCALL_{ERROR_P,ERRNO} macros work correctly.  */
 299 #define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...)               \
 300   ({                                                                    \
 301     long _ret = funcptr (args);                                         \
 302     err = ((unsigned long) (_ret) >= (unsigned long) -4095L);           \
 303     if (err)                                                            \
 304       _ret = -_ret;                                                     \
 305     _ret;                                                               \
 306   })
 307
 308 #endif /* __ASSEMBLER__ */
 309
 310 /* Pointer mangling is not yet supported for MIPS.  */
 311 #define PTR_MANGLE(var) (void) (var)
 312 #define PTR_DEMANGLE(var) (void) (var)
 313
 314 #endif /* linux/mips/sysdep.h */