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ffi.c
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1 /* -----------------------------------------------------------------------
2  ffi.c - Copyright (c) 2012 Alexandre K. I. de Mendonca <alexandre.keunecke@gmail.com>,
3  Paulo Pizarro <paulo.pizarro@gmail.com>
4 
5  Blackfin 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 #include <ffi.h>
28 #include <ffi_common.h>
29 
30 #include <stdlib.h>
31 #include <stdio.h>
32 
33 /* Maximum number of GPRs available for argument passing. */
34 #define MAX_GPRARGS 3
35 
36 /*
37  * Return types
38  */
39 #define FFIBFIN_RET_VOID 0
40 #define FFIBFIN_RET_BYTE 1
41 #define FFIBFIN_RET_HALFWORD 2
42 #define FFIBFIN_RET_INT64 3
43 #define FFIBFIN_RET_INT32 4
44 
45 /*====================================================================*/
46 /* PROTOTYPE *
47  /*====================================================================*/
48 void ffi_prep_args(unsigned char *, extended_cif *);
49 
50 /*====================================================================*/
51 /* Externals */
52 /* (Assembly) */
53 /*====================================================================*/
54 
55 extern void ffi_call_SYSV(unsigned, extended_cif *, void(*)(unsigned char *, extended_cif *), unsigned, void *, void(*fn)(void));
56 
57 /*====================================================================*/
58 /* Implementation */
59 /* */
60 /*====================================================================*/
61 
62 
63 /*
64  * This function calculates the return type (size) based on type.
65  */
66 
67 ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
68 {
69  /* --------------------------------------*
70  * Return handling *
71  * --------------------------------------*/
72  switch (cif->rtype->type) {
73  case FFI_TYPE_VOID:
74  cif->flags = FFIBFIN_RET_VOID;
75  break;
76  case FFI_TYPE_UINT16:
77  case FFI_TYPE_SINT16:
78  cif->flags = FFIBFIN_RET_HALFWORD;
79  break;
80  case FFI_TYPE_UINT8:
81  cif->flags = FFIBFIN_RET_BYTE;
82  break;
83  case FFI_TYPE_INT:
84  case FFI_TYPE_UINT32:
85  case FFI_TYPE_SINT32:
86  case FFI_TYPE_FLOAT:
87  case FFI_TYPE_POINTER:
88  case FFI_TYPE_SINT8:
89  cif->flags = FFIBFIN_RET_INT32;
90  break;
91  case FFI_TYPE_SINT64:
92  case FFI_TYPE_UINT64:
93  case FFI_TYPE_DOUBLE:
94  cif->flags = FFIBFIN_RET_INT64;
95  break;
96  case FFI_TYPE_STRUCT:
97  if (cif->rtype->size <= 4){
98  cif->flags = FFIBFIN_RET_INT32;
99  }else if (cif->rtype->size == 8){
100  cif->flags = FFIBFIN_RET_INT64;
101  }else{
102  //it will return via a hidden pointer in P0
103  cif->flags = FFIBFIN_RET_VOID;
104  }
105  break;
106  default:
107  FFI_ASSERT(0);
108  break;
109  }
110  return FFI_OK;
111 }
112 
113 /*
114  * This will prepare the arguments and will call the assembly routine
115  * cif = the call interface
116  * fn = the function to be called
117  * rvalue = the return value
118  * avalue = the arguments
119  */
120 void ffi_call(ffi_cif *cif, void(*fn)(void), void *rvalue, void **avalue)
121 {
122  int ret_type = cif->flags;
123  extended_cif ecif;
124  ecif.cif = cif;
125  ecif.avalue = avalue;
126  ecif.rvalue = rvalue;
127 
128  switch (cif->abi) {
129  case FFI_SYSV:
130  ffi_call_SYSV(cif->bytes, &ecif, ffi_prep_args, ret_type, ecif.rvalue, fn);
131  break;
132  default:
133  FFI_ASSERT(0);
134  break;
135  }
136 }
137 
138 
139 /*
140 * This function prepares the parameters (copies them from the ecif to the stack)
141 * to call the function (ffi_prep_args is called by the assembly routine in file
142 * sysv.S, which also calls the actual function)
143 */
144 void ffi_prep_args(unsigned char *stack, extended_cif *ecif)
145 {
146  register unsigned int i = 0;
147  void **p_argv;
148  unsigned char *argp;
149  ffi_type **p_arg;
150  argp = stack;
151  p_argv = ecif->avalue;
152  for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types;
153  (i != 0);
154  i--, p_arg++) {
155  size_t z;
156  z = (*p_arg)->size;
157  if (z < sizeof(int)) {
158  z = sizeof(int);
159  switch ((*p_arg)->type) {
160  case FFI_TYPE_SINT8: {
161  signed char v = *(SINT8 *)(* p_argv);
162  signed int t = v;
163  *(signed int *) argp = t;
164  }
165  break;
166  case FFI_TYPE_UINT8: {
167  unsigned char v = *(UINT8 *)(* p_argv);
168  unsigned int t = v;
169  *(unsigned int *) argp = t;
170  }
171  break;
172  case FFI_TYPE_SINT16:
173  *(signed int *) argp = (signed int) * (SINT16 *)(* p_argv);
174  break;
175  case FFI_TYPE_UINT16:
176  *(unsigned int *) argp = (unsigned int) * (UINT16 *)(* p_argv);
177  break;
178  case FFI_TYPE_STRUCT:
179  memcpy(argp, *p_argv, (*p_arg)->size);
180  break;
181  default:
182  FFI_ASSERT(0);
183  break;
184  }
185  } else if (z == sizeof(int)) {
186  *(unsigned int *) argp = (unsigned int) * (UINT32 *)(* p_argv);
187  } else {
188  memcpy(argp, *p_argv, z);
189  }
190  p_argv++;
191  argp += z;
192  }
193 }
194 
195 
196 
#define FFI_ASSERT(x)
Definition: ffi_common.h:72
#define FFIBFIN_RET_HALFWORD
Definition: ffi.c:41
void ffi_call_SYSV(unsigned(*)(struct call_context *context, unsigned char *, extended_cif *), struct call_context *context, extended_cif *, size_t, void(*fn)(void))
ffi_cif * cif
Definition: ffi_common.h:88
#define FFIBFIN_RET_VOID
Definition: ffi.c:39
void * rvalue
Definition: ffi_common.h:89
#define FFIBFIN_RET_BYTE
Definition: ffi.c:40
void ffi_call(ffi_cif *cif, void(*fn)(void), void *rvalue, void **avalue)
Definition: ffi.c:813
#define memcpy(d, s, n)
Definition: ffi_common.h:55
#define FFIBFIN_RET_INT64
Definition: ffi.c:42
void ffi_prep_args(char *stack, extended_cif *ecif)
Definition: ffi.c:46
ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
Definition: ffi.c:758
void ** avalue
Definition: ffi_common.h:90
#define FFIBFIN_RET_INT32
Definition: ffi.c:43