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-rw-r--r--qemu/util/fifo8.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/qemu/util/fifo8.c b/qemu/util/fifo8.c
new file mode 100644
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+++ b/qemu/util/fifo8.c
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+/*
+ * Generic FIFO component, implemented as a circular buffer.
+ *
+ * Copyright (c) 2012 Peter A. G. Crosthwaite
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu-common.h"
+#include "qemu/fifo8.h"
+
+void fifo8_create(Fifo8 *fifo, uint32_t capacity)
+{
+ fifo->data = g_new(uint8_t, capacity);
+ fifo->capacity = capacity;
+ fifo->head = 0;
+ fifo->num = 0;
+}
+
+void fifo8_destroy(Fifo8 *fifo)
+{
+ g_free(fifo->data);
+}
+
+void fifo8_push(Fifo8 *fifo, uint8_t data)
+{
+ if (fifo->num == fifo->capacity) {
+ abort();
+ }
+ fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data;
+ fifo->num++;
+}
+
+void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num)
+{
+ uint32_t start, avail;
+
+ if (fifo->num + num > fifo->capacity) {
+ abort();
+ }
+
+ start = (fifo->head + fifo->num) % fifo->capacity;
+
+ if (start + num <= fifo->capacity) {
+ memcpy(&fifo->data[start], data, num);
+ } else {
+ avail = fifo->capacity - start;
+ memcpy(&fifo->data[start], data, avail);
+ memcpy(&fifo->data[0], &data[avail], num - avail);
+ }
+
+ fifo->num += num;
+}
+
+uint8_t fifo8_pop(Fifo8 *fifo)
+{
+ uint8_t ret;
+
+ if (fifo->num == 0) {
+ abort();
+ }
+ ret = fifo->data[fifo->head++];
+ fifo->head %= fifo->capacity;
+ fifo->num--;
+ return ret;
+}
+
+const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num)
+{
+ uint8_t *ret;
+
+ if (max == 0 || max > fifo->num) {
+ abort();
+ }
+ *num = MIN(fifo->capacity - fifo->head, max);
+ ret = &fifo->data[fifo->head];
+ fifo->head += *num;
+ fifo->head %= fifo->capacity;
+ fifo->num -= *num;
+ return ret;
+}
+
+void fifo8_reset(Fifo8 *fifo)
+{
+ fifo->num = 0;
+ fifo->head = 0;
+}
+
+bool fifo8_is_empty(Fifo8 *fifo)
+{
+ return (fifo->num == 0);
+}
+
+bool fifo8_is_full(Fifo8 *fifo)
+{
+ return (fifo->num == fifo->capacity);
+}
+
+uint32_t fifo8_num_free(Fifo8 *fifo)
+{
+ return fifo->capacity - fifo->num;
+}
+
+uint32_t fifo8_num_used(Fifo8 *fifo)
+{
+ return fifo->num;
+}
+
+const VMStateDescription vmstate_fifo8 = {
+ .name = "Fifo8",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity),
+ VMSTATE_UINT32(head, Fifo8),
+ VMSTATE_UINT32(num, Fifo8),
+ VMSTATE_END_OF_LIST()
+ }
+};