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(__powerpc64__)
16
17#include "osfiber_asm_ppc64.h"
18
19#include "marl/export.h"
20
21MARL_EXPORT
22void marl_fiber_trampoline(void (*target)(void*), void* arg) {
23 target(arg);
24}
25
26MARL_EXPORT
27void marl_fiber_set_target(struct marl_fiber_context* ctx,
28 void* stack,
29 uint32_t stack_size,
30 void (*target)(void*),
31 void* arg) {
32 uintptr_t stack_top = (uintptr_t)((uint8_t*)(stack) + stack_size - sizeof(uintptr_t));
33 if ((stack_top % 16) != 0) {
34 stack_top -= (stack_top % 16);
35 }
36
37 // Write a backchain and subtract a minimum stack frame size (32/48)
38 *(uintptr_t*)stack_top = 0;
39#if !defined(_CALL_ELF) || (_CALL_ELF != 2)
40 stack_top -= 48;
41 *(uintptr_t*)stack_top = stack_top + 48;
42#else
43 stack_top -= 32;
44 *(uintptr_t*)stack_top = stack_top + 32;
45#endif
46
47 // Load registers
48 ctx->r1 = stack_top;
49#if !defined(_CALL_ELF) || (_CALL_ELF != 2)
50 ctx->lr = ((const uintptr_t *)marl_fiber_trampoline)[0];
51 ctx->r2 = ((const uintptr_t *)marl_fiber_trampoline)[1];
52#else
53 ctx->lr = (uintptr_t)marl_fiber_trampoline;
54#endif
55 ctx->r3 = (uintptr_t)target;
56 ctx->r4 = (uintptr_t)arg;
57
58 // Thread pointer must be saved in r13
59 __asm__ volatile("mr %0, 13\n" : "=r"(ctx->r13));
60}
61
62#endif // __powerpc64__
63