gpsp/libco/aarch64.c

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2018-01-10 03:14:18 +01:00
/*
libco.aarch64 (2017-06-26)
author: webgeek1234
license: public domain
*/
#define LIBCO_C
#include "libco.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#ifndef IOS
#include <malloc.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif
static thread_local uint64_t co_active_buffer[64];
static thread_local cothread_t co_active_handle;
asm (
".globl co_switch_aarch64\n"
".globl _co_switch_aarch64\n"
"co_switch_aarch64:\n"
"_co_switch_aarch64:\n"
" stp x8, x9, [x1]\n"
" stp x10, x11, [x1, #16]\n"
" stp x12, x13, [x1, #32]\n"
" stp x14, x15, [x1, #48]\n"
" str x19, [x1, #72]\n"
" stp x20, x21, [x1, #80]\n"
" stp x22, x23, [x1, #96]\n"
" stp x24, x25, [x1, #112]\n"
" stp x26, x27, [x1, #128]\n"
" stp x28, x29, [x1, #144]\n"
" mov x16, sp\n"
" stp x16, x30, [x1, #160]\n"
" ldp x8, x9, [x0]\n"
" ldp x10, x11, [x0, #16]\n"
" ldp x12, x13, [x0, #32]\n"
" ldp x14, x15, [x0, #48]\n"
" ldr x19, [x0, #72]\n"
" ldp x20, x21, [x0, #80]\n"
" ldp x22, x23, [x0, #96]\n"
" ldp x24, x25, [x0, #112]\n"
" ldp x26, x27, [x0, #128]\n"
" ldp x28, x29, [x0, #144]\n"
" ldp x16, x17, [x0, #160]\n"
" mov sp, x16\n"
" br x17\n"
);
/* ASM */
void co_switch_aarch64(cothread_t handle, cothread_t current);
cothread_t co_create(unsigned int size, void (*entrypoint)(void))
{
size = (size + 1023) & ~1023;
cothread_t handle = 0;
#if HAVE_POSIX_MEMALIGN >= 1
if (posix_memalign(&handle, 1024, size + 512) < 0)
return 0;
#else
handle = memalign(1024, size + 512);
#endif
if (!handle)
return handle;
uint64_t *ptr = (uint64_t*)handle;
/* Non-volatiles. */
ptr[0] = 0; /* x8 */
ptr[1] = 0; /* x9 */
ptr[2] = 0; /* x10 */
ptr[3] = 0; /* x11 */
ptr[4] = 0; /* x12 */
ptr[5] = 0; /* x13 */
ptr[6] = 0; /* x14 */
ptr[7] = 0; /* x15 */
ptr[8] = 0; /* padding */
ptr[9] = 0; /* x19 */
ptr[10] = 0; /* x20 */
ptr[11] = 0; /* x21 */
ptr[12] = 0; /* x22 */
ptr[13] = 0; /* x23 */
ptr[14] = 0; /* x24 */
ptr[15] = 0; /* x25 */
ptr[16] = 0; /* x26 */
ptr[17] = 0; /* x27 */
ptr[18] = 0; /* x28 */
ptr[20] = (uintptr_t)ptr + size + 512 - 16; /* x30, stack pointer */
ptr[19] = ptr[20]; /* x29, frame pointer */
ptr[21] = (uintptr_t)entrypoint; /* PC (link register x31 gets saved here). */
return handle;
}
cothread_t co_active(void)
{
if (!co_active_handle)
co_active_handle = co_active_buffer;
return co_active_handle;
}
void co_delete(cothread_t handle)
{
free(handle);
}
void co_switch(cothread_t handle)
{
cothread_t co_previous_handle = co_active();
co_switch_aarch64(co_active_handle = handle, co_previous_handle);
}
#ifdef __cplusplus
}
#endif