sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h

   1 /* Assembler macros for 64 bit S/390.
   2    Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
   3    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _LINUX_S390_SYSDEP_H
  22 #define _LINUX_S390_SYSDEP_H
  23
  24 #include <sysdeps/s390/s390-64/sysdep.h>
  25 #include <sysdeps/unix/sysdep.h>
  26
  27 /* For Linux we can use the system call table in the header file
  28         /usr/include/asm/unistd.h
  29    of the kernel.  But these symbols do not follow the SYS_* syntax
  30    so we have to redefine the `SYS_ify' macro here.  */
  31 /* In newer 2.1 kernels __NR_syscall is missing so we define it here.  */
  32 #define __NR_syscall 0
  33
  34 /*
  35  * Newer kernel versions redefined __NR_pread and __NR_pwrite to
  36  * __NR_pread64 and __NR_pwrite64.
  37  */
  38 #ifndef __NR_pread
  39 # define __NR_pread __NR_pread64
  40 #endif
  41 #ifndef __NR_pwrite
  42 # define __NR_pwrite __NR_pwrite64
  43 #endif
  44
  45 #undef SYS_ify
  46 #define SYS_ify(syscall_name)   __NR_##syscall_name
  47
  48 #ifdef __ASSEMBLER__
  49
  50 /* Linux uses a negative return value to indicate syscall errors, unlike
  51    most Unices, which use the condition codes' carry flag.
  52
  53    Since version 2.1 the return value of a system call might be negative
  54    even if the call succeeded.  E.g., the `lseek' system call might return
  55    a large offset.  Therefore we must not anymore test for < 0, but test
  56    for a real error by making sure the value in gpr2 is a real error
  57    number.  Linus said he will make sure the no syscall returns a value
  58    in -1 .. -4095 as a valid result so we can savely test with -4095.  */
  59
  60 #undef PSEUDO
  61 #define PSEUDO(name, syscall_name, args)                                      \
  62   .text;                                                                      \
  63   ENTRY (name)                                                                \
  64     DO_CALL (syscall_name, args);                                             \
  65     lghi %r4,-4095 ;                                                          \
  66     clgr %r2,%r4 ;                                                            \
  67     jgnl SYSCALL_ERROR_LABEL
  68
  69 #undef PSEUDO_END
  70 #define PSEUDO_END(name)                                                      \
  71   SYSCALL_ERROR_HANDLER;                                                      \
  72   END (name)
  73
  74 #undef PSEUDO_NOERRNO
  75 #define PSEUDO_NOERRNO(name, syscall_name, args)                              \
  76   .text;                                                                      \
  77   ENTRY (name)                                                                \
  78     DO_CALL (syscall_name, args)
  79
  80 #undef PSEUDO_END_NOERRNO
  81 #define PSEUDO_END_NOERRNO(name)                                              \
  82   SYSCALL_ERROR_HANDLER;                                                      \
  83   END (name)
  84
  85 #undef PSEUDO_ERRVAL
  86 #define PSEUDO_ERRVAL(name, syscall_name, args)                               \
  87   .text;                                                                      \
  88   ENTRY (name)                                                                \
  89     DO_CALL (syscall_name, args);                                             \
  90     lcgr %r2,%r2
  91
  92 #undef PSEUDO_END_ERRVAL
  93 #define PSEUDO_END_ERRVAL(name)                                               \
  94   SYSCALL_ERROR_HANDLER;                                                      \
  95   END (name)
  96
  97 #ifndef PIC
  98 # define SYSCALL_ERROR_LABEL syscall_error
  99 # define SYSCALL_ERROR_HANDLER
 100 #else
 101 # if RTLD_PRIVATE_ERRNO
 102 #  define SYSCALL_ERROR_LABEL 0f
 103 #  define SYSCALL_ERROR_HANDLER \
 104 0:  larl  %r1,errno;                                                          \
 105     lcr   %r2,%r2;                                                            \
 106     st    %r2,0(%r1);                                                         \
 107     lghi  %r2,-1;                                                             \
 108     br    %r14
 109 # elif defined _LIBC_REENTRANT
 110 #  if USE___THREAD
 111 #   ifndef NOT_IN_libc
 112 #    define SYSCALL_ERROR_ERRNO __libc_errno
 113 #   else
 114 #    define SYSCALL_ERROR_ERRNO errno
 115 #   endif
 116 #   define SYSCALL_ERROR_LABEL 0f
 117 #   define SYSCALL_ERROR_HANDLER \
 118 0:  lcr   %r0,%r2;                                                            \
 119     larl  %r1,SYSCALL_ERROR_ERRNO@indntpoff;                                  \
 120     lg    %r1,0(%r1);                                                         \
 121     ear   %r2,%a0;                                                            \
 122     sllg  %r2,%r2,32;                                                         \
 123     ear   %r2,%a1;                                                            \
 124     st    %r0,0(%r1,%r2);                                                     \
 125     lghi   %r2,-1;                                                            \
 126     br    %r14
 127 #  else
 128 #   define SYSCALL_ERROR_LABEL syscall_error@plt
 129 #   define SYSCALL_ERROR_HANDLER
 130 #  endif
 131 # else
 132 #  define SYSCALL_ERROR_LABEL 0f
 133 #  define SYSCALL_ERROR_HANDLER \
 134 0:  larl  %r1,_GLOBAL_OFFSET_TABLE_;                                          \
 135     lg    %r1,errno@GOT(%r1);                                                 \
 136     lcr   %r2,%r2;                                                            \
 137     st    %r2,0(%r1);                                                         \
 138     lghi  %r2,-1;                                                             \
 139     br    %r14
 140 # endif /* _LIBC_REENTRANT */
 141 #endif /* PIC */
 142
 143 /* Linux takes system call arguments in registers:
 144
 145         syscall number  1            call-clobbered
 146         arg 1           2            call-clobbered
 147         arg 2           3            call-clobbered
 148         arg 3           4            call-clobbered
 149         arg 4           5            call-clobbered
 150         arg 5           6            call-saved
 151
 152    (Of course a function with say 3 arguments does not have entries for
 153    arguments 4 and 5.)
 154    S390 does not need to do ANY stack operations to get its parameters
 155    right.
 156  */
 157
 158 #define DO_CALL(syscall, args)                                                \
 159   .if SYS_ify (syscall) < 256;                                                \
 160     svc SYS_ify (syscall);                                                    \
 161   .else;                                                                      \
 162     lghi %r1,SYS_ify (syscall);                                               \
 163     svc 0;                                                                    \
 164   .endif
 165
 166 #define ret                                                                   \
 167     br      14
 168
 169 #define ret_NOERRNO                                                           \
 170     br      14
 171
 172 #define ret_ERRVAL                                                            \
 173     br      14
 174
 175 #endif /* __ASSEMBLER__ */
 176
 177 #undef INLINE_SYSCALL
 178 #define INLINE_SYSCALL(name, nr, args...)                                     \
 179   ({                                                                          \
 180     long _ret = INTERNAL_SYSCALL (name, , nr, args);                          \
 181     if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_ret, ), 0))              \
 182      {                                                                        \
 183        __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, ));                         \
 184        _ret = -1;                                                             \
 185      }                                                                        \
 186     _ret; })
 187
 188 #undef INTERNAL_SYSCALL_DECL
 189 #define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 190
 191 #undef INTERNAL_SYSCALL_DIRECT
 192 #define INTERNAL_SYSCALL_DIRECT(name, err, nr, args...)                       \
 193   ({                                                                          \
 194     DECLARGS_##nr(args)                                                       \
 195     register long _ret asm("2");                                              \
 196     asm volatile (                                                            \
 197     "svc    %b1\n\t"                                                          \
 198     : "=d" (_ret)                                                             \
 199     : "i" (__NR_##name) ASMFMT_##nr                                           \
 200     : "memory" );                                                             \
 201     _ret; })
 202
 203 #undef INTERNAL_SYSCALL_SVC0
 204 #define INTERNAL_SYSCALL_SVC0(name, err, nr, args...)                         \
 205   ({                                                                          \
 206     DECLARGS_##nr(args)                                                       \
 207     register unsigned long _nr asm("1") = (unsigned long)(__NR_##name);       \
 208     register long _ret asm("2");                                              \
 209     asm volatile (                                                            \
 210     "svc    0\n\t"                                                            \
 211     : "=d" (_ret)                                                             \
 212     : "d" (_nr) ASMFMT_##nr                                                   \
 213     : "memory" );                                                             \
 214     _ret; })
 215
 216 #undef INTERNAL_SYSCALL_NCS
 217 #define INTERNAL_SYSCALL_NCS(no, err, nr, args...)                            \
 218   ({                                                                          \
 219     DECLARGS_##nr(args)                                                       \
 220     register unsigned long _nr asm("1") = (unsigned long)(no);                \
 221     register long _ret asm("2");                                              \
 222     asm volatile (                                                            \
 223     "svc    0\n\t"                                                            \
 224     : "=d" (_ret)                                                             \
 225     : "d" (_nr) ASMFMT_##nr                                                   \
 226     : "memory" );                                                             \
 227     _ret; })
 228
 229 #undef INTERNAL_SYSCALL
 230 #define INTERNAL_SYSCALL(name, err, nr, args...)                              \
 231   (((__NR_##name) < 256) ?                                                    \
 232     INTERNAL_SYSCALL_DIRECT(name, err, nr, args) :                            \
 233     INTERNAL_SYSCALL_SVC0(name, err,nr, args))
 234
 235 #undef INTERNAL_SYSCALL_ERROR_P
 236 #define INTERNAL_SYSCALL_ERROR_P(val, err)                                    \
 237   ((unsigned long) (val) >= -4095UL)
 238
 239 #undef INTERNAL_SYSCALL_ERRNO
 240 #define INTERNAL_SYSCALL_ERRNO(val, err)        (-(val))
 241
 242 #define DECLARGS_0()
 243 #define DECLARGS_1(arg1) \
 244         register unsigned long gpr2 asm ("2") = (unsigned long)(arg1);
 245 #define DECLARGS_2(arg1, arg2) \
 246         DECLARGS_1(arg1) \
 247         register unsigned long gpr3 asm ("3") = (unsigned long)(arg2);
 248 #define DECLARGS_3(arg1, arg2, arg3) \
 249         DECLARGS_2(arg1, arg2) \
 250         register unsigned long gpr4 asm ("4") = (unsigned long)(arg3);
 251 #define DECLARGS_4(arg1, arg2, arg3, arg4) \
 252         DECLARGS_3(arg1, arg2, arg3) \
 253         register unsigned long gpr5 asm ("5") = (unsigned long)(arg4);
 254 #define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 255         DECLARGS_4(arg1, arg2, arg3, arg4) \
 256         register unsigned long gpr6 asm ("6") = (unsigned long)(arg5);
 257
 258 #define ASMFMT_0
 259 #define ASMFMT_1 , "0" (gpr2)
 260 #define ASMFMT_2 , "0" (gpr2), "d" (gpr3)
 261 #define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4)
 262 #define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
 263 #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
 264
 265 #endif /* _LINUX_S390_SYSDEP_H */