-----------------------------------------------------------------------
ffi.c - Copyright (c) 2015 Michael Knyszek <mknyszek@berkeley.edu>
                      2015 Andrew Waterman <waterman@cs.berkeley.edu>
                      2018 Stef O'Rear <sorear2@gmail.com>

LOONGARCH 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 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.
-----------------------------------------------------------------------

define LIBFFI_ASM include <fficonfig.h> include <ffi.h>

Define aliases so that we can handle all ABIs uniformly

if SIZEOF_POINTER == 8 define PTRS 8 define LARG ld.d define SARG st.d else define PTRS 4 define LARG ld.w define SARG st.w endif

ifdef __loongarch_hard_float # if defined __loongarch_single_float # define FLT float # define FLEN 4 # define FLD fld.w # define FST fst.w # error “need check” # else # define FLT double # define FLEN 8 # define FLARG fld.d # define FSARG fst.d # endif else # define FLEN 0 # error “need check” endif

define FLTS 8

.text
.globl  ffi_call_asm
.type   ffi_call_asm, @function
.hidden ffi_call_asm

/*

 struct call_context {
     floatreg fa[8];
     intreg a[8];
     intreg pad[rv32 ? 2 : 0];
     intreg save_fp, save_ra;
 }
 void ffi_call_asm (size_t *stackargs, struct call_context *regargs,
                    void (*fn) (void), void *closure);
/

define FRAME_LEN (8 * FLTS + 8 * PTRS + 8 * 2)

ffi_call_asm:

.cfi_startproc

/*
  We are NOT going to set up an ordinary stack frame.  In order to pass
  the stacked args to the called function, we adjust our stack pointer to
  a0, which is in the _caller's_ alloca area.  We establish our own stack
  frame at the end of the call_context.

  Anything below the arguments will be freed at this point, although we
  preserve the call_context so that it can be read back in the caller.
 /

.cfi_def_cfa 5, FRAME_LEN # interim CFA based on a1
SARG    $fp, $a1, FRAME_LEN - 2*PTRS
.cfi_offset 22, -2*PTRS
SARG    $ra, $a1, FRAME_LEN - 1*PTRS
.cfi_offset 1, -1*PTRS

addi.d    $fp, $a1, FRAME_LEN
move      $sp, $a0
.cfi_def_cfa 22, 0 # our frame is fully set up

# Load arguments
move      $t1, $a2
move      $t2, $a3

FLARG   $fa0, $fp, -FRAME_LEN+0*FLTS
FLARG   $fa1, $fp, -FRAME_LEN+1*FLTS
FLARG   $fa2, $fp, -FRAME_LEN+2*FLTS
FLARG   $fa3, $fp, -FRAME_LEN+3*FLTS
FLARG   $fa4, $fp, -FRAME_LEN+4*FLTS
FLARG   $fa5, $fp, -FRAME_LEN+5*FLTS
FLARG   $fa6, $fp, -FRAME_LEN+6*FLTS
FLARG   $fa7, $fp, -FRAME_LEN+7*FLTS

LARG    $a0, $fp, -FRAME_LEN+8*FLTS+0*PTRS
LARG    $a1, $fp, -FRAME_LEN+8*FLTS+1*PTRS
LARG    $a2, $fp, -FRAME_LEN+8*FLTS+2*PTRS
LARG    $a3, $fp, -FRAME_LEN+8*FLTS+3*PTRS
LARG    $a4, $fp, -FRAME_LEN+8*FLTS+4*PTRS
LARG    $a5, $fp, -FRAME_LEN+8*FLTS+5*PTRS
LARG    $a6, $fp, -FRAME_LEN+8*FLTS+6*PTRS
LARG    $a7, $fp, -FRAME_LEN+8*FLTS+7*PTRS

/* Call */
jirl    $ra,$t1,0

/* Save return values - only a0/a1 (fa0/fa1) are used */
FSARG   $fa0, $fp, -FRAME_LEN+0*FLTS
FSARG   $fa1, $fp, -FRAME_LEN+1*FLTS

SARG    $a0, $fp, -FRAME_LEN+8*FLTS+0*PTRS
SARG    $a1, $fp, -FRAME_LEN+8*FLTS+1*PTRS

/* Restore and return */
addi.d    $sp, $fp, -FRAME_LEN
.cfi_def_cfa 3, FRAME_LEN
LARG    $ra, $fp, -1*PTRS
.cfi_restore 1
LARG    $fp, $fp, -2*PTRS
.cfi_restore 22
jirl $r0, $ra, 0
.cfi_endproc
.size   ffi_call_asm, .-ffi_call_asm

/*

 ffi_closure_asm. Expects address of the passed-in ffi_closure in t1.
 void ffi_closure_inner (ffi_cif *cif,
                         void (*fun) (ffi_cif *, void *, void **, void *),
                         void *user_data,
                         size_t *stackargs, struct call_context *regargs)
/

   .globl ffi_closure_asm
   .hidden ffi_closure_asm
   .type ffi_closure_asm, @function

ffi_closure_asm:

.cfi_startproc

addi.d    $sp,  $sp, -FRAME_LEN
.cfi_def_cfa_offset FRAME_LEN

/* make a frame */
SARG    $fp, $sp, FRAME_LEN - 2*PTRS
.cfi_offset 22, -2*PTRS
SARG    $ra, $sp, FRAME_LEN - 1*PTRS
.cfi_offset 1, -1*PTRS
addi.d    $fp, $sp, FRAME_LEN

/* save arguments */
FSARG   $fa0, $sp, 0*FLTS
FSARG   $fa1, $sp, 1*FLTS
FSARG   $fa2, $sp, 2*FLTS
FSARG   $fa3, $sp, 3*FLTS
FSARG   $fa4, $sp, 4*FLTS
FSARG   $fa5, $sp, 5*FLTS
FSARG   $fa6, $sp, 6*FLTS
FSARG   $fa7, $sp, 7*FLTS

SARG    $a0, $sp, 8*FLTS+0*PTRS
SARG    $a1, $sp, 8*FLTS+1*PTRS
SARG    $a2, $sp, 8*FLTS+2*PTRS
SARG    $a3, $sp, 8*FLTS+3*PTRS
SARG    $a4, $sp, 8*FLTS+4*PTRS
SARG    $a5, $sp, 8*FLTS+5*PTRS
SARG    $a6, $sp, 8*FLTS+6*PTRS
SARG    $a7, $sp, 8*FLTS+7*PTRS

/* enter C */
LARG    $a0, $t0, FFI_TRAMPOLINE_SIZE+0*PTRS
LARG    $a1, $t0, FFI_TRAMPOLINE_SIZE+1*PTRS
LARG    $a2, $t0, FFI_TRAMPOLINE_SIZE+2*PTRS
addi.d    $a3, $sp, FRAME_LEN
move      $a4, $sp

bl   ffi_closure_inner

/* return values */
FLARG   $fa0, $sp, 0*FLTS
FLARG   $fa1, $sp, 1*FLTS

LARG    $a0, $sp, 8*FLTS+0*PTRS
LARG    $a1, $sp, 8*FLTS+1*PTRS

/* restore and return */
LARG    $ra, $sp, FRAME_LEN-1*PTRS
.cfi_restore 1
LARG    $fp, $sp, FRAME_LEN-2*PTRS
.cfi_restore 22
addi.d    $sp, $sp, FRAME_LEN
.cfi_def_cfa_offset 0
jirl $r0, $ra, 0
.cfi_endproc
.size ffi_closure_asm, .-ffi_closure_asm

/*

 ffi_go_closure_asm.  Expects address of the passed-in ffi_go_closure in t2.
 void ffi_closure_inner (ffi_cif *cif,
                         void (*fun) (ffi_cif *, void *, void **, void *),
                         void *user_data,
                         size_t *stackargs, struct call_context *regargs)
/

   .globl ffi_go_closure_asm
   .hidden ffi_go_closure_asm
   .type ffi_go_closure_asm, @function

ffi_go_closure_asm:

.cfi_startproc

addi.d    $sp,  $sp, -FRAME_LEN
.cfi_def_cfa_offset FRAME_LEN

/* make a frame */
SARG    $fp, $sp, FRAME_LEN - 2*PTRS
.cfi_offset 22, -2*PTRS
SARG    $ra, $sp, FRAME_LEN - 1*PTRS
.cfi_offset 1, -1*PTRS
addi.d    $fp, $sp, FRAME_LEN

/* save arguments */
FSARG   $fa0, $sp, 0*FLTS
FSARG   $fa1, $sp, 1*FLTS
FSARG   $fa2, $sp, 2*FLTS
FSARG   $fa3, $sp, 3*FLTS
FSARG   $fa4, $sp, 4*FLTS
FSARG   $fa5, $sp, 5*FLTS
FSARG   $fa6, $sp, 6*FLTS
FSARG   $fa7, $sp, 7*FLTS

SARG    $a0, $sp, 8*FLTS+0*PTRS
SARG    $a1, $sp, 8*FLTS+1*PTRS
SARG    $a2, $sp, 8*FLTS+2*PTRS
SARG    $a3, $sp, 8*FLTS+3*PTRS
SARG    $a4, $sp, 8*FLTS+4*PTRS
SARG    $a5, $sp, 8*FLTS+5*PTRS
SARG    $a6, $sp, 8*FLTS+6*PTRS
SARG    $a7, $sp, 8*FLTS+7*PTRS

/* enter C */
LARG    $a0, $t2, 1*PTRS
LARG    $a1, $t2, 2*PTRS
move      $a2, $t2
addi.d    $a3, $sp, FRAME_LEN
move      $a4, $sp

bl    ffi_closure_inner

/* return values */
FLARG   $fa0, $sp, 0*FLTS
FLARG   $fa1, $sp, 1*FLTS

LARG    $a0, $sp, 8*FLTS+0*PTRS
LARG    $a1, $sp, 8*FLTS+1*PTRS

/* restore and return */
LARG    $ra, $sp, FRAME_LEN-1*PTRS
.cfi_restore 1
LARG    $fp, $sp, FRAME_LEN-2*PTRS
.cfi_restore 22
addi.d    $sp, $sp, FRAME_LEN
.cfi_def_cfa_offset 0
jirl $r0, $ra, 0
.cfi_endproc
.size ffi_go_closure_asm, .-ffi_go_closure_asm