qemu/hw/char/serial.c

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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 "qemu/bitops.h"
#include "hw/char/serial.h"
#include "hw/irq.h"
#include "migration/vmstate.h"
#include "chardev/char-serial.h"
2016-03-14 16:01:28 +08:00
#include "qapi/error.h"
#include "qemu/timer.h"
#include "sysemu/reset.h"
#include "sysemu/runstate.h"
#include "qemu/error-report.h"
#include "trace.h"
#include "hw/qdev-properties.h"
#include "hw/qdev-properties-system.h"
#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
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);
trace_serial_update_parameters(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)
{
serial: change retry logic to avoid concurrency Whenever serial_xmit fails to transmit a byte it adds a watch that would call it again when the "line" becomes ready. This results in a retry chain: serial_xmit -> add_watch -> serial_xmit Each chain is able to transmit one character, and for every character passed to serial by the guest driver a new chain is spawned. The problem lays with the fact that a new chain is spawned even when there is one already waiting on the watch. So there can be several retry chains waiting concurrently on one "line". Every chain tries to transmit current character, so character order is not messed up. But also every chain increases retry counter (tsr_retry). If there are enough concurrent chains this counter will hit MAX_XMIT_RETRY value and the character will be dropped. To reproduce this bug you need to feed serial output to some program consuming it slowly enough. A python script from bug #1335444 description is an example of such program. This commit changes retry logic in the following way to avoid concurrency: instead of spawning a new chain for each character being transmitted spawn only one and make it transmit characters until FIFO is empty. The change consists of two parts: - add a do {} while () loop in serial_xmit (diff is a bit erratic for this part, diff -w will show actual change), - do not call serial_xmit from serial_ioport_write if there is one waiting on the watch already. This should fix another issue causing bug #1335444. Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 17:41:08 +08:00
do {
assert(!(s->lsr & UART_LSR_TEMT));
if (s->tsr_retry == 0) {
assert(!(s->lsr & UART_LSR_THRE));
serial: change retry logic to avoid concurrency Whenever serial_xmit fails to transmit a byte it adds a watch that would call it again when the "line" becomes ready. This results in a retry chain: serial_xmit -> add_watch -> serial_xmit Each chain is able to transmit one character, and for every character passed to serial by the guest driver a new chain is spawned. The problem lays with the fact that a new chain is spawned even when there is one already waiting on the watch. So there can be several retry chains waiting concurrently on one "line". Every chain tries to transmit current character, so character order is not messed up. But also every chain increases retry counter (tsr_retry). If there are enough concurrent chains this counter will hit MAX_XMIT_RETRY value and the character will be dropped. To reproduce this bug you need to feed serial output to some program consuming it slowly enough. A python script from bug #1335444 description is an example of such program. This commit changes retry logic in the following way to avoid concurrency: instead of spawning a new chain for each character being transmitted spawn only one and make it transmit characters until FIFO is empty. The change consists of two parts: - add a do {} while () loop in serial_xmit (diff is a bit erratic for this part, diff -w will show actual change), - do not call serial_xmit from serial_ioport_write if there is one waiting on the watch already. This should fix another issue causing bug #1335444. Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 17:41:08 +08:00
if (s->fcr & UART_FCR_FE) {
assert(!fifo8_is_empty(&s->xmit_fifo));
serial: change retry logic to avoid concurrency Whenever serial_xmit fails to transmit a byte it adds a watch that would call it again when the "line" becomes ready. This results in a retry chain: serial_xmit -> add_watch -> serial_xmit Each chain is able to transmit one character, and for every character passed to serial by the guest driver a new chain is spawned. The problem lays with the fact that a new chain is spawned even when there is one already waiting on the watch. So there can be several retry chains waiting concurrently on one "line". Every chain tries to transmit current character, so character order is not messed up. But also every chain increases retry counter (tsr_retry). If there are enough concurrent chains this counter will hit MAX_XMIT_RETRY value and the character will be dropped. To reproduce this bug you need to feed serial output to some program consuming it slowly enough. A python script from bug #1335444 description is an example of such program. This commit changes retry logic in the following way to avoid concurrency: instead of spawning a new chain for each character being transmitted spawn only one and make it transmit characters until FIFO is empty. The change consists of two parts: - add a do {} while () loop in serial_xmit (diff is a bit erratic for this part, diff -w will show actual change), - do not call serial_xmit from serial_ioport_write if there is one waiting on the watch already. This should fix another issue causing bug #1335444. Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 17:41:08 +08:00
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);
}
}
serial: change retry logic to avoid concurrency Whenever serial_xmit fails to transmit a byte it adds a watch that would call it again when the "line" becomes ready. This results in a retry chain: serial_xmit -> add_watch -> serial_xmit Each chain is able to transmit one character, and for every character passed to serial by the guest driver a new chain is spawned. The problem lays with the fact that a new chain is spawned even when there is one already waiting on the watch. So there can be several retry chains waiting concurrently on one "line". Every chain tries to transmit current character, so character order is not messed up. But also every chain increases retry counter (tsr_retry). If there are enough concurrent chains this counter will hit MAX_XMIT_RETRY value and the character will be dropped. To reproduce this bug you need to feed serial output to some program consuming it slowly enough. A python script from bug #1335444 description is an example of such program. This commit changes retry logic in the following way to avoid concurrency: instead of spawning a new chain for each character being transmitted spawn only one and make it transmit characters until FIFO is empty. The change consists of two parts: - add a do {} while () loop in serial_xmit (diff is a bit erratic for this part, diff -w will show actual change), - do not call serial_xmit from serial_ioport_write if there is one waiting on the watch already. This should fix another issue causing bug #1335444. Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 17:41:08 +08:00
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;
}
serial: change retry logic to avoid concurrency Whenever serial_xmit fails to transmit a byte it adds a watch that would call it again when the "line" becomes ready. This results in a retry chain: serial_xmit -> add_watch -> serial_xmit Each chain is able to transmit one character, and for every character passed to serial by the guest driver a new chain is spawned. The problem lays with the fact that a new chain is spawned even when there is one already waiting on the watch. So there can be several retry chains waiting concurrently on one "line". Every chain tries to transmit current character, so character order is not messed up. But also every chain increases retry counter (tsr_retry). If there are enough concurrent chains this counter will hit MAX_XMIT_RETRY value and the character will be dropped. To reproduce this bug you need to feed serial output to some program consuming it slowly enough. A python script from bug #1335444 description is an example of such program. This commit changes retry logic in the following way to avoid concurrency: instead of spawning a new chain for each character being transmitted spawn only one and make it transmit characters until FIFO is empty. The change consists of two parts: - add a do {} while () loop in serial_xmit (diff is a bit erratic for this part, diff -w will show actual change), - do not call serial_xmit from serial_ioport_write if there is one waiting on the watch already. This should fix another issue causing bug #1335444. Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 17:41:08 +08:00
}
}
s->tsr_retry = 0;
serial: change retry logic to avoid concurrency Whenever serial_xmit fails to transmit a byte it adds a watch that would call it again when the "line" becomes ready. This results in a retry chain: serial_xmit -> add_watch -> serial_xmit Each chain is able to transmit one character, and for every character passed to serial by the guest driver a new chain is spawned. The problem lays with the fact that a new chain is spawned even when there is one already waiting on the watch. So there can be several retry chains waiting concurrently on one "line". Every chain tries to transmit current character, so character order is not messed up. But also every chain increases retry counter (tsr_retry). If there are enough concurrent chains this counter will hit MAX_XMIT_RETRY value and the character will be dropped. To reproduce this bug you need to feed serial output to some program consuming it slowly enough. A python script from bug #1335444 description is an example of such program. This commit changes retry logic in the following way to avoid concurrency: instead of spawning a new chain for each character being transmitted spawn only one and make it transmit characters until FIFO is empty. The change consists of two parts: - add a do {} while () loop in serial_xmit (diff is a bit erratic for this part, diff -w will show actual change), - do not call serial_xmit from serial_ioport_write if there is one waiting on the watch already. This should fix another issue causing bug #1335444. Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 17:41:08 +08:00
/* 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;
assert(size == 1 && addr < 8);
trace_serial_write(addr, val);
switch(addr) {
default:
case 0:
if (s->lcr & UART_LCR_DLAB) {
s->divider = deposit32(s->divider, 8 * addr, 8, 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);
serial: change retry logic to avoid concurrency Whenever serial_xmit fails to transmit a byte it adds a watch that would call it again when the "line" becomes ready. This results in a retry chain: serial_xmit -> add_watch -> serial_xmit Each chain is able to transmit one character, and for every character passed to serial by the guest driver a new chain is spawned. The problem lays with the fact that a new chain is spawned even when there is one already waiting on the watch. So there can be several retry chains waiting concurrently on one "line". Every chain tries to transmit current character, so character order is not messed up. But also every chain increases retry counter (tsr_retry). If there are enough concurrent chains this counter will hit MAX_XMIT_RETRY value and the character will be dropped. To reproduce this bug you need to feed serial output to some program consuming it slowly enough. A python script from bug #1335444 description is an example of such program. This commit changes retry logic in the following way to avoid concurrency: instead of spawning a new chain for each character being transmitted spawn only one and make it transmit characters until FIFO is empty. The change consists of two parts: - add a do {} while () loop in serial_xmit (diff is a bit erratic for this part, diff -w will show actual change), - do not call serial_xmit from serial_ioport_write if there is one waiting on the watch already. This should fix another issue causing bug #1335444. Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 17:41:08 +08:00
}
}
break;
case 1:
if (s->lcr & UART_LCR_DLAB) {
s->divider = deposit32(s->divider, 8 * addr, 8, val);
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;
assert(size == 1 && addr < 8);
switch(addr) {
default:
case 0:
if (s->lcr & UART_LCR_DLAB) {
ret = extract16(s->divider, 8 * addr, 8);
} 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 = extract16(s->divider, 8 * addr, 8);
} 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_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) {
qmp hmp: Make system_wakeup check wake-up support and run state The qmp/hmp command 'system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' from vl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended. This means that system_wakeup is silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it. Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all. All this considered, this patch changes qmp_system_wakeup to check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output of system_wakeup in a guest that does not have wake-up from suspend support (ppc64): (qemu) system_wakeup wake-up from suspend is not supported by this guest (qemu) And this is the output of system_wakeup in a x86 guest that has the support but isn't suspended: (qemu) system_wakeup Unable to wake up: guest is not in suspended state (qemu) Reported-by: Balamuruhan S <bala24@linux.vnet.ibm.com> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Message-Id: <20181205194701.17836-4-danielhb413@gmail.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Acked-by: Eduardo Habkost <ehabkost@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-06 03:47:01 +08:00
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
}
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, QEMUChrEvent event)
{
SerialState *s = opaque;
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;
}
static void serial_realize(DeviceState *dev, Error **errp)
{
SerialState *s = SERIAL(dev);
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);
}
qdev: Unrealize must not fail Devices may have component devices and buses. Device realization may fail. Realization is recursive: a device's realize() method realizes its components, and device_set_realized() realizes its buses (which should in turn realize the devices on that bus, except bus_set_realized() doesn't implement that, yet). When realization of a component or bus fails, we need to roll back: unrealize everything we realized so far. If any of these unrealizes failed, the device would be left in an inconsistent state. Must not happen. device_set_realized() lets it happen: it ignores errors in the roll back code starting at label child_realize_fail. Since realization is recursive, unrealization must be recursive, too. But how could a partly failed unrealize be rolled back? We'd have to re-realize, which can fail. This design is fundamentally broken. device_set_realized() does not roll back at all. Instead, it keeps unrealizing, ignoring further errors. It can screw up even for a device with no buses: if the lone dc->unrealize() fails, it still unregisters vmstate, and calls listeners' unrealize() callback. bus_set_realized() does not roll back either. Instead, it stops unrealizing. Fortunately, no unrealize method can fail, as we'll see below. To fix the design error, drop parameter @errp from all the unrealize methods. Any unrealize method that uses @errp now needs an update. This leads us to unrealize() methods that can fail. Merely passing it to another unrealize method cannot cause failure, though. Here are the ones that do other things with @errp: * virtio_serial_device_unrealize() Fails when qbus_set_hotplug_handler() fails, but still does all the other work. On failure, the device would stay realized with its resources completely gone. Oops. Can't happen, because qbus_set_hotplug_handler() can't actually fail here. Pass &error_abort to qbus_set_hotplug_handler() instead. * hw/ppc/spapr_drc.c's unrealize() Fails when object_property_del() fails, but all the other work is already done. On failure, the device would stay realized with its vmstate registration gone. Oops. Can't happen, because object_property_del() can't actually fail here. Pass &error_abort to object_property_del() instead. * spapr_phb_unrealize() Fails and bails out when remove_drcs() fails, but other work is already done. On failure, the device would stay realized with some of its resources gone. Oops. remove_drcs() fails only when chassis_from_bus()'s object_property_get_uint() fails, and it can't here. Pass &error_abort to remove_drcs() instead. Therefore, no unrealize method can fail before this patch. device_set_realized()'s recursive unrealization via bus uses object_property_set_bool(). Can't drop @errp there, so pass &error_abort. We similarly unrealize with object_property_set_bool() elsewhere, always ignoring errors. Pass &error_abort instead. Several unrealize methods no longer handle errors from other unrealize methods: virtio_9p_device_unrealize(), virtio_input_device_unrealize(), scsi_qdev_unrealize(), ... Much of the deleted error handling looks wrong anyway. One unrealize methods no longer ignore such errors: usb_ehci_pci_exit(). Several realize methods no longer ignore errors when rolling back: v9fs_device_realize_common(), pci_qdev_unrealize(), spapr_phb_realize(), usb_qdev_realize(), vfio_ccw_realize(), virtio_device_realize(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-17-armbru@redhat.com>
2020-05-05 23:29:24 +08:00
static void serial_unrealize(DeviceState *dev)
{
SerialState *s = SERIAL(dev);
qemu_chr_fe_deinit(&s->chr, false);
timer_free(s->modem_status_poll);
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,
};
static Property serial_properties[] = {
DEFINE_PROP_CHR("chardev", SerialState, chr),
DEFINE_PROP_UINT32("baudbase", SerialState, baudbase, 115200),
DEFINE_PROP_BOOL("wakeup", SerialState, wakeup, false),
DEFINE_PROP_END_OF_LIST(),
};
static void serial_class_init(ObjectClass *klass, void* data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
/* internal device for serialio/serialmm, not user-creatable */
dc->user_creatable = false;
dc->realize = serial_realize;
dc->unrealize = serial_unrealize;
device_class_set_props(dc, serial_properties);
}
static const TypeInfo serial_info = {
.name = TYPE_SERIAL,
.parent = TYPE_DEVICE,
.instance_size = sizeof(SerialState),
.class_init = serial_class_init,
};
/* Memory mapped interface */
static uint64_t serial_mm_read(void *opaque, hwaddr addr,
unsigned size)
{
SerialMM *s = SERIAL_MM(opaque);
return serial_ioport_read(&s->serial, addr >> s->regshift, 1);
}
static void serial_mm_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
SerialMM *s = SERIAL_MM(opaque);
value &= 255;
serial_ioport_write(&s->serial, addr >> s->regshift, 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,
},
};
static void serial_mm_realize(DeviceState *dev, Error **errp)
{
SerialMM *smm = SERIAL_MM(dev);
SerialState *s = &smm->serial;
error: Eliminate error_propagate() with Coccinelle, part 1 When all we do with an Error we receive into a local variable is propagating to somewhere else, we can just as well receive it there right away. Convert if (!foo(..., &err)) { ... error_propagate(errp, err); ... return ... } to if (!foo(..., errp)) { ... ... return ... } where nothing else needs @err. Coccinelle script: @rule1 forall@ identifier fun, err, errp, lbl; expression list args, args2; binary operator op; constant c1, c2; symbol false; @@ if ( ( - fun(args, &err, args2) + fun(args, errp, args2) | - !fun(args, &err, args2) + !fun(args, errp, args2) | - fun(args, &err, args2) op c1 + fun(args, errp, args2) op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; ) } @rule2 forall@ identifier fun, err, errp, lbl; expression list args, args2; expression var; binary operator op; constant c1, c2; symbol false; @@ - var = fun(args, &err, args2); + var = fun(args, errp, args2); ... when != err if ( ( var | !var | var op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; | return var; ) } @depends on rule1 || rule2@ identifier err; @@ - Error *err = NULL; ... when != err Not exactly elegant, I'm afraid. The "when != lbl:" is necessary to avoid transforming if (fun(args, &err)) { goto out } ... out: error_propagate(errp, err); even though other paths to label out still need the error_propagate(). For an actual example, see sclp_realize(). Without the "when strict", Coccinelle transforms vfio_msix_setup(), incorrectly. I don't know what exactly "when strict" does, only that it helps here. The match of return is narrower than what I want, but I can't figure out how to express "return where the operand doesn't use @err". For an example where it's too narrow, see vfio_intx_enable(). Silently fails to convert hw/arm/armsse.c, because Coccinelle gets confused by ARMSSE being used both as typedef and function-like macro there. Converted manually. Line breaks tidied up manually. One nested declaration of @local_err deleted manually. Preexisting unwanted blank line dropped in hw/riscv/sifive_e.c. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-08 00:06:02 +08:00
if (!qdev_realize(DEVICE(s), NULL, errp)) {
return;
}
memory_region_init_io(&s->io, OBJECT(dev),
&serial_mm_ops[smm->endianness], smm, "serial",
8 << smm->regshift);
sysbus_init_mmio(SYS_BUS_DEVICE(smm), &s->io);
sysbus_init_irq(SYS_BUS_DEVICE(smm), &smm->serial.irq);
}
static const VMStateDescription vmstate_serial_mm = {
.name = "serial",
.version_id = 3,
.minimum_version_id = 2,
.fields = (VMStateField[]) {
VMSTATE_STRUCT(serial, SerialMM, 0, vmstate_serial, SerialState),
VMSTATE_END_OF_LIST()
}
};
SerialMM *serial_mm_init(MemoryRegion *address_space,
hwaddr base, int regshift,
qemu_irq irq, int baudbase,
Chardev *chr, enum device_endian end)
{
SerialMM *smm = SERIAL_MM(qdev_new(TYPE_SERIAL_MM));
MemoryRegion *mr;
qdev_prop_set_uint8(DEVICE(smm), "regshift", regshift);
qdev_prop_set_uint32(DEVICE(smm), "baudbase", baudbase);
qdev_prop_set_chr(DEVICE(smm), "chardev", chr);
qdev_set_legacy_instance_id(DEVICE(smm), base, 2);
qdev_prop_set_uint8(DEVICE(smm), "endianness", end);
sysbus_realize_and_unref(SYS_BUS_DEVICE(smm), &error_fatal);
sysbus_connect_irq(SYS_BUS_DEVICE(smm), 0, irq);
mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(smm), 0);
memory_region_add_subregion(address_space, base, mr);
return smm;
}
static void serial_mm_instance_init(Object *o)
{
SerialMM *smm = SERIAL_MM(o);
qom: Less verbose object_initialize_child() All users of object_initialize_child() pass the obvious child size argument. Almost all pass &error_abort and no properties. Tiresome. Rename object_initialize_child() to object_initialize_child_with_props() to free the name. New convenience wrapper object_initialize_child() automates the size argument, and passes &error_abort and no properties. Rename object_initialize_childv() to object_initialize_child_with_propsv() for consistency. Convert callers with this Coccinelle script: @@ expression parent, propname, type; expression child, size; symbol error_abort; @@ - object_initialize_child(parent, propname, OBJECT(child), size, type, &error_abort, NULL) + object_initialize_child(parent, propname, child, size, type, &error_abort, NULL) @@ expression parent, propname, type; expression child; symbol error_abort; @@ - object_initialize_child(parent, propname, child, sizeof(*child), type, &error_abort, NULL) + object_initialize_child(parent, propname, child, type) @@ expression parent, propname, type; expression child; symbol error_abort; @@ - object_initialize_child(parent, propname, &child, sizeof(child), type, &error_abort, NULL) + object_initialize_child(parent, propname, &child, type) @@ expression parent, propname, type; expression child, size, err; expression list props; @@ - object_initialize_child(parent, propname, child, size, type, err, props) + object_initialize_child_with_props(parent, propname, child, size, type, err, props) Note that Coccinelle chokes on ARMSSE typedef vs. macro in hw/arm/armsse.c. Worked around by temporarily renaming the macro for the spatch run. Signed-off-by: Markus Armbruster <armbru@redhat.com> Acked-by: Alistair Francis <alistair.francis@wdc.com> [Rebased: machine opentitan is new (commit fe0fe4735e7)] Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200610053247.1583243-37-armbru@redhat.com>
2020-06-10 13:32:25 +08:00
object_initialize_child(o, "serial", &smm->serial, TYPE_SERIAL);
qdev_alias_all_properties(DEVICE(&smm->serial), o);
}
static Property serial_mm_properties[] = {
/*
* Set the spacing between adjacent memory-mapped UART registers.
* Each register will be at (1 << regshift) bytes after the
* previous one.
*/
DEFINE_PROP_UINT8("regshift", SerialMM, regshift, 0),
DEFINE_PROP_UINT8("endianness", SerialMM, endianness, DEVICE_NATIVE_ENDIAN),
DEFINE_PROP_END_OF_LIST(),
};
static void serial_mm_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
device_class_set_props(dc, serial_mm_properties);
dc->realize = serial_mm_realize;
dc->vmsd = &vmstate_serial_mm;
}
static const TypeInfo serial_mm_info = {
.name = TYPE_SERIAL_MM,
.parent = TYPE_SYS_BUS_DEVICE,
.class_init = serial_mm_class_init,
.instance_init = serial_mm_instance_init,
.instance_size = sizeof(SerialMM),
};
static void serial_register_types(void)
{
type_register_static(&serial_info);
type_register_static(&serial_mm_info);
}
type_init(serial_register_types)