1 /* 2 * Generic FIFO component, implemented as a circular buffer. 3 * 4 * Copyright (c) 2012 Peter A. G. Crosthwaite 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * You should have received a copy of the GNU General Public License along 12 * with this program; if not, see <http://www.gnu.org/licenses/>. 13 */ 14 15 #include "qemu-common.h" 16 #include "qemu/fifo8.h" 17 18 void fifo8_create(Fifo8 *fifo, uint32_t capacity) 19 { 20 fifo->data = g_new(uint8_t, capacity); 21 fifo->capacity = capacity; 22 fifo->head = 0; 23 fifo->num = 0; 24 } 25 26 void fifo8_destroy(Fifo8 *fifo) 27 { 28 g_free(fifo->data); 29 } 30 31 void fifo8_push(Fifo8 *fifo, uint8_t data) 32 { 33 if (fifo->num == fifo->capacity) { 34 abort(); 35 } 36 fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data; 37 fifo->num++; 38 } 39 40 uint8_t fifo8_pop(Fifo8 *fifo) 41 { 42 uint8_t ret; 43 44 if (fifo->num == 0) { 45 abort(); 46 } 47 ret = fifo->data[fifo->head++]; 48 fifo->head %= fifo->capacity; 49 fifo->num--; 50 return ret; 51 } 52 53 void fifo8_reset(Fifo8 *fifo) 54 { 55 fifo->num = 0; 56 } 57 58 bool fifo8_is_empty(Fifo8 *fifo) 59 { 60 return (fifo->num == 0); 61 } 62 63 bool fifo8_is_full(Fifo8 *fifo) 64 { 65 return (fifo->num == fifo->capacity); 66 } 67 68 const VMStateDescription vmstate_fifo8 = { 69 .name = "Fifo8", 70 .version_id = 1, 71 .minimum_version_id = 1, 72 .minimum_version_id_old = 1, 73 .fields = (VMStateField[]) { 74 VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity), 75 VMSTATE_UINT32(head, Fifo8), 76 VMSTATE_UINT32(num, Fifo8), 77 VMSTATE_END_OF_LIST() 78 } 79 }; 80