/* -----------------------------------------------------------------------
sysv.S - Copyright (c) 2013 Tensilica, Inc.
XTENSA 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 ENTRY(name) .text; .globl name; .type name,@function; .align 4; name:
#define END(name) .size name , . - name
/* Assert that the table below is in sync with ffi.h. */
#if FFI_TYPE_UINT8 != 5 \
|| FFI_TYPE_SINT8 != 6 \
|| FFI_TYPE_UINT16 != 7 \
|| FFI_TYPE_SINT16 != 8 \
|| FFI_TYPE_UINT32 != 9 \
|| FFI_TYPE_SINT32 != 10 \
|| FFI_TYPE_UINT64 != 11
#error "xtensa/sysv.S out of sync with ffi.h"
#endif
#define FFI_REGISTER_ARGS_OFFSET ((XTENSA_STACK_ALIGNMENT - \
FFI_REGISTER_NARGS * 4) & \
(XTENSA_STACK_ALIGNMENT - 1))
/* ffi_call_SYSV (rvalue, rbytes, flags, (*fnaddr)(), bytes, ecif)
void *rvalue; a2
unsigned long rbytes; a3
unsigned flags; a4
void (*fnaddr)(); a5
unsigned long bytes; a6
extended_cif* ecif) a7
*/
ENTRY(ffi_call_SYSV)
entry a1, 32 # 32 byte frame for using call8 below
mov a10, a7 # a10(->arg0): ecif
sub a11, a1, a6 # a11(->arg1): stack pointer
mov a7, a1 # fp
movsp a1, a11 # set new sp = old_sp - bytes
# align ffi_prep_args stack argument so that arguments
# passed on stack if any start on 16-byte aligned boundary
addi a11, a11, FFI_REGISTER_ARGS_OFFSET
movi a8, ffi_prep_args
callx8 a8 # ffi_prep_args(ecif, stack)
# prepare to move stack pointer back
# to point to arguments passed on stack
addi a6, a1, FFI_REGISTER_ARGS_SPACE
# we can pass up to 6 arguments in registers
# for simplicity, just load 6 arguments
l32i a10, a1, FFI_REGISTER_ARGS_OFFSET + 0
l32i a11, a1, FFI_REGISTER_ARGS_OFFSET + 4
l32i a12, a1, FFI_REGISTER_ARGS_OFFSET + 8
l32i a13, a1, FFI_REGISTER_ARGS_OFFSET + 12
l32i a14, a1, FFI_REGISTER_ARGS_OFFSET + 16
l32i a15, a1, FFI_REGISTER_ARGS_OFFSET + 20
# move stack pointer
movsp a1, a6
callx8 a5 # (*fn)(args...)
# Handle return value(s)
beqz a2, .Lexit
movi a5, FFI_TYPE_STRUCT
bne a4, a5, .Lstore
movi a5, 16
blt a5, a3, .Lexit
s32i a10, a2, 0
blti a3, 5, .Lexit
addi a3, a3, -1
s32i a11, a2, 4
blti a3, 8, .Lexit
s32i a12, a2, 8
blti a3, 12, .Lexit
s32i a13, a2, 12
.Lexit: retw
.Lstore:
addi a4, a4, -FFI_TYPE_UINT8
bgei a4, 7, .Lexit # should never happen
movi a6, store_calls
add a4, a4, a4
addx4 a6, a4, a6 # store_table + idx * 8
jx a6
.align 8
store_calls:
# UINT8
s8i a10, a2, 0
retw
# SINT8
.align 8
s8i a10, a2, 0
retw
# UINT16
.align 8
s16i a10, a2, 0
retw
# SINT16
.align 8
s16i a10, a2, 0
retw
# UINT32
.align 8
s32i a10, a2, 0
retw
# SINT32
.align 8
s32i a10, a2, 0
retw
# UINT64
.align 8
s32i a10, a2, 0
s32i a11, a2, 4
retw
END(ffi_call_SYSV)
/*
* void ffi_cacheflush (unsigned long start, unsigned long end)
*/
#define EXTRA_ARGS_SIZE 24
ENTRY(ffi_cacheflush)
entry a1, 32
1:
#if XCHAL_DCACHE_SIZE
dhwbi a2, 0
#endif
#if XCHAL_ICACHE_SIZE
ihi a2, 0
#endif
addi a2, a2, 4
blt a2, a3, 1b
retw
END(ffi_cacheflush)
/* ffi_trampoline is copied to the stack */
ENTRY(ffi_trampoline)
/* 32 bytes for spill + spill overflow area of a frame that uses
call8,
FFI_REGISTER_NARGS * 4 bytes for arguments passed in registers,
aligned up to 4 to maintain 16 byte stack alignment,
4 * 4 bytes for the result.
This size must be in sync with ffi_closure_SYSV_inner logic.
*/
entry a1, 32 + FFI_REGISTER_ARGS_SPACE + (4 * 4) # [ 0]
j 2f # [ 3]
.align 4 # [ 6]
1: .long 0 # [ 8]
2: l32r a15, 1b # [12]
_mov a14, a0 # [15]
callx0 a15 # [18]
# [21]
END(ffi_trampoline)
/*
* ffi_closure()
*
* a0: closure + 21
* a14: return address (a0)
*/
ENTRY(ffi_closure_SYSV)
/* intentionally omitting entry here */
# restore return address (a0) and move pointer to closure to a10
addi a10, a0, -21
mov a0, a14
# allow up to 4 arguments as return values
addi a11, a1, 4 * 4
# save up to 6 arguments to stack (allocated by entry below)
s32i a2, a11, 0
s32i a3, a11, 4
s32i a4, a11, 8
s32i a5, a11, 12
s32i a6, a11, 16
s32i a7, a11, 20
movi a8, ffi_closure_SYSV_inner
mov a12, a1
callx8 a8 # .._inner(*closure, **avalue, *rvalue)
# load up to four return arguments
l32i a2, a1, 0
l32i a3, a1, 4
l32i a4, a1, 8
l32i a5, a1, 12
# (sign-)extend return value
movi a11, FFI_TYPE_UINT8
bne a10, a11, 1f
extui a2, a2, 0, 8
retw
1: movi a11, FFI_TYPE_SINT8
bne a10, a11, 1f
sext a2, a2, 7
retw
1: movi a11, FFI_TYPE_UINT16
bne a10, a11, 1f
extui a2, a2, 0, 16
retw
1: movi a11, FFI_TYPE_SINT16
bne a10, a11, 1f
sext a2, a2, 15
1: retw
END(ffi_closure_SYSV)