Peter A. G. Crosthwaite | a3578d4 | 2012-08-01 20:26:12 +1000 | [diff] [blame] | 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 | |
Paolo Bonzini | fd7f0d6 | 2013-02-04 10:57:50 +0100 | [diff] [blame] | 15 | #include "qemu-common.h" |
| 16 | #include "qemu/fifo8.h" |
Peter A. G. Crosthwaite | a3578d4 | 2012-08-01 20:26:12 +1000 | [diff] [blame] | 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 | |
Beniamino Galvani | c4e57af | 2014-01-30 23:02:04 +0100 | [diff] [blame] | 40 | void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num) |
| 41 | { |
| 42 | uint32_t start, avail; |
| 43 | |
| 44 | if (fifo->num + num > fifo->capacity) { |
| 45 | abort(); |
| 46 | } |
| 47 | |
| 48 | start = (fifo->head + fifo->num) % fifo->capacity; |
| 49 | |
| 50 | if (start + num <= fifo->capacity) { |
| 51 | memcpy(&fifo->data[start], data, num); |
| 52 | } else { |
| 53 | avail = fifo->capacity - start; |
| 54 | memcpy(&fifo->data[start], data, avail); |
| 55 | memcpy(&fifo->data[0], &data[avail], num - avail); |
| 56 | } |
| 57 | |
| 58 | fifo->num += num; |
| 59 | } |
| 60 | |
Peter A. G. Crosthwaite | a3578d4 | 2012-08-01 20:26:12 +1000 | [diff] [blame] | 61 | uint8_t fifo8_pop(Fifo8 *fifo) |
| 62 | { |
| 63 | uint8_t ret; |
| 64 | |
| 65 | if (fifo->num == 0) { |
| 66 | abort(); |
| 67 | } |
| 68 | ret = fifo->data[fifo->head++]; |
| 69 | fifo->head %= fifo->capacity; |
| 70 | fifo->num--; |
| 71 | return ret; |
| 72 | } |
| 73 | |
Beniamino Galvani | c4e57af | 2014-01-30 23:02:04 +0100 | [diff] [blame] | 74 | const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num) |
| 75 | { |
| 76 | uint8_t *ret; |
| 77 | |
| 78 | if (max == 0 || max > fifo->num) { |
| 79 | abort(); |
| 80 | } |
| 81 | *num = MIN(fifo->capacity - fifo->head, max); |
| 82 | ret = &fifo->data[fifo->head]; |
| 83 | fifo->head += *num; |
| 84 | fifo->head %= fifo->capacity; |
| 85 | fifo->num -= *num; |
| 86 | return ret; |
| 87 | } |
| 88 | |
Peter A. G. Crosthwaite | a3578d4 | 2012-08-01 20:26:12 +1000 | [diff] [blame] | 89 | void fifo8_reset(Fifo8 *fifo) |
| 90 | { |
| 91 | fifo->num = 0; |
Beniamino Galvani | 58892d4 | 2014-01-30 23:02:05 +0100 | [diff] [blame] | 92 | fifo->head = 0; |
Peter A. G. Crosthwaite | a3578d4 | 2012-08-01 20:26:12 +1000 | [diff] [blame] | 93 | } |
| 94 | |
| 95 | bool fifo8_is_empty(Fifo8 *fifo) |
| 96 | { |
| 97 | return (fifo->num == 0); |
| 98 | } |
| 99 | |
| 100 | bool fifo8_is_full(Fifo8 *fifo) |
| 101 | { |
| 102 | return (fifo->num == fifo->capacity); |
| 103 | } |
| 104 | |
Beniamino Galvani | c4e57af | 2014-01-30 23:02:04 +0100 | [diff] [blame] | 105 | uint32_t fifo8_num_free(Fifo8 *fifo) |
| 106 | { |
| 107 | return fifo->capacity - fifo->num; |
| 108 | } |
| 109 | |
| 110 | uint32_t fifo8_num_used(Fifo8 *fifo) |
| 111 | { |
| 112 | return fifo->num; |
| 113 | } |
| 114 | |
Peter A. G. Crosthwaite | a3578d4 | 2012-08-01 20:26:12 +1000 | [diff] [blame] | 115 | const VMStateDescription vmstate_fifo8 = { |
| 116 | .name = "Fifo8", |
| 117 | .version_id = 1, |
| 118 | .minimum_version_id = 1, |
Juan Quintela | 8f1e884 | 2014-05-13 16:09:35 +0100 | [diff] [blame] | 119 | .fields = (VMStateField[]) { |
Peter A. G. Crosthwaite | a3578d4 | 2012-08-01 20:26:12 +1000 | [diff] [blame] | 120 | VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity), |
| 121 | VMSTATE_UINT32(head, Fifo8), |
| 122 | VMSTATE_UINT32(num, Fifo8), |
| 123 | VMSTATE_END_OF_LIST() |
| 124 | } |
| 125 | }; |