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a3578d4a PC |
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 | ||
aafd7584 | 15 | #include "qemu/osdep.h" |
d6454270 | 16 | #include "migration/vmstate.h" |
fd7f0d66 | 17 | #include "qemu/fifo8.h" |
a3578d4a PC |
18 | |
19 | void fifo8_create(Fifo8 *fifo, uint32_t capacity) | |
20 | { | |
21 | fifo->data = g_new(uint8_t, capacity); | |
22 | fifo->capacity = capacity; | |
23 | fifo->head = 0; | |
24 | fifo->num = 0; | |
25 | } | |
26 | ||
27 | void fifo8_destroy(Fifo8 *fifo) | |
28 | { | |
29 | g_free(fifo->data); | |
30 | } | |
31 | ||
32 | void fifo8_push(Fifo8 *fifo, uint8_t data) | |
33 | { | |
f71407ed | 34 | assert(fifo->num < fifo->capacity); |
a3578d4a PC |
35 | fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data; |
36 | fifo->num++; | |
37 | } | |
38 | ||
c4e57af8 BG |
39 | void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num) |
40 | { | |
41 | uint32_t start, avail; | |
42 | ||
f71407ed | 43 | assert(fifo->num + num <= fifo->capacity); |
c4e57af8 BG |
44 | |
45 | start = (fifo->head + fifo->num) % fifo->capacity; | |
46 | ||
47 | if (start + num <= fifo->capacity) { | |
48 | memcpy(&fifo->data[start], data, num); | |
49 | } else { | |
50 | avail = fifo->capacity - start; | |
51 | memcpy(&fifo->data[start], data, avail); | |
52 | memcpy(&fifo->data[0], &data[avail], num - avail); | |
53 | } | |
54 | ||
55 | fifo->num += num; | |
56 | } | |
57 | ||
a3578d4a PC |
58 | uint8_t fifo8_pop(Fifo8 *fifo) |
59 | { | |
60 | uint8_t ret; | |
61 | ||
f71407ed | 62 | assert(fifo->num > 0); |
a3578d4a PC |
63 | ret = fifo->data[fifo->head++]; |
64 | fifo->head %= fifo->capacity; | |
65 | fifo->num--; | |
66 | return ret; | |
67 | } | |
68 | ||
995d8348 PMD |
69 | static const uint8_t *fifo8_peekpop_buf(Fifo8 *fifo, uint32_t max, |
70 | uint32_t *numptr, bool do_pop) | |
c4e57af8 BG |
71 | { |
72 | uint8_t *ret; | |
cd04033d | 73 | uint32_t num; |
c4e57af8 | 74 | |
f71407ed | 75 | assert(max > 0 && max <= fifo->num); |
cd04033d | 76 | num = MIN(fifo->capacity - fifo->head, max); |
c4e57af8 | 77 | ret = &fifo->data[fifo->head]; |
995d8348 PMD |
78 | |
79 | if (do_pop) { | |
80 | fifo->head += num; | |
81 | fifo->head %= fifo->capacity; | |
82 | fifo->num -= num; | |
83 | } | |
cd04033d PMD |
84 | if (numptr) { |
85 | *numptr = num; | |
86 | } | |
c4e57af8 BG |
87 | return ret; |
88 | } | |
89 | ||
995d8348 PMD |
90 | const uint8_t *fifo8_peek_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr) |
91 | { | |
92 | return fifo8_peekpop_buf(fifo, max, numptr, false); | |
93 | } | |
94 | ||
95 | const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr) | |
96 | { | |
97 | return fifo8_peekpop_buf(fifo, max, numptr, true); | |
98 | } | |
99 | ||
a3578d4a PC |
100 | void fifo8_reset(Fifo8 *fifo) |
101 | { | |
102 | fifo->num = 0; | |
58892d47 | 103 | fifo->head = 0; |
a3578d4a PC |
104 | } |
105 | ||
106 | bool fifo8_is_empty(Fifo8 *fifo) | |
107 | { | |
108 | return (fifo->num == 0); | |
109 | } | |
110 | ||
111 | bool fifo8_is_full(Fifo8 *fifo) | |
112 | { | |
113 | return (fifo->num == fifo->capacity); | |
114 | } | |
115 | ||
c4e57af8 BG |
116 | uint32_t fifo8_num_free(Fifo8 *fifo) |
117 | { | |
118 | return fifo->capacity - fifo->num; | |
119 | } | |
120 | ||
121 | uint32_t fifo8_num_used(Fifo8 *fifo) | |
122 | { | |
123 | return fifo->num; | |
124 | } | |
125 | ||
a3578d4a PC |
126 | const VMStateDescription vmstate_fifo8 = { |
127 | .name = "Fifo8", | |
128 | .version_id = 1, | |
129 | .minimum_version_id = 1, | |
59c2dded | 130 | .fields = (const VMStateField[]) { |
59046ec2 | 131 | VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, capacity), |
a3578d4a PC |
132 | VMSTATE_UINT32(head, Fifo8), |
133 | VMSTATE_UINT32(num, Fifo8), | |
134 | VMSTATE_END_OF_LIST() | |
135 | } | |
136 | }; |