qemu/hw/spapr_vty.c
David Gibson 5f2e2ba262 pseries: Consolidate hack for RTAS display-character usage
Currently the pseries machine contains not one but two somewhat ugly hacks
to allow printing of early debug messages before the guest has properly
read the device tree.

First, we special case H_PUT_TERM_CHAR so that a vtermno of 0 (usually
invalid) will look for a suitable vty and use that.  This supports Linux's
early debug code which will use H_PUT_TERM_CHAR with vtermno==0 before
reading the device tree.  Second, we support the RTAS display-character call.
This takes no vtermno so we assume the address of the default first VTY.

This patch makes things more consistent by folding the second hack into the
first.  Now, display-character uses the existing vty_lookup() function to
do the same search for a suitable VTY.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2012-04-15 17:07:19 +02:00

221 lines
5.7 KiB
C

#include "qdev.h"
#include "qemu-char.h"
#include "hw/spapr.h"
#include "hw/spapr_vio.h"
#define VTERM_BUFSIZE 16
typedef struct VIOsPAPRVTYDevice {
VIOsPAPRDevice sdev;
CharDriverState *chardev;
uint32_t in, out;
uint8_t buf[VTERM_BUFSIZE];
} VIOsPAPRVTYDevice;
static int vty_can_receive(void *opaque)
{
VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)opaque;
return (dev->in - dev->out) < VTERM_BUFSIZE;
}
static void vty_receive(void *opaque, const uint8_t *buf, int size)
{
VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)opaque;
int i;
if ((dev->in == dev->out) && size) {
/* toggle line to simulate edge interrupt */
qemu_irq_pulse(dev->sdev.qirq);
}
for (i = 0; i < size; i++) {
assert((dev->in - dev->out) < VTERM_BUFSIZE);
dev->buf[dev->in++ % VTERM_BUFSIZE] = buf[i];
}
}
static int vty_getchars(VIOsPAPRDevice *sdev, uint8_t *buf, int max)
{
VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)sdev;
int n = 0;
while ((n < max) && (dev->out != dev->in)) {
buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];
}
return n;
}
void vty_putchars(VIOsPAPRDevice *sdev, uint8_t *buf, int len)
{
VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)sdev;
/* FIXME: should check the qemu_chr_fe_write() return value */
qemu_chr_fe_write(dev->chardev, buf, len);
}
static int spapr_vty_init(VIOsPAPRDevice *sdev)
{
VIOsPAPRVTYDevice *dev = (VIOsPAPRVTYDevice *)sdev;
if (!dev->chardev) {
fprintf(stderr, "spapr-vty: Can't create vty without a chardev!\n");
exit(1);
}
qemu_chr_add_handlers(dev->chardev, vty_can_receive,
vty_receive, NULL, dev);
return 0;
}
/* Forward declaration */
static target_ulong h_put_term_char(CPUPPCState *env, sPAPREnvironment *spapr,
target_ulong opcode, target_ulong *args)
{
target_ulong reg = args[0];
target_ulong len = args[1];
target_ulong char0_7 = args[2];
target_ulong char8_15 = args[3];
VIOsPAPRDevice *sdev;
uint8_t buf[16];
sdev = vty_lookup(spapr, reg);
if (!sdev) {
return H_PARAMETER;
}
if (len > 16) {
return H_PARAMETER;
}
*((uint64_t *)buf) = cpu_to_be64(char0_7);
*((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
vty_putchars(sdev, buf, len);
return H_SUCCESS;
}
static target_ulong h_get_term_char(CPUPPCState *env, sPAPREnvironment *spapr,
target_ulong opcode, target_ulong *args)
{
target_ulong reg = args[0];
target_ulong *len = args + 0;
target_ulong *char0_7 = args + 1;
target_ulong *char8_15 = args + 2;
VIOsPAPRDevice *sdev;
uint8_t buf[16];
sdev = vty_lookup(spapr, reg);
if (!sdev) {
return H_PARAMETER;
}
*len = vty_getchars(sdev, buf, sizeof(buf));
if (*len < 16) {
memset(buf + *len, 0, 16 - *len);
}
*char0_7 = be64_to_cpu(*((uint64_t *)buf));
*char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
return H_SUCCESS;
}
void spapr_vty_create(VIOsPAPRBus *bus, uint32_t reg, CharDriverState *chardev)
{
DeviceState *dev;
dev = qdev_create(&bus->bus, "spapr-vty");
qdev_prop_set_uint32(dev, "reg", reg);
qdev_prop_set_chr(dev, "chardev", chardev);
qdev_init_nofail(dev);
}
static Property spapr_vty_properties[] = {
DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev, SPAPR_VTY_BASE_ADDRESS, 0),
DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
DEFINE_PROP_END_OF_LIST(),
};
static void spapr_vty_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VIOsPAPRDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
k->init = spapr_vty_init;
k->dt_name = "vty";
k->dt_type = "serial";
k->dt_compatible = "hvterm1";
dc->props = spapr_vty_properties;
}
static TypeInfo spapr_vty_info = {
.name = "spapr-vty",
.parent = TYPE_VIO_SPAPR_DEVICE,
.instance_size = sizeof(VIOsPAPRVTYDevice),
.class_init = spapr_vty_class_init,
};
VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
{
VIOsPAPRDevice *sdev, *selected;
DeviceState *iter;
/*
* To avoid the console bouncing around we want one VTY to be
* the "default". We haven't really got anything to go on, so
* arbitrarily choose the one with the lowest reg value.
*/
selected = NULL;
QTAILQ_FOREACH(iter, &bus->bus.children, sibling) {
/* Only look at VTY devices */
if (!object_dynamic_cast(OBJECT(iter), "spapr-vty")) {
continue;
}
sdev = DO_UPCAST(VIOsPAPRDevice, qdev, iter);
/* First VTY we've found, so it is selected for now */
if (!selected) {
selected = sdev;
continue;
}
/* Choose VTY with lowest reg value */
if (sdev->reg < selected->reg) {
selected = sdev;
}
}
return selected;
}
VIOsPAPRDevice *vty_lookup(sPAPREnvironment *spapr, target_ulong reg)
{
VIOsPAPRDevice *sdev;
sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
if (!sdev && reg == 0) {
/* Hack for kernel early debug, which always specifies reg==0.
* We search all VIO devices, and grab the vty with the lowest
* reg. This attempts to mimic existing PowerVM behaviour
* (early debug does work there, despite having no vty with
* reg==0. */
return spapr_vty_get_default(spapr->vio_bus);
}
return sdev;
}
static void spapr_vty_register_types(void)
{
spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
type_register_static(&spapr_vty_info);
}
type_init(spapr_vty_register_types)