libffi/src/powerpc/ffi.c

   1 /* -----------------------------------------------------------------------
   2    ffi.c - Copyright (C) 2013 IBM
   3            Copyright (C) 2011 Anthony Green
   4            Copyright (C) 2011 Kyle Moffett
   5            Copyright (C) 2008 Red Hat, Inc
   6            Copyright (C) 2007, 2008 Free Software Foundation, Inc
   7            Copyright (c) 1998 Geoffrey Keating
   8
   9    PowerPC Foreign Function Interface
  10
  11    Permission is hereby granted, free of charge, to any person obtaining
  12    a copy of this software and associated documentation files (the
  13    ``Software''), to deal in the Software without restriction, including
  14    without limitation the rights to use, copy, modify, merge, publish,
  15    distribute, sublicense, and/or sell copies of the Software, and to
  16    permit persons to whom the Software is furnished to do so, subject to
  17    the following conditions:
  18
  19    The above copyright notice and this permission notice shall be included
  20    in all copies or substantial portions of the Software.
  21
  22    THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  25    IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR
  26    OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  27    ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  28    OTHER DEALINGS IN THE SOFTWARE.
  29    ----------------------------------------------------------------------- */
  30
  31 #include "ffi.h"
  32 #include "ffi_common.h"
  33 #include "ffi_powerpc.h"
  34
  35 #if HAVE_LONG_DOUBLE_VARIANT
  36 /* Adjust ffi_type_longdouble.  */
  37 void FFI_HIDDEN
  38 ffi_prep_types (ffi_abi abi)
  39 {
  40 # if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
  41 #  ifdef POWERPC64
  42   ffi_prep_types_linux64 (abi);
  43 #  else
  44   ffi_prep_types_sysv (abi);
  45 #  endif
  46 # endif
  47 }
  48 #endif
  49
  50 /* Perform machine dependent cif processing */
  51 ffi_status FFI_HIDDEN
  52 ffi_prep_cif_machdep (ffi_cif *cif)
  53 {
  54 #ifdef POWERPC64
  55   return ffi_prep_cif_linux64 (cif);
  56 #else
  57   return ffi_prep_cif_sysv (cif);
  58 #endif
  59 }
  60
  61 ffi_status FFI_HIDDEN
  62 ffi_prep_cif_machdep_var (ffi_cif *cif,
  63                           unsigned int nfixedargs MAYBE_UNUSED,
  64                           unsigned int ntotalargs MAYBE_UNUSED)
  65 {
  66 #ifdef POWERPC64
  67   return ffi_prep_cif_linux64_var (cif, nfixedargs, ntotalargs);
  68 #else
  69   return ffi_prep_cif_sysv (cif);
  70 #endif
  71 }
  72
  73 static void
  74 ffi_call_int (ffi_cif *cif,
  75               void (*fn) (void),
  76               void *rvalue,
  77               void **avalue,
  78               void *closure)
  79 {
  80   /* The final SYSV ABI says that structures smaller or equal 8 bytes
  81      are returned in r3/r4.  A draft ABI used by linux instead returns
  82      them in memory.
  83
  84      We bounce-buffer SYSV small struct return values so that sysv.S
  85      can write r3 and r4 to memory without worrying about struct size.
  86
  87      For ELFv2 ABI, use a bounce buffer for homogeneous structs too,
  88      for similar reasons. This bounce buffer must be aligned to 16
  89      bytes for use with homogeneous structs of vectors (float128).  */
  90   float128 smst_buffer[8];
  91   extended_cif ecif;
  92
  93   ecif.cif = cif;
  94   ecif.avalue = avalue;
  95
  96   ecif.rvalue = rvalue;
  97   if ((cif->flags & FLAG_RETURNS_SMST) != 0)
  98     ecif.rvalue = smst_buffer;
  99   /* Ensure that we have a valid struct return value.
 100      FIXME: Isn't this just papering over a user problem?  */
 101   else if (!rvalue && cif->rtype->type == FFI_TYPE_STRUCT)
 102     ecif.rvalue = alloca (cif->rtype->size);
 103
 104 #ifdef POWERPC64
 105   ffi_call_LINUX64 (&ecif, fn, ecif.rvalue, cif->flags, closure,
 106                     -(long) cif->bytes);
 107 #else
 108   ffi_call_SYSV (&ecif, fn, ecif.rvalue, cif->flags, closure, -cif->bytes);
 109 #endif
 110
 111   /* Check for a bounce-buffered return value */
 112   if (rvalue && ecif.rvalue == smst_buffer)
 113     {
 114       unsigned int rsize = cif->rtype->size;
 115 #ifndef __LITTLE_ENDIAN__
 116       /* The SYSV ABI returns a structure of up to 4 bytes in size
 117          left-padded in r3.  */
 118 # ifndef POWERPC64
 119       if (rsize <= 4)
 120         memcpy (rvalue, (char *) smst_buffer + 4 - rsize, rsize);
 121       else
 122 # endif
 123         /* The SYSV ABI returns a structure of up to 8 bytes in size
 124            left-padded in r3/r4, and the ELFv2 ABI similarly returns a
 125            structure of up to 8 bytes in size left-padded in r3. But
 126            note that a structure of a single float is not paddded.  */
 127         if (rsize <= 8 && (cif->flags & FLAG_RETURNS_FP) == 0)
 128           memcpy (rvalue, (char *) smst_buffer + 8 - rsize, rsize);
 129         else
 130 #endif
 131           memcpy (rvalue, smst_buffer, rsize);
 132     }
 133 }
 134
 135 void
 136 ffi_call (ffi_cif *cif, void (*fn) (void), void *rvalue, void **avalue)
 137 {
 138   ffi_call_int (cif, fn, rvalue, avalue, NULL);
 139 }
 140
 141 void
 142 ffi_call_go (ffi_cif *cif, void (*fn) (void), void *rvalue, void **avalue,
 143              void *closure)
 144 {
 145   ffi_call_int (cif, fn, rvalue, avalue, closure);
 146 }
 147
 148 ffi_status
 149 ffi_prep_closure_loc (ffi_closure *closure,
 150                       ffi_cif *cif,
 151                       void (*fun) (ffi_cif *, void *, void **, void *),
 152                       void *user_data,
 153                       void *codeloc)
 154 {
 155 #ifdef POWERPC64
 156   return ffi_prep_closure_loc_linux64 (closure, cif, fun, user_data, codeloc);
 157 #else
 158   return ffi_prep_closure_loc_sysv (closure, cif, fun, user_data, codeloc);
 159 #endif
 160 }
 161
 162 ffi_status
 163 ffi_prep_go_closure (ffi_go_closure *closure,
 164                      ffi_cif *cif,
 165                      void (*fun) (ffi_cif *, void *, void **, void *))
 166 {
 167 #ifdef POWERPC64
 168   closure->tramp = ffi_go_closure_linux64;
 169 #else
 170   closure->tramp = ffi_go_closure_sysv;
 171 #endif
 172   closure->cif = cif;
 173   closure->fun = fun;
 174   return FFI_OK;
 175 }