qemu/util/fifo8.c
Halil Pasic 59046ec29a migration: consolidate VMStateField.start
The member VMStateField.start is used for two things, partial data
migration for VBUFFER data (basically provide migration for a
sub-buffer) and for locating next in QTAILQ.

The implementation of the VBUFFER feature is broken when VMSTATE_ALLOC
is used. This however goes unnoticed because actually partial migration
for VBUFFER is not used at all.

Let's consolidate the usage of VMStateField.start by removing support
for partial migration for VBUFFER.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>

Message-Id: <20170203175217.45562-1-pasic@linux.vnet.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-02-13 17:27:13 +00:00

127 lines
2.7 KiB
C

/*
* 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/osdep.h"
#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, capacity),
VMSTATE_UINT32(head, Fifo8),
VMSTATE_UINT32(num, Fifo8),
VMSTATE_END_OF_LIST()
}
};