bsnes/libco/aarch64.c

117 lines
3.4 KiB
C

#define LIBCO_C
#include "libco.h"
#include "settings.h"
#include <assert.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <sys/mman.h>
#ifdef __cplusplus
extern "C" {
#endif
static thread_local unsigned long co_active_buffer[64];
static thread_local cothread_t co_active_handle = 0;
static void (*co_swap)(cothread_t, cothread_t) = 0;
#ifdef LIBCO_MPROTECT
alignas(4096)
#else
section(text)
#endif
static const uint32_t co_swap_function[1024] = {
0xa9002428, /* stp x8,x9,[x1] */
0xa9012c2a, /* stp x10,x11,[x1,#16] */
0xa902342c, /* stp x12,x13,[x1,#32] */
0xa9033c2e, /* stp x14,x15,[x1,#48] */
0xf9002433, /* str x19,[x1,#72] */
0xa9055434, /* stp x20,x21,[x1,#80] */
0xa9065c36, /* stp x22,x23,[x1,#96] */
0xa9076438, /* stp x24,x25,[x1,#112] */
0xa9086c3a, /* stp x26,x27,[x1,#128] */
0xa909743c, /* stp x28,x29,[x1,#144] */
0x910003f0, /* mov x16,sp */
0xa90a7830, /* stp x16,x30,[x1,#160] */
0xa9402408, /* ldp x8,x9,[x0] */
0xa9412c0a, /* ldp x10,x11,[x0,#16] */
0xa942340c, /* ldp x12,x13,[x0,#32] */
0xa9433c0e, /* ldp x14,x15,[x0,#48] */
0xf9402413, /* ldr x19,[x0,#72] */
0xa9455414, /* ldp x20,x21,[x0,#80] */
0xa9465c16, /* ldp x22,x23,[x0,#96] */
0xa9476418, /* ldp x24,x25,[x0,#112] */
0xa9486c1a, /* ldp x26,x27,[x0,#128] */
0xa949741c, /* ldp x28,x29,[x0,#144] */
0xa94a4410, /* ldp x16,x17,[x0,#160] */
0x9100021f, /* mov sp,x16 */
0xd61f0220, /* br x17 */
};
static void co_init() {
#ifdef LIBCO_MPROTECT
unsigned long addr = (unsigned long)co_swap_function;
unsigned long base = addr - (addr % sysconf(_SC_PAGESIZE));
unsigned long size = (addr - base) + sizeof co_swap_function;
mprotect((void*)base, size, PROT_READ | PROT_EXEC);
#endif
}
cothread_t co_active() {
if(!co_active_handle) co_active_handle = &co_active_buffer;
return co_active_handle;
}
cothread_t co_derive(void* memory, unsigned int size, void (*entrypoint)(void)) {
unsigned long* handle;
if(!co_swap) {
co_init();
co_swap = (void (*)(cothread_t, cothread_t))co_swap_function;
}
if(!co_active_handle) co_active_handle = &co_active_buffer;
if(handle = (unsigned long*)memory) {
unsigned long* p = (unsigned long*)((unsigned char*)handle + size);
handle[19] = (unsigned long)p; /* x29 (frame pointer) */
handle[20] = (unsigned long)p; /* x30 (stack pointer) */
handle[21] = (unsigned long)entrypoint; /* x31 (link register) */
}
return handle;
}
cothread_t co_create(unsigned int size, void (*entrypoint)(void)) {
unsigned long* handle;
if(!co_swap) {
co_init();
co_swap = (void (*)(cothread_t, cothread_t))co_swap_function;
}
if(!co_active_handle) co_active_handle = &co_active_buffer;
size += 256;
size &= ~15;
if(handle = (unsigned long*)malloc(size)) {
unsigned long* p = (unsigned long*)((unsigned char*)handle + size);
handle[19] = (unsigned long)p; /* x29 (frame pointer) */
handle[20] = (unsigned long)p; /* x30 (stack pointer) */
handle[21] = (unsigned long)entrypoint; /* x31 (link register) */
}
return handle;
}
void co_delete(cothread_t handle) {
free(handle);
}
void co_switch(cothread_t handle) {
cothread_t co_previous_handle = co_active_handle;
co_swap(co_active_handle = handle, co_previous_handle);
}
#ifdef __cplusplus
}
#endif