Home | History | Annotate | Download | only in alpha
      1 /* -----------------------------------------------------------------------
      2    ffi.c - Copyright (c) 2012  Anthony Green
      3            Copyright (c) 1998, 2001, 2007, 2008  Red Hat, Inc.
      4 
      5    Alpha Foreign Function Interface
      6 
      7    Permission is hereby granted, free of charge, to any person obtaining
      8    a copy of this software and associated documentation files (the
      9    ``Software''), to deal in the Software without restriction, including
     10    without limitation the rights to use, copy, modify, merge, publish,
     11    distribute, sublicense, and/or sell copies of the Software, and to
     12    permit persons to whom the Software is furnished to do so, subject to
     13    the following conditions:
     14 
     15    The above copyright notice and this permission notice shall be included
     16    in all copies or substantial portions of the Software.
     17 
     18    THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
     19    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     20    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     21    NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
     22    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
     23    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     24    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     25    DEALINGS IN THE SOFTWARE.
     26    ----------------------------------------------------------------------- */
     27 
     28 #include <ffi.h>
     29 #include <ffi_common.h>
     30 #include <stdlib.h>
     31 
     32 /* Force FFI_TYPE_LONGDOUBLE to be different than FFI_TYPE_DOUBLE;
     33    all further uses in this file will refer to the 128-bit type.  */
     34 #if defined(__LONG_DOUBLE_128__)
     35 # if FFI_TYPE_LONGDOUBLE != 4
     36 #  error FFI_TYPE_LONGDOUBLE out of date
     37 # endif
     38 #else
     39 # undef FFI_TYPE_LONGDOUBLE
     40 # define FFI_TYPE_LONGDOUBLE 4
     41 #endif
     42 
     43 extern void ffi_call_osf(void *, unsigned long, unsigned, void *, void (*)(void))
     44   FFI_HIDDEN;
     45 extern void ffi_closure_osf(void) FFI_HIDDEN;
     46 
     47 
     48 ffi_status
     49 ffi_prep_cif_machdep(ffi_cif *cif)
     50 {
     51   /* Adjust cif->bytes to represent a minimum 6 words for the temporary
     52      register argument loading area.  */
     53   if (cif->bytes < 6*FFI_SIZEOF_ARG)
     54     cif->bytes = 6*FFI_SIZEOF_ARG;
     55 
     56   /* Set the return type flag */
     57   switch (cif->rtype->type)
     58     {
     59     case FFI_TYPE_STRUCT:
     60     case FFI_TYPE_FLOAT:
     61     case FFI_TYPE_DOUBLE:
     62       cif->flags = cif->rtype->type;
     63       break;
     64 
     65     case FFI_TYPE_LONGDOUBLE:
     66       /* 128-bit long double is returned in memory, like a struct.  */
     67       cif->flags = FFI_TYPE_STRUCT;
     68       break;
     69 
     70     default:
     71       cif->flags = FFI_TYPE_INT;
     72       break;
     73     }
     74 
     75   return FFI_OK;
     76 }
     77 
     78 
     79 void
     80 ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
     81 {
     82   unsigned long *stack, *argp;
     83   long i, avn;
     84   ffi_type **arg_types;
     85 
     86   /* If the return value is a struct and we don't have a return
     87      value address then we need to make one.  */
     88   if (rvalue == NULL && cif->flags == FFI_TYPE_STRUCT)
     89     rvalue = alloca(cif->rtype->size);
     90 
     91   /* Allocate the space for the arguments, plus 4 words of temp
     92      space for ffi_call_osf.  */
     93   argp = stack = alloca(cif->bytes + 4*FFI_SIZEOF_ARG);
     94 
     95   if (cif->flags == FFI_TYPE_STRUCT)
     96     *(void **) argp++ = rvalue;
     97 
     98   i = 0;
     99   avn = cif->nargs;
    100   arg_types = cif->arg_types;
    101 
    102   while (i < avn)
    103     {
    104       size_t size = (*arg_types)->size;
    105 
    106       switch ((*arg_types)->type)
    107 	{
    108 	case FFI_TYPE_SINT8:
    109 	  *(SINT64 *) argp = *(SINT8 *)(* avalue);
    110 	  break;
    111 
    112 	case FFI_TYPE_UINT8:
    113 	  *(SINT64 *) argp = *(UINT8 *)(* avalue);
    114 	  break;
    115 
    116 	case FFI_TYPE_SINT16:
    117 	  *(SINT64 *) argp = *(SINT16 *)(* avalue);
    118 	  break;
    119 
    120 	case FFI_TYPE_UINT16:
    121 	  *(SINT64 *) argp = *(UINT16 *)(* avalue);
    122 	  break;
    123 
    124 	case FFI_TYPE_SINT32:
    125 	case FFI_TYPE_UINT32:
    126 	  /* Note that unsigned 32-bit quantities are sign extended.  */
    127 	  *(SINT64 *) argp = *(SINT32 *)(* avalue);
    128 	  break;
    129 
    130 	case FFI_TYPE_SINT64:
    131 	case FFI_TYPE_UINT64:
    132 	case FFI_TYPE_POINTER:
    133 	  *(UINT64 *) argp = *(UINT64 *)(* avalue);
    134 	  break;
    135 
    136 	case FFI_TYPE_FLOAT:
    137 	  if (argp - stack < 6)
    138 	    {
    139 	      /* Note the conversion -- all the fp regs are loaded as
    140 		 doubles.  The in-register format is the same.  */
    141 	      *(double *) argp = *(float *)(* avalue);
    142 	    }
    143 	  else
    144 	    *(float *) argp = *(float *)(* avalue);
    145 	  break;
    146 
    147 	case FFI_TYPE_DOUBLE:
    148 	  *(double *) argp = *(double *)(* avalue);
    149 	  break;
    150 
    151 	case FFI_TYPE_LONGDOUBLE:
    152 	  /* 128-bit long double is passed by reference.  */
    153 	  *(long double **) argp = (long double *)(* avalue);
    154 	  size = sizeof (long double *);
    155 	  break;
    156 
    157 	case FFI_TYPE_STRUCT:
    158 	  memcpy(argp, *avalue, (*arg_types)->size);
    159 	  break;
    160 
    161 	default:
    162 	  FFI_ASSERT(0);
    163 	}
    164 
    165       argp += ALIGN(size, FFI_SIZEOF_ARG) / FFI_SIZEOF_ARG;
    166       i++, arg_types++, avalue++;
    167     }
    168 
    169   ffi_call_osf(stack, cif->bytes, cif->flags, rvalue, fn);
    170 }
    171 
    172 
    173 ffi_status
    174 ffi_prep_closure_loc (ffi_closure* closure,
    175 		      ffi_cif* cif,
    176 		      void (*fun)(ffi_cif*, void*, void**, void*),
    177 		      void *user_data,
    178 		      void *codeloc)
    179 {
    180   unsigned int *tramp;
    181 
    182   if (cif->abi != FFI_OSF)
    183     return FFI_BAD_ABI;
    184 
    185   tramp = (unsigned int *) &closure->tramp[0];
    186   tramp[0] = 0x47fb0401;	/* mov $27,$1		*/
    187   tramp[1] = 0xa77b0010;	/* ldq $27,16($27)	*/
    188   tramp[2] = 0x6bfb0000;	/* jmp $31,($27),0	*/
    189   tramp[3] = 0x47ff041f;	/* nop			*/
    190   *(void **) &tramp[4] = ffi_closure_osf;
    191 
    192   closure->cif = cif;
    193   closure->fun = fun;
    194   closure->user_data = user_data;
    195 
    196   /* Flush the Icache.
    197 
    198      Tru64 UNIX as doesn't understand the imb mnemonic, so use call_pal
    199      instead, since both Compaq as and gas can handle it.
    200 
    201      0x86 is PAL_imb in Tru64 UNIX <alpha/pal.h>.  */
    202   asm volatile ("call_pal 0x86" : : : "memory");
    203 
    204   return FFI_OK;
    205 }
    206 
    207 
    208 long FFI_HIDDEN
    209 ffi_closure_osf_inner(ffi_closure *closure, void *rvalue, unsigned long *argp)
    210 {
    211   ffi_cif *cif;
    212   void **avalue;
    213   ffi_type **arg_types;
    214   long i, avn, argn;
    215 
    216   cif = closure->cif;
    217   avalue = alloca(cif->nargs * sizeof(void *));
    218 
    219   argn = 0;
    220 
    221   /* Copy the caller's structure return address to that the closure
    222      returns the data directly to the caller.  */
    223   if (cif->flags == FFI_TYPE_STRUCT)
    224     {
    225       rvalue = (void *) argp[0];
    226       argn = 1;
    227     }
    228 
    229   i = 0;
    230   avn = cif->nargs;
    231   arg_types = cif->arg_types;
    232 
    233   /* Grab the addresses of the arguments from the stack frame.  */
    234   while (i < avn)
    235     {
    236       size_t size = arg_types[i]->size;
    237 
    238       switch (arg_types[i]->type)
    239 	{
    240 	case FFI_TYPE_SINT8:
    241 	case FFI_TYPE_UINT8:
    242 	case FFI_TYPE_SINT16:
    243 	case FFI_TYPE_UINT16:
    244 	case FFI_TYPE_SINT32:
    245 	case FFI_TYPE_UINT32:
    246 	case FFI_TYPE_SINT64:
    247 	case FFI_TYPE_UINT64:
    248 	case FFI_TYPE_POINTER:
    249 	case FFI_TYPE_STRUCT:
    250 	  avalue[i] = &argp[argn];
    251 	  break;
    252 
    253 	case FFI_TYPE_FLOAT:
    254 	  if (argn < 6)
    255 	    {
    256 	      /* Floats coming from registers need conversion from double
    257 	         back to float format.  */
    258 	      *(float *)&argp[argn - 6] = *(double *)&argp[argn - 6];
    259 	      avalue[i] = &argp[argn - 6];
    260 	    }
    261 	  else
    262 	    avalue[i] = &argp[argn];
    263 	  break;
    264 
    265 	case FFI_TYPE_DOUBLE:
    266 	  avalue[i] = &argp[argn - (argn < 6 ? 6 : 0)];
    267 	  break;
    268 
    269 	case FFI_TYPE_LONGDOUBLE:
    270 	  /* 128-bit long double is passed by reference.  */
    271 	  avalue[i] = (long double *) argp[argn];
    272 	  size = sizeof (long double *);
    273 	  break;
    274 
    275 	default:
    276 	  abort ();
    277 	}
    278 
    279       argn += ALIGN(size, FFI_SIZEOF_ARG) / FFI_SIZEOF_ARG;
    280       i++;
    281     }
    282 
    283   /* Invoke the closure.  */
    284   closure->fun (cif, rvalue, avalue, closure->user_data);
    285 
    286   /* Tell ffi_closure_osf how to perform return type promotions.  */
    287   return cif->rtype->type;
    288 }
    289