/* -----------------------------------------------------------------------
   ffi.c - Copyright (c) 2003 Kaz Kojima
   
   SuperH SHmedia Foreign Function Interface 

   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 CYGNUS SOLUTIONS 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.
   ----------------------------------------------------------------------- */

#include <ffi.h>
#include <ffi_common.h>

#include <stdlib.h>

#define NGREGARG 8
#define NFREGARG 12

/* If the structure has essentialy an unique element, return its type.  */
static int
simple_type (ffi_type *arg)
{
  if (arg->type != FFI_TYPE_STRUCT)
    return arg->type;
  else if (arg->elements[1])
    return FFI_TYPE_STRUCT;

  return simple_type (arg->elements[0]);
}

static int
return_type (ffi_type *arg)
{
  unsigned short type;

  if (arg->type != FFI_TYPE_STRUCT)
    return arg->type;

  type = simple_type (arg->elements[0]);
  if (! arg->elements[1])
    {
      switch (type)
	{
	case FFI_TYPE_SINT8:
	case FFI_TYPE_UINT8:
	case FFI_TYPE_SINT16:
	case FFI_TYPE_UINT16:
	case FFI_TYPE_SINT32:
	case FFI_TYPE_UINT32:
	case FFI_TYPE_SINT64:
	case FFI_TYPE_UINT64:
	  return FFI_TYPE_UINT64;

	default:
	  return type;
	}
    }

  /* gcc uses r2 if the result can be packed in on register.  */
  if (arg->size <= sizeof (UINT64))
    return FFI_TYPE_UINT64;

  return FFI_TYPE_STRUCT;
}

/* ffi_prep_args is called by the assembly routine once stack space
   has been allocated for the function's arguments */

/*@-exportheader@*/
void ffi_prep_args(char *stack, extended_cif *ecif)
/*@=exportheader@*/
{
  register unsigned int i;
  register unsigned int avn;
  register void **p_argv;
  register char *argp;
  register ffi_type **p_arg;

  argp = stack;

  if (return_type (ecif->cif->rtype) == FFI_TYPE_STRUCT)
    {
      *(void **) argp = ecif->rvalue;
      argp += sizeof (UINT64);
    }

  avn = ecif->cif->nargs;
  p_argv = ecif->avalue;

  for (i = 0, p_arg = ecif->cif->arg_types; i < avn; i++, p_arg++, p_argv++)
    {
      size_t z;

      z = (*p_arg)->size;
      if (z < sizeof (UINT32))
	{
	  switch ((*p_arg)->type)
	    {
	    case FFI_TYPE_SINT8:
	      *(SINT64 *) argp = (SINT64) *(SINT8 *)(*p_argv);
	      break;
  
	    case FFI_TYPE_UINT8:
	      *(UINT64 *) argp = (UINT64) *(UINT8 *)(*p_argv);
	      break;
  
	    case FFI_TYPE_SINT16:
	      *(SINT64 *) argp = (SINT64) *(SINT16 *)(*p_argv);
	      break;
  
	    case FFI_TYPE_UINT16:
	      *(UINT64 *) argp = (UINT64) *(UINT16 *)(*p_argv);
	      break;
  
	    case FFI_TYPE_STRUCT:
	      *(UINT64 *) argp = (UINT64) *(UINT32 *)(*p_argv);
	      break;

	    default:
	      FFI_ASSERT(0);
	    }
	  argp += sizeof (UINT64);
	}
      else if (z == sizeof (UINT32))
	{
	  *(UINT64 *) argp = (UINT64) *(UINT32 *) (*p_argv);
	  argp += sizeof (UINT64);
	}
      else if (z == sizeof (UINT64))
	{
	  *(UINT64 *) argp = *(UINT64 *) (*p_argv);
	  argp += sizeof (UINT64);
	}
      else
	{
	  int n = (z + sizeof (UINT64) - 1) / sizeof (UINT64);

	  memcpy (argp, *p_argv, z);
	  argp += n * sizeof (UINT64);
	}
    }

  return;
}

/* Perform machine dependent cif processing */
ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
{
  int i, j;
  int size, type;
  int n, m;
  int greg;
  int freg;

  greg = (return_type (cif->rtype) == FFI_TYPE_STRUCT ? 1 : 0);
  freg = 0;
  cif->flags2 = 0;

  for (i = j = 0; i < cif->nargs; i++)
    {
      type = (cif->arg_types)[i]->type;
      switch (type)
	{
	case FFI_TYPE_FLOAT:
	  greg++;
	  cif->bytes += sizeof (UINT64) - sizeof (float);
	  if (freg >= NFREGARG - 1)
	    continue;
	  freg++;
	  cif->flags2 += ((cif->arg_types)[i]->type) << (2 * j++);
	  break;

	case FFI_TYPE_DOUBLE:
	  if (greg++ >= NGREGARG && (freg + 1) >= NFREGARG)
	    continue;
	  if ((freg + 1) < NFREGARG)
	    {
	      freg = (freg + 1) & ~1;
	      freg += 2;
	      cif->flags2 += ((cif->arg_types)[i]->type) << (2 * j++);
	    }
	  else
	    cif->flags2 += FFI_TYPE_INT << (2 * j++);
	  break;
	      
	default:
	  size = (cif->arg_types)[i]->size;
	  if (size < sizeof (UINT64))
	    cif->bytes += sizeof (UINT64) - size;
	  n = (size + sizeof (UINT64) - 1) / sizeof (UINT64);
	  if (greg >= NGREGARG)
	    continue;
	  else if (greg + n - 1 >= NGREGARG)
	    greg = NGREGARG;
	  else
	    greg += n;
	  for (m = 0; m < n; m++)
	    cif->flags2 += FFI_TYPE_INT << (2 * j++);
	  break;
	}
    }

  /* Set the return type flag */
  switch (cif->rtype->type)
    {
    case FFI_TYPE_STRUCT:
      cif->flags = return_type (cif->rtype);
      break;

    case FFI_TYPE_VOID:
    case FFI_TYPE_FLOAT:
    case FFI_TYPE_DOUBLE:
    case FFI_TYPE_SINT64:
    case FFI_TYPE_UINT64:
      cif->flags = cif->rtype->type;
      break;

    default:
      cif->flags = FFI_TYPE_INT;
      break;
    }

  return FFI_OK;
}

/*@-declundef@*/
/*@-exportheader@*/
extern void ffi_call_SYSV(void (*)(char *, extended_cif *), 
			  /*@out@*/ extended_cif *, 
			  unsigned, unsigned, long long,
			  /*@out@*/ unsigned *, 
			  void (*fn)());
/*@=declundef@*/
/*@=exportheader@*/

void ffi_call(/*@dependent@*/ ffi_cif *cif, 
	      void (*fn)(), 
	      /*@out@*/ void *rvalue, 
	      /*@dependent@*/ 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))
    {
      /*@-sysunrecog@*/
      ecif.rvalue = alloca(cif->rtype->size);
      /*@=sysunrecog@*/
    }
  else
    ecif.rvalue = rvalue;

  switch (cif->abi) 
    {
    case FFI_SYSV:
      /*@-usedef@*/
      ffi_call_SYSV(ffi_prep_args, &ecif, cif->bytes, 
		    cif->flags, cif->flags2, ecif.rvalue, fn);
      /*@=usedef@*/
      break;
    default:
      FFI_ASSERT(0);
      break;
    }
}

extern void ffi_closure_SYSV (void);
extern void __ic_invalidate (void *line);

ffi_status
ffi_prep_closure (ffi_closure *closure,
		  ffi_cif *cif,
		  void (*fun)(ffi_cif*, void*, void**, void*),
		  void *user_data)
{
  unsigned int *tramp;

  FFI_ASSERT (cif->abi == FFI_GCC_SYSV);

  tramp = (unsigned int *) &closure->tramp[0];
  /* Since ffi_closure is an aligned object, the ffi trampoline is
     called as an SHcompact code.  Sigh.
     SHcompact part:
     mova @(1,pc),r0; add #1,r0; jmp @r0; nop;
     SHmedia part:
     movi fnaddr >> 16,r1; shori fnaddr,r1; ptabs/l r1,tr0
     movi cxt >> 16,r1; shori cxt,r1; blink tr0,r63  */
#ifdef __LITTLE_ENDIAN__
  tramp[0] = 0x7001c701;
  tramp[1] = 0x0009402b;
#else
  tramp[0] = 0xc7017001;
  tramp[1] = 0x402b0009;
#endif
  tramp[2] = 0xcc000010 | (((UINT32) ffi_closure_SYSV) >> 16) << 10;
  tramp[3] = 0xc8000010 | (((UINT32) ffi_closure_SYSV) & 0xffff) << 10;
  tramp[4] = 0x6bf10600;
  tramp[5] = 0xcc000010 | (((UINT32) closure) >> 16) << 10;
  tramp[6] = 0xc8000010 | (((UINT32) closure) & 0xffff) << 10;
  tramp[7] = 0x4401fff0;

  closure->cif = cif;
  closure->fun = fun;
  closure->user_data = user_data;

  /* Flush the icache.  */
  asm volatile ("ocbwb %0,0; synco; icbi %0,0; synci" : : "r" (tramp));

  return FFI_OK;
}

/* Basically the trampoline invokes ffi_closure_SYSV, and on 
 * entry, r3 holds the address of the closure.
 * After storing the registers that could possibly contain
 * parameters to be passed into the stack frame and setting
 * up space for a return value, ffi_closure_SYSV invokes the 
 * following helper function to do most of the work.
 */

int
ffi_closure_helper_SYSV (ffi_closure *closure, UINT64 *rvalue, 
			 UINT64 *pgr, UINT64 *pfr, UINT64 *pst)
{
  void **avalue;
  ffi_type **p_arg;
  int i, avn;
  int greg, freg;
  ffi_cif *cif;

  cif = closure->cif;
  avalue = alloca (cif->nargs * sizeof (void *));

  /* Copy the caller's structure return value address so that the closure
     returns the data directly to the caller.  */
  if (cif->rtype->type == FFI_TYPE_STRUCT)
    {
      rvalue = *pgr;
      greg = 1;
    }
  else
    greg = 0;

  freg = 0;
  cif = closure->cif;
  avn = cif->nargs;

  /* Grab the addresses of the arguments from the stack frame.  */
  for (i = 0, p_arg = cif->arg_types; i < avn; i++, p_arg++)
    {
      size_t z;
      void *p;

      z = (*p_arg)->size;
      if (z < sizeof (UINT32))
	{
	  p = pgr + greg++;

	  switch ((*p_arg)->type)
	    {
	    case FFI_TYPE_SINT8:
	    case FFI_TYPE_UINT8:
	    case FFI_TYPE_SINT16:
	    case FFI_TYPE_UINT16:
	    case FFI_TYPE_STRUCT:
#ifdef __LITTLE_ENDIAN__
	      avalue[i] = p;
#else
	      avalue[i] = ((char *) p) + sizeof (UINT32) - z;
#endif
	      break;

	    default:
	      FFI_ASSERT(0);
	    }
	}
      else if (z == sizeof (UINT32))
	{
	  if ((*p_arg)->type == FFI_TYPE_FLOAT)
	    {
	      if (freg < NFREGARG - 1)
#ifdef __LITTLE_ENDIAN__
		avalue[i] = (UINT32 *) pfr + (1 ^ freg++);
#else
		avalue[i] = (UINT32 *) pfr + freg++;
#endif
	      else
#ifdef __LITTLE_ENDIAN__
		avalue[i] = pgr + greg;
#else
		avalue[i] = (UINT32 *) (pgr + greg) + 1;
#endif
	    }
	  else
#ifdef __LITTLE_ENDIAN__
	    avalue[i] = pgr + greg;
#else
	    avalue[i] = (UINT32 *) (pgr + greg) + 1;
#endif
	  greg++;
	}
      else if ((*p_arg)->type == FFI_TYPE_DOUBLE)
	{
	  if (freg + 1 >= NFREGARG)
	    avalue[i] = pgr + greg;
	  else
	    {
	      freg = (freg + 1) & ~1;
	      avalue[i] = pfr + (freg >> 1);
	      freg += 2;
	    }
	  greg++;
	}
      else
	{
	  int n = (z + sizeof (UINT64) - 1) / sizeof (UINT64);

	  avalue[i] = pgr + greg;
	  greg += n;
	}
    }

  (closure->fun) (cif, rvalue, avalue, closure->user_data);

  /* Tell ffi_closure_SYSV how to perform return type promotions.  */
  return cif->rtype->type;
}