/* ———————————————————————–
ffi.c - Copyright (c) 2015 Michael Knyszek <mknyszek@berkeley.edu>
2015 Andrew Waterman <waterman@cs.berkeley.edu>
2018 Stef O'Rear <sorear2@gmail.com>
RISC-V 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 define SARG sd else define PTRS 4 define LARG lw define SARG sw endif
if __riscv_float_abi_double define FLTS 8 define FLARG fld define FSARG fsd elif __riscv_float_abi_single define FLTS 4 define FLARG flw define FSARG fsw else define FLTS 0 endif
define fp s0
.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 + 16)
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 11, FRAME_LEN # interim CFA based on a1 SARG fp, FRAME_LEN - 2*PTRS(a1) .cfi_offset 8, -2*PTRS SARG ra, FRAME_LEN - 1*PTRS(a1) .cfi_offset 1, -1*PTRS addi fp, a1, FRAME_LEN mv sp, a0 .cfi_def_cfa 8, 0 # our frame is fully set up # Load arguments mv t1, a2 mv t2, a3
if FLTS
FLARG fa0, -FRAME_LEN+0*FLTS(fp) FLARG fa1, -FRAME_LEN+1*FLTS(fp) FLARG fa2, -FRAME_LEN+2*FLTS(fp) FLARG fa3, -FRAME_LEN+3*FLTS(fp) FLARG fa4, -FRAME_LEN+4*FLTS(fp) FLARG fa5, -FRAME_LEN+5*FLTS(fp) FLARG fa6, -FRAME_LEN+6*FLTS(fp) FLARG fa7, -FRAME_LEN+7*FLTS(fp)
endif
LARG a0, -FRAME_LEN+8*FLTS+0*PTRS(fp) LARG a1, -FRAME_LEN+8*FLTS+1*PTRS(fp) LARG a2, -FRAME_LEN+8*FLTS+2*PTRS(fp) LARG a3, -FRAME_LEN+8*FLTS+3*PTRS(fp) LARG a4, -FRAME_LEN+8*FLTS+4*PTRS(fp) LARG a5, -FRAME_LEN+8*FLTS+5*PTRS(fp) LARG a6, -FRAME_LEN+8*FLTS+6*PTRS(fp) LARG a7, -FRAME_LEN+8*FLTS+7*PTRS(fp) /* Call */ jalr t1 /* Save return values - only a0/a1 (fa0/fa1) are used */
if FLTS
FSARG fa0, -FRAME_LEN+0*FLTS(fp) FSARG fa1, -FRAME_LEN+1*FLTS(fp)
endif
SARG a0, -FRAME_LEN+8*FLTS+0*PTRS(fp) SARG a1, -FRAME_LEN+8*FLTS+1*PTRS(fp) /* Restore and return */ addi sp, fp, -FRAME_LEN .cfi_def_cfa 2, FRAME_LEN LARG ra, -1*PTRS(fp) .cfi_restore 1 LARG fp, -2*PTRS(fp) .cfi_restore 8 ret .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 sp, sp, -FRAME_LEN .cfi_def_cfa_offset FRAME_LEN /* make a frame */ SARG fp, FRAME_LEN - 2*PTRS(sp) .cfi_offset 8, -2*PTRS SARG ra, FRAME_LEN - 1*PTRS(sp) .cfi_offset 1, -1*PTRS addi fp, sp, FRAME_LEN /* save arguments */
if FLTS
FSARG fa0, 0*FLTS(sp) FSARG fa1, 1*FLTS(sp) FSARG fa2, 2*FLTS(sp) FSARG fa3, 3*FLTS(sp) FSARG fa4, 4*FLTS(sp) FSARG fa5, 5*FLTS(sp) FSARG fa6, 6*FLTS(sp) FSARG fa7, 7*FLTS(sp)
endif
SARG a0, 8*FLTS+0*PTRS(sp) SARG a1, 8*FLTS+1*PTRS(sp) SARG a2, 8*FLTS+2*PTRS(sp) SARG a3, 8*FLTS+3*PTRS(sp) SARG a4, 8*FLTS+4*PTRS(sp) SARG a5, 8*FLTS+5*PTRS(sp) SARG a6, 8*FLTS+6*PTRS(sp) SARG a7, 8*FLTS+7*PTRS(sp) /* enter C */ LARG a0, FFI_TRAMPOLINE_SIZE+0*PTRS(t1) LARG a1, FFI_TRAMPOLINE_SIZE+1*PTRS(t1) LARG a2, FFI_TRAMPOLINE_SIZE+2*PTRS(t1) addi a3, sp, FRAME_LEN mv a4, sp call ffi_closure_inner /* return values */
if FLTS
FLARG fa0, 0*FLTS(sp) FLARG fa1, 1*FLTS(sp)
endif
LARG a0, 8*FLTS+0*PTRS(sp) LARG a1, 8*FLTS+1*PTRS(sp) /* restore and return */ LARG ra, FRAME_LEN-1*PTRS(sp) .cfi_restore 1 LARG fp, FRAME_LEN-2*PTRS(sp) .cfi_restore 8 addi sp, sp, FRAME_LEN .cfi_def_cfa_offset 0 ret .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 sp, sp, -FRAME_LEN .cfi_def_cfa_offset FRAME_LEN /* make a frame */ SARG fp, FRAME_LEN - 2*PTRS(sp) .cfi_offset 8, -2*PTRS SARG ra, FRAME_LEN - 1*PTRS(sp) .cfi_offset 1, -1*PTRS addi fp, sp, FRAME_LEN /* save arguments */
if FLTS
FSARG fa0, 0*FLTS(sp) FSARG fa1, 1*FLTS(sp) FSARG fa2, 2*FLTS(sp) FSARG fa3, 3*FLTS(sp) FSARG fa4, 4*FLTS(sp) FSARG fa5, 5*FLTS(sp) FSARG fa6, 6*FLTS(sp) FSARG fa7, 7*FLTS(sp)
endif
SARG a0, 8*FLTS+0*PTRS(sp) SARG a1, 8*FLTS+1*PTRS(sp) SARG a2, 8*FLTS+2*PTRS(sp) SARG a3, 8*FLTS+3*PTRS(sp) SARG a4, 8*FLTS+4*PTRS(sp) SARG a5, 8*FLTS+5*PTRS(sp) SARG a6, 8*FLTS+6*PTRS(sp) SARG a7, 8*FLTS+7*PTRS(sp) /* enter C */ LARG a0, 1*PTRS(t2) LARG a1, 2*PTRS(t2) mv a2, t2 addi a3, sp, FRAME_LEN mv a4, sp call ffi_closure_inner /* return values */
if FLTS
FLARG fa0, 0*FLTS(sp) FLARG fa1, 1*FLTS(sp)
endif
LARG a0, 8*FLTS+0*PTRS(sp) LARG a1, 8*FLTS+1*PTRS(sp) /* restore and return */ LARG ra, FRAME_LEN-1*PTRS(sp) .cfi_restore 1 LARG fp, FRAME_LEN-2*PTRS(sp) .cfi_restore 8 addi sp, sp, FRAME_LEN .cfi_def_cfa_offset 0 ret .cfi_endproc .size ffi_go_closure_asm, .-ffi_go_closure_asm