1// Copyright 2019 The Marl Authors.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// https://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15#if defined(__x86_64__)
16
17#include "osfiber_asm_x64.h"
18
19#include "marl/export.h"
20
21//You can find an explanation of this code here: https://github.com/google/marl/issues/199
22
23MARL_EXPORT
24void marl_fiber_trampoline(void (*target)(void*), void* arg) {
25 target(arg);
26}
27
28MARL_EXPORT
29void marl_fiber_set_target(struct marl_fiber_context* ctx,
30 void* stack,
31 uint32_t stack_size,
32 void (*target)(void*),
33 void* arg) {
34 uintptr_t* stack_top = (uintptr_t*)((uint8_t*)(stack) + stack_size);
35 ctx->RIP = (uintptr_t)&marl_fiber_trampoline;
36 ctx->RDI = (uintptr_t)target;
37 ctx->RSI = (uintptr_t)arg;
38 ctx->RSP = (uintptr_t)&stack_top[-3];
39 stack_top[-2] = 0; // No return target.
40}
41
42#endif // defined(__x86_64__)
43