qemu-e2k/hw/char/sclpconsole.c

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/*
* SCLP event type
* Ascii Console Data (VT220 Console)
*
* Copyright IBM, Corp. 2012
*
* Authors:
* Heinz Graalfs <graalfs@de.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at your
* option) any later version. See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qemu/thread.h"
#include "qemu/error-report.h"
#include "qemu/module.h"
#include "hw/s390x/sclp.h"
#include "migration/vmstate.h"
#include "hw/qdev-properties.h"
#include "hw/s390x/event-facility.h"
#include "chardev/char-fe.h"
typedef struct ASCIIConsoleData {
EventBufferHeader ebh;
char data[0];
} QEMU_PACKED ASCIIConsoleData;
/* max size for ASCII data in 4K SCCB page */
#define SIZE_BUFFER_VT220 4080
typedef struct SCLPConsole {
SCLPEvent event;
CharBackend chr;
uint8_t iov[SIZE_BUFFER_VT220];
uint32_t iov_sclp; /* offset in buf for SCLP read operation */
uint32_t iov_bs; /* offset in buf for char layer read operation */
uint32_t iov_data_len; /* length of byte stream in buffer */
uint32_t iov_sclp_rest; /* length of byte stream not read via SCLP */
bool notify; /* qemu_notify_event() req'd if true */
} SCLPConsole;
#define TYPE_SCLP_CONSOLE "sclpconsole"
#define SCLP_CONSOLE(obj) \
OBJECT_CHECK(SCLPConsole, (obj), TYPE_SCLP_CONSOLE)
/* character layer call-back functions */
/* Return number of bytes that fit into iov buffer */
static int chr_can_read(void *opaque)
{
SCLPConsole *scon = opaque;
int avail = SIZE_BUFFER_VT220 - scon->iov_data_len;
if (avail == 0) {
scon->notify = true;
}
return avail;
}
/* Send data from a char device over to the guest */
static void chr_read(void *opaque, const uint8_t *buf, int size)
{
SCLPConsole *scon = opaque;
assert(scon);
/* read data must fit into current buffer */
assert(size <= SIZE_BUFFER_VT220 - scon->iov_data_len);
/* put byte-stream from character layer into buffer */
memcpy(&scon->iov[scon->iov_bs], buf, size);
scon->iov_data_len += size;
scon->iov_sclp_rest += size;
scon->iov_bs += size;
scon->event.event_pending = true;
sclp_service_interrupt(0);
}
/* functions to be called by event facility */
static bool can_handle_event(uint8_t type)
{
return type == SCLP_EVENT_ASCII_CONSOLE_DATA;
}
static sccb_mask_t send_mask(void)
{
return SCLP_EVENT_MASK_MSG_ASCII;
}
static sccb_mask_t receive_mask(void)
{
return SCLP_EVENT_MASK_MSG_ASCII;
}
/* triggered by SCLP's read_event_data -
* copy console data byte-stream into provided (SCLP) buffer
*/
static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
int avail)
{
SCLPConsole *cons = SCLP_CONSOLE(event);
/* first byte is hex 0 saying an ascii string follows */
*buf++ = '\0';
avail--;
/* if all data fit into provided SCLP buffer */
if (avail >= cons->iov_sclp_rest) {
/* copy character byte-stream to SCLP buffer */
memcpy(buf, &cons->iov[cons->iov_sclp], cons->iov_sclp_rest);
*size = cons->iov_sclp_rest + 1;
cons->iov_sclp = 0;
cons->iov_bs = 0;
cons->iov_data_len = 0;
cons->iov_sclp_rest = 0;
event->event_pending = false;
/* data provided and no more data pending */
} else {
/* if provided buffer is too small, just copy part */
memcpy(buf, &cons->iov[cons->iov_sclp], avail);
*size = avail + 1;
cons->iov_sclp_rest -= avail;
cons->iov_sclp += avail;
/* more data pending */
}
if (cons->notify) {
cons->notify = false;
qemu_notify_event();
}
}
static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
int *slen)
{
int avail;
size_t src_len;
uint8_t *to;
ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
if (!event->event_pending) {
/* no data pending */
return 0;
}
to = (uint8_t *)&acd->data;
avail = *slen - sizeof(ASCIIConsoleData);
get_console_data(event, to, &src_len, avail);
acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
*slen = avail - src_len;
return 1;
}
/* triggered by SCLP's write_event_data
* - write console data to character layer
* returns < 0 if an error occurred
*/
static ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
size_t len)
{
SCLPConsole *scon = SCLP_CONSOLE(event);
if (!qemu_chr_fe_backend_connected(&scon->chr)) {
/* If there's no backend, we can just say we consumed all data. */
return len;
}
/* XXX this blocks entire thread. Rewrite to use
* qemu_chr_fe_write and background I/O callbacks */
return qemu_chr_fe_write_all(&scon->chr, buf, len);
}
static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
{
int rc;
int length;
ssize_t written;
ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
written = write_console_data(event, (uint8_t *)acd->data, length);
rc = SCLP_RC_NORMAL_COMPLETION;
/* set event buffer accepted flag */
evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;
/* written will be zero if a pty is not connected - don't treat as error */
if (written < 0) {
/* event buffer not accepted due to error in character layer */
evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
}
return rc;
}
static const VMStateDescription vmstate_sclpconsole = {
.name = "sclpconsole",
.version_id = 0,
.minimum_version_id = 0,
.fields = (VMStateField[]) {
VMSTATE_BOOL(event.event_pending, SCLPConsole),
VMSTATE_UINT8_ARRAY(iov, SCLPConsole, SIZE_BUFFER_VT220),
VMSTATE_UINT32(iov_sclp, SCLPConsole),
VMSTATE_UINT32(iov_bs, SCLPConsole),
VMSTATE_UINT32(iov_data_len, SCLPConsole),
VMSTATE_UINT32(iov_sclp_rest, SCLPConsole),
VMSTATE_END_OF_LIST()
}
};
/* qemu object creation and initialization functions */
/* tell character layer our call-back functions */
static int console_init(SCLPEvent *event)
{
static bool console_available;
SCLPConsole *scon = SCLP_CONSOLE(event);
if (console_available) {
error_report("Multiple VT220 operator consoles are not supported");
return -1;
}
console_available = true;
qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
chr_read, NULL, NULL, scon, NULL, true);
return 0;
}
static void console_reset(DeviceState *dev)
{
SCLPEvent *event = SCLP_EVENT(dev);
SCLPConsole *scon = SCLP_CONSOLE(event);
event->event_pending = false;
scon->iov_sclp = 0;
scon->iov_bs = 0;
scon->iov_data_len = 0;
scon->iov_sclp_rest = 0;
scon->notify = false;
}
static Property console_properties[] = {
DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
DEFINE_PROP_END_OF_LIST(),
};
static void console_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
dc->props = console_properties;
dc->reset = console_reset;
dc->vmsd = &vmstate_sclpconsole;
ec->init = console_init;
ec->get_send_mask = send_mask;
ec->get_receive_mask = receive_mask;
ec->can_handle_event = can_handle_event;
ec->read_event_data = read_event_data;
ec->write_event_data = write_event_data;
set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
}
static const TypeInfo sclp_console_info = {
.name = "sclpconsole",
.parent = TYPE_SCLP_EVENT,
.instance_size = sizeof(SCLPConsole),
.class_init = console_class_init,
.class_size = sizeof(SCLPEventClass),
};
static void register_types(void)
{
type_register_static(&sclp_console_info);
}
type_init(register_types)