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.  */
37void FFI_HIDDEN
38ffi_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 */
51ffi_status FFI_HIDDEN
52ffi_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
61ffi_status FFI_HIDDEN
62ffi_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
73void
74ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
75{
76  /* The final SYSV ABI says that structures smaller or equal 8 bytes
77     are returned in r3/r4.  A draft ABI used by linux instead returns
78     them in memory.
79
80     We bounce-buffer SYSV small struct return values so that sysv.S
81     can write r3 and r4 to memory without worrying about struct size.
82
83     For ELFv2 ABI, use a bounce buffer for homogeneous structs too,
84     for similar reasons.  */
85  unsigned long smst_buffer[8];
86  extended_cif ecif;
87
88  ecif.cif = cif;
89  ecif.avalue = avalue;
90
91  ecif.rvalue = rvalue;
92  if ((cif->flags & FLAG_RETURNS_SMST) != 0)
93    ecif.rvalue = smst_buffer;
94  /* Ensure that we have a valid struct return value.
95     FIXME: Isn't this just papering over a user problem?  */
96  else if (!rvalue && cif->rtype->type == FFI_TYPE_STRUCT)
97    ecif.rvalue = alloca (cif->rtype->size);
98
99#ifdef POWERPC64
100  ffi_call_LINUX64 (&ecif, -(long) cif->bytes, cif->flags, ecif.rvalue, fn);
101#else
102  ffi_call_SYSV (&ecif, -cif->bytes, cif->flags, ecif.rvalue, fn);
103#endif
104
105  /* Check for a bounce-buffered return value */
106  if (rvalue && ecif.rvalue == smst_buffer)
107    {
108      unsigned int rsize = cif->rtype->size;
109#ifndef __LITTLE_ENDIAN__
110      /* The SYSV ABI returns a structure of up to 4 bytes in size
111	 left-padded in r3.  */
112# ifndef POWERPC64
113      if (rsize <= 4)
114	memcpy (rvalue, (char *) smst_buffer + 4 - rsize, rsize);
115      else
116# endif
117	/* The SYSV ABI returns a structure of up to 8 bytes in size
118	   left-padded in r3/r4, and the ELFv2 ABI similarly returns a
119	   structure of up to 8 bytes in size left-padded in r3.  */
120	if (rsize <= 8)
121	  memcpy (rvalue, (char *) smst_buffer + 8 - rsize, rsize);
122	else
123#endif
124	  memcpy (rvalue, smst_buffer, rsize);
125    }
126}
127
128
129ffi_status
130ffi_prep_closure_loc (ffi_closure *closure,
131		      ffi_cif *cif,
132		      void (*fun) (ffi_cif *, void *, void **, void *),
133		      void *user_data,
134		      void *codeloc)
135{
136#ifdef POWERPC64
137  return ffi_prep_closure_loc_linux64 (closure, cif, fun, user_data, codeloc);
138#else
139  return ffi_prep_closure_loc_sysv (closure, cif, fun, user_data, codeloc);
140#endif
141}
142