update vibration handling
[pcsx_rearmed.git] / deps / libretro-common / libco / x86.c
CommitLineData
3719602c
PC
1/*
2 libco.x86 (2009-10-12)
3 author: byuu
4 license: public domain
5*/
6
7#define LIBCO_C
8#include <libco.h>
9#include <assert.h>
10#include <stdlib.h>
11
12#ifdef __cplusplus
13extern "C" {
14#endif
15
16#if defined(_MSC_VER)
17 #define fastcall __fastcall
18#elif defined(__GNUC__)
19 #define fastcall __attribute__((fastcall))
20#else
21 #error "libco: please define fastcall macro"
22#endif
23
24static thread_local long co_active_buffer[64];
25static thread_local cothread_t co_active_handle = 0;
26static void (fastcall *co_swap)(cothread_t, cothread_t) = 0;
27
28//ABI: fastcall
29static unsigned char co_swap_function[] = {
30 0x89, 0x22, /* mov [edx],esp */
31 0x8b, 0x21, /* mov esp,[ecx] */
32 0x58, /* pop eax */
33 0x89, 0x6a, 0x04, /* mov [edx+0x04],ebp */
34 0x89, 0x72, 0x08, /* mov [edx+0x08],esi */
35 0x89, 0x7a, 0x0c, /* mov [edx+0x0c],edi */
36 0x89, 0x5a, 0x10, /* mov [edx+0x10],ebx */
37 0x8b, 0x69, 0x04, /* mov ebp,[ecx+0x04] */
38 0x8b, 0x71, 0x08, /* mov esi,[ecx+0x08] */
39 0x8b, 0x79, 0x0c, /* mov edi,[ecx+0x0c] */
40 0x8b, 0x59, 0x10, /* mov ebx,[ecx+0x10] */
41 0xff, 0xe0, /* jmp eax */
42};
43
44#ifdef _WIN32
45#include <windows.h>
46
47static void co_init(void)
48{
49 DWORD old_privileges;
50 VirtualProtect(co_swap_function,
51 sizeof co_swap_function, PAGE_EXECUTE_READWRITE, &old_privileges);
52}
53#else
54#include <unistd.h>
55#include <sys/mman.h>
56
57static void co_init(void)
58{
59 unsigned long addr = (unsigned long)co_swap_function;
60 unsigned long base = addr - (addr % sysconf(_SC_PAGESIZE));
61 unsigned long size = (addr - base) + sizeof co_swap_function;
62 mprotect((void*)base, size, PROT_READ | PROT_WRITE | PROT_EXEC);
63}
64#endif
65
66static void crash(void)
67{
68 assert(0); /* called only if cothread_t entrypoint returns */
69}
70
71cothread_t co_active(void)
72{
73 if (!co_active_handle)
74 co_active_handle = &co_active_buffer;
75 return co_active_handle;
76}
77
78cothread_t co_create(unsigned int size, void (*entrypoint)(void))
79{
80 cothread_t handle;
81 if (!co_swap)
82 {
83 co_init();
84 co_swap = (void (fastcall*)(cothread_t, cothread_t))co_swap_function;
85 }
86
87 if (!co_active_handle)
88 co_active_handle = &co_active_buffer;
89
90 size += 256; /* allocate additional space for storage */
91 size &= ~15; /* align stack to 16-byte boundary */
92
93 if ((handle = (cothread_t)malloc(size)))
94 {
95 long *p = (long*)((char*)handle + size); /* seek to top of stack */
96 *--p = (long)crash; /* crash if entrypoint returns */
97 *--p = (long)entrypoint; /* start of function */
98 *(long*)handle = (long)p; /* stack pointer */
99 }
100
101 return handle;
102}
103
104void co_delete(cothread_t handle)
105{
106 free(handle);
107}
108
109void co_switch(cothread_t handle)
110{
111 register cothread_t co_previous_handle = co_active_handle;
112 co_swap(co_active_handle = handle, co_previous_handle);
113}
114
115#ifdef __cplusplus
116}
117#endif