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QEMU-Nyx-fork/hw/char/serial.c
Marc-André Lureau f3575af130 hw/char/serial: retry write if EAGAIN 
If the chardev returns -1 with EAGAIN errno on write(), it should try
to send it again (EINTR is handled by the chardev itself).

This fixes commit 019288bf137183bf3407c9824655b753bfafc99f
"hw/char/serial: Only retry if qemu_chr_fe_write returns 0"

Tested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180716110755.12499-1-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-16 16:58:16 +02:00

1061 lines
32 KiB
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/*
* QEMU 16550A UART emulation
*
* Copyright (c) 2003-2004 Fabrice Bellard
* Copyright (c) 2008 Citrix Systems, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "hw/char/serial.h"
#include "chardev/char-serial.h"
#include "qapi/error.h"
#include "qemu/timer.h"
#include "qemu/error-report.h"
#include "trace.h"
//#define DEBUG_SERIAL
#define UART_LCR_DLAB 0x80 /* Divisor latch access bit */
#define UART_IER_MSI 0x08 /* Enable Modem status interrupt */
#define UART_IER_RLSI 0x04 /* Enable receiver line status interrupt */
#define UART_IER_THRI 0x02 /* Enable Transmitter holding register int. */
#define UART_IER_RDI 0x01 /* Enable receiver data interrupt */
#define UART_IIR_NO_INT 0x01 /* No interrupts pending */
#define UART_IIR_ID 0x06 /* Mask for the interrupt ID */
#define UART_IIR_MSI 0x00 /* Modem status interrupt */
#define UART_IIR_THRI 0x02 /* Transmitter holding register empty */
#define UART_IIR_RDI 0x04 /* Receiver data interrupt */
#define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */
#define UART_IIR_CTI 0x0C /* Character Timeout Indication */
#define UART_IIR_FENF 0x80 /* Fifo enabled, but not functionning */
#define UART_IIR_FE 0xC0 /* Fifo enabled */
/*
* These are the definitions for the Modem Control Register
*/
#define UART_MCR_LOOP 0x10 /* Enable loopback test mode */
#define UART_MCR_OUT2 0x08 /* Out2 complement */
#define UART_MCR_OUT1 0x04 /* Out1 complement */
#define UART_MCR_RTS 0x02 /* RTS complement */
#define UART_MCR_DTR 0x01 /* DTR complement */
/*
* These are the definitions for the Modem Status Register
*/
#define UART_MSR_DCD 0x80 /* Data Carrier Detect */
#define UART_MSR_RI 0x40 /* Ring Indicator */
#define UART_MSR_DSR 0x20 /* Data Set Ready */
#define UART_MSR_CTS 0x10 /* Clear to Send */
#define UART_MSR_DDCD 0x08 /* Delta DCD */
#define UART_MSR_TERI 0x04 /* Trailing edge ring indicator */
#define UART_MSR_DDSR 0x02 /* Delta DSR */
#define UART_MSR_DCTS 0x01 /* Delta CTS */
#define UART_MSR_ANY_DELTA 0x0F /* Any of the delta bits! */
#define UART_LSR_TEMT 0x40 /* Transmitter empty */
#define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
#define UART_LSR_BI 0x10 /* Break interrupt indicator */
#define UART_LSR_FE 0x08 /* Frame error indicator */
#define UART_LSR_PE 0x04 /* Parity error indicator */
#define UART_LSR_OE 0x02 /* Overrun error indicator */
#define UART_LSR_DR 0x01 /* Receiver data ready */
#define UART_LSR_INT_ANY 0x1E /* Any of the lsr-interrupt-triggering status bits */
/* Interrupt trigger levels. The byte-counts are for 16550A - in newer UARTs the byte-count for each ITL is higher. */
#define UART_FCR_ITL_1 0x00 /* 1 byte ITL */
#define UART_FCR_ITL_2 0x40 /* 4 bytes ITL */
#define UART_FCR_ITL_3 0x80 /* 8 bytes ITL */
#define UART_FCR_ITL_4 0xC0 /* 14 bytes ITL */
#define UART_FCR_DMS 0x08 /* DMA Mode Select */
#define UART_FCR_XFR 0x04 /* XMIT Fifo Reset */
#define UART_FCR_RFR 0x02 /* RCVR Fifo Reset */
#define UART_FCR_FE 0x01 /* FIFO Enable */
#define MAX_XMIT_RETRY 4
#ifdef DEBUG_SERIAL
#define DPRINTF(fmt, ...) \
do { fprintf(stderr, "serial: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) \
do {} while (0)
#endif
static void serial_receive1(void *opaque, const uint8_t *buf, int size);
static void serial_xmit(SerialState *s);
static inline void recv_fifo_put(SerialState *s, uint8_t chr)
{
/* Receive overruns do not overwrite FIFO contents. */
if (!fifo8_is_full(&s->recv_fifo)) {
fifo8_push(&s->recv_fifo, chr);
} else {
s->lsr |= UART_LSR_OE;
}
}
static void serial_update_irq(SerialState *s)
{
uint8_t tmp_iir = UART_IIR_NO_INT;
if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) {
tmp_iir = UART_IIR_RLSI;
} else if ((s->ier & UART_IER_RDI) && s->timeout_ipending) {
/* Note that(s->ier & UART_IER_RDI) can mask this interrupt,
* this is not in the specification but is observed on existing
* hardware. */
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.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;
} else if ((s->ier & UART_IER_MSI) && (s->msr & UART_MSR_ANY_DELTA)) {
tmp_iir = UART_IIR_MSI;
}
s->iir = tmp_iir | (s->iir & 0xF0);
if (tmp_iir != UART_IIR_NO_INT) {
qemu_irq_raise(s->irq);
} else {
qemu_irq_lower(s->irq);
}
}
static void serial_update_parameters(SerialState *s)
{
float speed;
int parity, data_bits, stop_bits, frame_size;
QEMUSerialSetParams ssp;
/* Start bit. */
frame_size = 1;
if (s->lcr & 0x08) {
/* Parity bit. */
frame_size++;
if (s->lcr & 0x10)
parity = 'E';
else
parity = 'O';
} else {
parity = 'N';
}
if (s->lcr & 0x04) {
stop_bits = 2;
} else {
stop_bits = 1;
}
data_bits = (s->lcr & 0x03) + 5;
frame_size += data_bits + stop_bits;
/* Zero divisor should give about 3500 baud */
speed = (s->divider == 0) ? 3500 : (float) s->baudbase / s->divider;
ssp.speed = speed;
ssp.parity = parity;
ssp.data_bits = data_bits;
ssp.stop_bits = stop_bits;
s->char_transmit_time = (NANOSECONDS_PER_SECOND / speed) * frame_size;
qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
DPRINTF("speed=%.2f parity=%c data=%d stop=%d\n",
speed, parity, data_bits, stop_bits);
}
static void serial_update_msl(SerialState *s)
{
uint8_t omsr;
int flags;
timer_del(s->modem_status_poll);
if (qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_GET_TIOCM,
&flags) == -ENOTSUP) {
s->poll_msl = -1;
return;
}
omsr = s->msr;
s->msr = (flags & CHR_TIOCM_CTS) ? s->msr | UART_MSR_CTS : s->msr & ~UART_MSR_CTS;
s->msr = (flags & CHR_TIOCM_DSR) ? s->msr | UART_MSR_DSR : s->msr & ~UART_MSR_DSR;
s->msr = (flags & CHR_TIOCM_CAR) ? s->msr | UART_MSR_DCD : s->msr & ~UART_MSR_DCD;
s->msr = (flags & CHR_TIOCM_RI) ? s->msr | UART_MSR_RI : s->msr & ~UART_MSR_RI;
if (s->msr != omsr) {
/* Set delta bits */
s->msr = s->msr | ((s->msr >> 4) ^ (omsr >> 4));
/* UART_MSR_TERI only if change was from 1 -> 0 */
if ((s->msr & UART_MSR_TERI) && !(omsr & UART_MSR_RI))
s->msr &= ~UART_MSR_TERI;
serial_update_irq(s);
}
/* The real 16550A apparently has a 250ns response latency to line status changes.
We'll be lazy and poll only every 10ms, and only poll it at all if MSI interrupts are turned on */
if (s->poll_msl) {
timer_mod(s->modem_status_poll, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
NANOSECONDS_PER_SECOND / 100);
}
}
static gboolean serial_watch_cb(GIOChannel *chan, GIOCondition cond,
void *opaque)
{
SerialState *s = opaque;
s->watch_tag = 0;
serial_xmit(s);
return FALSE;
}
static void serial_xmit(SerialState *s)
{
do {
assert(!(s->lsr & UART_LSR_TEMT));
if (s->tsr_retry == 0) {
assert(!(s->lsr & UART_LSR_THRE));
if (s->fcr & UART_FCR_FE) {
assert(!fifo8_is_empty(&s->xmit_fifo));
s->tsr = fifo8_pop(&s->xmit_fifo);
if (!s->xmit_fifo.num) {
s->lsr |= UART_LSR_THRE;
}
} else {
s->tsr = s->thr;
s->lsr |= UART_LSR_THRE;
}
if ((s->lsr & UART_LSR_THRE) && !s->thr_ipending) {
s->thr_ipending = 1;
serial_update_irq(s);
}
}
if (s->mcr & UART_MCR_LOOP) {
/* in loopback mode, say that we just received a char */
serial_receive1(s, &s->tsr, 1);
} else {
int rc = qemu_chr_fe_write(&s->chr, &s->tsr, 1);
if ((rc == 0 ||
(rc == -1 && errno == EAGAIN)) &&
s->tsr_retry < MAX_XMIT_RETRY) {
assert(s->watch_tag == 0);
s->watch_tag =
qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP,
serial_watch_cb, s);
if (s->watch_tag > 0) {
s->tsr_retry++;
return;
}
}
}
s->tsr_retry = 0;
/* Transmit another byte if it is already available. It is only
possible when FIFO is enabled and not empty. */
} while (!(s->lsr & UART_LSR_THRE));
s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
s->lsr |= UART_LSR_TEMT;
}
/* Setter for FCR.
is_load flag means, that value is set while loading VM state
and interrupt should not be invoked */
static void serial_write_fcr(SerialState *s, uint8_t val)
{
/* Set fcr - val only has the bits that are supposed to "stick" */
s->fcr = val;
if (val & UART_FCR_FE) {
s->iir |= UART_IIR_FE;
/* Set recv_fifo trigger Level */
switch (val & 0xC0) {
case UART_FCR_ITL_1:
s->recv_fifo_itl = 1;
break;
case UART_FCR_ITL_2:
s->recv_fifo_itl = 4;
break;
case UART_FCR_ITL_3:
s->recv_fifo_itl = 8;
break;
case UART_FCR_ITL_4:
s->recv_fifo_itl = 14;
break;
}
} else {
s->iir &= ~UART_IIR_FE;
}
}
static void serial_update_tiocm(SerialState *s)
{
int flags;
qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_GET_TIOCM, &flags);
flags &= ~(CHR_TIOCM_RTS | CHR_TIOCM_DTR);
if (s->mcr & UART_MCR_RTS) {
flags |= CHR_TIOCM_RTS;
}
if (s->mcr & UART_MCR_DTR) {
flags |= CHR_TIOCM_DTR;
}
qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_TIOCM, &flags);
}
static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val,
unsigned size)
{
SerialState *s = opaque;
addr &= 7;
trace_serial_ioport_write(addr, val);
switch(addr) {
default:
case 0:
if (s->lcr & UART_LCR_DLAB) {
if (size == 2) {
s->divider = (s->divider & 0xff00) | val;
} else if (size == 4) {
s->divider = val;
}
serial_update_parameters(s);
} else {
s->thr = (uint8_t) val;
if(s->fcr & UART_FCR_FE) {
/* 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_THRE;
s->lsr &= ~UART_LSR_TEMT;
serial_update_irq(s);
if (s->tsr_retry == 0) {
serial_xmit(s);
}
}
break;
case 1:
if (s->lcr & UART_LCR_DLAB) {
s->divider = (s->divider & 0x00ff) | (val << 8);
serial_update_parameters(s);
} else {
uint8_t changed = (s->ier ^ val) & 0x0f;
s->ier = val & 0x0f;
/* If the backend device is a real serial port, turn polling of the modem
* status lines on physical port on or off depending on UART_IER_MSI state.
*/
if ((changed & UART_IER_MSI) && s->poll_msl >= 0) {
if (s->ier & UART_IER_MSI) {
s->poll_msl = 1;
serial_update_msl(s);
} else {
timer_del(s->modem_status_poll);
s->poll_msl = 0;
}
}
/* Turning on the THRE interrupt on IER can trigger the interrupt
* if LSR.THRE=1, even if it had been masked before by reading IIR.
* This is not in the datasheet, but Windows relies on it. It is
* unclear if THRE has to be resampled every time THRI becomes
* 1, or only on the rising edge. Bochs does the latter, and Windows
* always toggles IER to all zeroes and back to all ones, so do the
* same.
*
* If IER.THRI is zero, thr_ipending is not used. Set it to zero
* so that the thr_ipending subsection is not migrated.
*/
if (changed & UART_IER_THRI) {
if ((s->ier & UART_IER_THRI) && (s->lsr & UART_LSR_THRE)) {
s->thr_ipending = 1;
} else {
s->thr_ipending = 0;
}
}
if (changed) {
serial_update_irq(s);
}
}
break;
case 2:
/* Did the enable/disable flag change? If so, make sure FIFOs get flushed */
if ((val ^ s->fcr) & UART_FCR_FE) {
val |= UART_FCR_XFR | UART_FCR_RFR;
}
/* FIFO clear */
if (val & UART_FCR_RFR) {
s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
timer_del(s->fifo_timeout_timer);
s->timeout_ipending = 0;
fifo8_reset(&s->recv_fifo);
}
if (val & UART_FCR_XFR) {
s->lsr |= UART_LSR_THRE;
s->thr_ipending = 1;
fifo8_reset(&s->xmit_fifo);
}
serial_write_fcr(s, val & 0xC9);
serial_update_irq(s);
break;
case 3:
{
int break_enable;
s->lcr = val;
serial_update_parameters(s);
break_enable = (val >> 6) & 1;
if (break_enable != s->last_break_enable) {
s->last_break_enable = break_enable;
qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_BREAK,
&break_enable);
}
}
break;
case 4:
{
int old_mcr = s->mcr;
s->mcr = val & 0x1f;
if (val & UART_MCR_LOOP)
break;
if (s->poll_msl >= 0 && old_mcr != s->mcr) {
serial_update_tiocm(s);
/* Update the modem status after a one-character-send wait-time, since there may be a response
from the device/computer at the other end of the serial line */
timer_mod(s->modem_status_poll, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->char_transmit_time);
}
}
break;
case 5:
break;
case 6:
break;
case 7:
s->scr = val;
break;
}
}
static uint64_t serial_ioport_read(void *opaque, hwaddr addr, unsigned size)
{
SerialState *s = opaque;
uint32_t ret;
addr &= 7;
switch(addr) {
default:
case 0:
if (s->lcr & UART_LCR_DLAB) {
ret = s->divider & 0xff;
} else {
if(s->fcr & UART_FCR_FE) {
ret = fifo8_is_empty(&s->recv_fifo) ?
0 : fifo8_pop(&s->recv_fifo);
if (s->recv_fifo.num == 0) {
s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
} else {
timer_mod(s->fifo_timeout_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->char_transmit_time * 4);
}
s->timeout_ipending = 0;
} else {
ret = s->rbr;
s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
}
serial_update_irq(s);
if (!(s->mcr & UART_MCR_LOOP)) {
/* in loopback mode, don't receive any data */
qemu_chr_fe_accept_input(&s->chr);
}
}
break;
case 1:
if (s->lcr & UART_LCR_DLAB) {
ret = (s->divider >> 8) & 0xff;
} else {
ret = s->ier;
}
break;
case 2:
ret = s->iir;
if ((ret & UART_IIR_ID) == UART_IIR_THRI) {
s->thr_ipending = 0;
serial_update_irq(s);
}
break;
case 3:
ret = s->lcr;
break;
case 4:
ret = s->mcr;
break;
case 5:
ret = s->lsr;
/* Clear break and overrun interrupts */
if (s->lsr & (UART_LSR_BI|UART_LSR_OE)) {
s->lsr &= ~(UART_LSR_BI|UART_LSR_OE);
serial_update_irq(s);
}
break;
case 6:
if (s->mcr & UART_MCR_LOOP) {
/* in loopback, the modem output pins are connected to the
inputs */
ret = (s->mcr & 0x0c) << 4;
ret |= (s->mcr & 0x02) << 3;
ret |= (s->mcr & 0x01) << 5;
} else {
if (s->poll_msl >= 0)
serial_update_msl(s);
ret = s->msr;
/* Clear delta bits & msr int after read, if they were set */
if (s->msr & UART_MSR_ANY_DELTA) {
s->msr &= 0xF0;
serial_update_irq(s);
}
}
break;
case 7:
ret = s->scr;
break;
}
trace_serial_ioport_read(addr, ret);
return ret;
}
static int serial_can_receive(SerialState *s)
{
if(s->fcr & UART_FCR_FE) {
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
* effect will be to almost always fill the fifo completely before
* the guest has a chance to respond, effectively overriding the ITL
* that the guest has set.
*/
return (s->recv_fifo.num <= s->recv_fifo_itl) ?
s->recv_fifo_itl - s->recv_fifo.num : 1;
} else {
return 0;
}
} else {
return !(s->lsr & UART_LSR_DR);
}
}
static void serial_receive_break(SerialState *s)
{
s->rbr = 0;
/* When the LSR_DR is set a null byte is pushed into the fifo */
recv_fifo_put(s, '\0');
s->lsr |= UART_LSR_BI | UART_LSR_DR;
serial_update_irq(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.num) {
s->timeout_ipending = 1;
serial_update_irq(s);
}
}
static int serial_can_receive1(void *opaque)
{
SerialState *s = opaque;
return serial_can_receive(s);
}
static void serial_receive1(void *opaque, const uint8_t *buf, int size)
{
SerialState *s = opaque;
if (s->wakeup) {
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
}
if(s->fcr & UART_FCR_FE) {
int i;
for (i = 0; i < size; i++) {
recv_fifo_put(s, buf[i]);
}
s->lsr |= UART_LSR_DR;
/* call the timeout receive callback in 4 char transmit time */
timer_mod(s->fifo_timeout_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->char_transmit_time * 4);
} else {
if (s->lsr & UART_LSR_DR)
s->lsr |= UART_LSR_OE;
s->rbr = buf[0];
s->lsr |= UART_LSR_DR;
}
serial_update_irq(s);
}
static void serial_event(void *opaque, int event)
{
SerialState *s = opaque;
DPRINTF("event %x\n", event);
if (event == CHR_EVENT_BREAK)
serial_receive_break(s);
}
static int serial_pre_save(void *opaque)
{
SerialState *s = opaque;
s->fcr_vmstate = s->fcr;
return 0;
}
static int serial_pre_load(void *opaque)
{
SerialState *s = opaque;
s->thr_ipending = -1;
s->poll_msl = -1;
return 0;
}
static int serial_post_load(void *opaque, int version_id)
{
SerialState *s = opaque;
if (version_id < 3) {
s->fcr_vmstate = 0;
}
if (s->thr_ipending == -1) {
s->thr_ipending = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
}
if (s->tsr_retry > 0) {
/* tsr_retry > 0 implies LSR.TEMT = 0 (transmitter not empty). */
if (s->lsr & UART_LSR_TEMT) {
error_report("inconsistent state in serial device "
"(tsr empty, tsr_retry=%d", s->tsr_retry);
return -1;
}
if (s->tsr_retry > MAX_XMIT_RETRY) {
s->tsr_retry = MAX_XMIT_RETRY;
}
assert(s->watch_tag == 0);
s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP,
serial_watch_cb, s);
} else {
/* tsr_retry == 0 implies LSR.TEMT = 1 (transmitter empty). */
if (!(s->lsr & UART_LSR_TEMT)) {
error_report("inconsistent state in serial device "
"(tsr not empty, tsr_retry=0");
return -1;
}
}
s->last_break_enable = (s->lcr >> 6) & 1;
/* Initialize fcr via setter to perform essential side-effects */
serial_write_fcr(s, s->fcr_vmstate);
serial_update_parameters(s);
return 0;
}
static bool serial_thr_ipending_needed(void *opaque)
{
SerialState *s = opaque;
if (s->ier & UART_IER_THRI) {
bool expected_value = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
return s->thr_ipending != expected_value;
} else {
/* LSR.THRE will be sampled again when the interrupt is
* enabled. thr_ipending is not used in this case, do
* not migrate it.
*/
return false;
}
}
static const VMStateDescription vmstate_serial_thr_ipending = {
.name = "serial/thr_ipending",
.version_id = 1,
.minimum_version_id = 1,
.needed = serial_thr_ipending_needed,
.fields = (VMStateField[]) {
VMSTATE_INT32(thr_ipending, SerialState),
VMSTATE_END_OF_LIST()
}
};
static bool serial_tsr_needed(void *opaque)
{
SerialState *s = (SerialState *)opaque;
return s->tsr_retry != 0;
}
static const VMStateDescription vmstate_serial_tsr = {
.name = "serial/tsr",
.version_id = 1,
.minimum_version_id = 1,
.needed = serial_tsr_needed,
.fields = (VMStateField[]) {
VMSTATE_UINT32(tsr_retry, SerialState),
VMSTATE_UINT8(thr, SerialState),
VMSTATE_UINT8(tsr, SerialState),
VMSTATE_END_OF_LIST()
}
};
static bool serial_recv_fifo_needed(void *opaque)
{
SerialState *s = (SerialState *)opaque;
return !fifo8_is_empty(&s->recv_fifo);
}
static const VMStateDescription vmstate_serial_recv_fifo = {
.name = "serial/recv_fifo",
.version_id = 1,
.minimum_version_id = 1,
.needed = serial_recv_fifo_needed,
.fields = (VMStateField[]) {
VMSTATE_STRUCT(recv_fifo, SerialState, 1, vmstate_fifo8, Fifo8),
VMSTATE_END_OF_LIST()
}
};
static bool serial_xmit_fifo_needed(void *opaque)
{
SerialState *s = (SerialState *)opaque;
return !fifo8_is_empty(&s->xmit_fifo);
}
static const VMStateDescription vmstate_serial_xmit_fifo = {
.name = "serial/xmit_fifo",
.version_id = 1,
.minimum_version_id = 1,
.needed = serial_xmit_fifo_needed,
.fields = (VMStateField[]) {
VMSTATE_STRUCT(xmit_fifo, SerialState, 1, vmstate_fifo8, Fifo8),
VMSTATE_END_OF_LIST()
}
};
static bool serial_fifo_timeout_timer_needed(void *opaque)
{
SerialState *s = (SerialState *)opaque;
return timer_pending(s->fifo_timeout_timer);
}
static const VMStateDescription vmstate_serial_fifo_timeout_timer = {
.name = "serial/fifo_timeout_timer",
.version_id = 1,
.minimum_version_id = 1,
.needed = serial_fifo_timeout_timer_needed,
.fields = (VMStateField[]) {
VMSTATE_TIMER_PTR(fifo_timeout_timer, SerialState),
VMSTATE_END_OF_LIST()
}
};
static bool serial_timeout_ipending_needed(void *opaque)
{
SerialState *s = (SerialState *)opaque;
return s->timeout_ipending != 0;
}
static const VMStateDescription vmstate_serial_timeout_ipending = {
.name = "serial/timeout_ipending",
.version_id = 1,
.minimum_version_id = 1,
.needed = serial_timeout_ipending_needed,
.fields = (VMStateField[]) {
VMSTATE_INT32(timeout_ipending, SerialState),
VMSTATE_END_OF_LIST()
}
};
static bool serial_poll_needed(void *opaque)
{
SerialState *s = (SerialState *)opaque;
return s->poll_msl >= 0;
}
static const VMStateDescription vmstate_serial_poll = {
.name = "serial/poll",
.version_id = 1,
.needed = serial_poll_needed,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_INT32(poll_msl, SerialState),
VMSTATE_TIMER_PTR(modem_status_poll, SerialState),
VMSTATE_END_OF_LIST()
}
};
const VMStateDescription vmstate_serial = {
.name = "serial",
.version_id = 3,
.minimum_version_id = 2,
.pre_save = serial_pre_save,
.pre_load = serial_pre_load,
.post_load = serial_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT16_V(divider, SerialState, 2),
VMSTATE_UINT8(rbr, SerialState),
VMSTATE_UINT8(ier, SerialState),
VMSTATE_UINT8(iir, SerialState),
VMSTATE_UINT8(lcr, SerialState),
VMSTATE_UINT8(mcr, SerialState),
VMSTATE_UINT8(lsr, SerialState),
VMSTATE_UINT8(msr, SerialState),
VMSTATE_UINT8(scr, SerialState),
VMSTATE_UINT8_V(fcr_vmstate, SerialState, 3),
VMSTATE_END_OF_LIST()
},
.subsections = (const VMStateDescription*[]) {
&vmstate_serial_thr_ipending,
&vmstate_serial_tsr,
&vmstate_serial_recv_fifo,
&vmstate_serial_xmit_fifo,
&vmstate_serial_fifo_timeout_timer,
&vmstate_serial_timeout_ipending,
&vmstate_serial_poll,
NULL
}
};
static void serial_reset(void *opaque)
{
SerialState *s = opaque;
if (s->watch_tag > 0) {
g_source_remove(s->watch_tag);
s->watch_tag = 0;
}
s->rbr = 0;
s->ier = 0;
s->iir = UART_IIR_NO_INT;
s->lcr = 0;
s->lsr = UART_LSR_TEMT | UART_LSR_THRE;
s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS;
/* Default to 9600 baud, 1 start bit, 8 data bits, 1 stop bit, no parity. */
s->divider = 0x0C;
s->mcr = UART_MCR_OUT2;
s->scr = 0;
s->tsr_retry = 0;
s->char_transmit_time = (NANOSECONDS_PER_SECOND / 9600) * 10;
s->poll_msl = 0;
s->timeout_ipending = 0;
timer_del(s->fifo_timeout_timer);
timer_del(s->modem_status_poll);
fifo8_reset(&s->recv_fifo);
fifo8_reset(&s->xmit_fifo);
s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
s->thr_ipending = 0;
s->last_break_enable = 0;
qemu_irq_lower(s->irq);
serial_update_msl(s);
s->msr &= ~UART_MSR_ANY_DELTA;
}
static int serial_be_change(void *opaque)
{
SerialState *s = opaque;
qemu_chr_fe_set_handlers(&s->chr, serial_can_receive1, serial_receive1,
serial_event, serial_be_change, s, NULL, true);
serial_update_parameters(s);
qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_BREAK,
&s->last_break_enable);
s->poll_msl = (s->ier & UART_IER_MSI) ? 1 : 0;
serial_update_msl(s);
if (s->poll_msl >= 0 && !(s->mcr & UART_MCR_LOOP)) {
serial_update_tiocm(s);
}
if (s->watch_tag > 0) {
g_source_remove(s->watch_tag);
s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP,
serial_watch_cb, s);
}
return 0;
}
void serial_realize_core(SerialState *s, Error **errp)
{
s->modem_status_poll = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *) serial_update_msl, s);
s->fifo_timeout_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *) fifo_timeout_int, s);
qemu_register_reset(serial_reset, s);
qemu_chr_fe_set_handlers(&s->chr, serial_can_receive1, serial_receive1,
serial_event, serial_be_change, s, NULL, true);
fifo8_create(&s->recv_fifo, UART_FIFO_LENGTH);
fifo8_create(&s->xmit_fifo, UART_FIFO_LENGTH);
serial_reset(s);
}
void serial_exit_core(SerialState *s)
{
qemu_chr_fe_deinit(&s->chr, false);
timer_del(s->modem_status_poll);
timer_free(s->modem_status_poll);
timer_del(s->fifo_timeout_timer);
timer_free(s->fifo_timeout_timer);
fifo8_destroy(&s->recv_fifo);
fifo8_destroy(&s->xmit_fifo);
qemu_unregister_reset(serial_reset, s);
}
/* Change the main reference oscillator frequency. */
void serial_set_frequency(SerialState *s, uint32_t frequency)
{
s->baudbase = frequency;
serial_update_parameters(s);
}
const MemoryRegionOps serial_io_ops = {
.read = serial_ioport_read,
.write = serial_ioport_write,
.impl = {
.min_access_size = 1,
.max_access_size = 1,
},
.endianness = DEVICE_LITTLE_ENDIAN,
};
SerialState *serial_init(int base, qemu_irq irq, int baudbase,
Chardev *chr, MemoryRegion *system_io)
{
SerialState *s;
s = g_malloc0(sizeof(SerialState));
s->irq = irq;
s->baudbase = baudbase;
qemu_chr_fe_init(&s->chr, chr, &error_abort);
serial_realize_core(s, &error_fatal);
vmstate_register(NULL, base, &vmstate_serial, s);
memory_region_init_io(&s->io, NULL, &serial_io_ops, s, "serial", 8);
memory_region_add_subregion(system_io, base, &s->io);
return s;
}
/* Memory mapped interface */
static uint64_t serial_mm_read(void *opaque, hwaddr addr,
unsigned size)
{
SerialState *s = opaque;
return serial_ioport_read(s, addr >> s->it_shift, 1);
}
static void serial_mm_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
SerialState *s = opaque;
value &= 255;
serial_ioport_write(s, addr >> s->it_shift, value, 1);
}
static const MemoryRegionOps serial_mm_ops[3] = {
[DEVICE_NATIVE_ENDIAN] = {
.read = serial_mm_read,
.write = serial_mm_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid.max_access_size = 8,
.impl.max_access_size = 8,
},
[DEVICE_LITTLE_ENDIAN] = {
.read = serial_mm_read,
.write = serial_mm_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid.max_access_size = 8,
.impl.max_access_size = 8,
},
[DEVICE_BIG_ENDIAN] = {
.read = serial_mm_read,
.write = serial_mm_write,
.endianness = DEVICE_BIG_ENDIAN,
.valid.max_access_size = 8,
.impl.max_access_size = 8,
},
};
SerialState *serial_mm_init(MemoryRegion *address_space,
hwaddr base, int it_shift,
qemu_irq irq, int baudbase,
Chardev *chr, enum device_endian end)
{
SerialState *s;
s = g_malloc0(sizeof(SerialState));
s->it_shift = it_shift;
s->irq = irq;
s->baudbase = baudbase;
qemu_chr_fe_init(&s->chr, chr, &error_abort);
serial_realize_core(s, &error_fatal);
vmstate_register(NULL, base, &vmstate_serial, s);
memory_region_init_io(&s->io, NULL, &serial_mm_ops[end], s,
"serial", 8 << it_shift);
memory_region_add_subregion(address_space, base, &s->io);
return s;
}
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