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

   1 /* Assembler macros for 64 bit S/390.
   2    Copyright (C) 2001, 2002, 2003, 2004, 2005 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 #include <dl-sysdep.h>  /* For RTLD_PRIVATE_ERRNO.  */
  27 #include <tls.h>
  28
  29 /* For Linux we can use the system call table in the header file
  30         /usr/include/asm/unistd.h
  31    of the kernel.  But these symbols do not follow the SYS_* syntax
  32    so we have to redefine the `SYS_ify' macro here.  */
  33 /* In newer 2.1 kernels __NR_syscall is missing so we define it here.  */
  34 #define __NR_syscall 0
  35
  36 /*
  37  * Newer kernel versions redefined __NR_pread and __NR_pwrite to
  38  * __NR_pread64 and __NR_pwrite64.
  39  */
  40 #ifndef __NR_pread
  41 # define __NR_pread __NR_pread64
  42 #endif
  43 #ifndef __NR_pwrite
  44 # define __NR_pwrite __NR_pwrite64
  45 #endif
  46
  47 #undef SYS_ify
  48 #define SYS_ify(syscall_name)   __NR_##syscall_name
  49
  50 #ifdef __ASSEMBLER__
  51
  52 /* Linux uses a negative return value to indicate syscall errors, unlike
  53    most Unices, which use the condition codes' carry flag.
  54
  55    Since version 2.1 the return value of a system call might be negative
  56    even if the call succeeded.  E.g., the `lseek' system call might return
  57    a large offset.  Therefore we must not anymore test for < 0, but test
  58    for a real error by making sure the value in gpr2 is a real error
  59    number.  Linus said he will make sure the no syscall returns a value
  60    in -1 .. -4095 as a valid result so we can savely test with -4095.  */
  61
  62 #undef PSEUDO
  63 #define PSEUDO(name, syscall_name, args)                                      \
  64   .text;                                                                      \
  65   ENTRY (name)                                                                \
  66     DO_CALL (syscall_name, args);                                             \
  67     lghi %r4,-4095 ;                                                          \
  68     clgr %r2,%r4 ;                                                            \
  69     jgnl SYSCALL_ERROR_LABEL
  70
  71 #undef PSEUDO_END
  72 #define PSEUDO_END(name)                                                      \
  73   SYSCALL_ERROR_HANDLER;                                                      \
  74   END (name)
  75
  76 #undef PSEUDO_NOERRNO
  77 #define PSEUDO_NOERRNO(name, syscall_name, args)                              \
  78   .text;                                                                      \
  79   ENTRY (name)                                                                \
  80     DO_CALL (syscall_name, args)
  81
  82 #undef PSEUDO_END_NOERRNO
  83 #define PSEUDO_END_NOERRNO(name)                                              \
  84   SYSCALL_ERROR_HANDLER;                                                      \
  85   END (name)
  86
  87 #undef PSEUDO_ERRVAL
  88 #define PSEUDO_ERRVAL(name, syscall_name, args)                               \
  89   .text;                                                                      \
  90   ENTRY (name)                                                                \
  91     DO_CALL (syscall_name, args);                                             \
  92     lcgr %r2,%r2
  93
  94 #undef PSEUDO_END_ERRVAL
  95 #define PSEUDO_END_ERRVAL(name)                                               \
  96   SYSCALL_ERROR_HANDLER;                                                      \
  97   END (name)
  98
  99 #ifndef PIC
 100 # define SYSCALL_ERROR_LABEL syscall_error
 101 # define SYSCALL_ERROR_HANDLER
 102 #else
 103 # if RTLD_PRIVATE_ERRNO
 104 #  define SYSCALL_ERROR_LABEL 0f
 105 #  define SYSCALL_ERROR_HANDLER \
 106 0:  larl  %r1,rtld_errno;                                                     \
 107     lcr   %r2,%r2;                                                            \
 108     st    %r2,0(%r1);                                                         \
 109     lghi  %r2,-1;                                                             \
 110     br    %r14
 111 # elif defined _LIBC_REENTRANT
 112 #  if USE___THREAD
 113 #   ifndef NOT_IN_libc
 114 #    define SYSCALL_ERROR_ERRNO __libc_errno
 115 #   else
 116 #    define SYSCALL_ERROR_ERRNO errno
 117 #   endif
 118 #   define SYSCALL_ERROR_LABEL 0f
 119 #   define SYSCALL_ERROR_HANDLER \
 120 0:  lcr   %r0,%r2;                                                            \
 121     larl  %r1,SYSCALL_ERROR_ERRNO@indntpoff;                                  \
 122     lg    %r1,0(%r1);                                                         \
 123     ear   %r2,%a0;                                                            \
 124     sllg  %r2,%r2,32;                                                         \
 125     ear   %r2,%a1;                                                            \
 126     st    %r0,0(%r1,%r2);                                                     \
 127     lghi   %r2,-1;                                                            \
 128     br    %r14
 129 #  else
 130 #   define SYSCALL_ERROR_LABEL syscall_error@plt
 131 #   define SYSCALL_ERROR_HANDLER
 132 #  endif
 133 # else
 134 #  define SYSCALL_ERROR_LABEL 0f
 135 #  define SYSCALL_ERROR_HANDLER \
 136 0:  larl  %r1,_GLOBAL_OFFSET_TABLE_;                                          \
 137     lg    %r1,errno@GOT(%r1);                                                 \
 138     lcr   %r2,%r2;                                                            \
 139     st    %r2,0(%r1);                                                         \
 140     lghi  %r2,-1;                                                             \
 141     br    %r14
 142 # endif /* _LIBC_REENTRANT */
 143 #endif /* PIC */
 144
 145 /* Linux takes system call arguments in registers:
 146
 147         syscall number  1            call-clobbered
 148         arg 1           2            call-clobbered
 149         arg 2           3            call-clobbered
 150         arg 3           4            call-clobbered
 151         arg 4           5            call-clobbered
 152         arg 5           6            call-saved
 153
 154    (Of course a function with say 3 arguments does not have entries for
 155    arguments 4 and 5.)
 156    S390 does not need to do ANY stack operations to get its parameters
 157    right.
 158  */
 159
 160 #define DO_CALL(syscall, args)                                                \
 161   .if SYS_ify (syscall) < 256;                                                \
 162     svc SYS_ify (syscall);                                                    \
 163   .else;                                                                      \
 164     lghi %r1,SYS_ify (syscall);                                               \
 165     svc 0;                                                                    \
 166   .endif
 167
 168 #define ret                                                                   \
 169     br      14
 170
 171 #define ret_NOERRNO                                                           \
 172     br      14
 173
 174 #define ret_ERRVAL                                                            \
 175     br      14
 176
 177 #endif /* __ASSEMBLER__ */
 178
 179 #undef INLINE_SYSCALL
 180 #define INLINE_SYSCALL(name, nr, args...)                                     \
 181   ({                                                                          \
 182     long _ret = INTERNAL_SYSCALL (name, , nr, args);                          \
 183     if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_ret, ), 0))              \
 184      {                                                                        \
 185        __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, ));                         \
 186        _ret = -1;                                                             \
 187      }                                                                        \
 188     _ret; })
 189
 190 #undef INTERNAL_SYSCALL_DECL
 191 #define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 192
 193 #undef INTERNAL_SYSCALL_DIRECT
 194 #define INTERNAL_SYSCALL_DIRECT(name, err, nr, args...)                       \
 195   ({                                                                          \
 196     DECLARGS_##nr(args)                                                       \
 197     register long _ret asm("2");                                              \
 198     asm volatile (                                                            \
 199     "svc    %b1\n\t"                                                          \
 200     : "=d" (_ret)                                                             \
 201     : "i" (__NR_##name) ASMFMT_##nr                                           \
 202     : "memory" );                                                             \
 203     _ret; })
 204
 205 #undef INTERNAL_SYSCALL_SVC0
 206 #define INTERNAL_SYSCALL_SVC0(name, err, nr, args...)                         \
 207   ({                                                                          \
 208     DECLARGS_##nr(args)                                                       \
 209     register unsigned long _nr asm("1") = (unsigned long)(__NR_##name);       \
 210     register long _ret asm("2");                                              \
 211     asm volatile (                                                            \
 212     "svc    0\n\t"                                                            \
 213     : "=d" (_ret)                                                             \
 214     : "d" (_nr) ASMFMT_##nr                                                   \
 215     : "memory" );                                                             \
 216     _ret; })
 217
 218 #undef INTERNAL_SYSCALL_NCS
 219 #define INTERNAL_SYSCALL_NCS(no, err, nr, args...)                            \
 220   ({                                                                          \
 221     DECLARGS_##nr(args)                                                       \
 222     register unsigned long _nr asm("1") = (unsigned long)(no);                \
 223     register long _ret asm("2");                                              \
 224     asm volatile (                                                            \
 225     "svc    0\n\t"                                                            \
 226     : "=d" (_ret)                                                             \
 227     : "d" (_nr) ASMFMT_##nr                                                   \
 228     : "memory" );                                                             \
 229     _ret; })
 230
 231 #undef INTERNAL_SYSCALL
 232 #define INTERNAL_SYSCALL(name, err, nr, args...)                              \
 233   (((__NR_##name) < 256) ?                                                    \
 234     INTERNAL_SYSCALL_DIRECT(name, err, nr, args) :                            \
 235     INTERNAL_SYSCALL_SVC0(name, err,nr, args))
 236
 237 #undef INTERNAL_SYSCALL_ERROR_P
 238 #define INTERNAL_SYSCALL_ERROR_P(val, err)                                    \
 239   ((unsigned long) (val) >= -4095UL)
 240
 241 #undef INTERNAL_SYSCALL_ERRNO
 242 #define INTERNAL_SYSCALL_ERRNO(val, err)        (-(val))
 243
 244 #define DECLARGS_0()
 245 #define DECLARGS_1(arg1) \
 246         register unsigned long gpr2 asm ("2") = (unsigned long)(arg1);
 247 #define DECLARGS_2(arg1, arg2) \
 248         DECLARGS_1(arg1) \
 249         register unsigned long gpr3 asm ("3") = (unsigned long)(arg2);
 250 #define DECLARGS_3(arg1, arg2, arg3) \
 251         DECLARGS_2(arg1, arg2) \
 252         register unsigned long gpr4 asm ("4") = (unsigned long)(arg3);
 253 #define DECLARGS_4(arg1, arg2, arg3, arg4) \
 254         DECLARGS_3(arg1, arg2, arg3) \
 255         register unsigned long gpr5 asm ("5") = (unsigned long)(arg4);
 256 #define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 257         DECLARGS_4(arg1, arg2, arg3, arg4) \
 258         register unsigned long gpr6 asm ("6") = (unsigned long)(arg5);
 259
 260 #define ASMFMT_0
 261 #define ASMFMT_1 , "0" (gpr2)
 262 #define ASMFMT_2 , "0" (gpr2), "d" (gpr3)
 263 #define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4)
 264 #define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
 265 #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
 266
 267 /* Pointer mangling support.  */
 268 #if defined NOT_IN_libc && defined IS_IN_rtld
 269 /* We cannot use the thread descriptor because in ld.so we use setjmp
 270    earlier than the descriptor is initialized.  */
 271 #else
 272 /* For the time being just use stack_guard rather than a separate
 273    pointer_guard.  */
 274 # ifdef __ASSEMBLER__
 275 #  define PTR_MANGLE(reg, tmpreg) \
 276   ear     tmpreg,%a0;                   \
 277   sllg    tmpreg,tmpreg,32;             \
 278   ear     tmpreg,%a1;                   \
 279   xg      reg,STACK_GUARD(tmpreg)
 280 #  define PTR_MANGLE2(reg, tmpreg) \
 281   xg      reg,STACK_GUARD(tmpreg)
 282 #  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
 283 # else
 284 #  define PTR_MANGLE(var) \
 285   (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
 286 #  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
 287 # endif
 288 #endif
 289
 290 #endif /* _LINUX_S390_SYSDEP_H */