From 8ac73103bf12ce4f776940cb17f3ced15a362f23 Mon Sep 17 00:00:00 2001 From: Stef O'Rear Date: Sun, 11 Mar 2018 05:55:15 -0700 Subject: [PATCH] New RISC-V port (#281) * Add RISC-V support This patch adds support for the RISC-V architecture (https://riscv.org). This patch has been tested using QEMU user-mode emulation and GCC 7.2.0 in the following configurations: * -march=rv32imac -mabi=ilp32 * -march=rv32g -mabi=ilp32d * -march=rv64imac -mabi=lp64 * -march=rv64g -mabi=lp64d The ABI currently can be found at https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md . * Add RISC-V to README * RISC-V: fix configure.host Upstream-Status: Backport [https://github.com/libffi/libffi/commit/3840d49aaa831d649b1597518a2903dfed0d57f3] Signed-off-by: Alistair Francis --- Makefile.am | 4 + configure.ac | 5 + src/riscv/ffi.c | 445 ++++++++++++++++++++++++++++++++++++++++++ src/riscv/ffitarget.h | 68 +++++++ src/riscv/sysv.S | 214 ++++++++++++++++++++ 5 files changed, 736 insertions(+) create mode 100644 src/riscv/ffi.c create mode 100644 src/riscv/ffitarget.h create mode 100644 src/riscv/sysv.S diff --git a/Makefile.am b/Makefile.am index 0e40451..3837650 100644 --- a/Makefile.am +++ b/Makefile.am @@ -32,6 +32,7 @@ EXTRA_DIST = LICENSE ChangeLog.v1 ChangeLog.libgcj \ src/powerpc/asm.h src/powerpc/aix.S src/powerpc/darwin.S \ src/powerpc/aix_closure.S src/powerpc/darwin_closure.S \ src/powerpc/ffi_darwin.c src/powerpc/ffitarget.h \ + src/riscv/ffi.c src/riscv/ffitarget.h src/riscv/sysv.S \ src/s390/ffi.c src/s390/sysv.S src/s390/ffitarget.h \ src/sh/ffi.c src/sh/sysv.S src/sh/ffitarget.h src/sh64/ffi.c \ src/sh64/sysv.S src/sh64/ffitarget.h src/sparc/v8.S \ @@ -122,6 +123,9 @@ endif if MIPS nodist_libffi_la_SOURCES += src/mips/ffi.c src/mips/o32.S src/mips/n32.S endif +if RISCV +nodist_libffi_la_SOURCES += src/riscv/ffi.c src/riscv/sysv.S +endif if BFIN nodist_libffi_la_SOURCES += src/bfin/ffi.c src/bfin/sysv.S endif diff --git a/configure.ac b/configure.ac index ce30853..33375aa 100644 --- a/configure.ac +++ b/configure.ac @@ -226,6 +226,10 @@ case "$host" in TARGET=MIPS; TARGETDIR=mips ;; + riscv*-*-*) + TARGET=RISCV; TARGETDIR=riscv + ;; + nios2*-linux*) TARGET=NIOS2; TARGETDIR=nios2 ;; @@ -298,6 +302,7 @@ if test $TARGETDIR = unknown; then fi AM_CONDITIONAL(MIPS, test x$TARGET = xMIPS) +AM_CONDITIONAL(RISCV, test x$TARGET = xRISCV) AM_CONDITIONAL(BFIN, test x$TARGET = xBFIN) AM_CONDITIONAL(SPARC, test x$TARGET = xSPARC) AM_CONDITIONAL(X86, test x$TARGET = xX86) diff --git a/src/riscv/ffi.c b/src/riscv/ffi.c new file mode 100644 index 0000000..b744fdd --- /dev/null +++ b/src/riscv/ffi.c @@ -0,0 +1,445 @@ +/* ----------------------------------------------------------------------- + ffi.c - Copyright (c) 2015 Michael Knyszek + 2015 Andrew Waterman + 2018 Stef O'Rear + Based on MIPS N32/64 port + + 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. + ----------------------------------------------------------------------- */ + +#include +#include + +#include +#include + +#if __riscv_float_abi_double +#define ABI_FLEN 64 +#define ABI_FLOAT double +#elif __riscv_float_abi_single +#define ABI_FLEN 32 +#define ABI_FLOAT float +#endif + +#define NARGREG 8 +#define STKALIGN 16 +#define MAXCOPYARG (2 * sizeof(double)) + +typedef struct call_context +{ +#if ABI_FLEN + ABI_FLOAT fa[8]; +#endif + size_t a[8]; + /* used by the assembly code to in-place construct its own stack frame */ + char frame[16]; +} call_context; + +typedef struct call_builder +{ + call_context *aregs; + int used_integer; + int used_float; + size_t *used_stack; +} call_builder; + +/* integer (not pointer) less than ABI XLEN */ +/* FFI_TYPE_INT does not appear to be used */ +#if __SIZEOF_POINTER__ == 8 +#define IS_INT(type) ((type) >= FFI_TYPE_UINT8 && (type) <= FFI_TYPE_SINT64) +#else +#define IS_INT(type) ((type) >= FFI_TYPE_UINT8 && (type) <= FFI_TYPE_SINT32) +#endif + +#if ABI_FLEN +typedef struct { + char as_elements, type1, offset2, type2; +} float_struct_info; + +#if ABI_FLEN >= 64 +#define IS_FLOAT(type) ((type) >= FFI_TYPE_FLOAT && (type) <= FFI_TYPE_DOUBLE) +#else +#define IS_FLOAT(type) ((type) == FFI_TYPE_FLOAT) +#endif + +static ffi_type **flatten_struct(ffi_type *in, ffi_type **out, ffi_type **out_end) { + int i; + if (out == out_end) return out; + if (in->type != FFI_TYPE_STRUCT) { + *(out++) = in; + } else { + for (i = 0; in->elements[i]; i++) + out = flatten_struct(in->elements[i], out, out_end); + } + return out; +} + +/* Structs with at most two fields after flattening, one of which is of + floating point type, are passed in multiple registers if sufficient + registers are available. */ +static float_struct_info struct_passed_as_elements(call_builder *cb, ffi_type *top) { + float_struct_info ret = {0, 0, 0, 0}; + ffi_type *fields[3]; + int num_floats, num_ints; + int num_fields = flatten_struct(top, fields, fields + 3) - fields; + + if (num_fields == 1) { + if (IS_FLOAT(fields[0]->type)) { + ret.as_elements = 1; + ret.type1 = fields[0]->type; + } + } else if (num_fields == 2) { + num_floats = IS_FLOAT(fields[0]->type) + IS_FLOAT(fields[1]->type); + num_ints = IS_INT(fields[0]->type) + IS_INT(fields[1]->type); + if (num_floats == 0 || num_floats + num_ints != 2) + return ret; + if (cb->used_float + num_floats > NARGREG || cb->used_integer + (2 - num_floats) > NARGREG) + return ret; + if (!IS_FLOAT(fields[0]->type) && !IS_FLOAT(fields[1]->type)) + return ret; + + ret.type1 = fields[0]->type; + ret.type2 = fields[1]->type; + ret.offset2 = ALIGN(fields[0]->size, fields[1]->alignment); + ret.as_elements = 1; + } + + return ret; +} +#endif + +/* allocates a single register, float register, or XLEN-sized stack slot to a datum */ +static void marshal_atom(call_builder *cb, int type, void *data) { + size_t value = 0; + switch (type) { + case FFI_TYPE_UINT8: value = *(uint8_t *)data; break; + case FFI_TYPE_SINT8: value = *(int8_t *)data; break; + case FFI_TYPE_UINT16: value = *(uint16_t *)data; break; + case FFI_TYPE_SINT16: value = *(int16_t *)data; break; + /* 32-bit quantities are always sign-extended in the ABI */ + case FFI_TYPE_UINT32: value = *(int32_t *)data; break; + case FFI_TYPE_SINT32: value = *(int32_t *)data; break; +#if __SIZEOF_POINTER__ == 8 + case FFI_TYPE_UINT64: value = *(uint64_t *)data; break; + case FFI_TYPE_SINT64: value = *(int64_t *)data; break; +#endif + case FFI_TYPE_POINTER: value = *(size_t *)data; break; + + /* float values may be recoded in an implementation-defined way + by hardware conforming to 2.1 or earlier, so use asm to + reinterpret floats as doubles */ +#if ABI_FLEN >= 32 + case FFI_TYPE_FLOAT: + asm("" : "=f"(cb->aregs->fa[cb->used_float++]) : "0"(*(float *)data)); + return; +#endif +#if ABI_FLEN >= 64 + case FFI_TYPE_DOUBLE: + asm("" : "=f"(cb->aregs->fa[cb->used_float++]) : "0"(*(double *)data)); + return; +#endif + default: FFI_ASSERT(0); break; + } + + if (cb->used_integer == NARGREG) { + *cb->used_stack++ = value; + } else { + cb->aregs->a[cb->used_integer++] = value; + } +} + +static void unmarshal_atom(call_builder *cb, int type, void *data) { + size_t value; + switch (type) { +#if ABI_FLEN >= 32 + case FFI_TYPE_FLOAT: + asm("" : "=f"(*(float *)data) : "0"(cb->aregs->fa[cb->used_float++])); + return; +#endif +#if ABI_FLEN >= 64 + case FFI_TYPE_DOUBLE: + asm("" : "=f"(*(double *)data) : "0"(cb->aregs->fa[cb->used_float++])); + return; +#endif + } + + if (cb->used_integer == NARGREG) { + value = *cb->used_stack++; + } else { + value = cb->aregs->a[cb->used_integer++]; + } + + switch (type) { + case FFI_TYPE_UINT8: *(uint8_t *)data = value; break; + case FFI_TYPE_SINT8: *(uint8_t *)data = value; break; + case FFI_TYPE_UINT16: *(uint16_t *)data = value; break; + case FFI_TYPE_SINT16: *(uint16_t *)data = value; break; + case FFI_TYPE_UINT32: *(uint32_t *)data = value; break; + case FFI_TYPE_SINT32: *(uint32_t *)data = value; break; +#if __SIZEOF_POINTER__ == 8 + case FFI_TYPE_UINT64: *(uint64_t *)data = value; break; + case FFI_TYPE_SINT64: *(uint64_t *)data = value; break; +#endif + case FFI_TYPE_POINTER: *(size_t *)data = value; break; + default: FFI_ASSERT(0); break; + } +} + +/* adds an argument to a call, or a not by reference return value */ +static void marshal(call_builder *cb, ffi_type *type, int var, void *data) { + size_t realign[2]; + +#if ABI_FLEN + if (!var && type->type == FFI_TYPE_STRUCT) { + float_struct_info fsi = struct_passed_as_elements(cb, type); + if (fsi.as_elements) { + marshal_atom(cb, fsi.type1, data); + if (fsi.offset2) + marshal_atom(cb, fsi.type2, ((char*)data) + fsi.offset2); + return; + } + } + + if (!var && cb->used_float < NARGREG && IS_FLOAT(type->type)) { + marshal_atom(cb, type->type, data); + return; + } +#endif + + if (type->size > 2 * __SIZEOF_POINTER__) { + /* pass by reference */ + marshal_atom(cb, FFI_TYPE_POINTER, &data); + } else if (IS_INT(type->type) || type->type == FFI_TYPE_POINTER) { + marshal_atom(cb, type->type, data); + } else { + /* overlong integers, soft-float floats, and structs without special + float handling are treated identically from this point on */ + + /* variadics are aligned even in registers */ + if (type->alignment > __SIZEOF_POINTER__) { + if (var) + cb->used_integer = ALIGN(cb->used_integer, 2); + cb->used_stack = (size_t *)ALIGN(cb->used_stack, 2*__SIZEOF_POINTER__); + } + + memcpy(realign, data, type->size); + if (type->size > 0) + marshal_atom(cb, FFI_TYPE_POINTER, realign); + if (type->size > __SIZEOF_POINTER__) + marshal_atom(cb, FFI_TYPE_POINTER, realign + 1); + } +} + +/* for arguments passed by reference returns the pointer, otherwise the arg is copied (up to MAXCOPYARG bytes) */ +static void *unmarshal(call_builder *cb, ffi_type *type, int var, void *data) { + size_t realign[2]; + void *pointer; + +#if ABI_FLEN + if (!var && type->type == FFI_TYPE_STRUCT) { + float_struct_info fsi = struct_passed_as_elements(cb, type); + if (fsi.as_elements) { + unmarshal_atom(cb, fsi.type1, data); + if (fsi.offset2) + unmarshal_atom(cb, fsi.type2, ((char*)data) + fsi.offset2); + return data; + } + } + + if (!var && cb->used_float < NARGREG && IS_FLOAT(type->type)) { + unmarshal_atom(cb, type->type, data); + return data; + } +#endif + + if (type->size > 2 * __SIZEOF_POINTER__) { + /* pass by reference */ + unmarshal_atom(cb, FFI_TYPE_POINTER, (char*)&pointer); + return pointer; + } else if (IS_INT(type->type) || type->type == FFI_TYPE_POINTER) { + unmarshal_atom(cb, type->type, data); + return data; + } else { + /* overlong integers, soft-float floats, and structs without special + float handling are treated identically from this point on */ + + /* variadics are aligned even in registers */ + if (type->alignment > __SIZEOF_POINTER__) { + if (var) + cb->used_integer = ALIGN(cb->used_integer, 2); + cb->used_stack = (size_t *)ALIGN(cb->used_stack, 2*__SIZEOF_POINTER__); + } + + if (type->size > 0) + unmarshal_atom(cb, FFI_TYPE_POINTER, realign); + if (type->size > __SIZEOF_POINTER__) + unmarshal_atom(cb, FFI_TYPE_POINTER, realign + 1); + memcpy(data, realign, type->size); + return data; + } +} + +static int passed_by_ref(call_builder *cb, ffi_type *type, int var) { +#if ABI_FLEN + if (!var && type->type == FFI_TYPE_STRUCT) { + float_struct_info fsi = struct_passed_as_elements(cb, type); + if (fsi.as_elements) return 0; + } +#endif + + return type->size > 2 * __SIZEOF_POINTER__; +} + +/* Perform machine dependent cif processing */ +ffi_status ffi_prep_cif_machdep(ffi_cif *cif) { + cif->riscv_nfixedargs = cif->nargs; + return FFI_OK; +} + +/* Perform machine dependent cif processing when we have a variadic function */ + +ffi_status ffi_prep_cif_machdep_var(ffi_cif *cif, unsigned int nfixedargs, unsigned int ntotalargs) { + cif->riscv_nfixedargs = nfixedargs; + return FFI_OK; +} + +/* Low level routine for calling functions */ +extern void ffi_call_asm(void *stack, struct call_context *regs, void (*fn)(void)) FFI_HIDDEN; + +void ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue) +{ + /* this is a conservative estimate, assuming a complex return value and + that all remaining arguments are long long / __int128 */ + size_t arg_bytes = cif->nargs <= 3 ? 0 : + ALIGN(2 * sizeof(size_t) * (cif->nargs - 3), STKALIGN); + size_t rval_bytes = 0; + if (rvalue == NULL && cif->rtype->size > 2*__SIZEOF_POINTER__) + rval_bytes = ALIGN(cif->rtype->size, STKALIGN); + size_t alloc_size = arg_bytes + rval_bytes + sizeof(call_context); + + /* the assembly code will deallocate all stack data at lower addresses + than the argument region, so we need to allocate the frame and the + return value after the arguments in a single allocation */ + size_t alloc_base; + /* Argument region must be 16-byte aligned */ + if (_Alignof(max_align_t) >= STKALIGN) { + /* since sizeof long double is normally 16, the compiler will + guarantee alloca alignment to at least that much */ + alloc_base = (size_t)alloca(alloc_size); + } else { + alloc_base = ALIGN(alloca(alloc_size + STKALIGN - 1), STKALIGN); + } + + if (rval_bytes) + rvalue = (void*)(alloc_base + arg_bytes); + + call_builder cb; + cb.used_float = cb.used_integer = 0; + cb.aregs = (call_context*)(alloc_base + arg_bytes + rval_bytes); + cb.used_stack = (void*)alloc_base; + + int return_by_ref = passed_by_ref(&cb, cif->rtype, 0); + if (return_by_ref) + marshal(&cb, &ffi_type_pointer, 0, &rvalue); + + int i; + for (i = 0; i < cif->nargs; i++) + marshal(&cb, cif->arg_types[i], i >= cif->riscv_nfixedargs, avalue[i]); + + ffi_call_asm((void*)alloc_base, cb.aregs, fn); + + cb.used_float = cb.used_integer = 0; + if (!return_by_ref && rvalue) + unmarshal(&cb, cif->rtype, 0, rvalue); +} + +extern void ffi_closure_asm(void) FFI_HIDDEN; + +ffi_status ffi_prep_closure_loc(ffi_closure *closure, ffi_cif *cif, void (*fun)(ffi_cif*,void*,void**,void*), void *user_data, void *codeloc) +{ + uint32_t *tramp = (uint32_t *) &closure->tramp[0]; + uint64_t fn = (uint64_t) (uintptr_t) ffi_closure_asm; + + if (cif->abi <= FFI_FIRST_ABI || cif->abi >= FFI_LAST_ABI) + return FFI_BAD_ABI; + + /* we will call ffi_closure_inner with codeloc, not closure, but as long + as the memory is readable it should work */ + + tramp[0] = 0x00000317; /* auipc t1, 0 (i.e. t0 <- codeloc) */ +#if __SIZEOF_POINTER__ == 8 + tramp[1] = 0x01033383; /* ld t2, 16(t1) */ +#else + tramp[1] = 0x01032383; /* lw t2, 16(t1) */ +#endif + tramp[2] = 0x00038067; /* jr t2 */ + tramp[3] = 0x00000013; /* nop */ + tramp[4] = fn; + tramp[5] = fn >> 32; + + closure->cif = cif; + closure->fun = fun; + closure->user_data = user_data; + + __builtin___clear_cache(codeloc, codeloc + FFI_TRAMPOLINE_SIZE); + + return FFI_OK; +} + +/* Called by the assembly code with aregs pointing to saved argument registers + and stack pointing to the stacked arguments. Return values passed in + registers will be reloaded from aregs. */ +void FFI_HIDDEN ffi_closure_inner(size_t *stack, call_context *aregs, ffi_closure *closure) { + ffi_cif *cif = closure->cif; + void **avalue = alloca(cif->nargs * sizeof(void*)); + /* storage for arguments which will be copied by unmarshal(). We could + theoretically avoid the copies in many cases and use at most 128 bytes + of memory, but allocating disjoint storage for each argument is + simpler. */ + char *astorage = alloca(cif->nargs * MAXCOPYARG); + void *rvalue; + call_builder cb; + int return_by_ref; + int i; + + cb.aregs = aregs; + cb.used_integer = cb.used_float = 0; + cb.used_stack = stack; + + return_by_ref = passed_by_ref(&cb, cif->rtype, 0); + if (return_by_ref) + unmarshal(&cb, &ffi_type_pointer, 0, &rvalue); + else + rvalue = alloca(cif->rtype->size); + + for (i = 0; i < cif->nargs; i++) + avalue[i] = unmarshal(&cb, cif->arg_types[i], + i >= cif->riscv_nfixedargs, astorage + i*MAXCOPYARG); + + (closure->fun)(cif, rvalue, avalue, closure->user_data); + + if (!return_by_ref && cif->rtype->type != FFI_TYPE_VOID) { + cb.used_integer = cb.used_float = 0; + marshal(&cb, cif->rtype, 0, rvalue); + } +} diff --git a/src/riscv/ffitarget.h b/src/riscv/ffitarget.h new file mode 100644 index 0000000..fcaa899 --- /dev/null +++ b/src/riscv/ffitarget.h @@ -0,0 +1,68 @@ +/* -----------------------------------------------------------------*-C-*- + ffitarget.h - 2014 Michael Knyszek + + Target configuration macros for RISC-V. + + 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. + + ----------------------------------------------------------------------- */ + +#ifndef LIBFFI_TARGET_H +#define LIBFFI_TARGET_H + +#ifndef LIBFFI_H +#error "Please do not include ffitarget.h directly into your source. Use ffi.h instead." +#endif + +#ifndef __riscv +#error "libffi was configured for a RISC-V target but this does not appear to be a RISC-V compiler." +#endif + +#ifndef LIBFFI_ASM + +typedef unsigned long ffi_arg; +typedef signed long ffi_sarg; + +/* FFI_UNUSED_NN and riscv_unused are to maintain ABI compatibility with a + distributed Berkeley patch from 2014, and can be removed at SONAME bump */ +typedef enum ffi_abi { + FFI_FIRST_ABI = 0, + FFI_SYSV, + FFI_UNUSED_1, + FFI_UNUSED_2, + FFI_UNUSED_3, + FFI_LAST_ABI, + + FFI_DEFAULT_ABI = FFI_SYSV +} ffi_abi; + +#endif /* LIBFFI_ASM */ + +/* ---- Definitions for closures ----------------------------------------- */ + +#define FFI_CLOSURES 1 +#define FFI_TRAMPOLINE_SIZE 24 +#define FFI_NATIVE_RAW_API 0 +#define FFI_EXTRA_CIF_FIELDS unsigned riscv_nfixedargs; unsigned riscv_unused; +#define FFI_TARGET_SPECIFIC_VARIADIC + +#endif + diff --git a/src/riscv/sysv.S b/src/riscv/sysv.S new file mode 100644 index 0000000..2d09865 --- /dev/null +++ b/src/riscv/sysv.S @@ -0,0 +1,214 @@ +/* ----------------------------------------------------------------------- + ffi.c - Copyright (c) 2015 Michael Knyszek + 2015 Andrew Waterman + 2018 Stef O'Rear + + 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 +#include + +/* 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)); +*/ + +#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 + +#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(size_t *stackargs, struct call_context *regargs, + ffi_closure *closure); +*/ + + .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 */ + addi a0, sp, FRAME_LEN + mv a1, sp + mv a2, t1 + + 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