/*
* Copyright (c) 2013 Miodrag Vallat. <miod@openbsd.org>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* ``Software''), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* m88k Foreign Function Interface
*
* This file attempts to provide all the FFI entry points which can reliably
* be implemented in C.
*
* Only OpenBSD/m88k is currently supported; other platforms (such as
* Motorola's SysV/m88k) could be supported with the following tweaks:
*
* - non-OpenBSD systems use an `outgoing parameter area' as part of the
* 88BCS calling convention, which is not supported under OpenBSD from
* release 3.6 onwards. Supporting it should be as easy as taking it
* into account when adjusting the stack, in the assembly code.
*
* - the logic deciding whether a function argument gets passed through
* registers, or on the stack, has changed several times in OpenBSD in
* edge cases (especially for structs larger than 32 bytes being passed
* by value). The code below attemps to match the logic used by the
* system compiler of OpenBSD 5.3, i.e. gcc 3.3.6 with many m88k backend
* fixes.
*/
#include <ffi.h>
#include <ffi_common.h>
#include <stdlib.h>
#include <unistd.h>
void ffi_call_OBSD (unsigned int, extended_cif *, unsigned int, void *,
void (*fn) ());
void *ffi_prep_args (void *, extended_cif *);
void ffi_closure_OBSD (ffi_closure *);
void ffi_closure_struct_OBSD (ffi_closure *);
unsigned int ffi_closure_OBSD_inner (ffi_closure *, void *, unsigned int *,
char *);
void ffi_cacheflush_OBSD (unsigned int, unsigned int);
#define CIF_FLAGS_INT (1 << 0)
#define CIF_FLAGS_DINT (1 << 1)
/*
* Foreign Function Interface API
*/
/* ffi_prep_args is called by the assembly routine once stack space has
been allocated for the function's arguments. */
void *
ffi_prep_args (void *stack, extended_cif *ecif)
{
unsigned int i;
void **p_argv;
char *argp, *stackp;
unsigned int *regp;
unsigned int regused;
ffi_type **p_arg;
void *struct_value_ptr;
regp = (unsigned int *)stack;
stackp = (char *)(regp + 8);
regused = 0;
if (ecif->cif->rtype->type == FFI_TYPE_STRUCT
&& !ecif->cif->flags)
struct_value_ptr = ecif->rvalue;
else
struct_value_ptr = NULL;
p_argv = ecif->avalue;
for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types; i != 0; i--, p_arg++)
{
size_t z;
unsigned short t, a;
z = (*p_arg)->size;
t = (*p_arg)->type;
a = (*p_arg)->alignment;
/*
* Figure out whether the argument can be passed through registers
* or on the stack.
* The rule is that registers can only receive simple types not larger
* than 64 bits, or structs the exact size of a register and aligned to
* the size of a register.
*/
if (t == FFI_TYPE_STRUCT)
{
if (z == sizeof (int) && a == sizeof (int) && regused < 8)
argp = (char *)regp;
else
argp = stackp;
}
else
{
if (z > sizeof (int) && regused < 8 - 1)
{
/* align to an even register pair */
if (regused & 1)
{
regp++;
regused++;
}
}
if (regused < 8)
argp = (char *)regp;
else
argp = stackp;
}
/* Enforce proper stack alignment of 64-bit types */
if (argp == stackp && a > sizeof (int))
{
stackp = (char *) ALIGN(stackp, a);
argp = stackp;
}
switch (t)
{
case FFI_TYPE_SINT8:
*(signed int *) argp = (signed int) *(SINT8 *) *p_argv;
break;
case FFI_TYPE_UINT8:
*(unsigned int *) argp = (unsigned int) *(UINT8 *) *p_argv;
break;
case FFI_TYPE_SINT16:
*(signed int *) argp = (signed int) *(SINT16 *) *p_argv;
break;
case FFI_TYPE_UINT16:
*(unsigned int *) argp = (unsigned int) *(UINT16 *) *p_argv;
break;
case FFI_TYPE_INT:
case FFI_TYPE_FLOAT:
case FFI_TYPE_UINT32:
case FFI_TYPE_SINT32:
case FFI_TYPE_POINTER:
*(unsigned int *) argp = *(unsigned int *) *p_argv;
break;
case FFI_TYPE_DOUBLE:
case FFI_TYPE_UINT64:
case FFI_TYPE_SINT64:
case FFI_TYPE_STRUCT:
memcpy (argp, *p_argv, z);
break;
default:
FFI_ASSERT (0);
}
/* Align if necessary. */
if ((sizeof (int) - 1) & z)
z = ALIGN(z, sizeof (int));
p_argv++;
/* Be careful, once all registers are filled, and about to continue
on stack, regp == stackp. Therefore the check for regused as well. */
if (argp == (char *)regp && regused < 8)
{
regp += z / sizeof (int);
regused += z / sizeof (int);
}
else
stackp += z;
}
return struct_value_ptr;
}
/* Perform machine dependent cif processing */
ffi_status
ffi_prep_cif_machdep (ffi_cif *cif)
{
/* Set the return type flag */
switch (cif->rtype->type)
{
case FFI_TYPE_VOID:
cif->flags = 0;
break;
case FFI_TYPE_STRUCT:
if (cif->rtype->size == sizeof (int) &&
cif->rtype->alignment == sizeof (int))
cif->flags = CIF_FLAGS_INT;
else
cif->flags = 0;
break;
case FFI_TYPE_DOUBLE:
case FFI_TYPE_SINT64:
case FFI_TYPE_UINT64:
cif->flags = CIF_FLAGS_DINT;
break;
default:
cif->flags = CIF_FLAGS_INT;
break;
}
return FFI_OK;
}
void
ffi_call (ffi_cif *cif, void (*fn) (), void *rvalue, void **avalue)
{
extended_cif ecif;
ecif.cif = cif;
ecif.avalue = avalue;
/* If the return value is a struct and we don't have a return value
address then we need to make one. */
if (rvalue == NULL
&& cif->rtype->type == FFI_TYPE_STRUCT
&& (cif->rtype->size != sizeof (int)
|| cif->rtype->alignment != sizeof (int)))
ecif.rvalue = alloca (cif->rtype->size);
else
ecif.rvalue = rvalue;
switch (cif->abi)
{
case FFI_OBSD:
ffi_call_OBSD (cif->bytes, &ecif, cif->flags, ecif.rvalue, fn);
break;
default:
FFI_ASSERT (0);
break;
}
}
/*
* Closure API
*/
static void
ffi_prep_closure_args_OBSD (ffi_cif *cif, void **avalue, unsigned int *regp,
char *stackp)
{
unsigned int i;
void **p_argv;
char *argp;
unsigned int regused;
ffi_type **p_arg;
regused = 0;
p_argv = avalue;
for (i = cif->nargs, p_arg = cif->arg_types; i != 0; i--, p_arg++)
{
size_t z;
unsigned short t, a;
z = (*p_arg)->size;
t = (*p_arg)->type;
a = (*p_arg)->alignment;
/*
* Figure out whether the argument has been passed through registers
* or on the stack.
* The rule is that registers can only receive simple types not larger
* than 64 bits, or structs the exact size of a register and aligned to
* the size of a register.
*/
if (t == FFI_TYPE_STRUCT)
{
if (z == sizeof (int) && a == sizeof (int) && regused < 8)
argp = (char *)regp;
else
argp = stackp;
}
else
{
if (z > sizeof (int) && regused < 8 - 1)
{
/* align to an even register pair */
if (regused & 1)
{
regp++;
regused++;
}
}
if (regused < 8)
argp = (char *)regp;
else
argp = stackp;
}
/* Enforce proper stack alignment of 64-bit types */
if (argp == stackp && a > sizeof (int))
{
stackp = (char *) ALIGN(stackp, a);
argp = stackp;
}
if (z < sizeof (int) && t != FFI_TYPE_STRUCT)
*p_argv = (void *) (argp + sizeof (int) - z);
else
*p_argv = (void *) argp;
/* Align if necessary */
if ((sizeof (int) - 1) & z)
z = ALIGN(z, sizeof (int));
p_argv++;
/* Be careful, once all registers are exhausted, and about to fetch from
stack, regp == stackp. Therefore the check for regused as well. */
if (argp == (char *)regp && regused < 8)
{
regp += z / sizeof (int);
regused += z / sizeof (int);
}
else
stackp += z;
}
}
unsigned int
ffi_closure_OBSD_inner (ffi_closure *closure, void *resp, unsigned int *regp,
char *stackp)
{
ffi_cif *cif;
void **arg_area;
cif = closure->cif;
arg_area = (void**) alloca (cif->nargs * sizeof (void *));
ffi_prep_closure_args_OBSD(cif, arg_area, regp, stackp);
(closure->fun) (cif, resp, arg_area, closure->user_data);
return cif->flags;
}
ffi_status
ffi_prep_closure_loc (ffi_closure* closure, ffi_cif* cif,
void (*fun)(ffi_cif*,void*,void**,void*),
void *user_data, void *codeloc)
{
unsigned int *tramp = (unsigned int *) codeloc;
void *fn;
FFI_ASSERT (cif->abi == FFI_OBSD);
if (cif->rtype->type == FFI_TYPE_STRUCT && !cif->flags)
fn = &ffi_closure_struct_OBSD;
else
fn = &ffi_closure_OBSD;
/* or.u %r10, %r0, %hi16(fn) */
tramp[0] = 0x5d400000 | (((unsigned int)fn) >> 16);
/* or.u %r13, %r0, %hi16(closure) */
tramp[1] = 0x5da00000 | ((unsigned int)closure >> 16);
/* or %r10, %r10, %lo16(fn) */
tramp[2] = 0x594a0000 | (((unsigned int)fn) & 0xffff);
/* jmp.n %r10 */
tramp[3] = 0xf400c40a;
/* or %r13, %r13, %lo16(closure) */
tramp[4] = 0x59ad0000 | ((unsigned int)closure & 0xffff);
ffi_cacheflush_OBSD((unsigned int)codeloc, FFI_TRAMPOLINE_SIZE);
closure->cif = cif;
closure->user_data = user_data;
closure->fun = fun;
return FFI_OK;
}