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char/serial: Use generic Fifo8

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Use the generic Fifo8 helper provided by QEMU, rather than re-implement
privately.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This commit is contained in:
Peter Crosthwaite 2013-06-03 15:13:27 +10:00 committed by Michael Tokarev
parent 7f4f0a227f
commit 8e8638fa87
2 changed files with 39 additions and 74 deletions
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98
hw/char/serial.c
View File

@ -92,8 +92,6 @@
#define UART_FCR_RFR 0x02 /* RCVR Fifo Reset */
#define UART_FCR_FE 0x01 /* FIFO Enable */
#define XMIT_FIFO 0
#define RECV_FIFO 1
#define MAX_XMIT_RETRY 4
#ifdef DEBUG_SERIAL
@ -106,50 +104,14 @@ do {} while (0)
static void serial_receive1(void *opaque, const uint8_t *buf, int size);
static void fifo_clear(SerialState *s, int fifo)
static inline void recv_fifo_put(SerialState *s, uint8_t chr)
{
SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
memset(f->data, 0, UART_FIFO_LENGTH);
f->count = 0;
f->head = 0;
f->tail = 0;
}
static int fifo_put(SerialState *s, int fifo, uint8_t chr)
{
SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
/* Receive overruns do not overwrite FIFO contents. */
if (fifo == XMIT_FIFO || f->count < UART_FIFO_LENGTH) {
f->data[f->head++] = chr;
if (f->head == UART_FIFO_LENGTH)
f->head = 0;
}
if (f->count < UART_FIFO_LENGTH)
f->count++;
else if (fifo == RECV_FIFO)
if (!fifo8_is_full(&s->recv_fifo)) {
fifo8_push(&s->recv_fifo, chr);
} else {
s->lsr |= UART_LSR_OE;
return 1;
}
static uint8_t fifo_get(SerialState *s, int fifo)
{
SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
uint8_t c;
if(f->count == 0)
return 0;
c = f->data[f->tail++];
if (f->tail == UART_FIFO_LENGTH)
f->tail = 0;
f->count--;
return c;
}
}
static void serial_update_irq(SerialState *s)
@ -165,7 +127,7 @@ static void serial_update_irq(SerialState *s)
tmp_iir = UART_IIR_CTI;
} else if ((s->ier & UART_IER_RDI) && (s->lsr & UART_LSR_DR) &&
(!(s->fcr & UART_FCR_FE) ||
s->recv_fifo.count >= s->recv_fifo.itl)) {
s->recv_fifo.num >= s->recv_fifo_itl)) {
tmp_iir = UART_IIR_RDI;
} else if ((s->ier & UART_IER_THRI) && s->thr_ipending) {
tmp_iir = UART_IIR_THRI;
@ -262,8 +224,9 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque)
if (s->tsr_retry <= 0) {
if (s->fcr & UART_FCR_FE) {
s->tsr = fifo_get(s,XMIT_FIFO);
if (!s->xmit_fifo.count) {
s->tsr = fifo8_is_full(&s->xmit_fifo) ?
0 : fifo8_pop(&s->xmit_fifo);
if (!s->xmit_fifo.num) {
s->lsr |= UART_LSR_THRE;
}
} else if ((s->lsr & UART_LSR_THRE)) {
@ -317,7 +280,11 @@ static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val,
} else {
s->thr = (uint8_t) val;
if(s->fcr & UART_FCR_FE) {
fifo_put(s, XMIT_FIFO, s->thr);
/* xmit overruns overwrite data, so make space if needed */
if (fifo8_is_full(&s->xmit_fifo)) {
fifo8_pop(&s->xmit_fifo);
}
fifo8_push(&s->xmit_fifo, s->thr);
s->thr_ipending = 0;
s->lsr &= ~UART_LSR_TEMT;
s->lsr &= ~UART_LSR_THRE;
@ -368,28 +335,28 @@ static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val,
if (val & UART_FCR_RFR) {
qemu_del_timer(s->fifo_timeout_timer);
s->timeout_ipending=0;
fifo_clear(s,RECV_FIFO);
fifo8_reset(&s->recv_fifo);
}
if (val & UART_FCR_XFR) {
fifo_clear(s,XMIT_FIFO);
fifo8_reset(&s->xmit_fifo);
}
if (val & UART_FCR_FE) {
s->iir |= UART_IIR_FE;
/* Set RECV_FIFO trigger Level */
/* Set recv_fifo trigger Level */
switch (val & 0xC0) {
case UART_FCR_ITL_1:
s->recv_fifo.itl = 1;
s->recv_fifo_itl = 1;
break;
case UART_FCR_ITL_2:
s->recv_fifo.itl = 4;
s->recv_fifo_itl = 4;
break;
case UART_FCR_ITL_3:
s->recv_fifo.itl = 8;
s->recv_fifo_itl = 8;
break;
case UART_FCR_ITL_4:
s->recv_fifo.itl = 14;
s->recv_fifo_itl = 14;
break;
}
} else
@ -461,8 +428,9 @@ static uint64_t serial_ioport_read(void *opaque, hwaddr addr, unsigned size)
ret = s->divider & 0xff;
} else {
if(s->fcr & UART_FCR_FE) {
ret = fifo_get(s,RECV_FIFO);
if (s->recv_fifo.count == 0) {
ret = fifo8_is_full(&s->recv_fifo) ?
0 : fifo8_pop(&s->recv_fifo);
if (s->recv_fifo.num == 0) {
s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
} else {
qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock_ns (vm_clock) + s->char_transmit_time * 4);
@ -536,7 +504,7 @@ static uint64_t serial_ioport_read(void *opaque, hwaddr addr, unsigned size)
static int serial_can_receive(SerialState *s)
{
if(s->fcr & UART_FCR_FE) {
if (s->recv_fifo.count < UART_FIFO_LENGTH) {
if (s->recv_fifo.num < UART_FIFO_LENGTH) {
/*
* Advertise (fifo.itl - fifo.count) bytes when count < ITL, and 1
* if above. If UART_FIFO_LENGTH - fifo.count is advertised the
@ -544,8 +512,8 @@ static int serial_can_receive(SerialState *s)
* the guest has a chance to respond, effectively overriding the ITL
* that the guest has set.
*/
return (s->recv_fifo.count <= s->recv_fifo.itl) ?
s->recv_fifo.itl - s->recv_fifo.count : 1;
return (s->recv_fifo.num <= s->recv_fifo_itl) ?
s->recv_fifo_itl - s->recv_fifo.num : 1;
} else {
return 0;
}
@ -558,7 +526,7 @@ static void serial_receive_break(SerialState *s)
{
s->rbr = 0;
/* When the LSR_DR is set a null byte is pushed into the fifo */
fifo_put(s, RECV_FIFO, '\0');
recv_fifo_put(s, '\0');
s->lsr |= UART_LSR_BI | UART_LSR_DR;
serial_update_irq(s);
}
@ -566,7 +534,7 @@ static void serial_receive_break(SerialState *s)
/* There's data in recv_fifo and s->rbr has not been read for 4 char transmit times */
static void fifo_timeout_int (void *opaque) {
SerialState *s = opaque;
if (s->recv_fifo.count) {
if (s->recv_fifo.num) {
s->timeout_ipending = 1;
serial_update_irq(s);
}
@ -588,7 +556,7 @@ static void serial_receive1(void *opaque, const uint8_t *buf, int size)
if(s->fcr & UART_FCR_FE) {
int i;
for (i = 0; i < size; i++) {
fifo_put(s, RECV_FIFO, buf[i]);
recv_fifo_put(s, buf[i]);
}
s->lsr |= UART_LSR_DR;
/* call the timeout receive callback in 4 char transmit time */
@ -668,8 +636,8 @@ static void serial_reset(void *opaque)
s->char_transmit_time = (get_ticks_per_sec() / 9600) * 10;
s->poll_msl = 0;
fifo_clear(s,RECV_FIFO);
fifo_clear(s,XMIT_FIFO);
fifo8_reset(&s->recv_fifo);
fifo8_reset(&s->xmit_fifo);
s->last_xmit_ts = qemu_get_clock_ns(vm_clock);
@ -692,6 +660,8 @@ void serial_init_core(SerialState *s)
qemu_chr_add_handlers(s->chr, serial_can_receive1, serial_receive1,
serial_event, s);
fifo8_create(&s->recv_fifo, UART_FIFO_LENGTH);
fifo8_create(&s->xmit_fifo, UART_FIFO_LENGTH);
}
void serial_exit_core(SerialState *s)

15
include/hw/char/serial.h
View File

@ -28,17 +28,10 @@
#include "hw/hw.h"
#include "sysemu/sysemu.h"
#include "exec/memory.h"
#include "qemu/fifo8.h"
#define UART_FIFO_LENGTH 16 /* 16550A Fifo Length */
typedef struct SerialFIFO {
uint8_t data[UART_FIFO_LENGTH];
uint8_t count;
uint8_t itl; /* Interrupt Trigger Level */
uint8_t tail;
uint8_t head;
} SerialFIFO;
struct SerialState {
uint16_t divider;
uint8_t rbr; /* receive register */
@ -67,8 +60,10 @@ struct SerialState {
/* Time when the last byte was successfully sent out of the tsr */
uint64_t last_xmit_ts;
SerialFIFO recv_fifo;
SerialFIFO xmit_fifo;
Fifo8 recv_fifo;
Fifo8 xmit_fifo;
/* Interrupt trigger level for recv_fifo */
uint8_t recv_fifo_itl;
struct QEMUTimer *fifo_timeout_timer;
int timeout_ipending; /* timeout interrupt pending state */