hw/char/serial: Clean up unnecessary code

Since commit 5ec3a23e6c ("serial: convert PIO to new memory
api read/write") we don't need to worry about accesses bigger
than 8-bit. Use the extract()/deposit() functions to access
the correct part of the 16-bit 'divider' register.

Reported-by: Jonathan D. Belanger <jbelanger1@rochester.rr.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1904331
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201120161933.2514089-1-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Philippe Mathieu-Daudé 2020-11-20 17:19:33 +01:00 committed by Paolo Bonzini
parent b326b6ea79
commit 29daa894b6

View File

@ -24,6 +24,7 @@
*/
#include "qemu/osdep.h"
#include "qemu/bitops.h"
#include "hw/char/serial.h"
#include "hw/irq.h"
#include "migration/vmstate.h"
@ -338,11 +339,7 @@ static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val,
default:
case 0:
if (s->lcr & UART_LCR_DLAB) {
if (size == 1) {
s->divider = (s->divider & 0xff00) | val;
} else {
s->divider = val;
}
s->divider = deposit32(s->divider, 8 * addr, 8, val);
serial_update_parameters(s);
} else {
s->thr = (uint8_t) val;
@ -364,7 +361,7 @@ static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val,
break;
case 1:
if (s->lcr & UART_LCR_DLAB) {
s->divider = (s->divider & 0x00ff) | (val << 8);
s->divider = deposit32(s->divider, 8 * addr, 8, val);
serial_update_parameters(s);
} else {
uint8_t changed = (s->ier ^ val) & 0x0f;
@ -478,7 +475,7 @@ static uint64_t serial_ioport_read(void *opaque, hwaddr addr, unsigned size)
default:
case 0:
if (s->lcr & UART_LCR_DLAB) {
ret = s->divider & 0xff;
ret = extract16(s->divider, 8 * addr, 8);
} else {
if(s->fcr & UART_FCR_FE) {
ret = fifo8_is_empty(&s->recv_fifo) ?
@ -502,7 +499,7 @@ static uint64_t serial_ioport_read(void *opaque, hwaddr addr, unsigned size)
break;
case 1:
if (s->lcr & UART_LCR_DLAB) {
ret = (s->divider >> 8) & 0xff;
ret = extract16(s->divider, 8 * addr, 8);
} else {
ret = s->ier;
}