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
23 MARL_EXPORT
marl_fiber_trampoline(void (* target)(void *),void * arg)24 void marl_fiber_trampoline(void (*target)(void*), void* arg) {
25 target(arg);
26 }
27
28 MARL_EXPORT
marl_fiber_set_target(struct marl_fiber_context * ctx,void * stack,uint32_t stack_size,void (* target)(void *),void * arg)29 void 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