1fd7f0d66SPaolo Bonzini /* 2fd7f0d66SPaolo Bonzini * Generic FIFO component, implemented as a circular buffer. 3fd7f0d66SPaolo Bonzini * 4fd7f0d66SPaolo Bonzini * Copyright (c) 2012 Peter A. G. Crosthwaite 5fd7f0d66SPaolo Bonzini * 6fd7f0d66SPaolo Bonzini * This program is free software; you can redistribute it and/or 7fd7f0d66SPaolo Bonzini * modify it under the terms of the GNU General Public License 8fd7f0d66SPaolo Bonzini * as published by the Free Software Foundation; either version 9fd7f0d66SPaolo Bonzini * 2 of the License, or (at your option) any later version. 10fd7f0d66SPaolo Bonzini * 11fd7f0d66SPaolo Bonzini * You should have received a copy of the GNU General Public License along 12fd7f0d66SPaolo Bonzini * with this program; if not, see <http://www.gnu.org/licenses/>. 13fd7f0d66SPaolo Bonzini */ 14fd7f0d66SPaolo Bonzini 15fd7f0d66SPaolo Bonzini #include "qemu-common.h" 16fd7f0d66SPaolo Bonzini #include "qemu/fifo8.h" 17fd7f0d66SPaolo Bonzini 18fd7f0d66SPaolo Bonzini void fifo8_create(Fifo8 *fifo, uint32_t capacity) 19fd7f0d66SPaolo Bonzini { 20fd7f0d66SPaolo Bonzini fifo->data = g_new(uint8_t, capacity); 21fd7f0d66SPaolo Bonzini fifo->capacity = capacity; 22fd7f0d66SPaolo Bonzini fifo->head = 0; 23fd7f0d66SPaolo Bonzini fifo->num = 0; 24fd7f0d66SPaolo Bonzini } 25fd7f0d66SPaolo Bonzini 26fd7f0d66SPaolo Bonzini void fifo8_destroy(Fifo8 *fifo) 27fd7f0d66SPaolo Bonzini { 28fd7f0d66SPaolo Bonzini g_free(fifo->data); 29fd7f0d66SPaolo Bonzini } 30fd7f0d66SPaolo Bonzini 31fd7f0d66SPaolo Bonzini void fifo8_push(Fifo8 *fifo, uint8_t data) 32fd7f0d66SPaolo Bonzini { 33fd7f0d66SPaolo Bonzini if (fifo->num == fifo->capacity) { 34fd7f0d66SPaolo Bonzini abort(); 35fd7f0d66SPaolo Bonzini } 36fd7f0d66SPaolo Bonzini fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data; 37fd7f0d66SPaolo Bonzini fifo->num++; 38fd7f0d66SPaolo Bonzini } 39fd7f0d66SPaolo Bonzini 40c4e57af8SBeniamino Galvani void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num) 41c4e57af8SBeniamino Galvani { 42c4e57af8SBeniamino Galvani uint32_t start, avail; 43c4e57af8SBeniamino Galvani 44c4e57af8SBeniamino Galvani if (fifo->num + num > fifo->capacity) { 45c4e57af8SBeniamino Galvani abort(); 46c4e57af8SBeniamino Galvani } 47c4e57af8SBeniamino Galvani 48c4e57af8SBeniamino Galvani start = (fifo->head + fifo->num) % fifo->capacity; 49c4e57af8SBeniamino Galvani 50c4e57af8SBeniamino Galvani if (start + num <= fifo->capacity) { 51c4e57af8SBeniamino Galvani memcpy(&fifo->data[start], data, num); 52c4e57af8SBeniamino Galvani } else { 53c4e57af8SBeniamino Galvani avail = fifo->capacity - start; 54c4e57af8SBeniamino Galvani memcpy(&fifo->data[start], data, avail); 55c4e57af8SBeniamino Galvani memcpy(&fifo->data[0], &data[avail], num - avail); 56c4e57af8SBeniamino Galvani } 57c4e57af8SBeniamino Galvani 58c4e57af8SBeniamino Galvani fifo->num += num; 59c4e57af8SBeniamino Galvani } 60c4e57af8SBeniamino Galvani 61fd7f0d66SPaolo Bonzini uint8_t fifo8_pop(Fifo8 *fifo) 62fd7f0d66SPaolo Bonzini { 63fd7f0d66SPaolo Bonzini uint8_t ret; 64fd7f0d66SPaolo Bonzini 65fd7f0d66SPaolo Bonzini if (fifo->num == 0) { 66fd7f0d66SPaolo Bonzini abort(); 67fd7f0d66SPaolo Bonzini } 68fd7f0d66SPaolo Bonzini ret = fifo->data[fifo->head++]; 69fd7f0d66SPaolo Bonzini fifo->head %= fifo->capacity; 70fd7f0d66SPaolo Bonzini fifo->num--; 71fd7f0d66SPaolo Bonzini return ret; 72fd7f0d66SPaolo Bonzini } 73fd7f0d66SPaolo Bonzini 74c4e57af8SBeniamino Galvani const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num) 75c4e57af8SBeniamino Galvani { 76c4e57af8SBeniamino Galvani uint8_t *ret; 77c4e57af8SBeniamino Galvani 78c4e57af8SBeniamino Galvani if (max == 0 || max > fifo->num) { 79c4e57af8SBeniamino Galvani abort(); 80c4e57af8SBeniamino Galvani } 81c4e57af8SBeniamino Galvani *num = MIN(fifo->capacity - fifo->head, max); 82c4e57af8SBeniamino Galvani ret = &fifo->data[fifo->head]; 83c4e57af8SBeniamino Galvani fifo->head += *num; 84c4e57af8SBeniamino Galvani fifo->head %= fifo->capacity; 85c4e57af8SBeniamino Galvani fifo->num -= *num; 86c4e57af8SBeniamino Galvani return ret; 87c4e57af8SBeniamino Galvani } 88c4e57af8SBeniamino Galvani 89fd7f0d66SPaolo Bonzini void fifo8_reset(Fifo8 *fifo) 90fd7f0d66SPaolo Bonzini { 91fd7f0d66SPaolo Bonzini fifo->num = 0; 92*58892d47SBeniamino Galvani fifo->head = 0; 93fd7f0d66SPaolo Bonzini } 94fd7f0d66SPaolo Bonzini 95fd7f0d66SPaolo Bonzini bool fifo8_is_empty(Fifo8 *fifo) 96fd7f0d66SPaolo Bonzini { 97fd7f0d66SPaolo Bonzini return (fifo->num == 0); 98fd7f0d66SPaolo Bonzini } 99fd7f0d66SPaolo Bonzini 100fd7f0d66SPaolo Bonzini bool fifo8_is_full(Fifo8 *fifo) 101fd7f0d66SPaolo Bonzini { 102fd7f0d66SPaolo Bonzini return (fifo->num == fifo->capacity); 103fd7f0d66SPaolo Bonzini } 104fd7f0d66SPaolo Bonzini 105c4e57af8SBeniamino Galvani uint32_t fifo8_num_free(Fifo8 *fifo) 106c4e57af8SBeniamino Galvani { 107c4e57af8SBeniamino Galvani return fifo->capacity - fifo->num; 108c4e57af8SBeniamino Galvani } 109c4e57af8SBeniamino Galvani 110c4e57af8SBeniamino Galvani uint32_t fifo8_num_used(Fifo8 *fifo) 111c4e57af8SBeniamino Galvani { 112c4e57af8SBeniamino Galvani return fifo->num; 113c4e57af8SBeniamino Galvani } 114c4e57af8SBeniamino Galvani 115fd7f0d66SPaolo Bonzini const VMStateDescription vmstate_fifo8 = { 116fd7f0d66SPaolo Bonzini .name = "Fifo8", 117fd7f0d66SPaolo Bonzini .version_id = 1, 118fd7f0d66SPaolo Bonzini .minimum_version_id = 1, 119fd7f0d66SPaolo Bonzini .minimum_version_id_old = 1, 120fd7f0d66SPaolo Bonzini .fields = (VMStateField[]) { 121fd7f0d66SPaolo Bonzini VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity), 122fd7f0d66SPaolo Bonzini VMSTATE_UINT32(head, Fifo8), 123fd7f0d66SPaolo Bonzini VMSTATE_UINT32(num, Fifo8), 124fd7f0d66SPaolo Bonzini VMSTATE_END_OF_LIST() 125fd7f0d66SPaolo Bonzini } 126fd7f0d66SPaolo Bonzini }; 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