995d8348eb
To be able to peek at FIFO content without popping it, introduce the fifo8_peek_buf() method by factoring common content from fifo8_pop_buf(). Reviewed-by: Francisco Iglesias <frasse.iglesias@gmail.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20231109192814.95977-3-philmd@linaro.org> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
137 lines
3.0 KiB
C
137 lines
3.0 KiB
C
/*
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* Generic FIFO component, implemented as a circular buffer.
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*
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* Copyright (c) 2012 Peter A. G. Crosthwaite
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "qemu/osdep.h"
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#include "migration/vmstate.h"
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#include "qemu/fifo8.h"
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void fifo8_create(Fifo8 *fifo, uint32_t capacity)
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{
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fifo->data = g_new(uint8_t, capacity);
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fifo->capacity = capacity;
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fifo->head = 0;
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fifo->num = 0;
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}
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void fifo8_destroy(Fifo8 *fifo)
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{
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g_free(fifo->data);
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}
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void fifo8_push(Fifo8 *fifo, uint8_t data)
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{
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assert(fifo->num < fifo->capacity);
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fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data;
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fifo->num++;
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}
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void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num)
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{
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uint32_t start, avail;
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assert(fifo->num + num <= fifo->capacity);
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start = (fifo->head + fifo->num) % fifo->capacity;
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if (start + num <= fifo->capacity) {
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memcpy(&fifo->data[start], data, num);
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} else {
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avail = fifo->capacity - start;
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memcpy(&fifo->data[start], data, avail);
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memcpy(&fifo->data[0], &data[avail], num - avail);
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}
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fifo->num += num;
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}
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uint8_t fifo8_pop(Fifo8 *fifo)
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{
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uint8_t ret;
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assert(fifo->num > 0);
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ret = fifo->data[fifo->head++];
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fifo->head %= fifo->capacity;
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fifo->num--;
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return ret;
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}
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static const uint8_t *fifo8_peekpop_buf(Fifo8 *fifo, uint32_t max,
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uint32_t *numptr, bool do_pop)
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{
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uint8_t *ret;
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uint32_t num;
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assert(max > 0 && max <= fifo->num);
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num = MIN(fifo->capacity - fifo->head, max);
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ret = &fifo->data[fifo->head];
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if (do_pop) {
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fifo->head += num;
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fifo->head %= fifo->capacity;
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fifo->num -= num;
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}
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if (numptr) {
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*numptr = num;
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}
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return ret;
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}
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const uint8_t *fifo8_peek_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
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{
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return fifo8_peekpop_buf(fifo, max, numptr, false);
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}
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const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
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{
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return fifo8_peekpop_buf(fifo, max, numptr, true);
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}
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void fifo8_reset(Fifo8 *fifo)
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{
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fifo->num = 0;
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fifo->head = 0;
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}
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bool fifo8_is_empty(Fifo8 *fifo)
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{
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return (fifo->num == 0);
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}
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bool fifo8_is_full(Fifo8 *fifo)
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{
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return (fifo->num == fifo->capacity);
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}
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uint32_t fifo8_num_free(Fifo8 *fifo)
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{
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return fifo->capacity - fifo->num;
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}
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uint32_t fifo8_num_used(Fifo8 *fifo)
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{
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return fifo->num;
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}
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const VMStateDescription vmstate_fifo8 = {
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.name = "Fifo8",
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.version_id = 1,
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.minimum_version_id = 1,
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.fields = (const VMStateField[]) {
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VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, capacity),
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VMSTATE_UINT32(head, Fifo8),
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VMSTATE_UINT32(num, Fifo8),
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VMSTATE_END_OF_LIST()
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}
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};
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